Pelvis, Hip, and Thigh Injuries

Matthew Diltz

AVULSION FRACTURES AND APOPHYSEAL INJURIES

History/Findings

Avulsion fractures about the hip and pelvis are the result of failure of the bone at the tendinous insertion rather than the tendon itself. These injuries are more common in skeletally immature athletes with open apophyses that are more susceptible to failure than the tendinous insertion. These are usually the result of a sudden, forceful concentric or eccentric contracture or rapid, excessive passive lengthening.
Common sites of these avulsions about the pelvis are the insertion of the sartorius into the anterior-superior iliac spine, the rectus femoris superior head insertion into the anterior-inferior iliac spine, and the insertion of the hamstrings into the ischial tuberosity. These injuries are also seen in the proximal femur with the insertion of the hip abductors into the greater trochanter and the insertion of the iliopsoas into the lesser trochanter.
Radiographs may show avulsions that involve the bone. Magnetic resonance imaging (MRI) is a more sensitive test and can demonstrate the extent of injury to the muscle.

Treatment

Nonsurgical management has been the mainstay of treatment in most series with good to excellent results reported.
Indications for surgery include complete ruptures of the origin of the hamstring with retraction in active patient with functional disability, chronic ruptures associated with sciatic nerve compression, and large bone avulsion fragment that results in discomfort with sitting (8); however, most authorities do not recommend surgery for these injuries.
Metzmaker and Pappas (12) defined a rehabilitation treatment protocol for these injuries including (a) rest, using proper positioning to unload the injured apophysis and ice/analgesics; (b) initiation of gentle active and passive range of motion (ROM) exercises; (c) progressive resistance beginning when 75% of motion is achieved and ending when 50% of strength is returned; (d) integration of stretching and strengthening exercises with functional activity; and (e) return to competitive sport at 8-10 weeks. Skeletally immature patients are also susceptible to chronic traction injuries at these apophyses, and this is referred to as apophysitis. Apophysitis is treated conservatively with rest followed by functional rehabilitation of the involved muscle group.

STRESS FRACTURES

Pelvis

Pelvic stress fractures should be suspected in athletes such as long-distance runners and military recruits. The most common site is the junction between the ischium and inferior pubic ramus. Tenderness to palpation directly over the fractured bone can be helpful in locating the lesion. A positive standing sign has been described in which a patient develops discomfort in the groin while standing unsupported on the ipsilateral leg.
Plain radiographic signs, such as periosteal reaction or fracture line, can lag behind the clinical presentation by as long as 3 weeks. MRI and bone scan can provide an earlier diagnosis. Tumors should at least be considered in the differential diagnosis.
Treatment consists of rest with emphasis on protected weight-bearing, flexibility, and aerobic nonimpact exercises such as swimming or cycling. Return to sport can be delayed up to 6 months.

Femoral Neck

Although femoral neck stress fractures are not as common as pelvic stress fractures, if treated incorrectly, the results can be disastrous. Similar to pelvic stress fractures, these present with groin pain and an antalgic gait. Pain will be worsened by flexion and internal rotation of the hip. Again, radiographic evidence may lag behind by 3-4 weeks. MRI and bone scan may be helpful in earlier diagnosis.
Two types of femoral neck stress fractures exist. The first type is a compression-side femoral neck stress fracture. This occurs in the inferior medial aspect of the neck and usually respond to restriction to non-weight-bearing status until radiographic evidence of healing has occurred. The more worrisome type is the tension-side femoral neck stress fracture. This is a transverse fracture along the superior margin of the neck. Internal fixation is recommended for nondisplaced fractures. Immediate closed or open reduction and internal fixation is recommended for displaced fractures. Fracture displacement can lead to avascular necrosis of the femoral head (3).

SOFT TISSUE INJURIES

Muscle Strains

Soft tissue injuries to the periarticular structures surrounding the hip and pelvis are the most common injuries seen in athletes. In general, the great majority of soft tissue injuries about the hip and pelvis are musculotendinous strains.
The type of injury sustained is highly dependent on (a) skeletal age of the athlete, (b) physical condition, and (c) biomechanical forces involved in both the sport and nature of the trauma. The degree of injury can range from repetitive microinjury associated with each performance to a more significant single macroinjury caused by an abnormal biomechanical force. A certain degree of microtrauma occurs with every major exertional performance immediately manifested by swelling, sensitivity, and a recovery interval. If additional moderate or severe microinjury or macroinjury occurs, there may not be a normal healing response, which may lead to more significant changes in tissue structure and a negative effect on future athletic performance (4).
A strain is an injury to a musculotendinous structure caused by an indirectly applied force. The most common mechanism of injury is a result of eccentric contraction or stretching of an activated muscle. The site of injury is influenced by the rate of loading, mechanism of injury, and local anatomic factors. Low rates of loading will result in a failure at the tendon-bone junction by bone avulsion or disruption at its insertion. High rates of loading result in intratendinous or myotendinous juncture injuries.
These injuries can be graded on a 3-scale clinical grading system. Grade 1 injuries involve a simple stretching of soft tissue fibers. Grade 2 strains involve partial tearing of the musculotendinous unit; and grade 3, which are unusual, are secondary to extreme violent forces causing complete disruptions.

Contusions

Among the most frequently experienced hip and pelvic injuries sustained by athletes are soft tissue contusions. Contusions usually result from direct blows to a specific soft tissue area usually overlying a bony prominence. Contusions are most common in contact sports, especially football, but are also seen in other sports as well. In contact sports, the blow is usually caused by contact with another athlete. In noncontact sports, athletes usually sustain blows from contact with equipment (gymnastics), contact with high-velocity projectiles (lacrosse ball), or contact from the playing surface.
Contusions are often found over areas of bony prominences of the pelvis including the iliac crest (hip pointer), greater trochanter, ischial tuberosity, and pubic rami. Because of the varied anatomy of the pelvis, contusions can be superficial, especially when they overlie a relatively subcutaneous bone or lie deep within a large muscle mass. It is important to determine possible presence and extent of muscular hemorrhage because an increase in muscular hemorrhage often results in more severe symptoms and longer time before returning to sport (4).

HIP POINTER

Pain and hemorrhage over the iliac crest have been referred to as a hip pointer. These injuries include contusions, avulsion of the iliac apophysis, periostitis, or avulsion of the muscles that insert onto the iliac crest. On physical examination, the patient will have superficial or muscular hemorrhage, which will be painful on palpation. It is important to note by touch a defect, which would indicate an avulsion injury. Patients will have difficulty with rotation and side bending of the trunk.
Anterior-posterior and oblique x-rays of the pelvis will rule out an avulsion fracture, periostitis, or an acute fracture of the iliac wing.

HAMSTRING SYNDROME

Hamstring syndrome, described in track athletes, involves severe pain in and around the ischial tuberosity that radiates down the posterior aspect of the thigh to the popliteal area. Any activity that puts the hamstring in stretch can create this radiating pain. Sprinting, hurdling, and even sitting for long periods will cause pain.
Physical examination elicits exquisite tenderness at the ischial tuberosity and, at times, reproduction of sciatic pain with percussion of the nerve at the ischial tuberosity. Resisted leg extension will reproduce the pain. The sciatic nerve is thought to be entrapped between the semitendinosus and the biceps femoris by a fibrous band that constricts the 2 muscles (4).

THIGH CONTUSIONS/QUADRICEPS INJURY

Thigh contusions are common athletic injuries, most often encountered in football from direct trauma. These injuries can involve significant muscular damage, hematoma formation, and swelling. Therefore, the athlete can be extremely uncomfortable.
Initial treatment is rest, ice, and compression to minimize hematoma formation. Immobilization in flexion and initiation of early flexion exercises have been recommended to decrease myositis ossificans formation and improve functional outcome (16).

SPECIFIC CONDITIONS

Athletic Pubalgia

History/Findings

The term athletic pubalgia is often used interchangeably with sports hernia. It is a condition of chronic groin pain. The condition is common in soccer and ice hockey athletes. Typically, the patient reports activity-related pain that resolves with rest.
Most patients describe a hyperextension injury in association with hyperabduction of the thigh. Usually, the abdominal pain involves the inguinal canal near the insertion of the rectus abdominis muscle at the pubis.
Maneuvers that increase intra-abdominal pressure, such as a resisted sit-up, can reproduce the symptoms. A gross hernia is not detected. On imaging studies, 12% of patients have derangement of the insertion of the rectus on MRI. Adductor longus inflammation can also be present. Dynamic ultrasound can detect posterior wall defects.

Treatment

The initial treatment of athletic pubalgia consists of rest, ice, compression, and elevation. There are medical grade compression shorts that can help alleviate symptoms. After the symptoms resolve, an overseen slow transition back to sport is employed.
Often athletes present for evaluation after exhaustion of nonoperative management. These patients are on the verge of cessation of sport. In this case, surgical options are discussed. Many approaches have been tried in the treatment of sports hernia. Options include tissue repair, laparoscopic repairs, anterior repairs, and mesh repairs. The goal of surgery is repair or reinforcement of the anterior abdominal wall.