Springer Science and Business Media LLC Acta Medica Okayama 0341-2695 47 10 2023 Epidemiological features of acute medial meniscus posterior root tears 2537 2545 EN Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Purpose　Untreated or overlooked medial meniscus posterior root tears (MMPRTs) induce sequential knee joint degradation. We evaluated epidemiological features of acute MMPRT for its early detection and accurate diagnosis. Methods　Among 330 MMPRT patients from 2018 to 2020, those who underwent arthroscopic pullout repairs were enrolled. Patients who underwent non-operative treatment or knee arthroplasty, those with a cruciate ligament-deficient knee or advanced osteoarthritis of the knee, and those with insufficient data were excluded. Finally, we retrospectively evaluated data from 234 MMPRTs (female: 79.9%, complete tears: 92.7%, mean age: 65 years). Welch’s t-test and Chi-squared test were used for pairwise comparisons. Spearman’s rank correlation analysis was performed between age at surgery and body mass index (BMI). Multivariable logistic regression analysis with stepwise backward elimination was applied to the values as risk factors for painful popping events. Results　In both sexes, there were significant differences in height, weight, and BMI. In all patients, there was a significant negative correlation between BMI and age (ρ = － 0.36, p < 0.001). The BMI cutoff value of 27.7 kg/m2 had a 79.2% sensitivity and a 76.9% specificity for detecting MMPRT patients aged < 50 years. A painful popping event was confirmed in 187 knees (79.9%), and the frequency was significantly reduced in partial tears as compared to complete tears (odds ratio: 0.080, p < 0.001). Conclusion　Higher BMI was associated with a significantly younger age of MMPRT onset. Partial MMPRTs had a low frequency of painful popping events (43.8%). No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0949-2658 28 5 2023 The stability of repaired meniscal root can affect postoperative cartilage status following medial meniscus posterior root repair 1060 1067 EN Ximing Zhang Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Haowei Xue Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Background Transtibial pullout repair yields beneficial clinical outcomes in patients with medial meniscus (MM) posterior root tear. However, the relationship between repaired meniscal root healing status and postoperative clinical outcomes remains unclear. We aimed to evaluate changes in articular cartilage damage and clinical scores after pullout repair using two simple stitches (TSS). Methods Thirty-three patients who underwent pullout repair using TSS were assessed. Healing status was assessed by a semi-quantitative second-look arthroscopic scoring system comprising three evaluation criteria (width of bridging tissues, stability of the repaired root, and synovial coverage), 1 year postoperatively. MM medial extrusion (MMME) and cartilage damage were assessed preoperatively and 1 year postoperatively. The medial compartment was divided into 8 zones (A-H) for comparison of preoperative and 1-year postoperative cartilage damage. Clinical outcomes were evaluated using the Knee Injury and Osteoarthritis Outcome score, Lysholm score, International Knee Documentation Committee scores, and visual analogue scale pain score. Results Although cartilage damage did not aggravate significantly in most medial compartment areas, MMME progressed at 1 year postoperatively. No statistical differences were observed in cartilage damage between the central-to-medial area of the medial femoral condyle and the medial tibial plateau area at 1 year postoperatively. Regarding semi-quantitative healing scores, the stability score was significantly correlated with the International Cartilage Repair Society grade at 1 year postoperatively. All 1-year and 2-year clinical scores significantly improved compared with the preoperative scores. Conclusion Regarding TSS repair, stability of repaired meniscal root negatively correlated with cartilage damage in the medial compartment loading area. All 1-year and 2-year clinical scores significantly improved than those of the preoperative scores. Achieving MM stability is crucial for suppressing cartilage degeneration. Level of evidence IV case series study. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 77 1 2023 Ipsilateral Periprosthetic Fractures above and below the Knee Associated with Navigation Tracker Pin and Bone Fragility 71 74 EN Yasuaki Yamakawa Department of Orthopedic Surgery, Kochi Health Sciences Center Yusuke Kamatsuki Department of Orthopedic Surgery, Kochi Health Sciences Center Tomoyuki Noda Department of Orthopaedic Surgery, Okayama University Hospital Miho Kure Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Case Report 10.18926/AMO/64364 We report a case of ipsilateral periprosthetic fractures above and below the knee that occurred at different times due to navigation tracker pin and bone fragility. A 66-year-old Japanese woman with rheumatoid arthritis (RA) underwent a total knee arthroplasty. Four months post-surgery, a periprosthetic fracture above the knee at the navigation pin hole was detected. She underwent osteosynthesis and could walk independently, but she developed an ipsilateral tibial component fracture. Conservative treatment with a splint was followed by bone union. Patients with RA treated with oral steroids tend to develop ipsilateral periprosthetic fractures around the knee due to bone fragility. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0968-0160 38 2022 Clinical outcomes of medial meniscus posterior root repair: A midterm follow-up study 141 147 EN Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Background: Transtibial pullout repair of medial meniscus posterior root tears (MMPRTs) cannot prevent the progression of knee osteoarthritis. Conversions of knee arthroplasties are occasionally required following MMPRT repair. However, other knee-related surgical treatments following MMPRT repair are unclear. This study was aimed at investigating the midterm clinical outcomes and knee-related surgical events following MMPRT repair. Methods: Patients with MMPRT underwent pullout repair using FasT-Fix modified Mason -Allen (F-MMA) suturing with an all-inside meniscal repair device. Thirty-two patients with follow-up duration >2 years were enrolled. We assessed the clinical outcomes and postop-erative surgical treatment of both knees. Results: F-MMA pullout repair improved all clinical evaluation scores in patients with MMPRT at a mean follow-up of 36.1 months. Postoperative arthroscopic debridement was required for one patient. An additional MMPRT repair was performed in one patient on second-look arthroscopy. None of the patients required ipsilateral knee arthroplasty. In the contralateral knees, one pullout repair of a newly developed MMPRT and two knee arthroplasties were performed. Conclusions: This study demonstrated that F-MMA pullout repair yielded satisfactory clin-ical outcomes. However, subsequent knee-related surgeries were observed in 6.3% of the pullout-repaired knees and 9.4% of the contralateral knees. Our results suggest that sur-geons should be aware of the worsening and/or occurrence of contralateral knee joint dis-ease, even when the postoperative clinical outcomes are satisfactory following MMPRT repair. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0942-2056 30 11 2022 Increased cleft width during knee flexion is useful for the diagnosis of medial meniscus posterior root tears 3726 3732 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Hospital Naohiro Higashihara Department of Orthopaedic Surgery, Okayama University Hospital Masanori Tamura Department of Orthopaedic Surgery, Okayama University Hospital Ximing Zhang Department of Orthopaedic Surgery, Okayama University Hospital Haowei Xue Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Purpose This study aimed to evaluate changes in the cleft width, defined as the distance between the lateral edge of the medial tibial plateau and that of the medial meniscus (MM) posterior root, using open magnetic resonance imaging (MRI) in patients with MM posterior root tear (MMPRT). Methods This study included 25 patients (20 women and 5 men; mean age: 65.2 years) who were diagnosed with MMPRT and underwent pullout repair. Upon coronal imaging, the cleft width was evaluated at the 10° and 90° flexed knee positions. The difference in the cleft width (defined as the cleft width at 90° minus the cleft width at 10°) was also calculated. Upon sagittal imaging, the MM posterior extrusion (MMPE) at 90° was also evaluated. Separate univariate linear regression models were used to determine the association between the time from injury to MRI and radiographic measurements. Results The mean cleft width at 10° and 90° was 4.9 ± 2.6 mm and 7.4 ± 3.7 mm, respectively; the mean difference in cleft width was 2.5 ± 1.5 mm, and the mean MMPE at 90° was 3.7 ± 1.3 mm. There was a significant difference in cleft width at 10° and 90° (p < 0.001). The time from injury to MRI was significantly associated with the cleft width at 10° (R = 0.42; p = 0.023), cleft width at 90° (R = 0.59; p = 0.002), the difference in the cleft width (R = 0.62; p = 0.008), and MMPE at 90° (R = 0.53; p = 0.008). Conclusion This study demonstrates that the cleft width is significantly larger during knee flexion than during knee extension. Increased cleft width during knee flexion (“graben” sign) may help diagnose MMPRT, especially in cases where the cleft sign is unclear during knee extension. No potential conflict of interest relevant to this article was reported.

BMC Acta Medica Okayama 1471-2474 23 1 2022 Large flexion contracture angle predicts tight extension gap during navigational posterior stabilized-type total knee arthroplasty with the pre-cut technique: a retrospective study 78 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Shin Masuda Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Background This study aimed to determine the predictors of tight extension gap (EG) compared with the flexion gap (FG) during navigational posterior stabilized-type total knee arthroplasty using the pre-cut technique. Methods Nineteen patients with tight EG (defined as FG-EG >= 2 mm after pre-cut; group T) and 84 patients with an approximately equal gap (defined as FG-EG = 0-1 mm after pre-cut; group E) were enrolled. Medial tibial slope angle, hip knee ankle angle, flexion contracture angle, and active maximum flexion angle were compared between the two groups. Results The multivariate logistic regression model indicated that the probability of tight EG increased with flexion contracture angle (odds ratio, 1.13; 95% confidence interval 1.05-1.20; P <= 0.001). According to the receiver operating characteristic analysis, the flexion contracture angle cut-off value associated with tight EG was 15.0 degrees (sensitivity, 85%; specificity, 78%). Conclusion This study demonstrated that a large flexion contracture angle (cut-off 15.0 degrees) was associated with tight EG after pre-cut osteotomy during posterior stabilized-type total knee arthroplasty. Awareness of this risk factor may help improve preoperative predictability of tight EGs and preparedness for additional procedures, such as soft tissue release or capsulotomy, to correct them. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 09492658 2021 Semi-quantitative arthroscopic scoring system is related to clinical outcomes in patients after medial meniscus posterior root repair EN Ximing Zhang Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Haowei Xue Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Background Different methods are available to assess the healing status of repaired root for medial meniscus posterior root tears (MMPRT) using second-look arthroscopy. However, few studies are comparing them or validating their usefulness. Therefore, it was hypothesized that the semi-quantitative arthroscopic score might correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation. Methods Data of 61 patients who underwent MMPRT pullout repair and second-look arthroscopy were retrospectively evaluated. The semi-quantitative arthroscopic scoring system was divided into three evaluation criteria: scores from 0 to 10 points include the width of the bridging tissue, stability of the repaired root, and synovial coverage. The qualitative evaluation was classified into 4 status; complete healing, lax healing, scar tissue healing, and failed healing according to the stability and mobility of the repaired root. Multivariate linear regression analyses were used to identify predictors of 1-year postoperative clinical outcomes, including Knee Injury and Osteoarthritis Outcome, Lysholm, or International Knee Documentation Committee scores. Spearman's correlation analysis was used to analyze the correlation between second-look arthroscopic score/qualitative evaluation and 1-year postoperative clinical outcomes. In addition, the optimal cutoff point of semi-quantitative arthroscopic score was determined by receiver operating characteristic (ROC) curve. The Mann–Whitney U test was used to compare clinical outcomes between patients with semi-quantitative arthroscopic scores ≥8 and scores <8. Results All clinical scores significantly improved at 1 year postoperatively. A good correlation was observed between the semi-quantitative score and clinical scores, but none between qualitative evaluation and clinical scores. The optimal cutoff point of semi-quantitative second-look arthroscopic score was 8 points. Significantly, better clinical outcomes were observed in patients with semi-quantitative scores ≥8 points. Conclusions All 1-year postoperative clinical scores were significantly improved. The semi-quantitative arthroscopic scores correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation. Level of evidence IV case series study. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 0300-8207 2021 Comparison of posterior root remnant cells and horn cells of the medial meniscus EN Ximing Zhang Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Haowei Xue Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Keisuke Kintaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Purpose/Aim of the study: Previous studies have noted distinctions between medial meniscus posterior root and horn cells. However, the characteristics of root remnant cells have not been explored in detail. The purpose of this study was to evaluate the gene expression levels, proliferation, and resistance to mechanical stress of remnant and horn cells. Materials and Methods: Medial meniscus tissue samples were obtained from patients who underwent total or uni-compartmental knee arthroplasty. Cellular morphology, sry-type HMG box 9, type II collagen, and chondromodulin-I gene expression levels were analyzed. Collagen synthesis was assessed by immunofluorescence staining. Proliferation analysis after 4 h-cyclic tensile strain was performed. Results: Horn cells displayed triangular morphology, whereas root remnant cells appeared fibroblast-like. sry-type HMG box 9 mRNA expression levels were similar in both cells, but type II collagen and chondromodulin-I mRNA expressions were observed only in horn cells. The ratio of type II collagen-positive cells in horn cells was about 10-fold higher than that in root remnant cells, whereas the ratio of sry-type HMG box 9-positive cells was similar. A significant increase in proliferation was observed in root remnant cells compared to that in horn cells. Further, under cyclic tensile strain, the survival rate was higher in root remnant cells than in horn cells. Conclusions: Medial meniscus root remnant cells showed higher proliferation and resistant properties to cyclic tensile strain than horn cells and showed no chondromodulin-I expression. Preserving the medial meniscus posterior root remnant during pullout repair surgery might maintain mechanical stress-resistant tissue and support healing. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0942-2056 29 2020 Transtibial pullout repair of medial meniscus posterior root tears: effects on the meniscus healing score and ICRS grade among patients with mild osteoarthritis of the knee 3001 3009 EN Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Shota Takihira Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Purpose To assess the effects of transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) among patients with early osteoarthritis of the knee as measured by the meniscus healing score and to determine whether the meniscus healing score correlates with the International Cartilage Repair Society (ICRS) grade progression. Methods Forty-seven patients with mild osteoarthritic knees (Kellgren–Lawrence grade ≤ 2 and varus alignment < 5°) who underwent transtibial pullout repair less than 3 months after MMPRT onset were assessed. The association between meniscus healing scores at 1 year postoperatively and cartilage damage of the medial compartment (medial femoral condyle [MFC] and medial tibial plateau [MTP]) were evaluated. The MFC was divided into six zones (A to F) and the MTP into two zones (G and H). The mean ICRS grade for each zone was compared between the primary surgery and second-look arthroscopy. The correlation between cartilage damage and meniscus healing status at the time of second-look arthroscopy in each zone was analysed. Results The mean time interval from injury to surgery was 63 days, and all clinical scores showed significant improvement. There were no significant differences in the extent of cartilage damage in areas B, C, E, or F (n.s.) for MFC or in areas G and H (n.s.) for MTP. The meniscus healing score and cartilage damage were correlated in the loading areas (B, C, E, and H; － 0.53, － 0.45, － 0.33, and － 0.38, respectively; p < 0.05). Conclusion Transtibial pullout repair of MMPRTs among patients with mild osteoarthritic knees improved the clinical outcomes and showed a negative correlation between high meniscus healing scores and ICRS grades in the medial compartment loading area. This study suggests that early surgery should be undertaken for patients with mild osteoarthritic knee who develop MMPRTs. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0942-2056 28 11 2019 Transtibial fixation for medial meniscus posterior root tear reduces posterior extrusion and physiological translation of the medial meniscus in middle-aged and elderly patients 3416 3425 EN Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Shin Masuda Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Masaharu Yasumitsu Department of Orthopaedic Surgery, Iwakuni Clinical Center Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Purpose To investigate changes in meniscal extrusion during knee flexion before and after pullout fixation for medial meniscus posterior root tear (MMPRT) and determine whether these changes correlate with articular cartilage degeneration and short-term clinical outcomes. Methods Twenty-two patients (mean age 58.4 ± 8.2 years) diagnosed with type II MMPRT underwent open magnetic resonance imaging preoperatively, 3 months after transtibial fixation and at 12 months after surgery, when second-look arthroscopy was also performed. The medial meniscus medial extrusion (MMME) and the medial meniscus posterior extrusion (MMPE) were measured at knee 10° and 90° flexion at which medial meniscus (MM) posterior translation was also calculated. Articular cartilage degeneration was assessed using International Cartilage Research Society grade at primary surgery and second-look arthroscopy. Clinical evaluations included Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee subjective knee evaluation form, Lysholm score, Tegner activity level scale, and pain visual analogue scale. Results MMPE at 10° knee flexion was higher 12 months postoperatively than preoperatively (4.8 ± 1.5 vs. 3.5 ± 1.2, p = 0.01). MMPE at 90° knee flexion and MM posterior translation were smaller 12 months postoperatively than preoperatively (3.5 ± 1.1 vs. 4.6 ± 1.3, 7.2 ± 1.7 vs. 8.9 ± 2.0, p < 0.01). Articular cartilage degeneration of medial femoral condyle correlated with MMME in knee extension (r = 0.5, p = 0.04). All clinical scores significantly improved 12 months postoperatively. However, correlations of all clinical scores against decreased MMPE and increased MMME were not detected. Conclusions MMPRT transtibial fixation suppressed the progression of MMPE and cartilage degeneration and progressed MMME minimally in knee flexion position at 1 year. However, in the knee extension position, MMME progressed and correlated with cartilage degeneration of medial femoral condyle. MMPRT transtibial fixation contributes to the dynamic stability of the MM in the knee flexion position. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1877-0568 106 3 2020 Transtibial pullout repair of the lateral meniscus posterior root tear combined with anterior cruciate ligament reconstruction reduces lateral meniscus extrusion: A retrospective study 469 473 EN Yuki Okazaki Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yusuke Kamatsuki Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shin Masuda Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Takaaki Hiranaka Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yuya Kodama Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Background Lateral meniscus (LM) posterior root tear (PRT) is often associated with anterior cruciate ligament (ACL) injury and can result in rotational instability, joint overloading, and degenerative changes in the knee. Improved rotational stability and kinematics have been reported after LMPRT repair. However, it is unclear what repair technique can achieve the greatest reduction in LM extrusion (LME). Hypothesis We hypothesized that transtibial pullout repair would decrease LME to a greater extent than other repair techniques. Patients and methods Seventeen patients with ACL injury and complete LMPRT were evaluated. Nine underwent ACL reconstruction (ACLR) and transtibial pullout repair, and eight underwent ACLR and other repairs such as inside-out suturing. Double-bundle ACLR was performed using hamstring tendons, and LMPRT pullout repair was performed through the bone tunnel for the posterolateral bundle. Magnetic resonance imaging was performed immediately preoperatively and at > 6 months postoperatively, and LME was measured from coronal images only. Results A significantly greater decrease in the value of LME from pre- to postoperative measurement was observed in the transtibial pullout repair group (－0.5 ± 0.7 mm) than in the other-repair group (1.0 ± 0.9 mm, p < 0.01). Pre- and postoperative LME measurements were not significantly different between the two groups. Discussion The most important finding of this study was that transtibial pullout repair resulted in a greater decrease in LME than other repair techniques in patients with ACL injury and LMPRT. This technique might be useful for restoring hoop tension by decreasing LME. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 09422056 29 2020 Placement of an anatomic tibial tunnel significantly improves the medial meniscus posterior extrusion at 90° of knee flexion following medial meniscus posterior root pullout repair 1025 1034 EN Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Tomohito Hino Department of Orthopaedic Surgery, Okayama University Hospital Shin Masuda Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Purpose The purpose of this study was to evaluate the influence of tibial tunnel position in pullout repair for a medial meniscus (MM) posterior root tear (MMPRT) on postoperative MM extrusion. Methods Thirty patients (median age 63 years, range 35–72 years) who underwent transtibial pullout repairs for MMPRTs were included. Three-dimensional computed tomography images of the tibial surface were evaluated using a rectangular measurement grid for assessment of tibial tunnel position and MM posterior root attachment. Preoperative and postoperative MM medial extrusion (MMME) and posterior extrusion (MMPE) at 10° and 90° knee flexion were measured using open magnetic resonance imaging. Results Tibial tunnel centers were located more anteriorly and more medially than the anatomic center (median distance 5.8 mm, range 0–9.3 mm). The postoperative MMPE at 90° knee flexion was significantly reduced after pullout repair, although there was no significant reduction in MMME or MMPE at 10° knee flexion after surgery. In the correlation analysis of the displacement between the anatomic center to the tibial tunnel center and improvements in MMME, and MMPE at 10° and 90° knee flexion, there was a significant positive correlation between percentage distance and improvement of MMPE at 90° knee flexion. Conclusion This study demonstrated that the nearer the tibial tunnel position to the anatomic attachment of the MM posterior root, the more effective the reduction in MMPE at 90° knee flexion. Our results emphasize that an anatomic tibial tunnel should be created in the MM posterior root to improve the postoperative MMPE and protect the articular cartilage in a knee flexion position. Placement of an anatomic tibial tunnel significantly improves the MMPE at 90° of knee flexion after MM posterior root pullout repair. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0968-0160 27 3 2020 The distance between the tibial tunnel aperture and meniscal root attachment is correlated with meniscal healing status following transtibial pullout repair for medial meniscus posterior root tear 899 905 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Yusuke Kamatsuki Department of Orthopaedic Surgery, Kochi Health Science Center Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Shin Masuda Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, National Hospital Organization Iwakuni Clinical Center Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Background To investigate the relationship between tibial tunnel aperture location and postoperative meniscal healing. Methods We enrolled 25 patients (20 women and five men, mean age: 62.5 years) who underwent transtibial pullout repair for medial meniscus (MM) posterior root repair. The expected MM posterior root attachment center (AC) and tibial tunnel center (TC) were identified using three-dimensional computed tomography, and the minimum AC–TC distance was calculated. The meniscal healing status following transtibial pullout repair was assessed by second-look arthroscopy (mean postoperative period: 15 months) using a previously reported scoring system (meniscal healing score; range: 0–10). The association between AC–TC distance and meniscal healing score was investigated using univariate linear regression models. The optimal AC–TC distance cut-off for improved MM healing score (≥ 7) was determined using receiver operating characteristic analysis. Results The AC–TC distance and meniscal healing score were significantly associated (y = － 0.42x + 9.48, R2 = 0.342; P = 0.002), with the optimum AC–TC distance being 5.8 mm. This cut-off had a sensitivity of 100% and specificity of 53%. Conclusions This study demonstrates that AC–TC distance is significantly correlated with postoperative meniscal healing. Anatomical repair within 5.8 mm of the AC may result in improved meniscal healing. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0968-0160 27 3 2020 Comparison of the clinical outcomes of transtibial pull-out repair for medial meniscus posterior root tear: Two simple stitches versus modified Mason-Allen suture 701 708 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Shota Takihira Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, National Hospital Organization Iwakuni Clinical Center Yusuke Kamatsuki Department of Orthopaedic Surgery, National Hospital Organization Iwakuni Clinical Center Shin Masuda Department of Orthopaedic Surgery, Chikamori Hospital Taichi Saito Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Background Transtibial pullout repair of a medial meniscus posterior root tear (MMPRT) is a commonly used procedure, and several techniques have been reported. We hypothesised that pull-out repairs using two simple stitches (TSS) would have similar postoperative outcomes as those using the modified Mason-Allen suture with FasT-Fix (F-MMA). We aimed to investigate the clinical outcomes of these techniques, including the meniscal healing status and osteoarthritic change. Methods The data of 68 patients who underwent transtibial pull-out repair were retrospectively investigated. The patients were divided into two groups of 41 and 27 patients using F-MMA and TSS, respectively. The clinical outcomes were assessed preoperatively and at second-look arthroscopy (the mean period from surgery was one year) using the Knee injury and Osteoarthritis Outcome Score. The meniscal healing status, evaluated at second-look arthroscopy, was compared between the two groups. The cartilage damage was graded as per the classification of the International Cartilage Repair Society and compared at the primary surgery and second-look arthroscopy. Results Both groups showed significant improvement in each clinical score. No significant difference was seen in the clinical outcome scores and the meniscal healing status between the two groups at second-look arthroscopy. Moreover, no significant progression of cartilage damage was observed in both groups. Fourteen patients in the F-MMA group developed a complication of suture bar failures postoperatively; however, there were no complications in the TSS group. Conclusions The TSS and F-MMA techniques showed favourable clinical outcomes and would be established as clinically useful techniques for the MMPRT treatment. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0968-0160 27 1 2020 Medial meniscus posterior root repair decreases posteromedial extrusion of the medial meniscus during knee flexion 132 139 EN Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Hospital Shin Masuda Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, National Hospital Organization Iwakuni Clinical Center Yusuke Kamatsuki Department of Orthopaedic Surgery, Kochi Health Science Center Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomonori Tetsunaga Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Background Medial meniscus (MM) medial extrusion in the coronal plane does not always improve, even after repair. This study aimed to determine the extent of posteromedial extrusion of the MM during knee flexion before and after MM pullout repair using three-dimensional magnetic resonance imaging (MRI). Methods Data from 14 patients (mean age, 63.4 years; 86% female) who had undergone MM pullout repair at the current institution between August 2017 and October 2018 were retrospectively reviewed. The MRIs were performed pre-operatively and ≥ 3 months postoperatively. Three-dimensional MRIs of the tibial surface and MM were evaluated using Tsukada's measurement method before and after pullout repair. The expected center of MM posterior root attachment (point A), the point on the extruded edge of the MM farthest away from point A (point E), and the point of intersection of a line through the posteromedial corner of the medial tibial plateau and a line connecting points A and E (point I) were identified. Subsequently, the pre-operative and postoperative AE and IE distances were calculated and compared. Results Point E was laterally shifted by the pullout repair, whereas point I showed no significant change. The postoperative IE distance (6.7 mm) was significantly shorter than the pre-operative one (9.1 mm, P < 0.01). The postoperative AE distance (29.3 mm) was significantly shorter than the pre-operative one (31.5 mm, P < 0.01). Conclusions The AE and IE distances significantly decreased after MM posterior root repair, suggesting that transtibial pullout repair may be useful in reducing posteromedial extrusion of the MM. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 73 6 2019 Bilateral Anterior Cruciate Ligament Tear Combined with Medial Meniscus Posterior Root Tear 523 528 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shota Takihira Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Intelligent Orthopaedic System Development, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Eiji Nakata Department of Musculoskeletal Traumatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/57717 The case of an individual with a bilateral anterior cruciate ligament (ACL) tear combined with a medial meniscus (MM) posterior root tear is described. A 34-year-old Japanese man with bilateral ACL rupture that occurred > 10 years earlier was diagnosed with bilateral ACL tear combined with MM posterior root tear (MMPRT). We performed a transtibial pullout repair of the MMPRT with ACL reconstruction. The tibial tunnels for the MM posterior root repair and ACL reconstruction were created separately. Postoperatively, a good clinical outcome and meniscal healing were obtained. Our surgical technique may thus contribute to anatomical MM posterior root repair and ACL reconstruction. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 73 6 2019 The Early Arthroscopic Pullout Repair of Medial Meniscus Posterior Root Tear Is More Effective for Reducing Medial Meniscus Extrusion 503 510 EN Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Intelligent Orthopaedic System, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuya Kodama Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hino Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoyuki Noda Department of Musculoskeletal traumatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yasuaki Yamakawa Department of Emergency Healthcare and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoko Tetsunaga Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Original Article 10.18926/AMO/57714 Clinical studies have demonstrated that transtibial pullout repair led to favorable midterm outcomes in patients with medial meniscus posterior root tears (MMPRTs) although medial meniscal extrusion (MME) continued to be present. It has been unclear whether these residual postoperative MMEs existed after the pullout repair or had progressed at the very short-term evaluation after surgery. We sought to determine which characteristics of patients with MMPRTs influence the incidence of postoperative MME. The cases of 23 patients whose date of injury was known were analyzed. All patients underwent MMPRT pullout fixation. Preoperative and 3-month postoperative magnetic resonance imaging (MRI) examinations were performed. MME was retrospectively assessed on the mid-coronal plane of MRI scans. The preoperative and postoperative MME values were 4.2±1.2 mm and 4.3±1.5 mm, respectively (p=0.559). Pullout repair surgery was performed significantly earlier after the MMPRT-specific injury in patients whose postoperative MME improved compared to the patients whose MME did not improve (p<0.001). Our findings demonstrated that an early transtibial pullout repair of an MMPRT was more effective in reducing MME than a late repair. Surgeons should not miss the optimal timing for the pullout repair of an MMPRT, considering the period from the injury and the preoperative MME. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0942-2056 27 2 2018 Meniscal repair concurrent with anterior cruciate ligament reconstruction restores posterior shift of the medial meniscus in the knee-flexed position 361 368 EN Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School Yuya Kodama Department of Orthopaedic Surgery, Okayama University Graduate School Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School Tomohito Hino Department of Orthopaedic Surgery, Okayama University Graduate School Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School PURPOSE: The purpose of this study was to evaluate the shape and shift of the medial meniscus before and after meniscal repair concurrent with anterior cruciate ligament (ACL) reconstruction using magnetic resonance imaging (MRI) at 90° of knee flexion. METHODS: This study included 18 patients with ACL-deficient knees without meniscus tears (group A), 11 patients with medial meniscus tears alone (group M), and 15 patients with ACL-deficient knees complicated with medial meniscus tears (group AM). The posterior segment shape was evaluated using open MRI at 90° of knee flexion preoperatively and at 3 months postoperatively. The length, height, width, and posterior extrusion of the medial meniscus and posterior tibiofemoral distance were measured. These measurements were compared between the three groups. RESULTS: On preoperative MRI, a significant difference was observed in the posterior extrusion of the medial meniscus (group A, 1.2 ± 0.5 mm; group M, 1.7 ± 0.3 mm; group AM, 4.1 ± 1.5 mm, p < 0.001). All parameters did not differ between the three groups on postoperative MRI. In addition, the posterior width and extrusion of the medial meniscus were decreased significantly after meniscal repair concurrent with ACL reconstruction. CONCLUSIONS: This study demonstrated that the medial meniscus shifted posteriorly at 90° of knee flexion in ACL-deficient knees complicated with medial meniscus tears. Medial meniscal repair concurrent with ACL reconstruction improved the deformed morphology and posterior extrusion. MRI measurements of the posterior extrusion at the knee-flexed position may be clinically useful to assess the functional improvement of the medial meniscus following meniscal repair combined with ACL reconstruction. No potential conflict of interest relevant to this article was reported.

Taylor and Francis Acta Medica Okayama 0300-8207 61 6 2019 A histological study of the medial meniscus posterior root tibial insertion 546 553 EN Tomohito Hino Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Masataka Fujii Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yuya Kodama Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yusuke Kamatsuki Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shin Masuda Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery , Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Purpose/Aim of the study: Posterior root injury of the medial meniscus often leads to articular cartilage degeneration due to altered biomechanics. To avoid dysfunction, the attachment must be repaired using the transtibial pullout technique. To guide appropriate placement of the tibial tunnel, additional details on the normal anatomy of the meniscus insertion are needed. Therefore, we performed a histological analysis of a tibial bone slice with the medial meniscus posterior insertion obtained during total knee arthroplasty surgery. Materials and methods: Horizontal slices of the proximal tibia were obtained from 7 patients with osteoarthritis who underwent total knee arthroplasty. After decalcification, the region of the posterior horn was cut out and segmented into four pieces (2.0 mm thickness; medial to lateral). Sagittal sections were evaluated by safranin O staining or immunohistochemistry with anti-type collagen antibody. Results: Safranin O staining showed that the insertion of the posterior root consisted primarily of fibrocartilaginous layers in segment 2. Anatomically, segment 2 corresponded to the sagittal plane passing through the peak of the medial intercondylar tubercle. In this section, safranin O staining and immunohistochemistry revealed that the anterior one-third of the posterior root insertion was richer in proteoglycans and type II collagen than the central and posterior one-third. Conclusions: Anatomical insertion of the posterior root of the medial meniscus was located at the sagittal plane passing through the peak of the medial intercondylar tubercle. The structure of the medial meniscus posterior insertion was mainly localized in the anterior one-third. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 03412695 43 5 2018 Arthroscopic scoring system of meniscal healing following medial meniscus posterior root repair 1239 1245 EN Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Hospital Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Hospital Masataka Fujii Department of Orthopaedic Surgery, Okayama University Hospital Takaaki Tanaka Department of Orthopaedic Surgery, Okayama University Hospital Yuya Kodama Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital PURPOSE: Medial meniscus posterior root tear (MMPRT) leads to a rapid degradation of articular cartilage. In the treatment of MMPRT, transtibial pullout repair demonstrates a high clinical survival rate. However, there is no reliable method to evaluate the meniscal healing after surgery. We propose an arthroscopic scoring system for evaluating the meniscal healing status. The aim of this study was to investigate the correlations between second-look arthroscopic scores and clinical outcomes after transtibial pullout repair. METHODS: Twenty patients who had MMPRTs underwent transtibial pullout repairs. Clinical outcomes were assessed using the Japanese Knee Injury and Osteoarthritis Outcome Score (KOOS) and pain score evaluated by visual analogue scale at preoperatively and 1 year postoperatively. The healing status of repaired MM was assessed at one year post-operatively using a semi-quantitative arthroscopic scoring system (total, 10 points) composed of three evaluation criteria: (i) anteroposterior width of bridging tissues, (ii) stability of the MM posterior root, and (iii) synovial coverage of the sutures. Linear regression analysis was used to assess the correlation between second-look arthroscopic scores and clinical outcomes. RESULTS: Transtibial pullout repairs of MMPRTs significantly improved clinical evaluation scores at one year post-operatively. A median of second-look arthroscopic scores was 6.5 (5.75-8). A good correlation was observed between the arthroscopic score and KOOS quality of life (QOL) subscale. A moderate negative correlation between the arthroscopic score and pain score was observed. CONCLUSIONS: This study demonstrated that our semi-quantitative scoring system of meniscal healing correlated with the KOOS QOL subscale following MMPRT transtibial pullout repair. Our results suggest that the second-look arthroscopic score using this system may be a useful scale to determine and compare the healing status of the MM posterior root. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 09492658 24 6 2019 Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation 1058 1063 EN Takaaki Hiranaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuhisa Sugiu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shota Takihira Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shinichi Miyazawa Department of Intelligent Orthopaedic System Development, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Eiji Nakata Department of Musculoskeletal Traumatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences BACKGROUND: Several studies have demonstrated that posttraumatic knee osteoarthritis progresses even after anterior cruciate ligament reconstruction. Few reports described zone-specific cartilaginous damages after anterior cruciate ligament reconstruction. This study aimed to compare the status of articular cartilage at anterior cruciate ligament reconstruction with that at second-look arthroscopy. METHODS: This study included 20 patients (20 knees, 10 males and 10 females, mean age 22.4 years, Body mass index 24.4 kg/m2) that underwent arthroscopic anatomic double-bundle anterior cruciate ligament reconstruction and second-look arthroscopy. Mean periods from injury to reconstruction and from reconstruction to second-look arthroscopy were 3.4 and 15.3 months, respectively. Cartilage lesions were evaluated arthroscopically in the 6 articular surfaces and 40 articular subcompartments independently, and these features were graded with the International Cartilage Repair Society articular cartilage injury classification; comparisons were made between the grades at reconstruction and at second-look arthroscopy. Furthermore, clinical outcomes were assessed at reconstruction and at second-look arthroscopy, using the Lysholm knee score, Tegner activity scale, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, side-to-side difference of the KT-2000 arthrometer, and pivot shift test. RESULTS: Each compartment showed a deteriorated condition at second-look arthroscopy compared with the pre-reconstruction period. A significant worsening of the articular cartilage was noted in all compartments except the lateral tibial plateau and was also observed in the central region of the medial femoral condyle and trochlea after reconstruction. However, each clinical outcome was significantly improved postoperatively. CONCLUSIONS: Good cartilage conditions were restored in most subcompartments at second-look arthroscopy. Furthermore, posttraumatic osteoarthritic changes in the patellofemoral and medial compartments progressed even in the early postoperative period, although good knee stability and clinical outcomes were obtained. Care is necessary regarding the progression of osteoarthritis and the appearance of knee symptoms in patients undergoing anterior cruciate ligament reconstruction. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 18770568 105 1 2019 Transtibial pullout repair of medial meniscus posterior root tear restores physiological rotation of the tibia in the knee-flexed position 113 117 EN Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yuya Kodama Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Tomohito Hino Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Hirosuke Endo Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Tomonori Tetsunaga Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Kazuki Yamada Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences BACKGROUND: Medial meniscus posterior root tear (MMPRT) results in joint overloading and degenerative changes in the knee. Favorable clinical outcomes have been reported after transtibial pullout repair of MMPRT. To date, however, in vivo tibial rotational changes before and after root repair remain poorly understood. The purpose of this study was to investigate postoperative changes in tibial rotation following MMPRT pullout repair. HYPOTHESIS: Pathological external rotation of the tibia in the knee-flexed position is caused by MMPRT and is reduced after transtibial pullout repair. PATIENTS AND METHODS: Fifteen patients who underwent MMPRT pullout repair and 7 healthy volunteers were included. Magnetic resonance imaging examinations were performed in the 10° and 90° knee-flexed positions. The angles between the surgical epicondylar axis and a line between the medial border of the patellar tendon and the apex of the medial tibial spine were measured. Baseline was defined as a line lying at a right angle to the other, and a value was positive and negative when the tibia rotated internally and externally, respectively. RESULTS: In the volunteer's normal knees, tibial internal rotation was +1.00°±3.27° at 10° flexion and +4.14°±3.46° at 90° flexion. In the MMPRT preoperative knees, tibial internal rotation was +1.07°±3.01° at 10° flexion and +1.27°±2.96° at 90° flexion. In the postoperative knees, tibial internal rotation was +1.60°±2.85° at 10° flexion and +4.33°±2.89° at 90° flexion. DISCUSSION: This study demonstrates discontinuity of the MM posterior root may induce a pathological external rotation of the tibia during knee flexion and that MMPRT pullout repair reduces the pathological external rotation of the tibia in the knee-flexed position. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 18770568 105 1 2019 Injury patterns of medial meniscus posterior root tears 107 111 EN Takayuki Furumatsu Department of Orthopaedic Surgery, Okayama University Graduate School, Yuki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School, Yoshiki Okazaki Department of Orthopaedic Surgery, Okayama University Graduate School, Tomohito Hino Department of Orthopaedic Surgery, Okayama University Graduate School, Yusuke Kamatsuki Department of Orthopaedic Surgery, Okayama University Graduate School, Shin Masuda Department of Orthopaedic Surgery, Okayama University Graduate School, Shinichi Miyazawa Department of Orthopaedic Surgery, Okayama University Graduate School, Eiji Nakata Department of Orthopaedic Surgery, Okayama University Graduate School, Joe Hasei Department of Orthopaedic Surgery, Okayama University Graduate School, Toshiyuki Kunisada Department of Orthopaedic Surgery, Okayama University Graduate School, Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School, INTRODUCTION: Medial meniscus posterior root tear (MMPRT) can occur in middle-aged patients who have a posteromedial painful popping during light activities. MMPRTs are more common in patients with increased age, female gender, sedentary lifestyle, obesity, and varus knee alignment. However, injury mechanisms of minor traumatic MMPRTs are still unclear. We hypothesized that high flexion activities are the major cause of MMPRTs. The aim of this study was to clarify injury patterns of MMPRTs. MATERIALS AND METHODS: One hundred patients were diagnosed having MMPRTs after posteromedial painful popping episodes. Details of posteromedial painful popping episode, situation of injury, and position of injured leg were obtained from the patients by careful interviews. Injury patterns were divided into 8 groups: descending knee motion, walking, squatting, standing up action, falling down, twisting, light exercise, and minor automobile accident. RESULTS: A descending knee motion was the most common cause of MMPRTs (38%) followed by a walking injury pattern (18%) and a squatting action related to high flexion activities of the knee (13%). The other injury patterns were less than 10%. DISCUSSION: Descending knee motions associated with descending stairs, step, and downhill slope are the most common injury pattern of MMPRTs. High flexion activities of the knee are not the greatest cause of MMPRTs. Our results suggest that the descending action with a low knee flexion angle may trigger minor traumatic MMPRTs. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 69 6 2015 Contrast-enhanced Computed Tomography Screening Is Effective for Detecting Venous Thromboembolism not Prevented by Prophylaxis after Total Knee Arthroplasty 355 359 EN Yukimasa Okada Takayuki Furumatsu Shinichi Miyazawa Takaaki Tanaka Masataka Fujii Toshifumi Ozaki Nobuhiro Abe Original Article 10.18926/AMO/53910 Venous thromboembolism (VTE) is a potential complication occurring after total knee arthroplasty (TKA). We investigated the incidence of VTE after TKA using contrast-enhanced computed tomography (CT), and assessed the efficacy of VTE prophylaxis (fondaparinux and enoxaparin). At our hospital, 189 patients (225 knees) underwent TKA between April 2007 and October 2011. The 225 knees were divided into a control group with no VTE prophylaxis (31 cases), a fondaparinux group (107 cases), and an enoxaparin group (87 cases). Contrast-enhanced CT screening for VTE was performed in all cases on day 5 or 6 after TKA. D-dimer levels were measured on day 5 after TKA, and were significantly lower in the fondaparinux (9.8±3.8) and enoxaparin groups (9.4±4.9) than in the control group (15.6±9.8) (p＜0.001). However, no statistically significant difference in the incidence of VTE was observed among the groups (control, 61.3%;fondaparinux, 49.5%;enoxaparin, 50.6%). Prophylaxis was not effective for the prevention of VTE as detected by contrast-enhanced CT after TKA. CT should be performed after TKA, even when VTE prophylaxis is used. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0341-2695 37 1 2013 Comparison between normal and loose fragment chondrocytes in proliferation and redifferentiation potential 159 165 EN Kenichiro Sakata Takayuki Furumatsu Shinichi Miyazawa Yukimasa Okada Masataka Fujii Toshifumi Ozaki Loose fragments in osteochondritis dissecans (OCD) of the knee require internal fixation. On the other hand, loose fragments derived from spontaneous osteonecrosis of the knee (SONK) are usually removed. However, the difference in healing potential between OCD- and SONK-related loose fragments has not been elucidated. In this study, we investigated proliferative activity and redifferentiation potential of normal cartilage-derived and loose fragment-derived chondrocytes. Cells were prepared from normal articular cartilages and loose fragment cartilages derived from knee OCD and SONK. Cellular proliferation was compared. Redifferentiation ability of pellet-cultured chondrocytes was assessed by real-time PCR analyses. Mesenchymal differentiation potential was investigated by histological analyses. Positive ratio of a stem cell marker CD166 was evaluated in each cartilaginous tissue. Normal and OCD chondrocytes showed a higher proliferative activity than SONK chondrocytes. Chondrogenic pellets derived from normal and OCD chondrocytes produced a larger amount of safranin O-stained proteoglycans compared with SONK-derived pellets. Expression of chondrogenic marker genes was inferior in SONK pellets. The CD166-positive ratio was higher in normal cartilages and OCD loose fragments than in SONK loose fragments. The OCD chondrocytes maintained higher proliferative activity and redifferentiation potential compared with SONK chondrocytes. Our results suggest that chondrogenic properties of loose fragment-derived cells and the amount of CD166-positive cells may affect the repair process of osteochondral defects. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 1 2013 Histological Analysis of Failed Cartilage Repair after Marrow Stimulation for the Treatment of Large Cartilage Defect in Medial Compartmental Osteoarthritis of the Knee 65 74 EN Kenichiro Sakata Takayuki Furumatsu Nobuhiro Abe Shinichi Miyazawa Yoshimasa Sakoma Toshifumi Ozaki Case Report 10.18926/AMO/49259 Bone marrow-stimulating techniques such as microfracture and subchondral drilling are valuable treatments for full-thickness cartilage defects. However, marrow stimulation-derived reparative tissues are not histologically well-documented in human osteoarthritis. We retrospectively investigated cartilage repairs after marrow stimulation for the treatment of large cartilage defects in osteoarthritic knees. Tissues were obtained from patients who underwent total knee arthroplasty (TKA) after arthroscopic marrow stimulation in medial compartmental osteoarthritis. Clinical findings and cartilage repair were assessed. Sections of medial femoral condyles were histologically investigated by safranin O staining and anti-type II collagen antibody. Marrow stimulation decreased the knee pain in the short term. However, varus leg alignment gradually progressed, and TKA conversions were required. The grade of cartilage repair was not improved. Marrow stimulations resulted in insufficient cartilage regeneration on medial femoral condyles. Safranin O-stained proteoglycans and type II collagen were observed in the deep zone of marrow-stimulated holes. This study demonstrated that marrow stimulation resulted in failed cartilage repair for the treatment of large cartilage defects in osteoarthritic knees. Our results suggest that arthroscopic marrow stimulation might not improve clinical symptoms for the long term in patients suffering large osteoarthritic cartilage defects. No potential conflict of interest relevant to this article was reported.