AUGUST 2022 | The Surgical Technologist | 355 Kostretzis et al. Kinematic Alignment Total Knee Revision FIGURE 3 | (A) Right knee clinical examination where swelling of the biceps tendon is observed. (B) Pre-revision long leg standing X-Ray reveals a right TKA implant with mDFA of 4◦ varus and a mPTA of 1.5◦ varus (5.5◦ varus aHKA). On the intact left side, the mDFA is 3.0◦ valgus and mPTA 3.5◦ varus (aHKA of 0.5◦ varus). (C) right knee lateral view where the implant posterior tibial slope is 6.5◦. (D) Left knee lateral view where the native tibial slope is 2.0◦ posterior. Case 1 A 61-year-old male with a painful and unstable right TKA 2 years after the surgery. At clinical examination, important MCL laxity was observed along with a biceps femoris tendinitis (see Figure 3AandSupplementary Video 1). Compared to the intact contralateral lower limb, the prosthetic knee was implanted with increased femoral varus (+7.0◦), decreased tibial varus (– 2.0◦), and increased posterior tibial slope (+4.5◦, Figures 3B–D). During revision surgery and after implant removal (no bone loss), to correct the mDFA by 7◦, a 5-mm distal medial femoral augment was used in combination with a lateral distal condyle bone resection of 2 mm. Tibial bone surface was refreshed, by removing 4 mm of anterior bone (none posteriorly, reducing the slope) and 2 mm medially to adjust varus/valgus orientation. With trial implants in place, the observed laxities (MCL 1– 2 mm and LCL 3–4 mm) at 10◦ of flexion confirmed that we achieved our goals. As diaphyseal stem fixation would prevent the restoration of the patient’s joint orientations, on both femoral and tibial sides, 12 ×50-mm cemented stems were used. A standard PS insert was selected (Figures 4A–C). At 18 months follow-up, the patient reported to be pain-free with a WOMAC score of 15 and a ROM of 0–125◦. Frontiers in Surgery | www.frontiersin.org 7 August 2021 | Volume 8 | Article 721379
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