Ozaki, Toshifumi

We performed fixation using laminar screws in 2 patients in whom lateral mass screws, pedicle screws or transarticular screws could not be inserted. One was a 56-year-old woman who had anterior atlantoaxial subluxation (AAS). When a guide wire was inserted using an imaging guide, the hole bled massively. We thought the re-insertion of a guide wire or screw would thus increase the risk of vascular injury, so we used laminar screws. The other case was an 18-year-old man who had a hangman fracture. Preoperative magnetic resonance angiography showed occlusion of the left vertebral artery. A laminar screw was inserted into the patent side (i.e., the right side of C2). Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion, because the cervical pedicle is small and is adjacent laterally to the vertebral artery, medially to the spinal cord, and vertically to the nerve roots. Lateral mass screws are also reported to involve a risk of neurovascular injuries. The laminar screw method was thus thought to be useful, since arterial injuries could thus be avoided and it could also be used as a salvage modality for the previous misinsertion.

We biomechanically evaluated the bone fixation rigidity of an ONI plate (Group I) during fixation of experimentally created transcondylar humerus fractures in cadaveric elbows, which are the most frequently observed humeral fractures in the elderly, and compared it with the rigidity achieved by 3 conventional fixation methods:an LCP reconstruction plate 3.5 using a locking mechanism (Group II), a conventional reconstruction plate 3.5 (CRP) with a cannulated cancellous screw (Group III), and a CRP with 2 cannulated cancellous screws (CS) in a crisscross orientation (Group IV). In the axial loading test, the mean failure loads were:Group I, 98.9+/-32.6;Group II, 108.5+/-27.2;Group III, 50.0+/-7.5;and Group IV, 34.5+/-12.2 (N). Group I fixations failed at a significantly higher load than those of Groups III and IV (p0.05). In the extension loading test, the mean failure loads were:Group I, 34.0+/-12.4;Group II, 51.0+/-14.8;Group III, 19.3+/-6.0;and Group IV, 14.7+/-3.1 (N). Group IV fixations showed a significantly lower failure load than those of Group I (p0.05). The fixation rigidities against mechanical loading by the ONI plate and LCP plate were comparable. These results suggested that an ONI system might be superior to the CRP and CS method, and comparable to the LCP method in terms of fixation rigidity for distal humerus fractures.

Femoroacetabular impingement (FAI) is a condition characterized by the impingement of the femur and acetabulum. In Japan, this disorder has become recognized gradually. Here we report a rare case of surgically treated FAI, associated with an osseous protrusion on the acetabulum of a 30-year-old female. Plain computed tomography (CT) and reconstructive 3D-CT images clearly demonstrated an anterolateral bony protrusion. Hip arthroscopy showed no degeneration of the cartilage on either the femoral or acetabular side, but degeneration at the edge of labrum was observed in the region of the bony protrusion. The complete removal of the bony protrusion under hip arthroscopy was thus considered impracticable, and a small skin incision was therefore made anteriorly to approach the acetabulum. The Short-Form 36-Item Health Survey (SF-36) revealed improvement in all scores.

To assess the effects of service dogs on health-related quality of life (HRQOL), we conducted a survey of 10 service dog owners using SF-36v2 (Medical Outcomes Study 36 Item Short-Form Health Survey Version 2.0) and compared it with a matched control group of people with physical disabilities who did not have service dogs but were eligible for one. The scores for mental health and role emotional of service dog owners were relatively high, and their mental component summary was higher than the general population norm. These results indicate that service dogs affect the mentality of their owners. The comparison with the control group indicated that service dogs alleviate the mental burden of daily activities, and subjectively improved the physical functioning of their owners. This study showed that service dogs have positive functional and mental effects on their disabled owners.

Radiological findings on the fate of grafted Kiel bone implants for the treatment of bone tumors were evaluated in 25 lesions. The mean follow-up period was 14.8 years, ranging from 5 to 21.8 years. We classified the radiological findings into 4 grades; Excellent (4 lesions), Good (14 lesions), Fair (2 lesions), and Poor (5 lesions). All cases of the Poor grade were polyostotic fibrous dysplasia. The younger the patient at the time of the operation, the more rapidly Kiel bone grafts tended to be incorporated. The grafted bone can become enmeshed in the structure of the recipient bed (Good or Excellent grades) within 10 years in most cases, except in polyostotic fibrous dysplasia.

We compared gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) enhanced T1-weighted images (T1-Gd) with the histopathological findings in 13 patients with bone or soft tissue sarcomas. Signal intensity of the viable tumor tissue was increased in T1-Gd in 92% of the patients. The necrotic or cystic areas in the tumor were not enhanced, rendering them distinctly. The degree of enhancement of the edematous area around the tumor was similar to or more marked than that of the tumor in 54% of the patients. Area showing inflammatory cells infiltration and edematous areas in the tumor tissue were also enhanced. Thus, the effect of preoperative chemotherapy in tumor tissues other than necrotic and cystic areas tended to be underestimated in T1-Gd. Its effect should be comprehensively evaluated based on not only T1-Gd but also T2-weighted images and findings of other imaging techniques.

We evaluated the surgical problems encountered during treatment of 14 patients with malignant tumors originating in the pelvic region at our department. The tumor involved the iliac bone in 6 patients, the ischial bone in 2, the pubic bone in 2, and the gluteal region in 4. Invasion to the sacrum was observed in 7 patients. Twelve patients underwent surgical procedures consisting of intralesional resection in 6, marginal resection in 3, and wide margin resection in 3. Six of the 7 patients with sacral invasion developed local recurrence. Two patients with chondrosarcoma and one with parosteal osteosarcoma survived for 4 or more years, but the mean survival period in those with high grade malignant tumors was 11 months. These findings indicate the difficulties encountered in the treatment of malignant pelvic tumors.