Correction of varus deformity during TKA with reduction osteotomy

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Medical Device Technology

Background:

• Posteromedial tibial bony flare removal is a technique used in total knee arthroplasty (TKA) for correcting varus deformities in arthritic knees.
• The precise amount of deformity correction achieved through reduction osteotomy during TKA remains unclear.

Purpose of the Study:

• To quantify the deformity correction achieved by reduction osteotomy in varus knees during TKA.
• To investigate the correlation between the degree of deformity correction, the amount of bone osteotomized, and the initial varus deformity.

Main Methods:

• Prospective analysis of intraoperative data from 71 primary, computer-assisted TKAs.
• Measurement of varus deformity before and after reduction osteotomy using computer navigation.
• Quantification of the bone removed during osteotomy using a measuring scale.

Main Results:

• A mean reduction osteotomy of 7.5 ± 2 mm resulted in a mean correction of 3.5° ± 1°.
• An average of 2 mm of osteotomy was required for each 1° of varus deformity correction.
• Correction achieved correlated positively with osteotomy amount, especially in knees with <15° preoperative varus deformity (r = 0.77).

Conclusions:

• Reduction osteotomy offers predictable deformity correction (2 mm per 1°) in varus arthritic knees during TKA.
• Further research is needed to evaluate its efficacy as a soft-tissue-sparing procedure when performed early in TKA.