CASE REPORT. Antegrade tibia lengthening with the PRECICE Limb Lengthening technology

Transcription

1 CASE REPORT Antegrade tibia lengthening with the PRECICE Limb Lengthening technology Austin T. Fragomen, M.D. Hospital for Special Surgery New York, NY 1 1

2 PR O D U CTS CONDITION Nonunion of an attempted ankle arthrodesis with limb length discrepancy Patient History (Continued) PRODUCT 10.7 x 275 mm PRECICE Antegrade Tibial Nail SURGEON Austin T. Fragomen, M.D. Removal of hardware was performed as well astibio-talar revision arthrodesis, deep cultures, and application of external fixation with sparing of the subtalar joint (Fig. 2a, 2b). Intraoperative cultures were positive for methicillin sensitive staph aureus and she was treated with 6 weeks of IV vancomycin. The patient underwent removal of the external fixator 5 months post fusion surgery. Her subtalar joint went on to collapse into valgus over the ensuing 6 months. Patient History The patient is a 58-year-old female with Type II diabetes mellitus and peripheral neuropathy who presented with a nonunion of an attempted ankle arthrodesis. She had sustained an open ankle fracture dislocation treated with external fixation and staged internal fixation. The fracture went on to nonunion and collapse, and she underwent attempted tibio-talar arthrodesis with internal fixation. The fusion surgery resulted in a painful nonunion with a draining sinus and suspicion of deep infection (Fig. 1a, 1b). Eight months after frame removal, the patient had surgery to fuse the subtalar joint and correct deformity with a tricortical iliac crest autograft and internal fixation (Fig. 3a, 3b). Once the subtalar reconstruction was healed, she was allowed full weight bearing with a 3 cm shoe lift. The patient expressed intolerance of the shoe lift and a desire to have limb equalization. A long, standing radiograph showed a 41 mm limb length discrepancy (Fig. 4). Despite being a neuropathic diabetic, she healed the ankle and subtalar fusions and was now infection free. Experienced in external fixation, the patient was completely opposed to tibial lengthening with a frame. The patient was felt to be a reasonable candidate for internal tibial lengthening. Fig. 1a: A/P radiograph 2 of the right foot Fig. 2a: A/P radiograph of the right foot Fig. 2b: Lateral radiograph of the right foot Fig. 3a: A/P radiograph of Fig. 3b: Lateral the right foot radiograph of the right foot Fig. 4: A/P standing radiograph with a 37mm block Fig. 1b: Lateral radiograph of the right foot 3

3 Preoperative Planning The goal was for a 41 mm tibial lengthening. The planning of the lengthening nail required measuring the radiograph (Fig. 5a). The optimal osteotomy position for tibial lengthening with an intramedullary nail is in the metaphyseal-diaphyseal junction, which measured 120 mm distal to the knee joint line. This location provides enough proximal bone for the nail to control the proximal segment while still taking advantage of the superior metaphyseal bone regeneration potential. The canal measured 11 mm at the isthmus, and a 10.7 mm diameter nail was selected. Nail length was measured, and it was determined that 275 mm would give excellent control of the distal segment. The minimum nail length needed can be calculated. The osteotomy site was already selected to be 120 mm distal to the joint line (Fig. 5b). The minimum length of the nail remaining in the distal fragment after lengthening is always 80 mm. The amount of lengthening is 41 mm. This requires a 230 mm length nail at the minimum. Operative Procedure The patient was given spinal anesthesia and sedation, and a well-padded pneumatic tourniquet was placed on the right thigh. The right lower extremity was prepped and draped. The surgery began with a percutaneous fibular osteotomy using multiple drill holes and an osteotome under fluoroscopy (Fig. 6a). The osteotomy site was measured and the drill holes for the osteotomy were created serving as vent holes for the reaming. The posterior blocking screw was inserted posterior to the intended path of the nail in order to prevent insertion of flexion during tibial lengthening. A distal ankle syndesmotic screw was not inserted because the patient had undergone prior lateral malleolar excision. Steinman pins (3 mm) were inserted proximally and distally to mark rotation. A trans-patellar tendon approach was used, and the entry point was created with an acorn reamer. Sequential reaming over a ball-tipped guide wire was performed by 0.5 mm increments up to and including a 12.5 mm reamer tip. The guide wire was removed, the leg extended, and the osteotomy was completed with an osteotome. The knee was flexed again, and the nail was inserted. Proximal locking of the nail was completed, and the targeting device was removed. The rotation was checked and the distal locking was completed using perfect circles under fluoroscopy. A proximal syndesmotic screw was inserted (Fig. 6b). The magnet position was marked on the skin under fluoroscopy. 4 Fig. 5a Fig. 5: (a,b) Standing bipedal radiograph Fig. 5b Fig. 6a Fig. 6: (a,b) C-Arm fluoroscopy Fig. 6b 5

4 Postoperative Management Postoperative care included CPM (continuous passive motion) beginning on postoperative day 1. Venous thromboembolism prophylaxis with XARELTO was started post-op day 2 and continued for 2 weeks. The patient started external magnet adjustments post-op day 7 (Fig. 7a). The tibia was lengthened in 0.25 mm increments, 4 times per day for 4 days and then slowed to three times a day for 49 days. Full tibia radiographs were taken every two weeks during the lengthening process. When the goal of 41 mm was reached, the lengthening process was concluded (Fig. 7b). Interestingly, the fibula did not lengthen at the osteotomy site and instead pulled proximally from its distal aspect. This is common during lengthening after ankle fusion. During consolidation, the patient came in monthly. Results Fig. 7a Fig. 7b Fig. 7: (a,b) Lateral radiographs of the tibia The patient s lengthening site healed with strong callus (Fig. 8a, 8b). The anterior portion is typically slow to fill in completely. She is full weight bearing with no pain. Her foot is plantargrade, and she no longer uses a shoe lift. She continues to be infectionfree. Her IM nail will need to be removed when the anterior cortex is complete. Discussion Complex ankle arthrodesis often results in symptomatic unequal limb lengths. 1 Patients with diabetes and peripheral neuropathy are at increased risk for external fixator related complications. 2 This makes tibial lengthening with an intramedullary implant a very attractive option. This case report highlights the success achieved using an internal lengthening approach in a high risk patient. A staged series of surgeries was used primarily because of the fear of infection from a simultaneous ankle fusion and proximal osteotomy with an internal nail. However, in an ideal candidate the tibial osteotomy and nail insertion can be done while the patient is still wearing the frame provided that the frame fixation is inserted distally in the tibia and the lengthening nail is short, avoiding contact with the pins. References and Suggested Reading Tellisi N, Fragomen A, Ilizarov S, et al. Limb salvage reconstruction of the ankle with fusion and simultaneous tibial lengthening using the Ilizarov/Taylor Spatial Frame. HSS J 2008; 4: Fragomen AT, Borst E, Schachter L, et al. Complex ankle arthrodesis using the Ilizarov method yields high rate of fusion. Clin Orthop Real Res 2012;470(10); Fig. 8a : A/P radiograph of the tibia Fig. 8b: Lateral radiograph of the tibia 7

5 For more information about this exciting technology, please contact your local sales representative. 101 Enterprise, Suite 100 Aliso Viejo, CA Phone: (+1) Fax: (+1) NuVasive, Inc. All rights reserved., NuVasive, and Speed of Innovation are registered trademarks of NuVasive, Inc. PRECICE is a registered trademark of NuVasive Specialized Orthopedics, Inc. NuVasive Specialized Orthopedics, Inc. is a trademark of NuVasive, Inc. Third party trademarks are the property of their respective owners. Rx Only. The PRECICE Intramedullary Limb Lengthening (IMLL) System is composed of an implantable intramedullary nail, locking screws, reusable instruments, and a hand-held External Remote Controller (ERC). The PRECICE nail is a sterile single use device that is surgically implanted using the instruments and locking screws. The ERC is used daily after implantation to non-invasively lengthen or shorten the implant to a prescribed length. The PRECICE System is intended for limb lengthening of the femur and tibia. Contraindications include infection or pathologic conditions of bone such as osteopenia which would impair the ability to securely fix the device, metal allergies and sensitivities, patients whose distance from the surface of the treated limb to the intramedullary canal is greater than 51 mm for the 10.7 and 12.5 mm diameter implants or greater than 38 mm for the 8.5 mm diameter implant, patients with an irregular bone diameter that would prevent insertion of the PRECICE nail, patients in which the PRECICE nail would cross joint spaces or open epiphyseal growth plates, patients in which there is an obliterated medullary canal or other conditions that tend to retard healing such as blood supply limitations, peripheral vascular disease or evidence of inadequate vascularity, patients unwilling or incapable of following postoperative care instructions, patients weighing in excess of 114 Kg for the 10.7 and 12.5 mm diameter implants (models A-G, H, J, K, and U) or weighing in excess of 57 Kg for the 8.5 and 10.7 mm diameter implants models (A-G, H, J, K, U, N, M,P, and Q). The implantable device is only to be used by a trained licensed physician. Please refer to the PRECICE IMLL System instructions for use for complete Important Safety Information. Caution: Federal law restricts this device to sale by or on the order of a physician. 16-NUVA-1016