Late results of the Souter-Strathclyde total elbow prosthesis in rheumatoid arthritis. 6/19 implants loose after 5 years.

We performed total elbow replacement, using the Souter-Strathclyde prosthesis in 19 elbows of 18 patients with rheumatoid arthritis and followed the patients for 5 (1-11) years. Pain relief was achieved initially in all patients. The average range of flexion-extension was increased by 12 degrees and pronation-supination by 40 degrees. There were no infections. 1 patient sustained an intraoperative fracture of the medial epicondyle, 3 patients developed neuropathies and 1 patient had an immediate postoperative dislocation of the joint. At follow-up, 6 prostheses had radiographic loosening, with sagittal titling and migration of 4 humeral components. 2 patients had clinical symptoms of loosening.

Short-term ibuprofen to prevent ossification after hip arthroplasty. No effects in a prospective randomized study of 47 arthrosis cases.

Heterotopic ossification after hip arthroplasty can be prevented by ibuprofen given 3 months postoperatively. To evaluate the effectiveness of 10 days of ibuprofen treatment we performed a randomized, double-blind, prospective study on 57 patients with primary arthrosis, undergoing total hip arthroplasty. 47 patients completed the study and no effect on the incidence of ossification could be detected.

Low- vs high-viscosity cement in hip arthroplasty. No radiographic difference in 226 arthrosis cases followed for 5 years.

In 1984 and 1985, 352 hips were randomly assigned to total hip arthroplasty with either low- or high-viscosity cement at 5 Swedish orthopedic departments. Of the 267 hips finally included in the study, 226 were examined clinically and radiographically after 54-77 months. Radiographically, 21 definite stem loosenings and 1 probable stem loosening were observed (10 percent) and 4 additional stems had been exchanged before the 5-year examination. In the survivorship analysis, 261 stem prostheses were included and using this method, 7 percent were radiographically loose after 5 years. There were 4 definitely loose and 8 probably loose acetabular cups. No difference was found between cement of high and low viscosity with regard to prosthetic fixation.

The Souter-Strathclyde elbow replacement in rheumatoid arthritis. 13 patients followed for 5 (1-9) years.

13 Souter-Strathclyde unconstrained elbow prostheses for rheumatoid arthritis were followed for 5 (1-9) years. Pain relief was achieved in all the patients. Flexion-extension was increased by 22 degrees, and pronation/supination by 27 degrees. There were no infections. Three humeral components were radiographically loose, but no patient had any symptoms. One patient sustained a fracture of the distal humeral epicondyle, two patients developed neuropathies and one patient had a postoperative dislocation that needed treatment with an external Hoffman fixator.

Corrosion of modular hip prostheses.

Nine uncemented hip prostheses of modular design were revised because of late infection (2 cases), femoral stem loosening or fracture (2), loosening of threaded cups (3) and protrusion of bipolar cups (2). At surgery we found tissue discoloration and macroscopic corrosion in four of the nine prostheses, located at the head-neck junction. Histological examination in most cases showed extensive necrosis associated with metal particles, indicating metal toxicity. Metallographic examination of the prosthetic heads revealed structural imperfections and inhomogeneity of the metal. We suggest that the crevice between the head and neck is a potential site of corrosion in modular designs.

Anaerobic osteomyelitis. A new experimental rabbit model.

Experimental studies of osteomyelitis have been hampered by methodologic problems. For inducing experimental anaerobic osteomyelitis, the medullary cavity of the proximal tibial metaphysis of five New Zealand white rabbits was excavated and filled with a polyvinyl alcohol sponge. On the right side, 1 ml of a suspension containing Bacteroides fragilis (10(7) colony-forming units/ml) was injected, while on the left side, Ringer's solution was used as a control substance. Within five weeks, all animals developed clinical signs of osteomyelitis. The findings were verified by roentgenograms and bone scans. There was a significant rise in titers against the inoculated B. fragilis strain in every rabbit, and when killed at 18 weeks after the bacterial inoculation cultures containing the inoculated strain were obtained from all animals. No other bacterial strains were isolated. With one exception, cultures were positive in samples from both the inoculated and the control side, indicating hematogenous seeding. In one animal, the cultures from the inoculated side were negative, whereas on the control side, there was significant growth of the inoculated strain. Histologic examination of the infection sites showed low-grade chronic osteitis. In contrast to previous studies, which have indicated severe difficulty in obtaining a single-strain anaerobic osteomyelitis, the present method gives a high infection rate with reproducible immunologic, roentgenographic, and histologic reactions.

Ankle arthrodesis by the Heiple technique in rheumatoid arthritis.

The authors report on seven rheumatoid arthritic patients that successfully sustained ankle joint arthrodesis. They incorporated a chevron fusion technique previously described. Patients were followed an average of 44 +/- 11 months. They report a satisfactory result.

Reduction of contamination at total hip replacement by special working clothes.

We assessed wound, air and operative field contamination at 50 total hip operations, performed in a zonal ventilation system. Theatre staff wore either a specially designed polypropylene non-woven coverall or conventional cotton shirt and trousers. The surgeons wore partially impermeable operating gowns. The polypropylene coverall was associated with significantly lower air and wound counts. The coverall was warmer than cotton but judged to be acceptable. The combined use of zonal ventilation and the coverall achieved ultra-clean air conditions.

Integrity of the gluteus medius after the transgluteal approach in total hip arthroplasty.

The postoperative integrity of the conjoined aponeurosis of the gluteus medius and vastus lateralis was studied in 97 consecutive total hip arthroplasties in 95 patients performed via a transgluteal approach. Metal markers were placed in the gluteal/vastus aponeurosis, one on each side of the suture line, and the integrity of the repair was assessed on radiographs taken immediately after surgery and 2 weeks, 2 months, and 1 year after operation. Separation between the markers occurred in about half of the patients, but gross separations were rare. Since most separations showed a progressive increment, elongation of the sutured aponeurosis might be a more common mechanism than perioperative injury to the neurovascular pedicle. Moreover, the degree of separation did not correlate with pain, and Trendelenburg gait was significantly increased only in the group of patients with a separation greater than 2.5 cm, indicating that a moderate gluteal elongation may be readily compensated for.

Peptostreptococcus magnus does not cause hematogenous infections in experimental arthroplasties.

Rabbits with cemented endoprostheses in the knee joints were given 1-ml intravenous injections of suspensions containing Peptostreptococcus magnus (3 x 10(8) colony-forming units/ml) on three consecutive days seven weeks postoperatively. The animals were killed after another seven weeks. The bacterial challenge did not result in infection. This is in contrast to a previous study using the same experimental system with another anaerobic bacterial species, Propionibacterium acnes, which caused infection in approximately 50% of the animals. Both these bacteria have previously been reported to cause late infections in human arthroplasties. The present results may indicate differences in the spreading mechanisms, i.e., that Peptostreptococcus magnus may have a limited ability to cause hematogenic infections and that late infections of endoprostheses by Peptostreptococcus magnus are due to perioperative contamination.

Hematogenous infection after knee arthroplasty.

Twenty-five hematogenously infected knee arthroplasties in 20 patients (17 with rheumatoid arthritis and 3 with arthrosis) were followed for 3 years. Staphylococcus aureus was the major infecting organism. Three patients with four arthroplasties died of sepsis. Two patients had removal of the arthroplasty, one of which resulted in an above-the-knee amputation. Four out of five arthrodeses fused. Two knees healed after early debridement and two healed without surgery. Ten knees had successful revision arthroplasty. Rheumatoid arthritis and constrained prostheses increase the risk of hematogenous infection. Any infection and especially cutaneous lesions in a patient with a knee arthroplasty should be treated vigorously.

Orthopaedic infections by Serratia marcescens: a report of seven cases.

In recent decades, Serratia marcescens has been established as a cause of infections difficult to treat, and several outbreaks of nosocomial infections have been reported, mostly from the USA. However, serratia infections affecting bones and joints are very rare; only a few such cases have previously been reported from Europe. We report 7 patients with orthopaedic infections by S. marcescens chiefly of nosocomial origin where previous antibiotic therapy apparently was a predisposing factor. The clinical course was generally protracted, often requiring repeated surgical interventions. Also, in some cases adequate therapy was considerably delayed as serratia was considered to be a nonpathogenic saprophyte. Multiresistance to antibiotics was a major clinical problem. However, the third generation cephalosporins are often effective against serratia and the aminoglycosides can thus be avoided. The increased use of prophylactic antibiotic therapy in orthopaedic surgery may bring about an increase in the incidence of infections by multiresistant microorganisms in orthopaedic wards.

Factors associated with heterotopic bone formation in cemented total hip prostheses.

A series of 237 total hip replacements were analysed by means of a computer program. High body weight and postoperative fever, as well as several indications of a technically demanding operation, occurred significantly more often in the group of patients which developed paraarticular ossification postoperatively. The results point to a causal relation between tissue trauma and heterotopic bone formation. We wish to underline the importance of a gentle handling of tissues in the performance of a total hip replacement if the rate of ectopic bone is to be reduced to a minimum.

The influence of the total body exhaust suit on air and wound contamination in elective hip-operations.

An evaluation of the effect of total body exhaust clothing on air and wound contamination was made in an operating theatre with a zonal ventilation system. Sixty-four patients who underwent total hip replacement using the Charnley-Müller prosthesis were studied. The members of the surgical team wore total body exhaust suits (TBE-suit), or conventional theatre clothing (C-clothing) at alternate operations. Nearly half of the patients in each group were given prophylactic antibiotics. Both the mean and median values of airborne bacteria in the operating theatre were significantly lower during operations with TBE-suits than with conventional theatre clothing. The lowest number, 4.0 cfu/m3, was found at the site of the operation wound. Cultures from adhesive drapes showed growth in 46 per cent of the C-group and in 43 per cent of the TBE-group samples. Wound washouts showed growth in 43 per cent of the C-group and in 10 per cent of the TBE-group samples. Staphylococcus epidermidis was the most frequently isolated bacteria both from adhesive drapes and from wound washouts. The rate of superficial infections was slightly higher when C-clothing was used. Deep infections were found in one patient in the TBE-group and in two patients in the C-group. None of the infected patients had received prophylactic antibiotics.

Factors leading to rearthroplasty in a material with radiographically loose total hip prostheses.

The present project was undertaken in an attempt to analyse factors associated with clinical failure (defined as indication for rearthroplasty) of total hip arthroplasties when radiographic loosening of the femoral component was present. Out of 79 radiographically loose femoral components the rate of failure was 23 per cent. High viscosity bone cement was negatively correlated to clinical failure whereas male sex and high body weight was positively correlated to clinical failure. Signs of loosening appearing early in the period of observation significantly more often led to clinical failure than late appearance of loosening, which was encouraging for the long-term prognosis.

Factors associated with calcar resorption in cemented total hip prostheses.

Patient data and radiograms from a series of 237 total hip replacements were evaluated by means of a computer program. Middle-aged patients and those without other dysfunctions of the lower extremities than the primary hip disease were prone to develop calcar resorption. Patients who did not use supportive aids preoperatively and subjects doing well without aids postoperatively were more frequently represented in the group with calcar resorption. The CAD-prosthesis (Computer Assisted Design, Howmedica), was positively correlated to resorption at calcar at 6 months postoperatively compared to the Charnley-Müller prosthesis. A negative correlation to valgus oriented femoral components was noted. Vertical placement of the acetabular cup, large cups and a long distance between the femur and the pelvis was noted to occur more often in the group with calcar resorption. Mechanical factors are concluded to be predominant in early calcar resorption and are suggested to be of clinical importance for the long term results.

Factors associated with early loosening of cemented total hip prostheses.

Patient data and radiograms from a series of 237 consecutive total hip replacements were evaluated by means of a computer programme in an attempt to study factors correlated with early loosening. We found that the loosening rate was significantly influenced by several factors. The CAD-prosthesis (Computer Assisted Design, Howmedica) was found to be superior to the Charnley-Müller-prosthesis. The viscosity of the cement seemed to be an important factor in that low viscosity was positively correlated to loosening whereas high viscosity showed a negative correlation. Several technical details in the performance of the operations as well as loosening correlated with the surgeon. Males who preoperatively had fairly unrestricted physical activity and high body weight were more prone to early loosening. No correlation was found with the diagnosis, previous hip surgery, age, osteoporosis or cortisone treatment preoperatively. We wish to underline the importance of a thorough technique and suggest that total hip replacement should be performed by specialized surgeons.