Distal Clavicle Osteolysis (or AC Joint Osteolysis) is thought to be a stress failure of the distal clavicle due to an initial stress fracture, followed by cystic and erosive changes secondary to bone resorption.

Subsequent bone formation and remodeling cannot occur because of continued stress on the joint.

This condition was first described in 1959 by Ehricht.

Distal Clavicle Osteolysis is most common in athletes involved in prolonged weight training and appears to be on the increase. The recent increase in incidence may be due to the emphasis on strength training regimens in sport.

In a group of Danish weightlifters, the prevalence was found to be 27% compared with a normal (non–weight-lifting) control group.

See Also: Clavicle Anatomy
Distal Clavicle anatomy

Distal Clavicle Osteolysis Symptoms

The symptoms usually begin insidiously:

  • They are usually described as a painful, dull ache localized to the Acromio-clavicular joint.
  • The ache, which tends to be worse at the beginning of exercise, may radiate into the deltoid and trapezius.
  • Bench presses, dips, and push-ups are usually the most painful exercises.
  • Abduction of the arm beyond 90 degrees causes pain.
  • Throwing is also painful.

On examination, there is point tenderness at the A-C joint and forced arm adduction across the chest increases the symptoms.

Symptoms are bilateral in 20% of cases.

Radiographic Evaluation

Radiographs of the distal clavicle reveal the following findings:

  1. osteopenia,
  2. osteolysis,
  3. tapering,
  4. cystic changes.
Distal Clavicle Osteolysis imaging
Distal Clavicle Osteolysis

Differential Diagnoses

The most common differential diagnoses to be considered are:

  1. cervical spondylosis,
  2. rotator cuff disease.

Distal Clavicle Osteolysis can be distinguished from rotator cuff tendinitis by selective injection of anesthetic into the A-C joint. An abolishment of the pain with the provocative maneuvers subsequent to the injection helps confirm the diagnosis.

See Also: Rotator Cuff of the Shoulder

Distal Clavicle Osteolysis Treatment

The majority of patients with this condition respond to conservative management and activity modification, with most improving by reducing or eliminating their strength training activities.

However, even after several years, layoff, if strength training is reinstituted at the same level, the symptoms will commonly recur.

Other aspects of conservative intervention involve:

  1. heat,
  2. NSAIDs,
  3. ROM,
  4. stretching and strengthening exercises: The exercises should be performed below 90 degrees of abduction.
  5. Ultrasound has also been advocated.

Although a consideration, intra-articular injection of steroid does not provide long-lasting success. It is more helpful to aid in the diagnosis and predicting surgical success.

Distal Clavicle Osteolysis Surgical treatment in indicated if conservative treatment has failed.

The surgical treatment include Distal Clavicle Excision, either open or arthroscopic (only 0.5-1cm of distal clavicle should be resected).

Distal Clavicle Excision
Distal Clavicle Excision

References

  • Turnbull JR. Acromioclavicular joint disorders. Med Sci Sports Exerc. 1998 Apr;30(4 Suppl):S26-32. doi: 10.1097/00005768-199804001-00005. PMID: 9565953.
  • Ehricht HG: Die osteolyse im lateralen claviculaende nach pressluftschaden. Arch Orthop Unfallchir 50:576–582, 1959.
  • Scavenius M, Iverson BF: Nontraumatic clavicular osteolysis in weight lifters. Am J Sports Med 20:463–467, 1992.
  • Cahill BR: Atraumatic osteolysis of the distal clavicle: A review. Sports Med 13:214–222, 1992.
  • Cahill BR: Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg 64A:1053–1058, 1982.