Bankart lesion and Hill-Sachs lesion
MRI of a Bankart lesion

Definition

The labrum of the shoulder joint can be torn as a consequence of a forceful shoulder dislocation. When the damage only involves the labrum it is called a Bankart lesion. A Hill-Sachs lesion occurs when the lesion to the labrum presents simultaneously with a structural defect of the bone of the humeral head.

Illustration of a Bankart lesion

Pathology

A Bankart lesion consists of a tear of the glenoid labrum. When the humeral head pops out of the joint during a forceful, mostly anterior, shoulder dislocation, it may tear the capsule surrounding the shoulder joint and cause the detachment of the labrum from the glenoid. If a shoulder dislocation is produced by high-energy trauma, it can additionally impact on the humeral head. The abrupt displacement of the humerus causes the cartilage covering the humerus head to hit the glenoid. This leads to the formation of an indentation fracture to the humerus head generating the so called Hill-Sachs lesion. The lesion may vary in size and requires surgical treatment only if being from 1/8 to over 1/4 of the size of the labrum. This lesion occurs mostly in young individuals and shows an incidence of 35% of all anterior dislocations and up to 80% in recurring dislocations. Such lesions can be associated with axillary nerve injury and various fractures to the humeral head and bone.

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.

An anterior shoulder dislocation may lead to a Bankart lesion

Causes

The same mechanisms responsible for a shoulder dislocation are amongst the causes leading to Bankart and Hill-Sachs lesions. These pathologies are most often diagnosed together with an anterior shoulder dislocation and in patients with recurrent shoulder dislocations. 

Bankart and Hill-Sachs lesions are frequent in young men involved in contact sports and elderly women over 60 years due to falls.

Risk factors

Any sport or physical activity that predisposes to a shoulder dislocation presents a risk for Bankart and Hill-Sachs lesions. This includes individuals actively playing contact sports (football, rugby, hockey) and throwing activity (tennis, baseball, cricket). The increased incidence of falls onto the shoulder represents a higher risk in older people. The intrinsic poor vascularity of the glenoid labrum exposes this area to injury when strained. These pathologies can easily arise in patients with a congenital joint laxity, a condition named Ehlers-Danlos Syndrome that weakens the ligaments stabilising the joints.

Shoulder pain and instability are symptoms of a Bankart lesion, Hill-Sachs lesion

Symptoms

The most common symptom of Bankart and Sachs-Hill lesions is a feeling of instability of the shoulder joint particularly if these pathologies occur after repetitive dislocations. The patient may display excessive translation of the humeral head within the glenoid joint. Pain and a catching sensation with shoulder subluxation are also frequently described. Patients often state that when moving the arm behind the head they feel that shoulder is close to dislocate.

MRI showing a Bankart lesion
X-ray of a Hill-Sachs lesion. Note the dent on the humeral head.

Diagnosis

A medical history sets the beginning of a clinical investigation to evaluate the possible causes, injuries and previous shoulder dislocations that have lead to a recurrent shoulder dislocation. A high-energy trauma event particularly in active young individuals presents a higher risk for a Bankart or Hill-Sachs lesion, thus requiring a thorough medical analysis. Clinical examination provides a good indication for a dislocated shoulder and possibly other associated pathologies. Specific functional tests employed include the apprehension test, relocation test and sulcus sign. However, radiological imaging is required for the exact diagnosis of a Bankart and Hill-Sachs lesion. A Bankart lesion of the labrum is visualised at best by MRI using a contrast agent. X-rays and CT scansdo not detect easily a Bankart lesion as it involves soft tissue but are useful to diagnose a Hill-Sachs lesion to the humeral head and possible collateral fractures.

Treatment

Nonoperative treatment

The first approach of conservative treatment for a Bankart lesion due to shoulder dislocation is a closed reduction of the shoulder followed by temporary immobilisation with a sling until the inflammation has subsided. The patient requires treatment with pain killers and NSAID’s in the acute phase and subsequently undergo intensive physical therapy. However, with non-operative treatment there is a higher risk of recurrent dislocations. If the shoulder dislocates again, surgery is needed.

Example of arthroscopic surgery

Surgical treatment

Surgery for a Bankart lesion is highly recommended for active athletes, even after a single dislocation, especially those involved in contact sports, which increase the likelihood of a second shoulder dislocation and shoulder joint injury. Similarly to SLAP injuries, surgery consists in the repair of the labrum followed by the reattachment of the glenohumeral ligament to the glenoid rim mostly via arthroscopic surgery. The success rate of surgical repair is approximately 90% and patients are able to return to their sport activities.

With a Hill-Sachs lesion that occupies >30% of the humeral head surface, as established by CT or MRI scan, surgery is required due to the high instability of the shoulder. Surgical techniques vary: Allograft (transplant of a small bone tissue) into the lesion of the humeral head; remplissage (French translation for “fill-in”) in which a burr is introduced to decorticate the Hill-Sachs lesion and a large rotator cuff anchor is inserted into the bony defect; humeral rotation osteotomy or removal of bone parts; hemiarthroplasty and total shoulder arthroplasty are only used in patients over 50 years of age.

Shoulder shrug exercise

Rehabilitation

A number of exercises are available to strengthen the rotator cuff and the musculature of the shoulder and shoulder blades. Stretching is useful to restore flexibility and the range of movement of the shoulder joint. Following surgery the patient wears a sling for about three weeks until physiotherapy begins. In the recovery phase applications of cold pads, administration of pain killers and anti-inflammatory therapy with NSAIDs is standard rehabilitative management to improve symptoms. Physiotherapy consists of a number of methods:

Massage

Joint mobilisation

Ice/heat treatment

Physical exercise (pendular movements, shoulder shrug, rotation)

Education in sport and daily activities

Return to sport plan

Antiinflammatory treatment (NSAIDs)

Exercise with an elastic band strengthen the shoulder muscles

Prevention

The best prevention for a shoulder dislocation and consequent Bankart and Hill-Sachs lesions consists of physical training to strengthen the muscles around the shoulder and core. It is also recommended soon after recovery to avoid excessive training or intense activities potentially leading to recidivism.

In patients with increased risk due to strenuous sport activities, it is advised to wear proper safety equipment (braces) and padding during training. Where possible avoid falls in the elderly to prevent a shoulder dislocation.