14 Tendinopathies Around the Elbow Alan J. Johnstone and Nicola Maffulli Introduction affect males and females equally, and most commonly involve the dominant arm [2]. In most patients, overuse During the last 20 years, there has been a better under- of the limb gives rise to the symptoms with the severity standing of the underlying pathology of upper limb being influenced by the overall intensity and duration of tendinopathies. This knowledge, coupled with a better the activity. Characteristically, individuals, including understanding of the exact location of the pathology, competitive athletes, who place high demands on the has enabled surgeons to rationalize the use of existing upper extremities, are prone to developing epicondy- nonsurgical and surgical management options, and to lopathy,although any task which involves repetitive activ- consider future therapeutic options. Not only has this ities may induce these conditions. Sports commonly approach improved the overall success of management, associated with these conditions include racket sports,and but it has also reduced patient morbidity. Research has sports which involve a throwing action resulting in eccen- also clarified the pathology and clinical presentation of tric loading of the muscles of the forearm. Other less a variety of disorders involving neighboring structures common causes of epicondylopathy include a direct blow that can “mimic” symptoms commonly attributed to to the medial or lateral epicondyle. The symptoms may tendinopathies. These findings should reduce diagnostic also ensue following a sudden extreme effort or activity error and help to identify causes of refractory symptoms. resulting in injury. There also appears to be a group of However, despite the advances made, the management of patients susceptible to generalized tendinopathy: Nirschl a significant proportion of patients with tendinopathies referred to this group of patients as having a “mesenchy- around the elbow remains a clinical challenge. mal syndrome,” theorizing a possible genetic component giving rise to abnormal collagen formation [3]. These patients tend to have multiple problems that may include Tendon Injuries Around the Elbow rotator cuff pathology, epicondylopathy, carpal tunnel syndrome, triggering of the long finger flexor tendons, and Tennis Elbow extensor tendon pathology such as de Quervain’s disease. Confusion exists in the literature as to what constitutes Interestingly, routine rheumatological investigations tend “tennis elbow,” with some authors referring to lateral, to be normal in this population, although more recently, medial, and posterior forms. However, most surgeons Malmivaara et al have observed that a significant number reserve this term to describe involvement of the lateral of patients presenting with coexisting wrist and elbow epicondyle, referring to the similar condition involving tendinopathies have a higher incidence of rheumatoid the medial aspect of the elbow as “golfer’s elbow.”Triceps factor positivity (31%) or human leukocyte antigen-B27 tendinopathies are recognized as separate entities. positivity (38%) compared with a control group [4]. This finding suggests a possible inflammatory com- ponent in the pathogenesis of the tendinopathy in some Etiology and Epidemiology of Tennis and patients. Golfer’s Elbow Both tennis and golfer’s elbow occur in patients aged Pathology of Tennis Elbow between 35 to 50 years with a peak in the early 40s, although both conditions have been reported in teenagers Despite the possibility of an inflammatory cause in some, and in patients in their 70s and 80s [1]. These conditions in the majority of patients histology reveals a degenera- 128 14. Tendinopathies Around the Elbow 129 Table 14-1. Main ethiopathogenetic hypotheses in tennis elbow (in chronological order) Author Year Ethiopathogenetic hypothesis Trethwan 1929 Synovial fringe inflammation Cyriax 1939 Extensor carpi radialis brevis tear Bosworth 1954 Hyaline degeneration of the annular ligament Kaplan 1968 Neuritis of the radial nerve Roles and 1972 Radial nerve entrapment Maudsley Newman and 1975 Radial head fibrillation Goodfellow Coel et al. 1993 Inflammation in the anconeus muscle Patients with tennis elbow rarely experience significant tenderness over the posterior aspect of the epicondyle or Figure 14-1. Calcification over the common extensor origin. condylar ridge, and if posterior tenderness is present, the clinician should consider other possible causes to explain the patient’s symptoms. The resisted wrist extension test tive process within the tendon, and the histological (Thomsen test) is useful, as is point tenderness increased appearances is remarkably similar to tendinopathy at with extension of the elbow while the wrist is held in full other sites. Generally, the abnormal or pathological flexion and the forearm is pronated. However, reliance region of the tendon can easily be identified at surgery should not be placed upon the resisted middle finger [2]. Characteristically, the abnormal region of the tendon extension test in differentiating between tennis elbow is gray compared with the surrounding normal tendon, and compression of the posterior interosseous nerve [2]. and may be slightly edematous [5]. It is also frequently One simple test, which can help to confirm the diagnosis friable, and may contain small flecks of calcification at the outpatient clinic, is to inject local anesthetic around (Figure 14-1). Histology is consistent with disordered the site of maximal tenderness, usually the anterior aspect healing superimposed on a degenerative process, lacking of the epicondyle or condylar ridge, or both sites depend- the classical features of acute inflammation [6]. In partic- ing upon the examination findings. A positive test will ular, a granulation type of tissue containing fibroblasts is either temporarily abolish or significantly improve a visualized and is referred to as “angiofibroblastic hyper- patient’s symptoms compared with the pre-injection find- plasia.” Adjacent to this abnormal tissue, the neighboring ings. However, it is important to use a small volume of tendon is hypercellular, containing histiocytes, lympho- local anesthetic (2 to 3mL) to reduce the risk of a false cytes, and occasional polymorphonuclear leukocytes, positive test. interspersed with small areas of localized degeneration. Differential Diagnosis of Tennis Elbow Tennis Elbow Although the majority of patients presenting with activ- Tennis elbow affects approximately 1% to 2% of the pop- ity-induced lateral elbow pain have underlying degener- ulation and is between 5 and 9 times more common than ative changes within the common extensor origin, other its medial counterpart [7]. Although any of the common causes of lateral elbow pain should be considered, espe- extensor origin tendons can be involved, the extensor cially if the clinical presentation is not typical of tennis carpi radialis brevis tendon is the most commonly in- elbow or if the patient’s symptoms are resistant to appro- volved specific site [8]. Patients most commonly present priate conservative management. Narakas and Donnard with lateral elbow pain that frequently radiates into the suggested articular and neurogenic factors for lateral extensor musculature of the proximal forearm. In most elbow pain in addition to tendinogenic causes [10]. The patients, symptoms relate to activities that stress the wrist most widely accepted differential diagnoses include bur- extensor and supinator muscles, and especially to activi- sitis, stenosis of the annular ligament, inflammation of the ties that involve forceful gripping or lifting of heavy synovium adjacent to the radial head, entrapment of the objects. Clinical examination classically localizes tender- radial or posterior interosseous nerves, chondromalacia ness to the anterior and lateral aspect of the epicondyle, or early osteoarthritis of the radial head or capitellum, and frequently over the distal part of the anterior aspect cervical nerve root entrapment, and laxity or instability of the lateral condylar ridge [9] (Table 14-1). of the lateral elbow ligament complex [2]. Generally, it is 130 A.J. Johnstone and N. Maffulli possible to exclude these differential diagnoses clinically return to their chosen activities without limitation. and, if necessary, by obtaining plain radiographs of the Secondary aims include encouraging healing of the elbow. However, a detailed clinical and anatomical study injured tendon and reducing the risk of recurrence of the documented entrapment of the posterior interosseous condition. nerve co-existing in up to 5% of patients with tennis elbow [11,12]. This finding could in part explain why a Nonsurgical Management significant proportion of patients fail to improve after Most studies document the overwhelming success of apparently adequate conservative management. Entrap- nonsurgical methods in the management of tennis elbow, ment of the posterior interosseous nerve should be con- with Nirschl reporting a personal success rate of 93% sidered if genuine weakness of the wrist extensor muscles [13]. Unfortunately, recurrences are also common, espe- can be demonstrated and if elbow pain is exacerbated by cially if patients return to their previous level of activity resisted supination of the forearm. without modification of the aggravating activity. Many different nonsurgical approaches have been Investigations used to treat patients with tennis elbow. These include It is usually possible to make the diagnosis of tennis rest, activity modification,