Outcomes of Simultaneous Lengthening and ACL Reconstruction in Fibular Hemimelia: A Retrospective Case Series.

Background: Fibular hemimelia is the most common congenital long bone deficiency. It is often associated with femoral and tibial deficiencies which result in a clinically evident leg length discrepancy. The primary soft tissue concern is ACL/PCL deficiency. If treatment includes bony lengthening, joint stability is imperative to avoid complications. In this study, we detail a novel technique for long bone lengthening and ACL reconstruction in a single, cohesive surgery. This consolidates the need for multiple procedures and offers improved limb length symmetry and knee stability for this patient population. Clinical outcomes of pediatric patients with hemimelia who underwent either femoral or tibial lengthening with PRECICE® nail and concomitant ACL reconstruction are presented. Methods: After IRB approval, we identified five patients with complex fibular hemimelia who underwent ACL reconstruction and concomitant lengthening with at least two years of follow-up. Two patients (40%) presented with congenital short femur, and three (60%) with congenital short tibia. In each case, ACL reconstruction and either femoral or tibial guided growth via PRECICE® nail were performed. Operative techniques involving both soft tissue and bony methodology are described in detail. Results: All patients had objective improvement in knee stability as assessed both intra and post operatively, as well as successful intermedullary lengthening without complications related to joint stability. Three patients had minor complications unrelated to joint stability that did not interfere with overall result. Conclusion: Fibular hemimelia associated with hypoplasia of bony and soft tissue structures can be successfully addressed with concomitant ligamentous reconstruction at the time of implantation of lengthening devices. This addresses knee instability and reduces both number of operative procedures and potential complications related to joint instability while pursuing bony lengthening. Level of Evidence: V.

Limb salvage reconstruction of the lower limb with complex ankle arthrodesis and magnetic internal lengthening nail.

PURPOSE: With advances in orthopedic implants, the use of intramedullary lengthening devices has gained increasing popularity as an alternative technique compared to lengthening with external fixators, with alleged comparable or better outcomes. The aim of this study is to report our single-center technique and outcomes of combined ankle arthrodesis and proximal tibial lengthening using external fixator with a motorized intramedullary nail, respectively. METHOD: Fourteen patients with post-traumatic advanced ankle arthritis underwent staged ankle arthrodesis with external fixator and proximal tibial lengthening using the PRECICE® ILN. Amount of shortening, length achieved, bone healing index, infection rate, ankle fusion rate, and ASAMI score were evaluated. RESULTS: The average age was 44 years old (range, 30-62). The mean follow up is 70 months (range, 43-121.4). The average amount of limb shortening for patients after ankle fusion was 36.7 mm (18-50) while lengthening was 35.9 mm (range, 18-50). Patients had the nail implanted for an average of 479 days (range, 248-730). Ankle fusions were healed in an average of 178.3 days. There were no surgical infections. All osteotomy-lengthening sites healed after an average 202 days (106-365). The mean bone healing index (BHI) was 56.0 days/cm (21.2-123.6) among the whole cohort. There were no cases of nonunion. ASAMI bone scores were excellent or good among all patients. CONCLUSION: Ankle arthrodesis with external fixation along with proximal tibial lengthening using motorized IMN yielded high rates of fusion and successful lengthening. This technique could be offered as a reasonable alternative to using external fixation for both purposes. LEVEL OF EVIDENCE: Level IV, Retrospective cohort study.

Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study.

INTRODUCTION: The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting. MATERIALS AND METHODS: A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite. RESULTS: A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified. CONCLUSION: MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

PRECICE nail for the management of posttraumatic bone defects with nonunion or malunion: Experience from a Latin American center.

BACKGROUND: To evaluate the clinical outcomes using the PRECICE magnetic limb lengthening intramedullary nail for the correction of lower limb length discrepancies (LLD) in adults with posttraumatic nonunion or malunion defects in a Latin American center. METHODS: A retrospective review of 25 adult patients with LLD associated with posttraumatic nonunion or malunion defects of femur or tibia treated with the PRECICE nail between January 2018 and December 2020. The primary outcomes considered were lengthening length achieved in mm, incidence of complications and quality of life (EQ-5D-3 L questionnaire). RESULTS: Twenty-five cases (20 femoral and 5 tibial nails) were performed, with a median follow-up of 27 months (Interquartile range-IQR: 17.5 to 34.5). The average age was 36.5 ± 12.9 years; 10 cases were women. Fifteen cases had an LLD secondary to a malunion defect and 10 cases had an LLD secondary to a nonunion. PRECICE nails were inserted for the treatment of a median LLD of 40.0 mm (IQR: 30.2 to 74.2) in the femur and 30.0 mm (28.5 to 50.0) in the tibia. An accuracy of 100% was reported in 18 cases (Femur: 14 and tibia: 4) and consolidation was achieved in 22/25 cases with the PRECICE nail in situ. Complications were recorded in 9 (36%) cases (6/20 femur, 3/5 tibia), mainly related to the consolidation process (5/9). The median EQ-5D and EQ-VAS were 0.79 (IQR: 0.63 to 0.79) and 80.0 (IQR: 50.0 to 90.0), respectively. CONCLUSIONS: The results of this study demonstrated that the PRECICE nail is an effective device for the management of posttraumatic LLD during the treatment of nonunion or malunion bone defects of femur and tibia, offering a reasonable quality of life, despite its postoperative complication risk.

Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms.

Aims: The Precice Stryde® internal magnetic lengthening nail allowed many patients a full weight-bearing experience during femur and tibia lengthening, but concerns over corrosion, pain and radiographic changes led to the implant's recall. Despite the recall, it is important to understand the rate of these occurrences and their influence on the overall success of the lengthening procedure. We aimed to investigate radiographic changes, patient-reported symptoms and bone healing indices for our cohort of Stryde lengthening. Materials and methods: Our surgical database and electronic medical record system were used to review and document patient demographics, indications for lengthening, length achieved, bone healing index (BHI), location and type of radiographic changes, time until radiographic changes were first visible, presence of pain symptoms (not attributable to surgery or distraction), time to implant removal and if the pain symptoms resolved following implant extraction. Results: From January 2019 to February 2021, 90 Stryde nails (78 femur and 12 tibia) were implanted in 63 patients. The cohort included 48 males and 15 females. The average length [± standard deviation (SD)] achieved was 58.4 ± 22.7 mm. The 66 bones (73%) developed radiographic changes and were found to be 58/78 (74%) femurs and 8/12 (67%) tibias. The average time to initial radiographic changes was 168 ± 108.1 days (femur) and 276 ± 126.8 days (tibia). Late-onset pain developed in 10 femur lengthening (11.1% of all nails) surgeries across eight patients (12.7% of all patients). All patients' pain resolved; three instances prior to nail removal and the remaining seven after nail removal. No patients were re-presented with worsening pain or radiographic changes following implant removal. Radiographic or symptomatic abnormalities did not impair bone formation. The BHI for femurs with (29.6 ± 16.6 days/cm, n = 58) vs without (29.4 ± 17.9 days/cm, n = 20) radiographic or symptomatic irregularity were nearly identical (p = 0.961). The difference between BHI for tibias with (39.3 ± 7.8 days/cm, n = 8) vs without (86.1 ± 38.2 days/cm, n = 4) radiographic changes was influenced by outliers and underpowered to draw a conclusion. Conclusion: Bone lengthening with the Stryde nail was associated with high rates of radiographic abnormalities, but symptoms were uncommon and resolved with explantation. The radiographic changes did not affect bone healing in the femur. Clinical significance: Radiographic changes including bone hypertrophy and osteolysis were common after bone lengthening with the Stryde nail, but the development of pain following consolidation was rare and resolved with implant removal.The BHI in femurs was not affected by radiographic changes. How to cite this article: Reif TJ, Geffner A, Hoellwarth JS, et al. Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms. Strategies Trauma Limb Reconstr 2023;18(2):94-99.

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.

Antegrade Intramedullary Femoral Lengthening and Distal Temporary Hemiepiphysiodesis for Combined Correction of Leg Length Discrepancy and Coronal Angular Deformity in Skeletally Immature Patients.

Leg length discrepancies (LLD) are frequently associated with coronal malalignment. Temporary hemiepiphysiodesis (HED) is a well-established procedure for the correction of limb malalignment in skeletally immature patients. For treatment of LLD > 2 cm, lengthening with intramedullary devices gains increasing popularity. However, no studies have investigated the combined application of HED and intramedullary lengthening in skeletally immature patients. This retrospective single-center study evaluated the clinical and radiological outcomes of femoral lengthening with an antegrade intramedullary lengthening nail combined with temporary HED performed in 25 patients (14 females) between 2014 and 2019. Temporary HED through the implantation of flexible staples of the distal femur and/or proximal tibia was either performed prior (n = 11), simultaneously (n = 10) or subsequently (n = 4) to femoral lengthening. The mean follow-up period was 3.7 years (±1.4). The median initial LLD was 39.0 mm (35.0-45.0). Twenty-one patients (84%) presented valgus and four (16%) showed varus malalignment. Leg length equalization was achieved in 13 of the skeletally mature patients (62%). The median LLD of the eight patients with residual LLD > 10 mm at skeletal maturity was 15.5 mm (12.8-21.8). Limb realignment was observed in nine of seventeen skeletally mature patients (53%) in the valgus group, and in one of four patients (25%) in the varus group. Combining antegrade femoral lengthening and temporary HED is a viable option to correct LLD and coronal limb malalignment in skeletally immature patients; however, achieving limb length equalization and realignment may be difficult in cases of severe LLD and angular deformity, in particular.

Breakage of a re-activated PRECICE® nail: A case report.

INTRODUCTION AND IMPORTANCE: Distraction osteogenesis using motorized nails have shown promising results. These high-priced nails are regularly removed following successful lengthening sessions. The internal lengthening mechanism inside such nails is presumably intact and perhaps capable of running additional lengthening. Motorized nails are relatively weaker than conventional nails. This case report presented a broken re-activated PRECICE nail which has not been previously reported. PRESENTATION OF CASE: A 21-year-old male patient with right short tibia. He has completed an uneventful lengthening session using tibial PRECICE® nail. A residual length discrepancy persisted despite 4 cm length gain. Attempt of re-lengthening was conducted utilizing the pre-implanted PRECICE® nail. The re-lengthening session run smoothly throughout distraction phase. Late in the consolidation phase, partial nail breakage occurred. The patient acknowledged intermittent gentle weightbearing against the physician's recommendations. The broken nail was removed on emergency basis. Cast immobilization with non-weightbearing continued until achievement of full consolidation clinically and radiographically. CLINICAL DISCUSSION: Most of commercially available lengthening motorized nails are considered less rigid compared to conventional nails and hence more susceptible to deformation and metal failure. However, nail breakage has been reported in both conventional and lengthening nails. Re-activation of PRECICE nail for additional lengthening session could carry higher risk of breakage. CONCLUSION: Possibility of nail breakage may be higher in re-activated PRECICE® nails relative to newly implanted PRECICE® nails. More studies are required to evaluate behavior of re-activated lengthening nails. Defective lengthening nails must not be re-activated. The patient compliance is essential for successful re-activation of lengthening nails.

A clinical and radiological matched-pair analysis of patients treated with the PRECICE and STRYDE magnetically driven motorized intramedullary lengthening nails.

AIMS: Distraction osteogenesis with intramedullary lengthening devices has undergone rapid development in the past decade with implant enhancement. In this first single-centre matched-pair analysis we focus on the comparison of treatment with the PRECICE and STRYDE intramedullary lengthening devices and aim to clarify any clinical and radiological differences. METHODS: A single-centre 2:1 matched-pair retrospective analysis of 42 patients treated with the STRYDE and 82 patients treated with the PRECICE nail between May 2013 and November 2020 was conducted. Clinical and lengthening parameters were compared while focusing radiological assessment on osseous alterations related to the nail's telescopic junction and locking bolts at four different stages. RESULTS: Osteolysis next to the telescopic junction was observed in 31/48 segments (65%) lengthened with the STRYDE nail before implant removal compared to 1/91 segment (1%) in the PRECICE cohort. In the STRYDE cohort, osteolysis initially increased, but decreased or resolved in almost all lengthened segments (86%) after implant removal. Implant failure was observed in 9/48 STRYDE (19%) and in 8/92 PRECICE nails (9%). Breakage of the distal locking bolts was found in 5/48 STRYDE nails (10%) compared to none in the PRECICE cohort. Treatment-associated pain was generally recorded as mild and found in 30/48 patients (63%) and 39/92 (42%) in the STRYDE and PRECICE cohorts, respectively. Temporary range of motion (ROM) limitations under distraction were registered in 17/48 (35%) segments treated with the STRYDE and 35/92 segments (38%) treated with the PRECICE nail. CONCLUSION: Osteolysis and periosteal reaction, implant breakage, and pain during lengthening and consolidation is more likely in patients treated with the STRYDE nail compared to the PRECICE nail. Temporary ROM limitations during lengthening occurred independent of the applied device. Implant-related osseous alterations seem to remodel after implant removal.Cite this article: Bone Joint J 2023;105-B(1):88-96.

[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.

Unroofing osteotomy for dissociated tibial intramedullary magnetic rod during implant removal: a case report.

The PRECICE® intramedullary rod (NuVasive, San Diego, CA) utilizes multiple telescopic components to magnetically drive limb lengthening. These devices are routinely explanted after desired growth correction is met. To the author's knowledge, this is the first description of an osteotomy assisted extraction of a disassociated tibial magnetic lengthening rod. A 17-year-old girl with fibular hemimelia and resolved left tibial length discrepancy after successful surgical lengthening underwent a complex implant removal approximately seven years after regenerate consolidation. During implant removal, the telescopic portion of the rod remained lodged in the tibial medullary canal and a subsequent unroofing osteotomy of the tibia was performed. Tibial limb length discrepancies are oftentimes corrected with complex implants comprised of multiple fragile components that are routinely explanted. During the unfortunate event of a telescopic intramedullary rod dissociation, an unroofing osteotomy can be successfully performed to removal all implant components.

Motorized Intramedullary Nail Lengthening in the Older Population.

Limb lengthening has not been widely employed in the elderly population due to concerns that outcomes will be inferior. The purpose of this multicenter, retrospective case-control series was to report the bone healing outcomes and complications of lower limb lengthening in older patients (≥60 years) using magnetic intramedullary lengthening nail (MILN). Our hypothesis was that healing parameters including consolidation days, the consolidation index, maturation days, and the maturation index, as well as the number of adverse events reported in the older population, would be no different to those of the general adult population. We retrospectively reviewed charts and radiographs from patients ≥60 years of age with limb-length discrepancies who underwent femoral or tibial lengthening using a MILN. Parameters were compared among the age categories "≤19 years," "20-39 years," "40-59 years," or "≥60 years" and propensity-matched cohorts for the age groups 20-59 years and ≥60 years. Complications were reported as percentages for each age category. In the study period, 354 MILN were placed in 257 patients. Sixteen nails were placed in patients 60 years of age or older (mean 65 ± 5 years; range 60-72 years). Comparisons of healing parameters showed no difference between those aged 60+ and the younger cohort. Complication percentages were not statistically significant (p = 0.816). Limb lengthening with MILN may therefore be considered a safe and feasible option for a generally healthy elderly population.

Use of the PRECICE nail for distraction osteogenesis after tumor resection.

INTRODUCTION: Reconstructing long bone defects following intercalary tumor resection presents an exciting challenge with a greater range of surgical solutions than more typical situations requiring arthroplasty. Segmental bone transport (distraction osteogenesis) is the least utilized option for intercalary reconstruction; however, it arguably provides patients with the most desirable result. Distraction osteogenesis can be used in the management of multiple skeletal conditions including deformity (congenital or acquired), or in the presence of bone defects (by trauma or planned surgical excision). Lack of broader adoption of transport is likely due to the highly technical demands and common complications of utilizing fine-wire fixators via the Ilizarov method. More recently, internal lengthening nails such as the PRECICE nail have been employed to facilitate distraction osteogenesis without the added complexity of external fixation. AREAS COVERED: This review will examine the literature on the indications, design, and safety of the PRECICE nail (NuVasive) for intercalary reconstruction after tumor resection. EXPERT OPINION: Bone transport using the PRECICE nail represents a viable alternative to Ilizarov distraction and has the benefit of avoiding the complications of an external fixator. For large defects, the PRECICE nail can be supplemented with a locking plate for additional stability and maintenance of limb length.

An Update on the Intramedullary Implant in Limb Lengthening: A Quinquennial Review Part 2: Extending Surgical Indications and Further Innovation.

The use of the intramedullary lengthening nail has gained in popularity over the last decade. The reduction in complications associated with the use of external fixators and excellent patient outcomes has resulted in the largest change in management of limb length discrepancy since the concept of distraction osteogenesis was accepted by the Western world in the 1980s. Success following "simple" limb lengthening has led to surgeons extending the indications for the lengthening nail, including different bone segments, lengthening associated with potential joint instability and lengthening combined with acute deformity correction. There has been a drive for further implant modification to reduce complications, and enable full weight bearing during the lengthening process. This would offer the opportunity to consider simultaneous limb lengthening. The aim of this review is to evaluate the literature published over the last five years and highlight important learning points and technical tips for these expanding indications.

An update on the intramedullary implant in limb lengthening: A quinquennial review Part 1: The further influence of the intramedullary nail in limb lengthening.

The goal of limb lengthening is to restore length to bone, safely stretch soft tissues and improve quality of life with minimal complications. Traditionally this was achieved with the use of external fixators, associated with complications related to pin site tethering and infections, joint stiffness and regenerate deformity and fracture following frame removal. The duration of treatment also impacts on patient mental health and well-being. In order to reduce external fixator time, intramedullary nails have been introduced as an adjunct, either at the initial surgery or after completion of lengthening. Complications related to the external fixator still remained and innovation has led to the popularisation of the intramedullary lengthening nail. The lengthening mechanism of the nail can be divided into those with ratchet systems and those driven by motors. In the ratchet group, patients are required to manually rotate their limb, with movement at the osteotomy site, in order to create forward movement. This was often associated with pain, and in some cases led to the requirement of general anaesthesia to enable rotation and continuation of lengthening. Further issues were reported related to lengthening rate control. Once the nail had lengthened sufficiently for the osteotomy to disengage, rapid lengthening termed a 'runaway' nail could occur. The nails were limited to forward movement, and once length was gained it could not be retracted, leading to poor regenerate formation and soft tissue contractures. The introduction of the Fitbone implant utilised a transcutaneous electrical conduit, powered by a high frequency electrical signal, enabling more control over the lengthening. The Precice intramedullary lengthening system is controlled by the use of an external device with two rotating neodymium magnets, which produce rotation of a third magnet in the nail. By altering the direction of the magnet rotation, the lengthening can be controlled both forwards and backwards with sub-millimetre precision. Following initial excellent outcomes published, the use of the lengthening intramedullary nail has become accepted by many as the implant of choice in limb lengthening. The aim of this article comes in two parts. The first to highlight the latest research and clinical results in the last five years using an intramedullary implant during limb lengthening, and the second to report the outcome in extended surgical indications and further implant innovation.

Technical considerations and early results of magnetic compressive intramedullary nailing for humeral shaft delayed unions and nonunions.

Background: Expandable magnetic rods and intramedullary nails are being used in a number of innovative ways, including limb length discrepancy and scoliosis correction. However, recently, the full complement of these devices has been further explored, with the utilization of their compressive capacity to improve fracture healing. The purpose of the present study was to report on early results of compressive magnetic intramedullary nailing for humeral shaft delayed unions and nonunions. Methods: This retrospective case series was completed at a level 1 trauma center, with adult patients who underwent compressive intramedullary nailing from 2017 to 2021 for humeral shaft nonunion or delayed union. The primary indication for this procedure was nonunion in the setting of previous conventional fixation, but a subset of patients with atrophic nonunions and risk factors for recalcitrant nonunion were also included. Results: Fourteen patients, with a mean age of 51 ± 17 years, underwent compressive magnetic intramedullary nailing. Nine patients had previously underwent surgery, 6 of which had undergone multiple prior procedures. Five others were initially treated nonoperatively and underwent surgery 4.1 ± 2.9 months out from injury. Ten patients went on to union at a mean of 2.9 ± 2.4 months. One patient experienced hardware failure with nail cut-out at 2 weeks, and one required revision surgery for a wound infection. Three other patients were lost to follow-up, one of which was deceased for reasons unrelated to surgery. Conclusion: Compressive magnetic intramedullary nails are a viable solution for complex humeral shaft nonunions, particularly in the setting of previously well-fixed fractures and those at risk of recalcitrant nonunion. However, comparative and prospective studies looking at union rates and secondary procedures are needed to more clearly define their role in treatment and assure their safety, given recent concerns regarding osteolysis at the nail modular junction.

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.

Technical considerations for the management of segmental osseous defects with an internal bone transport nail.

INTRODUCTION: Traditionally, distraction osteogenesis has been accomplished with an external fixator. All internal transport utilizing magnetic intramedullary nails is a newer technique for bone reconstruction. The Precice Bone Transport Nail is a new implant that allows for noninvasive transport via a magnetically driven motor. AREAS COVERED: This report describes the function of the Bone Transport Nail along with the technical considerations on how to successfully manage bone defects with this new technology. Appropriate use of the nail, preoperative planning, intraoperative considerations, and postoperative management are discussed in detail. EXPERT OPINION: The Precice Bone Transport Nail utilizes the technology of the original Precice nail to provide an all-internal option for reconstruction of intercalary defects. This obviates the need for an additional plate with a standard Precice nail when performing bone transport and allows for a less invasive option that decreases operating room time. It provides a more cosmetic result than external fixation and avoids the risks of pin tract infection. Preoperative planning is essential to appropriate execution of the operative procedure and to perform a successful transport. A thorough understanding of the nail design and limitations are a prerequisite as this implant is significantly different from a standard intramedullary nail.

Changes in the femoral osteotomy level coefficient and neck shaft angle during limb lengthening with an intramedullary magnetic nail.

BACKGROUND: The intramedullary magnetic IM nail enables bone graduated distraction. Proximal femur osteotomies for ante grade IM lengthening nails have a tendency towards varus-procurvatum malalignment. We examined the effect of the level of the osteotomy and of trochanteric versus piriformis entry points on the neck shaft angle (NSA) during lengthening with the PRECICE IM magnetic nail. METHODS: A novel parameter, the osteotomy level coefficient (OLC), was introduced as a guide to determine the level of an osteotomy at the proximal femur. The OLC was defined as the ratio between the distances from the tip of the greater trochanter to the osteotomy divided by the full length of the femur. A retrospective review of all femoral lengthening procedures with the PRECICE ante grade IM lengthening nail between 2013 and 2018 was carried out. RESULTS: 31 femurs were lengthened in 30 patients (16 males and 14 females, mean age at surgery years 17.1. The average amount of lengthening was 4.4 cm. Trochanteric entry points were used in 24 femurs, and piriformis entry points in seven femurs. The OLC values ranged from 0.16 to 0.34 (average 0.25). The average follow-up period was 10.15 months. The distraction index average 10.5 days/cm (Range 8.6-11.9), Consolidation index 32.1 days/cm (14.3-51.9). The average post-operative NSA was significantly reduced from 133.5º to 128.5º [t (31) = 5.57, p = 0.000]. There was no correlation between the OLC and the change in the NSAs. The trochanteric entry point showed a greater tendency to reduce the NSA (Mdif = - 6, SD = 4.8) compared to the piriformis entry point (Mdif = - 0.86, SD = 2.27) [t (31) = -3.96, p = 0.001]. CONCLUSION: Proximal femur lengthening with the PRECICE IM nail significantly reduced the NSA and might cause Varus deformity. The level of osteotomy by OLC did not influence the amount of NSA reduction. The trochanteric entry points have a greater tendency to reduce the NSA compared to the piriformis entry points.

STRYDE versus PRECICE magnetic internal lengthening nail for femur lengthening.

INTRODUCTION: Magnetic internal lengthening nails (MILNs) have been used for femoral lengthening to avoid complications associated with external fixation. The titanium version of the MILN (PRECICE®) has been in use since 2011 but had limitations (50-75 lb) in post-operative weight bearing. A new stainless-steel version of the MILN (STRYDE®) allows 150-250 lb of post-operative weight bearing. The aim is to compare the outcomes of using these two different MILNs for both unilateral and bilateral femoral lengthening. METHODS: A single-center, retrospective cohort study was conducted in which patients' records were reviewed from the period from January 2017 to March 2020. A total of 66 femoral lengthening procedures were included in the study and were divided into two groups: STRYDE® group (30 femora) and PRECICE® group (36 femora). Outcomes assessed were the 6-months post-operative Limb Deformity-Scoliosis Research Society (LD-SRS) Score, adjacent joint range of motion (ROM), average distraction rate, bone healing index (BHI), and complications. RESULTS: No statistically significant difference was found between the two groups in regard to the (LD-SRS) score, hip ROM, or knee ROM. Statistically significant differences were found between the two groups in regard to BHI (average of 0.84 months/cm and 0.67 months/cm for STRYDE® and PRECICE®, respectively) and distraction rate (average of 0.6 mm/day and 0.9 mm/day for STRYDE® and PRECICE®, respectively). No mechanical nail complications were reported in the STRYDE® group compared to three events of nail failure in the PRECICE® group. One femur in the PRECICE® group needed BMAC injection for delayed healing compared to four femurs in the STRYDE® group. CONCLUSION: The STRYDE® MILN yields comparable functional results to those of PRECICE® MILN and shows fewer mechanical nail complications. However, STRYDE® MILN requires a slower distraction rate and yields slower healing (larger BHI). LEVEL OF EVIDENCE: Level III, Therapeutic study.