Aaron M. Chamberlain

Factors affecting outcome after structural failure of repaired rotator cuff tears

BACKGROUND Failure of structural healing is not infrequent after rotator cuff repair and often is not associated with clinical outcome. The goals of this study are to describe outcomes in a cohort of patients with a failed rotator cuff repair and to evaluate factors associated with clinical outcome. METHODS This was a retrospective study of all patients with failure of structural integrity after rotator cuff surgical repair. A threshold American Shoulder and Elbow Surgeons (ASES) score of 80 points was used to allocate patients into either the successful (≥80 points; Group 1) or unsuccessful (<80 points; Group 2) cohorts. Demographics, patient-centered instruments for shoulder function, radiographic parameters, and shoulder motion were compared between groups. RESULTS On the basis of the postoperative ASES score, thirty-three patients (54.1%) were included in Group 1 and twenty-eight patients (45.9%) were included in Group 2. Fifteen patients (53.6%) in Group 2 reported a labor-intensive occupation compared with two patients (6.1%) in Group 1 (p < 0.001). Multiple regression analysis demonstrated that labor-intensive occupation (odds ratio [OR], 202.3; p = 0.026), preoperative Simple Shoulder Test (SST) score (OR, 0.50; p = 0.028), and preoperative external rotation (OR, 0.91; p = 0.027) were associated with inclusion in Group 2. Age and other demographic variables, including sex, dominant-sided surgery, and medical comorbidities, were similar for the groups. CONCLUSIONS Successful outcomes were achieved in 54% of patients with failed rotator cuff repair. Those who self-identified their occupation as being labor-intensive represented a special group of patients who are at high risk for a poor outcome after a failed rotator cuff repair.

Determining the minimal clinically important difference for the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and visual analog scale (VAS) measuring pain after shoulder arthroplasty.

BACKGROUND Minimal clinically important differences (MCIDs) for the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and a visual analog scale (VAS) measuring pain have not been previously described using an anchor-based method after shoulder arthroplasty. The purpose of this study was to determine the MCIDs for these measures after shoulder arthroplasty for glenohumeral arthritis or advanced rotator cuff disease. METHODS Primary anatomic total shoulder arthroplasty (TSA), primary reverse TSA, or hemiarthroplasty was performed in 326 patients by 1 of 5 shoulder and elbow surgeons. The SST score, ASES score, and VAS pain score were collected preoperatively and at a minimum of 2 years postoperatively (mean, 3.5 years). The MCIDs were calculated for the ASES score, SST score, and VAS pain score using an anchor-based method. RESULTS The MCIDs for the ASES score, SST score, and VAS pain score were 20.9 (P < .001), 2.4 (P < .0001), and 1.4 (P = .0158), respectively. Duration of follow-up and type of arthroplasty (anatomic TSA vs reverse TSA) did not have a significant effect on the MCIDs (P > .1) except shorter follow-up correlated with a larger MCID for the ASES score (P = .0081). Younger age correlated with larger MCIDs for all scores (P < .024). Female sex correlated with larger MCIDs for the VAS pain score (P = .123) and ASES score (P = .05). CONCLUSIONS Patients treated with a shoulder arthroplasty require a 1.4-point improvement in the VAS pain score, a 2.4-point improvement in the SST score, and a 21-point improvement in the ASES score to achieve a minimal clinical importance difference from the procedure.

Patterns of tear progression for asymptomatic degenerative rotator cuff tears

BACKGROUND The purpose of this study was to examine patterns of rotator cuff tear size progression in degenerative rotator cuff tears and to compare tear progression risks for tears with and without anterior supraspinatus tendon disruption. METHODS Asymptomatic full-thickness rotator cuff tears with minimum 2-year follow-up were examined with annual shoulder ultrasound examinations. Integrity of the anterior 3 mm of the supraspinatus tendon determined classification of cable-intact vs. cable-disrupted tears. Tear enlargement was defined as an increase of 5 mm or more in width. Tear propagation direction was calculated from measured changes in tear width in reference to the biceps tendon on serial ultrasound examinations. RESULTS The cohort included 139 full-thickness tears with a mean subject age of 63.3 years and follow-up duration of 6.0 years. Ninety-six (69.1%) of the tears were considered cable intact. Cable-disrupted tears were larger at baseline (median, 19.0 mm vs. 10.0 mm; P < .0001) than cable-intact tears. There was no difference in the risk of enlargement (52.1% vs. 67.4%; P = .09) or time to enlargement (3.2 vs. 2.2 years; P = .37) for cable-intact compared with cable-disrupted tears. There was no difference in the magnitude of enlargement for cable-intact and cable-disrupted tears (median, 7.0 mm vs.9.0 mm; P = .18). Cable-intact tears propagated a median of 5 mm anteriorly and 4 mm posteriorly, whereas cable-disrupted tears propagated posteriorly. CONCLUSIONS The majority of degenerative rotator cuff tears spare the anterior supraspinatus tendon. Although tears classified as cable disrupted are larger at baseline than cable-intact tears, tear enlargement risks are similar for each tear type.

Arthroscopic Debridement and Capsular Release for the Treatment of Shoulder Osteoarthritis

PURPOSE The purpose of this study was to evaluate patients who underwent isolated arthroscopic debridement and capsular release without any other procedures for primary glenohumeral osteoarthritis to determine clinical and functional outcomes and time until conversion to shoulder arthroplasty. METHODS We performed a retrospective review of 33 patients who underwent arthroscopic debridement and capsular release for shoulder osteoarthritis at our institution between 2006 and 2011. All procedures were performed by a single surgeon (K.Y.). Patients were evaluated for intraoperative arthritis grade, preoperative and postoperative range or motion, American Shoulder and Elbow Surgeons (ASES) score, pain score self-assessments, radiographic evaluation, and conversion to total shoulder arthroplasty. Clinical follow-up was on average 40.3 weeks postoperatively and telephone interview follow-up was performed at a minimum of 2 years postoperatively in all patients. RESULTS There was an initial improvement in range of motion and pain scores; however, patients in our study returned to preoperative levels approximately 3.8 months after debridement and capsular release. Twenty patients (60.6%) reported that they were not satisfied with the outcome of the procedure. Total shoulder arthroplasty was undertaken in 14 (42.4%) patients an average of 8.8 months after arthroscopy. Among the 19 (57.6%) patients who did not go on to have total shoulder arthroplasty, ASES scores (42.2 to 50.8; P = .41) and visual analog scale pain scores (7.8 to 7.4; P = .59) were similar preoperatively and at final telephone follow-up. CONCLUSIONS Isolated arthroscopic debridement and capsular release without any other procedures were associated with only temporary pain relief and improvement in motion. Although there are limited nonarthroplasty surgical options available for glenohumeral arthritis, isolated arthroscopic debridement and capsular release may not provide substantial benefit to justify its use in most patients. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Radiographic characterization of the B2 glenoid: the effect of computed tomographic axis orientation

BACKGROUND Glenoid retroversion may accelerate glenoid loosening after total shoulder arthroplasty. Accurate measurement of preoperative glenoid deformity is critical for decision-making and prognostication. The purpose of this study was to determine whether glenoid version, inclination, and depth and humeral subluxation measurements on computed tomography (CT) scan slices oriented in the plane of the body differ from those oriented in the scapular plane and those obtained by automated 3-dimensional reconstruction software in the setting of a biconcave B2-type glenoid. METHODS Thirty-one preoperative CT scans in patients undergoing total shoulder arthroplasty with Walch B2-type glenoids underwent a standardized measurement protocol by 3 observers. Glenoid version, inclination, and depth and humeral subluxation were measured on 2-dimensional CT images in the plane of the body, on 2-dimensional images in the plane of the scapula, and by a validated, automated 3-dimensional software program. RESULTS Correction of CT slice axis into the plane of the scapula decreased measured retroversion by 2.4° to 4.7° (P < .004) and inclination by 21° (P < .001). Whereas uncorrected version measurements do not differ from automated software measurements, corrected measurements do (P < .001). Whereas corrected inclination measurements do not differ from automated measurements, uncorrected measurements do (P < .001). Automated measurements differed from both corrected and uncorrected subluxation (P < .001 in both cases). CONCLUSION If CT images are not reoriented into the plane of the scapula, version and inclination will be significantly overestimated. In the setting of a retroverted, deformed glenoid, automated software may produce similar inclination measurements to corrected 2-dimensional CT, but it produces significantly altered measurements of version and subluxation.

Dislocation following reverse total shoulder arthroplasty

BACKGROUND The etiology of instability following reverse total shoulder arthroplasty (RTSA) remains incompletely understood. The purpose of this study was to describe the shared characteristics, etiologies, and outcomes of early and late dislocations requiring operative revision. METHODS We identified all patients at our institution who underwent operative revision of an RTSA for instability. Baseline demographic, clinical, and radiographic data were collected. Standardized outcome scores were collected preoperatively and at final follow-up. Characteristics of dislocations that occurred less than 3 months postoperatively (early) were compared with those that occurred more than 3 months postoperatively (late). RESULTS Twenty-two patients met the criteria, and follow-up was obtained on 19 patients at 4.9 ± 2.5 years, with 14 early and 5 late dislocations. Most patients in both groups were men, were aged over 70 years, and had a history of shoulder surgery. On analysis of instability etiology, 68% had inadequate soft-tissue tensioning (10% due to partial axillary nerve injuries). The remaining patients had asymmetric liner wear, mechanical liner failure, or impinging heterotopic ossification. Asymmetric liner wear accounted for 60% of late dislocations. Recurrent instability after revision was present in 29% of early and 40% of late dislocators. DISCUSSION No significant differences in outcomes or recurrence rates were found for early and late dislocations. Of the late dislocations, 80% had evidence of adduction impingement, via either heterotopic ossification or asymmetric polyethylene wear. Post-RTSA instability had 2 distinct etiologies: (1) instability due to inadequate soft-tissue tensioning and/or axillary nerve palsy and (2) instability due to impingement or liner failure.

Radiographic progression of arthritic changes in shoulders with degenerative rotator cuff tears

BACKGROUND Very little longitudinal information has been available regarding the relationship of cuff tears and arthritis. The purpose of this study was to determine the midterm risk of and risk factors for rotator cuff tear arthropathy progression in a cohort of subjects with an asymptomatic rotator cuff tear. METHODS Baseline (visit 1), 5-year (visit 2), and most recent follow-up (visit 3) radiographs were reviewed in a cohort of 105 subjects enrolled for longitudinal surveillance of asymptomatic degenerative rotator cuff tears and 33 controls. The radiographs were assessed in a blinded, randomized fashion by 3 observers who graded glenohumeral arthritic changes using the Hamada scores, Samilson-Prieto (SPO) scores, and acromiohumeral interval (AHI). RESULTS Osteoarthritis (SPO classification), cuff tear arthropathy (Hamada classification), and AHI progressed between visits 1 and 3 (median, 8 years; P < .001 in all cases). SPO progression was not significantly different for partial- vs. full-thickness vs. control baseline tear types (P = .19). Both full-thickness and partial-thickness tears had greater progression in Hamada scores than controls did in the first 5 years of follow-up (P = .02 and P = .03, respectively), but scores did not differ between partial- and full-thickness tears. Tears with and without enlargement did not differ in progression in SPO grade, Hamada grade, or AHI. CONCLUSIONS Glenohumeral arthritic changes progress significantly but remain minimal within an 8-year period in early to moderate degenerative cuff disease. Whereas the presence of a rotator cuff tear influences progression in Hamada grade, the magnitude of radiographic progression is not influenced by tear severity or enlargement at midterm time points.

A novel reduction technique for elbow dislocations.

The purpose of this study was to review a novel reduction maneuver for elbow dislocations. This was a retrospective review comparing a traditional elbow reduction method with a new single-person reduction technique. The reductions were performed during a 3-year period. Patients were evaluated in the Emergency Department of a large level I trauma center. All patients had posterolateral elbow dislocations. Sixteen patients were studied, with 6 in the traditional group and 10 in the novel single-person reduction group. All patients had successful reductions in the Emergency Department, but 2 of the patients in the traditional group were moved to the single-person reduction group after unsuccessful attempts. The traditional method required more sedations, assistance, and supplies. The authors had no nerve, vascular, or iatrogenic fractures in their series, and the technique was performed by 1 person without additional equipment. This technique is a valid option for orthopedic surgeons treating elbow dislocations.

Persistent motion loss after free joint mobilization in a rat model of post-traumatic elbow contracture

BACKGROUND Post-traumatic joint contracture (PTJC) in the elbow is a challenging clinical problem due to the anatomical and biomechanical complexity of the elbow joint. METHODS We previously established an animal model to study elbow PTJC, wherein surgically induced soft tissue damage, followed by 6 weeks of unilateral immobilization in Long-Evans rats, led to stiffened and contracted joints that exhibited features similar to the human condition. In this study, after 6 weeks of immobilization, we remobilized the animal (ie, external bandage removed and free cage activity) for an additional 6 weeks, after which the limbs were evaluated mechanically and histologically. The objective of this study was to evaluate whether this decreased joint motion would persist after 6 weeks of free mobilization (FM). RESULTS After FM, flexion-extension demonstrated decreased total range of motion (ROM) and neutral zone length, and increased ROM midpoint for injured limbs compared with control and contralateral limbs. Specifically, after FM total ROM demonstrated a significant decrease of approximately 22% and 26% compared with control and contralateral limbs for injury I (anterior capsulotomy) and injury II (anterior capsulotomy with lateral collateral ligament transection), respectively. Histologic evaluation showed increased adhesion, fibrosis, and thickness of the capsule tissue in the injured limbs after FM compared with control and contralateral limbs, which is consistent with patterns previously reported in human tissue. CONCLUSION Even with FM, injured limbs in this model demonstrate persistent joint motion loss and histologic results similar to the human condition. Future work will use this animal model to investigate the mechanisms responsible for PTJC and responses to therapeutic intervention.

Clinical outcomes after decompression of the nerve to the teres minor in patients with idiopathic isolated teres minor fatty atrophy.

BACKGROUND The purpose of this manuscript is to describe what we believe to be the first series of patients surgically treated for idiopathic isolated teres minor atrophy and to present the results of surgical decompression of the nerve to the teres minor. METHODS This is a retrospective cohort of 22 patients who underwent decompression of the nerve to the teres minor for isolated teres minor atrophy. Clinical data including duration of symptoms, additional diagnoses, concurrent procedures, preoperative physical examination findings, imaging data, and preoperative visual analog scale (VAS), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) scores were collected from the medical record. Postoperative patient-based clinical outcome measures including VAS, SST, and ASES scores were obtained during clinical examination or by telephone interview. RESULTS Average length of follow-up was 26 months. Nine patients had concurrent procedures performed. Preoperatively, 12 of 14 (86%) had external rotation weakness in Hornblowers position. Postoperatively, pain scores decreased an average of 4 points; ASES scores increased 31.7 ± 20.2 points; SST scores increased 3.1 ± 2.3 points. No external rotation weakness was noted postoperatively in any tested patient. Two patients developed adhesive capsulitis. No other complications occurred. CONCLUSIONS Isolated compression of the nerve to the teres minor is a rare and novel clinical entity. In properly selected cases, open release of the fascial sling enveloping the nerve branches to the teres minor can provide relief of symptoms and clinical improvement.