Effect of Femoral Resection on Coronal Overall Alignment after Conventional Total Knee Arthroplasty

Abstract

Background:A good postoperative alignment in total knee arthroplasty (TKA) is the key to achieving satisfactory results. We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA.Methods:We conducted a retrospective analysis of 212 primary TKAs in 188 patients. Intramedullary (IM)-guided resection was applied on the femoral side while extramedullary (EM)-guided resection was used on the tibial side. Using full-length X-ray, the preoperative femoral valgus angle and lower extremity alignment, as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment, were measured.Results:Postoperatively, good prosthetic alignment was achieved in 191 cases (90.1%) on the tibial side and in 144 cases (67.9%) on the femoral side (χ2 = 5.441, P = 0.02). Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane. Data were divided into five subgroups based on the valgus or varus status of the prostheses. The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414, respectively; in varus on both sides were 0.658 and 0.377, respectively; in valgus, 0.555 and 0.030; femoral side varus and tibial side valgus, 0.702 and 0.211; femoral side valgus and tibial side varus, −0.416 and 0.287. The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment, except for the tibial prosthetic alignment when femoral prosthesis was in valgus (P = 0.153).Conclusions:In conventional TKA, tibial side EM-guided resection may offer satisfactory postoperative alignment, and femoral resection relying on IM guide may lead to more undesirable results. Postoperative coronal alignment is mainly affected by the femoral resection. Therefore, femoral side operation should receive adequate attention from the surgeons.

Patient-Specific Instruments Based on Knee Joint Computed Tomography and Full-Length Lower Extremity Radiography in Total Knee Replacement

“…As Zhao et al . [ 2 ] reported postoperative malalignment of the femur when conventional instruments were used, the PSI has an intrinsic advantage with respect to guiding the femoral bone cut. Caillouette and Anzel[ 15 ] reported fat embolism during the intramedullary procedure in conventional TKR; however, there was no complication in the knee replacement using PSI.…”

“…Most TKRs are still performed using conventional instruments, with outliers in the malalignment rate reaching as high as 32%. [ 1 2 ] Malalignment can lead to multiple complications, such as instability and abnormal stress distribution, which consequently affects not only the satisfaction of the patient but also the survival of the implant. [ 3 ] Therefore, improving the accuracy of TKRs is still a challenge for all orthopaedic surgeons.…”

Radiographic Measurement of Femoral Lateral Bowing and Distal Femoral Condyle Resection Thickness

“…Distal femoral resection is a vital step in restoring limb alignment and should be performed perpendicular to the femoral mechanical axis. [ 17 ] Accurate measurements are critical for the preoperative planning of TKA. The influence of the results of the radiographic measurements due to femoral rotation is problematic and can be detrimental to the operative outcome.…”

Robotic-assisted total knee arthroplasty is more advantageous for knees with severe deformity: a randomized controlled trial study design

“…Thus, accurate placement of the prosthesis and normal alignment of the lower limb axis play a key role in reducing postoperative complications and improving the survivor time of the prosthesis, and directly affects long-term TKA results 4 . In conventional surgical techniques in TKA, surgical instruments are matched to determine the placement of prosthesis, which is highly dependent on the operator’s experience, and has some problems such as low accuracy and repeatability 5 . To address these problems, a robotic‑assisted system is applied in TKA.…”