Surgery or Sling After a First Shoulder Dislocation
A young patient who redislocates because early stabilization was skipped accumulates more labral and bone loss with each event, turning what could have been a routine soft-tissue repair into a bone-grafting procedure.
Key terminology
- Greater tuberosity
- Bony knob on the outer humeral head where the supraspinatus, infraspinatus and teres minor attach - can break off during a dislocation
- Glenoid
- Shallow socket on the scapula that the humeral head sits against - a big reason the shoulder is the most commonly dislocated large joint
- Labrum
- Ring of fibrocartilage around the glenoid rim - deepens the socket and anchors the capsule and ligaments that hold the humeral head in
- Arthroscopic stabilization
- Keyhole surgery that sews the torn labrum and capsule back onto the glenoid with suture anchors - aka arthroscopic Bankart repair
- Hill-Sachs lesion
- Dent in the back of the humeral head, made when it slams into the glenoid rim as it dislocates forward
- Bankart lesion
- Front-lower labrum torn off the glenoid rim in an anterior dislocation - sometimes takes a fragment of bone with it (bony Bankart)
- Latarjet procedure
- Moves the tip of the coracoid, with its attached tendons, onto the front of the glenoid - rebuilds bone lost to repeated dislocations
- Axillary nerve
- Wraps around the back of the humeral neck to supply the deltoid and the skin over the lateral shoulder - the nerve most often hurt in a dislocation
Takeaways
- Age at first dislocation is the strongest predictor of recurrence. In the 10-year Hovelius cohort, 34% of shoulders in patients 12-22 years old required surgery for recurrent instability, versus 28% at 23-29 years and only 9% at 30-40 years (Hovelius et al, J Bone Joint Surg Am 1996;78:1677-1684, PMID 8934481).
- Even nonoperative treatment leaves many young patients stable long term. At 25-year follow-up, about half of dislocations in patients 12-25 years old had not recurred or had become stable over time, though 38% of that age group eventually needed surgical stabilization, versus 18% of patients 26-40 years old (Hovelius et al, J Bone Joint Surg Am 2008;90:945-952, PMID 18451384).
- A concurrent greater tuberosity fracture is protective, not worrisome. Only 2 of 24 shoulders with a greater tuberosity fracture at the time of first dislocation went on to redislocate (p<0.001), likely because the fracture absorbed energy that would otherwise have torn the capsule and labrum (Hovelius et al, J Bone Joint Surg Am 2008;90:945-952, PMID 18451384).
- RCT evidence favors early stabilization in young, high-risk patients. A meta-analysis of level 1 trials found 6.3% recurrent instability after arthroscopic stabilization versus 46.6% after immobilization alone, mean age in the early twenties (Belk et al, Am J Sports Med 2022;51:1634-1643, PMID 35148222).
- Each recurrence compounds the anatomic damage that eventual surgery has to fix. Hill-Sachs lesions are present in 71% of first-time dislocations versus 85% of recurrent ones, and Bankart lesions in 59% versus 66% (Rutgers et al, Knee Surg Sports Traumatol Arthrosc 2022;30:2130-2140, PMID 34988633).
- Glenoid bone loss above roughly 25% changes the operation, not just the timing. Beyond this threshold an isolated arthroscopic Bankart repair has high failure rates, and bone augmentation such as a Latarjet procedure is generally required instead (Yamamoto and Itoi, Clin Orthop Surg 2015;7:425-429, PMID 26640623).
- Document the axillary nerve before and after any reduction. Axillary nerve injury, isolated or combined with another nerve or rotator cuff injury, complicates up to 16% of anterior dislocations (Atef et al, Int Orthop 2015;40:519-524, PMID 26133290).