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

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

Bilateral Developmental Dysplasia of the Hip: Does Closed Reduction Have a Role in Management? Outcome of Closed and Open Reduction in 92 Hips.

BACKGROUND: Bilateral developmental dysplasia of the hip (DDH) is believed to have a worse outcome than unilateral DDH with the optimal treatment unclear. To define indications for treatment we report a retrospective series of 92 hips (46 patients) who underwent closed reduction (CR) and/or open reduction (OR). METHODS: A total of 58 hips in 29 patients underwent attempted CR using our standardized protocol. In the same 12 year time period, 54 hips in 27 patients underwent an OR. Outcome measures included resolution of acetabular dysplasia, need for further surgery, development of osteonecrosis (ON), and modified Severin Grade. RESULTS: CR was successful in 57% of hips; in this group secondary surgery was required in 15% and ON was seen in 12%. In the OR group, 11% failed to stabilize and required further early surgery: ON rate was 15% overall, and secondary surgery was required in 5%. In Tonnis 2/3 hips younger than 2 years, Severin grading was comparable following CR and OR, with 92% and 90% graded as Severin 1, respectively. The rate of significant ON was higher after CR in Tonnis 2/3 hips (12%) than after OR (0%). Overall, Tonnis 4 hips did badly: 94% failed CR and following OR, further surgery for redislocation/residual dysplasia was required in 21%. CONCLUSIONS: CR can be successful in Tonnis 2/3 bilateral hips, with acceptable rates of secondary surgery, ON, and Severin grading, the latter equivalent to open reduction. Importantly, persisting with casting of a unilateral dislocation, to allow the contra-lateral hip to stabilize, does not have an adverse effect. CR is not advised in Tonnis 4 bilateral hips. Parents should be counseled that the outcome of surgery for bilateral hips is not as good as for unilateral DDH, particularly for Tonnis 4 hips which are more difficult to stabilize and more likely to require supplementary surgery even after open reduction. LEVEL OF EVIDENCE: Level IV-Therapeutic Study.

A mosaic activating mutation in AKT1 associated with the Proteus syndrome.

BACKGROUND: The Proteus syndrome is characterized by the overgrowth of skin, connective tissue, brain, and other tissues. It has been hypothesized that the syndrome is caused by somatic mosaicism for a mutation that is lethal in the nonmosaic state. METHODS: We performed exome sequencing of DNA from biopsy samples obtained from patients with the Proteus syndrome and compared the resultant DNA sequences with those of unaffected tissues obtained from the same patients. We confirmed and extended an observed association, using a custom restriction-enzyme assay to analyze the DNA in 158 samples from 29 patients with the Proteus syndrome. We then assayed activation of the AKT protein in affected tissues, using phosphorylation-specific antibodies on Western blots. RESULTS: Of 29 patients with the Proteus syndrome, 26 had a somatic activating mutation (c.49G→A, p.Glu17Lys) in the oncogene AKT1, encoding the AKT1 kinase, an enzyme known to mediate processes such as cell proliferation and apoptosis. Tissues and cell lines from patients with the Proteus syndrome harbored admixtures of mutant alleles that ranged from 1% to approximately 50%. Mutant cell lines showed greater AKT phosphorylation than did control cell lines. A pair of single-cell clones that were established from the same starting culture and differed with respect to their mutation status had different levels of AKT phosphorylation. CONCLUSIONS: The Proteus syndrome is caused by a somatic activating mutation in AKT1, proving the hypothesis of somatic mosaicism and implicating activation of the PI3K-AKT pathway in the characteristic clinical findings of overgrowth and tumor susceptibility in this disorder. (Funded by the Intramural Research Program of the National Human Genome Research Institute.).

Management of severe congenital femoral deficiency: Does surgical intervention enhance prosthetic function?

BACKGROUND OBJECTIVE: The purpose of this study was to evaluate prosthetic outcome in patients with severe congenital femoral deficiency and the potential benefits of surgical intervention on prosthetic fitting and gait. METHODS: A retrospective review identified 26 active case records with a proximal femoral focal deficiency using a prosthesis. Validated outcome measures evaluated comfort, function, and prosthetic use and quality-of-life assessment. Outcome compared age groups and surgical intervention. Gait analysis performed in 7 patients further evaluated hip and knee function. RESULTS: Eleven male patients and 15 female patients, including 13 children (mean age 10 years, range 5-16) and 13 adults (mean age 36 years, range 23-63) were evaluated. Better prosthetic function and PedsQL scores were recorded in the pediatric group. There was a trend for better scores after surgery. Gait analysis demonstrated reduced hip extension compensated by knee flexion in 3 patients, 2 patients had hip extension with near normal kinematics, 1 untreated patient walked with an unsteady gait, and the remaining walked well using an ischial-bearing prosthesis with pelvic compensatory movements. CONCLUSION: The management strategy in severe proximal femoral focal deficiency remains a major challenge. Hip reconstruction seems to improve functional scores. Overall, the scores seem to decline into adulthood but not significantly. Gait analysis before further surgical intervention is recommended because compensatory knee flexion may improve step length in terminal stance. Limited numbers, with short follow-up, prevents clear guidance on the benefit of surgery.

Early Weight Bearing in Lengthening Nails.

How to cite this article: Tissingh EK, Wright J, Calder P. Early Weight Bearing in Lengthening Nails. Strategies Trauma Limb Reconstr 2023;18(1):63.

Miserable malalignment syndrome associated knee pain: a case for infra-tubercle tibial de-rotation osteotomy using an external fixator.

INTRODUCTION: Miserable malalignment syndrome is a complex torsional lower limb deformity with limited consensus on surgical treatment. We present the outcome of de-rotation of the tibia alone using an external fixator. METHODS: Fifteen patients (22 segments) were operated on between 2012 and 2020; 13 presented with anterior knee pain, and two presented with out-toeing. Gait analysis was done in nine patients, and CT scan rotational profile, including tibial tubercle-trochlear groove distance, femoral version, and tibial torsion, were calculated. Kujala knee pain score and visual analogue pain score (VAS) were recorded. All underwent infra-tubercular osteotomy of the tibia and midshaft osteotmy of the fibula and application of a hexapod circular frame to gradually internally rotate the tibia until the foot aligned with the patella. RESULTS: There was no preoperative clinical or radiographic evidence for patellar instability, femoral anteversion 30° (21°-54°), and external tibial torsion 50° (37-70). The mean age at surgery was 21 years (12-37) with a mean follow-up of 20 months (9-83). All osteotomies healed, and the frames were removed at a mean of 111 days (80-168). The mean VAS score improved from 8(5-9) to 1(0-4) postoperatively (P < 0.001). The mean Kujala knee pain score increased from 53 (30-75) to 92 (54-100) postoperatively (P < 0.001). The mean preoperative foot progression angle (FPA) was 37° (20°-50°), with 13 postoperatively walking with neutral FPA. One patient walked with symmetrical + 10° and the other with - 5° FPA. All patients reported relief of knee pain and were satisfied with the alignment. CONCLUSION: Gradual correction of severe external tibia torsion with a hexapod external fixator and an infra-tubercle tibial osteotomy could provide an optimum method to eliminate knee pain and improve limb alignment in miserable malalignment syndrome.

An update on the intramedullary implant in limb lengthening: A quinquennial review Part 1: The further influence of the intramedullary nail in limb lengthening.

The goal of limb lengthening is to restore length to bone, safely stretch soft tissues and improve quality of life with minimal complications. Traditionally this was achieved with the use of external fixators, associated with complications related to pin site tethering and infections, joint stiffness and regenerate deformity and fracture following frame removal. The duration of treatment also impacts on patient mental health and well-being. In order to reduce external fixator time, intramedullary nails have been introduced as an adjunct, either at the initial surgery or after completion of lengthening. Complications related to the external fixator still remained and innovation has led to the popularisation of the intramedullary lengthening nail. The lengthening mechanism of the nail can be divided into those with ratchet systems and those driven by motors. In the ratchet group, patients are required to manually rotate their limb, with movement at the osteotomy site, in order to create forward movement. This was often associated with pain, and in some cases led to the requirement of general anaesthesia to enable rotation and continuation of lengthening. Further issues were reported related to lengthening rate control. Once the nail had lengthened sufficiently for the osteotomy to disengage, rapid lengthening termed a 'runaway' nail could occur. The nails were limited to forward movement, and once length was gained it could not be retracted, leading to poor regenerate formation and soft tissue contractures. The introduction of the Fitbone implant utilised a transcutaneous electrical conduit, powered by a high frequency electrical signal, enabling more control over the lengthening. The Precice intramedullary lengthening system is controlled by the use of an external device with two rotating neodymium magnets, which produce rotation of a third magnet in the nail. By altering the direction of the magnet rotation, the lengthening can be controlled both forwards and backwards with sub-millimetre precision. Following initial excellent outcomes published, the use of the lengthening intramedullary nail has become accepted by many as the implant of choice in limb lengthening. The aim of this article comes in two parts. The first to highlight the latest research and clinical results in the last five years using an intramedullary implant during limb lengthening, and the second to report the outcome in extended surgical indications and further implant innovation.

An Update on the Intramedullary Implant in Limb Lengthening: A Quinquennial Review Part 2: Extending Surgical Indications and Further Innovation.

The use of the intramedullary lengthening nail has gained in popularity over the last decade. The reduction in complications associated with the use of external fixators and excellent patient outcomes has resulted in the largest change in management of limb length discrepancy since the concept of distraction osteogenesis was accepted by the Western world in the 1980s. Success following "simple" limb lengthening has led to surgeons extending the indications for the lengthening nail, including different bone segments, lengthening associated with potential joint instability and lengthening combined with acute deformity correction. There has been a drive for further implant modification to reduce complications, and enable full weight bearing during the lengthening process. This would offer the opportunity to consider simultaneous limb lengthening. The aim of this review is to evaluate the literature published over the last five years and highlight important learning points and technical tips for these expanding indications.

Tension-band Plating for Leg-length Discrepancy Correction.

Aim: Dual tension-band plates are used for temporary epiphysiodesis and longitudinal guided growth. The study aim was to assess rate of correction, to identify development of femoral and tibial intra-articular deformity during correction and to document resumption of growth after plate removal. Materials and methods: A retrospective study of 34 consecutive patients treated with dual tension-band plates between 2012 and 2020 was performed. Twenty-four patients had surgery at the distal femur, six at the proximal tibia and four at both. Twenty-five female patients were treated at a mean age of 11.6 (±1.4) years and nine male patients at 13.5 (±1.5) years. Measurements were performed on standardised long-leg radiographs and included leg-length discrepancy (LLD), joint line congruency angle (JLCA), tibial roof angle, femoral floor angle and notch-intercondylar distance. Measurements were taken pre-operatively, at the end of discrepancy correction and at skeletal maturity. Results: The LLD reduced by a mean of 12.9 mm (95% CI 10.2-15.5) with the mean residual difference 8.4 mm (95% CI 5.4-11.4). The mean correction rate for the proximal tibia was 0.40 (SD 0.33) mm/month and 0.68 (SD 0.36) mm/month for the distal femur. A significant mean change in residual LLD [-2.5 mm (95% CI -4.2 to -0.7)] was observed between plate removal and skeletal maturity at the femoral level only. After length discrepancy correction, the tibial roof angle showed a significant difference of 8.4° (95% CI 13.4-3.4) between legs. In femoral epiphysiodesis patients, no important differences were observed. Conclusion: A significant reduction in LLD can be achieved using dual tension-band plating. A change in intra-articular morphology was observed only in the proximal tibia and not in the distal femur. In the authors' opinion, tension-band plating is a useful tool for leg-length equalisation but should be reserved for younger patients or when residual growth is difficult to predict. It is one of the management strategies for limb-length difference prior to skeletal maturity. How to cite this article: Tolk JJ, Merchant R, Calder PR, et al. Tension-band Plating for Leg-length Discrepancy Correction. Strategies Trauma Limb Reconstr 2022;17(1):19-25.

Use of the Pixel Value Ratio Following Intramedullary Limb Lengthening: Uncomplicated Full Weight-bearing at Lower Threshold Values.

Aims: The pixel value ratio (PVR) can be used to assess regenerate consolidation after lengthening and guide advice for full weight-bearing (FWB). This study aimed to analyse the PVR in adults having femoral lengthening, the time to FWB and compare findings with the reported values in the literature. Materials and methods: A retrospective database review identified 100 eligible patients who underwent lengthening using the PRECICE nail (68 antegrade and 32 retrograde). The PVR was calculated in each cortex on plain radiographs at every visit. The ratio between the regenerate and an average from the adjacent normal bone was calculated and plotted against the clinical decision to allow FWB. Results: Eighty-seven patients (58 men and 29 women) were assessed; eleven had bilateral lengthening and two patients underwent lengthening twice. The median age was 30.5 years. The underlying cause of shortening was post-traumatic in 46%, with the remaining due to a wide variety of causes, including congenital 16%, syndromic 12% and other causes. The median lengthening achieved was 45 mm, at a median of 57.5 days. The PVR increased with each visit (p <0.0001). FWB was allowed at a median of 42 days after the last day of lengthening, with PVR values of 0.83, 0.84, 0.93 and 0.84 for the anterior, posterior, medial and lateral cortex noted, respectively (average 0.85). There were no implant failures, shortening or regenerate fractures. No differences were detected between antegrade and retrograde nails or with lengthening greater or less than 45 mm. One surgeon allowed earlier FWB at median 31 days with no nail failures. Conclusion: PVR is a valuable tool that quantifies regenerate maturity and provides objectivity in deciding when to allow FWB after intramedullary lengthening with the PRECICE nail. FWB was permitted at an earlier time point, corresponding with lower PVR values than have been reported in the literature and with no mechanical failure or regenerate deformation. How to cite this article: Elsheikh AA, Wright J, Stoddart MT, et al. Use of the Pixel Value Ratio Following Intramedullary Limb Lengthening: Uncomplicated Full Weight-bearing at Lower Threshold Values. Strategies Trauma Limb Reconstr 2022;17(1):14-18.

Osteofibrous dysplasia of the tibia : the importance of deformity in surveillance.

AIMS: Osteofibrous dysplasia (OFD) is a rare benign lesion predominantly affecting the tibia in children. Its potential link to adamantinoma has influenced management. This international case series reviews the presentation of OFD and management approaches to improve our understanding of OFD. METHODS: A retrospective review at three paediatric tertiary centres identified 101 cases of tibial OFD in 99 patients. The clinical records, radiological images, and histology were analyzed. RESULTS: Mean age at presentation was 13.5 years (SD 12.4), and mean follow-up was 5.65 years (SD 5.51). At latest review, 62 lesions (61.4%) were in skeletally mature patients. The most common site of the tibial lesion was the anterior (76 lesions, 75.2%) cortex (63 lesions, 62.4%) of the middle third (52 lesions, 51.5%). Pain, swelling, and fracture were common presentations. Overall, 41 lesions (40.6%) presented with radiological deformity (> 10°): apex anterior in 97.6%. A total of 41 lesions (40.6%) were treated conservatively. Anterior bowing < 10° at presentation was found to be related to successful conservative management of OFD (p = 0.013, multivariable logistic regression). Intralesional excision was performed in 43 lesions (42.6%) and a wide excision of the lesion in 19 (18.8%). A high complication rate and surgical burden was found in those that underwent a wide excision regardless of technique employed. There was progression/recurrence in nine lesions (8.9%) but statistical analysis found no predictive factors. No OFD lesion transformed to adamantinoma. CONCLUSION: This study confirms OFD to be a benign bone condition with low rates of local progression and without malignant transformation. It is important to distinguish OFD from adamantinoma by a histological diagnosis. Focus should be on angular deformity, monitored with full-length tibial radiographs. Surgery is indicated in symptomatic patients and predicted by the severity of the initial angular deformity. Surgery should focus more on the deformity rather than the lesion. Cite this article: Bone Joint J 2022;104-B(2):302-308.

Development of a patient-reported outcome measure in limb reconstruction : a pilot study assessing face validity.

AIMS: Patients undergoing limb reconstruction surgery often face a challenging and lengthy process to complete their treatment journey. The majority of existing outcome measures do not adequately capture the patient-reported outcomes relevant to this patient group in a single measure. Following a previous systematic review, the Stanmore Limb Reconstruction Score (SLRS) was designed with the intent to address this need for an effective instrument to measure patient-reported outcomes in limb reconstruction patients. We aim to assess the face validity of this score in a pilot study. METHODS: The SLRS was designed following structured interviews with several groups including patients who have undergone limb reconstruction surgery, limb reconstruction surgeons, specialist nurses, and physiotherapists. This has subsequently undergone further adjustment for language and clarity. The score was then trialled on ten patients who had undergone limb reconstruction surgery, with subsequent structured questioning to understand the perceived suitability of the score. RESULTS: Ten patients completed the score and the subsequent structured interview. Considering the tool as a whole, 100% of respondents felt the score to be comprehensible, relevant, and comprehensive regarding the areas that were important to a patient undergoing limb reconstruction surgery. For individual questions, on a five-point Likert scale, importance/relevance was reported as a mean of 4.78 (4.3 to 5.0), with ability to understand rated as 4.92 (4.7 to 5.0) suggesting high levels of relevance and comprehension. Flesch-Kincaid reading grade level was calculated as 5.2 (10 to 11 years old). CONCLUSION: The current SLRS has been shown to have acceptable scores from a patient sample regarding relevance, comprehensibility, and comprehensiveness. This suggests face validity, however further testing required and is ongoing in a larger cohort of patients to determine the reliability, responsiveness, precision, and criterion validity of the score in this patient group. Cite this article: Bone Jt Open 2021;2(9):705-709.

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

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

Analysis of retrieved STRYDE nails.

AIMS: The aim of this study was to present the first retrieval analysis findings of PRECICE STRYDE intermedullary nails removed from patients, providing useful information in the post-market surveillance of these recently introduced devices. METHODS: We collected ten nails removed from six patients, together with patient clinical data and plain radiograph imaging. We performed macro- and microscopic analysis of all surfaces and graded the presence of corrosion using validated semiquantitative scoring methods. We determined the elemental composition of surface debris using energy dispersive x-ray spectroscopy (EDS) and used metrology analysis to characterize the surface adjacent to the extendable junctions. RESULTS: All nails were removed at the end of treatment, having achieved their intended lengthening (20 mm to 65 mm) and after regenerate consolidation. All nails had evidence of corrosion localized to the screw holes and the extendable junctions; corrosion was graded as moderate at the junction of one nail and severe at the junctions of five nails. EDS analysis showed surface deposits to be chromium rich. Plain radiographs showed cortical thickening and osteolysis around the junction of six nails, corresponding to the same nails with moderate - severe junction corrosion. CONCLUSION: We found, in fully united bones, evidence of cortical thickening and osteolysis that appeared to be associated with corrosion at the extendable junction; when corrosion was present, cortical thickening was adjacent to this junction. Further work, with greater numbers of retrievals, is required to fully understand this association between corrosion and bony changes, and the influencing surgeon, implant, and patient factors involved. Cite this article: Bone Jt Open 2021;2(8):599-610.

Regenerate Deformity with the Precice Tibial Nail.

Limb lengthening by distraction osteogenesis is an accepted orthopaedic surgical technique. The Precice intramedullary lengthening system is the most recent innovation in limb lengthening. Early results have been favourable in femoral lengthening but there is little reported on the outcome in tibial lengthening. The aim of this study is to present our early results of Precice tibial lengthening, and the stepwise evolution of our surgical technique. MATERIALS AND METHODS: A case series of 17 consecutive tibial lengthenings were prospectively analysed. Healing index, length achieved, range of motion, and complications were recorded. The initial cases followed the recommended surgical technique. Progressive regenerate deformity during lengthening required changes to the surgical method. RESULTS: No cases were lost to follow-up. All the nails lengthened at the desired rate. There were no complications of infection or poor regenerate formation. Progressive valgus and procurvatum was prevented in later cases by the positioning of Poller blocking screws at the time of nail insertion. CONCLUSION: The tibial Precice nail is successful in obtaining length and good regenerate formation. The recommended technique was insufficient to control the deforming forces from the lower limb muscle compartments during lengthening. We therefore recommend the addition of multiple blocking screws in an amended technique. HOW TO CITE THIS ARTICLE: Wright SE, Goodier WD, Calder P. Regenerate Deformity with the Precice Tibial Nail. Strategies Trauma Limb Reconstr 2020;15(2):98-105.

Reducing the Risk of Ring Breakage in Taylor Spatial Frames: The Effect of Frame Configuration on Strain at the Half-ring Junction.

AIM: We have encountered four cases with Taylor spatial frames (TSF) (Smith & Nephew, Memphis, TN, USA) with breakage at the half-ring junction of the distal ring. This study examines the strain produced on different locations of the distal ring during loading and the effects on the strain of altering the frame construct. MATERIALS AND METHODS: We mounted two ring TSF constructs on tibia saw bone models. The proximal ring was the same in all constructs and consisted of a 2/3 180 mm ring attached with three wires. Construct 1 is reproducing the configuration of cases where failure was seen. The distal 155 mm ring is attached with three half pins. The half-ring junction is located in the midline. Construct 2 has a different half pin placement and an additional wire on the distal ring. Constructs 3 and 4 have the same half pin configuration to construct 1 but the distal ring is rotated 60° internally and externally, respectively. Strain gauges were attached to different locations and measurements recorded during loading. Statistical analysis was performed. RESULTS: Highest strain values were recorded at the half-ring junction of constructs 1 and 2 (>600 microstrains (µÎµ) in tension). Rotating the ring 60° internally significantly reduces the strain at the half-ring junction (<300 µÎµ) whilst external rotation by 60° further reduces the strain (<180 µÎµ). Ring strain is higher in areas close to half pin attachments. CONCLUSION: The highest strain is in the half-ring junction as the half rings are subjected to different loading modes. The thickness of the half-ring is halved and the second moment of area reduced further increasing breakage risk. Placing this junction close to the half pin-frame interface, as dictated by the anatomical safe zone further increases the strain. Rotating the distal ring 60° significantly reduces the strain at the half-ring junction. CLINICAL SIGNIFICANCE: Ring breakage is a rare but significant complication. This is the first study to address this potential mode of TSF failure. Insights and technical tips from this study can help reduce this. HOW TO CITE THIS ARTICLE: Iliadis AD, Bebja R, Wang K, et al. Reducing the Risk of Ring Breakage in Taylor Spatial Frames: The Effect of Frame Configuration on Strain at the Half-ring Junction. Strategies Trauma Limb Reconstr 2020;15(3):146-150.

Thromboprophylaxis in Intramedullary Limb Lengthening Surgery.

AIM: The use of intramedullary lengthening devices is becoming increasingly popular. There are limited data regarding the incidence of venous thromboembolism following intramedullary lengthening surgery and no reports or guidance for current practice on use of thromboprophylaxis. Following a case of post-operative deep vein thrombosis in our institution, we felt that it is important to assess best practice. We conducted a national survey to collect data that would describe current practice and help develop consensus for treatment. MATERIALS AND METHODS: We identified surgeons across the UK that perform adult intramedullary limb lengthening through the British Limb Reconstruction Society membership and a Precise Users database. Surgeons were contacted and asked to respond to an online survey. Responses to thromboprophylaxis regimes employed in their practice and cases of venous thromboembolism were collated. RESULTS: 24 out of 54 surgeons identified responded with a total of 454 cases of adult intramedullary lengthening (352 femoral and 102 tibial nails) performed over a five year period (January 2015-January 2020). Only one case of deep venous thrombosis (DVT) following femoral lengthening was reported. There is wide variability in practice both in terms of thromboprophylaxis risk assessment, choice of medications and duration of treatment. The vast majority of surgeons (85%) felt that there was insufficient evidence available to guide their practice. CONCLUSIONS: Intramedullary lengthening is a surgical treatment growing in popularity. There are limited data available to guide decision-making regarding aspects of treatment such as thromboprophylaxis. This is reflected in the wide variation in practice reported in this study. There are both a need and a desire to gather data that will allow us to come to a consensus and to guide safe practice. CLINICAL SIGNIFICANCE: Venous thromboembolism is a potential complication of lower limb lengthening surgery. We report on national incidence and current practices of thromboprophylaxis to allow for informed decision-making and help develop consensus for best practice. HOW TO CITE THIS ARTICLE: Iliadis AD, Timms A, Fugazzotto S, et al. Thromboprophylaxis in Intramedullary Limb Lengthening Surgery. Strategies Trauma Limb Reconstr 2020;15(3):151-156.

Providing a paediatric trauma and orthopaedics service during the peak of the COVID-19 pandemic: The Royal National Orthopaedic Hospital experience.

INTRODUCTION: In response to the COVID-19 pandemic, there was a rapidly implemented restructuring of UK healthcare services. The The Royal National Orthopaedic Hospital, Stanmore, became a central hub for the provision of trauma services for North Central/East London (NCEL) while providing a musculoskeletal tumour service for the south of England, the Midlands, and Wales and an urgent spinal service for London. This study reviews our paediatric practice over this period in order to share our experience and lessons learned. Our hospital admission pathways are described and the safety of surgical and interventional radiological procedures performed under general anaesthesia (GA) with regards to COVID-19 in a paediatric population are evaluated. METHODS: All paediatric patients (≤ 16 years) treated in our institution during the six-week peak period of the pandemic were included. Prospective data for all paediatric trauma and urgent elective admissions and retrospective data for all sarcoma admissions were collected. Telephone interviews were conducted with all patients and families to assess COVID-19 related morbidity at 14 days post-discharge. RESULTS: Overall, 100 children underwent surgery or interventional radiological procedures under GA between 20 March and 8 May 2020. There were 35 trauma cases, 20 urgent elective orthopaedic cases, two spinal emergency cases, 25 admissions for interventional radiology procedures, and 18 tumour cases. 78% of trauma cases were performed within 24 hours of referral. In the 97% who responded at two weeks following discharge, there were no cases of symptomatic COVID-19 in any patient or member of their households. CONCLUSION: Despite the extensive restructuring of services and the widespread concerns over the surgical and anaesthetic management of paediatric patients during this period, we treated 100 asymptomatic patients across different orthopaedic subspecialties without apparent COVID-19 or unexpected respiratory complications in the early postoperative period. The data provides assurance for health care professionals and families and informs the consenting process.Cite this article: Bone Joint Open 2020;1-6:287-292.

External fixation for the correction of adult post-traumatic deformities.

Malalignment of the lower limb is a significant factor in the progression of arthritis of the knee and ankle, and correction of deformity can slow the progress and reduce symptoms. It is less clear that malalignment can cause arthritis de novo, but in post traumatic deformity it has been shown that a fracture of the tibia can increase the risk of pain and stiffness of the knee and ankle irrespective of deformity. The management of deformity of the lower limb by external fixation requires a careful systematic method of deformity analysis combining clinical and radiographic assessment is essential to avoid the pitfalls of overlooking potential soft tissue problems, and hidden secondary deformities. External fixators are powerful tools for the correction of deformity, but a sound grounding in deformity analysis is essential.

The role of external fixation in paediatric limb lengthening and deformity correction.

Limb deformity and shortening remains a common presenting complaint in paediatric orthopaedics. The ability to restore length, alignment with consistent bone formation allows standardised treatment in these difficult conditions. The use of an external fixator produces a stable construct which allows manipulation of the bone segments, with a controlled rate and rhythm. Deformity analysis permits the surgeon to plan osteotomy levels and frame application to produce accurate correction. Complications, especially in congenital conditions remain an issue and modification of the treatment is required to try and reduce their incidence. New types of fixators, the latest being hexapod frames, have increased the versatility in deformity correction. The aim of this paper is to review the use of external fixators in elective paediatric orthopaedics and highlight the latest changes in technique and application for the limb reconstruction surgeon.