Limb Lengthening With Precice Intramedullary Lengthening Nails in Children and Adolescents

Rate of Osteonecrosis After Femoral Lengthening with Intramedullary Lengthening Nails

BACKGROUND

There has been historical concern that the use of intramedullary nails could present undue risk of osteonecrosis of the femoral head due to compromise of the femoral blood supply. Intramedullary lengthening nails are rapidly becoming commonplace in lengthening procedures. As such, the primary objective of this study was to analyze the rates of osteonecrosis following femoral lengthening. The secondary objective was to characterize general trends in femoral lengthening.

METHODS

This retrospective cohort study evaluated patients who had undergone femoral lengthening at a single institution from 2012 to 2021. Retrospective chart review and radiographic evaluation of osteonecrosis were conducted. The primary end point was radiographic evidence of osteonecrosis. The secondary variables were the starting point of the femoral nail, the total amount of lengthening, and the time to consolidation.

RESULTS

Two hundred and forty-seven patients were included in the analysis, including 111 males and 136 females, with a mean age of 17 years. No patient had radiographic evidence of osteonecrosis (0%) or coxa valga (0%). The average amount of lengthening was 4.88 cm (range, 1.5 to 8.5 cm). No patient had any extensive complications, such as alterations in the proximal femoral anatomy.

CONCLUSIONS

This largest study to date investigating complications following femoral lengthening using intramedullary lengthening nails revealed that femoral lengthening is a well-tolerated procedure, and osteonecrosis is an infrequent complication.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

What's new in pediatric lower limb reconstruction?

The last years brought many advances relevant to lower limb reconstruction. It feels like guided growth has been looked at from every angle, and still there are new emerging concepts like rotational guided growth waiting to be validated. New hexapod external devices are more accurate and easier to use, and new unilateral fixators allow for more versatile and stable fixation and lengthening. Intramedullary nail lengthening has found its place as a standard procedure for various diagnoses in children and young adults. First results of new and exciting approaches like extramedullary implantable nail lengthening and lengthening plates have been reported. Pharmaceutical treatment has changed the course of certain diseases and must be integrated and considered when making a reconstructive treatment plan. As reconstructive surgery is rapidly advancing so are the technical options for prosthetic fitting, which makes it difficult for caregivers as well as for parents to make the decision between reconstruction and amputation surgery for the most severe cases of congenital deficiencies. This review is highlighting new developments of lower limb reconstruction and is reviewing the current literature.

Antegrade femoral lengthening and simultaneous hemiepiphysiodesis for congenital femoral deficiency

Purpose

Congenital femoral deficiency is characterized by limb length discrepancy and genu valgum. Lengthening of the femur along its anatomic axis increases valgus alignment by medial knee translation. Pairing limb lengthening with simultaneous medial distal femoral hemiepiphysiodesis can simultaneously correct two limb deformities.

Methods

All skeletally immature patients with congenital femoral deficiency who underwent antegrade femoral lengthening and concomitant guided growth over a 4-year period were reviewed. Length and alignment data were quantified during lengthening, consolidation, and for 1 year after guided growth implants were removed or the patient reached skeletal maturity. Digital simulation was performed for all lengthenings to assess the mechanical alignment that would have been achieved had lengthening been performed without medial distal femoral hemiepiphysiodesis.

Results

Nine patients (five males, four females, mean age = 12.3 ± 1.9 years) underwent 10 antegrade intramedullary femoral lengthenings with simultaneous medial distal femoral hemiepiphysiodesis. All had improvement in valgus alignment (average improvement in mechanical axis deviation was 18 ± 11 mm, average change in limb alignment was 6 ± 5°). In simulated lengthenings without guided growth, all limbs would have experienced increased lateral mechanical axis deviation of 5 ± 3 mm. The hemiepiphysiodesis implant and lengthening device were explanted simultaneously in 7 of 10 lengthenings.

Conclusion

Simultaneous medial distal femoral hemiepiphysiodesis with antegrade femoral lengthening for ongenital femoral deficiency can minimize the number of surgical episodes for the skeletally immature patient. The lengthening device and guided growth construct can be removed simultaneously in a majority of cases, saving children one or two additional surgical treatments.

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.

Evaluation of simultaneous bilateral femoral distraction osteogenesis with antegrade intramedullary lengthening nails in achondroplasia with rhizomelic short stature: a retrospective study of 15 patients with a minimum follow-up of 2 years

BACKGROUND AND PURPOSE

Bilateral femoral distraction osteogenesis in patients with achondroplasia is insufficiently reported. We aimed to perform the first study that exclusively analyzed simultaneous bilateral femoral distraction osteogenesis with motorized intramedullary lengthening nails via an antegrade approach in patients with achondroplasia focused on reliability, accuracy, precision, and the evolving complications.

PATIENTS AND METHODS

In this retrospective singlecenter study we analyzed patients with achondroplasia who underwent simultaneous bilateral femoral lengthening with antegrade intramedullary lengthening nails between October 2014 and April 2019. 15 patients (30 femoral segments) of median age 14 years (interquartile range [IQR] 12-15) were available for analysis. The median follow-up was 29 months (IQR 27-37) after nail implantation.

RESULTS

The median distraction length per segment was 49 mm (IQR 47-51) with a median distraction index of 1.0 mm/day (IQR 0.9-1.0), and a median consolidation index of 20 days/cm (IQR 17-23). Reliability of the lengthening nails was 97% and their calculated accuracy and precision were 96% and 95%, respectively. The most common complication was temporary restriction of knee range of motion during distraction in 10 of 30 of the lengthened segments. 1 patient was treated with 2 unplanned additional surgeries due to premature consolidation.

CONCLUSION

The method is reliable and accurate with few complications.

Re-use of Motorised Intramedullary Limb Lengthening Nails

Aim

This study reviews the re-use of implanted motorised intramedullary lengthening nails previously used for limb lengthening.

Materials and methods

A retrospective review was performed on the re-use of motorised intramedullary lengthening nails. All patients had a magnetically controlled intramedullary lengthening nail in the femur, tibia, or humerus previously utilised for either lengthening or compression. Patients were included if the magnetically controlled intramedullary lengthening nail underwent attempted re-use either in the same lengthening episode or in a temporally separate lengthening treatment requiring another corticotomy.

Results

Ten patients with 12 lengthening episodes were analysed including five tibial, five femoral and two humeral segments. Overall, seven of 12 nails (58%) were successfully re-deployed without the need for nail exchange. Two of three nails were successfully retracted and re-used for continued distraction in the same lengthening treatment. Five of nine nails (56%) were successfully reactivated in a subsequent, later lengthening episode.

Conclusion

Re-use of a magnetically controlled limb lengthening nail is an off-label technique that may be considered for patients requiring ongoing or later lengthening of the femur, tibia or humerus. Regardless of whether the nail is used in the same lengthening episode or separate lengthening episode, surgeons should be prepared for exchange to a new implant.

Clinical significance

Re-use of a magnetically controlled intramedullary lengthening nail will reduce surgical trauma and save implant cost in limb lengthening treatment but may only be possible in half of attempted cases.

How to cite this article

Georgiadis AG, Nahm NJ, Dahl MT. Re-use of Motorised Intramedullary Limb Lengthening Nails. Strategies Trauma Limb Reconstr 2023;18(2):106-110.

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.

Complications and risk factors of intramedullary bone lengthening nails: a retrospective multicenter cohort study of 314 FITBONE and PRECICE nails

BACKGROUND AND PURPOSE

Intramedullary bone-lengthening nails have become increasingly popular. The 2 most used and successful nails are the FITBONE and the PRECICE nails. Uniform reporting is lacking on complications of intramedullary bone-lengthening nails. The purpose was therefore to assess and categorize the complications of lower limb bone-lengthening nails and investigate risk factors.

PATIENTS AND METHODS

We performed a retrospective review of patients operated on with intramedullary lengthening nails at 2 hospitals. We included only lower limb lengthening with FITBONE and PRECICE nails. Recorded patient data was patient demographics, nail information, and any complication. Complications were graded according to severity and origin classification. Complication risk factors were assessed with modified Poisson regression.

RESULTS

314 segments in 257 patients were included. The FITBONE nail was predominantly used (75%), and most of the lengthenings were performed in the femur (80%). 53% of the patients had complications. 269 complications were identified in 175 segments (144 patients). Device-related complications were most frequent (0.3 complications/segment), followed by joint complications (0.2 complications/segment). An increased relative risk was found for complications in the tibia compared with the femur and for age groups above 30 years compared with the 10-19 years group.

CONCLUSION

Complications with intramedullary bone lengthening nails were more frequent than has previously been reported, with 53% of patients sustaining a complication. Future studies need to document the complications meticulously so that the true risk can be established.

Motorized Plate Lengthening of the Femur in Children: A Preliminary Report

BACKGROUND

Limb lengthening by distraction osteogenesis can be performed with motorized internal devices, but intramedullary implants risk avascular necrosis of the femoral head in young children. A method of internal limb lengthening using a motorized expandable plate has been developed and preliminary results are presented.

METHODS

Seven skeletally immature patients (ages 2.7 to 9.7 y) with congenital femoral deficiencies underwent femoral lengthening with the use of a magnetic expandable plate. Surgical details, lengthening parameters, Limb Lengthening and Reconstruction Society-Angular deformity, Infection, Motion index, and complications were reviewed and classified according to the modified Clavien-Dindo system.

RESULTS

An average lengthening was 4.1 cm (range, 3.3 to 4.4 cm) comprising 18% of initial femoral segment length (range, 14% to 21%). The average lengthening phase was 50.2 days (range, 40 to 57 d) and weight-bearing was initiated at an average of 13 weeks from surgery (range, 8 to 18 wk). Limb deformities and length discrepancies were of moderate complexity, with an Limb Lengthening and Reconstruction Society-Angular deformity, Infection, Motion score of 6.57 (range, 6 to 7). Complication rates were comparable to previously reported methods of femoral lengthening. One patient underwent reoperation for patellar instability and 1 patient experienced radiographic hip subluxation which was observed. Small magnitude varus was observed in regenerate in 3 of 7 cases, none requiring treatment. Preoperative planning consisted of careful localization of the corticotomy site, acute deformity correction at the lengthening site in 3 cases, and implant orientation.

CONCLUSIONS

Limb lengthening with motorized internal plates is feasible for young children with congenital femoral deficiency for whom intramedullary lengthening is unsafe or if external fixation is to be avoided. However, the fundamental principles of distraction osteogenesis and risks of lengthening for congenital discrepancies remain unchanged. Specific considerations herein include: careful planning of implant length and positioning, adjacent joint protection with adjunctive means, and mitigating deformity of the regenerate during distraction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Correction of post-traumatic lower-limb discrepancy with Precice intramedullary lengthening nails: a review of 34 adults with an average follow-up of 2 years

BACKGROUND AND PURPOSE

We report results and complications of gradual bone lengthening for post-traumatic lower-limb length discrepancy (LLD) with Precice intramedullary lengthening nails in 34 adults.

PATIENTS AND METHODS

Inclusion criteria were lower-limb lengthening using the Precice nail, posttraumatic etiology, age older than 18 years, and minimum follow-up of 12 months after implantation. 34 patients met the inclusion criteria. Radiological and clinical outcome data were collected.

RESULTS

Precice lengthening was performed in the femur in 28 patients (21 antegrade, 7 retrograde) and in the tibia in 6. Mean patient age at time of surgery was 32 years (18-72). Mean preoperative LLD was 31 mm (20-71). Acute correction of axial or rotational malalignment was performed in 11 segments. At final follow-up (mean 2 years [1.1-3.6]), 33 of 34 nails had been removed. All lengthening sites were healed, and all patients mobilized with full weight-bearing. 14 adverse events occurred in 11 patients and were categorized as problems (n = 5), obstacles (n = 3), and complications (n = 6). Unplanned surgery was necessary in 7 patients, 3 of whom did not complete treatment with Precice.

INTERPRETATION

Correction of posttraumatic LLD with or without axial malalignment using Precice intramedullary lengthening nails is associated with a low number of complications and good functional outcome. However, one-fifth of patients in this series needed further unplanned surgery for revision of obstacles or complications.