Assessment of arthrogenic quadriceps muscle inhibition by physical examination in the supine position during isometric contraction is feasible as demonstrated by electromyography: a cross-sectional study.

BACKGROUND: Preventing severe arthrogenic muscle inhibition (AMI) after knee injury is critical for better prognosis. The novel Sonnery-Cottet classification of AMI enables the evaluation of AMI severity but requires validation. This study aimed to investigate the electromyography (EMG) patterns of leg muscles in the examination position from the classification during isometric contraction to confirm its validity. We hypothesised that the AMI pattern, which is characterised by quadriceps inhibition and hamstring hypercontraction, would be detectable in the supine position during isometric contraction. METHODS: Patients with meniscal or knee ligament injuries were enrolled between August 2023 and May 2024. Surface EMG was assessed during submaximal voluntary isometric contractions (sMVIC) at 0° extension in the supine position for the vastus medialis (VM) and vastus lateralis (VL) muscles and at 20° flexion in the prone position for the semitendinosus (ST) and biceps femoris (BF) muscles. Reference values for normalisation were obtained from the EMG activity during the gait of the uninjured leg. The Kruskal-Wallis test was used to compare the activation patterns of the muscle groups within the same leg, and the post-hoc tests were conducted using the Mann-Whitney U test and Bonferroni correction. RESULTS: Electromyographic data of 40 patients with knee injuries were analyzed. During sMVIC, the extensor and flexor muscles of the injured leg showed distinct behaviours (P < 0.001), whereas the uninjured side did not (P = 0.144). In the injured leg, the VM differed significantly from the ST (P = 0.018), and the VL differed significantly from the ST and BF (P = 0.001 and P = 0.026, respectively). However, there were no statistically significant differences within the extensor muscle groups (VM and VL, P = 0.487) or flexor muscle groups (ST and BF, P = 0.377). CONCLUSION: AMI was detectable in the examination position suggested by the Sonnery-Cottet classification. The flexor and extensor muscles of the injured leg exhibited distinct activation behaviours, with inhibition predominantly occurring in the quadriceps muscles, whereas the hamstrings showed excitation.

Sensory Neuropraxia After Distal Biceps Repair is Not Associated With Patient-Reported Outcomes or Satisfaction: A Retrospective Cohort Study.

BACKGROUND: Cutaneous neuropraxia is the most common complication following distal biceps tendon repair (DBTR). Currently, no patient demographic factors have been implicated in its occurrence, course, or resolution. The purpose of this study is to explore various patient demographics and their association with postoperative neuropraxia. Further it investigates how mental health scores correlate with patient-reported outcomes, and whether occurrence of neuropraxia alters this association. METHODS: This retrospective review evaluates a consecutive series of patients who underwent distal biceps repair with a single-incision cortical button technique. Patients with reported outcome data at a minimum of 1 year (n = 47) were included for analysis. Demographic data including age, sex, body mass index (BMI), diabetes, smoking status, and occurrence of neuropraxia were recorded. Patient-reported outcome measures (PROMs) include the American Shoulder and Elbow Surgeons-Elbow (ASES-E) score, Single Assessment Numeric Evaluation (SANE) score, Visual Analog Scale (VAS) for pain, Disabilities of the Arm, Shoulder, and Hand Score (QuickDASH), and Veterans RAND 12 (VR-12) Mental Component Score (MCS) and Physical Component Score (PCS) quality-of-life assessment. RESULTS: Postoperative neuropraxia of any duration occurred in 45% (21/47) of patients in this cohort following DBTR. Of these, 62% (13/21) reported resolution of symptoms by the latest follow-up. Mean time to resolution of neuropraxia was 148 days. Patient age, BMI, smoking history, time to surgery, tear thickness, and increasing surgeon experience across the study period were not significantly associated with the incidence or time to resolution of postoperative neuropraxia. Scores for patient satisfaction, VAS, ASES, QuickDASH, SANE, VR-12 MCS, VR-12 PCS, and flexion ROM did not differ significantly between patients with and without postoperative neuropraxia. CONCLUSION: Patient satisfaction following DBTR was not significantly associated with postoperative neuropraxia. Patient and surgical characteristics did not influence the occurrence or time to resolution of neuropraxia. The occurrence of postoperative neuropraxia did not result in significant functional limitations.

Arthroscopic suprapectoral biceps tenodesis utilizing the subacromial locking stitch anchor (SALSA) technique.

Biceps tenodesis is an accepted treatment option for various pathologies of the long head of the biceps tendon and labrum. Many techniques have been published, both arthroscopic and open, that utilize various fixation techniques and locations of the tenodesis, yet none has been proven to be superior. We introduce a novel method, the SALSA (subacromial locking stitch anchor), an all-arthroscopic suprapectoral biceps tenodesis utilizing a running locking stitch from a double-loaded biocomposite anchor. This technique provides a reliable method of multipoint fixation including the transverse humeral ligament that avoids many of the potential complications encountered with other techniques.

Hamstrings on focus: Are 72 hours sufficient for recovery after a football (soccer) match? A multidisciplinary approach based on hamstring injury risk factors and histology.

This study aimed to assess acute and residual changes in sprint-related hamstring injury (HSI) risk factors after a football (soccer) match, focusing on recovery within the commonly observed 72-h timeframe between elite football matches. We used a multifactorial approach within a football context, incorporating optical and ultrastructural microscopic analysis of BFlh (biceps femoris long head) muscle fibres, along with an examination of BFlh fibre composition. Changes in sprint performance-related factors and HSI modifiable risk factors were examined until 3 days after the match (MD +3) in 20 football players. BFlh biopsy specimens were obtained before and at MD +3 in 10 players. The findings indicated that at MD +3, sprint-related performance and HSI risk factors had not fully recovered, with notable increases in localized BFlh fibre disruptions. Interestingly, match load (both external and internal) did not correlate with changes in sprint performance or HSI risk factors nor with BFlh fibre disruption. Furthermore, our study revealed a balanced distribution of ATPase-based fibre types in BFlh, with type-II fibres associated with sprint performance. Overall, the results suggest that a 72-h recovery period may not be adequate for hamstring muscles in terms of both HSI risk factors and BFlh fibre structure following a football match.

Long Head of the Biceps Tendon Plays a Role in Stress Absorption and Humeral Head Restriction during the Late Cocking and Deceleration Phases of Overhead Throwing: A Finite Element Study.

BACKGROUND: Emerging evidence suggests that the long head of the biceps (LHBT) may play a role in stabilizing the glenohumeral joint, and this has led to controversy around the efficacy of biceps tenotomy for superior labral anterior and posterior (SLAP) lesions. Therefore, the aim of this finite element analysis (FEA) study was to determine the stress absorption and humeral head translation restriction effects of the LHBT within the glenohumeral joint during the late cocking and deceleration phases of overhead throwing with a view to resolving the controversy around tenotomy. METHODS: Eight FEA models were created using computed tomography and magnetic resonance imaging data from normal glenohumeral joints. The models represented four LHBT conditions: uninjured, subpectoral tenodesis, tenotomy, and type II SLAP lesions. The late cocking and deceleration phases of the overhead throwing were simulated for each model. The impacts of the four LHBT conditions on glenohumeral joint stress absorption and humeral head displacement restriction were studied based on 1) stress and related distributions on the cartilage, labrum, capsule, and LHBT and 2) humeral head translation variation. RESULTS: The FEA analysis showed that the magnitude of the contact stress on the articular cartilage, labrum, and capsule was the lowest in the uninjured models, followed by the subpectoral tenodesis, tenotomy, and type II SLAP lesion models. Humeral head translation was the most restricted in the subpectoral tenodesis models, followed by the tenotomy and type II SLAP lesion models. CONCLUSION: Finite element analysis demonstrated that the LHBT plays a significant role in stress absorption and displacement restriction in the late cocking and deceleration phases of overhead throwing. Subpectoral tenodesis of the LHBT exhibited lesser amount of stress and humeral head translation than those of tenotomy, thereby making it a better option for patients who engage in overhead throwing.

Superior Capsular Reconstruction using the Long Head of Biceps Tendon: A Biomechanical Assessment of Tenodesis Location and Angle of Fixation.

BACKGROUND: Massive irreparable rotator cuff tears (MIRCT) treated with superior capsular reconstruction (SCR) using the long head of the biceps tendon have shown satisfactory early results. Different techniques and positions for biceps tenodesis have been described. This study aimed to evaluate the effect of tenodesis location and glenohumeral fixation angle for graft tensioning on the biomechanics of a SCR using a single strand biceps technique. METHODS: Eight cadaveric shoulders were mounted to a custom biomechanical simulator which employed static tone loads to the deltoid and rotator cuff muscles. All cadavers were first tested in the intact condition, and then in the simulated MIRCT condition by sectioning the tendinous insertions of the supraspinatus and upper border of the infraspinatus. SCR using the long head of the biceps tendon was then evaluated. Three biceps tenodesis locations relative to the greater tuberosity (anterior, middle, and posterior) and two glenohumeral fixation angles (0° and 30°) for graft tensioning were tested. An optical tracking system was used to quantify superior-inferior (SI) and anterior-posterior (AP) humeral head translation relative to the glenoid, while the functional abduction force was quantified using a load sensor. All tests were conducted at 0°, 30° and 60° of glenohumeral abduction in a randomized fashion. RESULTS: When assessing isolated superior humeral head migration, all biceps tenodesis locations were effective at decreasing superior migration, with no tenodesis location significantly better than the other (P=0.213). However, biceps grafts tensioned at 30° of glenohumeral abduction were significantly better at reducing proximal humeral migration as compared to graft tensioning at 0° abduction (P=0.008). Posterior humeral head translation observed in the MIRCT condition was significantly reduced when tensioning the biceps tendon at 30° of glenohumeral abduction compared to 0° for all tenodesis locations (P≤0.043). Tenodesis location also significantly influenced posterior humeral head translation (P=0.001), with middle and posterior positions restoring near normal humeral head position when fixed at 30° glenohumeral abduction. All SCR techniques using the biceps tendon improved the functional abduction force relative to the MIRCT condition, although no statistically significant differences were observed relative to the intact condition (P≥0.448). DISCUSSION: SCR using the long head biceps tendon is biomechanically effective in reducing posterosuperior translation of the humeral head in the setting of a MIRCT. Graft tensioning and fixation at 30° of glenohumeral abduction combined with either a middle or posterior tenodesis location on the greater tuberosity most effectively restores near normal time-zero humeral head kinematics.

Effect of verjuice (Vitis vinifera L.) on physicochemical and textural properties of beef M. biceps femoris.

The objective of this study was to investigate the effect of verjuice on beef M. biceps femoris (BF). BF blocks were marinated with 30%, 70%, and 100% verjuice solutions containing 2% NaCl, for different marination times (12, 24, 48, and 72 h). Verjuice marination reduced the pH values of BF samples from 6.77 in control sample to 3.66 in 100% of verjuice for 72 h. The decreased values of water holding capacity (from 54.06% to 47.46%) with increasing verjuice concentration (from 30% to 100% for 72 h) confirmed the drop of proteins isoelectric point of the muscle due to salt presence preventing fibers swelling. Less cookout was observed with increasing acid concentration. Marination time had no significant effect on L* and a* coordinates of uncooked samples while acidification made the samples lighter and less red. Enzymatic proteolysis of myosin and troponin-T concomitant with increase in myofibrillar fragmentation index contributed to the decrease of shear force in a way dependent on verjuice concentration and marination time. Sensory panelists gave the highest score to cooked samples marinated with 70% verjuice solution.

Long-term patient-reported outcomes of open subpectoral biceps tenodesis with cortical button fixation.

BACKGROUND: Open subpectoral biceps tenodesis (OSBT) with cortical button fixation has been shown to deliver acceptable results in the short and intermediate term for long head of the biceps (LHB) pathology with the benefit of smaller bone tunnel diameter and a reduced risk of postoperative humeral shaft fracture. The primary purpose of this study was to determine whether OSBT with cortical button fixation results in significant improvements in patient reported outcomes (PROs) from pre-operative to long-term final follow-up. METHODS: A retrospective analysis of patients who underwent OSBT with cortical button fixation at a single institution between the years of 2012 and 2014 was conducted and PROs were collected in the intermediate (> 2 years follow-up) and long term (> 9 years follow-up). PROs were measured pre-operatively, at intermediate follow-up, and at long-term follow-up using three validated questionnaires: American Shoulder and Elbow Surgeons (ASES) score, Disabilities of the Arm, Shoulder, and Hand (DASH) score, and Oxford Shoulder Score (OSS). Patients were additionally asked at final follow-up if they would undergo the same procedure again if they needed it. RESULTS: Twenty-nine (29) patients with a mean age of 51.16 ± 9.06 years at the time of surgery were included in the study at final follow-up. Mean final follow-up time was 10.2 ± 0.5 years (range: 9.2-11.1 years). All PROs (ASES, OSS, and DASH) demonstrated statistically significant improvements from pre-operative to final follow-up with p < 0.01 for each. The proportions of patients exceeding established values for minimum clinically important difference (MCID) were 96.55%, 93.10%, and 75.86% for ASES, OSS, and DASH respectively. Only one patient had required re-operation as of final follow-up. None experienced humeral fractures post-operatively. A significant majority (89.66%; p < 0.01) of patients reported that they would undergo the same procedure again if they needed it. Fifty-three (53) patients were included in the study at intermediate follow-up with a mean follow-up time of 3.5 ± 1.4 years (range: 2-5.3 years). There were no statistically significant differences in any of the PRO measures from intermediate to long-term follow-up. CONCLUSION: This study reported a minimum 9-year follow-up of patients undergoing OSBT with cortical button fixation for the management of LHBT pathology in the setting of concomitant shoulder procedures. All patients had significantly improved functional outcomes assessed with ASES, OSS, and DASH and no obvious differences in median group scores were found between patients assessed at intermediate (mean 3.5 years) and final (mean 10.2 years) follow-up. No infections, fractures, or fixation failures were reported.

Rehabilitation With Eccentric Training Using Kettlebell and Kinesio Taping in a Young Volleyball Player With Proximal Biceps Tendinopathy: A Case Report.

A prevalent overuse injury among athletes, especially to those participating in sports like volleyball that demand repeated overhead motions, is biceps tendinopathy. The painful condition known as biceps brachii tendinopathy is characterized by changes in the structure of the tendon together with chronic degeneration. Furthermore, the biceps aid in the acceleration and deceleration of the arm in numerous overhead sports. The biceps may experience excessive strain as a result of poor training or exhaustion. It is commonly known that the long head of the biceps tendon plays a significant role in producing pain, particularly when it comes to anterior shoulder discomfort and dysfunction in athletes and working people. Athletes' biceps tendon conditions fall into three broad categories: degeneration, instability, and abnormalities that are of source. This case details the use of kettlebell eccentric exercise and kinesio taping in the rehabilitation of a young volleyball player with biceps tendinopathy. The four primary aspects of the rehabilitation regimen were kinesio taping, pain management and rest, eccentric training with kettlebells, and initial assessment and patient education. Kettlebell eccentric training was used to enhance eccentric strength and encourage tendon remodeling, and kinesio taping was used to give pain relief and structural stability. This case study emphasizes the value of an all-encompassing rehabilitation strategy catered to the unique requirements of every athlete by demonstrating the effectiveness of kinesio taping and eccentric exercise with kettlebells in the treatment of biceps tendinopathy.

Proximal humerus open reduction internal fixation with and without biceps tenodesis: assessment of early clinical outcomes.

Background: The role of biceps tenodesis (BT) during open reduction internal fixation (ORIF) of proximal humerus fractures (PHFs) remains unclear. A subset of patients undergoing ORIF have persistent pain with unclear etiology. The purpose of our study was to compare outcomes of ORIF of PHFs with and without concomitant BT. We hypothesize patients undergoing BT at the time of ORIF will have improved patient-reported outcome scores with fewer secondary procedures related to treatment of the biceps. Methods: In this retrospective cohort study, all patients undergoing ORIF for a PHF at a single level one trauma center from January 2019 to June 2022 were reviewed. Patients under the age of 18 were excluded. Primary outcomes were patient-reported outcomes measurement information system physical function, depression, and pain interference scores at 5 time points up to final follow-up. Secondary outcomes included total operative time, complications, subsequent procedures, steroid injections, and range of motion. Chi-square tests were performed for categorical values and paired t-tests for continuous variables. Results: 71 patients met inclusion criteria: 41 undergoing ORIF without BT and 30 undergoing ORIF with BT. Average follow-up was 11 months. There were no statistically significant differences in patient demographics between groups. There were no differences in patient-reported outcomes measurement information system scores at any time point postoperatively. At final follow-up patients in the ORIF with BT group had higher forward flexion than those who did not undergo BT (142 vs. 123 degrees, respectively, P < .02). There were no differences in surgical time, revision rates, postsurgical complications, or postoperative injections between groups. Conclusion: BT performed during ORIF of PHFs did not result in significantly different functional or patient-reported outcomes between groups, except for greater forward flexion at final follow-up. Although BT was done more commonly in severe PHFs, patients in both groups had similar rates of subsequent biceps-related procedures and revision surgery.

Biceps tenotomy vs. tenodesis: an ACS-NSQIP analysis of postoperative outcomes and utilization trends.

Background: While studies have assessed comparative rates of restoration of shoulder function and alleviation of symptoms, comparative systemic postoperative complication rates between biceps tenotomy and tenodesis have yet to be assessed. The purpose of the present study was to use a national administrative database to perform a comprehensive investigation into 30-day complication rates after biceps tenotomy versus tenodesis, thus providing valuable insights for informed decision-making by clinicians and patients regarding the optimal surgical approach for pathologies of the long head of the biceps tendon. Methods: The National Surgical Quality Improvement Program database was queried to analyze postoperative complication rates and metrics associated with biceps tenotomy and tenodesis. Patient data spanning from 2012 to 2021 was extracted, with relevant variables assessed to identify and compare these two surgical approaches. Adjusted and unadjusted analyses were utilized to analyze patient demographics, comorbidities, operative times, lengths of stay, readmissions, adverse events, and yearly surgical volume, along with trends in usage, across cohorts. Results: Of 11,527 total patients, 264 (2.29%), 6826 (59.22%), and 4437 (38.49%) underwent tenotomy, tenodesis with open repair, and tenodesis with arthroscopic repair, respectively. Tenotomy operative times ([mean ± SD]: 66.25 ± 44.76 minutes) were shorter than those for open tenodesis (78.83 ± 41.82) and arthroscopic tenodesis (75.98 ± 40.16). Conversely, tenotomy patients had longer hospital days (0.88 ± 4.86 days) relative to open tenodesis (.08 ± 1.55) and arthroscopic tenodesis (.12 ± 2.70). Multivariable logistic regression controlling for demographics and comorbidities demonstrated that patients undergoing tenodesis were less likely to be readmitted (adjusted odds ratio [AOR]: 0.42, 95% confidence interval [CI]: 0.17-0.98, P = .050) or sustain serious adverse events (AOR: 0.27, 95% CI: 0.13-0.57, P < .001), but equally likely to sustain minor adverse events (AOR: 0.87, CI: 0.21-3.68, P = .850), compared with patients undergoing tenotomy. Lastly, comparing utilization rates from 2012 to 2021 revealed a significant decrease in the proportion of tenotomy (from 6.2% to 1.0%) compared to open tenodesis (from 41.0% to 57.3%) and arthroscopic tenodesis (52.8% to 41.64%; P trend = .001). Conclusion: To our knowledge, this is the first large national database study investigating postoperative complication rates between the various surgical treatments for pathologies of the long head of the biceps tendon. Our results suggest that tenodesis yields fewer serious adverse events and lower readmission rates than tenotomy. We also found a shorter operative time for tenotomy. These findings support the increased utilization of tenodesis relative to tenotomy in recent years.

Biceps tenotomy vs. tenodesis in patients undergoing transtendinous repair of partial thickness rotator cuff tears.

Background: Patients with partial thickness rotator cuff tears (PTRCTs) often present with concurrent pathology of the long head of the biceps tendon (LHBT). To address both conditions simultaneously, long head of the biceps (LHB) tenotomy or tenodesis can be performed at the time of arthroscopic rotator cuff repair (RCR). This study aims to compare postoperative shoulder active range of motion (AROM) and complications following transtendinous RCR with concurrent LHB tenodesis or tenotomy. Methods: A total of 90 patients with PTRCTs met inclusion criteria for this study. Patients who underwent tear-completion-and-repair, revision surgery, or open repair of the LHB tendon were excluded. Patients were stratified into tenotomy, arthroscopic suprapectoral tenodesis, or no biceps operation cohorts and were propensity matched 1:1:1 on age, sex, body mass index, and smoking status. Primary outcome measures included AROM in forward flexion, abduction, external rotation, and internal rotation at 6 weeks, 3 months, and 6 months postoperatively. The development of severe stiffness and rates of rotator cuff retear at final follow-up were recorded as secondary outcomes. Results: When comparing the tenotomy and tenodesis cohorts, tenotomy patients were found to have increased AROM at 3 months in forward flexion (153.2° vs. 130.1°, P = .004), abduction (138.6° vs. 114.2°, P = .019), and external rotation (60.4° vs. 43.8°, P = .014), with differences in forward flexion remaining significant at 6 months (162.4° vs. 149.4°, P = .009). There were no significant differences in interval rates of recovery in any plane between cohorts. Additionally, there were no significant differences in rates of symptomatic retears between groups (P = .458). Rates of severe postoperative stiffness approached but did not achieve statistical significance between tenotomy (4.2%) and tenodesis (29.2%) cohorts (P = .066). Smoking status was a significant predictor of severe stiffness (odds ratio, 13.69; P = .010). Conclusion: Despite significant differences in absolute AROM between cohorts, the decision to perform tenotomy or tenodesis was not found to differentially affect rates of AROM recovery for patients undergoing arthroscopic transtendinous RCR for PTRCT. Notably, however, transient stiffness complications were more commonly observed in smokers, and data trends suggested an increased risk of stiffness for patients undergoing LHB tenodesis. Overall, postoperative stiffness is likely multifactorial and attributable to both patient- and procedure-specific factors, and LHB tenotomy may be more appropriate for patients with risk factors for developing stiffness postoperatively.

Management of the Spastic Elbow Deformity in Adult Patients With Upper Motor Neuron Syndrome.

Spastic elbow deformity in patients with upper motor neuron injuries results from an imbalance of flexor and extensor forces across the ulnohumeral joint. Although not all deformities reflect the same underlying imbalances, the elbow most commonly rests in a flexed position. Patients may present with a combination of muscle spasticity, myostatic contracture, and/or joint contracture. A focused history and physical examination are essential for developing individualized surgical plans that account for variations in deformity severity and patient goals. Patients may present with or without volitional control; goals and treatment options differ depending on the degree of control present. Techniques include hyperselective neurectomy, tendon lengthening, muscle origin release, myotomy, tenotomy, periarticular soft tissue release, and skin rearrangement. This article presents a comprehensive review of the surgical approach to the volitional and nonvolitional spastic elbow deformities.

Decreased Strength, Complication Rate and Higher Satisfaction in Conservative Treatment of Partial Distal Biceps Tendon Rupture Compared to Surgical Treatment: A Systematic Review.

Background: Treatment modalities for partial distal biceps tendon (DBT) ruptures include conservative management (immobilization, medication, and physical therapy) or surgery. Selecting treatment modality can present a challenge to both patient and provider. Hypothesis: It was hypothesized that patients undergoing surgical treatment for partial DBT rupture would have higher complications but better overall strength, range of motion (ROM), and patient satisfaction. Study Design: Systematic Review. Methods: A systematic review was performed in adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cochrane, Embase, and Medline databases were searched for studies published through May 2023. Studies were included if they examined patients with a partial DBT rupture who underwent treatment. Exclusion criteria were non-human studies, studies not in English, reviews, technical notes, letters to the editor, surgical technique papers, and studies reported in a prior review. Results: 13 studies consisting of 290 patients with a partial DBT tear were included in this review. 75% of the patients were male and the ages ranged from 23 - 75 years. The follow up for the patients ranged from 1 - 94 months. 55 patients underwent conservative treatment versus 256 patients underwent surgical treatment. Outcomes examined by the studies included pain, strength, range of motion (ROM), complications, patient reported outcomes (PROs), return to activity, and patient satisfaction. Conclusion: Treatment for partial DBT tear via surgery or conservative treatment both produce good clinical outcomes. There are similar outcomes between treatment options for pain and ROM. Conservative treatment had some poorer outcomes in terms of strength after treatment. Surgical treatment had more complications and a few patients with decreased satisfaction. Overall, both are viable treatment options, requiring a physician and patient discussion regarding the pros and cons of both options as a part of a shared decision-making process that incorporates patient priorities.

Improved restoration of biomechanical factors using a narrow-box shape reconstruction compared to a wide one in superior capsular reconstruction for irreparable supraspinatus tendon tears. A biomechanical study using a static shoulder simulator.

PURPOSE: To biomechanically compare superior glenohumeral translation, subacromial contact pressures and area in a box-shape reconstruction using the long head of biceps tendon (LHBT) in an irreparable supraspinatus tendon tear model. METHODS: Seven cadaveric shoulders (mean age 61 years; range 32-84 years; SD 22.3) were tested with a custom testing rig used to evaluate superior translation, subacromial contact pressures and areas at 0°, 30° and 60° of glenohumeral abduction. Conditions tested included the native state, a complete tear of the supraspinatus tendon, a wide box-shaped, double-bundle LHBT superior capsular reconstruction (wide BS-SCR), and a narrow box-shaped, double-bundle LHBT superior capsular reconstruction (narrow BS-SCR). RESULTS: Compared to the wide box-shape SCR, the narrow box-shape SCR had statistically significant lower median contact pressure at 30° and 60°. The subacromial contact area showed a statistically significant difference at 0° (p=0.001) and 30° (p=0.004) for the narrow compared to wide box-shape SCR. At an abduction angle of 0°, the narrow SCR could restore superior translation statistically significant better compared to the wide construct. For all angles, the wide and narrow box-shaped SCR increased the median subacromial distance statistically significantly. The contact areas in 30° and 60° of abduction were higher for all scenarios, both peaking in the intact state in 30° with approximately 600 mm2. CONCLUSIONS: In comparison to a wide box-shape, a narrow box-shape SCR using the LHBT has biomechanical advantages in regard of subacromial contact pressures, the subacromial contact areas as well as the acromiohumeral distance. The width of the reconstruction therefore has direct influence in the success of the technique.

Three-Headed Biceps Brachii Muscle: A Rare Site of Proximal Median Nerve Entrapment.

The biceps brachii muscle is a highly variable muscle in the anterior compartment of the arm, and the most common variants include additional heads or slips. The median nerve courses with the brachial artery in the medial arm near the biceps brachii muscle, crosses the elbow, and enters the forearm deep to the bicipital aponeurosis. While entrapment of the median nerve in the carpal tunnel is one of the most common neuropathies, more proximal entrapments by the bicipital aponeurosis or other variants have been reported. In a 94-year-old embalmed female cadaver received through the Humanity Gift Registry of Pennsylvania, a biceps brachii muscle with an additional slip that arose from the coracoid process was found, which bridged over the median nerve and blended with the investing fascia of the forearm flexors via aponeurosis. Because of the course of this muscular slip in the arm and its relationship to the median nerve, this may be an additional site of proximal entrapment of the median nerve. It is important to consider these rare sites of nerve entrapment when diagnosing patients with median nerve neuropathy.

Raised body mass index and reduced muscle bulk reduces the incidence of Popeye's deformity post tenotomy of long head of biceps brachii.

OBJECTIVES: The development of the Popeye's deformity is a known complication of long head of the biceps tendon (LHBT) tenotomy. Incidence of developing Popeye's deformity after LHBT tenotomy ranges between 13% and 70%. While this complication is well tolerated, it can be avoided with proper patient selection. We aim to study patient and clinical factors resulting in the development of the Popeye's deformity after LHBT tenotomy so as to better identify suitable surgical candidates. METHODS: 91 patients underwent unilateral rotator cuff repairs and concomitant LHBT tenotomy between March 2013 and March 2017. Assessment of patient factors contributing to Popeye's deformity included patient demographics, and physical attributes were analyzed and correlated. Patients also completed a questionnaire regarding their overall postoperative satisfaction. Prospectively collated Visual Analog Pain Scale (VAS), Constant-Murley shoulder score (CSS), University of California, Los Angeles Shoulder Score (UCLA), and Oxford Shoulder Score (OSS) were compared at 6 and 24 months post operation between patients who developed Popeye's deformity and those who did not. RESULTS: The incidence of post-tenotomy Popeye's sign was 58.9%. Majority of patients were satisfied with their procedure, postoperative function, and cosmesis. Patients who developed Popeye's sign had a statistically significant lower body mass index (BMI) (24.9 â€‹± â€‹4.2 â€‹kg/m2 versus 27.3 â€‹± â€‹4.3 â€‹kg/m2, p â€‹= â€‹0.048) (rpb â€‹= â€‹- 0.210, p â€‹> â€‹0.05) and had a greater biceps-circumference-(in flexion)-to-wrist-circumference ratio (1.91 â€‹± â€‹0.16 versus 1.83 â€‹± â€‹0.13, p â€‹= â€‹0.012) (rpb â€‹= â€‹0.319, p â€‹< â€‹0.05) than those who did not. Nevertheless, the development of Popeye's sign did not affect clinical outcomes (VAS, CSS, UCLA, and OSS; p â€‹> â€‹0.05) at 24 months. CONCLUSIONS: The incidence of Popeye's deformity is high post LHBT tenotomy. There was a greater incidence in patients with lower BMI and greater biceps brachii muscle bulk. However, this complication is well tolerated. By better selecting our patients, we can achieve better outcomes and minimize potential complications. LEVEL OF EVIDENCE: Level-III evidence. TYPE OF STUDY: Retrospective comparative study.

Analysis of induced dynamic biceps EMG signal complexity using Markov transition networks.

Purpose: Surface electromyography (sEMG) is a non-invasive technique to characterize muscle electrical activity. The analysis of sEMG signals under muscle fatigue play a crucial part in the branch of neurorehabilitation, sports medicine, biomechanics, and monitoring neuromuscular pathologies. In this work, a method to transform sEMG signals to complex networks under muscle fatigue conditions using Markov transition field (MTF) is proposed. The importance of normalization to a constant Maximum voluntary contraction (MVC) is also considered. Methods: For this, dynamic signals are recorded using two different experimental protocols one under constant load and another referenced to 50% MVC from Biceps brachii of 50 and 45 healthy subjects respectively. MTF is generated and network graph is constructed from preprocesses signals. Features such as average self-transition probability, average clustering coefficient and modularity are extracted. Results: All the extracted features showed statistical significance for the recorded signals. It is found that during the transition from non-fatigue to fatigue, average clustering coefficient decreases while average self-transition probability and modularity increases. Conclusion: The results indicate higher degree of signal complexity during non-fatigue condition. Thus, the MTF approach may be used to indicate the complexity of sEMG signals. Although both datasets showed same trend in results, sEMG signals under 50% MVC exhibited higher separability for the features. The inter individual variations of the MTF features is found to be more for the signals recorded using constant load. The proposed study can be adopted to study the complex nature of muscles under various neuromuscular conditions.

Contribution of external reference frame to tactile localization.

The purpose of the present study was to elucidate whether an external reference frame contributes to tactile localization in blindfolded healthy humans. In a session, the right forearm was passively moved until the elbow finally reached to the target angle, and participants reached the left index finger to the right middle fingertip. The locus of the right middle fingertip indicated by the participants deviated in the direction of the elbow extension when vibration was provided to the biceps brachii muscle during the passive movement. This finding indicates that proprioception contributes to the identification of the spatial coordinate of the specific body part in an external reference frame. In another session, the tactile stimulus was provided to the dorsal of the right hand during the passive movement, and the participants reached the left index finger to the spatial locus at which the tactile stimulus was provided. Vibration to the biceps brachii muscle did not change the perceived locus of the tactile stimulus indicated by the left index finger. This finding indicates that an external reference frame does not contribute to tactile localization during the passive movement. Humans may estimate the spatial coordinate of the tactile stimulus based on the time between the movement onset and the time at which the tactile stimulus is provided.

Acute Distal Biceps Tendon Repair With Cortical Button Offers Good Functional Outcomes: A Retrospective Study Focusing on Range of Motion, Muscle Strength and Pain.

Background Distal biceps tendon (DBT) rupture is not one of the most common upper limb injuries. Surgical intervention is recommended for these injuries to restore muscular strength and functionality. Multiple different techniques are documented in the literature, however there is no definitive consensus on the most effective surgical treatment. The objective of this study was to assess the functional results of patients who underwent repair of DBT utilizing cortical button fixation procedures. Methods This study is a retrospective single-unit case series consisting of 54 patients who underwent DBT repair at Heartlands Hospital in Birmingham, United Kingdom. The patients' functional outcomes was assessed by the Mayo Elbow Performance Score (MEPS). Results The mean age was 51±11.01 years. Patients were operated on 4.72±7.083 days after the injury. The mean pain Visual Analogue Scale (VAS) 6 months after the surgery was 0.54±0.50. At 6 months follow-up, the average extension deficit was 2.69° (0-10), flexion 132° (120-140), supination76° (50- 85), and 77° for pronation (78-95). Patients were followed up routinely for 6 months. Mayo Elbow Performance (MEP) Score was utilized to assess the functional outcome and the mean MEP score was 91.43±8.26 which showed excellent functional outcomes for the cohort. Conclusion DBT repair with cortical button fixation yielded favorable functional outcomes at 6 months, notably restoring supination strength. This approach offers anatomical reinsertion while minimizing nerve damage risk.