Objective To review the research progress of the location marker of rotational alignment of the distal femur. Methods The recent literature concerning the location marker of rotational alignment of the distal femur at home and abroad was extensively reviewed and analyzed. Results Femoral prosthesis malrotational alignment could lead to some patellofemoral complications, such as dislocation of the patella, snapping, wear, and patellar pain. There are many methods to determining femoral component rotational alignment in the artificial total knee arthroplasty, including transepicondylar axis line, anterior posterior axis, the posterior condyles line, flexion gap balance technology, and computer navigation technology. Correct choice of the rotational alignment of the distal femur is crucial in reducing postoperative complications and the revision rate. Suitable reference axis is chosen during total knee arthroplasty to ensure the accuracy of the rotation axis of the femoral prosthesis, but it is currently still controversial. Conclusion The rotational alignment of the distal femur is an extremely important part to affect the prognosis of total knee arthroplasty. The methods to determine the rotational alignment of the distal femur need to be further improved.
Objective To investigate the rotational mismatch of total kneereplacement with medial 1/3 of tibial tuberosity as bony landmark in osteoarthritic patients with varus or valgus deformity. Methods Axial images on computed tomography of 62 knees (including 55 varus deformities and 7 valgus deformities) in 32 Chinese osteoarthritic patients who had total knee arthroplasty were analyzed, compared with that of 10 healthy knees. On images of the distal femur, the angle between the lines of surgical epicondylar axis(SEA) and posterior condylar axis was measured as posterior condylar angle (PCA), and on images of the proximal tibia, a baseline for the anteriorposterior axis of each component was drawn based on the SEA for the femur and the medial 1/3 of the tibial tuberosity for the tibia. The angle between these lines (Angle α) was defined as therotational mismatch between the components when they were aligned to the anatomic landmarks of each bone. Results The sulcus of medial epicondyle of femur could be identified on CT images of over 80% osteoarthritic knees; the median value of PCA was +2.36°, with an individual variation of 0° to +7.5°. Angle α was +6.45±3.68°(range, 0° to +11.8°) in 10 healthy knees, which increased significantly to +10.85±10.47°(range, 0° to +28.1°)in 55 varus knees (P＜0.05), which also increased significantly to +11.6±7.3°(range, -6.5° to +26.8°) in 7 valgus knees (P＜ 0.05). Conclusion With the medial 1/3 of the tibial tuberosity as the rotational landmark for the tibial component, there was a tendency to align the tibial component in external rotational position relative to the femoral component in knees with normal alignment, the rotational mismatch increased in Chinese osteoarthritic knees with varus and valgus deformity.
Objective To review the advance in the researchand clinical application of the tibial rotational alignment technique in the total knee arthroplasty in China and abroad. Methods The recent literature concerned with the tibial rotational alignment technique in the totalknee arthroplasty was extensively reviewed and briefly summarized. Results According to the literature reviewed, the traditional tibial rotational references for the total knee arthroplasty were affected by many factors, so that the references were not accurate enough. There have been no unified references.ConclusionChoosing the range from the medial border of the tibial tubercle to the medial 1/3 of the tibial tubercle, decided by the degrees of the varus deformities and the valgus deformities, to determine the rotaional alignment of the tibial component will create an optimal tibiofemoral rotational alignment.
ObjectiveTo investigate the effect of medial 1/3 anatomical orientation of the tibial tubercle on the rotational alignment of Gemini MK-Ⅱ tibial components in total knee arthroplasty (TKA). MethodsBetween March 2011 and December 2012, 61 cases (67 knees) of varus knee osteoarthritis underwent Gemini MK-Ⅱ knee arthroplasty, and the clinical data were retrospectively analyzed. There were 12 males and 49 females, with an average age of 67.6 years (range, 50-82 years). The body mass index ranged from 20.9 to 33.7 kg/m2 (mean, 28.2 kg/m2). Unilateral TKA was performed in 55 cases and bilateral TKA in 6 cases. The duration of knee osteoarthritis ranged from 2 to 30 years (mean, 12.1 years). According to radiographic changes, 56 knees were rated as Kellgren-Lawrence grade Ⅲ and 11 knees as grade IV. During TKA, the tibial rotational alignment was determined by medial 1/3 anatomical orientation of the tibial tubercle. The anteroposterior and lateral X-ray films and CT scan were taken to measure the tibial rotational angle (TRA) at pre-and post-operation and to analyze the relative factors for TRA by Pearson correlation analysis. ResultsAll the patients were followed up 18-41 months (mean, 20.5 months). The range of motion (ROM) significantly increased from (98.806±16.969)° preoperatively to (116.806±11.458)° at last follow-up (t=-11.760, P=0.000). The knee society score (KSS) significantly increased from 111.239±20.344 to 160.522±17.872 at last follow-up (t=-27.271, P=0.000). The anatomical tibiofemoral angle (ATFA), posterior condylar angle (PCA), and TRA were all improved after TKA, showing significant differences when compared with preoperative ones (P<0.05). Rotational malalignment was observed in 11 knees (16.42%) before TKA, and in 14 knees (20.90%) at 1 week after TKA, showing no significant difference (χ2=0.443, P=0.506). There were 8 knees (11.94%) of internal rotation (>8°) and 6 knees (8.96%) of external rotation (>8°). The postoperative tibial prosthesis TRA had no correlation with the preoperative ATFA and tibial plateau TRA, the postoperative PCA and ATFA (r=-0.174, P=0.159; r=0.220, P=0.074; r=0.237, P=0.053; r=-0.095, P=0.442). ConclusionIn patients with varus knee osteoarthritis, medial 1/3 anatomical orientation of the tibial tubercle will contribute to the development of tibial rotational malalignment when TKA is performed by using Gemini MK-Ⅱ tibial components.