Background Patellar tendinopathy produces activity-related pain and focal tenderness at the attachment of the patellar tendon at the lower pole of the patella. Despite its frequency and negative impact on athletics, no evidence-based guidelines for management of this overuse injury exist. Since functional outcomes of conservative and surgical treatments remain suboptimal, new diagnostic and therapeutic strategies have to be developed and evaluated.
Objectives The purpose of this study was to determine the efficacy and safety of Hyaluronan alone and Hyaluronan combined with Botulinum toxin vs placebo injection in patellar tendinopathy.
Methods Sixty-three patients were treated from January 2010 to December 2012. The observation period averaged 21.3 months (range 4-71). All patients were graded stage 1-3 by Blazina’s classification. Hyaluronan was injected into the interface between the patellar tendon and the infrapatellar fat pad at the proximal insertion, or into the region of maximum tenderness. Patients were randomized using a computer generated program to one of: Hyaluronan 2.8cc (750- 1300kDa), 2.8cc Hyaluronan + 100 units Botulinus toxin or 2.8cc saline placebo. Injection was repeated at 7 days. Assessments were obtained at baseline, 7, 14, 30 and 90 days. Participants were volleyball, soccer, football, tennis and basketball players with symptoms of patellar tendinopathy for a minimum of 3 to a maximum duration of 12 months. Primary outcome measure was the VISA-P (Victorian Institute of Sport Assessment - patella) score. Secondary outcomes with regard to pain during function tests (jump tests) including patient’s pain VAS on weight bearing (0-100mm), patients’ global assessment of knee injury (5 point categorical scale), patients’ assessment of normal function/activity (5 point categorical scale), physician’s global assessment of knee injury (5 point categorical scale), patients/physician satisfaction assessment (10 point categorical scale), time to return to pain-free and disability-free sport and adverse events as per WHO definition.
Results The 63 patients included 28 males. Three placebo patients withdrew after 14 days due to lack of efficacy, two patients experienced local pain at the injection site in the Hyaluronan combined with Botulinum toxin group and one patient in the placebo group. No serious adverse events were reported. At 14, 30 and 90 days after treatment, the mean VISA-P scores for the Hyaluronan group improved (3%, 6% and 8%, P <.001) and Hyaluronan combined with Botulinum toxin improved (6%, 16% and 12%, P <.001) respectively. No change was observed in the placebo group. Similar improvement in secondary outcomes were also observed in the Hyaluronan and Hyaluronan combined with Botulinum toxin groups. Return to pain free sport was significantly higher in the combined group (P<0.01).
Conclusions Hyaluronan injection alone or in combination with Botulinum toxin for athletic patients with patellar tendinopathy is an effective treatment option.
References Visentini PJ, Khan KM, Cook JL, et al: The VISA score: An index of the severity of jumper’s knee (patellar tendinosis). J Sci Med Sport 1:22, 1998
Blazina, M. E., R. K. Kerlan, F. W. Jobe, V. S. Carter and G. J. Carlson. Jumper’s knee. Orthopedic Clinics of North America 4: 665-678, 1973.
Disclosure of Interest None Declared