National Trends in Inpatient Hospital Outcomes of Children with Osteogenesis Imperfecta and the Importance of Extraskeletal Manifestations: A Kids' Inpatient Database Study.

OBJECTIVE: To investigate the extent of extraskeletal manifestations along with inpatient outcomes and complications associated with osteogenesis imperfecta (OI). STUDY DESIGN: This cross-sectional study utilized the Kids' Inpatient Database as a part of the Healthcare Cost and Utilization Project to investigate inpatient hospital outcomes and management in patients with OI from 1997 through 2016. Data regarding hospital characteristics, cost of treatment, inpatient outcomes, and procedures were collected and analyzed. RESULTS: There were 7291 admissions that listed OI as a diagnosis in the Kids' Inpatient Database from 1997 through 2016. Unexpectedly, more than one-third of all admissions in these children with OI presented with an extraskeletal manifestation. The rate of major complications was 3.85%. The rate of minor complications was 19.4%, most commonly respiratory problems. The mortality rate was 18.2% in the neonatal period and 1.0% in all other admissions. Total charges of hospital stay increased over the years. CONCLUSIONS: We identified a striking prevalence of extraskeletal manifestations in OI along with inpatient outcomes and complications associated with OI, of which respiratory complications were predominant. We observed a significant financial burden for patients with OI and identified additional risks for financial crisis, in addition to disparities in care identified among socioeconomic groups. These data contribute to a more holistic understanding of OI from diagnosis to management.

Health-related quality of life in 205 children with arthrogryposis multiplex congenita.

PURPOSE: Arthrogryposis multiplex congenita (AMC) describes a heterogeneous group of rare congenital conditions. Health-related quality of life (HRQL) may be reduced in AMC due to broadly heterogeneous physical impairments and participation limitations. This study described HRQL in children and youth with AMC, compared HRQL between child self- and parent-proxy reports, and identified factors associated with better/worse HRQL. METHODS: Data on 205 children with AMC (age 8-21 years) from a North American AMC registry across eight hospital sites was used. HRQL was assessed cross-sectionally using the Patient Reported Outcome Measurement Information System (PROMIS) and European Quality of Life-5 Dimensions-Youth-3 Levels (EQ-5D-Y-3 L) by self-report, parent proxy-report or both. RESULTS: Mean child-reported PROMIS T-scores were significantly lower than the normal mean for the Upper Extremity (mean = 33.0) and Mobility (mean = 37.2) but in the normal range for Pain Interference (mean = 46.6) and Peer Relationships (mean = 51.7). A lot of problems in EQ-5D-Y-3 L was reported by 37% in Feeling Worried/ Sad/ Unhappy, 46% in Having Pain/Discomfort, 50% in Doing Usual Activities, 56% in Mobility, and 57% in Looking After Myself. Compared to child-report, parents reported significantly worse PROMIS T-scores and higher problems in EQ-5D domains. Wheelchair use, being small for gestational age, prolonged hospitalization after birth, increased number of orthopedic surgeries, and caregiver's stress were associated with lower HRQL scores. CONCLUSION: Findings indicate the importance of considering both the child's and parents' reports of HRQL, and to provide multimodal interventions that focus on the effect of childhood and parental characteristics to promote HRQL among children with AMC.

Our study describes health aspects of quality of life (HRQL) in a large sample of children with arthrogryposis multiplex congenita (AMC). Information on HRQL is crucial for clinicians treating AMC to improve treatment outcomes, and for individuals with AMC and their families to understand various aspects of life in AMC. Our results showed that most children with AMC have mild to moderate problems in mobility (e.g., getting around, walking), self-care (e.g., taking shower), and doing usual activities. We found that the parents tend to perceive worsened HRQL for the child with AMC. Our findings also showed that children who had low birthweight for gestational age, were hospitalized for prolonged periods as an infant, had multiple orthopedic surgeries, and use a wheelchair are more likely to have lower HRQL. Children who have a parent who expressed high caretaking stress tend to have lower mobility and physical functioning. Our findings will help develop more personalized care plans for children with AMC considering various individual and familial characteristics.

Talectomy for arthrogrypotic foot deformities: A systematic review.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is one of the most common congenital joint contracture syndromes. Talectomy has been proposed for severe foot deformities in AMC, but the literature is limited. The purpose of this systematic review is to evaluate the indications, outcomes and complications of talectomy in arthrogrypotic foot deformities. METHODS: The articles were found through Embase and Medline. Screening was conducted by two independent investigators with disagreements resolved by a third reviewer. Relevant data regarding demographics, outcomes and complications were collected. RESULTS: Of 232 feet, 71.98 % and 62.22 % had clinical and radiographic improvements respectively. Amongst 122 patients, 92.62 % could ambulate following surgery. Recurrent deformities and revision surgery were seen in 16.81 % and 13.36 % of cases respectively. CONCLUSIONS: Talectomy is a valid surgical option for severe arthrogrypotic foot deformities with favorable post-operative outcomes and low complication rate.

Retrograde Application of Humerus Fassier-Duval Rod in Osteogenesis Imperfecta: A New Surgical Technique.

BACKGROUND: The aim of this study is to describe the technique of retrograde application of Fassier-Duval (FD) rod for the humerus in patients with osteogenesis imperfecta (OI). This technique was developed to overcome the downsides of the previously used techniques of humerus rodding. METHODS: The study was done at a tertiary care pediatric orthopaedic hospital from April 2014 to August 2021. Skeletally immature patients with OI who underwent retrograde FD rodding were included. This surgery was performed for humeral shaft fractures/bowing limited to the distal half of the bone to ensure appropriate stability of the fixation. Surgical technique of the procedure is described in detail. RESULTS: Six patients with OI, of which 2 (33.3%) had FD rodding bilaterally, were included. The mean age at rodding was 7.6±3.5 (range: 3 to 14) years. The mean duration of postoperative follow-up was 45.5±18.0 (range: 24 to 75) months. All patients had full healing of the fracture/osteotomy, with functional alignment of their humeri. No surgical complications were observed; however, 1 (12.5%) segment only had a traumatic humerus fracture following a fall that was associated with rod migration, occurring 60 months postoperatively. This was treated with a retrograde FD rodding again, with fracture augmentation with plate and screws. CONCLUSIONS: The retrograde FD rodding technique of the humerus in OI patients is relatively simple and preserves the soft tissue surrounding the shoulder joint, with favorable outcomes. Studies with larger sample size and long-term follow-up duration are needed. LEVEL OF EVIDENCE: Level IV-case series.

Research platform for children with arthrogryposis multiplex congenita: Findings from the pilot registry.

A pediatric registry for arthrogryposis multiplex congenita (AMC) proposes to advance research by providing the platform to inform the distribution, etiology, and natural history of AMC. The registry was piloted on 40 families of children (mean = 8.25 years, 48% males) presenting with AMC across two hospitals in North America. Data on the child's demographic and newborn variables, mothers' and fathers' demographic variables, lifestyle habits, and medical history were collected using a telephone interview with the primary caregiver and review of medical charts. Mean gestational age was 38 weeks, 97% of children presented with lower extremity deformities, and 74% of neonatal interventions targeted the lower extremity. Newborns spent an average of 14 days in the hospital (range 2-56 days) mostly for diagnostic workup and feeding difficulties. Half (49%) of the sample had internal organ involvement. Genetic testing was done on 48% of the children, including chromosome studies, single gene, whole-exome/genome sequencing, and/or microarray studies. Genetic findings were inconclusive in most. Two-thirds of mothers (67%) reported inconsistently feeling fetal movements. This pilot study contributed to the refinement of participant selection, identification of data source, expansion of data sets, and areas for future exploration prior to the implementation of a multisite AMC pediatric registry.

Treatment and outcomes of arthrogryposis in the lower extremity.

In this multiauthored article, the management of lower limb deformities in children with arthrogryposis (specifically Amyoplasia) is discussed. Separate sections address various hip, knee, foot, and ankle issues as well as orthotic treatment and functional outcomes. The importance of very early and aggressive management of these deformities in the form of intensive physiotherapy (with its various modalities) and bracing is emphasized. Surgical techniques commonly used in the management of these conditions are outlined. The central role of a multidisciplinary approach involving all stakeholders, especially the families, is also discussed. Furthermore, the key role of functional outcome tools, specifically patient reported outcomes, in the continuous monitoring and evaluation of these deformities is addressed. Children with arthrogryposis present multiple problems that necessitate a multidisciplinary approach. Specific guidelines are necessary in order to inform patients, families, and health care givers on the best approach to address these complex conditions.

Strategies of enhancing bone regenerate formation in distraction osteogenesis.

Distraction osteogenesis (DO) is a commonly used technique in multiple orthopedic sub-specialties, including trauma, oncology and pediatrics. This technique aims to produce new bone formation in the distraction gap in a controlled manner. The issue with this technique has been the high risk of complications, one of which is poor regenerate formation during the distraction process. Although several factors (including patient and operative factors) and techniques (including surgical, mechanical and pharmacological) have been described to ensure successful regenerate formation during the process of DO, these factors are sometimes difficult to control clinically. Our aim from this review is to highlight the different factors that affect DO, modalities to assess the regenerate and review treatment options for poor regenerate in the distraction gap. In addition, we propose a management protocol derived from the available literature that can be used to facilitate the management of inadequate regenerate formation.

Assessment of the effect of systemic delivery of sclerostin antibodies on Wnt signaling in distraction osteogenesis.

Sclerostin is a known inhibitor of the Wnt signaling pathway which is involved in osteogenesis and, when inactivated, stimulates bone formation. To our knowledge, this effect has not been studied in the context of distraction osteogenesis (DO). Tibial DO was conducted on a total of 24 wild-type mice, which were then divided into 2 groups-a saline injection group (control) and an anti-sclerostin (Scl-Ab) injection group (treatment). The mice in the treatment group received 100 mg/kg intravenous injections of the antibody weekly until killing. The 12 mice in each group were subdivided into four time points according to post-osteotomy time of killing-11 days (mid-distraction), 17 days (late distraction), 34 days (mid-consolidation) and 51 days (late consolidation), with 3 mice per subgroup. After killing, the tibia specimens were collected for immunohistochemical analysis. Our results show that the group injected with anti-sclerostin had an earlier peak (day 11) in the distraction phase of the osteogenic molecules involved in the Wnt signaling pathway in comparison to the placebo group. In addition, downregulation of the inhibitors of this pathway was noted in the treatment group when compared with the placebo group. Furthermore, LRP-5 showed a significant increase in expression in the treatment group. Sclerostin inhibition has a significant effect on the DO process through its effect on the Wnt pathway. This effect was evident through the decreased effect of sclerostin on LRP-5 and earlier upregulation of the osteogenic molecules involved in this pathway.

Functional Outcome of Forearm Rodding in Children With Osteogenesis Imperfecta.

BACKGROUND: The impact of corrective forearm surgery on functional ability in children with osteogenesis imperfecta (OI) has not previously been reported. This study addresses this issue. METHODS: A retrospective chart review was conducted on 19 children with OI who underwent 22 corrective forearm procedures between 1996 and 2013. Functional ability was assessed preoperatively and every year postoperatively using the Pediatric Evaluation of Disability Inventory (PEDI). RESULTS: The mean PEDI self-care score increased by 6.8 (P=0.017) and the mean PEDI mobility score increased by 7.2 (P=0.020) at 1-year postsurgery. Functional gains were greater in moderate OI (types IV, V, and VI) than in severe OI (type III). Improved function was maintained in the majority of cases at a mean of 8.9 years postcorrection. CONCLUSIONS: Corrective forearm surgery in children with OI leads to improved functional ability. LEVEL OF EVIDENCE: Level IV.

Functional Outcome of Humeral Rodding in Children With Osteogenesis Imperfecta.

BACKGROUND: The impact of humeral rodding on functional ability in children with osteogenesis imperfecta (OI) has not previously been reported. This article investigates this issue. METHODS: A retrospective chart review was conducted on 35 children with OI who underwent humeral rodding at our institution between 1995 and 2013. Fassier-Duval rods were inserted in 19 cases, K-wires in 13 cases, and Rush rods in 3 cases. Functional ability was assessed preoperatively and every year postoperatively using the self-care and mobility domains of the Pediatric Evaluation of Disability Inventory (PEDI). RESULTS: The mean PEDI self-care score increased by 5.7 (P=0.028) and the mean PEDI mobility score increased by 3.6 (P=0.008) at 1-year postsurgery. Improved function was maintained in the majority of cases at a mean of 7.0 years postcorrection. CONCLUSIONS: Humeral rodding in children with OI leads to significant improvement in functional ability. LEVEL OF EVIDENCE: Level IV.

Incidence of knee height asymmetry in a paediatric population of corrected leg length discrepancy: a retrospective chart review study.

PURPOSE: The purpose of the study is to provide a methodology to quantify knee height asymmetry (KHA) and to establish the incidence of knee height asymmetry in a patient population visiting the limb length discrepancy clinic in a paediatric-orthopaedic hospital centre. METHOD: A retrospective chart review was performed on all patients who attended the limb length discrepancy clinic and underwent corrective surgery at the Shriners Hospital for Children-Canada from December 2009 to December 2015. Full-standing anteroposterior radiographs were used to measure pre- and post-surgery limb length discrepancy and knee height asymmetry for 52 individuals included in the study. RESULTS: Sixty-seven percent of the studied population had a KHA of 20 mm or less, 25% had a KHA between 20 and 40 mm, and 8% had a KHA of over 40 mm. The average KHA preoperatively for all 52 individuals was 17 ± 14 mm (range 0-59 mm), which represents roughly 2.5% of total limb length. There was a 3-mm non-significant reduction in KHA size between pre-and post-operative states (p = 0.22). CONCLUSION: The current study provides a method to quantify knee height asymmetry. Using this method, it was shown that knee height asymmetry is frequent in youth with limb length discrepancy in both pre- and post-corrective surgery states. The relatively high incidence of knee height asymmetry highlights the importance to investigate the impact of knee height asymmetry in youth living with a limb length discrepancy.

Utility outcome assessment of pes planus deformity.

BACKGROUND: Despite being a common condition, there are no objective measures in the literature to reflect the burden of pes planus on affected individuals. Our primary objective was to evaluate this burden by recruiting a sample from the general population using validated utility outcome measures. METHODS: Participants were recruited online and filled a questionnaire to help measure the health burden of pes planus. Three recognized utility outcome scores were used to compare the health burden of monocular blindness, binocular blindness, and pes planus. These included the standard gamble (SG), time trade-off (TTO), and visual analogue score (VAS). Paired t test, independent t test, and linear regression were used for statistical analysis. RESULTS: Ninety-two participants were included in the final analysis. The utility outcome scores (VAS, TTO, SG) for pes planus were 73±17, 0.90±0.08, and 0.88±0.12, respectively. The linear regression analysis showed that age was inversely proportional to the time trade-off. However, race, educational level, and income were not significant predictors of utility outcome score for pes planus. CONCLUSIONS: This study shows that the perceived burden of living with pes planus is comparable to living with some debilitating conditions. Our participants were willing to sacrifice 3.6 years of life, and have a procedure with a theoretical 12% mortality risk to attain perfect health.

Does Sclerostin Depletion Stimulate Fracture Healing in a Mouse Model?

BACKGROUND: Sclerostin is a secreted glycoprotein that inhibits the intracellular Wnt signaling pathway, which, when inactivated, stimulates bone formation. This has been seen in fracture studies, which have shown larger and stronger calluses with accelerated fracture healing in sclerostin knockout and sclerostin antibody injection models. However, the effects of these two mechanisms have not been compared in the context of fracture healing. QUESTIONS/PURPOSES: We sought to determine the degree to which sclerostin inhibition (Scl-Ab injection) and complete sclerostin depletion inhibit fracture healing in a mouse model as evaluated by (1) morphometric trabecular bone measures at the fracture site, and (2) fracture site structural strength. METHODS: Ten-week-old male sclerostin knockout (n = 20) and wild type (n = 40) mice underwent insertion of a tibial intramedullary pin after which a midshaft tibial osteotomy was performed. The mice were divided in three groups: sclerostin knockout (n = 20), wild type with sclerostin antibody injection (intravenous dose of 100 mg/kg weekly) (n = 20), and wild type with saline injection (n = 20). The mice for each group where subdivided and euthanized at 14, 21, 28, and 35 days after surgery, at which time the fractured tibias were assessed with microCT (to assess morphometric trabecular bone measures: bone volume to total volume (BV/TV), trabecular thickness, trabecular number, and structural model index at the fracture site. Biomechanical testing in the form of three-point bending also was done to assess fracture site structural strength. A difference greater than 3.7% in our primary outcome (BV/TV) would be required to detect a difference between groups with a power of 80%, as per our power analysis. RESULTS: The wild type with sclerostin antibody and the sclerostin knockout groups showed increased trabecular BV/TV at the fracture site compared with the wild type group with saline at all times, however no difference was seen between the treatment groups with the numbers available, except at 28 days postoperatively when the sclerostin knockout group showed greater BV/TV than the wild type sclerostin antibody group (47.0 ± 3.5 vs 40.1 ± 2.1; p < 0.05). On biomechanical testing the wild type sclerostin antibody showed increased stiffness at Days 14 and 28 compared with the wild type with saline group (70.9 ± 6.4 vs 14.8 ± 8.1; p = 0.001), (106.8 ± 24.3 vs 74.9 ± 16.0; p = 0.004); respectively. However, with the numbers available, no differences were detected between the wild type with sclerostin antibody and the sclerostin knockout groups in terms of whole-bone structural strength. CONCLUSIONS: Sclerostin antibody injections showed promising results, which were not different with the numbers available, from results achieved with complete depletion of sclerostin, especially at earlier stages of the healing process, and therefore completed the healing process at an earlier time. CLINICAL RELEVANCE: Sclerostin antibody injections appear to enhance fracture healing to a degree that is not different than complete sclerostin depletion, but larger animal studies are required to assess the accurate dosage and timing of administration in the fracture healing process to further evaluate its potential clinical utility to enhance fracture healing.

Safety and Efficacy of Botulinum Toxin A in Children Undergoing Lower Limb Lengthening and Deformity Correction: Results of a Double-blind, Multicenter, Randomized Controlled Trial.

BACKGROUND: Lengthening of the lower limb is a complex procedure in which pain management and complications such as pin-site infections and muscle contractures impact the family and affect the child's quality of life. As a result, the paralytic and antinociceptive actions of neurotoxins may be indicated in managing these complications; however, few studies have explored ways to improve outcomes after lengthenings. The objective of this study was to evaluate the safety and efficacy of botulinum toxin A (BTX-A) in children undergoing lower limb lengthenings and deformity correction. METHODS: Participants with a congenital or acquired deformity of the lower extremity requiring surgery to one limb were randomized to receiving either BTX-A as a single dose of 10 units per kilogram body weight, or an equivalent volume of saline solution. Pain, medication, quality of life, and physical function were assessed at different time-points. Adverse events were recorded in all participants. T test and χ tests were used to compare potential differences across both groups. RESULTS: Mean age of the 125 participants was 12.5 years (range, 5 to 21 y), and lengthenings averaged 4.2 cm. Maximum pain scores on day 1 postoperatively were lower in the BTX-A group (P=0.03) than in the placebo group, and remained significant favoring botox when stratifying by location of lengthening (femur vs. tibia). Clinical benefits for BTX-A were found for 3 quality of life domains at mid-distraction and end-distraction. When stratifying according to location of lengthening, there were significantly fewer pin-site infections in the tibia favoring botox (P=0.03). The amount of adverse events and bone healing indices were no different in both groups. CONCLUSIONS: The clinical differences in quality of life, the lower pain on the first postoperative day, and the lower number of pin-site infections in the tibia favoring BTX-A support its use as an adjunctive treatment to the lengthening process. The detailed analyses of pain patterns help inform families on the pain expectations during lower limb lengthenings. The amount of adverse events were no different in both groups, and bone healing rates were similar, indicating that the use of BTX-A in children undergoing limb lengthening and deformity correction is safe. LEVEL OF EVIDENCE: Level I.

The potential roles of nanobiomaterials in distraction osteogenesis.

Distraction osteogenesis (DO) technique is used worldwide to treat many orthopedic conditions. Although successful, one limitation of this technique is the extended period of fixators until the bone is consolidated. The application of growth factors (GFs) is one promising approach to accelerate bone regeneration during DO. Despite promising in vivo results, its use is still limited in the clinic. This is secondary to inherent limitations of these GFs. Therefore, a development of delivery systems that allow sustained sequential release is necessary. Nanoparticles and nanocomposites have prevailing properties that can overcome the limitations of the current delivery systems. In addition, their use can overcome the current challenges associated with the insufficient mechanical properties of scaffolds and suboptimal osteogenic differentiation of transplanted cells in the distraction gap. We discuss the clinical implications, and potential early applications of the nanoparticles and nanocomposites for developing new treatments to accelerate bone regeneration in DO.

Congenital fibular deficiency.

Congenital fibular deficiency (CFD) is characterized by a wide spectrum of manifestations ranging from mild limb length inequality (LLI) to severe shortening, with foot and ankle deformities and associated anomalies. The etiology of CFD remains unclear. Treatment goals are to achieve normal weight bearing, a functional plantigrade foot, and equal limb length. The recent Birch classification system has been proposed to provide a treatment guide: the functionality of the foot, LLI, and associated anomalies should be taken into account for decision-making. Treatment options include orthosis or epiphysiodesis, Syme or Boyd amputation and prosthetic rehabilitation, limb lengthening procedures, and foot and ankle reconstruction. The outcome of amputation for severe forms of CFD has shown favorable results and fewer complications compared with those of limb lengthening. Nevertheless, advances in the limb lengthening techniques may change our approach to treating patients with CFD and might extend the indications for reconstructive procedures to the treatment of severe LLI and foot deformities.

Pseudoarthrosis of the Distal Humerus in Pediatric Osteogenesis Imperfecta Patients: A Case Series and Literature Review.

Osteogenesis imperfecta (OI) is a rare skeletal disorder that increases a patient's susceptibility to bone fracture. One complication commonly associated with fractures in this population is the occurrence of non-union leading to pseudoarthrosis. In this case series, three cases of non-union of the distal humerus leading to pseudoarthrosis in the pediatric OI population are presented. One case presents a successful attempt at treatment, one case presents a failed attempt at treatment, and the third case presents a patient's refusal to get treated. Furthermore, a literature review highlighting other institutions' attempts, successes, and failures at treating this clinical entity is presented. Combining the data retrieved from our institution and others, this review demonstrates that there is currently no standard for treating these patients. Additionally, based on the small case series and literature review presented in this article, definitive guidelines for the treatment of pseudoarthrosis of the distal humerus in pediatric OI patients cannot be outlined. However, our findings suggest that both non-surgical and surgical treatments could be viable options for patients with asymptomatic pseudoarthrosis of the distal humerus.

Activation of Wnt signaling in human fracture callus and nonunion tissues.

The Wnt signaling pathway is a key molecular process during fracture repair. Although much of what we now know about the role of this pathway in bone is derived from in vitro and animal studies, the same cannot be said about humans. As such, we hypothesized that Wnt signaling will also be a key process in humans during physiological fracture healing as well as in the development of a nonunion (hypertrophic and oligotrophic). We further hypothesized that the expression of Wnt-signaling pathway genes/proteins would exhibit a differential expression pattern between physiological fracture callus and the pathological nonunion tissues. We tested these two hypotheses by examining the mRNA levels of key Wnt-signaling related genes: ligands (WNT4, WNT10a), receptors (FZD4, LRP5, LRP6), inhibitors (DKK1, SOST) and modulators (CTNNB1 and PORCN). RNA sequencing from calluses as well as from the two nonunion tissue types, revealed that all of these genes were expressed at about the same level in these three tissue types. Further, spatial expression experiments identified the cells responsible of producing these proteins. Robust expression was detected in osteoblasts for the majority of these genes except SOST which displayed low expression, but in contrast, was mostly detected in osteocytes. Many of these genes were also expressed by callus chondrocytes as well. Taken together, these results confirm that Wnt signaling is indeed active during both human physiological fracture healing as well as in pathological nonunions.

Distal Femur Anterior Hemiepiphysiodesis for Fixed Knee Flexion Deformity in Neuromuscular Patients: A Systematic Review.

BACKGROUND: In the past decade, distal femur anterior hemiepiphysiodesis for fixed knee flexion deformity has gained popularity. In this study, we aim to systematically review the literature on this technique as a treatment for fixed knee flexion deformity in patients with neuromuscular disorders. METHODS: A systematic review was performed in the following databases: PubMed, Embase, and Medline. The inclusion criteria included anterior hemiepiphysiodesis of the distal femur for patients with neuromuscular disorders and fixed knee flexion deformities. RESULTS: Our search yielded 419 titles. A total of 12 articles were qualified for final review based on the inclusion and exclusion criteria. The total number of patients was 279, with 483 knees corrected. The male to female ratio was 2.1:1, and the mean age of the patients was 11.3 ± 1.4 years (range 4-17 years). The mean preoperative flexion deformity was 23.1° ± 10.0° (range 10°-90°). The mean residual flexion deformity at the final follow-up was 8.6° ± 9.0° (range 0°-32.5°), which corresponds to a statistically significant decrease compared with the preoperative deformity (p < 0.05). CONCLUSION: Anterior hemiepiphysiodesis for fixed knee flexion deformity provides favourable outcomes with low complication rates in patients with neuromuscular disorders. Future studies should focus on comparing the long-term outcomes of the different metal implants used for these operations. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.