Aims. The aim of this retrospective cohort study was to assess and investigate the safety and efficacy of using a distal tibial osteotomy compared to proximal osteotomy for limb lengthening in children. Methods. In this study, there were 59 consecutive tibial lengthening and deformity corrections in 57 children using a circular frame. All were performed or supervised by the senior author between January 2013 and June 2019. A total of 25 who underwent a distal tibial osteotomy were analyzed and compared to a group of 34 who had a standard proximal tibial osteotomy. For each patient, the primary diagnosis, time in frame, complications, and lengthening achieved were recorded. From these data, the frame index was calculated (days/cm) and analyzed. Results. All patients ended their treatment with successful lengthening and deformity correction. The frame index for proximal versus distal osteotomies showed no significant difference, with a mean 48.5 days/cm (30 to 85) and 48.9 days/cm (28 to 81), respectively (p = 0.896). In the proximal osteotomy group, two patients suffered complications (one refracture after frame removal and one failure of regenerate maturation with subsequent valgus deformity) compared to zero in the distal osteotomy group. Two patients in each group sustained obstacles that required intervention (one necessitated guided growth, one fibula lengthening, and two required change of wires). There was a similar number of problems (pin-site infections) in each group. Conclusion. Our data show that distal tibial osteotomies can be safely employed in limb lengthening for children using a circular frame, which has implications in planning a surgical strategy; for example, when treating a tibia with shortening and distal deformity, a second osteotomy for proximal lengthening is not required. Cite this article: Bone Joint J 2022;104-B(11):1273–1278

Aims. The aim of this study is to evaluate the surgical treatment with the best healing rate for patients with proximal femoral unicameral bone cysts (UBCs) after initial surgery, and to determine which procedure has the lowest adverse event burden during follow-up. Methods. This multicentre retrospective study was conducted in 20 tertiary paediatric hospitals in France, Belgium, and Switzerland, and included patients aged < 16 years admitted for UBC treatment in the proximal femur from January 1995 to December 2017. UBCs were divided into seven groups based on the index treatment, which included elastic stable intramedullary nail (ESIN) insertion with or without percutaneous injection or grafting, percutaneous injection alone, curettage and grafting alone, and insertion of other orthopaedic hardware with or without curettage. Results. A total of 201 patients were included in the study. The mean age at diagnosis was 8.7 years (SD 3.9); 77% (n = 156) were male. The mean follow-up was 9.4 years (SD 3.9). ESIN insertion without complementary procedure had a 67% UBC healing rate after the first operation (vs 30% with percutaneous injection alone (p = 0.027), 43% with curettage and grafting (p = 0.064), and 21% with insertion of other hardware combined with curettage (p < 0.001) or 36% alone (p = 0.014)). ESIN insertion with percutaneous injection presented a 79% healing rate, higher than percutaneous injection alone (p = 0.017), curettage and grafting (p = 0.028), and insertion of other hardware combined with curettage (p < 0.001) or alone (p = 0.014). Patients who underwent ESIN insertion with curettage had a 53% healing rate, higher than insertion of other hardware combined with curettage (p = 0.009). The overall rate of postoperative complications was 25% and did not differ between groups (p = 0.228). A total of 32 limb length discrepancies were identified. Conclusion. ESIN insertion, either alone or combined with percutaneous injection or curettage and grafting, may offer higher healing rates than other operative procedures. Limb length discrepancy remains a major concern, and might be partly explained by the cyst’s location and the consequence of surgery. Therefore, providing information about this risk is crucial. Cite this article: Bone Joint J 2024;106-B(5):508–514

Introduction. Patients who are symptomatic with concurrent acetabular dysplasia and proximal femoral deformity may have Perthes disease. Osteotomies to correct both the acetabular and proximal femur deformities may optimise biomechanics and improve pain and function. In this study, we assessed the long-term results for such a combined procedure. Methods. We included patients who underwent concurrent pelvic and proximal femoral osteotomies by the senior surgeon (JNOH) with a minimum follow-up of 5 years. A modified triple pelvic interlocking osteotomy was performed to correct acetabular inclination and/or version with a concurrent proximal femoral osteotomy to correct valgus/varus and/or rotational alignment. We assessed functional scores, radiological paramenters, arthroplasty conversion rate, time interval before conversion to arthroplasty and other associated complications. Results. We identified 63 patients (64 hips) with a mean age of 29.2 years (range 14.3–51) at a mean follow-up of 10.1 years (range 5.1–18.5). The mean sourcil inclination postoperatively was 4.9. O. (range 1–12) compared to 24. O. (range 14.5–33) preoperatively. The mean Tonnis grade postoperatively was 2.2 (1–3) compared to 1.8 (range 1–2) preoperatively. At the last follow-up assessment, the mean Oxford Hip Score was 56 (range 60–47), Non-arthritic Hip Score was 71 (range 59–80) and UCLA activity score was 8 (range 5–10). There were 12 (18.8%) conversions to arthroplasty at a mean of 7.9 years (range 2.2–12.2) after surgery. Other associated complications include 1 sciatic nerve injury, 1 deep infection and 5 non-unions that required refixation. Discussion. Symptomatic acetabular dysplasia with concurrent proximal femoral deformity is difficult to treat. The use of combined pelvic and femoral osteotomies can optimise acetabular and femoral head alignment to improve pain and function with more than 4 out of 5 hips preserved at 10 years

Aims. Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction. Methods. A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3). Results. No significant differences in RA (p = 0.174) and TS (p = 0.787) were observed. The limb axes were significantly corrected in patients with VVD (p < 0.001). The change in tibial slope (∆TS) did not correlate (r = -0.026; p = 0.885) to the plate’s position on the physis when assessed by lateral radiographs. Conclusion. We were not able to confirm the reported change in the bony morphology of the proximal tibia on AP radiographs in our patient population. In addition, no significant change in TS was detected on the lateral radiographs. A significant correction of the VVD in the lower limb axes was evident. Position of the implant did not correlate with TS change. Therefore, eight-plate epiphysiodesis is a safe and effective procedure for correcting VVD in children without disturbing the knee joint morphology. Cite this article: Bone Joint J 2020;102-B(10):1412–1418

Aims. Preserving growth following limb-salvage surgery of the upper limb in children remains a challenge. Vascularized autografts may provide rapid biological incorporation with the potential for growth and longevity. In this study, we aimed to describe the outcomes following proximal humeral reconstruction with a vascularized fibular epiphyseal transfer in children with a primary sarcoma of bone. We also aimed to quantify the hypertrophy of the graft and the annual growth, and to determine the functional outcomes of the neoglenofibular joint. Patients and Methods. We retrospectively analyzed 11 patients who underwent this procedure for a primary bone tumour of the proximal humerus between 2004 and 2015. Six had Ewing’s sarcoma and five had osteosarcoma. Their mean age at the time of surgery was five years (two to eight). The mean follow-up was 5.2 years (1 to 12.2). Results. The overall survival at five and ten years was 91% (confidence interval (CI) 95% 75% to 100%). At the time of the final review, ten patients were alive. One with local recurrence and metastasis died one-year post-operatively. Complications included seven fractures, four transient nerve palsies, and two patients developed avascular necrosis of the graft. All the fractures presented within the first postoperative year and united with conservative management. One patient had two further operations for a slipped fibular epiphysis of the autograft, and a hemi-epiphysiodesis for lateral tibial physeal arrest. Hypertrophy and axial growth were evident in nine patients who did not have avascular necrosis of the graft. The mean hypertrophy index was 65% (55% to 82%), and the mean growth was 4.6 mm per annum (2.4 to 7.6) in these nine grafts. At final follow-up, the mean modified functional Musculoskeletal Tumour Society score was 77% (63% to 83%) and the mean Toronto Extremity Salvage Score (TESS) was 84% (65% to 94%). Conclusion. Vascularized fibular epiphyseal transfer preserves function and growth in young children following excision of the proximal humerus for a malignant bone tumour. Function compares favourably to other limb-salvage procedures in children. Longer term analysis is required to determine if this technique proves to be durable into adulthood. Cite this article: Bone Joint J 2018;100-B:535–41

We reviewed three infants with destructive osteomyelitis involving the proximal tibial epiphysis at a follow-up of eight to 22 years. All cases showed early radiographic destructive changes in the medial or lateral aspects of the epiphysis and metaphysis. Despite the ominous early appearance of the epiphysis, all cases showed spontaneous re-ossification of the epiphysis with restoration of the tibial condyle and preservation of joint congruity. The patients, however, developed a valgus or varus deformity which was treated satisfactorily with one to three proximal tibial osteotomies. The potential for regeneration of the epiphysis following infantile osteomyelitis of the proximal tibia suggests these cases should be treated expectantly with regard to joint congruity

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

Proximal femoral resection (PFR) is a proven pain-relieving procedure for the management of patients with severe cerebral palsy and a painful displaced hip. Previous authors have recommended post-operative traction or immobilisation to prevent a recurrence of pain due to proximal migration of the femoral stump. We present a series of 79 PFRs in 63 patients, age 14.7 years (10 to 26; 35 male, 28 female), none of whom had post-operative traction or immobilisation. A total of 71 hips (89.6%) were reported to be pain free or to have mild pain following surgery. Four children underwent further resection for persistent pain; of these, three had successful resolution of pain and one had no benefit. A total of 16 hips (20.2%) showed radiographic evidence of heterotopic ossification, all of which had formed within one year of surgery. Four patients had a wound infection, one of which needed debridement; all recovered fully. A total of 59 patients (94%) reported improvements in seating and hygiene. The results are as good as or better than the historical results of using traction or immobilisation. We recommend that following PFR, children can be managed without traction or immobilisation, and can be discharged earlier and with fewer complications. However, care should be taken with severely dystonic patients, in whom more extensive femoral resection should be considered in combination with management of the increased tone. Cite this article: Bone Joint J 2014; 96-B:701–6

Introduction. Perthes' disease is associated with coxa breva, plana and magna, and a high riding prominent greater trochanter causing abductor shortening and weakness, leg shortening and extra-articular impingement. A trochanteric advancement with an infero-lateralising oblique sliding osteotomy of the proximal femur would lengthen femoral neck, improve abductor length and strength, relieve impingement and improve leg length. We assessed the mid-term outcomes for this procedure. Method. We included patients who underwent the operation by the senior author (JNOH) with more than 2 years follow-up. The osteotomies were performed minimally invasively under image intensifier guidance and fixed with blade plate or locking plates. We assessed functional scores, radiological changes in neck length, Tonnis grading for arthritis and evidence of femoral head avascular necrosis, time interval for conversion to hip arthroplasty and associated complications. Results. Twenty four patients (25 hips) underwent the procedure at mean age of 18.7 years (range:9.3–38.8) with a mean follow-up of 5 years (range:2–13.8). At the last assessment, the mean Oxford Hip Score was 41.6 (range:58–27), Non-Arthritic Hip Score was 53.4 (range:25–77) and UCLA activity score was 4.2 (range:2–6). For changes in neck length, the mean “Head-centre-to-Greater-trochanteric-tip-distance” was 60 mm (range:43–78) compared to 39 mm (range:30–48) pre-operatively and the mean “Head-centre-to-Lesser-trochanteric-tip-distance” was 54 mm (range:47–64) compared to 37 mm (range:31–41) pre-operatively. The mean Tonnis grade was 1.5 (range:1–3) compared to 1.3 (range:1–2) pre-operatively. Two patients underwent arthroplasty conversion at 2 and 13.8 years later. One patient needed head-neck debridement for impingement and 2 patients underwent trochanteric refixation for non-union. There were no cases of avascular necrosis. Discussion. Symptomatic Perthes' hip deformity in adolescents and young adults is difficult to treat with joint preserving surgery. The mid-term clinical, functional and radiological results for double proximal femur osteotomy are encouraging

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

Proximal femoral varus osteotomy improves the biomechanics of the hip and can stimulate normal acetabular development in a dysplastic hip. Medial closing wedge osteotomy remains the most popular technique, but is associated with shortening of the ipsilateral femur. We produced a trigonometric formula which may be used pre-operatively to predict the resultant leg length discrepancy (LLD). We retrospectively examined the influence of the choice of angle in a closing wedge femoral osteotomy on LLD in 120 patients (135 osteotomies, 53% male, mean age six years, (3 to 21), 96% caucasian) over a 15-year period (1998 to 2013). A total of 16 of these patients were excluded due to under or over varus correction. The patients were divided into three age groups: paediatric (< 10 years), adolescent (10 to 16 years) and adult (> 16 years). When using the same saw blades as in this series, the results indicated that for each 10° of angle of resection the resultant LLD equates approximately to multiples of 4 mm, 8 mm and 12 mm in the three age groups, respectively. Statistical testing of the 59 patients who had a complete set of pre- and post-operative standing long leg radiographs, revealed a Pearson’s correlation coefficient for predicted versus radiologically observed shortening when using a wedge of either 10° or 20° of 0.93 (p <  0.001). The 95% limits of agreement from the Bland–Altman analysis for this subgroup were –3.5 mm to +3.3 mm. It has been accepted that a 10 mm discrepancy is clinically acceptable. This study identified a geometric model that provided satisfactory accuracy when using specific saw blades of known thicknesses for this formula to be used in clinical practice. Cite this article: Bone Joint J 2014;96-B:1124–9

The aim was to assess the effect of caudal block on patients who have had proximal femoral &/or pelvic osteotomy compared to patients who have had epidural anaesthesia with regards to pain relief and hospital stay. We looked at two patient cohorts; epidural & caudal pain relief in aforementioned procedures. Interrogation of our clinical database (WinDip, BlueSpeir&clinical notes) identified 57 patients: 33 proximal femoral osteotomy, 13 pelvic osteotomy and 11 combined(25 Males 32 Females), aged 1–18 years-old between 2012–2014, in two institutions. A database of demographics, operative indications, associated procedures, analgesia and type of anaesthesia was constructed in relation to daily pain score and length of hospital stay. 39 patients had epidural anaesthesia, and 18 had caudal block. Cerebral palsy with unstable hips was the commonest indication(21), followed by dysplastic hip(10), Perthes disease(8) and other causes(18). The Face, Legs, Activity, Cry, Consolability(FLACC) scale was used to assess pain. Length of hospital stay in caudal block patients was 3.1 days(1–9), in epidural anaesthesia patients stay was 4.46 days(2–13). Paediatrics high dependency unit after an epidural was needed in 20(Average stay 3.4 days) compared to 1 who received caudal block. Caudal block FLACC pain score in the first 36 hours was 1.23(0–4) compared to 0.18(0–2) in patients who had an epidural. Caudal block is associated with less hospital stay and fewer admissions to the high dependency unit, it also provides adequate pain relief post osteotomies when compared to epidural, therefore could be performed at units lacking epidural facilities. A change in related practice however should be cautious and supported by further studies

Purpose of Study. To assess the radiological outcomes of medial screw epiphyseodesis of the proximal femoral physis in the management of lateral growth arrest following treatment of developmental dysplasia of the hip. Methods. We identified 10 patients noted to have lateral growth disturbance of the proximal femoral physis, 9 of which were managed with medial screw epiphyseodesis. Serial radiographs were reviewed. A new technique was employed to monitor progression of lateral growth arrest and also to assess the role of screw epiphyseodesis in preventing further deterioration or indeed allowing for improvement. This method involved calculating the tilt angle (angle formed between a horizontal reference line and a line joining medial and lateral points of physis) and following its progression with increasing age. Results. 10 patients were included in the study, 7 females and 3 males. 1 patient did not have screw epiphyseodesis performed and is used as a control. The left hip was affected in 8 and the right hip in 2 patients. Average age at surgery (medial screw epiphyseodesis) was 12 years. 5 of the 9 patients that had screw epiphyseodesis demonstrated improvement in tilt angles (i.e. correction of deformity) with sequential follow up. 2 patients failed to improve. 2 demonstrated no change. In the control case, rapid deterioration was seen in the tilt angle following 9 years of age although this reached a plateau at age 11. Conclusion. Although the numbers in this series are modest, our results do give support for the role of medial screw epiphyseodesis in the presence of lateral growth arrest for guided growth of the proximal femoral physis. Our results suggest that screw epiphyseodesis should be performed at approximately 9 years of age to optimise potential for guided growth and to prevent further deterioration

We studied radiographs of 125 children (105 boys, 20 girls) with unilateral Legg-Calvé-Perthes’ disease to examine the epiphyseal development of the femoral head in the contralateral (unaffected) hip. The epiphyseal height (EH) and width (EW) of the unaffected hip were measured on the initial anteroposterior pelvic radiograph. In 109 of the patients (87.2%) the EH was below the mean for normal Japanese children and a significantly small EH (below −2 . sd. s) was observed in 23 patients (18.4%). By contrast, the EW of most patients (95.2%) lay within ± 2 SDs of normal values except for six with a significantly small EW. A strong positive linear correlation (R = 0.87) was observed in the EH:EW ratio in the patients. A smaller EH than expected for EW in our series indicated epiphyseal flattening of the femoral head in Legg-Calvé-Perthes’ disease. Our findings support the hypothesis that a delay in endochondral ossification in the proximal capital femoral epiphysis may be associated with the onset of Perthes’ disease

Aims. To investigate the risk factors for unsuccessful radial head reduction (RHR) in children with chronic Monteggia fractures (CMFs) treated surgically. Methods. A total of 209 children (mean age 6.84 years (SD 2.87)), who underwent surgical treatment for CMFs between March 2015 and March 2023 at six institutions, were retrospectively reviewed. Assessed risk factors included age, sex, laterality, dislocation direction and distance, preoperative proximal radial metaphysis width, time from injury to surgery, reduction method, annular ligament reconstruction, radiocapitellar joint fixation, ulnar osteotomy, site of ulnar osteotomy, preoperative and postoperative ulnar angulation, ulnar fixation method, progressive ulnar distraction, and postoperative cast immobilization. Independent-samples t-test, chi-squared test, and logistic regression analysis were used to identify the risk factors associated with unsuccessful RHR. Results. Redislocation occurred during surgery in 48 patients (23%), and during follow-up in 44 (21.1%). The mean follow-up of patients with successful RHR was 13.25 months (6 to 78). According to the univariable analysis, time from injury to surgery (p = 0.002) and preoperative dislocation distance (p = 0.042) were identified as potential risk factors for unsuccessful RHR. However, only time from injury to surgery (p = 0.007) was confirmed as a risk factor by logistic regression analysis. Receiver operating characteristic curve analysis and chi-squared test confirmed that a time from injury to surgery greater than 1.75 months increased the rate of unsuccessful RHR above the cutoff (p = 0.002). Conclusion. Time from injury to surgery is the primary independent risk factor for unsuccessful RHR in surgically treated children with CMFs, particularly in those with a time from injury to surgery of more than 1.75 months. No other factors were found to influence the incidence of unsuccessful RHR. Surgical reduction of paediatric CMFs should be performed within the first two months of injury whenever possible. Cite this article: Bone Jt Open 2024;5(7):581–591

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. Methods. All patients treated for PD in our institution between January 2013 and June 2020 were reviewed retrospectively. Patients with unilateral PD, LLD of ≥ 5 mm, and long-leg standing radiographs at skeletal maturity were included. Total leg length, femoral and tibial length, articulotrochanteric distance (ATD), and subtrochanteric femoral length were compared between PD side and the unaffected side. Furthermore, we compared leg length measurements between patients who did and who did not have a contralateral epiphysiodesis. Results. Overall, 79 patients were included, of whom 21 underwent contralateral epiphysiodesis for leg length correction. In the complete cohort, the mean LLD was 1.8 cm (95% confidence interval (CI) 1.5 to 2.0), mean ATD difference was 1.8 cm (95% CI -2.1 to -1.9), and mean subtrochanteric difference was -0.2 cm (95% CI -0.4 to 0.1). In the epiphysiodesis group, the mean LLD before epiphysiodesis was 2.7 cm (95% CI 1.3 to 3.4) and 1.3 cm (95% CI -0.5 to 3.8) at skeletal maturity. In the nonepiphysiodesis group the mean LLD was 2.0 cm (95% CI 0.5 to 5.1; p = 0.016). The subtrochanteric region on the PD side was significantly longer at skeletal maturity in the epiphysiodesis group compared to the nonepiphysiodesis group (-1.0 cm (95% CI -2.4 to 0.6) vs 0.1 cm (95% CI -1.0 to 2.1); p < 0.001). Conclusion. This study demonstrates that LLD after PD originates from the proximal segment only. In patients who had contralateral epiphysiodesis to balance leg length, this is achieved by creating a difference in subtrochanteric length. Arthroplasty surgeons need to be aware that shortening of the proximal femur segment in PD patients may be misleading, as the ipsilateral subtrochanteric length in these patients can be longer. Therefore, we strongly advise long-leg standing films for THA planning in PD patients in order to avoid inadvertently lengthening the limb. Cite this article: Bone Joint J 2021;103-B(11):1736–1741

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

Aims. The most important complication of treatment of developmental dysplasia of the hip (DDH) is avascular necrosis (AVN) of the femoral head, which can result in proximal femoral growth disturbances leading to pain, dysfunction, and eventually to early onset osteoarthritis. In this study, we aimed to identify morphological variants in hip joint development that are predictive of a poor outcome. Methods. We retrospectively reviewed all patients who developed AVN after DDH treatment, either by closed and/or open reduction, at a single institution between 1984 and 2007 with a minimal follow-up of eight years. Standard pelvis radiographs obtained at ages one, two, three, five, and eight years, and at latest follow-up were retrieved. The Bucholz-Ogden classification was used to determine the type of AVN on all radiographs. Poor outcome was defined by Severin classification grade 3 or above on the latest follow-up radiographs and/or the need for secondary surgery. With statistical shape modelling, we identified the different shape variants of the hip at each age. Logistic regression analysis was used to associate the different modes or shape variants with poor outcome. Results. In all, 135 patients with AVN were identified, with a minimum of eight years of follow-up. Mean age at time of surgery was 7.0 months (SD 0.45), and mean follow-up was 13.3 years (SD 3.7). Overall, 46% had AVN type 1 while 54% type 2 or higher. More than half of the patients (52.6%) had a poor outcome. We found 11 shape variants that were significantly associated with a poor outcome. These shape variants were predominantly linked to AVN type 2 or higher. Conclusion. Specific morphological characteristics on pelvis radiographs of AVN hips were predictive for poor outcome, at a very young age. There was an overall stronger association to Bucholz-Ogden types 2-3-4 with the exception of two modes at age two and five years, linked to AVN type 1. Cite this article: Bone Joint J 2021;103-B(5):999–1004

Aims

The aim of this study was to describe the incidence of refractures among children, following fractures of all long bones, and to identify when the risk of refracture decreases.

Aims

Fixation techniques used in the treatment of slipped capital femoral epiphysis (SCFE) that allow continued growth of the femoral neck, rather than inducing epiphyseal fusion in situ, have the advantage of allowing remodelling of the deformity. The aims of this study were threefold: to assess whether the Free-Gliding (FG) SCFE screw prevents further slip; to establish whether, in practice, it enables lengthening and gliding; and to determine whether the age of the patient influences the extent of glide.