Radiographs of 366 removed limb-lengthening nails reveal differences in bone abnormalities between different nail types.

AIMS: Limb-lengthening nails have largely replaced external fixation in limb-lengthening and reconstructive surgery. However, the adverse events and high prevalence of radiological changes recently noted with the STRYDE lengthening nail have raised concerns about the use of internal lengthening nails. The aim of this study was to compare the prevalence of radiological bone abnormalities between STRYDE, PRECICE, and FITBONE nails prior to nail removal. METHODS: This was a retrospective case series from three centres. Patients were included if they had either of the three limb-lengthening nails (STYDE, PRECICE, or FITBONE) removed. Standard orthogonal radiographs immediately prior to nail removal were examined for bone abnormalities at the junction of the telescoping nail parts. RESULTS: In total, 306 patients (168 male, 138 female) had 366 limb-lengthening nails removed. The mean time from nail insertion to radiological evaluation was 434 days (36 to 3,015). Overall, 77% of STRYDE nails (20/26) had bone abnormalities at the interface compared with only 2% of FITBONE (4/242) and 1% of PRECICE nails (1/98; p < 0.001). Focal osteolysis in conjunction with periosteal reaction at the telescoping interface was only observed in STRYDE nails. CONCLUSION: Bone abnormalities at the interface of telescoping nail parts were seen in the majority of STRYDE nails, but only very rarely with FITBONE or PRECICE nails. We conclude that the low prevalence of radiological changes at the junctional interface of 242 FITBONE and 98 PRECICE nails at the time of nail removal does not warrant clinical concerns. Cite this article: Bone Joint J 2021;103-B(11):1731-1735.

Early results from a single centre's experience with the STRYDE nail : a cause for concern?

AIMS: The STRYDE nail is an evolution of the PRECICE Intramedullary Limb Lengthening System, with unique features regarding its composition. It is designed for load bearing throughout treatment in order to improve patient experience and outcomes and allow for simultaneous bilateral lower limb lengthening. The literature published to date is limited regarding outcomes and potential problems. We report on our early experience and raise awareness for the potential of adverse effects from this device. METHODS: This is a retrospective review of prospective data collected on all patients treated in our institution using this implant. We report the demographics, nail accuracy, reliability, consolidation index, and cases where concerning clinical and radiological findings were encountered. There were 14 STRYDE nails implanted in nine patients (three male and six female) between June 2019 and September 2020. Mean age at surgery was 33 years (14 to 65). Five patients underwent bilateral lengthening (two femoral and three tibial) and four patients unilateral femoral lengthening for multiple aetiologies. RESULTS: At the time of reporting, eight patients (13 implants) had completed lengthening. Osteolysis and periosteal reaction at the junction of the telescopic nail was evident in nine implants. Five patients experienced localized pain and swelling. Macroscopic appearances following retrieval were consistent with corrosion at the telescopic junction. Tissue histology was consistent with effects of focal metallic wear debris. CONCLUSION: From our early experience with this implant we have found the process of lengthening to be accurate and reliable with good regenerate formation and consolidation. Proposed advantages of early load bearing and the ability for bilateral lengthening are promising. We have, however, encountered concerning clinical and radiological findings in several patients. We have elected to discontinue its use to allow further investigation into the retrieved implants and patient outcomes from users internationally. Cite this article: Bone Joint J 2021;103-B(6):1168-1172.

The STRYDE limb lengthening nail is susceptible to mechanically assisted crevice corrosion: an analysis of 23 retrieved implants.

Background and purpose - We noted several adverse events in patients in whom the first version of the STRYDE limb-lengthening nail (NuVasive Specialized Orthopaedics, San Diego, CA) had been implanted. Pain, osteolysis, periosteal reactions, and cortical hypertrophy at the nail junction were noted. Here, we present the analysis of 23 retrieved STRYDE implants.Materials and methods - We undertook visual inspection of the retrieved nails and screws, mechanical evaluation of the junction, micro-CT analyses, microscopic inspection of the bushing, screws, screw holes, and separated parts of the implants. Positive material identification (PMI) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the chemical composition. The hardness of the material was also investigated.Results - 20/23 retrieved nails had visible signs of corrosion, i.e., discoloration at the telescopic junction. Micro-CT verified corrosion attacks in 12/12 scanned bushings. Corrosion, predominantly mechanically assisted crevice corrosion, was observed at the locking screws and screw holes in 20/23 nails. Biological material inside the nail was observed in addition to oozing from the junction of 2 nails during hardware removal, which was experimentally reproducible. Notably, the mechanical construction of the bushing changed from PRECICE P2 to STRYDE nails.Interpretation - STRYDE nails are not hermetically sealed, and liquid can pass the bushing. Biodur 108 itself is corrosion resistant; however, mechanically assisted crevice corrosion of the bushing, locking screws, and screw holes may be aggravated due to manufacturing aiming for increased strength and hardness of the alloy.Observing several adverse events, we recently published a nationwide cross-sectional analysis of all 30 STRYDE limb- lengthening nails (NuVasive, Specialized Orthopedics, San Diego, CA) that were implanted in Denmark (Rölfing et al. 2021a). 27/30 STRYDE nails have now been removed and we present data from metallurgical analysis of 23 of the retrieved implants.

Has the Threshold for Epiphysiodesis Versus Lengthening Changed in the Era of Magnetically Controlled Nails?

INTRODUCTION: Limb length discrepancy (LLD) is common in both the pediatric and adult population. Length inequalities can be due to a multitude of etiologies including congenital, developmental, and acquired causes. There has been little consensus on the morbidity of LLD and, as a result, the threshold necessary for treatment of LLD to prevent morbidity. Advances in magnetically controlled lengthening devices achieve greater accuracy and patient satisfaction and create an opportunity to lower the threshold for limb lengthening. DISCUSSION: Asymptomatic LLD is relatively common in both pediatric and adult populations. Only ~10% of the population has equal leg length. LLD of <5 cm may lead to long-term morbidities such as scoliosis, lower back pain, gait abnormalities, stress on hip or knee joint, and lower extremity symptomatic versus asymptomatic osteoarthritis. The teaching in most orthopaedic textbooks is to adjust the shoe if symptomatic for discrepancies up to 2 cm; consider an orthotic, epiphysiodesis, or skeletal shortening for 2.5 to 5 cm; and possible limb reconstruction for >5 cm. The assumption is that there are no long-term consequences of mild LLD. However, data in recent literature show that small discrepancies may contribute to pathologic changes such as pain, gait abnormalities, and osteoarthritis. Major advances have been made in limb lengthening over the past 40 years. The increased accuracy and superior patient satisfaction of the magnetically controlled lengthening nail versus external fixation methods argue for including lengthening for LLD of <5 cm. CONCLUSION: If mild LLD can cause long-term pathology, it is important to counsel families on the full range of options for limb equalization no matter the size of the discrepancy. The evolution in technology and understanding of limb lengthening has provided additional safe surgical options. Therefore, the historic treatment protocol for addressing limb differences may need to include lengthening for smaller discrepancies even <2 cm.

Pain, osteolysis, and periosteal reaction are associated with the STRYDE limb lengthening nail: a nationwide cross-sectional study.

Background and purpose - Observing serious adverse events during treatment with the Precice Stryde bone lengthening nail (NuVasive, San Diego, CA, USA), we conducted a nationwide cross-sectional study to report the prevalence of adverse events from all 30 bone segments in 27 patients treated in Denmark.Patients and methods - Radiographs of all bone segments were evaluated regarding radiographic changes in February 2021. We determined the number of bone segments with late onset of pain and/or radiographically confirmed osteolysis, periosteal reaction, or cortical hypertrophy in the junctional area of the nail.Results - In 30 bone segments of 27 patients we observed radiographic changes in 21/30 segments of 20/27 patients, i.e., 19/30 osteolysis, 12/30 periosteal reaction (most often multi-layered), and 12/30 cortical hypertrophy in the area of the junction between the telescoping nail parts. Late onset of pain was a prominent feature in 8 patients. This is likely to be a prodrome to the bony changes. Discoloration (potential corrosion) at the nail interface was observed in multiple removed nails. 15/30 nails were still at risk of developing complications, i.e., were not yet removed.Interpretation - All Stryde nails should be monitored at regular intervals until removal. Onset of pain at late stages of limb lengthening, i.e., consolidation of the regenerate, should warrant immediate radiographic examination regarding osteolysis, periosteal reaction, and cortical hypertrophy, which may be associated with discoloration (potential corrosion) of the nail. We recommend removal of Stryde implants as early as possible after consolidation of the regenerate.

Systematic review of complications with externally controlled motorized intramedullary bone lengthening nails (FITBONE and PRECICE) in 983 segments.

Background and purpose - In recent years motorized intramedullary lengthening nails have become increasingly popular. Complications are heterogeneously reported in small case series and therefore we made a systematic review of complications occurring in lower limb lengthening with externally controlled motorized intramedullary bone lengthening nails.Methods - We performed a systematic search in PubMed, EMBASE, and the Cochrane Library with medical subject headings: Bone Nails, Bone Lengthening, and PRECICE and FITBONE nails. Complications were graded on severity and origin.Results - The search identified 952 articles; 116 were full text screened, and 41 were included in the final analysis. 983 segments were lengthened in 782 patients (age 8-74 years). The distribution of nails was: 214 FITBONE, 747 PRECICE, 22 either FITBONE or PRECICE. Indications for lengthening were: 208 congenital shortening, 305 acquired limb shortening, 111 short stature, 158 with unidentified etiology. We identified 332 complications (34% of segments): Type I (minimal intervention) in 11% of segments; Type II (substantial change in treatment plan) in 15% of segments; Type IIIA (failure to achieve goal) in 5% of segments; and Type IIIB (new pathology or permanent sequelae) in 3% of segments. Device and bone complications were the most frequent.Interpretation - The overall risk of complications was 1 complication for every 3 segments lengthened. In 1 of every 4 segments, complications had a major impact leading to substantial change in treatment, failure to achieve lengthening goal, introduction of a new pathology, or permanent sequelae. However, as no standardized reporting method for complications exists, the true complication rates might be different.

Pediatric Lower Limb Lengthening Using the PRECICE Nail: Our Experience With 50 Cases.

BACKGROUND: Limb lengthening using intramedullary externally controlled motorized devices is becoming increasingly popular. There is limited literature regarding their use in the pediatric and adolescent population. This study reviews outcomes on 50 consecutive cases of intramedullary lower limb lengthening surgery in this population. METHODS: A retrospective review of all pediatric and adolescent patients treated in our institution by intramedullary lengthening for lower limb length discrepancy using the PRECICE and STRYDE intramedullary lengthening nails between 2013 and 2019. All patients were operated by a single surgeon. Data were prospectively recorded. We report on nail accuracy and reliability, consolidation index, time to full weight-bearing from completion of lengthening, joint range of movement, ASAMI bone and functional scores, presence of problems, obstacles and complications, and patient reported outcome measures (PROMS). RESULTS: Fifty cases (43 femoral and 7 tibial nails) were performed in 42 patients (20 males, 48% and 22 females, 52%). Six patients had bilateral lengthening and 2 patients had sequential lengthening. There were 28 antegrade femoral, 13 retrograde femoral and 5 tibia PRECICE nails, 2 tibial and 2 femoral PRECICE STRYDE nails. Mean age at surgery was 15 years old (12 to 17). Mean preoperative length discrepancy was 49 mm (20 to 90). Mean achieved lengthening was 46.5 mm (20 to 80). Mean percentage lengthening was 12.6% (5% to 25%). Nail accuracy was 96% and reliability 90%. Average distraction rate was 0.92 mm/d for femur and 0.64 mm/d for tibias. Consolidation index was 28 d/cm (18 to 43) and 39 d/cm (20 to 47), respectively. Time from completion of lengthening to independent full weight-bearing as observed in clinic was 45 days (21 to 70) and 34.2 days (23 to 50), respectively. ASAMI bone and functional scores were favorable and PROMS demonstrated high patient satisfaction levels. No significant complications were observed. CONCLUSIONS: We have demonstrated excellent clinical results and high patient satisfaction with intramedullary lengthening in a pediatric/adolescent population. We highly recommend thorough preoperative preparation, patient education, and a multidisciplinary approach. LEVEL OF EVIDENCE: Level IV.

Extracorporal noninvasive acute retraction of STRYDE® for continued lengthening in cases with limited nail stroke: a technical less invasive solution to reload the STRYDE®.

With STRYDE® nails (NuVasive Specialized Orthopedics, San Diego, CA), lengthening nails for full weight-bearing during callus distraction have been available CE-certified since February 2019 in Europe. At present only antegrade femur nails and tibia nails with various lengths and diameters are available. Due to a mismatch of bone length and realizable (implantable) nail length e.g., in cases of skeletal dysplasia or achondroplastic dwarfism, it may happen that a desired lengthening of 6-8 cm cannot be realized because of a nail stroke from only 5 cm. Retrograde usage of antegrade piriformis nails is technically possible as an individual (off label use) procedure since so far no retrograde implants are available. A new method of surgical intervention for retraction of the STRYDE nails at the end of the nail stroke with ongoing callus distraction in patients with bilateral femoral extension under anesthesia with extracorporeal use of the fast distractor device is described in detail. It is safe and with low risk for a reload of a capacity of 3-4 cm for antegrade and retrograde femoral implantation situation for the patient. The acute reload of the STRYDE nail stroke for further distraction is possible without skin incision or invasive soft tissue approaches. Application of the fast distractor extracorporeal within a few minutes is described in detail. The intervention is technically reproducible and can be performed for the proximal femur with antegrade STRYDE nails as well as for the distal femur with retrograde STRYDE nails in adult patients.

Continuous lengthening potential after four years of magnetically controlled spinal deformity correction in children with spinal muscular atrophy.

Magnetically controlled growing rods (MCGR) are commonly implanted for the treatment of early-onset scoliosis. While most authors report favorable short-term results, little is known about long-term deformity correction. This prospective cohort study assesses spinal deformity control in a homogeneous spinal muscular atrophy (SMA) patient group treated with MCGR implants, a standardized lengthening protocol and a minimum follow-up of four years. 17 SMA patients with progressive scoliosis were treated with MCGR implanted parallel to the spine with rib-to-pelvis fixation. Radiologic measurements were performed before and after MCGR implantation and during external lengthening procedures. These included measurements of the scoliotic curve, kyphosis, lordosis, pelvic obliquity and the spinal length. Additional clinical data of the complications were also analyzed. 17 children (mean age 7.4 years) were surgically treated and underwent a total of 376 lengthenings. Complication rates were 3.5% in respect to all interventions or 41% of the patients had complications during 3.5% of the lengthening sessions. The initial implantation significantly reduced the main scoliotic curve by 59%, with the correction remaining constant throughout the follow-up. Pelvic obliquity was also significantly and permanently corrected by 72%, whereas kyphosis and lordosis were not influenced. The spinal length could be significantly increased mostly during the first year of treatment. Bilateral implantation of MCGRs for correction of spinal deformity in children with SMA showed no decrease of the lengthening potential during a four-year follow-up. Therefore, the previously described 'law of diminishing returns' could not be applied to this patient population.Level of Evidence/Clinical relevance: Therapeutic Level IV.

Alargamiento óseo con clavo intramedular magnético experiencia preliminar y lecciones aprendidas / Bone lengthening with magnetic intramedullary nail preliminary experience and learned lessons

OBJETIVOS: Mostrar resultados, complicaciones y lecciones aprendidas utilizando el clavo intramedular magnético (IML, Intramedullary Magnetic Lengthener) en un grupo de pacientes sometidos a alargamiento óseo. PACIENTES Y MÉTODOS: Entre enero 2017 y diciembre 2019, 9 pacientes (15 segmentos), edad entre 15 y 39 años, fueron sometidos a alargamiento óseo con IML: 5 pacientes tuvieron alargamiento femoral bilateral por talla baja, 1 paciente se sometió a alargamiento de Piernas bilateral por Tibia vara y acortamiento mesomélico y 3 recibieron alargamientos femorales unilaterales por discrepancia de longitud de extremidades. Todos fueron operados por el mismo cirujano, con técnica standard. Se indicó kinesiterapia al menos 5 veces por semana durante la fase de distracción. RESULTADOS: En todos se logró el objetivo de alargamiento planteado. No hubo complicaciones intra ni postoperatorias graves (TVP, TEP, Embolia grasa), ni fallas del sistema distractor. Un paciente desarrolló contracturas articulares de ambas rodillas por no adhesión a Kinesiterapia. Ninguno requirió aporte de injerto óseo, sin embargo en 2 pacientes de alargamiento de Fémur bilateral, se presentó deformidad en varo, que hizo necesario recambio a clavo convencional y un paciente desarrolló una parálisis transitoria del Nervio Peroneo común. CONCLUSIONES: El advenimiento de los IML significó un gran avance en el campo de la osteogénesis por distracción, sin embargo, aún se trata de un procedimiento complejo, que debe ser planificado cuidadosamente para minimizar los riesgos y complicaciones. Una selección meticulosa del paciente y la evaluación física y psicológica previa, son fundamentales para el éxito del procedimiento. Los casos bilaterales requieren de un seguimiento cercano, por el riesgo de falla del implante.

objective: We show our results, complications and lessons learned using the Intramedullary Magnetic Lengthener (IML) in a group of patients who were subjected to bone lengthening. PATIENTS AND METHODS: Between January 2017 and December 2019, 9 patients (15 segments), aged between 15 and 39 years, underwent bone lengthening with IML: 5 patients had bilateral femoral lengthening due to short stature, 1 patient had bilateral leg lengthening due to Tibia vara and mesomelic shortening and 3 had unilateral femoral lengthening for limb length discrepancy. All were operated by the same surgeon, with standard technique. Physical therapy was indicated at least 5 times per week during the distraction phase. RESULTS: In every case, the proposed lengthening amount was achieved. There were no serious intraoperative or postoperative complications (DVT, Pulmonary Embolism, Fat Embolism), nor failures of the distractor system. One patient developed knee joint contracture due to non-adherence to Physical therapy. None required bone grafting, however, in 2 patients with bilateral Femur, a varus deformity appeared, which required nail exchange with a conventional trauma nail. One case developed a transit common Peroneal Nerve palsy. CONCLUSIONS: IMLs represent a great advance in the bone lengthening realm, however, it is still a complex procedure, which must be carefully planned to minimize risks and complications. Meticulous patient selection and prior physical and psychological evaluation are essential to the success of the procedure. Bilateral cases need a closer follow up, because implant failure is a potential risk.

Tibial lengthening using a retrograde magnetically driven intramedullary lengthening device in 10 patients with preexisting ankle and hindfoot fusion.

Background and purpose - Motorized intramedullary lengthening nails (ILNs) have been developed as an alternative to external fixators for long bone lengthening. The antegrade approach represents the standard method for tibial ILN insertion. In patients with preexisting ankle and hindfoot fusion a retrograde approach provides an alternative technique that has not been evaluated so far. We report the outcome of this method in 10 patients. Patients and methods - This retrospective study included 10 patients (mean age 18 years [13-25]) with preexisting ankle and hindfoot fusion who underwent tibial lengthening with a retrograde ILN (PRECICE). The mean leg length discrepancy (LLD) was 58 mm (36-80). The underlying conditions were congenital (n = 9) and post tumor resection (n = 1). The main outcome measures were: ILN reliability, distraction achieved, distraction index (DIX), time to bone healing, consolidation index (CIX), complications, and functional results. Results - All patients achieved the goal of lengthening (mean 48 mm [26-80]). Average DIX was 0.6 mm/day (0.5-0.7) and mean CIX was 44 days/cm (26-60). Delayed consolidation occurred in 2 patients and healed after ILN dynamization or nail exchange with grafting. Toe contractures in 2 other patients were resolved with physiotherapy or tenotomy. Until last follow-up (mean 18 months [12-30]) no true complications were encountered, knee motion remained unaffected, and full osseous consolidation occurred in all patients. Interpretation - In patients with LLD and preexisting ankle and hindfoot fusion distal tibial lengthening using a retrograde ILN is a reliable alternative to the standard approach with equivalent bone healing potential and low complication rates leaving the knee unaffected.

Thumb lengthening using a three-dimensional half-ring distraction frame.

The purpose of this study was to evaluate the use of a three-dimensional half-ring distraction frame for thumb phalangeal lengthening. From February 2009 to March 2015, 23 patients (23 thumbs) with thumb loss were treated with a half-ring distraction frame. Active movements of the metacarpophalangeal (MCP) joint were measured with a goniometer. These measurements were compared with the opposite hand. Differences were considered statistically significant at p<0.05. Clinical outcome was assessed based on the modified Mayo score. Bone union and good alignment were achieved in all patients. The mean distraction time was 44 days (range, 35-62 days). The mean time to union was 20 days (range, 49-86 days). The mean palmar and radial abduction of the thumb was 60° (range, 53°-65°) and 63° (range, 58°-70°), respectively; on the uninjured side, these measurements were 62° (range, 56°-65°) and 64° (range, 60°-73°), respectively (p>0.05). The mean extension-flexion arc of the MCP joint was 46° (range, 40°-50°); the measurement on the uninjured side was 48° (40°-54°) (p>0.05). The mean follow-up period was 51 months (4.25 years) (range, 48-65 months). The mean modified Mayo Score was 138 (range, 113-145). There were 19 excellent, 3 good, and 1 fair results. The half-ring distraction frame is a viable alternative for thumb lengthening as it provides stable, three-dimensional fixation, resulting in good hand function.

Limb lengthening history, evolution, complications and current concepts.

Limb lengthening continues to be a real challenge to both the patient and the orthopaedic surgeon. Although it is not a difficult operative problem, there is a long and exhausting postoperative commitment which can jeopardize early good results. I aim to review the history, evolution, biology, complications and current concepts of limb lengthening. Ilizarov's innovative procedure using distraction histeogenesis is the mainstay of all newly developing methods of treatment. The method of fixation is evolving rapidly from unilateral external fixator to ring fixator, computer assisted and finally lengthening intramedullary nails. The newly manufactured nails avoid many of the drawbacks of external fixation but they have their own complications. In general, the indications for limb lengthening are controversial. The indications have been extended from lower limb length inequality to upper extremity lengthening, including humeral, forearm and phalangeal lengthening. A wide range in frequency of complications is recorded in the English literature, which may reach up to 100% of cases treated. With developing experience, cosmetic lengthening has become possible using external or internal lengthening devices with an acceptable rate of problems.Level of evidence: V.

Spinal Lengthening With Magnetically Controlled Growing Rods: Data From the Largest Series of Explanted Devices.

STUDY DESIGN: Laboratory analysis of explanted MAGnetic Expansion Control (MAGEC) rods. OBJECTIVE: The aim of this study was to identify the in vivo lengthening of MAGEC rods. SUMMARY OF BACKGROUND DATA: Little data is available regarding the lengthening achieved by MAGEC rods. METHODS: Cases were identified from the largest series of independently analyzed explanted MAGEC rods. The in vivo growth of rods was determined by the distance between the first "growth mark" and the actuator. The instrumented spinal lengthening was calculated for each construct. Constructs were considered functional if all rods could lengthen with external remote controller activation and no rods were "telescoping". RESULTS: Fifty-five MAGEC constructs (99 rods) from 53 patients treated at 10 centers were included. The mean age at insertion was 8.5 years with rods implanted a mean of 35 months. Sixty rods were suitable for analysis with mean lengthening 21.7 mm, 8.9 mm/year. Of these 60 rods, three were maximally distracted. Mean instrumented spinal lengthening for 38 suitable cases was 22.1 mm, 8.4 mm/year. This was positively correlated with the duration of implantation (r = 0.34, P = 0.04) but negatively with patient age at insertion (r = -0.35, P = 0.03). The rate of instrumented spinal lengthening was negatively correlated with duration of implantation (r = -0.47, P = 0.004). Of 55 constructs, 34 were nonfunctional at time of removal with nine functional and 12 indeterminate. Functional constructs had been implanted significantly less time (20.0 vs. 39.7 months, P < 0.001) and lengthened less than those nonfunctional (12.3 mm vs. 23.3 mm, P = 0.04). CONCLUSION: This multicenter explant study represents the largest cohort managed with MAGEC rods reported. Rods are very rarely removed having fully lengthened with mean instrumented spinal growth of 22 mm over the implant's life. This may be explained by a high rate of lengthening mechanism failure in received rods after around 3 years in vivo. Our findings question the effectiveness of the MAGEC system and mandate urgent comparative clinical studies. LEVEL OF EVIDENCE: 4.

Multi-Axis Fatigue Experimentation System of Intramedullary Implants for Femur and Tibia.

Current designs of leg-lengthening implants have faced serious failures due to inadequacies in the mechanical design. The failure typically is the result of fatigue induced by a combined loading condition with axial and shear components acting in the tubular body of the implant. One of the reasons leading to the failure is improper verification testing for the design of the fatigue limit. The current test standards for pre-clinical design phases of nail implants are relatively straightforward and widely accepted yet cannot produce the three-dimensional stress state representative of the anticipated operation in a patient during the consolidation phase. This work introduces a major improvement toward a method for verifying fatigue life of tubular as well as solid implants under combined torque, axial load, and bending. The report describes a new loading fixture, a calibration method, and compares the qualification results of finite element simulation analyses and experimental measurements during cyclic loading tests. The findings state that the fixture produces controlled multi-axial loadings to study varied osteotomy locations, quasi-static strength and fatigue of intramedullary implants at an intermediate, 2 Hz, cycle rate. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:984-995, 2020.

Health-related quality of life in early-onset-scoliosis patients treated with growth-friendly implants is influenced by etiology, complication rate and ambulatory ability.

BACKGROUND: Progressive Early-Onset Scoliosis (EOS) in children may lead to surgical interventions with growth-friendly implants, which require repeated lengthening procedures in order to allow adequate growth. Quality of life was studied using the validated German version of the EOS-Questionnaire (EOSQ-24-G) in surgically treated EOS children with different lengthening modalities. METHODS: EOSQ-24-G and the KINDLR questionnaire were given to families with EOS children who had been treated by either vertical expandable prosthetic titanium rib implants and repetitive lengthening surgeries every 6 months or children who had received a magnetically expansion controlled implant, which was externally lengthened every 3 months. Results were compared according to differences between the two tests, and with possible influencing factors such as surgical method, severity of scoliosis, relative improvement of curvature, etiology, weight, age, travelling distance, complications, ambulatory ability and others. RESULTS: 56 children with an average curve angle of 69° corrected to 33° (52%; average age 5.6 yrs) answered the EOSQ-24-G and the KINDLR after an average follow-up of 3.9 years. Health-related quality of life (HRQoL) was not affected by the initial scoliosis correction, the number of surgeries or the implant type. However, there was a negative correlation with non-ambulatory status, complications during treatment and for children with a neuromuscular scoliosis. CONCLUSION: Using the validated EOSQ-24-G, no statistically significant differences were found between the group of children receiving repetitive surgeries and children with external lengthening procedures without surgery. However, results were influenced by the etiology, complication rate or ambulatory ability. LEVEL OF EVIDENCE/CLINICAL RELEVANCE: Therapeutic Level IV.

Extreme bone lengthening by bone transport with a unifocal tibial corticotomy: a case report.

BACKGROUND: Bone transport is used for the treatment of extensive limb bone defects. The application of ring or unilateral external fixators combined with single or double corticotomy are well documented; however, there are few cases adopting a single corticotomy to repair bone defects > 24 cm. CASE PRESENTATION: The present case study describes an 18-year-old male, who was involved in a traffic accident and was diagnosed with open fracture of the right tibia. The patient received emergency surgery in a local hospital and was transferred to The Second People's Hospital of Yunnan for further treatment 3 months later. The patient was diagnosed with fracture nonunion and infection following admission. Complete debridement was performed three times to control the infection. The infection was resolved after 26 days and the 24.5 cm massive tibia defect remained the biggest challenge. The bone transport technique involving a unilateral external fixator and single corticotomy was employed to treat the bone defect. Docking site union was achieved and bone consolidation was complete 40 months after corticotomy. The external fixator was subsequently removed. The bone healing index was 1.6 months/cm. The Association for the Study and Application of the Method of Ilizarov criteria (ASAMI) revealed a good functional and bone repair result. Similarly, Knee Society Score (KSS) yielded good result and the The Lower Extremity Functional Scale (LEFS) was 65. A total of 45 months after injury, the patient was able to walk painlessly without ambulatory assistive devices and resumed daily activities successfully. Eighteen months after the bone and soft tissue wound have healed, the SF-36 score was 86, and the LEFS was 70. CONCLUSION: To the best of the authors' knowledge, the present study described the longest bone defect repair performed using bone transport with single level corticotomy.

Limb lengthening with one Precice nail over its capacity.

The Precice nail is used to treat limb length discrepancies and has a low complication rate and a high patient satisfaction rate. While the Precice nail can be used for lengthening, unlike other lengthening nails, it can also be used for shortening. We report a 37-year-old female patient with a 14 cm limb length discrepancy that was treated with a new surgical technique using the shortening feature of the Precice nail. Following maximum possible lengthening using the nail and without waiting for union on the osteotomy line, the distal interlocking screws were removed, and the nail was shortened by external remote control with the help of the fixator. The distal interlocking screws were then reattached to continue lengthening. This surgical technique can be used safely and satisfactorily in cases with more shortness as we can correct the extremity length discrepancy using only one nail.

Lengthening With Monolateral External Fixation Versus Magnetically Motorized Intramedullary Nail in Congenital Femoral Deficiency.

BACKGROUND: Limb lengthening for congenital femoral deficiency (CFD) with or without fibular hemimelia can be performed with both external and internal devices. The purpose of this study is to compare clinical outcomes of femoral lengthening utilizing monolateral external fixation versus a magnetically motorized intramedullary nail in patients with CFD with or without fibular hemimelia. METHODS: This retrospective review included 62 patients with femoral lengthening, 32 patients had monolateral external fixation (group A), 30 patients had internal lengthening nail (group B). Mean age in years was 9.4±3.8 and 15.4±4.9 for groups A and B, respectively. Mean follow-up in years was 4.47±2.7 and 1.86±0.7 years for groups A and B, respectively. RESULTS: Mean lengthening achieved was 5.6±1.7 and 4.8±1.4 cm for group A and group B, respectively (P=0.052). Mean distraction index was 0.7±0.2 mm/d for group A and 0.7±0.2 mm/d for the group B (P=0.99). Mean consolidation index for group A was 29.3±12.7 and 34.8±11.2 d/cm for group B (P=0.08). Mean arc of motion before surgery and at final follow-up were similar between groups (P=0.35). Group A had significantly less range of motion at the end of distraction (P=0.0007) and at consolidation (P<0.0001). Both groups had similar rates of obstacles and complications. A significant difference between groups was found in the total problems (P<0.001) specifically with pin site/superficial infection (P<0.0001). CONCLUSIONS: The intramedullary nail had superior range of motion during the lengthening phase and at consolidation and an overall lower problem complication rate, while maintaining similar distraction and healing indices to monolateral external fixation. Internal lengthening nails represent a significant advance in technology for CFD lengthening. LEVEL OF EVIDENCE: Level IV-therapeutic.

Lower limb lengthening over an intramedullary nail: a long-term follow-up study of 28 cases.

BACKGROUND: Limb lengthening using an external fixator requires a long period of external fixation and may be associated with several complications such as axial deformity, fracture of the regenerated bone, and joint stiffness. With the goal of reducing the time of external fixation as well as some of these complications, we performed femoral or tibial lengthening over an intramedullary nail, according to Paley's technique, in 28 patients, followed up after a mean period of 8 years. MATERIALS AND METHODS: Twenty-eight patients treated for lower limb discrepancy by limb lengthening over an intramedullary nail were reviewed from 5 to 11 years after healing of regenerated bone. There were 20 femurs and 8 tibiae, with average age at surgery of 14.2 years and average length inequality of 6.1 cm for femurs and 5.3 cm for tibiae. RESULTS: The mean lengthening was 5.8 cm for femurs and 4.8 cm for tibiae. The mean period of radiographic consolidation of the regenerated bone was 6 months for femoral lengthening and 4.5 months for tibial lengthening. At follow-up, we observed 8 excellent results, 15 good results, 4 fair results, and 1 poor result, based on Paley's evaluation criteria. The main complications were one deep infection, one nonunion of the distracted segment, one breakage of the distal fiche of the external fixator, and one breakage of both distal locking screws of the intramedullary nail. DISCUSSION: We believe that limb lengthening over an intramedullary nail still represents a good method to treat limb length discrepancy because it reduces the time of external fixation, prevents axial deformities and fractures of regenerated bone, and allows early rehabilitation. The new intramedullary lengthening nails, which theoretically are the ideal device for treating limb length inequality, are still very expensive and need longer follow-up for definitive evaluation. LEVEL OF EVIDENCE: 4.