ABSTRACTS 353

cDNA was also amplified for receptors for TGF-beta (type 1) and PDGF (beta), as well as GAPDH as a housekeeping control. Additional arthrofibrotic tissue was formalin fixed and paraffin embedded for histo- logic evaluation.

Results: All of the arthrofibrotic specimens ex- pressed PDGF-A, PDGF-B, and IGF-I. None ex- pressed IGF-II or EGF. Five expressed TFG-beta and five expressed bFGF. Mature scar did not express any of the growth factors. All of the samples (including mature scar) expressed the receptors and GAPDH. His- tology showed fibroblast proliferation in all the sam- pies. Bone or cartilage formation was not observed.

Discussion: Multiple growth factors expressed during acute phases of would repair continue to be expressed by the arthrofibrotic tissue. Mature scar does not express these factors. The expression of these factors may act in a paracrine and/or autocrine manner to deregulate the control of growth in arthrofibrotic cells. Not all of the arthrofibrotic specimens expressed the same factors, and perhaps these differences explain the occurrence of car- tilage of the bone in some cases, although we did not observe this in our histologic sections.

Growth factor manipulation has a potential role in treating arthrofibrosis, or in preventing its occurrence.

in order to determine sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for each diagnostic modality.

Results: We found rotator cuff tears, either partial or complete, in 126 of our patients. Based on physical examination alone, we had an accuracy of 81% for detecting tears of the rotator cuff with a sensitivity of 94%. Based on MRI alone, the community-based cen- ters had an accuracy of 59% for detecting rotator cuff tears with a sensitivity of 77%. When we further ana- lyzed our data, we noted an accuracy of 76% for de- tecting partial tears and 87% for detecting full tears. Similarly, the MRI studies revealed an accuracy of 55% for detecting partial tears and 65% for detecting full tears.

Conclusions: Our conclusions from this study are that a thorough history and physical examination per- formed by an orthopaedic surgeon is superior to an MRI study alone in detecting tears of the rotator cuff from community-based imaging centers. We do be- lieve that MRI has a role in the diagnosis of shoulder pathology, but only in select cases and never in lieu of an orthopaedic examination. Ultimately, it is the orthopaedic surgeon who is most qualified to determine which patients require additional imaging studies.

A Comparison Between Physical Examination and MRI in the Detection of Rotator Cuff Tears Con- firmed With Arthroscopy. Bradley D. Wiener, An- drew J. Feldman, and Edward J. Rossario. Guttenberg, New Jersey, and New York, New York, U.S.A.

Purpose: Because of the growing trend towards managed care groups, "gatekeepers" have increas- ingly relied on specialized imaging studies to evaluate patients with primary disorders involving the musculo- skeletal system. Our goal was to determine if a thor- ough history and physical examination by an orthopae- dic surgeon was comparable in terms of diagnostic accuracy and sensitivity for rotator cuff tears, to mag- netic resonance imaging (MRI) studies obtained in a community-based center and reviewed by a commu- nity-based radiologist.

Methods: We prospectively documented the physi- cal examinations and MRI results of 144 consecutive patients who underwent shoulder arthroscopy at our institution. We then reviewed each physical examina- tion and MRI, along with the interpretations by the radiologist, after definitive identification of any rotator cuff pathology at arthroscopy. Particular attention was made as to whether the rotator cuff tears were partial or complete. Statistical analysis was then performed

Recognition and Treatment of Refractory Posterior Capsular Contracture of the Shoulder. Johnathan Ticker, Gloria Beam, and Jon J. P. Warner. Massape- qua, New York, U.S.A.

Introduction: Some patients who present with re- fractory impingement syndrome may have primarily "non-outlet" impingement due to capsular con- tracture. We have identified a subset of patients with long-standing shoulder pain associated primarily with loss of internal rotation causing non-outlet impinge- ment. The purpose of this study is to describe the pro- file of these patients with refractory contracture of the posterior capsule of the glenohumeral joint and the technique of arthroscopic capsular release as an effec- tive form of treatment.

Methods: Over a 3 year period, the senior author surgically treated 281 patients with refractory pain due to impingement syndrome or adhesive capsulitis as the primary etiology. A subset of 9 patients was identified who had discrete, painful loss of internal rotation, par- ticularly evident with the arm in 90 ° of abduction, and often associated with painful limitation of forward flexion. The dominant arm was involved in 7 patients, and there were 5 males and 4 females, with an average age of 40 years (range, 20-57). No patient had diabetes

Arthroscopy, Vol 12, No 3, 1996