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.

Prophylactic Intramedullary Rodding After Femoral Lengthening in Patients With Achondroplasia and Hypochondroplasia.

BACKGROUND: Femoral fracture after femoral lengthening in patients with achondroplasia and hypochondroplasia is a frequent complication, occurring in up to 30%. The purpose of this study is to demonstrate the effectiveness of prophylactic intramedullary rodding in preventing this complication. METHODS: Multicenter retrospective study involving 86 femoral lengthening procedures in 43 patients with achondroplasia or hypochondroplasia. Forty-two femora (21 patients) were prophylactically managed with intramedullary Rush rodding after external fixation removal (11 females and 10 males, mean age 14.6 years) compared with 44 femora (22 patients) without prophylactic intramedullary rodding (13 females and 9 males, mean age 15.2 years). The mean amount of lengthening in the rodding group was 13.3 cm (52.6%) with an External Fixation Index of 25.8 days/cm; in patients without rodding was 14.3 cm (61.5%) and 24.5 days/cm, respectively. RESULTS: Seven cases (15.9%) without rodding developed fractures. Four of them required surgical correction due to displacement or shortening. Only 1 patient (2.4%) had fracture of the femur after prophylactic rodding, and surgery was not required. The incidence of femur fracture was significantly lower in the prophylactic rodding group compared with the nonrodding group (2.4% vs. 15.9%, respectively; P =0.034). There were no cases of infection or avascular necrosis. CONCLUSIONS: Prophylactic intramedullary rodding is a safe and effective method for preventing femoral fractures after femoral lengthening in patients with achondroplasia or hypochondroplasia. LEVEL OF EVIDENCE: Level III-a retrospective comparative study.

Simultaneous femoral and tibial lengthening for severe limb length discrepancy in fibular hemimelia.

BACKGROUND: Fibular Hemimelia (FH) is the most common longitudinal limb deficiency. Significant limb length discrepancy (LLD) will necessitate long treatment times and multiple settings to compensate for LLD when associated with femoral shortening. This study evaluates the outcome of simultaneous femoral and tibial lengthening using the Ilizarov frame. METHODS: This retrospective study included the cases of 12 children with severe limb length discrepancy caused by combined FH and ipsilateral femoral shortening from May 2015 to August 2022. The total LLD ranged from 7 to 14.5 cm. All patients underwent single-session femoral and tibial lengthening using the Ilizarov ring external fixator technique. Additional procedures were performed in the same setting, including Achilles tendon lengthening, fibular anlage excision, peroneal tendons lengthening, and iliotibial band release. Follow-up ranged from 2 to 4 years. RESULTS: The planned limb lengthening was achieved in ten cases (83%). No cases of joint subluxation or dislocation were encountered. No neurovascular injury has occurred during the treatment course. In all cases, the bone healing index was better on the femoral side than on the tibia. Poor regeneration and deformity of the tibia occurred in two cases (16.6%). CONCLUSION: Simultaneous femoral and tibial lengthening using the Ilizarov fixator is a relatively safe procedure with the result of correction of total LLD in one session in a shorter time and less morbidity.

Femoral lengthening using limb reconstruction system augmented with only one antegrade flexible nail in children: early results.

Several techniques have been described for decreasing the duration of external fixator use, augmenting stability, and minimizing complications. The purpose of the present study was to evaluate the clinical results and complications of femoral lengthening procedures using the Limb Reconstruction System (LRS) in combination with a single antegrade flexible intramedullary nail (FIN). Femoral lengthening with LRS and FIN was applied to 14 patients (aged 6-16 years) between 2017 and 2021. The etiology was a congenital femoral deficiency in 12 patients and post-traumatic growth arrest in two. A single nail was inserted antegradely through the trochanteric apophysis in each patient. Radiographs and medical records of the patients were assessed retrospectively. The mean lengthening achieved was 4.8 ±â€…1.0 cm. The mean duration of external fixation was 181 days (range 139-248 days) and the mean healing index was 39.6 ±â€…12.1 days/cm. The mean values of mechanical medial proximal tibial angle, mechanical lateral distal tibial angle, mechanical lateral proximal femoral angle, and mechanical lateral distal femoral angle were within the normal range at the last follow-up. Seven of the 14 cases had a regenerate deformity that caused a displacement of more than 2 mm in the mechanical axis deviation, none of them was greater than 10 mm and considered clinically insignificant. Fracture was seen in two limbs with regenerate deformity. This study suggests that LRS in combination with only one FIN may be an effective alternative for femoral lengthening, with acceptable complication rates.

Long-term effects of retrograde approach on the knee after motorized femoral limb lengthening.

BACKGROUND AND PURPOSE: The retrograde femoral approach is an established technique for implantation of nails for leg lengthening and correction and in cases of distal femoral fractures. The purpose of this study was to determine the 10-year outcome of this technique by analyzing the clinical long-term effects and radiological status of the knee after leg lengthening via a retrograde femoral approach. PATIENTS AND METHODS: This retrospective single-center study included 13 patients (median age at surgery 17 [range 15-20] years) who underwent unilateral, retrograde, femoral lengthening with a motorized nail. Outcome measurements were graded variables of the SF-36, ISKD score, and Lysholm score. MRI of both knees was performed in all patients. MRI was evaluated for the presence of degenerative changes and compared with the healthy contralateral knee. Cartilage condition was graded according to the International Cartilage Repair Society (ICRS) scoring system. RESULTS: All patients were pain-free and had a full range of motion 10 (range 10.0-12.2) years after surgery. All postoperative knees showed fibrosis of Hoffa's fat pad and moderate to severe cartilage defects (ICRS Grade 2-4) of the trochlear groove (nail entry site). 6 out of 13 operated knees exhibited retropatellar cartilage defects. CONCLUSION: Our study showed that patients were pain-free, but cartilage defects at the entry point and arthrofibrosis at Hoffa's fat pad were observed without causing clinical impairment.

Acute shortening and double-level lengthening versus bone transport for the management of large tibial bone defects after trauma and infection.

OBJECTIVE: The aim of this study was to present our experience with a new modified Ilizarov technique of acute shortening and double-level lengthening (ASDL) for the management of large tibial bone defects after trauma and infection and compare it with bone transport (BT). METHODS: A retrospective comparative study was performed on 47 patients with large tibial defects after trauma and infection from June 2014 to June 2018. Depending on different Ilizarov methods, these patients were divided into ASDL group (n = 21) and BT group (n = 26). The difference in bone lengthening time, time in frame, external fixation index, docking site healing time were recorded and compared between the two groups. Bone and functional results were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria. Complications encountered in both groups were categorized according to the classification of Paley, including problems (treated nonoperatively), obstacles (treated operatively), and sequelae (unresolved at last). RESULTS: All patients were followed for at least two years since the lengthening frame was removed. All cases achieved complete union at the docking site and consolidation of the regenerate callus. The mean bone loss was 8.9 cm (range 6.5-16.0 cm) in ASDL group vs. 10.3 cm (range 5.2-18.5 cm) in BT group. The mean bone lengthening time was 2.4 ± 0.7 months in ASDL group vs. 4.1 ± 1.4 months in BT group (p<0.001); time in frame was 9.1 months (range 7.0-14.5 months) in ASDL group vs. 17.7 months (range 13.5-23.0 months) in BT group (p<0.001); and external fixation index was 1.04 months/cm (range 0.83-1.38 months/cm) in ASDL group vs. 1.91 months/cm (range 1.28-2.70 months/cm) in BT group (p<0.001). The incidence of obstacles occurred in ASDL group was significantly lower than that in BT group (p<0.001). There was no significant difference in the bone (p = 0.635) and functional results (p = 0.293) between the two groups. CONCLUSION: Compared with bone transport, our modified technique of acute shortening and double-level lengthening could reduce bone lengthening time, time in frame, external fixation index and postoperative complications. It showed better clinical effects in patients with large tibial bone defects after trauma and infection.

Mechanical Failures in Magnetic Intramedullary Lengthening Nails.

BACKGROUND: Magnetic intramedullary lengthening nails (MILNs) have gained popularity in recent years for the treatment of limb-lengthening discrepancies. We sought to catalog mechanical failures and their prevention and management in a large, single-institution series. We specifically assessed the rate of mechanical failures, the types of failures observed, and management strategies. METHODS: We retrospectively reviewed 377 patients (420 limbs) who underwent limb lengthening with early (P1) or later (P2) MILN iterations with ≥12-month follow-up. Mechanical failure was defined as mechanical breakage of the instrumentation or nail and/or failure of the internal lengthening mechanism. Failure assessment was arranged by lengthening phases and was sorted with a complication classification system. All lengthening and alignment parameters were assessed radiographically. RESULTS: Mechanical failure was observed in 40 nails (9.5%), most of which (63%) were corrected with an additional surgical procedure. The mechanical failure rate was 11.3% in P1 nails and 9% in P2 nails. Two nails failed the intraoperative distraction test, and 1 nail was found to have a broken washer during the insertion phase. Sixteen nails had mechanical failures in the lengthening phase. Some nails (8 of 16) required nail replacement surgery. Thirteen nails failed during the consolidation phase; 7 of these cases were managed by replacement with either a functional MILN or a conventional intramedullary nail. Eight failures happened during the extraction phase and were managed intraoperatively. CONCLUSIONS: A 9.5% overall rate of mechanical failure of MILNs was observed in this large series. Resolution was achieved with an additional surgery in most cases. Nail distraction and weight-bearing compliance should be closely monitored during the lengthening and consolidation phases. Nail removal can be difficult and requires a careful study of radiographs for locking-screw bone overgrowth and backup removal equipment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Experiences in the Use of Motorized Intramedullary Nails after Complex Injuries to the Extremities. / Erfahrungen bei der Anwendung motorisierter Marknägel nach komplexen Extremitätenverletzungen.

The treatment of complex injuries of the extremities after comminuted fractures or non-unions is a challenging area in the field of trauma surgery. Internal, motorized implants nowadays enable a patient-oriented and progressive treatment of these cases. The present article aims to present modern treatment strategies of complex injuries of the extremities, support the use of novel, motorized intramedullary nails and provide experiences for the handling with lengthening nails or transport nails. For this purpose, the preoperative planning including selection of patients, presentation of internal lengthening and transport systems and the most important factors during preparation of the surgery are described. Moreover, critical steps during the implantation of motorized nails and also during potential follow-up interventions are highlighted and the postoperative protocol including precise recommendations for the transport und consolidation phase are provided. Finally, the experiences are illustrated by presentation of the four different cases. The use of internal, motorized implants represents the latest step in the treatment of complex injuries of the extremities. These implants improve the quality of life and the authors recommend its use. However, these implants require a high expertise and adaption of established treatment protocols in these challenging trauma cases. Follow-up analyses with a considerably large number of cases are necessary and the research on implants to solve persisting problems in the area of complex injuries of the extremities has to be pursued intensively.

Combined lengthening for acquired leg length discrepancy: Are there advantages of hydroxyapatite-coated intramedullary nails?

INTRODUCTION: The aim of this multicenter prospective study was to analyze the outcomes of bone lengthening by external fixator associated with flexible intramedullary nailing (FIN) in acquired limb length discrepancy (LLD). HYPOTHESIS: Hydroxyapatite (HA)-coated FIN enables reduced External Fixation Index in limb lengthening for acquired leg length discrepancies in comparison to non-HA-coated FIN. MATERIAL AND METHODS: This study included 54 patients (mean age, 17.9 years) operated on for femoral or tibial lengthening by combined technique (External fixator with FIN) for acquired length discrepancy. Titanium non-HA-coated FIN (29 cases) or HA-coated FIN (25 cases) were used. The factors that might influence external fixation index, complication occurrence and outcome were analyzed: age, amount of lengthening, nail diameter, HA-coating vs. non-HA-coated nails. RESULTS: The mean External Fixation Indexes (EFI) of groups compared for non-HA-coated nails vs. HA-coated nails were not significantly different: 26.5 d/cm and 27.2 d/cm in femoral lengthening and 34.9 d/cm and 31.7 d/cm in tibial lengthening. Positive correlation between the "nail diameter/inner distance between cortices at osteotomy site" ratio and EFI in tibial lengthening was revealed (p=0.034). The nail types and the "nail diameter/medullary canal diameter" ratio interact and have significant simultaneous effect on EFI in femoral lengthening (p=0.021). DISCUSSION: The results of this study revealed no differences with regards to EFI using HA-coated or non-HA-coated titanium FIN in lengthening for acquired leg-length discrepancies. Combined technique allowed reduced EFI and avoided major complications. Both non-HA-nail and HA-coated nail lengthening provided good and excellent outcomes. LEVEL OF EVIDENCE: III; (controlled trial without randomization) prospective comparative study.

Current trends on limb length discrepancy treatment: results of a survey among 11 dedicated Italian centres.

Limb length discrepancies (LLD) are quite frequent, especially in lower limbs. The evolution of the available devices and the refinement of the techniques for correcting the differences in limb length have progressively improved the approach to these deformities. Nevertheless, several points still remain debated. The aim of the study was to investigate the Italian pediatric orthopedic surgeons' choices in approaching and treating LLD in both lower and upper limbs. A survey on the treatment of limb length discrepancy was sent to a group of 11 Italian orthopedic centers, specialising in limb lengthening and belonging to the Italian Society of Pediatric Orthopedics and Trauma and the Italian Society of External Fixation. Despite improvements in knowledge of bone biology and distractional osteogenesis as well as the increase in available hardware for lengthening, many aspects of LLD correction still remain debated. Both the relative rarity of the conditions which lead to significant shortening and the lack of wide groups of patients analysed at adult age, continue to be the main limitations for every surgeon who deals with LLD. Only by overcoming our own convictions and sharing our experiences in multicentric studies, may we reach our goal of developing a shared treatment protocol.

Evaluation of the ulna lengthening by distraction osteogenesis in congenital radial deficiency.

PURPOSE: Publications evaluating the results of the ulna lengthening in congenital radial deficiency are based only on small groups of subjects which yield statistical studies of low scientific value. The aim was to examine the effectiveness of ulna lengthening in radial longitudinal deficiency and determine the number and quality of complications based on one of the most numerous study groups described in the literature. METHODS: The material consists of a study group with 31 upper limbs of unmatured patients diagnosed with type III and IV radial longitudinal deficiency. The study group was evaluated based on the parameters known from the literature. The difficulties during elongation were classified according to Paley's classification. RESULTS: The study group contained patients with a mean age of 9 years, and the number of boys and girls was comparable. Ulna length significantly increased after elongation compared to the initial bone length. The patient's age didn't affect the ulna lengthening, and the amount of elongation didn't significantly affect the total stabilization period. However, the total stabilization time increased with increasing patient age. Difficulties affected more than half of the cases. CONCLUSIONS: Ulna elongation in congenital radial deficiency results in significant lengthening of the ulna, and thus the entire forearm, compared to the initial bone length. This technique has a high percentage of difficulty, so its use should be considered after cautious discussion with the parents and patients.

Braquimetatarsia: propuesta de tratamiento en base a técnicas de alargamiento: a propósito de dos casos / Brachymetatarsia: treatment proposal based on lengthening techniques: about two cases / Braquimetatarsia: proposta de tratamento baseada em técnicas de alongamento: sobre dois casos

Braquimetatarsia es el acortamiento anormal de uno o más metatarsianos. Tiene una incidencia de 0.02%-0.05% predominando en mujeres de 25 a 1. En un 72% puede ser bilateral. La etiología no es clara pero se plantea el cierre prematuro de la fisis dando un retardo en el crecimiento. La mayoría de las veces presenta síntomas causados por alteración en la mecánica de la parábola metatarsal como dolor e hiperqueratosis. Puede existir metatarsalgia y agregar en la evolución desviaciones digitales adicionales. El principal motivo de consulta es estético. El objetivo del reporte es mostrar dos técnicas quirúrgicas y los resultados clínicos correspondientes usando el score AOFAS, además de los resultados imágenológicos con hasta 5 años de seguimiento. Se describen dos pacientes y se analizan dos técnicas quirúrgicas diferentes para alargar los metatarsianos. Se trata de alargamientos agudos con interposición de injerto intercalar, en un caso mediante el procedimiento de Sandro Gianini con injerto de cresta ilíaca y en el otro con injerto de metatarsiano adyacente con modificación de la longitud del segundo y tercer metatarsiano restituyendo en ambos casos la parábola metatarsal. Obtuvimos buenos resultados al igual que series numerosas pudiendo recomendarse en casos similares.

Brachymetarsal is the abnormal shortening of one or more metatarsals. It has an incidence of 0.02%-0.05%, predominantly in women from 25 to 1. In 72% it can be bilateral. The etiology is not clear, but premature closure of the physis is suggested, giving growth retardation. Most of the time it presents symptoms caused by an alteration in the mechanics of the metatarsal parabola, such as pain and hyperkeratosis. There may be metatarsalgia and add additional digital deviations in the evolution. The main reason for consultation is aesthetic. The objective of the work is to show the surgical technique and the clinical results using the AOFAS score, in addition to the imaging results with up to 5 years of follow-up. Two patients are described and two different surgical techniques to lengthen the metatarsals are analyzed. These are acute lengthenings with intercalary graft interposition, in one case using the S.Gianini procedure with an iliac crest graft and in the other with an adjacent metatarsal graft with modification of the length of the second and third metatarsals, restoring in both cases the metatarsal parabola. We obtained good results. results as well as numerous series and can be recommended in similar cases.

Braquimetatarsal é o encurtamento anormal de um ou mais metatarsos. Tem incidência de 0,02%-0,05%, predominantemente em mulheres de 25 a 1 ano. Em 72% pode ser bilateral. A etiologia não é clara, mas sugere-se o fechamento prematuro da fise, causando retardo de crescimento. Na maioria das vezes apresenta sintomas decorrentes de uma alteração na mecânica da parábola metatarsal, como dor e hiperqueratose. Pode haver metatarsalgia e adicionar desvios digitais adicionais na evolução. O principal motivo da consulta é a estética. O objetivo do trabalho é mostrar a técnica cirúrgica e os resultados clínicos utilizando o escore AOFAS, além dos resultados de imagem com até 5 anos de seguimento. Materiais e métodos: São incluídos dois pacientes e analisadas duas técnicas cirúrgicas diferentes para alongar os metatarsos. São alongamentos agudos com interposição de enxerto intercalar, em um caso utilizando a técnica de S. Gianini com enxerto de crista ilíaca e no outro com enxerto de metatarso adjacente com modificação do comprimento do segundo e terceiro metatarsos, restaurando em ambos os casos o metatarso parábola. Obtivemos bons resultados, bem como inúmeras séries, podendo ser recomendados em casos semelhantes.

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.

[Bone lengthening by motorized centromedullary nail]. / L'allongement osseux par clou centromédullaire motorisé magnétique.

Bone lengthening surgeries are difficult procedures for both the patient and the professional. Complications are common and pediatric orthopedists have been working to reduce them. The discovery of progressive bone lengthening was a first step in improving these procedures, followed by the advent of external fixators. More recently, internal lengthening systems have emerged as one of the greatest technological advances in these procedures. Bone lengthening with an electromagnetic nail, which is becoming increasingly popular, has drastically reduced the complications of these surgeries.

[Paramedical care related to the implantation of a motorized spinal lengthening nail]. / Soins paramédicaux liés à l'implantation d'un clou d'allongement médullaire motorisé.

The Fitbone® system is one of the most recent motorized bone lengthening techniques. It allows a precise control of the extension while reducing pain and complications. It requires special assistance from the paramedical team, before and after the procedure, as it may cause adjustment problems in some patients.

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.

Bifocal femoral lengthening assisted by preoperative 3-dimensional design in the restoration of posttraumatic limb length discrepancy.

BACKGROUND: To assess the clinical outcomes of preoperative three-dimensional planning followed by bifocal femoral lengthening in the treatment of posttraumatic limb length discrepancy (LLD). METHODS: A total of 8 eligible patients with posttraumatic femoral LLD > 6 cm were admitted to our institution from January 2015 to January 2018 and treated by bifocal femoral lengthening with the assistance of 3-dimensional imaging technology. The following data were collected: detailed demographic information, the amount of lengthening, external fixation time (EFT), external fixation index (EFI), postoperative bone and functional outcomes, and complications in the follow-up period. RESULTS: All included patients were successfully followed up for in an average of 55.4 ± 6.7 months after removal of the external fixator. There were six males and two females with an average age of 38.4 ± 12.2 years. The mean preoperative LLD was 69.2 ± 6.2 mm. The mean lengthening amount was 67.5 ± 6.9 mm. The mean EFT was 180.1 ± 20.2 days. The EFI was 26.73 ± 1.36 days/cm on average. All patients achieved satisfactory postoperative bone and functional outcomes. No major complications such as nerve or vascular injury were observed. CONCLUSIONS: Bifocal femoral lengthening with preoperative three-dimensional design provided precise surgical guidance and resulted in satisfactory postoperative outcomes, demonstrating that it is an effective treatment for posttraumatic femoral LLD.

What Are the Risks and Functional Outcomes Associated With Bilateral Humeral Lengthening Using a Monolateral External Fixator in Patients With Achondroplasia?

BACKGROUND: Many patients with achondroplasia experience functional impairments because of rhizomelic upper extremities (proximal limb shortening). Bilateral humeral lengthening may overcome these functional limitations, but it is associated with several risks, such as radial nerve palsy and insufficient bone regeneration. Only a few studies have reported on patient satisfaction and functional outcome after humeral lengthening in patients with achondroplasia. Furthermore, the reported numbers of adverse events associated with lengthening procedures using external fixators vary widely. QUESTIONS/PURPOSES: (1) Does bilateral humeral lengthening with a monolateral external fixator in patients with achondroplasia reliably improve patient function and autonomy, and what proportion of patients achieved at least 8 cm of humeral lengthening? (2) What adverse events occur after bilateral humeral lengthening with monolateral external fixators? METHODS: Between 2011 and 2019, 44 patients underwent humeral lengthening at our institution. Humeral lengthening was performed in patients with severe shortening of the upper extremities and functional impairments. In humeri in which intramedullary devices were not applicable, lengthening was performed with monolateral external fixators in 40 patients. Eight patients were excluded because they underwent unilateral lengthening for etiologies other than achondroplasia, and another four patients did not fulfill the minimum study follow-up period of 2 years, leaving 28 patients with bilateral humeral lengthening to treat achondroplasia available for analysis in this retrospective study. The patients had a median (interquartile range) age of 8 years (8 to 10), and 50% (14 of 28) were girls. The median follow-up time was 6 years (4 to 8). The median humeral lengthening was 9 cm (9 to 10) with a median elongation of 73% (67% to 78%) from an initial median length of 12 cm (11 to 13). To determine whether this treatment reliably improved patient function and autonomy, surgeons retrospectively evaluated patient charts. An unvalidated retrospective patient-reported outcome measure questionnaire consisting of nine items (with answers of "yes" or "no" or a 5-point Likert scale) was administered to assess the patient's functional improvement in activities of daily living, physical appearance, and overall satisfaction, such that 45 points was the highest possible score. The radiographic outcome was assessed on calibrated radiographs of the humerus. To ascertain the proportion of adverse events, study surgeons performed a chart review and telephone interviews. Major complications were defined as events that resulted in unplanned revision surgery, nerve injury (either temporary or permanent), refracture of the bone regenerate, or permanent functional sequelae. Minor complications were characterized as events that resolved without further surgical interventions. RESULTS: On our unvalidated assessment of patient function and independence, all patients reported improvement at their most recent follow-up compared with scores obtained before treatment (median [IQR] 24 [16 to 28] before surgery versus 44 [42 to 45] at latest follow-up, difference of medians 20 points, p < 0.001). A total of 89% (25 of 28) of patients achieved the desired 8 cm of lengthening in both arms. A total of 50% (14 of 28) of our patients experienced a major complication. Specifically, 39% (11 of 28) had an unplanned reoperation, 39% (11 of 28) had a radial nerve palsy, 18% (5 of 28) had a refracture of the regenerate, and 4% (1 of 28) concluded treatment with a severe limb length discrepancy. In addition, 82% (23 of 28) of our patients experienced minor complications that resolved without further surgery and did not involve radial nerve symptoms. Radial nerve palsy was observed immediately postoperatively in eight of 13 segments, and 1 to 7 days postoperatively in five of 13 segments. The treatment goal was not achieved because of radial nerve palsy in 5% (3 of 56) of lengthened segments, which occurred in 7% (2 of 28) of patients. Full functional recovery of the radial nerve was observed in all patients after a median (IQR) of 3 months (2 to 5). Refractures of bone regenerates were observed in 11% (6 of 56) of humeri in 18% (5 of 28) of patients. Of those refractures, 1 of 6 patients was treated nonsurgically with a hanging cast, while 5 of 6 patients underwent revision surgery with intramedullary rodding. CONCLUSION: Most patients with achondroplasia who underwent humeral lengthening achieved the treatment goal without permanent sequelae; nonetheless, complications of treatment were common, and the road to recovery was long and often complicated, with many patients experiencing problems that were either painful (such as refracture) or bothersome (such as temporary radial nerve palsy). However, using a subjective scale, patients seemed improved after treatment; nevertheless, robust outcomes tools are not available for this condition, and so we must interpret that finding with caution. Considering our discoveries, bilateral humeral lengthening with a monolateral external fixator should only be considered in patients with severe functional impairments because of rhizomelic shortening of the upper extremities. If feasible, internal lengthening devices might be preferable, as these are generally associated with higher patient comfort and decreased complication rates compared with external fixators. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Quality of life of children during distraction osteogenesis: a comparison between intramedullary magnetic lengthening nails and external fixators.

BACKGROUND: Distraction osteogenesis is a very demanding process. For decades, external fixation was the only reliable option for gradual deformity correction. Recently, intramedullary magnetic nails have gained popularity. This research aimed to assess the quality of life in children during gradual deformity correction using intramedullary lengthening nails compared to external fixation. METHOD: Prospective analysis included children who had gradual lower limb deformity correction between 2017 and 2019. Group A included children who had magnetic lengthening nails; patients in group B had external fixation devices. Child health utility 9D (CHU- 9D) and EuroQol 5D youth (EQ- 5D-Y) were used to measure the quality of life at fixed points during the distraction osteogenesis process. The results were used to calculate the utility at each milestone and the overall quality of life adjusted years (QALYs). RESULTS: Thirty-four children were recruited, group A had 16 patients, whilst group B had 18 patients. The average ages were 16.0 years and 14.7 years for groups A and B, respectively. Group A patients reported significantly better utility compared to group B. This was observed during all stages of treatment (P = 0.00016). QALYs were better for group A (0.44) compared to group B (0.34) (P < 0.0001). CONCLUSION: The quality of life was generally better in group A compared to group B. In most patients, the health utility progressively improved throughout treatment. In the same way, QALYs were better with the lengthening nails compared to external fixators. The magnetic lengthening devices (PRECICE nails) which were used in this research were recently relabelled to restrict their applications in children; this study was conducted before these restrictions.