Intraoperative customization of intramedullary nails - First results

Intramedullary nailing is a valuable treatment option for many types of fractures. Furthermore nailing is applicable for osteosynthesis following osteotomy in deformity correction. For intraoperative fine-tuning of alignment in intramedullary (IM) nailing procedures, a bending device for customization of IM nails under sterile conditions was developed. We have performed a retrospective clinical study to analyze and describe the technical requirements, indications and limitations for intraoperative customization of IM nails.

In 41 cases of deformity correction with IM nailing, we applied intraoperative sterile bending of IM nails. The patient age ranged from 13 to 64 years. We evaluated the radiological outcome (precision of the intervention) of 31 completed cases, comparing the preoperative planning with the final result on long-standing radiographs (LSR). The diameter of the nails ranged from 8,5mm to 13mm. Cases with fracture or non-union treatment with intraoperative application of the bending device were excluded and analyzed separately.

All removed implants were examined - none of them showed any signs of material fatigue. The amount of intraoperative bending of the nails was 1° to 12°. A high level of precision was achieved, with a median postoperative axis deviation to the preoperative planning of 3,5mm. In a polio patient with limited bone quality, the implant removal caused an undisplaced cortical crack. There were no other complications. There was uneventful and fast bone healing in all patients.

Intraoperative customization of intramedullary nails is a valuable technique for precise alignment control with IM nailing. With this technique, the benefits of IM nailing can be used for a wide range of indications, including deformity correction. The sterile bending device is safe and easy to handle. It is strong enough to bend all commercially available IM nails. Monofocal or linear bending in multiple planes is possible. However, when defining the site of bending, one must consider the removal of the implant in the future.