Neonatal clinical examination and selective ultrasound screening are not reliable for the early diagnosis of hip dysplasia: A retrospective cohort study.

AIM: To compare the incidence, clinical features and timing of initial treatment of early- and later-presenting developmental dysplasia of the hip (DDH) in infancy in the context of a risk-based selective ultrasound screening programme. METHODS: We conducted a retrospective observational study of infants born at a tertiary perinatal centre in Melbourne, Australia, between July 2016 and June 2020 and treated for DDH up to 18 months of age at a tertiary paediatric centre. The incidence of DDH was calculated for early- and later-presenting cases. Clinical features and ultrasound indications were analysed using multivariate logistic regression. RESULTS: There were 192 infants with DDH requiring treatment, 100 (52%) of which were not detected by universal neonatal hip examination and selective ultrasound screening based on risk factors (overall incidence 6.3 per 1000 livebirths). The median age at which treatment was commenced was delayed by 8 weeks for the later-presenting group compared to those detected through screening (16.7 vs. 7.9 weeks, P < 0.001). Skin crease asymmetry was associated with later presentation (adjusted odds ratio (aOR) 44.03, 95% confidence interval (CI) 9.99-333), whilst breech presentation (aOR 0.08, 95% CI 0.02-0.26) and Barlow/Ortolani test positivity (aOR 0.06, 95% CI 0.01-0.25) were associated with early presentation. Only 39 (1.45%) infants receiving a screening ultrasound had DDH. CONCLUSION: Approximately half of all infants with DDH were not detected by combining risk-based selective ultrasound screening with neonatal clinical findings, highlighting the failure of this screening method to reliably detect a significant proportion of dysplastic infant hips.

18 F-FDG PET and PET/CT as a diagnostic method for Ewing sarcoma: A systematic review and meta-analysis.

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of 18 -fluorodeoxyglucose-positron emission tomography (18 F-FDG PET) and PET/computed tomography (PET/CT) in imaging primary and metastatic lesions in Ewing sarcoma (ES). METHODS: PubMed, Cochrane, Scopus, and Web of Science were searched for relevant studies. Data concerning 18 F-FDG PET/CT diagnostic accuracy were extracted and then analyzed using Open Meta-analyst software. Reported diagnostic accuracy outcomes included sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), and diagnostic odds ratio. RESULTS: Thirty-one studies with a total of 735 patients were included in this meta-analysis. The sensitivity and specificity of 18 F-FDG PET/CT were: 92.6% and 74.1% for total ES lesions, 96.7% and 68.3% for ES primary lesions, 76.1% and 92.4% for lung metastasis, 83.9% and 93.2% for bone metastasis, and 89.9% and 92.6% for ES recurrence, respectively. CONCLUSION: 18 F-FDG PET/CT is sensitive and accurate in diagnosing, staging, and detecting the recurrence of ES compared with non-PET imaging. It has high accuracy for diagnosing recurrence of ES in bone metastases; however, CT remains a superior diagnostic method for detecting lung metastasis.

Intramedullary Fixation of Double-Barrel Vascularised Fibula Grafts With Subsequent Lengthening for Reconstruction of the Distal Femur in Patients With Osteosarcoma.

BACKGROUND: The use of vascularised fibula grafts is an accepted method for reconstructing the distal femur following resection of malignant childhood tumors. Limitations relate to the mismatch of the cross-sectional area of the transplanted fibula graft and the local bone, instability of the construct and union difficulties. We present midterm results of a unique staged technique-an immediate defect reconstruction using a double-barrel vascularised fibula graft set in in A-frame configuration and a subsequent intramedullary femoral lengthening. METHODS: We retrospectively included 10 patients (mean age 10 y) with an osteosarcoma of the distal femur, who were treated according to the above-mentioned surgical technique. All patients were evaluated with regards to consolidation of the transplanted grafts, hypertrophy at the graft-host junctions, leg length discrepancies, lengthening indices, complications as well as functional outcome. RESULTS: The mean defect size after tumor resection was 14.5 cm, the mean length of the harvested fibula graft 22 cm, resulting in a mean (acute) shortening of 4.7 cm (in 8 patients). Consolidation was achieved in all cases, 4 patients required supplementary bone grafting. Hypertrophy at the graft-host junctions was observed in 78% of the evaluable junctions. In total 11 intramedullary lengthening procedures in 9 patients had been performed at the last follow up. The mean Muskuloskeletal Society Rating Scale (MSTS) score of the evaluable 9 patients was 85% (57% to 100%) with good or excellent results in 7 patients. CONCLUSIONS: A-frame vascularised fibula reconstructions showed encouraging results with respect to defect reconstruction, length as well as function and should therefore be considered a valuable option for reconstruction of the distal femur after osteosarcoma resection. The surgical implementation is demanding though, which is emphasized by the considerable high number of complications requiring surgical intervention, even though most were not serious. LEVEL OF EVIDENCE: Level IV-case series.

The Gait Outcomes Assessment List for Children With Lower Limb Difference (GOAL-LD): Assessment of Reliability and Validity.

BACKGROUND: The Gait Outcomes Assessment List for children with Lower Limb Difference (GOAL-LD) is a patient and parent-reported outcome measure that incorporates the framework of the International Classification of Functioning, Disability, and Health. This prospective multicenter cohort study evaluates the validity and reliability of the GOAL-LD and the differences between parent and adolescent report. METHOD: One hundred thirty-seven pediatric patients aged over 5 years attending limb reconstruction clinics at the participating sites were assessed at baseline, and a self-selected cohort also completed an assessment 2 to 6 weeks later. Construct and criterion validity were assessed by comparing GOAL-LD scores with a measure of limb deformity complexity (LLRS-AIM) and the Pediatric Outcomes Data Collection Instrument, using Spearman correlation coefficients. Face and content validity were determined through ratings of item importance. Test-retest reliability was reported as an intraclass correlation coefficient and internal consistency using Cronbach α. Adolescent reports were compared with their parents using paired t tests. RESULTS: The GOAL-LD demonstrated a moderate negative correlation with the LLRS-AIM (r=-0.40, P<0.001) and was able to discriminate between deformity complexity groups as defined by the LLRS-AIM (χ2=11.43, P=0.022). Internal consistency was high across all domains (α≥0.68 to 0.97). Like domains of the Pediatric Outcomes Data Collection Instrument and the GOAL-LD were well correlated. Parents reported a lower total GOAL-LD score when compared with adolescents (mean difference 3.04; SE 1.06; 95% confidence interval, 0.92-5.16; P<0.01); however this difference was only significant for body image and self-esteem (Domain F) and gait appearance (Domain D). Test-retest reliability remained high over the study period (intraclass correlation coefficient 0.85; SE 0.03; 95% confidence interval, 0.77-0.91). CONCLUSIONS: The GOAL-LD is a valid and reliable self and parent-reported outcome measure for children with lower limb difference. Parents report a lower level of function and attribute a higher importance to items when compared with their children. The GOAL-LD helps to communicate parent and child perspectives on their function and priorities and therefore has the capacity to facilitate family centered treatment planning and care. LEVEL OF EVIDENCE: Level II-diagnostic. Prospective cross-sectional and a longitudinal cohort design.

Pedicled fibular transfer for biologic knee extensor tendon reinsertion following proximal tibial resection in pediatric osteosarcoma: Long-term outcomes.

INTRODUCTION: Proximal tibial sarcoma resections result in a reconstructive challenge, necessitating joint and extensor mechanism reconstruction. The gait and functional outcomes for children reconstructed with a combination of megaprosthesis and pedicled fibular flap for extensor mechanism reconstruction, are presented. METHODS: Four patients, aged 11-18 years old, were available for comprehensive analysis. The proximal tibial osteosarcoma was resected, and the reconstructive technique involved a megaprosthesis for the knee joint, used in combination with a pedicled fibula flap as a biologic structure for reinsertion of the knee extensor mechanism. Outcomes were measured with three-dimensional gait analysis and patient questionnaires. RESULTS: Minor postoperative wound issues occurred in some patients, requiring debridement with skin grafting. One patient fractured their transferred fibula, requiring fixation. The follow up period ranged from 1.7 to 24 years postoperatively. The longevity and quality of reconstructions were strong, measured by both objective and patient-reported outcomes. All patients reported independent walking >500 m in the Functional Mobility Scale and rated their walking as a nine or 10 (out of 10) on the Functional Assessment Questionnaire. Knee society scoring revealed overall satisfaction rate of 75-80%. No patients required gait aids. The gait profile analysis revealed effective gait patterns, with patterns deviating 5.4-7° from "typical gait." Deviations >6.5° are considered abnormal. CONCLUSION: The long-term results of combining a megaprosthesis with a pedicled fibula flap for extensor reinsertion, revealed a high level of independent function. The patients performed well, without the need for aids, and gait study evidence of minimal gait deviations.

Syme Amputation: Function, Satisfaction, and Prostheses.

BACKGROUND: Syme amputation (SA) is a term used to describe an amputation at the level of the ankle joint in which the heel pad is preserved. It is performed for a number of indications in a pediatric population. SA is purported to hold the advantage of allowing weight bearing without a prosthesis. A limb length discrepancy (LLD) is useful for ambulation without a prosthesis but can be restrictive with regards to the fitting of modern prostheses. METHODS: A voluntary survey was distributed to persons living with SA. Recruitment occurred through hospital electronic database and electronic advertising. Data collected included baseline demographic information, data pertaining to weight bearing in different environments, as well as 2 validated outcome measures: the Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R activity restriction scale) and the Locomotor Capabilities Index-5 (LCI-5). An illustration was designed to allow participants to classify their LLD by zone in relation to their nonamputated limb. RESULTS: At total of 47 persons living with SA participated. The average age at amputation was 3.7 years (range, 0.5 to 14.1 y), and at survey completion 15.8 years (1.7 to 60.3). Five of the described "zones" of LLD were represented. Average LCI-5 score was 52.6. Mean TAPES-R activity restriction scale was 0.59, the lowest mean being achieved by zone E participants, indicating the least restriction. Ability to walk without a prosthesis was lower in those participants over 11 years, when compared with those under, as well as being dependent on the walking environment. CONCLUSIONS: Our study found no trend indicating that a very low LLD was functionally optimal, and indeed found participants with a moderate LLD (zone E) to have the least mean restriction with regard to their prosthesis. Our study demonstrates that ambulation without a prosthesis depends on the environment (ie, flooring), and rates decrease significantly into adulthood. Optimal care should not focus simply "preserving length," but rather functional optimization and length modulation in parallel with a nuanced understanding of actual daily activities and prosthetic options. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Osteosarcoma in a Child Below 2 Years of Age: Case Report and Review of the Literature.

BACKGROUND: Osteosarcoma in children below the age of 5 is extremely rare. OBSERVATION: We report on a previously well 14-month-old male infant, who presented with a reluctance to weight-bear on his right leg and had an associated limp. Plain imaging and a magnetic resonance imaging scan demonstrated a lytic lesion in the right distal femur. An open surgical biopsy confirmed the diagnosis of osteosarcoma. There was no significant family history of cancer and genetic screening for Li-Fraumeni syndrome was negative. CONCLUSIONS: This case highlights the importance of timely consideration of osteosarcoma in an infant, when the clinical presentation and medical imaging are consistent with that diagnosis.

Preoperative Assessment for Complex Lower Limb Deformity.

Successful limb reconstruction surgery not only relies on surgical skill but probably more on assessment and planning before intervention. A clear appreciation of the child as a whole, an understanding of natural history and the ability to carefully evaluate the patient clinically are key to successful treatment. The appropriate use of investigations and the ability to analyze, plan and execute a treatment plan is challenging and requires experience and training. This paper outlines some of the steps required to assess the patient with a complex limb deformity.

Septic arthritis in children.

BACKGROUND: Septic arthritis in children is an orthopaedic emergency that has serious consequences if not diagnosed promptly and treated effectively. The presenting symptoms include pain, non-weight bearing and fever. Inflammatory markers are raised and ultra-sonography demonstrates a joint effusion. OBJECTIVE: The purpose of this article is to provide an overview of septic arthritis in children. DISCUSSION: Definitive treatment involves surgical drainage and lavage of the joint, followed by high-dose, empirical, intravenous (IV) antibiotics. Treatment is tailored to the causative organism, if this is identified. For an uncomplicated case of septic arthritis, 2 days of IV antibiotics followed by a 3-week course of oral antibiotics is usually sufficient. Long-term follow-up is necessary to monitor for sequelae of septic arthritis, including cartilage damage, growth disturbance and avascular necrosis of the femoral head.

Paediatric hip ultrasound.

Aims: The aim of this study was to investigate the agreement in interpretation of the quality of the paediatric hip ultrasound examination, the reliability of geometric and morphological assessment, and the relationship between these measurements. Methods: Four investigators evaluated 60 hip ultrasounds and assessed their quality based the standard plane of Graf et al. They measured geometric parameters, described the morphology of the hip, and assigned the Graf grade of dysplasia. They analyzed one self-selected image and one randomly selected image from the ultrasound series, and repeated the process four weeks later. The intra- and interobserver agreement, and correlations between various parameters were analyzed. Results: In the assessment of quality, there a was moderate to substantial intraobserver agreement for each element investigated, but interobserver agreement was poor. Morphological features showed weak to moderate agreement across all parameters but improved to significant when responses were reduced. The geometric measurements showed nearly perfect agreement, and the relationship between them and the morphological features showed a dose response across all parameters with moderate to substantial correlations. There were strong correlations between geometric measurements. The Graf classification showed a fair to moderate interobserver agreement, and moderate to substantial intraobserver agreement. Conclusion: This investigation into the reliability of the interpretation of hip ultrasound scans identified the difficulties in defining what is a high-quality ultrasound. We confirmed that geometric measurements are reliably interpreted and may be useful as a further measurement of quality. Morphological features are generally poorly interpreted, but a simpler binary classification considerably improves agreement. As there is a clear dose response relationship between geometric and morphological measurements, the importance of morphology in the diagnosis of hip dysplasia should be questioned.

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.

Enhancing Value and Uptake for Whole-Population Cohorts of Children and Parents: Methods to Integrate Registries into the Generation Victoria Cohort.

Health registries are critical to understanding, benchmarking and improving quality of care for specific diseases and conditions, but face hurdles including funding, bias towards clinical rather than population samples, lack of pre-morbid and outcomes data, and absent cross-registry harmonisation and coordination. Children are particularly under-represented in registry research. This paper lays out novel principles, methods and governance to integrate diverse registries within or alongside a planned children's mega-cohort to rapidly generate translatable evidence. GenV (Generation Victoria) will approach for recruitment parents of all newborns (estimated 150,000) over two years from mid-2021 in the state of Victoria (population 6.5 million), Australia. Its sample size and population denominator mean it will contain almost all children with uncommon or co-morbid conditions as they emerge over time. By design, it will include linked datasets, biosamples (including from pregnancy), phenotypes and participant-reported measures, all of which will span pre-morbid to long-term outcomes. We provide a vignette of a planned new registry for high-risk pregnancies to illustrate the possibilities. To our knowledge, this is the first paper to describe such a methodology designed prospectively to enhance both the clinical relevance of a large multipurpose cohort and the value and inclusivity of registries in a population.

Ligamentum teres tenodesis in medial approach open reduction for developmental dislocation of the hip.

BACKGROUND: When closed reduction of a developmental dislocation of the hip fails, some form of open reduction is required. In recent years, the many advantages of the medial approach open reduction have been emphasized. However, there have been suggestions that the rate of growth disturbance in the proximal femur and the requirement for secondary surgical procedures may be higher with this route than with others. The purpose of this study was to investigate the efficacy and safety of a modified medial approach open reduction, in which the stability of the reduction is enhanced by resection of the redundant ligamentum teres and suturing of the stump of the tendon to the anteromedial capsule. METHODS: The hospital records and radiographs of 92 infants and children with 109 dislocated hips were reviewed retrospectively. Key demographic and pretreatment data were collected by the first author and compared with the outcome at the most recent follow-up. In addition, 69 children returned for a clinical evaluation by the first author. The outcome at the most recent follow-up was graded according to Severin, and associations were sought between pretreatment grade of dislocation according to Tonnis, the presence of ossific nucleus, changes in the acetabular index, the requirements for secondary surgery, associations with previous treatment, and the position of abduction in the postoperative cast. RESULTS: At a mean follow-up of 9 years, 89% of hips were classified as Severin grade 1 or 2. Avascular necrosis (AVN) was classified according to the system of Kalamchi and MacEwen. The incidence of AVN was 41%, but two thirds of these were grade 1 (temporary irregular ossification), and the Severin grading in these hips was not compromised. The presence of ossification in the capital epiphysis and a range of abduction of less than 60 degrees in the hip spica were noted to be protective against the development of AVN. Three hips redislocated and required additional treatment. Thirty-eight hips required a total of 44 additional surgical procedures. CONCLUSIONS: We have demonstrated that it is possible to use a medial approach for open reduction of the congenitally dislocated hip in combination with tenodesis of the ligamentum teres to the anteromedial joint capsule. The incidence of growth disturbance in the proximal femur is high and cumulative with long-term follow-up. However, in this large series, the rate of hip stability, growth disturbance, and need for secondary surgery are comparable to other series. We conclude that the many advantages of open reduction by the medial approach outweigh the disadvantages.

Impact of web-based clinical practice guidelines on paediatric fracture clinics.

BACKGROUND: In an effort to standardize management and reduce over-treatment of uncomplicated paediatric fractures, the Victorian Pediatric Orthopaedic Network and the Royal Children's Hospital, Melbourne, created publically available web-based paediatric fracture pathways. The aim of this study was to determine the impact of web-based fracture pathways on the clinic volume at a tertiary-care paediatric fracture clinic. METHODS: A comparative retrospective review was performed at a large, urban, tertiary-care children's hospital. Fracture clinic data from two 12-week periods before and after implementation of the fracture pathways were compared. For each study period, data collected included: total number of emergency department visits, number of fracture clinic visits, number of fracture clinic visits for patients that presented with upper extremity fractures for which web-based fracture pathways were available, number of radiology department visits for X-rays, and number of fracture clinic visits for patients requiring orthopaedic intervention in the operating room (closed or open reductions). RESULTS: The number of fracture clinic visits for patients with upper extremity fractures decreased 12% post-pathway implementation, from 954 visits to 842 visits. The number of radiology department visits for patients with upper extremity fractures decreased 24% post-pathway implementation, from 714 to 544 visits. CONCLUSION: The implementation of web-based fracture pathways for upper extremity paediatric fractures was associated with a decrease in clinic resource utilization at a tertiary-care children's hospital.

High recurrence after calf lengthening with the Ilizarov apparatus for treatment of spastic equinus foot deformity.

Both gastrocnemius recession and Achilles tendon lengthening lead to scarring in the calf and have high reported recurrence rates when performed under the age of 8 years. Triceps surae lengthening by external fixation seemed to be a valuable alternative. Twelve calf lengthenings have been performed with an Ilizarov device with a mean correction of 27 degrees. No calcaneal gait was observed, but there was a slow continuous loss of dorsiflexion over the observation period. The Ilizarov technique has a higher recurrence rate than most operative procedures for calf lengthening, but carries virtually no risk in producing calcaneus. The technique cannot be recommended for routine clinical use and may only be an alternative for selected cases.

The radiographic classification of the bone-screw interface in paediatric tibial lengthening.

Bone-screw loosening in monolateral external fixators is a significant problem. This study classifies the radiographic appearance of the bone-screw interface and predicts which screws will become loose and those that will remain solidly fixed to bone. Five radiographic features were identified at the bone-screw interface. The classification of these features was validated using interobserver and intraobserver studies. The reliability of the classification was improved by image enhancement with simple filters. Some radiographic features predicted which screws would eventually become loose, allowing the clinician to make earlier management decisions regarding the adjustment of screws.

Assessment of the Pediatric Foot Mass.

Masses in the pediatric foot are relatively uncommon and can present a diagnostic challenge. The literature lacks a comprehensive overview of these types of lesions. Most are benign soft-tissue lesions that can be diagnosed on the basis of history and physical examination. However, some rare malignant neoplasms can mimic benign masses. It is imperative to recognize these lesions because the consequences of a delayed or missed diagnosis can be substantial. A thorough history and physical examination of all pediatric patients with foot lesions are crucial to ensure that any lesion not readily identified as benign is appropriately managed.

Gradual femoral lengthening with the Albizzia intramedullary nail.

BACKGROUND: Gradual limb lengthening with currently used external fixation techniques can result in less than optimal outcomes, with complications including infection, stiffness of adjacent joints, and secondary axial deviation of the extremity. We describe a totally implantable lengthening device designed to provide results similar to those achieved with external fixation devices, with fewer complications and improved outcomes. METHODS: Between 1993 and 1997, thirty-one patients (forty-one femora) underwent limb lengthening with a new internal fixation technique (Albizzia) to treat a congenitally short extremity (thirteen patients), post-traumatic limb-length inequality (eleven patients), or developmental problems (seven patients). Twenty-one patients (twenty-one femora) underwent unilateral surgery to equalize the limb lengths, and ten (twenty femora) underwent bilateral surgery to correct short stature. The mean age was twenty years and one month (range, twelve to thirty-nine years). After intramedullary corticotomy of the diaphysis of the femur, an intramedullary nail was inserted in an antegrade fashion. Fifteen alternating internal and external rotation maneuvers of the lower limb elongated the nail by 1 mm. The outcomes were assessed clinically and radiographically at a mean of fifty months postoperatively. RESULTS: The gain in femoral length averaged 3.4 cm (range, 2 to 5.5 cm) after the unilateral lengthening procedures and 6.3 cm (range, 4.6 to 8.4 cm) after the bilateral procedures. Patients underwent an average of three operations on each limb; these procedures included, in addition to the nail insertion and nail removal, ratcheting under general anesthesia in thirteen limbs and eleven procedures to treat complications in nine patients. At the time of follow-up, no patient had axial deviation of the limb secondary to lengthening. CONCLUSIONS: Femoral lengthening with use of the minimally invasive Albizzia technique provides a reasonable alternative to external fixation that is well tolerated by patients and results in excellent function with little or no distortion of body image.

Acute correction of lower limb deformity and simultaneous lengthening with a monolateral fixator.

We have reviewed, retrospectively, all children with a lower limb deformity who underwent an acute correction and lengthening with a monolateral fixator between 1987 and 1996. The patients were all under the age of 19 years and had a minimum follow-up of eight months after removal of the fixator. A total of 41 children had 57 corrections and lengthening. Their mean age was 11.3 years (3.2 to 18.7) and there were 23 girls and 18 boys. The mean maximum correction in any one plane was 23 degrees (7 to 45). In 41 bony segments (either femur or tibia) a uniplanar correction was made while various combinations were carried out in 16. The site of the osteotomy was predominantly diaphyseal, at a mean of 47% (17% to 73%) of the total bone length and the mean length gained was 6.4 cm (1.0 to 17.0). Univariate analysis identified a moderately strong relationship between the bone healing index (BHI), length gained, maximum correction and grade-II to grade-III complications. For logistic regression analysis the patients were binary coded into two groups; those with a good outcome (BHI < or = 45 days/cm) and those with a poor outcome (BHI > 45 days/cm). Various factors which may influence the outcome were then analysed by calculating odds ratios with 95% confidence intervals. This analysis suggested a dose response between increasing angular correction and poor BHI which only reached statistical significance for corrections of larger magnitude. Longer lengthenings were associated with a better BHI while age and the actual bone lengthened had little effect. Those patients with a maximum angulatory correction of less than 30 degrees in any one plane had an acceptable consolidation time with few major complications. The technique is suitable for femoral deformity and shortening, but should be used with care in the tibia since the risk of a compartment syndrome or neurapraxia is much greater.