Orthopedics

Case Reports 

Reconstruction of Humeral Head Defect for Locked Posterior Shoulder Dislocation

Chetan S. Modi, MBChB, MRCS, DipSEM; Laurence Wicks, MBChB; Kuntrapaka Srinivasan, FRCS(Orth)

Abstract

Locked posterior shoulder dislocation is a rare injury and is often missed on examination, usually due to inadequate imaging and potentially resulting in significant loss of shoulder function. An important feature of the physical examination is identification of the patient’s inability to externally rotate their arm. These injuries are associated with defects in the humeral head articular surface, also known as reverse Hill-Sachs lesions. Medium-sized defects involving 25% to 50% of the articular surface can be reconstructed using several methods, including subscapularis or lesser tuberosity transfer, rotational osteotomy of the humerus, osteochondral autografting, and allograft reconstruction.

We describe reconstruction of a 40% anteromedial humeral head articular surface defect associated with a missed locked posterior shoulder dislocation. Our technique used a deltopectoral approach with soft tissue dissection through the rotator interval to enable direct access to the defect with preservation of the rotator cuff muscles. The impacted articular surface was elevated, and the void was filled with moldable putty consisting of tricalcium phosphate with carboxymethylcellulose (Calstrux; Stryker Biotech, Hopkinton, Massachusetts). The articular fragment was then secured in position with size 5 Ethibond (Ethicon, Inc, Somerville, New Jersey) bone sutures. The patient regained excellent function and range of motion, with computed tomography scanning at 9 months demonstrating a smooth humeral articular surface with excellent graft incorporation.

This technique avoids donor site morbidity and potential risks with allograft use while maintaining normal shoulder joint anatomy with preservation of the rotator cuff muscles for less complicated prosthetic reconstruction if required in the future.

Locked posterior shoulder dislocation is a rare injury and is often missed on examination, usually due to inadequate imaging and potentially resulting in significant loss of shoulder function. These injuries are associated with defects in the humeral head articular surface also known as reverse Hill-Sachs lesions. Medium-sized defects involving 25% to 50% of the articular surface can be reconstructed using several methods, including subscapularis or lesser tuberosity transfer, rotational osteotomy of the humerus, osteochondral autografting, and allograft reconstruction.

This article describes the reconstruction of a 40% anteromedial humeral head articular surface defect with synthetic bone substitute. Internal fixation was not necessary, and clinical and functional outcomes were excellent. This technique avoids donor site morbidity and potential risks with allograft use while maintaining normal shoulder joint anatomy with preservation of the rotator cuff muscles for less complicated prosthetic reconstruction if required in the future.

A 64-year-old active man presented with left shoulder pain following a low-energy fall from a standing position. He had developed a right-sided hemiplegia following a cerebrovascular accident 15 months prior and was therefore strongly left-hand dominant. An anteroposterior (AP) radiograph of the shoulder was interpreted as normal, and treatment was commenced with rest, analgesics, and a broad-arm sling.

Clinical examination 2 weeks later revealed painful and restricted range of movement of the glenohumeral joint in all directions. Abduction and forward flexion were limited to 30°, and internal rotation was limited to 15° with the arm fixed in internal rotation. The AP radiograph revealed a light-bulb sign1 consistent with a posterior dislocation (Figure 1). Computed tomography scanning confirmed a locked posterior dislocation with a reverse Hill-Sachs lesion involving approximately 40% of the anteromedial humeral articular surface (Figure 2). The decision for surgical management was made at that stage.

At surgery, the patient was placed in a beach chair position under general anaesthesia. Closed reduction of the glenohumeral joint was performed first. A deltopectoral approach was then used with preservation of the cephalic vein.

Soft tissue dissection was performed through the rotator interval to enable direct access to the defect within the anteromedial part of the humeral articular surface with…

Abstract

Locked posterior shoulder dislocation is a rare injury and is often missed on examination, usually due to inadequate imaging and potentially resulting in significant loss of shoulder function. An important feature of the physical examination is identification of the patient’s inability to externally rotate their arm. These injuries are associated with defects in the humeral head articular surface, also known as reverse Hill-Sachs lesions. Medium-sized defects involving 25% to 50% of the articular surface can be reconstructed using several methods, including subscapularis or lesser tuberosity transfer, rotational osteotomy of the humerus, osteochondral autografting, and allograft reconstruction.

We describe reconstruction of a 40% anteromedial humeral head articular surface defect associated with a missed locked posterior shoulder dislocation. Our technique used a deltopectoral approach with soft tissue dissection through the rotator interval to enable direct access to the defect with preservation of the rotator cuff muscles. The impacted articular surface was elevated, and the void was filled with moldable putty consisting of tricalcium phosphate with carboxymethylcellulose (Calstrux; Stryker Biotech, Hopkinton, Massachusetts). The articular fragment was then secured in position with size 5 Ethibond (Ethicon, Inc, Somerville, New Jersey) bone sutures. The patient regained excellent function and range of motion, with computed tomography scanning at 9 months demonstrating a smooth humeral articular surface with excellent graft incorporation.

This technique avoids donor site morbidity and potential risks with allograft use while maintaining normal shoulder joint anatomy with preservation of the rotator cuff muscles for less complicated prosthetic reconstruction if required in the future.

Locked posterior shoulder dislocation is a rare injury and is often missed on examination, usually due to inadequate imaging and potentially resulting in significant loss of shoulder function. These injuries are associated with defects in the humeral head articular surface also known as reverse Hill-Sachs lesions. Medium-sized defects involving 25% to 50% of the articular surface can be reconstructed using several methods, including subscapularis or lesser tuberosity transfer, rotational osteotomy of the humerus, osteochondral autografting, and allograft reconstruction.

This article describes the reconstruction of a 40% anteromedial humeral head articular surface defect with synthetic bone substitute. Internal fixation was not necessary, and clinical and functional outcomes were excellent. This technique avoids donor site morbidity and potential risks with allograft use while maintaining normal shoulder joint anatomy with preservation of the rotator cuff muscles for less complicated prosthetic reconstruction if required in the future.

Case Report

Figure 1: AP radiograph of the left shoulder
Figure 1: AP radiograph of the left shoulder.

A 64-year-old active man presented with left shoulder pain following a low-energy fall from a standing position. He had developed a right-sided hemiplegia following a cerebrovascular accident 15 months prior and was therefore strongly left-hand dominant. An anteroposterior (AP) radiograph of the shoulder was interpreted as normal, and treatment was commenced with rest, analgesics, and a broad-arm sling.

Clinical examination 2 weeks later revealed painful and restricted range of movement of the glenohumeral joint in all directions. Abduction and forward flexion were limited to 30°, and internal rotation was limited to 15° with the arm fixed in internal rotation. The AP radiograph revealed a light-bulb sign1 consistent with a posterior dislocation (Figure 1). Computed tomography scanning confirmed a locked posterior dislocation with a reverse Hill-Sachs lesion involving approximately 40% of the anteromedial humeral articular surface (Figure 2). The decision for surgical management was made at that stage.

At surgery, the patient was placed in a beach chair position under general anaesthesia. Closed reduction of the glenohumeral joint was performed first. A deltopectoral approach was then used with preservation of the cephalic vein.

Soft tissue dissection was performed through the rotator interval to enable direct access to the defect within the anteromedial part of the humeral articular surface with preservation of the rotator cuff muscles. Shoulder retractors and self-retainers were used to provide adequate exposure of the defect during the reconstructive process. Partial release of the deltoid muscle and pectoralis major tendon were performed to improve exposure to the humeral head defect. The size and extent of the humeral head defect was confirmed and the glenoid was noted to be well preserved.

The impacted articular surface was elevated, and the void was filled with moldable putty consisting of tricalcium phosphate with carboxymethylcellulose (Calstrux; Stryker Biotech, Hopkinton, Massachusetts). The articular fragment was then secured in position with size 5 Ethibond bone sutures (Ethicon, Inc, Somerville, New Jersey) . Several sutures were placed on the the lateral side of the defect to minimize injury to the articular surface and to avoid fragmentation. This provided adequate stability to enable the articular fragment to unite and biointegration to occur thus restoring joint congruity. The rotator interval was subsequently repaired, and the shoulder reduction was found to be stable. Postoperatively, the shoulder was immobilized in 30° abduction, 15° flexion, and 20° external rotation with a plaster-of-paris cast for 6 weeks. Physiotherapy for active and passive range of motion exercises was then commenced.

Figure 2: Preoperative CT showing posterior locked shoulder dislocation Figure 3: Postoperative CT showing graft incorporation with smooth articular surface and fracture union

Figure 2: Preoperative CT showing posterior locked shoulder dislocation. Figure 3: Postoperative CT showing graft incorporation with smooth articular surface and fracture union.

The patient made gradual progress with the therapists and had a pain free range of active motion with 170° abduction, 45° external rotation, and 40° internal rotation with no symptoms or signs of instability at 9 months postoperatively. Computed tomography scanning demonstrated a smooth humeral articular surface with excellent graft incorporation and healing at the fracture site (Figure 3).

Discussion

Locked posterior dislocation of the shoulder is a rare injury and accounts for <2% of all shoulder dislocations.2 It is a frequently missed injury with diagnosis requiring a careful history, clinical examination, and AP, axillary, and lateral scapular radiographs.3 An important feature of the physical examination is the identification of the patient’s inability to externally rotate their arm. Axillary radiographs are vital in these trauma patients to avoid missing this significant injury. Treatment is dependent on the general condition and requirements of the patient, duration of dislocation, size of the humeral head impression defect, and presence of changes in the glenoid.4

Small defects with <25% involvement of the humeral articular surface can be treated with either closed or open reduction with transfer of subscapularis (McLaughlin procedure5) or the lesser tuberosity (Modified McLaughlin prodedure6) if still unstable.3,4 Large defects with >50% involvement of the humeral articular surface or dislocations older than 6 months usually require hemiarthroplasty if the glenoid is well preserved, or total shoulder arthroplasty if glenoid damage coexists.3,4

Several methods for treating medium-sized defects involving 25% to 50% of the humeral articular surface have been described,3 including transfer of the subscapularis,5 transfer of the lesser tuberosity,6 rotational osteotomy of the humerus,7 allograft reconstruction,8 and autograft reconstruction.9

Transfer of the subscapularis and transfer of lesser tuberosity had good results in a series of 8 patients treated by Hawkins et al,4 14 patients treated by Checchia et al,10 and 4 patients treated by Burkett et al.11

Connor et al9 described a unique situation with the presence of bilateral posterior fracture dislocations with a medium-sized defect in 1 shoulder and a large unreconstructable defect in the other shoulder. They were therefore able to perform osteochondral autografting for a lesion that involved 30% to 40% of the humeral articular surface with an excellent outcome in 1 shoulder at 2 years.

Gerber et al8 described allograft reconstruction for defects involving at least 40% of the humeral articular surface in 4 patients. A cryopreserved femoral head was used in 3 patients and a fresh autoclaved femoral head in 1 patient; internal fixation was used in 3 patients. Results were excellent in 2 cases, good in 1, and fair in 1 with a minimum 5-year follow-up.

The technique and patient outcome described in this article are similar to those described by Gerber et al.8 Synthetic bone substitute was used in both cases to reconstruct a defect involving 40% of the humeral articular surface; neither case required internal fixation; and excellent clinical outcome was achieved with the patient demonstrating painless full range of motion of the shoulder with no instability at 9 months. Our technique avoids the risk of donor-site morbidity from autografting and also avoids the exposure to foreign material and its associated potential risks when performing allograft reconstruction. Our surgical approach through the rotator interval allowed direct access to the anteromedial part of the humeral articular surface, thereby enabling reconstruction of the defect while preserving the rotator cuff muscles.

This technique maintains the normal anatomy of the shoulder joint with an intact rotator cuff and stability8 to simplify prosthetic reconstruction if required in the future compared to other techniques such as rotational osteotomy and transfer of the subscapularis or lesser tuberosity.

References

  1. Apley AG, Solomon L. Apley’s System of Orthopaedics and Fractures. 7th ed. Butterworth-Heinemann: Oxford; 1993:572-573.
  2. Cheng SL, Mackay MB, Richards RR. Treatment of locked posterior fracture-dislocations of the shoulder by total shoulder arthroplasty. J Shoulder Elbow Surg. 1997; 6(1):11-17.
  3. Cicak N. Posterior dislocation of the shoulder. J Bone Joint Surg Br. 2004; 86(3):324-332.
  4. Hawkins RJ, Neer CS 2nd, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg Am. 1987; 69(1):9-18.
  5. McLaughlin HL. Posterior dislocation of the shoulder. J Bone Joint Surg Am. 1952; 24(3):584-590.
  6. Hughes M, Neer CS II. Glenohumeral joint replacement and postoperative rehabilitation. Phys Ther. 1975; 55(8):850-858.
  7. Vukov V. Posterior dislocation of the shoulder with a large anteromedial defect of the head of the humerus. Int Orthop. 1985; 9(1):37-40.
  8. Gerber C, Lambert SM. Allograft reconstruction of segmental defects of the humeral head for the treatment of chronic locked posterior dislocation of the shoulder. J Bone Joint Surg Am. 1996; 78(3):376-382.
  9. Connor PM, Boatright RJ, D’Alessandro DF. Posterior fracture-dislocation of the shoulder: treatment with acute osteochondral grafting. J Shoulder Elbow Surg.1997; 6(5):480-485.
  10. Checchia S, Santos P, Miyazaki A. Surgical treatment of acute and chronic posterior fracture-dislocation of the shoulder. J Shoulder Elbow Surg. 1998; 7(1):53-65.
  11. Burkett CM, Roberts CS, Franklin GA. Successful treatment of chronic, locked posterior shoulder dislocations in young trauma patients with the modified mclaughlin procedure. Eur J Trauma. 2006; 32(2): 179-184.

Authors

Messrs Modi, Wicks, and Srinivasan are from the Heart of England NHS Foundation Trust, Birmingham, United Kingdom.

Messrs Modi, Wicks, and Srinivasan have no relevant financial relationships to disclose.

Correspondence should be addressed to: Chetan S. Modi, MBChB, MRCS, DipSEM, 23 Harts Green Rd, Harborne, Birmingham, West Midlands B17 9TZ, United Kingdom.

DOI: 10.3928/01477447-20090728-43

10.3928/01477447-20090728-43

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