Test-Retest Reliability of a Commercial Linear Position Transducer (GymAware PowerTool) to Measure Velocity and Power in the Back Squat and Bench Press.

Orange, ST, Metcalfe, JW, Marshall, P, Vince, RV, Madden, LA, and Liefeith, A. Test-retest reliability of a commercial linear position transducer (GymAware PowerTool) to measure velocity and power in the back squat and bench press. J Strength Cond Res 34(3): 728-737, 2020-This study examined the test-retest reliability of the GymAware PowerTool (GYM) to measure velocity and power in the free-weight back squat and bench press. Twenty-nine academy rugby league players (age: 17.6 ± 1.0 years; body mass: 87.3 ± 20.8 kg) completed 2 test-retest sessions for the back squat followed by 2 test-retest sessions for the bench press. GYM measured mean velocity (MV), peak velocity (PV), mean power (MP), and peak power at 20, 40, 60, 80, and 90% of 1 repetition maximum (1RM). GYM showed good reliability (intraclass correlation coefficient [ICC] and standard error of measurement percentage, respectively) for the measurement of MV at loads of 40 (0.77, 3.9%), 60 (0.83, 4.8%), 80 (0.83, 5.8%), and 90% (0.79, 7.9%) of 1RM in the back squat. In the bench press, good reliability was evident for PV at 40 (0.82, 3.9%), 60 (0.81, 5.1%), and 80% (0.77, 8.4%) of 1RM, and for MV at 80 (0.78, 7.9%) and 90% (0.87, 9.9%) of 1RM. The measurement of MP showed good to excellent levels of reliability across all relative loads (ICC ≥0.75). In conclusion, GYM provides practitioners with reliable kinematic information in the back squat and bench press, at least with loads of 40-90% of 1RM. This suggests that strength and conditioning coaches can use the velocity data to regulate training load according to daily readiness and target specific components of the force-velocity curve. However, caution should be taken when measuring movement velocity at loads <40% of 1RM.

Validity and Reliability of a Wearable Inertial Sensor to Measure Velocity and Power in the Back Squat and Bench Press.

Orange, ST, Metcalfe, JW, Liefeith, A, Marshall, P, Madden, LA, Fewster, CR, and Vince, RV. Validity and reliability of a wearable inertial sensor to measure velocity and power in the back squat and bench press. J Strength Cond Res 33(9): 2398-2408, 2019-This study examined the validity and reliability of a wearable inertial sensor to measure velocity and power in the free-weight back squat and bench press. Twenty-nine youth rugby league players (18 ± 1 years) completed 2 test-retest sessions for the back squat followed by 2 test-retest sessions for the bench press. Repetitions were performed at 20, 40, 60, 80, and 90% of 1 repetition maximum (1RM) with mean velocity, peak velocity, mean power (MP), and peak power (PP) simultaneously measured using an inertial sensor (PUSH) and a linear position transducer (GymAware PowerTool). The PUSH demonstrated good validity (Pearson's product-moment correlation coefficient [r]) and reliability (intraclass correlation coefficient [ICC]) only for measurements of MP (r = 0.91; ICC = 0.83) and PP (r = 0.90; ICC = 0.80) at 20% of 1RM in the back squat. However, it may be more appropriate for athletes to jump off the ground with this load to optimize power output. Further research should therefore evaluate the usability of inertial sensors in the jump squat exercise. In the bench press, good validity and reliability were evident only for the measurement of MP at 40% of 1RM (r = 0.89; ICC = 0.83). The PUSH was unable to provide a valid and reliable estimate of any other criterion variable in either exercise. Practitioners must be cognizant of the measurement error when using inertial sensor technology to quantify velocity and power during resistance training, particularly with loads other than 20% of 1RM in the back squat and 40% of 1RM in the bench press.

Unusual Anatomy at Carotid Endarterectomy.

The cervical internal carotid artery (ICA) is classically differentiated from the external carotid artery by an absence of branches. We present a rare case of an anomalous branch originating from the cervical ICA seen during carotid endarterectomy. This article describes the origin of this anatomical variation and its implication for clinicians.

Congenital hand difference associated with 12q13.13 microdeletion.

We report the case of a 15-year-old boy with a de novo chromosomal deletion in the 12q13.13 region, presenting with congenital hand difference. This case emphasizes the clinical significance of recognizing such genetic anomalies and their implications.

Well-being, turnover intention, and stigma attitudes of mental health transition-to-practice nurses: A cross-sectional study.

There is global recognition that mental health nursing can be stressful and have detrimental effects on nurses' well-being and retention. With substantial nursing shortages, there is an urgent need to attract and retain nurses to sustain this workforce and provide effective mental healthcare. Mental health transition programs provide vital recruitment pathways and support novice registered nurses, enrolled nurses and experienced registered generalist nurses moving into this field. There is little evidence, however, on the well-being, resilience, and retention of nurses transitioning into mental health. The primary aims for this cross-sectional study were to describe demographic characteristics, perceived stress, well-being, resilience, mental illness stigma attitudes, work satisfaction, and turnover intention of four nurse cohorts entering mental health transition programs: generalist registered nurses, graduate and post-graduate registered nurses, and enrolled nurses; to explore relationships between these variables; and explore differences between these four nurse cohorts. Findings (n = 87) included overall moderate perceived stress, moderate well-being and resilience, high work satisfaction, low stigma, and low turnover intention. Higher turnover intention was associated with lower age and work satisfaction, and higher perceived stress. Generalist RNs had significantly higher stress and stigmatizing attitudes than Enrolled Nurses. Secondary analysis of well-being scores identified 14 nurses with scores indicating depression, with significantly lower resilience and work satisfaction, and significantly higher stress than the rest of the sample. To help prevent attrition, it is vital that mental health services provide tailored well-being initiatives during transition and intervene early to provide support for nurses with mental distress.

Inter- and intra-observer reliability and agreement of O2Pulse inflection during cardiopulmonary exercise testing: A comparison of subjective and novel objective methodology.

Cardiopulmonary exercise testing (CPET) is the 'gold standard' method for evaluating functional capacity, with oxygen pulse (O2Pulse) inflections serving as a potential indicator of myocardial ischaemia. However, the reliability and agreement of identifying these inflections have not been thoroughly investigated. This study aimed to assess the inter- and intra-observer reliability and agreement of a subjective quantification method for identifying O2Pulse inflections during CPET, and to propose a more robust and objective novel algorithm as an alternative methodology. A retrospective analysis was conducted using baseline data from the HIIT or MISS UK trial. The O2Pulse curves were visually inspected by two independent examiners, and compared against an objective algorithm. Fleiss' Kappa was used to determine the reliability of agreement between the three groups of observations. The results showed almost perfect agreement between the algorithm and both examiners, with a Fleiss' Kappa statistic of 0.89. The algorithm also demonstrated excellent inter-rater reliability (ICC) when compared to both examiners (0.92-0.98). However, a significant level (P ≤0.05) of systematic bias was observed in Bland-Altman analysis for comparisons involving the novice examiner. In conclusion, this study provides evidence for the reliability of both subjective and novel objective methods for identifying inflections in O2Pulse during CPET. These findings suggest that further research into the clinical significance of O2Pulse inflections is warranted, and that the adoption of a novel objective means of quantification may be preferable to ensure equality of outcome for patients.

Proton NMR analysis of plasma is a weak predictor of coronary artery disease.

Multivariate analysis of 1H-NMR spectra of blood sera was reported previously to predict angiographically defined advanced coronary artery disease (CAD) with >90% accuracy and specificity. The analysis depended mainly on the major lipid regions of the spectra, but many variables, including gender and drug treatment, affect lipid composition and are potential confounders. We have determined the predictive power of the same methodology for angiographically defined CAD using plasma samples from groups of male patients, classified by statin treatment, who had normal coronary arteries (NCAs) or CAD. Predictions for NCA and CAD groups were only 80.3% correct for patients not treated with statins and 61.3% for treated patients, compared with random correct predictions of 50%. A confidence limit of >99% was achieved for 36.2% of predictions for untreated groups and 6.2% for treated groups. Detection of CAD by 1H-NMR with >99% confidence was therefore very weak compared with angiography.

Legg-Calvé-Perthes: interobserver and intraobserver reliability of the modified Herring lateral pillar classification.

BACKGROUND: The purpose of our study was to independently assess the reliability of the modified Herring lateral pillar classification. METHODS: Thirty-five standardized true anteroposterior radiographs of children in the fragmentation phase were independently assessed by 6 senior observers on 2 separate occasions (6 wk apart). The κ analysis was used to assess the interobserver and intraobserver agreement. RESULTS: Intraobserver analysis revealed at best only moderate agreement for 2 observers. Three observers showed fair consistency, whereas 1 remaining observer showed poor consistency between repeated observations (P < 0.01). The highest scores for interobserver agreement varying between moderate to good could only be established between 2 observers. For the remaining observers results were just fair (P < 0.01). CONCLUSIONS: This study highlights the lack of agreement between senior clinicians when applying the modified lateral pillar classification. The results from the Herring group were significantly better than ours, but utilized a weighted κ for analysis, which may have given artificially high scores. To our knowledge, this is the first time the modified lateral pillar classification has been independently tested for its reproducibility by a specialist pediatric orthopaedic unit.

Localization of latent transforming growth factor-ß binding protein-1 in human coronary atherosclerotic plaques.

BACKGROUND: Transforming growth factor-ß (TGFß) and its receptors have been detected by immunohistochemistry in the normal vessel wall and in atherosclerotic lesions of human coronary arteries. However, TGFß is normally secreted as an inactive complex associated with a latent TGFß-binding protein (LTBP). Therefore, detection of TGFß antigen only in the arterial wall does not imply the activated form of the growth factor. METHODS AND RESULTS: In situ hybridization and immunohistochemistry demonstrated LTBP1 mRNA and protein expression throughout the media and intima of early coronary artery lesions, with the highest levels of protein at the luminal surface. In advanced lesions, LTBP1 mRNA and protein were detected mainly in regions of high cell density, such as the fibrous cap. CONCLUSIONS: Assays of the TGFß signalling pathway will be required to determine the activity associated with TGFß antigen in the vessel wall.

Expression of mRNA isoforms of latent transforming growth factor-ß binding protein-1 in coronary atherosclerosis and human tissues.

Latent transforming growth factor-ß binding protein-1 (LTBP1) has been implicated in the control of secretion, localization, and activation of TGFß (transforming growth factor-ß). We developed a quantitative reverse-transcriptase polymerase chain reaction (Q-RT-PCR) assay using an RNA internal standard to examine the expression of three alternatively spliced isoforms of LTBP1 (LTBP1Δ41, LTBP1Δ53, and LTBP1Δ55) in a variety of human tissues. The assays were also used to determine the expression of LTBP1L and LTBP1S isoforms and total LTBP1. The Q-RT-PCR assays were highly reproducible and showed that in most tissues LTBP1Δ55 and LTBP1L were minor components of LTBP1. The proportion of LTBP1Δ41 ranged from 2% of total LTBP1 mRNA in early coronary atherosclerotic lesions to 54% in advanced lesions.

Validity of various portable devices to measure sit-to-stand velocity and power in older adults.

BACKGROUND: Movement velocity and power in a single STS are related to functional performance in older adults. Identifying accessible tools that provide valid measures of STS velocity/power would allow practitioners to evaluate physical function in clinical settings where time, space and finances are limited. RESEARCH QUESTION: Does a linear position transducer (LPT), iPhone application (App), and inertial measurement unit (IMU) obtain valid measurements of velocity and power during a single STS compared with 3D motion capture? METHODS: Twenty-seven community-dwelling older adults aged ≥60 years completed a single STS test with mean velocity and power simultaneously measured with 3D motion capture, an LPT, IMU and App. Acceptable validity was established if the Pearson correlation coefficient (r) was very high (≥0.7) and bias as a standardised effect size (ES) was small (<0.6). The relationship between STS velocity/power and 30s chair STS performance was also evaluated. RESULTS: Measures of STS velocity obtained by the LPT (r = 0.94, ES = -0.21) and App (r = 0.89, ES = -0.19) were very highly valid when compared to 3D motion capture, and were very strongly related to 30s STS performance (r ≥0.74). The LPT (r = 0.87, ES = 0.13) and App (r = 0.74, ES = -0.12) also showed very high correlations and negligible bias for measuring STS power. Data collected by the IMU failed to meet our pre-determined threshold of acceptable validity for STS velocity (r = 0.72, ES = 1.00) or power (r = 0.61, ES = 0.34). SIGNIFICANCE: The LPT and iPhone App, but not the IMU, are valid tools for measuring STS velocity and power in community-dwelling older adults. Clinicians can use STS velocity obtained by either the LPT or App as a simple and valid proxy for functional status, which could help identify patients at high-risk of incident disability.

Effects of In-Season Velocity- Versus Percentage-Based Training in Academy Rugby League Players.

PURPOSE: To compare the effects of velocity-based training (VBT) vs percentage-based training (PBT) on strength, speed, and jump performance in academy rugby league players during a 7-wk in-season mesocycle. METHODS: A total of 27 rugby league players competing in the Super League U19s Championship were randomized to VBT (n = 12) or PBT (n = 15). Both groups completed a 7-wk resistance-training intervention (2×/wk) that involved the back squat. The PBT group used a fixed load based on a percentage of 1-repetition maximum (1-RM), whereas the VBT group used a modifiable load based on individualized velocity thresholds. Biomechanical and perceptual data were collected during each training session. Back-squat 1-RM, countermovement jump, reactive strength index, sprint times, and back-squat velocity at 40-90% 1-RM were assessed pretraining and posttraining. RESULTS: The PBT group showed likely to most likely improvements in 1-RM strength and reactive strength index, whereas the VBT group showed likely to very likely improvements in 1-RM strength, countermovement jump height, and back-squat velocity at 40% and 60% 1-RM. Sessional velocity and power were most likely greater during VBT compared with PBT (standardized mean differences = 1.8-2.4), while time under tension and perceptual training stress were likely lower (standardized mean differences = 0.49-0.66). The improvement in back-squat velocity at 60% 1-RM was likely greater following VBT compared with PBT (standardized mean difference = 0.50). CONCLUSION: VBT can be implemented during the competitive season, instead of traditional PBT, to improve training stimuli, decrease training stress, and promote velocity-specific adaptations.

Management of acute and chronic iliofemoral venous outflow obstruction: a multidisciplinary team consensus.

The aim of this manuscript was to establish a consensus for the management of acute and chronic venous obstruction among specialists in the UK. Specialist physicians representing vascular surgery, interventional radiology and hematology were invited to 3 meetings to discuss management of acute and chronic iliofemoral obstruction. The meetings outlined controversial areas, included a topic-by-topic review; and on completion reached a consensus when greater than 80% agreement was reached on each topic. Physicians from 19 UK hospitals agreed on treatment protocols and highlighted areas that need development. Potential standard treatment algorithms were created. It was decided to establish a national registry of venous patients led by representatives from the treating multidisciplinary teams. Technical improvements have facilitated invasive treatment of patients with acute and chronic venous obstruction; however, the evidence guiding treatment is weak. Treatment should be conducted in centers with multi-disciplinary input; robust, coordinated data collection; and regular outcome analysis to ensure safe and effective treatment and a basis for future evolvement.

Associations between comorbidity, and overall survival and bladder cancer specific survival after radical cystectomy: results from the Alberta Urology Institute Radical Cystectomy database.

PURPOSE: We determined the associations between comorbidity, and overall survival and bladder cancer specific survival after radical cystectomy. MATERIALS AND METHODS: The Alberta Urology Institute Radical Cystectomy database is an ongoing multi-institutional computerized database containing data on all adult patients with a diagnosis of primary bladder cancer treated with radical cystectomy in Edmonton, Canada from April 1994 forward. The current study is an analysis of consecutive database patients treated between April 1994 and September 2007. Comorbidity information was obtained through a medical record review using the Adult Comorbidity Evaluation 27 instrument. The outcome measures were overall survival and bladder cancer specific survival. Cox proportional regression analysis was used to determine the associations between comorbidity, and overall survival and bladder cancer specific survival. RESULTS: Of the database patients 160 (34%), 225 (48%) and 83 (18%) had no/mild comorbidity, moderate comorbidity and severe comorbidity, respectively. Compared to patients with no or mild comorbidity, multivariate Cox proportional regression analyses that included age, adjuvant chemotherapy, surgeon procedure volume, pathological T stage, pathological lymph node status, total number of lymph nodes removed, surgical margin status and lymphovascular invasion showed that increased comorbidity was independently associated with overall survival (moderate HR 1.59, 95% CI 1.16-2.18, p = 0.004; severe HR 1.83, 95% CI 1.22-2.72, p = 0.003) and bladder cancer specific survival (moderate HR 1.50, 95% CI 1.04-2.15, p = 0.028; severe HR 1.65, 95% CI 1.04-2.62, p = 0.034). CONCLUSIONS: Increased comorbidity was independently associated with an increased risk of overall mortality and bladder cancer specific mortality after radical cystectomy.

Associations among age, comorbidity and clinical outcomes after radical cystectomy: results from the Alberta Urology Institute radical cystectomy database.

PURPOSE: We determined the associations among age, comorbidity and clinical outcomes after radical cystectomy. MATERIALS AND METHODS: The study was a retrospective cohort analysis of 314 consecutive patients with primary bladder cancer treated with radical cystectomy between January 2000 and December 2006 in Edmonton, Canada. Comorbidity was obtained through a medical record review using the Adult Comorbidity Evaluation-27 instrument. The main clinical outcomes were 90-day mortality, early postoperative complications, and major and minor early postoperative complications. Logistic regression analyses were used to determine predictors of clinical outcomes. RESULTS: The 90-day mortality, any early postoperative complications, and major and minor early postoperative complications occurred in 18 (5.7%), 148 (47.1%), 78 (24.8%) and 92 (29.3%) patients, respectively. In univariate and multivariate logistic regression analysis age was not associated with 90-day mortality or early postoperative complications. In contrast, compared to patients with no or mild comorbidity, multivariate logistic regression analysis adjusted for age and surgeon procedure volume showed that severe comorbidity was associated with an increased risk of 90-day mortality (OR 6.4, p = 0.03). In addition, compared to patients with no or mild comorbidity, multivariate logistic regression analysis adjusted for age, sex, surgeon procedure volume, type of urinary tract reconstruction and American Joint Committee on Cancer stage showed that moderate and severe comorbidity were associated with any early postoperative complications (moderate OR 5.2, p <0.001; severe OR 7.0, p <0.001), major early postoperative complications (moderate OR 11.4, p <0.001; severe OR 15.2, p <0.001) and minor early postoperative complications (moderate OR 2.1, p = 0.019; severe OR 2.2, p = 0.038). CONCLUSIONS: Increasing comorbidity was independently associated with an increased risk of 90-day mortality and early postoperative complications after radical cystectomy.

Contralateral slip prediction in slipped capital femoral epiphysis: is bone age the answer?

Prophylactic pinning of an asymptomatic hip in Slipped Capital Femoral Epiphysis (SCFE) is controversial. Bone age has been used as a predictor of future contralateral slip risk and also in the decision making for prophylactic intervention. The efficacy of bone age at predicting a contralateral slip was tested in this study. Eighteen Caucasian children prospectively had bone age assessment using wrist and hand radiographs when presenting with a unilateral SCFE. After in situ fixation of the affected side prospective monitoring was performed at regular intervals in the outpatient department. Surgical intervention was undertaken if the contralateral hip was symptomatic. Three children (2 boys and 1 girl) went on to develop a contralateral slip at a mean of 20 months from initial presentation. Six children were deemed at risk of contralateral slip due to a bone age of > or = 12.5 years for boys and > or = 10.5 years for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to a contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). The sensitivity and specificity were 33% and 66% respectively. The positive predictive value was 15% and the diagnostic efficiency was 61%. Although this is a small study, it would appear that delayed bone age by itself is not a good predictor of future contralateral slip. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. A prospective long term longitudinal study is required.

A transforming growth factorbeta1 signal peptide variant increases secretion in vitro and is associated with increased incidence of invasive breast cancer.

There is evidence that transforming growth factor (TGF)beta acts as a suppressor of tumor initiation but also as a promoter of tumor progression when the antiproliferative effect of the TGFbeta signaling pathway has been overridden by other oncogenic mutations. Several somatic mutations that disrupt the TGFbeta-SMAD signaling pathway have been reported in human breast tumors. We have examined the association between single nucleotide polymorphisms (SNPs) in the TGFbeta1 gene and the incidence of invasive breast cancer in three case-control series, with a maximum of 3987 patients and 3867 controls, median age approximately 50 years, and range 22-92 years. The promoter SNP, C-509T, and the T +29C signal-peptide SNP (encoding Leu10Pro) are in strong linkage disequilibrium. They are both significantly associated with increased incidence of invasive breast cancer in a recessive manner [odds ratios: (TT versus C-carrier), 1.25; 95% confidence intervals 1.06-1.48; P = 0.009 and (ProPro versus Leu-carrier), 1.21; 95% confidence intervals 1.05-1.37; P = 0.01]. The G-800A SNP was not significantly associated with incidence of breast cancer. The C-509T SNP is not contained within a known consensus sequence for a promoter regulatory element and therefore unlikely to affect TGFbeta1 expression, whereas the Leu10Pro signal peptide substitution potentially affects TGFbeta1 secretion. Transfections of HeLa cells with constructs encoding either the Pro or Leu forms of TGFbeta1 and driven by the cytomegalovirus promoter indicate that the signal peptide with Pro at residue 10 causes a 2.8-fold increase in secretion compared with the Leu form. These data indicate that the allele encoding Pro10 is associated with increased rates of TGFbeta1 secretion and with increased incidence of invasive breast cancer for the population samples described. It is estimated that 3% of all breast cancer cases may be attributable to Pro10 homozygosity.

Posterior common femoral branch pseudoaneurysm: an unusual arterial complication following femoral venous access.

A 70-year-old male presented with groin pain and swelling 11 days following a pulmonary vein isolation procedure via an unguided femoral venous puncture for atrial fibrillation. On the fourth visit, his haemoglobin level had dropped from 14.2 gl-1 to 10.7g l-1. Repeat duplex imaging revealed a large haematoma with deep flow. A CT angiogram revealed a pseudoaneurysm of a right common femoral branch artery. A subsequent angiogram revealed active bleeding, and the feeding artery was coiled. Pseudoaneurysms are recognized complications of vascular intervention, but more commonly occur anteriorly in major vessels. This elusive presentation reminds us of several important points. First, with the increasing use of interventional techniques across all medical specialties, the use of image guidance to aid vessel access is paramount for safety; not all specialties currently practise this routinely. Furthermore, we should consider arterial injury in all patients, including those who have had venous puncture. Injuries may not necessarily occur at the anterior vessel wall, and may well be deeper. Finally, there should be a low threshold for alternative imaging if symptoms are out of context with clinical findings.

Selective modulation of the SM22alpha promoter by the binding of BTEB3 (basal transcription element-binding protein 3) to TGGG repeats.

We have previously identified a C2H2 zinc-finger transcription factor [BTEB3 (basal transcription element-binding protein 3)/KLF13 (Krüppel-like factor 13)] that activates the minimal promoter for the smooth muscle-specific SM22alpha gene in other types of cell. We show that recombinant BTEB3 binds to three TGGG motifs in the minimal SM22alpha promoter. By mutation analysis, only one of these boxes is required for BTEB3-dependent promoter activation in P19 cells and BTEB3 activates or inhibits reporter gene expression depending on the TGGG box to which it binds. Transient transfection experiments show that BTEB3 also activates reporter gene expression from the SM22alpha promoter in VSMCs (vascular smooth muscle cells). Similar studies showed that BTEB3 did not activate expression from the promoter regions of the smooth muscle myosin heavy chain or smooth muscle alpha-actin promoters, which contain similar sequences, implying that promoter activation by BTEB3 is selective. The expression of BTEB3 is readily detectable in VSMCs in vitro and is modulated in response to injury in vivo.

Unexpected long femur in adults with acetabular dysplasia.

Femoral length symmetry is assumed when assessing a patient with a dysplastic acetabulum. An unexpected long femur has been observed in some adults with acetabular dysplasia. We undertook a retrospective observation study of 18 adults with unilateral and 11 adults with bilateral acetabular dysplasia. Femoral lengths were assessed using CT measurements. The ipsilateral femur was found to be 5-10 mm longer in 66% (12 patients) with unilateral dysplastic acetabulae. Femoral lengths varied greatly in the presence of bilateral dysplastic acetabulae. In the presence of a acetabular dysplasia, asymmetry of femoral lengths is common and unpredictable. Femoral and total limb length assessment (with CT) is advised preoperatively. This will alert the surgeon and patient to the possible risk of post operative ipsilateral limb lengthening.