Tennis elbow, also known as humeral epicondylitis, is a common clinical condition that is characterized by pain in the lateral aspect of the elbow when the patient grips and lifts objects with force. According to statistics, epicondylitis occurs in 10%-50% of tennis players; it can also occur in people who engage in repetitive and inappropriate force activities over a long period of time. It has been found that epicondylitis of the humerus is actually a degeneration of the tendon of the short extensor carpi radialis (ECRB) or the extensor digitorum communis (EDC), rather than a result of local inflammation. Moreover, the finding of neuropeptides at the radial short extensor carpi radialis suggests that neuroinflammation may be one of the reasons why patients present with pain in the lateral part of the elbow joint.
The most common cause of tennis elbow is a tendon injury caused by repetitive forceful pulling of the forearm extensors, which occurs in patients between 35 and 50 years of age. Young or professional tennis players are at increased risk of developing tennis elbow due to overuse of the elbow joint. Some researchers suggest that tennis elbow may be caused by a failure of repair after tendon injury and local vascular damage. The normal tendon repair can be interrupted by subsequent injury, while the damaged tendon continues to impede tendon repair. prof. Cyriax believes that the muscle-bone junction is the most susceptible to injury because the tendon fibers there are relatively unsupplied with blood.
The main manifestations are pain in the lateral aspect of the elbow joint, which may radiate to the forearm and may be aggravated by gripping or lifting with the affected limb.
Physical examination should include an examination of the cervical spine, as pain due to nerve root compression at C5-C6 or C6-C7 can be misdiagnosed as humeral epicondylitis. Patients can be observed for lateral elbow pain by moving the cervical spine and performing the Spurlings test. The stability of the scapula is important for tennis pumping, and without a stable point of force for the rotator cuff muscles, the function of the shoulder joint will be significantly limited. Thus, when a tennis player does not have enough shoulder strength to make a single draw, he uses the extensor muscles, which leads to overuse of the extensor muscles and degenerative tendon degeneration. Palpation of the lateral epicondyle of the humerus reveals tenderness and pressure pain in the lateral epicondyle and anterior aspect of the forearm. Pain in the lateral epicondyle of the humerus can occur with the wrist joint extended in elbow extension and forearm rotation anteriorly or with the wrist joint fully flexed Additionally, patients often have decreased grip strength due to pain in the lateral epicondyle of the humerus, which is a stable and sensitive diagnostic indicator of tennis elbow, so grip strength of the affected limb also needs to be measured by a hand-held grip strength meter.
Diagnosis of tennis elbow also requires consideration of symptoms caused by abnormalities in the nerve structures, such as radial nerve entrapment syndrome and posterior interosseous nerve compression that can cause pain in the lateral elbow joint. One study found that 5% of patients with humeral epicondylitis may have radial nerve compression because deep branches of the radial nerve pass behind the Frohse arch along the edge of the posterior rotator muscle fibers. When deep pressure pain in the radial head and limitation of forearm rotation posteriorly occurs, it indicates radial nerve injury, while pressure pain in the humeral epicondyle and limitation of wrist extension suggest that the patient has tennis elbow. The posterior interosseous nerve may be compressed at the point of entry into the posterior rotator muscle.
Nirschl et al. divided conservative treatment into three phases, based primarily on the acute inflammatory phase, the chronic inflammatory phase, and the muscle strength deficiency phase. There are more conservative treatments, ranging from those aimed primarily at symptom relief to etiologic treatment. However, due to individual differences, there is still no uniform standard of treatment.
The first thing that is carried out is health education of the patient and correction of wrong activity patterns. The common conservative treatments for tennis elbow are ultrasound therapy, ultrasound drug penetration therapy, electrical stimulation, iontophoresis, heat therapy and cryotherapy. Manipulative therapy can also be used to treat tennis elbow, such as moving the affected limb or massage.
In addition, active muscle strength restoration programs such as wrist extensor restoration should be done in conjunction with scapular and rotator cuff muscle group restoration. Some researchers suggest that tennis elbow can be treated by stretching the wrist extensors and forearm muscles, with the wrist joint as if it were supported and the top cocked, or by stretching with a reverse force
Muscle strength and flexibility training can be effective in treating tennis elbow, with centrifugal strength training considered to be the most effective method. It restores strength to the tendon mainly by simulating the production of collagen by mechanoreceptors that help the tendon to recover, but also improves the collagen queues in the tendon and stimulates the formation of collagen cross lines, thus increasing the tensile strength of the tendon.
Centrifugal strength training begins by immobilizing the forearm with the elbow and wrist in the extended position and making a fist. The patient uses the opposite hand to lower the affected wrist joint and then raises it to the original position. Each set is repeated 5-15 times for a total of 3 sets and is recommended to be done daily. It is normal to experience mild discomfort during training, but if the pain is severe, stop training immediately. Once the patient can easily complete the training, the resistance can be increased by adding gravity or rubber bands.
Another method of centrifugal strength training for the wrist is by tying weights to the end of a rope. Patients complete the centrifugal strength training by controlling the rise and fall of the weights through the handle, with the healthy arm holding the handle during the intervals of repetitive motion. The studies all showed significant pain relief, but the importance of the training, the weight of the weights, and the duration of the training varied from study to study. Most studies point to good results with 10-15 training sessions and a duration of 6-12 weeks.
Tennis players swing and hit the ball primarily by mobilizing the muscles of the scapula, shoulder and elbow, and injury to any of these areas increases the load on the extensor muscles. Clerks who use computers for long periods of time can also develop tennis elbow due to overuse of the wrist extensor muscles. Therefore, the primary treatment options for tennis elbow are pain relief, health education, and proximal muscle exercises. This includes core muscle strength training for rotational function of the shoulder and elbow joints, scapular muscle training, posterior rotation training with elevation of 45° and 90°, and diagonal patterns of D1 and D2 extension and flexion (proprioceptive neuromuscular easing technique).
Surgical treatment
When conservative treatment of tennis elbow fails, the surgical treatment options available are: incisional debridement and repair or simple debridement, percutaneous decompression and arthroscopic debridement. Regardless of the surgical approach chosen, the principle of surgical treatment is the same: removal of degenerative tissue at the radial short extensor carpi radialis (and the common extensor tendon if involved).
In general, the majority of patients with tennis elbow showed significant postoperative symptomatic relief, and Nirschl et al. followed 130 patients with tennis elbow who underwent incisional debridement for up to 10 years, showing that 97% of patients showed significant symptomatic improvement and 93% returned to their pre-morbid level of motion. In contrast, Thorton et al. used a modified surgical technique of Nirschl to fix the repaired tendon to the lateral epicondyle of the humerus with suture anchors, and the patient’s grip strength was well restored after surgery.
Arthroscopic debridement for tennis elbow can be equally effective and can also address intra-articular lesions, as Szabo et al. found that 44% of patients had a combination of intra-articular lesions. Another advantage of arthroscopic treatment is the short return to work time (11 days on average).
Solheim et al. followed 300 patients with tennis elbow for 3-6 years, and although both groups had a good clinical prognosis, the arthroscopic group had higher mean shoulder, arm, and hand dysfunction scores, and the patients recovered better after surgery. The time to return to work was shorter in the arthroscopic group.
Excessive debridement can damage the lateral collateral ligament of the elbow resulting in posterior lateral rotational instability. The lateral collateral ligament can be well protected during arthroscopic debridement by keeping the lateral collateral ligament parallel to the superior half of the radial head. Complications such as heterotopic ossification and paralysis distal to the incision have also been studied.
Small suture anchors are then inserted into the lateral epicondyle of the humerus to thoroughly flush the surgical area of bone debris to avoid heterotopic ossification. The repaired radial short extensor carpi radialis is secured to the external epicondyle of the humerus with a suture anchor. Finally, the wound is closed layer by layer, and posterior lateral splinting for one week is sufficient.
There are many reasons for the occurrence of pain in the lateral epicondyle of the humerus in tennis elbow, but there is still no standard treatment protocol. Most patients can obtain symptomatic relief and functional recovery with conservative treatment, and the remaining patients can have a good clinical prognosis with surgical treatment. In conclusion, more research is needed to prove the most appropriate method and amount of exercise and the treatment of tennis elbow.