Is a left-sided medial proximal tibial angle (MPTA) of 83 degrees and a lateral distal femoral angle (LDFA) of 86 degrees indicative of a varus deformity that would benefit from high tibial osteotomy?

From the Research

Yes, a left-sided medial proximal tibial angle (MPTA) of 83 degrees and a lateral distal femoral angle (LDFA) of 86 degrees indicates a varus deformity that would likely benefit from high tibial osteotomy (HTO). The normal MPTA is typically 87±3 degrees, so 83 degrees represents tibial varus [ 1 ]. The normal LDFA is 87±3 degrees, so 86 degrees is within normal limits for the femur. Since the deformity is primarily in the tibia with a normal femoral alignment, a medial opening wedge HTO would be the appropriate surgical intervention. This procedure corrects the mechanical axis by creating an osteotomy on the medial side of the proximal tibia and opening it to shift the weight-bearing axis laterally.

Key Considerations

• The goal of HTO is to offload the medial compartment, reducing pain and potentially delaying the need for total knee arthroplasty, especially in younger, active patients with unicompartmental arthritis [ 1 ].
• Post-operatively, patients typically require partial weight-bearing for 6-8 weeks with physical therapy focusing on range of motion and quadriceps strengthening.
• The success of the procedure depends on proper preoperative planning to achieve the target correction angle, which is typically aiming for a slight valgus overcorrection of 2-4 degrees [ 2 ].
• High tibial osteotomy has been shown to be a safe and effective treatment for medial compartment arthrosis of the knee accompanied by varus alignment [ 2 ].

Surgical Technique

• The medial opening wedge approach is a commonly used technique for HTO, which involves creating an osteotomy on the medial side of the proximal tibia and opening it to shift the weight-bearing axis laterally [ 1 ].
• The choice of surgical technique and osteotomy fixation device depends on the individual patient's needs and the surgeon's preference [ 2 ].

Outcome

• The outcome of HTO depends on various factors, including the accuracy of the osteotomy, the stability of the fixation, and the patient's overall health and activity level [ 3 ].
• Proper preoperative planning and precise surgical technique are essential to achieve good results and minimize complications [ 3 ].