CHAPTER 1 MUSCULOSKELETAL SIGNS 1 Anterior drawer test Anterior drawer test Mechanism/s The ACL arises from the anterior aspect of the tibial plateau and inserts into the medial aspect of the lateral femoral condyle. It limits anterior movement of the tibia upon the femur. Loss of continuity of the ACL permits 90º inappropriate anterior movement of the tibia and thus knee joint instability. Sign value A literature review of six studies reported variable sensitivity of 27–88%, specificity of 91–99%, FIGURE 1.1 positive LR of 11.5 and negative LR of Anterior drawer test for anterior cruciate 2 ligament injury 0.5. A literature review by Solomon DH et al. of nine studies reported a sensitivity of 9–93% and specificity of 23–100%.1 Description While a positive anterior drawer With the patient lying supine, the knee sign (+LR 11.5)2 has been suggested to at 90° flexion and the foot immobilised be strong evidence of ACL injury, the by the examiner, the proximal third results are not uniform, with another of the tibia is pulled towards the study reporting a +LR 2.0 (sensitivity examiner. In a positive test, there is 83%, specificity 57%, –LR 0.3).3 A anterior (forward) movement of the negative anterior drawer sign cannot tibia without an abrupt stop.1 reliably exclude ACL injury (sensitivity Condition/s 27–88%; –LR 0.5).2 When strong clinical suspicion persists, further associated with diagnostic steps are necessary (e.g. • Anterior cruciate ligament (ACL) interval re-examination, MRI, injury arthroscopy). CLINICAL PEARL 2 Apley’s grind test Apley’s grind test 1 is increased rotation relative to the unaffected side, this is suggestive of a ligamentous lesion. If rotation plus compression is more painful or there is decreased rotation relative to the unaffected side, this is suggestive of meniscal injury.4 Condition/s associated with • Meniscal injury Mechanism/s FIGURE 1.2 Direct mechanical force upon the Apley’s grind test injured meniscus elicits tenderness. Sign value A review by Hegedus EJ et al. reported Description a pooled sensitivity of 60.7% and With the patient lying prone and the specificity of 70.2% with an odds ratio knee at 90° flexion, the lower leg is of 3.4.5 Significant heterogeneity in passively internally and externally the data limits its accuracy. Overall, rotated while axial pressure is applied Apley’s grind test has limited diagnostic to the lower leg. The test is considered utility, limited supporting data and, positive if tenderness is elicited. in the acute setting, the manoeuvre The process can also be combined produces severe pain.6 with or without distraction. If rotation McMurray’s grind test has more plus distraction is more painful or there robust supporting data. 3 Apley’s scratch test Apley’s scratch test Condition/s associated with Common • Rotator cuff muscle injury • Labral tear • Anterior shoulder dislocation • Bicipital tendonitis • Adhesive capsulitis (frozen shoulder) • Acromioclavicular joint injury Mechanism/s The shoulder joint is a complex structure. Its components include the humeral head, glenoid fossa, acromion, clavicle, scapula and surrounding soft FIGURE 1.3 tissue structures. Under normal One of three manoeuvres of Apley’s circumstances the shoulder joint is scratch test capable of a vast range of movement. Based on Woodward T, Best TM. The painful Apley’s scratch test assesses shoulder: part 1, clinical evaluation. Am Fam Phys 2000; 61(10): 3079–3088. glenohumeral abduction, adduction, flexion, extension, internal rotation and external rotation. Tenderness or limited range of movement suggests injury to Description one or more components of the Apley’s scratch test is a general range shoulder joint. of movement assessment of the shoulder joint (i.e. glenohumeral, Sign value acromioclavicular, sternoclavicular and Apley’s scratch test is a useful scapulothoracic joints). The patient is component of the general shoulder instructed to touch the unaffected exam but has limited utility for a shoulder anteriorly and posteriorly specific diagnosis. The position of the (behind their head), and touch the shoulder at which tenderness or limited inferior scapula posteriorly (behind range of movement occurs should be their back). Tenderness and/or limited noted. In the patient with an abnormal range of movement while performing Apley’s scratch test, further diagnostic these movements is considered an manoeuvres should be performed to abnormal test.7 narrow the differential diagnosis. 4 Apparent leg length inequality (functional leg length) Apparent leg length 1 inequality (functional leg length) ABC FIGURE 1.4 Measurement of leg lengths A The apparent leg length is the distance from the umbilicus to the medial malleolus; B pelvic rotation causing an apparent leg length discrepancy; C the true leg length is the distance from the anterior superior iliac spine to the medial malleolus. Based on Firestein GS, Budd RC, Harris ED et al., Kelley’s Textbook of Rheumatology, 8th edn, Philadelphia: WB Saunders, 2008: Fig 42-24. Description Ligamentous laxity A disparity between the relative The ligaments on one side (e.g. in the distance from the umbilicus to the hip joint) may be more flexible or medial malleolus of each leg.8 By longer than their counterparts, making definition it implies asymmetry of the the femur sit lower in the joint capsule. lower extremities in the absence of a Joint contracture bony abnormality. (See ‘True leg A joint contracture impairs full range length inequality’ in this chapter.) of movement. If the knee joint is contracted in a flexed position, the Condition/s length of the affected side will be less associated with than the opposite leg during maximal • Altered foot mechanics attempted extension. • Adaptive shortening of soft tissues Altered foot mechanics • Joint contractures Excessive pronation of the foot eventuates in and/or may be • Ligamentous laxity accompanied by a decreased arch • Axial malalignments height compared to the ‘normal’ foot, resulting in a functionally shorter Mechanism/s limb.8 An apparent or functional leg length inequality may occur at any point from the pelvis to the foot.8 5 Apparent leg length inequality (functional leg length) Sign value significant effect is controversial.8 The test should be interpreted in relation The distance (anywhere from to the patient’s history and full gait 3–22 mm) at which apparent leg length assessment. inequality results in a clinically 6 Apprehension test Apprehension test 1 • Rotator cuff muscle injury • Glenoid labrum injury • Glenoid defect (e.g. Bankart’s fracture) • Humeral head defect (e.g. Hill– Sachs fracture) Less common – atraumatic • Connective tissue disorder: Ehlers–Danlos syndrome, Marfan’s syndrome FIGURE 1.5 • Congenital absence of glenoid Apprehension test The arm is abducted and placed in an Mechanism/s externally rotated position. Note the right Glenohumeral joint instability is caused arm of the examiner is providing anterior traction on the humerus, pulling the by dysfunction of the bony and/or soft posterior part of the humeral head forward. tissue structures that maintain joint The same test can be done from the back, stability: glenoid, humeral head, joint with the patient sitting up and the examiner capsule, capsuloligamentous or pushing forward on the posterior head of glenohumeral ligaments, labrum, and the humerus. rotator cuff muscles. The shoulder joint is susceptible to instability due to its inherent mobility and complex soft Description tissue structures responsible for stability. The apprehension test is an assessment In the apprehension test, the joint is of glenohumeral joint instability. With placed into a position vulnerable to the patient sitting or lying supine, the instability. It is the typical position shoulder is placed into 90° abduction, precipitating traumatic anterior 90° external rotation and 90° elbow shoulder dislocation. For this reason, a flexion. The examiner applies pressure significant number of healthy patients to the posterior aspect of the proximal will experience apprehension during humerus and attempts to move the this manoeuvre. humeral head anteriorly (see Figure 1.5). The test is positive if the Sign value patient experiences apprehension due to T’Jonck L et al. reported a sensitivity impending subluxation or dislocation of 88.0%, specificity of 50%, positive of the glenohumeral joint.9 likelihood ratio of 1.8 and negative likelihood ratio of 0.23.10 Condition/s The apprehension test for associated with glenohumeral joint instability is a moderately useful screening test. Based More common on available data, the test has limited – traumatic utility to rule in the diagnosis. It is not • Recurrent glenohumeral joint used in the setting of acute anterior subluxation or dislocation shoulder dislocation. 7 Apprehension–relocation test (Fowler’s sign) Apprehension–relocation test (Fowler’s sign) • Glenoid labrum injury • Glenoid defect (e.g. Bankart’s fracture) • Humeral head defect (e.g. Hill– Sachs fracture) Less common – atraumatic • Connective tissue disorder: FIGURE 1.6 Ehlers–Danlos syndrome, Marfan’s Apprehension–relocation (Fowler) test syndrome Note that pressure is applied anteriorly to the proximal humerus. • Congenital absence of glenoid Description Mechanism/s The apprehension–relocation test is an The underlying anatomy and causes of assessment of glenohumeral joint glenohumeral joint instability are instability. The relocation manoeuvre outlined under ‘Apprehension test’ and is typically performed following the apply here. In the apprehension– apprehension test (see ‘Apprehension relocation test, symptomatic relief is test’). With the patient sitting or lying due to restoration of the normal supine, the shoulder is placed into 90° anatomical relationship of the humeral abduction, 90° external rotation and head in the glenohumeral joint. 90° elbow flexion. The examiner applies pressure to the anterior aspect Sign value of the proximal humerus and attempts T’Jonck L et al. reported a sensitivity to move the humeral head posteriorly. of 85%, specificity of 87%, positive The test is positive if the patient likelihood ratio of 6.5 and negative 10 experiences relief of apprehension (i.e.