Approach to the adult with unspecified hip pain

INTRODUCTION — Hip pain is common in adults and often causes functional disability. Among adults who play sports, the incidence of chronic hip pain is 30 to 40 percent [1,2]; among all adults over 60, the incidence of hip pain is 12 to 15 percent [3,4]. Hip joint labral injuries and synovitis are common causes of hip pain in younger adults, while trochanteric pain syndrome and osteoarthritis become more common with aging. Important medical causes include referred pain from lumbosacral radiculopathy and aortoiliac arterial insufficiency.

This topic will provide a general approach to the adult with a chief complaint of hip pain. Evaluation of the athlete and active adult with a likely musculoskeletal cause of hip pain, the diagnosis and treatment of specific disorders of the hip, and evaluation of hip pain in children are all discussed separately. (See "Approach to hip and groin pain in the athlete and active adult" and "Approach to hip pain in childhood".)

ANATOMY AND BIOMECHANICS — The anatomy and biomechanics of the hip and groin are reviewed separately. (See "Musculoskeletal examination of the hip and groin", section on 'Anatomy and biomechanics'.)

HISTORY — Pain is the most common complaint among adults with hip problems. Identifying the location of the hip pain can help narrow the differential diagnoses and direct the history and examination.

Pain history — A pain history should be obtained, including:

●Onset (eg, sudden, gradual, traumatic or nontraumatic)

●Provocative and palliating factors (eg, increased pain with weight-bearing)

●Quality

●Radiation (eg, to or from the low back)

●Site (eg, lateral, anterior, or posterior hip)

●Symptoms associated with pain (eg, paresthesia, mechanical symptoms such as catching, systemic symptoms such as fever)

●Time course (overall duration, length of episodes)

Specific questions can help lead the clinician towards the correct diagnosis. Such questions may include:

●Did trauma precede the onset of pain? (See "Overview of common hip fractures in adults" and "Minor pelvic fractures (pelvic fragility fractures) in the older adult".)

●Do you develop achiness in the hip or buttocks after walking a certain distance? Is this pain associated with weakness of the hip or thigh while walking? Do you have a history of coronary artery or peripheral vascular disease?

•A positive response to one or more of these questions raises the possibility of aortoiliac arterial insufficiency as the cause of hip pain. (See "Clinical features and diagnosis of lower extremity peripheral artery disease".)

●Is there a personal or family history of rheumatologic disease? Is the patient experiencing symptoms suggestive of rheumatologic disease? Specific questions to ask include:

•Are any other joints (in addition to the hip) painful, swollen, or inflamed? Did symptoms and signs begin during young adulthood, and were they not preceded by trauma?

-A positive response may indicate rheumatologic disease such as rheumatoid arthritis or spondyloarthritis (eg, psoriatic arthritis). (See "Clinical manifestations of rheumatoid arthritis" and "Clinical manifestations and diagnosis of psoriatic arthritis".)

•Have you developed any rashes, especially of the elbows, knees, or scalp? Is there a personal or family history of psoriasis?

-A positive response may indicate psoriatic arthritis.

•Are you experiencing any gastrointestinal disturbances requiring evaluation?

-The combination of gastrointestinal symptoms and signs with arthritic joint pain may be due to inflammatory bowel disease (Crohn disease, ulcerative colitis). (See "Clinical manifestations, diagnosis, and prognosis of Crohn disease in adults" and "Clinical manifestations, diagnosis, and prognosis of ulcerative colitis in adults".)

•Are you experiencing eye pain or redness or any eye condition requiring specialist assessment?

-Iritis/uveitis can be associated with a number of systemic inflammatory diseases such as spondyloarthritis. (See "Overview of the clinical manifestations and classification of spondyloarthritis".)

•Did you have a systemic illness or infection prior to the onset of hip pain?

-If yes, hip pain may be due to a sexually transmitted disease or a gastrointestinal infection associated with a reactive arthritis.

●Are you experiencing any focal weakness, such as inability to push off with your foot or raise (dorsiflex) your foot?

•A positive response suggests lumbar radiculopathy. (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

●Are you experiencing any numbness or tingling in your thigh, leg, or foot?

•A positive response may indicate meralgia paresthetica or lumbar spine pathology (L2/L3 radiculopathy affects anterior hip/groin region; L5/S1 radiculopathy affects lateral hip and buttock).

●Does lying on the hip at night cause pain?

•A positive response is typical in patients with joint pathology, injury to the gluteal tendons, or greater trochanteric pain syndrome. (See "Greater trochanteric pain syndrome (formerly trochanteric bursitis)".)

●Do you experience any mechanical joint symptoms, such as catching or clicking?

•A positive response may indicate a loose body or labral injury.

Although the answers are rarely diagnostic themselves, the clinician should ask about activities that aggravate hip pain. Most hip pain is aggravated by weightbearing activity such as prolonged standing or walking, or more vigorous activity such as running. Clinicians should inquire about other medical history, medications (eg, glucocorticoids), and family history. Active systemic symptoms, such as fever, fatigue, weight loss, and diffuse myalgia or bone pain, raise concern about a medical cause and warrant in-depth evaluation. Nocturnal pain in the absence of increased activity or lying on the affected side increases concern for systemic disease. Prior procedures or treatments for hip pain should be noted.

PHYSICAL EXAMINATION — Below, the author provides an approach to the examination of the adult presenting with hip pain of unclear origin. Details pertaining to the performance of the musculoskeletal examination of the hip are provided separately. Depending upon the patient and the clinical scenario, it may be important to examine the abdomen, genitourinary system, low back, and/or lower extremity neurovascular function, in addition to the hip proper. (See "Musculoskeletal examination of the hip and groin" and "Evaluation of the adult with nontraumatic abdominal or flank pain in the emergency department", section on 'Physical examination' and "Evaluation of the adult with abdominal pain" and "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

Many common hip conditions stem from altered lower limb biomechanics, and many patients presenting with hip pain manifest an antalgic gait. Thus, it is important to begin the examination by observing the patient's gait and movement. (See "Clinical assessment of walking and running gait".)

Gait assessment should include observing the patient walking normally followed by having the patient walk on their heels and then on their toes to assess for distal limb weakness. Such weakness may indicate lumbar radiculopathy. A "waddling" or Trendelenburg gait may be indicative of hip joint pathology causing restricted joint motion (eg, osteoarthritis, osteonecrosis). Inability to bear weight may indicate a hip fracture or weakness from lumbar radiculopathy. (See "Clinical manifestations and diagnosis of osteoarthritis", section on 'Hip' and "Overview of common hip fractures in adults" and "Minor pelvic fractures (pelvic fragility fractures) in the older adult" and "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

Lateral pelvic instability is common in adult patients presenting with hip pain and may be contributory or a consequence of the underlying condition. Lateral pelvic instability causes exaggerated movement of the lateral hip structures (gluteus medius tendons, tensor fascia lata, and trochanteric bursa) over the lateral femur as well as compression of anterior and medial hip structures (hip joint, labrum, proximal adductor tendons). Having the patient stand on one leg or perform a partial single-leg squat may reveal such instability (picture 1). In a positive Trendelenburg test (figure 1), the healthy side of the pelvis sags, causing the waistline to appear tilted (ie, no longer parallel to the ground). This finding is likely due to gluteal muscle weakness. Other functional testing such as deep squatting or single-leg hopping causes severe pain with many hip and spine conditions and therefore has limited diagnostic use.

With the patient standing, assess active motion of the lumbar spine to determine whether particular movements elicit pain. Low back pain with lumbar flexion suggests disc pathology, while pain with lumbar extension suggests lumbar facet joint arthropathy (although these are by no means hard and fast rules). With the patient seated, the neural slump test (cervical flexion with unilateral knee extension (picture 2)) can be performed to see if symptoms suggestive of lumbar radiculopathy are elicited. If these maneuvers fail to reproduce the patient's pain, hip pain referred from the lumbar spine is an unlikely cause of their symptoms. (See "Evaluation of low back pain in adults" and "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

For the next portion of the examination, ask the patient to lie supine. Ask them to lift their buttocks off the bed and then relax. From this position, leg length discrepancy can be assessed. In older patients, a significant discrepancy (>2 cm) may indicate osteoarthritis or osteonecrosis with joint collapse. A straight leg-raise maneuver may elicit lumbar nerve root irritability. (See "Evaluation of low back pain in adults".)

Palpate the anterior hip joint for tenderness and other abnormalities. Tenderness may be caused by hip arthritis of any type, labral tear, or iliopsoas bursitis. Focal tenderness over a superior pubic ramus suggests fracture. Limited passive hip motion, particularly when compared with the contralateral hip, suggests hip joint pathology (most often osteoarthritis). Assessment using the flexion, adduction, and internal rotation (FADIR; (picture 3)) and flexion, abduction, and external rotation (FABER/Patrick; (picture 4)) tests may reveal anterior hip impingement or posterior hip impingement, respectively. Anterior hip impingement is associated with labral tear, femoroacetabular impingement (FAI) syndrome, or osteoarthritis; posterior hip impingement is associated with osteoarthritis.

Hip internal and external rotation mobility can also be reduced by the loss of articular cartilage or growth of acetabular osteophytes from osteoarthritis or by pain and muscle spasm from acute synovitis. A normal 50-year-old averages 45 to 50 degrees of internal and external rotation. Osteoarthritis, acute synovitis, or septic arthritis may reduce this to as little as 5 to 10 degrees. Internal rotation is often affected first in osteoarthritis and may not be noticed by the patient.

Focal tenderness at the symphysis pubis and a positive adductor squeeze test in a patient with anterior hip pain of gradual onset and a history of overuse of the groin musculature suggests osteitis pubis.

Maneuvers to assess the sacroiliac joint (SIJ) include the hip posterior thrust test, Gaenslen test (picture 5), and lateral compression and distraction of the pelvis. These can be performed in patients with buttock or lower back pain in whom SIJ pathology is suspected [5].

A neurovascular assessment can be performed at this stage of the examination. This may include sensory testing (figure 2), assessment of a Tinel sign for meralgia paresthetica, and palpation of arterial pulses and bruits. (See "Meralgia paresthetica (lateral femoral cutaneous nerve entrapment)".)

Next, ask the patient to lie onto their nonpainful hip in a side-lying position. This allows better assessment of lateral hip structures. Palpation at this region includes the origin of the gluteal tendons, the trochanteric bursa (located just cephalad of the greater femoral trochanter), and the mass of the gluteal muscles. Resisted hip abduction (picture 6) may reveal pain or weakness suggestive of gluteal tendon pathology (eg, gluteus medius or minimus tendinosis or tear), often associated with trochanteric bursitis. Sensory testing of the lateral femoral cutaneous nerve can also be performed from this position.

With the patient prone, palpate the lumbar spine and SIJ as well as the hamstring origin at the ischial tuberosity. Resisted hip extension may reveal pain or weakness, which suggests gluteus maximus tendon pathology, possibly associated with trochanteric bursitis.

DIAGNOSTIC APPROACH

Step one: Determine if pain is related to trauma — Even minor trauma (eg, fall from a chair) can cause a fracture of the hip or pelvis in a frail, older adult. These cases are generally obvious from the history and patient presentation. Patients who may have sustained major internal injury should be evaluated in the emergency department.

In the absence of a clear history of trauma, occult hip fractures (eg, nondisplaced pubic ramus or femoral neck fracture) may be difficult to diagnose but should be suspected in older adults or those with poor bone health (eg, osteoporosis). Examination reveals difficulty with weight-bearing, anterolateral hip tenderness with femoral neck fracture, and significant pain with passive hip motion, especially internal and external rotation. Plain radiographs of the hip may not reveal such a fracture; the patient must remain non-weightbearing if the diagnosis is suspected until computed tomography (CT), magnetic resonance imaging (MRI), or serial examination of the hip rules out the diagnosis. (See "Overview of common hip fractures in adults" and "Minor pelvic fractures (pelvic fragility fractures) in the older adult" and "Geriatric trauma: Initial evaluation and management", section on 'Musculoskeletal injuries of the pelvis, hip, and extremities' and "Femoral stress fractures in adults".)

Step two: Determine if a dangerous medical condition is the cause — The patient's presentation and a careful history should suggest whether a dangerous medical cause of hip pain should be considered in the differential diagnosis. Dangerous, nontraumatic causes of hip pain include aortoiliac arterial insufficiency, septic arthritis, osteonecrosis, and tumor. If untreated, these causes may involve an underlying threat to life or result in destruction of the joint. When identified or suspected, any of these conditions requires immediate evaluation by the appropriate specialist.

●Aortoiliac arterial insufficiency can present with pain or claudication in the buttock, hip, and occasionally the thigh. Risk factors for cardiovascular disease are usually present. Patients often describe an achy pain that may be associated with weakness of the hip or thigh while walking. Examination may reveal arterial bruits and diminished groin or distal lower extremity pulses, unilaterally or bilaterally. Muscle atrophy and slow wound healing in the legs may be seen. Urgent referral and imaging is needed to determine the presence and extent of disease. (See "Clinical features and diagnosis of lower extremity peripheral artery disease".)

●Septic arthritis usually affects older adults with systemic medical problems such as diabetes or who are otherwise immunocompromised. The patient may have or recently have had a systemic infection. Systemic symptoms may include generalized weakness or fevers and chills. An adjacent nidus of infection (eg, skin wound) may be present, but most septic arthritis occurs via hematogenous seeding of a joint in a patient with bacteremia. Examination may reveal localized warmth, redness, or swelling of the hip joint, but these are often absent because of the depth of the hip joint. Joint motion is painful and restricted in all movement planes. (See "Septic arthritis in adults".)

●Osteonecrosis (ie, avascular necrosis, aseptic necrosis) describes a pathological process (involving vascular compromise or defective bone repair) leading to death of the affected portion of the bone. The process is most often progressive and causes destruction of the hip joint within three to five years. Risk factors associated with osteonecrosis are reviewed in detail separately. (See "Clinical manifestations and diagnosis of osteonecrosis (avascular necrosis of bone)", section on 'Risk factors'.)

Glucocorticoid use and excessive alcohol intake are associated with over 80 percent of nontraumatic cases of osteonecrosis. Hip pain is the most common presenting symptom. In cases affecting the femoral head, groin pain is most common, followed by thigh and buttock pain. Pain generally occurs with weight-bearing; pain at rest or at night is common. Diagnosis is made by imaging.

●Primary or secondary bone tumors may only present with pain later in the disease course. Pain is localized, may wax and wane, and may be associated with localized soft tissue swelling. Pain associated with malignant tumors is often worse at night. Systemic symptoms such as weight loss or night sweats raise suspicion if present but may be absent. Bone tumors around the hip joint generally involve the proximal femur and may be benign (eg, osteochondroma, osteoma, osteoid osteoma, osteoblastoma, giant cell tumor, aneurysmal bone cyst, fibrous dysplasia, enchondroma) [6] or malignant (eg, osteosarcoma, chondrosarcoma, Ewing sarcoma, giant cell tumor, fibrous histiocytoma) [7]. In addition to primary bone tumors, cancers may metastasize to bone; those most likely to do so are listed in the following table (table 1). Initial diagnosis is made by imaging. (See "Bone tumors: Diagnosis and biopsy techniques".)

Warning: Intraabdominal conditions can refer pain to the hip — Abdominal conditions such as inguinal hernia or appendicitis may refer pain to the anteromedial hip. Most often, the distinction between hip-related and intraabdominal causes of pain is clear. However, it is important to consider intraabdominal causes if the diagnosis remains unclear despite proceeding carefully through the steps described above or if the patient's hip pain is accompanied by signs of systemic illness (eg, fever, sweats, weight loss) or signs of gastrointestinal, urologic, or gynecologic illness (eg, inguinal mass, abdominal tenderness, hematuria, vaginal discharge). (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults" and "Acute appendicitis in adults: Clinical manifestations and differential diagnosis".)

Step three: Determine if osteoarthritis or rheumatologic disease is a likely cause

●Osteoarthritis of the hip typically presents with pain of insidious onset that is felt deep in the anterior hip or groin (although pain may refer to the buttock or lumbar spine), exacerbated by activity, and relieved by rest. Both hips may be affected. Rising from a seated position often elicits hip pain. Both active and passive hip movements are painful; internal rotation tends to be reduced sooner and more profoundly than external rotation. As disease becomes advanced, pain occurs with progressively less activity, eventually occurring at rest and at night. There may be anterior hip tenderness, reduced hip motion in multiple planes, and pain with both the flexion, adduction, and internal rotation (FADIR; (picture 3)) and flexion, abduction, and external rotation (FABER/Patrick; (picture 4)) tests. (See "Clinical manifestations and diagnosis of osteoarthritis", section on 'Hip'.)

●Rheumatoid arthritis, spondyloarthritis (eg, psoriatic arthritis or reactive arthritis), and crystal arthropathies (eg, gout or pseudogout) involving the hip manifest examination findings similar to hip osteoarthritis [8,9]. These inflammatory diagnoses are suspected on the basis of a history or examination findings demonstrating the involvement of multiple joints, other organ involvement, or a family history of rheumatologic disease. It is important to look for rashes, nodules, eye changes (eg, iritis), and other findings associated with both seropositive and seronegative arthritides. Appropriate laboratory testing may be helpful. (See "Clinical manifestations of rheumatoid arthritis" and "Clinical manifestations and diagnosis of psoriatic arthritis" and "Clinical manifestations and diagnosis of gout" and "Clinical manifestations and diagnosis of calcium pyrophosphate crystal deposition (CPPD) disease".)

Step four: Determine if radiculopathy or nerve entrapment is a likely cause — Compression of lumbosacral nerve roots or of peripheral nerves can manifest as hip pain. Nerve-related pain is often associated with paresthesias or an "electric" sensation and typically radiates along the course of the nerve, as opposed to the focal pain associated with an isolated musculoskeletal injury. Lumbosacral nerve involvement should be considered in any patient with hip pain accompanied by low back pain, especially if lower extremity weakness is present.

●Lumbar radiculopathy – Hip pain referred to the proximal, lateral thigh or accompanied by weakness suggests lumbar radiculopathy. Low back pain typically coexists. Examination helps to identify the involved nerve root (table 2 and table 3), which may be compressed due to disc protrusion or facet joint arthropathy. Symptoms may be reproduced by active motion of the lumbar spine or neural testing (seated slump testing). There may be weakness of hip flexion, knee extension, and hip adduction. Sensation may be reduced over the anterior thigh down to the medial aspect of the lower leg. A reduced knee reflex is common in the presence of moderate weakness. (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

●Sacroiliac neuropathy – Nerve lesions at the sacroiliac joint (SIJ) may refer pain to the gluteal region. Typically, pain and tenderness are present at the SIJ, while provocative testing of the SIJ (eg, supine hip posterior thrust test, Gaenslen test (picture 5), or lateral pelvic compression) exacerbates symptoms. Motor and sensory deficits depend upon the level affected. S1 radiculopathy is most common. It causes pain that radiates down the posterior aspect of the leg into the foot from the back, causes weakness of plantar ankle flexion (most specific) and possibly weakness of knee flexion and extension. Sensation is reduced on the posterior aspect of the leg and the lateral edge of the foot. Ankle reflex loss is typical. (See "Musculoskeletal examination of the hip and groin", section on 'Tests of sacroiliac region'.)

●Peripheral neuropathy – The lateral femoral cutaneous nerve is a pure sensory nerve that courses from the lumbosacral nerve plexus, through the abdominal cavity, under the inguinal ligament (where it is susceptible to compression), and into the subcutaneous tissue of the thigh. Symptoms typically involve burning pain or paresthesia localized to the superior and lateral thigh. Examination reveals abnormal sensation (picture 7). Tinel's test over the nerve at the level of the inguinal ligament (1 cm anteromedial to the anterior superior iliac spine) may reproduce the paresthesia or pain. (See "Meralgia paresthetica (lateral femoral cutaneous nerve entrapment)".)

Step five: Determine if pain is focal, suggesting a discrete musculoskeletal diagnosis — Patients without acute trauma in whom major medical, rheumatologic, and nerve-related conditions have been excluded likely have a discrete musculoskeletal cause for their pain. The most likely diagnoses depend upon the pain's location and chronicity [10]. Below, the author briefly describes the conditions associated with pain at particular aspects of the hip. As this discussion is focused solely on pain location, there is some overlap with the conditions described above.

Athletes and active adults with hip pain often have an acute injury or a chronic musculoskeletal condition, typically stemming from overuse. The approach and diagnostic workup for athletes and active adults with likely musculoskeletal pain is discussed in detail separately. (See "Approach to hip and groin pain in the athlete and active adult".)

●Lateral hip pain – Pain at the lateral hip is nearly always localized to the region immediately superior to the greater trochanter, as this is the site of the gluteal tendon insertions and trochanteric bursa (figure 3 and figure 4 and figure 5). Pain may radiate down the lateral thigh to the lateral knee along the iliotibial band (ITB; (figure 6)), as ITB tightness may be due to pathology of the gluteal tendon or bursa. Paresthesia in the lateral hip and thigh may indicate entrapment of the lateral femoral cutaneous nerve (meralgia paresthetica), especially if the pain is burning in nature. Pain in the gluteal muscles themselves (superolateral buttock region) may occur from muscle spasm but may be due to hip joint pathology causing referred pain in the buttock. (See "Iliotibial band syndrome" and "Meralgia paresthetica (lateral femoral cutaneous nerve entrapment)".)

Focal palpation should distinguish the point of maximal tenderness. Pain localized to the superoposterior aspect of the greater trochanter suggests greater trochanteric pain syndrome (GTPS), formerly known as trochanteric bursitis. GTPS is caused by gluteal tendon pathology, typically tendinopathy, sometimes associated with trochanteric bursitis. Pain and weakness with hip abduction (picture 6) and extension can assist with the diagnosis of GTPS. (See "Greater trochanteric pain syndrome (formerly trochanteric bursitis)".)

●Anterior hip pain – Anterior hip pain is often due to hip joint pathology, although pain of acute onset may be due to labral injury, proximal hip flexor muscle strain (figure 7), or iliopsoas bursitis (figure 8). However, most often, pain is insidious in onset. Pain from hip joint osteoarthritis is often described as achy, exacerbated by activity, and relieved by rest. Rising from a seated position causes pain. It is worth noting that pain from avascular necrosis or a tumor may present with similar symptoms. Hip pain described as sharp or "knife like" is often due to hip joint pathology such as labral tears [11]. Femoroacetabular impingement (FAI) produces anterior hip pain that is often worst when the hip is moved to the ends of its range of movement, especially internal and external rotation. Pain localized to the region of the adductor tendon origins may indicate adductor tendon pathology or referred pain from osteitis pubis. Note that some intraabdominal conditions can refer pain to the anteromedial hip region, as discussed just below. (See "Clinical manifestations and diagnosis of osteoarthritis", section on 'Hip' and "Adductor muscle and tendon injury".)

●Posterior hip and buttock pain – Pathology within the hip joint (labral tears, synovitis, chondral injuries) can refer pain to the buttock or lower back, although proximal hamstring pathology (figure 9), piriformis syndrome (figure 10), SIJ pathology (figure 11), and lumbar radiculopathy from the L5 to S1 levels (figure 12) must be considered. While hip joint pathology may refer pain to the knee, pain referred to the leg or foot generally indicates lumbar spine radiculopathy. (See "Hamstring muscle and tendon injuries" and "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

ETIOLOGY

Bone lesions: fracture, contusion (hip pointer), osteonecrosis, tumor, osteitis pubis — In the absence of a history of trauma, occult hip fractures (eg, nondisplaced pubic ramus or femoral neck fracture) may be difficult to diagnose but should be suspected in older adults or those with poor bone health (eg, osteoporosis). Examination reveals difficulty weight-bearing, anterolateral hip tenderness with femoral neck fracture, and significant pain with passive hip motion, especially rotation. Routine plain radiographs of the hip may not reveal a fracture; the patient must remain non-weightbearing if the diagnosis is suspected until magnetic resonance imaging (MRI) or serial examination of the hip rules out the diagnosis. (See "Overview of common hip fractures in adults" and "Minor pelvic fractures (pelvic fragility fractures) in the older adult" and "Geriatric trauma: Initial evaluation and management", section on 'Musculoskeletal injuries of the pelvis, hip, and extremities' and "Femoral stress fractures in adults".)

A ”hip pointer” is a contusion of the superior iliac crest sustained from a fall or a blow during a sporting event [12]. The trauma causes contusion and subperiosteal edema of the iliac bone and, potentially, hematoma in surrounding muscle and soft tissue. Patients typically present with pain localized to the superior iliac crest, varying degrees of skin bruising, and exquisite tenderness at the superior iliac crest. Weight-bearing may be painful, as may movements involving the hip, lateral spinal flexion, and torso rotation. Plain radiographs can exclude fractures, including avulsions. Ultrasound may demonstrate a subperiosteal fluid collection. Treatment is conservative, consisting of relative rest, ice, compression, and analgesics. Some clinicians give injections of a glucocorticoid and local anesthetic for severe pain, recalcitrant lesions, or after needle drainage of documented subperiosteal fluid collections (hematomas or seromas).

Osteonecrosis, (ie, avascular necrosis, aseptic necrosis) describes a pathologic process involving vascular compromise or defective bone repair that ultimately leads to death of the affected portion of the bone. The process is most often progressive and, when affecting the bones of the hip, causes joint destruction within three to five years if untreated. A variety of traumatic and nontraumatic factors are associated with the development of osteonecrosis; glucocorticoid use and excessive alcohol intake are associated with over 80 percent of nontraumatic cases. The most common presenting symptom of osteonecrosis is pain. In cases affecting the femoral head, groin pain is most common, followed by thigh and buttock pain. Pain generally occurs with weight-bearing, but pain at rest or at night are common. Early diagnosis of osteonecrosis may provide the opportunity to prevent joint destruction and the need for joint replacement. However, most patients present late in the course of the disease. The diagnosis is made radiographically. (See "Clinical manifestations and diagnosis of osteonecrosis (avascular necrosis of bone)".)

Primary or secondary bone tumors can develop at the hip but may only present with pain later in the disease course. Pain is localized, may wax and wane, and may be associated with localized soft tissue swelling. Pain associated with malignant tumors is often worse at night. Systemic symptoms such as weight loss or night sweats raise suspicion for bone tumor. Diagnosis is often made when initial plain radiographs are found to be abnormal. (See "Bone tumors: Diagnosis and biopsy techniques".)

Osteitis pubis is a bony stress reaction, generally localized to the superior pubic ramus adjacent to the symphysis, that usually presents with pain at the proximal adductors but may also cause suprapubic pain and pain that radiates to one or both adductors and the perineum. Initially, pain manifests as an aching after activity or as morning pain and stiffness but progresses to pain with activity as bone stress worsens. Osteitis pubis develops most often in athletes but can occur following pelvic stress of any kind (eg, trauma, pelvic surgery, pregnancy). (See "Osteitis pubis" and "Approach to hip and groin pain in the athlete and active adult", section on 'Osteitis pubis'.)

Aortoiliac arterial insufficiency — Aortoiliac arterial insufficiency can present with pain or claudication in the buttock, hip, and occasionally the thigh. Patients often describe the pain as achy, and it may be associated with weakness of the hip or thigh while walking. Examination may reveal diminished groin pulses unilaterally or bilaterally as well as diminished distal lower extremity pulses. Occasionally, a bruit may be appreciated over the iliac or femoral arteries. Other findings may include muscle atrophy and slow wound healing in the legs. (See "Clinical features and diagnosis of lower extremity peripheral artery disease".)

Joint pathology: labral tear, chondral damage, FAI, osteoarthritis, septic arthritis, rheumatologic conditions — Hip joint pathology is a common cause of hip pain, but it is often difficult to make a precise diagnosis based solely on the history and examination. Possible causes include a tear of the acetabular labrum, osteoarthritis, septic arthritis, and systemic disease such as rheumatoid arthritis. Among younger, active patients, femoroacetabular impingement (FAI) may be the source of pain. It is discussed in greater detail separately. (See "Approach to hip and groin pain in the athlete and active adult", section on 'Femoroacetabular impingement'.)

In young, active adults, labral injury is relatively common, while osteoarthritis more often presents in adults over 40. The principal symptom associated with hip joint pathology is pain, which often localizes to the anterior hip and groin and, less commonly, the buttocks or lower back. Labral pathology generally occurs in the anterosuperior (weightbearing) aspect of the hip joint, often causing anterior hip or groin pain. The pain may be described as sharp ("knife sharp") and can cause mechanical hip symptoms such as "catching" or "locking," although this is uncommon. Examination often reveals pain with hip flexion, adduction, and internal rotation (FADIR; (picture 3)), although anterior hip impingement from any cause my produce a positive test. (See "Approach to hip and groin pain in the athlete and active adult", section on 'Acetabular labrum injury'.)

With hip osteoarthritis, the insidious onset of pain is the dominant feature. Pain is typically felt deep in the anterior hip or groin, exacerbated by activity, and relieved by rest (although it should be noted that hip joint pain may also refer to the buttock or lumbar spine). Rising from a seated position often causes hip pain. Both active and passive hip movements are painful. As disease becomes advanced, pain occurs with progressively less activity, eventually occurring at rest and at night. On examination, there may be anterior hip tenderness greater than the other side, reduced hip range of motion (internal rotation less than 15 degrees and flexion less than 115 degrees [13]), and pain with both the FADIR (picture 3) and flexion, abduction, and external rotation (FABER/Patrick; (picture 4)) tests. (See "Clinical manifestations and diagnosis of osteoarthritis", section on 'Hip'.)

Other causes of hip joint inflammation such as rheumatoid arthritis or seronegative arthritis (psoriatic arthritis, reactive arthritis) manifest examination findings similar to hip osteoarthritis and are suspected on the basis of a history or examination findings demonstrating the involvement of additional joints/organs or a family history of rheumatic disease. It is important to look for rashes, nodules, eye changes (eg, iritis), and other findings associated with seronegative and seropositive arthritides. Likewise, septic arthritis may be suspected on the basis of history. More often, it affects older adults with other systemic medical problems such as diabetes or who are otherwise immunocompromised. Systemic symptoms may include generalized weakness or fevers and chills, and an adjacent nidus of infection (eg, skin wound) may be present. Examination may reveal localized warmth, redness, or swelling of the hip joint. Joint motion is painful and restricted in all movement planes. (See "Clinical manifestations of rheumatoid arthritis" and "Septic arthritis in adults".)

The clinical presentation of FAI is insidious and often deceptive. Mild symptoms of groin pain may occur variably for a long time (years) before abruptly worsening, finally affecting sport participation. Early in the course, symptoms are minimal but are usually most noticeable after sitting with hips flexed to 90 degrees for a relatively long period (eg, working at a desk, taking a long automobile or plane ride) and then rising to the standing position. Symptoms may include pain, joint stiffness, and catching. (See "Approach to hip and groin pain in the athlete and active adult", section on 'Femoroacetabular impingement'.)

Nerve compression — Compression of peripheral nerves or lumbosacral nerve roots can manifest as hip pain. The possibility of lumbosacral nerve involvement should be considered in any patient with hip pain, especially when accompanied by low back pain.

The lateral femoral cutaneous nerve is a pure sensory nerve that courses from the lumbosacral nerve plexus, through the abdominal cavity, under the inguinal ligament (where it is susceptible to compression), and into the subcutaneous tissue of the thigh. Symptoms typically involve burning pain or paresthesia localized to the superior and lateral thigh. Examination reveals abnormal sensation (picture 7 and figure 2). Tinel's test over the nerve at the level of the inguinal ligament (1 cm anteromedial to the anterior superior iliac spine) may reproduce the paresthesia or pain. (See "Meralgia paresthetica (lateral femoral cutaneous nerve entrapment)".)

Hip pain referred to the proximal lateral thigh or accompanied by weakness or impaired reflexes suggests lumbar radiculopathy. Examination generally enables identification of the involved nerve root (table 2 and table 3), which may be compressed due to disc protrusion or facet joint arthropathy. Symptoms may be reproduced by active motion of the lumbar spine, direct palpation of the lumbar spine, or neural testing (seated slump testing). (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

Nerve lesions at the sacroiliac joint (SIJ) may refer pain to the gluteal region. Typically, pain and tenderness are present at the SIJ, while provocative testing of the SIJ (eg, supine hip posterior thrust test, Gaenslen test (picture 5), or lateral pelvic compression) exacerbates symptoms. (See "Musculoskeletal examination of the hip and groin", section on 'Tests of sacroiliac region'.)

Greater trochanteric pain syndrome (trochanteric bursitis) — Greater trochanteric pain syndrome (GTPS), formerly known as trochanteric bursitis, is caused by gluteal tendon pathology, typically tendinopathy, sometimes associated with trochanteric bursitis. It is most prevalent in adults over 50. Patients typically complain of lateral hip pain in the area of the greater trochanter, especially while lying on the hip at night, after prolonged walking or standing, or when rising from a chair or climbing stairs. Examination reveals focal tenderness over the greater trochanter. Pain and weakness commonly manifest during gait or testing of hip muscle strength. In particular, passive hip adduction, resisted hip abduction (picture 6), and resisted external derotation (picture 8) are likely to exacerbate the patient's symptoms. Hip mobility is generally unaffected, and passive motion of the joint is typically normal. (See "Greater trochanteric pain syndrome (formerly trochanteric bursitis)" and "Musculoskeletal examination of the hip and groin".)

Other, infrequent causes of hip pain — In the setting of a sedentary adult with undifferentiated hip pain, it is less likely that musculoskeletal causes account for the pain. However, if the diagnosis remains unclear after a thorough history and examination (and possibly imaging) have largely ruled out important medical causes, it is worthwhile to consider musculoskeletal causes such as piriformis syndrome, Gilmore groin, snapping hip, and ligamentum teres tear. The diagnosis of musculoskeletal causes of hip pain is discussed in detail separately. (See "Approach to hip and groin pain in the athlete and active adult".)

LABORATORY TESTING — Laboratory testing may be indicated if the history and examination raise suspicion for systemic disease, such as rheumatologic disease. Initial laboratory testing may include:

●Complete blood count and differential

●C-reactive protein or erythrocyte sedimentation rate

●Rheumatoid factor

●HLA-B27

●Antinuclear antibodies

DIAGNOSTIC IMAGING

Plain radiographs — Plain radiographs should be performed in patients with acute hip pain to exclude fracture, in moderate to severe chronic hip pain, or as initial assessment of hip osteoarthritis [14,15]. Further imaging may be required based upon the results in combination with clinical findings or in cases of hip pain recalcitrant to treatment. Further imaging studies, especially magnetic resonance imaging (MRI) or computed tomography (CT), may be necessary when the history, physical examination, and plain radiographs are inconclusive. Imaging of the painful hip is discussed in detail separately. (See "Imaging evaluation of the painful hip in adults".)

Weightbearing pelvis radiograph — A weightbearing anteroposterior (AP) plain radiograph of the hip and pelvis enables assessment of the width of the articular hip joint, pelvic obliquity, general bone density, and the integrity of the sacroiliac joints (SIJs). Normal articular width of the hip joint is 4 to 5 mm. Marked narrowing of the joint space, sclerosis of the joint space margins, and periarticular osteophyte formation are consistent with osteoarthritis (image 1).

Ultrasonography — Ultrasonography is used to identify hip effusion, to assess surrounding soft tissues such as the trochanteric bursa, and to guide hip joint aspiration or injection. The performance of musculoskeletal ultrasound of the hip is reviewed in detail separately. (See "Musculoskeletal ultrasound of the hip".)

Bone scan — Radionuclide scans (triple-phase bone scans) to localize osteoblastic activity or to localize sites of soft tissue inflammation have largely been supplanted by MRI. Radionuclide bone scan may be used if there is a suspicion of metastatic disease, but it has been largely reserved for suspected fracture or osteonecrosis not demonstrated by plain film radiography and only when MRI is not available or contraindicated. Increased activity is nonspecific and can be seen with fracture, osteonecrosis, acute and chronic arthritis, and metastatic bone lesions. (See "Imaging evaluation of the painful hip in adults", section on 'Types of imaging exams'.)

Magnetic resonance imaging — MRI is the most sensitive and specific imaging technique for musculoskeletal conditions. It is the preferred study for soft tissue injury (eg, bursitis, tendon injury, soft tissue tumors), bony and joint pathology (eg, osteoarthritis, labral injury, osteonecrosis, infection, fractures, osteitis pubis, and bony tumors), and neurovascular structures [15]. MRI with intraarticular gadolinium improves the assessment of chondral lesions and labral tears. (See "Imaging evaluation of the painful hip in adults", section on 'Magnetic resonance imaging'.)

DIAGNOSTIC PROCEDURES

Local anesthetic block — Local anesthetic block can be helpful for distinguishing the cause of pain in difficult cases. In many instances, ultrasound can be used to identify structures of interest and guide injections.

●Local anesthetic block placed below the gluteus medius tendon at the periosteum of the trochanteric process can be used to confirm the presence of trochanteric pain syndrome (picture 9). Local anesthetic block of the deeper gluteus medius bursa can also be performed (picture 10).

●Local anesthetic block of the lateral femoral cutaneous nerve can be used to distinguish meralgia paresthetica from referred pain from the lumbosacral roots.

●Local anesthetic block at the sacroiliac joint (SIJ) can confirm this as the source of posterior hip pain (picture 11).

Hip aspiration — Immediate arthrocentesis is recommended when hip pain is acute, severe, and suspected to be due to joint infection. (See "Synovial fluid analysis".)

Because of the deep-seated location of the hip joint, diagnostic aspiration requires fluoroscopic, computed tomography (CT), or ultrasound guidance. The choice of imaging modality depends upon institutional resources and expertise as well as clinician preference. If no fluid is withdrawn, a small amount of contrast should be instilled to confirm the intraarticular location of the needle tip.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hip and groin pain".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Hip pain in adults (The Basics)" and "Patient education: Avascular necrosis of the hip (The Basics)")

SUMMARY AND RECOMMENDATIONS

●History – A careful history and physical examination help to determine the etiology of hip pain. The pain history should include the following: site, onset, quality, time course, provocative and palliating factors, radiation, and associated symptoms. More focused questions may suggest an underlying etiology:

•Trauma immediately preceding acute onset of pain

•Pain onset related to activity of particular duration (eg, occurs only after walking a certain distance, possibly suggesting vascular insufficiency)

•Pain in multiple joints or associated with other discrete findings (eg, rash, gastrointestinal disturbances, eye findings) may suggest rheumatologic or other systemic disease

•Pain associated with focal weakness or radiation may suggest radiculopathy or nerve entrapment

•Pain caused by lying on affected hip at night may suggest musculoskeletal cause (see 'History' above)

●Physical examination – In the text, the author provides an approach to the examination of the adult presenting with hip pain of unclear origin. Details about how to perform the musculoskeletal examination of the hip are provided separately (see "Musculoskeletal examination of the hip and groin").

Depending upon the patient and the clinical scenario, it may be important to examine the abdomen, genitourinary system, low back, and/or lower extremity neurovascular function, in addition to the hip proper. (See "Evaluation of the adult with nontraumatic abdominal or flank pain in the emergency department", section on 'Physical examination' and "Evaluation of the adult with abdominal pain" and "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis".)

●Diagnostic approach – Our approach to diagnosing hip pain in the adult consists of the following steps (see 'Diagnostic approach' above and 'Etiology' above):

•Step one: Determine if pain is related to trauma. (See 'Step one: Determine if pain is related to trauma' above.)

Even minor trauma (eg, fall from a chair) can cause a fracture of the hip or pelvis in a frail, older adult. These cases are generally obvious from the history and patient presentation. In the absence of a clear history of trauma, occult hip fractures (eg, nondisplaced pubic ramus or femoral neck fracture) may be difficult to diagnose but should be suspected in older adults or those with poor bone health (eg, osteoporosis).

•Step two: Determine if a dangerous medical condition is the cause. (See 'Step two: Determine if a dangerous medical condition is the cause' above and 'Warning: Intraabdominal conditions can refer pain to the hip' above.)

The patient's presentation and a careful history should suggest whether a dangerous medical cause of hip pain should be considered in the differential diagnosis. Dangerous, nontraumatic causes of hip pain include aortoiliac arterial insufficiency, septic arthritis, osteonecrosis, and tumor. Note that abdominal conditions such as inguinal hernia or appendicitis may refer pain to the anteromedial hip.

•Step three: Determine if osteoarthritis or rheumatologic disease is a likely cause. (See 'Step three: Determine if osteoarthritis or rheumatologic disease is a likely cause' above.)

Osteoarthritis of the hip is relatively common and typically presents with pain of insidious onset that is felt deep in the anterior hip or groin, exacerbated by activity, and relieved by rest. Rising from a seated position often elicits hip pain. Both active and passive hip movements are painful; internal rotation tends to be reduced sooner and more profoundly than external rotation. Other potential causes of hip pain in this category include rheumatoid arthritis, spondyloarthritis, and crystal arthropathy.

•Step four: Determine if radiculopathy or nerve entrapment is a likely cause. (See 'Step four: Determine if radiculopathy or nerve entrapment is a likely cause' above.)

Compression of lumbosacral nerve roots or of peripheral nerves can manifest as hip pain. Nerve-related pain is often associated with paresthesias or an "electric" sensation and typically radiates along the course of the nerve.

•Step five: Determine if pain is focal, suggesting a discrete musculoskeletal diagnosis. (See 'Step five: Determine if pain is focal, suggesting a discrete musculoskeletal diagnosis' above.)

At this step, the most likely diagnoses depend upon the pain's location (lateral, anterior, or posterior) and chronicity. Lateral hip pain is common and is nearly always localized to the region immediately superior to the greater trochanter, the site of the gluteal tendon insertions and trochanteric bursa. Anterior hip pain is often due to hip joint pathology.

●Diagnostic testing – Laboratory testing is often unnecessary for determining the cause of hip pain but may be indicated if the history and examination raise suspicion for rheumatologic or other systemic disease. Diagnostic imaging should be used judiciously and is best reserved for patients with acute hip pain to exclude fracture or moderate to severe chronic hip pain, or as an initial assessment of hip osteoarthritis. Further imaging (typically magnetic resonance imaging [MRI]) may be required based upon the results of initial radiographs in combination with clinical findings or in cases of hip pain recalcitrant to treatment. (See 'Laboratory testing' above and 'Diagnostic imaging' above and 'Diagnostic procedures' above.)

ACKNOWLEDGMENT — The editorial staff at UpToDate acknowledge Bruce Anderson, MD, who contributed to an earlier version of this topic review.