CHAPTER 1 Evaluation of Hip Pain in Adults
So-called hip pain in an adult can originate from the hip joint, may be referred from another location (i.e., pelvis, lumbar spine, or sacroiliac joints), or may be the result of a systemic process. Evaluation of this pain requires a careful and thorough history and physical examination. The evaluation should include orthopedic and nonorthopedic components because many nonorthopedic conditions may manifest as hip pain. Evaluation of a patient with hip pain requires an understanding of musculoskeletal disorders related to the hip and a vast array of nonorthopedic diagnoses distant from the hip region.
As with all organ systems, evaluation begins with a thorough history and physical examination. Most of the time, the etiology of pain may be determined by using the history and physical examination, and then may be confirmed by imaging studies such as plain radiography, MRI, and CT. Common diagnoses causing hip pain include stress fractures, avascular necrosis, snapping hip disorders, labral tears, bursitis, synovitis, fractures, muscle strains, osteitis pubis, compression neuropathies, femoral acetabular impingement, dysplasia, osteoporosis, and arthritis (osteoarthritis and inflammatory arthritis). Although beyond the scope of this chapter, acute hip pathologies such as infection, contusions, fractures, and dislocations, must always be considered if suggested by the history and physical examination. A simple mnemonic that can be helpful for assessment of the painful hip is CTV MIND:
The location, frequency, chronicity, and modifying pain factors all are important to consider when evaluating a patient with hip discomfort. Many patients lump all pain in the lower extremity into their description of “hip pain.” It is important to elicit a clear location of pain. Patients report that they have “hip pain,” but with careful questioning this pain is discovered to be in the posterior buttocks, lateral thigh, groin, anterior thigh, or low back. Pain in the buttocks or lateral thigh may be related to pathology in the lumbar spine or sometimes the thigh musculature.
Radiation of the pain can help determine its etiology. Pain originating in the posterior buttocks and radiating down the lateral thigh and leg into the foot is often spine related. Groin or thigh pain with radiation to the knee is often the result of pathology of the joint capsule or synovial lining.1
The timing of onset and duration of the pain are important in differentiating the various pathologies. Acute sudden onset of pain is usually related to trauma or sports injuries. Traumatic etiologies such as acute fractures and dislocations are readily diagnosed and should be addressed immediately. Patients with nontraumatic acute injuries may experience disability only in their hobby or activity of interest. Labral tears may occur after a sudden twisting motion during routine sports activity and cause significant disability. The patient may be asymptomatic at rest but unable to participate in his or her activity. More chronic symptoms also may characterize a labral tear and can develop over years and be accompanied by limited range of motion and declining function.
Many other questions should be asked about the pain characteristics. Is the condition improving, worsening, or staying the same? Does this pain awaken the patient at night? What (e.g., position, medication) makes the symptoms better? What makes the symptoms worse? Are there any activities or positions unique to the patient that exacerbate the symptoms?
A past medical history should be obtained from all patients. It is important to determine if the patient has a history of hip disease during childhood (e.g., developmental dysplasia of the hip, slipped capital femoral epiphysis, Legg-Calvé-Perthes disease) or has had previous surgery on the hip. Systemic diseases that may be related to hip disease include coagulopathies, collagen vascular diseases, and malignancies. A history of asthma or skin disorder that has been treated with oral or intravenous steroids may suggest avascular necrosis as the cause of the pain. A social history also is important; avascular necrosis should be suspected in patients with a history of alcoholism.
The patient should be asked about social and recreational interests. Soccer, rugby, and marathon running all have been shown to be associated with an increased incidence of degenerative arthritis of the hip.2–6 Runners who have drastically increased their mileage and military recruits have a high propensity for stress fractures around the hip. A family history also should be evaluated; osteoarthritis of the hip and hand are associated with a high genetic influence.7
A thorough review of systems is important in the patient with hip pain. The differential diagnosis of hip and groin pain includes many nonmusculoskeletal disorders. If the source of the groin pain is obviously not the hip, and the review of systems reveals another potential source of the pathology, appropriate referrals to primary care physicians, surgeons, urologists, and gynecologists may be appropriate. Questions that are related to the patient’s general health and that probe topics such as weight loss, fevers, chills, and malaise should be asked. Unexplained weight loss may indicate a malignancy, and fevers and chills may guide the examiner toward a diagnosis of infection.
Disorders of the abdominal wall, such as inguinal hernias or rectus abdominis strains, may cause hip pain. Patients should be questioned to determine whether they have any bulges or palpable masses in the groin that might represent a hernia. Hernias are often more pronounced with coughing or other Valsalva maneuvers.
It is important to perform a through review of the gastrointestinal and genitourinary systems because hip and groin pain may originate from abdominal or pelvic pathology. Nausea, vomiting, constipation, diarrhea, and gastrointestinal bleeding can indicate a gastrointestinal cause of pain such as inflammatory bowel disease, diverticulosis, diverticulitis, abdominal aortic aneurysm, or appendicitis. Urinary symptoms such as frequency, polyuria, nocturia, or hematuria may suggest a urinary tract infection or nephrolithiasis.
The male and female reproductive systems should be addressed to rule out pathology that might be causing the pain. Prostatitis, epididymitis, hydroceles, varicoceles, testicular torsions, and testicular neoplasms all have been known to cause groin pain in men. Women of childbearing age should be asked about their menstrual history to determine if an ectopic pregnancy, dysmenorrhea, or endometriosis is a cause of their pain. Women also should be asked if they have had any signs or a history of sexually transmitted diseases that may have resulted in pelvic inflammatory disease. Very active women with eating disorders, amenorrhea, and osteoporosis (the so-called female athlete triad) have a very high rate of stress fractures.8 Finally, musculoskeletal causes not related to the hip, such as back pain, history of herniated disks, and sacroiliac injuries, must be considered.
The physical examination begins long before the examiner’s hands are placed on the patient. When the patient first walks into the examination room or the waiting area, the examiner should evaluate the patient’s gait and stance. Does the patient have an antalgic gait? What is the patient’s standing posture? Does the patient walk with ambulatory aids? The patient should be specifically asked to walk for the examiner. On the affected side, the patient may have a shortened stance phase or stride length to limit the amount of time weight is loaded on the affected extremity. If the patient has weak abductors, he or she may walk with a Trendelenburg lurch. With this type of gait, the patient compensates for abductor weakness by leaning over the painful hip in an attempt to shift the center of gravity to the affected side. With the patient undressed, the examiner should evaluate for skin lesions, obvious deformities, or surgical scars.
A complete set of vital signs including temperature is important to attain if infection is suspected. An elevated temperature may clue the examiner into the diagnosis of septic arthritis or non–hip-related sepsis, such as prostatitis, urinary tract infection, pelvic inflammatory disease, or psoas abscess.9