1.3 Locking System for veterinary use

Michael Kowaleski, Erik Asimus, Loic Déjardin, W Brian Saunders

The 1.3 Locking System is intended for the treatment of fracture and arthrodesis in canines and felines weighing less than 2 kg. This recently approved system, developed by our industrial partner DePuy Synthes in collaboration with the Small Animal Expert Group (SAEG) is a solution for fracture management in the smaller breed canine and feline population for which the 1.5 LCP System is too large.

The 1.3 Locking System consists of stainless steel 1.3 mm screws, locking plates, instruments, and an implant module set. The set contains an extensive range of implant options (Fig 1) to accommodate various fracture types and locations. 1.3 mm locking and cortex screws are compatible with 1.5 mm LCP plates.  

The plates are low profile to minimize soft-tissue irritation (Fig 2). Stacked combi holes allow the use of a locking screw or a cortex screw in the same round conical plate hole (Fig 3) and the cut-to-length feature (Fig 4) minimizes inventory. 

Screws are self-tapping and possess a self-retaining Star Drive recess which allows improved torque transmission and an increased resistance to stripping (Fig 5). The threaded head profile creates a fixed angle construct, and its low profile means that it sits flush with the surface of the plate.

The following two cases provided by SAEG member Erik Asimus illustrate common canine fractures in miniature breed dogs. Each fracture is treated with a different option dependent on the size of the radius and the ulna, the weight of the dog, and the type of fracture.

Case 1

Open reduction and internal fixation of distal radial and ulna fractures with a single 1.3 radial plate (Fig 6).

The patient was a 6-month-old, 1 kg (exactly 0.950 kg) Pomeranian dog presenting with a radial fracture of the left thoracic limb after a jump from ≈ 50 cm.  The 1.5 mm System was too large for the width of the radius (2.2 mm) and the width of the radial medullary canal (0.5 mm) (Fig 7). The 1.3 mm adaptation plate was a perfect plate for this fracture. This plate option permitted the use of cortex and locking screws.

An open but do-not-touch approach was performed, and the plate was fixed with one proximal and one distal cortex screws and one proximal and one distal locking screws (Fig 8). After 1 month the fracture of the radius was healed, and the dog had a complete functional recovery (Fig 9).

Case 2

Open reduction and internal fixation of distal radial and ulna fractures with a 1.3 radial plate and a 1.3 ulnar plate (Fig 10).

The patient was a 2.5-month-old, 1 kg Japanese Spitz dog presenting with a radial-ulna fracture of the left thoracic limb after a jump from the sofa. The LCP 1.3 T-plate was perfectly adapted for the distal radial fracture. As the dog was "active" and as the ulna was about the same size as the radius (Fig 11), a four-hole LCP 1.3 adaptation plate was used on the ulna.

An open but do-not-touch approach was performed, and the plate was fixed with both cortex screws and locking screws for both plates (Fig 12). After 4 months, the fractures were totally healed with normal bone growth and the dog had a complete functional recovery (Fig 13).

Clinical Application of the 1.3 Locking System

Live from the Shard at the AO Davos Courses 2021, Michael Kowaleski and Erik Asimus present the 1.3 Locking System for veterinary use.

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