Plate or Sling for the Displaced Midshaft Clavicle
A displaced midshaft clavicle fracture heals in a sling for most adults, while the few who develop a nonunion face months of pain and a later operation, and a plate brings its own hardware irritation and second surgery.
Key terminology
- Midshaft clavicle fracture
- This break sits in the middle third of the collarbone, directly over the subclavian vessels and brachial plexus. It is the most common clavicle fracture pattern.
- Nonunion
- The fracture has still not healed months after the injury. It can cause ongoing pain and motion at the break, and many need surgery to heal.
- Skin tenting
- A displaced fragment pushes the skin up from beneath until it blanches. The skin can break down and turn a closed fracture into an open one.
- Shortening
- The fragments override, so the clavicle ends up shorter. The sternocleidomastoid pulls the medial fragment up while the weight of the arm drags the lateral fragment down.
- Malunion
- The fracture heals in a shortened or angled position. A symptomatic clavicle malunion can leave a drooping shoulder, a bump and visible asymmetry.
- Constant score
- This shoulder score combines pain, daily activity, motion and strength on a 0 to 100 scale. Higher is better.
- DASH score
- This patient questionnaire rates disability of the whole arm on a 0 to 100 scale. Lower is better, and a gap of a few points may be too small for a patient to notice.
Takeaways
- Most clavicle fractures are midshaft, and most heal in a sling. About 80% of clavicle fractures sit in the middle third. In a prospective cohort of 868 fractures treated without surgery, only 4.5% of diaphyseal fractures were still ununited at 24 weeks (Lenza et al, Cochrane Database Syst Rev 2019;1:CD009363, PMID 30666620; Robinson et al, J Bone Joint Surg Am 2004;86:1359-1365, PMID 15252081).
- An open fracture, skin tenting, neurovascular injury or a floating shoulder means surgery. A floating shoulder is a clavicle fracture plus a scapular neck fracture on the same side, which leaves the shoulder girdle unstable. Complete displacement with shortening >2 cm is a relative indication that many surgeons use (McIntosh, J Pediatr Orthop 2016;36 Suppl 1:S41-S43, PMID 27100042; Kraal et al, World J Orthop 2023;14:604-611, PMID 37662664).
- Plate fixation heals displaced midshaft fractures faster and with fewer nonunions and malunions. In the COTS trial of 132 adults, the plate group had 2 nonunions vs 7 with a sling, and 0 symptomatic malunions vs 9. Mean time to union was 16.4 vs 28.4 weeks, and function scores favored the plate at every time point (COTS, J Bone Joint Surg Am 2007;89:1-10, PMID 17200303).
- Most of the functional benefit of a plate comes from preventing nonunion. In a 200-patient Edinburgh trial, plating cut nonunions from 16 to 1 and gave a slightly better 1-year DASH score (3.4 vs 6.1) and Constant score (92.0 vs 87.8). With nonunions excluded, the groups scored the same at every time point. Other trials agree that a plate speeds early recovery and function evens out by 6 to 12 months (Robinson et al, J Bone Joint Surg Am 2013;95:1576-1584, PMID 24005198; Qvist et al, Bone Joint J 2018;100-B:1385-1391, PMID 30295536).
- Displacement, comminution, female sex and older age raise the nonunion risk in a sling. Each was an independent predictor after a diaphyseal fracture treated without surgery. Displacement entered the final model as lack of cortical apposition, meaning no bone contact between the fragments (Robinson et al, J Bone Joint Surg Am 2004;86:1359-1365, PMID 15252081).
- A plate trades nonunion for hardware problems, and overall reoperation rates end up similar. Counting plate removal, secondary operations were 17.6% after plating vs 16.6% after a sling. Hardware removal for discomfort (10.2%) and infection (3.2%) were seen only in the surgery group, while symptomatic malunion was more common without surgery (11.3% vs 1.2%) (Woltz et al, J Bone Joint Surg Am 2017;99:1051-1057, PMID 28632595; Lenza et al, Cochrane Database Syst Rev 2019;1:CD009363, PMID 30666620).
- Pooled trials show fewer nonunions with a plate and no clinically important gain in function. Across 6 RCTs, the nonunion risk ratio with a plate was 0.14, and 1-year Constant and DASH scores were only 4.4 and 5.1 points better. A Cochrane review of 14 studies rated the evidence low quality and found a 2.3-point Constant gain, below a clinically important difference (Woltz et al, J Bone Joint Surg Am 2017;99:1051-1057, PMID 28632595; Lenza et al, Cochrane Database Syst Rev 2019;1:CD009363, PMID 30666620).
- Without an absolute indication, the displaced midshaft fracture is a shared decision. About 10 patients need a plate to prevent 1 nonunion. A patient who picks a sling can be told that nonunion occurs in slightly more than 10%, and that a nonunion is harder to treat than the acute fracture (Axelrod et al, Clin Orthop Relat Res 2020;478:392-402, PMID 31574019; Lenza et al, Cochrane Database Syst Rev 2019;1:CD009363, PMID 30666620).