Equine ulnar fracture repair with locking compression plates can be associated with inadvertent penetration of the lateral cortex of the radius

Abstract

Use of LHS in the distal part of a LCP applied to the caudal aspect of the ulna is associated with a risk of inadvertent injury to the lateral cortex of the radius.

Use of locking compression plates in ulnar fractures of 18 horses*

“…With the locking compression system, locking screws must be placed at a fixed angle perpendicular to the plate and as a result, there is risk of inadvertent penetration of the lateral cortex of the radius with screws placed in the distal aspect of the plate . We did not encounter this in our series.…”

“…Other reported complications following the use of the LCP in ulnar fractures include residual lameness and catastrophic radial fracture . One report speculated that residual lameness might be due to the presence of the implant since plate removal resulted in improvement in 2/3 horses .…”

“…Recently, two reports cited catastrophic radial fracture as a complication of LCP placement on the caudal aspect of the ulna . Since the locking screws must be placed at a fixed angle perpendicular to the plate, locking screws placed in the distal aspect of the plate can potentially penetrate and weaken the lateral cortex of the radius.…”

Use of String of Pearls Locking Plate System, Intramedullary Pin and Lag Screws for the Treatment of an Intra-Articular Olecranon Fracture in a Lamb

“…Olecranon fracture repair by plate fixation in horses involves the application of a locking compression or dynamic compression plate caudally from the most proximal aspect of the olecranon distally to beyond the transition from ulna to radius, with caudally inserted screws ideal for rigid fixation in adult horses. 21 Inadvertent penetration of the lateral cortex of the radius with locking head screws is a possible complication following caudal plate application 21 and may result in devastating radial fracture and subject these patients to euthanasia. In the authors' opinion, the lateral application of the plate improves accuracy of central screw insertion through increased bone stock, thereby reducing the likelihood of implant-associated complications.…”

Management of ulna fractures in adult horses

“…Therefore, cortex screws should be inserted through the distal two plate holes to prevent inserting the LHSs into the lateral cortex of the radius, if the plate is placed far lateral. Screw insertion into the lateral radial cortex may predispose to catastrophic failure of the construct through a complete fracture of the radius (Figure 5) (Kümmerle et al, 2013). Another option to prevent such an incident is the twisting of the distal aspect of the plate to facilitate oblique insertion of the screws.…”