Hip Pain

Anterior Hip and Groin

10.1 Femoral Stress Fracture

Int J Sports Med 1993;14:347; Skeletal Radiol 1986;15:133; Clin Orthop 1994;303:155

Cause: Typically follows change in training volume or intensity.

Epidem: Most common in running sports. Amenorrheic females are particularly susceptible.

Pathophys:

Imbalance between osteoblastic and osteoclastic cell activity with bone reabsorption outpacing bone formation leading to weakening of cortex.
Femoral neck injuries classified as distractive (superior cortex) and compressive (inferior cortex).
Related to intrinsic factors (foot mechanics, poor flexibility, muscle imbalance, coxa vara, etc) and extrinsic factors (running surface, shoe selection, etc).

Sx: Vague, increasing groin or thigh pain, made worse with activity. Late finding is pain with active hip flexion and at rest.

Si:

Tenderness in the affected groin.
Pain with a single-leg stance.
Passive internal rotation of the hip is painful.
Pain with active hip flexion common late finding.

Crs: Insidious onset with gradual worsening pain. If untreated can result in frank fracture. Return to play time variable.

Diff Dx: Femoral head avascular necrosis (see 10.2), acetabular labral tear (see 10.3), adductor strain/tendinitis (see 10.5), iliopectineal bursitis (see 10.4), iliopsoas tendon strain (see 10.6), osteitis pubis (see 10.7).

X-ray:

Plain radiographs are usually normal in early stress reaction, may demonstrate cortical sclerosis or frank fracture in later studies.
Triple-phase bone scan is very sensitive even in early stress fractures.
MRI is useful in diagnosing stress fractures and may be less expensive than bone scan.

Rx: Based on location of injury.

Femoral neck-distraction cortex: treat aggressively, refer early. Often requires surgical treatment.
Femoral neck-compression side: the main treatment is rest, followed with periodic plain radiographs to document healing.
Crutch ambulation with toe-to-floor weight bearing for 6-12 w is the norm.
Minimum of 6 w required before the pt can gradually resume normal weight-bearing activity.
Physical therapy directed at improved flexibility and balanced muscle strengthening should be employed, as symptoms allow.
Pts should be referred to an orthopedic surgeon if symptoms persist, there is evidence of fracture on plain radiograph, or if there is evidence of avascular necrosis on any study.
Femoral shaft and pubis stress fracture treatment includes rest and activity substitution using pain as a guide (advise the pt to exercise to pain, not through pain). Rarely requires surgical intervention.

10.2 Femoral Head Avascular Necrosis

Orthopedics 1994;17:789; Semin Arthroplasty 1991;2:241

Cause: Most often not identified.

Epidem: Predisposing factors include: prolonged corticosteroid use, heavy alcohol abuse, stress injury or fracture. Over 50% are idiopathic.

Pathophys: Loss of normal vascular watershed involving all or part of femoral head, resulting in tissue death.

Sx:

Insidious onset of atraumatic groin and anterior leg pain.
Present at rest, worse with activity.
May be bilateral.

Si:

Tenderness in the affected groin.
Pain with a single-leg stance.
Passive internal rotation of the hip is painful.

Crs: Typically progressive pain and development of DJD.

Cmplc: Degenerative joint disease with limited function and chronic pain.

Diff Dx:

Femoral stress fracture (see 10.1), acetabular labral tear (see 10.3), adductor strain/tendinitis (see 10.5), iliopectineal bursitis (see 10.4), iliopsoas tendon strain (see 10.6), osteitis pubis (see 10.7).

X-ray:

Plain radiographs normal early, later demonstrate sclerosis, progressive cortical flattening, and degenerative joint disease.
MRI will demonstrate early disease prior to radiographic changes.

Rx:

Early surgical intervention is possible, including cortical drilling and vascularized bone grafting. Results vary.
Symptomatic treatment for pain relief.
Activity modification.
Total hip arthroplasty for late DJD.

Return to Activity: Minimal weight bearing until symptoms resolve then gradual return to weight-bearing exercise, avoiding pain.

10.3 Acetabular Labral Tear

Orthopedics 1995;18:753; Clin Orthop Relat Res 2003;406:38

Cause: Twisting injury on weight-bearing hip.

Epidem: Incidence unknown. Most common in collision sports.

Pathophys:

Tear of the fibrocartilaginous ring around peripheral acetabulum.
Recently described entity thought to be responsible for many cases of chronic anterior hip/groin pain.

Sx:

Deep, anterior hip pain, intermittently present, typically described as sharp or stabbing.
May or may not have history of macro-traumatic event.
Pain is worse with activity.

Si:

May not have tenderness on palpation.
Often pain with passive external or internal rotation.
Thomas flexion-to-extension test: patient lies on the contralateral side with both hips maximally flexed. The affected hip is then moved from full flexion to full extension. Painful click suggests labral tear.

Crs: Frequently chronic anterior hip pain not responsive to treatment. May resolve with decreased activity.

Diff Dx:

Femoral stress fracture (see 10.1), femoral head avascular necrosis (see 10.2), adductor strain/tendinitis (see 10.5), iliopectineal bursitis (see 10.4), iliopsoas tendon strain (see 10.6), osteitis pubis (see 10.7).

X-ray:

Plain radiographs normal.
Diagnostic lidocaine injection (intra-articular) alleviates pain temporarily.
MRI arthrogram may demonstrate tear.
Diagnostic arthroscopy is the gold standard.

Rx:

Trial of PRICEMM (see 1.1) and physical therapy.
Arthroscopy in cases with persistent pain, although results are variable.

10.4 Iliopectineal Bursitis

J Rheumatol 1995;22:1971

Cause: Overuse injury.

Epidem: Most common in running, dancing, martial arts.

Pathophys:

Bursa in the deep anterior soft tissues between the iliopectineal eminence and iliopsoas muscle/tendon.
Inflammation related to overuse, poor flexibility, and abnormal gait mechanics.

Sx:

Gradual onset of deep anterior hip pain.
Exacerbated with activity, particularly with hip extension.

Si:

Tenderness may be reproducible.
Limp is common.
Pain with active internal rotation and passive extension of hip.

Crs: Insidious onset, persistent symptoms.

Diff Dx:

Femoral stress fracture (see 10.1), femoral head avascular necrosis (see 10.2), acetabular labral tear (see 10.3), adductor strain/tendinitis (see 10.5), iliopectineal bursitis (see 10.4), iliopsoas tendon strain (see 10.7), osteitis pubis (see 10.7).

X-ray: