Cranio-cervical connection is a well-established biomechanical concept. However, literature of this connection and its impact on cervical alignment is scarce. Chin incidence (CI) is defined as a complementary to the angle between chin tilt (CHT) and C2 slope (C2S) axes. This study aims to investigate the relationship between cervical sagittal alignment parameters and CI with its derivatives.

A retrospective cross-sectional study carried out in a tertiary center. CT-neck radiographs of non-orthopedics patients were included. They had no history of spine related symptoms or fractures in cranium or pelvis. Images’ reports were reviewed to exclude those with tumors in the c-spine or anterior triangle of the neck.

A total of 80 patients was included with 54% of them were males. The mean of age was 30.96± 6.03. Models of predictability for c2-c7 cobb's angle (CA) and C2-C7 sagittal vertical axis (SVA) using C2S, CHT, and CI were significant and consistent r20.585 (f(df3,76) =35.65, P ≤0.0001, r=0.764), r20.474 (f(df2,77) =32.98, P ≤0.0001, r=-0.550), respectively. In addition, several positive significant correlations were detected in our model in relation to sagittal alignment parameters. Nonetheless, models of predictability for CA and SVA in relation to neck tilt (NT), T1 slope (T1S) and thoracic inlet axis (TIA) were less consistent and had a significant marginally weaker attributable effect on CA, however, no significant effect was found on SVA r20.406 (f(df1,78) =53.39, P ≤0.0001, r=0.620), r20.070 (f(df3,76) =1.904, P 0.19), respectively. Also, this study shows that obesity and aging are linked to decreased CI which will result in increasing SVA and ultimately decreasing CA.

CI model has a more valid attributable effect on the sagittal alignment in comparison to TIA model. Future investigations factoring this parameter might enlighten its linkage to many cervical spine diseases or post-op complications (i.e., trismus).

The lateral wall thickness (LWT) in trochanteric femoral fractures is a known predictive factor for postoperative fracture stability. Currently, the AO/OTA classification uses a patient non-specific measure to assess the absolute LWT (aLWT) and distinguish stable A1.3 from unstable A2.1 fractures based on a threshold of 20.5 mm. This approach potentially results in interpatient deviations due to different bone morphologies and consequently variations in fracture stability. Therefore, the aim of this study was to explore whether a patient-specific measure for assessment of the relative LWT (rLWT) results in a more precise threshold for prediction of unstable fractures.

Part 1 of the study evaluated 146 pelvic radiographs to assess left-right symmetry with regard to caput-collum-angle (CCD) and total trochanteric thickness (TTT), and used the results to establish the rLWT measurement technique. Part 2 reevaluated 202 patients from a previous study cohort to analyze their rLWT versus aLWT for optimization purposes.

Findings in Part 1 demonstrated a bilateral symmetry of the femur regarding both CCD and TTT (p ≥ 0.827) allowing to mirror bone's morphology and geometry from the contralateral intact to the fractured femur. Outcomes in Part 2 resulted in an increased accuracy for the new determined rLWT threshold (50.5%) versus the standard 20.5 mm aLWT threshold, with sensitivity of 83.7% versus 82.7% and specificity 81.3% versus 77.8%, respectively.

The novel patient-specific rLWT measure can be based on the contralateral femur anatomy and is a more accurate predictor of a secondary lateral wall fracture in comparison to the conventional aLWT. This study established the threshold of 50.5% rLWT as a reference value for prediction of fracture stability and selection of an appropriate implant for fixation of trochanteric femoral fractures.

The Nottingham Hip Fracture Score (NHFS) was developed in 2007 as a predictor of 30-day mortality after hip fracture surgery following a neck of femur fracture. The National Hip Fracture Database is the standard used which calculated their own score using national data.

The NHF score for 30-day mortality was calculated for 50 patients presenting with a fractured neck femur injury between January 2020 to March 2020. A score <5 was classified as low risk and >/=5 as high risk. Aim was to assess the accuracy in calculating the Nottingham Hip Fracture Score against the National Hip Fracture Database. To explore whether it should it be routinely included during initial assessment to aid clinical management?

There was an increase in the number of mortalities observed in patients who belonged to the high-risk group (>=5) compared to the low risk group. COVID-19 positive patients had worse outcomes with average 30-day mortality of 6.78 compared to the average of 6.06. GEH NHF score per month showed significant accuracy against the NHFD scores.

The identification of high-risk groups from their NHF score can allow for targeted optimisations and elucidation of risk factors easily gathered at the point of hospitalisation. The NHFS is a valuable tool and useful predictor to stratify the risk of 30-day mortality and 1-year mortality after hip fracture surgery. Inclusion of the score should be considered as mandatory Trust policy for neck of femur fracture patients to aid clinical management and improve patient safety overall.

Abstract

The clinical success of posterior lumbar interbody fusion (PLIF) may be limited by pseudarthrosis, defined as the absence of solid fusion 1 year after surgery. Currently, CT is used to diagnose pseudarthrosis but is not able to be conclusive earlier than 1 year after surgery. No non-invasive technique is available to reliably assess bone graft incorporation in the early phase after PLIF.

Positron Emission Tomography (PET) is a nuclear imaging modality that is able to identify changes at the cellular and molecular level in an early stage, well before manifestation of anatomical changes. PET/CT with the bone seeking tracer ¹⁸F-fluoride allows localization and quantification of bone metabolism.

This study investigates whether an ¹⁸F-fluoride PET/CT scan early after PLIF is able to predict the fusion status at 1 year postoperative on CT.

Twenty patients after PLIF were enrolled after written informed consent. At 6 weeks and at 1 year after PLIF, intravenous injection of ¹⁸F-fluoride was followed by a static scan at 60 minutes (Philips, Gemini TF PET/CT). Processing of images resulted in a bone metabolism parameter i.e. standardized uptake value (SUV). This parameter was determined for 3 regions of interest (ROIs): the intervertebral disc space (IDS) and the upper and lower endplate (UE and LE, respectively) of the operated segment.

Interbody fusion was scored on a diagnostic CT scan made 1 year postoperatively and was defined as the amount of complete bony bridges between vertebrae, i.e 0, 1 or 2. Based on these scores, patients were divided in either the pseudarthrosis group (score 0) or the fusion group (scores 1 and 2). Differences between groups were analyzed using the independent samples Mann-Whitney U-test.

Ten patients were classified as pseudarthrosis (0 bridges: n=10) and 10 patients as fused (1 bridge: n=5, 2 bridges: n=5).

Patients in the pseudarthrosis group showed significantly lower bone metabolism values in the IDS on the 6 weeks PET/CT scan compared to patients in the fusion group (SUV_IDS,6w13.3±5.62 for pseudarthrosis and 22.6±6.42 for the fusion group, p=0.003), whereas values at the endplates were similar (SUV_UE,6w20.3±5.85 for pseudarthrosis and 21.6±4.24 for the fusion group, p=0.282). Furthermore, only in the pseudarthrosis group, bone metabolism in the IDS was significantly lower than at the endplates (p=0.006). In the fusion group, bone metabolism in the IDS and at the endplates was similar (p=0.470).

The PET/CT scan at 1 year postoperative showed that in the pseudarthrosis group, bone metabolism of the IDS remained lower compared to the endplates (SUV_IDS,1y13.2±4.37, SUV_UE,1y16.4±5.33, p=0.004), while in the fusion group, IDS and endplate bone metabolism was similar (SUV_IDS,1y13.6±2.91, SUV_UE,1y14.4±3.14, p=0.397).

This study shows that low bone metabolism values in the IDS of the operated segment as seen on ¹⁸F-fluoride PET/CT 6 weeks after PLIF, is related to development of pseudarthrosis 1 year postoperatively. These results suggest that ¹⁸F-fluoride PET/CT might be an early diagnostic tool to identify patients prone to develop pseudarthrosis after PLIF.

Late presentation of DDH continues to remain a major problem particularly in the developing countries. Femoro-Acetabular Zones (FAZ) system is created to find a relation between acetabular maturity and severity of dislocation, in one hand, and the success of closed reduction, on the other hand. We hypnosis that the lower the acetabular index and the closer the femoral head to the acetabulum, the more likely the success of treatment. Thus, a retrospective study was performed on late diagnosed DDH hips that underwent closed treatment at a particular hospital in the Middle East. FAZ are drawn on the AP view of the pelvic x-ray and is based on a perpendicular from the acetabular index at the lateral margin of the superior acetabular rim then another perpendicular to Perkin's line is drawn. This gives three zones, graded I-III. The center of femoral metaphysis is identified denoting the position of the femoral head in relation to the zone classification. FAZ system was applied on 65 pelvic radiographs; mean patient age was 24 months (range: 12 to 36 months) with a minimum follow up of 3 years. Overall, 37 of 65 hips (57%) achieved a satisfactory outcome (Severin I&II), while 22 hips (33%) were found to be unsatisfactory (Severin III). 6 hips (10%) needed an open reduction (p-value 0.001). FAZ could perfectly predict the successful cases. FAZ system is a simple and novel classification and if employed, could reasonably predict the outcome of non-surgical treatment of DDH after walking age.

Good lag screw holding power in trabecular bone of the femoral head is a requisite to achieve stability in the management of proximal femoral fractures. It has been demonstrated that insertion torque and pullout strength of lag screw are linearly correlated. Therefore, insertion torque measurement could be a method to estimate the achieved screw purchase. Manual perception is not reliable [1], but the use of an instrumented screwdriver would make the procedure feasible.

The aim of this study was to assess the accuracy achievable using the insertion torque as predictor of lag screw purchase.

Four different screw designs (two cannulated and two solid-core screws) were investigated in this study. Each screw was inserted into a block of trabecular bone tissue following a standardised procedure designed to maximise the experimental repeatability. The blocks of trabecular tissue were extracted from human as well as bovine femora to increase the range of bone mineral density.

The prediction accuracy was evaluated by plotting pullout strength versus insertion torque, performing a linear regression analysis and calculating the difference (as percentage) between predicted and measured values.

Insertion torque showed a strong linear correlation (coefficient of determination R²: 0.95–0.99) with the pullout strength of lag screw. However the prediction error in pullout strength estimation was greater than 40% for small values of insertion torque, decreasing down to 15% when the lag screw was driven into good quality bone tissue.

Measuring insertion torque can supply quantitative information about the achieved lag screw purchase. Since screw design and insertion procedure have been shown to affect both the insertion torque and the pullout strength [2], the prediction model must be screw-specific and determined, closely simulating the clinical procedure defined by the screw manufacturer. However, the surgeon must be aware that, even under highly repeatable experimental conditions, the prediction error was found to be high when small insertion torque was measured, i.e. when the screw was driven in low quality bone tissue. Therefore, insertion torque is not reliable in evaluating lag screw purchase in the management of proximal femur fracture of osteoporotic patients.

Background

Epidural steroid injections can provide temporary relief of symptoms in the treatment of lumbar spinal stenosis. Surgery is indicated when conservative measures fail. We hypothesise that patients who gain temporary relief of symptoms from the administration of epidural steroid injections are more likely to result in an improvement in symptoms following surgical intervention compared to patients who do not respond to injection therapy.

Introduction

Patellofemoral pain and instability can be quantified by using the tibial tuberosity to trochlea groove (TT-TG) distance with more than or equal to 20mm considered pathological requiring surgical correction. Aim of this study is to determine if knee joint rotation angle is predictive of a pathological TT-TG.

Surgical reconstruction of articular surfaces by transplantation of osteochondral autografts has shown considerable promise in the treatment of focal articular lesions. During mosaicplasty, each cylindrical osteochondral graft is centred over the recipient hole and delivered by impacting the articular surface. Impact loading of articular cartilage has been associated with structural damage, loss of the viability of chondrocytes and subsequent degeneration of the articular cartilage. We have examined the relationship between single-impact loading and chondrocyte death for the specific confined-compression boundary conditions of mosaicplasty and the effect of repetitive impact loading which occurs during implantation of the graft on the resulting viability of the chondrocytes.

Fresh bovine and porcine femoral condyles were used in this experiment. The percentage of chondrocyte death was found to vary logarithmically with single-impact energy and was predicted more strongly by the mean force of the impact rather than by the number of impacts required during placement of the graft. The significance of these results in regard to the surgical technique and design features of instruments for osteochondral transplantation is discussed.