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.
ObjectiveTo explore the effectiveness of UC ultra-congruent rotating platform prosthesis in the treatment of knee osteoarthritis by comparing with fixed-bearing implant. MethodsThe clinical data were retrospectively analyzed, from 98 patients (98 knees) with knee osteoarthritis undergoing primary total knee arthroplasty between January 2011 and December 2012. The UC ultra-congruent rotating platform prosthesis was used in 56 cases (mobile-bearing group) and fixed-bearing implant was used in 42 cases (fixed-bearing group). There was no significant difference in gender, age, side, weight, disease duration, grading of arthritis, the number of varus and valgus malformation, preoperative range of motion of the knee, the Knee Society Score (KSS) score, the visual analogue scale (VAS) score, femorotibial angle, tibial angle, and articular surface angle between 2 groups (P>0.05). The operation time (including anesthetic time), intraoperative blood loss, hospitalization time, total hospitalization expenses, postoperative range of motion of the knee, the KSS score, and the VAS score were compared. The femorotibial angle, tibial angle, and articular surface angle were measured on the basis of anteroposterior and lateral X-ray films, and prosthesis loosening was observed. ResultsThere was no significant difference in the operation time, intraoperative blood loss, and hospitalization time between 2 groups (P>0.05), while the total hospitalization expenses of fixed-bearing group were significantly lower than those of the mobile-bearing group (t=8.506, P=0.000). The patients were followed up 16-30 months in the mobile-bearing group, and for 16-38 months in the fixed-bearing group. Postoperative complications occurred in 3 cases (7.14%) of the fixed-bearing group (1 case of fat liquefaction of incision, 1 case of joint stiff, and 1 case of anterior knee pain), and in 3 cases (5.36%) of the mobile-bearing group (1 case of delayed wound healing, and 2 cases of anterior knee pain); there was no significant difference in the complication rate between 2 groups (χ2=0.133, P=0.516). At last follow-up, the KSS score, VAS score, range of motion of the knee, femorotibial angle, tibial angle, and articular surface angle were superior significantly to those before operation in both groups (P<0.05), but no significant difference was found between 2 groups (P>0.05). No radiographic signs of radiolucent line, prosthetic dislocation, patellar dislocation, prosthetic loosening, and fracture was found. ConclusionUC ultra-congruent rotating platform prosthesis in the treatment of knee osteoarthritis can effectively improve the knee joint function and relief pain, which has the same short-term effectiveness to fixed-bearing implant.