Patellar tendinopathy is one of the most frequent causes of non-traumatic knee pain and reduced function in patients. Standard treatment options for patellar tendinopathies include non-steroidal anti-inflammatory drugs, corticosteroids, cryotherapy, manual therapy, eccentric exercises, and ultrasound. Unfortunately many patients fail to respond to these therapies and return to normal activity levels, and recurrence rates for those who do respond are unacceptably high. Many patients who fail to respond display persistent degenerative changes on imaging studies suggesting a failure to regenerate the pathological tissue. Developing new therapies that can directly promote the synthesis of new, healthy extracellular matrix tissue could therefore address an important therapeutic need and make a substantial improvement in our ability to effectively treat patellar tendinopathy and reduce recurrence rates. Somatropin (human growth hormone of recombinant DNA origin) has been shown to increase protein synthesis and matrix production when delivered directly into the tendon. This study will evaluate the ability of somatropin to improve clinical outcomes and tissue quality in patients with chronic tendinopathy.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Active drug
Placebo, the diluent used to reconstitute somatropin
Over a 12 week period beginning at the second study visit patients will perform a standard of care eccentric exercise training regime. Each session consists of three bilateral exercises: leg press, back squat, and hack squat. Subjects will complete four sets in each exercise with a 2-3 minute rest between sets. The repetitions/loads are: 15 repetition maximum (RM) week 1, 12RM weeks 2-3, 10RM weeks 4-5, 8RM weeks 6-8 and 6RM weeks 9-12. All exercises are performed from complete 0º to 90º of knee flexion and back again. Each of the eccentric and concentric phases will occur over a period of 3 seconds, respectively for a total of 6 seconds per contraction.
Bilateral biopsies will be performed on an elective basis, although the investigators will aim to have 8 subjects in each group receive the biopsy. Biopsies will be obtained at the 26 week time point. The data obtained from the biopsy will help address the mechanism behind observed changes in outcome scores, physical measurements or imaging studies. The biopsy will be performed under ultrasound guidance and using sterile technique with a disposable 14G, 2cm biopsy instrument.
Hospital for Special Surgery
New York, New York, United States
Change in Victorian Institute of Sport Assessment Patellar outcome score from enrollment
Time frame: Week 1 to week 26
Change in patient completed visual analog scale (VAS) of knee pain levels
Time frame: Week 1, 2, 3, 4, 9, 14, 26
Change in patient completed Victorian Institute of Sport Assessment Patellar outcome score
Time frame: Week 1, 2, 3, 4, 9, 14, 26
Change in patient completed Patient Reported Outcomes Measurement Instrument System (PROMIS) Physical Function Computer Adaptive Test
Time frame: Week 1, 2, 3, 4, 9, 14, 26
Change in patient completed Patient Reported Outcomes Measurement Instrument System (PROMIS) Short Form Global Health Scale
Time frame: Week 1, 2, 3, 4, 9, 14, 26
Ultrasound assessment of patellar tendon quality
Five point assessment scale of tendon quality (0 Normal, Normal tendon structure; 1 Mild, Ill-defined abnormal hypoechogenicity; 2 Moderate, Well-defined abnormal hypoechogenicity; 3 Severe, Well-defined abnormal hypoechogenicity and anechoic clefts; 4 Complete, Full-width tendon disruption or tear)
Time frame: Weeks 1, 14, 26
Electron micrographs of patellar tendon biopsy sample
Bilateral biopsies will be taken, and the size (measured in squared nanometers) will be measured
Time frame: Week 26
Gene expression of patellar tendon biopsy sample
Bilateral biopsies will be taken, and the expression of genes will be measured with microarrays or RNA-sequencing
Time frame: Week 26
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