Femoral Lengthening in Children with Congenital Femoral Deficiency: A Systematic Review.

BACKGROUND: Congenital femoral deficiency (CFD) presents a significant challenge in pediatric orthopaedics, characterized by a spectrum of congenital anomalies ranging from mild femoral shortening to complete absence of the proximal femur and hip joint. This review aims at reviewing the latest concepts of femoral limb lengthening modalities in treating CFD, to explore the efficacy, complications, and long-term outcomes of various surgical techniques. METHODS: A comprehensive search of the literature was performed for clinical studies involving lengthening in patients with proximal focal femoral deficiency (PFFD) in several databases. RESULTS: We analyze the evolution of limb lengthening procedures, from the Wagner and Ilizarov methods to the latest advancements in distraction osteogenesis, and assess their role in addressing the functional needs of patients. We also analyze the possible risk factors for the occurrence of complications with each method and alternatives to avoid them. CONCLUSION: The review highlights the importance of individualized treatment plans, considering factors such as the degree of femoral deficiency and the potential for achieving a functional limb length; however, it requires a multidisciplinary approach and careful preoperative planning to optimize patient outcomes. The review underlines the need for ongoing research to refine surgical techniques and to compare them and improve the quality of life for individuals with PFFD. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.

Simultaneous correction of leg length discrepancy and angular deformity of the distal femur with retrograde Precice nails: a retrospective analysis of 45 patients.

BACKGROUND AND PURPOSE: Magnetically controlled motorized intramedullary lengthening nails (ILNs) can be employed for simultaneous correction of angular deformities of the distal femur and leg length discrepancy. This spares typical complications of external fixators but requires precise preoperative planning and exact intraoperative execution. To date, its results are insufficiently reported. We aimed to elucidate the following questions: (i) Is acute angular deformity correction and gradual femoral lengthening via a retrograde ILN a reliable and precise treatment option? (ii) What are the most common complications of treatment? METHODS: Acute angular deformity correction and subsequent gradual lengthening of the distal femur with retrograde ILN was retrospectively analyzed in 45 patients (median patient age: 15 years, interquartile range [IQR] 13-19 and median follow-up: 40 months, IQR 31-50). Outcome parameters were accuracy, precision, reliability, bone healing, and complications of treatment. RESULTS: The median distraction was 46 mm (IQR 29-49), median distraction and consolidation index 0.9 mm/day (IQR 0.7-1.0) and 29 days/cm (IQR 24-43), respectively. The median preoperative mechanical axis deviation (MAD) was 30 mm (IQR 23-39) in the varus cohort and -25 mm (IQR -29 to -15) in the valgus cohort and reduced to a mean of 8 mm (standard deviation [SD] 8) and -3 (SD 10), respectively. Accuracy, precision, and reliability of lengthening were 94%, 95% and 96%, respectively. Accuracy and precision of deformity correction were 92% and 89%, respectively. In total, 40/45 of patients achieved distraction with a difference of less than 1 cm from the initial plan and a postoperative MAD ranging from -10 mm to +15 mm. In 13/45 patients unplanned additional surgeries were conducted to achieve treatment goal with nonunion being the most frequent (4/45) and knee subluxation (3/45) the most severe complication. CONCLUSION: Acute deformity correction and subsequent lengthening of the distal femur with retrograde ILN is a reliable and accurate treatment achieving treatment goal in 89% but unplanned additional surgeries in 29% of patients should be anticipated.

Clinical evaluation of new bone formation during limb lengthening in children using ultrasound combined with superb microvascular imaging.

Aims: Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children. Methods: In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs. Results: We categorized the new bone formation into three stages: stage I (early lengthening), in which there was no obvious callus formation on radiographs and ultrasound; stage II (lengthening), in which radiographs showed low-density callus formation with uneven distribution and three sub-stages could be identified on ultrasound: in Ia punctate callus was visible; in IIb there was linear callus formation which was not yet connected and in IIc there was continuous linear callus. In stage III (healing), the bone ends had united, the periosteum was intact, and the callus had disappeared, as confirmed on radiographs, indicating healed bone. A progressive increase in the number of vertical vessels was noted in the early stages, peaking during stages IIb and IIc, followed by a gradual decline (p < 0.001). Delayed healing involved patients with a prolonged stage IIa or those who regressed to stage IIa from stages IIb or IIc during lengthening. Conclusion: We found that the formation of new bone in paediatric patients undergoing limb lengthening could be reliably evaluated using ultrasound when combined with the radiological findings. This combination enabled an improved assessment of the prognosis, and adjustments to the lengthening protocol. While SMI offered additional insights into angiogenesis within the new bone, its role primarily contributed to the understanding of the microvascular environment rather than directly informing adjustments of treatment.

Aquatic therapy in congenital malformation during the use of external fixator for bone lengthening: It is possible?

OBJECTIVES: The objective of this study is to describe the rehabilitation of individuals with Congenital Malformations (CMF) during the use of an External Fixator (EF) in Aquatic Therapy (AT) and to analyze the association between diagnosis, EF type and location with rehabilitation process outcomes, surgical intervention, and adverse effects. METHODS: This retrospective study included 29 medical records from which the personal and rehabilitation data of the patient were collected. The AT used was described and the outcome variables were associated. The medical records were selected by screening the database of the CMF clinic at the AACD. The inclusion criteria were participants with CMF who used EF treated between 2011 and 2019 of both genders and without age restriction. The exclusion criteria were incomplete medical record data or not undergoing AT while using EF. The extracted data included diagnosis, gender, age, EF type and location, objective of the surgery, adverse events, surgical interventions, time of rehabilitation in AT, physiotherapeutic objectives, and rehabilitation process outcomes in AT. RESULTS: The mean age of the participants was 12.1 ± 3.99 years, with male predominance (55 %) and hemimelia cases (37 %). The most used EF was circular (51 %), located in the femur (37 %), and the main objective of surgery was bone lengthening (52 %). The most recurrent adverse effect was infection (62 %) and 76 % completed AT. There was no association between the variables analyzed. CONCLUSIONS: It was possible to describe CMF rehabilitation with EF in AT. There was no association between the variables analyzed.

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

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

Comparing Relative Value Units for Intramedullary Limb Lengthening Procedures to Common Pediatric Orthopaedic Surgeries to Determine Adequate Compensation.

OBJECTIVE: Reimbursement for surgical procedures is determined by a computation of the relative value unit (RVU) associated with CPT codes. It is based on the amount of work required to provide a service, resources available, and level of expertise involved. Given the evolution of changes in the limb lengthening field, we wanted to evaluate whether the RVU values were comparable across different orthopaedic subspecialties. Consequently, this study compares the work relative value unit (wRVU) totals of 3 common pediatric orthopaedic surgeries-arthroscopic ACL reconstruction, spinal fusion for adolescent idiopathic scoliosis, and antegrade femoral intramedullary limb lengthening. METHODS: This was an IRB-approved, multicenter, retrospective chart review. Charts of subjects who had ACL reconstructions, including meniscal repairs; spinal fusion surgeries for adolescent idiopathic scoliosis (7 to 12 levels), including Ponte osteotomies, and femoral antegrade internal limb lengthening procedures, each completed by fellowship-trained orthopaedic surgeons were reviewed. Comparisons were carried out between several parameters, including mean duration per procedure, number of CPT codes billed per procedure, number of postoperative visits in the 90-day global period, and the wRVU for each procedure. RESULTS: Fifty charts (25 per center) per procedure were reviewed. The wRVU per hour was lowest in the antegrade femur lengthening group ( P < 0.0001). The number of postoperative visits in the 90-day global postsurgery period was significantly higher in the antegrade femur lengthening group ( P < 0.0001). Intramedullary limb lengthening also had the least number of CPT codes billed. CONCLUSIONS: RVUs per time are statistically lowest in the limb lengthening group and highest in the scoliosis group. The limb lengthening patient also requires significantly more visits and time in the postoperative period compared with the other groups. These extra visits during the global period do not add any RVU value to the lengthening surgeon and occupy clinic spots that could be filled with new patients. Based on these data, a review of the RVU values assigned to the limb lengthening codes may be necessary. LEVEL OF EVIDENCE: Level III-retrospective comparison study.

Fibular hemimelia: reconstruction of difficult cases with tibial lengthening and ankle arthrodesis.

PURPOSE: Management of fibular hemimelia includes either prosthetic care with or without a suitable amputation or tibial lengthening. Many studies have documented the success of both procedures. Most parents of these children refuse an amputation or have no access to good prosthetic care. The author presents a limb-salvage procedure with tibial lengthening and ankle stabilization. METHODS: Twelve children of fibular hemimelia with 14 extremities had been subjected to limb lengthening after lateral leg release. To correct the valgus procurvatum, double oblique diaphyseal osteotomy (DODO) of the tibia was performed in 11 extremities. The age of the patients ranged from two to 15 years with the median of five years. All were male. The proposed procedure included three stages of loosening, lengthening, and stabilization with ankle arthrodesis at a later stage. RESULTS: All patients returned for follow-up for the first four years and had been walking on their sensate feet. With DODO followed by fixator/traction could straighten and lengthen the tibia simultaneously and correct the valgus procurvatum. Ankle stabilization provided stability and a plantigrade foot. A follow-up of six to 30 years with a median of ten years has been reported. CONCLUSION: A new procedure of loosening, lengthening, and stabilization of the leg with ankle arthrodesis has been proposed. A follow-up of 30 years with a median of ten years of the said procedure has been reported. The procedure provides a long-lasting plantigrade and painless foot that has sensation and proprioception. An amputation at any level has not been recommended.

Lengthening in congenital posteromedial bowing of tibia: a follow-up series at skeletal maturity.

PURPOSE: Congenital posteromedial bowing (CPMB) of tibia is a rare, usually self-resolving condition that is present at birth. The data on the long-term outcome of lengthening, choice of fixator, outcome in early and late age groups, and complications is sparse, hence the need for this study. METHODS: This retrospective study included 93 patients with 94 affected legs from 1991 to 2023. The patients were categorized into early (under 10 years) and late (10 years or above) intervention groups. Eighteen patients with nineteen lengthening episodes who attained skeletal maturity made the basis of this study and will be discussed in detail. RESULTS: The outcome for the lengthening group at maturity was satisfactory, with 5.53 cm of average length gained per lengthening episode, a mean LLD of 0.31 cm at final follow-up, a mean age of 23.63 years (range 14-38 years), and an average follow-up of 12.51 years (range 3-28 years) post-lengthening, but the procedure was associated with difficulties like ankle stiffness, tibial valgus, pin tract infections, and fractures through regenerate. CONCLUSION: This study represents a large single-centre series on CPMB. We recommend that surgery for lengthening should be done at an older age, close to skeletal maturity, wherever possible to reduce the risk of repeat lengthening procedures. Based on our experience, we recommend the use of a circular fixator. Uniplanar distractors should have an adequate number and spread of Schanz screws in each segment to reduce the risk of valgus malalignment of distracting segments of bone.

Preliminary Results of Calcaneal Lengthening Osteotomy Combined With Extra-articular Subtalar Arthrodesis for Severe Pes Planovalgus Deformity in Children With Cerebral Palsy: A New Surgical Technique.

OBJECTIVE: Pes planovalgus is the most common foot deformity seen in patients with cerebral palsy (CP). There are several different treatment modalities to treat this condition. Single or double calcaneal osteotomies, extra-articular arthrodesis, calcaneo-cuboido-cuneiform osteotomy, intraarticular arthrodesis, and arthroereisis are some of these modalities. Currently, there is insufficient information to determine the most effective treatment approach for pes planovalgus in children with CP. The aim of this study is to show the short to mid-term results of the new technique which combines calcaneus lengthening osteotomy, extra-articular subtalar arthrodesis, and soft tissue reconstruction that aims to decrease recurrence and complication rates of pes planovalgus surgery for patients with ambulatory CP. METHODS: Patients with CP who were treated with calcaneal lengthening surgery and extra-articular subtalar arthrodesis between 2018 and 2021 were investigated retrospectively. All patients were ambulatory and Gross Motor Function Classification System I-II-III. Functional levels of the patients were assessed with the American Orthopaedic Foot and Ankle Society, Ankle-Hindfoot Score, and the Foot and Ankle Ability Score (Foot and Ankle Ability Measure) in preoperative and postoperative periods. On anteroposterior x-rays, talus-first metatarsal, talocalcaneal, talonavicular coverage angle and on lateral x-rays talus-first metatarsal, talocalcaneal, calcaneal inclination angle and talar tilt angle were evaluated. RESULTS: The mean follow-up was 46 (range: 36 to 60) months. The mean American Orthopaedic Foot and Ankle Society increased from 41 (20 to 79) to 74 (38 to 93; P < 0.001). The mean Foot and Ankle Ability Measure increased significantly from 35 (7 to 73) to 54 (29 to 96; P <0.001). Clinical results were "satisfactory" for 32 feet, while they were "unsatisfactory" for 2 feet. Significant deformity correction was observed in all radiologic parameters. CONCLUSION: Our technique is found to be efficient for patients with Gross Motor Function Classification System I-II-III CP with pes planovalgus deformity. In short to mid-term follow-up, the technique achieved successful clinical and radiologic results with low complication rates. Superiority of this technique compared with the traditional ones can only be shown with randomized prospective studies. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Metatarsal lengthening by distraction osteogenesis for brachymetatarsia in paediatric patients: is it safe and effective?

PURPOSE: The primary aim is to assess the efficacy of the surgical callus distraction technique of the metatarsus in paediatric patients. Secondary objectives are to assess complications and treatment duration. We have also described the details of our surgical technique. MATERIALS AND METHODS: A case series review of paediatric patients who had metatarsal lengthening at our unit between 2014 and 2022. Patient demographics, duration of time in frame, complications and metatarsal length achieved were recorded. The AOFAS Midfoot and the MOXFQ were taken pre-operatively and at final follow-up. RESULTS: Sixteen metatarsals in 8 patients (14 feet) underwent lengthening between 2014 and 2022 using the MiniRail OrthoFix 100 (Orthofix Medical Inc, Lewisville, TX, USA). The mean age was 13.3 (12-17) years. The average duration between surgery and implant removal was 5.2 months. According to Paley's classification, there was one obstacle encountered in a patient who required a revision of their osteotomy and one problem in another patient who had an infected metatarsophalangeal joint stabilising k-wire treated with oral antibiotics. The Mean AOFAS Midfoot score improved from 53.10 to 86.40 (p < 0.0001) and the Mean MOXFQ improved from 32.5000 to 12.1250 (p < 0.05); these were statistically significant. CONCLUSION: Gradual metatarsal lengthening using the MiniRail external fixator is a safe and effective method to treat brachymetatarsia in paediatric patients. This preliminary report describes and supports metatarsal lengthening in appropriate patients. Holistic care in terms of a pre-operative assessment, psychological support and preparation for the extended rehabilitation period are vital.

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

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

Distraction osteogenesis in combined sequential use of external fixation and nailing (lengthening and then nailing): An experimental study in rabbits.

Limb lengthening relies on the process of distraction osteogenesis. The active periosteal bone formation has been detected in clinical practice with a lengthening and then nail (LATN) technique but has not been confirmed by experimental studies to date. The aim of this study is to compare the tissue regeneration of the distraction regenerate during tibial lengthening in rabbits using a LATN technique. This study was performed on 54 mature rabbits of the Soviet Chinchilla breed, which were divided into three groups of 18 animals. In group 1 (control), the tibia was lengthened in an external fixator. In group 2, the LATN technique was modeled and in group 3, lengthening over nail (LON) was modeled. The total duration of the experiment was 45 days. On the 10th, 15th, 20th, 30th, and 45th day X-ray, computed tomography and morphological studies were performed. In the experimental groups (2 and 3), a more pronounced periosteal bone formation in the area of regenerate was noted when compared to group 1. In group 2 (LATN), wide cortical plates were formed from the intermediate and periosteal areas. In this group, the maximum densitometric density values were noted. Endosteal bone formation was preserved in all groups. The LON and LATN techniques, when compared with the classical Ilizarov lengthening, do not demonstrate any deficiency in the tissue regeneration of the bone tissue at the regenerate sites. The most powerful bone structures are formed with the sequential use of the external fixation and nailing (LATN).

Passive Eversion Assessment for Progressive Collapsing Foot Deformity After Lateral Column Lengthening: A Cadaveric Biomechanical Study.

BACKGROUND: Reduced hindfoot eversion motion has been proposed as a cause of increased lateral foot pressure following lateral column lengthening (LCL) for progressive collapsing foot deformity (PCFD). A subjective intraoperative assessment of passive eversion has been suggested to help evaluate correction; however, it is unclear how passive eversion correlates with objective measurements of foot stiffness. Our objectives were to quantify the relationship between the maximum passive eversion in hindfoot joints following LCL with plantar pressure during stance and to determine the influence of wedge size on these outcomes. METHODS: Ten cadaveric specimens extending from the mid-tibia distally were tested on a 6-degrees-of-freedom robot to simulate the stance phase of level walking. Five conditions were tested: intact, simulated PCFD, and 3 LCL wedge conditions (4, 6, and 8 mm). Outcomes included the lateral-to-medial forefoot plantar pressure (LM) ratio during stance and the maximum passive eversion measured in the hindfoot joints. Simple linear regressions were performed to evaluate relationships between outcomes and wedge sizes. RESULTS: A strong negative relationship was found between passive subtalar eversion and the LM ratio during stance (r[38] = -0.46; p = 0.0007), but not between passive talonavicular eversion and the LM ratio (r[38] = -0.02; p = 0.37). Wedge size was strongly related to subtalar eversion (r[38] = -0.77; p < 0.0001), talonavicular eversion (r[38] = -0.55; p = 0.0003), and the LM ratio (r[38] = 0.70; p < 0.0001). Increased wedge size resulted in average decreases in subtalar and talonavicular eversion of 1.0° (95% confidence interval [CI]: 0.8° to 1.3°) and 1.2° (95% CI: 0.6° to 1.6°), respectively. Increased wedge size also increased the LM ratio by 0.38 (95% CI: 0.25 to 0.50), indicating a lateral shift in plantar pressure. CONCLUSIONS: Decreased hindfoot eversion following LCL was related to increased lateral plantar pressure during stance. Increasing wedge size correlated with decreasing passive hindfoot eversion and increasing lateral plantar pressure, suggesting that intraoperative preservation of eversion motion may be important for preventing excessive lateral loading. CLINICAL RELEVANCE: To avoid overcorrection or undercorrection of the deformity, hindfoot eversion assessment in addition to radiographic evaluation may be important for optimizing the amount of lengthening to achieve successful LCL.

Conventional vs Augmented Reality-Guided Lateral Calcaneal Lengthening Simulated in a Foot Bone Model.

BACKGROUND: Acquired adult flatfoot deformity (AAFD) results in a loss of the medial longitudinal arch of the foot and dysfunction of the posteromedial soft tissues. Hintermann osteotomy (H-O) is often used to treat stage II AAFD. The procedure is challenging because of variations in the subtalar facets and limited intraoperative visibility. We aimed to assess the impact of augmented reality (AR) guidance on surgical accuracy and the facet violation rate. METHODS: Sixty AR-guided and 60 conventional osteotomies were performed on foot bone models. For AR osteotomies, the ideal osteotomy plane was uploaded to a Microsoft HoloLens 1 headset and carried out in strict accordance with the superimposed holographic plane. The conventional osteotomies were performed relying solely on the anatomy of the calcaneal lateral column. The rate and severity of facet joint violation was measured, as well as accuracy of entry and exit points. The results were compared across AR-guided and conventional osteotomies, and between experienced and inexperienced surgeons. RESULTS: Experienced surgeons showed significantly greater accuracy for the osteotomy entry point using AR, with the mean deviation of 1.6 ± 0.9 mm (95% CI 1.26, 1.93) compared to 2.3 ± 1.3 mm (95% CI 1.87, 2.79) in the conventional method (P = .035). The inexperienced had improved accuracy, although not statistically significant (P = .064), with the mean deviation of 2.0 ± 1.5 mm (95% CI 1.47, 2.55) using AR compared with 2.7 ± 1.6 mm (95% CI 2.18, 3.32) in the conventional method. AR helped the experienced surgeons avoid full violation of the posterior facet (P = .011). Inexperienced surgeons had a higher rate of middle and posterior facet injury with both methods (P = .005 and .021). CONCLUSION: Application of AR guidance during H-O was associated with improved accuracy for experienced surgeons, demonstrated by a better accuracy of the osteotomy entry point. More crucially, AR guidance prevented full violation of the posterior facet in the experienced group. Further research is needed to address limitations and test this technology on cadaver feet. Ultimately, the use of AR in surgery has the potential to improve patient and surgeon safety while minimizing radiation exposure. CLINICAL RELEVANCE: Subtalar facet injury during lateral column lengthening osteotomy represents a real problem in clinical orthopaedic practice. Because of limited intraoperative visibility and variable anatomy, it is hard to resolve this issue with conventional means. This study suggests the potential of augmented reality to improve the osteotomy accuracy.

A modified lateral column lengthening for the treatment of flexible flatfoot: From clinical applications to finite element analysis.

BACKGROUND: Finite element (FE) analysis and clinical follow-up were used to evaluate the efficacy of a modified lateral column lengthening (H-LCL) for treating flexible flatfoot. METHODS: By applying inclusion and exclusion criteria, we selected patients who underwent H-LCL surgery at our institution from January 2019 to January 2023. We compared the Visual Analog Scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Pain Interference (PI), and Physical Function (PF) scores in Patient-Reported Outcomes Measurement Information System (PROMIS) between preoperative and final follow-up assessments of patients, as well as FE submodels. Furthermore, evaluate the H-LCL's biomechanical characteristics and clinical outcome before and after surgery. RESULTS: A total of 66 patients met the criteria. The average surgery time was 69.47 ± 13.22 min, and the follow-up duration was 15.18 ± 6.40 months. In the last follow-up, VAS and PI decreased compared to before surgery, while AOFAS and PF increased compared to before surgery. Meary's angle (dorsoplantar image and lateral image), calcaneal valgus angle, and talonavicular coverage angle decreased compared to before surgery, while the pitch angle increased compared to before surgery. In FE analysis, postoperative tension on the plantar fascia (PF), spring ligament (SL), and posterior tibial tendon (PTT) decreased compared to before surgery, pressure on the talonavicular joint and subtalar joints also decreased compared to before surgery, and there was no significant change in pressure on the calcaneocuboid joint. CONCLUSION: H-LCL in correcting flexible flatfoot resulted in a significant improvement of clinical outcome scores and led to good radiological correction of flatfoot deformities. It can reduce the soft tissue and interosseous pressure in maintaining the foot arch.

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.