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OBJECTIVE: The purpose of this study was to examine the relationship between obesity and patient-administered outcome measures after total joint arthroplasty. RESEARCH METHODS AND PROCEDURES: A voluntary questionnaire-based registry contained 592 primary total hip arthroplasty patients and 1011 primary total knee arthroplasty patients with preoperative and 1-year data. Using logistic regression, the relationships between body mass index and the several outcome measures, including Short Form-36 and Western Ontario and McMaster Universities Osteoarthritis Index, were examined. RESULTS: There was no difference between obese and non-obese patients regarding satisfaction, decision to repeat surgery, and Delta physical component summary, Delta mental component summary, and Delta Western Ontario and McMaster Universities Osteoarthritis Index scores (p > 0.05 for all). Body mass index was associated with an increased risk of having difficulty descending or ascending stairs at 1 year (odds ratio, 1.2 to 1.3). DISCUSSION: Obese patients enjoy as much improvement and satisfaction as other patients from total joint arthroplasty.

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BACKGROUND: Rotator cuff disease or injury is one of the most frequently seen orthopaedic conditions, and surgical repair of rotator cuff tears is a common procedure. A prospective analysis of the operation, with consistent assessment of patient characteristics, variables associated with the rotator cuff tear and repair techniques, and outcome factors, was performed. METHODS: One hundred and five shoulders with a chronic rotator cuff tear underwent open surgical repair and acromioplasty between 1975 and 1983. The patients were followed for an average of 13.4 years (range, two to twenty-two years). There were sixteen small tears, forty medium tears, thirty-eight large tears, and eleven massive tears. The tears were repaired directly (seventy-two tears), by V-Y plasty (twelve), by tendon transposition (twenty), or by reinforcement with a fascia lata graft (one). The long head of the biceps had been previously torn in eleven shoulders and was tenodesed in three other shoulders. In fifty-six shoulders, the distal part of the clavicle was excised for treatment of degenerative arthritic changes, often associated with osteophyte formation. RESULTS: Satisfactory pain relief was obtained in ninety-six shoulders (p < 0.0001). There was significant improvement in active abduction (p < 0.001) and external rotation (p < 0.007) as well as in strength in these directions of movement (p < 0.03 and p < 0.002, respectively). At the latest follow-up evaluation, the result was rated as excellent for sixty-eight shoulders, satisfactory for sixteen, and unsatisfactory for twenty-one. Tear size was the most important determinant of outcome with regard to active motion, strength, rating of the result, patient satisfaction, and need for a reoperation. Older age, less preoperative active motion, preoperative weakness, distal clavicular excision, and a transposition repair technique were all associated with larger tear size. There were eight reoperations; five were for rerepair of a persistent or recurrent rotator cuff tear. CONCLUSIONS: Standard tendon repair techniques combined with anterior acromioplasty, postoperative limb protection, and monitored physiotherapy can produce consistent and lasting pain relief and improvement in range of motion. Improving the results of this procedure will depend upon the development of new techniques to address the active motion and strength deficiencies following repair of massive rotator cuff tears.

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Columbia-Rambouillet cross-bred sheep were used to study the revascularization and ligamentization process of anterior cruciate ligament (ACL) reconstruction over a 6-month period using basic histology, immunohistochemistry, and electron microscopy. The reconstruction technique studied was a quadruple-hamstring, interference screw fixation technique. Further, these specimens, after retrieval at 6, 12, and 26 weeks, were compared with human arthroscopic 'second looks' and with 10 en bloc specimens obtained when a cruciate-sacrificing total knee replacement was performed. The study showed that, with this reconstruction technique, Sharpey's fibers were seen at 6 weeks in both sheep and human specimens. The intratunnel specimens showed proliferative chondrification, then ossification of the matrix. Intra-articular neovascularization, ligamentization, and junction ossification occurred. Myoblasts or smooth muscle cells appear to mediate the ligamentization as evidenced in electron microscopy by proliferate collagen manufacture. These myoblasts were seen in both the healing sheep and human second looks, but not seen in mature ACL grafts or in normal ACLs. At 6 months postoperatively, the sheep ACL reconstruction appeared clinically, histologically, and immunohistochemically indistinguishable from the normal sheep ACL. A correlation of this work with published animal studies in which biomechanical testing was performed and with human 'second looks' would imply that an ACL reconstruction may be vulnerable during this period of neovascularization and ligamentization.

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Thirty-four hips (22 patients) with history and physical findings consistent with osteonecrosis of the femoral head were evaluated preoperatively by radiographs, bone scans and magnetic resonance images. All patients with Stage 0, I, or II disease by the Ficat and Arlet classification underwent core decompression using the same technique. Osteonecrosis was confirmed histologically in all 34 hips. Eighteen of 22 patients had prognostic factors traditionally associated with poor outcome including collagen vascular diseases and continued use of steroids. Followup averaged 4 years for 18 patients with 29 hips. Four patients died secondary to systemic illness. Twelve patients had good or excellent results using the Modified Harris Hip Score with 6 patients needing hip arthroplasty. In this group of patients previously associated with poor prognosis, no hip fractures were seen and 66% good to excellent results were obtained.

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A survey was conducted of the entire membership of the American Association of Hip and Knee Surgeons to determine their experience with total hip arthroplasty (THA) device-related failures. Forty-seven percent of the membership reviewed their preceding 5-year clinical experience and returned the survey instrument. The aggregate 5-year volume encompassed experience with more than 60,000 hip arthroplasties. The median 5-year experience per respondent was 200 metal-based sockets and 214 metal stems. The frequency distribution of the number of hip arthroplasties per respondent was skewed to the right, with fewer surgeons reporting the higher volumes of arthroplasties. In aggregate, 60,115 of the acetabular components used were metal backed. Nonmetal acetabular component usage totaled 3,219. Complete polyethylene failure was defined as fracture or complete wear through of the polyethylene portion of the component. Complete polyethylene failure was seen in 172 metal-backed sockets (29/10,000). Seventy-seven all-polyethylene sockets had complete polyethylene failure (239/10,100). A total of 87 THAs were revised for modular acetabular dissociations for a dissociation rate of 15/10,000. In aggregate, 64,483 metal-stemmed components were used. Femoral stem fractures occurred in 172 for a rate of 27/10,000. A total of 56,965 metallic femoral components were reported as being modular. Dissociation between the femoral head and neck was uncommonly seen (3/10,000). Use of ceramic femoral heads was low (5,023); however, a total of 11 ceramic head fractures were revised in the 5-year period for a failure rate of 22/10,000. The risks of catastrophic prosthetic THA failure are low but vary according to hip component and the manufacturer of the part.

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Hitherto, the meniscus has been regarded as a developmental remnant. However, when removed in part or in total, it alters the normal biomechanical, biochemical, and physiologic processes of the knee joint. Although the pathogenesis of osteoarthritis (OA) is unknown, accelerated rates of normal metabolism may result in failure of the articular cartilage to maintain its mechanical integrity as a result of meniscectomy. In addition, an inflammatory state within the joint cavity may result in degenerative changes, due to a perturbation of the homeostatic anabolic and catabolic processes maintaining the knee joint. Animal models reliably reproduce the focal and relatively slow degeneration seen in humans. OA degeneration after meniscectomy has been described histologically with fibrillation, swelling, fissures, cell proliferation, clustering, cell nesting, and even necrosis. Biochemical changes, however, include proteoglycan loss, proteoglycan disaggregation, and an increase in proteoglycan synthesis. In addition to increased hydration, the main structural fibers of articular cartilage, composed of Type II collagen, are exposed to increased biomechanical forces. The minor collagens, e.g., Type IX collagen, may play a role in stabilizing the proteoglycan-Type II interaction, thus providing mechanical integrity. It appears that meniscectomy produces much more than wear-and-tear arthritis.

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This is a combined research study including use of a reproducible technique for ankle stress x-ray examinations (both preoperatively and postoperatively) and the use of the bovine bioprosthesis tendon implant for stabilization and augmentation of the lateral ankle ligaments. The surgical technique is fully described and the follow-up results indicate that there is long-term ankle stability, and that patient acceptance is very high.

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Twenty-nine soft tissue masses were studied with magnetic resonance imaging (MRI) which proved to be useful in the preoperative evaluation of these lesions. Other imaging modalities employed had significant limitations. Plain films were of little value because of the intrinsically low contrast of soft tissues. Angiography was not necessary unless MRI suggested a vascular lesion or proximity to major blood vessels. Computed tomography (CT) and MRI both readily identified fatty lesions and their relationship to adjacent structures. Some soft tissue tumors could not be delineated from normal muscle with CT, but were easily seen with MRI. MRI is ideally suited for the study of suspected soft tissue tumors because of its excellent soft tissue contrast and its ability to image directly in any plane. Optimum evaluation required imaging in at least two planes with spin echo sequences chosen to bring out both T1 and T2 features.

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The reader is presented with the important anatomical and biomechanical aspects of the shoulder and the most commonly seen injuries of the soft tissues. Ultrasonography is most efficacious in terms of noninvasiveness, accuracy, and cost during the initial presentation by patients with complaints, physical signs, and negative roentgenograms. It allows the practitioner to make treatment decisions when therapeutic modalities have their maximum benefit, that is, as soon after the injury as possible.

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This study introduces hydraulic resistance (HR) as a new method to measure intraosseous vascular outflow resistance in the human proximal femur. HR is the standard measure of resistance to fluid flow in porous matrices and is derived from serial pressure/flow determinations. Eighteen hips were studied in 11 patients taken to surgery for core decompression therapy of presumable atraumatic osteonecrosis of the femoral head. HR was much higher in osteonecrotic (174 +/- 29 mm Hg min/ml, SE) than in normal human cadaveric femora (14 +/- 6) and was also higher in subcapital (253 +/- 39) than intertrochanteric sites (78 +/- 17). HR correlated highly with baseline intraosseous pressure (r = 0.74, p less than 0.001). HR testing is a simple, practical method which quantifies outflow obstruction of the intraosseous circulation. We believe this test will be helpful in the diagnosis of atraumatic osteonecrosis and in the understanding of its underlying pathophysiology.

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In summary, the immune system provides two specific types of responses: humoral or B-cell immunity, and T-cell-mediated immunity to a specific stimulus. In response to a noxious stimulus, the inflammatory response utilizes some common cellular elements of the immune system and is not immunologically mediated. The antigen provides the foundation for all specific immune reactions. These molecules are unique and form the basis for transplantation immunology--the human MHC, or major histocompatibility complex. Genes code for molecules on the surface of cells which identify an individual by species-specific and individual-specific markers. Transplanted biologic materials may have cells, but they also have matrix or collagen components that are immunogenic. To determine and characterize these immune responses, a number of diagnostic methods are available. These range from routing H&E histological studies for cell population to sophisticated mitogenic stimulation assays for determining antigenicity and patient sensitization. Certainly immunobiology will be increasingly important as the use of biologic material and transplantation become more widespread.

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In a 60-year-old man, extensor tendon rupture was associated with coccidioidal tenosynovitis. Dissemination of Coccidioides immitis to the tenosynovium in the wrist is an unusual complication following pulmonary coccidioidomycosis.

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Sickle cell anemia and Kienböck's disease occurred in an 18-year-old man. The association of the two conditions seems not to have been previously reported.

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The chondroblastic component of a human osteosarcoma was established as a transplantable tumor in nude athymic mice for the first time. The collagen biosynthetic production of the excised tumor was studied in organ culture. The majority of the collagen secreted in the culture media was pro-Type II as identified by diethylaminoethyl cellulose (DEAE cellulose) chromatography, gel electrophoresis, and cyanogen bromide cleavage. This system should be useful for producing large quantities of human pro-Type II collagen and for studying neoplastic cell switching of collagen synthesis.

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Vaccinia virions propagated in the presence of [3H]ornithine were found to contain two labeled polyamines, spermine and spermidine. In complete virions the ratio of radioactively labeled spermine to spermidine was about 1:10, whereas in viral cores the ratio was 2:5. This suggests that some spermidine was preferentially lost during the conversion of virions to cores or that spermidine was present in the virions both inside and outside the core structure. Addition of [3H]ornithine to vaccinia virus-infected cells as late as 6 h postinfection demonstrated that, although the conversion of this precursor to polyamines was reduced by 50% or more as compared to mock-infected cells, complete inhibition of polyamine synthesis did not occur. Two percent or less of the total radioactivity associated with virions grown in the presence of [3H]ornithine was found to be acid soluble. Polyacrylamide gel electrophoretic analysis showed that all the structural polypeptides were labeled when virions were propagated in the presence of [3H]ornithine. When cores labeled with a mixture of 14C-labeled amino acids were extracted with 0.25 N H2SO4, 12 to 15% of the labeled core polypeptides were released and could be precipitated with acetone. About 40% of [3H]arginine-labeled polypeptides associated with cores were extracted with acid. Four polypeptides or groups of polypeptides were resolved after polyacrylamide gel electrophoresis analysis of the acid-soluble fraction of cores with molecular weights of about 58,000, 34,000, 24,000 and 10,000 to 12,000. About 40% of the [3H]arginine radioactivity extracted from cores coelectrophoresed with the 10,000 to 12,000-molecular weight polypeptide, indicating that this may represent an arginine-rich, histone-like structural polypeptide of the virion.

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