Bone transport with magnetic intramedullary nails in long bone defects.

BACKGROUND: This study describes the outcomes of internal bone transport with magnetic nails in five cases of traumatic segmental femoral bone defects. METHODS: Five patients with open fracture of the femur and diaphyseal bone loss were included between May 2018 and August 2020. The mean femoral defect was 8.7 cm (range 5.6-16.0). INTERVENTION: We used plate-assisted bone segment transport (PABST) with PRECICE magnetic nails. RESULTS: All five patients have fully consolidated. The mean consolidation time and index were 7.5 months and 0.8 mo/cm, respectively. The mean follow-up was 21.3 months. The main complications were reduced knee ROM, mild varus deformity and plate bending. Post-operative SF-36, Oxford Knee scores and ED-5Q-5L scores were also compiled for four of five patients. SF-36 and Oxford Knee scores were reported without pre-injury data for comparison. ED-5Q-5L index and VAS were compared UK population norm and were both found to be statistically insignificant (p = 0.071 and p = 0.068, respectively). CONCLUSION: Bone transport with magnetic nails has the capacity to obtain good functional recovery in long bone defects despite variable outcome pictures. In response to variable outcome reporting in the literature, we propose a standard reporting template for future studies to facilitate more rigorous analyses.

Lengthening Patients Previously Treated for Massive Lower Limb Reconstruction for Bone Tumors with the PRECICE 2 Nail.

The objective of this study was to determine the efficacy of the PRECICE 2® nail in the treatment of lower limb length discrepancy in patients with a history of bone tumors. This study reports on outcomes, complications, and the safety of the PRECICE 2 limb lengthening nail in a cohort of pediatric patients with limb length discrepancy after surgery for bone tumors. Seventeen patients were treated with intramedullary magnetic nails. The average patient age at the time of surgery was 19 (range 11-32). The PRECICE 2 nail was used on 14 femurs (6 retrograde and 8 anterograde) and 3 tibias. The average consolidation time was 141 days (range 50-360) with a mean CI of 31 ± 12 days/cm. The ASAMI bone score showed 14 (82%) excellent results, 1 (6%) good result, and 2 (12%) poor results. The ASAMI functional score showed 13 (84.6%) excellent results, 3 (11.5%) good results, and 1 (3.8%) fair result. Patients treated with chemotherapy for bone cancer did not show any increase in distraction time or consolidation time. A total of 3 (17%) problems, 1 obstacle (5.5%), and 1 complication (5.5%) were encountered in our case series. The PRECICE 2 nail allows for effective and accurate lengthening preserving the range of motion in patients treated for bone tumors.

Comparative fixation devices for preventing migration of the proximal tibiofibular joint during tibial lengthening: a tether versus screw fixation.

BACKGROUND: When lengthening the tibia segment using motorized internal lengthening nails (MILN), undesired distal migration of the proximal fibula segment is prevented by tibiofibular stabilization, traditionally using a screw. A tightened cortical suspensory fixation rope (tether) is an alternative option, but its appropriateness has never been studied. The primary outcome was comparing the amount of proximal fibular migration between patients who were stabilized with either a tether or a screw. The secondary outcome was to evaluate the effect of fibular migration on the clinical outcome between both groups. METHODS: A retrospective study was conducted on patients who underwent tibial lengthening with MILN between April 2016 and June 2022. Two cohorts were compared: 18 limbs with tether fixation versus 29 limbs with screw fixation. Data on the patient's age, sex, etiologies, and clinical outcomes were collected. Radiographic measurements included the lengthening distance and the amount of proximal fibular migration. RESULTS: In total, 47 limbs from 41 patients, with average age 35.01 ± 13.72 years old. There were 28 males (68.29%) and 13 females (31.71%). The tether group demonstrated a statistically significant greater distance of migration than the screw group (p < 0.001), with an average migration distance of 8.39 ± 5.09 mm and 2.59 ± 3.06 mm, respectively. No correlation was found between the amount of tibial lengthening and the distance of proximal fibular migration in both the tether group (p = 0.96) and the screw group (p = 0.32). There was no significant difference in the change of knee extension between both groups (p = 0.3), and no patients reported knee pain or tightness. CONCLUSION: A screw provides better resistance to proximal tibiofibular joint migration during MILN lengthening, but the difference appears clinically inconsequential. Either option appears suitable.

[First case series of femoral lengthening using a Precice® intramedullary nail in our center]. / Primera serie de casos de alargamiento femoral mediante clavo intramedular Precice® en nuestro centro.

INTRODUCTION: femoral lengthening using an intramedullary nail is one of the surgical options in the treatment of severe lower limb dysmetria in routine clinical practice. MATERIAL AND METHODS: a retrospective descriptive study was carried out on a series of five patients with a mean age of 15.4 years, who underwent femoral lengthening surgery using a Precice® intramedullary nail. The etiology in all cases was idiopathic. Preoperative and definitive postoperative theoretical lengthening or dysmetry was measured, as well as lengthening accuracy, distraction rate and index (mm/day and days/cm, respectively) and consolidation index (days/cm). Intraoperative and postoperative complications were identified in all cases. RESULTS: mean follow-up was 21 months (12-42), with no loss to follow-up. The mean duration of the surgical procedure was 126 minutes (105-160). The preoperative theoretical dysmetry was 38 ± 2.7 mm. The final mean lengthening was 41 ± 7.5 mm. The mean accuracy was 108% (91-125) and the distraction rate was 0.9 ± 0.4 mm/day. The distraction rate was 13.9 ± 5.1 days/cm and the consolidation rate was 26.6 ± 9.1 days/cm. Bone consolidation was observed in all patients with a mean of 113 ± 58 days. Regarding complications, a total of four minor muscular complications were found. CONCLUSION: the Precice® intramedullary nail is a good treatment option for cases of severe femoral shortening, providing good clinical and radiological results with a low rate of complications and implant failure.

INTRODUCCIÓN: el alargamiento femoral mediante clavo intramedular es una de las opciones quirúrgicas en el tratamiento de las dismetrías severas de miembros inferiores en la práctica clínica habitual. MATERIAL Y MÉTODOS: se realizó un estudio descriptivo retrospectivo de una serie de cinco pacientes con una media de edad de 15.4 años, intervenidos de alargamiento femoral mediante clavo intramedular Precice®. La etiología en todos los casos fue idiopática. Se midió la dismetría o alargamiento teórico prequirúrgico y el definitivo postquirúrgico, así como la precisión del alargamiento, la tasa y el índice de distracción (mm/día y días/cm respectivamente) y el índice de consolidación (días/cm). Se identificaron las complicaciones intra y postoperatorias en todos los casos. RESULTADOS: la media de seguimiento fue de 21 meses (12-42), sin pérdidas en el seguimiento. La duración media del procedimiento quirúrgico fue de 126 minutos (105-160). La dismetría teórica prequirúrgica fue de 38 ± 2.7 mm. El alargamiento medio final fue de 41 ± 7.5 mm. La precisión media fue de 108% (91-125) y la tasa de distracción de 0.9 ± 0.4 mm/día. El índice de distracción fue de 13.9 ± 5.1 días/cm y el índice de consolidación, de 26.6 ± 9.1 días/cm. La consolidación ósea se observó en la totalidad de los pacientes con una media de 113 ± 58 días. Con respecto a las complicaciones, se encontraron un total de cuatro complicaciones menores de índole muscular. CONCLUSIÓN: el clavo intramedular Precice® es una buena opción de tratamiento para casos de acortamiento femoral severo aportando buenos resultados clínicos y radiológicos con una baja tasa de complicaciones y fallo del implante.

Primera serie de casos de alargamiento femoral mediante clavo intramedular Precice® en nuestro centro / First case series of femoral lengthening using a Precice® intramedullary nail in our center

Resumen: Introducción: el alargamiento femoral mediante clavo intramedular es una de las opciones quirúrgicas en el tratamiento de las dismetrías severas de miembros inferiores en la práctica clínica habitual. Material y métodos: se realizó un estudio descriptivo retrospectivo de una serie de cinco pacientes con una media de edad de 15.4 años, intervenidos de alargamiento femoral mediante clavo intramedular Precice®. La etiología en todos los casos fue idiopática. Se midió la dismetría o alargamiento teórico prequirúrgico y el definitivo postquirúrgico, así como la precisión del alargamiento, la tasa y el índice de distracción (mm/día y días/cm respectivamente) y el índice de consolidación (días/cm). Se identificaron las complicaciones intra y postoperatorias en todos los casos. Resultados: la media de seguimiento fue de 21 meses (12-42), sin pérdidas en el seguimiento. La duración media del procedimiento quirúrgico fue de 126 minutos (105-160). La dismetría teórica prequirúrgica fue de 38 ± 2.7 mm. El alargamiento medio final fue de 41 ± 7.5 mm. La precisión media fue de 108% (91-125) y la tasa de distracción de 0.9 ± 0.4 mm/día. El índice de distracción fue de 13.9 ± 5.1 días/cm y el índice de consolidación, de 26.6 ± 9.1 días/cm. La consolidación ósea se observó en la totalidad de los pacientes con una media de 113 ± 58 días. Con respecto a las complicaciones, se encontraron un total de cuatro complicaciones menores de índole muscular. Conclusión: el clavo intramedular Precice® es una buena opción de tratamiento para casos de acortamiento femoral severo aportando buenos resultados clínicos y radiológicos con una baja tasa de complicaciones y fallo del implante.

Abstract: Introduction: femoral lengthening using an intramedullary nail is one of the surgical options in the treatment of severe lower limb dysmetria in routine clinical practice. Material and methods: a retrospective descriptive study was carried out on a series of five patients with a mean age of 15.4 years, who underwent femoral lengthening surgery using a Precice® intramedullary nail. The etiology in all cases was idiopathic. Preoperative and definitive postoperative theoretical lengthening or dysmetry was measured, as well as lengthening accuracy, distraction rate and index (mm/day and days/cm, respectively) and consolidation index (days/cm). Intraoperative and postoperative complications were identified in all cases. Results: mean follow-up was 21 months (12-42), with no loss to follow-up. The mean duration of the surgical procedure was 126 minutes (105-160). The preoperative theoretical dysmetry was 38 ± 2.7 mm. The final mean lengthening was 41 ± 7.5 mm. The mean accuracy was 108% (91-125) and the distraction rate was 0.9 ± 0.4 mm/day. The distraction rate was 13.9 ± 5.1 days/cm and the consolidation rate was 26.6 ± 9.1 days/cm. Bone consolidation was observed in all patients with a mean of 113 ± 58 days. Regarding complications, a total of four minor muscular complications were found. Conclusion: the Precice® intramedullary nail is a good treatment option for cases of severe femoral shortening, providing good clinical and radiological results with a low rate of complications and implant failure.

Limb lengthening with fully implantable magnetically actuated mechanical nails (PHENIX(®))-preliminary results.

Limb lengthening and deformity correction with fully implantable systems is becoming more and more widespread. Different actuation techniques are known and every system has its specific limitations in distraction control and/or stability. A new system with magnetic actuation offers outstanding options. The mechanism of the Phenix M2(®) bone lengthening nail (Phenix Medical, France) is driven by a strong external magnet. The device can provide lengthening, shortening and bone transport. Between December 2011 and November 2012 we applied the nail in 10 patients with an average age of 25 years (range 15-40 years). There were 6 femoral and 4 tibial procedures. The intended distraction goal was achieved in 8 of 10 patients. In three cases we simultaneously corrected malalignment. Average lengthening was 4.6 cm (range 1.3-7.6 cm). Average distraction index was 0.85 mm/day (range 0.6-1.3mm/day). Average weight bearing index was 27 days/cm (range 16-37 days/cm). Three patients had revisions due to early distraction arrest. The early results are comparable to those of other intramedullary systems in the literature like the ISKD(®), the Albizzia(®) or the Fitbone(®) system. All intramedullary procedures require accurate analysis and planning, advanced operative technique and close follow-up. The custom made design of the Phenix nail with unique options for size, stroke and locking provides new options for small bones and improved stability. The shortening option may be helpful for soft tissue problems, joint subluxation and additional stimulation of bone formation. Magnetic forces have to be considered and too much soft tissue around the nail might be a limiting factor. The magnetically actuated Phenix nail offers new therapeutic options in limb lengthening.