1.3 Locking System for veterinary use
Michael Kowaleski, Erik Asimus, Loic Déjardin, W Brian Saunders
Fig 1 The 1.3 Locking Systemconsists of stainless-steel locking plates in different sizes and withdifferent shapes to fit specific fracture types. 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.
Fig 2 Plates are low profileto minimize soft-tissue irritation. 
Fig 3 Round conical hole canaccept both locking and cortex screws depending on fixation principle required. 
Fig 4 Plate cutterdemonstrates the cut-to-length feature available in all plates across thesystem. 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.
Fig 5 Stardrive recess allows improved torque transmission and an increased resistance tostripping. 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).
Fig 6a-b Preoperative AP and lateral x-rays. Complete transverse fractures of the distal diaphysis ofthe left radius with a lateroproximal displacement of the radial fracture.Ulnar fracture is subperiosteal. 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.
Fig 7 a-b AP and lateral x-rays of the right radius-ulna showing the width of the radius andthe width of the radial medullary canal. 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).
Fig 8 a-b Postoperative craniocaudal and lateral x-rays. Good apposition and alignment of the radial fractures were achieved. 
Fig 9 a-b Postoperative craniocaudal and mediolateral x-rays at 1 month. 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).
Fig 10 a-b Preoperative AP and lateral x-rays. Complete transverse fractures of the distal diaphysis of the left radius/ulna with a lateral displacement of the radial and ulnar fractures. 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.
Fig 11 a-b AP and lateral x-rays of the right radius-ulna showing the relative size of the two bones. 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).
Fig 12 a-b Postoperative craniocaudal and lateral x-rays. Good apposition and alignment of the radial and ulnar fractures were achieved. 
Fig 13 a-b Postoperative craniocaudal and mediolateral x-rays at 4 months. Clinical Application of the 1.3 Locking System
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