Treatment of Infection after Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To analyze the clinical results of treatment for infected TKA and find a reasonable method of treatment. MATERIALS AND METHODS: Between March 1988 and August 1997, 34 patients with infection after total knee arthroplasty were treated at Kyung Hee University Hospital. The average follow-up period was 4 year 8 months. At-the time of infection management, the average age was 59 years (range, 20 to 79 years); there were 31 women and three men. Infected patients were managed with several methods. Twenty patients were treated with one-stage or two-stage reimplantation, and arthrodesis was done in 12 cases. Two cases were treated conservatively. We assessed knee function before and after revision, according to the knee rating system of The Hospital for Special Surgery. RESULTS: Prior to revision operation, the average knee score in 20 reimplantation cases was 52 points, and the average range of motion was 76. After revision, the average knee score was 84 points, and the average range of motion was 90. All patients had complete union at an average 5.3 months after arthrodesis. There were no recurrences of infection after one-stage or two-stage reimplantation, or fusion. CONCLUSIONS: Thoughtful method of treatment should be decided in managing infected total knee arthroplasty.

The Relation Between Clinical Results and Correction Angle in Proximal Tibial Osteotomy

PURPOSE: To determine the relation between clinical results and correction angle in proximal tibial osteotomy through the retrospective study. MATERIALS AND METHODS: Seventy-two valgus osteotomies of the tibia were performed in forty-nine patients from 1985 to 1992; average follow-up period was 7 year 11 months(range, 5 to 12 years). We classi- fied the patients into three groups according to the tibiofemoral angle measured at the last follow-up. Group I includes patients with less than valgus 6 degrees of tibiofemoral angle, Group II with from valgus 7 degrees to 9 degrees and Group III with more than valgus 10 degrees. RESULTS: The Insalls Hospital for Special Surgery knee score was gradually decreased in time as 95 at postoperative 2 years, 92 at 5 years and 82 at the last follow-up. The average preoperative tibiofemoral angle was varus 3.4 degrees and the average postoperative tibiofemoral angle was corrected as valgus 8.0 degrees, 7.9 degrees at two years, valgus 7.0 degrees at five years and valgus 5.4 degrees at the last follow-up. The group I, 40 cases(mean 9 year 7 month follow-up), showed postoperative valgus 6.4(3-15) degrees and val- gus 2.6 degrees at the last follow-up. Loss of correction was 3.8 degrees and knee score was 76 at the last fol- low-up. The group II, 21 cases(8 year 1 month), showed postoperative valgus 9.0(7-11) degrees and 7.6 degrees at the last follow-up. Loss of correction was 1.4 degrees and knee score was 83.5 at the last follow- up. The group III, 11 cases(7 year 7 month) showed postoperative valgus 11.4(10-15) degrees and 10.9 degrees at the last follow-up. Loss of correction was 0.5 degrees and knee score was 97 at the last follow-up. The group III showed better maintenance of postoperative correction angle and clinical results than the other gf OUpS. CONCLUSION: Deductively, it is essential to correct tibiofemoral angle more than 7, especially ranged from 10 to 15 degrees for the best long-term clinical results.

Osteolysis around Screw in Cementless Total Knee Replacement / 대한정형외과학회잡지

Screw fixation of the tibial component offers advantages in initial fixation in cementless total knee replacement. But the high incidence of screw related osteolysis was reported. The purpose of this study is to evaluate clinical results of cementless total knee replacement and to look for radiographic changes at the screw-bone interface. From January 1988 to December 1991, primary cementless total knee replacements with Miller Galante I (Zimmer, Warsaw. IN) were performed to 53 knees at Kyung Hee university hospital. Among them, 21 cases which could be followed-up for more than 4 years were studied retrospectively about the clinical and radiographic results. The mean follow-up period was 5.5 years(ranged from 4.2 years to 8 years). At the last follow-up period, knee scores of Hospital for Special Surgery were improved from mean 56 points to 90 points and the range of motion from 72 degrees to 110 degrees. In the last follow-up radiographs, osteolysis around screw was classified as linear(type I ), cystic(type II ) and cavitary(type III ) according to the width of the lucency around screws. Among 21 cases, radiographic findings of osteolysis around screw were detected in 10 cases but not in 11 cases. But clinical results were similar between these two groups. Among the total 84 screws(4 screws in each case), 21 screws(25%) showed screw related osteolysis typed as I in 13 screws(15.4%), II in 4 screws(4.8%) and III in 4 screws(4.8%). Among the 13 cases that followed-up more than 6 years, 20 screws(38%) showed screw related osteolysis typed as in 11 screws(21.2%), I in 5 screws(9.6%) and II in 4 screws(7.8%). The most frequently involved site of screw was anteromedial(33.3%). In conclusion, after mean 5.5 year follow-up, the clinical results were satisfactory but the development of osteolysis around screw might be an indicator of the implant failure.