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ACJ Reconstruction / Stabilisation

Surgical technique guide for acromioclavicular joint reconstruction and stabilisation — Rockwood classification, Weaver-Dunn, suspensory fixation (Dog-Bone/TightRope), and acute vs chronic management for FRCS exam preparation

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Superior / deltotrapezial approach | advanced

Surgical Imaging

Three-panel intraoperative sequence showing ACJ reconstruction with hook plate and coracoclavicular fixation
ACJ reconstruction intraoperative sequence: (a) clavicle exposed via superior incision — asterisk marks torn ACLC; (b) hook plate positioned beneath the acromion (ACLC arrow) with two transosseous sutures (TO1, TO2) reinforcing coracoclavicular fixation; (c) completed reconstruction with hook plate and coracoclavicular repair.Credit: Schliemann B et al., BMC Musculoskelet Disord 2016 (PMC5012011) — CC BY 4.0
Intraoperative view showing clavicle and acromion with torn acromioclavicular ligament complex arrow
Intraoperative anatomy of acute ACJ dislocation: clavicle (superior) and acromion (right) exposed via saber incision. White arrowhead identifies the torn and retracted acromioclavicular ligament complex (ACLC) — repair of this structure alongside coracoclavicular fixation is critical to restoring horizontal stability.Credit: Schliemann B et al., BMC Musculoskelet Disord 2016 (PMC5012011) — CC BY 4.0
Intraoperative view showing clavicle and acromion with acromioclavicular joint gap marked by white arrowhead
ACJ disruption intraoperatively: clavicle and acromion labeled, with white arrowhead identifying the widened acromioclavicular joint space. The deltotrapezial fascia has been divided to expose the joint — its meticulous repair at closure restores the dynamic muscular stabilisers of the ACJ.Credit: Schliemann B et al., BMC Musculoskelet Disord 2016 (PMC5012011) — CC BY 4.0

Rockwood III Is Not Automatically Operative — Know the Controversy

The operative vs non-operative debate for Rockwood III ACJ injury remains unresolved. The systematic review by Ceccarelli et al. (PMID 19384625), the Cochrane meta-analysis by Tamaoki et al. (PMID 31604007), and the current-concepts systematic review by Beitzel/Mazzocca et al. (PMID 23369483) show no consistent superiority of surgery for Rockwood III at 1-2 year follow-up. International expert consensus (ISAKOS upper extremity committee) recommends non-operative treatment as first line for type III, with surgery reserved for failure of conservative management or selected high-demand patients. Examiners expect you to articulate both sides and individualise the decision.

Rockwood Classification

Grade I: Sprain AC ligament, CC intact. No displacement.

Grade II: AC ligament torn, CC sprained. Less than 25% superior displacement on stress views.

Grade III: Both AC and CC ligaments torn. 25-100% superior displacement. Controversial.

Grade IV: Posterior displacement of clavicle into trapezius muscle. Always operative.

Grade V: 100-300% superior displacement. Always operative.

Grade VI: Inferior (subcoracoid) dislocation. Always operative (rare, high-energy).

Coracoclavicular Ligament Anatomy

Conoid ligament: Posteromedial, cone-shaped, vertical fibres. Inserts posteromedial clavicle 4-6cm from AC joint. Primary restraint to superior and posterior translation.

Trapezoid ligament: Anterolateral, horizontal fibres. Inserts anterolateral clavicle 2-4cm from AC joint. Primary restraint to axial (compression) and lateral forces.

Normal CC distance: 11-13mm on stress X-ray. Greater than 5mm asymmetry or greater than 25% displacement = Grade III.

Both ligaments must be reconstructed for multi-directional stability.

Timing: Acute vs Chronic

Acute (less than 3 weeks): Direct repair possible, anatomy clearer, CC ligament ends accessible. Suspensory fixation alone may suffice without graft.

Sub-acute (3 weeks to 3 months): Inflammatory phase — technically harder. Augmented with graft or synthetic tape.

Chronic (greater than 3 months): CC ligament retracted and fibrosed, cannot be directly repaired. Formal reconstruction with graft (hamstring autograft or synthetic ligament) mandatory. AC capsule also attenuated.

Key principle: The later the surgery, the more complex the reconstruction required.

Neurovascular Risks

Thoracic outlet proximity: Brachial plexus and subclavian vessels pass under clavicle within 1-2cm of the operative field during clavicle tunnel drilling — respect depth limits.

Lateral pectoral nerve: Runs with the pectoral branch of thoracoacromial artery, at risk during aggressive retraction medial to the coracoid base.

Deltoid and trapezius innervation: Axillary nerve (deltoid, C5-C6) and spinal accessory nerve (trapezius, CN XI) vulnerable during aggressive deltotrapezial split extension.

Coracoid base drilling: Subclavian artery lies posteromedial — angle drill antero-inferiorly, never posteromedially.

Graft Choice

Hamstring autograft (semitendinosus): Most common biological option. Looped through coracoid and clavicle tunnels. Provides multi-directional strength. Donor site morbidity minimal.

Synthetic ligament (LARS or Ligasyn): Immediate strength, no donor site. Concerns re: long-term fatigue failure. Suitable for athletes needing rapid return.

Coracoacromial ligament (Weaver-Dunn): Transfer of CA ligament to clavicle. Historical gold standard. Weak reconstruction (CA ligament transfer restores only about a quarter of the native CC complex load-to-failure of roughly 500-725 N) — high loss-of-reduction rate.

Dog-Bone / TightRope buttons: Suture-based suspensory construct. Rapid setup, excellent initial strength. Coracoid fracture risk 4-10%.

Reasons for Failure

Loss of reduction (10-25%): Most common failure mode. Related to graft strength, tunnel position, rehabilitation compliance.

Coracoid fracture (4-10%): Thin coracoid base, aggressive tunnel drilling, excessive post-op loading. Requires revision with alternative fixation.

Hardware migration: Bosworth screw must be removed at 6-8 weeks (before patient forgets). Migration to mediastinum and great vessels reported — life-threatening.

Residual pain: AC joint arthritis (25-30% at 5 years), subacromial impingement from superior malposition.

Graft rupture: Rare with biological graft if protected rehabilitation followed.

Mnemonic

ROCKWOODROCKWOOD — Acromioclavicular Injury Classification

Hook:Use ROCKWOOD to recall the grading logic: I and II are partial injuries (AC sprained or torn, CC intact), III is the controversial complete injury, IV/V/VI are always operative based on direction and degree of displacement.

Mnemonic

WEAVERWEAVER — Weaver-Dunn Modification Key Steps

Hook:The Weaver-Dunn was elegant but biomechanically weak — the transferred coracoacromial ligament restores only roughly a quarter of the native coracoclavicular complex load-to-failure (intact CC complex approximately 500-725N). This explains the high loss-of-reduction rate and why modern anatomic free-graft and suspensory techniques have largely superseded it (Mazzocca 2005, PMID 16282577).

Rockwood Grade and Operative Decision

Grades I and II — Non-Operative (Universal Consensus)

Grade I (AC ligament sprain, CC intact): Sling 1-2 weeks, early mobilisation, analgesia. Return to sport 2-3 weeks. No surgery.

Grade II (AC ligament torn, CC sprained): Sling 2-3 weeks, physiotherapy from week 2. Return to sport 4-6 weeks. Symptomatic AC joint arthritis in up to 40% at 5 years — may require distal clavicle excision later.

Grade III — The Controversy

Rockwood III: Non-Operative vs Operative Management

Grades IV, V, VI — Operative (Universal Consensus)

Grade IV: Posterior displacement into trapezius. Tenting of posterior skin. Requires reduction and stabilisation regardless of demand level.

Grade V: 100-300% superior displacement. Muscle tent, severe deformity, brachial plexus traction symptoms possible. Always operative.

Grade VI: Inferior (subcoracoid/subclavicular) dislocation. High-energy mechanism, often associated with rib fractures, pneumothorax, brachial plexus injury. Rare — always operative.

Stress Radiograph Technique (Zanca View)

The Zanca view is the gold standard radiograph for ACJ injury grading: 10-15° cephalic tilt, bilateral simultaneous views on a single film with 50% reduced penetration. Bilateral views allow direct comparison of CC distance (normal 11-13mm bilaterally). Stress views (holding 5-10kg weights) may increase displacement in equivocal Grade II/III cases and are useful in the outpatient setting when acute films are not diagnostic.

Radiographic measurements:

  • CC distance: measured from inferior cortex of clavicle to superior cortex of coracoid process
  • Greater than 5mm absolute asymmetry or greater than 25% relative increase = significant CC injury
  • Grade V definition: CC distance greater than double the contralateral side (100-300% displacement)

Comparison of Reconstruction Techniques

ACJ Reconstruction Technique Comparison


Clinical Decision Scenarios

Use these scenarios to practise clinical reasoning and management decisions

CLINICAL SCENARIOStandard

Scenario 1: Acute Rockwood III in a 28-Year-Old Cyclist

CLINICAL PROMPT

"A 28-year-old recreational cyclist presents to your fracture clinic following a fall from his bicycle onto the shoulder. He has pain and a visible step deformity at the AC joint. Zanca view X-rays show 80% superior displacement of the clavicle relative to the acromion, with the CC distance increased to 14mm compared to 11mm on the other side. How do you counsel him?"

PRACTICAL APPROACH
This is a Rockwood Grade III ACJ injury — both the AC ligaments and CC ligaments are disrupted, with 25-100% superior displacement. The management is genuinely controversial and I would counsel this patient specifically, not just apply a blanket policy. My approach: First, I take a thorough history regarding his occupation, sporting demands, and functional goals. As a recreational cyclist (rather than a competitive overhead athlete or heavy manual labourer), he falls into the 'low-to-moderate demand' category where evidence supports a trial of non-operative treatment first. I would explain that the best available evidence — including the Cochrane systematic review (Tamaoki) and current-concepts reviews — shows no significant difference in functional outcomes between operative and non-operative treatment at 1 year for Rockwood III, with conservatively treated patients actually recovering faster at 6 weeks, that the majority of patients return to full activity with conservative management, and that surgery carries a higher rate of adverse events. I would prescribe a broad arm sling for 2-3 weeks, early mobilisation, physiotherapy, and review at 6-8 weeks. If at 3 months he has persisting pain, functional limitation, or deformity that is bothering him cosmetically or functionally, I would discuss operative reconstruction (suspensory fixation with or without biological augmentation). I would document this shared decision-making conversation. I would also acknowledge that some surgeons advocate early surgery for young active patients with Rockwood III on the grounds that acute repair is technically easier and avoids chronic deformity, citing Mazzocca et al. 2007. I would not dismiss this view but explain that the evidence does not yet definitively support routine early surgery for all Grade III injuries.
CLINICAL SCENARIOAdvanced

Scenario 2: Chronic Rockwood V — 6 Months Post-Injury

CLINICAL PROMPT

"A 35-year-old construction worker presents with a 6-month history of right shoulder pain, visible superior deformity, and inability to work at height or lift over 5kg. He had a Rockwood V ACJ dislocation that was treated non-operatively by another surgeon. Clinical examination confirms complete superior dislocation of the clavicle with 200% displacement on Zanca view and a positive piano-key sign. He is motivated to return to full work. Describe your management and reconstruction technique."

PRACTICAL APPROACH
This is a chronic Rockwood Grade V ACJ injury (100-300% superior displacement) in a high-demand worker who has failed the natural history of non-operative treatment. Rockwood Grade V is generally an operative indication even acutely, and at 6 months with functional limitation and work disability, reconstruction is clearly indicated. Pre-operatively, I would obtain: bilateral Zanca views for CC distance comparison, axillary lateral to confirm no posterior component (this is Grade IV, not V), CT scan to assess coracoid morphology and size for tunnel planning, and MRI shoulder to exclude associated rotator cuff or SLAP pathology. I would counsel the patient regarding the complexity of chronic reconstruction: the CC ligaments are retracted and fibrosed, preventing direct repair; formal reconstruction with biological graft (semitendinosus autograft) or synthetic tape is required; there is a 10-20% risk of loss of reduction; and recovery to full manual work is 4-6 months. My operative plan would be a modified suspensory reconstruction with hamstring graft augmentation. Step by step: (1) Saber-cut superior incision, deltotrapezial split. (2) Debride scar tissue overlying distal clavicle and coracoid. (3) Harvest ipsilateral semitendinosus (30-35cm). (4) Expose coracoid base, pass coracoid drill guide 1cm from tip, create 4mm tunnel with depth stop angled antero-inferiorly. (5) Create two clavicle tunnels at anatomic conoid (45-50mm from AC joint) and trapezoid (25-30mm) positions. (6) Pass looped semitendinosus graft through coracoid tunnel, pass both limbs through clavicle tunnels. (7) Under fluoroscopic guidance, reduce clavicle to anatomic position. (8) Secure graft with interference screws or tenodesis sutures over clavicle. (9) Augment with suture tape (InternalBrace concept) if available. (10) Resect distal clavicle 5mm (arthritic joint in chronic cases). (11) Repair deltotrapezial fascia meticulously. Post-op: sling 6 weeks, physiotherapy, full return to heavy work at 5-6 months.
CLINICAL SCENARIOAdvanced

Scenario 3: Post-op Day 14 with Neck and Arm Paraesthesia

CLINICAL PROMPT

"A 42-year-old patient returns to your clinic 14 days after ACJ suspensory reconstruction. She reports increasing pain in the neck and right arm, with paraesthesia in the medial forearm (C8/T1 distribution) and weakness of grip. Her wound appears clean and she is afebrile. There was no intraoperative complication documented. What do you suspect, and how do you investigate and manage this?"

PRACTICAL APPROACH
This presentation — new medial arm and forearm paraesthesia (C8/T1), grip weakness, and increasing neck pain at 14 days post ACJ reconstruction — suggests thoracic outlet or medial cord brachial plexus compromise. My differential diagnosis in order of priority is: (1) Thoracic outlet syndrome (TOS) from persistent or recurrent superior clavicle elevation if reduction has been lost — the superior-displaced clavicle can narrow the costoclavicular space and compress the lower trunk of the brachial plexus, particularly C8-T1 fibres (medial cord). (2) Direct brachial plexus traction injury from intraoperative positioning — beach chair positioning carries a risk of traction neurapraxia particularly to the lower trunk; this would have been present from the immediate post-op period but the patient may not have noticed initially due to pain and medication. (3) Haematoma with neural compression in the costoclavicular or thoracic outlet region — less likely at 14 days but possible if a slow bleed. (4) Hardware malposition or migration impinging on neural structures. Investigation: (1) Urgent repeat Zanca view and AP shoulder — is the reduction maintained? If re-displaced, the superior clavicle may be causing direct TOS. (2) CT of the thoracic outlet and shoulder region — assess clavicle position, exclude haematoma, assess coracoid integrity and hardware position. (3) Urgent MRI of the brachial plexus (neurogram sequence) — identifies traction injury, haematoma, or compression at any level. (4) EMG/nerve conduction studies at 3-4 weeks — confirms distribution, severity, and degree of axonal injury. (5) Blood tests: FBC, inflammatory markers to exclude infection. Management: (1) If re-displacement confirmed: early revision surgery to restore reduction and decompress the thoracic outlet. This is the most important cause to exclude. (2) If reduction maintained and no haematoma: conservative management — physiotherapy (postural and scapular stabilisation), cervical collar if needed, neuropathic analgesia (pregabalin). (3) If haematoma: washout and decompression. (4) Neurological follow-up and serial EMG at 3 and 6 months. (5) Vascular surgery referral if subclavian involvement. Document thoroughly, discuss openly with patient, and involve the neurosurgical or peripheral nerve team early if no improvement by 4-6 weeks.

ACJ Reconstruction / Stabilisation — Exam Summary

Clinical summary

Evidence Base — Verified Key Studies

Evaluation and Treatment of Acromioclavicular Joint Injuries

5
Mazzocca AD, Arciero RA, Bicos J • Am J Sports Med (2007)
Clinical Implication: Reconstruction must restore BOTH planes of stability; isolated vertical (CC) fixation alone leaves residual horizontal instability and is a recognised cause of failure.
Verify on PubMed (PMID 17251175)

A Biomechanical Evaluation of an Anatomical Coracoclavicular Ligament Reconstruction

5
Mazzocca AD, Santangelo SA, Johnson ST, Rios CG, Dumonski ML, Arciero RA • Am J Sports Med (2006)
Clinical Implication: A free-tendon-graft reconstruction of both the conoid and trapezoid restores anteroposterior translation closer to the native joint than the Weaver-Dunn — the biomechanical rationale for the modern two-tunnel anatomic technique.
Verify on PubMed (PMID 16282577)

Anatomy of the Clavicle and Coracoid Process for Reconstruction of the Coracoclavicular Ligaments

5
Rios CG, Arciero RA, Mazzocca AD • Am J Sports Med (2007)
Clinical Implication: Tunnel positions can be predicted from intra-operative clavicle length using the constant ratios — placing the conoid tunnel posteromedially at roughly one-third and the trapezoid tunnel at roughly one-sixth of clavicle length from the lateral end.
Verify on PubMed (PMID 17293463)

Surgical Versus Conservative Interventions for Treating Acromioclavicular Dislocation in Adults (Cochrane Review)

1
Tamaoki MJS, Lenza M, Matsunaga FT, Belloti JC, Matsumoto MH, Faloppa F • Cochrane Database Syst Rev (2019)
Clinical Implication: Supports a trial of non-operative management first for most patients, particularly Rockwood type III, reserving surgery for failure of conservative treatment or selected high-demand cases. The evidence base remains low quality.
Verify on PubMed (PMID 31604007)

Two-Year Outcomes After Primary Anatomic Coracoclavicular Ligament Reconstruction

4
Millett PJ, Horan MP, Warth RJ • Arthroscopy (2015)
Clinical Implication: Anatomic free-graft CC reconstruction gives good-to-excellent outcomes in patients who avoid a complication, but a clinically meaningful revision-requiring complication rate must be discussed during consent.
Verify on PubMed (PMID 25998014)

References

  1. Weaver JK, Dunn HK. "Treatment of acromioclavicular injuries, especially complete acromioclavicular separation." J Bone Joint Surg Am. 1972;54(6):1187-1194. PMID: 4652050. [Original description of the coracoacromial ligament transfer to the resected distal clavicle]

  2. Mazzocca AD, Arciero RA, Bicos J. "Evaluation and treatment of acromioclavicular joint injuries." Am J Sports Med. 2007;35(2):316-329. PMID: 17251175. doi:10.1177/0363546506298022. [Comprehensive review of ACJ anatomy, biomechanics, classification and treatment; emphasises horizontal as well as vertical instability and the limitations of the Weaver-Dunn]

  3. Mazzocca AD, Santangelo SA, Johnson ST, Rios CG, Dumonski ML, Arciero RA. "A biomechanical evaluation of an anatomical coracoclavicular ligament reconstruction." Am J Sports Med. 2006;34(2):236-246. PMID: 16282577. doi:10.1177/0363546505281795. [Cadaveric study: anatomic free-graft CC reconstruction has less anterior/posterior translation and more closely approximates the intact joint than the modified Weaver-Dunn]

  4. Rios CG, Arciero RA, Mazzocca AD. "Anatomy of the clavicle and coracoid process for reconstruction of the coracoclavicular ligaments." Am J Sports Med. 2007;35(5):811-817. PMID: 17293463. doi:10.1177/0363546506297536. [Defines conoid and trapezoid footprints: conoid ~47mm (M)/43mm (F) and trapezoid ~25mm (M)/23mm (F) from the lateral clavicle; conoid/trapezoid-to-clavicle-length ratios constant at ~0.31 and ~0.17]

  5. Beitzel K, Cote MP, Apostolakos J, et al. "Current concepts in the treatment of acromioclavicular joint dislocations." Arthroscopy. 2013;29(2):387-397. PMID: 23369483. doi:10.1016/j.arthro.2012.11.023. [Systematic review: consensus for non-operative type I-II and initial non-operative type III, operative type IV-VI; insufficient evidence for early vs delayed and anatomic vs non-anatomic]

  6. Millett PJ, Horan MP, Warth RJ. "Two-year outcomes after primary anatomic coracoclavicular ligament reconstruction." Arthroscopy. 2015;31(10):1962-1973. PMID: 25998014. doi:10.1016/j.arthro.2015.03.034. [31 shoulders (Rockwood III and V) with free tendon allograft; ASES improved 58.9 to 93.8; 22.6% required revision surgery for graft attenuation, clavicle fracture, distal clavicle hypertrophy or adhesive capsulitis]

  7. Martetschläger F, Horan MP, Warth RJ, Millett PJ. "Complications after anatomic fixation and reconstruction of the coracoclavicular ligaments." Am J Sports Med. 2013;41(12):2896-2903. PMID: 24007761. doi:10.1177/0363546513502459. [59 procedures; overall complication rate 27.1%; coracoid fracture, clavicle fracture and graft rupture described; construct survivorship 86.2% at 12 months and 83.2% at 24 months]

  8. Ceccarelli E, Bondi R, Alviti F, Garofalo R, Miulli F, Padua R. "Treatment of acute grade III acromioclavicular dislocation: a lack of evidence." J Orthop Traumatol. 2008;9(2):105-108. PMID: 19384625. doi:10.1007/s10195-008-0013-7. [Systematic review: clinical results comparable between operative and non-operative grade III, with more complications in the surgical group; non-operative treatment remains valid first-line]

  9. Tamaoki MJS, Lenza M, Matsunaga FT, Belloti JC, Matsumoto MH, Faloppa F. "Surgical versus conservative interventions for treating acromioclavicular dislocation of the shoulder in adults." Cochrane Database Syst Rev. 2019;10:CD007429. PMID: 31604007. doi:10.1002/14651858.CD007429.pub3. [Cochrane review, 6 trials, 357 patients: no difference in 1-year DASH function; conservatively treated patients recovered faster at 6 weeks; higher adverse-event rate with surgery (RR 2.82)]

  10. Salzmann GM, Walz L, Buchmann S, Glabgly P, Venjakob A, Imhoff AB. "Arthroscopically assisted 2-bundle anatomical reduction of acute acromioclavicular joint separations." Am J Sports Med. 2010;38(6):1179-1187. PMID: 20442326. doi:10.1177/0363546509355645. [23 patients (mostly Rockwood V); Constant score improved 34.3 to 94.3 at 24 months; supports the anatomic 2-tunnel/double-bundle concept and stresses precise tunnel and button placement]