Subvastus Approach for Total Knee Arthroplasty : Complete Quadriceps Sparing Technique

Background :

Minimally invasive approaches are a more recent development aimed at reducing damage to soft tissues. The subvastus or Southern approach to the knee was described as early as 1929. This approach for primary total knee arthroplasty (TKA) preserves the integrity of the extensor mechanism and maintains the vascular supply to the patella.

It provides excellent exposure of the knee joint with preservation of all peri-articular soft tissues. The benefits of the subvastus approach make it a valuable technique for primary TKA. This combination of advantages ensures rapid recovery, better knee range of motion, and excellent patient satisfaction.

Aim of the Study :

The goal of this study was to compare the subvastus method with the usual medial parapatellar technique for total knee replacement in patients with osteoarthritis based on quadriceps function recovery in the days following surgery.

Methods :

We retrospectively reviewed case notes of 36 patients with osteoarthritis who underwent total knee replacement in Satkhira Medical College Hospital and private clinics over a period from August 2019 to August 2024.

All cases were evaluated regarding early post-surgical clinical outcomes including range of motion (ROM), pain on a visual analog scale, and Knee Society Score (KSS). Preoperative quadriceps strength, BMI, and baseline demographics were recorded from pre-operative workup case notes.

Starting from the first postoperative day, the first unassisted straight leg raise (SLR) was recorded as the main determinant of muscle function. The data were evaluated to determine quadriceps muscle function following total knee replacement.

Result :

When compared to the medial parapatellar approach, quadriceps muscle function returned sooner with the subvastus technique. Patients in their sixties showed the highest improvement.

Preoperative quadriceps strength had a major impact on muscle recovery after surgery.

Conclusion :

The subvastus method for total knee replacement is associated with faster recovery of quadriceps muscle strength, resulting in shorter hospital stay and reduced postoperative therapy.