Search

Background: Classification of fractures of the greater tuberosity has shown poor reliability, in part as a result of an inability to assess fracture displacement accurately. We used fluoroscopic images of prepositioned osteotomized greater tuberosity fragments in cadavers to determine the accuracy of radiographic interpretation, the interobserver reliability, and the effect that radiographs might have on surgical decision-making.Methods: Twelve osteotomies of the greater tuberosity (three each with 2, 5, 10, and 15 mm of displacement) were created in whole-body cadavers. Six fluoroscopic images (anteroposterior views in external and internal rotation, anteroposterior views in neutral rotation with 15 degrees of cephalic and 15 degrees of caudal tilt, a lateral outlet view, and an axillary view) were made after each osteotomy. Four experienced orthopaedic surgeons measured displacement in millimeters on seventy-two randomized images. Four views in sequence (the anteroposterior view in internal rotation and the outlet view together, then the axillary view, and then the anteroposterior view in external rotation) of each osteotomy pattern were then viewed, and each surgeon was asked whether surgery would be indicated on the basis of each set of images.Results: No one fluoroscopic view was significantly more accurate than another. There was a trend toward increased accuracy of imaging of minimally displaced (Conclusions and Clinical Relevance: To our knowledge, we are the first to examine the accuracy and reliability of interpreting images of known displacements of the greater tuberosity. Multiple radiographic views are needed to evaluate displacement of the greater tuberosity appropriately. The anteroposterior view in external rotation can profile the greater tuberosity and help demonstrate small displacements. Treatment decisions should be consistent between surgeons when multiple views are used. [ABSTRACT FROM AUTHOR]

Background: Revision rotator cuff repair is a surgical challenge, and the results have generally been inferior to those of primary repair. We examined the results of revision rotator cuff repair in a large series of patients and assessed which subgroups of patients had the greatest chance for a satisfactory functional outcome.Methods: A revision rotator cuff repair was performed in eighty patients after the failure of a previous operative repair. The average age of the patients at the time of the revision was fifty-nine years. Prior to revision, the average pain score was 7.4 points (with 0 points indicating no pain and 10 points, severe pain) and the active range of motion of the shoulder averaged 105 degrees of elevation, 39 degrees of external rotation, and internal rotation to the eleventh thoracic vertebra. All patients underwent repeat repair of the rotator cuff tendons to bone. Additional procedures included revision acromioplasty (fifty-three patients; 66%) and distal clavicular excision (twenty-six patients; 33%), among others.Results: After an average duration of follow-up of forty-nine months, the result was rated as satisfactory (excellent, good, or fair) in fifty-five patients (69%) and as unsatisfactory (poor) in twenty-five (31%). At the time of the latest follow-up, the average pain score had improved to 3.0 points and the active range of motion averaged 130 degrees of elevation, 53 degrees of external rotation, and internal rotation to the tenth thoracic vertebra. Improved results were associated with an intact deltoid origin, good-quality rotator cuff tissue, preoperative active elevation of the arm above the horizontal, and only one prior procedure. All seventeen patients who met all four of these criteria had a satisfactory result.Conclusions: The results of revision rotator cuff repair are inferior to those of primary repair. While pain relief can be reliably achieved in most patients, the functional results are improved principally in patients with an intact deltoid origin, good-quality rotator cuff tissue, preoperative elevation above the horizontal, and only one prior procedure. [ABSTRACT FROM AUTHOR]

Background: Recreation of normal anatomical relationships may be important to optimize the outcome of proximal humeral arthroplasty. With use of computerized tomographic data and three-dimensional computer modeling, we concurrently studied both extramedullary and intramedullary humeral morphology, including canal shape, and related these findings to the design of proximal humeral prostheses.Methods: Sixty cadaveric humeri (thirty pairs: fifteen from male donors and fifteen from female donors) were studied. Three-dimensional computer models were built from canal and periosteal contours extracted from computerized tomographic data and multiple measured anatomical parameters, including humeral canal axis, humeral head center, and hinge point offset; greater tuberosity and bicipital groove offset; humeral head center, radius, thickness, retroversion, and inclination; and size and torsion of sections of the canal.Results: On the average, the humeral head center was offset both medially (seven millimeters) and posteriorly (two millimeters) from the humeral axis. The humeral head hinge point did not line up with the axis but instead was laterally offset by an average of seven millimeters. The average humeral head thickness was nineteen millimeters. The humeral head thickness and length were proportionately linked. There was marked variability in all of these parameters. Humeral head inclination averaged 41 degrees but was less variable than previously described, with 95 percent of our sample within the range of 35 to 46 degrees. The proximal section of the humeral canal was retroverted, and the retroversion was found to be similar to that of the humeral head on statistical analysis. Version of the middle and distal sections of the canal, however, was dissimilar to that of the proximal section of the canal. Proximal humeral retroversion was found to be extremely variable and averaged 19 degrees. The accuracy, reliability, and repeatability of the computer-based-model measurements were found to be excellent.Conclusions: Measurements of external proximal humeral morphology made with three-dimensional computer models of cadaveric specimens derived from the Midwestern United States agreed, in general, with those described for different populations evaluated with different measuring techniques. Proximal humeral morphology was extremely variable as highlighted by the large ranges of measurements seen for all variables. Examination of the intramedullary morphology showed that there is an internal version, with measurements dependent on the canal distance distal to the anatomical neck.Clinical Relevance: Because of the marked variabilities seen in proximal humeral morphology, newer prosthetic designs are now allowing surgeons to control multiple prosthetic variables. An understanding of the normal values for proximal humeral morphology can serve as an important guideline for component selection, especially when the normal anatomy is distorted. Additionally, variations in intramedullary version may have important consequences for future designs of press-fit proximal humeral replacement. [ABSTRACT FROM AUTHOR]

Background: Neer and Foster previously described the inferior capsular shift procedure for treating multidirectional instability of the shoulder and reported preliminary results that were quite satisfactory. The purpose of our study was to perform a longer-term follow-up evaluation of the efficacy of the inferior capsular shift procedure for treating multidirectional instability of the shoulder.Methods: An inferior capsular shift procedure was used to treat multidirectional instability of the shoulder in forty-nine patients (fifty-two shoulders). All patients had failed to respond to an exercise program. In this series, the operative approach (anterior or posterior) was based on the major direction of the instability, as determined by the preoperative history and physical examination and as verified by examination with the patient under anesthesia. In all of the patients, the inferior capsular shift was the primary attempt at operative stabilization. The repair consisted of a lateral-side (or humeral-side) shift of the capsule to reduce capsular redundancy and, when necessary, a reattachment of the avulsed labrum to the anteroinferior aspect of the glenoid.Results: A redundant capsular pouch was seen in all of the shoulders in this series. In addition, detachment of the anteroinferior aspect of the labrum was found in ten shoulders and an anterior fracture of the glenoid rim was seen in two shoulders. At an average of sixty-one months (range, twenty-four to 132 months), results were available for forty-nine shoulders (forty-six patients). Thirty shoulders (61 percent) had an excellent overall result, sixteen (33 percent) had a good result, one (2 percent) had a fair result, and two (4 percent) had a poor result. Forty-seven (96 percent) of the forty-nine shoulders remained stable at the time of follow-up. Two of the thirty-four shoulders that had been repaired through an anterior approach began to subluxate anteroinferiorly again. None of the fifteen shoulders that had been repaired through a posterior approach had recurrent instability. Full function, including the ability to perform strenuous manual tasks, was restored to forty-five shoulders (92 percent). A return to sports was possible after thirty-one (86 percent) of the thirty-six procedures done in athletes; however, a return to the premorbid level of participation was possible after only twenty-five (69 percent) of the thirty-six procedures.Conclusions: The results in this series demonstrate the efficacy and the durability of the results of the inferior capsular shift procedure for the treatment of shoulders with multidirectional instability. The procedure directly addresses the major pathological feature - a redundant joint capsule. Similar results were seen with either an anterior or a posterior approach, and we continue to approach shoulders with multidirectional instability on the side of greatest instability. A postoperative brace was reserved for patients in whom a posterior approach had been used or in whom an anterior approach had involved extensive posterior capsular dissection (ten of the thirty-four shoulders treated with the anterior approach). [ABSTRACT FROM AUTHOR]

Abstract: Learning from the healthcare system's response to the COVID-19 pandemic is essential to better prepare for potential future crises. We sought to assess mortality rates for patients admitted for acute decompensated heart failure (HF) and to analyze which factors demonstrated a statistically significant correlation with this primary endpoint. We performed a retrospective analysis of patients hospitalized with a primary diagnosis of acute decompensated HF within the New York City Health and Hospitals 11-hospital system across the different COVID surge periods. Mortality information was collected in 4,405 participants (mean [SD] age 70.54 [14.44] years, 1885 [42.87%] female).The highest mortality existed in the first surge (9.02%), then improved to near prepandemic levels (3.65%) in the second (3.91%) and third surges (5.94%, p < 0.0001). In-hospital mortality inversely correlated with receipt of a COVID-19 vaccination, but had no correlation with left ventricular ejection fraction or the number of vaccination doses. Mortality for acute decompensated HF patients improved after the first surge, suggesting that hospitals adequately adapted to provide quality care. As future infectious outbreaks may occur, emergency preparedness must ensure that adequate focus and resources remain for other clinical entities, such as HF, to ensure optimal care is delivered across all areas of illness., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 National Association for Healthcare Quality.)

Background: Atrial fibrillation (AF) is among the most common arrhythmias associated with an increased risk of cardioembolic phenomena, including stroke. Percutaneous left atrial appendage occlusion (LAAO) has proven beneficial in reducing stroke and mortality in patients with atrial fibrillation who have contraindications to anticoagulation. However, the sex differences in outcomes following LAAO have not been studied systematically., Methods: Electronic databases PUBMED, Embase, and Web of Science were systematically searched until March 2022 for studies evaluating patient outcomes following LAAO for AF. The primary outcomes of interest were the risks of periprocedural stroke, major bleeding, pericardial complications, and all-cause mortality. Secondary outcomes included stroke risks, major bleeding, device-related thrombus, cardiovascular and all-cause mortality on long-term follow-up. A random-effects model meta-analysis was conducted, and heterogeneity was assessed using the I-squared test., Results: Sixteen studies were included in the final analysis encompassing 111,775 patients, out of which 45,441 (40.7 %) were women. Women had a significantly higher risk of peri-procedural complications including all-cause mortality [relative risk (RR), 95 % confidence intervals (CI); RR 1.94, 95 % CI 1.40-2.69], stroke [RR 1.85, 95 % CI 1.29-2.67], major bleeding [RR 1.63, 95 % CI 1.08-2.44], and pericardial events [RR 1.80, 95 % CI 1.58-2.05]. However, there were no statistically significant differences between sexes in terms of risk of stroke, major bleeding, device-related thrombus, cardiovascular and all-cause mortality on long-term follow-up., Conclusion: Among patients undergoing LAAO implantation, women were at higher risk of periprocedural complications than men. This risk was not significant on long-term follow-up., Competing Interests: Conflict of interest Authors report no disclosures pertaining to this article., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Immunotherapy for cancer treatment has gained increased attention in recent years. Recently, our group reported the case of a patient with glioblastoma who underwent vaccination based on dendritic cells and experienced a strong Th1 immune response together with near-complete tumor remission. Here we report the results of a phase I/II prospective, non-controlled clinical trial with 37 patients harboring glioblastoma or grade 4 astrocytomas. At the time of first recurrence after surgery, patients began receiving monthly intradermal injections of allogenic DC-autologous tumor cell hybridomas. Overall survival, quality of life, and immunological profiles were assessed prospectively. Compared with patients in the Genomic Data Commons data bank, overall survival for vaccinated patients with glioblastoma was 27.6 ± 2.4 months (vs. 16.3 ± 0.7, log-rank p < 0.001, hazard ratio 0.53, 95%CI 0.36-0.78, p < 0.01), and it was 59.5 ± 15.9 for vaccinated astrocytoma grade 4 patients (vs. 19.8 ± 2.5, log-rank p < 0.05, hazard ratio 0.18, 95%CI 0.05-0.62, p < 0.01). Furthermore, seven vaccinated patients (two IDH-1-mutated and five wild type) remain alive at the time of this report (overall survival 47.9 months, SD 21.1, range: 25.4-78.6 months since diagnosis; and 34.2 months since recurrence, range: 17.8 to 40.7, SD 21.3). We believe that the data reported here can foster the improvement of treatment protocols for high-grade gliomas based on cellular immunotherapy.

Chromosomal organization, scaling from the 147-base pair (bp) nucleosome to megabase-ranging domains encompassing multiple transcriptional units, including heritability loci for psychiatric traits, remains largely unexplored in the human brain. In this study, we constructed promoter- and enhancer-enriched nucleosomal histone modification landscapes for adult prefrontal cortex from H3-lysine 27 acetylation and H3-lysine 4 trimethylation profiles, generated from 388 controls and 351 individuals diagnosed with schizophrenia (SCZ) or bipolar disorder (BD) (n = 739). We mapped thousands of cis-regulatory domains (CRDs), revealing fine-grained, 10 4 -10 6 -bp chromosomal organization, firmly integrated into Hi-C topologically associating domain stratification by open/repressive chromosomal environments and nuclear topography. Large clusters of hyper-acetylated CRDs were enriched for SCZ heritability, with prominent representation of regulatory sequences governing fetal development and glutamatergic neuron signaling. Therefore, SCZ and BD brains show coordinated dysregulation of risk-associated regulatory sequences assembled into kilobase- to megabase-scaling chromosomal domains., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background : Pectoralis major ruptures are increasing in incidence primarily due to an increase in awareness, activity level among young males between 20 and 40 years of age, and use of anabolic steroids. Although the majority of pectoralis major ruptures are acute injuries, many chronic ruptures are unrecognized and it is imperative to understand the proper evaluation of these injuries, as well as the appropriate treatment for acute and chronic ruptures. Purpose : Pectoralis major ruptures can lead to deformity and physical disability if left untreated. This review paper discusses both acute and chronic ruptures as well as indications for nonoperative treatment and operative treatment to give the reader the best understanding of this diagnosis and proper management. Methods : A systematic review of the literature was performed using a search of electronic databases. Search terms such as pectoralis major rupture, pectoralis major repair, pectoralis major tendon transfer , and pectoralis major nonoperative treatment were used. Case reports, systematic reviews, prospective and retrospective studies were included to provide a comprehensive review. The only exclusion criteria consisted of studies not published in English. This review article includes the anatomy and biomechanics of the pectoralis major muscle, proper evaluation of the patient, operative and nonoperative treatment of acute and chronic pectoralis major ruptures, and outcomes of the recommended treatment. Conclusion : Nonoperative treatment is indicated for patients with medical comorbidities, older age, incomplete tears, or irreparable damage. Patients treated non-operatively have been shown to lose strength, but regain full range of motion. Patients with surgery before 6 weeks reported better outcomes than patients with surgery between 6 and 8 weeks. The chronicity of the rupture (>8 weeks) increases the likelihood of reconstruction, involving the use of autografts or allografts. Patients treated with delayed repair had significantly better strength, satisfaction, and outcomes than patients with nonoperative treatment. The pectoralis tendon can also be transferred in patients with rotators cuff tears, atrophy, or significant functional limitation. Tendon transfers have been shown to have unpredictable outcomes, but overall satisfactory results.

Tendinopathy is a common and progressive musculoskeletal disease. Increased apoptosis is an end-stage tendinopathy manifestation, but its contribution to the pathology of the disease is unknown. A previously established in vivo model of fatigue damage accumulation shows that increased apoptosis is correlated with the severity of induced tendon damage, even in early onset of the disease, supporting its implication in the pathogenesis of the disease. Consequently, this study aimed to determine: (1) whether apoptosis could be inhibited after fatigue damage and (2) whether its inhibition could lead to remodeling of the extracellular matrix (ECM) and pericellular matrix (PCM), to ultimately improve the mechanical properties of fatigue-damaged tendons. The working hypothesis was that, despite the low vascular nature of the tendon, apoptosis would be inhibited, prompting increased production of matrix proteins and restoring tendon mechanical properties. Rats received 2 or 5 d of systemic pan-caspase inhibitor (Q-VD-OPh) or dimethyl sulfoxide (DMSO) carrier control injections starting immediately prior to fatigue loading and were sacrificed at days 7 and 14 post-fatigue-loading. Systemic pan-caspase inhibition for 2 d led to a surprising increase in apoptosis, but inhibition for 5 d increased the population of live cells that could repair the fatigue damage. Further analysis of the 5 d group showed that effective inhibition led to an increased population of cells producing ECM and PCM proteins, although typically in conjunction with oxidative stress markers. Ultimately, inhibition of apoptosis led to further deterioration in mechanical properties of fatigue-damaged tendons.

Isolated injuries to the teres major muscle occur in competitive sporting activities such as baseball pitching, hockey and tennis. We report a similar event of a physically fit man sustaining an isolated teres major rupture while waterskiing. Non-operative management was chosen, with pain resolution and no appreciable functional limitations at follow up. Because teres major muscle injury was suspected at the time of imaging, we present a dedicated imaging protocol to optimize assessment for teres major injury.

Pathologic processes intrinsic and extrinsic to the tendons have been proposed as the underlying cause of rotator cuff disease, but the precise etiology is not known. Tear formation is, in part, attributable to the accumulation of subrupture tendon fatigue damage. We review the molecular, mechanical, and structural changes induced in tendons subjected to controlled amounts of fatigue loading in an animal model of early tendinopathy. The distinct tendon responses to low and moderate levels of loading, as opposed to high levels, provide insight into the potential mechanisms for the therapeutic benefits of exercise in the treatment of rotator cuff tendinopathy. The progression of damage accumulation leading to fiber rupture and eventual tendon tearing seen with higher loading illustrates the progression from tendinopathy to full-thickness tearing. We hope that this more realistic animal model of tendon fatigue damage will allow better assessment of biologic, mechanical, tissue-engineering, and rehabilitation strategies to improve repair success., (Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

Tendinopathies are commonly attributable to accumulation of sub-rupture fatigue damage from repetitive use. Data is limited to late stage disease from patients undergoing surgery, motivating development of animal models, such as ones utilizing treadmill running or repetitive reaching, to investigate the progression of tendinopathies. We developed an in vivo model using the rat patellar tendon that allows control of the loading directly applied to the tendon. This manuscript discusses the response of tendons to fatigue loading and applications of our model. Briefly, the fatigue life of the tendon was used to define low, moderate and high levels of fatigue loading. Morphological assessment showed a progression from mild kinks to fiber disruption, for low to high level fatigue loading. Collagen expression, 1 and 3 days post loading, showed more modest changes for low and moderate than high level fatigue loading. Protein and mRNA expression of Ineterleukin-1β and MMP-13 were upregulated for moderate but not low level fatigue loading. Moderate level (7200 cycles) and 100 cycles of fatigue loading resulted in a catabolic and anabolic molecular profile respectively, at both 1 and 7 days post loading. Results suggest unique mechanisms for different levels of fatigue loading that are distinct from laceration.

Though open stabilization using the Bankart procedure is still considered the "gold standard," few studies have examined the long-term outcomes. Between 1988 and 2001, 64 patients met inclusion criteria and had an open stabilization performed. Forty-one patients were available for follow-up at an average of 6.5 years. Forty (98%) patients reported having a stable shoulder. Average loss of external rotation was 4 degrees and average Rowe score was 96. This study further supports the trustworthiness of an open anatomic subcapsulolabral reconstruction for recurrent anterior instability and provides another standard from which to compare newer surgical methods.

Bleeding into large joints is the most common orthopaedic manifestation of hemophilia. Involvement of the shoulder rarely is reported, lending to its relative neglect in the orthopaedic literature. Through retrospective chart and radiographic reviews, the incidence and progression of radiographic and clinical changes that occur in the shoulder of patients with hemophilia is described. We retrospectively reviewed 822 patient charts and found 93 patients with symptomatic shoulders. Seventy-nine of these 93 patients were rated according to Pettersson's scoring method. The clinical charts were reviewed for the presence of shoulder symptoms and dysfunction. A spectrum of radiographic changes was seen beginning with mild subchondral irregularity and greater tuberosity cyst formation progressing to joint space narrowing, osteophyte formation, marginal erosion, and deformity. Of the 54 patients for whom an adequate shoulder history was available, the severity of symptoms correlated with the Pettersson score. The current study is the largest to date examining the type and progression of radiographic changes caused by hemophilic shoulder arthropathy. We observed a consistent pattern of radiographic changes, the severity of which correlated directly with shoulder symptoms.

Elevation of the deltoid insertion (DI) has been recommended, but little is known about its anatomy or importance for deltoid function. The purpose of this study is to determine the dimensions of the DI with specific reference to the deltopectoral approach. The deltoid was exposed and detached at its origin in 36 cadaveric shoulders. The morphology of the DI was documented, and its relationship with the pectoralis major insertion and the axillary and radial nerves was recorded. The anterior, middle, and posterior deltoid muscle fibers entered into the DI in a V-shaped tendinous confluence with a broad posterior band and a narrow separate anterior band, which accounted for the anterior one fifth of the DI (0.44 cm). The deltoid insertion was separated from the pectoralis major insertion by as little as 2 mm in 31 of 36 specimens. The distance between the axillary nerve and the DI averaged 5.6 cm anteriorly and 4.5 cm posteriorly. The distance between the radial nerve and posterior deltoid insertion averaged 2.4 cm proximally and 1.6 cm distally. Exposure during the deltopectoral approach is most limited by the close proximity of the deltoid and pectoralis major insertions. Our study would suggest that partial anterior DI release (greater than one fifth) could compromise the anterior deltoid. The axillary and radial nerves are not at significant risk when operating in the region of the anterior DI.

Many causes of suprascapular nerve entrapment have been described including a small spinoglenoid notch, a tight ligament, boney spurs, and ganglion cysts. In the current patient, suprascapular nerve entrapment was caused by a lipoma in the suprascapular notch. The patient presented with painful shoulder motion that could have been attributed to rotator cuff and acromioclavicular joint disease. However, magnetic resonance imaging and electromyography were consistent with suprascapular nerve entrapment. Treatment of the rotator cuff disease and excision of the lipoma led to resolution of the patient's symptoms. This case is presented as an unusual cause of suprascapular nerve entrapment with a review of its course and anatomy.

Surgical treatment of symptomatic pathology of the long head of the biceps tendon generally consists of either biceps tenotomy or tenodesis. Biceps tenodesis is generally recommended for younger patients and has been well described using open techniques. With advancements in arthroscopic ability and equipment, new arthroscopic techniques have recently been reported. These techniques can be especially useful when used in conjunction with other arthroscopic procedures such as distal clavicle resection, rotator cuff repair, and subacromial decompression. We present a modification of the techniques suggested by other researchers. In this technique, a bone anchor is used as a pulley at the bottom of the tunnel to pull the tendon into position. This is followed by interference screw fixation. To our knowledge, this technique has not been previously described.

Specialized magnetic resonance imaging (MRI) was performed in 42 painful shoulder arthroplasties, 22 of which underwent subsequent revision surgery, allowing surgical confirmation of the pathology identified on MRI. One hemiarthroplasty was excluded because of motion artifact, leaving 21 studies (19 patients) to be correlated retrospectively to the surgical findings. At the time of revision surgery, there were full-thickness rotator cuff tears in 11 of 21 shoulders; MRI correctly predicted these in 10 of 11 shoulders. Full-thickness subscapularis tears were the most common finding (8/11 shoulders). Of the 21 shoulders, 10 did not have a rotator cuff tear, and MRI correctly predicted the absence of a tear in 8 of 10. MRI also correctly predicted glenoid cartilage wear in 8 of 9 shoulders. With limited pulse-sequence parameter modification, the data from this preliminary study suggest that MRI may be a useful technique with which to determine the integrity of the rotator cuff and residual cartilage and, thus, is potentially a tool in the management of painful shoulder arthroplasty.

Subcoracoid transfer of the pectoralis major has recently been described as a reconstruction for subscapularis insufficiency. The purpose of this study was to examine the surgically relevant anatomy of this transfer. The importance of understanding this anatomy was recently highlighted to us following our encounter with musculocutaneous neuropraxia in 2 patients after transfer of the entire pectoralis major, one deep to the musculocutaneous nerve. Dissections were performed on 20 fresh, whole human cadavers in which the entire pectoralis major muscle, medial and lateral pectoral nerves, and musculocutaneous nerve were explored and quantified. The relationship between the pectoralis major and the conjoined tendon was studied in situ and after simulated transfers. The medial and lateral pectoral nerves were located far medial to the pectoralis major tendon insertion and appeared to be safe from injury as long as surgical dissection remained lateral to the pectoris minor and less than 8.5 cm from the humeral insertion. Transfer of the pectoralis major superficial to the musculocutaneous nerve created less tension than transfer deep to the musculocutaneous nerve. Because proximal innervation of the coracobrachialis and short head of the biceps is not an uncommon occurrence, a split pectoralis major transfer, release of the proximal musculocutaneous branches, or debulking of the pectoralis major muscle belly may be required in some instances to prevent tension on the nerve. Because of the variability and location of the musculocutaneous nerve, it should always be visualized operatively. Transfer of the pectoralis major tendon lateral to the biceps tendon appeared to best restore the muscle length-tension relationship.

Stereophotogrammetry was used to investigate the functional relations between the articular surface geometry, contact patterns, and kinematics of the glenohumeral joint. Nine normal shoulder specimens were elevated in the scapular plane by using simulated muscle forces in neutral rotation (NR) and starting rotation (SR). Motion was quantified by analyzing the translations of the geometric centers of the humeral head cartilage and bone surfaces relative to the glenoid surface. In both NR and SR, the ranges of translations of the center of the humeral head cartilage surface were greatest in the inferior-superior direction (NR 2.0 +/- 0.7 mm, SR 2.9 +/- 1.2 mm). Results of this study also show that joints with less congruence of the articular surfaces exhibit larger translations, and elevation in SR yields greater translations than in NR. Kinematic analyses with the humeral head bone surface data yielded larger values of translation than analyses that used the cartilage surface data, suggesting that similar overestimations may occur in radiographic motion studies. Results of this study demonstrate that small translations of the humeral head center occurred in both SR and NR. The proximity of the origin of the helical axes to the geometric center of the humeral head articular surface confirmed that glenohumeral elevation is mainly rotation about this geometric center with small translations.