Aims. The aim of this study was to describe the incidence of refractures among children, following fractures of all long bones, and to identify when the risk of refracture decreases. Methods. All patients aged under 16 years with a fracture that had occurred in a bone with ongoing growth (open physis) from 1 May 2015 to 31 December 2020 were retrieved from the Swedish Fracture Register. A new fracture in the same segment within one year of the primary fracture was regarded as a refracture. Fracture localization, sex, lateral distribution, and time from primary fracture to refracture were analyzed for all long bones. Results. Of 40,090 primary fractures, 348 children (0.88%) sustained a refracture in the same long bone segment. The diaphyseal forearm was the long bone segment most commonly affected by refractures (n = 140; 3.4%). The median time to refracture was 147 days (interquartile range 82 to 253) in all segments of the long bones combined. The majority of the refractures occurred in boys (n = 236; 67%), and the left side was the most common side to refracture (n = 220; 62%). The data in this study suggest that the risk of refracture decreases after 180 days in the diaphyseal forearm, after 90 days in the distal forearm, and after 135 days in the diaphyseal tibia. Conclusion. Refractures in children are rare. However, different fractured segments run a different threat of refracture, with the highest risk associated with diaphyseal forearm fractures. The data in this study imply that children who have sustained a distal forearm fracture should avoid hazardous activities for three months, while children with a diaphyseal forearm fracture should avoid these activities for six months, and for four and a half months if they have sustained a diaphyseal tibia fracture. Cite this article: Bone Joint J 2023;105-B(8):928–934

We investigated patterns of refracture and their risk factors in patients with congenital pseudarthrosis of the tibia after Ilizarov osteosynthesis. We studied 43 cases in 23 patients. Temporal and spatial patterns of refracture and refracture-free survival were analysed in each case. The refracture-free rate of cumulative survival was 47% at five years and did not change thereafter. Refracture occurred at the previous pseudarthrosis in 16 of 19 cases of refracture. The risk of refracture was significantly higher when osteosynthesis was performed below the age of four years, when the tibial cross-sectional area was narrow, and when associated with persistent fibular pseudarthrosis. Refracture occurs frequently after successful osteosynthesis in these patients. Delaying osteosynthesis, maximising the tibial cross-sectional area and stabilising the fibula may reduce the risk of refracture

In a retrospective study we reviewed 28 refractures of the forearm in children, which occurred at a mean of 14 weeks after conservative treatment of the primary fracture. The cause for the refracture was incomplete healing of a primary greenstick fracture in 21 cases (84%). Twenty-two recurrent fractures were treated conservatively, but two had a second refracture. Fifteen patients were followed for over two years. Definitive angulation of more than 10° caused a deficit of forearm rotation. To prevent refracture of the forearm in children, complete and circular consolidation of the primary fracture must be guaranteed

The December 2023 Children’s orthopaedics Roundup. 360. looks at: A comprehensive nonoperative treatment protocol for developmental dysplasia of the hip in infants; How common are refractures in childhood?; Femoral nailing for paediatric femoral shaft fracture in children aged eight to ten years; Who benefits from allowing the physis to grow in slipped capital femoral epiphysis?; Paediatric patients with an extremity bone tumour: a secondary analysis of the PARITY trial data; Split tibial tendon transfers in cerebral palsy equinovarus foot deformities; Liposomal bupivacaine nerve block: an answer to opioid use?; Correction with distal femoral transphyseal screws in hemiepiphysiodesis for coronal-plane knee deformity

The incidence of refracture following the removal of screws and plates from the diaphyses of 115 forearm bones in 80 patients has been studied. Refracture occurred in four adult patients as a result of minimal trauma, in two patients at the original fracture site after premature plate removal, at the site of a countersunk interfragmentary screw in one and at the original fracture site in another who had required three operative procedures to achieve 'union'. It is suggested that refracture could have been avoided in at least two of these patients. If the 3.5 mm plating system has been used, the incidence of refracture should be minimal

Aim

In previous small series, some authors have suggested a difference between re-fractures through immature callus and remodelled bone. We aimed to determine whether different fracture patterns occur in early and late re-fractures of paediatric forearm bones.

A novel, validated three dimensional finite element model of the femur was used to characterize the stress concentration in the bone at the proximal end of a fracture fixation plate. A supracondylar fracture of the distal femur fixed with a plate was modeled utilizing physiologic load patterns simulating several phases of a cycle of gait. The relative maginitude and length of the zone of increased stress was characterized. The effects of varying plate geometry and material in the attempt to decrease stress concentration at the end of the plated were investigated.

The exact nature and distribution of stresses around femoral fracture fixation plates remains unclear making it difficult to determine how close to existing hardware a distal femoral plate can be implanted. Our objective was to use a novel, validated finite element (FE) model to examine the stress distribution at the proximal end of the plate.

The von Mises element stresses in the bone without the implant were compared to those with the implant. Additionally, we determined the effect of metal (titanium versus stainless steel), and plate taper (ten, thirty and forty-five degrees) on stresses at the proximal end of the plate.

The peak von Mises stress in the plated bone occurred below the corners of the plate, and was approximately four times that in the un-plated case (thirty-eight MPa versus nine MPa). We identified a distance of 34 mm (approximately one bone diameter) beyond the edge of the plate before stresses returned to within 1% of the un-plated control. The choice of metal did not affect the state of stress distribution in the bone beyond the proximal edge of the plate. In addition, the stress concentrations decreased proportionally as the taper angle decreased from forty-five to ten.

Utilizing this FE model we report the following:

Stresses are concentrated at the end of plates and return to within normal limits approximately one bone diameter beyond the edge of the plate.

Funding: The authors gratefully acknowledge the financial support of Materials and Manufacturing Ontario (MMO) and the Dean’s New Faculty Seed Grant at Ryerson University.

Aims. The timing of when to remove a circular frame is crucial; early removal results in refracture or deformity, while late removal increases the patient morbidity and delay in return to work. This study was designed to assess the effectiveness of a staged reloading protocol. We report the incidence of mechanical failure following both single-stage and two stage reloading protocols and analyze the associated risk factors. Methods. We identified consecutive patients from our departmental database. Both trauma and elective cases were included, of all ages, frame types, and pathologies who underwent circular frame treatment. Our protocol is either a single-stage or two-stage process implemented by defunctioning the frame, in order to progressively increase the weightbearing load through the bone, and promote full loading prior to frame removal. Before progression, through the process we monitor patients for any increase in pain and assess radiographs for deformity or refracture. Results. There were 244 frames (230 patients) included in the analyses, of which 90 were Ilizarov type frames and 154 were hexapods. There were 149 frames which underwent single-stage reloading and 95 frames which underwent a two-stage reloading protocol. Mechanical failure occurred after frame removal in 13 frames (5%), which suffered refracture. There were no cases of change in alignment. There was no difference between refracture patients who underwent single-stage or two-stage reloading protocols (p = 0.772). In all, 14 patients had failure prevented through identification with the reloading protocol. Conclusion. Our reloading protocol is a simple and effective way to confirm the timing of frame removal and minimize the rate of mechanical failure. Similar failure rates occurred between patients undergoing single-stage and two-stage reloading protocols. If the surgeon is confident with clinical and radiological assessment, it may be possible to progress directly to stage two and decrease frame time and patient morbidity. Cite this article: Bone Jt Open 2022;3(5):359–366

Aims. There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method. Methods. The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress. Results. Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa). Conclusion. Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research. Cite this article: Bone Jt Open 2023;4(8):612–620

Our study seeks to determine whether characteristics of radiographs taken post-reduction of a forearm fracture can indicate future risk of refracture or loss of reduction. We hypothesize that reducing forearm fractures too precisely may be counterproductive and provide less benefit than reductions left slightly offset prior to cast immobilization. We conducted a retrospective review of 1079 pediatric patients treated for forearm fractures between January 2014 and September 2021 in a 327 bed regional medical center. Percent fracture displacement, location, orientation, comminution, fracture line visibility and angle of angulation were determined by AP and lateral radiographs. Percent fracture displacement was derived by: (Displacement of Bone Shafts / Diameter) x 100% = %Fracture Displacement. Patients treated with closed reduction were reduced from a mean displacement of 29.26±36.18% at an angulation of 22.67±16.57 degrees to 7.88±9.07% displacement and 3.89±6.68 degrees angulation post-reduction. Patients developing complications including a loss of reduction or refracture were found to have post-operative radiographs with a lower percent displacement (0.50±1.12) than those not developing complications (8.65±9.21)(p=0.0580). Post-reduction angulation (p=1.000), average reduction in angulation (p=1.000) and average reduction in displacement percent(p=0.2102) were not significantly associated with development of complications. Percent displacement of radial shafts was seen to be the most important metric to monitor in post-operative radiographs for patients undergoing closed reduction of a forearm fracture. We theorize a slight displacement provides greater surface area for osteoblastic expansion and callus formation leading to a decreased risk of refracture or loss of reduction. While our sample size precludes our ability to measure the ideal amount of post-reduction displacement for optimal healing, our results demonstrate that some degree of shaft displacement is required for optimal healing conditions

Aims. The aim of this study was to define the complications and long-term outcome following adolescent mid-shaft clavicular fracture. Methods. We retrospectively reviewed a consecutive series of 677 adolescent fractures in 671 patients presenting to our region (age 13 to 17 years) over a ten-year period (2009 to 2019). Long-term patient-reported outcomes (abbreviated version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score and EuroQol five-dimension three-level (EQ-5D-3L) quality of life score) were undertaken at a mean of 6.4 years (1.2 to 11.3) following injury in severely displaced mid-shaft fractures (Edinburgh 2B) and angulated mid-shaft fractures (Edinburgh 2A2) at a minimum of one year post-injury. The median patient age was 14.8 years (interquartile range (IQR) 14.0 to 15.7) and 89% were male (n = 594/671). Results. The majority of fractures were mid-shaft (n = 606) with angulation (Edinburgh 2A2, n = 241/606, 39.8%) or displacement (Edinburgh 2B1/2, n = 263/606, 43.4%). Only 7% of the displaced mid-shaft fractures underwent acute fixation (n = 18/263). The incidence of refracture over ten years following nonoperative management of mid-shaft fractures was 3.2% (n = 19/588) and all united without surgery. Fracture type, severity of angulation, or displacement were not associated with refracture. One nonunion occurred following nonoperative management in a displaced mid-shaft fracture (0.4%, n = 1/245). Of the angulated fractures, 61 had angulation > 30°, of which 68.9% (n = 42/61) completed outcome scores with a median QuickDASH of 0.0 (IQR 0.0 to 0.6), EQ-5D-3L 1.0 (1.0 to 1.0), and 98% satisfaction with shoulder function. For the displaced fractures, 127 had displacement beyond one cortical width of bone for which completed outcome scores were provided in 72.4% (n = 92/127). Of these 15 had undergone acute fixation. Following nonoperative treatment, the median QuickDASH was 0.0 (IQR 0.0 to 2.3), EQ-5D-3L 1.0 (1.0 to 1.0), and satisfaction with shoulder function was 95%. There were no significant differences in the patients’ demography or functional outcomes between operative and nonoperative treatments. Conclusion. Nonoperative management of adolescent mid-shaft clavicle fractures results in excellent functional outcomes at long-term follow-up. Nonunion is exceptionally rare following nonoperative management and the relative indications for surgical intervention in adults do not appear to be applicable to adolescents. Cite this article: Bone Joint J 2021;103-B(5):951–957

This study was conducted to investigate the characteristics, complications, radiologic features and clinical course of patients undergoing reduction of forearm fractures in order to better inform patient prognosis and postoperative management. We conducted a retrospective cohort study of 1079 pediatric patients treated for forearm fractures between January 2014 and September 2021 in a 327 bed regional medical center. A preoperative radiological assessment and chart review was performed. Percent fracture displacement, location, orientation, comonution, fracture line visibility and angle of angulation were determined by AP and lateral radiographs. Percent fracture displacement was derived by: (Displacement of Bone Shafts / Diameter) x 100% = %Fracture Displacement. Angle of angulation and percent fracture displacement were calculated by averaging AP and lateral radiograph measurements. 80 cases, averaging 13.5±8.3 years, were identified as having a complete fracture of the radius and/or ulna with 69 receiving closed reduction and 11 receiving fixation via an intramedullary device or percutaneous pinning. Eight patients (10%) experienced complications with four resulting in a refracture and four resulting in significant loss of reduction (LOR) without refracture. Fractures in the proximal ⅔s of the radius were associated with a significant increase in complications compared to fractures in the distal ⅓ of the radius (31.6% vs 3.4%) (P=.000428). Likewise, a higher percent fracture displacement was associated with a decreased risk of complications (28.7% vs 5.9% displacement)(P=0.0403). No elevated risk of complications was found based on fracture orientation, angulation, fracture line visibility, forearm bone(s) fractured, sex, age or arm affected. Our result highlights radius fracture location and percent fracture displacement as markers with prognostic value following forearm fracture. These measurements are simply calculated via pre-reduction radiographs, providing an efficient method of informing risk of complications following forearm fracture

Introduction. This is a report of the outcome of management of congenital pseudoarthrosis of the tibia (CPT) at skeletal maturity. Materials and Methods. Retrospective study. Inclusion criteria:. CPT Crawford IV. Skeletally maturity. Availability of radiographs and medical records. Outcome: union rate, healing time, residual deformities, ablation and refracture. Results. 23 patients who reached maturity were analysed. Time to union was 7.6 months. Union rate 70%. External fixation group: 7 patients, age 6.1 years, all united, 1 needed Bone graft. Average union time 8.2 months, no residual mal-alignment, no amputations, 2/7 needed corrective osteotomies and residual LLD in 2/7 < 1 cm. Numbers of surgery was 3. Vascularized fibular graft was done in 3 cases; all had failed previous attempts. Union time was 7 months. 2/3 united, 1 had amputation due to extensive disease. All patients had residual mal-alignment. Rodding group included 13 patients, age 3.2 years, union rate 61%, union time 8.3 months. Average LLD 1 cm with 1 patient LLD > 2 cm. Residual knee mal-alignment in 2/13, 4 had procurvatum and 55% of patients had ankle valgus. Fibula pseudoarthrosis. Refracture was reported in 53% of the rodding group. The causes of refracture were mal-alignment in 3, traumatic in 2 and idiopathic in 2. Total surgeries no 5. 2 patients had amputations after an unsuccessful 1. st. attempt. Our current trend of treatment was applied on 8 patients. They are not skeletally mature yet. the treatment combined excision of hamartoma, tibial rodding, wrapped periosteal graft with/out neutralization frame, and fibular fixation. Average age 3.8 years, union time was 10 months, Union rate 80%, no residual deformities. Conclusions. Our study shows the evolution of the treatment of CPT with increasing union rate, fewer residual deformities, and numbers of surgeries with more recent techniques

Aims. The aim of this retrospective cohort study was to assess and investigate the safety and efficacy of using a distal tibial osteotomy compared to proximal osteotomy for limb lengthening in children. Methods. In this study, there were 59 consecutive tibial lengthening and deformity corrections in 57 children using a circular frame. All were performed or supervised by the senior author between January 2013 and June 2019. A total of 25 who underwent a distal tibial osteotomy were analyzed and compared to a group of 34 who had a standard proximal tibial osteotomy. For each patient, the primary diagnosis, time in frame, complications, and lengthening achieved were recorded. From these data, the frame index was calculated (days/cm) and analyzed. Results. All patients ended their treatment with successful lengthening and deformity correction. The frame index for proximal versus distal osteotomies showed no significant difference, with a mean 48.5 days/cm (30 to 85) and 48.9 days/cm (28 to 81), respectively (p = 0.896). In the proximal osteotomy group, two patients suffered complications (one refracture after frame removal and one failure of regenerate maturation with subsequent valgus deformity) compared to zero in the distal osteotomy group. Two patients in each group sustained obstacles that required intervention (one necessitated guided growth, one fibula lengthening, and two required change of wires). There was a similar number of problems (pin-site infections) in each group. Conclusion. Our data show that distal tibial osteotomies can be safely employed in limb lengthening for children using a circular frame, which has implications in planning a surgical strategy; for example, when treating a tibia with shortening and distal deformity, a second osteotomy for proximal lengthening is not required. Cite this article: Bone Joint J 2022;104-B(11):1273–1278

The aim of this study was to define the long-term outcome following adolescent clavicle fracture. We retrospectively reviewed all adolescent fractures presenting to our region (13–17years) over a 10-year period. Patient reported outcomes were undertaken at a minimum of 4 years post-injury (QuickDASH and EQ-5D) in completely displaced midshaft fractures (Edinburgh 2B, >2cm displacement, n=50) and angulated midshaft fractures (Edinburgh 2A2, >30 degrees angulation, n=32). 677 clavicle fractures were analysed. The median age was 14.8 (IQR 14.0–15.7) and 89% were male. The majority were midshaft (n=606, 89.5%) with either angulation (39.8%) or simple fully displaced (39.1%). Only 3% of midshaft fractures underwent acute fixation (n=18/606), all of which were fully displaced. The incidence of refracture following non-operative management of midshaft fractures was 3.2% (n=19/588), all united with non-operative management. Fracture type, severity of angulation or displacement was not associated with risk of refracture. There was one case of non-union encountered following non-operative management of all displaced midshaft fractures (0.4%, n=1/245). At a mean of 7.6 years following injury, non-operative management of both displaced and angulated fractures had a median QuickDASH was 0.0 (IQR 0.0–2.3), EQ-5D was 1.0 (IQR 1.0–1.0). 97% of angulated fractures and 94% of displaced fractures were satisfied with their final shoulder function. We conclude that Non-operative management of adolescent midshaft clavicle fractures result in excellent functional outcomes with a low rate of complications at long-term follow up. The relative indications for surgical intervention for clavicle fractures in adults do not appear to be applicable to adolescents

Acute metatarsal fractures are a common extremity injury. While surgery may be recommended to reduce the risk of nonunion or symptomatic malunion, most fractures are treated with nonoperative management. However, there is significant variability between practitioners with no consensus among clinicians on the most effective nonoperative protocol, despite how common the form of treatment. This systematic review identified published conservative treatment modalities for acute metatarsal fractures and compares their non-union rate, chronic pain, and length of recovery, with the objective of identifying a best-practices algorithm. Searches of CINAHL, EMBASE, MEDLINE, and CENTRAL identified clinical studies, level IV or greater in LOE, addressing non-operative management strategies for metatarsal fractures. Two reviewers independently screened the titles, abstracts, and full texts, extracting data from eligible studies. Reported outcome measures and complications were descriptively analyzed. Studies were excluded if a rehabilitation program outlining length of immobilization, weight-bearing and/or strengthening approaches was not reported. A total of 12 studies (8 RCTs and 4 PCs), from the 2411 studies that were eligible for title screening, satisfied inclusion criteria. They comprised a total of 610 patients with acute metatarsal fractures, with a mean age of 40.2 years (range, 15 – 82). There were 6 studies that investigated avulsion fractures, 2 studies on true Jones fractures, and 4 studies with mixed fracture types. Studies assessed a variety of treatment modalities including: WB and NWB casts, elasticated support bandages, hard-sole shoes, plaster slippers, metatarsal shoe casts, and air cast boots. Most studies investigated the outcomes of NWB casts and elasticated support bandages. The NWB short leg cast had no reported non-unions, delayed-unions, or refractures for avulsion fractures. In true Jones fractures, there was an average non-union rate of 23.6% (range, 5.6 – 27.8%), delayed-union rate of 11.8% (range, 5.6 – 18.8%), and refracture rate of 3% (range, 0 – 5.6%). Overall, the average AOFAS score was 87.2 (range, 84 – 91.7) and the average VAS score was 83.7 (range, 75 – 93). The elasticated support bandage had an average non-union rate of 3.4% (range, 0 – 12%), and delayed-union rate of 3.8% for acute avulsion fractures, with no reported refractures. No included study arm investigated outcomes of elasticated support bandages for the true Jones fracture. The average AOFAS score for elasticated support bandages was 93.5 (range, 90 – 100). The average VAS score was 88.9 (range, 90 – 100). Most acute metatarsal fractures heal well, with good-to-excellent functional outcomes and moderate-to-high patient satisfaction. Conservative strategies for avulsion fractures are highly successful and based on this data the authors recommend patients undergo a schedule that involves 3 – 4 weeks in an elasticated support bandage, short leg cast, or equivalent, and WB thereafter as tolerated, with return-to-activity after clinical union. Despite poorer conservative outcomes for true Jones fractures, patients should undergo 8 weeks in a NWB short leg cast, followed by a walking cast or hard-sole shoe for an additional 4 – 6 weeks, or until clinical union. However, surgical consultation is recommended

Introduction. Traditionally, radiological union of fractures treated with an Ilizarov frame is confirmed by a period of dynamization - destabilisation of the frame for a period prior to removal. Reduced clinic availability during the COVID-19 pandemic caused a shift to selective dynamisation in our department, whereby lower risk patients had their frames removed on the same day as destabilisation. This study investigates the effects of this change in practice on outcomes and complication rates. Materials & Methods. Adult patients treated with circular frames between April 2020 and February 2022 were identified from our Ilizarov database. Patients were divided into 2 groups: - “dynamised” if their frame was destabilised for a period to confirm union prior to removal; or “not dynamised” if the decision was taken to remove the frame without a period of dynamisation, other than a short period in the clinic. A retrospective review of clinical notes was conducted to determine outcome. Results. 175 patients were included in the final analysis, 70 in the dynamised and 103 in the not dynamised groups, median follow-up was 33 months. 3 patients in the dynamised group failed dynamisation and had their period of fixation extended, subsequently having their frames removed without complication. Two patients suffered a refracture or non-union after frame removal in the dynamised group and none in the not dynamised group, this difference was not statistically significant. Conclusions. In our practice, selective frame removal without a period of dynamisation appears safe. This has the potential to shorten frame time and reduce the number of clinic appointments and radiographic investigations for these patients. Some patients find the period of dynamisation uncomfortable and associated with pin site infection, which can be avoided. We plan to continue this practice and collect further data to confirm these findings in a larger dataset

The Femoral Neck System (FNS) was introduced as an alternative device for the fixation of neck of femur fractures (NOFFs). The purported advantages include superior angular and rotatory stability compared to multiple cancellous screws, via a minimally invasive instrumentation that is simpler than conventional fixed angle devices. There were limited clinical studies regarding the utility of this device. We aimed to study the outcomes of NOFFs fixed with the FNS. This was a single-institution, retrospective review of all undisplaced elderly (≥60 years old) undisplaced young, and displaced young NOFFs fixed with the FNS. Demographics, surgical parameters, radiographic parameters, and clinical outcomes including complications were reviewed. Thirty-six subjects with a median age of 75 [44,89] years old, had NOFF fixation using the FNS. Thirty-one (86.1%) had undisplaced fractures. There were 6 (16.7%), 26 (72.2%), and 4 (11.1%) subjects with Pauwels types 1, 2, and 3 respectively. Thirty-two (88.9%) had posterior tilt of <20º. The mean duration of surgery was 71±18 minutes. Excluding 4 patients whom required revision surgery, 2 patients whom demised, and 10 patients whom defaulted reviews, the mean follow-up duration was 55±13 weeks. Four complications were recorded, namely implant cut out at the femoral head at week 8, breaking of the locking screw at the run-off region at week 22, avascular necrosis at week 25, and a refracture following near fall, causing the fracture to fail in varus at week 7 postoperation. While reasonably fast to instrument, failures still occur and it is likely multifactorial. However, the rate of reoperation is lower than what has been reported for NOFFs fixed with the a fixed-angle device or 3 cancellous screws. In conclusion, the FNS is a reasonably safe instrument to use. Surgeons’ discretion is still needed in patient selection, keeping in mind the need for satisfactory radiological parameters

Aims. The Fassier Duval (FD) rod is a third-generation telescopic implant for children with osteogenesis imperfecta (OI). Threaded fixation enables proximal insertion without opening the knee or ankle joint. We have reviewed our combined two-centre experience with this implant. Methods. In total, 34 children with a mean age of five years (1 to 14) with severe OI have undergone rodding of 72 lower limb long bones (27 tibial, 45 femoral) for recurrent fractures with progressive deformity despite optimized bone health and bisphosphonate therapy. Data were collected prospectively, with 1.5 to 11 years follow-up. Results. A total of 24 patients (33%) required exchange of implants (14 femora and ten tibiae) including 11 rods bending with refracture. Four (5%) required reoperation with implant retention. Loss of proximal fixation in the femur and distal fixation in the tibia were common. Four patients developed coxa vara requiring surgical correction. In total, 13 patients experienced further fractures without rod bending; eight required implant revision. There was one deep infection. The five-year survival rate, with rod revision as the endpoint, was 63% (95% confidence interval (CI) 44% to 77%) for femoral rods, with a mean age at implantation of 4.8 years (1.3 to 14.8), and 64% (95% CI 36% to 82%) for tibial rods, with a mean age at implantation of 5.2 years (2.0 to 13.8). Conclusion. FD rods are easier to implant but do not improve on the revision rates reported for second generation T-piece rods. Proximal femoral fixation is problematic in younger children with a partially ossified greater trochanter. Distal tibial fixation typically fails after two years. Future generation implants should address proximal femoral and distal tibial fixation to avoid the majority of complications in this series. Cite this article: Bone Joint J 2020;102-B(8):1048–1055