Acromioclavicular joint disruption

What is Acromio-Clavicular joint?

Acromio-clavicular joint (ACJ)is the joint between collar bone (clavicle) and the shoulder blade (Scapula) at the highest point of shoulder. It’s a strong joint that connects the arm to the body and is stabilised by two groups of ligaments. Acromio-clavicular (AC) ligament stabilises the joint between acromion and clavicle and is primarily responsible for horizontal stability.  The second and the most important stabiliser is the coraco-clavicular (CC) ligament that is outside the joint and is primarily responsible for vertical stability. Two muscles namely trapezius and deltoid provide the dynamic stability of the joint. This joint is essential for a synchronous shoulder movement and has gliding and rotational motion taking place with shoulder movement.

 

What is an Acromio-clavicular joint disruption?

Acromioclavicular joint disruption or shoulder separation is caused by an injury to the acromioclavicular joint due to direct fall onto the point of the shoulder or due to falling on the outstretched arm. The grade of AC joint injury depends on the displacement of the joint, the force of impact and injury to the supportive structures, especially acromioclavicular ligament and coracoclavicular ligament around the joint.

 ACJ disruption is most common in young male athletes who participate in contact sports like hockey, football, rugby and martial arts. It’s also common in cyclists and bikers when they fall off and land on the shoulder. It accounts for 10 % of injuries in contact sports and is also injured during shoulder dislocations.

The shoulder separation is divided into six types based on the severity of injury.

  • Type I involves sprain of AC ligament,
  • Type II involves rupture of AC ligament with a sprain in the coracoclavicular (CC) ligament and the increased CC distance will be less than 25% of the opposite side
  • Type III involves complete rupture of both AC&CC ligaments and displacement of joint upto 100% or CC distance 25% to 100% more than the opposite normal side.
  • Type IV is similar to Type III, except that the lateral end of clavicle is displaced posteriorly into the trapezius muscle. It is often misdiagnosed as Type II injury, assessment of ACJ using axillary view of X-ray is essential as conservative management could adversely affect the functional outcome of the shoulder.
  • Type V involves complete rupture of both AC&CC ligaments and displacement of joint more than 100%
  • Type VI is inferior dislocation of the clavicle and is very rare. Its essential to thoroughly evaluate the neurovascular integrity.

 

What are the symptoms of Acromio-clavicular joint disruption?

AC joint disruption can cause swelling, bruising and pain in the shoulder. The tip of the shoulder joint (highest point) usually becomes more prominent than the opposite shoulder. The swelling is usually very tender to touch and could hear/feel clicking and clunking with shoulder movement. You may also have restricted movement of the shoulder and the affected arm. Pain related to AC joint increases with the increase in the movement of the affected arm. In Grade III to V AC joint separations, you may have a noticeable bump on the shoulder, which are usually painful. In long standing (Chronic) ACJ separation the pain could spread to arm, upper chest and to root of neck due to alteration in the biomechanics of the joint.

 

How is it diagnosed?

Its diagnosis is made by a detailed medical history, physical examination and an X-ray. X-ray is usually performed to confirm the joint separation and rule out any fracture to the clavicle. X-rays of opposite shoulder and rarely CT scan may be needed in some cases

 

How is it treated?

Majority of the ACJ separations are Gr I &II and could be treated without surgery. The non-operative methods involve ice packs, rest, use shoulder sling, pain killers and physiotherapy. Once the pain settles down the shoulder could be mobilised as pain allows. Majority regain full function after this injury in spite of significant bump. Management of Grade III AC joint disruption is controversial, and the decision could be aided with age, hand dominance, hobbies and sports involving overhead activities. Research has shown that Gr IV-VI separations would benefit from surgery, however patient personality is an important factor that helps with the decision making.

Surgery is indicated in

  • Open injuries (wound)
  • Associated injuries to neighboring structures such as blood vessels, nerves, ligaments or clavicle
  • Severity of the joint disruption (Grade IV-VI)
  • Selected Grade III separation – persistent pain inspite of conservative treatment.
  • Persistence of pain after 3 months.

 

What happens if nothing is done?

If AC joint separation is not managed in time, it may lead to following complications-

  • Chronic subluxation and instability
  • AC joint arthritis
  • Residual pain at the joint
  • Radiating pain to the neck, shoulder blade, upper chest and arm.
  • Alteration of shoulder bio-mechanics leading to weakness and rarely protraction of shoulder

 

What are the non-operative treatments?

Grade I, Grade II and most of Grade III AC joint separation can heal easily with non-surgical treatment that usually comprises of painkillers, the short period of rest with a sling and physiotherapy. Grade I, II AC separations usually recover fully in six weeks to 3 months of conservative treatment. Grade III shoulder separations may take a little bit longer to recover.

The non-operative treatment involves-

  • The patient is advised to take full rest and avoid contact sports.
  • Ice packs are placed on the shoulder every two to three hours for about 20-30 minutes.
  • A shoulder sling is used to immobilize the arm and shoulder for 3 weeks.
  • Painkillers such as codeine and paracetamol are prescribed to relieve the pain.
  • Anti-inflammatory drugs such as aspirin and ibuprofen are prescribed to control swelling.
  • With the reduction of the pain, the patient is encouraged for gentle exercises for about 3 weeks, to maintain mobility and strength. The elbow, wrist and hand should be kept mobile during the period of immobilization. The exercises are gradually progressed to strengthening exercises after the healing of the joint.
  • Physiotherapy should focus on the treatment of scapular dyskinesia.

If the symptoms are persistent in spite of conservative treatment, further imaging to assess rotator cuff or labral/SLAP lesion is necessary. Rarely patients might need steroid injection into the ACJ and/or surgical excision of distal clavicle.

 

What does the operation involve?

The main aim of the surgical operation is to reconstruct the broken ligaments by the use of pins, screws or sutures. Surgery is required in symptomatic Grade III and Grade IV-VI AC joint disruption. ORIF (Open Reduction Internal Fixation) technique is usually used to treat the shoulder separation. In the ORIF technique, a small cut (bra strap incision) is done on the skin of affected area instead of open surgery to access the fracture.

  • Surgery is usually performed as a day case under general anaesthetic, a cut is made in the skin over the fracture site and tunnels are drilled over the posterior aspect of the clavicle (collar bone) and coracoid (shoulder blade) in order to reconstruct the ligaments.
  • The separation is reduced under direct vision and with the help of intra-operative radiographs then fixed internally with help of strong sutures (fiber wire, LARS, Ethibond etc) pins, screws or plates inorder to keep them in proper position during healing.
  • Coraco-clavicular, acromio-clavicular and in selected cases coraco-acromial ligaments are tied with the help of sutures or are replaced by the utilization of allograft tissue.
  • Trapezius and deltoid tears are repaired.
  • Skin is then closed with the help of absorbable sutures. A shoulder sling is applied for immobilisation of the affected shoulder and arm.

 

 What happens after surgery?

  • The local anaesthetic wears off 4-10 hrs after surgery; patients are encouraged to start taking painkillers before the pain starts i.e. on return home and for at least 48 hours from there. This way most of our patients report little or any pain.
  • The initial aim is to provide comfort and rest to the arm with the use of a sling.
  • Before discharge, your physiotherapist will teach you gentle exercises of fingers, wrist, elbow and pendulum exercises for the shoulder. This is necessary to prevent stiffness and pain and to maintain the strength of the muscles near your shoulder after healing.
  • After two weeks of the surgery, the patient is reviewed for wound check and physical therapy is advised to facilitate rehabilitation.
  • The shoulder sling is removed after 6 weeks and patients are allowed full range of movements.
  • The patient can progress to more strenuous activities (swimming, driving, lightweights in gym etc) from six weeks to three months. This will be guided by your surgeon and is based on radiographic and clinical assessment.
  • The wound should be massaged (typically after 2 weeks) using moisturising cream by the patient 3 times a day for 3 months once the wound is well healed. This reduces the scar sensitivity and scar-related complications (tenderness, helps scar to mature).
  • It is advisable to avoid contact sports or any injury to the affected area for 3 months. The duration may increase or decrease, based on the personality of injury and method of reconstruction.
  • Physiotherapy is important to return back to normal functioning and for complete recovery, it can take from 6 months to 2 years.

 

Are there any risks?

  • Infection (<5%)
  • Damage to nerves and blood vessels
  • Residual pain at the joint (10-30 %)
  • Hardware irritation (26%)
  • Fracture of clavicle or coracoid tunnels (5%)
  • Loss of AC joint reduction (26%)
  • Non-anatomical reconstruction of the joint
  • AC arthritis
  • Breaking or pullout of CC screw

 

What are the results of the operation?

The outcome of the surgery is excellent with minimal serious complications (<1%). The surgery may involve immobilization for 6 weeks and full recovery in around 3-12 months. The outcome following this surgery depends on the nature of your job, grade and severity of the injury, treatment involved and adherence to physiotherapy. However, is more predictable in the author’s experience.

 

When can I return to driving and work?

You can get back to work in 2-4 weeks if you have a desk job, however it might take up to 3 months if your job involves physical work. Regarding return to contact sports, it usually takes 3-6 months and depends on the severity of injury. You should be able to resume driving in 6-12 weeks. The above time line could vary based on the severity of injury and the treatment modality. Your physician will be able to advise you.

Acute ACJ injury:

Acromioclavicular joint disruption_1

  1. 30 year old gentleman had a fall from bicycle and had an acute ACJ dislocation or separation (arrow); B. The dislocation was reduced (black dotted line) and held with a strong suture attached to the metal buttons (arrows) on the collarbone (clavicle) and coracoid (shoulder blade).

Chronic ACJ injury:

Acromioclavicular joint disruption_2

  1. 40 year old gentleman had a fall from ladder and had an ACJ dislocation or separation (arrow)and was treated conservatively for 2 years; B. As he continued to struggle with pain and discomfort, he had lateral end clavicle excision, ACJ reconstruction with LARS ligament connecting the collarbone (clavicle) and coracoid (shoulder blade).

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