The effects of pulsed fluid irrigation on bony ingrowth in porous polyethylene implants.

Twelve adult dogs were used to evaluate the effect of pulsed isotonic saline irrigation on bony ingrowth. The distal supracondylar ridge of the knee was transected. Six dogs had the area irrigated with a pulsed lavage system for 15 sec and six dogs did not. A porous piece of polyethylene was then stapled to the cancellous surface. Three of each were evaluated histologically at 3 weeks and 6 weeks. The pulsed irrigation significantly decreased the depth of bone penetration into the sections of polyethylene.

Prophylactic indomethacin for the prevention of heterotopic bone formation following total hip arthroplasty.

In July 1977, prophylactic indomethacin for "high-risk" total hip arthroplasty candidates was adopted for the prevention of heterotopic bone formation. A total of 1053 patients were included in this retrospective study. Five hundred twenty-five patients were operated on before July 1977, whereas 528 patients had a total hip arthroplasty after July 1977, when the indomethacin program was initiated. Eighty-one of the 528 patients operated on after July 1977 were identified as high-risk surgical candidates and therefore received prophylactic coverage. None of the 81 patients treated with indomethacin developed the functionally disabling Grade II or III ectopic ossification. Statistical analysis revealed a marked different (p less than .001) between the overall incidence of heterotopic bone formation in patients operated on before July 1977 and that of patients who had hip procedures after July 1977, when the indomethacin program began. Surprisingly, the action of indomethacin on bone metabolism did not seem to retard fusion of the greater trochanter with the femur or alter the frequency of nonunion.

Systemic effects of polymethylmethacrylate. Increased serum levels of gamma-glutamyltranspeptidase following arthroplasty.

This study dealt with the effects of polymethylmethacrylate (PMMA) in total hip and knee arthroplasty patients on serum gamma-glutamyltranspeptidase GGTP levels. Patients undergoing open reduction and internal fixation of hip fractures served as control patients. Results of this study showed that 11 of 90 total hip patients and seven of 23 total knee patients had abnormally elevated GGTP levels at 5 and 10 days postoperatively. Abnormal elevations of GGTP levels in 40 hip fracture patients, however, were not noted. Clinical findings in this study included the observations that three of the 11 hip patients with elevated GGTP levels concurrently had symptoms of anorexia, nausea and/or vomiting, along with spiking temperatures in the postoperative period. These symptoms generally occurred by 5 days following surgery and resolved uneventfully by 10 days postoperatively. Likewise, two of the seven knee patients with elevated GGTP levels in the postoperative period had the symptoms described above. No symptoms were reported from the hip fracture patients.