39-year-old man with missed posterior shoulder dislocation
Click Here to Manage Email Alerts
A 39-year-old right-hand dominant man with epilepsy presents with 7 months of right shoulder pain. The patient reports he was exercising when he heard a pop with immediate swelling and limited range of motion.
He was concerned that he dislocated his shoulder as he has a history of one prior right shoulder dislocation and reduction in 2017 that occurred after he had a seizure. He presented to a local urgent care where radiographs were done, and he was told the glenohumeral joint was reduced and there was no fracture. He was subsequently treated with NSAIDs and an intra-articular steroid injection for mild glenohumeral joint arthritis. He also was evaluated by neurology to rule out cervical radiculopathy given pain radiation to his neck. His pain somewhat improved during the course of a few months, but he had persistent weakness, so he presented for a second opinion. At this time, physical examination was notable for significantly decreased active and passive range of motion. MRI of the right shoulder was obtained which demonstrated a locked posterior dislocation of the shoulder in a reverse Hill-Sachs lesion with deficient posterior labrum (Figure 1).
Source: Young Kwon, MD, PhD
What are the next best steps in management of this patient?
See answer below.
Open reduction and modified McLaughlin procedure
Given the chronicity and locked posterior humeral head dislocation in a large reverse Hill-Sachs deformity, the patient was indicated for an open reduction and modified McLaughlin procedure to obtain and maintain a concentrically reduced glenohumeral joint.
Modified McLaughlin technique
The patient was placed in a semi-reclined beach chair position for right shoulder surgery. Regional anesthesia with interscalene nerve block was utilized. Surgery began with the standard anterior incision for the deltopectoral approach. Skin flaps were raised both medially and laterally. The cephalic vein was identified and retracted laterally. The deltopectoral interval was developed and appropriate retractors were placed. The biceps tendon was identified, which contained a partial tear at the bicipital groove near the shoulder joint. Therefore, the proximal and diseased portion of the tendon was resected, and the distal biceps tendon was tagged for subsequent tenodesis. Using the proximal biceps tendon as a landmark, the bicipital groove was traced proximally, and the rotator interval was identified. Through the rotator interval, the humeral head defect was palpable. At this stage, the posterior dislocation was confirmed, but the humeral head could not be easily reduced. While carefully protecting the articular surface, the lesser tuberosity was osteotomized with a microsagittal saw and an osteotome to expose the glenohumeral joint (Figure 2A). With care to protect the articular cartilage, the humeral head was disengaged from the glenoid rim. With external rotation, the glenohumeral joint was then reduced anatomically.
As expected, there was a 2.5-cm by 3.5-cm reverse Hill-Sachs defect on the anterior portion of the humeral head (Figure 2B). The remaining articular cartilage appeared to be well maintained. With internal rotation, the defect was visualized intraoperatively to re-engage the posterior glenoid rim causing posterior glenohumeral dislocation. Therefore, the decision was made to proceed with the modified McLaughlin procedure to address the defect and obtain a stable joint.
The defect and the tuberosity were both prepared for fixation. The humeral defect was decorticated to obtain bleeding bone. The released lesser tuberosity was inserted into this defect. Medially, two double-loaded suture anchors (4.5-mm corkscrew, Arthrex) were inserted on the medial aspect of the bone defect at the humeral head (Figure 2C). These sutures were passed about the medial portion of the lesser tuberosity through the subscapularis tendon-bone interface and tied in a mattress fashion to establish an anti-rip suture and reduce the lesser tuberosity (Figure 2D). For supplemental fixation, a 4-mm cancellous screw with a washer was inserted through the lesser tuberosity into the humeral head (Figure 2E). The second set of sutures were then passed medially to these sutured, incorporated into another set of anchors (4.75-mm Swivelock, Arthrex), which were inserted into the lateral aspect of the humeral head to obtain a transosseous-equivalent double row fixation of the lesser tuberosity (Figure 2F). Range of motion at this time revealed a stable joint even at extreme internal rotation, without restricted forward elevation or external rotation. Finally, the eyelet free sutures from the lateral row of suture anchors were used for a soft tissue biceps tenodesis in the bicipital groove (Figure 2G).
Postoperative rehabilitation
Postoperatively, the patient was maintained in a gunslinger sling with lifting restrictions for 4 weeks. X-rays at 1 week demonstrated a reduced glenohumeral joint (Figures 3A and 3B), and gentle pendulum exercises and active elbow and wrist range of motion was allowed. At 4 weeks postoperatively, physical therapy was initiated for range of motion progression, with limitations of active or passive internal rotation past the iliac crest. At 8 weeks postoperatively, he began gentle strengthening with discontinuation of any range of motion restrictions. Radiographs obtained at this time demonstrated maintained glenohumeral joint reduction with intact hardware and integration of the lesser tuberosity into the humeral head defect (Figures 3C and 3D).
Discussion
Posterior shoulder dislocations are relatively rare, accounting for less than 5% of all shoulder dislocations. However, when these do occur, management is often complicated by delayed presentation and diagnosis, with up to 80% of cases initially missed. Treatment of posterior shoulder dislocations is dependent on the time at presentation (acute vs. chronic), number of dislocations (first vs. recurrent) and the presence and size of a humeral head defect. In cases of acute (less than 3 weeks), first-time, traumatic posterior dislocations with smaller humeral head defects (less than 30% of articular surface), closed reduction may be attempted. In the absence of bony lesions, as high as 44% of shoulders remain unstable, and thus could benefit from arthroscopic posterior shoulder stabilization involving a posterior capsular shift, labral repair and addressing any coexisting anterior pathologies (eg, rotator interval plication).
Locked posterior shoulder dislocations, as in this case, describe a subset of shoulders that do not reduce spontaneously due to an engaging anterior humeral head defect on the posterior glenoid rim. Thus, management necessitates surgical intervention by way of open reduction and additional stabilization. The latter historically involved a procedure described by Harrison L. Mclaughlin, MD, in which the subscapularis tendon was dissected from its insertion and used to fill the anterior humeral head defect using bone tunnels for fixation. This was later modified to include transfer of the lesser tuberosity (modified McLaughlin procedure) to employ bony apposition and more secure fixation.
Given the infrequency with which locked posterior shoulder dislocations occur, outcome studies are limited to mainly case series and case reports. Marcio Cohen, MD, and colleagues reported on 10 patients who underwent the modified Mclaughlin procedure with a minimum 2-year follow-up and reported significantly improved range of motion (forward elevation: 71° ± 5° to 126°± 37°; external rotation: 7°± 7° to 52° ± 18°; internal rotation gluteal region ± 1 vertebral level to L1 ± 4 vertebral levels) and functional outcome measures, including the Constant-Murley score (22 ± 2.4 to 65 ± 21.5), the mean University of California, Los Angeles score (9.8 ± 1.3 to 27 ± 9.7) and the mean VAS score (4.6 ± 0.8 to 2.4 ± 2.3). There were no cases of recurrent dislocation. However, two patients progressed to glenohumeral degenerative joint disease within the follow-up period. Emil G. Haritinian, MD, and colleagues reported on nine patients treated with a modified McLaughlin procedure and two patients with the McLaughlin procedure with a minimum 6-month follow-up (mean follow-up of 37 ± 58 months). Similarly, all patients had significantly improved range of motion and Constant-Murley scores at final follow-up. There were no recurrent dislocations, but two patients had progressed to Samilson-Prieto Allain stages 2 and 3 glenohumeral arthritis.
Key points:
- Posterior shoulder dislocations are commonly chronic on presentation due to delays in presentation and diagnosis, and a high index of suspicion must be maintained.
- The modified McLaughlin procedure effectively restores glenohumeral joint stability for locked posterior shoulder dislocations.
- Short-term and midterm range of motion and clinical outcomes after the modified McLaughlin procedure are good.
- References:
- Cohen M, et al. J Shoulder Elbow Surg. 2022;doi:10.1016/j.jse.2021.05.026.
- Delcogliano A, et al. Knee Surg Sports Traumatol Arthrosc. 2005;doi:10.1007/s00167-004-0524-6.
- Duralde XA, et al. J Shoulder Elbow Surg. 2006;doi:10.1016/j.jse.2006.04.003.
- Haritinian EG, et al. BMC Musculoskelet Disord. 2023;doi:10.1186/s12891-023-06200-8.
- Hawkins RJ, et al. J Bone Joint Surg Am. 1987;69:9-18.
- McLaughlin HL. J Bone Joint Surg Am. 1952;24:584-90.
- Paul J, et al. Arthroscopy. 2011;doi:10.1016/j.arthro.2011.06.015.
- Verma NN, et al. Arthroscopy. 2006;doi:10.1016/j.arthro.2006.04.086.
- For more information:
- Andrew S. Bi, MD; Christopher A. Colasanti, MD; Young Kwon, MD, PhD; and Nicole D. Rynecki, MD, can be reached at the department of orthopedic surgery at NYU Langone Orthopedic Hospital in New York. Bi’s email: andrew.bi@nyulangone.org. Colasanti’s email: christopher.colasanti@nyulangone.org. Kwon’s email: young.kwon@nyulangone.org. Rynecki’s email: nicole.rynecki@nyulangone.org.
- Edited by Andrew Bi, MD, and Pooja Prabhakar, MD. Bi is a chief resident in the department of orthopedic surgery at NYU Langone. He will pursue a fellowship in sports medicine at Rush University Medical center following residency completion. Prabhakar is a chief resident in the department of orthopaedic surgery at the University of Washington. She will pursue a fellowship in foot and ankle surgery at Baylor University Medical Center following residency completion. For more information on submitting Orthopedics Today Grand Rounds cases, please email orthopedics@healio.com.
Collapse
Read more about
Click Here to Manage Email Alerts