The 2018 systematic review found that patients undergoing a subvastus TKA regained an active straight-leg raise approximately 1.7 days earlier than patients undergoing a medial parapatellar approach (95% CI 1.0–2.3 days).  A prospective randomized trial similarly reported straight-leg raise at 3.2 vs 5.8 days (SV vs MP, P<0.001).  This is probably the most intuitive outcome to explain to patients because the subvastus approach preserves the quadriceps tendon/extensor mechanism.

The same meta-analysis found approximately 0.8 points less pain on a 0–10 VAS on postoperative day 1 with the subvastus approach.  More recent evidence is supportive: a 2023 network meta-analysis of 33 RCTs found the mini-subvastus approach produced significantly lower pain on postoperative days 1, 3, and 7 compared with medial parapatellar TKA; the day-1 difference was approximately 2 VAS points.

The 20-RCT meta-analysis demonstrated approximately 7° greater total knee ROM at one week with subvastus TKA (95% CI 3.2–10.7°).  The 2023 network meta-analysis also ranked subvastus particularly well for early ROM, with significantly greater ROM than medial parapatellar TKA on postoperative days 1, 3, 4, and 6.

Subvastus TKA was associated with roughly a 60% reduction in the odds of requiring a lateral retinacular release (OR 0.40; 95% CI 0.20–0.70).  An earlier meta-analysis produced almost the same result (OR 0.34; 95% CI 0.14–0.79).  This is consistent with preservation of the quadriceps mechanism and patellar blood supply/tracking rather than disrupting the quadriceps tendon and medial peripatellar tissues.