Typically, an arthrodesis procedure requires a change in position or alignment that is facilitated by the joint resection for the fusion. However, there are circumstances in which joints are fused for arthrosis, pain, or instability, but the alignment of the foot is suitable preoperatively (8). In these instances, trephine arthrodesis is a technically simple procedure that affords a successful rate of fusion with less soft tissue disruption and with an inherent stability to the fusion area from the preserved adjacent joint portions and ligaments. Potential disadvantages of the trephine technique include the need for the appropriatesized trephines, although these are often readily available, and the relative inability to reduce significant joint malalignment.

Trephine arthrodesis may be utilized with good results in the rearfoot and ankle but is especially useful in the midfoot, particularly when it is preferable to maintain the length or overall anatomy of the osseous segments such as when a short first ray or medial column is present (8,13,14 and 15). In these cases, bone resection for traditional arthrodesis would render the first ray or column even shorter, thereby disrupting the metatarsal parabola and forefoot mechanics (8). Another example is if both a naviculocuneiform and first metatarsocuneiform joint (MCJ) fusion are required, typical joint resection would create a significant degree of medial column shortening unless an interpositional bone graft is employed (8).

The tarsometatarsal joints are well suited for the trephine technique because the joint surfaces are relatively planar and small with an intrinsic stability afforded them by the neighboring articulations and ligaments, particularly at the central rays (8). Additionally, the joints are an area where fusion is frequently required, yet without requisite repositioning of the structures (8). It is especially useful for arthrodesis of an isolated tarsometatarsal joint, such as the second MCJ, as it maintains the metatarsal parabola while limiting surgical dissection and the potential difficulty of joint repositioning.

Trephines of incremental diameters are utilized that are constructed of a thin metal to reduce the amount of bone displacement with use. The manual P.I. plug cutters currently manufactured by Delta Surgical Instruments (Highland Mills, NY) are graduated in size (6 to 24 mm) and work well for this procedure although other hand and power trephine instruments are just as effective (8). The smaller trephine sizes are typically used for the midfoot joints.