Osteointegration of a Biocomposite Suture Anchor After Arthroscopic Shoulder Labral Repair.

PURPOSE: To evaluate osteoconductivity of a poly-L-lactide co-glycolide (PLG)-calcium sulfate (CS)-ß-tricalcium phosphate (ß-TCP) biocomposite suture anchor after arthroscopic shoulder labral repair. METHODS: The subjects of this study were patients who participated in a clinical trial for acquisition of marketing approval of a PLG-CS-ß-TCP biocomposite anchor in Japan. They underwent arthroscopic labral repair using the anchor, and computed tomographic (CT) images of the glenoid were obtained 2 years after surgery. Osteoconductivity at the anchor sites was evaluated with the CT images using the established ossification quality score. Shoulder function scores including the Rowe score and Japanese Shoulder Society shoulder instability score were also assessed 2 years after surgery. RESULTS: CT images and functional scores were obtained from 37 patients, comprising 29 men and 8 women with a mean age of 29 years (range, 25-33 years) at surgery. A total of 148 anchors were implanted in the 37 shoulders. Osteoconductivity was seen in 133 of 148 anchor sites (90.0%) 2 years after implantation. No significant differences in osteoconductivity were found by anchor diameter or position. The Rowe score significantly improved from 39.9 points (95% confidence interval [CI], 33.8-45.9 points) preoperatively to 96.6 points (95% CI, 95.1-98.1 points) at 2 years postoperatively (P < .001). The Japanese Shoulder Society shoulder instability score also significantly improved, from 63.1 points (95% CI, 58.4-67.7 points) preoperatively to 96.3 points (95% CI, 94.7-97.8 points) at 2 years postoperatively (P < .001). CONCLUSIONS: Biocomposite suture anchors made of PLG, CS, and ß-TCP exhibited some osteoconductivity 2 years after arthroscopic labral repair, as well as good clinical outcomes. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Determining optimal length of coracoid graft in the modified Bristow procedure for anterior shoulder instability: A three-dimensional finite element analysis.

BACKGROUND: There is a lack of consensus concerning the coracoid graft length in the modified Bristow procedure. OBJECTIVE: We attempted to determine the optimal graft length using the three-dimensional finite element method. METHODS: In a shoulder model with a 25% anterior glenoid defect, a coracoid graft of varying lengths (5, 10, 15, and 20 mm) was fixed using a half-threaded screw. First, a compressive load of 500 N was applied to the screw head to determine the graft failure load during screw tightening. Next, a tensile load (200 N) was applied to the graft to determine the failure load due to biceps muscle traction. RESULTS: In the screw compression, the failure loads in the 5-, 10-, 15-, and 20-mm models were 252, 370, 377, and 331 N, respectively. In the tensile load applied to the coracoid graft, the failure load exceeded 200 N for both the 5- and 10-mm models. CONCLUSION: The 5-mm graft had a high risk of fracture during intraoperative screw tightening. As for the biceps muscle traction, the 5- and 10-mm-grafts had a lower failure risk than the 15- and 20-mm-grafts. Therefore, we believe that the optimal length of the coracoid graft is 10 mm in the modified Bristow procedure.

Surgical treatment for osteochondritis dissecans of the humeral capitellum.

BACKGROUND: Surgical treatments have been selected to treat advanced osteochondritis dissecans (OCD) of the humeral capitellum. PURPOSE: To evaluate the clinical results of surgical treatments for advanced capitellar OCD lesion and to clarify problems of poor clinical results. METHODS: Cases were reviewed for 27 patients with advanced OCD lesions treated operatively. All patients were male baseball players, with a mean of 13.3 years at the time of surgery. Drilling only was performed for 3 patients, fragment fixation for 13 patients, and removal of the detached fragment with drilling for four patients. Since 2004, reconstruction of the articular surface with use of osteochondral autograft from the rib has been performed for 7 patients with osteochondral defect. Mean follow-up was 37.4 months. Follow-up assessment included modified elbow rating system, evaluation of radiographs, and return to sports. RESULTS: Mean subjective score improved significantly from 70 to 96 postoperatively. Mean objective score improved significantly 71 to 81 postoperatively. A postoperative return to baseball was achieved by 25 patients. On the final radiographs, 4 patients showed flattening of >70% of the capitellum or degenerative changes, including insufficient remodeling of the lateral margin of the capitellum. Although patients could return to baseball, postoperative total arc of the elbow was decreased compared with the preoperative total arc. CONCLUSION: Surgical treatments were useful to restore advanced OCD lesions. Our results suggest that reconstruction of the lateral margin of the capitellum is important for achieving good clinical results. LEVEL OF EVIDENCE: Level 4.

Determination of in vivo glenohumeral translation using fluoroscopy and shape-matching techniques.

The purpose of this study was to investigate glenohumeral translation in-vivo during active shoulder abduction in the scapular plane. Three-dimensional (3D) models of 9 shoulders were created from CT scans. Fluoroscopic views aligned to the plane of the scapula were recorded during active arm abduction with neutral rotation. 3D motions were determined using model-based 3D-to-two-dimensional (2D) registration. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 1.7 mm superior with arm abduction, from an inferior location to the glenoid center. The humeral head was centered within 1 mm from the glenoid center above 80 degrees abduction. Variability in glenohumeral translation between shoulders decreased significantly from initial to final arm abduction. Our findings agree with some authors' observations of inferior-to-central translation of the humerus and behavior as a congruent ball and socket. We believe this information will help improve the understanding of shoulder function.

New intramedullary nail for the surgical neck fracture of the proximal humerus in elderly patients.

BACKGROUND: Fractures of the proximal humerus are common and the repair of displaced fractures generally requires an operative approach. In elderly patients, osteoporosis makes internal fixation problematic and frequently contributes to failed fixation and poor clinical results. We have developed a new intramedullary nail (pin lock nail) for the repair of surgical neck fractures of the proximal humerus in patients with osteoporotic bones. A retrospective review is presented of the cases of 19 elderly patients with two-part or three-part fractures of the proximal humerus treated using the pin lock nail. METHODS: We treated 19 elderly patients with a mean age of 70.5 years. There were 13 two-part surgical neck fractures, 3 two-part surgical neck fractures with non-displaced greater tuberosity fracture, and 3 three-part surgical neck fractures with greater tuberosity fracture. All fractures were treated using the pin lock nail. Clinical results were evaluated using the Japanese Orthopaedic Association score at the last follow-up examination. On radiographic evaluation, duration to bone union of the fracture, backing out of the pin and screw, penetration of the proximal pin, and varus angulations of the humeral neck were examined. RESULTS: Mean duration of follow-up was 14 months (range 6-54 months). All fractures had united at an average of 3.3 months after surgery. No backing out of the pin and screw or penetration of the proximal locking pin was seen at the time of last follow-up. Thirteen of the 16 patients had no or minimal varus angulations of the humeral neck (< or =10 degrees). The mean overall JOA score was 84.3 points (range 65.5-100). CONCLUSIONS: Our data show that using the pin lock nail for the treatment of two-part and three-part humeral fractures is a reliable procedure, providing good results with careful postoperative management.

MR arthrography of shoulders after suture-anchor Bankart repair.

PURPOSE: To determine the ability of magnetic resonance (MR) arthrography to depict the anatomic reestablishment of the capsulolabral complex after suture-anchor Bankart repair. MATERIALS AND METHODS: Thirty patients (25 men, five women; mean age, 28 years) who had undergone suture-anchor Bankart repair of one shoulder underwent MR arthrography before second-look arthroscopy. Ninety-eight anchors were used for the sutures. MR arthrographic diagnosis of anatomic reestablishment of the capsulolabral complex was correlated with arthroscopic findings. Contingency table analysis was performed to determine the relationship between MR arthrographic findings and arthroscopic findings. RESULTS: MR findings of reattachment of the capsulolabral complex were in agreement with arthroscopic findings in 93 anchor points (accuracy, 93 of 98 anchor points; 95%). In 28 shoulders, oblique transverse images obtained with the shoulder in the abduction and external rotation position showed that the anterior band of the inferior glenohumeral ligament (AIGHL) abutted the humeral head and that reattachment of the AIGHL to the glenoid rim was seamless. Arthroscopy revealed satisfactory reestablishment of the capsulolabral complex in these shoulders. In the remaining two shoulders, a pool of contrast material was seen between the AIGHL and humeral head and a "divot" was detected at the point of reattachment of the AIGHL to the glenoid rim. Arthroscopy revealed unsatisfactory reestablishment of the capsulolabral complex. MR arthrographic findings of reattachment of the AIGHL were significantly associated with arthroscopic findings of reestablishment of the capsulolabral complex (P <.01). CONCLUSION: MR arthrography can be reliably used for the postoperative assessment of suture-anchor Bankart repair.