Clinical reasoning in the evaluation and management of undiagnosed chronic hip pain in a young adult.

KEY WORDS: Case report, Chronic hip pain, Clinical reasoning, Congenital hip dysplasia, Physical therapy evaluation, Physical therapy management.

Hip pain in adults has many causes. It often is associated with hip joint trauma or disease in people who are elderly.[1] Trauma to the hip joint, however, may occur at any age, and hip joint disease can develop in younger age groups as a result of congenital or acquired bony deformities.[2] Hip pain also may arise from the periarticular tissues, muscles, or nerves that surround the hip joint, or it may be a result of problems in the lumbar spine, sacroiliac (SI) joint, or the visceral organs in the abdominal cavity or pelvic region.[3] Given the wide range of possible causes and sources of hip pain, the generation and analysis of the patient's history and physical examination data are important to an understanding of the problem and its appropriate treatment. For example, when a patient with its nonspecific complaint such as "hip pain" is seen, the individual's history and data from the physical examination form a pattern of evidence that suggests one or more of the many possible that suggests one or more of the many possible causes and sources of hip pain are primarily responsible.

Several types of protocols for examination of the hip have been suggested.[2,4,5] None have been standardized, and the validity, reliability, sensitivity, and specificity of individual tests within these examinations are largely unknown. In addition, most of these protocols have not been described in the peer-reviewed literature. Most physical therapy examinations of the hip joint seem to have been compiled from a variety of general concepts related to pain, posture and movement, biomechanics, neurological mechanisms of referred pain, the soft tissue approaches of Cyriax,[6] and the patient's ability to function. Elements of the examination may include a medical history screening; detailed description of the hip pain; attempts to reproduce the pain by placing stress on various tissues; evaluation of posture and hip joint range of motion (ROM); assessment of hip muscle force, length (as indicated by ROM), and control of limb movements; gait analysis; screening of the lumbar spine of the lumbar spine and SI, knee, and ankle joints; and assessment of the ability to perform routine daily activities that involve the hip joint. Most of these tests of hip function are well known to clinicians. How clinicians use the information to develop hypotheses about pain production or to determine treatment for individual patients is less well known and may vary among therapists.

Several organization models for reasoning about chronic musculoskeletal pain exist. The model used may determine what information is collected, how the information is interpreted, and how the problems is labeld with a diagnosis or treated. Cyriax, for example, suggests using data collection and clinical reasoning to generate a diagnosis that links problems with structures. He suggests directing treatment to those particular structures.[6] The Maitland approach relates treatment less to a particular structure or diagnostic label than to a grouping of signs, and symptoms that indicate whether the primary problem is pain, stiffness, or spasm.[7] More recently, Sahrmann[8] has advocated that physical therapy be directed not to an individual structure or genetic problems such as pain, joint stiffness, or muscle spasm but rather at resolving the underlying movement inbalance that may cause these problems to occur or to be perpetuated. Sahrmann[8] has suggested that the key to analyzing chronic musculoskeletal pain is to recognize the abnormal movement pattern, and she suggests labeling the abnormal movement pattern as the diagnosis to be treated. None of these approaches have been studied with clinical trials, and there are almost no reports on their effectiveness in the peer-reviewed literature. The purpose of this case report is to illustrate the clinical reasoning used in an eclectic approach to analysis and management of undiagnosed chronic hip pain in an active young adult.

Case Description and Interview Data

The patient was a 21-year-old female student in a physical therapy program. During a physical therapy class laboratory session, I noticed that despite the student's otherwise relaxed sitting posture, her left hip was medially (internally) rotated. She said that she had left hip pain that interfered with her ability to participate comfortably in the recreational activities that she enjoyed, land she indicated her desire for a formal evaluation of her problem. In accordance with the state law that regulates physical therapy practice in Vermont,[9] she was able to refer herself to me for physical therapy evaluation and management. Physical therapy was provided to the patient at no cost.

A detailed history of past and current general health and neuromusculoskeletal problems was obtained orally from the patient. She did not report any general health problems or any symptoms associated with her trunk, left or right ankle, or right knee. She reported the following details related to these other problems in her left lower extremity.

Past Medical History Related to Left Hip

She said that her mother had told her she was born with what her mother thought was left hip dysplasia and had received treatment for this problem through some type of nighttime bracing as an infant. "Hip dysplasia" is a term used to describe abnormal development of either the acetabulum or the proximal femur, or both, which can lead to hip dislocation or subluxation.[10] If severe and left untreated, the problem can result in hip joint disease and gait abnormalities." Some hips, however, that are identified early after birth as being susceptible to dislocation spontaneously recover. Morrissy[10] speculated that these hips may develop into anatomically normal hip joints or may only show instability at some later point in life. According to the patient, she had had no other medical or surgical treatment for the dysplasia besides the nighttime bracing. No imaging procedures had been performed on the left hip since infancy. She therefore was unaware of the current status of her hip joint structure.

Post Medical History Related to Left Knee

The patient reported sustaining trauma to her left knee during a soccer game 6 years before I initially examined her. She collided with another player, causing her left knee to be forced inward from the lateral side. She was seen in a hospital emergency department and was told that she had a lateral patellar subluxation. The subluxation was managed for I week with a knee immobilizer, and she was restricted from bearing weight on the left lower extremity for I week. She subsequently under-went a series of physical therapy treatments for 2 1/2 months. These treatments consisted of active range of motion (AROM) of the knee and strengthening exercises for the quadriceps femoris and hamstring muscles. In addition, she was advised to wear a protective brace on her left knee while participating in any sport activity, and she reported that she did so.

The patient reported that her left patella spontaneously subluxated during various activities four more times during the 4 years after the initial injury. In some instances, she again underwent physical therapy for edema reduction and general lower-extremity strengthening, but in other instances, she simply used ice and rest. She stayed active in sports throughout this period. After the fifth time her patella subluxated (4 years after the initial subluxation) and because of the recurrent nature of the subluxations, she had surgery for a lateral release and medial tuck of the soft tissues surrounding the left patella. She said that she had experienced no further patellar subluxations during the 2 years since the surgery and that the knee was currently pain-free and functioning well.

Past History of Left Hip Pain

She reported that the initial onset of her left hip pain coincided with the first traumatic left patellar subluxation. She remembered recognizing and reporting that her left hip was actually more painful than her left knee at the time but that the hip was not evaluated. The left hip pain decreased in intensity, but it continued throughout the 4-year period between the first and fifth patellar subluxations and was markedly exacerbated for a short period immediately following the knee surgery. Because of this increase of hip pain, a physical therapist administered some treatments of ultrasound and superficial heat to the hip area during postoperative rehabilitation of the knee. No details of these treatments (eg, dosage, timing) are available. She reported no relief from the hip pain, and the thermal modalities were discontinued. At no time did the patient mention her history of left hip dysplasia, nor was an evaluation of hip function performed by the physical therapist or the physician.

Present History of Left Hip Pain

The patient described her present left hip pain as her primary complaint. Her left hip pain had been a problem for 6 years and had been worsening during the previous year. She stated that her "typical" pain was localized to the left posterior hip area, midway between the iliac crest and the ischial tuberosity, with no proximal, distal, medial, or lateral radiation of pain. She described the pain as being intermittent, deep, and achy and as giving her a strong sensation of "tightness" in the left hip when it was present. She said that for the previous 6 years the pain was always present with any sustained lower-extremity exercise. She reported hip pain, stiffness, left lower-extremity fatigue, and a limp after activities such as step aerobics, walking up and down hills, and playing soccer. She occasionally felt the left hip "give out" when walking downhill. She was unable to walk father than 1.6 kin (1 mile) on level surfaces or play soccer continuously for more than 20 minutes without the onset of hip pain. Sitting for longer than 1 hour also caused pain and stiffness in the left hip. The patient was asked to rate her pain using an ordinal scale of 0 (no pain) to 10 (worst pain imaginable). She reported that her level of pain had reached a rating of 8 in the past but that her current pain was consistently a rating of 4 with prolonged sitting and any of the activities described.

Examination

I observed the patient's standing posture from anterior, posterior, left, and right sagittal views. From a posterior view, the left iliac crest appeared to be higher than the right iliac crest and the skinfold at the left waist angle appeared to be deeper than on the right side. From an anterior view, an asymmetry was noted in the toe-out angle between the left and right sides, with the left lower extremity appearing to be more medially rotated than the right lower extremity. No other segmental malalignments or asymmetries between the left and right sides were noted.

Active range of motion of both lower extremities was observed with the patient positioned supine (for hip flexion, abduction, and adduction and for knee flexion and extension), sitting (for hip medial and lateral rotation), and prone (for hip extension and ankle plantar flexion and dorsiflexion). Positions described by Norkin and White[12] and normal values for ROM reported by Kendall et al[13] were used. The patient had full pain-free motion of all right lower-extremity joints and the left knee and ankle. Left hip flexion, extension, abduction, and adduction were also within normal limits and painfree. Active lateral rotation of the left hip appeared to be limited compared with lateral rotation of the right hip, and it was accompanied by left hip pain if the patient made an attempt to move into the restricted range.

Active medial rotation of the left hip was pain-free, slightly greater than on the right side, and demonstrated a ROM that was slightly more than the 45 degrees of medial rotation that Kendall et al[13] reported as average for this joint motion.

Because of the patient's difficulties with active lateral rotation of the left hip, follow-up tests of passive range of motion (PROM) and muscle force comparisons of the left and right hips were performed. The PROM measurements were taken by one examiner using a universal goniometer. The patient's left and right hip PROM was measured in the same patient positions used for AROM determination. All PROM measurements were within normal limits[13] and were symmetrical between sides, except for medial and lateral rotation of the left hip. Left lateral hip rotation was 25 degrees, as compared with right lateral rotation of 40 degrees. Further passive motion in the direction of left lateral rotation reproduced the patient's "typical" left hip pain. Passive medial rotation was greater for the left hip (50 [degrees]) than for the right hip (40 [degrees]), and it was pain-free.

Only a few reports in the literature discuss the validity and reliability of goniometric measurements. Gajdosik and Bohannon[14] stated that, in general, goniometric measurements have content validity if they are not "overinterpreted," and Miller[15] suggested that goniometric measurements are important as an indicator of the ability of a limb to move through an arc of motion. Ellis and Stowe[16] reported a 1% to 5% error in measuring hip ROM when testing was performed by a single examiner, and Ekstrand et al[17] concluded that a single tester who used standardized techniques could make accurate measurements of hip ROM. However, no studies that have specifically examined the validity and reliability of goniometric measurements of hip lateral rotation in young adults with suspected congenital hip dysplasia (CHD) have been reported.

The force-generating capacity of the muscles surrounding both hip joints was evaluated by one examiner using manual muscle testing (MMT) techniques and a scoring system adapted from Kendall et al[13] that used the numbers 0, 1, 2, 3, 4, and 5 in place of the words "Zero," "Trace," "Poor," "Fair," "Good," and "Normal." Resisted isometric contractions at a single joint angle approximately midway in the joint's available ROM were used for all hip MMT measurements, except for measurements of lateral rotation. Hip lateral rotator muscle force was measured with the patient in a sitting position, as described by Kendall et al.[13] For the MMT on each side, the hip joint was positioned at approximately 10 degrees of lateral rotation to accommodate the left hip joint's ROM limitations and to be able to compare hip muscle force of both sides in nearly equivalent joint positions. For all muscle force tests, the scale used was as follows: 5=the muscle can hold a test position against strong pressure; 4=the muscle can hold a test position against moderate pressure; 3=the muscle can hold the body part in a test position against resistance of gravity, but it cannot hold the body part in a test position if even slight pressure is added; 2=the muscle can move the body part only if the body part is placed in a test position that minimizes the effects of gravity; 1=only a feeble contraction of muscle can be felt, with no ability to move or hold the body part in any test position; and 0=no evidence of muscle contraction. No studies describing the validity and reliability of MMT grades for the muscles controlling the hip joint in young adults have been reported.

The patient had a slight decrease in force of all left hip joint muscles (graded 4) as compared with the right hip joint muscles (graded 5) except for the lateral rotator muscles. The left lateral rotator muscle group was graded 3, and the right lateral rotator muscle group was graded 5. The patient reported reproduction of her "typical" pain with the resisted isometric force test of the left hip lateral rotators. The pain, however, did not seem to be the limiting factor in her ability to perform the muscle contraction. I therefore believed that her difficulty was due to muscle weakness, not due to inhibition from pain. No other resisted motion produced pain at the left hip, and all resisted motions of the right hip muscle groups were pain-free.

Two general tests of hip function, the faber test[4] and the scour test,[4] were performed bilaterally and were considered abnormal on the left side. These tests are used to identify general hip dysfunction, although neither test specifically identifies hip dysfunction because the positions and movements involved also likely place stress on the SI joints.[2] Although these tests are in common use, the reliability and validity of measurements obtained with them have not been reported. In the faber test, the patient's left thigh rested considerably higher off the table than the right thigh in an equivalent test position and the patient reported reproduction of her "typical pain" in the hip with active or passive attempts to lower the thigh. In the scour test, the patient reported that her left hip felt "tight" and that she had a sensation of the hip "giving out" laterally, especially during the combined passive motion of hip medial rotation and adduction that forms part of the arc of this test movement. Both tests performed on the right hip were free of any associated symptoms. Because of the possibility of SI joint involvement, follow-up tests for irritability of the SI joints were performed. The SI joints were screened through application of passive pressure simultaneously on the crests of both ilia while the patient was lying supine, a screening technique described elsewhere4 and reported to have good reliability.[18] The pressure elicited no pain at the SI joints and did not reproduce her "typical" left hip pain.

To determine whether there was involvement of the lumbar spine, I observed her trunk while she stood; during AROM of the spine in flexion, extension, side bending, and rotation while standing; and during MMT of the trunk flexor, extensor, and lateral flexor muscle groups in supine, prone, and side-lying positions, according to the procedures outlined by Kendall et al.[13] No postural abnormalities related to the spine were noted, and AROM of the trunk appeared to be symmetrical and pain-free and did not reproduce her hip pain. The only apparent abnormality related to the trunk was in the MMT of the left lateral trunk flexors. 13 While she was positioned lying on her right side, she was unable to lift her upper body more than 5.08 cm (2 in) from the table. She had no difficulty with this maneuver when lying on her left side (ie, the test for the right lateral trunk flexors was within normal limits) or with any other trunk muscle MMT. The difficulty the patient experienced with left lateral trunk raising from the side-lying position was thought to be related to weakness of the left hip abductor muscles, not the lateral trunk muscles. Kendall et al[13] stated that in the test for lateral trunk muscle force, adequate hip abductor muscle force is necessary to stabilize the pelvis on the femur so as to provide a stable base from which the lateral trunk muscles can contract. Without such a base, the patient's ability to raise the trunk from the table may be limited. Studies supporting this assertion have not been published. Because left hip abductor muscle weakness had been found in the MMT, however, I believe that the patient's difficulty in left lateral trunk raising was due to hip abductor muscle weakness, not a lack of trunk muscle force.

Because muscle length at the hip joint, leg length, and bony torsion of the tibia can alter posture, these factors were also assessed. Muscle length in the hip joint area was examined using the Thomas test,[4] the Ober test,[4] and the hamstring muscle length test.[4] Leg-length discrepancy was examined by comparing the distance from the greater trochanter to the medial malleolus in each lower extremity.[4] Tibial torsion was assessed by visually observing the angle that a line between the malleoli made with the coronal plane.[4] No differences were found between the left and right sides in any of these tests. Palpation of the soft tissues and bony prominences of the left hip area revealed only one area of tenderness, which corresponded to the same location in which the patient felt her "typical" left hip pain (ie, an area approximately midway between the left posterior iliac crest and the ischial tuberosity). Deep palpation through the gluteus maximus muscle was required to elicit this pain, which was localized and caused no radiation of pain.

The patient's overall function was observed in two ways. Observational gait analysis was used to determine the presence of any deviations in ambulation on a level surface. She also was observed stepping down laterally from a stool. Gait was selected because of its importance to daily function, because of the patient's reported hip pain with ambulation, and because hip joint dysfunction can have an effect on the gait pattern that is visually obvious.[19] I chose the lateral step-down maneuver as a functional movement that I wanted to assess because the patient routinely performed this maneuver in her step aerobics class. She had identified this movement as particularly awkward and pain producing, and it was a functional activity that could be easily reproduced in the clinical environment. Both movement patterns were recorded on videotape and analyzed by one examiner using slow-motion and frame-by-frame playback. This procedure was used because of the known difficulty with reliability of visual observation of gait[20] and to minimize the repetition and subsequent fatigue that the patient might have to endure if analysis were performed without the taping. Krebs et al[20] found that videotaping in full-field and close-up frontal and sagittal views improved the reliability over using "live" subjects, but that the videotape method still produced only moderately reliable measurements. These researchers speculate4 that checking for the presence of specific gait deviations and using stop-action videotapes might further enhance reliability. However, there is no evidence to support this view.

The patient was videotaped while ambulating on a flat surface approximately 9 in (30 ft) long at what she considered to be her normal pace. She was videotaped using a single stationary camera and only from front and back views. In these views during the videotape playback, attention was focused primarily on searching for two gait abnormalities: any abnormal rotatory motions of the trunk or lower extremity and a lateral pelvic obliquity during the stance phase of the left lower extremity. These two characteristics were selected because of the findings of limited PROM during lateral rotation of the left hip joint and weakness of the left hip lateral rotators and abductors found in the MMT. No abnormal rotatory motions were obvious to the examiner from the anterior or posterior view. Comparison of coronal-plane pelvic position with the videotape stopped at what the observer believed was approximately mid-stance, however, revealed a noticeable contralateral drop of the pelvis when the patient was weight bearing on the left lower extremity. No such pelvic drop occurred when the patient was weight bearing on the right lower extremity.

The lateral step-down maneuver that the patient performed in her aerobics class was recreated by having the patient repetitively step down in the coronal plane using first the left lower extremity and then the right lower extremity from a 20.3-cm-high (8-in-high) stool while being videotaped. I believed that the patient had considerably more difficulty when lowering herself with the left lower extremity than with the right lower extremity. In slow-motion playback of the videotape, her movements were compared when lowering herself with the right (Uninvolved) versus the left (involved) lower extremity. When using the right lower extremity to lower herself, her arms generally remained at her side, the trunk stayed relatively erect, and the right weight-bearing knee and hip flexed while the pelvis dropped to the left (Fig. 1). In contrast, when she lowered herself using the left lower extremity, both arms abducted, the trunk inclined forward, the left weight-bearing hip tended to adduct and medially rotate, and the pelvis appeared to flex markedly forward on the hip and rotate backward in a counterclockwise direction (Fig. 2).

[Figure 1-2 ILLUSTRATION OMITTED]

Evaluation

I believed it unlikely that a visceral organ was the source of the patient's hip pain because of her high level of activity and the lack of any past or current history of general health problems. I also believed that the lumbar spine and the SI joints were not involved in her hip pain. The patient's location of pain, in the posterior buttock area, is more commonly associated with lumbar spine dysfunction than hip joint pathology, which is typically manifested as groin pain.[21] The patient's posterior buttock pain, however, could only be reproduced with hip movements, not spinal motion, and no other findings indicated lumbar spine abnormalities. The other potential origin for the patient's pain, the SI joint, neither produced pain at the SI joint when manual force was exerted on the ilia nor reproduced the patient's "typical" posterior buttock pain. Therefore, I believed that there was little evidence to indicate that the lumbar spine or the SI joint was the origin of her symptoms.

Numerous facts from the history and findings from the examination implicated the hip joint area. These findings were the reported history of CHD, the hip medial rotation noted while at rest in the sitting position, the loss of ROM in lateral rotation, the weakness associated with contraction of the lateral rotator muscle group and other hip muscles, the pelvic obliquity in gait, and most importantly, the fact that maneuvers that stressed structures directly involved with the hip (eg, hip joint PROM during lateral rotation and active contraction of the lateral rotator muscles) consistently reproduced her "typical" posterior hip pain.

I believed that the pattern of left hip ROM and muscle weakness that the patient demonstrated was related to the abnormal movement pattern she used to lower herself in the lateral step-down maneuver with the left lower extremity. At the start of the step-down maneuver, because of the pelvic obliquity that occurred with weight bearing on the left lower extremity, the left hip joint was already adducted. Furthermore, the left hip joint had less than normal ROM available in the direction of lateral rotation as the movement progressed. Therefore, to lower herself laterally to the ground using the left hip joint, I believed that the patient compensated by using her available hip joint flexion and medial rotation. Lack of adequate control by the left hip lateral rotator and abductor muscle groups contributed to producing this abnormal movement pattern and together with the ROM imbalance, altered the patient's center of gravity, forcing her trunk and arms to adjust to avoid a loss of balance.

Although the hip joint as the location of the problem seemed to be well supported by the examination findings, the mechanism at the hip joint that was producing the patient's symptoms remained unclear. Given the patient's reported history of CHD as an infant, hip joint disease or joint instability was a possible mechanism.[22]

I believed that hip joint disease was unlikely to be the cause of the patient's symptoms because neither her reported pain location (posterior buttock) nor her pattern of joint limitation (primary loss of lateral rotation) corresponded to the location of pain (groin area) and joint limitation (primary loss of medial rotation) typically associated with hip joint disease. In contrast, joint instability was suggested by the patient's report of the hip "giving out" occasionally when walking downhill or upstairs; the re-creation of this sensation with the scour test; and the fact that the patient was of an age at which joint instability, not hip joint disease, is a hallmark of CHD.[22] Furthermore, the decreased force of the left hip muscles found by MMT, the pelvic obliquity in gait, and the abnormal movement pattern in the lateral step-down maneuver could have been caused by an unstable hip joint that provided an inadequate fulcrum for hip joint muscle contraction. Despite the apparent weight of clinical evidence seeming to support joint instability from CHD as the mechanism for the patient's hip pain and dysfunction, this explanation was also not a perfect "fit" to the patient's signs because the direction of her hip joint limitation (lateral rotation) was opposite to that classically seen in persons with CHD (medial rotation).[22]

This misfit of signs prompted me to seek alternate explanations for why lateral rotation ROM in particular had become so limited. I believe that the patient's history of problems in the left lower extremity provided such an explanation. The patient's description of the mechanism of her initial trauma to the knee that had resulted in her first lateral patellar subluxation also suggests that there could have been trauma to the lateral rotator muscles or periarticular tissues of the hip joint. I believed it was possible that the lateral force at the knee that was responsible for the patellar subluxation could have simultaneously forced the left hip into a sudden excessive medial rotation, injuring the lateral rotator muscles or part of the capsuloligamentous structures and causing the extreme left hip pain that the patient recalled had occurred at the time of this incident.

I hypothesized that following the trauma, the lateral rotator muscles could have gradually weakened, producing the excessive hip joint medial rotation and loss of lateral rotation that was currently seen. Findings in the physical examination supported this hypothesis. The location of the patient's pain corresponded anatomically to the location of the deep lateral rotator muscles of the hip joint, which were exceptionally weak on the MMT relative to other muscle groups at the hip. These muscles were locally painful on contraction and tender to deep palpation even when the joint was immobile, suggesting a muscular component to the pain.

In addition, I believed that the patient's loss of PROM in lateral rotation might be explained by adhesions that developed over time due to sustained positioning of the hip joint in medial rotation. The patient's pattern of ROM loss is consistent with what Cyriax labeled a noncapsular pattern at the hip joint, which he believed develops from either a partial capsular adhesion or an extra-articular structure.[6] Hayes et al[23] found that the proportions of joint ROM loss that Cyriax defined as capsular patterns of the knee joint were not present with osteoarthritis of the knee. They concluded that a quantitative definition should be abandoned, but they believed that the concept of a pattern of ROM loss may still be useful. No research has been reported on the validity or reliability of the classification of capsular patterns of restriction at the hip joint.

Based on these considerations, I believed that the patient's hip problems were the result of interacting factors. I hypothesized that an undetected trauma had occurred at the left hip at the time of the initial patellar subluxation. This trauma had been imposed on a potentially unstable hip joint that, until the traumatic incident, had been functioning asymptomatically. Following the trauma and without intervention, the patient gradually developed muscle weakness and a joint contracture. The resultant abnormal movement pattern of the left hip now accentuated her preexisting potential for abnormal hip motion and contributed to the development of pathological hip motion and pain. I further believed that the apparent equivocal nature of some hip joint examination findings was likely a result of the gradual superimposition of a loss of ROM and muscle weakness on an underlying instability. This explanation would explain why the patient's clinical picture deviated from the textbook presentation of either singular possibility. Although it was clear that intervention could not alter any bony abnormality that might be present, I believed that the patient should be able to achieve some pain relief and improved hip function if the abnormal movement pattern induced by the periarticular tissue restrictions and muscle weakness could be resolved or at least minimized.

I informed the patient that only diagnostic imaging tests could confirm or rule out some type of femoral or acetabular bony abnormality (from her reported CHD) that might be the source of her joint instability. I also told her, however, that knowledge of the bony status would not change the planned physical therapy intervention and that I believed her hip pain was in large part caused by factors other than a bony abnormality. I advised her that knowing whether a bony abnormality existed might be important to a long-term prognosis regarding her hip joint function because hip instability caused by a bony abnormality can lead to the development of a degenerative disease later in life.[10,22,24] Given this information and based on the fact that the imaging tests represented time and expense to undergo, the patient decided to postpone diagnostic imaging at least until the effects of physical therapy were known.

Management and Outcomes

The patient's primary goal was to resume her full level of desired recreational activity and not be hampered by pain in the left hip. Based on the patient's goal of resumption of activity with less pain and the working hypothesis that the pain that limited her activity was largely the result of joint contracture and muscle weakness at the hip, treatment outcomes for both impairments and functional activities were established.

At the impairment level, the goals were to increase ROM of the left hip in lateral rotation and to increase force of the left hip joint muscles, especially the left hip lateral rotators and abductors. Goals related to function were for the patient to sit for longer periods of time, walk further, and play soccer longer. Additionally, observable improvement in the patient's movement pattern during the lateral step-down maneuver using the left lower extremity would indicate the successful transfer of improved joint ROM and muscle force to a functional movement that was uniquely meaningful and relevant to the patient. I thought that it was important to assess this latter outcome because, contrary to the working hypothesis guiding this patient's treatment, some types of impairments may not translate into functional problems[25] and impairment resolution does not automatically guarantee functional restoration.[26] Pain-free and full left hip PROM and force, elimination of the patient's pain with functional activities, and a return to a fully normal movement pattern in the lateral step-down maneuver were not anticipated because I suspected that a bony abnormality contributed to an underlying problem with left hip joint instability.

The patient was seen twice per week for 3 1/2 weeks for a supervised program of exercises. These exercises consisted primarily of left hip joint AROM and PROM into lateral rotation and strengthening of the left hip abductor and lateral rotator muscles. I did not use joint mobilization techniques because of the presumed underlying joint instability, the difficulty of performing the techniques in such a deep seated joint, and my belief that joint stiffness problems may be more efficiently managed with other types of active and passive exercises that can be done by the patient independently.[27] Passive range of motion and AROM were performed with the patient in the sitting position. For PROM, I moved the patient's hip joint to the extreme of its available lateral rotation range, just short of any compensatory pelvic or trunk motions from the patient and within the patient's tolerance for discomfort, and held it there for approximately 20 seconds before release. This procedure was performed 15 times. The patient then performed AROM from her resting position into lateral rotation through her available arc of motion while I provided mild manual resistance to the motion via hand placements just above the medial ankle and at the distal lateral thigh. The patient then attempted to isometrically contract the lateral rotator muscles of her left hip to hold the hip joint in a position just short of the limit of PROM previously achieved.

Exercises for the left hip abductors were performed with the patient in a right side-lying position, with the left hip neutral with regard to flexion and extension. The patient was instructed to keep the left (upper) knee straight, turn the kneecap out slightly, lift the limb from a pillow placed between the knees, and then hold the limb in an abducted position for approximately 5 seconds before lowering it back to the pillow. Active range of motion and isometric contractions of the lateral rotator muscles and the left hip abductor muscle exercises were performed in sets of three (up to 10 repetitions in each set or until the patient reported fatigue and was no longer able to isolate the motion effectively). She was instructed to add resistance in the form of ankle weights as she was able, with the only guideline being that she had to be able to continue to isolate the motion effectively without other joint compensations.

After two sessions, several other activities were added to the basic exercise and ROM routine. These activities were added to prepare the patient for a simple home program of exercise that she could perform independently during an anticipated 4-month period when she would not be able to attend supervised exercise sessions. These additional activities were (1) rocking backward in a quadruped position while attempting to sit for several minutes at a time with the ischial tuberosities symmetrically positioned on the heels of her feet, (2) moving from a standing position to a partial squat while attempting to maintain as much lateral rotation of the left hip as, possible, and (3) lying supine and prone while attempting to relax the left hip into simultaneous flexion, abduction, and lateral rotation (a "frog-leg position"). This home exercise program was designed to address the goals of increased ROM and control of the left hip joint area. Except for the instruction to practice these exercises "as muck as possible," no other guidelines related to number of repetitions or sessions per day were given to the patient.

At the end of the 3 1/2-week period and just prior to the patient's 4-month absence from treatment, her left hip PROM in lateral rotation was reassessed using the methods previously described. Left hip PROM in lateral rotation was 30 degrees (an increase of 5 [degrees]). The patient had progressed to lifting 3.6 kg (8 lb) in left hip abduction while maintaining control of the limb in abduction and slight lateral rotation. She was continuing to do isolated lateral hip rotation in a sitting position without any added resistance.

The patient's status was reevaluated following her 4-month absence from therapy. She reported that she had worked independently on her three-step home exercise program about three times per week. In addition, she had continued to attempt all recreational activities in which she wanted to participate. The patient's PROM, force, and functional activities were reevaluated in the same manner as previously described. Left hip PROM in lateral rotation was now 40 degrees (an increase of 15 [degrees] compared with her initial PROM). The force of the left hip abductor muscles was graded as 5 (Normal), and that of the left hip lateral rotators was graded as 4. The patient's movement pattern in the lateral step-down maneuver was videotaped and analyzed. In the lateral step-down maneuver, using the left (involved) side, the movement pattern she used appeared to have changed from the initial pattern demonstrated 4 months earlier. It now closely resembled the pattern she used on the right (uninvolved) side, with none of the compensatory motions she had demonstrated earlier (Fig. 3).

[Figure 3 ILLUSTRATION OMITTED]

The patient was questioned about the activities that she had initially reported as problematic and pain producing. She reported that, in general, she was able to participate in her desired level of recreational activity with no left hip discomfort and that she was free of the persistent deep aching sensation that she had previously felt in the left hip with recreational activities. She was playing soccer intensively for I hour twice a week (compared with an initial 20-minute maximum), and she was walking up to 4.8 kin (3 miles) at a time without any pain (compared with the initial 1.6-km limit that brought on her posterior buttock pain). She also reported that she had been able to return to rollerblading up to 4.8 kin at a time with no hip discomfort (an activity that she had earlier abandoned because of the hip pain it generated). Her sitting time was now unlimited by hip pain (previously restricted to 1 hour).

Not all of the patient's symptoms, however, had disappeared. She reported that she had had one incident of perceived instability in the 5 months since treatment had begun, which occurred when she "stepped on the leg in the wrong way." In addition, although more difficult to elicit and of a slightly lesser intensity (rated 3 instead of 4 on the pain scale), she continued to occasionally have the same sensation of hip tightness that she had felt initially. Unlike previously when this sensation accompanied all recreational activities, more intense activity was now required to produce the sensation. The sensation of hip tightness occurred only after particularly vigorous soccer play or with prolonged walking up steep hills. She reported that the hip tightness sensation was transient and no longer caused a limp after activity. I believe that the sensation of tightness perceived by the patient may have been related to episodic spasm of the lateral rotator muscles reacting to the increased forces involved in the more intense activities that she had resumed since the hip pain decreased. In summary, the reexamination suggested that at least part of the patient's hip pain and dysfunction had originated from the muscle weakness and joint stiffness problems she had developed, indicating support for the original hypotheses about her pain production and hip joint dysfunction.

Discussion

An important initial step in determining appropriate physical therapy management for a patient with a complaint of undiagnosed hip pain is an analysis of the problem. Al is true for most physical therapists who cannot order diagnostic imaging techniques, my analysis relied on clinical reasoning with the history and physical examination data. Clinical reasoning is a complex process in which knowledge, pattern recognition, and hypothesis generation are all considered to be important.[28] This case report illustrates how these three elements were used to analyze a problem of undiagnosed chronic hip pain in order to determine appropriate treatment.

In reasoning about this patient's complaint of hip pain, I relied on knowledge about CHD and elements from concepts put forward by Cyriax,[6] Maitland,[7] Sahrmann,[8] and others[2-5] as well as general logic to make connections among individual pieces of data, form hypotheses, and develop a treatment plan. For example, I used Cyriax's concepts of capsular and noncapsular patterns and testing of contractile structures with resisted isometric contractions[6] to form hypotheses about relative capsular and contractile tissue involvement at the hip joint and recognized the need for treatment directed at both joint and muscle. I combined knowledge about the problem of CHD and Maitland's notion of "making the features fit"[7] to recognize connections and discontinuities among data that led to hypotheses about the underlying status of hip joint structures. I used Sahrmann's concept of movement imbalance[8] to look beyond specific structures and note the abnormal functional movement pattern of excessive medial rotation and adduction that appeared to be contributing to and perpetuating the patient's hip pain and structural problems.

I agree with other authors[29] who have pointed out the importance of linking identified impairments to disabilities. In this patient, the impairments were painful stiffness and muscle weakness associated with hip joint lateral rotation, and the disabilities were manifested as pain with different recreational activities and an abnormal movement pattern. Treatment was directed primarily at the impairments, and an assumption was made that the disabilities would improve. This treatment relationship may not always occur.[26] It may have happened in this case because the patient Viewed the videotape of her lateral step-down maneuver and discussed the relationship between her impairments and the abnormal movement pattern of her hip with the therapist. In addition, during her home program, she performed partial squats that included the lateral rotation and abductor-lateral rotator muscle control similar to that needed in the lateral step-down maneuver. I believe that this informal education of the patient and the practice of a similar activity most likely helped her to transfer gains made in OROM and muscle force into an improved movement pattern of the left hip joint. I do not believe that focusing on the functional activity alone (eg, the lateral step-down maneuver) without bringing her attention to the abnormal movement pattern she was using would have been effective. I base this belief on the patient's report that she had been repetitively performing the lateral stepdown maneuver in her step aerobics class during the year prior to the initial evaluation with no relief of her pain. Evidence, however, is not available to support this view.

Without an imaging report, I could not be sure of the status of the bony structure of this patient's hip. I suspected an underlying instability that was caused by CHD. "Congenital hip dysplasia," however, is a global term that can refer to many different stages of what is a complex deformity,[24] and CHD itself may be associated with other bony abnormalities. I interpreted this patient's excessive PROM in medial rotation to mean that there was excessive periarticular tissue laxity in the hip joint in this direction that had developed from a certain use pattern of the limb. The high ratio of ipsilateral medial rotation to lateral rotation in the left hip that was found in this patient, however, might have been due to hip anteversion, which can be associated with CHD.[24] I also believed that the patient showed no signs of hip joint disease, based on the location of her pain and her pattern of hip joint limitation. The patient may simply have had an atypical presentation and degenerative changes were present. Furthermore, the relief of pain and improvement in impairments and function may have been part of the natural course of CHD, which can vary, especially in younger adults who have a mild case of CHD or who have not yet developed osteoarthritic changes.[10,24]

In order to collect data on the status of this patient's hip joint, I relied on several tests and theories to make decisions about the location and probable origin of her hip pain. Many of these measures, although in common clinical use, have not been evaluated for their validity or reliability or their ability to discriminate between different causes of hip pain, and they have not even been described in the peer-reviewed literature. Studies on the validity of commonly used lumbar spine and SI joint screening tests to eliminate the spine and SI joints as extrinsic sources of hip pain would be useful. How results of basic tests of hip joint function vary when applied in patients with different diagnoses and knowing what relationship, if any, they have with imaging test results would help to make these tests more discriminatory. Further study of the concept of capsular patterns as it may apply to the hip joint would be valuable in establishing whether this concept is valid and can be used reliably in reasoning about a patient's problem or as the basis of treatment decisions. Although considerable information is known about CHD in infants[10] and the results of severe, untreated dysplastic hips in older adults,[22,24] little is known about hip dysplasia in younger adults, who may have subtle instabilities. Research that includes longitudinal or descriptive studies that detect, follow, and describe movement abnormalities in this subset of the population with hip joint abnormality is needed. These types of studies might be useful to help educate patients about the course of the disease and spawn ideas related to prevention of future disability.

Even in the presence of a sound research base, there will still be uncertainty in making diagnostic and management decisions about individual patients, because the generalities of randomized trials do not take into account important unique details of the individual.[30,31] Furthermore, individuals can have multiple problems that coexist and interact, which may change the presentation and management of each problem[31] and make accurate diagnosis and treatment difficult. Therefore, revealing the clinical reasoning used to understand an individual patient's problem is important in determining appropriate treatment. This case report describes, for a complaint of hip pain, how clinical reasoning was used to combine data unique to the patient with what is known in the scientific and clinical literature about hip pain in order to achieve a successful outcome.

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NJ Zimny, PT, is Associate Professor, Department of Physical Theraphy, School of Allied Health Sciences, University of Vermont, 305 Rowell Bldg, Burlington, VT 05405 (USA) ([e-mail]).