Differential diagnosis and early management of rapidly progressing hip pain in a 59-year-old male

Abstract

Objective and importance

Rapidly progressing degeneration of the hip joint is an uncommon condition presenting to physical therapy. Differential diagnosis can often be difficult, as clinical and radiographic findings do not always coincide leaving clinicians with difficult decision making regarding course of treatment. The purpose of this case report was to describe the differential diagnosis and early management of a patient with rapidly progressing hip pain.

Clinical presentation

A 59-year-old male with a complicated medical history was referred with a diagnosis of severe bilateral hip osteoarthritis. Clinical presentation of insidious onset, severe bilateral groin and anterior thigh pain with rapid progression of functional decline lead to the differential diagnosis of bilateral avascular necrosis.

Intervention

The patient received seven manual physical therapy sessions over the course of one month.

Conclusion

During this time, the patient’s Lower Extremity Functional Scale score worsened from 33 to 21. The persistence of the patient’s painful symptoms and continued functional decline helped determine cessation of manual therapy and referral back to his GP for further diagnostic testing and eventual correct diagnosis. This case highlights the importance of monitoring patient prognosis using outcome measures leading to a change in patient management strategies.

Background

Osteoarthritis (OA) is the most common form of arthritis and accounts for more mobility disability in the elderly than any other disease.^1,2 A recent systematic review³ reported radiographic primary hip OA present in 5 to 10% of the general adult population.⁴ Clinical presentation of hip OA is characterized by joint pain, stiffness, reduced movement or function, and variable degrees of local inflammation.^5,6 In its advanced stages, joint contractures, muscle atrophy, and limb deformity can present.⁷ Early in disease, patients typically report a gradual onset of hip pain, which is episodic, with known precipitants and self-limiting pain episodes.⁴ As OA progresses, pain becomes more constant, with unanticipated episodes of sharp pain. Consistent pain tends to occur when structural disease is advanced. Progressive OA is also associated with morning stiffness, pain at rest or at night, decreased active joint movement, lower limb weakness, slower gait, reduced aerobic capacity, and decreased mobility.^4,7–9 These various impairments can lead to diverse disabilities associated with walking, climbing stairs, getting in and out of a car, cycling, putting on shoes, and social participation.⁹

Although there is no known cure for OA, disease related factors such as impaired muscle strength and decreased function are potentially amenable to intervention.¹⁰ A variety of non-pharmacological interventions have been described for the treatment of hip OA with fair evidence to support the benefits of physical therapy intervention in these patients. Exercise and physical activity can be targeted at the affected joint, and also at improving general mobility, function, well-being, and self-efficacy.¹¹ Medium beneficial effect sizes have been found in support of manual therapy to increase hip mobility, improve function, and reduce pain short-term in patients with mild hip OA.¹² A minimum of 6 weeks treatment is advised to ensure that patients experience some benefits of treatment and undergo behavioral changes.¹¹

The following differential diagnoses should be considered in an individual with signs or symptoms suggestive of hip OA: bursitis or tendonitis, chondral damage or loose bodies, femoral neck or pubic ramus stress fracture, labral tear, muscle strain, neoplasm, osteonecrosis of the femoral head, Paget’s disease, piriformis syndrome, psoriatic arthritis, rheumatoid arthritis, sacroiliac dysfunction, septic hip arthritis, and referred pain as a result of an L2–3 radiculopathy.¹³ Patient history, risk factors, and reported activity limitations should always be carefully considered before making a definitive diagnosis.¹³ Furthermore, if the patient’s symptoms are not diminishing with interventions aimed at normalization of the patient’s impairments, alternative diagnoses should be considered.¹³

The purpose of this case was to report on the differential diagnosis and early management of a patient with rapidly progressing hip pain. This case highlights the ability of the clinician to recognize a non-typical hip pain pattern with thought being given to the possible need for further medical consultation. Furthermore, the importance of regular reassessment is emphasized to help determine patient response to treatment and outside referral.

Patient Characteristics

The patient was a 59-year-old married, African American male referred from the department of general medicine with a diagnosis of severe bilateral OA of the hips and lumbar stenosis with chronic pain.

Medical history included diagnosis of Human immunodeficiency virus (HIV); Hepatitis B and C; Stage III Hodgkin’s disease; brain tumor removal; status post-cholecystectomy; pulmonary tuberculosis; peripheral arterial disease; bilateral deep vein thrombosis, status post IVC filters; L1 fracture; intravenous drug use (heroin, cocaine); history of smoking. Patient medication list included highly active antiretroviral therapy consisting of Epzicom and Kaletra for HIV, hydrocordone (Norco), and Warfarin. Initial medical treatment consisted of Norco for pain relief. The patient, however, continued to suffer from severe hip pain and functional limitations and was referred to physical therapy.

Examination

The patient presented with a 4-month history of bilateral hip, groin, and anterior thigh pain. The patient rated his pain as a 6/10 on the Numeric Pain Rating Scale (NPRS)¹⁴ and described the pain as a constant, deep, ‘ache’ with intermittent periods of ‘sharp’, and ‘shooting’ pain located bilaterally in the groin and anterior thigh (L>R) (Fig. 1). Aggravating factors included sit to stand, walking, kneeling, and rolling out of bed in the morning. The patient reported minimal pain relief with medication (Norco) and still standing.

Figure 1.

Body chart of reported pain.

The symptoms were described as insidious onset with rapid worsening during the four months prior to the initial visit with the physical therapist. X-ray and computerized tomography (CT) were performed on both hips. Initial X-ray findings demonstrated mild arthritic change of the hips bilaterally with superior joint space narrowing and small osteophytes arising from the acetabulum. The right hip also demonstrated the presence of subchondral cysts. Initial CT scans demonstrated significant osteoarthritic changes of the bilateral hip joints, greater on the right, with multiple subchondral cysts and flattening of the right femoral head secondary to osteochondral fractures. There was also suggestion of focal ostenecrosis in the anteromedial aspect of the right femoral head.

The Lower Extremity Functional Scale (LEFS) was used in this case report. The patient’s initial total LEFS score was 33/80. This is a 20 item, self-administered, region specific outcome instrument developed as a measure of self-rated lower extremity functional status with higher scores representative of improved function. The LEFS has been found to be a reliable, valid, and responsive measure of lower extremity disability in patients with end-stage OA of the hip or knee.^15,16

The patient was initially asked to perform a 30 second chair stand (30 s CST), which has been validated as a measure of lower extremity muscle strength in the elderly.^17,18 Participants are asked to rise from a seated position to a standing position with their arms folded across their chest as many times as possible in 30 seconds. The number completed are recorded for this test.^18,19 The 30 s CST appears to be the simplest yet most efficient test for assessing lower extremity strength and power, especially as its design reduces potential ‘floor’ effects, and allows for more variation in ability levels, thereby improving test responsiveness compared with alternative tests such as the five-times-sit-to-stand.^17,20 Reliability for the 30 s CST has been reported as 0.95 (ICC_1,1) in patients with OA of the hip or knee.¹⁷ At the baseline examination, the patient was unable to complete a single chair stand without upper extremity support.

At initial assessment, the patient demonstrated a bilateral hip flexion deformity during gait assessment with compensatory bilateral knee flexion. Range of motion testing of the hips was performed with a standard goniometer. Hip flexion was performed supine. Internal rotation was performed prone with a gravity inclinometer. Hip strength was measured grossly as 3/5 using manual muscle testing for bilateral hip internal rotation, external rotation, abduction, adduction. All end feels were classified as hard. The patient displayed a positive flexion abduction external rotation test, Quadrant test, and hip compression test bilaterally. In terms of joint play, anterior-posterior, posterior-anterior, and lateral glides of the hip were all judged as hypomobile bilaterally. Inferior glide and long axis traction were normal. Cutaneous sensation was assessed with light touch and was found to be symmetrical between the two lower extremities. Lower extremity myotomal testing was normal.

Clinical Impression

The evaluation of the patient’s examination and systems review lead to a differential diagnosis of bilateral avascular necrosis (AVN) of the femoral heads or hip OA (Table 1). The generated working hypothesis driving the clinical decision making process in determining a differential diagnosis was report of insidious onset, bilateral groin and anterior thigh pain with rapid progression of restricted ADLs combined with multiple medical comorbidities.

Table 1. Differential diagnosis hypothesis list.

Hypothesis	Supporting evidence	Negating evidence
Hip AVN	Bilateral	Negative on radiology reports
	Sudden onset
	Rapid progression of functional decline
	Multiple risk factors
	HIV
	Corticosteroid intake
Rapidly destructive arthrosis	Duration of hip pain 1–6 months	Male
	Rapid progression	Bilateral
	Mild OA changes on initial radiograph	IV drug use suggests AVN
		Presence of crescent sign on radiograph
Hip OA	Hip, anterior groin pain	Hip flexion>115
	IR<15 degrees	Morning stiffness>1 hour
	Age>50	Bilateral
	Hip pain with IR	Sudden onset
	CT confirmation of significant OA changes	Rapid progression
		Global loss of hip ROM
Lumbar spinal stenosis	Bilateral	No pain reproduction with passive accessory motion throughout lumbar spine
	Leg symptoms greater than back pain	Decreased pain in still
		Standing
		Age<70
		Onset of symptoms<6 months
		No relief with forward bending
		No report of urinary incontinence
		No report of intermittent claudication pain
		Normal reflex testing

Note: AVN, avascular necrosis; OA, osteoarthritis

While typical OA of the hip has a similar presentation, patients with OA typically report a more gradual onset of symptoms with less rapid progression of disability (Table 1). Rapidly destructive osteoarthritis of the hip was considered given the rapid progression of symptoms; however, this disease typically presents unilaterally and in overweight females.²¹ Diagnosis of lumbar spinal stenosis remained on the hypothesis list given the patient was initially referred with the diagnosis. However, the patient did not present with signs and symptoms typical of lumbar spinal stenosis as described by Sugioka et al.²²

Intervention

Given the severity of patient symptoms and the uncertainty of the nature of his problem, the therapist and patient mutually agreed upon a 1-month trial of physical therapy at which point, if no progress was being made the patient would be referred to the department of orthopaedic surgery. This decision was based upon the OA literature suggesting that performing surgery earlier in the course of functional decline may be associated with better long-term outcomes.^23–25 A guarded prognosis was anticipated from physical therapy intervention given the duration and severity of the symptoms combined with overall poor general health.

A summary of the treatment techniques is presented in Table 2. Given the patient’s accelerated functional decline, techniques to produce rapid and sufficient change in range of motion were chosen to determine whether increased range would improve the patient’s ability to dress and ambulate independently. While these mobilizations were firmly applied, the symptomatic response during application was continuously monitored and the patient was able to tolerate all techniques. The patient was seen for a total of seven treatment sessions and was discharged by day 27 with referral to orthopedic surgery.

Table 2. Physical therapy intervention summary.

Visit 1	Subjective exam, ROM testing, strength testing, gait assessment, special tests, patient education, home exercise program (HEP) initiated including prone lying and standing hip flexor stretch, SLR (3 sets of 10 twice daily). The patient was instructed to maintain normal daily activities within his pain tolerance and to avoid activities that exacerbated his symptoms.
Initial consultation
Visit 2	Grade IV joint mobilizations (30 seconds ×3 reps):
	• indirect traction
	• direct traction
	• prone posterior to anterior (P/A)
	• prone figure four positioning
	• curvilinear glide
	• passive IR with compression
Visit 3	Grade IV joint mobilizations (30 seconds ×3 reps):
	• indirect traction
	• direct traction
	• prone P/A with hip IR
	• supine lateral glides
	• prone figure four positioning
	• curvilinear glides
	• passive IR with compression
Visit 4	Grade IV joint mobilizations (30 seconds ×3 reps):
	• prone P/A with ½ bolster under the knee and hip ER
	Home exercise program progressed to include:
	• supine bridging
Visit 5	Grade IV joint mobilizations (30 seconds ×3 reps):
	• indirect traction
	• lateral traction
	• passive physiological flexion
	• prone P/A with hip IR and ½ bolster to accentuate hip extension
	• prone figure four positioning
	• curvilinear glide
	• prone passive IR stretch
	Aerobic
	• AirDyne bike ×10 minutes
Visit 6	Grade IV joint mobilizations (30 seconds ×3 reps):
	• Prone P/A with hip IR and ½ bolster to accentuate hip extension
	• Prone passive IR stretch
	Aerobic
	• AirDyne bike ×10 minutes
Visit 7	Aerobic
	• AirDyne bike ×5 minutes (stopped secondary to sharp, bilateral, anterior groin pain)
	Reassessment
	• ROM
	• Strength
	• Outcome measure

Note: SLR, Straight leg raise; P/A, posterior to anterior; IR, internal rotation; ER, external rotation.

Outcomes

Four weeks after the onset of physical therapy, the patient reported worsening of left hip pain at 7/10 on the NPRS at rest. The patient also complained of worsening functional status with activity limitations to don/doff shoes/socks and an inability to bend forward to don his pants. The patient demonstrated worsening on the LEFS (21 down from 33) and showed no improvement in the 30 s CST. There was a 14 and 45-degree loss in right and left hip flexion, respectively (Table 3). The worsening nature of symptoms dictated the decision to initiate further medical consultation and discontinue physical therapy. The patient was referred back to his primary care physician for updated imaging to determine progressive worsening of AVN as well as a request for referral to orthopaedics to determine if the patient was a possible candidate for surgery. Three weeks following discharge from physical therapy, follow-up X-ray imaging demonstrated a combination of increased sclerotic changes, slight flattening, and radiolucency of the bilateral femoral heads suggesting AVN with mild degenerative arthritis.

Table 3. Progression in range of motion and outcome measures.

ROM; Passive (°)	Initial	Week 1	Week 2	Week 3	Week 4 Discharge
Hip flexion
Right	120			125	106
Left	120			110	75
Hip IR
Right	0				10
Left	0				−14
Hip ER
Right	15				17
Left	15				14
Hip abduction
Right	15				10
Left	15				10
30 s CST	0				0
LEFS	33/80	51/80	48/80	48/80	21/80
NPRS	6/10	5/10	7/10	7/10	7/10

Note: ^o, degrees; IR, internal rotation; ER, external rotation; 30 s CST, 30 second chair stand; LEFS, lower extremity functional scale; NPRS, numeric pain rating scale.

Discussion

The purpose of this case was to report the examination and early management strategies of a patient with rapidly progressing hip pain who was eventually diagnosed with avascular necrosis. In this case report, the patient’s subjective report of sudden onset, bilateral groin and anterior thigh pain, and rapid progression of decreased function suggested the need for further medical consultation and investigation as these features did not fit a typical hip OA pattern as stated in the physician referral. However, given the lack of confirmatory imaging in support of AVN, the clinician remained open minded to the possibility that the patient may have an atypical variation of hip OA or rapidly destructive osteoarthritis of the hip and proceeded with treatment. A decision was made to closely monitor patient prognosis in response to treatment using regular weekly outcome measures to determine whether manual therapy could affect a change in hip range of motion and the functional activities of dressing, standing, and walking. Treatments provided were definitive, allowing the final decision regarding further medical consultation and investigation to be reached as quickly as possible. The persistence of the patient’s painful symptoms and continued functional decline helped determine cessation of treatment and referral back to his GP for further diagnostic testing.

This case highlights the need for clinicians to consider competing diagnoses when treatment intervention fails to improve patient symptoms. As primary health care providers, it is our duty to be aware when our services are no longer of benefit and refer appropriately when necessary. The clinician in this case used a combination of patient history, risk factors, and failed response to treatment to refer out for further work up which led to the eventual confirmed diagnosis of bilateral femoral AVN.

Conclusion

This case report describes the examination and treatment of a patient who was originally diagnosed with severe bilateral hip OA. Using patient history and clinical presentation, examination and evaluation revealed AVN as the more likely cause of patient’s signs and symptoms. By identifying progression of functional decline using regular outcome measures, the physical therapist is better equipped to manage patients and identify the need for outside referral to optimize best patient care.