Hallux valgus (HV) presents as a common forefoot deformity that causes problems with pain, mobility, footwear, and quality of life. The most common open correction used in the UK is the Scarf and Akin osteotomy, which has good clinical and radiological outcomes and high levels of patient satisfaction when used to treat a varying degrees of deformity. However, there are concerns regarding recurrence rates and long-term outcomes. Minimally invasive or percutaneous surgery (MIS) has gained popularity, offering the potential for similar clinical and radiological outcomes with reduced postoperative pain and smaller scars. Despite this, MIS techniques vary widely, hindering comparison and standardization. This review evaluates the evidence for both open Scarf and Akin osteotomy and newer-generation MIS techniques. Fourth-generation MIS emphasizes multiplanar rotational deformity correction through stable fixation. While MIS techniques show promise, their evidence mainly comprises single-surgeon case series. Comparative studies between open and MIS techniques suggest similar clinical and radiological outcomes, although MIS may offer advantages in scar length and less early postoperative pain. MIS may afford superior correction in severe deformity and lower recurrence rates due to correcting the bony deformity rather than soft-tissue correction. Recurrence remains a challenge in HV surgery, necessitating long-term follow-up and standardized outcome measures for assessment. Any comparison between the techniques requires comparative studies. Surgeons must weigh the advantages and risks of both open and MIS approaches in collaboration with patients to determine the most suitable treatment. Cite this article: Bone Joint J 2025;107-B(1):10–18

Aims. The aim of this study was to investigate the impact of the level of upper instrumented vertebra (UIV) in frail patients undergoing surgery for adult spine deformity (ASD). Methods. Patients with adult spinal deformity who had undergone T9-to-pelvis fusion were stratified using the ASD-Modified Frailty Index into not frail, frail, and severely frail categories. ASD was defined as at least one of: scoliosis ≥ 20°, sagittal vertical axis (SVA) ≥ 5 cm, or pelvic tilt ≥ 25°. Means comparisons tests were used to assess differences between both groups. Logistic regression analyses were used to analyze associations between frailty categories, UIV, and outcomes. Results. A total of 477 patients were included (mean age 60.3 years (SD 14.9), mean BMI 27.5 kg/m. 2. (SD 5.8), mean Charlson Comorbidity Index (CCI) 1.67 (SD 1.66)). Overall, 74% of patients were female (n = 353), and 49.6% of patients were not frail (237), 35.4% frail (n = 169), and 15% severely frail (n = 71). At baseline, differences in age, BMI, CCI, and deformity were significant (all p = 0.001). Overall, 15.5% of patients (n = 74) had experienced mechanical complications by two years (8.1% not frail (n = 36), 15.1% frail (n = 26), and 16.3% severely frail (n = 12); p = 0.013). Reoperations also differed between groups (20.2% (n = 48) vs 23.3% (n = 39) vs 32.6% (n = 23); p = 0.011). Controlling for osteoporosis, baseline deformity, and degree of correction (by sagittal age-adjusted score (SAAS) matching), frail and severely frail patients were more likely to experience mechanical complications if they had heart failure (odds ratio (OR) 6.6 (95% CI 1.6 to 26.7); p = 0.008), depression (OR 5.1 (95% CI 1.1 to 25.7); p = 0.048), or cancer (OR 1.5 (95% CI 1.1 to 1.4); p = 0.004). Frail and severely frail patients experienced higher rates of mechanical complication than ‘not frail’ patients at two years (19% (n = 45) vs 11.9% (n = 29); p = 0.003). When controlling for baseline deformity and degree of correction in severely frail and frail patients, severely frail patients were less likely to experience clinically relevant proximal junctional kyphosis or failure or mechanical complications by two years, if they had a more proximal UIV. Conclusion. Frail patients are at risk of a poor outcome after surgery for adult spinal deformity due to their comorbidities. Although a definitively prescriptive upper instrumented vertebra remains elusive, these patients appear to be at greater risk for a poor outcome if the upper instrumented vertebra is sited more distally. Cite this article: Bone Joint J 2024;106-B(11):1342–1347

Background. The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to classify the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods. We included 20 cavovarus feet from adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, 14 males). Patients included had flexible deformities, with no previous surgery. Previous work established majority of rotational deformity in cavovarus feet occurs at the talonavicular joint, which is often reduced during surgery. Using specialised software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using data from normal feet as a guide, the talonavicular joint of the cavovarus feet was digitally reduced to a ‘normal’ position. Models of the corrected position were exported and geometrically analysed using Blender 3.6 to identify anatomical trends. Results. We identified 3 types of cavovarus forefoot morphotypes. Type 1 was seen in 13 cases (65%) and was defined as a foot where only the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular correction. Type 2 was seen in 4 cases (20%) and was defined as a foot where the second and first metatarsals were progressively plantarflexed, with no significant adduction. Type 3 was seen in 3 cases (15%) and was defined as a foot where the metatarsals were still adducted after talonavicular de-rotation. Conclusion. We classify 3 forefoot morphotypes in cavovarus feet. It is important to recognise and anticipate the residual forefoot deformities after hindfoot correction as different treatment strategies may be required for different morphotypes to achieve balanced correction

Deformity correction has become a more common intervention in an attempt to mitigate pain from an arthritic ankle while hopefully preventing progression of intraarticular disease. Malunion takes the form of angulation, rotation, translation, and length discrepancy, all of which must be measured and addressed by the surgeon. Contact surface area within the ankle joint can decrease up to 40% with angular malalignment, with subsequent increase in contact pressures in the residual joint surface. As the apex of the deformity moves closer to the ankle joint, pressures increase further. There are no rules as to the magnitude of deformity that necessitates correction, but the literature suggests 15 degrees of varus alalignment, 10 degrees of valgus malalignment and 20 mm shift medial to the mechanical axis all should undergo correction. This lecture will explore: assessment of deformity, methods of correction, and literature results on the impact deformity correction has on ankle arthritis. As a separate issue, we will also address fibula length and the impact that shortening has on creating ankle arthritis and flatfoot

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the majority of deformities, however distal femoral deformity is difficult to assess because of the difference between anatomic and mechanical axes. We found the described technique involving constructing a line perpendicular to a line from the tip of the greater trochanter to the centre of the femoral head inaccurate, particularly if the trochanter is abnormal. We devised a novel technique which accurately determines the CORA and extent of distal femoral deformity, allowing accurate correction. Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylized as a block. A line bisecting the axis of the proximal femur is then extended distally to intersect the joint. The angle (θ) between the joint and the proximal femoral axis and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of the deformity, permitting accurate correction. We examined the utility and reproducibility of the new method using 100 normal femora. θ = 81 ± sd 2.5°. As expected, θ correlated with femoral length (r=0.74). P (expressed as the percentage of the distance from the lateral edge of the joint block to the intersection) = 61% ± sd 8%. P was not correlated with θ. Intra-and inter-observer errors for these measurements are within acceptable limits and observations of 30-paired normal femora demonstrate similar values for θ and p on the two sides. We have found this technique to be universally applicable and reliable in a variety of distal femoral deformities

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the majority of deformities, however distal femoral deformity is difficult to assess because of the difference between anatomic and mechanical axes. We found the described technique involving constructing a line perpendicular to a line from the tip of the greater trochanter to the centre of the femoral head inaccurate, particularly if the trochanter is abnormal. We devised a novel technique which accurately determines the CORA and extent of distal femoral deformity, allowing accurate correction. Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylized as a block. A line bisecting the axis of the proximal femur is then extended distally to intersect the joint. The angle (Θ) between the joint and the proximal femoral axis and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of the deformity, permitting accurate correction. We examined the utility and reproducibility of the new method using 100 normal femora. Θ = 81 ± sd 2.5. As expected, Θ correlated with femoral length (r=0.74). P (expressed as the percentage of the distance from the lateral edge of the joint block to the intersection) = 61% ± sd 8%. P was not correlated with Θ. Intra-and inter-observer errors for these measurements are within acceptable limits and observations of 30-paired normal femora demonstrate similar values for Θ and p on the two sides. We have found this technique to be universally applicable and reliable in a variety of distal femoral deformities

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and limb dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the majority of deformities, however distal femoral deformity is difficult to assess because of the difference between the anatomic and mechanical axes. We have found the described technique involving constructing a line perpendicular to a line from the tip of the greater trochanter to the centre of the femoral head inaccurate, particularly if the trochanter is abnormal. We have devised a novel technique which accurately determines the CORA and extent of distal femoral deformity, allowing accurate correction. Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylised as a block. A line bisecting the axis of the proximal femur is then extended distally to intersect the joint. The angle (𝛉) between the joint and the proximal femoral axis and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of the deformity, permitting accurate correction. We have examined the utility and reproducibility of the new method using one hundred normal femurs. Θ=81+/− sd 2.5°. As expected, 𝛉 correlated with femoral length (r=0.74). P (expressed as the percentage of the distal from the medial edge of the joint block to the intersection) = 61% +/− sd 8%. P was not correlated with 𝛉. Intra-and inter-observer errors for these measurements are within acceptable limits and observations of twenty paired normal femora demonstrate similar values for 𝛉 and p on the two sides. We have employed this technique in a variety of distal femoral deformities, including vitamin D resistant rickets, growth arrest, fibula hemimelia, post-traumatic deformity and Ellis-van Creveld syndrome. We find the system universally applicable and reliable

Extra-articular deformity may be present in patients requiring TKA. Underlying causes include trauma, metabolic bone disease, congenital deformity, or prior osteotomy. Patients with intra-articular deformity can have a combination of intra-articular bone loss and concomitant ligament contraction which can be managed in the standard fashion. In these cases establishing appropriate limb alignment and management of bone loss coincide well with the standard ligament balancing employed to provide a stable knee. However, if extra-articular deformity is not corrected extra-articularly, it must be corrected by a compensatory distal femoral or proximal tibial resection to reproduce appropriate limb alignment. Complex instabilities may result from this type of wedge resection because it occurs between the proximal and distal attachments of the collateral ligaments and so produces asymmetrical ligament length alterations. Femoral compensatory wedge resection for extra-articular deformity produces extension instability without affecting the flexion gap and so femoral deformities are POTENTIALLY more difficult to correct than tibial deformities where the compensatory tibial cut influences flexion AND extension equally. Lack of access to the intramedullary canal (as well as increased complexity of producing appropriately placed bone cuts) may be managed with computer guidance or patient specific instruments. The closer a deformity is to the knee, the greater its importance and the effect on the surgical correction. This is a directly proportional relationship, so that as the apex of the deformity moves from juxta-articular to more distant, the amount of corrective wedge needed to re-align the limb decreases proportionally. Rotatory deformities are complex and most commonly effect extensor mechanism tracking. In general the effect is similar to any other deformity in that proximity to the knee increases the likelihood that it will have a significant local effect. In general, these deformities are clinically, and radiographically more subtle and so must be searched for. They should be managed by an attempt to restore normal rotational parameters of the bone itself or appropriate compensation of component rotation in relation to the bone. As prosthetic constraint increases one may need to use intramedullary stems. Their use may be compromised by the deformity. Finally, the younger the patient and the more severe the deformity the more likely I am to treat the deformity by correction at the site of the deformity rather than compensating with abnormal bone resections. The older the patient and the milder the deformity (or the amount of wedge correction required) the more likely I am to manage the deformity with intra-articular correction and increased TKA constraint

Background. After surgical correction of thoracic scoliosis, an improvement in the cardio-respiratory adaptation to exercise would be expected because of the correction of the rib cage associated with the spinal deformity. This work intended to evaluate the physiologic responses to incremental exercise in patients undergoing surgical correction of adolescent idiopathic scoliosis (AIS). The hypothesis of this study was that the exercise limitations described in patients with AIS could be related with the physical deconditioning instead of being linked to the severity of the vertebral deformity. Methods. Cross-sectional study of the exercise tolerance in a series of patients with AIS type Lenke 1A, before and 2 years after surgical correction. Twenty patients with AIS and 10 healthy adolescents aged between 12 and 17 years old were evaluated. The average magnitude of the curves was 60.3±12.9 Cobb. Cardio-respiratory function was assessed before surgery and at 2-year follow-up by maximal exercise tolerance test on treadmill following a Bruce standard protocol. Maximal oxygen uptake (VO2), VCO2, expiratory volume (VE), and VE/VO2 ratio were registered. Results. Before surgery, AIS patients showed lower values than healthy controls in all cardio-respiratory parameters. The most important restrictions were the VO2max in ml/kg/min. (30.3±5.4 vs 49.9±7.5), VE (43.2±10.3 vs 82.3±10.7) and VE/CO2 ratio (25.0±3.9 vs 29.6±4.2). Contrary to expectations, two years after surgery most of these parameters decreased but differences with preoperative data were no statistically significant. Besides the great correction of the deformity (coronal plane, 71.5%; axial rotation, 49.3%), the cardio-respiratory tolerance to the exercise was not modified by surgery. Conclusions. Patients with moderate-severe AIS showed a limited tolerance to maximal exercise that does not change 2 years after surgery. This findings suggests that the reduced cardio-pulmonary function during exercise is not strictly associated to the spinal deformity, since great corrections of the spinal curves does not improve functional ventilatory parameters. In addition, the results point out a severe exercise deconditioning in AIS patients. Level of evidence. Level IV

The February 2023 Children’s orthopaedics Roundup³⁶⁰ looks at: Trends in management of paediatric distal radius buckle fractures; Pelvic osteotomy in patients with previous sacral-alar-iliac fixation; Sacral-alar-iliac fixation in patients with previous pelvic osteotomy; Idiopathic toe walking: an update on natural history, diagnosis, and treatment; A prediction model for treatment decisions in distal radial physeal injuries: a multicentre retrospective study; Angular deformities after percutaneous epiphysiodesis for leg length discrepancy; MRI assessment of anterior coverage is predictive of future radiological coverage; Predictive scoring for recurrent patellar instability after a first-time patellar dislocation.

Background. The improvement of the rib cage deformity (RCD) after surgery correction has not been correlated in detail with the correction of vertebral axial rotation (AR). The loss of at the rib cage after correction has been never monitored. The hypothesis of this work was that the aesthetic improvement of RCD in adolescent idiopathic scoliosis (AIS) does not follow completely the reduction of thoracic AR after correction surgery. Moreover, lesser correction of thorax deformity could be expected in mature patients with more rigid curves. Methods. Multicenter prospective study of the modifications of the rib cage deformity in 24 patients operated because of AIS Lenke type 1A. RDC was assessed in the preoperative MRI exams including the thoracic perimeter. Vertebral AR was quantified by the RaSac angle. Anterior and posterior rib hump, and the translation of the sternum were measured in mm according to standard protocols. All these parameters were assessed in the immediate post-op period and 2-years after surgery using CT-scan axial slides. In all cases, a vertebral derotation technique performed by asymmetric rod bending was used. Immature (Risser 0–2) and mature (Risser 3–4) patients were compared. Results. Mean age of patients was 14±2 years. The preoperative curve magnitude was 56.2±8.3 Cobb degrees. RaSac at the apex was 27.2±2.8 degrees. There were 10 immature and 14 mature patients. There were no differences between the two groups in all the radiological measurements of the curves. Immature patients showed lesser posterior rib hump as compared to mature cases (14.9±4.1 mm versus 38.1±22.9; p<0.001). Postoperative vertebral AR was lesser in immature patients (2.0±1.2 versus 7.9±2.4 degrees) and increased slightly at 2-year check-up. The posterior rib hump showed also a slightly increased 2 years after surgery. In 18 cases (75%), a contralateral anterior rib hump less than 3 mm emerged after surgery that diminished but not disappeared at 2-year check-up. Conclusions. The rib cage deformity showed a lesser correction than the vertebral axial rotation. Besides this finding, immature patients showed more rib cage plasticity showing both greater modifications after surgery, and higher loss of correction during follow-up. Level of evidence. Level IV

The December 2022 Spine Roundup³⁶⁰ looks at: Deep venous thrombosis prophylaxis protocol on a Level 1 trauma centre patient database; Non-specific spondylodiscitis: a new perspective for surgical treatment; Disc degeneration could be recovered after chemonucleolysis; Three-level anterior cervical discectomy and fusion versus corpectomy- anterior cervical discectomy and fusion “hybrid” procedures: how does the alignment look?; Rivaroxaban or enoxaparin for venous thromboembolism prophylaxis; Surgical site infection: when do we have to remove the implants?; Determination of a neurologic safe zone for bicortical S1 pedicle placement; Do you need to operate on unstable spine fractures in the elderly: outcomes and mortality; Degeneration to deformity: when does the patient need both?

There are three major diagnoses that have been associated with early hip degeneration and subsequent hip replacement in young patients: FAI, hip dysplasia and hip osteonecrosis. I will focus mainly on the first two. Both conditions, if diagnosed early in the symptomatic patient, can be surgically treated in order to try to prevent further hip degeneration. But, what is the natural history of these disorders?. Our recent paper published this year described the natural history of hip dysplasia in a group of patients with a contralateral THA. At an average of 20 years, 70% of hips that were diagnosed at Tönnis Grade 0, had progression in degenerative changes with 23% requiring a THA at 20 years. Once the hip degeneration progressed to Tönnis 1, then 60% of hips progressed and required a THA. This natural history study demonstrates that degeneration of a dysplastic hip will occur in over 2/3 of the hips despite the limitations of activity imposed by a contralateral THA. In this same study, we were unable to detect a significant difference in progression between FAI hips and those categorised as normal. FAI damage has been commonly considered to be “motion-induced” and as such, the limitations imposed by the THA, might have limited the progression in hip damage. Needless to say, progression was seen in about half of the hips at 10 years, but very few required a THA at final follow-up. We have recently presented data on a group of young asymptomatic teenagers with FAI. At 5 years of follow-up, the group of patients with limited ROM in flexion and internal rotation, cam deformity and increased alpha angles, depicting a more severe form of disease, showed MRI evidence of progression in hip damage and worst clinical scores than a control group. This data supports our initial impressions that FAI may truly lead to irreversible hip damage. Is surgery always the option? I indicate surgery when the patient is symptomatic and has a correctable structural problem that has failed non-operative management. The data suggests that few patients improve with physical therapy, but activity modification may be an option in patients with FAI as the hip damage is mainly activity related. This may not be the case with hip dysplasia. For hip dysplasia, my current recommendations are in the form of a periacetabular osteotomy (PAO) to correct the structural problem. The procedure leads to improvement in pain as it takes care of the 4 pain generators in the dysplastic hip: the labrum, cartilage, abductors, and resultant instability. The labrum and cartilage are off-loaded with the PAO, the instability is improved by providing containment and the abductor pain is improved by improving the hip mechanics by medializing the acetabulum. I perform a hip arthroscopy prior to the PAO in the majority to treat the labrum and to perform a head neck junction osteochondroplasty, if needed. Correction of the dysplasia to a more normal hip, will improve the outcome of these hips in the long-term. For FAI, arthroscopy has become the best option for management and today is considered the gold standard. A careful review of the imaging is important prior to surgical decision making as patient selection and surgical correction is key. Poor outcomes have been seen in patients with advanced degenerative changes (joint space narrowing, femoral head damage) or in patients with incomplete correction of the deformity. Open surgical correction is an option in cases where deformity precludes an arthroscopic treatment alone

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.

Postoperative functional outcomes and patients’ satisfaction after total knee arthroplasty are associated with postoperative range of motion. Severe deformities require surgical correction such as soft tissue release and appropriate bone resection. The goal of surgery is to correct the contracture and bring the knee to good range of motion. Using gap-balancing technique is one of the major techniques to obtain good range of motion. Although the gaps are well balanced, the thickness of tibial insert would affect the range of motion. In this study, we analyzed the difference between intraoperative extension joint gap and the thickness of implanted insert (DJI). The objective of this study was to investigate whether DJI affected the postoperative extension of the knee. A total of 155 knees were analyzed retrospectively. Subject included 27 males and 128 females with an average of 72.7 ± 7.0 years. The mean preoperative knee flexion angle was 136.1 ± 20.0°and the mean preoperative knee extension deficit was 4.0 ± 6.1°. All the patients had a diagnosis of varus-type osteoarthritis, identical prostheses (Stryker NRG posterior-stabilized type) implanted with a modified gap-balancing technique and no postoperative complications which may have affected the range of motion. Range of motion was measured using a goniometer before surgery and 12 months after surgery. Joint gap between femoral component and proximal tibia in full extension was measured by a tensor/ balancer device which added joint gap an expansion force by 30 inch pounds intra-operatively. Although we empirically regarded the appropriate DJI was 5 mm for this prosthesis, we determined the thickness of the tibial inserts considering preoperative range of motion. Thinner inserts compared with the joint gap was implanted for knees with flexion contracture and thicker inserts was implanted for knees with hyperextension. In this study, to determine the relationship of DJI and flexion contracture, the correlation coefficient between DJI and extension deficit was calculated. The diagram of DJI and postoperative extension angle is shown in Figure 1. The correlation coefficient between DJI and postoperative extension deficit was 0.24, which showed that DJI slightly affected the postoperative extension of the knee. Flexion contracture cannot be corrected by simply adjusting DJI

Introduction: Proper correction of proximal tibial deformities includes correction of the mechanical axis and parallelism of the knee to the ankle and ground. Optimally placed osteotomies are away from the very proximal deformity requiring controlled diaphyseal translation. The Metaphyseal Arc Correction System, a major simplification over the Ilizarov or Spatial Frame systems, is assessed in this study, as are methods to identify the plane of deformity. Method: Thirty-one consecutive cases of proximal tibial deformity in 18 patients were treated using the Metaphyseal Arc Correction Sysytem. There were six valgus deformities (three pts), one Morquio, two metaphyseal dwarfs ages six and eight years. The rest were varus deformities, 12 achondroplasia (six pts), eight infantile Blount’s (four pts) and five adolescent Blount’s (five pts). Comparison of two methods of identifying the plane of deformity was done in six cases: Herzenberg’s graphic method and the image method (rotating the limb until the maximum deformity is in the plane of the intensifier). Results: All but eight tibiae (five pts) were properly corrected. Four tibiae (two pts) were over corrected, two tibiae (one pt) were corrected but the knee and ankle were not parallel. Analysis of these six limbs revealed unrecognised deformity of the distal femur. Thus to get the joints parallel in four limbs the axis was overcorrected and in two limbs the axis was proper but the joints were not parallel. One failure occurred because the device was not placed in the plane of deformity, another because of premature fibula consolidation (or incomplete osteotomy). All other cases achieved deformity and axis correction with joint parallelism. Both methods of identifying the plane of deformity yielded similar results as long as the proximal tibia was centered to avoid image parallax. The graphic method gives accurate angles but could only be approximated clinically. There was one failure from inaccurate device placement using the image method. Ideally both methods should be used. Conclusion: The Metaphyseal Arc Correction System is convenient method of correcting proximal tibial deformities. It is easily applied and when properly positioned automatically corrects deformity, axis and joint parallelism, allowing optimum osteotomy placement. Positioning should use both the graphic and image methods. Failures were iatrogenic due to poor analysis, not the device

Lower limb mal-alignment due to deformity is a significant cause of early degenerative change and dysfunction. Standard techniques are available to determine the centre of rotation of angulation (CORA) and extent of the deformities. However, distal femoral deformity is difficult to assess because of the difference between anatomic and mechanical axes. We describe a novel technique which accurately determines the CORA and extent of distal femoral deformity. Using standard leg alignment views of the normal femur, the distal femoral metaphysis and joint line are stylised as a block. A line bisecting the anatomical axis of the proximal femur is then extended distally to intersect the joint. The angle (?) between the joint and the proximal femoral axis, and the position (p) where the extended proximal femoral axis intersects the joint line are calculated. These measurements can then be reproduced on the abnormal distal femur in order to calculate the CORA and extent of deformity, permitting accurate correction. We examined the utility and reproducibility of the new method using 100 normal femora. We found this technique to be universally robust in a variety of distal femoral deformities

Adolescent idiopathic scoliosis (AIS), defined by an age at presentation of 11 to 18 years, has a prevalence of 0.47% and accounts for approximately 90% of all cases of idiopathic scoliosis. Despite decades of research, the exact aetiology of AIS remains unknown. It is becoming evident that it is the result of a complex interplay of genetic, internal, and environmental factors. It has been hypothesized that genetic variants act as the initial trigger that allow epigenetic factors to propagate AIS, which could also explain the wide phenotypic variation in the presentation of the disorder. A better understanding of the underlying aetiological mechanisms could help to establish the diagnosis earlier and allow a more accurate prediction of deformity progression. This, in turn, would prompt imaging and therapeutic intervention at the appropriate time, thereby achieving the best clinical outcome for this group of patients.

Cite this article: Bone Joint J 2022;104-B(8):915–921.

Scoliosis surgery has moved towards all posterior correction, as modern implants are perceived to be powerful enough to overcome stiffer and more severe curves. However, shortening of the anterior spinal column remains most effective in creating thoracic kyphosis, and may still have a role in correcting both coronal and sagittal deformities. Furthermore, anterior correction of lumbar and thoracolumbar curves can theoretically reduce the distal fusion level, and may have significant impact on patients' post-operative function. A single surgeon series of 62 patients with idiopathic scoliosis were examined retrospectively. Radiographs and operation notes were examined by 2 spinal surgeons, sagittal and coronal parameters were measured before and after the operation. The patients were divided into 4 groups: 16 anterior and posterior fusions (AP), 16 anterior thoracolumbar fusions (A), 5 anterior thoracic releases and posterior fusions (AR), and 25 posterior fusions only (P). The mean age was 15.3 (range 10 – 20). The mean main thoracic Cobb angle pre-operatively was: 54° (AP), 43° (A), 63° (AR), and 50° (P). The mean thoracolumbar Cobb angle was: 55° (AP) and 51° (A). There was no significant difference in lumbar lordosis. The mean post-operative main thoracic Cobb angle was: 9° (AP), 13° (A), 9° (AR) and 15° (P). There was significant difference between AR and P groups. The mean post-operative thoracolumbar Cobb angle was: 8° (AP) and 6° for (A). There was a significant difference in the post-operative thoracic kyphosis between AP (mean 14°), A (mean 38°), AR (mean 19°) and P (mean 14°). Overall, the lumbar lordosis for all 4 groups reduced from a mean of 67° to 50°, with no significant difference between the groups. The distal level of fusion for A and AP groups were L3 for all cases, whereas 2 cases had to extend to L4 in the P group. Anterior release improved both coronal and sagittal correction when compared to posterior only surgery, however it is of unknown clinical significance. Anterior thoracolumbar fusion with or without posterior spinal fusion appeared to produce adequate coronal correction if fused to L3. No difference was found between all groups in post-operative lumbar lordosis