Diagnosis and Treatment of Musculoskeletal Disorders in Animals

In all cases of musculoskeletal pain and lameness, diagnostic procedures must be performed to determine the injury's nature, extent, and exact location. Evaluation of the source of pain and lameness always starts with a thorough history, gait analysis, and physical examination to isolate and identify the location of the lameness. Video clips are helpful when a proper gait analysis cannot be performed during the examination.

Efforts should be made to examine all four limbs and the axial spine to determine the source of lameness. The limb presented for lameness should be examined last (if possible) to prevent a heightened reaction when noninjured areas are touched. The examiner should bear in mind that in addition to orthopedic causes of lameness, soft tissue injuries (muscle and tendon) and neuropathies can cause lameness. In cats and dogs, the palpation of long bones and assessment of range of motion in joints are best accomplished in lateral recumbency. Because of the risk of eliciting a painful response, trained personnel should restrain animals to decrease the likelihood of injury.

Gait analysis is performed by walking and trotting patients and observing them for lameness or gait abnormalities. Gait analysis should be performed on a long enough runway with good traction to allow normal locomotion by the patient. A complete neurological assessment should also be performed to rule out the possibility of lameness caused by an underlying neurogenic cause. Isolation of areas where pain is elicited or detection of other abnormalities might lead to additional diagnostic testing.

In horses, application of hoof testers, flexion tests of joints, and diagnostic analgesia are additional components of the musculoskeletal examination. When gait and locomotion are evaluated in patients with weight-bearing lameness, the lame leg often has a shorter duration of ground contact. For patients with swinging leg lameness, the lame leg might abduct or adduct to avoid flexion of a painful joint. Some features of gait abnormality can also be quantified objectively by use of a force plate or a computerized gait analysis system.

After the suspected origin of lameness is localized, diagnostic imaging techniques (radiography, ultrasonography, MRI, CT, nuclear imaging, and thermography) can be performed to evaluate the soft tissue structures and bones in the region. Synovial fluid analysis of affected joints is necessary for diagnosis when joint sepsis is suspected. Once the diagnosis is made, a treatment plan can be developed, and the prognosis is based on the diagnosis, the extent of the disease, and the expected response to treatment.

Treatment options for diseases of the musculoskeletal system include rest, restricted or modified activity, immobilization of diseased or injured structures in external coaptation, anti-inflammatory and analgesic medications, physical therapy, acupuncture, extracorporeal shock wave therapy, and surgical repair.

Treatment options for managing musculoskeletal disorders have increased with regenerative therapy, in which growth factors, cytokines, and mesenchymal cell therapy have been used to augment healing. For many animals, a return to everyday activity is possible when diagnosis and subsequent treatment are performed early in the disease process.