Abstract
Background
The current literature tends to suggest that all the different approaches used for Knee Arthroplasty give similar results. The literature also cautions that the MINI quadriceps sparing approaches are to be utilized in very select cases as they are difficult to perform, take longer time, have a greater intra-op complication rate and are associated with a higher number of component malpositioning. Despite these warnings of the literature, the author has been impressed by the physiological nature of the subvastus approach for knee arthrotomy and the author has used this approach exclusively for all Knee arthroplasties in the last 4 years. All primary Knee Arthroplasties have been performed through the mini-subvastus approach, utilizing the principle of a mobile window, irrespective of the degree of pre-operative deformity, obesity, range of motion or previous surgery. All revision Knee Arthroplasties have also been performed through the subvastus approach. All the surgeries have been performed in the private sector in a highly competitive environment with the patient having easy access to various other high volume surgeons performing arthroplasties through a more standard approach.
Aim
To define the place of the subvastus approach in Knee arthroplasty on the basis of surgical experience gained after 1350 consecutive surgeries
Materials and Methods
All knees operated between Nov. 2005 to may 2010 are included in this study and have been prospectively evaluated by American Knee Society Scores. Pre and post-operative radiographs have been obtained in all. Additionally a significant number of knees have had pre and post-operative scanograms and skyline views taken. Surgical technique has involved the subvastus approach in all cases. The first 130 knees have been performed with the tourniquet and the remaining have been performed without a tourniquet but with the use of tranexamic acid peri-operatively. Surgical technique has evolved with the experience gained and would be discussed in detail. Computer navigation has been utilized to take the distal femoral cut in 110 knees. Intra and post-operative complications have been recorded. The author has used both CR and PS knees, mobile and fixed bearing, Gender specific and highflex knees with and without patellar resurfacing. The patients have been followed up at 6 weeks, 3 months and yearly.
Results
The American Knee Society scores have improved significantly in the follow-up period. The post-operative radiographs have shown good alignment in more than 99% of knees. The Hospital stay has been reduced to 3 days and 95% of patients were able to independently ambulate with only a walking stick by the third day without any quadriceps lag. There have been 3 vascular injuries, 1 medial collateral injury, 2 patellar tendon ruptures, 3 periprosthetic fractures and 7 infections of these 1350 knees (complication rate 1.5%.) There are 2 knees awaiting surgery for limb malalignment. The results in various types of knees are similar but the PS knees have achieved a higher degree of post-op knee flexion more easily.
Conclusions
The results obtained by this method are comparable if not better than the results obtained in other large series using more traditional approaches. The complication rate is similar but the patient recovery is much quicker. The approach is versatile, has wide applications and remains our approach of choice.
