RESUMEN
PURPOSE: The objective of this study was to investigate the effects of radiofrequency energy on human chondrocyte viability, and to correlate confocal laser microscopy fluorescence to sulfate uptake and to the histological integrity of articular cartilage. MATERIALS AND METHODS: The chondroplasty procedure for chondromalacic articular cartilage was performed using a 3.0-mm ArthroWand (Arthroscopic Electrosurgery System, ArthroCare Corporation) on fresh human articular cartilage. Radiofrequency energy was applied to the cartilage surface through the probe at a velocity of 10-mm per second in contact and non-contact mode. Three power settings were used. The treated cartilage was analyzed for chondrocyte viability by confocal laser microscopy and (35)S uptake. RESULTS: Confocal laser microscopy demonstrated partial-thickness chondrocyte death irrespective of treatment method. No mode of treatment or radiofrequency energy power setting resulted in full-thickness chondrocyte death. The depth of cartilage ablation was increased in the treated areas in contact mode in proportion to the power level and the time of treatment. No statistically significant difference in radiolabeled sulfate uptake of the specimens was observed with respect to the treatment modes and power settings. CONCLUSION: The extent of chondrocyte death by radiofrequency energy was not as significant as reported previously when the probe was moved at the speed of 10 mm/sec. Radiofrequency energy may be useful to treat chondromalacic cartilage in a contact mode using a proper energy level and delivery time.
Asunto(s)
Humanos , Cartílago , Cartílago Articular , Condrocitos , Electrocirugia , Fluorescencia , Microscopía ConfocalRESUMEN
PURPOSE: To evaluate the clinical and radiological results of revision total hip arthroplasty using cemetless acetabular cup and several kinds of morseled bone grafts. MATERIALS AND METHODS: We performed 20 cases of revision total hip arthroplasties between July 1993 and June 1996. Acetabular bone deficiency was classified as type I in 4 hips, type II in 13 hips, type III in 2 hips and type IV in one hip by AAOS classification. Autogenous bone graft was used in 10 cases, heterograft in 5 cases, allograft in 2 cases and a mixture with autografts and allografts in 2 cases. The average contact rate between cup and host bone was 33.5% in type I acetabular deficiency, 65.1% in type II, 50% in type III and 39% in type IV. RESULTS: The mean Harris hip score was 82.9 points at the last follow-up. Osseous union between host bone and graft bone occurred within 6 months in 14 cases. Radiological failure was noted in 8 cases at the last follow-up. Three cases were revised during the follow-up period. Five cases out of 7 cases in which the contact rate between acetabular cup and host bone was less than 50% were determined to be a radiologic failure. Only 2 cases of the 10 cases in which autogenous bone graft had failed grafts. The rate of complication was 7cases (35%). CONCLUSIONS: The usage of the hemispherical cementless acetabular cup with autogenous bone graft and increasing the contact rate between the acetabular cup and host bone could be a safe management method in revision total hip arthroplasty. We recomrnend avoiding the use of heterograft in cementless cup revision arthroplasty.