The effect of a portable HEPA-filtered body exhaust system on airborne microbial contamination in a conventional operating room.

OBJECTIVE: To study the effect of a portable HEPA-filtered air exhaust system (Stackhouse Freedom Surgical Helmet System) on airborne microbial contamination in a modern conventional operating room. DESIGN AND SETTING: Microbial air sampling was done with a two-stage Anderson sampler at the wound site during 46 total joint replacements. All operations were performed by the same surgeon in the same operating room at a large community hospital. RESULTS: In 18 cases done without air exhaust hoods, the number of bacterial and fungal colony-forming units (CFU) ranged from 0.6 to 11.7 (mean, 3.6). Air sampling during 28 operations with the operating team in air exhaust hoods revealed a mean of 3.6 CFU (range, 0 to 11.4). Bacterial CFU averaged 3.4 without hoods and 3.2 with exhaust hoods. Coagulase-negative staphylococci were the most common isolates (48% of isolates with hood, 55% without hood). No infections occurred. CONCLUSION: We concluded that these air exhaust hoods did not lower airborne microbial contamination detectable with this air sampling method, as compared to standard head cover and mask, in a modern conventional operating room.

Modular femoral stem removal during total hip arthroplasty using a universal modular stem extractor.

Removal of a modular head femoral prosthesis may be extremely difficult during revision total hip arthroplasty (THA). A universal modular stem extractor was developed that achieves a secure attachment to the stem taper, and applies tensile forces with a five-pound slaphammer. Clinical use indicates that this new device facilitates uncomplicated modular femoral stem removal.

Fluid contamination during orthopaedic procedures. A study of incidence, location, and prevention.

Certain orthopaedic procedures may expose health care providers to contamination of scrub clothing, personal undergarments, and/or skin by patients' body fluids. The incidence and site of fluid contamination were studied for an orthopaedic surgeon and his assistant during 54 orthopaedic operations from March through May 1989. Contamination was recorded in 35 of the cases (65%) for the surgeon, and in 37 (69%) for the assistant. The sites of contamination spanned the length of the lower extremities, with an overall 34% incidence above the knee. The surgeon and assistant then monitored fluid contamination during 43 cases from March through May 1990 while wearing water-impervious surgical pants. An additional 16 clinicians also tested these pants and answered questions regarding their comfort and utility. No cases of fluid contamination were recorded during the second phase of the study. The garment was reported to be comfortable and did not appear to add a heat factor, even with the use of lead aprons during fluoroscopic procedures.

Ipsilateral fractures of the femur and tibia in children and adolescents.

We reviewed forty-four consecutive cases of simultaneous fracture of the ipsilateral femur and tibia in forty-two children and adolescents. One patient died from concomitant cerebral injury and one had a fat-embolism syndrome. Thirty patients (thirty-two limbs) had an average follow-up of 5.1 years (range, one to fourteen years). Nineteen patients who had an average follow-up of 6.8 years were available for personal examination and roentgenography. Age was found to be the most important variable as related to clinical course. Of the fifteen patients who were less than ten years old, three had an early complication; the average time to full, unsupported weight-bearing was thirteen weeks; and the average combined femoral and tibial overgrowth was 1.8 centimeters. Of the fifteen children who were more than ten years old, eight had an early complication; the average time to full, unsupported weight-bearing was twenty weeks; and there was variable femoral and tibial growth. The juxta-articular pattern of fracture was associated with the highest incidence of early and late problems. Most of the children who were younger than ten years were treated successfully with closed methods, but limb-length discrepancy developed. The children who were older than ten years were treated successfully with reduction and fixation of the femoral fracture, but had a high rate of complications. There was a high incidence of concomitant injuries to the ligaments of the knee, resulting in long-term dysfunction of the extremity. Of the nineteen patients who had long-term follow-up, only seven had normal function without major problems. The remainder had a compromised result due to limb-length discrepancy, angular deformity, or instability of the knee, particularly ligamentous instability.

Metacarpal-phalangeal joint arthroplasty of the rheumatoid thumb.

Fifty patients with rheumatoid arthritis had 59 Swanson implants of the metacarpal-phalangeal joint of the thumb. Eleven patients (15 implants) have since died and only 1 patient (1 implant) has been lost to follow-up leaving 43 implants available for study. The most common preoperative deformity was a boutonniere deformity with a flexible interphalangeal joint. All thumbs had less pain after operation. The average range of active motion is 25 degrees, with a flexion arc from 15 to 40 degrees. There is an average key pinch strength of 4 pounds (range, 0.5 to 10). Improvement in activities of daily living were noted in 40 hands. One thumb required reoperation for instability; the implant was removed and a metacarpal-phalangeal arthrodesis was done. Radiographic progression of disease was noted in only one thumb at the interphalangeal joint and in two other thumbs at the carpometacarpal joint. None of these have required further operations. The maintenance of motion appears to help in activities of daily living as stability and pinch strength are often adequate.

Management of infection about total elbow prostheses.

Deep infection was a complication after twelve (7.3 per cent) of 164 primary total elbow replacements. Two additional patients who had an infection about an elbow prosthesis were referred for treatment after total elbow replacement elsewhere. A statistical analysis of all of these primary total elbow arthroplasties, including the two in patients who were referred from outside institutions, identified preoperative factors that placed a patient at significant risk for subsequent infection. The risk factors included a previous operation on the elbow, a previous infection in the region of the elbow, psychiatric illness, class-IV rheumatoid arthritis, drainage from the wound after operation, spontaneous drainage after ten days, and reoperation for any reason. Three modes of treatment were used for patients who had an established infection: débridement and salvage of the implant, resection arthroplasty, and arthrodesis. After early operative débridement and suppression of the infection with long-term antibiotic therapy, three patients were able to retain the prosthesis, with restoration of range of motion and function of the upper extremity. One prosthesis was reimplanted after a six-week course of intravenous administration of antibiotics.

Isolation of a plasma membrane-enriched fraction from collagenase-suspended rachitic rat growth plate chondrocytes.

An attempt was made to concentrate plasma membranes of homogenized chondrocytes isolated by collagenase digestion of rachitic rat epiphyseal growth plate cartilage. This study reports the characterization of enzymes in the plasma membrane of isolated chondrocytes and their comparison with extracellular matrix vesicle components. The plasma membrane-enriched fractions that were obtained showed a sevenfold increase in 5'-nucleotidase and a 15-fold increase in alkaline phosphatase, both of which are regarded as plasma membrane markers. SDS-polyacrylamide gel electrophoretic profiles of proteins extracted from membrane fractions contained several major protein bands also seen in isolated matrix vesicles. These studies indicate the usefulness of concentrating plasma membrane components from isolated chondrocytes, after the chondrocytes have been enzymatically freed from investing matrix and other stromal components by collagenase.