The purpose of the orthopaedic examination is to evaluate a patient for the presence or absence of orthopaedic disease and to localise the source of the problem. This examination is imperative to the appropriate selection of diagnostic tests and to discussion with owners regarding treatment options and prognoses.

The orthopaedic examination can be subdivided into three parts:

1.  Observe the patient sitting and standing
Watch the patient's behaviour when sitting, standing and lying down and particularly note transitions between these positions. Particular things to note include a patient struggling to rise on one particular limb, a patient not weight-bearing evenly on all four limbs, a patient holding a limb up at any stage, the digits on one limb not being spread evenly when weight-bearing, trembling of a limb, asymmetry or malalignment of a limb. Using these simple observations, it may be possible to appreciate which limb(s) is/are causing the problem.

2.  Gait assessment
Gait assessment can be used to further elucidate which limb(s) is/are affected and how severely. The patient should be taken to an area where they can be observed standing, walking and running. It is important to watch the patient walk at different paces and to watch the patient from in front, behind and the side. Watching the patient go up and down stairs and slopes can also be useful.

3.  Physical examination
The physical examination is critical in localising the source of the problem. Most dogs will tolerate a comprehensive orthopaedic examination without the use of sedation, although some tests, such as cranial drawer and tibial compression test, may be more sensitive when performed under sedation.¹

The key to a successful orthopaedic examination is to be methodical and thorough. Start with the dog standing and facing away from you and assess the degree of weightbearing on each limb. Palpate and compare the musculature of both thoracic and pelvic limbs, specifically looking for any muscle atrophy or asymmetry. Also palpate for joint effusions as these are often more easily palpable at stance. A basic neurological examination should be performed including assessing conscious proprioception on all four limbs.² The cervical, thoracic, lumbar and lumbosacral spine should also be assessed for range of motion and pain on palpation and manipulation. After this, each limb should methodically be examined leaving the affected limb until last. When assessing joints, evidence of any swelling, thickening, pain, heat, crepitus, overlying soft tissue abnormalities or alterations in range of motion (ROM) should be noted. When palpating bones, include any changes in outline or texture.

Examination of the Thoracic Limb

Check the interdigital skin for dermatitis, wounds or lacerations, the pads for wounds or foreign bodies and the claws and nailbeds for signs of disease or abnormalities in wear. Check each of the interphalangeal and metacarpophalangeal joints individually for normal ROM in extension and flexion and for instability medially and laterally. Deep palpation over the palmar sesamoid bones at the level of the metacarpophalangeal joints is recommended. Palpate each of the metacarpal bones individually.

The canine carpus is a hinge joint with a normal ROM from approximately 30° of flexion to 200° of extension. Check for medial and lateral instability. Check for carpal swelling or joint effusion which is normally most obvious dorsally.

Gently palpate the antebrachium working from the carpus proximally. Palpate the elbow carefully and check the ROM which is normally approximately 40° of flexion to 170° of extension. Collateral ligament integrity of the elbow is assessed using the degree of pronation and supination possible during manual rotation of the manus with the elbow and carpus both flexed to 90°.³ The normal ranges of pronation and supination are approximately 40–50° and 60–70°, respectively. Pain associated with simultaneous supination and elbow flexion can be associated with elbow pathology as can pain upon direct palpation over the medial coronoid process. Assess whether an effusion is present; this is best palpated laterally, caudal and distal to the lateral aspect of the humeral condyle in the region of the anconeus muscle.

The distal humerus is readily palpable. Progressing proximally, the mid-humerus becomes more difficult to palpate but the large biceps brachii muscle cranially and the triceps muscle group caudally are palpable. The proximal humeral diaphysis is again palpable with the greater tubercle being the most obvious point.

The shoulder joint lies relatively deep; it cannot be directly palpated and effusion is difficult to appreciate. Most movement in the shoulder occurs in the craniocaudal plane but internal/external rotation and abduction/adduction also contribute. Excessive abduction angles can be associated with pathology. The normal ROM is approximately 60° of flexion to 160° of extension with 30° of abduction.⁴ The biceps tendon lies in the intertubercular groove, medial to the medial aspect of the greater tubercle. Digital pressure can be applied directly to the biceps tendon in the region of the intertubercular groove if the shoulder joint is fully flexed and the elbow joint extended; a pain response suggests biceps tendon pathology. Shoulder pain can be difficult to differentiate from elbow pain as it is not possible to fully extend and flex the shoulder without manipulating the elbow.

The acromion, scapular spine, dorsal aspect of the scapula, supraspinatus and infraspinatus muscles are easily palpable in most patients and assessed for discomfort, swelling and alterations in shape or texture.

Examination of the Pelvic Limb

The examination of the pes is similar to that of the thoracic limb. The hock works as a constrained hinge joint with a large ROM from approximately 40°of flexion to 165° of extension. Full hock flexion and extension are not possible without simultaneous passive stifle flexion and extension. Medial and lateral hock stability should be assessed; a normal canine hock has no medial/lateral instability in flexion but a small amount may be appreciated in extension. Effusion, where evident, is usually most obvious at one of the four pouches of the hock joint which are positioned dorsomedially, dorsolaterally, plantaromedially and plantarolaterally.

Gently palpate the tibia from distal to proximal. Palpable landmarks include the medial malleolus distally and the tibial tuberosity cranially and proximally. The fibula can only be palpated for a short distance proximally from the lateral malleolus. The gastrocnemius muscle can be palpated caudal to the proximal tibia. As it progresses distally, it contributes to and becomes the common calcaneal tendon, which can be palpated up to the point of insertion on the proximal calcaneus. The integrity of the common calcaneal tendon should be assessed; it should not be possible to flex the hock without simultaneous stifle flexion.

The stifle is a complex hinge joint. A small concave depression should be palpable on each side of the patellar ligament, deep to which is the infrapatellar fat pad and stifle joint. When effusion is present, these depressions become difficult to appreciate and the borders of the straight patellar ligament become less distinct. The normal ROM of the stifle is from approximately 40° of flexion to 160° of extension. Lateral and medial collateral ligament integrity can be assessed with the stifle held in extension. The patella should track normally in the trochlear groove throughout a full range of motion of the stifle. Stability can be tested further by placing gentle medial and then lateral pressure on the patella with the stifle extended. Craniocaudal stability of the stifle should be tested to assess cruciate ligament integrity. This can be tested using either the cranial drawer test or the tibial compression test.

The condyle of the distal femur and the greater trochanter are the only readily palpable portions of the femur in most patients. The majority of the femoral diaphysis is not palpable but the overlying muscles are. Abnormalities of these muscles are uncommon excepting muscle atrophy associated with chronic lameness.

The hip is a ball and socket joint allowing movement in three dimensions - flexion/extension, internal/external rotation and abduction/adduction. A normal hip has a wide ROM from 50° of flexion to 160° of extension. It is impossible to fully extend the hip without also extending the stifle and putting pressure on the lumbosacral spine. If concurrent stifle or lumbosacral pathology exists, then these can result in false positive responses to hip extension. Ortolani tests are used to assess hip laxity in skeletally immature patients. They are an important part of the orthopaedic work-up of a dog with suspected hip dysplasia but are not usually part of the initial assessment.

The pelvis should be palpated for symmetry and stability. Anatomic landmarks include the ischial tuberosity, greater trochanter of the femur and cranial dorsal iliac spine. The relative positions of these landmarks make the shape of an inverted triangle in the normal patient. This relationship may be lost in instances of pelvic fracture or hip luxation.

Upon completion of the examination it should be possible to identify the affected limb and anatomic region of that limb, draw up a list of differential diagnoses, plan appropriate diagnostic tests and treatment options and formulate a clear and logical plan of action for patient management.

References

1.  Carobbi B, Ness MG. Preliminary study evaluating tests used to diagnose canine cranial cruciate ligament failure. J Small Anim Pract. 2009;50:224–226.

2.  Jeffrey N. Neurological examination of dogs. 1. Techniques. In Practice. 2001;23:118–130.

3.  Campbell JR. Nonfracture injuries to the canine elbow. J Am Vet Med Assoc. 1969;155:735–744.

4.  Cook JL, Renfro DC, Tomlinson JL, Sorensen JE. Measurement of angles of abduction for diagnosis of shoulder instability in dogs using goniometry and digital image analysis. Vet Surg. 2005;35:463–468.