Accuracy of the Tibial Component Alignment by Extramedullary System Using Simple Radiographic References in Total Knee Arthroplasty

Abstract

Background and Objectives: The tibial component alignment is an important issue for the longevity of total knee arthroplasty (TKA). The purpose of our study was to investigate the usefulness of proximal tibial references determined by pre-operative radiography and intraoperative C-arm-guided hip and ankle center marking for the extramedullary guided tibial cut in mild (<10°) and severe (≥10°) varus knee TKA. Materials and Methods: A total of 150 consecutive patients (220 cases) who underwent total knee arthroplasty who were recruited from July 2011 to April 2017 were reviewed retrospectively. Before surgery, the proximal tibial reference point and medio-lateral cut thickness difference were identified. Then, hip and ankle centers were checked using a C-arm intensifier intraoperatively. The hip–knee–ankle (HKA) alignment and medial proximal tibial angle (MPTA) were assessed pre-operatively and post-operatively. More than 3° varus or valgus of HKA alignment or tibial component angle was defined as an outlier. Results: Mean follow-up duration was 26.9 months. Among 220 cases, 111 cases are classified as mild varus group and 109 cases are classified as severe varus group. The HKA alignment is significantly improved (p < 0.001). The average tibial component angle after surgery is 90.1°. A total of 21 cases (9.5%) and 3 cases (1.4%) are classified as outliers of HKA alignment and MPTA, respectively. Among MPTA outliers, one case is in the mild varus group and two cases are in the in severe varus group (p = 0.62). Conclusion: Measurement of proximal tibial radiographic references and checking the C-arm-guided intraoperative hip and ankle center could be helpful to obtain the favorable coronal position of the tibial component in the extramedullary guided tibial cut.

Aseptic survival of the 1.5‐stage exchange arthroplasty for periprosthetic joint infection was acceptable when using an autoclaved femoral component and a new polyethylene insert

“…Femoral sagittal alignment with a γ angle between 0° and 3° was associated with the positive biomechanics in the finite element analyses [12, 13]. A varus or valgus coronal tibial alignment greater than 3° increases the risk of implant failure due to an imbalance in mediolateral compartmental pressure [2, 31]. Posterior tibial slope outside the range of 0–7° (≒ δ > 87 ± 3°) was associated with long‐term inferior survival [11].…”

“…Detailed analyses of AP and lateral radiographs according to the Knee Society radiological evaluation method were performed to evaluate the positions of components in α, β, γ, and δ angles [4,26]. Postoperatively, inappropriate HKA, α, β, γ, and δ angles were defined as HKA > 0 ± 3°, α > 95 ± 3°, β > 90 ± 3°, γ > 3 ± 3°, and δ > 87 ± 3°, respectively, based on previous literatures [2,6,[11][12][13][14].…”

Effect of Combined Exercise Program on Lower Extremity Alignment and Knee Pain in Patients with Genu Varum

“…MPTA is one of the most common variables used to measure the severity of OA and to can be simply measured from knee radiographs. Most previous studies [28,29] have reported that MPTA is improved through surgery such as total knee arthroplasty and high tibial osteotomy. A study has reported that corrective exercises including strength and mobilization exercises will help improve MPTA and functional tasks in knee joint.…”