Management of Snapping Scapula Syndrome.

Snapping scapula syndrome is a rare condition caused by the disruption of the gliding articulation between the anterior scapula and the posterior chest wall. The etiology of snapping scapula syndrome is multifactorial, and contributing factors include scapular dyskinesis, bursitis from repetitive use or trauma, and periscapular lesions. Although the majority of cases are initially treated with nonoperative modalities, recalcitrant snapping scapula syndrome can warrant surgical management. This report describes a 34-year-old amateur weight lifter with a 1-year history of increasing pain and fullness over his posterior shoulder region. He reported full shoulder motion associated with an audible, palpable, and painful crepitus, exacerbated with overhead movement and wall pushups. Previous periscapular stabilization exercises and corticosteroid injection yielded minimal resolution of his symptoms. Prior to being referred to the authors' clinic, the patient was evaluated at an outside facility and deemed a suboptimal candidate for arthroscopic bursectomy because of the large size and location of this lesion. Magnetic resonance imaging showed a large polylobulated fluid collection causing scapulothoracic distention. There was no evidence of osseous abnormalities originating from the scapular body. Computed tomography-guided placement of methylene blue and contrast dye was used to facilitate localization and, in an effort to minimize recurrence, ensure the complete removal of bursal tissue. During 8 weeks, this patient recovered unremarkably and returned to full-duty activities with resolution of symptoms. The authors present the management of chronic and recalcitrant snapping scapula syndrome, and report the open excision of the largest scapulothoracic bursal lesion described, to their knowledge, in the English literature. [Orthopedics. 2016; 39(4):e783-e786.].

Effect of tibial plateau fracture on lubrication function and composition of synovial fluid.

BACKGROUND: Intra-articular fractures may hasten posttraumatic arthritis in patients who are typically too active and too young for joint replacement. Current orthopaedic treatment principles, including recreating anatomic alignment and establishing articular congruity, have not eliminated posttraumatic arthritis. Additional biomechanical and biological factors may contribute to the development of arthritis. The objective of the present study was to evaluate human synovial fluid for friction-lowering function and the concentrations of putative lubricant molecules following tibial plateau fractures. METHODS: Synovial fluid specimens were obtained from the knees of eight patients (twenty-five to fifty-seven years old) with a tibial plateau fracture, with five specimens from the injured knee as plateau fracture synovial fluid and six specimens from the contralateral knee as control synovial fluid. Each specimen was centrifuged to obtain a fluid sample, separated from a cell pellet, for further analysis. For each fluid sample, the start-up (static) and steady-state (kinetic) friction coefficients in the boundary mode of lubrication were determined from a cartilage-on-cartilage biomechanical test of friction. Also, concentrations of the putative lubricants, hyaluronan and proteoglycan-4, as well as total protein, were determined for fluid samples. RESULTS: The group of experimental samples were obtained at a mean (and standard deviation) of 11 ± 9 days after injury from patients with a mean age of 45 ± 13 years. Start-up and kinetic friction coefficients demonstrated similar trends and dependencies. The kinetic friction coefficients for human plateau fracture synovial fluid were approximately 100% higher than those for control human synovial fluid. Hyaluronan concentrations were ninefold lower for plateau fracture synovial fluid compared with the control synovial fluid, whereas proteoglycan-4 concentrations were more than twofold higher in plateau fracture synovial fluid compared with the control synovial fluid. Univariate and multivariate regression analysis indicated that kinetic friction coefficient increased as hyaluronan concentration decreased. CONCLUSIONS: Knees afflicted with a tibial plateau fracture have synovial fluid with decreased lubrication properties in association with a decreased concentration of hyaluronan.

Topographic Patterns of Cartilage Lesions in Knee Osteoarthritis.

OBJECTIVE: Treatments for articular cartilage lesions could benefit from characterization of lesion patterns and their progression to end-stage osteoarthritis. The objective of this study was to identify, quantitatively, topographic patterns of cartilage lesions in the human knee. DESIGN: Photographs were taken of 127 unilateral distal femora (from 109 cadavers and 18 arthroplasty remnants) with full-thickness cartilage lesions. Using digital image analysis, the lesions were localized and normalized lesion size was determined for the patellofemoral groove (PFG) and the lateral and medial femoral condyles (LFC, MFC). Samples were classified into patterns using cluster analysis of the lesion size at each compartment. For each pattern, maps showing the extent and frequency of lesions were created. RESULTS: Four main patterns (a-d) were identified (each p<0.001), with the lesion size varying from small (a) to large in distinct regions (b-d). Pattern b had a predominant lesion (23% area) in the MFC, and smaller (<3%) lesions elsewhere. Pattern c had predominant lesions in the LFC (19%) and MFC (10%). Pattern d had a predominant lesion in the PFG (15%) and smaller lesions in the MFC (6%) and LFC (2%). The sub-patterns of a (a1, a2, a3) had relatively small lesions, with similarity between a2 and b, and a3 and d. CONCLUSION: The present methods facilitated quantitative identification of distinct topographic patterns of full-thickness cartilage lesions, based on lesion size and location. These results have implications for stratifying OA patients using precise quantitative methods and, with additional longitudinal data, targeting cartilage treatments.