Revision of failed hemiarthroplasty and anatomic total shoulder arthroplasty to reverse total shoulder arthroplasty.

BACKGROUND: The impending burden of revision shoulder arthroplasty has increased interest in outcomes of revision procedures. Revision of failed anatomic arthroplasty to reverse total shoulder arthroplasty has shown promise alongside concerning complication rates. METHODS: Patients who underwent revision shoulder arthroplasty during a 7-year period at a tertiary care health system were identified. Presurgical and operative data were analyzed for 110 patients who met inclusion and exclusion criteria. Patients were contacted at a mean follow-up of 57 ± 26 months (range, 23-113 months) from revision surgery for functional outcomes scores, reoperations, and implant survival. RESULTS: Implant survival was 92% at 2 years and 74% at 5 years. Mean American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, and visual analog scale pain scores were 63 ± 24 (range, 5-97), 60 ± 25 (range, 0-100), and 2.9 ± 2.9 (range, 0-10), respectively. Seventy percent of patients were "very satisfied" or "satisfied with their outcome. Complications occurred in 18 patients (20%), and 10 patients (11%) underwent reoperation. CONCLUSIONS: Modest patient results and satisfaction can be achieved with revision of a failed anatomic arthroplasty to a reverse total shoulder arthroplasty. As is typical of revision surgery, complications are common and can compromise results. Further study is needed to identify factors that may contribute to successful outcomes.

Outcomes of an anatomic total shoulder arthroplasty with a contralateral reverse total shoulder arthroplasty.

BACKGROUND: It is common for patients to require staged bilateral shoulder arthroplasties. There is a unique cohort of patients who require an anatomic total shoulder arthroplasty (TSA) and a contralateral reverse shoulder arthroplasty (RSA). This study compared the outcomes of patients with a TSA in 1 shoulder and an RSA in the contralateral shoulder. METHODS: Our institutional database was queried to identify all patients with a TSA and a contralateral RSA. Data collection included patient demographics, preoperative and latest follow-up shoulder range of motion, radiographic analysis, and postoperative complications. Identified patients were assessed at follow-up visits or contacted by phone for functional outcome scores. RESULTS: Nineteen patients met our inclusion/exclusion criteria. There was statistically significant greater internal rotation in the TSA shoulder (P= .044) but no significant difference in forward elevation (P = .573) or external rotation (P= .368). There was no radiographic evidence of humeral or glenoid component loosening of any arthroplasty implants. There were no significant differences between TSA and RSA shoulders for the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment (P= .381), Simple Shoulder Test (P = .352), Single Assessment Numerical Evaluation (P = .709), and visual analog scale satisfaction (P= .448) or pain scores (P= .305). Thirteen patients (68.4%) preferred the RSA side, 1 patient (5.3%; z = 4.04, P < .001) patient preferred the TSA side, and 5 patients expressed no preference. CONCLUSION: Despite known limitations and differences between TSA and RSA designs, patients who have received both implants are highly satisfied with both. The only parameter in which the TSA had superior outcomes was internal rotation.

Culture positivity in primary total shoulder arthroplasty.

BACKGROUND: The clinical significance of positive cultures in shoulder surgery remains unclear. This study determined the rate and characteristics of positive intraoperative cultures in a cohort of patients undergoing primary shoulder arthroplasty. METHODS: From February 2015 to March 2016, 94 patients, without prior surgery, underwent primary shoulder arthroplasty. Before surgery, all shoulders were prospectively enrolled and consented to obtain standardized intraoperative cultures. All patients received standard preoperative antibiotic prophylaxis. Standardized fluid and tissue locations were sampled and sent for aerobic and anaerobic cultures and held for 13 days. Patients and surgeon were blinded to the culture results. RESULTS: Average age at surgery was 70.5 years (range, 50-91 years), and 41 patients (47%) were male. At least 1 positive culture was found in 33 shoulders (38%), with 17 patients (19%) having ≥2 positive cultures. Cutibacterium (formerly Propionibacterium) acnes was the most common organism (67%), followed by coagulase-negative Staphylococcus (21%), Staphylococcus aureus (3%), and other organisms (18%). The rate of positive culture was higher in men (51%) than in women (26%, P = .016). Cutibacterium acnes was more common in men with positive cultures (95% vs. 17%, P < .001) and coagulase-negative Staphylococcus and Staphylococcus epidermidis were more common in women with positive cultures (42% vs. 10%, P = .071). CONCLUSION: Positive deep tissue cultures develop in a high percentage of patients undergoing primary shoulder arthroplasty despite antibiotic prophylaxis. The long-term clinical implication of this finding requires further study, especially with regard to the risk of late failures of shoulder arthroplasty.

The use of indomethacin in the prevention of postoperative radioulnar synostosis after distal biceps repair.

BACKGROUND: This study evaluated the incidence of symptomatic radioulnar synostosis/heterotopic ossification after distal biceps tendon repair in patients receiving indomethacin prophylaxis. We hypothesized that indomethacin use postoperatively would decrease the occurrence of symptomatic synostosis. METHODS: A single-center retrospective record review identified 124 patients undergoing distal biceps repair between 2011 and 2014. Patients were analyzed for administration of indomethacin, contraindications to administration, age, time to surgery, fixation method, medical comorbidities, and development of symptomatic synostosis. Oral indomethacin (75 mg, once daily) was prescribed postoperatively for 10 to 42 days per each attendings' protocol. RESULTS: After analysis, 112 patients met the inclusion criteria, with 7 undergoing a 1-incision distal biceps repair and 105 undergoing a 2-incision repair. Of those, 104 received indomethacin postoperatively, with a synostosis rate of 0.96% compared with 37.50% for the untreated group (P < .001). No statistically significant difference was found between fixation methods and synostosis. One patient with synostosis was a single-incision repair, and 3 were 2-incision suture bridge repairs. Three patients with synostosis had relative contraindications to administration of indomethacin, including concomitant warfarin use, clopidogrel use, and ulcerative colitis. CONCLUSION: Indomethacin use after distal biceps repair was associated with a statistically significant reduction in the rate of symptomatic radioulnar synostosis and did not have any associated adverse effects, including gastrointestinal bleeding or rerupture, despite prolonged use of up to 6 weeks. This study represents the largest study to report the outcomes of patients undergoing distal biceps repair with concomitant synostosis prophylaxis using indomethacin.

Profile of Current Opinion on Arthroscopic Acromioplasty: A Video Survey Study.

PURPOSE: To provide a baseline profile of current opinion on use of arthroscopic acromioplasty and evaluate the consistency of surgical decision making on whether or not to perform acromioplasty across different surgeon practices. METHODS: Twenty-two fellowship-trained orthopaedic shoulder surgeons from the Association of Clinical Elbow and Shoulder Surgeons completed an Internet-based survey on practices associated with acromioplasty, including questions related to 15 arthroscopic videos. Based on video cases, interobserver and intraobserver agreement regarding clinically based decisions related to acromioplasty were assessed. RESULTS: Acromioplasty was uncommonly performed in isolation among this group and was most commonly performed in conjunction with repair of full-thickness rotator cuff tears. Nineteen of 22 (86%) surgeons favored an arthroscopic approach for acromioplasty. Depth of bony resection was determined most commonly based on clinical judgment and experience (68%). The video portion of the survey revealed slight interobserver agreement for classification of acromion morphology (κ = 0.099), need for acromioplasty (κ = 0.020), and adequacy of decompression (κ = 0.1). In contrast, there was fair intraobserver reliability regarding acromion morphology (κ = 0.370) and decision whether to perform acromioplasty in a given case (κ = 0.348) whereas there was moderate intraobserver reliability in the presence of a reparable rotator cuff tear (κ = 0.507) and assessment of the adequacy of decompression (κ = 0.453). CONCLUSIONS: Although surgeons had similarities regarding principles of acromioplasty, including indications, surgical approach, and technique, there was lack of consensus when surgeons reviewed the video of clinical cases. Although surgeons may have similar goals in terms of treatment of pathology related to subacromial impingement, individual surgeon thresholds for the need and adequacy of decompression are varied and are not standardized. LEVEL OF EVIDENCE: Level V, expert opinion.

Is Arthroscopic Latarjet a Cost-Effective Procedure? A Decision Analysis.

Objectives: Arthroscopic Latarjet for glenohumeral stabilization has emerged as an alternative to the open approach; however, the evidence to date has questioned if this technique delivers improved outcomes. This analysis provides an assessment of the cost and utility associated with arthroscopic versus open Latarjet. Methods: The cost-effectiveness of Latarjet stabilization was modeled over a ten-year period. Institutional cases were reviewed for equipment utilization. Cost data from ambulatory surgical centers was obtained for each piece of equipment used intraoperatively. Based upon prior analyses, the operating room cost was assigned a value of $36.14 per minute. To determine effectiveness, a utility score was derived based upon prior analysis of shoulder stabilization using the EuroQol (EQ) 5D. For reoperations, a utility score of 0.01 was assigned for a single year for revision surgeries for instability and 0.5 for minor procedures. Probability of surgical outcomes and operative time for arthroscopic and open Latarjet were taken from prior studies comparing outcomes of these procedures. Decision-tree analysis utilizing these values was performed. Results: Based upon equipment and operating room costs, arthroscopic Latarjet was found to cost $2,796.87 more than the equivalent open procedure. Analysis of the utility of these procedures were 1.330 and 1.338 quality adjusted life years obtained over the modeled period for arthroscopic versus open Latarjet, respectively. For arthroscopic Latarjet to be cost-equivalent to open Latarjet, surgical time would need to be reduced to 41.5 minutes or the surgical equipment would need to be provided at no expense, while maintaining the same success rates. Conclusion: With nearly identical utility scores favoring open surgery, the added cost associated with arthroscopic Latarjet cannot be supported with available cost and utility data. To provide value, additional benefits such as decreased post-operative narcotic utilization, decreased blood loss, or lower complications of the arthroscopic approach must be demonstrated.

Effects of Patient Comorbidities and Demographics on Episode-of-Care Costs Following Total Shoulder Arthroplasty.

BACKGROUND: As demand for shoulder arthroplasty grows, adequate cost containment is of importance. Given the historical use of bundle payments for lower extremity arthroplasty, it is reasonable to anticipate that such programs will be universally implemented in shoulder arthroplasty. This project evaluates how patient demographics, medical comorbidities, and surgical variables affect episode-of-care costs in an effort to ensure accurate reimbursement scales and equitable access to care. METHODS: Consecutive series of primary total shoulder arthroplasty (anatomic and reverse) procedures were retrospectively reviewed at a single academic institution from 2014 to 2020 using claims cost data from Medicare and a private insurer. Patient demographics, comorbidities, and clinical outcomes were collected. A stepwise multivariate regression was performed to determine the independent effect of comorbidities and demographics on 90-day episode-of-care costs. RESULTS: Overall, 1,452 shoulder arthroplasty patients were identified (1,402 Medicare and 50 private payer patients). The mean 90-day cost for Medicare and private payers was $25,822 and $31,055, respectively. Among Medicare patients, dementia ($3,407, P = 0.003), history of stroke ($3,182, P = 0.005), chronic pulmonary disease ($1,958, P = 0.007), anemia ($1,772, P = 0.039), and heart disease ($1,699, P = 0.014) were associated with significantly increased costs. Demographics that significantly increased costs included advanced age ($199 per year in age, P < 0.001) and elevated body mass index ($183 per point, P < 0.001). Among private payers, hyperlipidemia ($6,254, P = 0.031) and advanced age ($713 per year, P < 0.001) were associated with an increase in total costs. CONCLUSION: Providers should be aware that certain demographic variables and comorbidities (history of stroke, dementia, chronic pulmonary disease, anemia, heart disease, advanced age, and elevated body mass index) are associated with an increase in total costs following primary shoulder arthroplasty. Further study is required to determine whether bundled payment target costs should be adjusted to better compensate for specific comorbidities. LEVEL OF EVIDENCE: Level IV case series.

Predicting Hospital Readmissions After Total Shoulder Arthroplasty Within a Bundled Payment Cohort.

INTRODUCTION: Given the rising demand for shoulder arthroplasty, understanding risk factors associated with unplanned hospital readmission is imperative. No study to date has examined the influence of patient and hospital-specific factors as a predictive model for 90-day readmissions within a bundled payment cohort after primary shoulder arthroplasty. The purpose of this study was to determine predictive factors for 90-day readmissions after primary shoulder arthroplasty within a bundled payment cohort. METHODS: After obtaining IRB approval, a retrospective review of a consecutive series of Medicare patients undergoing primary shoulder arthroplasty from 2014 to 2020 at a single academic institution was conducted. Patient demographic data, surgical variables, medical comorbidity profiles, medical risk scores, and social risk scores were collected. Postoperative variables included length of hospital stay, discharge location, and 90-day readmissions. Multivariate analysis was conducted to determine the independent risk factors of 90-day readmission. RESULTS: Overall, 3.6% of primary shoulder arthroplasty patients (127/3,523) were readmitted within 90 days. Readmitted patients had a longer hospital course (1.75 versus 1.45 P = 0.006), higher comorbidity profile (4.64 versus 4.24 P = 0.001), higher social risk score (7.96 versus 6.9 P = 0.008), and higher medical risk score (10.1 versus 6.96 P < 0.001) and were more likely to require a home health aide or be discharged to an inpatient rehab facility or skilled nursing facility ( P = 0.002). Following multivariate analysis, an elevated medical risk score was associated with an increased risk of readmission (odds ratio = 1.05, P < 0.001). DISCUSSION: This study demonstrates medical risk scores to be an independent risk factor of increased risk of 90-day hospital readmissions after primary shoulder arthroplasty within a bundled payment patient population. Additional incorporation of medical risk scores may be a beneficial adjunct in preoperative prediction for readmission and the potentially higher episode-of-care costs. LEVEL OF EVIDENCE: Level III, retrospective cohort.

Shoulder Synovitis Does not Affect Pain After Arthroscopic Rotator Cuff Repair.

Background: The goal of this study was to determine if there is an association between glenohumeral synovitis and early post-operative pain after arthroscopic rotator cuff repair. Methods: Fifty patients with symptomatic rotator cuff tears were prospectively enrolled prior to RCR. Baseline ASES score, VAS Pain score, forward elevation, and external rotation were recorded. Intra-operatively, synovitis was graded on a scale of zero to six as based on a previously validated scoring system. VAS Pain scores were obtained from patients post-operatively on days one through 14, week 6, and 3 months. Results: Average intra-operative synovitis score was 2.4 ± 1.6. No significant correlation was found between synovitis score and pre-operative forward elevation (P=0.171), external rotation (P=0.126), VAS Pain (P=0.623), or ASES (P=0.187) scores. No significant correlation was found between synovitis score and post-operative VAS Pain level at any time point. There was a moderate correlation between both pre-operative VAS Pain and ASES scores and post-operative VAS Pain in the first post-operative week. Workers' compensation patients had worse pain at 3 months post-operatively compared to non-workers compensation patients (P=0.038). Conclusion: This study reveals that macroscopically assessed glenohumeral synovitis does not have any significant correlation with pre-operative or post-operative pain in patients undergoing arthroscopic rotator cuff repair; although higher pre-operative pain levels, worse pre-operative ASES scores, and workers compensation status do influence post-operative pain levels in arthroscopic rotator cuff repair.

The recurrent unstable elbow: diagnosis and treatment.

The elbow is a difficult joint to treat because of the subtle nuances involved in pathology, examination, and treatment. Patients experiencing the sequelae of recurrent elbow instability can lose substantial function in the affected upper extremity. Elbow instability comprises a wide spectrum of diseases, ranging from valgus instability in the throwing athlete to traumatic recurrent rotatory instability to iatrogenic damage. For the orthopaedic surgeon to develop a systematic algorithm for treating elbow instability disorders, it is necessary to understand the basic elbow biomechanics and the alterations that occur in the unstable elbow. A thorough knowledge of the history, physical examination techniques, and imaging studies necessary to diagnose these injury patterns is also needed. Cutting-edge advances in the surgical reconstruction of the unstable elbow will allow those caring for patients with these difficult injuries to make the proper management decisions.

Hematoma following total elbow arthroplasty: incidence, management, and outcomes.

INTRODUCTION: This study investigates the incidence, risk factors for, and clinical outcomes of hematoma following total elbow arthroplasty. METHODS: We retrospectively reviewed patient and surgical characteristics as predictors of post-operative hematoma in 382 total elbow arthroplasty (196 primary, 157 revision, and 29 conversion) between May 2004 and February, 2017. For comparison of outcomes, cases were matched (1:2) with controls by age, gender, type of surgery, and surgical indication. RESULTS: Nineteen post-operative hematomas (5.0%; 19/382) were identified. Total elbow arthroplasty for post-traumatic arthritis (6.7%; 4/60), aseptic loosening (7.9%; 3/38), sequelae of periprosthetic joint infection (6.1%; 5/81), and non-union (28.6%; 2/7) had the highest incidence of hematoma. Clinic aspiration and compressive wrap was performed in 14 patients and avoided a return to the operating room in 78.6% (11/14). Seven patients (36.8%) required a return to the operating room, of which five (71.4%) had positive cultures and required treatment for prosthetic joint infection. Compared to the matched controls, hematoma formation predicted a higher rate of reoperation (36.8% versus 7.9%; p = 0.007) and a higher rate of subsequent prosthetic joint infection (35.7% versus 0%; p = 0.008). CONCLUSION: Hematoma formation is associated with both prosthetic joint infection and return to the operating room after total elbow arthroplasty. Strategies to prevent hematoma formation after total elbow arthroplasty may reduce complication rates.

Tendon properties remain altered in a chronic rat rotator cuff model.

BACKGROUND: Chronic rotator cuff tears are often associated with pain or poor function. In a rat with only a detached supraspinatus tendon, the tendon heals spontaneously which is inconsistent with how tears are believed to heal in humans. QUESTIONS/PURPOSES: We therefore asked whether a combined supraspinatus and infraspinatus detachment in the rat would fail to heal and result in a chronic injury in the supraspinatus tendon. METHODS: We acutely detached the supraspinatus and infraspinatus tendons in a rat model. At 4, 8, and 16 weeks post-detachment, biomechanical testing, collagen organization, and histological grading were evaluated for the detached supraspinatus and infraspinatus tendons and compared to controls. RESULTS: In the detached supraspinatus tendon, area and percent relaxation were increased at all time points while the modulus and stiffness were similar to those of controls at 4 and 8 weeks. Collagen disorganization increased at late time points while cellularity increased and cells were more rounded in shape. In the detached infraspinatus tendon, area and percent relaxation were also increased at late time points. However, the modulus values initially decreased followed by an increase in both modulus and stiffness at 16 weeks compared to control. In the detached infraspinatus, we also observed a decrease in collagen organization at all time points and increased cellularity and a more rounded cell shape. CONCLUSIONS: Due to the ongoing changes in mechanics, collagen organization and histology in the detached supraspinatus tendon compared to control animals at 16 weeks, this model may be useful for understanding the human chronic tendon tear. CLINICAL RELEVANCE: This rat rotator cuff chronic model can be used to test hypotheses regarding injury and repair mechanisms that cannot be addressed in human patients or in cadaveric studies.

Arthroscopic Latarjet for Shoulder Instability.

Arthroscopic Latarjet is a relatively new, but viable option for the treatment of anterior shoulder instability. Arthroscopic Latarjet has the advantage of faster recovery, reduced stiffness, identification of additional shoulder pathology, and improved cosmesis when compared with open Latarjet. By the majority of clinical and radiographic parameters, arthroscopic Latarjet produces equivalent outcomes compared with open Latarjet. A relatively substantial learning curve for arthroscopic Latarjet exists at about 25 cases; however, multiple studies have demonstrated comparable outcomes and surgical time after the learning curve.

Practice Management During the COVID-19 Pandemic.

On March 14, 2020, the Surgeon General of the United States urged a widespread cessation of all elective surgery across the country. The suddenness of this mandate and the concomitant spread of the COVID-19 virus left many hospital systems, orthopaedic practices, and patients with notable anxiety and confusion as to the near, intermediate, and long-term future of our healthcare system. As with most businesses in the United States during this time, many orthopaedic practices have been emotionally and fiscally devastated because of this crisis. Furthermore, this pandemic is occurring at a time where small and midsized orthopaedic groups are already struggling to cover practice overhead and to maintain autonomy from larger health systems. It is anticipated that many groups will experience financial demise, leading to substantial global consolidation. Because the authors represent some of the larger musculoskeletal multispecialty groups in the country, we are uniquely positioned to provide a framework with recommendations to best weather the ensuing months. We think these recommendations will allow providers and their staff to return to an infrastructure that can adjust immediately to the pent-up healthcare demand that may occur after the COVID-19 pandemic. In this editorial, we address practice finances, staffing, telehealth, operational plans after the crisis, and ethical considerations.

Glenohumeral synovitis score predicts early shoulder stiffness following arthroscopic rotator cuff repair.

BACKGROUND: This study was conducted to determine if there is an association between an intraoperative glenohumeral synovitis score (GHSS) and postoperative shoulder stiffness in patients undergoing arthroscopic rotator cuff repair (ARCR). METHODS: Intraoperative GHSS was collected retrospectively from standardized arthroscopic images on consecutive patients undergoing primary ARCR. Range of motion was collected preoperatively and postoperatively at 3 and 6 months. RESULTS: 290 consecutive patients underwent primary ARCR. At three-months follow-up, 32 (11.0%) patients had glenohumeral stiffness. Patients with stiffness had significantly higher mean GHSS. CONCLUSION: Higher intraoperative GHSS was associated with early postoperative shoulder stiffness at three-months after ARCR.

Concomitant rotator cuff repair and instability surgery provide good patient-reported functional outcomes in patients aged 40 years or older with shoulder dislocation.

BACKGROUND: Recurrent anterior shoulder dislocation in patients aged ≥ 40 years is not as rare as once thought. The mechanism of instability in this patient population is different-more likely to be attributed to rotator cuff pathology-compared with that in younger individuals. With an increasingly aging active population, surgical management has a rising role in preventing morbidity associated with recurrent instability. Our purpose was to evaluate outcomes of anterior shoulder instability repair (ie, Bankart or bony Bankart repair) with and without rotator cuff repair (RCR) in patients aged ≥ 40 years. METHODS: We conducted a retrospective chart review of all patients aged ≥ 40 years who underwent surgical repair for anterior shoulder instability from 2008-2016. Patients were categorized into 4 cohorts: Bankart repair only, bony Bankart repair only, Bankart repair with concomitant RCR, and bony Bankart repair with concomitant RCR. Demographic and history-of-instability data were collected. Clinical and functional outcomes assessed included the Single Assessment Numeric Evaluation score, American Shoulder and Elbow Surgeons score, Penn Shoulder Score, visual analog scale score for pain, Western Ontario Shoulder Instability Index score, and patient satisfaction score. RESULTS: A total of 146 patients were included in this study, with 103 patients (71%) having ≥2-year outcome scores. Outcome scores were not significantly different among groups. For patients who underwent Bankart repair only, bony Bankart repair only, Bankart repair with RCR, and bony Bankart repair with RCR, the Single Assessment Numeric Evaluation scores were 80.8 ± 19.7, 90.0 ± 10.7, 79.3 ± 29.4, and 87.2 ± 10.6, respectively (P = .284); American Shoulder and Elbow Surgeons scores, 83.8 ± 19.7, 92.4 ± 17.4, 82.5 ± 25.6, and 85.6 ± 12.7, respectively (P = .114); Penn Shoulder Scores for function, 84.5 ± 17.9, 90.9 ± 15.3, 83.6 ± 25.1, and 95.7 ± 13.0, respectively (P = .286); and Western Ontario Shoulder Instability Index scores, 481.0 ± 519.5, 292.1 ± 414.3, 548.9 ± 690.5, and 320.6 ± 258.7, respectively (P = .713). Age at the time of surgery significantly differed between cohorts (P < .001). No patients had recurrence of instability during the study period. CONCLUSION: Similar functional outcomes can be achieved in the surgical management of anterior instability in patients aged ≥ 40 years. Rotator cuff tears should be suspected and repaired in patients with anterior instability, especially those aged ≥ 50 years.

Alterations in function after rotator cuff tears in an animal model.

HYPOTHESIS: This study examined the effect of multiple rotator cuff tendon tears on shoulder function in an animal model. MATERIALS AND METHODS: Forty-eight Sprague-Dawley rats were divided into uninjured control, supraspinatus tendon detachment, supraspinatus+infraspinatus tendon detachment, or supraspinatus+subscapularis tendon detachment groups. Functional assessment was determined through ambulatory parameters (paw and stride measures) and range of motion prior to tendon detachment and at various time points after tendon detachment. RESULTS: Ambulatory parameters and total range of motion, representing measures of shoulder function, were significantly altered with rotator cuff tears. The addition of a second torn rotator cuff tendon (infraspinatus or subscapularis)had further detrimental effects on animal shoulder function compared to uninjured control. DISCUSSION: This study demonstrated functional changes in a rat rotator cuff model. Many of the permanent functional changes were likely present because the required motion used for those actions can no longer be performed. For parameters that were transient, compensation with another limb or subsidence of pain may have occurred. CONCLUSION: The findings in this study are consistent with the alterations in shoulder function observed with rotator cuff and other shoulder injuries in the human. Future studies using this model can begin to examine the root of the functional differences, whether it is pain, mechanical deficiency, or a combination of both, which cannot be fully studied clinically [corrected].

After rotator cuff tears, the remaining (intact) tendons are mechanically altered.

Although presumed, damage in the remaining (intact) rotator cuff tendons in the presence of an isolated supraspinatus tendon tear or multiple tendon tear has not been well studied. This study used an animal model of multiple rotator cuff tendon tears to investigate alterations in the remaining (intact) tendon mechanical properties at 4 and 8 weeks after injury. Twenty-four rats served as uninjured controls, whereas 72 were divided among 3 tendon detachment groups: supraspinatus tendon detachment, supraspinatus + infraspinatus tendon detachment, and supraspinatus + subscapularis tendon detachment. The remaining (intact) rotator cuff tendons had decreased mechanical properties in the presence of rotator cuff tears. The remaining (intact) subscapularis and infraspinatus tendon cross-sectional areas increased, whereas tendon modulus decreased after tears of both 1 and 2 tendons. The remaining (intact) tendon cross-sectional areas continued to increase with time after injury. These alterations could potentially lead to further tendon damage and tear progression.

Normal and Pathoanatomy of the Arthritic Shoulder: Considerations for Shoulder Arthroplasty.

The glenohumeral joint is a highly mobile, complex articulation that relies not only on the bony support between the humeral head and glenoid but also on appropriate balance and tension of the surrounding soft-tissue structures. Recreating the normal anatomic relationships is a basic premise in joint arthroplasty, which can be challenging in shoulder arthroplasty, as the normal glenohumeral anatomy has considerable variation from patient to patient. Also, as the anatomy of the glenohumeral joint becomes distorted with advanced shoulder pathology, it becomes a challenge to return the shoulder to its premorbid anatomic state. Failure to restore normal anatomic parameters after shoulder arthroplasty has been shown to have deleterious effects on postoperative function and implant survival. As the recognition of this has grown, shoulder prostheses have evolved to allow for considerable more variation in an attempt to recreate patient-specific anatomy. However, understanding the progression of shoulder pathology to better predict the patient's premorbid anatomy remains limited. A thorough understanding of the premorbid and pathologic anatomy of the glenohumeral joint will aid in preoperative planning and intraoperative execution and lead to a more predictable reconstruction of the shoulder, which is critical for a successful outcome after shoulder arthroplasty.

Failure of Anatomic Total Shoulder Arthroplasty with Revision to another Anatomic Total Shoulder Arthroplasty.

BACKGROUND: While outcomes of primary anatomic total shoulder arthroplasty (aTSA) are generally favorable, results after revision procedures are less reliable. This study examines the functional outcomes, complications, and implant survival in patients who underwent revision of aTSA to aTSA. METHODS: Patients who underwent revision aTSA were identified from 2008-2015. Demographic, clinical, surgical, and outcomes data were analyzed. Patient-reported outcomes including the American Shoulder and Elbow Surgeons Score (ASES), Single Assessment Numerical Evaluation (SANE), Visual Analog Scale for pain (VAS), the Short Form-12 Health Survey (SF-12), and patient satisfaction were recorded. RESULTS: Twenty patients underwent revision from a primary aTSA to aTSA (55% male, 62.0±6.8 years-old). Revision aTSA occurred at 2.5±3.4 years after index surgery. Seven (35%) required future revision at 1.8±1.9 years after revision aTSA. Among the 13 patients who did not undergo revision, twelve (92.3%) had over two-year follow-up (4.0±2.4 years). Average ASES score was 70.1±23.5, SANE 66.0±29.4, VAS 2.7±3.0, SF-12 Mental 52.4±10.5, SF-12 Physical 36.8±8.9, and satisfaction of 3.6±1.2. CONCLUSION: Results of revision aTSA to aTSA were unpredictable and the revision rate was high. The cases that do not undergo revision had satisfactory, but inconsistent functional results. Reverse arthroplasty may be more reliable in this patient population.