Objective To investigate the management of extention apparatus and cl inical results of total knee arthroplasty (TKA) of osteoarthritis. Methods Between June 2007 and June 2009, 386 patients (460 knees) with osteoarthritis received TKA, including 216 left knees and 244 right knees. There were 125 males (145 knees) and 261 females (315 knees) with an average age of 60.3 years (range, 58-85 years). The disease duration was 4-12 years (mean, 6.7 years). The X-ray films and CT scanning showed that all patients had femur-tibia joint degeneration and osteophyte formation at the edgeof joint. According to modified Burnett patellar resurfacing indication, whether or not to replace the patellar was determined, and the patellar track was determined by combining no thumb test and towel clamp traction test. Patella resurfacing was performed in 53 cases (56 knees, resurfacing group), no patella resurfacing in 333 cases (404 knees, non-resurfacing group), and lateral retinacular releasing 68 cases (72 knees). The postoperative imaging and knee society score (KSS), patellofemoral compl ications were analyzed. Results All wounds healed by first intention. All the patients were followed up 1-3 years (mean, 26 months). Deep infection occurred in 3 cases (1 case of resurfacing group and 2 cases of non-resurfacing group) at 3-7 months and they were cured after two-stage reversion. Patellofemoral compl ications occurred in 2 cases of resurfacing group (2/56, 3.57%) and in 9 cases of non-resurfacing group (9/404, 2.23%), showing no significant difference (χ2=0.38, P=0.54). There were significant differences in KSS and visual analogue scale (VAS) at 2 and 3 year after operation when compared with before operation (P lt; 0.05). No significant difference in KSS and VAS of resurfacing group and non-resurfacing group were observed at 3 years after operation (P gt; 0.05). Conclusion It is benefit for selective patellar resurfacing and the patellar tract improvement to select patellar resurfacing indication according to the multi-factor assessment and to determine the patellar tract by combining no thumb test and towel clamp traction test, which can reduce the patellofemoral compl ication rate after TKA.
Objective To compare the difference of anterior knee pain between mobile-bearing prosthesis and fixedbearing prosthesis after total knee arthroplasty (TKA). Methods Between January 2008 and October 2008, 72 patients withosteoarthritis were treated with primary TKA. All patients were randomly divided into fixed-bearing prosthesis group (n=37)and mobile-bearing prosthesis group (n=35). In fixed-bearing prosthesis group, there were 8 males and 29 females with an average age of 69.6 years (range, 57-76 years), weighing from 55 to 92 kg (mean, 66.7 kg); the locations were the left knee in 20 cases and the right knee in 17 cases; the body mass index (BMI) ranged from 17.6 to 37.3 (mean, 26.2); the disease duration was 3-22 years; the Knee Society Score (KSS) knee score, function score, patellar score, and pain score were 29.4 ± 15.3, 33.4 ± 16.8, 7.2 ± 2.5, and 2.5 ± 2.2, respectively; and the Insall-Salvati (I-S) index was 1.6 ± 0.3. In mobile-bearing prosthesis group, there were 9 males and 26 females with an average age of 68.2 years (range, 58-73 years), weighing from 50 to 86 kg (mean, 67.9 kg); the locations were the left knee in 30 cases and the right knee in 5 cases; the BMI ranged from 18.4 to 34.4 (mean, 25.6); the disease duration was 6-18 years; the KSS knee score, function score, patellar score, and pain score were 30.9 ± 14.7, 31.4 ± 14.4, 6.8 ± 3.1, and 2.0 ± 2.3, respectively; and the I-S index was 1.6 ± 0.2. There was no significant difference in general data between 2 groups (P gt; 0.05). Results All incisions healed by first intention; no deep vein thrombosis of lower l imbs or pulmonary embol ism occurred. All patients were followed up 12-16 months. In mobile-bearing prosthesis group, knee infection occurred in 1 case, dislocation of the knee in 1 case, and cl icking of the knee in 3 cases; in fixed-bearing prosthesis group, cl icking of the knee occurred in 1 case. There was no significant difference in KSS knee score, function score, patellar score, or pain score between 2 groups (P lt; 0.05) at last follow-up; and there was no significant difference in congruence angle, lateral patellofemoralangle, patellar tilt angle, lateral patellar displacement, patellar displacement, or I-S index between 2 groups at last follow-up (P gt; 0.05). Anterior knee pain occurred in 7 cases (18.9%) of the fixed-bearing prosthesis group and in 5 cases (14.3%) of the mobilebearing prosthesis group, showing no significant difference (χ2=0.227, P =0.634). There were significant differences in KSS knee score, function score, patellar score, and I-S index between patients with anterior knee pain and patients without anterior knee pain (P lt; 0.05). Conclusion Fixed-bearing prosthesis and mobile-bearing prosthesis have the same short-term effectiveness and the incidence of anterior knee pain.