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

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

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

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

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

Introduction

Leg length discrepancy (LLD) is a common sequalae of limb reconstruction procedures. The subsequent biomechanical compensation can be directly linked to degenerative arthritis, lower back pain, scoliosis and functional impairment. It becomes particularly problematic when >2cm, established as a clinical standard. This two-arm experimental study assesses how reliable an iPhone application is in the measurement of LLD at different distances in control and LLD patients.

Introduction: Percutaneous epiphyseodesis is a simple method of achieving leg length equality in cases of minor leg length discrepancy, however few studies document its effectiveness. A retrospective study was undertaken to assess this.

Materials and methods: Patient notes and radiographs were reviewed. The growth remaining method was used to estimate timing. Percutaneous epiphyseodesis was performed with a drill and curette under radiological guidance.

Results: A total of 24 skeletally mature patients with a mean preoperative leg length discrepancy (LLD) of 2.8cm were identified. Skeletal age was significantly different from chronological age in 5 of 11 cases where it had been performed. In all patients, there was radiographic evidence of physeal closure soon after epiphyseodesis. At skeletal maturity, 14 patients have a LLD of 0–1cm and are considered to have a satisfactory outcome. 10 patients have a LLD> 2cms. In 6 of these, either presentation was too late or the amount of discrepancy too large for complete correction to be expected. In the other 4, skeletal age assessment may have been useful in 3, and in one additional case of overgrowth of the short limb prior to maturity. A successful outome was more likely when skeletal age assessment had been used (82% versus 57%). Of the 18 cases where there was sufficient time for a full correction to be achieved, the overall success rate was 72%. There were no significant clinical or radiological complications.

Conclusions:

Percutaneous drill epiphyseodesis is an effective method of achieving physeal ablation with no significant complications.

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.

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 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

Guided growth using eight-plates is commonly used for correction of angular limb deformities in growing children. The principle is of tethering at the physeal periphery while enabling growth in the rest of the physis. The method is also applied for epiphysiodesis to correct limb-length discrepancy (LLD). Concerns have been raised regarding the potential of this method to create an epiphyseal deformity. However, this has not been investigated. The purpose of this study was to detect and quantify the occurrence of deformities in the proximal tibial epiphysis following treatment with eight-plates.

Aims

The present study investigated the five-year interval changes in pseudotumours and measured serum metal ions at long-term follow-up of a previous report of 28 mm diameter metal-on-metal (MoM) total hip arthroplasty (THA).

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

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

Leg-length inequality is not uncommon following primary total hip arthroplasty and can be distressing to the patient. An excellent clinical result with respect to pain relief, function, component fixation, range of motion and radiographic appearance can be transformed into a surgical failure because of patient dissatisfaction due to leg-length inequality. Postoperative leg-length discrepancy was determined radiographically for 200 patients who had had a primary custom total hip arthroplasty. In all cases the opposite hip was considered to have a normal joint center. The femoral component was designed and manufactured individually for each patient using screened marker x-rays. A graduated calliper was used at the time of surgery to control depth of femoral component insertion. The transverse acetabular ligament was used to control placement of the acetabular component and therefore restore acetabular joint center. Using this method 94% of subjects had a postoperative leg-length discrepancy that was 6mm or less when compared to the normal side (average, +0.38mm). The maximum value measured for leg-length discrepancy was +/−8mm. We describe a simple technique for controlling leg length during primary total hip arthroplasty and propose an alternative radiographic method for measuring leg-length discrepancy

We sought to determine the short to medium-term clinical and radiographic outcomes using a short stem in young adults with a proximal femoral deformity (PFD). We prospectively studied 31 patients (35 hips) with PFDs treated with an uncemented primary THA using a short stem with cervicometaphyseal fixation between 2011–2018. There were 19 male (23 hips) and 12 female (12 hips) patients, with a mean BMI of 26.7±4.1 kg/m. 2. Twelve cases had a previous surgical procedure, and six of them were failed childhood osteotomies. Mean age of the series was 44±12 years, mean follow-up was 81±27 months and no patients were lost to follow-up. PFDs were categorized according to a modified Berry´s classification. Average preoperative leg-length discrepancy (LLD) was −16.3 mm (−50 to 2). At a mean time of 81 months of follow-up, survival rate was 97% taking revision of the stem for any reason and 100% for aseptic loosening as endpoints. No additional femoral osteotomy was required in any case. Average surgical time was 66 minutes (45 to 100). There was a significant improvement in the mHHS score when comparing preoperative and postoperative values (47.3±10.6 vs. 92.3±3.7, p=0.0001). Postoperative LLD was in average 1 mm (−9 to 18) (p=0.0001). According to Engh's criteria, all stems were classified as stable without signs of loosening. Postoperative complications included 1 pulmonary embolism, 1 neurogenic sciatic pain, 1 transient sciatic nerve palsy that recovered completely after six months, and 2 acute periprosthetic joint infections. One patient suffered a Vancouver B2 periprosthetic femoral fracture 45 days after surgery and was revised with a modular distally fixed uncemented fluted stem. A type 2B short stem evidenced promising outcomes at short to medium-term follow up in young adult patients with PFDs, avoiding the need for corrective osteotomies and a revision stem

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

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