Faster quadriceps recovery with the far medial subvastus approach in minimally invasive total knee arthroplasty

Purpose

To identify whether less proximal muscle damage during minimally invasive surgery will allow faster recovery after total knee arthroplasty in comparison with a quadriceps incision approach. A limited medial parapatellar approach without tibial medial collateral ligament (MCL) release was compared to a subvastus approach without tibial medial collateral ligament release (far medial subvastus).

Methods

One hundred and eighty patients were studied. In the mini-parapatellar group, ninety patients and in the far medial subvastus group, the remaining ninety patients were included. The evaluation was based on the Knee Society Score, VAS, morphine consumption, range of motion, time to straight leg raising, walking without aid, stairs and period of hospitalization. Alignment on full leg radiographs and component position on plain films were measured.

Results

The far medial subvastus group showed faster recovery with earlier straight leg raising (1.7 ± 0.5 vs. 2.7 ± 0.4 days), postoperative weight bearing without aid (1.7 ± 0.6 vs. 2 ± 0.8 days) and stair negotiation (3 ± 0.4 vs. 4 ± 0.3 days) resulting in shorter length of stay (4 ± 0.5 vs. 5 ± 1.2 days). Comparable Knee Society Scores (88.5 ± 6.8 vs. 90 ± 10), Function Scores (90 ± 10) and alignment (5.4° ± 2.1° vs. 5.0° ± 2.4°) between the medial parapatellar and far medial subvastus group were observed at a follow-up of 24 months. An increase in operative time for the far medial subvastus was observed (55 ± 10.6 min vs. 67 ± 12 min tourniquet time) but without complications.

Conclusion

The MCL sparing far medial subvastus approach allows good surgical exposure, faster straight leg raising, full weight bearing without aid and shorter length of stay with most importantly no radiological malalignment.

Level of evidence

Therapeutic study, Level II.