Aims

The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs.

Aims. The first metatarsal pronation deformity of hallux valgus feet is widely recognized. However, its assessment relies mostly on 3D standing CT scans. Two radiological signs, the first metatarsal round head (RH) and inferior tuberosity position (ITP), have been described, but are seldom used to aid in diagnosis. This study was undertaken to determine the reliability and validity of these two signs for a more convenient and affordable preoperative assessment and postoperative comparison. Methods. A total of 200 feet were randomly selected from the radiograph archives of a foot and ankle clinic. An anteroposterior view of both feet was taken while standing on the same x-ray platform. The intermetatarsal angle (IMA), metatarsophalangeal angle (MPA), medial sesamoid position, RH, and ITP signs were assessed for statistical analysis. Results. There were 127 feet with an IMA > 9°. Both RH and ITP severities correlated significantly with IMA severity. RH and ITP were also significantly associated with each other, and the pronation deformities of these feet are probably related to extrinsic factors. There were also feet with discrepancies between their RH and ITP severities, possibly due to intrinsic torsion of the first metatarsal. Conclusion. Both RH and ITP are reliable first metatarsal pronation signs correlating to the metatarsus primus varus deformity of hallux valgus feet. They should be used more for preoperative and postoperative assessment. Cite this article: Bone Jt Open 2024;5(11):1037–1040

The development of spinal deformity in children with underlying neurodisability can affect their ability to function and impact on their quality of life, as well as compromise provision of nursing care. Patients with neuromuscular spinal deformity are among the most challenging due to the number and complexity of medical comorbidities that increase the risk for severe intraoperative or postoperative complications. A multidisciplinary approach is mandatory at every stage to ensure that all nonoperative measures have been applied, and that the treatment goals have been clearly defined and agreed with the family. This will involve input from multiple specialities, including allied healthcare professionals, such as physiotherapists and wheelchair services. Surgery should be considered when there is significant impact on the patients’ quality of life, which is usually due to poor sitting balance, back or costo-pelvic pain, respiratory complications, or problems with self-care and feeding. Meticulous preoperative assessment is required, along with careful consideration of the nature of the deformity and the problems that it is causing. Surgery can achieve good curve correction and results in high levels of satisfaction from the patients and their caregivers. Modern modular posterior instrumentation systems allow an effective deformity correction. However, the risks of surgery remain high, and involvement of the family at all stages of decision-making is required in order to balance the risks and anticipated gains of the procedure, and to select those patients who can mostly benefit from spinal correction

Background. Spinal deformity has a known deleterious effect upon the outcomes of total hip arthroplasty and acetabular component positioning. This study sought to evaluate the relationship between severity of spinal deformity parameters and acetabular cup position, rate of dislocation, and rate of revision among patients with total hip arthroplasties and concomitant spinal deformity. Methods. A prospectively collected database of patients with spinal deformity was reviewed and patients with total hip arthroplasty were identified. The full body standing stereoradiographic images (EOS) were reviewed for each patient. From these images, spinal deformity parameters and acetabular cup anteversion and inclination were measured. A chart review was performed on all patients to determine dislocation and revision arthroplasty events. Statistical analysis was performed to determine correlation of deformity with acetabular cup position. Subgroup analysis was performed for patients with spinal fusion, dislocation events, and revision THA. Results. One-hundred and seven spinal deformity patients were identified, with 139 hips for analysis. The rate of THA dislocation in this cohort was 8.0%, with a revision rate of 5.8% for instability. Patients who sustained dislocations had significantly higher spinopelvic tilt, T1-pelvic angle, and mismatch of lumbar lordosis and pelvic incidence. Among all patients, only 68.8% met the radiographic “safe zone” for anteversion in the standing position (Figure 1). A comparison of radiographic cup position on supine x-ray with standing EOS imaging demonstrated an increase in anteversion of 6.2 degrees. Standing decreased rate of safe zone anteversion of the cup by 20%. Conclusions. In this cohort, patients with THA and concomitant spinal deformity have a particularly high rate of dislocation. This dislocation risk may be driven by the degree of spinal deformity and by spinopelvic compensation, which is suggested by our findings. Arthroplasty surgeons should be aware of the elevated dislocation rate and consider a surgical strategy for maintaining hip stability in this population

Salter-Harris II fractures of the distal tibia affect children frequently, and when they are displaced present a treatment dilemma. Treatment primarily aims to restore alignment and prevent premature physeal closure, as this can lead to angular deformity, limb length difference, or both. Current literature is of poor methodological quality and is contradictory as to whether conservative or surgical management is superior in avoiding complications and adverse outcomes. A state of clinical equipoise exists regarding whether displaced distal tibial Salter-Harris II fractures in children should be treated with surgery to achieve anatomical reduction, or whether cast treatment alone will lead to a satisfactory outcome. Systematic review and meta-analysis has concluded that high-quality prospective multicentre research is needed to answer this question. The Outcomes of Displaced Distal tibial fractures: Surgery Or Casts in KidS (ODD SOCKS) trial, funded by the National Institute for Health and Care Research, aims to provide this high-quality research in order to answer this question, which has been identified as a top-five research priority by the British Society for Children’s Orthopaedic Surgery. Cite this article: Bone Joint J 2023;105-B(5):471–473

Aims. The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients. Methods. All patients who underwent a knee arthroplasty from 2019 to 2021 were included. Exclusion criteria were genu valgus, flexion contracture (> 5°), previous femoral osteotomy or fracture, total hip arthroplasty, and femoral rotational disorder. A total of 205 patients met the inclusion criteria. The mean age was 62.2 years (SD 8.4). The mean BMI was 33.1 kg/m. 2. (SD 5.5). The radiological measurements were performed twice by two independent reviewers, and included hip knee ankle (HKA) angle, mechanical medial distal femoral angle (mMDFA), anatomical medial distal femoral angle (aMDFA), femoral neck shaft angle (NSA), femoral bowing angle (FBow), the distance between the knee centre and the top of the FBow (DK), and the angle representing the FBow impact on the knee (C’KS angle). Results. The FBow impact on the mMDFA can be measured by the C’KS angle. The C’KS angle took the localization (length DK) and the importance (FBow angle) of the FBow into consideration. The mean FBow angle was 4.4° (SD 2.4; 0 to 12.5). The mean C’KS angle was 1.8° (SD 1.1; 0 to 5.8). Overall, 84 knees (41%) had a severe FBow (> 5°). The radiological measurements showed very good to excellent intraobserver and interobserver agreements. The C’KS increased significantly when the length DK decreased and the FBow angle increased (p < 0.001). Conclusion. The impact of the diaphyseal femoral deformity on the mechanical femoral axis is measured by the C’KS angle, a reliable and reproducible measurement. Cite this article: Bone Jt Open 2023;4(4):262–272

Preoperative talar valgus deformity increases the technical difficulty of total ankle replacement (TAR) and is associated with an increased failure rate. Deformity of ≥15° has been reported to be a contraindication to arthroplasty. The goal of the present study was to determine whether the operative procedures and clinical outcomes of TAR for treatment of end-stage ankle arthritis were comparable for patients with preoperative talar valgus deformity of ≥15° as compared to those with <15°. We will describe the evolving surgical technique being utilized to tackle these challenging cases. Fifty ankles with preoperative coronal-plane tibiotalar valgus deformity of ≥15° “valgus” group) and 50 ankles with valgus deformity of <15° (“control” group) underwent TAR. The cohorts were similar with respect to demographics and components used. All TARs were performed by a single surgeon. The mean duration of clinical follow-up was 5.5 years (minimum two years). Preoperative and postoperative radiographic measurements of coronal-plane deformity, Ankle Osteoarthritis Scale (AOS) scores and Short Form (SF)-36 scores were prospectively recorded. All ancillary (intraoperative) and secondary procedures, complications and measurements were collected. The AOS pain and disability subscale scores decreased significantly in both groups. The improvement in AOS and SF-36 scores did not differ significantly between the groups at the time of the final follow-up. The valgus group underwent more ancillary procedures during the index surgery (80% vs 26%). Tibio-talar deformity improved significantly toward a normal weight-bearing axis in the valgus group. Secondary postoperative procedures were more common in the valgus group (36%) than the controls (20%). Overall, re-operation was not associated with poorer patient outcome scores. Metal component revision surgery occurred in seven patients (three valgus and four controls). These revisions included two deep infections (2%), one in each group, which were converted to hindfoot fusions. Therefore, 94% of the valgus group retained their original components at final follow-up. Thus far, this is the largest reported study that specifically evaluates TAR with significant preoperative valgus alignment, in addition to having the longest follow-up. Satisfactory midterm results were achieved in patients with valgus mal-alignment of ≥15°. The valgus cohort required more procedures during and after their TAR, as well as receiving more novel techniques to balance their TAR. Whilst longer term studies are needed, valgus coronal-plane alignment of ≥15° should not be considered an absolute contraindication to TAR if the associated deformities are addressed

Aims. To assess if congenital foot deformity is a risk factor for developmental dysplasia of the hip (DDH). Methods. Between 1996 and 2012, 60,844 children were born in Sør-Trøndelag county in Norway. In this cohort study, children with risk factors for DDH were examined using ultrasound. The risk factors evaluated were clinical hip instability, breech delivery, a family history of DDH, a foot deformity, and some syndromes. As the aim of the study was to examine the risk for DDH and foot deformity in the general population, children with syndromes were excluded. The information has been prospectively registered and retrospectively analyzed. Results. Overall, 494 children (0.8%) had DDH, and 1,132 (1.9%) a foot deformity. Of the children with a foot deformity, 49 (4.3%) also demonstrated DDH. There was a statistically significant increased association between DDH and foot deformity (p < 0.001). The risk of DDH was highest for talipes calcaneovalgus (6.1%) and club foot (3.5%), whereas metatarsus adductus (1.5%) had a marginal increased risk of DDH. Conclusion. Compared with the general population, children with a congenital foot deformity had a significantly increased risk for DDH and therefore we regard foot deformity as a true risk factor for DDH. Cite this article: Bone Joint J 2020;102-B(11):1582–1586

Introduction. The arch of the foot has been described as a truss where the plantar fascia (PF) acts as the tensile element. Its role in maintaining the arch has likely been underestimated because it only rarely torn in patients with progressive collapsing foot deformity (PCFD). We hypothesized that elongation of the plantar fascia would be a necessary and sufficient precursor of arch collapse. Method. We used a validated finite element model of the foot reconstructed from CT scan of a female cadaver. Isolated and combined simulated ligament transection models were created for each combination of the ligaments. A collapsed foot model was created by simulated transection of all the arch supporting ligaments and unloading of the posterior tibial tendon. Foot alignment angles, changes in force and displacement within each of the ligaments were compared between the intact, isolated ligament transection, and complete collapse conditions. Result. Isolated release of the PF did not cause deformity, but lead to increased force in the long (142%) and short plantar (156%), deltoid (45%), and spring ligaments (60%). The PF was the structure most able to prevent arch collapse and played a secondary role in preventing hindfoot valgus and forefoot abduction deformities. Arch collapse was associated with substantial attenuation of the spring (strain= 41%) and interosseous talocalcaneal ligaments (strain= 27%), but only a small amount in the plantar fascia (strain= 10%). Conclusion. Isolated PF release did not cause arch collapse, but arch collapse could not occur without at least 10% elongation of the PF. Simulated transection of the PF led to substantial increase in the force in the other arch supporting ligaments, putting the foot at risk of arch collapse over time. Chronic degeneration of the PF leading to plantar fasciitis may be an early sign of impending PCFD

Previous studies of osteoarthritic knees have examined the relationship between the variables body mass index (BMI) and weight on the one hand and coronal plane deformity on the other. There is a consensus that weight and BMI are positively correlated to the degree and progression of a varus deformity. However, there does not appear to be a consensus on the effect of these variables on knees with a valgus deformity. Indeed, the view has been expressed that in knees with a severe deformity a relationship might not exist. A review of these studies reveals that in all cases, the alignment of the lower limb was obtained from a standing antero-posterior long leg radiograph. In no cases was the deformity in the sagittal plane measured. This study analyses the relationship between BMI, weight, deformity in the sagittal plane and valgus deformity. The study group consisted of 73 patients with osteoarthritis and valgus knees. All of them had failed conservative treatment for their symptoms and were listed for navigated TKA. Their weight and height were measured two weeks preoperatively and the BMI calculated. At operation the coronal and sagittal deformities were measured using the Orthopilot. ®. navigation system (BBraun Aesculap, Tuttlingen). The results were analysed using SPSS 15. Regression analysis showed a significant relationship (p< 0.05) with a negative correlation between valgus deformity and weight. the correlation coefficient for flexed knees (−0.59) showed a moderately strong relationship whereas that for extended knees (−0.38) showed a relatively weak relationship. It is acknowledged that there is an increased force on the lateral compartment with increased valgus deformity. a larger deformity causes a larger moment arm about the centre of the knee. this study has shown that at the time of surgery, individuals with lower weights have larger valgus deformities. we postulate, therefore, that when the moment due to the weight of the individual and the length of the moment arm exceeds a certain value, a symptomatic threshold is crossed. in the presence of a fixed flexion deformity, the force on the patella-femoral joint is increased, contributing further to the onset of discomfort. Further investigation into the subsets of valgus knees appears to be warranted

Aims. While residual fixed flexion deformity (FFD) in unicompartmental knee arthroplasty (UKA) has been associated with worse functional outcomes, limited evidence exists regarding FFD changes. The objective of this study was to quantify FFD changes in patients with medial unicompartmental knee arthritis undergoing UKA, and investigate any correlation with clinical outcomes. Methods. This study included 136 patients undergoing robotic arm-assisted medial UKA between January 2018 and December 2022. The study included 75 males (55.1%) and 61 (44.9%) females, with a mean age of 67.1 years (45 to 90). Patients were divided into three study groups based on the degree of preoperative FFD: ≤ 5°, 5° to ≤ 10°, and > 10°. Intraoperative optical motion capture technology was used to assess pre- and postoperative FFD. Clinical FFD was measured pre- and postoperatively at six weeks and one year following surgery. Preoperative and one-year postoperative Oxford Knee Scores (OKS) were collected. Results. Overall, the median preoperative navigated (NAV) FFD measured 6.0° (IQR 3.1 to 8), while the median postoperative NAV FFD was 3.0° (IQR 1° to 4.4°), representing a mean correction of 49.2%. The median preoperative clinical FFD was 5° (IQR 0° to 9.75°) for the entire cohort, which decreased to 3.0° (IQR 0° to 5°) and 2° (IQR 0° to 3°) at six weeks and one year postoperatively, respectively. A statistically significant improvement in PROMs compared with baseline was evident in all groups (p < 0.001). Regression analyses showed that participants who experienced a larger FFD correction, showed greater improvement in PROMs (β = 0.609, p = 0.049; 95% CI 0.002 to 1.216). Conclusion. This study found that UKA was associated with an approximately 50% improvement in preoperative FFD across all three examined groups. Participants with greater correction of FFD also demonstrated larger OKS gains. These findings could prove a useful augment to clinical decision-making regarding candidacy for UKA and anticipated improvements in FFD

Aims. To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity. Methods. Five databases (CENTRAL, CINAHL, PubMed, Embase, Web of Science) were systematically screened for studies investigating split tibialis anterior or split tibialis posterior tendon transfer for spastic equinovarus foot deformity, with gait-related outcomes (published pre-September 2022). Study quality and evidence were assessed using the Methodological Index for Non-Randomized Studies, the Risk of Bias In Non-Randomized Studies of Interventions, and the Grading of Recommendations Assessment, Development and Evaluation. Results. Overall, 17 studies (566 feet) were included: 13 studies used clinical grading criteria to report a postoperative ‘success’ of 87% (75% to 100%), 14 reported on orthotic use with 88% reduced postoperative use, and one study reported on ankle kinematics improvements. Ten studies reported post-surgical complications at a rate of 11/390 feet (2.8%), but 84 feet (14.8%) had recurrent varus (68 feet, 12%) or occurrence of valgus (16 feet, 2.8%). Only one study included a patient-reported outcome measure (pain). Conclusion. Split tendon transfers are an effective treatment for children and youth with CP and spastic equinovarus foot deformities. Clinical data presented can be used for future study designs; a more standardized functional and patient-focused approach to evaluating outcomes of surgical intervention of gait may be warranted. Cite this article: Bone Jt Open 2023;4(5):283–298

Introduction. Charcot neuroarthropathy is a limb threatening condition and the optimal surgical strategy for limb salvage in gross foot deformity remains unclear. We present our experience of using fine wire frames to correct severe midfoot deformity, followed by internal beaming to maintain the correction. Materials and Methods. Nine patients underwent this treatment between 2020–2023. Initial deformity correction by Ilizarov or hexapod butt frame was followed by internal beaming with a mean follow up of 11 months. A retrospective analysis of radiographs and electronic records was performed. Meary's angle, calcaneal pitch, cuboid height, hindfoot midfoot angle and AP Meary's angle were compared throughout treatment. Complications, length of stay and the number of operations are also described. Results. Mean age was 53 years (range:40–59). Mean frame duration was 3.3 months before conversion to beaming. Prior frame-assisted deformity correction resulted in consistently improved radiological parameters. Varying degrees of subsequent collapse were universal, but 5 patients still regained mobility and a stable, plantargrade, ulcer-free foot. Complications were common, including hardware migration (N=6,66%), breakage (N=2,22%), loosening (N=3,33%), infection (N=4,44%), 1 amputation and an unscheduled reoperation rate of 55%. Mean cumulative length of stay was 42 days. Conclusions. Aggressive deformity correction and internal fixation for Charcot arthropathy requires strategic and individualised care plans. Complications are expected for each patient. Patients must understand this is a limb salvage scenario. This management strategy is resource heavy and requires timely interventions at each stage with a well-structured MDT delivering care. The departmental learning points are to be discussed

Introduction and Objective. The treatment of severe deformities often requiring aggressive techniques such as vertebral resection and osteotomies with high comorbidity. To mitigate this risk, several methods have been used to achieve a partial reduction of stiff curves. The objective of this study was to evaluate and quantify the effectiveness of the Perioperative Halo-Gravity Traction (HGT) in the Treatment of Severe Spinal Deformity in Children. Materials and Methods. A historical cohort of consecutive childs with severe spinal deformity who underwent to a perioperative HGT as a part of the treatment protocol. Minimum follow-up of 2 years. Demographic, clinical and radiological data, including time duration of perioperative HGT and Cobb angle in the coronal and sagittal plane. The radiological variables were measured before the placement of the halo, after placement of the halo, at the end of the period of traction, after surgery and in the final follow-up. Results. Seventeen males (57%) and twenty females (43%) were included in the final analysis. The mean age was 6.5 years (SD 4.8). The most frequent etiology for the spinal deformity was syndromic (13 patients). The average preoperative Cobb angle was 88º (range, 12–135). HGT was used in 17 cases prior to a primary surgery and in 20 cases prior to a revision surgery. After the HGT, an average correction of 34% of the deformity was achieved (p <0.05). After the surgery this correction improved. At 2-year follow-up there was a correction loss of 20% (p <0.05). There were 3 complications (8.1%): 2 pin infections and cervical subluxation. Conclusions. The application of HGT in cases of severe rigid deformity is useful allowing a correction of the preoperative deformity of 34%, facilitating surgery. Preoperative HGT seems to be a safe and effective intervention in pediatric patients with high degree deformity

Constrained implants with intra-medullary fixation are expedient for complex TKA. Constraint is associated with loosening, but can correction of deformity mitigate risk of loosening?. Primary TKA's with a non-linked constrained prosthesis from 2010-2018 were identified. Indications were ligamentous instability or intra-medullary fixation to bypass stress risers. All included fully cemented 30mm stem extensions on tibia and femur. If soft tissue stability was achieved, a posterior stabilized (PS) tibial insert was selected. Pre and post TKA full length radiographs showed. i. hip-knee-ankle angles (HKAA). ii. Kennedy Zone (KZ) where hip to ankle vector crosses knee joint. 77 TKA's in 68 patients, average age 69.3 years (41-89.5) with OA (65%) post-trauma (24.5%) and inflammatory arthropathy (10.5%). Pre-op radiographs (62 knees) showed varus in 37.0%. (HKAA: 4. o. -29. o. ), valgus in 59.6% (HKAA range 8. o. -41. o. ) and 2 knees in neutral. 13 cases deceased within 2 years were excluded. Six with 2 year follow up pending have not been revised. Mean follow-up is 6.1 yrs (2.4-11.9yrs). Long post-op radiographs showed 34 (57.6%) in central KZ (HKKA 180. o. +/- 2. o. ). . Thirteen (22.0%) were in mechanical varus (HKAA 3. o. -15. o. ) and 12 (20.3%) in mechanical valgus: HKAA (171. o. -178. o. ). Three failed with infection; 2 after ORIF and one with BMI>50. The greatest post op varus suffered peri-prosthetic fracture. There was no aseptic loosening or instability. Only full-length radiographs accurately measure alignment and very few similar studies exist. No cases failed by loosening or instability, but PPF followed persistent malalignment. Infection complicated prior ORIF and elevated BMI. This does not endorse indiscriminate use of mechanically constrained knee prostheses. Lower demand patients with complex arthropathy, especially severe deformity, benefit from fully cemented, non-linked constrained prostheses, with intra-medullary fixation. Hinges are not necessarily indicated, and rotational constraint does not lead to loosening

Aims. This study examined windswept deformity (WSD) of the knee, comparing prevalence and contributing factors in healthy and osteoarthritic (OA) cohorts. Methods. A case-control radiological study was undertaken comparing 500 healthy knees (250 adults) with a consecutive sample of 710 OA knees (355 adults) undergoing bilateral total knee arthroplasty. The mechanical hip-knee-ankle angle (mHKA), medial proximal tibial angle (MPTA), and lateral distal femoral angle (LDFA) were determined for each knee, and the arithmetic hip-knee-ankle angle (aHKA), joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) types were calculated. WSD was defined as a varus mHKA of < -2° in one limb and a valgus mHKA of > 2° in the contralateral limb. The primary outcome was the proportional difference in WSD prevalence between healthy and OA groups. Secondary outcomes were the proportional difference in WSD prevalence between constitutional varus and valgus CPAK types, and to explore associations between predefined variables and WSD within the OA group. Results. WSD was more prevalent in the OA group compared to the healthy group (7.9% vs 0.4%; p < 0.001, relative risk (RR) 19.8). There was a significant difference in means and variance between the mHKA of the healthy and OA groups (mean -1.3° (SD 2.3°) vs mean -3.8°(SD 6.6°) respectively; p < 0.001). No significant differences existed in MPTA and LDFA between the groups, with a minimal difference in aHKA (mean -0.9° healthy vs -0.5° OA; p < 0.001). Backwards logistic regression identified meniscectomy, rheumatoid arthritis, and osteotomy as predictors of WSD (odds ratio (OR) 4.1 (95% CI 1.7 to 10.0), p = 0.002; OR 11.9 (95% CI 1.3 to 89.3); p = 0.016; OR 41.6 (95% CI 5.4 to 432.9), p ≤ 0.001, respectively). Conclusion. This study found a 20-fold greater prevalence of WSD in OA populations. The development of WSD is associated with meniscectomy, rheumatoid arthritis, and osteotomy. These findings support WSD being mostly an acquired condition following skeletal maturity. Cite this article: Bone Jt Open 2024;5(10):879–885

Aims. To determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory. Methods. Patients who underwent surgery for ASD, with a minimum of two-year follow-up, were retrospectively reviewed. In total, 210 patients were included and randomly allocated into training (70% of the sample size) and test (the remaining 30%) sets to develop the machine learning algorithm. Risk factors were included in the analysis, along with clinical characteristics and parameters acquired through diagnostic radiology. Results. Overall, 152 patients without and 58 with a history of surgical revision following surgery for ASD were observed; the mean age was 68.9 years (SD 8.7) and 66.9 years (SD 6.6), respectively. On implementing a random forest model, the classification of URO events resulted in a balanced accuracy of 86.8%. Among machine learning-extracted risk factors, URO, proximal junction failure (PJF), and postoperative distance from the posterosuperior corner of C7 and the vertical axis from the centroid of C2 (SVA) were significant upon Kaplan-Meier survival analysis. Conclusion. The major risk factors for URO following surgery for ASD, i.e. postoperative SVA and PJF, and their interactions were identified using a machine learning algorithm and game theory. Clinical benefits will depend on patient risk profiles. Cite this article: Bone Joint Res 2023;12(4):245–255

This paper outlines a valid and reliable, clinical method of assessing the amount of deformity in the congenital clubfoot. Clinical & MRI clubfoot scoring systems were developed to score the amount of deformity clinically & to image & score osteochondral pathology of the club-foot -MRI Total Score (MTS), MRI Hindfoot Contracture Score (MHCS), & MRI Midfoot Contracture Score (MMCS), Clinical Total Score (CTS), Clinical Hindfoot Contracture Score (CHCS), Clinical Midfoot Contracture Score (CMCS). Three independent observers tested the Clinical scoring systems Inter-observer reliability (Kappa Statistic) over one hundred consecutive clubfeet. Kappa values were CTS-0.92, CMCS-0.91, and CHCS-0.86- (almost perfect inter-observer reliability). Nineteen clubfeet were scored clinically and by thirty-eight MRI evaluations during treatment. Validity was evaluated by correlating the MRI and clinical scores (Pearson Correlation). The Pearson Correlations between clinical & MRI scores were CTS: MTS = 0.786 (P< 0.01), CHCS: MHCS = 0.712 (P< 0.01) & CMCS: MMCS = 0.651 (P< 0.01). All correlations were highly significant confirming validity. There is neither reliability nor validity in current methods of clubfoot assessment. This paper outlines a method of assessing the amount of deformity in the congenital clubfoot deformity using six well-described simple clinical signs that has been tested & found to be both valid and reliable. A clinical clubfoot scoring system was created- Clinical Total Score (CTS)- comprised of a Clinical Hind-foot Contracture Score (CHCS) & a Clinical Midfoot Contracture Score (CMCS). One hundred consecutive congenital clubfeet were scored for clinical deformity each week during cast treatment by three independent observers. Inter-observer reliability (Kappa Statistic) of this clinical scoring system was evaluated. A clubfoot MRI protocol & scoring system were developed to visualise & score osteochondral pathology of the clubfoot -MRI Total Score (MTS)- comprised of a MRI Hindfoot Contracture Score (MHCS) and a MRI Midfoot Contracture Score (MMCS). Nineteen clubfeet were scored clinically and by thirty-eight MRI evaluations during treatment. All MRI films were scored for amount of osteochondral pathology. Validity of this clinical scoring system was evaluated by correlating the MRI and clinical scores (Pearson Correlation). The Kappa values for inter-observer reliability were CTS-0.92, CMCS-0.91, and CHCS-0.86. All scores showed almost perfect inter-observer reliability. The Pearson Correlations between clinical & MRI scores were CTS: MTS = 0.786 (P< 0.01), CHCS: MHCS = 0.712 (P< 0.01) & CMCS: MMCS = 0.651 (P< 0.01). All correlations were highly significant confirming validity of the clinical scores. We have developed a clinical scoring system for club-feet that is reliable and valid

Introduction. The British Scoliosis Society published a document in 2008 which set out the minimum standards for paediatric spinal deformity services to achieve over a period of time. But how do the UK paediatric spinal deformity centres measure up to these benchmarks?. Methods. We performed a telephonic survey, contacting every UK spinal deformity centre. The questionnaire probed how each unit compared to the recommended standards. Results. Twenty three centres were interviewed, covering 81 surgeons in total (range 1-8 surgeons per centre). Four centres (17%) did not have 24-hour access to a MRI scanner and all but 2 centres had on-site facilities for long-cassette films/scoliograms. Five centres (22%) always had 2 consultant surgeons per case, 9 centres (39%) routinely have only 1 consultant surgeon per case, and the rest had 1 or 2 consultant surgeons depending on seniority. Six centres (26%) did not routinely have shared care of their patients with the paediatric team. All centres used intra-operative SSEP monitoring, a minority used MEP monitoring (34%), and all but 2 centres had either direct or indirect supervision by a consultant neurophysiologist. All centres have cell saver units available with over half using them routinely (14/23). None of the centres used routine chemoprophylaxis. All units used thromboembolic stockings, with five centres (22%) routinely using foot pumps. Nineteen centres (83%) routinely sent their spinal deformity patients to ITU/PICU postoperatively. Our survey also asked each center what supporting facilities were available, whether they ran adolescent clinics, and whether they participate in multi-disciplinary meetings and audit. In addition, we questioned what typed of drains each center used and the length of time that patients were followed-up. Conclusion. This survey shows how the UK spinal deformity units stand up against the BSS standards, provides an insight in to current UK practice and highlights areas for improvement

A medializing calcaneal osteotomy (MCO) is one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the hind- and midfoot alignment after PCFD correction, the subtalar joint remained obscured by superposition on plain radiography. Therefore, we aimed to perform a 3D measurement assessment of the hind- and subtalar joint alignment pre- compared to post-operatively using weightbearing CT (WBCT) imaging. Fifteen patients with a mean age of 44,3 years (range 17-65yrs) were retrospectively analyzed in a pre-post study design. Inclusion criteria consisted of PCFD deformity correct by MCO and imaged by WBCT. Exclusion criteria were patients who had concomitant midfoot fusions or hindfoot coalitions. Image data were used to generate 3D models and compute the hindfoot - and talocalcaneal angle as well as distance maps. Pre-operative radiographic parameters of the hindfoot and subtalar joint alignment improved significantly relative to the post-operative position (HA, MA. Sa. , and MA. Co. ). The post-operative talus showed significant inversion, abduction, and dorsiflexion of the talus (2.79° ±1.72, 1.32° ±1.98, 2.11°±1.47) compared to the pre-operative position. The talus shifted significantly different from 0 in the posterior and superior direction (0.62mm ±0.52 and 0.35mm ±0.32). The distance between the talus and calcaneum at the sinus tarsi increased significantly (0.64mm ±0.44). This study found pre-dominantly changes in the sagittal, axial and coronal plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings demonstrate the amount of alternation in the subtalar joint alignment that can be expected after MCO. However, further studies are needed to determine at what stage a calcaneal lengthening osteotomy or corrective arthrodesis is indicated to obtain a higher degree of subtalar joint alignment correction