On-the-job manual tasks that involve repetitive use of the wrist and/or elbow, including extreme bending or twisting, may cause lateral epicondylitis, also called tennis elbow, results of a new meta-analysis suggest.
Given these results, there should be increased attention to the prevention at work of such combinations of biomechanical exposure, wrote Alexis Descatha, MD, PhD, of CHU Poincaré in Garches, France, and colleagues in Arthritis Care & Research.
Specialists should advise patients about the importance of decreased biomechanical exposure as part of their treatment approach, according to the researchers, who also suggested workplace adaptations and collaborations between occupational health services, employers and employees.
Lateral epicondylitis is a relatively common upper-limb musculoskeletal disorder and the most common cause of lateral elbow pain in adults. A link has long been suspected between this disorder and work-related physical exposure, but the evidence was considered limited. However, recent prospective studies provide new evidence for the relationship.
Literature searches yielded five studies, all from France or the U.S., to include in the meta-analysis. One study was published in 2001, two in 2013, and two in 2014.
Although the definition of lateral epicondylitis was not exactly the same in all the studies, it was very similar and included pain in the lateral epicondyle.
Diagnosis of lateral epicondylitis was made through clinical examination; a positive physical examination was mandatory for three studies, and in two, it was based on a physical examination or evocative symptoms, or a previous diagnosis by a physician.
However, none of the studies included a detailed physical examination of the elbow to differentiate lateral epicondylitis from other disorders and none included imaging.
Exposure was assessed through self-report or observer measurement. All relevant exposure was a combination of biomechanical exposure involving the wrist and/or elbow.
Among 6,922 workers included in the five studies (3,449 who were followed), 256 cases of incident lateral epicondylitis were diagnosed 2.5 to 6 years after baseline.
All five studies found a significant, positive association between combined biomechanical exposure involving the wrist and/or elbow and the occurrence of lateral epicondylitis, with an equivalent dose-response relationship for three of the studies.
Descatha and colleagues calculated an odds ratio of 2.6 (95% CI 1.9-3.5) for the condition for exposure versus non-exposure. Heterogeneity was low at Q=1.4 (P >0.05), and the authors did not detect a major publication bias.
Sensitivity analyses that included only recent studies and those with mandatory physical examination found similar results.
Each study had its own limitations, which included lack of representation of the national workforce, attrition, and self reported assessment of diagnosis. However, the authors pointed out that all studies had a score of between 14 and 17 out of 20 on their assessment of methodological quality, which topped their threshold of 13 to indicate high quality.
Commenting on the research, Omid Alizadehkhaiyat, MD, PhD, of Liverpool Hope University in England, said the article provides further evidence of the fundamental role of repetitive forceful movement of the hand/wrist as a key risk factor in developing lateral epicondylitis.
The fact that the meta-analysis emphasized prospective studies is commendable, said Alizadehkhaiyat, who recently co-authored a comprehensive review of electromyographic studies of forearm muscles in tennis players.
The new meta analysis has important clinical implications for establishing effective preventative and therapeutic management strategies in the workplaces as this painful musculoskeletal condition can potentially lead to functional incapacity of the manual workers' with subsequent impact on their professional and social life, Alizadehkhaiyat told Medpage Today. The findings strongly support workplace adaptations and interventions to avert overuse mechanisms and associated faulty biomechanics.
M. Lucius Pomerantz, MD, an orthopaedic surgeon and upper extremity/hand specialist at Synergy Specialists Medical Group in San Diego, told MedPage Today that although the authors analyzed the data in an appropriate and thoughtful way, he would have been more reserved with his conclusions.
The underlying pathophysiology of tennis elbow is not fully understood, he said. The study was unable to identify if there are certain subsets of the population who are more susceptible to the disease, whether there are specific thresholds of effort to start the disease and if the disease course is altered by changing that work. We will have to identify these aspects before effective prevention can be implemented.
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