Arthroscopic Superior Capsule Reconstruction for Irreparable Rotator Cuff Tears: Comparison of Clinical Outcomes With and Without Subscapularis Tear.

BACKGROUND: Arthroscopic superior capsule reconstruction (SCR) was developed to restore shoulder superior stability, muscle balance, and function in patients with irreparable posterior-superior rotator cuff tears. PURPOSE: To assess the effects of concomitant subscapularis tendon tear, which may reduce glenohumeral stability and force coupling, on clinical outcomes of SCR for irreparable posterior-superior rotator cuff tears. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In total, 193 patients with irreparable posterior-superior rotator cuff tears underwent arthroscopic SCR using fascia lata autograft between 2007 and 2015. They were allocated to 3 groups: group 1, no subscapularis tear (160 patients); group 2, reparable subscapularis tear, which underwent arthroscopic repair (26 patients); and group 3, irreparable subscapularis tear (7 patients). American Shoulder and Elbow Surgeons (ASES) and Japanese Orthopaedic Association (JOA) scores, visual analog scale (VAS) score for pain, active shoulder range of motion (ROM), muscle strength (manual muscle test), and acromiohumeral distance were evaluated before surgery and at final follow-up (mean, 3 years, 7 months; range, 2-11 years). Postoperative complications were assessed. RESULTS: In groups 1 and 2, ASES, JOA, and VAS scores and shoulder ROM and muscle strength improved significantly after SCR with subscapularis repair (P < .001). SCR in group 3 significantly improved ASES, JOA, and VAS scores (P < .001), whereas shoulder ROM and muscle strength did not increase significantly. Postoperative acromiohumeral distance was significantly smaller in group 3 (5.7 ± 2.9 mm [mean ± SD]) than group 2 (9.1 ± 2.3 mm) (P = .002). Group 3 had a significantly higher rate of graft tear (P < .001) and postoperative infection (P < .001) than group 1. CONCLUSION: The presence of subscapularis tendon tear affects clinical outcomes and complication rates after SCR. The reparability of the subscapularis affects superior glenohumeral stability; therefore, an intact subscapularis or reparable subscapularis tendon tear is the best indication for arthroscopic SCR in patients with irreparable posterior-superior rotator cuff tendon tears.

Humeral Retroversion and Injury Risk After Proximal Humeral Epiphysiolysis (Little Leaguer's Shoulder).

BACKGROUND: The increased humeral retroversion on the dominant side of throwing athletes is thought to result from repetitive throwing motion. Little Leaguer's shoulder-a rotational stress fracture of the proximal humeral epiphyseal plate-may influence the risk of humeral retroversion and injury of the shoulder or elbow joint. PURPOSE: To investigate the effect of Little Leaguer's shoulder on humeral retroversion and the rates of shoulder and elbow injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: 10 high school baseball players (average age, 16.6 years; range, 16-18 years) who had experienced Little Leaguer's shoulder during elementary or junior high school (average age, 12.6 years; range, 11-15 years) were enrolled in the study. As a control group, 22 high school baseball players (average age, 16.9 years; range, 16-18 years) who had never had any shoulder or elbow injury during elementary and junior high school were included. Humeral retroversion on ultrasonographic measurement, shoulder range of motion, and rates of shoulder and elbow injuries were evaluated. RESULTS: Humeral retroversion was significantly greater on the dominant side than on the nondominant side in both players with Little Leaguer's shoulder (dominant, 104°± 8°; nondominant, 84°± 12°; P < .001) and controls (dominant, 91°± 13°; nondominant, 81°± 10°; P < .001). In the dominant shoulder, humeral retroversion was greater in the Little Leaguer's shoulder group than in the control group (P = .008). When the effects of humeral retroversion were excluded, maximal external rotation was significantly less in the dominant shoulder than in the nondominant shoulder in the Little Leaguer's shoulder group (by 11°± 12°, P = .02), whereas no significant difference was found between dominant (110°± 11°) and nondominant (111°± 13°) shoulders in the control group (P = .64). The rates of shoulder and elbow pain were significantly higher in the Little Leaguer's shoulder group (shoulder pain 80%, elbow pain 70%) than in the control group (shoulder pain 9%, P < .001; elbow pain 32%, P = .04). CONCLUSION: Humeral retroversion was increased in baseball players without any history of shoulder or elbow injury during elementary and junior high school and was further increased in players who had had Little Leaguer's shoulder. Increased humeral retroversion after Little Leaguer's shoulder may be a risk factor for future shoulder or elbow injury.

Superior Capsule Reconstruction for Reinforcement of Arthroscopic Rotator Cuff Repair Improves Cuff Integrity.

BACKGROUND: Retear of repaired rotator cuff tendons worsens patient outcome and decreases patient satisfaction. Superior capsule reconstruction (SCR) was developed to center the humeral head and thus restore the force couple for patients with rotator cuff tears. PURPOSE: To evaluate whether SCR for reinforcement before arthroscopic rotator cuff repair (ARCR) improves cuff integrity. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Thirty-four consecutive patients (mean age, 69.1 years) with severely degenerated but reparable rotator cuff tears underwent SCR with fascia lata autografts for reinforcement before ARCR. All tears were medium (1-3 cm) or large (3-5 cm), and the number of torn tendons was 2 (supraspinatus and infraspinatus) in 29 shoulders and 3 (supraspinatus, infraspinatus, subscapularis) in 5 shoulders. To assess the benefit of SCR for reinforcement, all data were compared with those after ARCR alone among 91 consecutive patients with medium or large rotator cuff tears (mean age, 63.6 years). The American Shoulder and Elbow Surgeons (ASES) and Japanese Orthopaedic Association (JOA) scores, active shoulder range of motion, and cuff integrity (Sugaya magnetic resonance imaging classification) were compared ( t test and chi-square test) between ARCR with and without SCR, as well as before surgery and at final follow-up. RESULTS: All 34 patients who underwent SCR before ARCR had neither postoperative retear nor type III cuff integrity, whereas those treated with ARCR alone had a 4% incidence (4 of 91) of retear and 8% incidence of type III cuff integrity. ASES and JOA scores, active elevation, active external rotation, and active internal rotation increased in both treatment groups ( P < .001). Postoperative ASES score and active range of motion did not differ between groups, although the Goutallier grade of the supraspinatus was higher for ARCR with SCR (mean, 2.8) than ARCR alone (mean, 2.1; P < .0001). CONCLUSION: SCR for reinforcement prevented retear at 1 year after ARCR and improved the quality of the repaired tendon on magnetic resonance imaging. Functional outcomes were similar between groups, even though degeneration of the torn tendons was greater among patients who underwent ARCR with SCR.

Little Leaguer's Shoulder Can Cause Severe Three-Dimensional Humeral Deformity.

We analyzed three-dimensional (3D) humeral deformity (valgus-varus, flexion-extension, and rotational deformation) after little leaguer's shoulder using 3D computed tomography in a 15-year-old male baseball player. Humeral retroversion was increased by 27.1° on the dominant side compared with the nondominant side. Compared with the nondominant shaft, the dominant humeral shaft was deformed in the varus direction (9.4°), resulting in a decreased neck-shaft angle (dominant side, 127.5°; nondominant side, 135.1°), and it was also deformed in the extension direction (21.0°). This case demonstrates that little leaguer's shoulder can cause markedly greater humeral retroversion than has been reported previously and can result in varus and extension deformation of the humerus. These findings suggest that humeral deformity in overhead throwing athletes may not always solely reflect adaptation to throwing.

Isolated glenohumeral range of motion, excluding side-to-side difference in humeral retroversion, in asymptomatic high-school baseball players.

PURPOSE: Glenohumeral range of motion is correlated with shoulder capsular condition and is thus considered to be predictive of shoulder pathology. However, in throwing athletes, a side-to-side difference in humeral retroversion makes it difficult to evaluate capsular condition on the basis of glenohumeral range of motion measured by using the conventional technique. The purpose of this study was to measure isolated glenohumeral rotation, excluding side-to-side differences in humeral retroversion, in asymptomatic high-school baseball players. METHODS: A total of 195 high-school baseball players (52 pitchers and 143 position players; median age, 16 years) and 20 high-school non-throwing athletes (median age, 16 years) without any shoulder symptoms were enroled in this study. Glenohumeral external and internal rotations were measured by using both a conventional technique and our ultrasound-assisted technique. This technique, neutral rotation, was standardized on the basis of the ultrasonographically visualized location of the bicipital groove to exclude side-to-side differences in humeral retroversion from the calculated rotation angle. Intra- and inter-observer agreements of rotational measurements were evaluated by using intra-class correlation coefficients (ICCs). RESULTS: Isolated glenohumeral rotation measurements, excluding side-to-side differences in humeral retroversion, demonstrated excellent intra-observer (ICC > 0.89) and inter-observer (ICC > 0.78) agreements. Isolated glenohumeral internal rotation was significantly less in the dominant shoulder than in the non-dominant shoulder in asymptomatic baseball players (P < 0.001). Isolated glenohumeral external rotation in baseball players was significantly greater than in non-throwing athletes (P < 0.05). In the baseball players, humeral torsion in the dominant shoulder was significantly greater than that in the non-dominant shoulder (P < 0.001), indicating that the retroversion angle was greater in dominant shoulders than in non-dominant shoulders. CONCLUSIONS: Isolated glenohumeral external and internal rotations can be measured with high intra- and inter-observer reliability with the exclusion of side-to-side differences in humeral retroversion. Capsular and muscular changes in the throwing shoulder may be better evaluated by using our ultrasound-assisted technique. LEVEL OF EVIDENCE: Cross-sectional study, Level III.

Nerve conduction and microanatomy in the rabbit sciatic nerve after gradual limb lengthening-distraction neurogenesis.

To clarify how the peripheral nerve adapts to elongation during gradual limb lengthening, electrophysiological and histomorphometric examinations were performed on the sciatic nerves in 18 rabbits. External fixators were used to lengthen the right femora by 30 mm (30%), at a daily rate of 0.5 mm (Group 1) or 2.0 mm (Group 2). Examinations were performed immediately after the limb lengthening procedure. Electrophysiologically, mild conduction slowing was observed in Group 1; a conduction block was evident in Group 2. Histologically, the mean diameter of myelinated fibers was unchanged in Group 1, but a significantly decreased diameter was observed in Group 2. Electron microscopy revealed that mild degenerative change of unmyelinated axons occurred sporadically in two cases in Group 2, but neither group showed evidence of thinning of myelin sheath of myelinated fibers. The mean internodal length (between nodes of Ranvier) of teased fibers was 1216+/-295 microm in the control contralateral side, 1484+/-347 microm in Group 1, and 1467+/-322 microm in Group 2. Thus the internodes were lengthened by 22.1% (Group 1) and 20.7% (Group 2) in comparison with those of the controls. Straightening of the geometry of paranodal myelin sheath was significantly correlated with the rate of distraction. These results indicate that myelinated nerve fibers adapt to gradual elongation by lengthening each Schwann cell body, not by proliferation of Schwann cells.