Hip Pointer Injuries

Etiology

The anterior iliac crest region and greater trochanter of the femur have, in most patients, minimal overlying adipose tissue. Thus, these areas are more susceptible to injury from direct trauma. The primary etiology is a direct blow to the iliac crest or greater trochanter during contact sports. American football and hockey are the most common sports that result in these injuries.[2] In American football, tackling and incidental collisions commonly cause direct trauma during competition. Rugby involves a similar underlying mechanism. In ice hockey, hip pointers can result from being checked into the boards or from contact with another player or the player’s equipment.[3] Iliac crest contusions may also result from noncontact sports or high- or low-energy trauma. In these settings, a direct fall or traumatic blow, such as that sustained during a motor vehicle collision, is often the precipitating factor.[4]

Epidemiology

Injuries to the hip and pelvis during sports participation are much less common than injuries involving the knee or ankle.[5][6][7] Hip injuries account for 5% to 10% of athletic injuries, and hip pointers represent an even smaller proportion of these injuries. Results from a review of National Football League injuries occurring from 1997 to 2006 showed an incidence of 0.3% and an average training absence of 5.6 days per injury.[8]

Pathophysiology

Following a direct impact to the iliac crest, a hematoma develops in the surrounding tissues and often includes varying degrees of bleeding into the hip abductor musculature. The iliac crest serves as the origin of several muscles that may be affected, depending on the severity and extent of the injury:

• Sartorius
• Gluteus medius
• Tensor fascia lata
• Abdominal musculature
  • Transverse or oblique muscles [9][10]

History and Physical

A detailed history, including current symptoms and the mechanism of injury, should be obtained. A hip pointer is usually caused by a direct blow or fall onto the iliac crest or greater trochanter. Patients most commonly present with varying degrees of ecchymosis and soft tissue contusion at the area of impact. Tenderness is typically localized directly over the injured region, and hip range of motion is often limited because of pain. Hip abductor strength is typically reduced, whereas hip flexor and extensor strength usually remains intact. Pain may also limit the apparent strength of the hip abductors and external rotators.

Evaluation

Radiographs are indicated when a fracture or myositis ossificans is suspected. Pelvic avulsion injuries are particularly important considerations in high school and college athletes because the apophyses of the ischial tuberosity and anterior superior iliac spine may not fuse until the third decade of life. Pediatric and adolescent athletes should be evaluated for the following potential pelvic avulsion injuries:

• Iliac crest avulsion injuries: Avulsion of the abdominal musculature
• Anterior superior iliac spine avulsion injuries: Avulsion of the sartorius or tensor fasciae latae
• Anterior inferior iliac spine avulsion injuries: Avulsion of the rectus femoris
• Ischial tuberosity avulsion injuries: Avulsion of the proximal hamstring muscles [5]

Radiographic findings are otherwise typically unremarkable in patients with a true, isolated iliac crest contusion or hip pointer injury. Computed tomography should be considered when pain persists or is more severe than expected based on examination findings. A bone scan can exclude stress fractures if initial symptoms do not resolve. Magnetic resonance imaging of an isolated iliac crest contusion may reveal a large hematoma but is otherwise typically unremarkable. A hip pointer must be distinguished from chronic exertional compartment syndrome, femoral neck fracture, avascular necrosis, hip fracture or dislocation, tendinitis, iliotibial band syndrome, osteitis pubis, sacroiliac joint injury, snapping hip syndrome, and slipped capital femoral epiphysis.

Treatment / Management

Initial treatment for a hip pointer injury includes ice, anti-inflammatory analgesics, compression, rest, and avoidance of weight-bearing, depending on the severity of the patient’s symptoms. As pain decreases, patients should begin range-of-motion and active resistance exercises. If a hematoma is present, aspiration can provide pain relief and may potentially reduce the risk of myositis ossificans. A local anesthetic, such as 1% to 2% lidocaine or 0.5% bupivacaine in a volume of 5 to 9 mL, may provide short-term pain relief. Local anesthetic injection is considered safe, although limited data support the practice. Similarly, although no studies support corticosteroid injections, clinicians in the sports medicine community commonly use them. If compartment syndrome is suspected, clinicians should measure compartment pressures and consult an orthopedic surgeon or sports medicine specialist. An orthopedic surgeon should also be consulted if the patient has an avulsion fracture or pain persists for longer than 2 weeks. Physical therapy is often prescribed.

Differential Diagnosis

The differential diagnosis for an iliac crest contusion or hip pointer includes the following conditions:

• Chronic exertional compartment syndrome
• Femoral neck fracture/hip fracture
• Avascular necrosis/osteonecrosis
• Hip dislocation or subluxation
• Hip tendinitis
• Iliotibial band syndrome
• Osteitis pubis
• Sacroiliac joint injury
• Snapping hip syndrome
• Slipped capital femoral epiphysis, usually in adolescents [11][12][13]

Prognosis

Most patients can gradually return to normal levels of activity within 2 to 3 weeks.

Complications

Complications include:

• Chronic pain or dysfunction
• Inability to return to prior athletic performance
• Missed diagnosis leading to persistent pain or disability