Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial

Abstract

Objective: To compare the effectiveness of progressive tendon-loading exercises (PTLE) with eccentric exercise therapy (EET) in patients with patellar tendinopathy (PT).

Methods: In a stratified, investigator-blinded, block-randomised trial, 76 patients with clinically diagnosed and ultrasound-confirmed PT were randomly assigned in a 1:1 ratio to receive either PTLE or EET. The primary end point was clinical outcome after 24 weeks following an intention-to-treat analysis, as assessed with the validated Victorian Institute of Sports Assessment for patellar tendons (VISA-P) questionnaire measuring pain, function and ability to play sports. Secondary outcomes included the return to sports rate, subjective patient satisfaction and exercise adherence.

Results: Patients were randomised between January 2017 and July 2019. The intention-to-treat population (mean age, 24 years, SD 4); 58 (76%) male) consisted of patients with mostly chronic PT (median symptom duration 2 years). Most patients (82%) underwent prior treatment for PT but failed to recover fully. 38 patients were randomised to the PTLE group and 38 patients to the EET group. The improvement in VISA-P score was significantly better for PTLE than for EET after 24 weeks (28 vs 18 points, adjusted mean between-group difference, 9 (95% CI 1 to 16); p=0.023). There was a trend towards a higher return to sports rate in the PTLE group (43% vs 27%, p=0.13). No significant between-group difference was found for subjective patient satisfaction (81% vs 83%, p=0.54) and exercise adherence between the PTLE group and EET group after 24 weeks (40% vs 49%, p=0.33).

Conclusions: In patients with PT, PTLE resulted in a significantly better clinical outcome after 24 weeks than EET. PTLE are superior to EET and are therefore recommended as initial conservative treatment for PT.

Keywords: exercise rehabilitation; overuse injury; randomised controlled trial; sports rehabilitation programs; tendinopathy.

Figure 1

Knee pain map for pain localisation. For the initial eligibility assessment, patients were asked to select one picture describing the location of pain most correctly; either (A) Pain on the medial side of the knee, (B) Pain on the lateral side of the knee, (C) Pain on the backside of the knee, (D) Pain behind and around the patella, (E) Pain directly under the patella or along the course of the patellar tendon or (F) Pain directly above the patella.

Figure 2

Exercise therapy performed in the PLTE group (intervention) and EET group (control). The exercises illustrated are exemplary images. The complete exercise programme is available in online supplemental appendix. EET, eccentric exercise therapy; PTLE, progressive tendon-loading exercises.

Figure 3

The CONSORT flow diagram. CONSORT, Consolidated Standards of Reporting Trials; PT, patellar tendinopathy; VISA-P, Victorian Institute of Sports Assessment for Patellar Tendons.

Figure 4

The UNADJUSTED time course of mean VISA-P score in the PTLE group (intervention) and EET group (control). Abbreviations: PTLE, progressive tendon-loading exercises; EET, eccentric exercise therapy. The error bars represent ±1 SE.

Figure 5

Individual changes in the VISA-P score from baseline in patients in the PLTE group (intervention) and EET group (control). Unadjusted individual changes in VISA-P score are shown after 12 weeks and 24 weeks exercise therapy. Adjusted mean between-group differences from baseline to 12 and 24 weeks are shown with 95% CIs. EET, eccentric exercise therapy; PLTE, progressive tendon-loading exercise; VISA-P, Victorian Institute of Sports Assessment for Patellar Tendons.