Daisuke Kawamura

Repair of articular cartilage defects with a novel injectable in situ forming material in a canine model.

We developed an ultra-purified in situ forming gel as an injectable delivery vehicle of bone marrow stromal cells (BMSCs). Our objective was to assess reparative tissues treated with autologous BMSCs implanted using the injectable implantation system into osteochondral defects in a canine model. Forty-eight osteochondral defects in the patella groove of the knee joint were created in 12 adult beagle dogs (two defects in each knee). The defects were divided into a defect group (n = 16), an acellular novel material implantation (material) group (n = 16), and a BMSCs implantation using the current vehicle system (material with BMSCs) group (n = 16). The reparative tissues at 16 weeks postoperatively were assessed through gross, histological, and mechanical analyses. The reparative tissues of the material with BMSCs group were substituted with firm and smooth hyaline-like cartilage tissue that was perfectly integrated into the host tissues. This treatment group obviously enhanced the subchondral bone reconstruction. The compressive modulus of the reparative tissues was significantly higher in the material with BMSCs group than the other groups. This study demonstrated that the implantation of BMSCs using our novel in situ forming material induced a mature hyaline-like cartilage repair of osteochondral defects in a canine model.

Predictive factors of long head of the biceps tendon disorders—the bicipital groove morphology and subscapularis tendon tear

BACKGROUND Disorders of the long head of the biceps (LHB) tendon contribute to anterior shoulder pain. Although LHB tendon disorders are associated with rotator cuff disease, distinguishing between biceps and rotator cuff pathology is difficult. The objective was to identify the predictors of LHB tendon disorders associated with a supraspinatus tear. METHODS In 55 patients (average age, 65 years) undergoing arthroscopic rotator cuff repair, bicipital groove morphology were assessed using computed tomography, and subscapularis tear and bicipital groove effusion were assessed using magnetic resonance imaging, retrospectively. The LHB tendon was evaluated arthroscopically according to the Lafosse classification. Univariate and multivariate ordinal logistic regression analyses were conducted for injury grade with all covariates. RESULTS The arthroscopic evaluation of the LHB tendon showed that there were 23 shoulders classified as grade 0, 15 as grade 1, and 17 as grade 2. Univariate logistic regression analysis showed that the width and depth, a medial spur of the bicipital groove, and a subscapularis tear were significantly associated with LHB tendon disorders. Multivariate ordinal logistic regression analysis identified a medial spur and subscapularis tear as significant predictors of LHB tendon disorders. CONCLUSIONS The preoperative computed tomography and magnetic resonance images, notably the presence of a spur on the bicipital groove or a subscapularis tear, were useful for identifying LHB tendon disorders. When these are found in preoperative images, the clinician should evaluate the patient for the presence of an LHB tendon disorder as a pain generator.

Therapeutic Effects of Intra-Articular Ultrapurified Low Endotoxin Alginate Administration on Experimental Osteoarthritis in Rabbits

Objective: We have developed an ultrapurified low endotoxin alginate (UPLE alginate), which can drastically reduce endotoxin levels. Our purposes were to examine the effects of UPLE alginate administration on osteoarthritis (OA) progression and to determine the adequate molecular weight of the UPLE alginate for therapeutic effects. Design: To induce knee OA, 35 Japanese White rabbits underwent anterior cruciate ligament transection. Intra-articular injections of 0.3 mL solution of each material were started at 4 weeks postoperatively for a total of 5 weekly injections. Seventy knees were divided into the following groups: AL430 (430 kDa molecular weight UPLE alginate), AL1000 (1,000 kDa), AL1700 (1,700 kDa), HA (hyaluronan), and NS (normal saline). At 9 weeks postoperatively, all knees were assessed macroscopically, histologically, and mechanically. Results: Macroscopically, the UPLE alginate groups exhibited milder cartilage degradation compared to that of the NS and HA groups. Histological findings of the UPLE alginate groups showed an obvious reduction in the severity of OA. The histological scores of Kikuchi et al. were superior in the alginate treatment groups compared to the NS group. The friction coefficient of the AL1000 group was significantly lower than that of the NS and HA groups. Conclusion: This study indicates that our UPLE alginates, especially AL1000, have promising potential as an effective agent in preventing OA progression.

Autologous Osteochondral Mosaicplasty for Centrally and Laterally Located, Advanced Capitellar Osteochondritis Dissecans in Teenage Athletes: Clinical Outcomes, Radiography, and Magnetic Resonance Imaging Findings:

Background: Autologous osteochondral mosaicplasty (ie, mosaicplasty) results in satisfactory clinical outcomes and reliable return to play for patients with large or unstable lesions due to osteochondritis dissecans (OCD) of the humeral capitellum. However, the association between the healing of the reconstructed cartilage and clinical outcomes remains unclear. Purpose: To evaluate the efficacy of mosaicplasty in teenage athletes through use of clinical scores and imaging. The secondary purpose was to compare the clinical outcomes with images of centrally and laterally located lesions. Study Design: Case series; Level of evidence, 4. Methods: This study analyzed 22 elbows (all male patients; mean age, 13.5 ± 1.2 years) with capitellar OCD managed with mosaicplasty. Patients were divided into 2 groups according to the location of the lesions: central (10 patients) and lateral (12 patients). Evaluation was performed through use of the clinical rating system of Timmerman and Andrews, plain radiographs, and magnetic resonance imaging (MRI; the cartilage repair monitoring system of Roberts). The mean follow-up period was 27.5 months (range, 24-48 months). Results: Lateral lesions were significantly larger than central lesions (147.1 ± 51.9 mm2 vs 95.5 ± 27.4 mm2, P = .01). No other significant differences were found between central and lateral lesions. Timmerman and Andrews scores for both central and lateral lesions improved significantly from 125.0 ± 30.1 points and 138.3 ± 34.5 points preoperatively to 193.5 ± 11.3 points and 186.7 ± 18.1 points, respectively, at final follow-up (P < .0001, P < .0001). Radiography identified complete graft incorporation in all cases and the absence of severe osteoarthritic changes or displaced osteochondral fragments. In the lateral group, the radial head ratio at final follow-up (1.83 ± 0.23) was significantly larger than the preoperative findings (1.75 ± 0.14, P = .049). The quality of joint surface reconstruction was found to be acceptable for central and lateral lesions on MRI evaluation. Conclusion: Mosaicplasty resulted in satisfactory clinical outcomes and smooth cartilage surface integrity in teenage athletes with OCD on their return to competition-level sports activities irrespective of lesion location.

FINGER FLEXION CONTRACTURE DUE TO MUSCULAR INVOLVEMENT OF SARCOIDOSIS

We describe a rare experience with the treatment of a patient with finger flexion contracture caused by muscular involvement of sarcoidosis, who had been misdiagnosed as having a trigger finger and underwent surgical release of the A1 pulley of her little finger. This report serves as a reminder that muscular involvement of sarcoidosis can cause finger flexion contractures.