AC joint separation

- AC Joint Separation: 
       - references:
              - Incidence of Associated Injuries With Acute Acromioclavicular Joint Dislocations Types III Through V

- Exam: 
    - palpate the AC joint during flexion and extension of shoulder; 
    - distract the arm as it is placed in adduction
    - significant prominence of the distal clavicle indicates unstable AC injury; 
    - BvR test for DJD: resisted shoulder upward flexion with arm hyperadducted; 
    - ref: Clinical evaluation of acromioclavicular joint pathology: sensitivity of a new test

- Radiology:
    - classification of AC separation 
    - acromioclavicular joint stresses views 
           - grade I injuries remain nondisplaced; 
           - type I and type II injuries can be differentiated on stress radiographs;
           - w/ pt standing, 10 lb weight is secured to affected upper limb;
           - w/ grade II injury, suspended  wt displaces AC joint articulation, which increases distance between clavicle & acromion; 
    - zanca view
    - scapular outlet view
    - cross body adduction view:
            - grade IIIA injuries: defined by a stable AC joint without overriding of the clavicle on the cross-body adduction view
            - unstable grade IIIB injury: defined by overriding clavicle on the cross-body adduction view

    - reference:
            - Radiological evaluation of the acromioclavicular joint
            - ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries.
            - Bilateral weighted radiographs are required for accurate classification of acromioclavicular separation: an observational study of 59 cases.

- Treatment:
       - non operative treatment:
               - Schlegel TF, et al, the authors prospectively studied natural history of untreated acute grade III  AC  separations;
               - 25 patients were treated nonoperatively with a sling for comfort through progressive early range of motion as tolerated;
               - 10 additional uninjured subjects underwent strength testing to evaluate difference between dominant and nondominant sides;
               - one patient underwent a surgical procedure at 2 weeks after injury because of cosmetic concerns;
               - 20 of the 25 patients completed the 1-year evaluation and strength-testing protocol;
               - 4/20 patients (20%) : long-term outcome was suboptimal, although for 3 of them it was not enough to warrant surgery;
               - 20 patients revealed no limitation of  ROM in injured extremity and no diff between sides in muscle strength;
               - bench press: showed a significant short-term difference, with the injured extremity being an average of 17% weaker;
               - ref: A prospective evaluation of untreated acute grade III acromioclavicular separations. 

       - operative treatment:
 ref: Changes in Surgical Procedures for Acromioclavicular Joint Dislocation Over the Past 30 Years
                 - surgical precautions:
                       - attempt to keep fixation over the anterior third of the clavicle (avoid more anterior translation);
                       - coracoclavicular cerclage techniques may provoke malreduction of the joint due to anterior subluxation; 
                       - consider some technique to defray pressure over the clavicle (endo button, plate ect) to avoid cut through;
                 - hook plate:
                       - careful not to over reduce the joint, as this will over stress the clavicle and the acromion.
                       - avoid using the smallest plate as this applies excessive stress on the clavicle;
                       - references:
                               - Treatment of Tossy III acromioclavicular joint injuries using hook plates and ligament suture.
                               - Surgical treatment of acute acromioclavicular joint injuries using a modified Weaver-Dunn procedure and clavicular hook plate.
                               - The use of a hook plate in the management of AC injuries. Report of 10 cases.
                               - Results using the AO hook plate for dislocations of the acromioclavicular joint 
                               - Surgical treatment of acute and chronic acromioclavicular dislocation Tossy type III and V using the Hook plate
                               - Hook plate fixation for acromioclavicular joint separations restores coracoclavicular distance more accurately than PDS augmentation, however presents with a high rate of acromial osteolysis.
                               - Fixation failure of the clavicular hook plate: a report of three cases 
                               - Clavicular hook plate: not an ideal implant
Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.
                               - Biomechanical analysis of acromioclavicular joint dislocation treated with clavicle hook plates in different lengths.

                 - CA ligament reconstruction:
                       - ligament is identified as it passes from tip of coracoid process and inserts along undersurface of anterior aspect of acromion;
                       - small piece of bone can be taken with the ligament from the acromion to allow bone-to-bone healing;
                       - references:
                               - Surgery about the coracoid: neurovascular structures at risk. 
                               - The cortical ring sign: a reliable radiographic landmark for percutaneous coracoclavicular fixation
                               - Clinical results of coracoacromial ligament transfer in acromioclavicular dislocations: A review of published literature.
                               - Method of Subcoracoid Graft Passage in Acromioclavicular Joint Reconstruction

                  - reconstruction w/o tendon graft:
                       - consider direct verticle suture limb(s) and a second suture limb running more lateral to engage lateral edge of clavicle
                                 (to reproduce trapezoid ligament);

                           - A Modified Technique of Reconstruction for Complete Acromioclavicular Dislocation: a Prospective Study. 
                           - Stability of acromioclavicular joint reconstruction: biomechanical testing of various surgical techniques in a cadaveric model.
                           - A cadaveric study examining acromioclavicular joint congruity after different methods of coracoclavicular loop repair.
                           - Consistency of long-term outcome of acute Rockwood grade III AC joint separations after K-wire transfixation.
                           - Mid-term outcome comparing temporary K-wire fixation versus PDS augmentation of Rockwood grade III acromioclavicular joint separations.           
                           - Failure of Coracoclavicular Artificial Graft Reconstructions from Repetitive Rotation
                           - Mid to long-term results of open AC-joint reconstruction using polydioxansulfate cerclage augmentation.
                           - Triple endobuttton technique for the treatment of acute complete acromioclavicular joint dislocations: preliminary results.

                 - reconstruction with tendon graft: (palmaris longus, gracilis, semitendinosis)
                          - surgical technique:
                                 - transverse incision over distal clavicle;
                                 - deltotrapezial fascia is then divided, exposing distal clavicle;
                          - coracoid:
                                 - superior aspect of the coracoid neck is exposed, and the soft tissue is elevated.
                                 - curved suture passer is placed medial to lateral under coracoid to retrieve suture in gracilis tendon graft and pull it
                                            around coracoid;
                          - clavicle
                                 - conoid limb of the graft
                                        - 4- to 5-mm hole is drilled in the posterior half of the distal clavicle, 45 mm from the distal end of clavicle;
                                 - trapezial limb of graft
                                        - 4- to 5-mm hole is drilled centerline on the clavicle 15 mm lateral to the first hole to accommodate the
                                                 trapezial limb of the graft;
                                 - distal clavicle excision
                                        - the distal 8 mm of the clavicle are excised with an oscillating saw.
                          - tendon passage and fixation:
                                 - free ends of the graft then are advanced through the clavicle drill holes and crossed (opposed);
                                 - distal clavicle is held reduced, and the graft is tensioned, and tendons are sutured
                                 - remaining sutures are then brought laterally to the AC joint and sutured to the acromion;
                 - references:
                         - Acromioclavicular joint dislocation: a comparative biomechanical study of the palmaris-longus tendon graft reconstruction with other augmentative methods in cadaveric models.
                         - Reconstruction of the Coracoclavicular Ligaments with Tendon Grafts: a Comparative Biomechanical Study. 
                         - Anatomical acromioclavicular ligament reconstruction: a biomechanical comparison of reconstructive techniques of the acromioclavicular joint.
                         - Clinical outcomes of coracoclavicular ligament reconstructions using tendon grafts.
                         - Acromioclavicular joint reconstruction using peroneus brevis tendon allograft.
                         - Clavicular fractures following coracoclavicular ligament reconstruction with tendon graft: a report of three cases.
                         - Type III Acromioclavicular Separation: Rationale for Anatomical Reconstruction
                         - Clinical Results of Single-Tunnel CC Ligament Reconstruction Using Autogenous Semitendinosus Tendon
                         - Semitendinosus tendon graft versus a modified Weaver-Dunn procedure for acromioclavicular joint reconstruction in chronic cases: a prospective comparative study.
                         - Clavicular Bone Tunnel Malposition Leads to Early Failures in Coracoclavicular Ligament Reconstructions



The acromioclavicular joint in rheumatoid arthritis.

Osteolysis of the distal part of the clavicle in male athletes

Bioabsorbable Screw Fixation in Coracoclavicular Ligament Reconstruction

Associated Lesions Requiring Additional Surgical Treatment in Grade 3 Acromioclavicular Joint Dislocations

- modified weaver dunn procedure: (for chronic injuries)

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Saturday, April 2, 2016 11:24 am