Disorders of the inert structures

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Disorders of the inert structures

The capsular pattern at the elbow is characterized by limitation of flexion and extension (Fig. 18.1), flexion usually being more limited than extension, although equal limitation of both movements does occur. Rotations remain full and painless except in advanced arthritis, in which they can be painful at the end of the range.

Fig 18.1 Capsular pattern. F, Flexion; E, extension; P, pronation; S, supination.

The following conditions are the most common.

Warning

Traumatic arthritis in combination with pain on pro/supination and/or painful weakness during isometric testing is suggestive of an intra-articular fracture.

Treatment

Traumatic arthritis recovers spontaneously but may take several months. Treatment with massage and/or exercises only irritates the joint and is therefore contraindicated.

The treatment of choice consists of two intra-articular injections of 20 mg of triamcinolone acetonide. The injection is given when the patient is first seen. The arm is kept in a sling for a couple of days. A week later a second injection is given and the joint should have recovered in 2 weeks’ time.

Technique: intra-articular injection

The patient lies prone on a couch with a small pillow under the elbow. The arm is held by the side with the forearm fully supinated. In this position the joint lines between humerus and radius and the radial side of the olecranon are both easily felt. A 2 mL syringe is filled with triamcinolone acetonide 10 mg/mL and a 2 cm thin needle is fitted. The needle is inserted at the joint line and aimed slightly obliquely under the olecranon (Fig. 18.2).

Fig 18.2 Intra-articular injection.

Rest in flexion

Another valuable treatment is rest in flexion. It can be used in those patients who cannot tolerate an injection. As soon as the patient is seen, the elbow is immobilized in as much flexion as possible by means of a collar-and-cuff bandage. Every day the elbow is flexed more, until full movement can be achieved; thereafter it is held in this position for 2 weeks. The elbow is then rested in slightly less flexion. Three days later the joint is re-examined and, if the range of flexion is still full, the forearm is allowed to extend a little further. Some 6 weeks later, the patient reaches the stage in which the arm can be worn in a sling. After 2 or 3 months, movements of the elbow should be full and painless. Another static progressive splinting method by means of a turnbuckle splint has proved to be useful in the treatment of long-standing post-traumatic stiffness of the elbow.10,11

Arthrosis

This condition may come on spontaneously in late middle age ¹² and is often bilateral. It may also occur as the result of a fracture or dislocation.¹³ Intra-articular distal humerus fractures, for example, are most often associated with the development of degenerative joint disease over time.¹⁴ Repeated minor injuries^15,16 or a loose body in the joint may also account for early arthritic changes.¹⁷

The patient, most often a male,¹⁸ complains that, after he uses his elbow excessively, the joint aches slightly. He may also find the inability to fully straighten the arm inconvenient.

On examination a slight capsular pattern is found with a hard end-feel on flexion. The end-feel on extension is also hard but this is because of capsular contracture and is not the normal bone-to-bone end-feel. There may be coarse crepitus. The radiograph may show the arthrotic changes, although a positive radiograph can also be compatible with full range and painless function at the joint.

The differential diagnosis is neuropathic arthropathy,¹⁹ which presents with gross painless limitation of movement in the capsular pattern.

An arthrotic joint does not of itself give rise to the sort of symptoms that warrant treatment. What may happen is that, on top of the arthrosis, a traumatic arthritis develops as the result of overuse. This can be treated as outlined earlier. Loose bodies are quite common and may also complicate the arthrosis (see below).

Monoarticular steroid-sensitive arthritis

A seronegative arthritis may occur, confined to one elbow joint. The pain is spontaneous in onset and the elbow very soon starts to swell.

A marked capsular pattern is found and, in due course, some limitation of pronation and supination may occur. In the acute and subacute stages, the end-feel is of muscle spasm. The joint is warm to the touch and synovial thickening can be found on palpation over the head of the radius laterally. In advanced cases muscle atrophy may also be seen. If, after some years, crepitus is present, it is of the silky type.

On radiography, decalcification and later erosion of cartilage may be visible.

Treatment with intra-articular triamcinolone suspension (see earlier) is symptomatically very effective in monoarticular steroid-sensitive arthritis; it stops the pain but produces hardly any change in the amplitude of movements. The patient may be pain-free for many months, whereupon the injection can be repeated without fear of steroid arthropathy because the elbow is not a weight-bearing joint.

Crystal synovitis

Gout (uric acid crystals) and pseudogout (calcium pyrophosphate crystals) seldom affect the elbow joint during a first attack (in only 4.5% of gout cases)²⁰ but more frequently cause acute olecranon bursitis.²¹ As disease develops, polyarticular attacks may occur, in which case the elbow joint is affected in 30% of cases.

The sudden unprovoked onset and the shiny red appearance of the joint are characteristic.

The following diagnostic criteria may be useful in gout. When uric acid crystals are found in the synovial fluid during microscopic, chemical or histological examination, or tophi are seen on the ears, the diagnosis is certain, as it also is when two of the following four criteria are present: history of a typical attack of gout at the big toe; history of two typical attacks of gout at another joint; clinical picture of tophus; remission within 48 hours of the acute attack after the administration of colchicine or phenylbutazone.²²

Haemarthrosis

Haemarthrosis may occur after injury to the joint, especially an intra-articular fracture or a direct contusion of the joint capsule, or, less commonly, in haemophilic patients. Bleeding into the joint leads to gross swelling and a marked capsular pattern.²³ Aspiration must be carried out immediately to avoid destruction of cartilage.

Rheumatoid-type arthritis

Polyarticular rheumatoid arthritis may affect the elbow joint. Apart from the gross swelling, rapidly ensuing limitation of extension is typical.²⁴ The elbow is also one of the sites of predilection, together with the knee and shoulder, for chondromatosis. Pigmented villonodular synovitis occurs most commonly at the knee, followed by elbow and ankle.²⁵

In these and the other rheumatoid-type arthritides, systemic medication is required, and sometimes even a surgical approach. Good results have been reported with total elbow arthroplasty.26–33

Septic arthritis

A bacterial infection of the elbow joint is always very serious. It may not only lead to total destruction of the joint but may also be life-threatening.³⁴

It can be the result of an open injury to the joint (e.g. open fracture), penetration of a foreign body (e.g. rose or bramble thorns during gardening or fruit picking) or direct inoculation of a bacterium during intra-articular injection, especially injection of a steroid suspension. It can also be caused by haematogenous dissemination from focal infections: dental abscess, cystitis, urethritis, skin infections. These causes are very dependent on the patient’s resistance to infections: patients with diabetes, renal failure or a deficient immune system (e.g. rheumatoid arthritis) are more likely to suffer from haematogenous dissemination followed by a septic arthritis.35–37

Symptoms start suddenly and are easily recognized. The joint shows the signs of a hyperacute inflammation: a great deal of pain, gross swelling, redness, warmth and gross limitation of movement in the capsular pattern. There are also general symptoms, such as high fever, a toxic appearance, pallor, loss of appetite and rigors.

Treatment consists of systemic antibiotic therapy and daily local aspiration ³⁸ and drainage by arthroscopy.³⁹

Tuberculous arthritis

Elbow tuberculosis is a rare disease which accounts for 1–3% of all cases of osteoarticular tuberculosis.⁴⁰ The diagnosis is very difficult to make because of the insidious onset with mild and non-specific local or systemic symptoms. The radiological findings are also non-specific in the early stage. Tuberculosis of the elbow is therefore easily misdiagnosed as degenerative arthritis or rheumatoid arthritis.⁴¹ Several months after the onset of symptoms, there is pain at night, and examination reveals a gross capsular pattern and a spastic end-feel. The radiograph reveals periarticular osteopenia, bone erosion and joint space narrowing.⁴² On haematological testing, the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are elevated.⁴³

The gold standard for the diagnosis of tuberculous arthritis is identification of Mycobacterium tuberculosis either directly or after culture of the synovial fluid.⁴⁴

Non-capsular pattern

Limitation of flexion or extension in isolation

Loose body in the joint

A loose body in the elbow joint is not uncommon and may hinder normal movements. It prevents the joint either from moving into full flexion, leaving extension free (Fig. 18.3), or from moving into full extension, leaving flexion free (Fig. 18.4). It then changes the hard end-feel of extension into a rather soft one.

Fig 18.3 Non-capsular pattern with limitation of flexion.

Fig 18.4 Non-capsular pattern with limitation of extension.

Three different clinical pictures can be considered, depending on the age group in which they appear: adolescents, adults or the elderly.

In adolescence

A loose body is a common cause of elbow trouble in adolescents and is the only non-traumatic cause of arthrosis encountered in a young person. The condition does not occur before the age of 14 and usually results from osteochondritis dissecans, mostly on the humeral capitellum,45,46 or an intra-articular chip fracture, conditions that may lead to exfoliation of one or more fragments of bone covered by articular cartilage.⁴⁷ Osteochondritis dissecans is not uncommon in young female gymnasts with hyperextension and valgus of the elbow.^48–50 It also affects young pitchers or athletes involved in high-demand, repetitive overhead activities.^51,52

The history is quite typical: the young person states that the elbow joint locks suddenly, usually in flexion. It is impossible to straighten the elbow to full range because of the pain. In a few days, the condition gradually subsides. One or more of these attacks may have occurred in the past, with pain-free episodes in between.

Clinical examination during an attack shows a non-capsular pattern: limitation of passive extension with a soft end-feel. During a pain-free period, examination is negative; the diagnosis is suggested by the typical history.

Diagnosis can be confirmed by anteroposterior radiography performed with the elbow in 45° of flexion,⁵³ because in this position the X-ray beam is almost parallel to the gap between the fragment and the underlying capitellar bone. Recently, magnetic resonance imaging (MRI) has been suggested for assessing osteochondritis dissecans,⁵⁴ and sonography also seems to be effective.^55,56

If the patient is seen during an attack, manipulative reduction can be carried out. However, arthroscopic 57,58 or surgical⁵⁹ removal of the loose piece(s) should always be advised for the following reasons: as the loose body has an osseous nucleus and still lies within its nutrient synovial fluid, it may grow and the condition may worsen at each attack. It is also important to realize that the loose body is considerably larger than it may seem on a radiograph, as it is covered with radiotranslucent cartilage. If surgery is not performed, loose bodies may finally cause gross arthrosis.⁶⁰ Limitation of extension may considerably hinder activities and should therefore be prevented.