Traumatic structural: where there is a de \201 nite history of trauma, usually anterior an d unilateral, resulting in damage to the labrum (Bankart lesion). The treatment is surgical , in the form of a Bankart repair. Atraumatic structural: it is due to capsular dysfunction due to repetitive microtrauma, usually in a background of increased laxity or structural a bnormalities of the articular surfaces. It is not uncommonly bilateral. Habitual non-struct ural (muscle patterning): there is no history of trauma, no structural damage to the articu lar surfaces, but an altered muscle patterning. This can start as a voluntary action (party trick), but becomes uncon- trolled. The diagnosis is dif \201 cult and sometimes requires EMG studies. Figure 5.14 Capsular proliferation around the acromioclavicular joint is visualized on US, and is identi \201 ed here by the solid arrows. The broken arrows demonstrate osteophytes. The joint space is narrowed and obliterated as a consequence and is not clearly seen. CHAPTER 5 Regional musculoskeletal anatomy and conditions 143 Treatment Treatment is initially conservative, with activity modi \201 cation and analgesi a. Symptomatic acromio/sternoclavicular os- teoarthritis that does not respond to conservat ive therapy may be treated with excision arthroplasty. At the acromial end, it is usually e xcised arthroscopically. On the sternal side, an open excision arthroplasty is carried out due to the proximity of big vessels. gaining a painless range of movement, involving gleno- humeral joint synovectomy with a sub acromial bursec- tomy. If rotator cuff disease is present it can be addressed at the time b y means of an acromioplasty and release of the coracoacromial ligament. Once articular cart ilage loss has occurred prosthetic replacement using either a hemiarthroplasty or total joi nt replacement is usually necessary. The results for rheumatoid arthritis patients are not as good as in patients with osteoarthritis. Osteoarthritis of the glenohumeral joint Osteoarthritis of the GHJ is rare and there is nor mally a predisposing factor, such as trauma, avascular necrosis of the humeral head, or in \202 ammatory disease. The articular cartilage in the GHJ is exposed to less force than we ight- bearing joints, making osteoarthritis less common. Typical presentation is of poorly localized shoulder pain with discomfort in the upper arm in an elderly patient. Examina- ti on reveals globaly restricted movements and the presence of an effusion. Prioritizing of surgical procedures Although the most symptomatic joint should be treated \201 rst, lower limb surgery normally takes priority over upper limb surgery, with upper l imb surgery normally deferred until the use of ambulatory aids is no longer required. The e lbow takes precedence over the shoulder, as a superior functional result is achieved when t he elbow is operated on before the shoulder. Treatment \200 Bicipital tendinitis Tenosynovitis of the long head of biceps is uncommon and is characteri zed by pain and tenderness over the long head of biceps in the bicipital groove of the hume rus. It may occur in association with degenerative disease of the rota- tor cuff but in the majority of cases occurs as a result of localized friction from the bone of the humeral bi cipital groove. The history is one of localized anterior shoulder pain which is exacerbated by use of the arm. Pain in the bicipital groove is exacerbated by resisted \202 exion an d supination of the forearm. Conservative treatment is normally sufficient with physiotherapy and analgesia. Arthroscopi c techniques are useful in the younger patient with shoulder symptoms and allow treatment o f co-existing soft tissue pathology, for example, subacro- mial decompression, capsular rel ease, and arthroscopic debridement. Severe glenohumeral disease often requires hemiarthro- plasty or total shoulder replacement. Both procedures result in signi \201 cant pain relie f, increased range of move- ment and function. The two types of prosthesis in com- mon use are either surface replacements or traditional stemmed implants. Up to 35% of patients who require a shoulder arthroplasty have rotator cuff tears. These should be repaired at the sa me time as the arthroplasty to achieve the best results. In general, the results of total s houlder replacement are superior to hemiarthroplasty with better functional results and les s pain. Treatment Conservative treatment is normally successful, although a localized glucocorticoi d injection is required in more severe cases. Rupture of the tendon of long head of biceps Rupture of the tendon of the long head of bice ps is not uncommon and often occurs in association with rotator cuff pathology. \200 The rheumatoid shoulder Shoulder symptoms are common in patients with estab- lished RA with more than 90% of patients having shoulder pain at 5 years following onset of in \202 amma tory disease. Patients present with symptoms of pain, swelling and a decreased range of mot ion. Rotator cuff insuf \201 ciency is common affecting more than 70% with approximately 3 0% developing full thickness tears. Rupture may be preceded by pain, but is often painless, and presents with bruising and, mor e characteristically, a \200\230Popeye \200\231 muscle as the muscle belly bulges distally . Rupture of the long head does not appear to have any signi \201 cant adverse effect on f unction and so nothing more than reassurance is required. Avulsion of the distal tendon ins ertion from the radial tuberosity, however, is a very different situation. This is rare and tends to occur in younger patients and particu- larly in body builders who overload the te ndon inser- tion. The rupture is painful as it occurs, but the pain quickly settles. The di agnosis is obtained from the his- tory and an inablity to palpate the cord-like structure o f the tendon in the antecubital fossa. The distal tendon of the biceps is a powerful supina tor of the forearm, as well as elbow \202 exor, and so surgical repair, by reattachment, is required. Non-surgical management In early shoulder involvement, there are no signi \201 cant osseou s changes, and treatment is medical, with analgesia, NSAIDs, and overall control of disease activity. Activity modi \201 cation, intra-articular, or subacromial glucocorticoid injec tions may also be helpful. Physiotherapy is useful in maintaining and regaining range of mo tion depending on the stage of the disease. Surgical management \200 Surgical management is indicated when conservative treatment has failed to control pain and maintain function. The choice of procedure is determined by the extent of disease in the a rticular cartilage, bone, and the periarticular soft tissues. Synovectomy and debridement a re indicated when there is articular cartilage preservation. The procedure can be performed open or arthroscopically with up to 80% Nerve disorders around the shoulder Peripheral nerves are highly susceptible to injury from stretch or compression, resulting in nerve ischaemia, oedema and conduction impairment. Th ese changes are proportional to the magnitude and duration of the insult, and eventually le ad to irreversible damage. THE SHOULDER GIRDLE: REGIONAL MUSCULOSKELETAL CONDITIONS 144 Suprascapular nerve Etiology The commonest locations of injury include the suprascap- ular notch, the spinoglenoid notch, and between the spine of the scapula, and the medial tendino us margin of infraspi- natus and supraspinatus during extreme abduction and internal rotati on of the shoulder. Causes include: \200 Spinal accessory nerve injury The spinal accessory nerve supplies the trapezius muscle. \200 It may be injured during trivial surgery, such as lymph node biopsies in the neck. Th e prognosis for recovery in these cases is poor and can result in signi \201 cant function al disability and pain. If this is the case, surgical reconstruc- tion with tendon transfer s (Eden \200\223Lange procedure) is indicated. It is also commonly affected by neurological amyotrophy. This presents with acute onset of severe pain, often at night, followed by wea kness and atrophy of the trapezius muscle. It can be bilateral. In contrast with iatrogenic damage, prognosis is good. It tends to resolve spontane- ously, although it may take 2 \200\2233 years. The treatment is supportive consisting in analgesia and physical therapy. Braces might be helpful, although they are generally poorly tolerated. In cases of incomple te recovery, recon- structive surgery can be considered. Trauma \200\223 shoulder dislocations, scapular, and clavicular fractures, penetrating tra uma, iatrogentic injury during surgery. Compression by a mass \200\223 commonly a ganglion cyst. Repetitive over-use. \200 Results are especially poor for suprascapular nerve injury secondary to ganglion cys t. Investigations Nerve conduction studies and imaging are the most useful techniques. US demo nstrates ganglion cysts and other mass lesions, which can be further visualized with CT and MR. MR has the added bene \201 t of identifying changes within supraspinatus and infraspi natus secondary to denervation (atrophy, fatty in \201 ltration, and high signal on T2-wei ghted images) that appear 3 weeks after injury. Further reading Bell S, Coghlan J, Richardson M. Hydrodilatation in the management of shoulder capsulitis. Aust Radiol 2003; 47: 247 \200\22351. Bigliani, L., Morrison, D, April, E. The morphology of the acromion and it relationship to rotator cuff tears. Orthopaed Trans 1986; 10: 228. Treatment Conservative treatment consists of: \200 Bunker TD Anthony PP. The pathology of frozen shoulder. A Dupuytren-like disease. J Bone Jt Surg Br 1995; 77: 677 \200\22383. Codman EA. The Shoulder. Rupture of the Supraspinatus Te ndon and Other Lesions In or About the Subacromial Bursa. Boston: Thomas Todd, 1934. Avoidance of activities that result in irritation and trauma of the nerve. Improve \202 e xibility of the surrounding muscles of the GHJ and strengthening of the scapular stabilizin g muscles. Surgical treatment is tailored to the precise underlying cause. \200 Harvie P, Ostlere SJ, Teh J, et al. Genetic in \202 uences in the etiology of tears of the rotator cuff. Sibling risk of a full-thickness tear. J Bone Jt Surg Br 2004; 86(5): 696 \200\223700. Suprascapular notch: release of the superior trans- verse scapular ligament for entrapment in the supras- capular notch. Spinoglenoid notch: release of the spinoglenoid ligament, sca pular spine, or medial tendinous margin of the rotator cuff for more distal lesions around the spinoglenoid notch. Ganglion cyst: US/CT guided aspiration of ganglion cysts. However, this is associated with a risk of recur- rence. Arthroscopic or open decompression of the c yst may be required. Hawkins RJ, Brock RM, Abrams JS, Hobeika P. Acromioplasty for impingement with an intact ro tator cuff. J Bone Jt Surg Br 1988; 70: 795 \200\2237. Hazelman BD. The painful stiff shoulder. Rheumatol Phys Med 1972; 11: 413 \200\22321. Lewis A, Kitamura T, Bayley JIL. The classi \201 cation of shoulder insta- bility: new lig ht through old windows. Curr Orthop 2004; 18: 97 \200\223108. Massoud SN, Levy O, Copeland SA Subacromial decompression. Treatment for small- and medium- sized tears of the rotator cuff. J Bone Jt Surg Br 2002; 84: 955 \200\22360. Neer CS. Anterior acromioplasty for the chronic impingement syndrome in the shoulder. J Bone Jt Surg Am 2005; 87: 1399. Axillary nerve injury Axillary nerve injuries can present in isolation or as part of a comb ined brachial plexus injury. Causes include: \200 Neer CS. The surgical management of rheumatoid arthritis. In: Crubbs RL, Mitchell NS (Eds) The Rheumatoid Shoulder. Philadelphia: JB Lippincott, 1971; 117 \200\22327. Traction injury to the shoulder (anterior dislocation of the shoulder). Closed blunt trauma . Penetrating trauma (sharp or blunt). Nerve compression due to mass effect (aneurysm, tumo r). Parsonage \200\223Turner syndrome (neuralgic amyotrophy). Quadrilateral space syndrome. Petersson CJ. Shoulder surgery in rheumatoid arthritis. Acta Orthopaed Scand 1986; 57: 222 \200\2236. \200 \200 Riley GP, Goddard MJ, Hazleman BL. Histopathological assessment and pathological signi \201 cance of matrix degeneration in suprasp- inatus tendons. Rheumatology (Oxf.) 2001; 40( 2): 293 \200\22323. Titelman RM, Lippitt SB, Rockwood CA Jr, Wirth MA Glenohumeral instability. In: Matsen FA 3 rd (Ed.), The Shoulder. Volume 2, 3rd edn. Philadelphia: Saunders 2004; 655 \200\223794. \200 Uhtoff HK, Loehr JW Calci \201 c tendinopathy of the rotator cuff: Pathogenesis, diagnosis , and management. J Am Acad Orthop Surg 1997; 5(4): 183 \200\22391. Investigations Investigations include nerve conduction studies and imaging as discussed for suprascapular nerve disorders. A subclavicular arteriogram may be appropriate if quadri- l ateral space syndrome is suspected (considered positive if posterior humeral circum \202 e x artery occlusion occurs with less than 60 of abduction). Yamaguchi K, Tetro AM, Blam O, Evanoff BA, Teefey SA, Middleton WD. Natural history of asym ptomatic rotator cuff tears: a longi- tudinal analysis of asymptomatic tears detected sonog raphically. J Shoulder Elbow Surg 2001; 10(3): 199 \200\223203. This page intentionally left blank THE ELBOW 146 The elbow Regional anatomy The elbow joint comprises both the ulnohumeral articulation and the radioh umeral articulation. The ulnohumeral articu- lation is a hinge joint, whilst the radiohumer al articulation is a \200\230universal joint \200\231 in that it can both hinge and pivot. It is a synovial joint and its cavity communicates with the prox- imal radioulnar joint. T he function of the elbow, working in conjunction with the shoulder, is to enable positionin g of the hand. Furthermore, swelling can occur around the proximal radius and thereby compress the posteri or interosseous nerve. See Figure 5.16. Ligaments \200 On the ulnar aspect two ligaments originate from the lateral epicondyle and diverge to inse rt onto the olecranon at either end of the lateral aspect of the ole- cranon fossa. The two divergent ends of these ligaments are joined by a transverse ligament which runs between t hem. On the radial aspect a ligamentous structure arises from the lateral epicondyle and ru ns distally. As it runs distally it diverges so that one bundle of \201 bres inserts into the ulnar, at the distal end of the radial side of the olecranon, and the other bundle mer ges with the lateral aspect of the annular ligament; the annular ligament is attached at ei ther end to the radial side of the ulnar and encircles the radial head. Bones Towards the distal end of the humerus the medial and lateral epicondyles are palpable on either side. They are distinguishable from the adjacent radial head laterally and olecr anon posteriorly if the elbow is \202 exed and extended. Distal to the epicondyles the ra dial end of the humerus is hemispherical (the capitellum) for articulation with the slightl y concave and circular proximal end of the radius. The ulnar end of the distal radius (the trochlear) is pulley- shaped, comprising two rims with a groove between. The trochlear arti culates with the olecranon fossa of the prox- imal ulnar. The olecranon fossa is a concavit y from end to end, but convex from side to side and so mirrors the shape of the trochlear. The radial aspect of the proximal ulnar has a concavity for articulation with the rim of th e radial head during pronation and supination. See Figure 5.15. Bursa lateral ligament annular ligament capsule humerus medial and lateral epicondyles Figure 5.16 Capsule and ligaments of the elbow joint ( lateral aspect). A bursa exists between the posterior surface of the olec- ranon and the overlying skin. Thi s bursa renders the skin over the olecranon mobile so as to facilitate \202 exion of the elbow and minimize shearing forces on the deep surface of that portion of skin. capitulum Muscles Flexion of the elbow is achieved by the combined effects of brachialis, biceps, and brachioradialis. \200 Brachialis inserts into the proximal ulnar in the region of the coronoid process, at the di stal end of the olecranon fossa. The biceps muscle has insertions onto both radius and ulna r. It inserts into the radius via a tendon which inserts into the radial tuberosity and int o the ulnar via an apone- urosis (the lacertus \201 brosus) that, ultimately, attaches to the proximal ulnar via the fascia overlying the common \202 exor muscles of the forearm. Brachioradialis has a longer lever arm, arguably, than both brachialis and biceps in that it takes origin from the lateral aspect of the distal humerus and inserts via its ten- don into the distal radius in the region of the radial styloid. Extension of the elbow is achie ved through the action of triceps, primarily. \200 trochlea superior radio-ulnar joint radius ulna Figure 5.15 Articular surfaces of elbow joint (anterior aspect). Joint capsule The joint capsule encloses the ulnohumeral and radiohum- eral articulations, and also the proximal radioulnar joint within a single joint space. An effusion or synoviti s can, therefore, produce \202 uctuant swellings immediately posterior to both the medial and lateral epicondyles of the humerus. The triceps tendon has a fairly broad insertion into the proximal ulnar, inserting into the olecranon process and the region immediately distal to this. CHAPTER 5 Regional musculoskeletal anatomy and conditions 147 Some \202 exion and extension of the elbow is also produced by the action of the common \202 exor and extensor mus- cles, whose primary actions are on the wrist and hand. Posterior interosseous nerve The nerve \201 bres that comprise the posterior interosseous nerve (PIN) leave the radial nerve in the antecubital fossa, super \201 cial to brachiali s, but deep to brachioradialis. The PIN runs away from the super \201 cial radial nerve, h aving given a branch to the extensor carpi radialis brevis, by passing deeply between the s uper \201 cial and deep layers of the supi- nator muscle, which it supplies. On leaving th e distal edge of the supinator the PIN branches to supply all remaining extensors and abduc tor pollicis longus. The terminal branch of the PIN runs along the posterior surface of the interosseous membrane between radius and ulnar (hence, its name) to supply the wrist joint . The muscles supplied by the PIN are presented in table 5.6. The PIN does not have a super \201 cial sensory area of supply and, therefore, a PIN lesion is not accompanied by senso ry disturbance of the skin. Muscles Extensor muscles and tendons arising at the elbow The common extensor origin, from which arises the fused proximal ends of extensor carpi radialis brevis (ECRB), extensor dig itorum communis (EDC), extensor digiti minimi (EDM), and extensor carpi ulnaris (ECU) is on the anterior aspect of the lateral epicondyle. The actions and innervation of the extensor muscles are presented in table 5.4. Table 5.4 Extensor muscles arising from the distal humerus Muscle Action Innervation Table 5.6 Muscles supplied by the posterior interosseous nerve Brachioradialis Elbow \202 exion Radial Extensor carpi radialis longus Wrist ext. and radial deviation Radial Muscle Action Extensor carpi radialis brevis Wrist ext. and radial extension Posterior Interosseous Externsor carpi radialis brevis Wrist and radial extension Anconeus Extends elbow Anconeus Extends elbow Radial Extensor digitorum communis Extends \201 ngers Extends \201 ngers Posterior interosseous Extensor digitorum communis Externsor digiti minimi Extends little \201 nger Externsor carpi ulnaris Wrist extension and ulnar deviation Extensor digiti minimi Extends little \201 nger Posterior Interosseous Supinator Supinates forearm Extensor carpi ulnaris Wrist ext. and ulnar deviation Posterior Interosseous Abductor pollicis longus Abducts thumb Extensor pollicis brevis Extends thumb MCPJ Supinator Supinates forearm Posterior interosseous Extensor pollicis longus Extends thumb Flexor muscles and tendons arising at the elbow The common \202 exor origin (pronator ter es, \202 exor carpi radialis, \202 exor digitorum super \201 cialis, palmaris longus, and \202 exor carpi ulnaris) is from the medial epicondyle. The actions and innervation o f the \202 exor muscles are pre- sented in table 5.5. Extensor indicis proprius Extends index \201 nger Further reading Standring S (Ed.). Grays Anatomy: the anatomical basis of clinical practice. Section V. Churchill Livingstone London: 2006. Last \200\231s Anatomy \200\223 Regional and Applied, 11th edn. Churchill Nerves around the elbow Ulnar nerve The ulnar nerve runs within the cubital tunnel immediat ely posterior to the medial epicondyle. The brachial artery, and median nerve lie anterolat eral to the medial epicon- dyle, and the posterior interosseous nerve lies anterome- dial t o the lateral epicondyle and in close proximity to the anterior part of the radial head and neck. Livingstone: 2006. Table 5.5 Flexor muscles arising from the distal humerus Muscle Action Innervation Pronator teres Pronation and elbow \202 exion Median Flexor carpi radialis Wrist \202 exion and radial Median deviation Palmaris longus Wrist \202 exion Median Flexor carpi ulnaris Wrist \202 exion and ulnar Ulnar deviation Flexor digitorum super \201 cialis Proximal interphalangeal joint \202 exion Median THE ELBOW: REGIONAL MUSCULOSKELETAL CONDITIONS 148 The elbow: regional musculoskeletal conditions Occasionally, a shooting pain is described into the dorsum of the hand. Shaking hands or fo rming a tight grip exacerbates the pain. Main differential diagnosis of elbow pain Articular \200 \200 \200 \200 In \202 ammatory, e.g. rheumatoid arthritis, crystal arthritis. Degenerative. Osteochondri tis dissicans. Traumatic. Examination \200 \200 Tenderness over the lateral epicondyle is typical. Pain on resisted wrist dorsi \202 exion is found with the elbow held in extension. Alternatively, pain is precipitated by extendin g the elbow with the wrist in \202 exion. Resisted supination is painful. The elbow demon strates a normal range of movement. Bursitis Olecranon bursitis. Tendinopathy \200 \200 \200 \200 \200 Lateral epicondylitis. Medial epicondylitis. Bicipital tendinopathy. Triceps tendinopathy. Investigations Investigations are not normally required as the diagnosis is clinical. \200 Nerve entrapment syndromes \200 Cubital tunnel syndrome. \200 Radial tunnel syndrome. \200 Pronator teres syndrome. \200 Referred pain. \200 Cervical radiculopathy. \200 Thoracic outlet syndrome. \200 Pancoast tumor. Plain radiographs may reveal soft tissue calci \201 cation, but are usually normal. US det ects tendinosis and a periosteal reaction is sometime seen. An example is given in Figure 5 .17. MR is used preoperatively on occasion to image the soft tissue abnormalities, and may reveal tendon tears, as well as chronic tendinosis. Bone pathology \200 Fracture. \200 Infection. \200 Tumor. Others \200 \200 \200 Olecranon impingement syndrome. Fibromyalgia. Regional chonic pain syndrome. Lateral epicondylitis Lateral epicondylitis is one of the most common soft tissue condition s in the arm. The term \200\230tennis elbow \200\231 has arisen as a result of a descripti on of the symptoms in the Lancet in 1882, then describing \200\230lawn tennis arm \200\231 . Figure 5.17 The image above was obtained on ultrasound. There is loss of the normal \201 brillar pattern of the tendon and hyperaemia was detected using the power Doppler tool. In this case, the cortex of the bone is smooth, although irregularity can be seen in more seve re cases. Epidemiology \200 A prevalence of 1 \200\2233% of the population is estimated for lateral epicondylitis. Most of those affected are between the ages of 40 and 60 years. Less than 5% are tennis players . Risk factors remain elusive and there does not appear to be a link with manual work, alth ough over-use may be a risk factor. Treatment In the majority of cases, lateral epicondylitis is self-limiting within a year an d does not require intervention. Treatment is therefore aimed at symptomatic bene \201 t. \200 \200 Rehabilitation with strengthening exercises and stretch- ing may be helpful. An elbow clasp reduces movement of the painful tendon, therefore providing short term pain relief, althou gh long-term bene \201 t remains to be shown. Topical and oral NSAIDs have been used with some success. The role of corticosteroid injection remains controver- sial, and current evi dence is that short-term bene \201 t may be gained by up to three injections, and is super ior to conservative management, physiotherapy, strapping, and oral NSAIDs. However, outcome appears better at 12 months in those patients who have not received corticosteroid injecti ons. Etiology The common extensor tendon origin is the site of inser- tion of extensor carpi rad ialis brevis and extensor com- munis tendons. Although the term \200\230epicondylitis \200 \231 implies an in \202 ammatory etiology, the current hypothesis is that re- peated micro trauma causes disruption of the tendon, which in turn results in a degenerative tendinosis. History \200 \200 An insidious onset is usual. Pain is localized to the lateral epicondyle or radiates along the extensor tendon. CHAPTER 5 Regional musculoskeletal anatomy and conditions 149 Olecranon bursitis The olecranon bursa lies behind the olecranon process, is super \201 ci al, and is therefore prone to traumatic bursitis and infection. In \202 ammatory disease, such as gout and rheuma- toid arthritis may also result in olecranon bursitis. However, oft en there is no cause identi \201 ed. Surgery is occasionally offered to refractory cases, and the extensor origin is stripped fr om the attachment to the lateral epicondyle and allowed to fall back into place, a techniqu e called a lateral release. Extensive surgery may result in elbow instability. The exact me chanism by which this technique is bene \201 cial remains unclear and there are no long-te rm outcome studies following surgery for lateral epicondylitis. Traumatic bursitis \200 Traumatic bursitis is also known as \200\230student \200\231s elbow \200\231. Pain is pres ent when local pressure is applied, such as resting the elbow on a table or against clothin g. Pain is well localized, and not provoked by either resisted or passive movements of the elbow. Examination reveals localized tenderness over the tip of the olecranon and distensio n of the bursa may be obvious. Traumatic bursitis is self-limiting in the majority of cases . Aspiration of the bursa will reveal clear \202 uid in those cases with a signi \201 ca nt swelling and treatment consists of local injection of corticosteroid. Rarely, surgical r esection is required. Medial epicondylitis Medial epicondylitis is also known as \200\230golfers elbow \200\231. It is estimated to be 5-8 times less common than lateral epicon- dylitis. There may be a h istory of over-use and the etiology is thought to be similar to that of lateral epicondylit is. History \200 \200 A history of insidious onset of pain, localized over the medial epicondyle is classical. Pa in radiates into the forearm and is exacerbated by lifting, gripping, and pronation of the forearm. There may be a history of sporting activity or recent increase in repetitive actio ns. Septic bursitis Septic bursitis is less common than traumatic bursitis and is often associa ted with an overlying cellulitis of the skin. There may also be a history of trauma with a skin abrasion providing the site of entry of infection. \200 Examination \200 There is tenderness over the medial epicondyle at the point of insertion of the common exte nsor tendons, and this may extend distally. Provocation is achieved by resisted pronation o f the forearm, with resisted \202 exion of the wrist when the arm is extended. Flexion of the \201 ngers, rather than the wrist may provoke pain at the medial epicondyle. Staph. aureus is the commonest organism causing septic bursitis, although streptococcus and Strep. epidermidis are also less commonly isolated. Localized pain, swelling, and tenderne ss are the presenting features, and there may be features of systemic sepsis. Examination r eveals a full range of movement of the elbow, although the bursa is painful and locally ten der. Aspiration of the bursa should be undertaken for both symptomatic relief and for diagn ostic purposes, and a gram stain of the pus and polarized light microscopy undertaken to ex amine for organisms and the presence of crystals. Antibiotic choice should cover gram posit ive organism pending culture sensitivities. Surgical excision and drainage is rarely necess ary, either during the cute episode or for repeated infection. Treatment As with lateral epicondylitis, symptoms are usually self- limiting and treatment is symptomatic with rehabilitation, and NSAIDs. The role of corticosteroid injection remain s even more poorly researched than in lateral epicondylitis. Bicipital tendinitis Bicipital tendinitis is rare in the elbow and occurs at the point of i nsertion of the biceps tendon onto the radius. History There is often a history of sport or repetitive movements. Pain is experienced over the bicipital tuberosity of the radius. Crystal bursistis \200 Examination Resisted \202 exion and supination provoke pain, as does full extension of th e elbow. Gout may present with an olecranon bursitis, and in this situation, tophaceous deposit are sometimes seen. Monosodium urate crystals are identi \201 ed under light microscopy of the bursal \202 uid. When infection has been excluded, the olecranon bursi- tis may be injec ted with corticosteroid and treatment of gout should be considered in the appropriate clini cal setting. Treatment Treatment involved rehabilitation and physiotherapy. Triceps tendinitis The pain is experienced behind the elbow over the insertion point of the triceps tendon on the olecranon. Osteoarthritis of the elbow Osteoarthritis of the elbow is unusual in patients who do not h ave in \202 ammatory arthritis or a history of trauma. History There is a history of localized tenderness and pain, and sometimes swelling, usuall y in men who undertake manual work. History \200 There is often a history of previous fracture, or osteo- chondritis dissecans. There is a s low progression of increasing elbow pain which is exacerbated by use. There may be restrict ion of elbow movement. If there are loose bodies within the elbow joint, there may be a his tory of joint locking. Examination There may be swelling of the triceps tendon with pain on resisted extension. Treatment Conservative treatment and avoidance of heavy manual work often settles the sympt oms. \200 THE ELBOW: REGIONAL MUSCULOSKELETAL CONDITIONS 150 Olecranon impingement syndrome This results from a traumatic injury and typically results i n posterior elbow pain. Pain is increased by extension of the elbow. There is often a histo ry of clicking or locking in the last few degrees of extension. There may also be crepitus and some restriction of extension. Plain radiographs reveal osteophyte formation. Examination \200 The joint margins are thickened due to osteophyte formation. There is restriction of flexio n and extension, but rotation may be preserved. Coarse crepitation occurs on movement of th e joint. Investigations Joint space narrowing and osteophyte formation is found on radiographs. Loos e bodies may also be seen. See Figure 5.18. Nerve entrapment around the elbow The median, ulnar, and radial nerves may be trapped aroun d the elbow, each giving rise to distinct clinical presentations. Nerve conduction studies are helpful in the investigation of nerve entrapment syndromes. Radial tunnel syndrome The deep branch of the radial nerve (posterior interosseus nerve or PIN) may become compressed as it passes through a tunnel formed by \201 brous tissue next to the super \201 cial head of the supinator muscle. As this is adjacent to the joint cap sule, compression of PIN may occur as a result of synovitis of the capsule. Presentation is usually with lateral elbow pain that radiates into the dorsal aspect of the forearm. Examination \200 Examination reveals local tenderness where the radial nerve crosses the head of the radius. Tinel \200\231s sign may be positive at this point. Provocation of the entrapment occurs w ith resisted supination of the elbow with the elbow in extension. If severe, a PIN palsy re sults, with clinical \201 ndings consistent with a more peripheral radial nerve palsy: \200 \200 Figure 5.18 Sclerosis, osteophytes and joint space narrowing is evident on this plain radio graph of an osteoarthritic elbow. An effusion can also be detected. Weak wrist extension due to paralysis of extensor carpi radialis brevis and extensor carpi ulnaris. Weak thumb abduction (abductor pollicis longus). Loss of thumb extension (extensor pollicis brevis and longus). Loss of finger extension (extensor indicis proprius, extensor digitorum communis and extensor digiti minimi). The diagnosis of a PIN palsy can be dif \201 cult if the palsy is partial and the differential diagnosis includes extensor tendon r upture at the wrist. In both cases, those muscles and tendons closest to the ulnar are affe cted \201 rst. The \200\230tenodesis test \200\231 can help differentiate between the tw o. The extensor tendons are intact if the wrist is passively \202 exed and the \201 nge rs extend due to tension in the extensor tendons. If they do not extend it is likely that t he tendons are ruptured. Treatment In the majority of cases, conservative measures with anal- gesia and self-managem ent are indicated. Physiotherapy and advice about avoidance of heavy physical work are impo rtant. \200 \200 If there is a history of locking, arthroscopic removal of loose bodies provides good sympto matic relief. If osteoarthritis primarily affects the lateral aspect of the joint, excision of the radial head results in pain relief. Rarely, replacement arthroplasty is indicated. Osteochonditis dissecans After the knee, the elbow is the most common site of osteochondrit is dissecans. Necrosis of part of the articular cartilage occurs, with associated necrosis of the underlying bone. Eventually, this separates from healthy bone resulting in a loose f ragment within the joint. This fragment is usually part of the capitulum of the humerus. Th e cause of osteo- chonditis dissecans is unclear. Treatment of PIN compression is conservative, but decompression of the PIN can be undertake n surgically in those with refractory symptoms or signi \201 cant motor \201 ndings. History There is a history of mild mechanical pain and, following separation of the fragmen t, there is a history of locking of the joint. The pronator teres syndrome (median nerve entrapment) Around the elbow, the median nerve ca n become entrapped as it passes through the two heads of the pronator teres muscle. Present ation is with anterior elbow pain and distal paraesthesia identical to that seen in carpal tunnel syndrome. Treatment consists of conservative measures, including physiotherapy, and NSAIDs, and sur- gery, is reserved for those who are not responding. Surgery involves relea se of the humeral head of pronator teres. Examination An effusion can be detected in the early stages and there may be some mild rest riction of movement. Treatment Treatment is conservative until the fragment results in locking, an indication fo r surgery. CHAPTER 5 Regional musculoskeletal anatomy and conditions 151 Examination The pain is exacerbated by resisted pronation of the forearm. Weakness of the \202 exors of the index and middle \201 ngers may result in resting \201 nger extensio n, the so-called \200\230papal sign \200\231. Examination There may be tenderness over the ulnar nerve as it lies within the groove behin d the medial epicondyle, and there is usually a positive Tinel \200\231s test. There is was ting of the intrinsic muscles of the hand in advanced cases Cubital tunnel syndrome The ulnar nerve runs in the groove behind the medial epi- condyle o n its path into the forearm. The main complaint is of pain on the medial side of the elbow with paraesthesia along the ulnar border of the forearm extending into the little and ring \201 ngers. There may be a history of weak grip. Treatment is with activity modi \201 ca tion, NSAIDs if severe, and splinting. Surgical techniques involve ulnar nerve trans- posit ion or less commonly, medial epicondylectomy. Further reading Bosworth DM. The role of the orbicular ligament in tennis elbow. J Bone Jt Surg Am 1955; 37: 527 \200\22333. Kraushaar BS, Nirschl RP. Tendinosis of the elbow (tennis elbow). Clinical features and \201 ndings of histological, immunohistological and electron micrsopic studies. J Bone Jt S urg Am 1999; 81: 259 \200\22378. Putnam MD, Cohen M. Painful conditions around the elbow. Orthopaed Clin N Am 1999; 30: 109 \200\22318. THE HAND AND WRIST 152 The hand and wrist The hand is the body \200\231s key functional asset, and for full function and positioning, a normal shoulder and elbow joint is necessary. radius, and acts as a pulley for the extensor pollicis longus tendon. The scapholunate inte rval lies just distal to and in line with Lister \200\231s tubercle or dorsal tubercle of t he distal radius. Movements of the wrist include palmar \202 exion, dorsi \202 exion, ul nar deviation, radial deviation, and circumduction. The intercarpal joints contribute to pa lmar \202 exion. Regional anatomy The anatomy of the wrist, the carpal tunnel, and the hand will be discusse d. The osteology of the hand and wrist are visualized in Figure 5.19. The carpal tunnel The carpal bones form an upside down arch (as viewed with the wrist in su pination) with the \202 exor retinaculum (= transverse carpal ligament) spanning the arch from the palmar surfaces of scaphoid and trapezium radially to the pisiform, triquetrum, a nd hamate ulnarly. The combination of arch and spanning \200\230roof \200\231 of the \202 exor retinaculum produces a tunnel, the carpal tunnel. Bones The wrist When the wrist is in a neutral position, the wrist and hand are in the same plane as the longitudinal axis of the radius and middle metacarpal. The term \200\230wris t joint \200\231 normally implies the radiocarpal joint, rather than the other articula- ti ons of the carpal bones. The hand The thumb metacarpal articulates with trapezium. The thumb \200\230carpometacarpa l \200\231 joint (CMCJ) and the metacar- pals of the \201 ngers articulate proximally wit h the trapezoid, capitate, and hamate. The thumb has only two phalanges \200\223 proximal and distal \200\223 and, therefore, only one interphalan- geal joint. The \201 ngers hav e a proximal, middle, and distal phalanx and, therefore, both a proximal and distal inter- phalangeal joint. The \201 rst CMCJ lies between trapezium and the base of the \201 rst metacarpal bone. It is a multiplane and very mobile joint allowing thumb extension, abduct ion, adduction, and opposition with the \201 ngers. Flexion/extension at the \201 rst C MCJ is up to 50 of movement and abduction/ adduction is up to 70 . The fourth and \201 fth CMCJs of the