4.5 mm LCP Narrow and Broad with Stacked Combination Holes

Jeffrey Watkins, Michael Kowaleski

The 4.5 mm LCP narrow and broad with stacked combination holes is indicated for long bone fractures, and joint arthrodesis for horses, as well as metaphyseal fractures.

Osteoarthritis of the interphalangeal (PIP) joint is a common cause of lameness in horses; therefore, PIP joint arthrodesis is performed with the goal of eliminating motion of this joint. To achieve arthrodesis for treatment of degenerative joint disease of the PIP joint this plate has an extended centre section that spans the joint space. The stacked combination hole is necessary to prevent impingement on the extensor process of the distal phalanx. This is a common procedure in western performance horsethey seem to be prone to developing degenerative joint disease of this joint as a result of the type of activities in which they are engaged. The lameness prevents them from engaging in their intended use, and is often debilitating. With arthrodesis, a high percentage (up to 75% in the forelimb and 90% in the hindlimb) are able to return to their intended erformance activity.

Compared to the standard locked plate design the toenail design at one end of the plate was eliminated and the most distal hole changed from a combination hole to a stacked combination hole. These changes allow the plate to be placed as close to the joint as possible. The two proximal combination holes face the same way (to achieve compression across the joint) and the gap between the stacked combination hole and the first combination hole was lengthened so that it matches the 4.5 mm narrow DCP (to span the joint).

The 4.5 mm narrow LCP comes in length of 3-16 holes and the 4.5 mm broad LCP in 6-18 holes. The implants are made of 316L stainless steel and fit in the large fragment plate set graphic case.

Horse with degenerative joint disease of the proximal interphalangeal joint (narrowed joint space and periosteal new bone formation).

(Case provided by Jeffrey Watkins, Tamu, USA)

Compression across the joint was achieved by placing the abaxial transarticular 5.5 mm cortical screws in lag fashion, then using the cortex screw in the load position of the proximal combination hole. The screws on either side of the joint are 5.0 mm locking screwsthe most distal screw is placed first, then the cortex screw is used to provide dynamic compression and the final locking screw is placed.

Knox PM, Watkins JP (2006) Proximal interphalangeal joint arthrodesis using a combination plate-screw technique in 53 horses (19942003). Equine Vet J; 38:538542.

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