Faculty Bibliography

A cadaver study was performed to determine the effect of arm position and capsular release on rotator cuff repair. Artificial defects were made in the rotator cuff to include only the supraspinatus (small) or both supraspinatus and infraspinatus (large). The defects were repaired in a standard manner with the shoulder abducted 30 degrees at the glenohumeral joint. Strain gauges were placed on the lateral cortex of the greater tuberosity and measurements were recorded in 36 different combinations of abduction, flexion/extension, and medial/lateral rotation. Readings were obtained before and after capsular release. With small tears, tension in the repair increased significantly with movement from 30 degrees to 15 degrees of abduction (p < 0.01) but was minimally affected by changes in flexion or rotation. Capsular release significantly reduced the force (p < 0.01) at 0 degree and 15 degrees abduction. For large tears, abduction of 30 degrees or more with lateral rotation and extension consistently produced the lowest values. Capsular release resulted in 30% less force at 0 degree abduction (p < 0.05)

Intrinsic disorders that can cause shoulder pain include arthritis, gout, pseudogout and osteonecrosis. In its mildest form, impingement syndrome may cause only minimal discomfort. At its worst, impingement syndrome may lead to rotator cuff tear. Bicipital tendinitis and rupture of the biceps tendon may also be associated with impingement. Early rehabilitative intervention is important. Physical therapy is directed toward restoring range of motion and muscle strength

We present a case of suppurative arthritis occurring in a patient with bilateral osteonecrosis of the femoral head. Predisposing factors were chronic alcoholism (osteonecrosis) and septicemia due to intravenous drug abuse (suppurative arthritis). Although the association of suppurative arthritis and osteonecrosis is rarely reported in the literature, the prevalence of osteonecrosis and of various factors predisposing to the development of suppurative arthritis should remind us of the possibility that a patient with osteonecrosis who develops sudden worsening of joint pain or fever may have developed suppurative arthritis of the affected joint, particularly when there is evidence of bone destruction

Shoulder disorders are most commonly manifested by pain and limited function. Careful history and examination help the physician localize the problem to the shoulder joint, the surrounding tissues or adjacent sites that can cause referred pain to the shoulder. Common extrinsic causes of shoulder pain include postural problems and cervical spine disorders

Hardware failure of the sliding screw system used in hip fracture fixation is rare. The fatigue failure of the sliding screw is always related clinically to nonunion or refracture along the path of the screw. In both situations, cyclic loading of the implant exceeds its endurance limit, and failure can ensue. Three cases of failure of the sliding screw are presented: a nonunion of a basicervical fracture, a nonunion secondary to stress fracture at the plate-barrel junction, and a refracture through the femoral neck after healing of an intertrochanteric fracture. A biomechanical analysis of the stresses on the sliding screw focuses on design features such as the internal threaded region used for the compression screw or the barrel length that creates increased stresses in the screw, thus lowering the number of cycles to failure. Based on this analysis, recommendations are made concerning implant design and surgical technique

Joint and soft tissue injections may be the only way to differentiate various arthritic disorders, accurately identify a septic joint, and apply focused treatment. Certain considerations can make these injections safer and more effective. This article reviews the principles of diagnostic and therapeutic use of joint and soft tissue injections and makes specific recommendations for common injection sites. Also described are appropriate aseptic techniques for aspirating and injecting joints, bursae, and soft tissue, as well as the judicious use of corticosteroid injections in this age group

There is general agreement that the implant of choice for intertrochanteric fractures is the sliding hip screw (SHS). However, considerable differences of opinion exist as to which plate angle--varying from 130 to 150 degrees--is preferred. Thus far there has been no cadaver-based biomechanical analysis of this problem. To examine these questions, we determined the effect of plate angle on plate strain and proximal medial femoral strain distribution in cadaver femurs fixed with 130, 135, 140, 145, and 150 degrees SHS after experimentally produced stable and unstable intertrochanteric fractures. Twenty-four fresh adult cadaver femurs were assigned randomly to either the 130, 135, 140, 145, or 150 degrees SHS group. Each femur was radiographed and bone mineral density was determined by dual-photon absorptiometry. Multiple-strain gauges were affixed to the femur, with specific focus on the proximal femur and plate. Femurs were loaded at 25 degrees adduction in increments of 70 N from 0 to 1,800 N in a servohydraulic testing machine. Femurs were tested in a progressive manner: (a) intact femur; (b) intact femur with SHS inserted; (c) a stable two-part intertrochanteric fracture reduced with SHS; (d) a four-part fracture with the posteromedial fragment (PMF) reduced anatomically by a lag screw; (e) the same fracture with the PMF rotated 180 degrees and held in place by a lag screw to approximate a 'near-anatomic' reduction; and (f) the same fracture with the PMF discarded. Screw sliding measurements were determined at regular intervals throughout each test.(ABSTRACT TRUNCATED AT 250 WORDS)