Faculty Bibliography

A telemeterized shoulder prosthesis was developed and tested, first in vitro and then in a cadaver implantation. The prototype prosthesis was instrumented with 3 strain gauges fixed within a hollow, tapered neck element whose output was used to determine the load vectors experimentally applied to the humeral head. Testing demonstrated accuracy of force measurement resolution to within 5% of actual applied forces. This design seems feasible for further investigations to develop a totally implantable telemeterized prosthesis

A prospective analysis was performed involving 680 geriatric patients with hip fractures to determine whether the demographic profile of patients with femoral neck fractures was similar to that of patients with intertrochanteric fractures. All patients were community dwelling, cognitively intact, previously ambulatory elderly with femoral neck or intertrochanteric fracture. Three hundred fifty-eight patients (52.6%) sustained a femoral neck fracture; 322 (47.4%), an intertrochanteric fracture. Patients with an intertrochanteric fracture were significantly older, more likely to be limited to home ambulation, and were more dependent regarding basic and instrumental activities of daily living. After stratification by gender and adjustment for age, these differences remained significant in women only. There were no differences in age, prefracture ambulatory ability, or dependence in activities of daily living in men with either type of fracture

A prospective, randomized, controlled, double-blind clinical study was performed to determine the short-term efficacy of subacromial injection of corticosteroids for the treatment of subacromial impingement syndrome. Forty patients were randomized to receive either six milliliters of 1 per cent lidocaine without epinephrine (the control group) or two milliliters containing forty milligrams of triamcinolone acetonide per milliliter with four milliliters of 1 per cent lidocaine without epinephrine (the corticosteroid group). The patients were re-examined serially until completion of the study. Nineteen patients, whose mean age was fifty-six years (range, thirty-two to eighty years), were randomized to the corticosteroid group, and twenty-one patients, whose mean age was fifty-seven years (range, thirty-two to eighty-one years), were randomized to the control group. The mean duration of symptoms before the injection was eight months for both groups. Eighteen patients in the corticosteroid group and nineteen patients in the control group had moderate or severe pain before the injection. At the most recent follow-up evaluation, at a mean of thirty-three weeks for the corticosteroid group and twenty-eight weeks for the control group, three patients in the corticosteroid group had moderate or severe pain, compared with fifteen patients in the control group. The mean active range of forward elevation and external rotation improved by 24 and 11 degrees, respectively, for the corticosteroid group and by 10 and 5 degrees, respectively, for the control group. We concluded that subacromial injection of corticosteroids is an effective short-term therapy for the treatment of symptomatic subacromial impingement syndrome. The use of such injections can substantially decrease pain and increase the range of motion of the shoulder

A prospective study was performed to determine the reliability of analysis of intraoperative frozen sections for the identification of infection during 175 consecutive revision total joint arthroplasties (142 hip and thirty-three knee). The mean interval between the primary and the revision arthroplasty was 7.3 years (range, three months to twenty-three years). To reduce selections bias, tissue was obtained for frozen sections during all revisions in patients who did not have active drainage from the wound or a sinus tract. Of the 175 patients, twenty-three had at least five polymorphonuclear leukocytes per high-power field on analysis of the frozen sections and were considered to have an infection. Of these twenty-three, five had five to nine polymorphonuclear leukocytes per high-power field and eighteen had at least ten polymorphonuclear leukocytes per high-power field. The frozen sections for the remaining 152 patients were considered negative. On the basis of cultures of specimens obtained at the time of the revision operation, nineteen of the 175 patients were considered to have an infection. Of the 152 patients who had negative frozen sections, three were considered to have an infection on the basis of the results of the final cultures. Of the twenty-three patients who had positive frozen sections, sixteen were considered to have an infection on the basis of the results of the final cultures; all sixteen had frozen sections that had demonstrated at least ten polymorphonuclear leukocytes per high-power field. The sensitivity and specificity of the frozen sections were similar regardless of whether an index of five or ten polymorphonuclear leukocytes per high-power field was used. Analysis of the frozen sections had a sensitivity of 84 per cent for both indices, whereas the specificity was 96 per cent when the index was five polymorphonuclear leukocytes and 99 per cent when it was ten polymorphonuclear leukocytes. However, the positive predictive value of the frozen sections increased significantly (p < 0.05), from 70 to 89 per cent, when the index increased from five to ten polymorphonuclear leukocytes per high-power field. The negative predictive value of the frozen sections was 98 per cent for both indices. The current study suggests that it is valuable to obtain tissue for intraoperative frozen sections during revision hip and knee arthroplasty. At least ten polymorphonuclear leukocytes per high-power field was predictive of infection, while five to nine polymorphonuclear leukocytes per high-power field was not necessarily consistent with infection. Less than five polymorphonuclear leukocytes per high-power field reliably indicated the absence of infection

Medial dislocation of the long head of the biceps branchii tendon is a rare occurrence and is often associated with degenerative or traumatic tears of the rotator cuff, specifically tears of the subscapularis tendon. Following a dislocation, the biceps tendon will assume either an intra- or extra-articular position depending on whether or not the subscapularis tendon detaches from its humoral insertion. Magnetic resonance imaging (MRI) has been found to provide valuable information concerning the location of the biceps tendon and the integrity of the rotator cuff. In this report, three patients with suspected dislocations of the biceps tendon are evaluated using MRI

Bilateral shoulder motor output measurements were obtained in 40 subjects with a Biodex dynamometer. The subjects included two groups, a younger group (20 to 30 years) and an older group (50 to 60 years). They were engaged in low to moderate levels of occupational and spare-time physical activity. Each subject performed three maximum effort shoulder movements in flexion/extension, abduction/adduction, and internal/external rotation at 60 degrees/sec and 120 degrees/sec. Side tested, axis, and speed were randomly selected. The findings indicate that a significant decline occurred in peak torque, work, and power for all axes of movement at both speeds when the older group was compared with the younger group. A decline in peak torque and work and a corresponding increase in power resulting from an increase in speed occurred in both age groups. The effect of age was the same at 60 degrees/sec and at 120 degrees/sec. Overall, no difference in dominant and nondominant motor function was seen in either the younger or older untrained men

Forty-two consecutive patients (20 men and 22 women, age range 39 to 78 years) with full-thickness rotator cuff tears underwent a comprehensive isokinetic strength assessment before and at 3-month intervals for 1 year after surgery. All patients underwent acromioplasty and rotator cuff repair and were treated with a standardized postoperative rehabilitation program. Isokinetic strength testing was performed in flexion/extension, abduction/adduction, and external/internal rotation at 60 degrees/sec. The unaffected contralateral shoulder was tested for comparison. Clinical outcomes were assessed with the University of California Los Angeles Shoulder Rating Scale (maximum = 35 points). The average University of California Los Angeles score was 31.2 by 1 year after operation. Patients with small and medium tears had an average rating of 33.5, whereas those with large and massive tears had an average score of 28.3. Strength increased gradually during the first postoperative year. The preoperative mean peak torque was 54%, 45%, and 64% of the uninvolved shoulder in flexion, abduction, and external rotation, respectively; after operation it increased to 78%, 80%, and 79% by 6 months and 84%, 90%, and 91% by 12 months. The greatest improvement in strength consistently occurred during the first 6 months after surgery. Patients also showed marked increases in both work and power. By 12 months after operation mean work had increased to 70% in flexion and abduction and 90% in external rotation of the uninvolved shoulder. Similarly, mean power had increased to 68%, 79%, and 90% of the uninvolved shoulder in flexion, abduction, and external rotation, respectively, by 12 months after operation. Recovery of strength correlated primarily with the size of the tear: for small and medium tears recovery of strength was almost complete during the first year, and for large and massive tears it was much slower and less consistent. By using isokinetic strength evaluation we found that recovery of strength after rotator cuff repair requires at least 1 year of rehabilitation

Five hundred and sixteen community-dwelling, ambulatory, geriatric hip fracture patients who were independent prior to fracture were followed prospectively to determine which patients regained their prefracture independent living status at 3-, 6-, and 12-month follow-up. At 3-, 6-, and 12-month follow-up, 78, 77, and 76% of the patients, respectively, had regained their prefracture independent living status. Analysis was performed to determine which pre- and postinjury factors were predictive of a patient regaining prefracture independent living status at 3, 6, and 12 months after fracture. Patients who were younger than age 85, independent in activities of daily living prior to fracture, independent in ambulation at hospital discharge, and who had three or more medical comorbidities were more likely to regain their prefracture independent living status