Incidence of peripheral nerve injury during shoulder arthroplasty when motor evoked potentials are monitored.

To report the incidence of clinically detectable nerve injuries when utilizing transcranial electrical motor evoked potentials (MEPs) during shoulder arthroplasty. A retrospective review of patients undergoing shoulder arthroplasty with continuous IONM was performed. The criteria for nerve alerts was an 80% amplitude reduction in MEPs. The primary outcome measure was post-operative clinically detectable nerve deficit. An additional retrospective analysis on a subset of cases using an all-or-none (100% amplitude reduction) criterion applied to the deltoid was performed. Two hundred eighty four arthroplasty cases were included. There were no permanent post-operative nerve injuries and two transient nerve injuries (0.7%). MEP alerts occurred in 102 cases (36.2%). Nineteen (6.7%) cases did not have signals return above alert threshold at closure. These cases were significantly associated with post-operative nerve injury (p = 0.03). There were no false negatives, making sensitivity 100% and specificity was 93.9%. In the subset of cases in which an all-or-none criterion was retrospectively applied to just the deltoid, MEP alerts occurred in just 17.9% of cases; specificity improved to 98.0%. We conclude that utilization of the real-time diagnostic MEP data during shoulder arthroplasty aids surgeons in decision making regarding impending peripheral nerve injuries.

Future surgery after revision shoulder arthroplasty: the impact of unexpected positive cultures.

BACKGROUND: The clinical implications and treatment of unexpected positive cultures (UPCs) in revision shoulder arthroplasty are not well defined. The purpose of this study was to describe results of patients with and without UPCs after revision shoulder arthroplasty. METHODS: A single institutional database was used to retrospectively identify all revision shoulder arthroplasties performed between January 1, 2011, and December 31, 2013. Patients with preoperative suspicion of infection were excluded. Multivariable regression analysis was used to identify risk factors for future surgery after revision shoulder arthroplasty. RESULTS: There were 117 revision shoulder arthroplasties without preoperative suspicion of infection. There were 28 of 117 (23.9%) with UPCs, of which 15 (57.1%) were Propionibacterium acnes; 18 of 28 (64.3%) patients received antibiotics for 6 weeks postoperatively without complications compared with 10 of 28 (35.7%) who received a routine 2-week empirical antibiotic regimen; 2 of 28 (7.1%) patients with UPCs required future surgery, and only 1 (3.6%) had a recurrent infection. Comparatively, 18 of 89 (20.2%) patients without UPCs (P = .109) required 25 additional surgeries. Average time to UPC was 4.3 years after index revision. Multivariable regression analysis of patient demographics, comorbidities, surgical procedure, and presence of UPCs found no independent predictors of reoperation. DISCUSSION: Nearly one-quarter of our institution's revision shoulder arthroplasties had UPCs. The patients without UPCs had a nonsignificantly higher risk of reoperation compared with those with UPCs. We did not identify clinical or demographic variables that independently correlated with reoperation. Further study will be necessary to determine the true clinical benefit of routine culture acquisition in cases with low suspicion for prosthetic joint infection.

Comparison of implant cost and surgical time in arthroscopic transosseous and transosseous equivalent rotator cuff repair.

BACKGROUND: We investigated the cost savings associated with arthroscopic transosseous (anchorless) double-row rotator cuff repair compared with double-row anchored (transosseous-equivalent [TOE]) repair. METHODS: All patients undergoing double-row arthroscopic rotator cuff repair from 2009 to 2012 by a single surgeon were eligible for inclusion. The study included 2 consecutive series of patients undergoing anchorless or TOE repair. Excluded from the study were revision repairs, subscapularis repairs, patients with poor tendon quality or excursion requiring medialized repair, and partial repairs. Rotator cuff implant costs (paid by the institution) and surgical times were compared between the 2 groups, controlling for rotator cuff tear size and additional procedures performed. RESULTS: The study included 344 patients, 178 with TOE repairs and 166 with anchorless repairs. Average implant cost for TOE repairs was $1014.10 ($813.00 for small, $946.67 for medium, $1104.56 for large, and $1507.29 for massive tears). This was significantly more expensive compared with anchorless repairs, which averaged $678.05 ($659.75 for small, $671.39 for medium, $695.55 for large, and $716.00 for massive tears). Average total operative time in TOE and anchorless groups was not significantly different (99 vs. 98 minutes). There was larger (although not statistically significant) case time variation in the TOE group. CONCLUSIONS: Compared with TOE repair, anchorless rotator cuff repair provides substantial implant-related cost savings, with no significant differences in surgical time for medium and large rotator cuff tears. Case time for TOE repair varied more with extremes in tear size.

Leukocyte esterase in the diagnosis of shoulder periprosthetic joint infection.

BACKGROUND: Shoulder periprosthetic joint infection (PJI) is difficult to diagnose with traditional methods. Leukocyte esterase (LE) has recently proven to be reliable in knee arthroplasty; however, its value in the shoulder has not been explored. We hypothesized that LE would display high sensitivity and specificity in shoulder PJI. METHODS: Two groups were prospectively evaluated: 45 primary and 40 revision shoulder arthroplasties. Synovial fluid and soft tissue cultures were obtained at surgery. Synovial fluid was evaluated with LE test strips. Any aspiration that contained erythrocytes was centrifuged and retested. Shoulder PJI was defined by modified Musculoskeletal Infection Society (MSIS) criteria. RESULTS: Of 5 primaries with positive tissue cultures (11%), only 1 was positive for LE. Of 16 revisions with positive cultures (40%), 4 had positive LE results. Among all patients with bacterial isolates, 6 aspirates were not interpretable (29%), despite centrifugation. LE had sensitivity of 25% and specificity of 75% to predict positive cultures in revisions. Ten revision patients met modified MSIS criteria for PJI. The sensitivity of LE in these patients was 30%, and the specificity was 67% (positive predictive value, 43%; negative predictive value, 83%). If bloody aspirates were considered positive, LE sensitivity in MSIS PJI increased to 60%, but the positive predictive value fell to 37.5%. CONCLUSION: LE is an unreliable diagnostic measure in shoulder PJI. The presence of erythrocytes within aspirates further decreased its accuracy. We conclude that LE should not be used for the routine identification of shoulder PJI.

SenseCam reminiscence and action recall in memory-unimpaired people.

Case studies of memory-impaired individuals consistently show that reminiscing with SenseCam images enhances event recall. This exploratory study examined whether a similar benefit would occur for the consolidation of memories in memory-unimpaired people. We tested delayed recall for atypical actions observed on a lengthy walk. Participants used SenseCam, a diary, or no external memory aid while walking, followed by reminiscence with SenseCam images, diary entries, or no aid, either alone (self-reminiscence) or with the experimenter (social reminiscence). One week later, when tested without SenseCam images or diary entries, prior social reminiscence produced greater recall than self-reminiscence, but there were no differences between memory aid conditions for action free recall or action order recall. When methodological variables were controlled, there was no recall advantage for SenseCam reminiscence with memory-unimpaired participants. The case studies and present study differ in multiple ways, making direct comparisons problematic. SenseCam is a valuable aid to the memory impaired, but its mnemonic value for non-clinical populations remains to be determined.

Diagnostic accuracy of noncontrast MRI for detection of glenohumeral cartilage lesions: a prospective comparison to arthroscopy.

BACKGROUND: The purpose of this study was to determine the prevalence of glenohumeral articular cartilage lesions in patients with rotator cuff tendinopathy and to assess the accuracy of noncontrast magnetic resonance imaging (MRI) in detecting these defects compared with the "gold standard" of arthroscopy. METHODS: Noncontrast MRI studies obtained in 84 consecutive patients undergoing shoulder arthroscopy for rotator cuff tendinopathy (mean age, 54.8 years; range, 17-82 years) were prospectively evaluated for glenohumeral cartilage lesions. Two fellowship-trained, experienced musculoskeletal radiologists were blinded from the arthroscopic findings and independently evaluated the glenoid and humeral head cartilage on 2 separate occasions. RESULTS: At arthroscopy, cartilage lesions of the humeral head were detected in 23 patients (frequency, 27.4%), and glenoid cartilage lesions were found in 20 patients (frequency, 23.8%). For detection of a humeral lesion on MRI, the radiologists' combined accuracy was 78%, sensitivity was 43%, and specificity was 91%. The combined accuracy for detection of glenoid lesions on MRI was 84%, sensitivity was 53%, and specificity was 93%. Combining the readers, low-grade lesions (International Cartilage Repair Society grades 1 and 2) of the glenoid and humerus were read as negative on MRI in 63% and 86% of cases, respectively. CONCLUSION: Overall accuracy of noncontrast MRI for detection of glenohumeral articular cartilage lesions is good; however, interpretation is reader dependent, and accuracy is significantly reduced for detection of low-grade lesions. On the basis of these findings, we recommend that patients with rotator cuff tendinopathy undergoing arthroscopy be informed that the presence and severity of cartilage lesions may be underestimated on MRI.

Physician Rating Websites: an Analysis of Physician Evaluation and Physician Perception.

BACKGROUND: The goal of this study was to evaluate current physician ratings websites (PRWs) to determine which factors correlated to higher physician scores and evaluate physician perspective of PRWs. METHODS: This study evaluated two popular websites, Healthgrades.com and Vitals.com, to gather information on practicing physician members of the American Shoulder and Elbow Society database. A survey was conducted of the American Shoulder and Elbow Society (ASES) membership to gather data on the perception held by individual physicians regarding PRWs. RESULTS: We found that patients were more likely to give physicians positive reviews and the average overall score was 8.35 (3.75-10). Patient wait time (P=0.052) trended toward significance as a major factor in determining the overall scores, while ratings in both physician bedside manner (P=0.001) and physician/staff courtesy (P=0.002) were significant in reflecting the overall score given to the physician. According to our survey, a majority of the respondents were indifferent to highly unfavorable to PRWs (88%) and the validity of their ratings (78%). CONCLUSION: As PRWs become increasingly popular amongst patients in this digital age, it is critical to understand that the scores are not reflective of a significant proportion of the physicians' patient population. Physicians can use this study to determine what affects a patient's experience and focus efforts on improving patients' perception of quality, overall satisfaction, and overall care. Consumers may use this study to increase their awareness of the potential for significant sampling error inherent in PRWs when making decisions about their care.

Shoulder Synovial Fluid Lipoprotein Levels and Their Relationship to the Rotator Cuff.

INTRODUCTION: Rotator cuff pathology has been proposed to occur through intrinsic and extrinsic mechanisms. Hyperlipidemia has been proposed as a mechanism of intrinsic rotator cuff pathology. This prospective observational study evaluates serum and synovial lipid profiles in patients with and without rotator cuff tears to further define the relationship of cholesterol and rotator cuff pathology. METHODS: Patients were prospectively enrolled with intact rotator cuff (37 patients) and rotator cuff tear requiring a repair (40 patients) groups. Exclusion criteria were medication for hypercholesterolemia, smoking, previous ipsilateral shoulder surgery, inflammatory arthritis, or history of shoulder infection. Serum and synovial fluid samples were collected at the time of surgery and analyzed for total cholesterol, HDL, non-HDL, and triglycerides. RESULTS: There were no significant differences seen in any lipid values between patients with rotator cuff and those without a tear. The calculated ratio of synovial lipids to serum lipids was also not significantly different between the patient groups with and without cuff tears. DISCUSSION: This study successfully evaluates the correlation between serum and synovial lipid levels in the glenohumeral joint. The ratio of lipid values between the serum and the synovial fluid was similar, thus defining a ratio of lipid levels between the blood and the shoulder joint regardless of the presence of a rotator cuff tear. All lipid values measured were similar in both the serum and synovial fluid between patients with and without cuff tears.

Agreement among ASES members on the AAOS Clinical Practice Guidelines.

The American Academy of Orthopaedic Surgeons (AAOS) has recently developed several clinical practice guidelines (CPG) involving upper extremity conditions. The purpose of the current study was to evaluate the practice patterns of members of the American Shoulder and Elbow Society (ASES) with regard to the CPGs. An e-mail survey was sent to the 340 members of the ASES. The survey contained 40 questions involving the subject matter of the 2 existing AAOS CPGs pertaining specifically to the shoulder: Optimizing the Management of Rotator Cuff Problems and the Treatment of Glenohumeral Joint Arthritis. Overall, 98 responses were obtained, for a response rate of 29%. Only 19 of 47 CPGs were not "inconclusive" and a recommendation was actually made. A majority (more than 50%) of surgeons agreed with 17 (90%) of 19 of these AAOS recommendations. A strong majority (more than 80%) adhered to 13 (68%) of 19 recommendations. There were 4 consensus recommendations, and more than 50% agreed with all of them. Of the 5 moderate recommendations, more than 50% agreed with 4 of them. There were 10 weak recommendations, and more than 50% of surgeons agreed with 9 of them. There was more than 80% agreement on 18 of 28 inconclusive recommendations. Although the AAOS CPGs are not meant to be fixed protocols, they are intended to unify treatment and/or diagnosis of common problems based on the best evidence available. Despite the majority of the AAOS CPG recommendations for rotator cuff problems and glenohumeral arthritis being inconclusive, most surgeons agree with most of the CPG recommendations.

The direct and indirect costs to society of treatment for end-stage knee osteoarthritis.

BACKGROUND: Although total knee arthroplasty for end-stage osteoarthritis is a cost-effective procedure, payers are focusing on its indications and cost because of its high and growing use. Improvements in pain and physical function from total knee arthroplasty could yield benefits in the form of increased work life and lower disability payments. The purpose of this study was to estimate the value of total knee arthroplasty from a societal perspective, including the costs and benefits to patients, employers, and payers. METHODS: A Markov model was used to estimate the value of total knee arthroplasty for patients with end-stage osteoarthritis of the knee by comparing direct and indirect costs between surgical and nonsurgical treatment scenarios. Direct costs included all medical costs for surgical and nonsurgical treatment of osteoarthritis of the knee. Indirect costs were related to lost wages due to an inability to work, lower earnings, or receipt of disability payments. Direct and indirect costs and quality-of-life measures were incorporated into the Markov model to estimate the impact of total knee arthroplasty on costs over patients' lifetimes and quality-adjusted life years. The assumptions used in the model were developed with use of claims and survey data as well as clinical expert opinion and the peer-reviewed literature. RESULTS: Compared with nonsurgical treatment, total knee arthroplasty increased lifetime direct costs by a mean of $20,635 (net present value in 2009 U.S. dollars). These costs were offset by societal savings of $39,565 from reduced indirect costs, resulting in a lifetime societal net benefit from total knee arthroplasty of $18,930 per patient. Eighty-five percent of these savings originated from increased employment and earnings, with the remaining 15% from fewer missed workdays and lower disability payments. CONCLUSIONS: The estimated lifetime societal savings from the more than 600,000 total knee arthroplasties performed in the U.S. in 2009 were estimated to be approximately $12 billion. These societal savings primarily accrued to patients and employers. The study demonstrates the importance of a societal perspective when considering the costs and benefits of total knee arthroplasty and policies that will affect access to this procedure.