Advertisement for orthosearch.org.uk
Results 1 - 20 of 75
Results per page:
The Bone & Joint Journal
Vol. 95-B, Issue 7 | Pages 993 - 1000
1 Jul 2013
Lee SC Shim JS Seo SW Lim KS Ko KR

We compared the accuracy of the growth remaining method of assessing leg-length discrepancy (LLD) with the straight-line graph method, the multiplier method and their variants. We retrospectively reviewed the records of 44 patients treated by percutaneous epiphysiodesis for LLD. All were followed up until maturity. We used the modified Green–Anderson growth-remaining method (Method 1) to plan the timing of epiphysiodesis. Then we presumed that the other four methods described below were used pre-operatively for calculating the timing of epiphysiodesis. We then assumed that these four methods were used pre-operatively. Method 2 was the original Green–Anderson growth-remaining method; Method 3, Paley’s multiplier method using bone age; Method 4, Paley’s multiplier method using chronological age; and Method 5, Moseley’s straight-line graph method. We compared ‘Expected LLD at maturity with surgery’ with ‘Final LLD at maturity with surgery’ for each method. Statistical analysis revealed that ‘Expected LLD at maturity with surgery’ was significantly different from ‘Final LLD at maturity with surgery’. Method 2 was the most accurate. There was a significant correlation between ‘Expected LLD at maturity with surgery’ and ‘Final LLD at maturity with surgery’, the greatest correlation being with Method 2. Generally all the methods generated an overcorrected value. No method generates the precise ‘Expected LLD at maturity with surgery’. It is essential that an analysis of the pattern of growth is taken into account when predicting final LLD. As many additional data as possible are required. Cite this article: Bone Joint J 2013;95-B:993–1000


The Bone & Joint Journal
Vol. 97-B, Issue 12 | Pages 1710 - 1717
1 Dec 2015
Nicholson AD Sanders JO Liu RW Cooperman DR

The accurate assessment of skeletal maturity is essential in the management of orthopaedic conditions in the growing child. In order to identify the time of peak height velocity (PHV) in adolescents, two systems for assessing skeletal maturity have been described recently; the calcaneal apophyseal ossification method and the Sanders hand scores.

The purpose of this study was to compare these methods in assessing skeletal maturity relative to PHV. We studied the radiographs of a historical group of 94 healthy children (49 females and 45 males), who had been followed longitudinally between the ages of three and 18 years with serial radiographs and physical examination. Radiographs of the foot and hand were undertaken in these children at least annually between the ages of ten and 15 years. We reviewed 738 radiographs of the foot and 694 radiographs of the hand. PHV was calculated from measurements of height taken at the time of the radiographs.

Prior to PHV we observed four of six stages of calcaneal apophyseal ossification and two of eight Sanders stages. Calcaneal stage 3 and Sanders stage 2 was seen to occur about 0.9 years before PHV, while calcaneal stage 4 and Sanders stage 3 occurred approximately 0.5 years after PHV.

The stages of the calcaneal and Sanders systems can be used in combination, offering better assessment of skeletal maturity with respect to PHV than either system alone.

Cite this article: Bone Joint J 2015;97-B:1710–17.


Bone & Joint Open
Vol. 4, Issue 10 | Pages 750 - 757
10 Oct 2023
Brenneis M Thewes N Holder J Stief F Braun S

Aims. Accurate skeletal age and final adult height prediction methods in paediatric orthopaedics are crucial for determining optimal timing of growth-guiding interventions and minimizing complications in treatments of various conditions. This study aimed to evaluate the accuracy of final adult height predictions using the central peak height (CPH) method with long leg X-rays and four different multiplier tables. Methods. This study included 31 patients who underwent temporary hemiepiphysiodesis for varus or valgus deformity of the leg between 2014 and 2020. The skeletal age at surgical intervention was evaluated using the CPH method with long leg radiographs. The true final adult height (FH. TRUE. ) was determined when the growth plates were closed. The final height prediction accuracy of four different multiplier tables (1. Bayley and Pinneau; 2. Paley et al; 3. Sanders – Greulich and Pyle (SGP); and 4. Sanders – peak height velocity (PHV)) was then compared using either skeletal age or chronological age. Results. All final adult height predictions overestimated the FH. TRUE. , with the SGP multiplier table having the lowest overestimation and lowest absolute deviation when using both chronological age and skeletal age. There were no significant differences in final height prediction accuracy between using skeletal age and chronological age with PHV (p = 0.652) or SGP multiplier tables (p = 0.969). Adult height predictions with chronological age and SGP (r = 0.769; p ≤ 0.001), as well as chronological age and PHV (r = 0.822; p ≤ 0.001), showed higher correlations with FH. TRUE. than predictions with skeletal age and SGP (r = 0.657; p ≤ 0.001) or skeletal age and PHV (r = 0.707; p ≤ 0.001). Conclusion. There was no significant improvement in adult height prediction accuracy when using the CPH method compared to chronological age alone. The study concludes that there is no advantage in routinely using the CPH method for skeletal age determination over the simple use of chronological age. The findings highlight the need for more accurate methods to predict final adult height in contemporary patient populations. Cite this article: Bone Jt Open 2023;4(10):750–757


The Bone & Joint Journal
Vol. 104-B, Issue 9 | Pages 1081 - 1088
1 Sep 2022
Behman AL Bradley CS Maddock CL Sharma S Kelley SP

Aims. There is no consensus regarding optimum timing and frequency of ultrasound (US) for monitoring response to Pavlik harness (PH) treatment in developmental dysplasia of the hip (DDH). The purpose of our study was to determine if a limited-frequency hip US assessment had an adverse effect on treatment outcomes compared to traditional comprehensive US monitoring. Methods. This study was a single-centre noninferiority randomized controlled trial. Infants aged under six months whose hips were reduced and centred in the harness at initiation of treatment (stable dysplastic or subluxable), or initially decentred (subluxated or dislocated) but reduced and centred within four weeks of PH treatment, were randomized to our current standard US monitoring protocol (every clinic visit) or to a limited-frequency US protocol (US only at end of treatment). Groups were compared based on α angle and femoral head coverage at the end of PH treatment, acetabular indices, and International Hip Dysplasia Institute (IHDI) grade on one-year follow-up radiographs. Results. Overall, 100 patients were included; 42 patients completed the standard protocol (SP) and 40 completed the limited protocol (LP). There was no significant difference in mean right α angle at the end of treatment (SP 70.0° (SD 3.2°) ; LP 68.7° (SD 2.9°); p = 0.033), nor on the left (SP 69.0° (SD 3.5°); LP 68.1° (SD 3.3°); p = 0.128). There was no significant difference in mean right acetabular index at follow-up (SP 23.1° (SD 4.3°); LP 22.0° (SD 4.1°); p = 0.129), nor on the left (SP 23.3° (SD 4.2°); LP 22.8° (SD 3.9°); p = 0.284). All hips had femoral head coverage of > 50% at end of treatment, and all were IHDI grade 1 at follow-up. In addition, the LP group underwent a 60% reduction in US use once stable. Conclusion. Our study supports reducing the frequency of US assessment during PH treatment of DDH once a hip is reduced and centred. Cite this article: Bone Joint J 2022;104-B(9):1081–1088


The Bone & Joint Journal
Vol. 103-B, Issue 3 | Pages 589 - 596
1 Mar 2021
Amin N Kraft J Fishlock A White A Holton C Kinsey S Feltbower R James B

Aims. Osteonecrosis (ON) can cause considerable morbidity in young people who undergo treatment for acute lymphoblastic leukaemia (ALL). The aims of this study were to determine the operations undertaken for ON in this population in the UK, along with the timing of these operations and any sequential procedures that are used in different joints. We also explored the outcomes of those patients treated by core decompression (CD), and compared this with conservative management, in both the pre- or post-collapse stages of ON. Methods. UK treatment centres were contacted to obtain details regarding surgical interventions and long-term outcomes for patients who were treated for ALL and who developed ON in UKALL 2003 (the national leukaemia study which recruited patients aged 1 to 24 years at diagnosis of ALL between 2003 and 2011). Imaging of patients with ON affecting the femoral head was requested and was used to score all lesions, with subsequent imaging used to determine the final grade. Kaplan-Meier failure time plots were used to compare the use of CD with non surgical management. Results. Detailed information was received for 85 patients who had developed ON during the course of their ALL treatment. A total of 206 joints were affected by ON. Of all joints affected by ON, 21% required arthroplasty, and 43% of all hips affected went on to be replaced. CD was performed in 30% of hips affected by ON. The majority of the hips were grade 4 or 5 at initial diagnosis of ON. There was no significant difference in time to joint collapse between those joints in which CD was performed, compared with no joint-preserving surgical intervention. Conclusion. There is a high incidence of surgery in young people who have received treatment for ALL and who have developed ON. Our results suggest that CD of the femoral head in this group of patients does not delay or improve the rates of femoral head survival. Cite this article: Bone Joint J 2021;103-B(3):589–596


The Bone & Joint Journal
Vol. 95-B, Issue 6 | Pages 855 - 860
1 Jun 2013
Gottliebsen M Møller-Madsen B Stødkilde-Jørgensen H Rahbek O

Permanent growth arrest of the longer bone is an option in the treatment of minor leg-length discrepancies. The use of a tension band plating technique to produce a temporary epiphysiodesis is appealing as it avoids the need for accurate timing of the procedure in relation to remaining growth. We performed an animal study to establish if control of growth in a long bone is possible with tension band plating. Animals (pigs) were randomised to temporary epiphysiodesis on either the right or left tibia. Implants were removed after ten weeks. Both tibiae were examined using MRI at baseline, and after ten and 15 weeks. The median interphyseal distance was significantly shorter on the treated tibiae after both ten weeks (p = 0.04) and 15 weeks (p = 0.04). On T. 1. -weighted images the metaphyseal water content was significantly reduced after ten weeks on the treated side (p = 0.04) but returned to values comparable with the untreated side at 15 weeks (p = 0.14). Return of growth was observed in all animals after removal of implants. Temporary epiphysiodesis can be obtained using tension band plating. The technique is not yet in common clinical practice but might avoid the need for the accurate timing of epiphysiodesis. Cite this article: Bone Joint J 2013;95-B:855–60


Bone & Joint Open
Vol. 4, Issue 10 | Pages 735 - 741
2 Oct 2023
Galloway AM Pini S Holton C Perry DC Redmond A Siddle HJ Richards S

Aims

Perthes’ disease is an idiopathic avascular necrosis of the developing femoral head, often causing deformity that impairs physical function. Current treatments aim to optimize the joint reaction force across the hip by enhancing congruency between the acetabulum and femoral head. Despite a century of research, there is no consensus regarding the optimal treatment. The aim of this study was to describe the experiences of children, their families, and clinicians when considering the treatment of Perthes’ disease.

Methods

A qualitative study gathered information from children and their families affected by Perthes’ disease, along with treating clinicians. Interviews followed a coding framework, with the interview schedule informed by behavioural theory and patient and public involvement. Transcripts were analyzed using the framework method.


The Bone & Joint Journal
Vol. 105-B, Issue 1 | Pages 82 - 87
1 Jan 2023
Barrie A Kent B

Aims

Management of displaced paediatric supracondylar elbow fractures remains widely debated and actual practice is unclear. This national trainee collaboration aimed to evaluate surgical and postoperative management of these injuries across the UK.

Methods

This study was led by the South West Orthopaedic Research Division (SWORD) and performed by the Supra Man Collaborative. Displaced paediatric supracondylar elbow fractures undergoing surgery between 1 January 2019 and 31 December 2019 were retrospectively identified and their anonymized data were collected via Research Electronic Data Capture (REDCap).


The Bone & Joint Journal
Vol. 106-B, Issue 7 | Pages 744 - 750
1 Jul 2024
Saeed A Bradley CS Verma Y Kelley SP

Aims

Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing.

Methods

This was a single-centre, prospective longitudinal cohort study of infants with DDH managed using a published, standardized Pavlik harness protocol between January 2012 and December 2016. RAD was measured at two years’ mean follow-up using acetabular index-lateral edge (AI-L) and acetabular index-sourcil (AI-S), and at five years using AI-L, AI-S, centre-edge angle (CEA), and acetabular depth ratio (ADR). Each hip was classified based on published normative values for normal, borderline (1 to 2 standard deviations (SDs)), or dysplastic (> 2 SDs) based on sex, age, and laterality.


Bone & Joint Open
Vol. 4, Issue 8 | Pages 635 - 642
23 Aug 2023
Poacher AT Hathaway I Crook DL Froud JLJ Scourfield L James C Horner M Carpenter EC

Aims

Developmental dysplasia of the hip (DDH) can be managed effectively with non-surgical interventions when diagnosed early. However, the likelihood of surgical intervention increases with a late presentation. Therefore, an effective screening programme is essential to prevent late diagnosis and reduce surgical morbidity in the population.

Methods

We conducted a systematic review and meta-analysis of the epidemiological literature from the last 25 years in the UK. Articles were selected from databases searches using MEDLINE, EMBASE, OVID, and Cochrane; 13 papers met the inclusion criteria.


The Bone & Joint Journal
Vol. 106-B, Issue 5 | Pages 501 - 507
1 May 2024
Galloway AM Keene DJ Anderson A Holton C Redmond AC Siddle HJ Richards S Perry DC

Aims

The aim of this study was to produce clinical consensus recommendations about the non-surgical treatment of children with Perthes’ disease. The recommendations are intended to support clinical practice in a condition for which there is no robust evidence to guide optimal care.

Methods

A two-round, modified Delphi study was conducted online. An advisory group of children’s orthopaedic specialists consisting of physiotherapists, surgeons, and clinical nurse specialists designed a survey. In the first round, participants also had the opportunity to suggest new statements. The survey included statements related to ‘Exercises’, ‘Physical activity’, ‘Education/information sharing’, ‘Input from other services’, and ‘Monitoring assessments’. The survey was shared with clinicians who regularly treat children with Perthes’ disease in the UK using clinically relevant specialist groups and social media. A predetermined threshold of ≥ 75% for consensus was used for recommendation, with a threshold of between 70% and 75% being considered as ‘points to consider’.


The Bone & Joint Journal
Vol. 106-B, Issue 7 | Pages 751 - 758
1 Jul 2024
Yaxier N Zhang Y Song J Ning B

Aims

Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children.

Methods

In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs.


The Bone & Joint Journal
Vol. 106-B, Issue 3 | Pages 277 - 285
1 Mar 2024
Pinto D Hussain S Leo DG Bridgens A Eastwood D Gelfer Y

Aims

Children with spinal dysraphism can develop various musculoskeletal deformities, necessitating a range of orthopaedic interventions, causing significant morbidity, and making considerable demands on resources. This systematic review aimed to identify what outcome measures have been reported in the literature for children with spinal dysraphism who undergo orthopaedic interventions involving the lower limbs.

Methods

A PROSPERO-registered systematic literature review was performed following PRISMA guidelines. All relevant studies published until January 2023 were identified. Individual outcomes and outcome measurement tools were extracted verbatim. The measurement tools were assessed for reliability and validity, and all outcomes were grouped according to the Outcome Measures Recommended for use in Randomized Clinical Trials (OMERACT) filters.


The Bone & Joint Journal
Vol. 105-B, Issue 3 | Pages 331 - 340
1 Mar 2023
Vogt B Toporowski G Gosheger G Laufer A Frommer A Kleine-Koenig M Roedl R Antfang C

Aims

Temporary hemiepiphysiodesis (HED) is applied to children and adolescents to correct angular deformities (ADs) in long bones through guided growth. Traditional Blount staples or two-hole plates are mainly used for this indication. Despite precise surgical techniques and attentive postoperative follow-up, implant-associated complications are frequently described. To address these pitfalls, a flexible staple was developed to combine the advantages of the established implants. This study provides the first results of guided growth using the new implant and compares these with the established two-hole plates and Blount staples.

Methods

Between January 2013 and December 2016, 138 patients (22 children, 116 adolescents) with genu valgum or genu varum were treated with 285 flexible staples. The minimum follow-up was 24 months. These results were compared with 98 patients treated with 205 two-hole plates and 92 patients treated with 535 Blount staples. In long-standing anteroposterior radiographs, mechanical axis deviations (MADs) were measured before and during treatment to analyze treatment efficiency. The evaluation of the new flexible staple was performed according to the idea, development, evaluation, assessment, long-term (IDEAL) study framework (Stage 2a).


The Bone & Joint Journal
Vol. 106-B, Issue 10 | Pages 1190 - 1196
1 Oct 2024
Gelfer Y McNee AE Harris JD Mavrotas J Deriu L Cashman J Wright J Kothari A

Aims

The aim of this study was to gain a consensus for best practice of the assessment and management of children with idiopathic toe walking (ITW) in order to provide a benchmark for practitioners and guide the best consistent care.

Methods

An established Delphi approach with predetermined steps and degree of agreement based on a standardized protocol was used to determine consensus. The steering group members and Delphi survey participants included members from the British Society of Children’s Orthopaedic Surgery (BSCOS) and the Association of Paediatric Chartered Physiotherapists (APCP). The statements included definition, assessment, treatment indications, nonoperative and operative interventions, and outcomes. Descriptive statistics were used for analysis of the Delphi survey results. The AGREE checklist was followed for reporting the results.


The Bone & Joint Journal
Vol. 105-B, Issue 2 | Pages 198 - 208
1 Feb 2023
Cheok T Smith T Wills K Jennings MP Rawat J Foster B

Aims

We investigated the prevalence of late developmental dysplasia of the hip (DDH), abduction bracing treatment, and surgical procedures performed following the implementation of universal ultrasound screening versus selective ultrasound screening programmes.

Methods

A systematic search of PubMed, Embase, The Cochrane Library, OrthoSearch, and Web of Science from the date of inception of each database until 27 March 2022 was performed. The primary outcome of interest was the prevalence of late detection of DDH, diagnosed after three months. Secondary outcomes of interest were the prevalence of abduction bracing treatment and surgical procedures performed in childhood for dysplasia. Only studies describing the primary outcome of interest were included.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_6 | Pages 12 - 12
1 Feb 2013
Larnert P Madan S Giles S Davies A Jones S Fernandes J
Full Access

Aim. To evaluate the influence of arthrodiatasis in the natural history of the stages of the disease radiologically and also the timing of arthrodiatasis. Materials and methods. 44 patients with Perthes' disease that had articulated hip distraction were radiologically evaluated. We assessed these based on Joseph's modified Elizabethtown classification before, during and soon after distraction. Other parameters used were the application of common radiological grading systems and other features. Results. 13 were operated before Stage 2b or before late fragmentation. Of these 10 skipped one or more stage/s during distraction or within one month from distractor removal. This phenomenon was not observed in any of the 28 patients who had the distractor put on during late fragmentation or later. However, these 28 patients had some enhancement in reossification. 3 patients had adolescent onset with destructive type in 2 and segmental collapse type in 1 where stages are not clearly seen. We also noticed that the late onset presenters with subluxation did show improvement of their subluxation and contractures. Application of the Herring and Salter–Thompson classifications could not be universally used as they were in different stages of the disease and due to incomplete frog leg views. Conclusions. Timing of surgery in the early stages of the disease appears to affect the natural evolution of the disease process by skipping the stage of fragmentation. This corroborates with Joseph's paper on osteotomies. This is an early observational study and based on this hypothesis a prospective study with clinical outcomes will follow


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_11 | Pages 10 - 10
1 Feb 2013
Walton R Martin E Wright D Garg N Bruce C
Full Access

Aim. Debate remains over the optimal treatment for severe unstable SCFE. AVN is the principle problem; current thinking suggests this can be minimized by emergent reduction and fixation within 24 hours. If emergent treatment is not possible, open osteotomy with a variable delay of 10–21 days has been advocated. We present our experience of delayed intracapsular cuneiform osteotomy (ICO). Methods. SCFE cases were identified through ICD-10 coding and theatre records. Unstable slips were identified and reviewed retrospectively. When ICO was performed, the hip was accessed via anterior approach without hip dislocation. A cuneiform shortening osteotomy of the neck with physeal excision was undertaken. The epiphysis was carefully reduced and stabilized with a single screw. Results. 46 unstable slips were treated during the study period. 16 hips underwent ICO, while the remaining cases were treated by closed pinning in situ (PIS) without capsulotomy. The rate of AVN following ICO in 16 hips was 25% in comparison to the PIS group, in which 40% developed AVN. AVN was not seen in those cases treated with ICO with a delay of at least 14 days. In contrast, AVN occurred regardless of the timing of PIS, including a rate of 33% in those treated emergently. Sub analysis of the PIS group revealed that AVN occurred more frequently (66.7% vs. 33.3%) when complete epiphyseal reduction occurred during patient positioning. While these results are not statistically significant, they are striking. Patients who developed AVN had a poor outcome in both groups, with 75% requiring further surgical intervention. There were 2 cases of heterotrophic ossification and meralgia paraesthetica respectively. Hardware failure occurred once. Conclusion. Timing and method of treatment for unstable SCFE remains controversial. This series suggests delayed intracapsular cuneiform osteotomy may result in a lower rate of AVN than closed reduction and pinning within 24 hours


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 8 | Pages 1143 - 1147
1 Aug 2012
Svehlík M Kraus T Steinwender G Zwick EB Saraph V Linhart WE

Although equinus gait is the most common abnormality in children with spastic cerebral palsy (CP) there is no consistency in recommendations for treatment, and evidence for best practice is lacking. The Baumann procedure allows selective fractional lengthening of the gastrocnemii and soleus muscles but the long-term outcome is not known. We followed a group of 18 children (21 limbs) with diplegic CP for ten years using three-dimensional instrumented gait analysis. The kinematic parameters of the ankle joint improved significantly following this procedure and were maintained until the end of follow-up. We observed a normalisation of the timing of the key kinematic and kinetic parameters, and an increase in the maximum generation of power of the ankle. There was a low rate of overcorrection (9.5%, n = 2), and a rate of recurrent equinus similar to that found with other techniques (23.8%, n = 5). As the procedure does not impair the muscle architecture, and allows for selective correction of the contracted gastrocnemii and soleus, it may be recommended as the preferred method for correction of a mild fixed equinus deformity


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_VII | Pages 10 - 10
1 Mar 2012
de Gheldere A Calder P Bradish C Eastwood D
Full Access

Purpose. To document the incidence and nature of complications associated with hemiepiphysiodesis using a screw and plate device (8-plate, Orthofix). Methods. We reviewed case notes and radiographs of 71 children (130 segments) with lower limb deformities treated with temporary hemiepiphyseal arrest using the 8-plate. 96% of deformities were in the coronal plane, 4% sagittal. 72% of coronal deformities demonstrated valgus malalignment. We defined three types of complications:. early (perioperative) complications eg infection and/or wound breakdown, bleeding, neurological impairment. implant related complications such as soft tissue irritation, plate breakage or migration,. complications involving the growth plate including rebound deformity, early physeal closure or iatrogenic deformity. Complications were related to variables of patient age, gender, diagnosis, location of deformity and associated surgery. Results. The average age at surgery was 10 years (range 3-16). There were 41 boys, 30 girls. 3/70 patients were treated for an idiopathic deformity: the remainder were affected by a wide range of pathologies (20% skeletal dysplasia, 20% metabolic bone disease). Full correction has occurred in 38% of patients. The remaining 45 children are all showing improvement in their deformity. 10 patients (14%) have had a complication: 3 patients had early complications (wound infection, wound breakdown and intra-operative hypotensive crisis) and 2 patients have had implant related complications (irritation and migration). In a further 5 patients there have been physis related problems: 1 over-correction, 1 recurrence and 3 cases in which the timing of the procedure or the ill-health of the physis did not allow correction to occur. Conclusion. The 8-plate is an effective device in the management of deformity secondary to pathological conditions. 10% of patients had complications: the majority were minor but care should be taken regarding the timing of the procedure related to the growth potential of the pathological physis