Tennis elbow, which is also known as external humeral epicondylitis, is a common degenerative disease of elbow tendon. The symptoms are mainly pain or tenderness on the lateral side of the affected elbow and restricted activities such as forearm pronation and supination, dorsal flexion of wrist, etc. The pain often becomes worse during heavy object grapping or carrying , which severely affects patient’s life. According to epidemiological statistics, roughly 3% of the population is affected by this disease annually. The incidence rate of general population is 1% to 3%, which is up to 7% for heavy worker. The range of predilection age is 40 to 50 years old, and there was no obvious difference between the two genders. Conservative treatments such as progressive load training, physiotherapy, bracing, topical application (hot/ice) , non-steroidal anti-inflammatory drugs, oral and topical steroid injections, botulinum toxin injection, cold laser, platelet-rich plasma, extracorporeal shock waves, etc. show high efficacy in most patients. However, nearly 20% of the patients are still not sensitive to these treatments. It is generally believed that the tennis elbow, which cannot be effectively relieved with pain and improved for functional activity after over 6 months of standardized conservative treatment, is called "refractory tennis elbow" and requires surgical intervention. Traditional surgical treatment is mainly based on the removal and release of (extensor carpi radialis brevis tendon) ECRB. Although satisfactory clinical results have been obtained, roughly 15% of the patients have postoperative problems such as long-term pain and partial loss of function based on Solheim E and other studies. It has been reported that the reattachment of tendon to the lateral epicondyle of humerus to reconstruct insertion can be taken as a solution to this problem after ECRB resection, and this treatment obtained good clinical result. However, this method lacks the support from randomized controlled double-blind trial of large samples. Objective To compare the clinical outcomes of the modified Nirschl procedure with ECRB insertion reconstruction using suture anchor and the simple modified Nirschl procedure with ECRB insertion debridement in the treatment of refractory tennis elbow, so as to explore the efficacy and necessity of ECRB insertion reconstruction with suture anchor.

From March 2013 to May 2016, 45 patients with refractory tennis elbow were randomly divided into observation group (23 cases) and control group (22 cases) . In the observation group, the modified Nirschl procedure was used to debride the degenerative tendon of ECRB insertion. Then, the ECRB was reattached to the external humeral epicondyle removed of cortex. In the control group, the modified Nirschl procedure was simply used to debride the degenerative tendon of ECRB insertion. The pain, grip strength, time return to work, Mayo score and Verhaar score were compared between the two groups before and 2, 3, 6 and 12 months after operation.

All the 45 patients completed experimental observation and obtained primary wound healing. The times of return to work were (4.97±1.33) months for the observation group and (3.55±1.27) months for the control group, and there was statistical difference between the two groups (P<0.05) . The Mayo score for the observation group was lower than that for the control group at the 2nd and 3rd postoperative months, and there was statistical difference between the two groups (P<0.05) . The Mayo score for the observation group was higher than that for the control group at the 12th postoperative month, and there was significant difference between the two groups (P<0.05) . The visual analogue score (VAS) of the two groups was significantly statistical different 12 months after operation (P<0.01) . The grip strength for the observation group was lower than that for the control group at the 2nd and 3rd postoperative months , and there was statistical difference between the two groups (P<0.05) . The grip strength for the observation group was higher than that for the control group at the 6th postoperative month, and there was statistical difference between the two groups (P<0.05) . The Verhaar score for the observation group was higher than that for the control group at the 3rd postoperative month, and there was statistical difference between the two groups (P<0.05) . The Verhaar score for the observation group was higher than that for the control group at the 6th and 12th postoperative months, and there was significantly statistical difference between the two groups (P<0.01) .

Modified Nirschl procedure with debridement and reconstruction of ECRB using suture anchor for the treatment of refractory tennis elbow is simple and minimally invasive. The ECRB was re-sutured to the reconstructive insertion point of external humeral epicondyle to restore its anatomical position, so as to maximize the recovery of forearm extensor strength and enable the returning of normal exercise and living standards.