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Purpose: The aim of the present study was to assess histologic changes in the temporomandibular joint (TMJ) of adult rats subjected to unilateral fracture of the mandibular condyle and soft tissue injury., Materials and Methods: The animals were divided into 2 groups: one had surgical treatment for soft tissue repair and the other had no soft tissue treatment. All histologic evaluations were performed according to the presence or absence of synovitis, vascularity, presence or absence of joint inflammation, and presence or absence of the articular disc. The contralateral TMJs also were evaluated., Results: The results showed few histologic changes in the synovial membrane and joint disc for the 2 groups and in the synovial membrane and disc of the contralateral side, where indirect trauma occurred in the unoperated joint., Conclusion: This study showed that treating or not treating soft tissues does not change the treatment results of condyle fracture or interfere with TMJ pathosis., (Copyright © 2014. Published by Elsevier Inc.)

Purpose: The purpose of this study was to retrospectively investigate magnetic resonance (MR) arthrography imaging findings associated with capsular laxity of the hip joint found at surgery., Methods: After institutional review board approval, 27 patients who had arthroscopy reports that described the presence or absence of capsular laxity of the hip joint were identified over a 2-year period. Preoperative MR images were retrospectively reviewed by 2 blinded radiologists. The following observations were recorded: (1) thickness, signal intensity, and defects of the anterior joint capsule; (2) thickness and signal intensity of the zona orbicularis; (3) width of the anterior and posterior joint recesses at the level of the femoral head; (4) presence of synovitis in the anterior joint recess; and (5) volume of intra-articular contrast and degree of hip rotation. Intrarater and inter-rater agreement was assessed., Results: Of the 27 patients, 17 were positive and 10 were negative for hip joint laxity at arthroscopy. The mean thickness of the anterior hip capsule was significantly different (P = .0043), measuring 2.5 mm (95% confidence interval [CI], 2.3 to 2.8 mm) in those with hip laxity and 3.3 mm (95% CI, 2.8 to 3.8 mm) in those without laxity. The mean width of the anterior joint recess was 5.8 mm (95% CI, 5.4 to 6.3 mm) in those with laxity and 3.6 mm (95% CI, 3.3 to 3.9 mm) in those without laxity and was significantly different (P < .0001). No other variables were considered useful because of a lack of significant differences between the 2 patient groups or low inter-rater agreement., Conclusions: On the basis of 95% CIs, hip joint laxity at MR arthrography is associated with widening of the anterior hip joint recess (>5 mm) and thinning of the adjacent joint capsule (<3 mm) lateral to the zona orbicularis., (Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: This study evaluated the role of magnetic resonance imaging (MRI) in cases of acute condylar injury and assessed soft tissue damage such as disc displacement, capsular tear, and hemarthrosis within the temporomandibular joint (TMJ)., Patients and Methods: This prospective study was conducted in 15 patients who presented with unilateral or bilateral condylar fracture or contusion with a unilateral or bilateral diagnosis of TMJ sprain/strain. Patients with trauma of less than 7 days previously with a unilateral or bilateral condylar fracture or contusion with a diagnosis of TMJ sprain/strain were included in the present study. The clinical diagnosis of TMJ sprain was made and further classified and graded according to the severity and type of injury. On confirmation of the diagnosis of condylar injury, patients underwent evaluation by MRI. All patients were treated by closed reduction of the condylar fracture and intermaxillary fixation for 14 to 21 days., Results: Of the 15 patients, 5 were children and 10 were adults. Of all 17 TMJ cases (2 bilateral, 13 unilateral), 2 condylar fractures were of the high variety and 13 were of the low variety. MRI diagnosis of disc displacement was established in 8 of 17 TMJ cases. There was a significant association between degrees of condylar injury and the MRI diagnosis of displaced disc and hemarthrosis. However, an MRI finding of capsular tear was not significantly associated with the degree of condylar injury., Conclusions: Soft tissue changes of the TMJ can be predicted accurately by MRI and are in direct proportion to the severity of the condylar injury of the mandible. Among the soft tissue changes, disc displacement and hemarthrosis seem to affect the outcome of functional treatment., (Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To document outcomes after anterior capsulolabral reconstruction for recurrent shoulder instability in 15 patients (20 shoulders) who have had multiple failed stabilizations or collagen disorders., Methods: Twenty shoulders with recurrent instability underwent revision stabilization with allograft reconstruction of anterior capsulolabral structures, which re-creates the labrum and capsular ligaments. The patients comprised 3 men and 12 women (mean age, 26 years [range, 18 to 38 years]) in whom multiple prior repairs failed and who had disability from continued pain and instability. Patients could choose to undergo either arthrodesis or salvage allograft reconstruction or to live with permanent disability. Of the patients, 5 had Ehlers-Danlos syndrome whereas 10 had hyperlaxity syndromes without genetic confirmation. Failure was defined as further instability surgery. Pain, shoulder function, instability (dislocations/subluxation), and American Shoulder and Elbow Surgeons scores were documented., Results: At follow-up, 9 of 20 shoulders (45%) remained stable. Recurrent instability was reported in 5 shoulders (25%), but the patients chose not to undergo further surgery. In the 14 shoulders without further stabilization (nonfailures), the mean American Shoulder and Elbow Surgeons score increased 43 points at a mean of 3.8 years (range, 2 to 6 years) postoperatively (P < .05). Mean satisfaction with outcome in nonfailures was 7 of 10 points (range, 1 to 10). Six shoulders failed by progressing to instability surgery at a mean of 8.6 months (range, 2.8 to 24 months). In the 6 shoulders that failed, the mean number of prior surgeries was 8 (range, 3 to 15) compared with a mean of 4 prior surgeries (range, 1 to 16) for the 9 nonfailures., Conclusions: Treating patients in whom multiple stabilizations have failed remains challenging. In our series 9 shoulders (45%) remained completely stable at 3.8 years. Recurrent instability (3 reinjuries) requiring further stabilization occurred in 6 (30%). Subsequent treatment for non-instability reasons was performed in 3 (15%). Instability was reported but revision surgery was not performed in 5 (25%). In 8 nonfailures (64%), the patients were highly satisfied with their surgical outcomes. Our results support this salvage procedure as a viable alternative to arthrodesis in young patients with end-stage shoulder instability or collagen disorders., Level of Evidence: Level IV, therapeutic case series., (Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Shoulder instability is a common diagnosis that often requires surgical treatment. A detailed knowledge of the shoulder anatomy and its stabilizing structures is of utmost importance for successful treatment of shoulder instabilities. Identifying anatomic variants (e.g., sublabral hole, meniscoid labrum, cordlike middle glenohumeral ligament, and Buford complex) and distinguishing them from pathologic findings may be especially difficult, as shown by the high interobserver variability. Over the last decade, basic research and arthroscopic surgery have improved our understanding of the shoulder anatomy and pathology. In the context of shoulder instability, injuries of the glenoid (bony Bankart), injuries of the glenoid labrum superiorly (SLAP) or anteroinferiorly (e.g., Bankart, anterior labroligamentous periosteal sleeve avulsion, and Perthes), capsular lesions (humeral avulsion of the glenohumeral ligament), accompanying cartilage lesions (Hill-Sachs, glenolabral articular disruption), and rotator interval and pulley lesions, as well as signs of dynamic instability impingement (posterior-superior impingement, anterior-superior impingement) can be exactly diagnosed (magnetic resonance imaging with intra-articular gadolinium, arthroscopy) and treated (arthroscopy). Therefore the purpose of this article is to review the current literature concerning shoulder anatomy/pathology related to shoulder stability/instability to improve clinical diagnosis and surgical treatment of our patients., (Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Traumatic anterior shoulder instability is a frequent problem and often requires surgical management. In the absence of significant bone deficiency, arthroscopic capsulolabral repair is associated with low recurrence rates and good functional outcome. However, capsulolabral deficiency, particularly after multiple previous attempts at repair, may preclude traditional arthroscopic Bankart techniques. Previous reports have described the use of autograft or allograft augmentation or coracoid transfer in the treatment of this difficult problem. The purpose of this report is to describe a novel technique of arthroscopic Bankart augmentation of capsulolabral deficiency using a split subscapularis tendon flap to reinforce a damaged capsule. In the absence of bone deficiency, this technique can restore anterior shoulder restraint without excessively constraining the glenohumeral joint., (Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

The rotator interval describes the anatomic space bounded by the subscapularis, supraspinatus, and coracoid. This space contains the coracohumeral and superior glenohumeral ligament, the biceps tendon, and anterior joint capsule. Although a definitive role of the rotator interval structures has not been established, it is apparent that they contribute to shoulder dysfunction. Contracture or scarring of rotator interval structures can manifest as adhesive capsulitis. It is typically managed nonsurgically with local injections and gentle shoulder therapy. Recalcitrant cases have been successfully managed with an arthroscopic interval release and manipulation. Conversely, laxity of rotator interval structures may contribute to glenohumeral instability. In some cases this can be managed with one of a number of arthroscopic interval closure techniques. Instability of the biceps tendon is often a direct result of damage to the rotator interval. Damage to the biceps pulley structures can lead to biceps tendon subluxation or dislocation depending on the structures injured. Although some authors describe reconstruction of this tissue sling, most recommend tenodesis or tenotomy if it is significantly damaged. Impingement between the coracoid and lesser humeral tuberosity is a relatively well-established, yet less common cause of anterior shoulder pain. It may also contribute to injury of the anterosuperior rotator cuff and rotator interval structures. Although radiographic indices are described, it appears intraoperative dynamic testing may be more helpful in substantiating the diagnosis. A high index of suspicion should be used in association with biceps pulley damage or anterosuperior rotator cuff tears. Coracoid impingement can be treated with either open or arthroscopic techniques. We review the anatomy and function of the rotator interval. The presentation, physical examination, imaging characteristics, and management strategies are discussed for various diagnoses attributable to the rotator interval. Our preferred methods for treatment of each lesion are also discussed., (Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: We compared high-resolution ultrasonography with magnetic resonance imaging (MRI), as the gold standard, to evaluate lateral and anterior capsule-condyle distances to detect disc displacement of the temporomandibular joint., Materials and Methods: This study included 28 patients (19 female and 9 male; age range, 16-51 years; mean age, 32.82 years), and in total, 56 joints were assessed with ultrasonography and MRI. Measurements were obtained for anterior capsule-condyle and lateral capsule-condyle distances in both open- and closed-mouth positions with high-resolution ultrasonography. These findings were also compared with those of MRI taken as reference. Receiver operating characteristic curve analysis was performed to assess our results. We assessed sensitivities, specificities, accuracies, and positive and negative predictive values for both open- and closed-mouth positions., Results: Diagnostic accuracy of ultrasonographic anterior capsule-condyle distance in the closed-mouth position to detect MRI-positive disc displacement (area under receiver operating characteristic curve, 0.689; P = .015) was the highest., Conclusions: The measurement of the distance between the most anterior point of the articular capsule and the most anterior point of the condyle can be used to assess disc displacement in diseased joints. However, it is necessary to determine the most accurate threshold value and to set cutoff values. These findings need to be confirmed by further research in a large number of patients to test the interexaminer agreement and the reproducibility of this method., (Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to measure in vivo axial-plane translation of the glenohumeral joint by use of magnetic resonance imaging in patients with and without SLAP lesions between the conventional adducted neutral rotation (AD) view and an abducted externally rotated (ABER) view., Methods: Seven patients with an intraoperative SLAP lesion that was unstable and required repair were selected into the SLAP group. Although they did not have normal shoulders, 15 patients were selected into the control or comparison group, most of whom had rotator cuff pathology. The glenohumeral contact point (CP) and humeral head center (HHC) were calculated and compared with the glenoid surface as a relative anterior or posterior translation. The relative posterior translation between the ABER and AD views for each patient was calculated as Delta CP and Delta HHC. These values were compared between the SLAP and control groups., Results: There was a significant difference in Delta CP between the SLAP and control groups (3.62 v 0.79 mm of relative posterior translation, P = .005). There was not a similar significant difference found in Delta HHC between the SLAP and control groups (3.19 mm v 1.48 mm of relative posterior translation, P = .14). There was a significant difference between the mean translations of the SLAP-ABER group and the SLAP-AD group for both CP (-3.65 mm v -0.04 mm, P = .008) and HHC (-2.22 mm v +0.97 mm, P = .03). The difference between the control-ABER group and the control-AD group was not as pronounced., Conclusions: The magnetic resonance imaging ABER view in patients with unstable SLAP lesions requiring repair showed in vivo glenohumeral posterior translation relative to the adducted neutral rotation view of greater than 3 mm., Clinical Relevance: This finding furthers the understanding of the pathokinematics in SLAP lesions., ((c) 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to investigate intra-articular hip joint pathologies in professional athletes who sustained dislocation and were treated with hip arthroscopy., Methods: Between August 23, 2000, and September 15, 2006, 14 professional athletes (12 male and 2 female) sustained a nonfracture traumatic hip dislocation during active competition and were treated by a single surgeon. A retrospective chart review of this cohort was done to report the intra-articular hip pathologies identified at the time of arthroscopy., Results: The average time from dislocation to relocation was 3.56 hours. The mean time from dislocation to surgery was 125 days (range, 0 to 556 days). The average age at the time of arthroscopy was 30.5 years (range, 16 to 46 years). All patients had labral tears. All patients had chondral defects. Two had isolated femoral head chondral defects, 6 had isolated acetabular chondral defects, and 6 had chondral defects on both surfaces. Eleven patients had loose osteochondral fragments. Eleven patients had partial or complete tears of the ligamentum teres. Nine patients had evidence of femoroacetabular impingement; 4 had isolated cam lesions, 1 had an isolated pincer lesion on the acetabular rim, and 4 patients had mixed type pathology. Two patients had capsulolabral adhesions. Two patients had a capsular tear. Additionally, 3 patients underwent intraoperative evaluation of the lateral epiphyseal vessels with Doppler imaging to confirm good blood flow to the femoral head with consistent pulse., Conclusions: The results of this study show that traumatic dislocation is accompanied by a variety of intra-articular hip joint pathologies, the most common being labral, chondral, intra-articular loose fragments, and disruption of the ligamentum teres.

Purpose: The purpose of this study was to evaluate the histologic morphology of human shoulder joint capsule after thermal capsulorrhaphy with monopolar radiofrequency energy (mRFE) during short- to long-term follow-up., Methods: This study comprised 27 patients who received an arthroscopic mRFE thermal capsulorrhaphy and 10 patients without mRFE treatment serving as the control group. Biopsy samples from 3 locations (anterior-superior, anterior-inferior, and posterior-medial) of the shoulder joint capsule were harvested from both the mRFE-treated patients and the control patients. The follow-up time for the mRFE treatment ranged from 3.5 to 62 months, which was divided into 3 groups: short, 3.5 to 12 months; medium, 14 to 25 months; and long, 31 to 62 months. The biopsy samples were analyzed via a histologic scoring system, evaluating an intact synovial layer, subsynovial edema, collagen morphology, cellularity, vascularity, and inflammatory cells. Histologic scores among each follow-up group were compared with each other and with those in the control group., Results: There were no significant differences in the histologic categories of intact synovial layer, subsynovial edema, collagen morphology, and inflammatory cells among the control and mid- and long-term mRFE groups. The short-term mRFE group had greater increased cellularity and vascularity compared with the mid- and long-term groups, which progressively improved toward the appearance in the normal control group with time., Conclusions: After mRFE capsulorrhaphy, histologic analysis revealed that the mRFE-treated shoulder joint capsule had almost returned to normal, except for persistent cellularity and increased vascularity, which were present at up to 5 years after this procedure., Level of Evidence: Level III, therapeutic case-control study.

Because the use of arthroscopy has increased recently for the treatment of elbow lesions, reports of complications have become more common. Nerve injury after arthroscopic anterior capsular release is an extremely rare complication, with 4 reported cases worldwide. We usually use a sharp-tipped electrocautery device with a 0.5-mm diameter during arthroscopic capsular release. In this case, because the former was not prepared, we used a ball-tipped electrocautery device with a 3-mm diameter. Herein, we experienced a case of radial nerve palsy after arthroscopic anterior capsular release using a ball-tipped electrocautery device on a degenerative elbow contracture. We supposed that the electrocautery device caused transiently thermal injury of the radial nerve despite proper portal entry site, intra-articular distension, and gentle arthroscopic manipulation. Elbow arthroscopy remains a technically difficult procedure with the potential for neurologic complications. To perform surgery safely, knowledge of the regional neuroanatomy and a thorough understanding of proper instrument usage are required.

Multidirectional instability of the shoulder can be a difficult diagnostic and therapeutic dilemma for orthopaedic surgeons. First described by Neer and Foster, the mainstay of treatment is usually conservative, with most patients doing very well with nonoperative management. In patients with recalcitrant symptoms, surgical treatment primarily has been aimed at addressing the pathologically increased capsular volume. Newer studies suggest that the pathology also includes abnormal labral morphology and perhaps inadequate neuromuscular control. The arthroscopic treatment of multidirectional instability has come to have comparable results to open techniques when the multifactorial nature of the disease is recognized and the multiple techniques are used in combination to fully treat all pathology. Thermal capsulorrhaphy cannot be recommended at this time, except perhaps as an adjunct to other capsular plication or capsulorrhaphy techniques. The advantages of a less invasive procedure make arthroscopic capsular plication attractive, but it is associated with increased technical difficulty and a steep learning curve. Further studies are needed to distinguish a clear advantage of one over the other. Regardless of the technique used, the key to success is addressing the capsular laxity and redundancy to restore anatomic capsuloligamentous tension without overconstraining the shoulder.

Purpose: Although an anteroinferior capsulolabral detachment (typical Bankart lesion) has been evaluated in other experimental studies, it has not yet been tested with an apprehension test in an intact shoulder model., Methods: Adjacent combinations of 4 zones of the capsuloligamentous complex were sequentially detached from the glenoid neck in 50 cadaveric shoulders. Stability was tested before and after each resection step: inferior stability with a sulcus test and anterior stability with an anterior drawer test and with a load-and-shift test in the apprehension position., Results: A metastable anteroinferior dislocation occurred in 18 specimens after section of 3 zones and in 14 only after section of 4 zones. A locked dislocation occurred after section of all 4 zones in 33 specimens and in the other 17 shoulders only after the posterior capsule was also cut., Conclusions: The humeral head cannot dislocate anteroinferiorly when there only is a Bankart lesion. In our study superior and posterior extension was necessary before the tensioning mechanism in external rotation and abduction failed enough for dislocation to occur., Clinical Relevance: Because the Bankart lesion is most likely not the only lesion present in patients with recurrent dislocation, a careful search for other lesions needs to be done when one is attempting surgical treatment. These lesions would need to be treated as well if one wants to avoid the risk of residual instability.

Purpose: To determine how much volume reduction can be obtained with varying amounts of arthroscopic capsular plication., Methods: Six fresh-frozen, cadaveric specimens were used. Specimens were rejected if a rotator cuff tear was present. The volume of each shoulder joint was measured under 3 conditions: no capsular shift, 5-mm capsular shift, and 10-mm capsular shift. For each shift, 4 sutures were placed arthroscopically, 2 anteriorly and 2 posteriorly. Repeated measures were used to confirm the validity of the measurements. Data were analyzed with parametric and nonparametric tests., Results: The average percentage of volume reduction at 5 mm of capsular plication from control was 16.2% (range, 9.7% to 21.5%). The percentage of volume reduction from control to 10 mm of capsular plication averaged 33.7% (range, 25.3% to 44.6%). Statistical significance was found with both parametric (P < .0001) and nonparametric tests (P < .0313)., Conclusions: The current study found that capsular volume reduction was related to the amount of capsular plication with reproducible results. Capsular plication can produce volume reduction comparable to other techniques., Clinical Relevance: The data could be used to determine the potential number of sutures and amount of tissue plication needed for the amount of laxity found at surgery.

Purpose: Intra-articular ganglia of the knee are rare and usually incidental findings of little clinical significance. Nevertheless some are large, symptomatic, and require treatment. We report on 3 patients with an intra-articular knee ganglion and an extrasynovial extension that was contained within the joint capsule. This seems to be a rare condition; a review of the English-language literature revealed no reports of similar cases., Type of Study: Case series., Methods: Three patients, 1 man and 2 women aged 27 to 40 years, presented with an almost identical history of anterior knee pain that had been treated conservatively for a long time as chondromalacia patellae. The symptoms, which were ill-defined, appeared to be deteriorating until a localized swelling appeared on the lateral side of the patella tendon in each case. On examination, a lateral meniscal cyst associated with an underlying meniscal tear was suspected. However, magnetic resonance imaging revealed a ganglion arising from the substance of the anterior cruciate ligament (case 1) and from the area of the tibial insertion of the anterior cruciate ligament (cases 2 and 3). All 3 ganglia extended anteriorly and then laterally over and in front of the lateral meniscus. The ganglia were approached through an anterior midline incision and lateral parapatellar arthrotomy, which allowed direct and easy access for complete excision. Histologic examination confirmed the diagnosis of a ganglion in all 3 cases., Results: The postoperative course was uneventful in all patients with no signs of recurrence at 1 year (case 1), 2 years (case 2), and 3 years (case 3)., Conclusions: Although the described condition seems very rare, we believe that it should be included in the differential diagnosis of cystic lesions about the knee joint., Level of Evidence: Level IV, case series, no, or historical control group.

Purpose: An ultrathin 15,000 fiberoptic-based arthroscope was evaluated for the detection of osteoarthritic intra-articular pathologies in sheep temporomandibular joints., Materials and Methods: Osteoarthritis was bilaterally induced in the temporomandibular joints in sheep. Twenty osteoarthritic temporomandibular joints were arthroscopically examined and rated with use of the ultrathin arthroscope. The arthroscopic observation was then compared with the histologic findings., Results: The arthroscope provided excellent vision of the osteoarthritic joints. Correlation between arthroscopic and histologic findings was 80%., Conclusion: The recently developed ultrathin (15,000) arthroscope was found to be a highly reliable and efficient tool to diagnose joint space pathologies of the osteoarthritic temporomandibular joint.

Purpose: The purpose of this study is to test the hypothesis that the efficacy of routine arthroscopic evaluation of the posterior compartments of the knee outweighs the morbidity or inefficiency., Type of Study: Prospective cohort analysis., Methods: One hundred consecutive knees underwent posteromedial and posterolateral evaluation according to an algorithm designed to maximize efficiency of technique. Loose bodies were defined as expected when preoperative imaging or arthroscopy of the rest of the knee revealed loose bodies. The number of attempts required for visualization or visualization not accomplished, morbidity (subjective femoral condylar scuffing or complications associated with the technique), and findings were recorded., Results: With regard to posteromedial, directly inserting the camera (as opposed to an obdurator) resulted in instrument breakage. In this study, 82% of posteromedial compartments were visualized on the first attempt, and 3% were not visualized. We found that 66% of femoral condyles had no damage, 28% mild, 3% moderate, and 3% severe. Loose bodies were found in 4 of 11 (36%) when expected and 0 of 86 when not expected, a significant difference. Five other posteromedial positive findings were observed. With regard to posterolateral, 93% of compartments were visualized on the first attempt, directly with the camera via the anterolateral portal. All were visualized. We found that 96% of femoral condyles had no damage, 4% mild, and 0% moderate or severe. Damage occurred significantly less frequently than with posteromedial. No findings were noted., Conclusions: Despite inefficiency, we recommend an obdurator for posteromedial visualization via the anterolateral portal. Posteromedial visualization was associated with morbidity but was efficacious in some cases and is strongly recommended when loose bodies are expected. Posterolateral visualization directly with the camera and via the anterolateral portal is efficient and associated with minimal morbidity but was not efficacious in the cohort evaluated., Level of Evidence: Level II.

Magnetic resonance imaging (MRI) is an effective method to evaluate cystic lesions of the knee. Intra-articular ganglia of the knee joint was considered to be rare before the advent of MRI. However, because an MRI is often used to diagnose knee pathology, the reported prevalence of intra-articular ganglia has increased. We describe two cases of an intra-articular ganglion arising from the posterior joint capsule. Both cysts appeared to be arising from the posterior cruciate ligament by both MRI as well as arthroscopy through a lateral infrapatellar portal. However, arthroscopy through a posteromedial portal revealed the cysts to originate from the posterior joint capsule. It suggests that some of the ganglion arising from the posterior cruciate ligament reported in the literature might actually be from the posterior joint capsule. To prevent recurrence of a ganglion cyst, when preoperative MRI shows the mass to be located posterior to the cruciate ligaments, we recommend that the relationship of the ganglion cyst to the posterior joint capsule be evaluated at arthroscopy through the posteromedial or posterolateral portal.

PROLOGUE: Several years ago, when we began to question microinstability as the universal cause of the disabled throwing shoulder, we knew that we were questioning a sacrosanct tenet of American sports medicine. However, we were comfortable in our skepticism because we were relying on arthroscopic insights, clinical observations, and biomechanical data, thereby challenging unverified opinion with science. In so doing, we assembled a unified concept of the disabled throwing shoulder that encompassed biomechanics, pathoanatomy, kinetic chain considerations, surgical treatment, and rehabilitation. In developing this unified concept, we rejected much of the conventional wisdom of microinstability-based treatment in favor of more successful techniques (as judged by comparative outcomes) that were based on sound biomechanical concepts that had been scientifically verified. Although we have reported various components of this unified concept previously, we have been urged by many of our colleagues to publish this information together in a single reference for easy access by orthopaedic surgeons who treat overhead athletes. We are grateful to the editors of Arthroscopy for allowing us to present our view of the disabled throwing shoulder. Part I: Pathoanatomy and Biomechanics is presented in this issue. Part II: Evaluation and Treatment of SLAP Lesions in Throwers will be presented in the May-June issue. Part III: The "SICK" Scapula, Scapular Dyskinesis, the Kinetic Chain, and Rehabilitation will be presented in the July-August issue. We hope you find it thought-provoking and compelling.

We present a case of ganglion cyst of the knee treated arthroscopically. Ganglion cysts typically arise from the anterior or the posterior cruciate ligament. In this case of an anomalous location, a 3.5-cm mass arose directly from the anterolateral articular capsule, lying over the lateral meniscus, displacing Hoffa's fat pad and joining the pretibial bursa. We removed it arthroscopically using only medial portals to avoid cystic wall damage and fluid leakage from the lateral portal. Arthroscopic evaluation was performed starting from the inferomedial portal to assess the cyst location, and shifting to the mid patellar portal. From that portal, we were able resect the cyst, opening the wall and shaving and aspirating the myxoid fluid.

We describe the case of fasciitis-like proliferation in the knee joint in a 52-year-old man. The polypoid lesion developed from the synovial joint capsule around the quadriceps tendon and was impinging on the patellofemoral joint. Histologic and immunohistochemical studies revealed a myofibroblastic proliferation similar to nodular fasciitis. Until now, only 3 other cases have been reported in the English and Japanese language literature.

Purpose: To determine the prevalence of proximal tibiofibular ganglion cysts in patients undergoing outpatient magnetic resonance imaging (MRI) of the knee., Type of Study: Observational cross-sectional study., Methods: From November 2000 to June 2001, every MRI of the knee performed at an outpatient imaging center was reviewed by a single examiner for the presence of a proximal tibiofibular ganglion cyst. In addition to the reason for ordering the MRI, demographic information on all patients was gathered., Results: A total of 654 knee MRI scans were performed at the outpatient imaging center during the study period. This study population consisted of 310 men and 344 women, with an average age of 43.4 years (range, 11 to 88 years). There were 308 left and 346 right knees imaged. The most common clinical diagnosis in these 654 patients was meniscal tear (42.8%). A total of 5 patients had a proximal tibiofibular ganglion cyst detected on MRI, yielding a prevalence of 0.76% (95% confidence interval [CI] = 0.1% to 1.4%). These cysts ranged in size from 1.0 to 2.8 cm in maximum diameter. Three were found in men and 2 in women. The mean age of these patients was 47.6 years (range, 42 to 54 years). The most common preimaging diagnosis in these patients was a medial meniscal tear (in 3 of 5)., Conclusions: This study is the first to provide data on the prevalence of proximal tibiofibular ganglion cysts in a population of patients with knee pain significant enough to warrant MRI. Over half of the patients found to have proximal tibiofibular ganglion cysts had no symptoms or signs attributable to them.

Purpose: The present study aimed to explore disc mobility and arthroscopically diagnosed morphologic changes in the temporomandibular joint (TMJ) associated with long-term mandibular discontinuity., Patients and Methods: Twelve patients (24 TMJs) who had undergone mandibulectomy including the unilateral condyle or segmental mandibulectomy without mandibular reconstruction, more than 8 months before this study were examined. The 24 TMJs were classified into 3 groups as follows: group 1, TMJs with a major mandibular fragment including the mandibular body (n = 11); group 2, TMJs with a mandibular ramus including the coronoid process (n = 5); and group 3, TMJs with only a condylar process, a mandibular ramus not including the coronoid process, or without a condyle (n = 8). Disc mobility was evaluated by magnetic resonance imaging, and arthroscopic observation of the superior joint compartment (SJC) was performed in all TMJs. The relationship between disc mobility and the arthroscopic findings was also studied., Results: The frequency of immobile discs differed significantly among groups 1 (0%), 2 (40.0%), and 3 (100%). Arthroscopic findings were normal in all SJCs of group 1. Various types of fibrous adhesions were observed in 40.0% of group 2 and in 75.0% of group 3. The development of fibrous adhesions in the SJC was significantly related to the presence of an immobile disc., Conclusions: Long-term immobilization of the TMJ in a nonfunctional state seems to promote the development of fibrous adhesions in the SJC. Preservation of the mandibular fragment including the coronoid process, during mandibulectomy appears to contribute to postoperative TMJ mobility. To ensure recovery of a physiologic TMJ after mandibulectomy, it seems important to re-establish TMJ mobility by establishing mandibular continuity as soon as possible., (Copyright 2001 American Association of Oral and Maxillofacial Surgeons.)

Recently, the use of thermal energy to shrink the redundant glenohumeral joint capsule in patients with instability has generated a great deal of interest. Proponents assert that the procedure avoids the need for an open stabilization and it may be used as an adjunct to an open or arthroscopic capsulolabral repair. The use of nonablative thermal energy to shrink soft-tissue collagen appears to induce ultra-structural and mechanical changes at or above 60 degrees C. The microscopic changes reflect the unwinding of the collagen triple helix and loss of the fiber orientation. The fibrils contract into a shortened state and reactive fibroblasts have been shown to grow into this treated area and synthesize the collagen matrix. The biomechanical properties of the tissue do not appear to be detrimentally altered if shrinkage is limited to less than 15% and if ablation or excess focal treatment is avoided. The endpoint of optimal shrinkage is not known and clinical estimations of tissue changes and volumetric reduction are used as guides to treatment. The first clinical follow-up study was only recently published in the peer-reviewed literature and prior preliminary reports were optimistic regarding the use of thermal energy for the treatment of glenohumeral instability. Thermal capsular shrinkage has been used as an adjunct to a capsulolabral repair, as well as an isolated treatment for the disorders of internal impingement and multidirectional instability. Additional evaluation is necessary to determine the optimal quantity of energy needed for tissue shrinkage without inadvertent tissue destruction. The long-term clinical effect, mechanical properties, and durability of the newly produced collagen need to be analyzed further. The basic science and clinical applications of this newly applied technology are reviewed in this article.

Purpose: The purpose of this study was to determine the temperatures along the course of the axillary nerve during radiofrequency (RF) capsulorrhaphy of the shoulder in a cadaver model. The hypothesis of this project was that temperatures capable of damaging neural tissue would be recorded during simulated RF capsulorrhaphy., Type of Study: Basic science evaluation., Methods: This study used 9 fresh-frozen cadaver shoulder capsules removed en bloc along with the underlying axillary nerve and soft tissue. The axillary nerve was instrumented with 4 thermocouples placed along the course of the nerve (2 thermocouples anterior and 2 posterior to the 6 o'clock position, spaced 7 mm apart). Each of the specimens underwent RF thermal capsulorrhaphy during which the temperature at each of the thermocouple positions was continuously recorded., Results: The average of the maximum temperature at each of the 4 positions measured along the course of the axillary nerve were 52.2 +/- 18.0 degrees C at the most anterior place probed, 45.8 +/- 5.44 degrees C (mid anterior), 44.5 +/- 8.7 degrees C (mid posterior), and 42.8 +/- 10.1 degrees C at the most posteriorly positioned probe. Two specimens had a maximum temperature greater than the 67 degrees C set point of the device, and 7 specimens had a maximum temperature greater than 45 degrees C in at least 1 thermocouple position., Conclusions: This study shows that heating of the axillary nerve can occur during RF capsular shrinkage of the shoulder and may potentially reach levels that can damage neural tissue.

Purpose: To determine temperature changes associated with radiofrequency (RF) energy-induced heating of bovine capsular tissue using a bipolar RF electrode versus a temperature-controlled, monopolar RF electrode., Type of Study: In vitro laboratory investigation using bovine capsular tissue., Methods: Samples of bovine tissue were placed in a saline bath (37 degrees C) and RF energy was applied using bipolar and monopolar RF electrodes at manufacturer-recommended settings for tissue shrinkage. Fluoroptic thermometry was used to record temperatures on the tissue surface and at depths of 1 mm and 2 mm during continuous delivery of RF energy at 1, 2, 3, 4, 5, and 10 second time increments., Results: The highest mean temperatures were recorded on the tissue surface, as follows (mean +/- SD; *P <.05, value compared with baseline): 1 sec 2 sec 3 sec 4 sec 5 sec 10 sec Bipolar 40.1 +/- 1.0* 48.2 +/- 4.7* 62.8 +/- 6.9* 76.0 +/- 7.6* 84.7 +/- 5.7* 94.7 +/- 1.9* Monopolar 39.0 +/- 0.7* 48.2 +/- 4.3* 67.7 +/- 7.0* 86.6 +/- 6.1* 93.8 +/- 2.7* 59.5 +/- 2.6* For the bipolar RF electrode, there was a strong linear relationship (R =.926) between mean surface temperatures versus time. The temperature-controlled, monopolar RF electrode did not appear to properly regulate the delivery of RF energy to maintain tissue temperatures at the selected level (i.e., 65 degrees C). The bipolar RF electrode produced a smaller temperature gradient (average difference, 9.2 degrees C) at the 1-mm tissue depth compared with the monopolar RF electrode (average difference, 14.6 degrees C). Temperature profiles at the 2-mm tissue depth were comparable for both types of RF electrodes., Conclusions: These data provide basic information pertaining to the temperature profiles produced by bipolar and monopolar RF electrodes applied to collagen-based tissue.

Summary: This in vitro study determined the temperature changes associated with radiofrequency (RF) energy-induced heating of bovine capsular tissue using bipolar RF electrodes. Tissue samples were placed in a saline bath (37 degrees C) and RF energy was applied using 2 different types of bipolar electrodes (VAPR T End Effect and Vapor T Side Effect; Mitek, Westwood, MA). Each electrode was activated for 3 seconds at 10 W, 16 W, and 20 W, for 6 separate data acquisitions. Fluoroptic thermometry designed to be unperturbed by RF fields was used to record temperatures on the tissue surface and at depths of 2 mm, 4 mm, and 5 mm, at 1-second intervals before (5 seconds), during (3 seconds), and after (7 seconds) the application of RF energy. The highest mean temperatures were recorded at the tissue surfaces for the different power settings for each RF electrode type, as follows: End Effect: 48.9 degrees C (10 W), 57.0 degrees C (16 W), and 67.3 degrees C (20 W). Side Effect: 51.5 degrees C (10 W), 62.1 degrees C (16 W), and 71.2 degrees C (20 W). All recorded surface temperatures were within the range known to be acceptable for tissue shrinkage. Gradient effects (i.e., higher-to-lower) were observed for the tissue temperatures measured at the different depth positions. None of the temperatures recorded at the different depths were excessive, suggesting that sensitive anatomic structures should not be damaged by RF energy-induced heating under the conditions described above.

Summary: The purpose of this article is to describe the outcome of an arthroscopic examination and the pathology in symptomatic shoulders of 41 professional overhand throwing athletes. With the arm in the position of the relocation test, 100% of the subjects had either contact between the rotator cuff undersurface and the posterosuperior glenoid rim or osteochondral lesions. Other key findings included undersurface cuff fraying in 93%, posterosuperior labral fraying in 88%, and anterior labral fraying in 36% of the subjects. This study supports the concept of impingement of the posterior cuff undersurface with the posterosuperior glenoid rim in the overhand throwing athlete with shoulder pain.

Summary: Limitation of internal rotation has been reported in conjunction with impingement syndrome of the shoulder. A group of 9 patients was identified who had discrete, painful loss of internal rotation associated with refractory impingement syndrome. The duration of symptoms averaged 18 months (range, 11 to 33 months), and all patients failed a course of physical therapy specifically addressing loss of internal rotation. Six patients reported traction as the mechanism of injury, and 3 developed motion loss and pain following a posterior capsular shift procedure. All patients underwent arthroscopy, and were observed to have a thickened posterior capsule. An arthroscopic release of the posterior capsule improved motion in all patients, with substantial relief of pain. At an average of 19 months follow-up (range, 11 to 35 months), internal rotation in 90 degrees of abduction improved from 10 degrees preoperatively to 47 degrees postoperatively, and there were no complications related to the procedure. We conclude that chronic loss of internal rotation secondary to posterior capsular contracture may be an explanation for refractory pain in some patients with an initial diagnosis of impingement syndrome. This condition appears to be amenable to arthroscopic posterior capsular release.

The recurrence of instability after arthroscopic stabilization has been significantly higher than after open repair. One of the reasons for the high failure rate is the inability of arthroscopic repairs to address the plastic deformity of the capsule that occurs in the glenohumeral ligament-labrum complex. The arthroscopic technique is used to repair the torn labrum to the glenoid, but without adequate tightening of the anterior capsule, which is successfully accomplished with an open technique. This report describes the new technique of arthroscopic Bankart repair with extracapsular and extra-articular knot using suture anchors that allows tightening of the anterior capsule sufficiently as with an open Bankart procedure.

Forty-three patients with a diagnosis of primary or secondary frozen shoulder who had symptoms for an average of 12 months and failed conservative treatment of at least 12 weeks of physical therapy, were treated with an arthrosopic capsular release. On completion of standard shoulder arthroscopy, intra-articular cautery was used to completely divide the anterior-inferior capsule, the intra-articular portion of the subscapularis tendon, and the middle glenohumeral, the superior glenohumeral, and the coracohumeral ligaments. The subacromial space was inspected in all patients. Eighteen patients had extensive subacromial fibrosis that required debridement. Subacromial decompression was reserved for patients with evidence of an acromial spur seen at the time of arthroscopy. Postoperatively, all patients showed substantial gains in shoulder range of motion, as well as diminished shoulder pain. Thirty-five patients completed a telephone survey at an average of 22 months after surgery. The average modified shoulder score was 19 (scale, 13 to 65), with 83% of patients indicating that their shoulder was normal or caused only mild symptoms. In conclusion, the authors believe that arthroscopic capsular release is an effective and safe alternative to manipulation in patients with a recalcitrant frozen shoulder.

The purpose of this multicenter retrospective study of arthroscopic release of the glenohumeral joint was to evaluate the technical feasibility, the results, and the potential correlations between results and cause of the stiffness. Twenty-six shoulders in 25 patients (19 women and six men) were re-evaluated 3 to 72 months (mean, 21 months) after arthroscopic release of the glenohumeral joint. Diagnoses were primary frozen shoulder in 13 cases, bipolar stiffness (rotator cuff tear plus capsular contraction) in 3 cases, and postinjury or postsurgery stiffness in 10 cases. Results were evaluated on passive range of motion, Constant's score, and subjective assessment. Anterior or anterior inferior capsular release was done at the anterior rim of the glenoid fossa. Posterior capsule release was not performed in this series. There were no intraoperative complications. Mean range of motion gains were 86 degrees for forward elevation, 72 degrees for abduction, 34 degrees for external rotation, and 6 spinal processes for internal rotation. Constant's range of motion score increased from 12.9 out of 40 to 32 out of 40 points. Thirteen patients were very satisfied, 5 satisfied, 5 improved, and 3 unchanged. Range of motion gains were independent from the cause of shoulder stiffness, but global results were better in the primary frozen shoulder group in terms of pain and strength. Arthroscopic release of the glenohumeral joint is feasible and safe. For primary frozen shoulders, in case of failure of the functional treatment, arthroscopic release is a less traumatic alternative to manipulation under general anesthesia. For bipolar stiffness, arthroscopy provides the opportunity for treating concomitant lesions. For postsurgical stiffness, arthroscopic release improves range of motion, but the shoulder often remains painful.

This study evaluated the effect of radiofrequency energy on the histological and ultrastructural appearance of joint capsular collagen. Femoropatellar joint capsular specimens from adult sheep were treated with one of three treatment temperatures (45 degrees C, 65 degrees C, and 85 degrees C) with a radiofrequency generator or served as control in a randomized block design. Twenty-four specimens (n = 6) were processed for histological examination as well as ultrastructural analysis using transmission electron microscopy. A computer-based area determination program was used to calculate the area affected in histological samples. Histological changes consisted of thermal tissue damage characterized by collagen fiber fusion and fibroblastic nuclear pyknosis at all application temperatures with clear demarcations between treated and untreated tissue. Mean tissue affected ranged from 50.4% for 85 degrees C to 22.5% for 45 degrees C. There was a strong correlation between treatment temperature and percent area affected (P < .001, R2 = .65). Ultrastructural alterations included a general increase in cross-sectional fibril diameter and loss of fibril size variation with increasing treatment temperature. Longitudinal sections of collagen fibrils showed increased fibril diameter and the loss of cross-striations in the treated groups. Thermally induced ultrastructural collagen fibril alteration is likely the predominant mechanism of tissue shrinkage caused by application of radiofrequency energy.

The purpose of this in vitro study was to evaluate the effect of radiofrequency energy on the length and temperature properties of the glenohumeral joint capsule in a sheep model. Dissected glenohumeral joint capsules were placed in a 37 degrees C tissue bath and treated with radiofrequency energy at temperature settings of 60 degrees, 65 degrees, 70 degrees, 75 degrees and 80 degrees C. Pretreatment and posttreatment tissue length was measured, and tissue temperature changes were recorded at distances of 0.0, 0.5, 1.0, 1.5 mm away from the probe path. Tissue shrinkage was found to be less than 4% for treatments below 65 degrees C, and increased to 14% for treatments at 80 degrees C. Posttreatment lengths of tissues treated at 65 degrees, 70 degrees, 75 degrees, 80 degrees C were significantly shorter than pretreatment lengths. The maximum tissue temperatures directly below the probe were observed to be 3.7 degrees to 6.7 degrees C lower than the set temperatures. As the distance from the probe was increased, the tissue temperature was found to decrease, reaching a value of less than 45 degrees C at 1.5 mm for all five treatment temperature settings. This study provided basic information on temperature settings, tissue shrinkage, and tissue temperature distribution of radiofrequency treatment.

Purpose: This study compared the magnetic resonance imaging (MRI) and pathologic findings in patients with disc displacement without perforation., Patients and Methods: Eleven patients and 30 asymptomatic volunteers underwent MRI using the three-dimensional (3D) fast imaging with a steady precession sequence (FISP) acquisition technique. The 11 patients (11 joints) then underwent discectomy, and the pathologic and MRI findings were compared., Results: MRI (FISP-3D) examination of the temporomandibular joint in 11 patients (11 joints) showed low signal intensity in the anterior band and the intermediate zone of the disc, and high signal intensity in the posterior band of the disc and retrodiscal tissue. On microscopic examination, the anterior band and intermediate zone of the disc were found to consist of dense collagenous bundles showing mild hyaline degeneration. Myxomatous degeneration was seen in the posterior band of the disc (11 joints), and edematous change was seen in the retrodiscal tissues (seven joints)., Conclusions: Pathologic changes in the disc and the retrodiscal tissues are accurately depicted by FISP-3D.

It is commonly claimed that unstable shoulders have an altered capsular elasticity and increased joint volume. To find out if there is a correlation between anterior instability and increased joint volume, 20 patients were examined while undergoing arthroscopic surgery of the shoulder. There were four anterior subluxators, 11 anterior dislocators, and five bilateral dislocators, and in all patients the contralateral shoulder was also examined. During continuous saline infusion, a pressure/volume curve was recorded within the range of 0-180 mm Hg. Joint volume was correlated with body surface area. Among the 15 patients with unilateral instability, there was no correlation between joint volume and body surface area. There were no differences in joint volume or capsular elasticity between the healthy and the unstable shoulder in any patient. It is concluded that capsular elasticity and joint volume contribute little to anterior shoulder instability and that instability probably depends more on damage to other stabilising structures in the joint.

Purpose: A method for producing disc displacement is presented in which remodeling events in the disc and posterior attachment (PA) are similar to those occurring in patients suffering from disc displacement (DD)., Method: Thirty-three adult New Zealand White rabbits were used in this study. A unilateral anterior DD was surgically induced in 18 animals. Six animals were sham operated and nine animals served as controls., Results: Macroscopically, DD was associated with gross thickening of the posterior band (PB), shortening of the disc anteroposteriorly, flexure of the intermediate zone (IZ), and loss of the biconcave shape. Microscopically, dramatic internal structural changes were observed in displaced discs, including extensive collagenous fiber reorganization and changes in cell morphology associated with a generalized loss of metachromatic staining. As in humans, the disc displacement caused abnormal loading of the PA and remodeling of this tissue into a disc-like structure characterized by the appearance of coarse collagenous fiber bundles and scattered chondrocytes surrounded by a matrix-containing cartilage-like glycosaminoglycans (GAGs)., Conclusion: These pathoanatomic changes bear a remarkable similarity to those described in human disc derangements and support the use of this method as an experimental model for the study of remodeling events in human DD arthropathies.

The objective of this study was to analyze the changes in the different components of the temporomandibular joint and their relation with age after subcondylar osteotomy. For this purpose 149 Wistar rats were divided into three groups: osteotomy, sham operation, and control. Two experimental ages (30 and 70 days) and radiologic, morphometric, macroscopic, and histologic methods of analysis were used. Different changes were observed in young and adult animals. Subcondylar mandibular osteotomy in growing rats caused anteroinferior displacement of the temporal and mandibular component of the joint. At the end of the experimental period only condylar displacement was maintained. Other changes were flattening of the mandibular condyle, which was transient, and lateral thickening of the articular disc. Subcondylar mandibular osteotomy in adult rats caused slight anterior displacement of the joint components at the end of the experimental period. At this age, although changes similar to those in growing animals were observed in some cases, in other cases the presence of pathologic findings, such as deformation of the condylar cartilage, thickening of the disc, intra-articular adherences, and osteolysis of the temporal fossa, were observed. Changes in the joint components were more marked in growing rats than in adults. In growing rats they affected the form of the condylar process to a greater extent, but the majority of these changes were transient. In adult rats, alterations in the joints were less pronounced, but they affected a greater number of joint components and were permanent.