Original Article
Different osteotomy solutions influence future total knee arthroplasty in patients with multiapical lower extremity deformities
Abstract
Background: Although osteotomy achieves success on correction of lower extremity deformities, a future total knee arthroplasty (TKA) is sometimes inevitable. The zigzagged fumer and tibia after previous osteotomy can somehow influence TKA. This study aimed to figure out how different osteotomy solutions, specifically, single-level or multi-level osteotomies, influence TKA in patients with multiapical lower limb deformities.
Methods: A 25-year-old female of varus deformity on both lower extremities was studied. Single-level osteotomy solutions were used to correct deformities. A templating (both two- and three-dimensional) of posterior-stabilized high-flex implant was performed for pre-TKA planning, under the circumstances of both real single-level and simulated multi-level osteotomy solutions. Parameters according to specific nomenclature were measured.
Results: The average location of the center of rotation of angulation was 17 cm from the knee joint orientation line on the left side, and 12 cm on the right. On the assessment of deformity correction, the medial proximal tibial angle (MPTA) improved from 76° to 87° on the left side and from 72° to 96° on the right. The mechanical lateral distal tibial angle (mLDTA) changed from 109° to 101° on the left side and from 98° to 90° on the right. Pre-TKA templating showed that the depths of the proximal tibial bone cut were different on both sides under single or multiple level osteotomy. Thus, the selected sizes of tibial component were different accordingly. Attributed to angulation of tibial anatomical axis, an impingement of the tibial stem upon the proximal lateral tibial cortex would likely occur on the right side after single osteotomy.
Conclusions: Prior correction procedures influence future TKA in patients with severe multiapical deformities in lower extremities. A sufficient and excellent preoperative plan of osteotomy is necessary not only for achieving present correction of alignment, but also for achieving a successful TKA yet to come.
Methods: A 25-year-old female of varus deformity on both lower extremities was studied. Single-level osteotomy solutions were used to correct deformities. A templating (both two- and three-dimensional) of posterior-stabilized high-flex implant was performed for pre-TKA planning, under the circumstances of both real single-level and simulated multi-level osteotomy solutions. Parameters according to specific nomenclature were measured.
Results: The average location of the center of rotation of angulation was 17 cm from the knee joint orientation line on the left side, and 12 cm on the right. On the assessment of deformity correction, the medial proximal tibial angle (MPTA) improved from 76° to 87° on the left side and from 72° to 96° on the right. The mechanical lateral distal tibial angle (mLDTA) changed from 109° to 101° on the left side and from 98° to 90° on the right. Pre-TKA templating showed that the depths of the proximal tibial bone cut were different on both sides under single or multiple level osteotomy. Thus, the selected sizes of tibial component were different accordingly. Attributed to angulation of tibial anatomical axis, an impingement of the tibial stem upon the proximal lateral tibial cortex would likely occur on the right side after single osteotomy.
Conclusions: Prior correction procedures influence future TKA in patients with severe multiapical deformities in lower extremities. A sufficient and excellent preoperative plan of osteotomy is necessary not only for achieving present correction of alignment, but also for achieving a successful TKA yet to come.
