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Biomedical subjects

C B Sledge

Publications and source records attributed to C B Sledge.

123 records · Page 7Linked to original sources
PubMedDate not supplied

Experimental radiation synovectomy by 165Dy ferric hydroxide macroaggregate.

The short half-life beta emitter 165Dy coprecipitated as a macroaggregate with ferric hydroxide (FHMA) has been shown to destroy knee synovium in the antigen-induced arthritic rabbit. Using 153Gd as a gamma tracer for leakage studies revealed that the leakage of this system from rabbit knee joints never exceeded 1.2% over 24 hours. This is such less than the leakage rates reported from any human studies or our rabbit studies using 198Au.

Animals↗
PubMedDate not supplied

Total knee arthroplasty experience at the Robert Breck Brigham Hospital.

Between 1973 and 1978, 1,474 metal-to-plastic knee arthroplasties were evaluated to determine the typical modes of failure and improved design concepts (Table 2). Although the concepts are still evolving, and longer follow-up is necessary, recent experience with nearly 1,000 semiconstrained devices allowing cruciate retention strongly suggests that duopatella and kinematic design concepts are correct. Soft tissue reconstruction is critical with these designs, since they rely heavily on soft tissue integrity and balance. If the concepts of soft tissue balance, prosthetic design, and physical rehabilitation are applied, total knee replacement is as reliable in relieving pain and restoring function as total hip replacement. The low incidence of radiolucency at the bone-cement interface (although the length of follow-up is relatively short), coupled with the results of in vitro bench testing, suggest that the longevity of this generation of knee implants should be adequate.

Biomechanical Phenomena↗
PubMedDate not supplied

Intra-articular radiation synovectomy.

Fifty-three knees in 44 patients with severe, chronic rheumatoid arthritis (RA) were treated by the instillation of an intra-articular radionuclide (dysprosium-165; 165Dy) coupled with a large, relatively inert carrier (ferric hydroxide macroaggregate). The extremely low leakage rates found in earlier animal experiments were confirmed in the human, with a mean leakage rate of 0.3% of the injected dose. This leakage corresponds to a total body dose of 0.4 rad and a liver dose of 2.5 rad, equivalent to a lumbosacral series of diagnostic radiographs. Eighty percent of the treated knees showed improvement, which was maintained as long as one year after treatment. There was a direct correlation between the preoperative radiographic stage and the response to treatment, with patients in Stages I and II more likely to have a good or excellent response at one year. There was also good correlation between clinical improvement and improvement in technetium-99m (99mTc)-pertechnetate flow scintigraphy. Chemical synovectomy by the instillation of appropriate radionuclides can be recommended as an effective means of reducing inflammation, effusion, and pain in patients with RA. The duration of favorable results cannot be predicted, but the results to date suggest that longevity should be comparable with that of surgical synovectomy. Like surgical synovectomy, radiation synovectomy is most effective in the early stages of the disease process, before there is extensive destruction of cartilage and bone.

Adolescent↗
PubMedDate not supplied

Six- to 11-year results of total hip arthroplasty in rheumatoid arthritis.

The results of 138 total hip arthroplasties in 98 rheumatoid arthritic patients were reviewed six to 11 years (mean, 7.0 years) after operation. While 96% of the patients were clinically improved as a result of surgery, radiographic analysis suggests that, despite their low functional requirements, this group of patients experiences mechanical loosening and failure with time. Improvements in prosthetic design and cementing technique should contribute to a lowered incidence of mechanical failure in the future. In addition to improvements in technology, the failure rate can be further diminished by recognition of the systemic problems associated with rheumatoid arthritis, e.g., high incidence of infection, osteopenia, and sequelae of multiple joint involvement. In reconstruction of the acetabulum, especially in the presence of protrusio, failure to restore the anatomic position and orientation of the acetabulum predisposes to loosening and migration.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Factors influencing the incidence and outcome of infection following total joint arthroplasty.

During a ten-year period, 4240 total hip, knee, and elbow arthroplasties were performed. The overall infection rate was 1.25%. Certain groups were identified as being at higher risk of infection following total joint arthroplasty: rheumatoid arthritics were at 2.6 times greater risk than osteoarthritics; patients undergoing total hip arthroplasty as a revision of a previous operation were eight times more likely to have infection than those undergoing a primary operation; and patients with metal-to-metal hinged knee prostheses, when compared with patients with metal-to-plastic knee prostheses, were 20 times more likely to have infection. The majority of infections could be attributed either to perioperative problems or late bacterial seeding from a distant site. Although most infections occurred by two years after operation, late infections, particularly in rheumatoid patients via the hematogenous route, occurred as long as nine years after operation. There was no correlation between the Gram's-staining characteristics of the pathogen and the outcome of the infected joint. Gram-negative organisms were frequent in the perioperative period and reflected either nosocomial infection or the ineffectiveness of the prophylactic antibiotic regimen used in inhibiting gram-negative pathogens. The major factors that influenced the outcome of the infected joint included the interval from the initial surgery to recognition of infection, the delay in institution of appropriate treatment, the particular joint that was infected, the integrity of the bone-cement interface, the type of prosthesis used, and the host susceptibility. Identification of high-risk groups and the recognition that patients with joint implants are at risk of infection at any time in the postoperative period may lead to a lowered infection rate in the future.

Aged↗
PubMedDate not supplied

Total knee arthroplasty in rheumatoid arthritis.

The results of total knee arthroplasty (TKA) have improved steadily during the past decade due to refinements in design, fixation, and surgical technique. A review of the evolution of prosthetic design and of the clinical performance of the concept of cruciate-sparing knee arthroplasty provides both direction for improvement and cause for optimism. The results of 798 TKAs performed in one institution were reviewed to validate the principles and concepts of prosthetic design and surgical technique. During the years reviewed the incidence of good and excellent results rose from 67% to 92%, while revision rates declined. Failures resulting in revision were due to loosening in 1.3% of the knees, patellofemoral pain in 1.8%, and infection in 0.4%. Patients with rheumatoid arthritis (RA) achieve results similar to those of patients with osteoarthritis with regard to range of motion and pain relief; the polyarticular nature of RA results in some decrease in functional outcome, primarily related to disease in other joints. In the relatively short follow-up evaluation, the failure rate is acceptably low, and radiolucent lines, indicative of potential later failure, appear to be diminishing in frequency and extent. The improving success rate in each successive series of TKAs reviewed in this paper provides grounds for optimism regarding the future of TKA, and important lessons can be derived from the failures.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Hip cartilage supported by methacrylate in canine arthroplasty.

A theoretically attractive approach to femoral head arthroplasty would be the preservation of a"biologic" bearing surface composed of autogenous articular cartilage and subchondral bone, supported by a prosthetic material with mechanical properties similar to those of trabecular bone. The substitution of such a material for bone would preclude incomplete revascularization of the femoral head and eventual bony collapse. The advantages of preserving the patient's hip joint, even in the face of a fracture that has caused the loss of vascular supply to the femoral head, are self-evident. To test this hypothesis, seven dogs underwent hip arthroplasty, whereby the trabecular bone of the femoral head was replaced with polymethylmethacrylate. When killed 2 1/2 years after operation all of the dogs demonstrated injury or loss of articular cartilage in the superior aspect of the femoral head. The lesions are consistent with advanced osteoarthritis by gross and histologic examination. These lesions apparently were produced by changing either the geometry or stiffness, or both, of the material supporting the articular cartilage. Supporting human articular cartilage with methacrylate for joint arthroplasty is not recommended.

Animals↗
PubMedDate not supplied

Bilateral total hip and knee replacement in adults with rheumatoid arthritis: an evaluation of function.

Sixteen patients with advanced rheumatoid arthritis who underwent total joint replacements of both hips and both knees were followed for an average of 22.8 months postoperatively. Their functional status before and after surgery was assessed by use of a special rating system for function. Fourteen of the 16 patients demonstrated higher total function scores at follow-up. Improvement was most marked in walking endurance, need for walking aids, and ability to climb stairs. Factors which were believed to predispose to less functional improvement included older age at initial surgery, longer duration of disease, more severe upper extremity involvement, and more frequent medical illnesses. There were 8 patients in whom combined hip and knee flexion in one or both lower extremities did not exceed 190 degrees after surgery. When this deficiency was combined with severe involvement of the upper extremities, difficulty with activities such as climbing stairs and arising from a chair was more common. Therefore, the goal of surgical treatment is to provide combined hip and knee flexion in excess of 190 degrees in these patients. Total joint arthroplasty has increased the likelihood of functional improvement in patients with severe rheumatoid arthritis involving the hips and knees, and encouraged the surgeon to operate earlier in the course of the disease as well as on patients with severely deformed joints.

Adult↗
PubMedDate not supplied

Giant cell synovitis associated with failed polyethylene patellar replacements.

Destroyed patellar articular surfaces were replaced with a high molecular weight polyethylene prosthesis in two patients. The patellofemoral articulation of the femur consisted of eburnated bone in one case and degenerative cartilage in the other. Both operations failed within one year because of a giant cell synovitis caused by a high volume (0.2 cc) of fine polyethylene (1-100 mu) wear particles. Ultra high molecular weight polyethylene should not be used as a prosthetic bearing surface to articulate against cortical, cancellous or eburnated bone or against degenerative articular cartilage in a major joint.

Aged↗
PubMedDate not supplied

Comparison of preoperative, intraoperative and early postoperative total hip replacement with and without trochanteric osteotomy.

A series of 100 consecutive patients with total hip replacements in whom trochanteric osteotomy was performed was compared with 100 patients in whom the greater trochanter was left in place. The groups were comparable with respect to age and incidence of osteoarthritis and connective tissue disorders. Although no statistically significant difference was noted among trochanterectomy groups or disease subgroups in terms of preoperative impairment as indicated by preoperative Harris score, 16 patients presented exposure problems necessitating trochanteric osteotomy despite preoperative plans to leave the trochanter in place. Salvage operations after unsuccessful previous operations were performed in 18 patients in the osteotomy group and 11 in the nonosteotomy group. Mean operating time was 3 hours for patients in the osteotomy group and 2 hours for those in the nonosteotomy group. Considerably more intraoperative and postoperative blood replacement was required in the patients having osteotomy. Patients sat, stood, walked, and left the hospital sooner in the nonosteotomy group than in the osteotomy group. Trochanteric bursitis requiring treatment 3 or more months after operation occurred in 17 patients having osteotomy and in 3 patients not having osteotomy. Hematomas developed in 15 patients in the osteotomy group and in 4 in the nonosteotomy group. Ectopic bone formation was observed in 12 of the osteotomy group, 8 with limitation of function, and 5 of the nonosteotomy group; non had symptoms. Six osteotomized patients had troublesome abductor weakness secondary to wire breakage and proximal migration of the trochanter. The rates of infection and thrombophlebitis were low in both groups. When exposure was not difficult, leaving the trochanter intact had many advantages.

Collagen Diseases↗