Aims. The Fassier Duval (FD) rod is a third-generation telescopic implant for children with osteogenesis imperfecta (OI). Threaded fixation enables proximal insertion without opening the knee or ankle joint. We have reviewed our combined two-centre experience with this implant. Methods. In total, 34 children with a mean age of five years (1 to 14) with severe OI have undergone rodding of 72 lower limb long bones (27 tibial, 45 femoral) for recurrent fractures with progressive deformity despite optimized bone health and bisphosphonate therapy. Data were collected prospectively, with 1.5 to 11 years follow-up. Results. A total of 24 patients (33%) required exchange of implants (14 femora and ten tibiae) including 11 rods bending with refracture. Four (5%) required reoperation with implant retention. Loss of proximal fixation in the femur and distal fixation in the tibia were common. Four patients developed coxa vara requiring surgical correction. In total, 13 patients experienced further fractures without rod bending; eight required implant revision. There was one deep infection. The five-year survival rate, with rod revision as the endpoint, was 63% (95% confidence interval (CI) 44% to 77%) for femoral rods, with a mean age at implantation of 4.8 years (1.3 to 14.8), and 64% (95% CI 36% to 82%) for tibial rods, with a mean age at implantation of 5.2 years (2.0 to 13.8). Conclusion. FD rods are easier to implant but do not improve on the revision rates reported for second generation T-piece rods. Proximal femoral fixation is problematic in younger children with a partially ossified greater trochanter. Distal tibial fixation typically fails after two years. Future generation implants should address proximal femoral and distal tibial fixation to avoid the majority of complications in this series. Cite this article: Bone Joint J 2020;102-B(8):1048–1055

We present a retrospective study of 27 patients treated by callus distraction using a unilateral external fixator of our own design for nonunion with bone loss and shortening of the femur caused by suppurative osteomyelitis. The unilateral external fixator was used either alone or in combination with an intramedullary nail. The mean age of the patients was 13.6 years (8 to 18). The fixator was used alone in 13 patients and with an intramedullary nail in 14. The bone results at a mean follow-up of 88 months (37 to 144) were excellent in 16 patients and good in 11. The functional results were excellent in 18 patients and good in nine. However, four patients still had draining sinuses at the latest follow-up. A residual deformity greater than 7° was present in seven femora, but this did not adversely affect function or require further treatment

The aim of the study was to review the effectiveness of rigid IM nailing in stabilisation and deformity correction of lower limb long bones in adolescents with metabolic bone disease which to our knowledge has not been studied before. Medical records and radiographs were retrospectively reviewed looking at indications, deformity correction, number of osteotomies-if needed, bone healing, time to healing and incidence of complications. Between Aug 2010 and Mar 2015 fifteen patients (24 segments) had rigid IM nailing. Ten patients had Osteogenesis Imperfecta, four with McCune Albright syndrome and one with hypophosphatemic rickets. 22 femora and two tibiae were IM nailed. The mean age of the patients was 13.1 (9.6–16.75 years). Eleven out 24 segments were previously rodded. Eight segments were for acute fractures. 13 bones had significant deformities requiring corrective osteotomies. One patient had previous fracture non union. All patients were allowed to partial weight bear immediately postoperatively and were fully mobile six weeks following surgery. Mean follow up was 24 months (3–51 months) post-operatively. All deformities were corrected. All fractures and osteotomies radiologically united. Mean radiological union time was 5.5 months (6 weeks – 11 months). Patients with acute fractures had mean radiological union time of 4 months. Patients who had osteotomies had a mean radiological union time of 7.1 months. The patient with previous non union had BMP at the same time and radiologically healed in 10 months. Two patients had persistent bisphosphonate osteotomy lines but were asymptomatic. One patient had removal of a prominent distal locking screw and one had persistent Trendelenburg gait. Rigid intramedullary nailing is effective in stabilisation and deformity correction of long bones in adolescent patients with brittle bone disease. The technique has a low complication rate. We recommend the use of this technique in paediatric limb reconstruction in managing metabolic bone conditions

This purpose of this study was to investigate whether prophylactic pinning of the contralateral hip in unilateral slipped upper femoral epiphysis affects subsequent femoral morphology. To determine the effect of prophylactic pinning on growth we compared contralateral hip radiographs of 24 proximal femora prophylactically pinned with 26 cases observed, in a cohort of patients with unilateral SUFE. Validated measurements were used to determine hip morphology; the articulo-trochanteric distance (ATD) and the ratio of the trochanteric-trochanteric distance (TTD) to articulo-trochanteric distance (TTD:ATD) in addition to direct measurement of the femoral neck length. Post-operative radiographs were compared to radiographs taken at a 12–84 months follow-up. Comparing pinned and unpinned hips the neck length was shorter (mean 5.1 mm vs 11.1 mm) and the ATD was lower (p=0.048). The difference between initial and final radiograph TTD:ATD ratio for each case was calculated. The average was 0.63 in the prophylactically pinned group and 0.25 in the unpinned group (p=0.07). When hips of the same patient were compared on final radiographs, there was a smaller difference in TTD:ATD between the two sides when the patient had been prophylactically pinned (0.7) as opposed to observed (1.47). This was not statistically significant (p=0.14). Universal prophylactic pinning of the contralateral hip in slipped upper femoral epiphysis is controversial and alteration of the proximal femoral morphology is one reason for this. Our results show that prophylactic pinning does not stop growth but does alter subsequent proximal femoral morphology by causing a degree of coxa vara and breva. Some loss of growth in the prophylactically pinned hip contributes to reduction in leg length inequality at skeletal maturity which is advantageous. No iatrogenic complications were observed with single cannulated screw fixation. Prophylactic pinning prevents the potential catastrophe of a subsequent slip, is safe and the effect on growth is, if anything, beneficial. Level of evidence: III

Background. In poliomyelitis; hand to knee gait is the sum of quadriceps weakness and fixed knee flexion deformity. Limb shortening is another added problem. Usually, each problem is attacked separately; with variable end results and complication rates for each procedure. Patients and methods. 22 patients (16–46 y.); with poliomyelitis with hand to knee gait due to fixed knee flexion deformity of mild to moderate degree (10–400); and limb shortening of 4.5–9.5 cm., were managed simultaneously by a single operation. A distal femoral metaphyseal anterior closing wedge (recurvatum) corrective osteotomy was done to treat acutely the fixed knee flexion deformity(and subsequently hand to knee gait). A modified Wagner or Orthofix frame was applied as a mono-plane mono-axial lengthening device to stabilize the osteotomy and to lengthen the short limb. Lengthening was started in all cases two weeks post-operatively. Results. All cases showed full correction of the deformity with elimination of the hand to knee gait problem and all showed the desired limb length equalization. The femora were lengthened to an average of 6.4 cm.(= 21 % of original femoral bone length), range of lengthening was: 4–9 cm. (= 11–26 %). The average healing index was 37 days per centimeter (with a range of 31 to 53 days per centimeter.). Conclusion. Simultaneous management of hand to knee and limb shortening could be achieved by a single osteotomy which is used to extend the knee acutely and for distraction two weeks later using a mono-lateral frame. Results were good, complications were few and accepted and the procedure is well tolerated by the patients

Aims

Using 90% of final height as a benchmark, we sought to develop a quick, quantitative and reproducible method of estimating skeletal maturity based on topographical changes in the distal femoral physis.

Elastic stable intramedullary nailing (ESIN) is generally acknowledged to be the treatment of choice for displaced diaphyseal femoral fractures in children over the age of three years, although complication rates of up to 50% are described. Pre-bending the nails is recommended, but there are no published data to support this. Using synthetic bones and a standardised simulated fracture, we performed biomechanical testing to determine the influence on the stability of the fracture of pre-bending the nails before implantation. Standard ESIN was performed on 24 synthetic femoral models with a spiral fracture. In eight cases the nails were inserted without any pre-bending, in a further eight cases they were pre-bent to 30° and in the last group of eight cases they were pre-bent to 60°. Mechanical testing revealed that pre-bending to 60° produced a significant increase in the stiffness or stability of the fracture. Pre-bending to 60° showed a significant positive influence on the stiffness compared with unbent nails. Pre-bending to 30° improved stiffness only slightly.

These findings validate the recommendations for pre-bending, but the degree of pre-bend should exceed 30°. Adopting higher degrees of pre-bending should improve stability in spiral fractures and reduce the complications of varus deformity and shortening.

Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH).

We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The Mann‑Whitney U test and Pearson’s chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study.

There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus.

Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened limbs in patients with ACH or HCH. In patients with thin callus formation, some measures to stimulate bone formation should be considered as early as possible.

Cite this article: Bone Joint J 2014;96-B:1269–73.

Extensive limb lengthening may be indicated in achondroplastic patients who wish to achieve a height within the normal range for their population. However, increasing the magnitude of lengthening is associated with further complications particularly adjacent joint stiffness and fractures. We studied the relationship between the magnitude of femoral lengthening and callus pattern, adjacent joint stiffness and fracture of the regenerate bone in 40 femoral lengthenings in 20 achondroplastic patients. They were divided into two groups; group A had lengthening of less than 50% and group B of more than 50% of their initial femoral length. The patterns of radiological callus formation were classified according to shape, type and features. The incidence of callus features, knee stiffness and regenerate bone fracture were analysed in the two groups. Group B was associated with an increased incidence of concave, lateral and central callus shapes, adjacent joint and stiffness and fracture. Statistically, the incidence of stiffness in adjacent joints and regenerate bone fracture was significantly associated with the magnitude of lengthening.

We suggest that careful radiological assessment of the patterns of callus formation is a useful method for the evaluation and monitoring of regenerate bone.

There is much debate about the nature and extent of deformities in the proximal femur in children with cerebral palsy. Most authorities accept that increased femoral anteversion is common, but its incidence, severity and clinical significance are less clear. Coxa valga is more controversial and many authorities state that it is a radiological artefact rather than a true deformity.

We measured femoral anteversion clinically and the neck-shaft angle radiologically in 292 children with cerebral palsy. This represented 78% of a large, population-based cohort of children with cerebral palsy which included all motor types, topographical distributions and functional levels as determined by the gross motor function classification system.

The mean femoral neck anteversion was 36.5° (11° to 67.5°) and the mean neck-shaft angle 147.5° (130° to 178°). These were both increased compared with values in normally developing children. The mean femoral neck anteversion was 30.4° (11° to 50°) at gross motor function classification system level I, 35.5° (8° to 65°) at level II and then plateaued at approximately 40.0° (25° to 67.5°) at levels III, IV and V. The mean neck-shaft angle increased in a step-wise manner from 135.9° (130° to 145°) at gross motor function classification system level I to 163.0° (151° to 178°) at level V. The migration percentage increased in a similar pattern and was closely related to femoral deformity.

Based on these findings we believe that displacement of the hip in patients with cerebral palsy can be explained mainly by the abnormal shape of the proximal femur, as a result of delayed walking, limited walking or inability to walk. This has clinical implications for the management of hip displacement in children with cerebral palsy.

Difficulties posed in managing developmental dysplasia of the hip diagnosed late include a high-placed femoral head, contracted soft tissues and a dysplastic acetabulum. A combination of open reduction with femoral shortening of untreated congenital dislocations is a well-established practice. Femoral shortening prevents excessive pressure on the located femoral head which can cause avascular necrosis. Instability due to a coexisting dysplastic shallow acetabulum is common, and so a pelvic osteotomy is performed to achieve a stable and concentric hip reduction. We retrospectively reviewed 15 patients (18 hips) presenting with developmental dysplasia of the hip aged four years and above who were treated by a one-stage combined procedure performed by the senior author. The mean age at operation was five years and nine months (4 years to 11 years). The mean follow-up was six years ten months (2 years and 8 months to 8 years and 8 months). All patients were followed up clinically and radiologically in accordance with McKay’s criteria and the modified Severin classification. According to the McKay criteria, 12 hips were rated excellent and six were good. All but one had a full range of movement. Eight had a limb-length discrepancy of about 1 cm. All were Trendelenburg negative. The modified Severin classification demonstrated four hips of grade IA, six of grade IB, and eight of grade II. One patient had avascular necrosis and one an early subluxation requiring revision.

One-stage correction of congenital dislocation of the hip in an older child is a safe and effective treatment with good results in the short to medium term.

We reviewed prospectively, after skeletal maturity, a series of 24 patients (25 hips) with severe acute-on-chronic slipped capital femoral epiphysis which had been treated by subcapital cuneiform osteotomy. Patients were followed up for a mean of 8 years, 3 months (2 years, 5 months to 16 years, 4 months). Bedrest with ‘slings and springs’ had been used for a mean of 22 days (19 to 35) in 22 patients, and bedrest alone in two, before definitive surgery. The Iowa hip score, the Harris hip score and Boyer’s radiological classification for degenerative disease were used.

The mean Iowa hip score at follow-up was 93.7 (69 to 100) and the mean Harris hip score 95.6 (78 to 100). Degenerative joint changes were graded as 0 in 19 hips, grade 1 in four and grade 2 in two. The rate of avascular necrosis was 12% (3 of 25) and the rate of chondrolysis was 16% (4 of 25). We conclude that after a period of bed rest with slings and springs for three weeks to gain stability, subcapital cuneiform osteotomy for severe acute-on-chronic slipped capital femoral epiphysis is a satisfactory method of treatment with an acceptable rate of complication.