Moderate clinical improvement after revision arthroplasty of the severely stiff knee

Revision of the severe stiff total knee arthroplasty (TKA) is challenging, and clinical outcome is inferior to other indications for revision. The purpose of the present study was to determine clinical outcome of TKA revision in patients with severe stiffness (range of motion (ROM) ≤ 70°) and evaluate a possible influence of accompanying findings, such as component malposition, aseptic loosening or instability.

A prospective cohort of 40 patients with a preoperative ROM ≤ 70° and a minimum of 2-year follow-up after total system revision (Genesis or Legion stemmed condylar implant) was evaluated. ROM, Knee Society Scoring System (KSS) and visual analogue scale (VAS) pain scores were obtained preoperatively and at 2 years. Patient satisfaction and complication rate were assessed. Component malposition was most frequently reported as accompanying finding (n = 27). Comparisons between pre- and postoperative outcome (p < 0.05) and between different subgroups (component malposition, aseptic loosening, and instability) based on accompanying findings were made (no statistical comparison).

ROM, KSS and VAS pain scores improved significantly (p < 0.001): median ROM at two years 85° (range 10-125) and median gain 25° (range -10 to +85). Median VAS satisfaction was 53.5 points (range 15-98). Seventeen patients reported at least one complication, including one re-revision. Six patients underwent manipulation under anaesthesia, and five were referred to the pain clinic. No clear differences between subgroups were observed.

TKA revision in patients with severe stiffness resulted in a moderate but significant improved clinical outcome after 2 years. Accompanying abnormalities such as component malposition, aseptic loosening or instability did not influence clinical outcome. Realistic patient counselling on the moderate outcome and possible remaining limitations in daily life might help to improve patient satisfaction.

Therapeutic studies-case series with no comparison group, Level IV.