Locomotor system

Introduction

Musculoskeletal symptoms are a major cause of pain and disability, accounting for a quarter of all general practitioner consultations in the United Kingdom (UK), with significant economic consequences. Common musculoskeletal conditions, such as back pain and osteoarthritis, are the dominant causes of chronic pain, disability and work loss in the UK and many other countries, consuming considerable health and social service resources. In addition, inflammatory arthritis and connective tissue disorders may present with musculoskeletal symptoms. As such, it is critical that clinicians are able to assess patients with such symptoms and initiate appropriate management or referral to a specialist centre. Early diagnosis and treatment of inflammatory arthritis, such as rheumatoid arthritis, has been consistently shown to improve patients’ long-term outcome with the early initiation of disease-modifying therapy. The autoimmune rheumatic disorders, although much less common, cause significant morbidity with the potential for end-organ damage which may be fatal if not recognized and treated early.

The objectives of performing a musculoskeletal assessment are to:

• ▪

  Make an accurate diagnosis

• ▪

  Assess the severity and consequences of the condition

• ▪

  Construct a clear management plan

Taking an effective structured history and making a simple, focused examination are likely to be more important than imaging and serology, which on their own may be falsely reassuring. 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

This brief screening examination, which should take 1 to 2 minutes, has been devised for use in routine clinical assessment. This brief global assessment of the gait, arms, legs and spine (GALS) is typically used by both non-specialist and specialist alike ( Box 15.1 ). The routine requires some practise to become proficient, but once achieved, it has been shown to be highly sensitive in detecting significant abnormalities of the musculoskeletal system. It involves inspecting carefully for joint swelling and abnormal posture, as well as assessing the joints for normal movement. Typically, the clinician will then focus on particular areas of interest with more dedicated and targeted examinations.

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 will be described in this chapter.

Screening examination

Arms

Ask the patient to follow instructions as in Table 15.2 (see Figs 15.4–15.9 ).

Table 15.2

Instructions for examining arms

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

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 include all the components of the adult version, with minor additions as follows:

Ask the child to walk on his tiptoes and then on the 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 his arms up 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 incorporation of a brief musculoskeletal examination into the routine examination should lead to a more detailed assessment if any abnormalities are found ( Table 15.4 ).

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. Pain is a common presenting complaint and, as such, the clinician is expected to explore this fully. Using the WILDA ( W ords, I ntensity, L ocation, D uration, A ggravating/alleviating factors) pain assessment approach may be helpful in drawing out key aspects of the patient’s history and clarifying the nature of the complaint (see also Chapter 11 ).

Words

‘I have pain’ is not descriptive enough to inform a clinician about the character of the pain symptoms. Patients may have more than one type of pain and should be encouraged to describe their pain as much as possible. Neuropathic pain can be described as burning, shooting, tingling, radiating, lancinating or numbness. Somatic pain may be described as dull or throbbing and can usually be well localized. Somatic pain is most commonly described in the context of musculoskeletal pain afflicting joints and the spine.

Pain described as squeezing, pressure, cramping, distention, dull, deep and stretching is visceral in origin.

Intensity

It may be useful to use a simple visual analogue scale or ask the patient to rate his pain on a 0 to 10 scale. This may allow for monitoring and assessing progression of the underlying disorder.

Location

An accurate location of pain is often very helpful, although it must be remembered that joint pain may radiate. Patients should be asked, ‘Where is your pain?’ or ‘Do you have pain in more than one area?’

Pain may be referred or radiate from an affected joint ( Box 15.2 ).

Duration

The temporal description of pain is important in understanding the root cause. Pain may be constant, episodic or a combination of both. Is the patient ever pain free? Can he clearly identify the time of onset and is there a pattern of periodicity? For example, an osteoporotic vertebral fracture may be acute and self-limiting, which contrasts with the severe, constant and gnawing pain of a spinal metastatic deposit that prevents sleep.

Aggravating/alleviating factors

Aggravating and alleviating factors are often very helpful when trying to make a diagnosis. Back pain or stiffness that improves with exercise may point to an inflammatory cause, whereas pain that worsens after use is often described in the setting of degenerative arthritis.

Back pain is the most common musculoskeletal complaint; as such, it deserves further consideration. When taking a history of a patient’s back symptoms it is important to identify potential ‘red flags,’ which mandate further imaging or investigations, to exclude a potentially sinister underlying diagnosis. If red flag signs are present, then referral to a specialist for further evaluation is advised and a patient should be advised to rest and to avoid physical activity until then. Importantly, nerve root pain (unilateral sciatica) is not itself a cause for alarm, and conservative treatment should be effective. A list of red flag symptoms associated with back pain can be found in Table 15.5 , with potential associated causes.

Pain may be referred or radiate from an affected joint (see Box 15.2 ). 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. Fibromyalgia falls under an umbrella term—Central Sensitization Syndromes (CSS) and so may present with overlapping symptoms with other conditions such as irritable bowel syndrome, chronic fatigue and temporo-mandibular joint (TMJ) disorders. 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). As with any condition, the good clinician will also draw out the consequences of the disorder in terms of the impact on the patient’s day-to-day function and quality of life. The effect on relationships, work and social activities will help the clinician to gauge the severity of the problem and possibly elicit issues of stress and psychosocial pressure.

Non-inflammatory joint disease

Pain of a non-inflammatory origin is more directly related to function and use and usually is relieved with rest. This is in contrast to inflammatory joint pain, which is often present at rest as well as in use, and tends to vary from day to day and from week to week. Stiffness, particularly in the morning or after a period of inactivity, is often a feature in the history of inflammatory joint pain and typically lasts no more than 30 minutes. However, in severe cases the duration may be much longer. Subjective joint swelling may be described and indeed patients with knee osteoarthritis may present with a significant effusion. Joint swelling in this context tends to be more intermittent than the persistent joint swelling and warmth seen in inflammatory conditions.

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 caused by 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

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). The pattern of joint involvement often aids in making a list of likely differential diagnoses. For example, rheumatoid arthritis is typically a symmetrical inflammatory arthritis of the small and large joints, often presenting with metacarpophalangeal (MCP), wrist and metatarsophalangeal (MTP) joint involvement. There are only a few causes of an exactly symmetrical arthropathy ( Box 15.3 ). An asymmetrical inflammatory arthritis presentation is often seen in spondyloarthropathies, such as reactive arthritis. An inflammatory monoarthritis presentation must arouse a suspicion of infection alongside other potential conditions, such as gout or psoriatic arthritis. A history of fever or sweating may be helpful and, if possible, synovial fluid should be aspirated from the joint to look for an infection. Monoarthritis will certainly raise the suspicion of an infected joint, but may also be seen in the context of crystal arthropathies and spondyloarthropathies, particularly psoriatic arthritis in which the knee or elbow is often singularly affected. Other conditions have such a classic history that it is almost diagnostic. For example, acute inflammation in the first metatarsophalangeal joint (hallux) suggests a diagnosis of gout ( Box 15.4 ). The pain and stiffness of the shoulder and hip girdles in polymyalgia rheumatica is also typical ( Box 15.5 ). The pattern of the spondyloarthropathies can also be diagnostic with inflammatory sacroiliac and spinal pain and stiffness, lower limb arthritis, Achilles tendinitis and plantar fasciitis.

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. Crystal arthropathies tend to affect the same joints recurrently with the first MTP joint most common followed by ankle and knee.

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. Recurrent painful swelling of the same joint may be indicative of a crystal arthropathy, such as gout or calcium pyrophosphate disease.

Flitting or migratory joint pains

The term ‘flitting’ or migratory joint pains 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 15.6 ). 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. It is critical that a full systems enquiry and physical examination are performed when inflammatory connective tissue 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. 15.16 ). 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. 15.17 ). 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 are 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.

Soft tissue symptoms

Soft tissue problems, which are common, 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 in runners, shoulder rotator cuff tendinopathy in swimmers or throwers). It is important to define the exact site of the symptoms and the factors that either make them worse or induce relief. The mechanism of injury is also important and can help guide a focused examination. The localization of symptoms to specific soft tissue structures can be confirmed by careful examination ( Box 15.7 ). The possible structures involved are joint, tendon, ligament, bursa and muscle. Local palpation may be enough to locate bursitis or enthesitis (inflammation at the attachment of a ligament or tendon to bone) accurately. A careful examination may reveal that the complaint and symptoms do not arise from joint pathology, but from soft tissue tendon or ligament structure next to the joint. This often changes the differential diagnosis. Movement of the joint region often elicits pain or discomfort in a particular direction, which can direct the clinician to the affected structure. Subacromial bursitis typically produces pain when the shoulder is abducted to 80° and resolves at 130° to 140°, described as a painful arc, whereas anterior and posterior movements are maintained.