To compare the results associated with the standard medial parapatellar approach and the midvastus approach in primary total knee arthroplasty.

A total of 70 cases who underwent total knee arthroplasty were evaluated. All patients have varus deformity in standing AP view, but subluxation of the patella on the Merchant view was excluded. Medial parapatellar approach (35 cases) and midvastus approach (35 cases) were used. The operation time, blood loss, incidence of lateral release, time to perform straight leg raising, time to get 90 ° flexion, range of motion, VAS, Knee Society Knee Scores, tibio-femoral angle and patella tilt were compared. The results were analyzed using the student's t-test.

No significant difference was noted between medial parapatellar and midvastus approach regarding to the operation time, blood loss, range of motion, VAS and Knee Society Knee Scores (p>0.05). However, midvastus approach provide two significant advantages of the incidence of lateral release (40% vs 6%) and the time to perform straight leg raising (4.5 days vs 1.9 days) (p<0.05).

Midvastus approach is an efficacious alternative to the medial parapatellar approach in terms of the excellent exposure and reducing the incidence of lateral retinacular release.