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Purpose: Range of motion adaptations in the shoulders of overhead throwing athletes have been reported, but knowledge about the development of soft-tissue adaptations is limited. The purpose of this study was to investigate differences in posterior shoulder capsule thickness and internal rotation between the throwing and non-throwing shoulder., Methods: On the basis of the sample size calculation, we assessed 63 youth elite handball players (33 boys and 30 girls, mean age: 13.6 ± 0.9 years) for glenohumeral internal and external rotational range of motion, humeral retrotorsion, and posterior capsule thickness (PCT) with a manual goniometer and a portable ultrasound device and calculated sports-specific differences between the throwing and non-throwing shoulder as well as correlations with PCT., Results: Youth handball players showed side-to-side differences in internal rotation, external rotation, and humeral retrotorsion between the throwing and non-throwing shoulder. Posterior shoulder capsules were 1.21 times thicker (95% confidence interval: 1.1-1.3) in the throwing shoulder than in the non-throwing shoulder (1.3 ± 0.3 mm vs. 1.2 ± 0.2 mm, P < .0001). Loss of internal rotation did not correlate with PCT., Conclusions: In youth elite handball athletes, posterior shoulder tightness and subsequent sports-specific loss of internal rotation in the throwing shoulder are not related to PCT. Thus, in this age class, other (soft-tissue) factors must be responsible for this condition., (Copyright © 2020 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Assessment of a painful or stiff shoulder arthroplasty can be challenging. The cause of pain can sometimes be easily identified. However, some patients have normal levels of inflammatory markers, normal plain films, and no clinical signs to indicate a diagnosis. Indolent organisms may not raise blood marker levels or result in obvious radiologic findings such as loosening. We report the utility of performing arthroscopy in these patients for a diagnostic advantage., Methods: We retrospectively reviewed the health records of all patients who underwent diagnostic shoulder arthroscopy over a 3-year period. Patients were included if they were aged 18 years or older, had undergone previous arthroplasty surgery, and had symptoms of shoulder pain or stiffness. Patients were excluded if they had any traditional symptoms of infection or had a raised serum white cell count or C-reactive protein level prior to diagnostic arthroscopy., Results: Fourteen patients met the initial inclusion criteria. The mean interval between index surgery and arthroscopic evaluation was 65.4 months (standard deviation, 58 months; range, 17-192 months). Arthroscopic biopsy specimens returned positive culture results in 3 patients (21%). Rotator cuff tears were noted in 8 patients (57%). Capsular contraction requiring release was noted in 2 patients (10%). In all patients, the diagnostic arthroscopy directed the next stage of management., Conclusions: Diagnostic arthroscopy allows a full assessment of implants, the rotator cuff, the native articular surfaces, and scar tissue, as well as biopsy specimens to be obtained for indolent infection, in patients considering revision arthroplasty surgery. This allows a more informative consent process for patients, directs surgical management, and on occasion, allows for therapeutic intervention in a painful or stiff shoulder arthroplasty., (Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.)

Background: Although frozen shoulder (FS) is a common shoulder disorder, its pathogenesis is not yet determined. The function of matrix metalloproteinases (MMPs) is related to extracellular matrix remodeling. The purposes of this study were to investigate the pattern of sequential expression of MMPs in a rat model of shoulder contracture and to compare the expression of MMPs in the joint capsule between patients with FS and a control group., Methods: We obtained joint capsules from rats immobilized by molding plaster (a shoulder contracture model) at baseline, 3 days, 1 week, and 3 weeks (4 rats per time point; 16 rats in total). The expression of the inflammatory cytokine interleukin 6 (IL-6), MMP-2, and MMP-9 was examined by immunohistochemistry. We also obtained joint capsules from 21 patients with FS and 13 control patients with instability to quantify the expression levels of MMP-2 and MMP-9 by immunohistochemistry., Results: In the rat model, IL-6 and MMP-9 tended to be overexpressed in the joint capsule at 3 days and 1 week and MMP-2 at 3 days, 1 week, and 3 weeks. MMP-2 and MMP-9 were significantly overexpressed in the joint capsules of the patients with FS compared with those of control patients., Conclusion: The results from both human and animal studies suggest the involvement of MMP-2 and MMP-9 in the development of FS. Animal study showed that the sequential expression of IL-6 and MMPs may be associated with fibrosis of the joint capsule., (Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The etiology of frozen shoulder (FS) is unclear. Accordingly, this study used a label-free quantitative shotgun proteomic approach to elucidate the pathogenesis of FS based on protein expression levels., Methods: Tissue samples from the rotator interval (RI), middle glenohumeral ligament (MGHL), and anterior-inferior glenohumeral ligament (IGHL) were collected from 12 FSs with severe stiffness and 7 shoulders with a rotator cuff tear (RCT) as controls. Protein mixtures were digested and analyzed by nano-liquid chromatography/electrospray ionization-tandem mass spectrometry. Relative protein expression levels were calculated by the signal intensity of identified peptide ions on mass spectra. Differentially expressed proteins between FS and RCT samples were evaluated by a gene enrichment analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes., Results: We identified 1594 proteins, 1358 of which were expressed in all 6 tissue groups. We detected more upregulated proteins in the upper (RI and MGHL) FS groups and the lower (IGHL) RCT group than in the comparative groups, respectively. Various proteins with functions in tissue repair, collagen metabolism and fibrillation, cell-cell and cell-matrix adhesion, blood coagulation, and the immune response were expressed more highly in the RI and MGHL FS groups than in the RCT group. Proteins with functions in phagocytosis, glutathione metabolism, retinoid metabolism, and cholesterol metabolism were expressed more highly in the IGHL RCT group than in the FS group., Conclusions: The pathophysiology of FS differs between the upper and lower parts of the joint capsule. Different treatment strategies for FS may be appropriate, depending on the location., (Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The number of anterior shoulder dislocations that predispose to recurrence is unknown; some clinicians recommend surgical repair after the initial episode and others after multiple recurrences. The purpose of this study was to quantify the forces during successive anterior dislocations of cadaveric shoulders and to inspect the capsule and labrum afterwards, in order to assess the propensity for recurrence., Materials and Methods: Twenty-two human cadaveric shoulders were tested using a custom cadaveric shoulder dislocation device with simulated muscle loading. Each was positioned in the apprehension position and the humerus was moved in horizontal abduction until the shoulder dislocated. The joint reaction force was measured, as was the force that developed passively in the pectoralis major muscle. Following 3 successive dislocations, each was inspected for anterior capsulolabral lesions., Results: There was a significant decrease in force after the second dislocation. In 11, there was no labral avulsion and a significant decrease in force after the first dislocation. In the other 11, there was a labral avulsion and a significant decrease in force after the second dislocation., Conclusion: Two successive anterior shoulder dislocations may increase propensity for recurrence; but this is influenced by the type of capsulolabral lesion that occurs. No labral avulsion, likely a result of capsular stretching, may be a worse prognostic finding than labral avulsion after the initial episode., (Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.)

Background: The purpose of this study was to evaluate wear debris in periprosthetic tissues at the time of revision total elbow arthroplasty. Polyethylene, metallic, and bone cement debris were characterized, and the tissue response was quantified., Materials and Methods: Capsular and medullary tissue samples were collected during revision surgery. Polyethylene debris was characterized by scanning electron microscopy after tissue digestion. The concentrations of metal and cement debris were quantified by inductively coupled plasma mass spectrometry. Tissue response was graded with a semiquantitative histologic method., Results: Polyethylene particle size varied from the submicron range to over 100 μm. The mean diameter ranged from 0.6 μm to about 1 μm. Particles in the synovial tissues were larger and less abundant than those in tissues from the medullary canal. Cement, titanium alloy, and low levels of cobalt-chrome debris were also present, with cement predominating over metal debris. Histiocyte response was associated with small polyethylene particles (0.5-2 μm), and giant cells were associated with large polyethylene particles (>2 μm). Histiocyte scores positively correlated with the polyethylene particle number and the presence of metal., Discussion: We have shown that periprosthetic tissues of total elbow patients who have undergone revision for loosening and osteolysis contain polyethylene, cement, and metal debris. Although the polyethylene particles were of a size and shape that have been previously shown to result in activation of phagocytic cells, osteolysis after total elbow arthroplasty is a multimodal process. Because of the presence of multiple wear particle sources, a cause-and-effect relationship between polyethylene debris and osteolysis cannot be established with certainty., (Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

Background: Our understanding of the pathogenesis of frozen shoulder and why it is so painful is undetermined. This study investigated the expression of neuronal proteins in the capsular tissue of frozen shoulder., Methods: Shoulder capsular samples were collected from 8 patients with idiopathic adhesive capsulitis and 10 patients with a rotator cuff tear but no stiffness (controls). Samples were analyzed by immunohistochemistry using antibodies against protein gene product 9.5 (PGP9.5), a general nerve marker; growth associated protein 43 (GAP43), a nerve growth marker; nerve growth factor receptor p75; and CD34, an endothelial cell marker., Results: Samples from frozen shoulders showed subsynovial hypercellularity and fibroblastic proliferation, with increased expression of nerve growth factor receptor p75 and CD34 compared with controls. Nerves positive for PGP9.5 and GAP43 were more abundant in samples of frozen shoulder (2.8 ± 0.2 and 2.4 ± 0.4 per field; P < .01) compared with controls (1.6 ± 0.3 and 1.3 ± 0.3 per field; P < .05). Expression of neuronal proteins followed that of CD34., Conclusion: Increased expression of nerve growth factor receptor and new nerve fibers were found in the shoulder capsular tissue of patients with frozen shoulder compared with those without a frozen shoulder. These data suggest that neoinnervation and neoangiogenesis in the shoulder capsule are important events in the pathogenesis of frozen shoulder and may help explain the often-severe pain of patients with frozen shoulder., (Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

Hypothesis and Background: Baseball players commonly present with decreases in internal rotation (IR) and concurrent increases in external rotation (ER) motion. Several glenohumeral (GH) adaptations have been theorized to cause these changes in motion, including humeral retroversion (HR) and posterior capsule thickness (PCT). However, limited data exist examining the inter-relationship between HR and PCT. Therefore, the purpose of this study was to measure HR, GH IR and ER rotation, and PCT., Materials and Methods: HR and PCT were measured with an ultrasound system (Sonosite Titan; Sonosite, Bothell, WA, USA), and GH IR and ER were measured with a digital inclinometer., Results: The dominant arm had significantly more HR (15.6°, P = .0001) than the nondominant arm. Pearson correlation coefficients showed a significant negative relationship between HR and GH IR (-0.472, P = .001) and a significant positive relationship between HR and GH ER (0.295, P = .042). A significant positive correlation was also found between HR and PCT (0.427, P = .003)., Discussion: This was the first study to identify a relationship between HR and PCT in addition to GH IR and ER. The identification of these multiple correlations appears to suggest that the loss of IR caused by HR may be placing additional stress on the posterior capsule during the deceleration phase of the throw, thereby causing a fibroblastic healing response., Conclusions: HR has previously been identified as a positive adaptation because of the increase in ER without anterior capsule attenuation. However, this study suggests that HR may be contributing to the negative adaptation of PCT., (Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

Hypothesis: Biceps tendon pathology is common with rotator cuff tears. The mechanisms for biceps changes, and therefore its optimal treatment, are unknown. Our objective was to determine the effect of rotator cuff tears on regional biceps tendon pathology. We hypothesized that histologic and compositional changes would appear before organizational changes, both would appear before mechanical changes, and changes would begin at the tendon's insertion site., Materials and Methods: Detachment of supraspinatus and infraspinatus tendons or sham surgery was done in 65 Sprague-Dawley rats. Rats were euthanized at 1, 4, or 8 weeks for regional measurements of histologic, compositional, organizational (1, 4 and 8 weeks), or mechanical properties (4 and 8 weeks only)., Results: One week after tendon detachments, decreased organization and more rounded cell shape were found in the intra-articular space of the biceps tendon. Aggrecan expression was increased along the entire length of the tendon, whereas all other compositional changes were only at the tendon's proximal insertion into bone. With time, this disorganization and more rounded cell shape extended the length of the tendon. Organizational and cell shape changes also preceded detrimental mechanical changes: decreased modulus in the intra-articular space was found after 8 weeks., Conclusions: Results support a degenerative component to pathology in the biceps tendon. In addition, changes resembling a tendon exposed to compressive loading occurring first in the intra-articular space indicate that the biceps tendon plays an increased role as a load-bearing structure against the humeral head in the presence of rotator cuff tears., (Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

Recurrent posterior glenohumeral instability, although a less common clinical entity than anterior instability, must be recognized and appropriately treated for a successful outcome. Pathologic findings that may need to be addressed include posterior Bankart lesions, humeral avulsion of the posterior inferior glenohumeral ligament (PIGHL), intrasubstance ligament attenuation, and combined lesions. In this review, we present 2 patients with the same pathoanatomic findings of recurrent posterior shoulder instability secondary to posterior humeral avulsion of the glenohumeral ligament with an associated posterior Bankart lesion. This combination of pathology is referred to as a "floating PIGHL" lesion. We review both patient's preoperative clinical findings and imaging studies and detail the necessary steps for a successful repair., (Copyright2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

The inferior capsular shift procedure described by Neer is an effective treatment for multidirectional shoulder instability. To determine the amount of volume reduction that occurs with the inferior capsular shift procedure, 13 cadaver shoulders were dissected down to the capsule. A viscous liquid was injected into each shoulder and the baseline volume recorded. A humeral-based capsular release to the 8 o'clock position (right shoulder) was performed, the capsule was shifted, and the volume was recorded. The capsule was released further to the 6 o'clock position and then to the 4 o'clock position. The mean shoulder volume significantly dropped after each successive shift. From baseline, the volume decreased 33% after the first shift, 42% after the second, and 66% after the third. Progressive release of the capsule results in significantly more volume reduction owing to greater elimination of the inferior axillary pouch. A more complete glenohumeral capsular release may be necessary in certain clinical situations.

This study evaluates the structural and biochemical alterations of the elbow capsule after trauma through microscopy and immunohistochemistry. We compared capsules from 37 patients undergoing surgery for elbow contracture with normal capsules from 7 donors. Contracture capsules were significantly thicker than control capsules (P < .05) and exhibited extensive disorganization of collagen fiber bundle arrangement. Levels of specific cytokines involved in connective tissue turnover were measured. The results showed that the levels of cytokines matrix metalloproteinase (MMP) 1, MMP-2, and MMP-3 were greater as compared with control capsules (P < .05). This was associated with collagen disorganization, fibroblast infiltration, and in some specimens, lymphocytic infiltration in the capsular tissue. In contracture specimens, there was a localization of tissue inhibitor of matrix metalloproteinase 2 staining only in the vicinity of the synovial membrane and in blood vessels. Immunohistochemistry for type III collagen showed a greater presence in the control capsules compared with contracture capsules. This study demonstrates pathologic thickening, disorganization of the collagen fiber arrangement, and involvement of cytokines in the pathology of post-traumatic contracture of the elbow.

We evaluated histologically 10 biopsy specimens taken preoperatively from the anterior-inferior glenohumeral ligament from patients with atraumatic instability who had undergone radiofrequency capsular shrinkage, 10 taken immediately postoperatively, and 13 taken before revision. The synovial and subsynovial layers returned to normal histology in biopsy specimens taken from 6 months onwards. Collagen bundles in the fibrous layer continued to have a reparative histology during the period of the study (up to 37 months). The type of radiofrequency probe used (monopolar or bipolar) had no effect on the histologic healing process (P > 0.5, chi2 test). A histologic score was introduced, and this was found to have an excellent intraobserver agreement (weighted kappa, 0.840) and a moderate interobserver agreement (weighted kappa, 0.698).

Capsular attenuation has been seen after thermal capsulorrhaphy surgery. The purpose of this study was to evaluate the mechanical, histologic, and morphologic effects on capsular tissue after cumulative applications of radiofrequency energy. Ovine patellofemoral capsular tissue was treated with 1, 2, 4, or 8 applications of bipolar radiofrequency energy and then analyzed. No acute capsular ablation or destruction was seen grossly, even in the 8-application group. No definitive visual clues that excessive radiofrequency energy had been applied were seen. There was significant shrinkage and loss of tensile stiffness for all thermal application groups. Given the small sample sizes, post-application failure load, percent relaxation, and stiffness were not observed to be significantly different among the groups. Cumulative applications produced minimal further tissue shrinkage but were accompanied by larger, though not statistically significant, mechanical property losses and increased depth of tissue penetration. These findings suggest that there is no benefit to repeated applications of radiofrequency energy to capsular tissue.

The aim of this study was to find intraarticular lesions after manipulation under general anesthesia in patients with primary frozen shoulder. In a prospective trial conducted between 2001 and 2003 in 30 patients with primary frozen shoulder, the affected shoulders were manipulated while the patients were under general anesthetia. Exclusion criteria were secondary stiffness caused by rotator cuff tears and glenohumeral arthritis. After manipulation, each patient was examined by arthroscopy, and any intraarticular lesions were documented. In all patients, during manipulation, a significant improvement in the range of motion was achieved. Under anesthesia, flexion improved on average from 70 degrees +/- 33 degrees to 180 degrees +/- 15 degrees, abduction from 50 degrees +/- 20 degrees to 170 degrees +/- 25 degrees, and external rotation from -5 degrees +/- 10 degrees to +40 degrees +/- 20 degrees. Arthroscopy revealed hemarthrosis in all patients after manipulation. In 22 patients, localized synovitis was detected in the area of the rotator interval, whereas in 8 patients, disseminated synovitis was observed as a feature of adhesive capsulitis. After manipulation, the capsule was seen to be ruptured superiorly in 11 patients, the anterior capsule was ruptured up to the infraglenoid pole in 24 patients, and 16 patients each had a capsular lesion located posteriorly. In 18 patients no additional joint damage was found after manipulation. In 4 patients, iatrogenic superior labrum anterior-posterior lesions were observed. Further injuries detected were 3 fresh partial tears of the subscapularis tendon, 4 anterior labral detachments (1 with a small osteochondral defect), and 2 tears of the middle glenohumeral ligament. Even though manipulation under anesthesia is effective in terms of joint mobilization, the method can cause iatrogenic intraarticular damage.

The purpose of this study was to compare the percentage of glenohumeral intracapsular volume reduction after open inferior capsular shift and arthroscopic thermal capsulorrhaphy. Twelve matched, fresh-frozen cadaveric shoulders were used for the study. Intraarticular glenohumeral volume measurements were obtained by injecting a viscous fatty acid sulfate solution into the joint. In the 6 right shoulders, a standard anterior-inferior capsular shift was performed, and in the 6 matching left shoulders, an arthroscopic thermal capsular shrinkage was performed. After the procedures, the capsular volumes were re-measured. The open inferior shift procedure resulted in a mean decrease in glenohumeral volume of 50.2% (range, 43%-56%). Arthroscopic thermal capsulorrhaphy decreased shoulder intraarticular volume by a mean of 29.7% (range, 26%-36%). Both the open capsular shift and arthroscopic thermal shrinkage procedures produced well-documented volumetric reductions in the shoulder capsules. The open shift reduced intraarticular shoulder volume significantly more than arthroscopic thermal capsular shrinkage.

Instability of the glenohumeral joint can be associated with anteroinferior capsulolabral rupture. To understand its static stabilizing effect better, the collagen fiber orientation of the inferior glenohumeral ligament (IGHL), a component of the anteroinferior capsulolabrum, was studied with a small angle light scattering technique. Three rectangular samples (approximately 11 x 6 mm) were excised from the axillary pouch, one from the anterior band (AB) of the IGHL and one control sample from the long head of the biceps tendon of 7 cadaveric shoulders. The small angle light scattering technique scans the tissue with a helium-neon laser beam and quantifies the fiber alignment based on the resultant scattering pattern. The fiber orientation was quantified by an orientation index, defined as the angle within which 50% of the fibers lie. The axillary pouch had a random orientation, whereas the AB-IGHL was random with some regions of localized alignment. The percentage of tissue with an orientation index range of 25 degrees to 45 degrees was 23.2% +/- 8.5% and 29.0% +/- 13.1% for the axillary pouch and the AB-IGHL, respectively, whereas that for the long head of the biceps tendon was 61.6% +/- 15.2%. This suggests that the collagen fibers in the IGHL are not highly aligned and the anteroinferior capsulolabrum can be modeled as a continuous sheet. Moreover, a biomechanical evaluation of the anteroinferior capsulolabrum that investigates the possibility that the mechanical properties may be directionally independent should be conducted.

Treatment of recurrent posterior or multidirectional glenohumeral instability in athletes with traditional operative management has produced variable results at long-term follow-up. The purpose of this study was to determine whether an arthroscopic thermal capsuloplasty of the posterior capsule with a radiofrequency probe significantly decreases anterior-posterior glenohumeral translation. Successive posterior and anterior loads of 10, 15, and 20 N were applied sequentially to 7 cadaveric shoulder joints that were mounted in a translation testing apparatus with an electromagnetic tracking device measuring posterior and anterior glenohumeral translation. Arthroscopic thermal capsuloplasty was then performed on the posterior capsular tissue with a radiofrequency probe. The identical posterior-anterior loading protocol was then repeated, and translations were recorded. The results demonstrated no statistically significant differences in the mean posterior translation measurements before and after arthroscopic thermal capsuloplasty of the posterior capsule for the 10-N (+8.9%), 15-N (-3.1%), or 20-N (-1.8%) load (P >.50 to.62). Slightly greater changes occurred in anterior translation after posterior capsuloplasty at 10 N (-1.0%), 15 N (-6.0%), and 20 N (-10.3%). However, these changes were not found to be significant either (P =.06 to.62). The results of this study demonstrated that neither posterior nor anterior glenohumeral translation was significantly decreased by thermal capsuloplasty of the posterior capsule. Perhaps the lack of substantial collagenous material in the thin posterior capsule accounts for the inability of thermal capsuloplasty to be effective in this region.

The treatment of recurrent anterior, posterior, or multidirectional glenohumeral instability by operative closure of the rotator interval has been proposed. The purpose of this study was to determine whether arthroscopic thermal capsuloplasty of the rotator interval with the radiofrequency probe significantly decreases anterior-posterior glenohumeral translation. Anterior and posterior loads of 10, 15, and 20 N were sequentially applied to 8 cadaveric shoulder joints while mounted in a translation testing apparatus with an electromagnetic tracking device measuring anterior and posterior glenohumeral translation. Arthroscopic thermal capsuloplasty was then performed on the rotator interval with a radiofrequency probe. The identical anterior-posterior loading protocol was then repeated, and translations were recorded. The results showed a significant reduction in anterior and posterior translation after thermal capsuloplasty. After rotator interval thermal capsuloplasty, anterior translation decreased by 31.5%, 28.8%, and 27.2% for the 10-, 15-, and 20-N loads, respectively. Posterior translation decreased by 43.1%, 43.8%, and 40.7%, respectively. The results of this study indicate that arthroscopic thermal capsuloplasty of the rotator interval is an effective way by which to decrease both anterior and posterior glenohumeral translation in vitro. To date, no in vivo studies that sufficiently document long-term clinically successful outcomes of such a procedure exist. Future studies are warranted to evaluate the effects of the biologic response to thermal shrinkage and whether these reduced glenohumeral translations will be maintained.

The purpose of this study was to evaluate 4 cases in which axillary nerve injury was observed after radiofrequency capsular shrinkage of the shoulder. These cases were used to evaluate the clinical circumstances under which axillary nerve injury occurred, the time frame over which these injuries recovered, and the ultimate outcome observed in these patients. The case histories of each of these 4 patients were carefully evaluated. In 2 of the 4 cases, purely sensory findings were found, and in 2 cases both sensory and motor injuries occurred. In each case the inferior axillary recess was treated using the Oratech Interventions Tac-S probe. The authors conclude that injury to the axillary nerve during this procedure is possible and postulate that heat penetration through the capsule to the nerve is the most likely cause of injury.

Sixteen patients underwent detailed arthroscopic evaluation; all had moderate to severe, primarily unexplained shoulder pain provoked by anterior elevation and internal rotation, and all were nonresponsive to subacromial injection of local anesthetic. None of the patients had any symptoms or signs of instability. Partial subscapularis lesions were documented in 10 of 13 patients who had undergone preoperative arthro-magnetic resonance imaging. At arthroscopy, an isolated lesion of the common humeral insertion of the superior glenohumeral and coracohumeral ligaments (a so-called pulley lesion) was found in 3 cases, a lesion associating a pulley and an articular side partial subscapularis lesion in 10 cases, and an isolated articular side partial subscapularis tear in 3 cases. The most painful movement, which consisted of flexion and internal rotation, caused impingement of the involved ligamentous and/or capsular insertions in all patients. If the arm was elevated above 90 degrees, the zone of mechanical contact was between the long head of the biceps and the pulley region and superiormost aspect of the labrum; if elevation was decreased, impingement occurred between the tendinous insertion of the subscapularis and the anterior glenoid labrum and rim. This study suggests that in addition to the posterosuperior impingement of the supraspinatus tendon originally described by Walch, anterosuperior impingement of the deep surface of the subscapularis is a form of intraarticular impingement responsible for painful structural disease of the shoulder.

The purpose of this study was to determine whether there are changes in anterior and posterior glenohumeral translation after arthroscopic thermal capsuloplasty with a radiofrequency probe. Anteriorly directed loads of 15 N and 20 N were sequentially applied to the humerus of each of 5 cadaveric glenohumeral joints, and anterior translation on the glenoid was measured through use of a customized translation apparatus and an electromagnetic tracking device. The tests were then repeated with posteriorly directed forces, and posterior translation was measured. During testing, the glenoid was rigidly fixed and the glenohumeral joint was positioned to simulate 90 degrees of shoulder abduction and 90 degrees of external rotation. By means of the radiofrequency probe, thermal energy was then applied to the anteroinferior capsuloligamentous structures; anterior and posterior translation measurements were repeated. The results showed a significant reduction in anterior and posterior translations after thermal capsuloplasty (P < .05). Anterior translation decreased from 6.8 to 4.0 mm (a 41% decrease) with the 15-N load and from 8.6 to 4.9 mm (a 42% decrease) with the 20-N load. Posterior translation decreased from 9.3 to 5.8 mm (a 36% decrease) with the 15-N load and from 10.4 to 6.5 mm (a 35% decrease) with the 20-N load. The results of this study indicate that the radiofrequency probe can be used to decrease both anterior and posterior glenohumeral translation in vitro. The biological effect on heat-treated tissues over time needs to be studied to prove that this is a satisfactory treatment for glenohumeral instability.

We assessed the clinical utility of 42 arthroscopic releases for lateral epicondylitis in 40 patients (average age, 43 years) with an average of 14 months of symptomatic history before surgery. At arthroscopy, we found 15 type I lesions (intact capsule), 15 type II lesions (linear capsular tear), and 12 type III lesions (complete capsular tear), and associated disorders were found in 69% of the patients. At an average follow-up of 2.8 years, patients were asked to report on elbow pain and function. Subjectively, the patients rated their pain at rest as an average of 0.9 (0 = no pain; 10 = severe pain). They rated their pain with activities of daily living as 1.4 and their pain with sports and work as 1.9. Functionally, they averaged 11.1 of 12 possible points. Of the 39 elbows in the 37 patients who were available for follow-up, 37 were rated "better" or "much better." Patients returned to work in an average of 2.2 weeks. Grip strength averaged 96% of the strength of the unaffected limb. Arthroscopic tennis elbow release is a reliable treatment that allows patients an expedited return to work and may result in greater postsurgical grip strength.

In magnetic resonance imaging of peripheral nerve palsy, changes of signal intensity are often found in paralyzed muscles. The purpose of this report is to clarify the relation between magnetic resonance imaging findings and clinical examination in suprascapular nerve palsy. The subjects were 12 patients with suprascapular nerve palsy who underwent magnetic resonance imaging examinations. In 9 of 12 cases ganglion cysts were found at the spinoglenoid notches. On T1-weighted images the signal intensity of infraspinatus muscle was high in four cases but normal in the supraspinatus muscle in all cases. On T2-weighted images the signal intensity of infraspinatus muscle was high in six cases, and that for supraspinatus muscle was high in one case. In two cases the high intensity of palsied muscles became normal after the palsy recovered. Magnetic resonance imaging is a useful examination of peripheral nerve palsy not only for the detection of ganglion cysts but also for assessing the stage of paralysis.

This study evaluates the role of the glenoid labrum and capsule in the prevention of shoulder dislocation. Fifteen shoulder joints from nine fresh cadavers were used. The labrum and capsule were cut into sections 5 mm wide, and the strength of each slice to rupture was measured. The rupture site was observed microscopically. The anterior-inferior portion was the weakest, with a mean force necessary to cause rupture of 3.84 +/- 1.00 kg/5 mm. The rupture site was the portion of the labrum close to the cartilage of the glenoid. Histologic structure and degenerative changes of the labrum did not differ in the anterior to posterior portions. These results show that the anterior-inferior portion of the labrum is relatively weak. This finding may explain the lesion commonly identified in anterior shoulder dislocation.