Distal Biceps Tendon Repair Using a Double Intracortical Button Anatomical Footprint Repair Technique.

INTRODUCTION: Distal biceps tendon repair is usually performed via a double-incision or single-incision bicortical drilling technique. However, these techniques are associated with specific complications and usually do not allow for anatomical footprint restoration. It was the aim of this study to report the clinical results of a double intracortical button anatomical footprint repair technique for distal biceps tendon tears. We hypothesized that this technique would result in supination strength comparable to the uninjured side with a low re-rupture rate and minimal bony or neurological complications. MATERIAL AND METHODS: This was a retrospective, single-surgeon cohort study of a consecutive series of 22 patients with a mean (SD) age of 50.7 (9.4) years and at least 1-year follow-up after distal biceps tendon repair. At final follow-up, complications, range of motion (ROM), the Patient-rated Elbow Evaluation (PREE), Mayo Elbow Performance Score (MEPS), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, visual analog scale (VAS) for pain, patient satisfaction and supination strength in neutral as well as 60° of supination were analyzed. Radiographic evaluation was performed on a CT scan. RESULTS: One patient (4.5%) experienced slight paresthesia in the area of the lateral antebrachial cutaneous nerve. Heterotopic ossification was seen in one patient (4.5%). All patients recovered full ROM except for one who had 10° of loss of flexion and extension. Median PREE score was 4.6 (0-39.6), median MEP was 100 (70-100) and median DASH was 1.4 (0-16.7). All but one patient were very satisfied with the outcome. The affected arm had a mean of 98% (± 13) of neutral supination strength (p=0.633) and 94% (± 12) of supination strength in 60° (p=0.054) compared to the contralateral, unaffected side. There were four cases (18.2%) of cortical thinning due to at least one button and one case of button pull-out (4.5%). CONCLUSIONS: The double intracortical button anatomical footprint repair technique seems to provide reliable restoration of supination strength, excellent patient satisfaction while minimizing complications, particularly nerve damage and heterotopic ossification.

The influence of rotator cuff tear type and weight bearing on shoulder biomechanics in an ex vivo simulator experiment.

Glenohumeral biomechanics after rotator cuff (RC) tears have not been fully elucidated. This study aimed to investigate the muscle compensatory mechanism in weight-bearing shoulders with RC tears and asses the induced pathomechanics (i.e., glenohumeral translation, joint instability, center of force (CoF), joint reaction force). An experimental, glenohumeral simulator with muscle-mimicking cable system was used to simulate 30° scaption motion. Eight fresh-frozen shoulders were prepared and mounted in the simulator. Specimen-specific scapular anthropometry was used to test six RC tear types, with intact RC serving as the control, and three weight-bearing loads, with the non-weight-bearing condition serving as the control. Glenohumeral translation was calculated using instantaneous helical axis. CoF, muscle forces, and joint reaction forces were measured using force sensors integrated into the simulator. Linear mixed effects models (RC tear type and weight-bearing) with random effects (specimen and sex) were used to assess differences in glenohumeral biomechanics. RC tears did not change the glenohumeral translation (p > 0.05) but shifted the CoF superiorly (p ≤ 0.005). Glenohumeral translation and joint reaction forces increased with increasing weight bearing (p < 0.001). RC and deltoid muscle forces increased with the presence of RC tears (p ≤ 0.046) and increased weight bearing (p ≤ 0.042). The synergistic muscles compensated for the torn RC tendons, and the glenohumeral translation remained comparable to that for the intact RC tendons. However, in RC tears, the more superior CoF was close to where glenoid erosion occurs in RC tear patients with secondary osteoarthritis. These findings underscore the importance of early detection and precise management of RC tears.

Current Evidence Regarding Shoulder Instability in the Paediatric and Adolescent Population.

Paediatric and adolescent shoulder instability is caused by a unique combination of traumatic factors, ligamentous laxity, and pattern of muscle contractility. The multifactorial nature of its aetiology makes interpretation of the literature difficult as nomenclature is also highly variable. The purpose of this review is to summarize the existing literature and shed light on the nuances of paediatric and adolescent shoulder instability. The epidemiology, clinical features, imaging, and management of all forms of paediatric shoulder instability are presented. The main findings of this review are that structural abnormalities following a dislocation are uncommon in pre-pubertal paediatric patients. Young post-pubertal adolescents are at the highest risk of failure of non-operative management in the setting of traumatic instability with structural abnormality, and early stabilisation should be considered for these patients. Remplissage and the Latarjet procedure are safe treatment options for adolescents at high risk of recurrence, but the side-effect profile should be carefully considered. Patients who suffer from instability due to generalized ligamentous laxity benefit from a structured, long-term physiotherapy regimen, with surgery in the form of arthroscopic plication as a viable last resort. Those who suffer from a predominantly muscle patterning pathology do not benefit from surgery and require focus on regaining neuromuscular control.

Test-retest reliability of isometric shoulder muscle strength during abduction and rotation tasks measured using the Biodex dynamometer.

BACKGROUND: The Constant score (CS) is often used clinically to assess shoulder function and includes a muscle strength assessment only for abduction. The aim of this study was to evaluate the test-retest reliability of isometric shoulder muscle strength during various positions of abduction and rotation with the Biodex dynamometer and to determine their correlation with the strength assessment of the CS. METHODS: Ten young healthy subjects participated in this study. Isometric shoulder muscle strength was measured during 3 repetitions for abduction at 10° and 30° abduction in the scapular plane (with extended elbow and hand in neutral position) and for internal and external rotation (with the arm at 15° abduction in the scapular plane and elbow flexed at 90°). Muscle strength tests with the Biodex dynamometer were measured in 2 different sessions. The CS was acquired only in the first session. Intraclass correlation coefficients (ICCs) with 95% confidence interval, limits of agreement, and paired t tests for repeated tests of each abduction and rotation task were calculated. Pearson's correlation between the strength parameter of the CS and isometric muscle strength was investigated. RESULTS: Muscle strength did not differ between tests (P > .05) with good to very good reliabilities for abduction at 10° and 30°, external rotation and internal rotation (ICC >0.7 for all). A moderate correlation of the strength parameter of the CS with all isometric shoulder strength parameters was observed (r > 0.5 for all). CONCLUSION: Shoulder muscle strength for abduction and rotation measured with the Biodex dynamometer are reproducible and correlate with the strength assessment of the CS. Therefore, these isometric muscle strength tests can be further employed to investigate the effect of different shoulder joint pathology on muscle strength. These measurements consider a more comprehensive functionality of the rotator cuff than the single strength evaluation in abduction within the CS as both abduction and rotation are assessed. Potentially, this would allow for a more precise differentiation between the various outcomes of rotator cuff tears.

Current Understanding and New Advances in the Surgical Management of Reparable Rotator Cuff Tears: A Scoping Review.

Rotator cuff (RC) tears are among the most common musculoskeletal disorders and can be associated with pain, weakness, and shoulder dysfunction. In recent years, there have been significant advances with regard to the understanding of rotator cuff disease and its management. With technological improvements and advanced diagnostic modalities, there has been much progress as to improved understanding of the pathology. Similarly, with advanced implant designs and instrumentation, operative techniques have evolved. Furthermore, refinements in postoperative rehabilitation protocols have improved patient outcomes. In this scoping review, we aim to provide an overview of the current knowledge on the treatment of rotator cuff disorders and to highlight recent advances in its management.

Load-Induced Glenohumeral Translation After Rotator Cuff Tears: Protocol for an In Vivo Study.

BACKGROUND: Rotator cuff tears are a common shoulder injury, but they sometimes remain undiagnosed, as symptoms can be limited. Altered shoulder biomechanics can lead to secondary damage and degeneration. In biomechanical analyses, the shoulder (ie, the glenohumeral joint) is normally idealized as a ball-and-socket joint, even though a translation is often observed clinically. To date, no conclusive changes in glenohumeral translation have been reported in patients with rotator cuff tears, and it is unknown how an additional handheld weight that is comparable to those used during daily activities will affect glenohumeral translations in patients with rotator cuff tears. OBJECTIVE: This study aims to assess the load-induced glenohumeral translation (liTr) in patients with rotator cuff tears and its association with the load-induced changes in muscle activation (liMA). METHODS: Patients and asymptomatic controls will be recruited. Participants will fill out health questionnaires and perform 30° arm abduction and adduction trials, during which they will hold different handheld weights of a maximum of 4 kg while motion capture and electromyographic data are collected. In addition, fluoroscopic images of the shoulders will be taken for the same movements. Isometric shoulder muscle strength for abduction and rotation will be assessed with a dynamometer. Finally, shoulder magnetic resonance images will be acquired to assess muscle status and injury presence. The dose-response relationship between additional weight, liTr, and liMA will be evaluated. RESULTS: Recruitment and data collection began in May 2021, and they will last until the recruitment target is achieved. Data collection is expected to be completed by the end of 2022. As of November 2022, data processing and analysis are in progress, and the first results are expected to be submitted for publication in 2023. CONCLUSIONS: This study will aid our understanding of biological variations in liTr, the influence of disease pathology on liTr, the potential compensation of rotator cuff tears by muscle activation and size, and the association between liTr and patient outcomes. The outcomes will be relevant for diagnosis, treatment, and rehabilitation planning in patients with rotator cuff tears. TRIAL REGISTRATION: ClinicalTrials.gov NCT04819724; https://clinicaltrials.gov/ct2/show/NCT04819724. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/43769.

Reliability of the Fluoroscopic Assessment of Load-Induced Glenohumeral Translation during a 30° Shoulder Abduction Test.

Rotator cuff tears are often linked to superior translational instability, but a thorough understanding of glenohumeral motion is lacking. This study aimed to assess the reliability of fluoroscopically measured glenohumeral translation during a shoulder abduction test. Ten patients with rotator cuff tears participated in this study. Fluoroscopic images were acquired during 30° abduction and adduction in the scapular plane with and without handheld weights of 2 kg and 4 kg. Images were labelled by two raters, and inferior-superior glenohumeral translation was calculated. During abduction, glenohumeral translation (mean (standard deviation)) ranged from 3.3 (2.2) mm for 0 kg to 4.1 (1.8) mm for 4 kg, and from 2.3 (1.5) mm for 0 kg to 3.8 (2.2) mm for 4 kg for the asymptomatic and symptomatic sides, respectively. For the translation range, moderate to good interrater (intra-class correlation coefficient ICC [95% confidence interval (CI)]; abduction: 0.803 [0.691; 0.877]; adduction: 0.705 [0.551; 0.813]) and intrarater reliabilities (ICC [95% CI]; abduction: 0.817 [0.712; 0.887]; adduction: 0.688 [0.529; 0.801]) were found. Differences in the translation range between the repeated measurements were not statistically significant (mean difference, interrater: abduction, -0.1 mm, p = 0.686; adduction, -0.1 mm, p = 0.466; intrarater: abduction 0.0 mm, p = 0.888; adduction, 0.2 mm, p = 0.275). This method is suitable for measuring inferior-superior glenohumeral translation in the scapular plane.

Prospective multicentre mid-term clinical and radiological outcomes of 159 reverse total shoulder replacements and assessment of the influence of post-operative complications.

Background: The aim of our prospective multicentre study is to evaluate the five-year follow-up outcomes of primary reverse shoulder replacement utilizing two different designs of glenoid baseplates. Methods: There were 159 reverse shoulder replacements (91 cemented and 68 uncemented stems, 67 Trabecular Metal baseplates and 92 Anatomical Shoulder baseplates in 152 patients (99 women) with a mean age of 74.5 (58-90) years. The principal diagnosis was rotator cuff arthropathy in 108 shoulders. Results: Clinical and functional results improved significantly overall; the adjusted Constant Murley score improved from 28.2 ± 13.3 pre-operatively to 75.5 ± 22.8 (p < 0.0001) and the mean Subjective Shoulder Value improved from 27.5 ± 20 to 73.8 ± 21.3 points (p < 0.0001). Radiologically, there was good bony stability in 88% and 86% of cemented and uncemented stems without significant impact on the Constant Murley score and Subjective Shoulder Value at one, two and five years post-surgery. There were no significant clinical differences between Trabecular Metal and Anatomical Shoulder baseplates at five years. There were four cases of intraoperative shaft fractures that were managed with cables. Although the Trabecular Metal baseplates showed better integration radiologically, there was no significant difference in the mean of Constant Murley, Subjective Shoulder Value and the range of motion depending on the grade of inferior scapular notching at one-, two- and five-year intervals. Conclusions: Reverse total shoulder arthroplasty restores the function in shoulder with significant improvements in function and moderate complications with minor differences between both designs of baseplates that were not reflected clinically.

Risk factor analysis for above-knee amputation in patients with periprosthetic joint infection of the knee: a case-control study.

BACKGROUND: Periprosthetic joint infection (PJI) is a severe complication following knee arthroplasty. Therapeutic strategies comprise a combination of surgical and antibiotic treatment modalities and aim to eradicate the infection. Sometimes control of the disease can only be attained by above-knee amputation (AKA). While a vast amount of literature exists illuminating predisposing factors for PJI, risk factors favoring the endpoint AKA in this context are sparsely known. METHODS: The purpose of this investigation was to delineate whether patients with PJI of the knee present specific risk factors for AKA. In a retrospective case-control study 11 cases of PJI treated with AKA were compared to 57 cases treated with limb salvage (LS). The minimum follow-up was 2 years. Comorbidities, signs and symptoms of the current infection, factors related to previous surgeries and the implant, microbiology, as well as therapy related factors were recorded. Comparative analysis was performed using student's t-test, chi-square test or Fisher's exact test. Binary differences were calculated using odds ratio (OR). Reoperation frequency was compared using Mann-Whitney U test. In-depth descriptive analysis of 11 amputees was carried out. RESULTS: A total of 68 cases aged 71 ± 11.2 years were examined, 11 of which underwent AKA and 57 had LS. Severe comorbidities (p = 0.009), alcohol abuse (p = 0.015), and preoperative anemia (p = 0.022) were more frequently associated with AKA. Preoperative anemia was found in all 11 amputees (100%) and in 33 of 57 LS patients (58%) with an average preoperative hemoglobin of 99.9 ± 15.1 g/dl compared to 118.2 ± 19.9 g/dl (p = 0.011). No other parameters differed significantly. AKA patients underwent a median of eight (range 2-24) reoperations, LS patients a median of five (range 2-15). CONCLUSION: Factors potentially influencing the outcome of knee PJI are diverse. The indication of AKA in this context remains a rarity and a case-by-case decision. Patient-intrinsic systemic factors such as alcohol abuse, severe comorbidities and preoperative anemia may elevate the individual risk for AKA in the setting of PJI. We recommend that anemia, being a condition well amenable to therapeutic measures, should be given special consideration in management of PJI patients. TRIAL REGISTRATION: This study was registered with Kantonale Ethikkommission Zürich, (BASEC-No. 2016-01048).

Small anteroposterior inclination of the acromion is a predictor for posterior glenohumeral erosion (B2 or C).

BACKGROUND: Anatomic factors associated with static posterior translation of the humeral head with or without glenohumeral osteoarthritis are unknown. We tested the hypothesis that there is an association between glenoid wear, glenoid version, and/or anteroposterior acromial tilt. METHODS: Ninety-nine patients with glenohumeral joint degeneration involving advanced glenoid cartilage wear and/or rotator cuff disease scheduled for anatomic or reverse total shoulder replacement underwent standardized conventional radiographic and computed tomographic shoulder imaging. Measurements included glenoid version, humeral torsion, posterior acromial slope, and critical shoulder angle. The glenoid shape was classified according to Walch et al, and the integrity of the rotator cuff was assessed. RESULTS: Patients with glenoid type B2 or C had a median of 4° more glenoid retroversion (P = .022), a 5° less steep acromion (posterior acromial slope, 61° vs 56°; P = .004), and a higher combined score (glenoid version minus slope; odds ratio, 0.93 [95% confidence interval, 0.89-0.97]; P < .001; cutoff, -27°) than those with type A or B1. When the rotator cuff was torn, osteoarthritic changes were milder than when the cuff was intact (eg, P < .001 for supraspinatus). CONCLUSION: The study's hypothesis that the bony anatomy of the scapula and in particular the acromion is correlated with the type of glenoid wear was confirmed. Both a more horizontal acromial orientation in the sagittal plane and increased posterior glenoid version are found in osteoarthritis of the shoulder associated with eccentric, posterior glenoid wear. Tears of the rotator cuff are significantly associated with concentric osteoarthritis of the glenoid.

Total knee arthroplasty in patients with a history of illicit intravenous drug abuse.

PURPOSE: Injection drug users are at high risk for both infection with blood-borne pathogens, namely, human immune deficiency virus (HIV), hepatitis-B, -C virus, various bacterial infections, as well as early primary and secondary joint degeneration. When total knee arthroplasty (TKA) is anticipated the risk of septic complications is a major concern. The purpose of this study was to assess the clinical and radiographic outcome of patients with a history of intravenous drug use after total knee arthroplasty. The primary outcome was revision rate. Secondary outcomes were the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Knee Society Score (KSS) and radiographic loosening. METHODS: We retrospectively reviewed the records of 1,692 TKA performed or revised in our institution. Data of 18 TKA in 12 patients (11 male, 1 female; average age 42, range 23-62 years) with a history of intravenous opioid abuse were available for final analysis. RESULTS: The mean follow up was 125 (range 25-238) months. Seven patients required revision surgery due to periprosthetic joint infection after 62 months (range 5-159): one two staged revision, three arthrodesis and three amputations. The median prosthesis survival was 101 (95%-CI 48-154) months. CONCLUSION: Total knee arthroplasty in patients with a history of intravenous drug abuse is associated with major complications, including above-the-knee amputation. If permanent abstinence from intravenous drug abuse is doubtful, other therapeutic options including primary arthrodesis should be considered.