Antalgic Gait in Adults

Etiology

The etiology of an antalgic gait usually relates to a disorder of the lower back or lower extremity. It can be caused by traumatic, infectious, inflammatory, vascular, or neoplastic processes.[3][4][5] This adaptive alteration of gait avoids placing undue pressure on painful areas and attempts to minimize the recruitment of muscle and joint groups that may be affected by the above processes.[6]

Epidemiology

The likelihood of experiencing a gait disorder from any cause increases with age, affecting more than 60% of patients greater than 80 years old.[7] It is a common complaint of patients presenting to the emergency department and to primary care offices.

History and Physical

A detailed history and examination will often identify the source of the antalgic gait in an adult.

History

It is essential to ask about the site and character of the pain, as well as any exacerbating or relieving factors to narrow down your differential diagnoses. Establishing the time frame of onset will also provide important clues. A more acute onset may support a differential of trauma or an infective process, such as septic arthritis or a fracture, while a more chronic history may suggest a neoplastic, vascular, or inflammatory process, such as a sarcoma or rheumatological disease. Gaining an understanding of the patient's overall well-being may provide clues that support an infective, inflammatory, or neoplastic cause of their antalgic gait, such as reports of elevated temperature, feeling generally well, or feeling lethargic. In adults, it is important to ask about past medical history that may pose as a risk factor for an infectious etiology, such as diabetes or rheumatological disease.[8] 

In addition, certain medications may predispose patients to fractures, infections, or hemarthroses, such as chronic corticosteroid use, immunosuppressive medications, and anticoagulative medications, respectively.[9] Other important questions to include are whether there has any history of trauma, whether they have experienced any similar pain before, and what over-the-counter or prescription medications the patient has tried. This will give insight into how severe their pain is and, in turn, narrow down the differential diagnoses. A recent history of a new or sudden increase in physical activity, such as long-distance running, may also provide important clues to the diagnosis.[4]

Physical Examination

A full physical examination should be carried out, including a detailed lower limb, hip, and spine examination. Attention should be paid to any tenderness over the spinous processes, which may signal a fracture, epidural abscess, or discitis.[10] Careful examination of the hip and lower extremity may reveal signs of inflammation, such as swelling, erythema, or warmth, as well as signs of injury, such as bruising or deformity. Each lower extremity joint, including the hip, should be examined through a full range of motion to help isolate and identify the source of the pain. In the case of an acute monoarthritis, septic arthritis ought to be considered, and urgently ruled out.[11]

A complete neurovascular exam is important to assess for possible vascular causes of pain, such as claudication, as well as to identify the presence of neuropathy.[12] Finally, it is important to watch the patient walk as this may provide important clues as to the etiology and source of the pain, such as limitation in flexion or extension of a certain joint or avoidance of one part of the foot.[6][13]

Evaluation

In some cases, a careful history and examination may not provide enough information to identify the cause of the antalgic gait accurately, and further testing may be necessary.

Initial tests include basic bedside observations such as temperature and heart rate. Pyrexia may indicate infection, while tachycardia may give insight into the severity of the pain. Initial blood tests would consist of a full blood count with inflammatory markers such as erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP). White cell count and inflammatory markers may be raised on the background of an infective or inflammatory process. Depending on the history provided, the inclusion of other specific blood tests such as an international normalized ratio (INR) in a patient on chronic warfarin therapy may also be indicated. More specific rheumatological markers may be helpful in a patient with a history or suspicion of rheumatologic disease. In the context of an acute monoarthritis, blood cultures should also be taken to rule out bacteremia and identify any specific causative organisms.[14]

Initial imaging studies such as X-rays may be ordered to provide additional information on possible sites of injury or fracture. X-rays can also provide information about degenerative changes or the presence of effusion in painful joints. If a vascular source of pain is suspected, lower extremity venous doppler or arterial ultrasound would be the imaging study of choice.[15] In some cases, magnetic resonance imaging (MRI) may be necessary to evaluate for infectious or musculoskeletal etiology, particularly if a tumor, epidural abscess, septic arthritis, or discitis is clinically suspected or if a patient fails conservative therapy for another suspected etiology.

Performing a synovial aspirate may be indicated if there is clear synovitis.[14] This may identify any causative organisms and allow for the tailoring of antibiotic therapy, should it be indicated. It also allows the clinician to distinguish a crystal arthropathy from an infective cause.[16]

Treatment / Management

Management of an antalgic gait is aimed at identifying and treating the underlying cause of pain with referral to the appropriate specialist.

Sprains and fractures should be immobilized and splinted with appropriate orthopedic follow-up.[17] Crutches or a walking boot may be provided for additional support. Ice and elevation of the affected extremity, as well as a course of non-steroidal anti-inflammatory medication, may be recommended.

Inflammatory conditions should be treated with non-steroidal anti-inflammatories and appropriate primary care or rheumatology follow-up. Physical therapy can also be helpful in the management of long-term conditions such as sciatica, degenerative disc disease, and lumbar radiculopathy.[12] Orthotics may be indicated to help with deformities related to chronic diseases, such as rheumatoid arthritis.[18] Encouraging weight loss may also help decrease stress on the joints of the back and lower extremities.[19](B2)

Vascular causes of antalgic gait will require a specialist referral and possibly blood-thinning medication.[15](B3)

Infectious causes of antalgic gait can medical emergencies and require prompt diagnosis with emergent orthopedic consultation and/or admission for joint aspiration, intravenous antibiotics, and possible surgery.[20]

Neoplastic causes require oncology input and possibly neurosurgical consultation and follow-up.

Differential Diagnosis

Traumatic

• Fracture or sprain of the lower extremity
• Vertebral body fracture
• Hip fracture

Infectious

• Epidural abscess
• Osteomyelitis
• Discitis
• Septic arthritis

Inflammatory

• Gout
• Lumbar Radiculopathy
• Sciatica
• Bursitis of the hip or knee
• Rheumatoid arthritis
• Osteoarthritis
• Plantar fasciitis
• Neuropathy
• Pelvic girdle pain in pregnancy
• Chronic anterior pelvic ring instability

Vascular

• Vascular disease
• Claudication
• Deep venous thrombosis

Neoplastic

• Tumor
• Pathologic fracture

Prognosis

Most adults with antalgic gait improve with appropriate treatment of the underlying cause. Minor injuries will heal on their own with appropriate care and rest. Infectious, inflammatory, and neoplastic causes may have a more prolonged course but typically improve with an interprofessional approach and specialist evaluation.

Complications

The most serious complication of an antalgic gait is the potential for missed pathology, such as septic arthritis, tumor, or severe vascular disease, which can be life or limb-threatening.[15][21][22] It is important to do a thorough evaluation of these conditions and not assume that an antalgic gait is always related to a minor injury.