CJSM Blog Journal Club — is rESWT an effective therapy for chronic, distal biceps tendinopathy?

I’m pleased to welcome Jason Zaremski MD, one of our junior associate editors, who has contributed our first on-line journal club article.

Dr. Zaremski is a primary care sports medicine specialist who is board certified in Physical Medicine and Rehabilitation. He is an assistant professor at the University of Florida in the Department of Orthopaedics and Rehabilitation.

Dr. Zaremski is also a member of one of our affiliated societies, the American Medical Society for Sports Medicine, and was appointed last year as the AMSSM junior associate editor.  He’s been busy behind the scenes on many CJSM initiatives already; this is his first foray onto the blog, and we’ve been looking forward to his contribution.  Enjoy!

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Clinical Journal of Sports Medicine

Online Journal Club

Jason L Zaremski

Title: Furia JP, et al. Radial Extracorporeal Shock Wave Therapy Is Effective and Safe in Chronic Distal Biceps Tendinopathy. Clin J Sport Med 2017;27:430–437.

Introduction:

This is the first online Journal Club Commentary for the Clinical Journal of Sports Medicine’s new initiative for its Online Journal Club. Furia and colleagues sought to determine the efficacy and safety of radial extracorporeal shock wave therapy (rESWT) for chronic distal biceps tendinopathy (cDBT). This is a retrospective case control study with level three evidence. The specific aim of the study is to determine whether rESWT is safe and effective for the management of cDBT.

Methods:

This is a retrospective case control study with patients aged 30-64 evaluated from the first author’s clinical practice. After a history and physical examination was performed to clinically diagnose cDBT, inclusion criteria included: a six-month history of DBT refractory to other forms of nonoperative treatment, and all patients also had radiographs to rule out soft tissue tumors or bony irregularities.  Exclusion criteria included patients younger than 18 years old, those with pregnancy, local infection, local tumors, rheumatoid arthritis, end-stage arthritis, loose bodies, prior elbow surgery, and unresolved fractures. It should be noted the author’s did not perform magnetic resonance imaging scans and ultrasonography in all patients.

All patients who met the inclusion criteria and did not meet the exclusion criteria were ultimately placed into two different groups:  (1) Nonoperative physical therapy with a course of ibuprofen or naproxen, and a topical anti-inflammatory agent or (2) rESWT.  A total of forty-eight patients completed the final review at 12 months and were included in the study, split evenly into 24 patients (24 elbows) in the rESWT and traditional nonoperative treatment arms.

Treatment Arm Demographics:

            There were no statistically significant differences between either group with respect to age, gender, the affected side, mean duration of pain before treatment, mean visual analog scale (VAS) score, and mean Roles and Maudsley (RM) score at baseline [the RM is a subjective, 4 point scale used by many previous researchers in the evaluation of rESWT]. All patients in both groups participated in some regular recreational sporting activity 3–5 times per week. 10 of the patients in the rESWT group and 9 of the patients in the control group worked as laborers.

Study Design/Interventions:

All treatments were performed by the first author, in a clinic setting using an evidence based protocol. A radial extracorporeal shock wave device was used in all instances.  Each patient received a single session of rESWT with a standard amount of shock waves and energy flux density (EFD) throughout without the use of local anesthesia.  A standard procedure protocol was described in detail. Post-procedure the treated elbow was assessed for hematoma, bruising, and swelling. Patients were allowed immediate range of motion but advised to avoid heavy lifting for a period of two weeks. No upper extremity forearm, biceps, and shoulder muscle strengthening was usually permitted for four weeks after the treatment.

Outcome Measures:

VAS Score, RM score, a modified QuickDASH Score-Sports (MQD-S), and a modified QuickDASH Score-Work (MQD-W). The VAS and RM scores were collected at baseline (BL) and 1 month (M1), 3 months (M3), and 12 months (M12) after inclusion into the study during the follow-up examinations. The MQD-S and MQD-W scores were calculated at M12. Authors defined treatment success as individual improvement in VAS score by more than 60% at M3.

Statistical Measures:

Statistical measures were appropriate. The authors calculated mean and standard error of the mean at each time point for the patients in both groups. Comparisons between patients in each group at baseline were performed with t Student’s test, Mann–Whitney U test, and x2 test. The development of mean VAS scores and mean RM scores after the treatment was investigated with repeated-measures analysis of variance (RM ANOVA) followed by post hoc Bonferroni tests for pairwise comparisons. Comparisons between patients in each group with respect to mean MQD-S scores and mean QD-W scores at M12 were performed with the Mann– Whitney U test. Treatment success was tested with Fisher exact test. In all analyses, an effect was considered statistically significant if its associated P value was smaller than 0.05. The last author performed the statistical analysis with anonymized data sent by the primary author.

Results/Outcomes:

Mean pretreatment VAS scores for the rESWT and control groups were 8.3 and 8.5, respectively. Three and 12 months after inclusion in the study, the mean VAS scores for the rESWT and control groups were 3.4 and 5.6 (P = <0.001) and 2.7 and 4.7 (P= < 0.001), respectively. Twelve-month follow-up MQD-Sports and MQD-Work scores for the rESWT and control groups were 3.7 and 1.7 (P = <0.001) and 3.8 and 1.8 (P , 0.001), respectively. Differences in mean RM scores were statistically significant between groups at 3 months after the treatment.

Fourteen patients (14/24 = 58.3%) in the rESWT group, but only 1 patient (1/24 = 4.2%) in the control group, showed individual improvement in VAS score by more than 60% at M3. At M12, 17 patients (70.8%) in the rESWT group and 4 patients (16.6%) in the control group showed individual improvement in VAS score of more than 60%. Differences between the groups were statistically significant at M3 (P = <0.001) and M12 (P = <0.001).

All patients in the rESWT group and 20 of 24 patients in the control group were able to return to their preferred sports and did so at their preinjury levels. Time to return to sport was variable and ranged from 2 to 6 weeks.

There were 3 minor complications, all in the ESWT group. Two patients had pain during the treatment that resolved after the procedure and one patient with a history of carpal tunnel syndrome had tingling in the median nerve distribution after the treatment that resolved several hours after the treatment.

Strengths:

The authors should be commended that there are comparison groups with similar demographic backgrounds. While there are many studies revealing the use of shock wave therapy for tendinopathic conditions, this is a largest study for cDBT. In addition to the success the results show, there were no substantial complications and no patients required retreatment leading to a high degree of patient satisfaction.  Finally, it should be mentioned that the authors performed the procedures without local anesthesia, which could have interfered with the shock waves.

Weaknesses:

While a strong manuscript, there are some concerns with the design of this study. There was no randomization, a lack of blinding to each group, as well as a lack of blinding by the physician. It is also a bit concerning that all procedures were performed by the same physician. In addition, it is not stated how long symptoms were present in all patients in both groups, only that symptoms were present for at least six months. Follow-up ended at 12 months, and the study would have benefited from a long term follow-up data point. Regarding of severity of injury, the authors stated that MRI and/or ultrasound was not used for all patients. It would be important to know to what degree of injury, neovascularization, and/or partial tearing may have been present prior to the start of treatment. It may also be important to perform a follow-up imaging study with the same modality to assess if there was potential tendon repair or, simply, destruction of pain generators (such as potential neovessels). The authors state patients recruited for this study failed physical therapy but do not state what type of physical therapy for performed (e.g. eccentric exercises). From a statistical perspective, it is not explained why the authors defined treatment success as individual improvement in VAS score by more than 60% at M3 and M12 as opposed to another percentage.

It should also be noted that the senior author who performed the data analysis serves as paid consultant for and receives benefits from Electro Medical Systems, the manufacturer and distributor of the radial extracorporeal shock wave device, Swiss DolorClast.

Conclusion

The authors propose that this study indicates that the use of rESWT for cDBT is safe, effective, reduces pain, improves elbow function without adverse effects. Thus, the authors state that clinicians should consider rESWT before surgical intervention in the management of cDBT.

Practice Pearl

Based upon this manuscript, in concert with the significant evidence of the positive effects of shock wave therapy in tendinopathic injuries, rESWT for cDBT should be considered for clinical practice for those individuals that have access to this modality of treatment. However, advanced imaging should be obtained pre and post treatment to objectively assess extent of healing of soft tissue versus subjective pain relief only.

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Thanks Jason for this contribution.  Looking forward to more!!!  Continue the journal club discussion on our comments page below, or Tweet us @CJSMonline