Medial epicondylitis, also known as golfer’s elbow, pitcher’s elbow, and medial tennis elbow, is an overuse injury which results from repetitive trauma to the common flexor tendon (flexor carpi radialis, flexor carpi ulnaris, palmaris longus) as well as the pronator teres. The term epicondylitis is a misnomer as the injury pattern is considered to be tendinosis rather than tendonitis, with histology of the injured area revealing non- inflammatory tissue. According to a Finnish study, medial epicondylitis has a prevalence of 0.4% as opposed to lateral epicondylitis which has a prevalence of 1.3%. 
Medial epicondylitis can occur in patients of all ages, but predominantly affect patients in the fourth and fifth decades of life with no gender predominance. Potential etiology of the injury includes overuse and repetitive microscopic or macroscopic avulsion injuries of the common flexor tendon, most commonly the flexor carpi radialis and pronator teres, or from a single traumatic event.
In the latter, the patient may recall hearing a “pop” around the site of the medial epicondyle following some stress in which an object was pulled from the patient’s hand. Medial epicondylitis is diagnosed by point tenderness just distal and anterior to the medial epicondyle as well as pain that is reproduced by resisted flexion and pronation of the wrist. The two most common problems that can mimic medial epicondylitis are cubital tunnel syndrome and medial ulnar collateral ligament insufficiency.
There is both an acute and chronic phase of medial epicondylitis; the former is characterized by symptoms mostly during activity while the chronic consists of constant, dull pain that may only slightly worsen with activity Risk factors for medial epicondylitis include smoking, obesity, repetitive movements for at least 2 h daily, and activities which place more than 20 kg of force on the arm.
Surgical intervention for medial epicondylitis is considered the last line of treatment for the condition and is only attempted after conservative treatment has failed to relieve the patient of pain. Most clinicians consider persistent pain for more than 6-12 months an indication for surgical treatment.
The purpose of this study was to determine whether the Z-lengthening approach for common flexor tendon debridement is a viable option for cases of medial epicondylitis refractory to non-surgical treatment based on patient satisfaction, visual analog scale (VAS) pain score, Nirschl and Pettrone clinical assessment, disability of the arm, shoulder, and hand (DASH) score, and the McGowan grading system. The authors hypothesized that patients treated with the Z-lengthening approach for common flexor debridement will experience significant pain relief and adequate function post-operatively.
