Anatomic factors associated with degeneration and fraying of the coracoacromial ligament.

BACKGROUND: The coracoacromial ligament (CAL) is frequently observed to be damaged during arthroscopy and it is unclear how demographic, anatomic, and radiographic factors are related to CAL degeneration in full-thickness rotator cuff tears. METHODS: A prospective study was conducted of patients at a single institution undergoing shoulder arthroscopy for first-time, full-thickness rotator cuff tears. We evaluated preoperative anteroposterior radiographs to obtain critical shoulder angle, glenoid inclination, acromial index, acromiohumeral distance, lateral acromial angle, and acromial morphology. We documented CAL quality, rotator cuff tear size and pattern during arthroscopy. Multiple logistic regression was used to identify predictive factors for encountering severe CAL fraying during arthroscopy. RESULTS: Shoulders had mild CAL degeneration in 58.1% of cases, whereas severe CAL degeneration was present in 41.9% of shoulders. Patients with severe CAL attrition were significantly older (62.0 years vs. 58.0 years, P=0.042). Shoulders with severe CAL attrition had large rotator cuff tears in 54.1% of cases (P<0.001), and tears involving the infraspinatus (63.2% vs. 29.6%, P=0.003). The severe degeneration group was more likely to have a larger critical shoulder angle measurement on preoperative radiographs than those in the mild attrition group (36.1°±3.6° [range, 30°-45°] vs. 34.1°±3.8° [range, 26°-45°], P=0.037). CONCLUSIONS: While the clinical impact of CAL degeneration remains uncertain, increased severity of CAL degeneration is associated with older age, larger rotator cuff tear size, presence of infraspinatus tearing, and increased preoperative critical shoulder angle. Level of evidence: III.

Complications after operative treatment of high-grade acromioclavicular injuries.

BACKGROUND: Treatment of Rockwood type III-V acromioclavicular (AC) joint injuries remains controversial. Numerous reconstruction techniques have been proposed. The purpose of this study was to describe the complication profile in a large cohort of patients who underwent surgical management of AC joint separations using a variety of reconstruction strategies. METHODS: All patients who underwent surgery for AC joint injuries from 2013 to 2019 at a single institution were identified. Chart review was performed to capture patient demographics, radiographic measurements, operative techniques, postoperative complications, and revision surgery. Structural failure was defined as a radiographic loss of reduction of greater than 50% when comparing immediate and final postoperative imaging. Logistic regression analysis was performed to identify risk factors for complications and revision surgery. RESULTS: Of the 279 patients included in the study, 66 (24%) had type III separations, 20 (7%) type IV, and 193 (69%) type V. Fifty-three percent underwent surgery acutely (<6 weeks of injury), and 40% were chronic (>3 months). A total of 252 of the 279 surgeries (90%) were performed open and 27 (10%) were arthroscopically assisted. Allograft was used in 164 of 279 (59%) cases. Specific operative techniques (with or without allograft) included hook plating (1%), modified Weaver Dunn (16%), cortical button fixation (18%), and suture fixation (65%). At mean 28-week follow-up, 108 complications were identified in 97 patients (35%). Complications were identified at mean 20 ± 21 weeks. Sixty-nine structural failures (25%) were identified. Persistent AC joint pain requiring injection, clavicle fracture, adhesive capsulitis, and hardware complications were the other most common complications. Twenty-one patients (8%) underwent unplanned revision surgery at mean 38 ± 28 weeks after the index procedure, with the most common indication for structural failure, hardware complications, or fracture of the clavicle or coracoid. Patients who had surgery after 6 weeks from injury had a significantly greater risk of having a complication (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.34-7.77, P = .009) and a significantly greater risk of having structural failure (OR 2.65, 95% CI 1.38-5.28, P = .004). Patients who had an arthroscopic technique had a greater risk of structural failure (P = .002). Complications, structural failure, and revision surgery were not significantly correlated with use of allograft or specific operative techniques. CONCLUSION: Surgical management of AC joint injuries is associated with a relatively high complication profile. Loss of reduction in the postoperative period is common. However, the revision surgery rate is low. These findings are important for patient preoperative counseling.

30-Day Postoperative Complications After Surgical Treatment of Proximal Humerus Fractures: Reverse Total Shoulder Arthroplasty Versus Hemiarthroplasty.

INTRODUCTION: The purpose of this study was to evaluate risk factors associated with complications after reverse total shoulder arthroplasty (TSA) and hemiarthroplasty for the treatment of proximal humerus fractures. METHODS: A retrospective review of the American College of Surgeons National Surgical Quality Improvement Program database was conducted. Current Procedural Terminology codes were used to identify patients treated for proximal humerus fracture with reverse TSA or hemiarthroplasty between 2005 and 2018. RESULTS: One thousand five hundred sixty-three shoulder arthroplasties were conducted: 436 hemiarthroplasties and 1,127 reverse TSA. The overall complication rate was 15.4% (15.7% reverse TSA; 14.7% hemiarthroplasty) (P = 0.636). Most frequent complications included transfusion 11.1%, unplanned readmission 3.8%, and revision surgery 2.1%. A 1.1% incidence of thromboembolic events was noted. Complications occurred most frequently in patients older than 65 years; male; and patients with anemia, American Society of Anesthesiologists classification III-IV, inpatient procedure, bleeding disorders, duration of surgery >106 minutes, and length of stay >2.5 days. Patients with body mass index >36 kg/m2 had a decreased risk of 30-day postoperative complications. DISCUSSION: There was a 15.4% complication rate in the early postoperative period. In addition, no notable difference was found in complication rates between groups (hemiarthroplasty: 14.7%; reverse TSA 15.7%). Future studies are needed to determine whether there is a difference between these groups in the long-term outcome and survivorship of these implants.

Establishing maximal medical improvement following aseptic revision of shoulder arthroplasty.

BACKGROUND: Shoulder arthroplasty surgery volume continues to increase yearly. As the prevalence of shoulder replacement continues to rise, there will be a growing number of revision surgeries performed for a variety of indications. Understanding patient outcomes and recovery time following these procedures is critical, particularly as it relates to revision surgery, which generally has worse outcomes and longevity than primary arthroplasty. The point at which the peak of potential improvement is reached can be defined as the point of maximal medical improvement (MMI). The timing to MMI has previously been reported in the literature following both primary anatomic and reverse total shoulder arthroplasty. However, to our knowledge, timing to MMI following revision shoulder arthroplasty has not been defined. The purpose of the present study, therefore, is to establish the time to MMI following aseptic revision shoulder arthroplasty using validated patient-reported outcome measures. MATERIALS AND METHODS: A retrospective cohort study was conducted following patients who underwent aseptic revision shoulder arthroplasty over a defined 3-year period. Multiple fellowship-trained shoulder and elbow surgeons from a single institution performed all operations. Those with at least 24 months of follow-up and multiple time points of postoperative patient-reported outcome scores were included in the analysis. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores and Single Assessment Numeric Evaluation (SANE) scores were prospectively recorded and followed over time. Exclusion criteria included revision surgeries done for infection, staged procedures following infection, and revision for periprosthetic fracture. RESULTS: Twenty-two patients met inclusion criteria. The mean preoperative ASES and SANE scores were 41.8 and 30.5, respectively. There was a trend toward improvement in both the ASES and SANE scores through the 6-9-month postoperative follow-up point, at which point clinically significant improvement was achieved, with mean values of, respectively, 76.9 and 81.2. No further improvement was achieved 9 months after surgery, although scores were generally maintained through an average final follow-up of 30 months, with final ASES and SANE scores of 70.1 and 67.8, respectively. CONCLUSIONS: Following aseptic revision shoulder arthroplasty, clinically significant improvements in patient-reported outcome scores are seen up to 9 months postoperatively, the point at which MMI is achieved. These findings serve to guide clinicians in counseling patients regarding their expected postoperative recovery following revision shoulder arthroplasty.

Three-dimensional measures of posterior bone loss and retroversion in Walch B2 glenoids predict the need for an augmented anatomic glenoid component.

HYPOTHESIS: The purpose of this study is to evaluate whether the amount of measured posterior bone loss on 2- and 3-dimensional (2D and 3D) imaging of Walch B2 glenoids can reliably predict the plan for an augmented anatomic glenoid component. METHODS: Patients with Walch B2 glenoids and preoperative computed tomography (CT) scans were retrospectively identified. 2D axial CT scans were reviewed and posterior bone loss was measured by 3 independent reviewers. Images were then formatted into BluePrint (Wright Medical) preoperative planning software. The same 3 reviewers again measured posterior bone loss on 3D imaging. Additionally, all cases were planned with BluePrint software. An augment was used when the following criteria were unable to be satisfied with standard implants: <10° retroversion, <10° superior inclination, ≥90% backside contact, <2 mm medial reaming, and ≤1 peg perforation. RESULTS: Forty-two patients were included in the final analysis with a mean age of 63.1 ± 6.3 years. As measured by BluePrint, the mean retroversion was 23° ± 7° (range = 9°-40°), the mean superior inclination was 5° ± 6° (range = -9° to 22°), and the mean posterior subluxation was 80% ± 17% (range = 41%-95%). The mean 2D bone loss measurements (3.5 ± 1.6 mm) were significantly lower than the mean 3D bone loss (4.0 ± 1.8 mm) measurements (P = .03). There was substantial agreement between reviewers on both 2D and 3D measurements with an interclass correlation of 0.815 (95% confidence interval [CI] 0.714-0.889, P < .001) and an interclass correlation of 0.802 (95% CI 0.683-0.884, P < .001), respectively. Augments were used in 73.8%, 63.4%, and 63.4% of cases by reviewers 1, 2, and 3, respectively, with moderate agreement with a Fleiss kappa of 0.592 (95% CI 0.416-0.769, P < .001). Augment size was moderately, positively correlated with the amount of bone loss on 3D imaging but not with 2D imaging. After multivariate logistic regression, both 3D bone loss and retroversion were found to be predictive for a plan to use an augment. CONCLUSION: Planning for a posterior augment in Walch B2 glenoids is better predicted with 3D imaging than with 2D imaging, as 2D imaging may underestimate posterior bone loss. Additionally, use of a larger augment size is moderately correlated with posterior bone loss on 3D imaging but not 2D imaging. Standard 2D imaging may be limited in cases of posterior bone loss, and 3D imaging may be beneficial for preoperative planning in Walch B2 glenoids.

Subscapularis integrity, function and EMG/nerve conduction study findings following reverse total shoulder arthroplasty.

BACKGROUND: During reverse total shoulder arthroplasty, the functionality of the subscapularis remains unknown. The purpose of this study was to determine the integrity and function of the repaired subscapularis after reverse total shoulder arthroplasty using ultrasound, electromyography (EMG), and nerve conduction studies (NCS) to assess postoperative tendon healing, muscle, and nerve function. MATERIALS AND METHODS: Patients who underwent reverse total shoulder arthroplasty and repair with minimum 6-month follow-up were included in the study. Patient-reported outcome, physical examination, ultrasound examination of the subscapularis tendon, subscapularis EMG, and lower subscapular NCS were performed. In addition, contralateral subscapularis ultrasound, EMG, and lower subscapular nerve nerve NCS were performed to establish normative values (abnormal defined at >20% increased latency or >50% decreased amplitude). Phi coefficients of association and point biserial coefficients were used to correlate the ultrasound examination, EMG, and NCS results with the functional outcomes. RESULTS: A total of 20 patients were included. Four patients had abnormal but intact subscapularis tendons on ultrasound. Nine patients had abnormal lower subscapular NCS compared with the contralateral shoulder. All patients had normal subscapularis EMGs. No significant correlation was found between the ultrasound and NCS results. No significant correlations were found between the ultrasound or the NCS results and any of the independent outcome variables. CONCLUSION: This study demonstrates that the subscapularis remains neurologically functional after reverse total shoulder arthroplasty, based on EMG and NCS findings. Although side-to-side differences in lower subscapular NCS were identified in 45% of the postoperative shoulders, these abnormalities did not correlate with functional outcomes.

Incidence and predictors of positive intraoperative cultures in primary shoulder arthroplasty following prior ipsilateral shoulder surgery.

BACKGROUND: To our knowledge, the rate of positive intraoperative cultures in patients undergoing primary shoulder arthroplasty with prior ipsilateral nonarthroplasty shoulder surgery is unknown. The aim of this study was to determine the incidence and predictors of positive cultures in these patients. METHODS: We performed a retrospective review of patients with prior ipsilateral shoulder surgery with intraoperative cultures taken at the time of primary shoulder arthroplasty. We evaluated culture results, demographics, and number of prior surgeries. Regression analysis was used to determine patient-related risk factors that predict positive cultures. RESULTS: A total of 682 patients underwent primary shoulder arthroplasty, 83 had at least 1 prior ipsilateral shoulder surgery: 65.1% male, mean age 64.2 ± 10.9 years. For the cohort of 83 patients, an average of 3.2 ± 1.2 tissue samples were obtained for each patient, with a mean of 0.84 ± 1.14 tissue cultures being positive (range 0-5). Thirty-seven of the 83 patients (44.5%) had at least 1 positive culture, with Cutibacterium acnes the most frequent organism (31/37; 83.4%). An average of 1.9 ± 0.96 tissue cultures resulted positive (range 1-5) for the 37 patients who had positive cultures, 40.5% (15/37) had only 1 positive tissue culture (12/15 C acnes, 2/15 Staphylococcus epidermidis, and 1/15 vancomycin-resistant enterococcus). Male sex and history of prior shoulder infection were predictive of culture positivity (odds ratios: 2.5 and 20.9, respectively). Age, race, medical comorbidities, number of prior shoulder surgeries, and time from index shoulder surgery were not predictive of culture positivity. CONCLUSION: About 45% of patients with no clinical signs of infection and a history of prior ipsilateral shoulder surgery undergoing primary shoulder arthroplasty grew positive intraoperative cultures. The significance of these findings remains unclear with regard to risk of periprosthetic infection and how these patients should be managed.

Preoperative glenoid considerations for shoulder arthroplasty: a review.

Preoperative assessment of the glenoid in the setting of shoulder arthroplasty is critical to account for variations in glenoid morphology, wear, version, inclination, and glenohumeral subluxation.Three-dimensional computed tomography (3D CT) scan assessment of the morphology of glenoid erosion allows for a more accurate surgical decision-making process to correct deformity and restore the joint line.Newer technology has brought forth computer-assisted software for glenoid planning in shoulder arthroplasty and patient-specific instrumentation.There have been promising early findings, although further evaluation is needed to determine how this technology impacts implant survivorship, function, and patient-reported outcomes. Cite this article: EFORT Open Rev 2020;5:126-137. DOI: 10.1302/2058-5241.5.190011.

Surgically relevant anatomy of the axillary and radial nerves in relation to the latissimus dorsi tendon in variable shoulder positions: A cadaveric study.

BACKGROUND: The purpose of this study was to define the relationship of the axillary and radial nerves, particularly how these are affected with changing arm position. METHODS: Twenty cadaveric shoulders were dissected, identifying the axillary and radial nerves. Distances between the latissimus dorsi tendon and these nerves were recorded in different shoulder positions. Positions included adduction/neutral rotation, abduction/neutral rotation for the axillary nerve, adduction/internal rotation, adduction/neutral rotation, adduction/external rotation, and abduction/external rotation for the radial nerve. RESULTS: Width of the latissimus tendon at its humeral insertion was 29.3 ± 5.7 mm. Mean distance from the latissimus insertion to the axillary nerve in adduction/neutral rotation was 24.2 ± 7.1 mm, the distance increased to 41.1 ± 9.8 mm in abduction/neutral rotation. Mean distance from the latissimus insertion to the radial nerve was 15.3 ± 5.5 mm with adduction/internal rotation, 25.8 ± 6.9 mm in adduction/neutral rotation, and 39.5 ± 6.8 mm in adduction/external rotation. Mean distance increased with abduction/external rotated 51.1 ± 7.4 mm. CONCLUSIONS: Knowing the axillary and radial nerve locations relative to the latissimus dorsi tendon decreases the risk of iatrogenic nerve injury. Understanding the dynamic nature of these nerves related to different shoulder positions is critical to avoid complications.

Outcomes of Posterior Glenoid Bone-Grafting in Anatomical Total Shoulder Arthroplasty: A Systematic Review.

BACKGROUND: Total shoulder arthroplasty offers a reliable means with which to treat glenohumeral joint arthritis. Posterior glenoid bone loss presents a unique challenge with an increased risk of glenoid component failure. The use of posterior bone-grafting is one method to address glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty. The purpose of the present study was to assess the outcome and survival of the glenoid component following the use of bone graft to address posterior glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty. METHODS: A systematic review of posterior glenoid bone-grafting in patients undergoing anatomical total shoulder arthroplasty was performed. Studies evaluating patient-reported outcomes, complications, and imaging assessments of the glenoid component as well as of bone graft structural healing and integrity following posterior glenoid bone-grafting were included. Data extracted included demographic characteristics, Walch classification, bone-grafting method, clinical outcomes measures, complications, radiolucency around the glenoid component, graft failure, posterior humeral head subluxation, and time of the latest follow-up. RESULTS: Six studies met the inclusion and exclusion criteria. Ninety-four patients from these 6 studies underwent posterior glenoid bone-grafting with anatomical total shoulder arthroplasty. The mean age was 59.7 years, and the mean duration of follow-up was 5.7 years. Overall, 57% of the patients had an excellent postoperative Neer score. At the time of the latest follow-up, 28.7% had evidence of radiolucency and 35% had humeral head subluxation or instability. Thirteen patients (14%) underwent revision of the glenoid component by the time of the latest follow-up. CONCLUSIONS: The present study demonstrated a 28.7% complication rate, a 14% revision rate, a 17% graft failure rate, and a 35% rate of recurrence of posterior humeral head subluxation. Posterior glenoid bone-grafting to correct bone loss is associated with a substantial risk of postoperative complications. The treatment of posterior glenoid bone loss remains a challenge in patients undergoing anatomical total shoulder arthroplasty. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Innervation of the subscapularis: an anatomic study.

BACKGROUND: Successful healing of the subscapularis during anatomic total shoulder arthroplasty surgery is critical to optimize functional outcomes and avoid complications. The purpose of this study was to examine the upper and lower subscapularis nerve insertion in relation to the musculotendinous junction to estimate the risk of nerve injury. Our hypothesis was that arm position changes the risks to these nerves when exposing the anterior glenoid. METHODS: Twenty cadaveric shoulders were dissected, and the subscapular nerves were identified from the posterior cord of the brachial plexus to the muscle insertion. The nerve length from the origin to the muscle insertion and the distance to the myotendinous junction were measured in various shoulder positions including neutral, external, and internal rotation. RESULTS: The mean length of the upper subscapular nerve was 51.4 ± 12.8 mm; that of the lower subscapular nerve was 50.5 ± 14 mm. The mean distance from the insertion of the upper subscapular nerve to the myotendinous junction 53.0 ± 14.7 mm with external rotation, 38.5 ± 9.7 mm with neutral rotation, and 30.0 ± 9.2 mm with internal rotation. The mean distance from the lower subscapular nerve to the myotendinous junction was 44.5 ± 13.8 mm with external rotation, 31.9 ± 9.3 mm with neutral rotation, and 25.4 ± 8.8 mm with internal rotation. The internally rotated position placed these nerves closest to the glenohumeral joint. CONCLUSION: The upper and lower subscapular nerves insert in the muscle belly close to the myotendinous junction, putting them at risk of iatrogenic injury. Care must be taken to avoid damage with retractor placement in the anterior glenoid neck as these nerves are at risk of compression or torsional injury.

Diagnostic Accuracy of the Scapular Retraction Test in Assessing the Status of the Rotator Cuff.

BACKGROUND: Currently, clinical physical examination maneuvers alone provide variable reliability in diagnosing full-thickness rotator cuff tears (RCTs). PURPOSE: To assess the diagnostic accuracy of the scapular retraction test (SRT) to predict full-thickness RCTs. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 331 patients were prospectively evaluated in this cohort study. SRT was performed to assess the status of the rotator cuff. A positive SRT indicates an intact rotator cuff, and a negative SRT indicates a full-thickness RCT. Magnetic resonance imaging (MRI) was used as the gold standard. The examiner was blinded to the results until completing the physical examination. Statistical analysis was performed to assess the sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratios of the SRT. RESULTS: The prevalence of full-thickness RCTs diagnosed on MRI was 54.4% (180 of 331). Among the 180 patients with an MRI-confirmed full-thickness RCT, the SRT was negative for 147. Of 150 patients with an intact rotator cuff by MRI, 122 had a positive SRT. In diagnosing full-thickness RCTs, the SRT had a sensitivity of 81.7% (95% CI, 77.2%-85.4%), specificity of 80.8% (95% CI, 75.5%-85.3%), and accuracy 81.3%. The positive predictive value was 83.5% (95% CI, 78.9%-87.4%); the negative predictive value, 78.7% (95% CI, 73.5%-83.1%); the positive likelihood ratio, 4.3 (95% CI, 3.1-5.8); the negative likelihood ratio, 0.23 (95% CI, 0.17-0.30); and the diagnostic odds ratio, 18.7 (95% CI, 10.4-34.0). CONCLUSION: The results of this diagnostic study indicate that the SRT can accurately be used to clinically assess the status of the rotator cuff. This physical examination maneuver was found to be accurate, sensitive, and specific in diagnosing full-thickness RCTs. Additionally, our results indicate that it is equally as accurate to predict an intact rotator cuff tendon. Providing an accurate, reliable, and reproducible physical examination test will allow clinicians to diagnosis the integrity of the rotator cuff and will help guide treatment recommendations.