Changes in microbiological spectrum and antibiotic susceptibility in two-stage exchange for periprosthetic shoulder infections.

BACKGROUND: Periprosthetic joint infections (PJI) are a major concern in shoulder arthroplasty, which in some cases require two-stage exchange. While it was shown that low-virulence bacteria are the most isolated pathogens in shoulder PJI, little is known about changes in microbiological spectrum and resistance patterns during two-stage revision. METHODS: This retrospective study included all patients (n = 25) who received a two-stage revision from January 2011 to December 2020 for shoulder PJI in one institution. Microbiological spectrum, antimicrobial resistance patterns, and re-revision rates of culture positive first- and second-stage procedures were analyzed. The mean follow-up time was 29.7 months (range 8; 115 months). At final follow-up, subjective shoulder value (SSV) and visual analog scale (VAS) score for pain and satisfaction with the surgery were assessed. RESULTS: In 25 patients, a total of 54 2-stage exchange procedures were performed and positive cultures were obtained in 36 of these surgeries (66.7%). A total of 7 out of 25 patients (28.0%) showed a positive microbiological culture at first and second stages. In those patients, the mean time between first and second stages was 30.9 weeks (range 6; 70). Three out of those seven patients (42.9%) had a polymicrobial spectrum with one microorganism persistent at stage two, including Cutibacterium acnes (n = 1) and Staphylococcus epidermidis (MRSE) (n = 2). In all these cases, antimicrobial resistance patterns changed. All cultures with monomicrobial spectrum (n = 4) at first stage showed a changed spectrum. Patients with positive first- and second-stage revisions showed a mean SSV of 49.3% ± 23.5 versus 52.9% ± 29.5 in single positive patients (p = 0.76). Re-revision was performed in five cases, two of those in patients with positive first- and second-stage cultures. CONCLUSION: There is a high rate of changes in microbiological spectrum and resistance patterns between culture positive first- and second-stage procedures as well as subsequent re-revisions. Intraoperative samples during reimplantation should be taken and resistance reconsidered in case of re-revision.

Safety and efficacy of switching from low molecular weight heparin to dabigatran in patients undergoing elective total hip or knee replacement surgery.

BACKGROUND: The aim of this study was to assess the safety and efficacy of switching therapy from low molecular weight heparin (LMWH; enoxaparin) to dabigatran for prevention of venous thromboembolic events (VTE) in patients undergoing elective total hip or knee replacement surgery (THR/TKR). METHODS: This was a prospective, multicenter, open-label, single-arm, observational, study in patients undergoing THR or TKR who were to receive enoxaparin 40 mg for thromboprophylaxis. Enoxaparin was initiated before or after surgery according to local practice, and was switched to dabigatran 220 mg once daily at a time point chosen by the investigator. The coprimary endpoints were major bleeding events, and the composite of symptomatic VTE and all-cause mortality, from last use of enoxaparin to 24 h after last intake of dabigatran. RESULTS: Altogether, 168 (81 THR, 87 TKR) patients were enrolled, of whom 161 received both enoxaparin and dabigatran, 2 received dabigatran only and 5 received enoxaparin only. The median time of the first dabigatran tablet was 24.0 h after the last LMWH dosage and the median number of days on dabigatran treatment was 36 days. No symptomatic VTE or death occurred during the study. One major bleeding event was seen at the surgical site and required treatment cessation. Three minor bleeding events were observed. CONCLUSIONS: In the normal clinical setting, switching from LMWH to dabigatran in patients who had undergone THR and TKR was safe and effective in preventing VTE. The reported adverse events and serious adverse events were consistent with the known safety profile for dabigatran. Switching from a subcutaneous to an oral anticoagulant may offer greater convenience in the outpatient setting after discharge. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01153698.

Electromyographic analysis: shoulder muscle activity revisited.

INTRODUCTION: Restoring optimal strength and biomechanics of a pathologic shoulder knowledge of activity patterns of healthy glenohumeral muscles is mandatory. Yet, data on normal shoulder muscle activity are not always conclusive. The study was undertaken (a) to evaluate muscle activity patterns in the healthy shoulder using surface and fine-wire electromyography (EMG), and (b) to assess method's suitability in the clinical setting especially regarding painfulness and practicability. MATERIALS AND METHODS: Surface and fine-wire EMG was performed on 11 healthy subjects (2f/9 m, Ø age 28 years) to assess 14 muscles including rotator cuff muscles during 8 planar standardised shoulder movements (abduction, forward flexion, internal and external rotation in neutral, 45° and 90° abduction). Pain was assessed using the visual analogue scale before testing, after inserting the fine-wire electrodes, after maximal voluntary contraction, before and after exercises, and after electrode removal. RESULTS: The most important finding regarding EMG activity patterns in the healthy shoulder was that the subscapularis activity was found to play a major role in abduction and forward flexion. Furthermore, this study was able to show that EMG measurements, especially fine-wire EMG, is prone to high failure rates (up to 32%); however, pain was not a limiting factor. CONCLUSION: The present study (1) revealed a new insight, especially finding the subscapularis activity playing a major role in abduction and forward flexion of the healthy shoulder; and (2) motion analysis system and the use of fine-wire electrodes were prone to failure; however, pain was not a limiting factor. LEVEL OF EVIDENCE: Basic Science, Electrodiagnostic Study.

Measurement of the acromiohumeral interval on standardized anteroposterior radiographs: a prospective study of observer variability.

BACKGROUND: An acromiohumeral interval narrower than 6 mm has been considered pathologic and strongly indicative for rotator cuff tears by numerous authors. This prospective study assessed interobserver and intraobserver variability in the radiographic measurement of the acromiohumeral interval. MATERIAL AND METHODS: Five board-certified orthopedic surgeons independently reviewed 58 blinded, standardized anteroposterior shoulder radiographs. The acromiohumeral interval was measured in millimeters. The 5 investigators classified each image a second time in random order. RESULTS: After the same 58 radiographs had been evaluated by the 5 investigators at both examination time points, no significant differences were noted in the interobserver and intraobserver measurements (P < .05). The respective maximum interobserver and intraobserver differences were 4 and 3 mm (range, 0-4 mm). CONCLUSION: The assessment of the acromiohumeral interval using standardized anteroposterior radiographs is a reliable and reproducible method of measurement. LEVEL OF EVIDENCE: Level 1; Investigating a diagnostic test.

Cross-cultural adaptation and validation of the German version of the Western Ontario Shoulder Instability index.

BACKGROUND: The Western Ontario shoulder instability index (WOSI) is a disease-specific quality of life measurement tool with 21 items for patients with shoulder instability. Here, we report on translation and validation of the German version of the WOSI according to international guidelines. PATIENTS AND METHODS: A total of 86 patients in three groups were included in this study. In group I, 24 patients underwent surgical stabilization of the shoulder. Preoperatively and at 12 months post-operatively the WOSI, Rowe score, UCLA, Constant score, and the SF-36 were evaluated. In group II, 25 patients were evaluated 2.6 +/- 1.2 years after sustaining a primary traumatic shoulder dislocation. Group III consisted of 37 healthy men and women with normal, healthy shoulders. Evaluation of Pearson's correlation coefficient between WOSI and Rowe score, UCLA, SF-36 and Constant score and for test-retest reliability was made. Moreover, Cronbach's alpha and floor, and ceiling effects were analyzed. RESULTS: Internal consistency was high (Cronbach's alpha 0.92).Test-retest reliability (Pearson correlation coefficient) was excellent (r = 0.92). The construct validity showed a significant correlation between the WOSI and the scores investigated. There were no floor or ceiling effects for the German WOSI score. CONCLUSION: The German translation of the WOSI is a valid and reliable tool, applicable to outcome studies on patients with shoulder instability.

Shoulder impingement: relationship of clinical symptoms and imaging criteria.

OBJECTIVE: To establish, in patients with subacromial impingement syndrome, (1) the relationship between pain and shoulder function, as determined by the Constant score, and morphological findings, as determined by radiographs and magnetic resonance imaging (MRI) and (2) the relationship between acromial shape and minimum acromiohumeral distance (AHD). DESIGN: Cross-sectional study. SETTING: Tertiary care center. PATIENTS: Forty-seven patients (33 males and 14 females; mean age, 51.7 years) with unilateral subacromial impingement syndrome who had failed to respond to conservative therapy for at least 6 months. INTERVENTIONS: The Constant score was determined preoperatively; acromial shape (type I, flat; type II, curved; and type III, hooked) was evaluated on preoperative outlet view radiographs and oblique sagittal T1-weighted MRIs; AHD was evaluated on preoperative anteroposterior radiographs and oblique coronal T1-weighted MRIs. MAIN OUTCOME MEASURES: Correlation coefficients and the simple kappa statistic were calculated. Student t test and mean differences with 95% confidence limits were reported for group comparisons. RESULTS: The Constant score was fairly correlated with AHD (r = 0.39, P < 0.01) but not with acromial shape. Patients with an AHD < or =7 mm on MRI scored significantly lower than those with an AHD >7 (mean difference, 18.5; P < 0.01). Acromial shape and AHD were not correlated, neither on radiographs nor on MRI. CONCLUSIONS: AHD seems to better reflect the clinical status of patients with subacromial impingement, but without rotator cuff tears, than acromial shape. Acromial shape is not a good descriptor of subacromial space narrowing.

Interscalene versus subacromial continuous infusion of ropivacaine after arthroscopic acromioplasty: a randomized controlled trial.

INTRODUCTION: Interscalene and subacromial infusion of local anesthetics have both been shown to be effective in alleviating pain after shoulder arthroscopy. We performed a prospective randomized clinical trial in which both methods were compared in patients after acromioplasty. METHODS: Forty patients received a subacromial (n = 20) or an interscalene (n = 20) continuous infusion of 2% ropivacaine (2 mL/h) after arthroscopic acromioplasty. Visual analog scale pain scores, additional medication requirements, and side effects were evaluated for 43 hours. The incidence of night pain was recorded. RESULTS: Compared with the subacromial infusion, the continuous interscalene infusion of ropivacaine in the operated-on shoulder resulted in significantly reduced visual analog scale pain scores measured during rest, and also during exercise at 8 and 12 hours after surgery. The incidence of night pain was significantly lower in the interscalene group (P = .018). CONCLUSION: A continuous subacromial infusion of 0.2% ropivacaine (2 mL/h) is inferior to continuous interscalene infusion, particularly during the first 12 hours, but could be an alternative in patients with contraindications of interscalene anesthesia or when acromioplasty is performed as an outpatient procedure.

Vascular cell adhesion molecule 1 in patients with severe osteoarthritis of the hip : A prospective cross-sectional study.

BACKGROUND: Osteoarthritis (OA) of the hip is a frequent and debilitating joint disease. Only few clinical risk factors for hip OA are established and clinically applicable biomarkers to identify patients at risk are still lacking. The glycoprotein vascular cell adhesion molecule 1 (VCAM-1) is expressed by chondrocytes and synovial tissue and was a predictive marker for development of severe large joint OA in a previous study. OBJECTIVE: It was tested whether increased serum levels of VCAM-1 are prevalent in patients with severe OA of the hips. METHODS: In this prospective, multicenter, cross-sectional study, risk factors of severe hip OA were investigated in patients scheduled for hip joint arthroplasty and 100 patients were randomly selected for validation of VCAM-1 as a potential biomarker for hip OA. Serum samples were analyzed by an enzyme-linked immunosorbent assay and compared with a sex and age-matched control cohort. RESULTS: The groups were similar in age, gender ratio and prevalence of diabetes. Serum concentrations of VCAM-1 were 8% higher in OA patients compared to controls, without reaching statistical significance (818 ng ml-1, 95% confidence interval, CI 746-891 ng ml-1 versus 759 ng m-1, 95% CI 711-807 ng ml-1; P = 0.4839). CONCLUSION: The results of this study show that serum concentrations of VCAM-1 cannot distinguish patients with severe hip OA from age and sex-matched controls.

HFE hemochromatosis screening in patients with severe hip osteoarthritis: A prospective cross-sectional study.

OBJECTIVE: Despite the high frequency of HFE gene mutations in Western Europe, widespread screening for HFE hemochromatosis is not recommended due to its variable phenotype. Joint pain and a premature osteoarthritis-like disease including the hip joints are the most frequent manifestation in patients with HFE hemochromatosis and iron overload. Therefore, screening of patients with severe osteoarthritis of the hip could identify patients with HFE hemochromatosis. METHODS: In this prospective cross-sectional study, 940 patients aged <70 years with end-stage osteoarthritis of the hip undergoing elective joint replacement surgery were screened for HFE hemochromatosis and compared to age- and sex-matched controls. RESULTS: No greater prevalence of C282Y homozygosity mutation or elevated serum ferritin or transferrin saturation levels was found in the study cohort with severe osteoarthritis of the hip than in controls from the general population. CONCLUSION: Our screening approach could not identify an increased prevalence of HFE gene mutations and iron overload in younger patients with severe osteoarthritis of the hip.

Anatomic Double-Bundle Reinsertion After Acute Proximal Anterior Cruciate Ligament Injury Using Knotless PushLock Anchors.

Direct anterior cruciate ligament (ACL) repair has been described with different suture techniques after acute ACL injury, but these procedures showed high failure rates. Recent studies, however, led to a better understanding of the biology of primary ACL healing. This article describes a novel technique combining the "healing response technique" with primary anatomic double-bundle ACL reinsertion after an acute proximal ACL tear using nonabsorbable No. 2 FiberWire (Arthrex, Naples, FL) and PushLock knotless suture anchors (Arthrex). We recommend this technique for patients with acute proximal avulsion-type ACL injuries. Postoperatively, we recommend a knee brace locked in full extension for at least 4 weeks to ensure adequate immobilization and then to increase knee flexion slowly over the next 4 weeks for subsequent healing of the ACL repair. Our technique combines anatomic positioning and reinsertion of the ACL bundles with microfracturing of the region delivering stem cells and growth factors to the repaired ACL, creating optimal conditions for the healing period. In certain cases this technique might be an alternative to conventional ACL reconstruction with autograft or allograft tendons.

Distinction between supraspinatus, infraspinatus and subscapularis tendon tears with ultrasound in 332 surgically confirmed cases.

The aim of this retrospective study was to determine the diagnostic value of preoperative ultrasonography for the characterisation of size and location of the involved tendons. in 332 consecutive patients who underwent surgery, all preoperative ultrasonographic reports were reviewed and ultrasound (US) and surgical findings were compared. Ultrasound criteria for cuff tears were complete nonvisualisation of the cuff tendons or localised absence and focal discontinuity. In all but 12 cases, US diagnoses corresponded with intraoperative findings (sensitivity 98%, confidence interval 95.1-99.3; specificity 93%, CI 85.7-97.1; accuracy 97%, CI 93.8-98.1). Size and location of the tear were correctly predicted in 69 of 96 cases (accuracy 87%, sensitivity 89%, specificity 87%). US demonstrated less extensive tears than observed at surgery in 18%. Ultrasonography was highly accurate and sensitive for detecting rotator cuff tears, but seems to be a method of limited value for evaluation of the size of cuff tears, in particular, for the detection of small tears.

[Prevention of venous thromboembolism in musculoskeletal surgery]. / Thromboseprophylaxe in der muskuloskelettalen Chirurgie.

Musculoskeletal surgery is associated with a high risk of venous thrombosis and pulmonary embolism. The introduction of direct oral anticoagulants (DOAK) has broadened the possibilities for prevention of venous thromboembolism in the course of orthopedic and trauma surgery. Addressing this recent development, the Austrian Societies of Orthopedics and Orthopedic Surgery (ÖGO), Trauma Surgery (ÖGU), Hematology and Oncology (OeGHO) and of Anaesthesiology, Reanimation und Intensive Care Medicine (ÖGARI) have taken the initiative to create Austrian guidelines for the prevention of thromboembolism after total hip and knee replacement, hip fracture surgery, interventions at the spine and cases of minor orthopedic and traumatic surgery. Furthermore, the pharmacology of the DOAK and the pivotal trial data for each of the three currently available substances - apixaban, dabigatran, and rivaroxaban - are briefly presented. Separate chapters are dedicated to "anticoagulation and neuroaxial anesthesia" and "bridging".

Outcome assessment of hemiarthroplasty of the shoulder: a 5-year follow-up with 4 evaluation tools.

BACKGROUND: Outcome measurement of shoulder arthroplasty is not standardized. We compared 3 scores and 1 evaluation form. PATIENTS AND METHODS: We report on 35 hemiarthroplasties of the shoulder (32 cementless). Mean age of the patients was 62 (29-87) years. After a mean follow-up of 6 years (range 2-18 years) patients were evaluated with the Neer score, the Constant-Murley score, the score of the University of California in Los Angeles (UCLA) and the Society of Shoulder and Elbow Surgeons Basic Shoulder Evaluation Form. We also performed radiographic evaluation and sonographic evaluation of the rotator cuff. RESULTS: Although pain relief and patient satisfaction were promising, the overall results of the respective score showed low values (Neer score 56/100 points, Constant-Murley score 43/100 points, and UCLA score 19/35 points on average). INTERPRETATION: We recommend choice of a score with a high impact of pain and patient satisfaction. Furthermore, ability to cope with activities of daily living should be of more importance than strength.

Comparison of MRI and conventional radiography for assessment of acromial shape.

OBJECTIVE: Our aim was to determine the value of different MRI planes independently and in combination for assessment of acromial shape. MATERIALS AND METHODS: Sixty-one patients with subacromial impingement syndrome who had undergone acromioplasty after failure to respond to conservative treatment were included in the study. Parasagittal T2-weighted MR images and outlet view radiographs of the affected shoulders were acquired preoperatively. Three-dimensional models of all acromions were constructed from the MR images, and the Bigliani type of acromion depicted by these models was determined. Results were compared with the acromial type assessed during acromioplasty. To provide a reliable reference for further processing and correlation, we used only those 56 acromions with agreement on acromial shape between intraoperative findings and 3D models. Then, acromial shape was determined for three MRI slice positions (S-1, lateral acromial edge; S-2, just lateral of acromioclavicular joint; and S-3, lateral portion of acromioclavicular joint), for a combination of S-1 and S-2, and for the radiographs. RESULTS: Kappa coefficients were 0.36 (36%) for S-1, 0.41 (41%) for S-2, and -0.10 (-10%) for S-3. For the outlet view radiographs, the kappa coefficient was 0.55 (55%), showing better correlation than any single slice position. Best results, however, were achieved with a combination of S-1 and S-2, with a kappa coefficient of 0.66 (66%). CONCLUSION: For determination of acromial shape, outlet view radiographs are superior to any single MRI slice position, but inferior to a combination of two MRI slices (S-1 and S-2). If a single MRI slice is being used, the slice position just lateral to the acromioclavicular joint is recommended.

Suprascapular nerve entrapment. A meta-analysis.

We performed a review of the literature between 1959 and 2001. We found 88 cases of suprascapular nerve entrapment, which fulfilled our inclusion criteria. Suprascapular nerve entrapment is rare and mainly occurs in patients under 40 years of age. Males are more likely to suffer from a ganglion compressing the nerve than females. If the patient's history reveals a trauma, it is more likely that the ligament is compromising the nerve. Ganglions usually cause isolated infraspinatus atrophy, whereas a combined atrophy of the supra- and infraspinatus muscles is more common in cases in which the nerve is compressed by the ligament.

The German version of the Oxford Shoulder Score--cross-cultural adaptation and validation.

INTRODUCTION: The evaluation of health-related quality of life is an established criterion for the evaluation of therapeutic measurement. Especially in the English language, a great number of different questionnaires have been developed. The original, English-language 12-item Oxford shoulder score (OSS) is a recently developed and validated patient-completed outcome measure specifically designed for the evaluation of patients suffering from shoulder pathology other than instability. Because of the lack of a comparable instrument in German, this questionnaire was translated into German and subsequently tested for validity and reliability in a cross-sectional study. MATERIAL AND METHODS: Translation of the OSS was done according to the guidelines in the literature. One hundred two patients completed the German version of the OSS and the SF-36. Additionally, the Constant shoulder score and the UCLA shoulder score were included into the validation process. The psychometric properties feasibility and patient-burden parameters were also tested. RESULTS: The patients completed all questionnaires. The mean time required for completing the OSS was 3 min, 25 s; the mean time required for evaluation of the questionnaire was 35 s. The internal consistency tested by the Cronbach's alpha (0.94) was high. The reproducibility tested by two different methods showed no significant difference. The construct validity showed a significant correlation between the OSS and the other scores. CONCLUSION: The instrument proved to be valid by demonstrating the same correlations predicted by standard clinical assessments and a generic patient-based instrument. Application and evaluation in clinical trial proved feasible and minimally time consuming. Therefore, the German translation of the Oxford shoulder score is a valid and reliable tool, applicable to outcome studies on shoulder patients.