Abstract
Today minimally invasive surgery inspires orthopaedic surgeons to consider techniques that minimize morbidity and produce equal or better outcomes. Minimally invasive surgery–total knee arthroplasty (MIS-TKA) approach involves a medial para-patellar incision which leads to a smaller skin incision, limited soft tissue dissection and sparing of the Quadriceps muscle.
This prospective and retrospective study was carried out at Dayanand Medical College and Hospital, Ludhiana (India) from January 2007 to June 2010 to evaluate forty nine patients with unilateral and six patients of Bilateral MIS-TKA. Patients with osteoarthritis and rheumatoid arthritis undergoing primary TKA using cemented modular posteriorly stabilized prosthesis were included in the study. All the procedures were performed through anterior midline incision measuring 8.5–10 cms (mean 9.2 cms). Extent of the incision into the quadriceps tendon was limited to the level of superior pole of patella and vastus medialis muscle was not split. Patella was not everted but retracted laterally. Four in One Nexgen legacy, minimal invasive surgery instrumentation was used. Aggressive physiotherapy was started on the first postoperative day with knee bending and walking on day two. The patients were evaluated according to knee society knee score and function score at one, three and six months and again at one year postoperatively.
Mean final knee score improved from 30 to 91 (p-value = .00001). Mean functional score improved from 25 to 78 (p-value = .00001). Mean stability score improved from 19.46 to 22.98 points postoperatively. Patients with lesser preoperative flexion contracture had better outcomes and preoperative range of motion predicted final range of motion. Mean ROM improved from preoperative value of 85 to 101 at discharge, 114 at 12 weeks and 120 at 6 months (p-value = .0007, .0006, .0009 respectively). 79.1% patients were completely pain-free on the final follow-up. Mean tourniquet time was 65 minutes (55–75). 91.4% patients suffered <300 ml blood loss in drains. One patient each of patellar maltracking and deep infection was seen in our study.
We concluded that MIS-TKA with quadriceps sparing approach in our patients lead to a limited arthrotomy, decreased blood loss, less blood transfusion requirements, less postoperative pain, faster recovery of motion and return of function. This study proposes that MIS-TKR has many advantages over the conventional procedure and these are mainly attributed to the sparing of quadriceps muscle.
