The effects of medial meniscal transplantation techniques on intra-articular contact pressures.

This study aimed to compare medial compartment contact pressures in knees treated with medial meniscal transplantation using either a bone plug or bone trough technique. Peak pressure, mean pressure, and contact area of the medial compartment were determined in 8 cadaveric specimens at 0 degrees and 30 degrees of flexion under a 1000-N load. Contact mechanics were measured for the intact knee, after meniscectomy, and after medial meniscal transplant with either a bone plug technique or a bone trough technique. Total medial meniscectomy resulted in decreased contact area, increased medial contact pressure, and increased medial peak contact pressure. When comparing meniscal transplant techniques at both 0 degrees and 30 degrees, no significant difference (P < 0.05) was noted regarding contact mechanics after transplantation. The bone trough technique shows similar contact mechanics to the double bone plug technique and maintains the natural hoop stress of the meniscus during medial meniscal transplantation.

Outcome of arthroscopic repair of type II SLAP lesions in worker's compensation patients.

PURPOSE: Arthroscopic stabilization has become the accepted treatment for type II superior labral anterior and posterior (SLAP) lesions. Short-term results using a variety of techniques were promising, but most reports focus on motivated athletes. The purpose of our report is to evaluate the results of arthroscopic fixation of type II SLAP lesions in 21 patients who suffered a work-related injury and are receiving workers' compensation. The hypothesis was that in patients with a single event trauma who were receiving workers' compensation, clinical results would be inferior to those previously reported. METHODS: Twenty-two consecutive workers' compensation patients with type II SLAP lesions underwent arthroscopic stabilization between October 1994 and December 1996. All patients received suture anchors with nonabsorbable suture secured around the labrum for definitive fixation. Average age at surgery was 43 and average follow-up time was 27.9 months. Seventeen patients (89%) had an acromioplasty at the time of labral stabilization. Outcome was assessed by analysis of visual analog pain scale, simple shoulder test (SST) and general health status questionnaire (SF-36), subjective patient satisfaction, and ability to return to work. RESULTS: Visual analog pain scales improved by an average of 3 points although all patients had significant complaints of pain at follow-up. Simple shoulder test responses showed improvement in 9 out of 12 categories. The SF-36 results showed significant improvements only in the bodily pain category and role: physical category. Five patients required reoperation for persistent pain. However, only seven patients (437%) returned to work at their previous functional level, nine patients (47%) returned to work but at less strenuous jobs, and three patients (16%) did not return to work. CONCLUSIONS: Currently recommended treatment for type II SLAP lesions is arthroscopic stabilization. When this procedure is performed in workers' compensation, patients a with single event trauma to the shoulder, objective parameters, and patient self-assessment surveys do show improvement. However, results are inferior to those previously reported in the literature.

Contact pressure at osteochondral donor sites in the patellofemoral joint.

BACKGROUND: The lowest contact pressure point is presumed to be the best site to harvest an osteochondral plug and minimize morbidity. HYPOTHESIS: Patellofemoral contact pressures are not uniform and are lowest along the medial patellofemoral articulation. STUDY DESIGN: Controlled laboratory study. METHODS: Seven cadaveric knees were tested with an electroresistive, dynamic pressure sensor placed onto the femoral side of the patellofemoral joint. The extensor mechanism was loaded with 89.1 N and 178.2 N, and the knee was manually cycled 3 times (0 degrees -105 degrees ) per load. Mean trochlear pressures were calculated. RESULTS: Mean contact pressures were greatest in the central trochlea (5.80 kgf/cm(2)), followed by the lateral (2.56 kgf/cm(2)) and medial trochlea (1.60 kgf/cm(2)) at 89.1 N (P <.05). At 178.2 N, pressures increased to 9.47, 5.81, and 2.75 kgf/cm(2), respectively (P <.05). Lateral trochlear pressures decreased moving distally from 1.25 to 0.50 kgf/cm(2) at 89.1 N and 4.57 to 1.29 kgf/cm(2) at 178.2 N. CONCLUSIONS: Contact pressures are lowest along the medial trochlea and decrease distally along the lateral trochlea. CLINICAL RELEVANCE: Osteochondral plugs from the medial femoral trochlea may be desirable if trochlear size permits. If harvesting from the lateral femoral trochlea, consider harvesting distally near the sulcus terminalis.

Clinical evaluation of injuries to the acromioclavicular and sternoclavicular joints.

Acromioclavicular injuries are common and most often can be accurately diagnosed using history, physical examination, and routine radiography. Sternoclavicular subluxations and dislocations may also be accurately characterized with only history, physical examination, and routine radiography (i.e., serendipity view). In many cases of sternoclavicular dislocation, however--especially posterior--CT scanning or MR imaging will be necessary. Posterior sternoclavicular dislocation may cause compression of mediastinal structures. When this is suspected, angiography or CT angiography is indicated. Physeal injuries should be suspected at either end of the clavicle in adolescent patients.

Comparing outcomes of anterior cervical discectomy and fusion in workman's versus non-workman's compensation population.

BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is an accepted surgical procedure to treat degenerative conditions, including disc herniations and spinal stenosis. The literature on lumbar spine surgery reports that patients with a workman's compensation claim have less successful clinical results. Regarding the cervical spine, however, different conclusions have been drawn. PURPOSE: The purpose of this study was to directly compare the functional outcomes of ACDF in patients with and without a workman's compensation claim and to determine whether a compensation claim adversely affected the clinical outcome. STUDY DESIGN: This is a retrospective study examining the long-term results of ACDF in the workman's and non-workman's compensation populations. PATIENT SAMPLE: Eighty consecutive patients undergoing ACDF were retrospectively analyzed. The patients were divided into two groups: 30 patients in Group 1 (workman's compensation) and 50 patients in Group 2 (non-workman's compensation). The average age of Group 1 was 45 years (range, 31 to 57) and Group 2 was 45 years (range, 30 to 79). The patients were followed for an average length of 4 years (range, 2 to 7 years). OUTCOME MEASURES: We evaluated the surgical results using a functional outcome scoring system (Odom's Criteria), visual analog scale and a radiographic grading scale. The questionnaire was independently administered in a standard question-answer format at the 1-year follow-up. Statistical analyses was performed using a Levene's test. METHODS: All surgeries were performed by the same attending physician. A left-sided approach and Smith-Robinson fusion technique with autograft or allograft without instrumentation was used in all cases. A hard cervical orthosis was used postoperatively for 8 weeks. Radiographic examination including lateral flexion and extension views were obtained at a minimum of 12 months postoperatively. Furthermore, radiographic analysis was performed each subsequent postoperative year. The radiographs were analyzed by two independent physicians in a blind fashion for evidence of radiographic fusion. RESULTS: At follow-up no discernible difference was noted for functional outcomes. Eighty-three percent of patients in Group 1 and 90% of patients in Group 2 noted excellent or good results. This was not statistically significant (p=.280). In Group 1, 97% of patients returned to work at an average of 18 weeks, whereas 98% of patients in Group 2 returned to work at an average of 10 weeks postoperatively. Upon radiographic evaluation, 64% of patients in Group 1 were determined to have a solid fusion (Grade 3). The fusion rate in Group 2 was 72%. This was not statistically significant. However, the fusion rate among smokers was 50%, and among nonsmokers it was 80%. This was statistically significant (p=.001). CONCLUSIONS: Workman's compensation claims did not adversely affect the functional outcome of ACDF. It should be noted that a significant increase in pseudarthroses was noted with the smoking population. Patient selection is a critical factor in determining functional outcome, with 83% good to excellent results if the pathology, clinical presentation and radiographic findings correlate