How much does inferior capsular shift reduce shoulder volume?

The purpose of this study was to quantitate the effect of inferior capsular shift on shoulder volume. Four fresh frozen cadaveric shoulders were analyzed. Volume before and after shift was determined using 3 techniques: (1) Magnetic resonance imaging sequences were digitized to computer and analyzed for volume via a 35-mm camera using Cue 2 software. The capsule was delineated by contrast between light and dark regions. Volume was calculated by summing the total area of respective slices. (2) Ultrasound images, obtained after surgical exposure of the capsule, were digitized. Volume was calculated using the formula for a prolate ellipsoid. (3) An 18-gauge needle was used to inject and evacuate saline via an anterior approach. Quantity of aspirated fluid provided a direct measure of volume. Inferior capsular shift was performed. After the operation, measurements were repeated. Inferior capsular shift reduced volume in all shoulders with each technique. On average, inferior capsular shift reduced joint volume by 57 %). A measurable reduction in shoulder joint volume is an effect of capsular shift. This measurement may have clinical application if volume is an indicator of instability or laxity.

Adhesive capsulitis of the shoulder: MR diagnosis.

OBJECTIVE: Adhesive capsulitis is a clinical syndrome of pain and severely decreased joint motion ("frozen shoulder") caused by thickening and contraction of the joint capsule and synovium. Although arthrographic criteria for the diagnosis have been described, to our knowledge, the MR characteristics have not been reported. Accordingly, we studied the MR findings in 10 patients with this syndrome. MATERIALS AND METHODS: MR images of 25 subjects were included in the study. Nine had adhesive capsulitis documented by arthrography, and one had adhesive capsulitis proved at surgery. The MR findings in these patients were compared with those of 15 asymptomatic volunteers. Images were assessed for thickness of the joint capsule and synovium, for thickness of the coracohumeral ligament, and for volume of articular fluid. Capsule and synovium thickness was measured adjacent to the axillary recess. The volume of intraarticular fluid was calculated from direct measurements of the axillary recess and biceps tendon sheath. The rotator cuff interval was qualitatively evaluated for the presence of abnormal tissue. RESULTS: Thickening of capsule and synovium on MR images was characteristic of adhesive capsulitis, with a significant difference between mean thickness in patients with adhesive capsulitis (5.2 mm) and in asymptomatic volunteers (2.9 mm) (p < .01). Capsule and synovium thickness greater than 4 mm was a specific (95%) and sensitive (70%) criterion for the diagnosis of adhesive capsulitis. There was no significant difference in volume of articular fluid or thickness of the coracohumeral ligament between patients with adhesive capsulitis and asymptomatic volunteers (p > .5). The rotator cuff interval was not useful for assessing changes of adhesive capsulitis. CONCLUSION: Joint capsule and synovium thickness greater than 4 mm is a useful MR criterion for the diagnosis of adhesive capsulitis. The volume of articular fluid seen on MR images is not significantly diminished in patients with adhesive capsulitis.

Case report 815: Tear of the rotator interval.

Rotator interval tears are an uncommon, but clinically important subtype of rotator cuff tear. As MRI assumes an ever increasing role in the imaging evaluation of the painful shoulder, radiologists must be aware of this entity and appreciate the difficulty in diagnosing these tears with MRI. Differentiation of a true rotator interval tear from normal synovium and capsule in this space is most likely not possible with MRI, and symptoms may be referred and misleading. It is therefore important to correlate the MR findings with the clinical history and physical examination.

Ligamentous anatomy of the medial carpal region.

The purpose of this study is to elucidate the ligamentous anatomy of the medial carpus in order to characterize the pathologic basis of pisiform subluxation secondary to traumatic ligament rupture. Medial carpal ligamentous anatomy has been studied in the past by anatomic dissection and analyzed in terms of comparative morphology. A review of this literature reveals that the anatomy of the region requires further definition. We have performed cadaveric dissections that reveal that the ulnar or medial carpal ligament complex is composed of three structures: (1) the triangular fibrocartilage, (2) the meniscus homologue, and (3) the ulnar collateral ligament. We conclude that the medial carpal ligament complex has an insertion into the pisiform bone.

Arthroscopic treatment of anterior cruciate ligament avulsion.

A new technique is described for arthroscopic reduction and internal fixation (ARIF) of avulsion fractures involving the insertion of the anterior cruciate ligament (ACL). Conventional methods of treatment of ACL avulsion in adults may lead to suboptimal results owing to stiffness from either prolonged immobilization or the morbidity of arthrotomy. Contemporary techniques of arthroscopic reduction and percutaneous pinning do not achieve rigid fixation and thus still require cast immobilization. The placement of cannulated screws through the anteromedial arthroscopic portal provides rigid fixation while avoiding arthrotomy, allowing early mobilization and return to activity. The possibility of interstitial damage to the ACL and implications regarding tensioning of the ligament are considered A typical case illustrates ARIF of ACL avulsion. The technique minimizes morbidity and optimizes function.

Midtarsal fracture-subluxation. Case report and review of the literature.

Avulsion of the navicular tuberosity in association with fracture at the calcanecuboid joint is a characteristic pattern of injury resulting from an acute valgus and dorsiflexion stress. Only 22 cases of this unusual injury pattern have been reported, and confusion exists regarding treatment. Recommendations for management focus primarily on the calcaneocuboid disruption. Only two of these reports specifically addressed the posterior tibial tendon avulsion. Each component of this injury pattern should be considered separately. Calcaneocuboid fractures should be treated conservatively or operatively, depending on the extent of articular involvement. Conversely, the navicular tuberosity avulsion should be considered as the acute phase of a syndrome potentially leading to a chronic, posterior tibial tendon-deficient foot. Depending on the degree of displacement of the navicular avulsion fracture, prompt surgical intervention may be justified. A 73-year-old woman illustrates the rationale and treatment of a typical case.