Stiffness after knee arthrotomy: evaluation of prevalence and results after manipulation under anaesthesia

The aim of the present study was to determine the prevalence and the effect of manipulation under anaesthesia in patients with Total Knee Arthroplasty (TKA), "revision-knee" and all forms of other intra-articular surgical procedures. We aimed to determine differences in the outcome according to the number of previous surgeries and according to time of manipulation under anaesthesia (MUA).

One thousand three hundred and forty-four elective intra-articular surgeries (no trauma cases) were performed at our institution between 2004 and 2009. Fifty-two of them underwent MUA because of postoperative knee stiffness with a flexion less than 90°. The prevalence for stiffness after primary TKA was 4.54%, for revision-knee procedures 5.11%, and for other forms of intra-articular surgery 1.29%.

Flexion was statistically significantly improved directly after MUA in the group after primary TKA with a mean gain of 35.13°±17.03°, in the group with revision procedures of 41.31°±9.08° and in the group with other forms of intra-articular surgery of 24.37°±5.21°. Patients with more than two previous operations showed significantly worse results (P=0.039). No statistically significant difference (P=0.307) was seen according to time (>/<30 days) of MUA.

MUA is a valuable technique to increase ROM after TKA in patients with stiff knees, for "revision-knees" and all other patients with reduced flexion after different forms of intra-articular knee surgical procedures (excluding trauma cases). The results were similar for early and delayed MUA relative to the last surgery. The patients can therefore undergo conservative treatment (e.g. physiotherapy) before the MUA without the risk of poorer outcome. The results after MUA in patients with many previous operations were significantly worse and so an open/arthroscopic arthrolysis should be discussed earlier for this subgroup.