Akio Minami

Long term outcome of osteochondritis dissecans of the humeral capitellum.

Long term outcome of osteochondritis dissecans of the humeral capitellum was determined for 53 patients. The average age of the patients at the time of treatment was 16.6 years (range, 10-34 years). The average followup was 12.6 years (range, 3-25 years). Seven of 14 (50%) patients who were treated conservatively and 18 of 39 (46%) who were treated by surgical removal of the fragment were found to have residual elbow symptoms associated with daily living activities (poor outcome). The initial radiographs of the elbow were available for 45 patients; a poor outcome was seen in six of 19 (32%) early lesions and 13 of 26 (50%) advanced lesions. Fourteen elbows had evidence of osteoarthritis on the initial radiographs, and a poor outcome was seen for nine (64%) of these elbows. After removal or detachment of the fragment, seven osteochondral defects were assessed as large, and all seven had a poor outcome. These long term results suggest that the residual elbow symptoms associated with daily living activities in approximately 50% of patients may be associated with advanced lesions, osteoarthritis of the elbow, and a large osteochondral defect.

Analysis of transforming activity of human synovial sarcoma-associated chimeric protein SYT-SSX1 bound to chromatin remodeling factor hBRM/hSNF2 alpha.

Human synovial sarcoma has been shown to exclusively harbor the chromosomal translocation t(X;18) that produces the chimeric gene SYT-SSX. However, the role of SYT-SSX in cellular transformation remains unclear. In this study, we have established 3Y1 rat fibroblast cell lines that constitutively express SYT, SSX1, and SYT-SSX1 and found that SYT-SSX1 promoted growth rate in culture, anchorage-independent growth in soft agar, and tumor formation in nude mice. Deletion of the N-terminal 181 amino acids of SYT-SSX1 caused loss of its transforming activity. Furthermore, association of SYT-SSX1 with the chromatin remodeling factor hBRM/hSNF2α, which regulates transcription, was demonstrated in both SYT-SSX1-expressing 3Y1 cells and in the human synovial sarcoma cell line HS-SY-II. The binding region between the two molecules was shown to reside within the N-terminal 181 amino acids stretch (aa 1–181) of SYT-SSX1 and 50 amino acids (aa 156–205) of hBRM/hSNF2α and we found that the overexpression of this binding region of hBRM/hSNF2α significantly suppressed the anchorage-independent growth of SYT-SSX1-expressing 3Y1 cells. To analyze the transcriptional regulation by SYT-SSX1, we established conditional expression system of SYT-SSX1 and examined the gene expression profiles. The down-regulation of potential tumor suppressor DCC was observed among 1,176 genes analyzed by microarray analysis, and semi-quantitative reverse transcription–PCR confirmed this finding. These data clearly demonstrate transforming activity of human oncogene SYT-SSX1 and also involvement of chromatin remodeling factor hBRM/hSNF2α in human cancer.

Vascularised fibular grafts

The results and complications of 104 vascularised fibular grafts in 102 patients are presented. Bony union was ultimately achieved in 97 patients, with primary union in 84 (84%). The mean time to union was 15.5 weeks (8 to 40). In 13 patients, primary union was achieved at one end of the fibula and secondary union at the other end. In these patients, the mean time to union was 31.1 weeks (24 to 40). Five patients failed to achieve union, with a resultant pseudarthrosis (3 patients) or amputation (2 patients). There were various complications. Immediate thrombosis occurred in 14 cases. In two of 23 patients with osteomyelitis, infection recurred at two and six months after surgery, respectively. Both patients had active osteomyelitis less than one month before the operation. Bony infection occurred in a patient with a synovial sarcoma of the forearm one year after surgery. In 15 patients, 19 fractures of the fibular graft occurred after bony union, all except one within one year after union. In patients in whom an external fixator had been used, fracture occurred soon after its removal. Union was difficult to achieve in cases of congenital pseudarthrosis of the tibia. Appropriate alignment of the fibular graft is an important factor in preventing stress fracture. The vascularised fibula should be protected during the first year after union. Postoperative complications at the donor site included transient palsy of the superficial peroneal nerve in three patients, contracture of flexor hallucis longus in two and valgus deformity of the ankle in three. Vascularised fibular grafts are useful in the reconstruction of massive bony defects. We believe that meticulous preoperative planning, including choosing which vessels to select in the recipient and the type of fixation devices to use, and care in the introduction of the vascularised fibula, can improve the results and prevent complications.

Clinical results of treatment of triangular fibrocartilage complex tears by arthroscopic debridement

In order to determine indications for arthroscopic debridement and the management of triangular fibrocartilage complex (TFCC) tears, we reviewed 16 wrists retrospectively. The mean patient age was 30 years, with a range of 20 to 53 years. The follow-up period averaged 35 months. Two groups were identified: post-traumatic tears (n = 11) and degenerative tears (n = 5). The results of arthroscopic debridement were compared and analyzed based on the preoperative and postoperative evaluation of pain, range of motion, grip strength, return to work, patient acceptance, and complications. Failures were further evaluated to determine identifiable lesions or anatomic defects associated with poor results. Patients with positive ulnar variance and lunotriquentral interosseous ligament tears had a poor clinical outcome. Good results correlated with grip strength; all patients with post-traumatic TFCC tears had excellent results, while those with degenerative TFCC tears did poorly.

Ulnar shortening for triangular fibrocartilage complex tears associated with ulnar positive variance.

Twenty-five patients with triangular fibrocartilage complex (TFCC) tears associated with ulnar positive variance who did not respond to conservative management were treated by ulnar shortening. The follow-up period averaged 35 months. All patients complained of pain, restricted forearm rotation, and weakness of grip. Arthroscopy was performed in 23 of 25 wrists to assess the status of the TFCC and the degree of the degenerative change of the proximal aspect of the lunate and triquetrum. Arthroscopic findings consisted of 15 class 1 and 8 class 2 tears according to Palmers classification. When the TFCC showed a traumatic flap tear, only the torn flap was removed arthroscopically. Ulnar shortening averaged 3 mm. Transverse osteotomies healed in all patients at a mean postoperative time of 7 weeks. Twenty-three patients had either complete relief or occasional mild pain of the wrist. Two patients with persistent pain had additional procedures performed. Postoperative x-ray films revealed slight degenerative changes at the distal radioulnar joint in 7 patients. Complications included 1 reflex sympathetic dystrophy and 2 fractures through the osteotomy site after early plate removal. Ulnar shortening is a useful procedure for TFCC tears associated with ulnar positive variance.

Accuracy analysis of pedicle screw placement in posterior scoliosis surgery: comparison between conventional fluoroscopic and computer-assisted technique.

Study Design. The accuracy of pedicle screw placement was evaluated in posterior scoliosis surgeries with or without the use of computer-assisted surgical techniques. Objective. In this retrospective cohort study, the pedicle screw placement accuracy in posterior scoliosis surgery was compared between conventional fluoroscopic and computer-assisted surgical techniques. Summary of Background Data. There has been no study systemically analyzing the perforation pattern and comparative accuracy of pedicle screw placement in posterior scoliosis surgery. Methods. The 45 patients who received posterior correction surgeries were divided into 2 groups: Group C, manual control (25 patients); and Group N, navigation surgery (20 patients). The average Cobb angles were 73.7° and 73.1° before surgery in Group C and Group N, respectively. Using CT images, vertebral rotation, pedicle axes as measured to anteroposterior sacral axis and vertebral axis, and insertion angle error were measured. In perforation cases, the angular tendency, insertion point, and length abnormality were evaluated. Results. The perforation was observed in 11% of Group C and 1.8% in Group N. In Group C, medial perforations of left screws were demonstrated in 8 of 9 perforated screws and 55% were distributed either in L1 or T12. The perforation consistently occurred in pedicles in which those axes approached anteroposterior sacral axis within 5°. The average insertion errors were 8.4° and 5.0° in Group C and Group N, respectively, which were significantly different (P < 0.02). Conclusion. The medial perforation in Group C occurred around L1, especially when pedicle axis approached anteroposterior sacral axis. This consistent tendency was considered as the limitation of fluoroscopic screw insertion in which horizontal vertebral image was not visible. The use of surgical navigation system successfully reduced the perforation rate and insertion angle errors, demonstrating the clear advantage in safe and accurate pedicle screw placement of scoliosis surgery.

Autologous Osteochondral Mosaicplasty for Capitellar Osteochondritis Dissecans in Teenaged Patients

Background Autologous osteochondral mosaicplasty is a new technique to provide hyaline repair for articular defects. Although recent studies have reported the successful treatment of articular defects in the knee and ankle joints with this surgical procedure, little attention has been given to the surgical efficacy of mosaicplasty in the treatment of osteochondritis dissecans of the humeral capitellum. Purpose To clarify the clinical outcomes of mosaicplasty for teenaged patients with advanced lesions of capitellar osteochondritis dissecans. Study Design Case series; Level of evidence, 4. Methods Eight teenaged patients with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. All patients were baseball players who were affected on the right side, which was also their throwing side. The surgical technique involves obtaining small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyles and transplanting them to prepared osteochondral defects. At a mean follow-up of 24 months, all patients were evaluated clinically and radiographically. Results Seven of the 8 patients were free from elbow pain, and the remaining patient had mild pain occasionally. The mean clinical score described by Timmerman and Andrews (a maximum of 200 points) significantly improved from 140 points to 183 points postoperatively. All patients except one had excellent or good clinical results. Radiographically, the graft incorporation and a normal contour of the subchondral cortex were found in all patients. Magnetic resonance imaging showed that the preoperative heterogeneity of the lesion had disappeared and the signal intensity returned to normal. Six of the 8 patients, including all 3 pitchers, returned to competitive-level baseball. Conclusion Mosaicplasty for advanced lesions of capitellar osteochondritis dissecans in teenaged baseball players can provide satisfactory clinical and radiographic results.

The Effect of Growth Factors on Biomechanical Properties of the Bone–Patellar Tendon–Bone Graft After Anterior Cruciate Ligament Reconstruction A Canine Model Study

Background No studies have dealt with the effect of growth factors on the free tendon autograft in anterior cruciate ligament reconstruction. Hypothesis Application of exogenous transforming growth factor-β and epidermal growth factor may affect the structural properties and histology of the bone-patellar tendon-bone autograft after anterior cruciate ligament reconstruction. Study Design Controlled laboratory study. Methods Twenty dogs underwent anterior cruciate ligament reconstruction with the autogenous bone-patellar tendon-bone graft in bilateral knees. In 10 animals, 12 ng transforming growth factor-β and 300 ng epidermal growth factor mixed with fibrin sealant of 0.6 mL were applied to the left knee. In the remaining 10 dogs, fibrin sealant alone was applied to the left knee. No additional treatments were applied to the right knee. Results The growth factor application increased the stiffness and maximum failure load of the femur-graft-tibia complex at 12 weeks (P = .016 and P = .012, respectively); the sham treatment did not significantly affect them. Histologically, most of the cells in the grafts treated with growth factors had spindle-shaped nuclei; cells in the other grafts had round-shaped nuclei. Conclusions Application of transforming growth factor-β and epidermal growth factor improves the structural properties of the autograft after anterior cruciate ligament reconstruction in the canine model. Clinical Relevance Application of growth factors is a possible strategy to prevent graft deterioration in anterior cruciate ligament reconstruction.

Donor Site Evaluation after Autologous Osteochondral Mosaicplasty for Cartilaginous Lesions of the Elbow Joint

Background One significant disadvantage of autologous osteochondral mosaicplasty (mosaicplasty) is the harvesting of osteochondral grafts from the normal articular area of the knee joint. However, the effect of harvesting grafts on knee function remains unclear. Purpose To clarify the functional effects on the donor knee of harvesting osteochondral grafts and to perform magnetic resonance imaging evaluation of donor site repair after mosaicplasty for capitellar osteochondritis dissecans in young athletes. Study Design Case series; Level of evidence, 4. Methods Eleven male competitive athletes with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. The surgical technique involves obtaining small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyle at the level of the patellofemoral joint and transplanting them to osteochondral defects in the capitellum. Assessment at a mean follow-up of 26 months included local findings of the donor knees, a Lysholm knee scoring scale, International Knee Documentation Committee standard evaluation form, and magnetic resonance imaging evaluation. Results All patients returned to a competitive level of their previous sports without any donor site disturbances. Based on the Lysholm knee score and International Knee Documentation Committee evaluation form, all knees were graded as excellent and normal, respectively. The magnetic resonance imaging showed 50% to 100% defect fill in 6 of 9 patients and normal or nearly normal signals in 4 patients at the donor sites. Conclusion No adverse effects of osteochondral graft harvest on donor knee function were found after mosaicplasty for capitellar osteochondritis dissecans in young athletes. However, magnetic resonance imaging indicates that the donor site is resurfaced with fibrous tissue.

Vascularized fibular graft after excision of giant-cell tumor of the distal radius: wrist arthroplasty versus partial wrist arthrodesis.

&NA; Several reconstructive procedures have been described for the complete defect of the distal radius that is created after a wide excision of a giant‐cell tumor of bone, including hemiarthroplasty using the vascularized fibular head and partial wrist arthrodesis between a vascularized fibula and the scapholunate portion of the proximal carpal row. The objectives of this study are to compare clinical and radiographic results between the partial wrist arthrodesis and the wrist arthroplasty, and to discuss which procedure is superior. Four patients with giant‐cell tumors involving the distal end of the radius were treated with en bloc resection and reconstruction with a free vascularized fibular graft. The wrists in two patients were reconstructed with an articular fibular head graft and the remaining two patients underwent partial wrist arthrodesis using a fibular shaft transfer. There was radiographic evidence of bone union at the host‐graft junctions in all cases. In the newly reconstructed wrist joint, there was palmar subluxation of the carpal bones and degenerative changes in both patients. Local recurrence was seen in one patient. According to the functional results described by Enneking et al., the mean functional score was 67 percent. The functional scores including wrist/forearm range of motion in the cases with partial wrist arthrodesis were superior to those with wrist arthroplasty. A partial wrist arthrodesis using a vascularized fibular shaft graft appears a more useful and reliable procedure for reconstruction of the wrist after excision of the giant‐cell tumor of the distal end of the radius than a wrist arthroplasty using the vascularized fibular head, although our study includes only a small number of patients.