Influence of Restitution Time in Treatment of Patellar Tendinopathy

The purpose of the present project is to investigate if the restitution time from loading in an exercise-based 12 weeks rehabilitation regime for patellar tendinopathy influences the clinical outcome, tendon structure and function.The investigators hypothesize that greater restitution from loading (1 exercise day per week) will yield a greater positive clinical outcome, and tissue structure and function in patients with patellar tendinopathy compared to less restitution (3 exercise days per week), when impact activities are restricted in both groups.

Inclusion Criteria:Sports active men and women.Age (18-60) years old.BMI (18.5-28)Understand and read DanishUni- or bilateral patellar tendinopathySymptom onset >90 days agoExclusion Criteria:Patellar tendinopathy longer than 24 monthsSmokingPrevious surgery in the knee on the ipsilateral side.Corticosteroid injection in the patellar tendon on the ipsilateral side within the last 6 months.Any confounding diagnosis to the knee jointKnown arthritisKnown diabetesInability to follow rehabilitation or complete follow-upsEnrolled in a resistance based-rehabilitation program for the affected patellar tendon within the previous three monthHave a work were it is not feasible to avoid pain provoking tasksExtra criteria sub-study oneInclusion criteria:• Five patients from the main study, rating "improved" and "not improved" respectively, will be invited to participate in sub-study one.Exclusion criteria:ClaustrophobiaPregnancyBreastfeedingExtra criteria sub-study two:Inclusion criteria:Patients from the main study, that rate themselves 'not improved' in symptoms after 12 week.Patients who have not achieved Patient Acceptable Symptom State (PASS) after week 20, 24, 28, 32, 36 and 40, will be invited to participate in sub- study two.Exclusion criteria:PregnancyBreastfeedingPreviously had an allergic reaction for steroid (Depomedrol).Previously had an allergic reaction for local anesthesia treatment.