Prediction of Leg Length Discrepancy After Unilateral Total Knee Replacement in Varus Deformity

To What degree total knee replacement (TKA) affects leg length discrepancy in patients with varus deformity? Varus deformity, the most commonly encountered deformity in patients undergoing TKA is associated with limb alignment and varying degrees of contractures of medial soft tissue structures, laxity of the lateral soft tissue structures, flexion deformity and medial bone erosion at the knee joint .The challenges in performing TKA in a varus arthritic knee include restoration of limb alignment, balancing the medial and lateral soft tissue tension, equalizing flexion and extension gaps and restoring medial bone loss

Limb length discrepancy (LLD)less than 2cm is usually not noticeable and does not require treatment. LLD over 2cm is usually noticed by the individual affected leading to self compensation by walking on the ball of the foot (toe down) or by tilting the pelvis and curving the spine.Untreated LLD can lead to lower back pain and long leg arthritis of the hip LLD and its effects on patient function have been discussed in depth in the literature with respect to hip arthroplasty but there are few studies that have examined the effect on function of limb length discrepancy following TKA. Improved surgical techniques and rehabilitation protocols have resulted in excellent knee function and range of motion following TKA. The investigators are aiming from the study to improve functional outcome in patients with knee osteoarthritis undergoing TKA.

Inclusion Criteria: - 1-Cases of osteoarthritis of the knee with varus deformity undergoing unilateral TKA. 2-Cases with previous unilateral TKA undergoing TKA of the other side. Exclusion Criteria: 1-Cases of osteoarthritis of the knee with valgus deformity. 2-Revision total knee replacement cases. 3-Patients with total hip replacement. 4-Extra-articular lower limb deformities. 5-Cases of bilateral TKA done at same setting. 6-Patients with previous knee surgery. 7-Patients with complicated inrta-operative TKA .

Khalifa AA, Mullaji AB, Gendy AN, Ahmed AM, Bakr HM, Khalifa YE, Abdelaal AM. Prediction of leg length change (LLC) after correcting varus and flexion deformity in patients undergoing TKA. Eur J Orthop Surg Traumatol. 2021 Aug;31(6):1199-1205. doi: 10.1007/s00590-020-02853-6. Epub 2021 Jan 9.

1. MihalkoWM, Saleh KJ, Krackow KA, Whiteside LA. Soft-tissue balancing during total knee arthroplasty in the varus knee. J Am Acad Orthop Surg. 2009;17:766-74.