gms | German Medical Science

Objectives: Patients with severe osteoarthritis of the knee joint and distinct ligament instability or misalignment are often unable to engage in physical activity or sports.

One of the main goals in implanting a primary LINK® Endo-Model® Rotational Hinge Knee Arthroplasty (ERH-TKA) is to increase mobility and to enable patients to participate in recreational activities.

The aim of this retrospective cohort study was to assess physical activity after primary LINK® Endo-Model® Rotational Hinge Knee Arthroplasty (ERH-TKA) with a mean follow-up of 4 years (minimum follow-up 3 years).

Methods: In this retrospective cohort study, the functional outcome of 113 consecutive patients (119 ERH-TKAs) who underwent surgery between January 2013 and December 2017 was evaluated. The University of California, Los Angeles Activity Score (UCLA) was used to evaluate the physical activity. In addition, physical activity before symptom onset and after primary ERH-TKA and return to activity were described using the Schulthess clinical activity score.

Results and conclusion: Mean age at surgery was 73 ± 8.8 (40 to 87) years. 20 patients died (21 ERH TKAs), six were lost to follow-up (7 ERH TKAs) and six patients were not included because of incomplete data. According to results of Schulthess activity score, 62 of 80 patients (78%) participated in at least one sport before symptom onset. After surgery, 48 of these patients resumed their physical activity, which corresponds to a return-to-activity rate of 77%. Out of 18 previously inactive patients, three (17%) started sports after surgery. 38 out of 51 patients returned to sports within three months and a further eight (total 46 out of 51) within six months after surgery.33 of 51 patients (65%) are practicing more than one sport. Of these, long walks (40 patients, 78%) and fitness training (23 patients, 45%) are the most practiced sports. 39 patients (76%) are physically active three or more times per week, 21 patients (41%) at least five times per week. Additionally, there was a significant improvement in UCLA-Score from 3.2±1.4 (1 - 8) preoperatively to 4.3±1.8 (1 - 9) (p< 0.0001). Whereas preoperatively, three patients showed a high activity level (UCLA> 7 points), postoperatively, this number increased to ten patients. However, UCLA before symptom onset was 5.9±1.9 (2-10) (p<0.0001).

The data show that even in extreme osteoarthritis with the need for a rotating hinge knee prothesis many patients are able to return to sports and, using UCLA, a moderate increase in activity level postoperatively could be demonstrated. However, only few patients achieved a high activity level.