Groin injuries
From Medical-Wiki
As the largest joint in the body, the hip is the structure most commonly involved in groin injuries. The joint, the muscles that act on it, and the stabilizing soft tissues are typically the sites injured when a patient presents with a “pulled groin.” Contusions, hematomas, and muscular tears are the most common types of acute injuries. Chronic injuries may arise from repetitive motion phenomena—primarily in athletes.
Because the groin is also an area where the abdomen meets the legs, structures of the perineum are also at risk. These include the lower rectus abdominis musculature, the inguinal region, the symphysis pubis, the upper portions of the adductor muscles of the thigh, and the genitalia and the scrotum.
Abdominal wall tears can involve the adductor longus, the rectus femoris, the rectus abdominis, the sartorius, the gracilis, and the iliopsoas. Injury of the rectus abdominis, common in skaters, hockey players, and swimmers, is a common cause of chronic groin pain. Severe injuries may even require surgical repair or reinforcement.
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Demographics
Particular attention should be offered to children, adolescents, and women who complain of hip pain. In these populations, groin pain is often attributed to minor injuries when it is often representative of a far more serious disorder. Any child from the age of 2 to 15 who complains of groin pain and has an atalgic gait should be closely investigated. This is particularly true if the child has a fever. Avascular necrosis (AVN) of the hip, is a not uncommon disease in this age group.
Athletes
In addition to direct trauma from contact sports such as football, basketball, rugby, and hockey, athletes may experience muscle strains. These strains typically are caused by forced adduction of the hip such as soccer, swimming, football, and hockey or those that involve forced abduction, any sport where a split—planned or forced, can occur.
Adolescent athletes represent a population with particular risks because they have a weaker growth plate that increases the possibility for apophyseal avulsion fractures. In addition, knee pain may actually be referred pain from hip derangements—and vice versa.
Females
It has recently been demonstrated that female body mechanics have the possibility to present as slightly different injuries and also require slightly different recovery treatments. Some of the factors involved in these differences are differences in metabolism, circulation, cardio-respiratory capacity, body shape, size, and composition. [1]
Differential diagnosis
A full differential diagnosis includes intra-abdominal disorders such as appendicitis, lymphadenitis, and inflammatory bowel disorder; genitourinary abnormalities such as urinary tract infections, sexually transmitted diseases, gynecologic, scrotal, and testicular abnormalities, and nephrolithiasis; referred lumbosacral pain from lumbar disk disease; and hip joint disorders including osteoarthritis, hip fractures, Legg-Calve-Perthes disease, synovitis, slipped capital femoral epiphysis, osteochondritis desiccans, acetabular labral tears; abdominal wall injuries including abdominal wall tears and a variety of hernias including a sportsman’s hernia; and osteitis pubis.
Diagnosis
Assessing groin injuries is complicated by the fact that quite often patients have more than one cause. One study of 21 patients suggested that 19 had at least two diagnoses. [2]
Physical findings
Examination of patients with groin injuries should begin with a careful search for an event that precipitated the pain. A history of exacerbating factors should also be pursued—not only athletic factors but activities of daily life as well (walking up and down stairs, inactivity, etc.) Examination should include inspection for symmetry including leg length, a search for any anatomic deformity, examination of gait, and if a patient is an athlete, as possible, an assessment of their specific performance. [3]
Perhaps the most common athletic groin injury is an adductor strain. This injury is demonstrated on physical exam by palpating the painful muscle and then having the patient adduct the leg against resistance. It should be noted that osteitis pubis and sports hernias exam in fashions quite similar.
Osteitis pubis can be difficult to differentiate from an adductor strain. It is seen most often in distance runners and soccer players. It is a very common problem. It may also occur in combination with an adductor strain—obviously causing a diagnostic dilemma. A less common condition is osteomyelitis of the pubic symphysis, a condition that can be seen following a pelvic surgical procedure but has been reported as occurring spontaneously in athletes. Patients who have osteitis pubis may present with exercise-induced lower abdominal and medial thigh pain. These symptoms do not appear suddenly—they are of gradual onset.
If patients do not have tenderness over the pubic symphysis, they probably do not have osteitis pubis. If patients have pain with adduction, the distal symphysis is indicated as being involved. If patients have pain doing sit-ups, the proximal portion is probably involved.
Obvious fractures of the hip cause groin pain, but are usually easy to diagnose. The typical acute fracture will present with the affected leg in external rotation. It will appear shortened because the muscles acting on the hip joint depend upon the integrity of the joint for function. When continuity of the joint is disrupted, the leg appears shortened. When an injury presents with these findings, it is important to asses the leg’s vascular integrity—with Doppler if possible.
However, impacted fractures or stress fractures may present with no more than a slightly atalgic gait and vague complaint of anterior groin or medial thigh pain. It is important to evaluate the possibility of femoral neck fractures whenever their possibility is even raised. Many impacted fractures have been missed because patients walked into doctors’ offices with complaints of diffuse groin pain, able to walk because of their fractures’ stability, imparted by the impaction. However, impaction does not prevent against nonunion and necrosis—diagnosis is important. [4]
Radiological findings
X-rays may be needed to exclude fractures or avulsion injuries. MRI may even be needed to confirm muscular strain or tears as well as partial or complete tendon tears. While ultrasound is capable of visualizing muscular and tendinous tears, it cannot visualize strains. Therefore, it may be judicious to schedule MRI directly. When looking for a site of injury, statistically the most common site for an adductor injury is the tendinous insertion of the adductor longus or gracilis.
Early on, plain x-rays of patients with osteitis pubis will often be normal. Later on, there may be widening of the pubic symphysis and evidence of periarticular sclerosis. This may be very difficult to identify in adolescents because of growth plates. Bone scans have been used, but these studies have a high rate of false negatives. Fortunately, MRI has a much higher sensitivity as well as specificity. This study has become the imaging technique of choice. [5]
Because MRI has grown in popularity, the Academy of Radiology has issued a policy paper that defines specific indications and concerns regarding its use in evaluating groin injuries. [6]
When hip fractures are either of the stress variety or subtle and anatomically stable, MRI is the imaging technique of choice—if plain films are unrevealing. [7]
Treatment
Treatment of adductor injuries are a notoriously frustrating proposition. It appears that the physical modalities, i.e. massage, stretching, transcutaneous electrical nerve stimulation, and laser treatment, are not as effective as active training exercise. Chronic adductor longus strains that have lingered for months appear to do well after surgical tenotomy, and complete tears of the tendinous insertion do better with surgical repair.
Treatment should be reassurance, rest, and a gradual return to normal activity. [8]
