The effectiveness of extracoporeal shockwave therapy in the treatment of patellar tendinopathy: a systematic review

Wei Guo wg575@nyu.edu Abstract:
Background:
Patellar tendinopathy is a common overuse condition.1 Although extracoporeal shockwave therapy (ESWT) is one of the common conservative treatments to this disease, there is still debate of the effectiveness and the optimal protocol.
Purpose:
The purpose of this study is to systematically review and summarize the effectiveness of extracoporeal shockwave therapy in the treatment of patellar tendinopathy and find out the optimal protocol from published articles.
Data Sources:
Pubmed(Mediline), NYU library database (EBSCO)
Study Selection:
Randomized controlled trials (RCTs) and cohort and case-control studies on evaluating the effectiveness of ESWT in the treatment of patellar tendinopathy were eligible. One reviewer selected studies by inclusion and exclusion criteria.
Data Extraction:
One reviewer screened studies based on their inclusion and exclusion criteria. He extracted the study methods, design, intervention, and results.
Data Synthesis:
Three RCTs with "good" and "excellent" evidence level and one cohort study met all the inclusion criteria were included as key references. One RCTs showed there was no difference between the ESWT group and the controlled group in primary measure: Victorian Institute of Sport Assessment–Patella (VISP-P) score, but there is statistically significant difference in secondary measure: Visual Analogue Scale (VAS). Two RCTs and the cohort study showed there was statistically significant improvement in ESWT group in both primary and secondary outcome measure. No articles studied the optimal protocol.
Limitations:
Non-English studies were excluded. Small number of studies was included. Only one reviewer rated the studies.
Conclusions:
The ESWT seems to be an effective conservative intervention for patellar tendinopathy. The intensity, frequency, treatment session and number of impulses need further study.
Introduction and purpose:
Tendinopathy refers to tendon injury. Patellar tendonipathy leads to a decrease of functions and many symptoms like swelling and anterior knee pain.1,2 The prevalence of patellar tendonipathy in elite and recreational basketball players has been reported to be 32 and 12%, respectively, while in elite and recreational volleyball players it is 45 and 14%, respectively.1 In adolescent athletes with an average age of 13 years, prevalence of patellar tendinopathy is 5.8%.1The risk factors are related to frequently jumping.2 Currently, patellar tendinopathy is treated with injection therapy like platelet-rich injection, exercise training like eccentric training, arthroscope and alternative treatment modalities such as extracorporeal shockwave.3 However, because of lack of evidence, the selection of treatment is without evidence-based choice recommendation. 5
There is growing evidence shock wave therapy is effective to some musculoskeletal injuries like plantar fasciitis, calcific tendinitis, frozen shoulder.4 5 But no formal review has been published on the effectiveness of ESWT in the treatment of patellar tendinopathy in which randomized controlled studies have been scrutinized according to a structured quality assessment guideline. Thus, the aim of this study is to examine the shockwave therapy’s effectiveness to the treatment of patellar tendinopathy and the optimal protocol.

Method
This study searched within the following databases: The NYU library database (EBSCO) and Pubmed. Only one RCTs article was related to topic. The following exact search:("extracoporeal shockwave therapy " OR "shockwave therapy") AND ("patellar tendon" OR "patellar tendonipathy" OR "jumper's knee") yielded 468 articles, including duplicates found across the databases searched. Randomized controlled trails(RCTs) published in English and measuring the effectiveness of ESWT for the treatment of patellar