Locomotor system

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13 Locomotor system

David P. D’Cruz

Introduction

Musculoskeletal symptoms are a major cause of pain and disability, accounting for a quarter of all GP consultations with significant economic consequences. In later life, musculoskeletal diseases are the single most important cause of disability, requiring considerable health and social service resources. Inflammatory arthritis can lead to irreversible joint damage. Early referral to specialist care to consider disease-modifying therapy is critical in preventing disability. The autoimmune rheumatic disorders, although much less common, cause significant morbidity and may be fatal if not recognized and treated early.

The objectives of performing a musculoskeletal assessment are:

to make an accurate diagnosis

to assess the severity and consequences of the condition

to construct a clear management plan.

The clinical methods involved are those practised at the bedside: a careful, structured history and a thorough examination. Although modern musculoskeletal medicine uses complex imaging and immunological investigations, in most patients with locomotor disorders, diagnosis can be achieved at the bedside without complex investigations.

General assessment: the ‘GALS’ locomotor screen

A full assessment of the musculoskeletal system can be time-consuming. The gait, arms, legs and spine (GALS) screen is a rapid and sensitive screening method for detecting musculoskeletal disorders that can easily be incorporated into the general physical examination.

Screening history

If answers to the following four questions are negative, a musculoskeletal disorder is unlikely:

1 Do you have any pain or stiffness in your muscles, joints or back?

2 Have you ever had gout or arthritis?

3 Can you dress yourself completely without difficulty?

4 Can you walk up and down stairs without difficulty?

Positive answers imply the need for a more detailed assessment, as described in this chapter.

Screening examination

Instruction	Normal outcome
‘Raise arms out sideways and up above your head’	180° elevation through abduction without wincing
‘Touch the middle of your back’	Touches above T10 with both hands
‘Straighten your elbows right out’	Elbows extend to 180° or slightly beyond (females) symmetrically
‘Place hands together as if to pray, with elbows right out’	90° wrist extension and straight fingers
‘The same with hands back to back’	90° wrist flexion
‘Place both hands out in front, palms down, fingers out straight’	No wrist/finger swelling/deformity, 90° pronation
Metacarpophalangeal (MCP) cross-compression	No tenderness
‘Turn hands over’	90° supination No palmar swellings, wasting or erythema
‘Make a fist and hide your nails’	Can hide fingernails
‘Pinch index, middle finger and thumb together’	Can do
Also look for swelling between the heads of the metacarpals and gently squeeze across the MCP joints to elicit tenderness	Tenderness may be elicited

Figure 13.4 ‘Put your hands behind your head, elbows back.’ Observe for pain or restricted movement.

Figure 13.5 ‘Put your hands out palms down and then turn your hands over.’

Figure 13.6 ‘Make a fist with both hands.’

Figure 13.7 ‘Place your hands together as if to pray, with elbows right out.’

Figure 13.8 ‘Do the same with your hands back to back.’

Figure 13.9 Look for swelling between the heads of the metacarpals and gently squeeze across the metacarpophalangel joints to elicit tenderness.

Legs

With the patient still standing:

Examine the lower limbs for swelling, deformities or limb shortening. Normal: no knee deformity, anterior or popliteal swelling, no muscle-wasting, no hindfoot swelling or deformity.

Then, with the patient lying on a couch, continue the examination following the instructions in Table 13.2 (see Figs 13.10–13.14).

Table 13.2 Instructions for examining legs

Instruction	Normal outcome
Flex hip and knee, holding knee	No bony crepitus, 140° knee flexion
Passively rotate hips	90° total pain-free rotation
Bulge test/patellar tap	No detectable fluid
Palpate popliteal fossa	No swelling
Inspect feet	No deformity, callosities or forefoot widening (daylight sign)
Test subtalar and ankle movement	Pain-free calcaneal mobility at subtalar joint, dorsiflexion beyond plantigrade and 30° plantarflexion

Figure 13.10 Gently flex the hips and knees, feeling for crepitus at the knee during movement, and look for pain and restriction of movement. Look for knee effusion.

Figure 13.11 (A) Bulge test and (B) Patellar tap.

Figure 13.12 Palpate popliteal fossa.

Figure 13.13 Test subtalar and ankle movement.

Figure 13.14 Squeeze across metacarpophalangeal (MTP) joints and inspect the soles of the feet.

This examination can be conducted in approximately 2 minutes, especially if the clinician performs the movements and asks the patient to follow them. The precise order of the examination is not important and clinicians usually develop their own pattern of examination.

Children

Children should have their height and weight measured and plotted on centile charts to assess growth. When examining children, the assessment of the musculoskeletal system should be done with a parent present and includes all the components of the adult version with minor additions:

Gait

Ask the child to walk on his tip toes and then on their heels.

From the front, ask the child to put his hands together (as if praying) and also put his hands back to back and then have him reach up his arms towards the sky.

Additionally, when assessing the spine, ask the child to open his mouth and insert three of his own fingers into it.

Symmetry is key and any asymmetry should be assessed for pathology. It is normal for toddlers to be ‘bow-legged’, ‘knock-kneed’ and ‘flat-footed’. Various foot and toe appearances are also normal including in-toeing, out-toeing and ‘curly’ toes. These appearances usually resolve as the child grows.

Recording the results

The findings of this locomotor screen should be noted routinely in the medical record. For example, a normal screen might be recorded as follows:

The incorporation of this brief musculoskeletal examination into the routine examination should lead to a more detailed assessment if any abnormalities are found.

Specific locomotor history

General demographic details such as age, sex and occupation should be recorded. Start the full musculoskeletal history with the presenting complaint and ask the patient to describe the sequence of symptoms, related features and events since the onset. Characteristic diagnostic points may emerge. For example, the pain from an osteoporotic vertebral fracture which is acute and self-limiting is very different from the severe, constant and gnawing pain of a spinal metastatic deposit that prevents sleep and may be associated with weight loss – so-called ‘red flag’ symptoms. Similarly, the acute, severe, usually continuous throbbing pain of joint infection is different from the intermittent pain of osteoarthritis.

Pain may be referred or radiate from an affected joint:

Neck pain may radiate through the occiput to the vertex or to the shoulder and down the arm, with paraesthesiae if there is nerve-root impingement.

Shoulder joint pain may radiate to the elbow and below.

Thoracic spine nerve root pain may radiate around the chest and mimic cardiac pain.

Lumbar spinal root pain may radiate through the buttock and leg to the knee and below, with paraesthesiae in the foot with a large disc prolapse – this is called ‘sciatica’.

Hip-joint pain may radiate to the knee and below.

Knee pain may radiate above and below the joint.

With these pain patterns in mind, the joints above and below the apparently affected area should be examined.

Chronic pain syndromes

Chronic pain syndromes need to be distinguished from other rheumatic disorders and a careful history is essential. A number of pain descriptors used by patients can indicate the influence of non-organic amplifying factors. For example, at least in the English language, words like ‘searing’, ‘torturing’ and ‘terrifying’ can be used by patients with chronic widespread pain and fibromyalgia. These debilitating disorders are often accompanied by poor sleep patterns, severe fatigue and depressed mood. The difficulty of cultural, religious and linguistic influences in interpreting pain should not be underestimated.

Joint disease

A combination of pain and stiffness, leading to loss of function, is a classic feature of joint disease. Usually one component predominates, as with stiffness in inflammation, and pain in mechanical joint problems. Therefore, specific questions will establish whether symptoms are non-inflammatory (e.g. osteoarthritis) or inflammatory (e.g. rheumatoid arthritis). The impact of musculoskeletal disease on the patient’s functional ability and quality of life should be assessed by simple open questions. For example, difficulty with activities of daily living and work capability should be documented.

Non-inflammatory joint disease

In degenerative joint disease, there may be a feeling of stiffness in the affected joint after resting which rapidly disappears with activity. This inactivity stiffness typically lasts only a few minutes and nearly always less than 30 minutes. Pain in the affected joint on activity, usually improving with rest, is typical. A clicking sensation in a joint, particularly in the knee, is a common complaint but is usually a normal phenomenon and distinct from crepitus. Locking of a joint may occur. In the knee, this means that the knee becomes locked in such a way that it will not extend fully, although it may flex. In other joints, locking is less well defined and simply means that at some point through its range of motion the joint becomes stuck, usually associated with pain and often followed by swelling. Locking is due to material within the joint interfering with movement at the articular surfaces. In the knee, this is usually part of one of the menisci, or a cartilaginous loose body.

Inflammatory joint disease

Early morning stiffness

Early morning joint stiffness that persists for more than 30 minutes is an important symptom of active inflammatory joint disease. Ask about redness (rubor), warmth (calor), tenderness/pain (dolor) and swelling (tumour), the classic features of inflammation.

If the history suggests inflammation, and if only one joint is involved (monoarticular disease), always consider infection. Ask if there has been any fever or sweating, and if the joint is inflamed with signs of an effusion, fluid should be aspirated to look for infection.

Distribution of joint disease

The pattern of joint involvement is important. Common patterns are: monoarticular (single joint), pauciarticular (up to four joints), polyarticular (many joints) and axial (spinal involvement). Symmetry is useful in distinguishing various inflammatory arthropathies. There are only a few causes of an exactly symmetrical arthropathy (Box 13.1). Other conditions have such a classic history that this is diagnostic. For example, acute inflammation in the first metatarsophalangeal joint (hallux) suggests a diagnosis of gout (Box 13.2). The pain and stiffness of the shoulder and hip girdles in polymyalgia rheumatica is also typical (Box 13.3). The pattern of the spondyloarthropathies can also be diagnostic with inflammatory sacroiliac and spinal pain and stiffness, lower limb arthritis, Achilles tendonitis and plantar fasciitis.

Box 13.2 Acute gout

A 48-year-old publican presented with sudden severe pain and swelling of his left big toe. He was unable to weightbear or wear a shoe, and said that he could not even bear the weight of his bed clothes on the toe at night. His past history included hypertension, for which he was taking a thiazide diuretic, and his alcohol intake was excessive. On examination, he had tophi on the ears (Fig. 13.15) and the left first metatarsophalangeal joint was red, hot, swollen and exquisitely painful to touch. Aspiration of the joint revealed urate crystals.

Figure 13.15 Gouty tophus on the ear. Other sites include the elbows, fingers and toes.

Box 13.3 Polymyalgia rheumatica

A 74-year-old woman presented with a 2-month history of pain around her hips and shoulders. The key points in the history were that these regions were extremely stiff for 4 hours each morning and inability to turn over in bed, and that there was no joint swelling. Clinically there was pain and some limitation of movement at the shoulders and hips, but no synovitis. Her erythrocyte sedimentation rate was 96 mm/1st hour, and she had a dramatic response within 2 days to a moderate dose of prednisolone.

Recurrent attacks of joint pain

Ask if the same joint is always involved. If not, define the patterns of involvement, the severity and duration of the episodes and any associated clinical symptoms.

Episodic joint pain

Ask if attacks of joint pain are acute and associated with redness around the joint, with the attacks lasting about 48 hours (occasionally up to 1 week) and migrating to other joints. This is typical of palindromic rheumatism, which may progress to rheumatoid arthritis.

Flitting or migratory joint pains

This term is used to describe inflammation beginning in one joint and then involving others, usually one at a time for about 3 days each. Gonococcal arthritis should be considered; this is characterized by typical fleeting skin lesions and urethritis, in addition to joint pain. In rheumatic fever, there is associated cardiac involvement, and erythema marginatum and subcutaneous nodules may occur.

The other features in the history that should be brought out are best considered under the differential diagnosis of polyarthritis (Box 13.4). Many arthropathies may have a monoarticular presentation.

Inflammatory connective tissue diseases

The autoimmune rheumatic disorders, such as systemic lupus erythematosus (SLE), Sjögren’s syndrome, inflammatory myopathies, systemic sclerosis and the vasculitides, are multisystem disorders. A careful systems enquiry is essential if this diagnosis is suspected. Associated features of these conditions include systemic symptoms such as weight loss, malaise or fevers, and rash, especially if the latter is photosensitive or vasculitic (Fig. 13.16). Alopecia, oral and genital ulceration, Raynaud’s phenomenon and symptoms of neurological, cardiac, pulmonary and gastrointestinal involvement may occur. Dry eyes and dry mouth (sicca symptoms) are common and can be documented with Schirmer’s test (Fig. 13.17). Renal disease is a serious complication of the autoimmune rheumatic disorders, especially in SLE and the systemic vasculitides. Clinical assessment should always include measuring blood pressure and dip-testing the urine for blood and protein, and microscopy of the urine sediment for casts or dysmorphic red cells if this is positive. Ear, nose and throat involvement with sinusitis, facial pain and deafness is common in Wegener’s granulomatosis and Churg–Strauss syndrome. A history of arterial and venous thromboses or miscarriages, especially in the context of livedo reticularis, should raise the suspicion of the antiphospholipid syndrome.

Figure 13.16 Extensive rash in sun-exposed areas in a woman with systemic lupus erythematosus and anti-Ro antibodies.

Figure 13.17 Schirmer’s test – a sterile strip of filter paper is hooked over the lower eyelid. Less than 5 mm of wetness after 5 minutes is abnormal and is associated with autoimmune rheumatic disease.

Soft tissue symptoms

Soft tissue problems are common and usually consist of pain, a dull ache, tenderness or swelling. In the elderly these symptoms often appear spontaneously, but in younger people there is usually a history of injury or overuse, through either occupation (e.g. tenosynovitis of the long flexor tendons of the hand) or sport (e.g. Achilles tendinitis). It is important to define the exact site of the symptoms, and the factors that either make them worse or induce relief. The localization of symptoms to specific soft tissue structures can be confirmed by careful examination (Box 13.5). The possible soft tissues involved are joint, tendon, ligament, bursa and muscle.

The bones

Bone pain is characteristically deep-seated and localized, but referred pain may confuse the clinical picture. In the case of fractures, unless pathological, there will almost always be a history of injury. In athletes, however, a fracture may be due to chronic overuse, as in stress fractures of the tibia or metatarsals in runners. The spontaneous onset of pain may suggest Paget’s disease (with bony enlargement, e.g. skull or tibia) or metastatic deposits. Infection must also be considered, particularly in younger patients or in immunodeficiency states. Consider also congenital or familial disorders as predisposing factors, for example multiple osteochondromata or brittle bone disease (osteogenesis imperfecta).

Examination: general principles

Observe the patient entering the room (Box 13.6). Abnormalities of gait and posture may provide clues that can be pursued in history taking. Observation of any difficulty in undressing and getting onto the examination couch will further help in assessment. The patient must always be asked to stand and walk, even when it is obvious that this may be difficult. Note how much help the patient requires from others or from sticks, crutches, etc. The musculoskeletal system includes the muscles, bones, joints and soft tissue structures such as tendons and ligaments. Remember that although muscle-wasting may be due to primary muscle disease (e.g. polymyositis), it is more commonly secondary to disuse, perhaps because of a painful joint, or to neuropathy due to nerve-root compression or peripheral neuropathy (Fig. 13.18). Examination of the muscles is discussed further in Chapter 14.

Figure 13.18 Thenar wasting due to carpal tunnel syndrome. This is often associated with osteoarthritis: note nodal change on the terminal interphalangeal joints of the index fingers.

The bones

The examination of the bones should always be directed by information obtained from the history.

Inspection

Look for any alterations in shape or outline and measure any shortening. In Paget’s disease (osteitis deformans), bowing of the long bones, particularly the tibia (Fig. 13.19) and femur, is associated with bony enlargement and, usually, increased local temperature. The skull is also commonly involved, but this may not be apparent until the disease is advanced. Early involvement of the skull bones can be detected on X-rays (Fig. 13.20). Alterations in the shape of bones also occur in rickets as a result of epiphyseal enlargement. Deformity of the chest in rickets is due to osteochondral enlargement (rickety rosary).

Figure 13.19 Paget’s disease of the right tibia. Note tibial bowing and bony enlargement (A) and bony enlargement sclerosis with some patchy porosis in the X-ray of the upper tibia (B).

Figure 13.20 Paget’s disease, causing deformity of the skull (A). Note the thickened skull vault with remodelled bone (B).

Localized swellings of long bones may be caused by infections, cysts or tumours. Spontaneous fractures may occasionally be the presenting symptom in the diagnosis of secondary carcinoma, multiple myeloma, generalized osteitis fibrosa cystica (hyperparathyroidism) or osteogenesis imperfecta.

Palpation

On palpation, bone tenderness occurs in local lesions when there is destruction, elevation or irritation of the periosteum, as in generalized osteitis fibrosa cystica, myelomatosis, bone infections, occasionally in carcinomatosis of bones and, rarely, in leukaemia. Injury is the commonest cause.

Fractures

Fractures are common and may involve any bone. They are painful, distressing for the patient and expensive for the community (Box 13.7). Fractures in healthy bones commonly involve the long bones and are usually due to trauma. Fractures of the wrists, hips and vertebrae are more frequently complications of bone disease, such as osteoporosis. Multiple rib fractures, caused by falls, may be found in heavy alcohol users, but may only be seen as healed lesions on chest X-ray. Fractures occur without apparent trauma when a bone is weakened by disease, especially with metastatic malignant deposits in bone (pathological fractures). Traumatic fractures invariably present with local pain, swelling and loss of function, but pathological fractures may be relatively silent. The history will reveal the circumstances of the trauma, whether accidental or due to physical abuse, and should be carefully documented, if necessary with diagrams or digital photographs of the clinical findings. If clinical photographs are taken, prior written consent is needed.