Study suggests double plating may strengthen canine scapula repair: full analysis

A newly published biomechanical study in Veterinary Surgery adds evidence for dual plating in one of small animal orthopedics’ less common fracture scenarios: the comminuted canine scapular body fracture. In an ex vivo fracture gap model, researchers reported that adding a second plate to the scapula significantly improved construct stiffness and reduced displacement compared with single plate fixation, suggesting double plating may offer a more stable repair strategy for these challenging injuries. (pmc.ncbi.nlm.nih.gov)

The question matters because scapular fractures in dogs are uncommon, and that rarity has limited the evidence base for fixation strategies. A retrospective series of 105 canine scapular fractures found they represented a small share of overall fracture cases, while standard orthopedic references note that scapular body fractures can be difficult to manage surgically because the scapula is a thin, flat bone with variable screw purchase and substantial surrounding muscle forces. (pubmed.ncbi.nlm.nih.gov)

In the new study, the University of Wisconsin–Madison team created a comminuted fracture gap model in 28 scapulae from 14 paired canine specimens. All constructs received a 2.4 mm plate along the cranial aspect of the scapular spine, and half also received a secondary 2.0 mm plate on the caudolateral border. The specimens were then cyclically loaded from -20 to -200 N for 7,200 cycles. After exclusions related to technical issues and actuator slippage, 13 single-plate and 11 double-plate specimens were included in the main statistical analysis. (pmc.ncbi.nlm.nih.gov)

The mechanical differences were substantial. Predicted mean displacement was -0.81 mm in the single-plate group versus -0.48 mm in the double-plate group, and predicted mean stiffness was 392.8 N/mm versus 563.7 N/mm, respectively, with both differences reaching statistical significance. Maximum displacement was also lower with double plating. There was no construct failure during testing, and primary plate strain at maximum displacement did not differ significantly between groups. The authors also noted that strain across the fracture gap remained below the level generally associated with impaired healing in comminuted fractures, which supports the biologic plausibility of bridging fixation in this setting. (pmc.ncbi.nlm.nih.gov)

This study also fits with the group’s earlier clinical experience. The paper cites a prior case report describing a dog with a comminuted scapula fracture treated with double plate fixation that returned to controlled weight bearing within 24 hours and went on to bony union. That doesn’t prove superiority in clinical practice, but it does give the biomechanical findings a practical anchor. At the same time, earlier work comparing locking and nonlocking plate constructs in the canine scapula found no distinct mechanical advantage for either plate system alone, highlighting that plate configuration and construct design may be more important questions than locking versus nonlocking in this anatomy. (pmc.ncbi.nlm.nih.gov)

Why it matters: For veterinary surgeons, the takeaway isn’t that every scapular fracture needs two plates. It’s that in a highly comminuted scapular body fracture, where anatomic reconstruction may be limited and bridging fixation is the goal, a second plate may improve resistance to cyclic deformation. That could matter for early limb use, implant protection, and maintenance of alignment in patients that are difficult to confine or that generate high shoulder loads. Still, this was an ex vivo model, not a clinical trial, and the study did not establish whether double plating improves pain, time to union, complication rates, or long-term function in live patients. (pmc.ncbi.nlm.nih.gov)

The findings may also be most relevant for referral and specialty settings, where surgeons are more likely to see the subset of scapular fractures severe enough to warrant operative repair. Because scapular fractures are often associated with high-energy trauma and concurrent injuries, case selection, imaging, and overall stabilization still matter as much as implant choice. In that sense, the paper is best read as a technique-supporting study rather than a practice-changing mandate. (pubmed.ncbi.nlm.nih.gov)

What to watch: The field now needs retrospective or prospective clinical series comparing single- and double-plate repairs in dogs with naturally occurring scapular fractures, with attention to union, complications, return to function, and whether the added implant cost and surgical time are justified by better outcomes. (pmc.ncbi.nlm.nih.gov)