Introduction. Kinematically or anatomically aligned total knee arthroplasty (TKA) has been reported to provide improved clinical outcomes by replicating patient's original joint line [1][2]. It has been known that tibial (joint line) varus varies among patients, and the tibial varus would increase over progression of arthritis and bone remodeling. For those patients with significant deformity, the current tibial varus may significantly differ from its pre-diseased state. In this exploratory study, geometry and alignment of the tibial growth plate were measured with respect to tibial anatomical landmarks in order to better understand modes of tibial deformity and seek possible application in reconstructing pre-diseased joint alignment. Methods. CT scans of sixteen healthy Japanese knees (M6:F10, Age 31.9±13.9 years) were studied. Three-dimensional reconstruction models were created using Mimics 17 (Materialise, Leuven, Belgium). First, a mid-sagittal tibial reference plane, for comparing the varus/valgus orientation of the tibial plateau to that of the growth plate, was defined by the medial margin of the tibial tuberosity, origin of the PCL and center of the foot joint. The tibial plateau (or joint line plane) was determined from three points; dwell point of femur (aligned in extension) on lateral tibial articular surface, and two points at anterior and posterior rim of medial tibial articular surface sampled in the sagittal view and coinciding with dwell point of femur on medial tibia. Then, a three-dimensional model of the tibial growth plate was extracted using the Livewire function and mask editing tools in Mimics. To determine 3D orientation of the growth plate (GP), the vertical mass moment of inertia axis was calculated for the 3D model. The inertia axes were also determined for medial and lateral half of the GP (Figure 1). Results. Tibial plateau (TP) had 2.39±1.72 degrees of varus in coronal view and 11.12±3.90 degrees of posterior inclination in sagittal view. The shape of the GP is noticeably different between medial and lateral. The medial half tends to incline posteriorly towards medial, while the lateral half is twisted anteriorly. In coronal view, GP axis was in 1.27±1.49 degrees valgus to midsagittal plane. Normal axis of the TP was in varus to the GP axis by 3.66±1.79 degrees. The GP medial half was in 5.81±2.49 degrees valgus and 1.63±2.59 degrees anteriorly inclined with respect to the TP. The GP lateral half was in 11.65±2.07 degrees varus and 18.66±4.44 degrees anteriorly inclined relative to the TP. Discussion. The preliminary results from 16 healthy knees suggested that the tibial growth plate is aligned to midsagittal plane and tibial plateau in varus/valgus orientations with relatively small variations. More study samples will be required to validate usefulness of this method in surgical planning. Distinctive shape difference for medial and lateral half of the growth plate was also observed. Future study should also include diseased knees with various levels of deformities

Introduction. Design evolution of total knee arthroplasty (TKA) has improved implant durability and clinical outcomes. However, it has been reported that some patients have limited satisfaction with their operated knees [1]. In view of better patient satisfaction, there have been growing interests in anatomically aligned TKA. The anatomically aligned TKA technique aims to replicate natural joint line of the patients [2][3]. However, restoration of natural joint line may be difficult for the knees with severe deformity, as their joint alignment with respect to bony landmarks at a time of surgery may be critically different from their pre-diseased state. The purpose of this study is to investigate alignment of the tibial growth plate with respect to tibial anatomical landmarks for possible application in estimation of pre-diseased joint alignment. Methods. Three-dimensional tibial models were created from CT scans of 22 healthy Japanese knees (M7:F15, Age 31.0±12.6 years) using Mimics (Materialise NV, Leuven, Belgium). The mid-sagittal plane of the tibia was defined by medial margin of the tibial tuberosity, origin of the PCL and center of the foot joint. The tibial plateau (or joint line plane) was determined by following three points; a dwell point of aligned femur on lateral tibial articular surface, and two points at anterior and posterior rim of medial tibial articular surface defined within sagittal plane that coincide with dwell point of femur on medial tibia. All measurements were made with respect to the mid-sagittal plane. The shape of the tibial growth plate (GP) was extracted using Livewire function and mask editing tools of Mimics. To determine 3D orientation of the GP, moment of inertia axes were calculated for the 3D model. The inertia axes were also determined for medial and lateral half of the GP (Figure 1). Results. Tibial plateau (TP) had 2.38±1.78 degrees of varus and 11.37±3.76 degrees of posterior inclination. In coronal view, the GP axis was in varus alignment to the normal axis of the TP by 3.29±1.45 degrees. The shape of the GP is found to be different for medial and lateral half. The posterior inclination of the medial half tends to follow the TP, while the lateral half is twisted anteriorly (Figure 2). The GP medial half was in 5.03±2.89 degrees valgus and 1.62±2.37 degrees anteriorly inclined relative to the TP. The GP lateral half was in 10.38±2.62 degrees varus and 18.11±3.79 degrees anteriorly inclined relative to the TP. Discussion. The results from 22 healthy knees suggested that the tibial growth plate is aligned to tibial plateau in varus orientations with relatively small deviations. Distinctive shape difference for medial and lateral half of the growth plate was also observed. Limitation of this study is a number of subjects available for the analysis. Future study should consider inclusion of arthritic knees with various levels of deformities. For figures/tables, please contact authors directly.

Introduction and aims. Growth plate cartilage is responsible for bone growth in children. Injury to growth plate can often lead to faulty bony repair and bone growth deformities, which represents a significant clinical problem. This work aims to develop a biological treatment. Methods. Recent studies using rabbit models to investigate the efficacy of bone marrow mesenchymal stem cells (MSC) to promote cartilage regeneration and prevent bone defects following growth plate injury have shown promise. However, translational studies in large animal models (such as lambs), which more closely resemble the human condition, are lacking. Results. Very recently, our labs have shown that ovine bone marrow MSC are multipotential and can form cartilage-like tissue when transplanted into mice. However, using a growth plate injury model in lambs, analogous to those described in the rabbit, autologous marrow MSC seeded into gelatine scaffold containing chondrogenic factor TGF-1, failed to promote growth plate regeneration. T o date, no large animal studies have reported successful regeneration of injured growth plate cartilage using MSC highlighting the possibility that ex vivo expanded MSC may not represent a viable cellular therapy for growth plate injury repair. In addition, using a growth plate injury repair model in young rats, our studies have also focused on understanding mechanisms of the faulty repair and identifying potential targets for enhancing growth plate regeneration using endogenous progenitor cells. We have observed that bony repair of injured growth plate is preceded sequentially by inflammatory, fibrogenic, chondrogenic and osteogenic responses involving both intramembranous and endochondral ossification mechanisms. We have observed infiltration of mesenchymal progenitor cells into the injury site, some of which have the potential to differentiate to osteoblasts or chondrocytes and contribute to the bony repair of the injured growth plate. Conclusion. This presentation will focus on our studies examining the efficacy of ex vivo expanded autologous MSC to enhance growth plate regeneration in the ovine model and work using a rat model aimed at identifying potential targets for enhancing cartilage regeneration by mobilising endogenous stromal progenitor cells

Introduction. Intramedullary lengthening devices have been in use in older children with closed /open growth plates with good success. This study aims to present the early experience of the FITBONE nail since withdrawal of the PRECICE nail. Materials & Methods. Retrospective analysis of both antegrade and retrograde techniques were utilized. Only patients where union was achieved and full weight bearing commenced were included. The complication rate, length gained, distraction index, weight bearing index (WBI) as well as mechanical axes were analysed. Results. 14 (7 males, 7 females) of a total of 16 (7 males, 7 females) patients with a mean age of 16.9 years with varied diagnosis of LLD were analysed. The mean length gained was 38 mm with an average distraction index of 0,74 mm/day. WBI in these patients on average was 59,6 days/cm lengthened. 6 complications were observed, including two nonunions (successfully treated) and a knee subluxation. Mechanical axis deviation improved from 13,3 mm to 6 mm on average. Overall there has been a nonsignificant tendency for WBI to decrease (Spearman's rank correlation coefficient −0.47, p=0.08) with increasing number of cases done, while no correlation between length gained and WBI (−0.01, p=0.96, respectively) was observed. Some nuances will be discussed. Conclusions. Limb lengthening with the FITBONE nail is relatively safe and efficient, however no significant change was seen in the outcome with previous motorized nails

Introduction. Genu valgum is a common presentation in paediatric patients with congenital limb deformities. The aim of this study is to assess the outcome of guided growth surgery in paediatric patients referred via our physiotherapy pathway with isolated genu valgum and associated patellar instability. Materials & Methods. Patients were identified from our prospective patellar instability database. Inclusion criteria was acquired or congenital genu valgum associated with patellar instability in skeletally immature patients. The mechanical lateral-distal femoral angle was assessed on long leg alignment radiographs (mLDFA <85 degrees). Surgical treatment was the placement of a guided growth plate (PediPlate, OrthoPediatrics, USA) on the medial distal femoral physis (hemi-epiphysiodesis). KOOS-child scores were collected pre-operatively and post-operatively (minimum at 6 months). Results. Eleven patients (seven female) with mean age of 12(range 5–15) were identified. Five patients had congenital talipes equinovarus(CTEV), one fibular hemimelia, one di-George syndrome, one septic growth arrest and three had idiopathic genu valgum. Pre- and post-operative KOOS-child scores showed overall improvement: 58(range 36–68) to 88(65–99) and knee symptoms subscores: 64(43–71) to 96(68–100) p<0.01, t-test. Mean follow-up was 10 months (range 3–23). No subsequent dislocations/subluxations occurred during follow-up. Conclusions. Guided growth surgery is an effective way of treating symptomatic patellar instability in skeletally immature patients with genu valgum in the absence of other structural pathology. It was most common in our cohort in patients with unilateral CTEV. We would recommend to screen syndromic and congenital limb deformity patients for patellar instability symptoms in the presence of genu valgum

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs. Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures. We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons). We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs. Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures. We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons). We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries

Guided growth is commonly performed by placing an extra-periosteal two-hole plate across the growth plate with one epiphyseal and one metaphyseal screw. Recent work by Keshet et al. (2019) investigated the efficacy of the removal of the metaphyseal screw only (“sleeper plate”) after correction. They concluded the practice to be unnecessary as only 19% of patient show recurrence of deformity. The aim of this study is to examine the incidence of rebound and undesired bony in-growth of the plate (“tethering”) after metaphyseal screw removal only. In this retrospective case series, patient data on 144 plates inserted around the knee was obtained. Plates still in situ (n=69) at time of study and full hardware removal (n=50) were excluded. The remaining 25 plates had a metaphyseal screw only removed after deformity correction. We analyzed the rate of re-bound, tethering and maintenance of correction in two age groups at latest follow-up for a mean of 3.5 years (1.25 to five). Fisher's exact test with Freeman-Halton extension was used to analyze the two by three contingency table. Twenty-five plates were identified as “sleeper plates” in our series. 13 plates (52%) maintained the achieved correction after a mean of 21 months (four to 39), nine plates (36%) required screw re-insertion due to rebound after a mean of 22 months (12-48) from screw removal, and four plates (16%) showed tethering with undesired continuation of guided growth after a mean of 14 months (seven to 22) from screw removal. Younger patients (years at time of plate insertion) had higher rates of rebound and tethering (p=.0112, Fisher's exact test). All Tethering occurred in titanium plates, none occurred in steel plates. The sleeper plate is an acceptable treatment strategy for coronal deformities around the knee. Rebounding and tethering are potential outcomes that occur in younger patients and should be disclosed to patients; titanium plates may increase the risk of tethering, however further long-term follow-up is needed. We stress the importance of close post-operative follow up to identify tethering early and prevent over correction. The sleeper plate technique is a viable option in younger children with congenital abnormalities, however, continued monitoring of alignment is necessary after screw removal to check for rebound and tethering

Anterior cruciate ligament (ACL) injuries are being seen with increasing frequency in children. Treatment of the ACL deficient knee in skeletally immature patients is controversial. To determine the outcome of anatomic transphyseal ACL reconstruction in tanner stage 1 and 2 patients with open growth plates at a minimum of 2 years after surgery. Between 2007–2008, 16 prepubescent skeletally immature patients underwent anatomic transphyseal ACL reconstruction using soft tissue grafts. All patients were tanner stage 1 and 2 and all had open growth plates. Outcomes were assessed at a minimum of 2 years after surgery and included: limb alignment, limb length, instrumented testing with KT-1000 and International Knee Documentation Committee (IKDC) score. Mean age at the time of surgery was 12 years (8–14). Graft choices included: living-related donor hamstring tendon allograft (n=14), hamstring tendon autograft (n=1) and fresh frozen allograft (n=1). Mean IKDC subjective score was 96 (84–100). Sixty-two percent of patients had <3mm side-to-side difference on instrumented KT-1000 testing and 88% had a negative pivot shift. At 2 years after surgery, all patients had returned to strenuous activities and normal or nearly normal overall IKDC score was documented in 94% of patients. There were no cases of limb malalignment or growth arrest. We present a large series of anatomic transphyseal ACL reconstruction in tanner stage 1 and 2 patients with open growth plates at a minimum of 2 years following surgery. Excellent clinical outcomes were obtained with high levels of return to desired activities. Importantly, no growth disturbances were seen in this series of patients

Aims. Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate. Patients and Methods. The medical records and radiographs of all patients who underwent CHAOS for femoral deformity at our institution between 2005 and 2011 were retrospectively reviewed. Records were available for all 55 consecutive procedures undertaken in 49 patients with a mean age of 35.6 years (10.9 to 75.3) at the time of surgery. Results. Patients were assessed at a mean interval of 44 months (6 to 90) following surgery. The indications were broad; the most common were vitamin D resistant rickets (n = 10), growth plate arrest (n = 6) and post-traumatic deformity (n = 20). Multi-planar correction was required in 33 cases. A single level osteotomy was performed in 43 cases. Locking plates were used to stabilise the osteotomy in 33 cases and intramedullary nails in the remainder. Complications included two nonunions, one death, one below-knee deep vein thrombosis, one deep infection and one revision procedure due to initial under-correction. There were no neurovascular injuries or incidence of compartment syndrome. Conclusion. This is the largest reported series of femoral deformity corrections using the CHAOS technique. This series demonstrates that precise intra-operative realignment is possible with a hexapod external fixator prior to definitive stabilisation with contemporary internal fixation. This combination allows reproducible correction of complex femoral deformity from a wide variety of diagnoses and age range with a low complication rate. Cite this article: Bone Joint J 2017;99-B:283–8

To determine if there are osteochondritis dissecans (OCD) lesions of the knee that are so unstable on MRI that they are incapable of healing without operative intervention. A secondary objective was to determine the ability of orthopaedic residents to accurately grade OCD lesions according to the Kijowski criteria of stable and unstable. A retrospective review was performed of patients who had femoral condyle OCD lesions from 2009-present. Only patients with open growth plates and serial MRIs were included. Each MRI was classified according to the Kijowski classification by a junior orthopaedic surgery resident as well as an MSK trained radiologist. A weighted kappa value was used to assess the inter-rater agreement. The final analysis included 16 patients (17 knees) with 49 MRI's. The weighted kappa agreement between reviewers for overall lesion stability was moderate (0.570 [95% CI 0.237–0.757]). The initial MRI lesion was graded as stable in 59% (10/17) of the knees. Two of these 10 knees became unstable during the study period, however, both stabilised again on subsequent MRIs, one with surgery and the other without surgery. The initial MRI was graded as unstable in 41% (7/17) of the knees. Two of the seven knees (29%) later demonstrated MRI evidence of lesion stability without surgical intervention. The most important finding in this study was the ability of unstable OCD lesions on MRI to heal without operative intervention. The ability of an orthopaedic surgery resident to grade these lesions on MRI was moderate

The aim of this study is to use a defined population of patients with meningococcal septicaemia to calculate the incidence of orthopaedic complications. Medical records and radiographs were analyzed retrospectively for all patients admitted to the Paediatric Intensive Care Unit (PICU) of the Bristol Royal Hospital for Children from 01/01/2001 to 31/12/2012 with meningococcal septicaemia. Of the 130 patients with meningococcal septicaemia alive at discharge, 10 developed orthopaedic sequelae, representing an overall incidence in this patient population of 7.7%. 9 patients required an amputation, mostly in the lower limb, 16/22 (72.7%). 48 growth plate abnormalities were identified in 8 patients. 39 (81.3%) The most commonly affected was the distal tibia (38.5%). 10 ankles were identified as having a varus malalignment. 6 patients had documented leg length discrepancy. Using a clearly defined denominator this study has identified an incidence of orthopaedic sequelae following meningococcal septicaemia of 7.7%. The National Institute for Clinical Excellence (NICE) suggested that the incidence of growth disturbance is approximately 3%. This study highlights the underestimation of orthopaedic complications following meningococcal septicaemia. Close follow up of at risk patients should be considered to reduce the potential impact of these debilitating injuries

Background. Constitutional knee varus increases the risk of medial OA disease due to increase in the knee adduction moment and shifting of the mechanical axis medially. Hueter-Volkmann's law states that the amount of load experienced by the growth plate during development influences the bone morphology. For this reason, heightened sports activity during growth is associated with constitutional varus due to added knee adduction moment. In early OA, X-rays often show a flattened medial femoral condyle extension facet (EF). However, it is unknown whether this is a result of osteoarthritic wear, creep deformation over decades of use, or an outcome of Hueter-Volkmann's law during development. A larger and flattened medial EF can bear more weight, due to increased load distribution. However, a flattened EF may also extrude the meniscus, leading meniscus degeneration and joint failure. Therefore, this study aimed to investigate whether varus knees have flattened medial EFs of both femur and tibia in a cohort of patients with no signs yet of bony attrition. Methods. Segmentation and morphology analysis was conducted using Materialise software (version 8.0, Materialise Inc., Belgium). This study excluded knees with bony attrition of the EFs based on Ahlbäck criteria, intraoperative findings, and operation notes history. Standard reference frames were used for both the femur and tibia to ensure reliable and repeatable measurements. The hip-knee-angle (HKA) angle defined varus or valgus knee alignment. Femur: The femoral EFs and flexion facets (FFs) had best-fit spheres fitted with 6 repetitions. (Fig1). Tibia: The slopes of the antero-medial medial tibial plateau were approximated using lines. (fig2). Results. 72 knees met the inclusion and exclusion criteria. The average age was 59 ± 11 years. The youngest was 31 and the oldest 84 years. Thirty-three were male and 39 were female. There was good intra- and inter-observer reliability for EF sphere fitting. Femur: The results demonstrated that the medial femoral condyle EF is flattened in knees with constitutional varus, as measured by the Sphere Ratios between the medial and lateral EF (varus versus straight: p = 0.006), and in the scaled values for the medial EF sphere radius (varus versus straight: p = 0.005). There was a statistically significant, moderate and positive correlation between the medial femoral EF radius, and the medial femoral EF-FF AP offset. (fig3). Tibia: There was a statistically significant difference between the steepness of the slopes of the medial tibial plateau EF in varus and valgus knees, suggesting varus knees have a less concave (flatter) medial EF. (fig3). Conclusions. In comparison to straight knees, varus knees have flattened medial EFs in both femur and tibia. As this was the case in knees with no evidence of bony attrition, this could mean flattened medial EFs may be a result of medial physis inhibition during development, due to Hueter-Volkmann's law. Flattened medial EFs may increase load distribution in the medial compartment, but could also be a potential aetiology in primary knee OA due to over extrusion of the medial meniscus and edge loading

Meningococcal infection is the most common infective cause of death in children and causes significant morbidity in survivors. Patients admitted to the Paediatric Intensive Care Unit (PICU) of the Bristol Royal Hospital for Children from 01/01/2001 to 31/12/2012 with a primary diagnosis of meningococcal septicaemia were reviewed. A total of 10 (7.7%) of 130 patients developed orthopaedic complications. Those affected were significantly younger (p < 0.05), remained on PICU for longer (p < 0.001) and boys had a greater risk of developing orthopaedic complications (risk ratio: 3.1; 95% CI: 0.69–14.14). 9 patients required an amputation, 16/22 (72.7%) in the lower limb. Patient requiring amputation had multiple limb involvement. 48 growth plate abnormalities were identified in 8 patients, 39 (81.3%) in the lower limb, most commonly in the distal tibia. This study has identified a high incidence of musculoskeletal morbidity. Close surveillance of these patients is recommended to identify growth arrest before the onset of clinically significant deformity. It identifies a defined population of patients with meningococcal septicaemia using admission to PICU as an entry criterion allowing accurate determination of the incidence and characteristics of the skeletal consequences of this condition

Background:. Tibia Vara (Blount's disease) is characterized by a growth disturbance of the posteromedial proximal tibial physis. This results in the typically complex tibial deformity of varus, procurvatum and internal tibial torsion. Knee instability is due to medial tibial joint depression and lateral ligament complex attenuation. Femoral angular and rotational deformity are associated features. Obesity often complicates management. Langenskiöld observed six stages of the disorder on X-ray (stage 6 not occurring before 9 years) and obtained good results with proximal tibial realignment osteotomy if performed before the age of 8 years. Our experience is very different. Purpose:. To evaluate our experience with treatment of a consecutive cohort of patients with early onset Blount's disease in terms of clinical findings, recurrence rate and factors associated with recurrence and treatment methods and indications. Methods:. A retrospective chart and imaging review was completed of 100 extremities (58 patients) treated surgically for early onset Blount's disease. Follow-up ranged between 1 and 7 years. Results:. These children all presented with a history of onset of deformity between the ages of 1 and 3 years. Their age at first treatment varied between 2 and 10 years. Langenskiöld stage V and VI occurred in younger patients than originally described. The recurrence rate of extremities treated with simple osteotomy was 42% (25/58). Factors associated with recurrence include age >4 (p<0.001), obesity (p=0.007), instability (p=0.003), severity of deformity (femoro-tibial angle) (p<0.001), medial physeal slope (p<0.001) and advanced Langenskiöld stage (p<0.001). Surgical treatment included the use of growth retardation alone, dome realignment osteotomy with and without growth retardation, oblique proximal tibial (Rab) osteotomy, 3-in-1 procedure (medial elevation, tibial osteotomy and lateral epiphyseodesis) and gradual correction with hexapod fixators was used in some recurrent cases. In addition we describe a new surgical technique which obtains acute deformity correction at the level of the growth plate. Conclusion:. We propose that the disease follows a more aggressive course in the black population of Kwa-Zulu Natal, South Africa. The management is often complex and recurrence is not uncommon

Extracorporeal irradiation of resected bone segments has been used for pelvic reconstruction for 12 years in our unit. The technique allows for a perfect fit, preservation of muscle attachments, and thus, facilitating reconstruction, more rapid osteotomy of autograft bone, low cost, and a low infection rate. Of particular interest is its use in children; revascularisation appears more complete with irradiated autograft, as compared to allograft. There is sparing of adjacent growth plates if the irradiation is given outside the body, whereas external beam radiation would destroy the proximal femoral growth plate—leading to significant leg length discrepancy. Avoiding external beam irradiation also removes any risk of late radiation induced sarcoma and removes the late effects of soft tissue fibrosis due to external beam irradiation. Twenty-seven pelvic reconstructions have been done over a 12-year period, with three failures due to infection and seven due to further disease. Four of these have been for de-differentiated chondrosarcoma of the pelvis, where local recurrence led to failure. In the presence of de-differentiated pelvic chondrosarcoma, we do not recommend this form of reconstruction. Long term functional outcome scores for the first 50 cases completed between August 1996 and June 2003 gave a TESS score of 82% and MSTS score of 78%. This is more than comparable to published series using other forms of reconstruction

Introduction. Prophylactic pinning of the contralateral hip in the treatment of slipped upper femoral epiphysis (SUFE) has been shown to be safer than continued observation of the contralateral hip. This treatment remains controversial due to the potential for harm caused to an apparently unaffected hip. There is evidence that pinning of an already slipped epiphysis causes growth disturbance of the proximal femur, however this has been questioned in that the slip occurs at the hypertrophic layer of the growth plate with no damage to the germative layer. Aim. To determine whether prophylactic pinning affects subsequent growth of the unaffected hip in cases of unilateral SUFE. Method. In order to determine the effect of prophylactic pinning we compared radiographs of skeletally mature patients who had either undergone prophylactic pinning (group 1), pinning of the affected side only (group 2), and adults with no history of SUFE (group 3). We measured the articulo-trochanteric distance (ATD) and calculated the ratio of the trochanteric-trochanteric distance to articulo-trochanteric distance. These measures have been used in previous studies and have been shown to be reliable indicators of disturbed proximal femoral growth. As this was a pilot study we recruited 8 to each group. Results. The absolute sum of the ATDs were 219mm (average 27.3mm) Group 1, 213mm (average 26.6mm) Group2 and 258mm (average 32.5mm). The average trochanter-trochanter: ATD ratio in group 1 was 2.7 (1.9–3.8) compared to 2.7 (2.3–3.2) and 2.3 (1.9–2.7) in groups 2 and 3 respectively. Conclusion. Our results suggest no difference in subsequent growth between hips that are prophylactically pinned and those that are not. Abnormal growth was observed in unpinned hips suggesting undiagnosed SUFE in some cases. In this series pinning had no effect on proximal femoral growth in patients with SUFE

INTRODUCTION. Appropriate, well characterized animal models remain essential for preclinical research. This study investigated a relevant animal model for cancellous bone defect healing. Three different defect diameters of fixed depth were compared in both skeletally immature and mature sheep. This ovine model allows for the placement of four confined cancellous defects per animal. METHODS. Defects were surgically created and placed in the cancellous bone of the medial distal femoral and proximal tibial epiphyses (See Figure 1). All defects were 25 mm deep, with defect diameters of 8, 11, and 14 mm selected for comparison. Defects sites were flushed with saline to remove any residual bone particulate. The skeletally immature and mature animals corresponded to 18 month old and 5 year old sheep respectively. Animals were euthanized at 4 weeks post-operatively to assess early healing. Harvested sites were graded radiographically. The percentage of new bone volume within the total defect volume (BV/TV) was quantified through histomorphometry and μ-CT bone morphometry. Separate regions of interest were constructed within the defect to assess differences in BV/TV between periosteal and deep bone healing. Defect sites were PMMA embedded, sectioned, and stained with basic fuschin and methylene blue for histological evaluation. RESULTS. The animals tolerated the surgery well, with no incidence of fractures within the four weeks. Healing of the defects progressed via endochondral ossification, with none of the defects being completely healed within the 4 week time point. Bone volume fraction (BV/TV) significantly decreased with an increasing defect diameter. Actual bone volume (BV), however, increased with defect diameter, suggesting a correlation between biological response and severity of injury. Three distinct healing regions were found to exist within the defect and along the axis of the defect, with significant differences detected in the BV/TV between adjacent regions. Histologically, the 5 year old animals appeared to have decreased osteoblast activity, and lower osteocyte density within the newly formed woven bone. On occasion, the defects were found to intersect the tibial growth plate in the 18 month old animals, with bone replacing the proliferating chondrocyte zone (See Figure 2). Additionally, the 14 mm defect was not able to be placed in the tibia of sheep due to the possibility of the defect entering the tibial intramedullary (IM) canal, and the lack of cancellous bone between the tibial plateau and IM canal. Both these issues considerably affect this model and should be avoided. CONCLUSION. The surgical placement of 11 mm diameter defects in the proximal tibial and distal femoral epiphyses of skeletally mature sheep presents a suitable large animal model to study early healing of cancellous bone defects. This refined model allows for the placement of four separate non-healing defects within a single sheep, and allows for the possibility to reduce animal numbers required to obtain information

Construction of a functional skeleton is accomplished through co-ordination of the developmental processes of chondrogenesis, osteogenesis, and synovial joint formation. Infants whose movement in utero is reduced or restricted and who subsequently suffer from joint dysplasia (including joint contractures) and thin hypo-mineralised bones, demonstrate that embryonic movement is crucial for appropriate skeletogenesis. This has been confirmed in mouse, chick, and zebrafish animal models, where reduced or eliminated movement consistently yields similar malformations and which provide the possibility of experimentation to uncover the precise disturbances and the mechanisms by which movement impacts molecular regulation. Molecular genetic studies have shown the important roles played by cell communication signalling pathways, namely Wnt, Hedgehog, and transforming growth factor-beta/bone morphogenetic protein. These pathways regulate cell behaviours such as proliferation and differentiation to control maturation of the skeletal elements, and are affected when movement is altered. Cell contacts to the extra-cellular matrix as well as the cytoskeleton offer a means of mechanotransduction which could integrate mechanical cues with genetic regulation. Indeed, expression of cytoskeletal genes has been shown to be affected by immobilisation. In addition to furthering our understanding of a fundamental aspect of cell control and differentiation during development, research in this area is applicable to the engineering of stable skeletal tissues from stem cells, which relies on an understanding of developmental mechanisms including genetic and physical criteria. A deeper understanding of how movement affects skeletogenesis therefore has broader implications for regenerative therapeutics for injury or disease, as well as for optimisation of physical therapy regimes for individuals affected by skeletal abnormalities.

Cite this article: Bone Joint Res 2015;4:105–116