Current concepts in management of ACJ injuries
Introduction
The acromio-clavicular (AC) joint is a di-arthrodial joint which acts as a link between axial and appendicular skeleton and contributes to the complex pattern of movement of the shoulder joint. AC joint injuries are most commonly seen in young adults and about 43% of injuries occur in second decade of life. AC joint injuries are 5 times more common in men and often involve contact sports.1,2 Despite being a common injury, there is no consensus regarding optimal management of AC joint dislocation. In recent years numerous techniques have been developed and described. Controversy exists regarding the choice of surgical procedure for treatment of injuries and the timing of surgery.3,4 The following work attempts to review literature regarding recent developments in the treatment of acute AC joint injuries and provide recommendations based on sound clinical evidence.
The AC joint is a synovial joint and its articular surface is made up of hyaline cartilage with an interposed disc of cartilage identical to a meniscus. This meniscus undergoes attrition over-time and is practically absent by the fourth decade of life. The articular surface area is small, whereas load transmitted is high. Cadaveric study of AC joint morphology has demonstrated three main types of AC joints 1)Flat, 2)Oblique and 3)Curved (Fig. 1).5 The forces are uniformly distributed in a flat acromion, however a curved or an oblique joint may have asymmetric stress transfer promoting damage to the articular cartilage.
The AC joint is stabilised by the AC ligaments which are thickenings in the joint capsule and the coraco-clavicular (CC) ligaments. The joint experiences significant translational forces in the anteroposterior and superolateral directions due to weight of the arm and muscle pull. The AC ligament provides about 90% of the AP stability and 20–50% of resistance to superior migration. The CC ligament consists of the conoid ligament medially and the trapezoid laterally. They are the primary restraint to inferior and medial translation of the acromion in respect to the clavicle.6
Section snippets
Classification
The sequential pattern of injury beginning with the AC ligaments, progressing to the coraco-clavicular ligaments and finally involving the deltoid and trapezial muscles was originally described by Cadenat.7 Rockwood described a classification which is most commonly accepted presently (Fig. 2).2 In type I injury, the AC and CC ligaments are all intact and the radiographic examination is normal. In type II injuries, the force of trauma is severe enough to rupture the AC ligaments, yet not severe
Acromioclavicular fixation
Acromio-clavicular fixation allows healing of the disrupted coraco-acromial ligaments by restoring the distance between the clavicle and the coracoid. Satisfactory outcomes have been reported in literature with Kirchner Wire (K wire) fixation and ligament repair. However, the procedure is rarely used today because of high incidence of migration of K wires and loss of reduction.15,16
Coraco-clavicular fixation
The coraco-clavicular distance can be maintained either by rigid fixation with a screw or the use of non-rigid synthetic materials. Bosworth described coraco-clavicular stabilisation with a lag screw.23 Rockwood and Young modified the technique to include CC ligament repair or reconstruction depending on the time of surgery. A bicortically placed screw provides about 80% more strength than the native ligament.24 However, this technique does not allow the clavicle to move in relation to the
Ligament reconstruction
The Weaver-Dunn procedure involves stabilisation of the AC joint by transfer of native CA ligament from acromion to the distal clavicle. The original technique also included excision of the distal clavicle. Initial reports from Weaver and Dunn revealed a 75% good-excellent outcome.28 Biomechanical studies have demonstrated that the native CA ligament is weakest amongst the various constructs tested.29 The initial strength of the CA ligament construct was found to be only a quarter of the native
Conclusion
In the recent years there has been an exponential increase in the number of publications on repair and reconstruction of AC joint.48 However, most of the recent studies are case series and lack long-term follow-up. Lack of standardisation in terms of population homogeneity, severity and chronicity of the injury prevents drawing up recommendations based on sound evidence. Significant questions still remain unanswered, with regards to type of graft to be used, number of ligaments reconstructed,
Declaration of interest
None.
References (51)
Rockwood type III acromioclavicular dislocation: surgical versus conservative treatment
J Shoulder Elb Surg
(2008)- et al.
Arthroscopic treatment of acute acromioclavicular joint dislocation
Arthrosc J Arthrosc R Surg Offic Publ Arthrosc Assoc North Am Int Arthrosc Assoc
(2004) Chronic acromioclavicular separation: the medium term results of coracoclavicular ligament reconstruction using braided polyester prosthetic ligament
Injury
(2007)- et al.
Arthroscopic reconstruction for acromioclavicular joint dislocation
Arthrosc J Arthrosc Relat Surg
(2001) ‘Current concepts in the treatment of acromioclavicular joint dislocations
Arthrosc J Arthrosc Relat Surg
(2013)Epidemiology of acromioclavicular joint injury in young athletes
Am J Sports Med
(2012)The Shoulder
(2009)- et al.
Management of chronic unstable acromioclavicular joint injuries
J Orthop Traumatol
(2017) Controversies relating to the management of acromioclavicular joint dislocations
The Bone & Joint Journal
(2013)Classification of the morphology of the acromioclavicular joint using cadaveric and radiological analysis
Consult Orthop Surg J Bone Joint Surg [Br]
(2010)
Biomechanical and radiographic analysis of partial coracoclavicular ligament injuries
Am J Sports Med
The treatment of dislocations and fractures of the outer end of the clavicle
Int Clin
A comparative analysis of operative versus nonoperative treatment of grade III acromioclavicular separations
Clin Orthop Relat Res
‘Conservative or surgical treatment of acromioclavicular dislocation. A prospective, controlled, randomized study
J Bone Jt. Surg
Long-term results of conservative treatment for acromioclavicular dislocation
J Bone Jt. Surg
Results of operative and nonoperative treatment of rockwood types III and V acromioclavicular joint dislocation: a prospective, randomized trial with an 18- to 20-year follow-up
Orthop J Sports Med
Functional outcomes of type V acromioclavicular injuries with nonsurgical treatment
J Am Acad Orthop Surg
Sports activity after anatomic acromioclavicular joint stabilisation with flip-button technique
Knee Surg Sports Traumatol Arthrosc: Off J ESSKA
Consistency of long-term outcome of acute rockwood grade III acromioclavicular joint separations after K-wire transfixation
J Trauma Inj Infect Crit Care
‘Long-term results of the surgical treatment of type III acromioclavicular dislocations
J Bone Jt. Surg
Mid-term results after operative treatment of rockwood grade III-V acromioclavicular joint dislocations with an AC-hook-plate
Eur J Med Res BioMed Central
Treatment of tossy III acromioclavicular joint injuries using hook plates and ligament suture
J Orthop Trauma
Clavicular hook plate may induce subacromial shoulder impingement and rotator cuff lesion - dynamic sonographic evaluation
J. Orthop Surgery Res BioMed Central
Arthroscopic fixation of acute acromioclavicular joint disruption with TightRopeTM: outcome and complications after minimum 2 (2–5) years follow-up
J Orthop Surg
Multicenter randomized clinical trial of nonoperative versus operative treatment of acute acromio-clavicular joint dislocation
J Orthop Trauma
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