Prevalence and Clinical Characteristics of Osteochondritis Dissecans of the Humeral Capitellum Among Adolescent Baseball Players.

BACKGROUND: The prevalence and clinical characteristics of osteochondritis dissecans (OCD) of the humeral capitellum among adolescent baseball players are unknown. PURPOSE: To determine the OCD prevalence in adolescent competitive baseball players and to investigate the clinical characteristics of these patients. STUDY DESIGN: Cross-sectional and case-control study; Level of evidence, 3. METHODS: A total of 2433 baseball players (mean age, 14.5 ± 1.5 years) belonging to junior high school and high school baseball clubs were enrolled. Players completed a questionnaire, and the elbow of each player's throwing arm was assessed by ultrasonography. Participants with abnormal results on ultrasonography were further examined through radiographic study. The OCD lesions were classified into stages based on radiographic results, and demographic data were compared between players with and without OCD lesions. RESULTS: Osteochondritis dissecans of the humeral capitellum was found in 82 (3.4%) elbows by ultrasonography. Players with an OCD lesion began playing baseball at an earlier age (P = .016), had a longer duration of competitive play (P = .0013), and had experienced more present (P = .0025) and past (P < .0001) elbow pain compared with players without a lesion. There were no differences between the 2 groups in the position played (P = .26). Sixty-eight patients underwent further radiographic examination for OCD (radiography, computed tomography, magnetic resonance imaging). Of these players, 10 (14.7%) were classified as having stage I OCD (radiolucent stage); 26 (38.2%), stage II (fragmentation stage); 9 (13.2%), stage III (loose body stage); 9 (13.2%), stage IV (residual stage); and 14 (23.5%), stage V (postoperative stage). CONCLUSION: The prevalence of OCD of the humeral capitellum, including latent cases, was 3.4% among adolescent baseball players. Players with OCD lesions began playing baseball at earlier ages, had played for longer periods, and had experienced more elbow pain. The player's current baseball position may not be related to the existence of OCD lesions in adolescents.

Weekly teriparatide administration for the treatment of delayed union: a report of two cases.

UNLABELLED: Two cases of delayed union that were effectively treated with weekly TPTD administration are described. The effect of this therapy was observed within 4 weeks. INTRODUCTION: In the first case, a 72-year-old woman underwent osteotomy for the treatment of hallux valgus. Bone union was still not observed 4 months after surgery. Therefore, weekly teriparatide (56.5 mg) injections were administered, resulting in the initiation of bone union within 4 weeks and complete bone union 4 months after the first teriparatide injection. In the second case, a 72-year-old woman underwent open reduction and internal fixation of an olecranon fracture. Bone union was delayed 4 months after surgery; therefore, weekly teriparatide (56.5 mg) injections were started. RESULTS: The initiation of bone union was slightly evident within 4 weeks, and complete healing was achieved 4 months after the first teriparatide injection. In both cases, no serious teriparatide-related adverse effects were observed. CONCLUSION: Weekly teriparatide administration was effective for bone healing and useful for delayed union; moreover, the effect of this therapy showed within 4 weeks.

Bone marrow-derived cells from the footprint infiltrate into the repaired rotator cuff.

BACKGROUND: Cells from the bone marrow are considered important during the rotator cuff repair process, but the kinetics of bone marrow-derived cells in this process is unknown. PURPOSE: To analyze the kinetics of bone marrow cells during the rotator cuff repair process, to review whether or not they are histologically involved in rotator cuff healing, and to analyze the biomechanics of the repaired tissues. METHODS: Bone marrow chimeric rats that express green fluorescent protein (GFP) only in bone marrow- and circulation-derived cells were created. Bilateral supraspinatus tendons were separated from the greater tuberosity of the humeral head to produce a rotator cuff transection model. Drilling into the bone marrow was performed in the greater tuberosity of the right humerus and the supraspinatus tendon was repaired (drilling group), while the supraspinatus tendon was repaired on the left shoulder without drilling (control group). We examined the histology of the rotator cuff, the ultimate force-to-failure, and the proportion of GFP-positive cells in the repaired rotator cuff at 2, 4 and 8 weeks after surgery. RESULTS: Mesenchymal cells were observed in the repaired rotator cuff at 2 weeks in both groups. There were more GFP-positive cells in the drilling group than the control group at 2, 4 and 8 weeks. The ultimate force-to-failure was significantly higher in the drilling group than the control group at 4 and 8 weeks. CONCLUSION: Bone marrow-derived cells passed through holes drilled in the humerus footprint, infiltrated the repaired rotator cuff and contributed to postsurgical rotator cuff healing.

Characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells for the treatment of rotator cuff defect--what is the ideal graft for the treatment of massive rotator cuff defects?

PURPOSE: We examined the characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells to repair rotator cuff defects. We also clarified which graft with or without live cells was superior in the early remodeling process. MATERIALS AND METHODS: Sprague-Dawley (SD) rats and green fluorescent protein (GFP) rats were used; they were divided into 3 groups: in group SD, the Achilles tendons of GFP rats were transplanted into the defects of SD rats; in group GFP, the Achilles tendons of SD rats were transplanted into GFP rats; in group GFP-Fr, frozen Achilles tendons of SD rats were transplanted into GFP rats. At 3 and 7 days after surgery, these sections were examined histologically and immunohistochemically with anti-heat shock protein (HSP) 47 and anti-macrophage antibodies. RESULTS: Donor cells gradually decreased, but HSP47-positive donor cells were detected at 3 days in group SD. Host cells infiltrated into the graft from the surrounding tissue, and their numbers in groups SD and GFP gradually increased more significantly than in group GFP-Fr. Macrophages derived from the donor tissue were absent in all groups. The remodeling process of the frozen graft was slower than that in the case of the graft that was not frozen. CONCLUSION: These results demonstrate that live donor cells have a positive effect on the remodeling process. Therefore, autografts with live cells considered to be preferred to frozen allografts or synthetic materials without live cells for transplant for rotator cuff defects.

Behavior of host and graft cells in the early remodeling process of rotator cuff defects in a transgenic animal model.

Autologous tissue graft is one of the treatment options for a large rotator cuff defect. To develop appropriate strategies for enhanced solid graft integration at the bone-tendon interface and tendon-tendon interface, clarifying the fate of the graft and host cells that contribute to repair and remodeling is necessary. We have developed a new grafting model using green fluorescent protein-transgenic rats and wild-type rats to simulate autologous transplantation for examining the behavior of the host and graft cells in the remodeling process after tendon grafting. We found that the host cells commenced proliferation in the graft at 1 day after grafting. The host cells infiltrated into the graft from the subacromial synovium, proximal tendon, and bone-tendon insertion. The number of graft-derived cells decreased with time. Our result clearly demonstrated that host cells, rather than graft cells, were essential for rotator cuff remodeling after tendon grafting for rotator cuff defect.