Objective To explore the application value of self-made tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty (TKA) for improving the lower extremity force line. Methods Between January and August 2012, 13 cases (21 knees) of osteoarthritis with tibial extra-articular deformity were treated, including 5 males (8 knees) and 8 females (13 knees) with an average age of 66.5 years (range, 58-78 years). The disease duration was 2-5 years (mean, 3.5 years). The knee society score (KSS) was 45.5 ± 15.5. Extra-articular deformities included 1 case of knee valgus (2 knees) and 12 cases of knee varus (19 knees). Preoperative full-length X-ray films of lower extremities showed 10-21° valgus or varus deformity of tibial extra joint. Self-made tibial mechanical axis locator was used to determine and mark coronal tibial mechanical axis under X-ray before TKA, and then osteotomy was performed with extramedullary positioning device according to the mechanical axis marker. Results All incisions healed by first intention, without related complications of infection and joint instability. All patients were followed up 5-12 months (mean, 8.3 months). The X-ray examination showed lt; 2° knee deviation angle in the others except 1 case of 2.9° knee deviation angle at 3 days after operation, and the accurate rate was 95.2%. No loosening or instability of prosthesis occurred during follow-up. KSS score was 85.5 ± 15.0 at last follow-up, showing significant difference when compared with preoperative score (t=12.82, P=0.00). Conclusion The seft-made tibial mechanical axis locator can improve the accurate rate of the lower extremity force line in TKA for tibia extra-articular deformity.
Objective To evaluate the effectiveness of total knee arthroplasty (TKA) using three-dimensional (3D) printing technology for knee osteoarthritis (KOA) accompanied with extra-articular deformity. Methods Between March 2013 and December 2015, 15 patients (18 knees) with extra-articular deformity and KOA underwent TKA. There were 6 males (6 knees) and 9 females (12 knees), aged 55-70 years (mean, 60.2 years). The mean disease duration was 10.8 years (range, 7-15 years). The unilateral knee was involved in 12 cases and bilateral knees in 3 cases. The clinical score was 57.44±1.06 and the functional score was 60.88±1.26 of Knee Society Score (KSS). The range of motion of the knee joint was (72.22±0.18)°. The deviation of mechanical axis of lower limb was (18.89±0.92)° preoperatively. There were 8 cases (10 knees) with extra-articular femoral deformity, 5 cases (5 knees) with extra-articular tibial deformity, and 2 cases (3 knees) with extra-articular femoral and tibial deformities. Bone models and the navigation templates were printed and the operation plans were designed using 3D printing technology. The right knee joint prostheses were chosen. Results The operation time was 65-100 minutes (mean, 75.6 minutes). The bleeding volume was 50-150 mL (mean, 90.2 mL). There was no poor incision healing, infection, or deep venous thrombosis after operation. All patients were followed up 12- 30 months (mean, 22 months). Prostheses were located in the right place, and no sign of loosening or subsidence was observed by X-ray examination. At last follow-up, the deviation of mechanical axis of lower limb was (2.00±0.29)°, showing significant difference when compared with preoperative one (t=13.120, P=0.007). The KSS clinical score was 87.50±0.88 and function score was 81.94±1.41, showing significant differences when compared with preoperative ones (t=27.553, P=0.000; t=35.551, P=0.000). The range of motion of knee was (101.94±1.42)°, showing significant difference when compared with preoperative one (t=31.633, P=0.000). Conclusion For KOA accompanied with extra-articular deformity, TKA using 3D printing technology has advantages such as individualized treatment, reducing the difficulty of operation, and achieving the satisfactory function.
Objective To investigate the effectiveness of lateral condyle sliding osteotomy (LCSO) in total knee arthroplasty (TKA) for the treatment of lateral femoral bowing deformity. Methods The clinical data of 17 patients with lateral femoral bowing deformity treated by LCSO during TKA between July 2018 and July 2020 was retrospectively analysed. There were 3 males and 14 females, with an average of 63.2 years (range, 58-68 years). The etiology of lateral femoral bowing deformity included 12 cases of femoral developmental deformity and 5 cases of femoral fracture malunion. Kellgren-Lawrence classification of knee osteoarthritis was 4 cases of grade Ⅲ and 13 cases of grade Ⅳ. The preoperative hip-knee shaft was 9.5°-12.5° (mean, 10.94°). The disease duration was 3-25 years (mean, 15.1 years). The mechanical lateral distal femur angle (mLDFA), hip-knee-ankle angle (HKA), and mechanical axis deviation (MAD) of the distal femur were measured before operation and at last follow-up to evaluate the correction of extra-articular deformities in the joints and the recovery of mechanical force lines of the lower extremities. The knee society score (KSS) knee score and function score, visual analogue scale (VAS) score, knee joint range of motion (ROM) were used to evaluate effectiveness. The knee varus/valgus stress test and osteotomy healing by X-ray films were performed to evaluate the joint stability and the safety of LCSO. Results All incisions of the patients healed by first intention after operation, and there was no early postoperative complication such as infection of the incision and deep vein thrombosis of the lower extremities. All 17 patients were followed up 12-36 months, with an average of 23.9 months. The osteotomy slices all achieved bony healing, and the healing time was 2-5 months, with an average of 3.1 months. After operation, the knee varus/valgus stress tests were negative, and there was no relaxation and rupture of the lateral collateral ligament, instability of the knee joint, loosening, revision and infection of the prosthesis occurred. At last follow-up, mLDFA, HKA, MAD, knee ROM, VAS score, KSS knee score and function score significantly improved when compared with preoperative ones (P<0.05). Conclusion LCSO is effective and safe in TKA with lateral femoral bowing deformity. Extra-articular deformities are corrected intra-articularly. The mechanical force line and joint balance of the lower extremities can be restored simultaneously in an operation.