Locking X-Plate 2.4/2.7, Extra Small
Posttraumatic arthritis, rheumatoid arthritis, and neurological disorders can cause severe deformities such as cavus foot, equinovarus talipes, and planovalgus. Treatment of these deformities by an osteotomy or a fusion of one or several joints bears the risk of screw breakage due to high shear forces. Other disadvantages are long healing and rehabilitation time. Metatarsophalangeal arthroplasty may leave a large defect if it fails.
The locking X-plate 2.4/2.7 was developed to treat these deformities of the foot by a rigid fixation construct with high primary stability. It is a stand-alone implant in osteotomies and serves as a neutralization plate in arthrodesis of foot joints in combination with one or two compression screws. Primary indications are first metatarsal-cuneiform fusions, proximal first metatarsal osteotomies (crescentic, open wedge, Mann, Ludloff, and proximal Chevron), and first metatarsal-phalangeal fusions.
The locking X-plate 2.4/2.7 is a geometric, low-profile, and easy-to-bend implant. This enables further usage for calcaneal osteotomies (Evans and Dwyer), metatarsal nonunions, supramalleolar osteotomies, and diabetic foot reconstruction.
Now an additional size is available, extra small, with a foot print of 16 x 8 mm. Overall, there are four different sizes of the plates, according to the anatomical region and to the size of the foot: extra small, small, medium, and large. It is also likely to be used in countries where the ethnic anatomy is rather smaller than in other parts of the world.
The plate has four locking holes that accommodate 2.7 mm locking or cortical screws, and can be directed using the bending threaded pins so the screws cannot collide. The screw holes are thicker than the actual body of the plate to allow bending without compromising the threads of the holes, and to provide the best stability for biomechanical demands. The two dorsal holes are more angulated and enable the surgeon to cross the osteotomy site when fixing proximal metatarsal osteotomies providing the highest stability. Interfragmentary compression can be achieved through a separate interfragmentary screw.
Plates can be bent with pliers to get the anatomical shape of the bone, although they are available prebent according to the shape of a CT database of the foot. The arch design corresponds to the oldest architectural principles to get an ideal stress distribution with least amount of material and so produce minimal effect on the bone periosteum.
Advantages of using locking X-plates in foot and ankle surgery include more stable fixation of the osteotomy and fusion site, closer bone contact, shorter bone healing time, and thus early weight bearing, avoiding transfer lesions due to minimal shortening, less dorsal malunion or nonunion, and less elevation of the MTP1-head.
Proximal first metatarsal growth-plate injury resulting in haluxvalgus. Arthrosis of first tarsometatarsal and second metatarsal hammer toe. Pain during activities and in general shoe wear.
Case provided by Carl Hasselman, Pennsylvania, USA
First MTP fusion and modified McBride with a distal soft-tissue release and second metatarsophalangeal (MTP) capsulotomy. A mini tight rope was used to hold and reduce the alignment of the first metatarsal. The X-plate was used to hold rigid fixation of the fusion. A K-wire was used for the second MTP capsulotomy.
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