Hello, my name is Blair Tweedy and I'm here to present a novel technique for tarsometatarsal joint fusion using calcaneal precision bone grafting. This was a study carried out at the Freeman Hospital in Newcastle, United Kingdom. There are no disclosures. Tarsometatarsal joint arthritis is common and is most often treated surgically with joint arthrodesis. Techniques for fixation include the use of wires, screws, non-locking and locking plates. And this may or may not include bone graft, which is most commonly harvested from the Ayurvedic grass. Unit rates in the literature are reported at 90%. In our study, we would like to introduce our precision bone grafting technique, which is a novel technique with localised bone graft harvest. There is reduced joint preparation, better maintenance of bony anatomy. We used locking plate fixation and overall we believe this provides a reduced graft site morbidity with improved union rates and hopefully improved foot function. This is a retrospective case series of 20 patients treated between 2016 and 2019, making a total of 39 joints for fusion. Of these, 27 underwent bone grafting, with 16 performed using the precision bone grafting technique. Locking plates were used in all cases. In the traditional surgical technique, there is a docile approach to the midfoot, evaluation of the joints and joint preparation down to bleeding bone beds, generally using flat cuts. The arthrodesis site may or may not be packed with additional bone graft and fixations and compression, with union rates at around 90%. There are several problems with this surgery, however, including an alteration in the anatomy of the foot and shortening of the midfoot, failures of fixation and graft site morbidity, particularly when using the iliac crest as a site. In the precision technique, again the docile approach is used, but prior to joint preparation, a locking plate is contoured and provisionally fixed to the bone. Then the joint site is prepared using the precision grafting instruments to remove a cylinder bone block from the joint in question. This extends deeper into the metaphyseal bone, but preserves 2mm of joint surface on the medial and lateral sides of the joint. Then the instruments are again used to harvest bone graft from the calcaneus. This creates a longer cylinder and length of bone, with cortical bone ends on the proximal and distal extent of the graft that is harvested. This harvested graft is then impacted back into the fusion site. In so doing, the impacted bone goes in compression mode, with the cortical end caps providing additional structural support. The pre-contoured locking plate is then fixed back down onto the bone using the earlier made screw holes. This provides a stable construct for fixation and ideally progressing to healing. In summary, we believe that this technique is beneficial as the arthrodesis site extends into metaphyseal bone, there is a greater fusion surface area by virtue of using cylindrical bone blocks rather than flat cuts, the calcaneal bone graft provides a large volume cylinder for impaction with cortical end caps generating additional support, there is reduced graft site morbidity as the graft is harvested locally, with locking plates providing resistant fixation, and the foot anatomy is overall better preserved, which may provide a better restoration of normal foot biomechanics. In our series, 38 out of 39 joints reached fusion, with only one non-union in a traditional bone graft group. All patients treated with the precision bone grafting technique went on to union without delay. In conclusion, fusion with locking plates remains an appropriate treatment for TMTG arthritis. In this precision technique, local donor site bone grafting does not appear to generate inferior outcomes and avoids the morbidity of the islet crest graft harvest. This is a novel technique with use of cylindrical bone grafts and precision bone graft instruments, and this technique we believe generates an increased fusion surface area and may provide a better restoration of normal foot biomechanics.

tarsometatarsal joint fusion

calcaneal precision bone grafting

locking plate

fusion surface area

foot anatomy