Groin strain

Definition

Commonly termed groin strain, it refers to the tearing of the adductor muscles located at the groin in the inner side of the thighs.

Detailed anatomy of the muscle tissue depicting individual myofibrils or muscle fibres

Pathology

A strain of the groin occurs when pulling one or more adductor muscles. This group of muscles originates in the pelvic ring and attach along the inner side of the femur. They are the adductor brevis, adductor longus, adductor magnus gracilis, obturator externus, pectineus, which together form the hamstrings. These muscles are used when flexing and bending the hip joint when running and kicking. The damage can be minimal or result into a complete rupture of the muscle and avulsion. The pathology is graded as:

Grade 1: tear of few muscle fibres causing light pain and minimal functional impairment

Grade 2: damage to significant number of fibres resulting in moderate loss of function (most common)

Grade 3: complete rupture (avulsion) of a muscle and severe functional loss.

Colles' fracture with bone displacement seen before (left) and after closed reduction (right) in a cast

Classification

The fractures of the distal radius are defined with various classification systems including the AO (Arbeitsgemeinschaft fuer Osteosynthese) system. They relate to the mechanisms of injury and bone fracture characteristics and provide a guideline towards suitable treatments. The most frequent types of distal radius fracture are:

No 1.

Colles’ fracture is the most common type of fracture in which the distal bone of the radius tilts upwards following an outer bending of the wrist as it happens when falling on the hand

Smith’s fracture or reversed Colles’ fracture occurs when the distal portion of the radius tilts downwards following the inward bending of the wrist

Barton fracture is an intra-articular fracture of the distal radius with dislocation of the radiocarpal joint

Chauffeur fracture is an intra-articular fracture of the radial styloid process, also known as Hutchinson fracture or backfire fracture.

Left: Distal radius intraarticular, displaced fracture; Middle: Older distal radius fracture with callus formation; Right: Distal radius and ulna fracture, extraarticular and displaced

No 2.

Intra-articular fracture extends to the wrist joint (or articulation)

Extra-articular fracture is located outside of the wrist joint

Open fracture when bone fragments perforate the skin

Comminuted fracture when the bone breaks into multiple fragments

Non-displaced when the anatomical alignment of the bone is maintained or displaced when the bone fragments move apart.

Melone’s classification describes the characteristics of intra-articular fractures of the radius:

i    Stable fracture

ii    Unstable "die-punch"

iii   "Spike" fracture

iv Split fracture

v   Explosion injuries

Acetabular fracture of the pelvis

Acetabular fractures

These fractures are divided into:

Anterior pillar (not weight bearing part of joint)

Posterior pillar (often associated with dislocation of the hip including the weight bearing part of joint)

Transverse

Comminuted involving both column type 

Sacral / coccygeal fractures

The sacrum is a triangular-shaped bone formed by 5 fused vertebrae, which provide a posterior wall to the pelvic ring. At each side of the sacrum, the ala structures articulate with the ilium bones forming the sacro-iliac joints. Sacral fractures are usually parallel to the spine and can involve the ala. Less frequently sacral fractures may display an “H” shape, including a transversal fracture uniting both sides of the sacrum. Three zones are described where sacral fractures can occur that are along vertical lines relative to the alignment of the foramina. Sacral fractures may result in sacral instability and require treatment via sacroplasty (injection of bone glue into the fracture). Surgery is necessary in case of associated neurological symptoms.

Fractures of the coccyx involve the tailbone, the terminal portion of the spine situated below the sacrum formed by 3 to 5 fused vertebrae. Coccyx fractures occur when falling on a seated position. They are more common in elderly women and seldom require surgical treatment.

Anatomical illustration of a sprinter showing the strain of the inner thigh adductor muscles

Causes

A groin strain is a frequent pathology encountered in 10-30% of soccer and hockey players when the contraction of the adductor muscles (more frequently in the adductor longus) is so intense to cause a tear with external rotation of the abducted leg. Such tears occur with sudden muscle contraction while accelerating (springers) or as a muscle pull with intense stretching (long distance ball kick). A groin strain is frequent in sports such as:

Ice hockey

Soccer

Football

Running, sprinting

Long jumper athletes

Gymnastic

Skiing

Horse riding

In older age groin strains are more frequent as muscles loose flexibility

Risk factors

By being a typical sports injury the risk for a groin strain is enhanced with poor warm up without stretching prior to training. The pathology is more frequent in older athletes. Overuse and repetitive groin muscle activities can lead to adductor tendinopathy and eventually to muscle tears. The sports mentioned previously increase the risk of a groin tear. Additional risk factors are:

Lack of groin flexibility

Muscle weakness (groin, pelvis, core muscles)

Muscle strength discrepancy

Joint stiffness

Inadequate training technique

Incorrect posture during activity

Pain in the inner side of the thigh is a symptom of a groin strain

Symptom

The symptoms for a groin tear become evident at the time of injury and are particularly felt with activities of the adductor muscles. The typical symptoms include:

Sudden sharp pain to the groin area and inner thigh

Pain increasing with movement

Pain when squeezing the legs

Pain after cooling down

Muscle stiffness

Bruise

Inability to walk or play sport

Walking with a limp

Swelling

Muscle spasm

Muscle weakness

Clinical examination to test for groin tear

Diagnosis

The diagnosis of a groin tear is mostly obtained with clinical examination. Tenderness sensations at the site of a muscle tear and through the pubic area are clear signs of the pathology. In more severe tears, decreased muscle strength is observed while the examiner adducts the leg and the patient fails to resist the pressure. Due to the nature of this pathology, mostly MRI and ultrasound suffice to detect muscle tears in the region, swelling, haemorrhage and oedema.

An X-ray may be recommended in groin tears with suspected injury of the bony structures around the pelvis.

Treatment

Icing is beneficial to reduce inflammation after a groin tear

Nonoperative treatment

A groin tear is mostly treated conservatively beginning with a phase of rest followed by a rehabilitative regime. The prognosis varies from 3 weeks in mild tears to 6 weeks or longer in more severe cases. With muscle avulsion the prognosis may last for months. Additional conservative treatment includes:

Rest

Ice applications

Pain management with analgesics

Anti-inflammatory drugs (NSAIDs)

Local steroid injection

Reduced weight bearing if necessary

Surgery is only performed in case of a severe muscle rupture

Surgical treatment

Surgical treatment of a groin tear is rare and only performed in case of larger muscle ruptures and total muscle avulsion that includes the detachment of the bony area of muscle insertion. Open surgery is the method used and involves an incision over the area of tear to allow suturing the torn muscle or to reattach the tendon origin to the bone. Following surgery the patient may require the use of crutches for a few weeks. Occasionally symptoms may last for up to 6 months.

Massage of the affected muscles increases blood perfusion and muscle fibre mobility after injury

Rehabilitation

Physical therapy is indicated following a short period of rest. The rehabilitation program consists of gentle stretching and physical exercise of increasing strength. The therapist will also guide the patient to a planned return to sport including education in modifying those activities that may cause recidivism. A groin strain strapping can be applied immediately after injury to reduce swelling by compression as well as a preventative tool after recovery. Physiotherapy management includes:

Rest

Ice treatment

Local compression to reduce swelling

Anti-inflammatory therapy (NSAIDs)

Use of crutches

Stretching

Massage

Ultrasound

Electrotherapy

Activity modifying regime

Return to activity plan

A constriction bandage can reduce recidivism of groin tears

Prevention

Groin strains have a high rate of recidivism. Therefore it is critical to maintain the improved physical condition achieved with weeks of rehabilitation. The following rules will assist in preventing a groin tear:

Avoid premature return to sport

Gradual resume of sport by reducing activity time, and vigour (e.g. slower running speed)

Practicing movements posing stress to the adductor muscles

Including stretches and warm-ups for proper preparation to sport

Use groin straps, brace and groin shorts during activities.

Wear proper fitting shoes