We evaluated an operative technique, described by the Exeter Hip Unit, to assist accurate introduction of the femoral component. We assessed whether it led to a reduction in the rate of leg-length discrepancy after total hip arthroplasty (THA). A total of 100 patients undergoing THA were studied retrospectively; 50 were undertaken using the test method and 50 using conventional methods as a control group. The groups were matched with respect to patient demographics and the grade of surgeon. Three observers measured the depth of placement of the femoral component on post-operative radiographs and measured the length of the legs. There was a strong correlation between the depth of insertion of the femoral component and the templated depth in the test group (R = 0.92), suggesting accuracy of the technique. The mean leg-length discrepancy was 5.1 mm (0.6 to 21.4) pre-operatively and 1.3 mm (0.2 to 9.3) post-operatively. There was no difference between Consultants and Registrars as primary surgeons. Agreement between the templated and post-operative depth of insertion was associated with reduced post-operative leg-length discrepancy. The intra-class coefficient was R ≥ 0.88 for all measurements, indicating high observer agreement. The post-operative leg-length discrepancy was significantly lower in the test group (1.3 mm) compared with the control group (6.3 mm, p < 0.001). The Exeter technique is reproducible and leads to a lower incidence of leg-length discrepancy after THA. Cite this article: Bone Joint J 2015;97-B:154–9

Aims. Children treated for osteosarcoma around the knee often have a substantial leg-length discrepancy at skeletal maturity. The aim of this study was to investigate the results of staged skeletal reconstruction after a leg lengthening procedure using an external fixator in these patients. Patients and Methods. We reviewed 11 patients who underwent staged reconstruction with either an arthroplasty (n = 6) or an arthrodesis (n = 5). A control group of 11 patients who had undergone wide excision and concurrent reconstruction with an arthroplasty were matched for gender, location, and size of tumour. We investigated the change in leg-length discrepancy, function as assessed by the Musculoskeletal Tumor Society Scale (MSTS) score and complications. Results. A mean 5.2 cm (1.7 to 8.9) of lengthening was achieved. The mean MSTS scores significantly improved after staged reconstruction (p = 0.003) but were still worse than those of the control group (p = 0.049). However, the MSTS scores of the arthroplasty subgroup were comparable with those of the controls, although the extensor lag was greater and the range of movement was less. The patient group experienced more complications, but all of these resolved. Conclusion. Approximately 5 cm of lengthening and significant functional improvement can be achieved by staged reconstruction and lengthening, without major complications. Although it has limitations, this method of treatment seems to be a satisfactory surgical option for growing children with a significant leg-length discrepancy after excision of an osteosarcoma around the knee. Cite this article: Bone Joint J 2017;99-B:401–8

Transtrochanteric curved varus osteotomy was designed to avoid some of the disadvantages of varus wedge osteotomy, such as post-operative leg-length discrepancy. In this retrospective study we investigated the leg-length discrepancy and clinical outcome after transtrochanteric curved varus osteotomy undertaken in patients with osteonecrosis of the femoral head. Between January 1993 and March 2004, this osteotomy was performed in 42 hips of 36 patients with osteonecrosis of the femoral head. There were 15 males and 21 females with a mean age at surgery of 34 years (15 to 68). The mean follow-up was 5.9 years (2.0 to 12.5). The mean pre-operative Harris hip score was 64.0 (43 to 85) points, which improved to a mean of 88.7 (58 to 100) points at final follow-up. The mean varus angulation post-operatively was 25° (12° to 38°) and the post-operative mean leg-length discrepancy was 13 mm (4 to 25). The post-operative leg-length discrepancy showed a strong correlation with varus angulation (Pearson’s correlation coefficient; r = 0.9530, p < 0.0001), which may be useful for predicting the leg-length discrepancy which can occur even after transtrochanteric curved varus osteotomy

The aim of this study was to assess whether a femoral component which retained the neck reduced the incidence of leg-length inequality following total hip arthroplasty. A retrospective review was undertaken of 130 consecutive primary total hip arthroplasties performed between April 1996 and April 2004 using such an implant. There were 102 suitable patients for the study. Standardised pre- and post-operative pelvic radiographs were measured by an independent investigator to the nearest millimetre. The leg-length inequality was reduced from a mean pre-operative value of −0.71 cm to a mean of 0.11 cm post-operatively. Of the 102 patients 24 (23.5%) had an equal leg-length post-operatively, and 95 (93.1%) had a leg-length inequality between −1 cm and 1 cm

We investigated the spines of 15 patients who had significant leg-length inequality as a result of femoral shaft fractures sustained after skeletal maturity but below the age of 21 years. The patients were examined at least 10 years after fracture. The spines were studied clinically and radiographically before and after correction of leg-length inequality with a shoe-raise. Lateral spinal flexion was measured from radiographs. The lumbar scoliosis associated with the leg-length inequality was compensatory: after equalisation of leg-length the overall curve and the axial rotation were corrected completely. There was also an equal range of lateral flexion to either side after correction. Minor malalignments of the whole spine remained despite correction of the compensatory scoliosis, and within the lumbar spine correction of the scoliosis had not occurred equally at all levels. No patients complained of significant discomfort and neither structural abnormalities nor degenerative changes were seen on the radiographs

Aims. The purpose of this study was to examine whether leg-length discrepancy (LLD) following unilateral total hip arthroplasty (THA) affects the incidence of contralateral head collapse and subsequent THA in patients with bilateral osteonecrosis, and to determine factors associated with subsequent collapse. Patients and Methods. We identified 121 patients with bilateral non-traumatic osteonecrosis who underwent THA between 2003 and 2011 to treat a symptomatic hip, and who also exhibited medium-to-large lesions (necrotic area ≥ 30%) in an otherwise asymptomatic non-operated hip. Of the 121 patients, 71 were male (59%) and 50 were female (41%), with a mean age of 51 years (19 to 71) at the time of initial THA. All patients were followed for at least five years and were assessed according to the presence of a LLD (non-LLD vs LLD group), as well as the LLD type (longer non-operated side vs shorter non-operated side group). Results. Overall, 68 hips (56%) became painful and progressed to collapse at a mean of 2.6 years (0.2 to 13.8), resulting in 59 THAs (49%). The five-year collapse-free survival rate for the non-LLD group was 59% (95% confidence interval (CI) 46.8 to 71.8) compared with 45% (95% CI 32.9 to 57.5) for the LLD group (p = 0.036), and 66% (95% CI 55.2 to 77.2) for the longer non-operated side group compared with 32% (95% CI 19.1 to 44.9) for the shorter non-operated side group (p < 0.001). Multivariate regression analyses found that large lesions had a higher risk of collapse than medium-size lesions (odds ratio (OR) 4.19, 95% confidence interval (CI) 1.69 to 10.38; p = 0.002). Meanwhile, patients with a LLD < 3 mm (OR 0.20, 95% CI 0.08 to 0.52; p = 0.001) or a longer non-operated leg (OR 0.11, 95% CI 0.04 to 0.28; p < 0.001) after THA were less likely to experience a subsequent collapse. Conclusion. We found that LLD may be a modifiable risk factor for femoral head collapse. Minimizing LLD and particularly avoiding a shorter non-operated limb after THA may lead to a lower risk of collapse of the asymptomatic hip in patients with bilateral non-traumatic osteonecrosis. Cite this article: Bone Joint J 2019;101-B:303–310

We have developed a clinical method for the graphic recording, analysis and planning of treatment of leg-length discrepancy during growth. Initially, the clinically determined discrepancy is plotted against the chronological age yearly, and then in late childhood at six-monthly intervals. CT and measurements of skeletal age are made in middle and late childhood to confirm the clinical findings. In a prospective study in 20 children, we observed that only eight had a linear increase in discrepancy. The observed pattern of increase was therefore used to estimate the mature discrepancy. Epiphyseodesis reference slopes were used to determine the most appropriate time and type of epiphyseodesis. In all children, the leg-length discrepancy at maturity was within 1 cm of the predicted amount. Changes in discrepancy due to leg lengthening or correction of deformity were also plotted graphically. We conclude that the clinical graphic method is simple to use, takes into account the varying patterns of discrepancy, and minimises radiation dosage

We have reviewed the results of amputation through the ankle in the management of 37 children with congenital leg-length discrepancy, followed up for a mean of 7.6 years after operation. In general good function was achieved and 18 patients considered their activities to be unrestricted. The main factor affecting the functional result was the underlying condition for which operation had been performed. Although heel pad migration, scar rotation and os calcis remnants were seen, these could be accommodated by the prosthesis. Syme's amputation is tolerated well in the younger child and, in patients with a predicted leg-length discrepancy of over 15 cm associated with an abnormal foot, we recommend the operation as a primary procedure between the ages of 18 months and two years

Aims

Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA.

We present the results of 38 children with leg inequality treated by circumferential periosteal release. Leg-length discrepancy was expressed as a percentage of the longer limb. All patients showed a decrease in percentage difference at one year after operation, the mean difference dropping from 7.24% to 5.45%. The size of the response was directly related to the age of the patient at operation, being more pronounced in the younger patients. The response was not related to sex, diagnosis, or rate of growth of the patient immediately preceding operation

Ollier’s disease is characterised by severe deformity of the extremities and retarded growth because of multiple enchondromas. For correction of deformity, the Ilizarov method has been used although it has many complications. A 17-year-old boy with Ollier’s disease had a limb-length discrepancy of 17.4 cm, with a valgus deformity of the right knee and recurvatum of the femur of 23°. He had undergone three unsuccessful attempts to correct the deformities by using external fixators. We used a fully implantable, motorised, lengthening and correction nail (Fitbone) to achieve full correction of all the deformities without complications. We decided to carry out the procedure in three stages. First, we lengthened the femur by 3.6 cm and the tibia by 4 cm. We then exchanged the femoral nail for a longer implant and achieved a further 6 cm of length. This reduced the shortening to 3.8 cm. When the boy has finished secondary school we will adjust the remaining discrepancy.

Aims. The hypothesis of this study was that thigh circumference, distinct from body mass index (BMI), may be associated with the positioning of components when undertaking total hip arthroplasty (THA) using the direct anterior approach (DAA), and that an increased circumference might increase the technical difficulty. Patients and Methods. We performed a retrospective review of prospectively collected data involving 155 consecutive THAs among 148 patients undertaken using the DAA at an academic medical centre by a single fellowship-trained surgeon. Preoperatively, thigh circumference was measured at 10 cm, 20 cm, and 30 cm distal to the anterior superior iliac spine, in quartiles. Two blinded reviewers assessed the inclination and anteversion of the acetabular component, radiological leg-length discrepancy, and femoral offset. The radiological outcomes were considered as continuous and binary outcome variables based on Lewinnek’s ‘safe zone’. Results. Similar trends were seen in all three thigh circumference groups. In multivariable analyses, patients in the largest 20 cm thigh circumference quartile (59 cm to 78 cm) had inclination angles that were a mean of 5.96° larger (95% confidence interval (CI) 2.99° to 8.93°; p < 0.001) and anteversion angles that were a mean of 2.92° larger (95% CI 0.47° to 5.37°; p = 0.020) than the smallest quartile. No significant differences were noted in leg-length discrepancy or offset. Conclusion. There was an associated increase in inclination and anteversion as thigh circumference increased, with no change in the risk of malpositioning the components. THA can be performed using the DAA in patients with large thigh circumference without the risk of malpositioning the acetabular component. Cite this article: Bone Joint J 2019;101-B:529–535

Objectives. The primary objective of this study was to compare accuracy in restoring the native centre of hip rotation in patients undergoing conventional manual total hip arthroplasty (THA) versus robotic-arm assisted THA. Secondary objectives were to determine differences between these treatment techniques for THA in achieving the planned combined offset, component inclination, component version, and leg-length correction. Materials and Methods. This prospective cohort study included 50 patients undergoing conventional manual THA and 25 patients receiving robotic-arm assisted THA. Patients undergoing conventional manual THA and robotic-arm assisted THA were well matched for age (mean age, 69.4 years (. sd. 5.2) vs 67.5 years (. sd. 5.8) (p = 0.25); body mass index (27.4 kg/m. 2. (. sd. 2.1) vs 26.9 kg/m. 2. (. sd. 2.2); p = 0.39); and laterality of surgery (right = 28, left = 22 vs right = 12, left = 13; p = 0.78). All operative procedures were undertaken by a single surgeon using the posterior approach. Two independent blinded observers recorded all radiological outcomes of interest using plain radiographs. Results. The correlation coefficient was 0.92 (95% confidence interval (CI) 0.88 to 0.95) for intraobserver agreement and 0.88 (95% CI 0.82 to 0.94) for interobserver agreement in all study outcomes. Robotic THA was associated with improved accuracy in restoring the native horizontal (p < 0.001) and vertical (p < 0.001) centres of rotation, and improved preservation of the patient’s native combined offset (p < 0.001) compared with conventional THA. Robotic THA improved accuracy in positioning of the acetabular component within the combined safe zones of inclination and anteversion described by Lewinnek et al (p = 0.02) and Callanan et al (p = 0.01) compared with conventional THA. There was no difference between the two treatment groups in achieving the planned leg-length correction (p = 0.10). Conclusion. Robotic-arm assisted THA was associated with improved accuracy in restoring the native centre of rotation, better preservation of the combined offset, and more precise acetabular component positioning within the safe zones of inclination and anteversion compared with conventional manual THA

Aims. The aim of this study was to describe, analyze, and compare the survival, functional outcome, and complications of minimally invasive (MI) and non-invasive (NI) lengthening total femoral prostheses. Patients and Methods. A total of 24 lengthening total femoral prostheses, 11 MI and 13 NI, were implanted between 1991 and 2016. The characteristics, complications, and functional results were recorded. There were ten female patients and ten male patients. Their mean age at the time of surgery was 11 years (2 to 41). The mean follow-up was 13.2 years (seven months to 29.25 years). A survival analysis was performed, and the failures were classified according to the Modified Henderson System. Results. The overall implant survival was 79% at five, ten, and 20 years for MI prostheses, and 84% at five years and 70% at ten years for NI prostheses. At the final follow-up, 13 prostheses did not require further surgery. The overall complication rate was 46%. The mean revision-free implant survival for MI and NI prostheses was 59 months and 49 months, respectively. There were no statistically significant differences in the overall implant survival, revision-free survival, or the distribution of complications between the two types of prosthesis. Infection rates were also comparable in the groups (9% vs 7%; p = 0.902). The rate of leg-length discrepancy was 54% in MI prostheses and 23% in NI prostheses. In those with a MI prosthesis, there was a smaller mean range of movement of the knee (0° to 62° vs 0° to 83°; p = 0.047), the flexion contracture took a longer mean time to resolve after lengthening (3.3 months vs 1.07 months; p < 0.001) and there was a lower mean Musculoskeletal Tumor Society (MSTS) score (24.7 vs 27; p = 0.295). Conclusion. The survival and complications of MI and NI lengthening total femoral prostheses are comparable. However, patients with NI prosthesis have more accurate correction of leg-length discrepancy, a better range of movement of the knee and an improved overall function

Percutaneous physiodesis is an established technique for treating mild leg-length discrepancy and problems of expected extreme height. Angular deformities resulting from incomplete physeal arrest have been reported, and little is known about the time interval from percutaneous physiodesis to actual physeal arrest. This procedure was carried out in ten children, six with leg-length discrepancy and four with expected extreme height. Radiostereometric analysis was used to determine the three-dimensional dynamics of growth retardation. Errors of measurement of translation were less than 0.05 mm and of rotation less than 0.06°. Physeal arrest was obtained in all but one child within 12 weeks after physiodesis and no clinically-relevant angular deformities occurred. This is a suitable method for following up patients after percutaneous physiodesis. Incomplete physeal arrest can be detected at an early stage and the procedure repeated before corrective osteotomy is required

Aims. The aim of this study was to examine whether hips with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH) have significant asymmetry in femoral length, and to determine potential related factors. Patients and Methods. We enrolled 90 patients (82 female, eight male) with DDH showing unilateral OA changes, and 43 healthy volunteers (26 female, 17 male) as controls. The mean age was 61.8 years (39 to 93) for the DDH groups, and 71.2 years (57 to 84) for the control group. Using a CT-based coordinate measurement system, we evaluated the following vertical distances: top of the greater trochanter to the knee centre (femoral length GT), most medial prominence of the lesser trochanter to the knee centre (femoral length LT), and top of the greater trochanter to the medial prominence of the lesser trochanter (intertrochanteric distance), along with assessments of femoral neck anteversion and neck shaft angle. Results. The percentages of hips with an absolute difference of > 5 mm in femoral GT and LT lengths were significantly larger in the DDH group (24% for both) compared with those of the control group (2% and 7%, respectively). The femoral length GT of the affected femur was significantly shorter in Crowe I and longer in Crowe IV than that of the unaffected side. The affected-to-unaffected difference of the intertrochanteric distance showed positive correlation with that of the femoral length GT in Crowe I and Crowe II/III, and negative correlation with that of the femoral length LT in the Crowe I and Crowe IV groups. Conclusion. Hips with unilateral end-stage OA secondary to DDH show significant asymmetry in femoral length between both the greater and lesser trochanter and the knee compared with controls. The intertrochanteric distance was a morphological factor related to femoral-length asymmetry. When undertaking total hip arthroplasty (THA) in the presence of DDH, long leg radiographs or CT measurements should be used to assess true leg-length discrepancy. Cite this article: Bone Joint J 2019;101-B:297–302

Aims. The use of a noninvasive growing endoprosthesis in the management of primary bone tumours in children is well established. However, the efficacy of such a prosthesis in those requiring a revision procedure has yet to be established. The aim of this series was to present our results using extendable prostheses for the revision of previous endoprostheses. Patients and Methods. All patients who had a noninvasive growing endoprosthesis inserted at the time of a revision procedure were identified from our database. A total of 21 patients (seven female patients, 14 male) with a mean age of 20.4 years (10 to 41) at the time of revision were included. The indications for revision were mechanical failure, trauma or infection with a residual leg-length discrepancy. The mean follow-up was 70 months (17 to 128). The mean shortening prior to revision was 44 mm (10 to 100). Lengthening was performed in all but one patient with a mean lengthening of 51 mm (5 to 140). Results. The mean residual leg length discrepancy at final follow-up of 15 mm (1 to 35). Two patients developed a deep periprosthetic infection, of whom one required amputation to eradicate the infection; the other required two-stage revision. Implant survival according to Henderson criteria was 86% at two years and 72% at five years. When considering revision for any cause (including revision of the growing prosthesis to a non-growing prosthesis), revision-free implant survival was 75% at two years, but reduced to 55% at five years. Conclusion. Our experience indicates that revision surgery using a noninvasive growing endoprosthesis is a successful option for improving leg length discrepancy and should be considered in patients with significant leg-length discrepancy requiring a revision procedure. Cite this article: Bone Joint J 2018;100-B:370–7

When performing total hip replacement (THR) in high dislocated hips, the presence of soft-tissue contractures means that most surgeons prefer to use a femoral shortening osteotomy in order to avoid the risk of neurovascular damage. However, this technique will sacrifice femoral length and reduce the extent of any leg-length equalisation. We report our experience of 74 THRs performed between 2000 and 2008 in 65 patients with a high dislocated hip without a femoral shortening osteotomy. The mean age of the patients was 55 years (46 to 72) and the mean follow-up was 42 months (12 to 78). All implants were cementless except for one resurfacing hip implant. We attempted to place the acetabular component in the anatomical position in each hip. The mean Harris hip score improved from 53 points (34 to 74) pre-operatively to 86 points (78 to 95) at final follow-up. The mean radiologically determined leg lengthening was 42 mm (30 to 66), and the mean leg-length discrepancy decreased from 36 mm (5 to 56) pre-operatively to 8.5 mm (0 to 18) postoperatively. Although there were four (5%) post-operative femoral nerve palsies, three had fully resolved by six months after the operation. No loosening of the implant was observed, and no dislocations or infections were encountered. Total hip replacement without a femoral shortening osteotomy proved to be a safe and effective surgical treatment for high dislocated hips

Aims. The aim of this study was to identify the association between asymmetrical skin creases of the thigh, buttock or inguinal region and pathological developmental dysplasia of the hip (DDH). Patients and Methods. Between 1 January 1996 and 31 December 2016, all patients referred to our unit from primary or secondary care with risk factors for DDH were assessed in a “one stop” clinic. All had clinical and sonographic assessment by the senior author (RWP) with the results being recorded prospectively. The inclusion criteria for this study were babies and children referred with asymmetrical skin creases. Those with a neurological cause of DDH were excluded. The positive predictive value (PPV) for pathological DDH was calculated. Results. A total of 105 patients met the inclusion criteria. There were 71 girls and 34 boys. Only two were found to have pathological DDH. Both also had unilateral limited abduction of the hip in flexion and a positive Galeazzi sign with apparent leg-length discrepancy. Thus, if the specialist examination of a patient with asymmetrical skin creases was normal, the PPV for DDH was 0%. Conclusion. Isolated asymmetrical skin creases are an unreliable clinical sign in the diagnosis of pathological DDH. Greater emphasis should be placed on the presence of additional clinical signs to guide radiological screening in babies and children. Cite this article: Bone Joint J 2018;100-B:675–9

Aims. Extendible endoprostheses have been available for more than 30 years and have become more sophisticated with time. The latest generation is ‘non-invasive’ and can be lengthened with an external magnetic force. Early results have shown a worryingly high rate of complications such as infection. This study investigates the incidence of complications and the need for further surgery in a cohort of patients with a non-invasive growing endoprosthesis. Patients and Methods. Between 2003 and June 2014, 50 children (51 prostheses) had a non-invasive growing prosthesis implanted for a primary bone sarcoma. The minimum follow-up was 24 months for those who survived. Their mean age was 10.4 years (6 to 14). The incidence of complications and further surgery was documented. Results. The mean follow-up was 64 months (20 to 145). The overall survivorship of the patients was 84% at three years and 70% at five years. Revision-free survival was 81.7% at three years and 61.6% at five years with competing risk analysis. Deep infection occurred in 19.6% of implants at a mean of 12.5 months (0 to 55). Other complications were a failure of the lengthening mechanism in five prostheses (9.8%) and breakage of the implant in two (3.9%). Overall, there were 53 additional operations (0 to 5 per patient). A total of seven patients (14%) underwent amputation, three for local recurrence and four for infection. Their mean limb length discrepancy was 4.3 mm (0 to 25) and mean Musculoskeletal Tumor Society Score functional score was 26.5 (18 to 30) at the final follow-up. Conclusions. When compared with previously published early results, this mid-term series has shown continued good functional outcomes and compensation for leg-length discrepancy. Infection is still the most common complication: post-operative wound healing problems, central line infection and proximal tibial location are the main risk factors. Cite this article: Bone Joint J 2016;98-B:1697–1703

We analysed retrospectively the risk factors leading to femoral overgrowth after flexible intramedullary nailing in 43 children (mean age 7.1 years (3.6 to 12.0)) with fractures of the shaft of the femur. We reviewed their demographic data, mechanism of injury, associated injuries, the type and location of the fractures, the nail–canal diameter (NCD) ratios and femoral overgrowth at a mean follow-up of 40.7 months (25.2 to 92.7). At that time, the children were divided into two groups, those with femoral overgrowth of < 1 cm (Group 1), and those with overgrowth of ≥ 1 cm (Group 2). The mean femoral overgrowth of all patients was 0.6 cm at final follow-up. Overgrowth of ≥ 1 cm was noted in 11 children (25.6%). The NCD ratio was significantly lower in Group 2 than in Group 1, with an odds ratio of 30.0 (p = 0.003). We believe that a low NCD ratio is an indicator of an unstable configuration with flexible intramedullary nailing, and have identified an association between a low NCD ratio and femoral overgrowth resulting in leg-length discrepancy after flexible intramedullary nailing in paediatric femoral shaft fractures. Cite this article: Bone Joint J 2013;95-B:254–8

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

We present a case of early retrieval of an Oxinium femoral head and corresponding polyethylene liner where there was significant surface damage to the head and polyethylene. The implants were retrieved at the time of revision surgery to correct leg-length discrepancy just 48 hours after the primary hip replacement. Appropriate analysis of the retrieved femoral head demonstrated loss of the Oxinium layer with exposure of the underlying substrate and transfer of titanium from the acetabular shell at the time of a reduction of the index total hip replacement. In addition, the level of damage to the polyethylene was extensive despite only 48 hours in situ. The purpose of this report is to highlight the care that is required at the time of reduction, especially with these hard femoral counter-faces such as Oxinium. To our knowledge, the damage occurring at the time of reduction has not been previously reported following the retrieval of an otherwise well-functioning hip replacement

Congenital pseudarthrosis of the tibia remains one of the most difficult orthopaedic problems. We describe early excision and the use of the Masquelet technique to reconstruct the bone defect in a child aged 14 months. Consolidation sufficient for complete weight-bearing was achieved by seven weeks. After two and a half years, the child was asymptomatic with a fully reconstructed tibia and no leg-length discrepancy

We describe 11 children with fibular hypoplasia and three- or four-ray feet, two bilaterally. This deformity is a less severe form of the better known congenital short tibia with absent or dysplastic fibula. If the leg-length discrepancy is minor, no treatment or a simple orthosis are used. Epiphysiodesis or leg lengthening by callotasis is appropriate for mild to moderate discrepancy. If the foot is non-functional, or the projected leg-length discrepancy is too great, early amputation and a prosthesis are advised

We describe the application of a non-invasive extendible endoprosthetic replacement in skeletally-mature patients undergoing revision for failed joint replacement with resultant limb-length inequality after malignant or non-malignant disease. This prosthesis was developed for tumour surgery in skeletally-immature patients but has now been adapted for use in revision procedures to reconstruct the joint or facilitate an arthrodesis, replace bony defects and allow limb length to be restored gradually in the post-operative period. We record the short-term results in nine patients who have had this procedure after multiple previous reconstructive operations. In six, the initial reconstruction had been performed with either allograft or endoprosthetic replacement for neoplastic disease and in three for non-neoplastic disease. The essential components of the prosthesis are a magnetic disc, a gearbox and a drive screw which allows painless lengthening of the prosthesis using the principle of electromagnetic induction. The mean age of the patients was 37 years (18 to 68) with a mean follow-up of 34 months (12 to 62). They had previously undergone a mean of six (2 to 14) open procedures on the affected limb before revision with the non-invasive extendible endoprosthesis. The mean length gained was 56 mm (19 to 107) requiring a mean of nine (3 to 20) lengthening episodes performed in the outpatient department. There was one case of recurrent infection after revision of a previously infected implant and one fracture of the prosthesis after a fall. No amputations were performed. Planned exchange of the prosthesis was required in three patients after attainment of the maximum lengthening capacity of the implant. There was no failure of the lengthening mechanism. The Mean Musculoskeletal Tumour Society rating score was 22 of 30 available points (18 to 28). The use of a non-invasive extendible endoprosthesis in this manner provided patients with good functional results and restoration of leg-length equality, without the need for multiple open lengthening procedures

Survivors of infantile meningococcal septicaemia often develop progressive skeletal deformity as a result of physeal damage at many sites, particularly in the lower limb. Distal tibial physeal arrest typically occurs with sparing of the distal fibular physis leading to a rapidly progressive varus deformity. There have been reports of isolated cases of this deformity, but to our knowledge there have been no papers which specifically describe the development of the deformity and the options for treatment. Surgery to correct this deformity is complex because of the patient’s age, previous scarring and the multiplanar nature of the deformity. The surgical goal is to restore leg-length equality and the mechanical axis at the end of growth. Surgery should be planned and staged throughout growth in order to achieve the best functional results. We report our experience in six patients (seven ankles) with this deformity, who were managed by corrective osteotomy using a programmable circular fixator

Tibial nonunion represents a spectrum of conditions which are challenging to treat, and optimal management remains unclear despite its high rate of incidence. We present 44 consecutive patients with 46 stiff tibial nonunions, treated with hexapod external fixators and distraction to achieve union and gradual deformity correction. There were 31 men and 13 women with a mean age of 35 years (18 to 68) and a mean follow-up of 12 months (6 to 40). No tibial osteotomies or bone graft procedures were performed. Bony union was achieved after the initial surgery in 41 (89.1%) tibias. Four persistent nonunions united after repeat treatment with closed hexapod distraction, resulting in bony union in 45 (97.8%) patients. The mean time to union was 23 weeks (11 to 49). Leg-length was restored to within 1 cm of the contralateral side in all tibias. Mechanical alignment was restored to within 5° of normal in 42 (91.3%) tibias. Closed distraction of stiff tibial nonunions can predictably lead to union without further surgery or bone graft. In addition to generating the required distraction to achieve union, hexapod circular external fixators can accurately correct concurrent deformities and limb-length discrepancies. Cite this article: Bone Joint J 2015;97-B:1417–22

We report a case of spontaneous physeal growth arrest of the distal femur in a nine-year-old child with Ewing’s sarcoma of the proximal femur treated with chemotherapy and endoprosthetic replacement. Owing to the extent of disuse osteoporosis at the time of surgery, the entire intramedullary canal up to the distal femoral physis was filled with cement. Three years later, the femur remained at its pre-operative length of 19 cm. Pre-operative calculations of further growth failed to account for the growth arrest, and the initial expandable growing prosthesis inserted has been revised to a longer one in order to address the leg-length discrepancy. To our knowledge, this is the only reported case of distal femoral physeal growth arrest following cemented endoprosthetic replacement of the proximal femur

We reviewed 16 patients with spina bifida and unilateral dislocation of the hip at an average age of 17 years. Nine had a high neurological level (thoracic to L3) and seven a low lesion (L4 to sacral). We assessed the influence of unilateral dislocation of the hip on leg-length discrepancy, hip pain, hip stiffness and pressure sores of the ischial tuberosity. In non-walking patients with high-level lesions, unilateral dislocation gave little functional disability and did not appear to require reduction. In walking patients with low-level lesions, leg-length discrepancy led to a poor gait and functional problems which could be prevented by reduction of the dislocation. In all patients with low lesions, surgery was successful in maintaining reduction; in two of five patients with high lesions it was unsuccessful

Fifteen patients who limped and had early fatigue on walking caused by ischaemic necrosis after treatment for congenital dislocation of the hip had distal and lateral transfer of the greater trochanter. Nine of them in whom the predicted leg-length discrepancy was more than 3 cm also had epiphysiodesis of the contralateral leg. At skeletal maturity the limp was eliminated and walking distance was significantly improved in them all. In those who had epiphysiodesis the average leg-length discrepancy was 0.7 cm at maturity. Two of those not treated by epiphysiodesis used a heel raise of 1.5 cm. In seven cases the two operations were performed simultaneously without serious complications. This procedure is recommended at about the age of 12 years

We have compared the biomechanical nature of the reconstruction of the hip in conventional total hip arthroplasty (THA) and surface replacement arthroplasty (SRA) in a randomised study involving 120 patients undergoing unilateral primary hip replacement. The contralateral hip was used as a control. Post-operatively, the femoral offset was significantly increased with THA (mean 5.1 mm; −2.8 to 11.6) and decreased with SRA (mean −3.3 mm; −8.9 to 8.2). Femoral offset was restored within . sd. 4 mm in 14 (25%) of those with THA and in 28 (57%) of the patients receiving SRA (p < 0.001). In the THA group, the leg was lengthened by a mean of 2.6 mm (−6.04 to +12.9), whereas it was shortened by a mean of 1.9 mm (−7.1 to +2.05) in the SRA group, compared with the contralateral side. Leg-length inequality was restored within . sd. 4 mm in 42 (86%) of the SRA and 33 (60%) of the THA patients. The radiological parameters of acetabular reconstruction were similar in both groups. Restoration of the normal proximal femoral anatomy was more precise with SRA. The enhanced stability afforded by the use of a large-diameter femoral head avoided over-lengthening of the limb or increased offset to improve soft-tissue tension as occurs sometimes in THA. In a subgroup of patients with significant pre-operative deformity, restoration of the normal hip anatomy with lower pre-operative femoral offset or significant shortening of the leg was still possible with SRA

Between 1996 and 2003 six institutions in the United States and France contributed a consecutive series of 234 fractures of the femur in 229 children which were treated by titanium elastic nailing. Minor or major complications occurred in 80 fractures. Full information was available concerning 230 fractures, of which the outcome was excellent in 150 (65%), satisfactory in 57 (25%), and poor in 23 (10%). Poor outcomes were due to leg-length discrepancy in five fractures, unacceptable angulation in 17, and failure of fixation in one. There was a statistically significant relationship (p = 0.003) between age and outcome, and the odds ratio for poor outcome was 3.86 for children aged 11 years and older compared with those below this age. The difference between the weight of children with a poor outcome and those with an excellent or satisfactory outcome was statistically significant (54 kg vs 39 kg; p = 0.003). A poor outcome was five times more likely in children who weighed more than 49 kg

We undertook a retrospective study of 50 consecutive patients (41 male, 9 female) with an infected nonunion and bone defect of the femoral shaft who had been treated by radical debridement and distraction osteogenesis. Their mean age was 29.9 years (9 to 58) and they had a mean of 3.8 (2 to 19) previous operations. They were followed for a mean of 5.9 years (2.0 to 19.0). The mean duration of the distraction osteogenesis was 24.5 months (2 to 39). Pin-track infection was observed in all patients. The range of knee movement was reduced and there was a mean residual leg-length discrepancy of 1.9 cm (0 to 8) after treatment. One patient required hip disarticulation to manage intractable sepsis. In all, 13 patients had persistant pain. Bony union was achieved in 49 patients at a mean of 20.7 months (12 to 35). Although distraction osteogenesis is commonly used for the treatment of infected femoral nonunion with bone defects, it is associated with a high rate of complications

We performed a paired study of mature patients with Perthes’ disease to compare the radiological results after treatment between conservatively- and surgically-treated groups. One patient was selected from each group to create the pairs for this study. Each pair was strictly matched for gender, body mass index, age at onset, stage at the first visit, necrotic area and radiological at-risk signs and each was assessed by comparing the values of six radiological measurements. Eighteen pairs (36 hips) fitted the criteria. The radiological measurements which showed a statistically better result in the surgical groups were Mose’s method, the acetabular-head index and leg-length discrepancy. There were no statistical differences in the slope of the acetabular roof and the articulotrochanteric distance. Four hips in the conservative group were in Stulberg class II, five in class III and nine in class IV. In the surgical group, 13 were in Stulberg class II, four in class III and one in class IV. We conclude that surgical treatment improved the sphericity of the femoral head and provided greater acetabular cover, but did not reform the acetabular roof. It was noteworthy that a greater leg-length discrepancy and a smaller articulotrochanteric distance were not seen in the surgical group. Our study suggests that surgical treatment is preferable in patients with severe Perthes’ disease

Delayed sciatic nerve palsy is uncommon after primary hip replacement. Two kinds of sciatic palsy have been reported with regard to the time of onset: early palsy related to wound haematoma or lumbosacral nerve elongation which occurs between surgery and 18 days, is more frequent than delayed palsy, occurring between 10 and 32 months, which is usually caused by cement extrusion or heat produced by cement polymerisation. We present two cases of delayed, transient sciatic nerve palsy arising at three weeks and four months after primary cementless arthroplasty, respectively, without haematoma and with a normal lumbar spine. These palsies were possibly caused by excessive tension from minor limb lengthening of 2 cm to 4 cm required to achieve leg-length equality. As the initial symptoms were limited to calf pain and mild numbness in the foot, surgeons should be aware of this mode of onset, particularly when it is delayed after hip replacement. Both patients recovered fully by 12 months after surgery so we did not undertake surgical exploration of the nerve in either patient

Between December 2004 and June 2006, 136 patients (156 total hip replacements), were sent from the waiting list of the Cardiff Vale NHS Trust to the NHS Treatment Centre, Weston-super-Mare, in an attempt to reduce the waiting time for total hip replacement. Because of concerns about their outcome, each patient was contacted and invited to attend a review appointment with a consultant specialising in hip and revision hip replacement. A total of 98 patients (113 hips) were reviewed after a mean of 23 months (11 to 30). There were 104 cemented hips, seven hybrid and two cementless. An acetabular inclination of > 55° was seen in 18 (16%). Radiolucent lines around the acetabular component were seen in 76 (67%). The femoral component was in more than 4° of varus in 47 (42%). The medial floor had been breached in 13 (12%) and there was a leg-length discrepancy of more than 1 cm in ten (9%). There were three dislocations, one femoral fracture, one pulmonary embolus, one deep infection and two superficial wound infections. To date, 13% (15 hips) have been revised and a further 4% (five hips) await revision, mostly for a painful loose acetabular component. The revision rate far exceeds the 0.5% five-year failure rate reported in the Swedish Registry for the components used. This initiative and the consequent need for correction of the problems created, has significantly increased the workload of our unit

In skeletally immature patients, resection of bone tumours and reconstruction of the lower limb often results in leg-length discrepancy. The Stanmore non-invasive extendible endoprosthesis, which uses electromagnetic induction, allows post-operative lengthening without anaesthesia. Between 2002 and 2009, 55 children with a mean age of 11.4 years (5 to 16) underwent reconstruction with this prosthesis; ten patients (18.2%) died of disseminated disease and one child underwent amputation due to infection. We reviewed 44 patients after a mean follow-up of 41.2 months (22 to 104). The mean Musculoskeletal Tumor Society score was 24.7 (8 to 30) and the Toronto Extremity Salvage score was 92.3% (55.2% to 99.0%). There was no local recurrence of tumour. Complications developed in 16 patients (29.1%) and ten (18.2%) underwent revision. The mean length gained per patient was 38.6 mm (3.5 to 161.5), requiring a mean of 11.3 extensions (1 to 40), and ten component exchanges were performed in nine patients (16.4%) after attaining the maximum lengthening capacity of the implant. There were 11 patients (20%) who were skeletally mature at follow-up, ten of whom had equal leg lengths and nine had a full range of movement of the hip and knee. This is the largest reported series using non-invasive extendible endoprostheses after excision of primary bone tumours in skeletally immature patients. The technique produces a good functional outcome, with prevention of limb-length discrepancy at skeletal maturity

Flexible intramedullary nailing is gaining popularity as an effective method of treating long-bone fractures in children. We retrospectively reviewed the records and radiographs of 56 unstable fractures of the tibia in 54 children treated between March 1997 and May 2005. All were followed up for at least two months after the removal of the nails. Of the 56 tibial fractures, 13 were open. There were no nonunions. The mean time to clinical and radiological union was ten weeks. Complications included residual angulation of the tibia, leg-length discrepancy, deep infection and failures of fixation. All achieved an excellent functional outcome. We conclude that flexible intramedullary fixation is an easy and effective method of management of both open and closed unstable fractures of the tibia in children

Aims

In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component.

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

Aims

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA.

Aims

Uncemented implants are now commonly used at reimplantation of a two-stage revision total hip arthoplasty (THA) following periprosthetic joint infection (PJI). However, there is a paucity of data on the performance of the most commonly used uncemented femoral implants – modular fluted tapered (MFT) femoral components – in this setting. This study evaluated implant survival, radiological results, and clinical outcomes in a large cohort of reimplantation THAs using MFT components.

We describe a technique of ‘cross-hip distraction’ to reduce a dislocated hip with subsequent reconstruction of the joint for septic arthritis with extensive femoral osteomyelitis. A 27-year-old woman presented with a dislocated, collapsed femoral head and chronic osteomyelitis of the femur. Examination revealed a leg-length discrepancy of 7 cm and an irritable hip. A staged technique was used with primary clearance of osteomyelitis and secondary reconstruction of the hip. A cross-hip monolateral external fixator was used to establish normal anatomy followed by an arthroplasty. A good functional outcome was achieved. The use of cross-hip distraction avoids soft-tissue and nerve damage and achieved improved abductor function before arthroplasty

We report our early experience with the use of a non-invasive distal femoral expandable endoprosthesis in seven skeletally immature patients with osteosarcoma of the distal femur. The patients had a mean age of 12.1 years (9 to 15) at the time of surgery. The prosthesis was lengthened at appropriate intervals in outpatient clinics, without anaesthesia, using the principle of electromagnetic induction. The patients were functionally evaluated using the Musculoskeletal Tumour Society scoring system. The mean follow-up was 20.2 months (14 to 30). The prostheses were lengthened by a mean of 25 mm (4.25 to 55) and maintained a mean knee flexion of 110° (100° to 120°). The mean Musculoskeletal Tumour Society score was 68% (11 to 29). Complications developed in two patients; one developed a flexion deformity of 25° at the knee joint, which was subsequently overcome and one died of disseminated disease. The early results from patients treated with this device have been encouraging. The implant avoids multiple surgical procedures, general anaesthesia and assists in maintaining leg-length equality

Aims

Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct.

Aims

The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components.

Aims

Ilium is the most common site of pelvic Ewing’s sarcoma (ES). Resection of the ilium and iliosacral joint causes pelvic disruption. However, the outcomes of resection and reconstruction are not well described. In this study, we report patients’ outcomes after resection of the ilium and iliosacral ES and reconstruction with a tibial strut allograft.

Aims

The benefit of a dual-mobility acetabular component (DMC) for primary total hip arthroplasties (THAs) is controversial. This study aimed to compare the dislocation and complication rates when using a DMC compared to single-mobility (SM) acetabular component in primary elective THA using data collected at a single centre, and compare the revision rates and survival outcomes in these two groups.

Aims

Perthes’ disease (PD) often results in femoral head deformity and leg length discrepancy (LLD). Our objective was to analyze femoral morphology in PD patients at skeletal maturity to assess where the LLD originates, and evaluate the effect of contralateral epiphysiodesis for length equalization on proximal and subtrochanteric femoral lengths.