Extracapsular subcutaneous endoscopic treatment for refractory lateral epicondylalgia: technique, retrospective results, and prognostic factors

BACKGROUND: The extracapsular subcutaneous endoscopic treatment is a new and under-researched approach to the endoscopic treatment of refractory lateral epicondylalgia. We aimed to introduce the techniques of the method and the mid-long term clinical effects. Furthermore, we intended to identify demographic and surgical-related factors correlated with prognosis of extracapsular subcutaneous method. METHODS: Patients with a minimum of 6 months of conservative treatment for lateral epicondylalgia were recruited from March 2012 to July 2018. Key surgical techniques including microfracture and endoscopic suture were used. Visual analog scale (VAS), Mayo Elbow Performance Score (MEPS), and Disability of Arm (Shoulder and Hand, DASH) scores were used to evaluate clinical results. Univariable analysis and multivariable logistic regression were used to analyze effects of demographic characteristics and treatment techniques on prognosis. RESULTS: Seventy-eight patients were treated with modified subcutaneous extracapsular surgery. No serious complications such as neurovascular injury or infection occurred. Postoperative VAS, MEPS, and DASH scores significantly improved (P<0.001). Age was associated with prognosis regarding VAS score (P=0.023). Older age was an independent relevant factor for poor prognosis regarding VAS score (OR =0.914, 95% CI: 0.842–0.993, P=0.033), and microfracture during surgery related to poor prognosis for DASH score (OR =0.056, 95% CI: 0.004–0.783, P=0.032). Plaster fixation was an independent factor related to good prognosis regarding DASH score (OR =11.156, 95% CI: 1.009–123.363, P=0.049). CONCLUSIONS: Extracapsular subcutaneous method of refractory lateral epicondylalgia has satisfactory and stable clinical results with high safety. Techniques of extracapsular method include debridement, microfracture, and tendon suture under endoscope. Young age, no microfracture, and postoperative plaster fixation were associated with good long-term prognosis.