Safety Considerations

Special care should be taken when evaluating the hip joint of a patient who has previously undergone total hip replacement. In the early postoperative period, the clinician should ask patients whether their surgeon has informed them of any specific restrictions. For example, hip revision surgery may involve compromise to the hip abductor muscles, and active hip abduction may be contraindicated in the early postoperative period. Similarly, patients may be instructed to avoid weight bearing during the initial 6 weeks after complex revision hip reconstructive surgery and occasionally after uncemented or complicated primary hip replacement surgery. Hip precautions in the early postoperative period are meant to minimize the risk of hip dislocation, although with the newer surgical techniques, these restrictions are being relaxed. The restrictions involve limiting hip flexion beyond 90°, internal rotation of the hip in flexion, external rotation of the hip in extension, and hip adduction beyond the midline. When testing ROM, the risk of anterior dislocation of the hip is greatest with the hip in extension, adduction, and external rotation. The risk of posterior dislocation is greatest when the hip is flexed, internally rotated, and adducted.

Leg Lengths

In the early postoperative period after total hip replacement surgery, the clinician should be careful with respect to the evaluation of leg lengths. Hip arthritis is commonly associated with joint collapse, fixed flexion deformity, and adductor tendon contraction that leads to significant functional shortening of the involved lower extremity. The limb may initially appear functionally long to the patient after surgery, given the correction of the deformity that is achieved intraoperatively. Residual soft-tissue contractures about the ipsilateral or contralateral hip, or pelvic tilt secondary to degenerative scoliosis, may also give the patient the perception of having a relatively short or long lower limb after surgery. Even if a small, true leg-length discrepancy is discovered after careful examination, it may be best to wait for at least 6 months after hip replacement surgery before recommending corrective shoe raises or inserts. This time frame allows for some contractures to resolve, and many patients will no longer require leg-length adjustment.

Antalgic or Painful Gait

The hallmark of an antalgic gait is a shortened stance phase on the affected side, but as the patient tries to minimize both the duration and the magnitude of painful forces across the affected area, numerous compensatory patterns of gait may be observed. For example, patients with a painful great toe may walk on the lateral border of the foot or on the heel to remove force from the painful toe, and they are unlikely to exhibit the normal ankle plantar flexion and toe lift during preswing. A painful knee will tend to be kept in either flexion or extension, and heel strike is often modified by a short step onto a flat foot to keep the center of gravity over the knee and minimize the force acting across a distance behind or in front of the knee joint. Forces across the hip joint are particularly increased during stance phase because of the distance between the hip joint and the center of gravity. In addition to decreasing the duration of stance phase, patients with painful hip joint conditions often try to center the body over the affected hip joint, to minimize the joint reaction force. This involves a lateral movement of the trunk over the affected limb during stance. Thrusting the body weight over the hip joint minimizes pain by decreasing the force across the joint and by decreasing the necessity for the abductors—the gluteus medius and minimus, which may be involved with muscle spasm—to contract to maintain body balance; hence, it reduces pain and muscle spasm to some extent. This gait pattern is a combination of an antalgic gait and a compensated Trendelenburg gait. It is differentiated from an isolated Trendelenburg gait in the decreased stance phase observed in the combined gait pattern.

Trendelenburg Sign and Gait

In 1895, Friedrich Trendelenburg described a clinical sign present in patients with weak hip abductors due to poliomyelitis or congenital hip dislocation. The Trendelenburg sign is observed by having the standing patient alternately raise each leg for at least 30 seconds. The examiner stands behind the patient and observes the pelvis. Normally, the pelvis rises up on the unsupported side due to contraction of the gluteus medius to maintain body balance, but the trunk should not swing over the stance leg by more than a few degrees. In a positive uncompensated Trendelenburg sign, the pelvis drops down toward the unsupported side. This indicates weakness of the abductor muscles of the planted leg (Figure 5-7). The dropping pelvis will be observed only if the patient is prevented from compensating for the weak abductor muscles by thrusting the body over the planted leg. If the patient must thrust the weight over the leg in stance phase when lifting the opposite leg, this is considered a positive compensated Trendelenburg sign (Figure 5-8). Normally, a patient should be able to maintain the muscle force for at least 30 seconds. If the sign is initially negative (normal) but becomes positive within 30 seconds, this is known as a delayed (compensated or uncompensated) Trendelenburg sign and suggests muscle weakness or progressive pain inhibition of muscle contraction.

FIGURE 5-7 UNCOMPENSATED TRENDELENBURG SIGN.

FIGURE 5-8 COMPENSATED TRENDELENBURG SIGN OR GAIT.

Assessment of the gait pattern may reveal a compensated Trendelenburg gait or, rarely, an uncompensated Trendelenburg gait. In an uncompensated Trendelenburg gait, the pelvis drops on the unsupported side during single-leg stance. This is rarely observed, as the patient would fall over without support on the opposite side with a cane or crutch. To compensate for the weak abductors, patients usually swing the body over the affected side, thus placing the center of gravity directly over the hip joint and eliminating the need for the abductors to contract. The appearance is similar to that of a compensated Trendelenburg/antalgic gait caused by hip joint pain with loading (described earlier), except that the stance phase duration is relatively normal in the absence of hip pain. A severe bilateral compensated Trendelenburg gait, or waddling gait, is characteristic of bilateral hip dislocation or weakness of the hip abductor muscles due to muscular dystrophy or poliomyelitis.

A positive Trendelenburg sign or gait may result from hip arthritis, an unstable hip, abductor muscle weakness due to poliomyelitis or muscular dystrophy, L5 nerve root impingement, and, indirectly, from loss of normal abductor muscle tension due to hip dislocation. The sign can also be positive if the rib cage impinges on the pelvis in scoliosis. Severe knee varus deformity can cause a false-positive Trendelenburg sign or gait, because the hip abductors are poorly tensioned (i.e., the femur is always in relative abduction with respect to the pelvis).

Leg-Length Discrepancy

To the patient, one leg may appear or feel relatively longer than the opposite leg for a number of reasons, including pelvic tilting due to spinal deformity (pelvis raised on the side of the shorter leg), fixed hip abduction, or fixed equinus of the ankle or foot. Conversely, a leg may feel short if there is a fixed hip adduction or a fixed flexion deformity of the hip or knee joint. With true leg-length discrepancy, the shoulder on the side of the short leg drops during that leg’s stance phase. The knee of the longer leg may be held flexed when standing with the feet together, as the patient attempts to keep the pelvis level (see p. 56 for Leg-length Measurement).

Astasia-Abasia

Although malingering is rarely encountered in normal medical practice, one does occasionally encounter a patient who is dealing with issues of secondary gain or a patient with psychological issues that result in abnormal gait patterns not based on any neuromuscular pathology. A malingering patient complaining of leg pain may demonstrate an increased duration of stance phase on the symptomatic leg, often accompanied by dramatic facial expressions of pain and the hands gripping the symptomatic leg, as the patient attempts to persuade the examiner how painful the leg really is. Others stand shaking and quivering, taking very small steps before collapsing into a nearby chair. It is important in these situations to be certain that there is no neurological problem that might account for the gait pattern. When recording findings that do not seem to be based on physiological pathology, it is best to simply report the incongruous findings (e.g., increased stance duration on the symptomatic side), rather than attaching a label to the patient such as “malingering patient” or functional overlay syndrome.

Gluteus Maximus Gait

An individual with hip extensor weakness tends to thrust the pelvis forward while leaning back with the trunk and shoulders at heel strike. This passively extends the hip until the iliofemoral ligament becomes taut and stabilizes the lower extremity (see Figures 5-2 and 5-3). The center of gravity can then move forward over the planted leg without it collapsing.

Drop-Foot Gait

Nerve injury to the peroneal division of the sciatic nerve results in weakness of the foot and ankle dorsiflexor muscles. With severe weakness of ankle dorsiflexion, the toes drag on the floor during swing phase, unless the patient lifts the foot higher than normal by exaggerated flexion of the hip and knee (high-steppage gait). The patient may also clear the ground by circumducting the leg out to the side during swing (circumduction gait). During heel strike, a weak tibialis anterior muscle cannot hold the foot, which slaps to the ground shortly after heel strike (slap-foot gait).

Is There Pathology of the Soft Tissues, Muscles, or Tendons?

Femoral neurovascular structures. The vascular status of both limbs should always be determined as part of a lower-extremity evaluation. A quick arterial screening test involves examining the quality of the distal skin and palpating the pedal pulses (dorsalis pedis and posterior tibial). If distal arterial circulation is intact, there is usually no proximal impediment to arterial flow, and a detailed examination of femoral and popliteal pulses may not be required. The femoral artery can be palpated just lateral to the midpoint of the inguinal ligament. The femoral vein lies immediately medial to the artery but usually cannot be palpated. The femoral nerve lies lateral to the artery, within the iliopsoas muscle sheath, and also cannot be palpated (Figure 5-9). Lymph nodes that drain the leg are located medial to the vein. Some nodes are normally palpable, but enlarged, painful nodes may indicate infection or other pathology.

FIGURE 5-9 THE FEMORAL TRIANGLE.

Sciatic nerve and adjacent structures. With the patient in the lateral position, and the hip slightly flexed, the sciatic nerve may occasionally be palpable in thin individuals, just superior to a line connecting the ischial tuberosity and the greater trochanter, where the nerve lies on the obturator internus tendon and the quadratus femoris muscle. Tenderness in this area and just above it, in the greater sciatic notch region, may indicate sciatic nerve irritation or piriformis muscle spasm or inflammation. The piriformis muscle lies somewhat higher, above the line between the greater trochanter and the ischial tuberosity, but it usually cannot be palpated. The sciatic nerve typically exits through the greater sciatic notch just below the piriformis muscle, but it may penetrate the muscle or exit entirely above it (Figure 5-10).

FIGURE 5-10 THE SCIATIC NERVE AND SURROUNDING STRUCTURES.

Bursae. A bursa is a potential space with very little fluid that facilitates movement of adjacent soft tissues. It is usually not palpable unless bursitis with fluid distension has developed. Bursae are compressible but may be quite firm to palpation. A chronic bursitis may lead to loculation of the bursa, making it difficult to aspirate. There are a number of bursae about the hip joint. In trochanteric bursitis, there is tenderness over the greater trochanter and its posterolateral aspect, pain on resisted abduction and rotation, and, rarely, a local swelling. There is little or no pain on hip flexion or extension. Iliopectineal bursitis is associated with tenderness and sometimes a swelling just lateral to the femoral pulse in the groin, just below the inguinal ligament. The bursa becomes more tense and painful with hip extension. In ischiogluteal bursitis (“weaver’s bottom”), there is tenderness and sometimes swelling over the ischial tuberosity. With hip flexion, the gluteus maximus moves off the tuberosity, and the bursa becomes more readily palpable and easier to inject. The differential diagnosis includes avulsion or tendinitis of the hamstrings, fracture, or osteitis of the tuberosity.

Iliopsoas tendon pathology. Iliopsoas dysfunction is a common source of complaints in athletes. The muscle belly of the iliacus can be palpated in a thin individual above the inguinal ligament. The iliopsoas tendon insertion into the lesser trochanter can be felt in some individuals with the hip in a relaxed position of 30° to 45° of flexion with slight external rotation and abduction. To palpate the lesser trochanter and distal iliopsoas tendon requires deep palpation in the femoral triangle just lateral to the femoral pulse.

A snapping sensation of the iliopsoas tendon may occur in dancers and other athletes. It can best be demonstrated by the patient recreating the maneuver that causes their symptoms but may be demonstrable in some cases by taking the hip from a flexed, abducted, and externally rotated position to an extended, adducted, and internally rotated position passively, or by asking the patient to do so actively. Passive stretch of an inflamed muscle or tendon will result in pain. The iliopsoas can be passively stretched by hip extension using a modified Thomas test, which we will discuss shortly.

Active muscle contraction is painful in the face of an inflamed musculotendinous unit. The iliopsoas can be isolated to some degree with the patient seated at 90° and the hip slightly externally rotated. The patient is then asked to flex the hip against resistance with the knee flexed or extended. Pain in the groin region may be due to inflammation along the iliopsoas or at its insertion into the lesser trochanter.

Adductor tendon pathology. The adductor longus and the gracilis tendons originate from the pubis just lateral to the pubic symphysis, where they may be palpated. They become prominent and can usually be visualized when the hip is abducted. A position of hip and knee flexion with hip abduction, while keeping the feet together in a frog-leg position on the examining table, may be more comfortable for the patient to maintain than abduction with the hip in extension. These tendons may be tender to palpation due to tendinitis or injury. Occasionally, the insertion of the tendon into bone may be traumatically avulsed, causing pain.

Piriformis muscle pathology. Piriformis syndrome is caused by piriformis muscle sprain or inflammation or by irritation or compression of the sciatic nerve as it passes the piriformis muscle posterior to the hip joint. A history of blunt, local trauma is common. Piriformis syndrome is associated with posterior hip pain produced by resisted external rotation of the hip with the hip and knee flexed at 90° (Pace test). Buttock pain—exacerbated by passive hip Flexion, Adduction, and Internal Rotation (FAIR test)—is also commonly present. In the piriformis test, the piriformis muscle is isolated by flexing the hip to approximately 60°, with comfortable knee flexion, in either the supine position or a lateral decubitus position. The examiner then passively stretches the piriformis muscle by bringing the knee into adduction (Figure 5-11). Active abduction of the limb against resistance can also be tested. Pain results if the muscle or tendon is strained, and radicular pain may indicate sciatic nerve irritation at the level of the piriformis muscle.

FIGURE 5-11 PIRIFORMIS TEST.

A number of tests have been developed to evaluate specific conditions. These are applied as required based on the history of potential pathology.

Is There a Labral Tear of the Hip Joint?

Athletes complaining of groin pain should be evaluated for a possible tear of the hip joint labrum. A history of clicking in the hip joint is a highly sensitive symptom for this condition, but it is not specific. Stressing the labrum by internally rotating the flexed hip in adduction and applying axial compression may cause pain in the presence of a labral tear. A recent study found this maneuver to have a sensitivity of 75% for detecting labral tears but a specificity of only 43%. Apprehension and pain on external rotation of the extended hip may also be associated with a labral tear.

Is the Iliotibial Band Tight?

With the patient in the lateral position, the uppermost hip being evaluated is abducted and extended, and the knee is flexed. On removal of the medial support, the normal hip passively adducts to allow contact of the knee with the examining table (Ober test). A tight iliotibial band prevents the hip from adducting passively (Figure 5-12). In complete deformity due to severe contraction of the iliotibial band, the hip is held flexed, abducted, and externally rotated; the knee is flexed with a genu valgus deformity; and pes equinovarus, unequal leg lengths, and compensatory lumbar lordosis are often present.

FIGURE 5-12 OBER TEST.

Is There Iliotibial Snapping?

As noted above, one cause of so-called snapping hip involves the iliotibial band snapping over the greater trochanter. This occurs more commonly in a tight iliotibial band. The snapping is often best demonstrated by the patient. Often in single-leg stance, with the hip moved between flexion and extension, the addition of slight rotation in either direction will elicit the snap. The examiner may also ask the patient to lie in the lateral position, with the affected hip uppermost, and flex and extend the hip in both internal and external rotation to try and elicit the snapping.

Is the Tensor Fascia Lata Muscle Tight?

Hip and knee flexion deformity may be caused by a tight tensor fascia lata muscle. Whether this is the case can be determined by the Young test: The hip is abducted to relax the tight tensor fascia lata muscle, and the hip and knee flexion deformity disappears if it was caused by a tight tensor fascia lata muscle.

Are the Hamstring Muscles Tight?

The hamstring muscles cross both the hip and the knee joints. Hamstring muscle tension can be properly assessed only if hip flexion is normal, the hamstring muscles are relaxed (by flexing the knee), and there is no evidence of sciatic nerve root irritation. While the patient is sitting with hips and knees in 90° flexion, the knee is extended on the side being tested. If the hamstrings are tight on that side, the patient will lean back to extend the hip and avoid tension in the tight hamstring (tripod sign or flipping sign). To balance themselves on the examining table as they lean back, patients may place their arms behind them, creating a tripod to support the trunk (Figure 5-13).

FIGURE 5-13 TRIPOD SIGN.

Is the Rectus Femoris Muscle Tight?

The rectus femoris muscle crosses both the hip and the knee joint. Muscle contracture can be demonstrated by noting movement at one joint as the muscle is stretched at the other. In the Ely test, the patient lies prone as the affected knee is flexed; a tight rectus muscle will cause the hip joint to flex, resulting in elevation of the affected buttock (Figure 5-14). Conversely, if the patient is supine, and the knee is flexed over the end of the examining table, the affected knee will extend as the hip joint is extended. (Hip extension is accomplished by flexing the opposite hip passively to flatten the lumbar lordosis, as in the Thomas test, and then pushing the affected hip into extension.)

FIGURE 5-14 ELY TEST.

Is There Pathology Involving Bony Structures?

Pubic rami. Tenderness, and sometimes swelling, over the pubic rami and symphysis pubis occurs in osteitis pubis. It may also occur in spondyloarthropathies, trauma, and with pelvic infection, and the area should be palpated if this is suspected.

Greater trochanters. The greater trochanters are readily palpated in most individuals, in supine or standing position, by placing the extended fingers of both hands on the lateral aspect of each upper thigh and feeling gently from the buttock posteriorly to the thigh anteriorly, until the firm bony prominence of the greater trochanter is detected. The superior and posterior aspect of the greater trochanter is usually the most readily palpable, and the superolateral area is generally the point of tenderness in trochanteric bursitis (Figure 5-15). Trochanteric bursitis is a common cause of hip pain, and palpation for tenderness in this area is usually part of a routine hip examination.

FIGURE 5-15 BONY STRUCTURES OF THE HIP AND PELVIS: ANTERIOR ASPECT.

Iliac crests and anterior and posterior superior iliac spines. The iliac crest can be readily palpated in most individuals. The relative position of the two iliac crests in relation to the spine and the lower extremities is used to evaluate joint deformity and ROM. The most medial and distal point of the iliac crest is the anterior superior iliac spine (ASIS). This landmark is used as a reference point when measuring leg lengths, when assessing pelvic position in the measurement of hip ROM, and when evaluating pelvic obliquity. From behind, in the prone or standing patient, the PSIS can be palpated by following the iliac crest downward and posterior, until the most distal and medial point is reached (Figure 5-16). This landmark is used to further delineate the spatial orientation of the pelvis. It is also useful during surgery as a landmark for posterior approaches to the hip and acetabulum. Palpation upward from the midline at the level of the posterior superior iliac spines reveals the S1 spinous process and, above it, the more prominent L5 spinous process.

FIGURE 5-16 BONY STRUCTURES OF THE PELVIS: POSTERIOR ASPECT.

Ischial tuberosity. The ischial tuberosity is most easily felt with the patient lying in the lateral decubitus position with the hip flexed. This area should be palpated if ischial bursitis is suspected.

Hip Flexion

To test active ROM, the patient should be lying supine with legs extended and should be instructed to bring one knee up to the chest as far as possible; this will test hip flexion. Extension is generally tested once the patient has either moved to lie on one side or is lying prone. In a prone position, the patient is instructed to move the leg up off the examination table. Care must be taken to make sure the patient is not extending at the lumbar spine to achieve this.

After the active flexion has been recorded, passive ROM should be tested. The patient should start by lying supine with the knee flexed, and the hip is flexed passively until a firm end point is reached (Figure 5-21). This may not occur until the knee touches the chest (about 120°), but other normal individuals may demonstrate only 100° of flexion. Even patients with a solid hip fusion may appear to have some hip flexion mobility due to pelvic rotation. To eliminate the possibility of misinterpreting pelvic rotation as hip flexion, the examiner should place a hand behind the upper pelvis and lower lumbar spine to monitor pelvic rotation. Once that firm end point has been palpated, the examiner should add a little extra stress in the direction being tested to test for stress pain that may be indicative of an actively inflamed joint.

FIGURE 5-21 HIP FLEXION.

Hip flexion power can be assessed with the patient supine or in a sitting position, beginning with the hip in approximately 90° of flexion. Although the rectus femoris also crosses the hip and knee joint, the iliopsoas muscle (L2, L3) is the main hip flexor. Because it inserts posteriorly into the lesser tuberosity of the femur, the iliopsoas can be isolated by externally rotating the hip during flexion strength testing.

Hip Extension

Hip extension beyond neutral is limited in normal individuals to less than 20°. In the prone position, with the knee extended to slacken the rectus femoris muscle and the pelvis stabilized, the hip is actively and then passively extended. The point at which the pelvis begins to rotate represents the maximum amount of hip joint extension. The gluteus maximus (S1, S2, and also L5) is the principal hip extensor muscle, although there is some contribution from the hamstrings as well. Power can be tested in the prone position by applying pressure on the sacrum and asking the patient to lift the leg off the examining table. In the prone position, both hands can be applied on the distal limb to resist the powerful extension force, as the pelvis rests in a stable position on the examining table. Performing the test with the knee flexed isolates the gluteus maximus muscle. The patient with a fixed hip-flexion deformity may be unable to lift the leg off the table, depending on the degree of compensatory lumbar lordosis that can be generated. In this situation, the knee should be dropped off the side of the examining table, allowing the hip to flex so that strength can be tested. Alternatively, hip extensor strength can be tested in the supine position, beginning with the hip in flexion and resisting full hip extension with a hand under the heel.

Thomas test for fixed flexion deformity. When assessing hip ROM, it is essential to rule out a fixed flexion deformity. Such a deformity, which is common with hip joint arthritis, may be masked in the supine position due to an exaggerated lumbar lordosis that allows the legs to lie flat on the examining table. To assess for fixed hip-flexion deformity, the lumbar lordosis must be flattened completely by rotating the pelvis back, but care should be taken to avoid overrotating the pelvis and thereby overestimating the amount of deformity. The easiest way to rotate the pelvis is to use the opposite leg as a fulcrum. By passively bringing the opposite flexed hip and knee up toward the patient’s chest, while feeling for flattening of the lumbar lordosis with the other hand behind the lower back, the correct pelvic position can readily be achieved. The patient may be asked to hold the flexed hip in this position with the hands placed around the knee to “hug” it toward the chest. Sometimes it is easier to flex both hips and knees until the lordosis is flattened. The hip to be tested is then extended until an end point is reached. If the femur can be dropped completely down to the examining table, no fixed flexion deformity of the hip is present, although extension may still be limited compared with the other side. The angle between the examining table and the femur of the limb being tested represents the degree of fixed flexion deformity in that hip joint (Figure 5-22). This maneuver was first described by Hugh Owen Thomas in the late 1870s and has become known as the Thomas test. It should be noted that a flexion deformity of the knee may masquerade as a fixed hip-flexion deformity, because it prevents the femur from lying flat on the table. In this circumstance, one can drop the lower leg of the side being tested off the side of the examining table. The angle between the table and the femur will then represent the magnitude of any fixed hip-flexion deformity. A fixed flexion deformity of the hip may be caused by capsular or muscle contracture or by joint deformity.

FIGURE 5-22 THOMAS TEST.

Abduction

Active and passive hip abduction can be measured in both flexion and extension. With the patient lying supine, the pelvis is stabilized by placing the examiner’s hand on the opposite ASIS. The patient is instructed to abduct one leg at a time. Maximum abduction occurs at the point just before the ASIS begins to move, with any further movement representing pelvic tilt as opposed to hip joint motion (Figure 5-23). The same movement is then performed passively. Similarly, with the hip and knee in 90° of flexion, the knee is moved laterally toward the examining table. Again, lifting off of the opposite hemipelvis indicates the beginning of pelvic motion and the limit of hip joint abduction. Assessing abduction of both limbs simultaneously obviates the problem of having to stabilize the pelvis and can also reveal subtle differences between the two sides more readily than individual limb testing can. Normal hip abduction is about 45° in extension and 60° in flexion, although there is considerable interindividual variation. The gluteus medius (L5; also L4 and S1), along with the gluteus maximus (S1, S2) and the tensor fascia lata, which insert into the iliotibial band, represent the main hip abductors. Hip abduction power is most easily tested in the opposite lateral decubitus position. In this position the pelvis is stabilized on the examining table by the body. The examiner can then resist hip abduction either in full extension or in varying degrees of hip flexion.

FIGURE 5-23 HIP ABDUCTION.

Adduction

When testing hip adduction, it is best to abduct the contralateral leg to provide space for the leg being evaluated, rather than crossing the legs during testing. Testing active adduction involves asking the patient to adduct one leg across the midline toward the resting leg. The pelvis should be stabilized. The same movement can then be performed passively. Again, this can be performed in the supine position with the hip extended or with the hip flexed. Normal hip adduction is up to 30°. The adductor muscles include adductor magnus, adductor brevis, adductor longus, pectineus, and gracilis (L3, L4, L5, S1). Adduction strength is best assessed by beginning with the hip in an abducted position and asking the patient to return it to the midline.

Internal and External Rotation

Rotation can be assessed in either the prone position (Figure 5-24) or supine position, and it can be evaluated with either the hip in flexion or in extension. Active and passive internal and external rotation are generally performed as part of the same movement. With the patient in the supine position and the knee flexed to 90°, the patient is asked to rotate the raised foot down toward the resting foot while keeping the thigh flexed at 90°. This will test external rotation. Rotating the foot in the other direction will test internal rotation. This same movement is then performed passively. The examiner should make note of the relative position of each hemipelvis to detect pelvic rotation that could result in overestimation during rotation testing; however, it usually is not necessary to stabilize the pelvis manually. The main external rotators of the hip are the piriformis, obturator externus, obturator internus, gemelli, and quadratus femoris muscles (L4, L5, S1). The iliopsoas and pectineus muscles are also weak external rotators. The normal range of external rotation is about 45°. Internal hip rotation is less powerful than external rotation. The normal range is about 40°. The gluteus medius, gluteus minimus, and tensor fascia lata are the main internal rotators (L4, L5, S1), with assistance from the semitendinosus and semimembranosus. Alternatives to testing this range-of-motion test rotation in hip extension, which can be accurately quantified with the patient prone. In the prone position, with the knees flexed to 90°, the angle between the tibia and an imaginary line perpendicular to the examining table can be used as a goniometer to measure internal and external hip rotation. It is important to remember that internal hip rotation involves rotation of the lower leg, rotating away from the midline, whereas external hip rotation involves rotation of the lower leg toward the midline. Rotation in hip extension with the patient supine, determined by rolling the leg medially and laterally, is less accurate and requires consideration of the transepicondylar femoral axis and the patella. Relying on the foot to demonstrate the amount of internal or external hip rotation can lead to errors.

FIGURE 5-24 HIP INTERNAL AND EXTERNAL ROTATION IN PRONE POSITION.

For assessment of the strength of rotation with the hip extended, the patient lies prone with the knees 90° flexed. To test internal rotation, the patient is asked to move the foot from the midline laterally against the examiner’s resistance. Similarly, external rotation of the hip is tested by asking the patient to move the foot medially against the examiner’s resistance.

Rotation in 90° of hip flexion can be performed with the patient sitting, knees flexed over the edge of the examining table, or with the patient supine. In both positions, the tibia can be used as a goniometer relative to an imaginary midline bisecting the pelvis. To test rotation power in hip flexion, the supine or sitting patient begins with the hips and knees flexed to 90°. To test internal hip rotation, the patient is asked to move the foot from the midline laterally against the examiner’s resistance. To test external hip rotation, the patient is asked to move the foot medially against resistance.

In general, at least 120° of hip flexion, 20° of abduction, and 20° of external rotation are required for performing activities of daily living. Hip joint stiffness makes it difficult for an individual to reach the toes for foot care (shoe tying requires about 120° flexion) or even to pull on socks and pants (requiring about 90° of hip flexion).

Is the Sacroiliac Joint Painful?

There are many tests that attempt to stress the SI joints. The FABER test (Flexion, ABduction, and External Rotation) is also known as the Patrick test, but the ankle-to-knee or heel-to-knee test is the most common term for it. With the patient in the supine position, the affected hip is externally rotated with the knee flexed, so that the affected ankle can be placed on top of the opposite knee in a number-four position. Applying downward pressure to the affected knee stresses the hip joint and may cause typical hip pain. In the absence of hip pathology, when the pelvis is stabilized by applying pressure over the opposite iliac crest, the affected SI joint is stressed (Figure 5-25). Pain in the gluteal region of the stressed side is considered a positive test.

FIGURE 5-25 FABER TEST.

The Gillet test evaluates the amount of SI motion in the coronal plane. With the patient standing, the examiner palpates the spinous process of S2 with one hand and the PSIS with the other. As the patient flexes the hip on the side being evaluated, the PSIS should normally move posteriorly and inferiorly with respect to S2. Absence of movement suggests sacroiliitis with fusion of the joint.

What Is the Degree of Femoral Anteversion?

The femoral neck emerges at an angle from the femoral shaft relative to the femoral condyles distally. The angle changes from approximately 30° of anteversion in infants to 10° to 15° in adults. An assessment of femoral anteversion (forward torsion) and tibial torsion is essential when evaluating disorders of the lower extremities. Anteversion of the hip is the acute angle made by the femoral neck in relation to the femoral condyles. Excessive anteversion is more common in girls than in boys and can be associated with the patellae facing inward (“squinting patellae” and “toeing in”).

Although a computed tomographic (CT) scan provides the most accurate method of measuring the degree of femoral anteversion, an approximation can be achieved by considering the position of the greater trochanter during hip rotation (Craig test). In a normal individual, the greater trochanter will be felt most prominently and directly lateral with 10° to 15° of internal hip joint rotation when the femoral neck is parallel to the floor. The degree of internal rotation required to bring the trochanter into this position can be noted in a prone patient with the knees flexed to 90°. The examiner places the greater trochanter into the most prominent position by rotating the hip. The angle between the leg and an imaginary line perpendicular to the floor from the knee denotes the degree of rotation required to achieve this position, which corresponds to the degree of femoral anteversion (Figure 5-26).

FIGURE 5-26 CRAIG TEST.

Trochanteric Bursitis

With the patient lying on the nonpainful side, the greater trochanter is palpated to find the most tender area. The bursa is generally located in the posterolateral region. Once the area has been marked and prepared, a 25 gauge needle is inserted perpendicular to the skin, until the trochanter is reached, and then withdrawn slightly before a lidocaine-corticosteroid mixture is injected in a fan-shaped fashion (Figure 5-29). In most patients, a 1½ inch needle is adequate to reach the trochanter. In patients with greater adiposity, a longer needle may be required.

FIGURE 5-29 ASPIRATION AND INJECTION OF THE TROCHANTERIC BURSA.