MIS Value in THR, TKR Questioned

Do the advantages of minimally invasive total hip replacement (THR) or total knee replacement (TKR) surgeries outweigh the higher complication rates reported? That is the question that investigators asked in a study designed to determine whether minimally invasive surgery (MIS) enhances recovery after total hip or knee replacement. John M. Lloyd, FRCS, of Bournemouth, United Kingdom, presented the study findings at the 13th EFORT Congress in May 2012, in Berlin, Germany.

The investigators defined MIS surgery as incisions less than 10 cm in the hip and less than 14 cm in the knee. They then searched the literature using MEDLINE and PubMed databases, including case series, randomized controlled trials and systematic reviews, to determine the outcomes when MIS was used in THR or TKR.

They found that improvement in recovery with MIS for THR and TKR was multi-factorial and, when combined with improved anesthetic and rapid rehabilitation pathways, the procedures result in enhanced recovery, Lloyd said. However, he noted that only a small amount of data indicated that MIS alone made a significant difference.

If we look at length of stay, there were very few randomized controlled trials investigating this but it was very clear from the evidence available that there are benefits for unicompartmental knee replacement (UKR), ” Lloyd said in the July 12 news release. “However, if we hone down to total knee replacement, there does not appear to be any clear advantage.

The study found that complication rates of MIS associated with low- to medium-volume surgeons were unacceptably high when compared to more traditional approaches. “Purely in isolation, [MIS] does not appear to reduce the length of hospital stay, ” Lloyd said. “And there do appear to be higher complication rates. I think only time will tell whether these small benefits are at the expense of long-term implant survival.”

“[MIS] offers marginal benefits in total hip and knee replacement recovery. For the average user, I think any benefit would clearly be overshadowed by an unacceptably high complication rate, ” he said. “We therefore conclude, with the exception of [UKR], it [MIS] should not be part of a fast track hip and knee pathway.”