Abstract

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).

Sarcopenia has been observed to be a predictor of mortality in international studies of patients with metastatic disease of the spine. This study aimed to validate sarcopenia as a prognostic tool in a New Zealand setting. A secondary aim of this study was to assess the intra-observer reliability of measurements of psoas and vertebral body cross sectional areas on computed tomography imaging.

A cohort of patients who had presented to Waikato Hospital with secondary neoplasia in the spinal column from 2014 to 2018 was selected. Cross sectional psoas and vertebral body areas were measured at the mid-pedicle L3 level, followed by calculation of the psoas to vertebral body cross sectional area ratio. Psoas to vertebral body cross sectional area ratio was compared with survivorship. The strength of the correlation between sarcopenia and survivorship was compared with the correlation between serum albumin and survivorship, as well as the correlation between the Metastatic Spine Risk Index (MSRI) and survivorship.

A total of 110 patients who received operative (34) and non-operative (76) were included. The results demonstrate that psoas to vertebral body cross sectional area ratio is not statistically significantly correlated with survivorship (p=0.53). Serum albumin is significantly correlated with survivorship (p<0.0001), as was the MSRI. There is good intra-observer and inter-observer reliability for measurements of psoas to vertebral body cross sectional area.

This study failed to demonstrate the utility for the psoas to vertebral body cross sectional area ratio that other studies have demonstrated in estimating survivorship. Serum albumin levels remain a useful prognostic indicator in patients with secondary tumours in the vertebral column.

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.

Several studies have highlighted the relationship between anterior cruciate (ACL) injury and knee geometry particularly tibial slope (TS). However, clinical data are inconsistent, whether the lateral or medial or slopes have a different influence on ACL injury. Our goal was to assess whether the medial, lateral slopes are associated with ACL injury and whether meniscus geometry is associated with ACL injury. In addition, we sought to determine if lateral meniscal height could serve as a simple surrogate measurement for ACL injury risk.

A case-controlled study compared 68 patients with an ACL injury and 68 matched nested controls. Radiological analysis of MRI measured the anterior-posterior distance of the medial and lateral plateaus, the tibial slope of both plateaus and meniscus geometry. Groups were compared using a Mann-Whitney test and α < 0 .05.

The lateral tibial plateau slope was significantly higher in the ACL injured group (6.92 degrees ±5.8) versus the control group 2.68 ±5.26 (p 0.0001). In addition, the lateral meniscal slope was significantly steeper with (ACL injuries: −1 ±4.7 versus −4.73 ±4.4 (p 0.0001) in the control group. The ACL Injured group had a significantly lower lateral meniscal height 0.76 cm ±0.09, compared to the control group that has 0.88 cm ±0.12 (p 0.0001). The Lateral meniscal height had a sensitivity of 76.47% and specificity 75% for predicting ACL injury using a cut off of

Patients with ACL-injury had significantly higher lateral tibial plateau slope. Lateral meniscus height was found to be an easy measurement to make on MRI with a high specificity for predicting ACL injury. Lateral tibial slope and meniscal Geometry can be used to identify patients with high risk of an ACL injury, that might benefit from further surgery to optimize rotational stability in high-risk patients.

Aim

This study assesses the ability of the JS-BACH classification of bone infection to predict clinical and patient-reported outcomes in prosthetic joint infection (PJI).

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

Pelvic osteotomies for hip dysplasia results can be variable and depend on the amount of preexisting arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a technique designed to measure early arthritis, and could be used to select hips that would benefit from a joint-preserving reconstructive procedure. Our objective was to investigate the role of preoperative dGEMRIC in predicting the success of PAO in patients 40 and above. We hypothesized that patients who failed had lower preoperative dGEMRIC index compared to those who did not.

Following IRB approval, patients 40 or older who underwent PAO between 1990–2013 and had preoperative dGEMRIC scan and minimum follow-up of 4 years were identified. Patients with prior hip surgeries or any pathologies were removed leading to a total of 70 patients (Age: 44.2 ± 2.9 years old, BMI: 25.7 ± 4.5 Kg/m²). We only included the first hip undergoing PAO for those with bilateral PAO. Out of 70, 19 had failure defined by the need for total hip replacement or WOMAC pain score of 10 and above within 10 years after index PAO surgery. Articular cartilage was segmented on the 3D pre-operative dGEMRIC scan. The average thickness and dGEMRIC index across the whole articular surface were analyzed.

Failed hips had a lower dGEMRIC index by 115 ± 20 ms (P<0.001). All but one failed hips had a dGMERIC index of 400 or less (range: 313 – 479 ms), while all survived hips had a dGMERIC index of greater than 400 (range: 403 – 691 ms). Similar trends were observed when comparing the dGEMRIC index within the 6 subgroups (P<0.01). There were no differences in cartilage thickness (combined femoral head and acetabular cartilage) between the failed and survived hips (p>0.2).

Patients with a high dGMERIC index (indicating high GAG content) may have a higher chance of successful outcomes following PAO. Current efforts are underway to develop a multi-modal predictive model to evaluate risk of failure after PAO.

Abstract

Aims

Hip arthroscopy has gained prominence as a primary surgical intervention for symptomatic femoroacetabular impingement (FAI). This study aimed to identify radiological features, and their combinations, that predict the outcome of hip arthroscopy for FAI.

Pilon fractures are associated to significant soft tissue injury, as well as soft tissue complications. The soft tissue on the medial side of the distal tibia is often involved, likely due to a lack of muscle investment. Medial approaches and medial plate application may well add to the soft tissue trauma. The objective of this study was to examine the relationship between medial plating and soft tissue complications in our center.

This is a retrospective study based on a prospective database. Pilon cases treated with plate and screw fixation were identified between 2011 and 2014. Injury characteristics, patient demographics, and soft tissue complications were collected from chart review. Soft tissue complications recorded included any wound or skin problem, as well as patient complaints of hardware irritation leading to hardware removal. Logistic regression was employed. Independent variables for the model included medial plating, the presence of open fracture, smoking status and diagnosis of diabetes. Two models were created, one with the dependent variable as presence of any soft tissue complication, and the second model with the dependent variable as presence of a wound complication, which required surgical intervention.

The study included 91 patients, 89 of whom had full data with an average follow up of 11.6 months (1–33 months). The incidence of soft tissue complications, including hardware irritation, was 26% (n=23), and 13% (n=12) required surgical treatment. Smoking status was the only predictor of soft tissue complications with an odds ratio of 3.6 (95%CI 1.2, 10.4; p=0.02), while controlling for other independent variables. The model explained 12% of the variation in soft tissue complications (Cox and Snell 0.119, p=0.028). In the second model, presence of a medial plate predicted soft tissue complications requiring surgical intervention with an odds ratio of 8.8 (95%CI 1.1, 73.7; p=0.045), while controlling for the other independent variables. The model explained 10% of the variation in soft tissue complications requiring surgical intervention (Cox and Snell 0.095, p=0.035).

The use of a medial plate does not appear to correlate to general soft tissue complications in pilon fractures. Smoking status increased the odds of a soft tissue complication more than three fold. The use of medial plating did increase the odds of soft tissue complications that required surgical treatment almost nine fold. It appears medial plating is not related to soft tissue complications, however treating soft tissue compilations in the presence of a medial plate may require more invasive methods.

Aim

Since surgical site infections (SSIs) remain among the most common complications of orthopedic (trauma) surgery, there has been unwavering attention for potential predictors of a SSI.

Specifically in surgical fields with a high complication rate, such as foot/ankle surgery, risk factor identification is of great importance. Recently, some studies have suggested environmental factors such as season to be of influence on the number of SSI. Specifically patients operated on in the summer are reported to have a higher incidence of SSIs, compared to other seasons. The aim of this study is to identify if “seasonality” is a significant predictor for SSI in a cohort of (trauma) surgical foot and ankle procedures.

This is the first study in the Ponseti-era to compare severity and outcomes in cases of idiopathic congenital talipes equinovarus (CTEV) diagnosed antenatally versus those diagnosed at birth. Small pre-Ponseti studies showed antenatal diagnosis to be a predictor of severity and poor prognosis.

Prospective data collection was used to compare indicators of severity and outcomes for idiopathic CTEV between these two groups. These include Pirani score, number of casts, follow-up Roye score and need for surgery.

68 children with 106 affected feet were included. Antenatal diagnosis (AD) was made in 45 children (71 feet), with birth diagnosis (BD) in 23 children (35 feet). Mean follow-up age was 4.8 years (AD = 4.9, BD = 4.7), male:female ratio 2:1 (AD=BD) with bilateral CTEV in 55% (AD = 58%, BD=52%). Mean initial Pirani scores were 5.25 in the AD group vs 4.86 in the BD group (p=0.06). Mean Roye score at follow-up was 1.39/4 in the AD group vs 1.26/4 in the BD group (p=0.33) with 33% vs 30% complaining of pain respectively (p=0.80). Surgery was needed in 11/71 (15.5%) in the AD group vs 1/35 (2.9%) in the BD group (p=0.06))

There is no significant difference in severity between antenatal and birth diagnoses of idiopathic CTEV and no difference in outcomes between these groups when treated with the Ponseti regime. Although small, our sample size is greater than the largest published comparable study.

Aim

Compare clinical outcomes following staged revision arthroplasty for periprosthetic joint infection (PJI) secondary to either multidrug resistant (MDR) bacteria or non-MDR (NMDR) bacteria.

Aim

Traditionally, serum white blood count (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been utilized as markers to evaluate septic arthritis (SA). Recently, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified as prognostic factors for treatment failure, mortality and morbidity in various clinical settings. To date, these markers have not been utilized for evaluating outcomes after hip and knee SA.

Thus, the purpose of this study was to determine the ability of admission NLR and PLR to predict treatment failure and postoperative 90-day mortality in hip and knee SA.

Purpose:

Paediatric forearm fractures are commonly seen and treated by closed reduction and plaster cast application in theatre. Historically, cast application has been subjectively evaluated for its adequacy in maintaining fracture reduction. More recently emphasis has been placed on objectively evaluating the adequacy of cast application using indicators such as the Canterbury index (CI). The CI has been used in predicting post-reduction, re-displacement risk of patients by expressing the casting and padding indices as a ratio.

The CI has been criticized for not including cast 3 point pressure, fracture personality and lack of standardization of X-ray views as well as practical requirement of physical measurement using rulers.

The aim of this study was to determine whether subjective evaluation of these indices, on intra-operative fluoroscopy and the day 1 to 7 postoperative X-ray, was accurate in predicting a patient's ultimate risk of re-displacement, following reduction and casting.

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.

Introduction

More than 60% of patients presenting with a hip fracture have significant medical co-morbidities and a one year mortality rate between 14% and 47%. The rating scale for the American Society of Anaesthetists (ASA) is a reliable predictor of both surgical risk and mortality with ASA 4 patients having 100% mortality at one year.1,2

This is a study to investigate the diagnostic and prognostic value of MRI in spinal cord injury.

We performed this prospective study on sixty two patients of acute spinal trauma. We evaluated the epidemiology of spinal trauma & various traumatic findings by MRI. MRI findings were correlated with clinical findings at admission & discharge according to ASIA impairment scale. Four types of MR signal patterns were seen in association with spinal cord injury-cord edema / non haemmorhagic cord contusion (CC), severe cord compression (SCC), cord hemorrhage (CH) and epidural heamatoma (EH). Isolated lesion of cord contusion was found in 40%. All other MR signal patterns were found to be in combination. In cord contusion we further subdivided the group into contusion of size < 3 cm and contusion of size > 3 cm to evaluate any significance of length of cord contusion. In cord heammorhage involving >1cm of the cord, focus was said to be sizable.

On bivariate analysis, there was a definitive correlation of cord contusion (CC) involving <3cm & > 3cm of cord with sensory outcome. In >3cm, chances of improvement was 5.75 times lesser than in patients with CC involving <3cm of cord (odds ratio = 5.75 (95% CI: 0.95, 36), Fisher's exact p = 0.0427 (p<.05). In severe cord compression (SCC) the risk of poor outcome was more (odds ratio 4.3 and p=0.149) however was not statistically significant. It was noted that the patients in which epidural hematoma (EH) was present, no improvement was seen, however, by statistical analysis it was not a risk factor and was not related with the outcome (odds ratio – 0.5 and p = 0.22). Presence of cord oedema / non haemorrhagic contusion was not associated with poor outcome (odds ratio 0.25 and p=0.178). On multiple logistic regression / multivariate analysis for estimating prognosis, sizable focus of haemorrhage was most consistently associated with poor outcome (odds ratio −6.73 and p= 0.32) however it was not statistically significant. The risk of retaining a complete cord injury at the time of follow up for patients who initially had significant haemorrhage in cord was more than 6 fold with patients without initial haemorrhage (odds ratio 6.97 and p= .0047).

Besides being helpful in diagnosis, MRI findings may serve as a prognostic indicator for clinical, neurological and functional outcome in acute spinal trauma patients.

Introduction

The role of soft tissue balancing in optimizing functional outcome and patient satisfaction after total knee arthroplasty surgery is gaining interest. This is due in part to the inability of pure alignment to demonstrate excellent functional outcomes 6. Consistent soft tissue balancing has been aided by novel technologies that can quantify loads across the joint at the time of surgery 4. In theory, compressive load equilibrium should be correlated with ligamentous equilibrium between the medial and lateral collateral ligaments. The authors propose to use the Collateral Ligaments Strain Ratio (CLSR) as a functional tool to quantify and track surgical changes in laxity of the collateral ligaments and correlate this ratio to validated functional scores and patient reported outcomes. The relationship with intra-operative balancing of compartmental loads can then be scrutinized. The benefits of varus-valgus balancing within 2o include increased range of motion 7, whereas pressure imbalance between the medial and lateral joint compartments has been linked to condylar liftoff and abnormal kinematics post-TKA 8.

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.

Primary Total Knee Arthroplasty (TKA) is considered to be one of the most successful orthopedic surgical interventions performed. Long-term results have been generally excellent, with 10–15 year survival rates as high as 90–95% reported, few complications, and reoperations occurring in approximately one percent of patients per year. One of the most important outcome measures of TKA is the range of motion. It has been demonstrated that a 67° of knee flexion is needed for the swing phase of the gait, 83° to climb stairs, 90° to descend stairs, and 93° to rise from chair.

This is a prospective study of 50 patients who underwent Total Knee Arthroplasty at Dayanand Medical College & Hospital, Ludhiana between March 2008 & April 2009. Patients with a primary diagnosis of osteoarthritis, rheumatoid arthritis, or traumatic arthritis in which Natural Knee II implant (Zimmer) was used were included in the study. Absolute exclusion criteria were infection, sepsis, osteomyelitis, revision of a previous total knee replacement or deformities of the hip and spine. Preoperative demographic data, including sex, age at surgery, side affected, body mass index, primary diagnosis, tibio-femoral angle, knee score and functional score, and preoperative passive ROM were obtained. Patients underwent a medial parapatellar approach, with cement used to fix both the femoral and tibial components. Patellar resurfacing was not performed. Following surgery, patients underwent physical therapy at home or in a physiotherapy center, as appropriate. ROM and flexion were calculated at three and six months postoperatively.

54% of the patients were of age 60–75 years and 70% of them were females. 92% patients suffered from osteoarthritis. 80% patients had a BMI of <30 points. 63.46% patients had a preoperative knee flexion of <90°. The average preoperative knee flexion improved from 94.94° to 107.21° at 3 months and 112.12° at 6 months postoperatively (p-value=0.000056). The average preoperative knee flexion in patients with preoperative knee flexion <90°, 90°–110° and >110° changed from 88.33°-106.36°-108.73°, 102.67°-108.33°-114° and 120.50°-110°-117.50° at 3 months and 6 months respectively. The average preoperative knee score was 46.55 and functional score was 50.30, which improved to 95.62 (p-value=0.000015) and 75.60 (p-value=0.000213) respectively.

Postoperative ROM is a function of many factors, with preoperative ROM being one of the most important. The knee ROM tends to regress towards a mean with excellent preoperative ROM loosing and poor preoperative ROM improving. Several factors related to surgical techniques have been found to be important. These include the tightness of the retained posterior cruciate ligament, the elevation of the joint line, increased patellar thickness, and a trapezoidal flexion gap. Vigorous rehabilitation after surgery appears useful, while continuous passive motion has not been found to be effective. Obesity and previous surgery are poor prognostic factors. In general, the clinical results of TKA were satisfactory in terms of pain relief and overall function. It was found that measurement of preoperative flexion gives the surgeon a good parameter for predicting flexion after arthroplasty.

Studies have shown that the trees minor plays an important role after total (TSA) and reverse (RSA) shoulder arthroplasty, as well as in maintenance of function in the setting of infraspinatus wasting. In this regard, teres minor hypertrophy has been described as a compensatory change in response to this infraspinatus wasting, and has been suggested that this compensatory hypertrophy may mitigate the loss of infraspinatus function in the patient with a large rotator cuff tear. The purpose of this study was to determine the prevalence of teres minor hypertrophy in a cohort of patients undergoing rotator cuff repair, and to determine its prognostic effect, if any, on outcomes after surgical repair.

Over a 3 year period, all rotator cuff repairs performed in a single practice by 3 ASES member surgeons were collected. Inclusion criteria included both preoperative and postoperative validated outcomes measures (minimum 2 year), and preoperative Magnetic Resonance Imaging (MRI) scanning. 144 patients met all criteria. MRIs were evaluated for rotator cuff tear tendon involvement, tear size, and Goutallier changes of each muscle. In addition, occupational ratios were determined for the supraspinatus, infraspinatus, and teres minor muscles. Patients were divided into 2 groups, based upon whether they had teres minor hypertrophy or not, based on a previously established definition. A 2 way ANOVA was used to determine the effect of teres minor hypertrophy(tear size by hypertrophy) and Goutallier

Teres minor hypertrophy was a relatively common finding in this cohort of rotator cuff patients, with 51% of all shoulders demonstrating hypertrophy. Interestingly, in patients without an infraspinatus tear, teres minor hypertrophy was still present in 19/40 (48%) of patients. Teres minor hypertrophy had a significant, negative effect ASES scores after rotator cuff repair in patients with and without infraspinatus tearing, infraspinatus atrophy, and fatty infiltrative changes (P<0.05). In general, the presence of teres minor hypertrophy showed 10–15% less improvement (Figure 1) than when no hypertrophy was present, and this was consistent across all tear sizes, independent of Goutallier changes.

Teres minor hypertrophy is a common finding in the setting of rotator cuff tearing, including in the absence of infraspinatus tearing. Contrary to previous publications, the presence of teres minor hypertrophy in patients with rotator cuff repair does not appear to be protective as a compensatory mechanism. While further study is necessary to determine the mechanism or implication of teres minor hypertrophy in setting of rotator cuff repair, our results show it is not a positive of outcomes following rotator cuff repair.

C-type natriuretic peptide is the most abundant natriuretic peptide in the central nervous system. It has been implicated in neurogenesis and may have a significant role in spinal regeneration. We postulated that the spinal concentration of CNP would be reflected in the plasma concentrations of both CNP and the pro-hormone (NTproCNP) and this may be an indicator of repair potential in spinal injuries.

Concurrent plasma and CSF concentrations of CNP forms were measured in 51 subjects undergoing spinal anaesthesia for elective total hip and knee replacement. Associations with CNP activity and metabolism in CSF were sought by measuring CSF levels of cGMP and neprilysin respectively.

Elevated concentrations of NTproCNP (1045±359 pmol/L) were found in CSF and greatly exceeded those of CNP (7.9±3.2 pmol/L). The ratio of NTproCNP to CNP in CSF (145±55) was much higher than in plasma (31±27). A significant inverse relation was found between plasma and CSF CNP concentrations (r=−0.29, p<0.05). cGMP and neprilysin were unrelated to CNP levels in CSF

Despite markedly elevated levels of NTproCNP in CSF, it is unlikely that these contribute to systemic levels in healthy adults. Identifying NTproCNP as the dominant CNP form in CSF opens up the possibility of its use in future studies exploring CNP regulation within the CNS and possible applications in diagnosis and monitoring of healing in patients with spinal cord injury.

The management of pelvic fractures remains a challenging problem for orthopaedic surgeons. The prompt recognition of unstable fracture patterns is important in reducing mortality and morbidity. It is perceived wisdom that a fracture of the transverse process of L5 is a predictor of pelvic fracture instability. There is a paucity of evidence in the literature to support this belief. The aim of our study was to determine if a fracture of the transverse process of L5 was a predictor of pelvic fracture instability.

The Hospital Trauma database was reviewed. Between 2006 and 2009, 65 pelvic fractures were identified. They were classified according to the Burgess and Young classification. There were 37 stable and 28 unstable fractures. 14 patients had an associated fracture of the transverse process of L5; 9 were associated with an unstable fracture pattern. The odds ratio was 3; the relative risk 1.7.

A fracture of the transverse process of L5 is associated with an increased risk of pelvic fracture instability. Its presence should alert the attending physicians to the possibility of an unstable injury.

Aims

Fracture of the odontoid process (OP) in the elderly is associated with mortality rates similar to those of hip fracture. The aim of this study was to identify variables that predict mortality in patients with a fracture of the OP, and to assess whether established hip fracture scoring systems such as the Nottingham Hip Fracture Score (NHFS) or Sernbo Score might also be used as predictors of mortality in these patients.

Background

There has been increased focus on understanding the risk factors associated with scapular notching in reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the effect of scapular morphology and surgical technique on the occurrence of scapular notching using the notching index as a comprehensive predictive tool.

Introduction: The radiographic evaluation of the antero-lateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion. The aim of our study was to analyse the reliability of The frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Patients and Methods: Thirty two patients who presented with femoroacetabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

Results: A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Conclusions: Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate measurement of the alpha angle.

INTRODUCTION: Median Nerve has small vessel on the volar aspect of the nerve which is filled with blood and results in so called ‘ BLUSHING’ of the nerve once it has been decompressed. It was thought that the nerve which didnot blush meant an inadequate decompression was carried out.

PURPOSE: To evaluate whether ‘Blushing’ of the Median Nerve is correlated with adequate decompression and level of recovery in Carpal Tunnel Syndrome through Mini Palmar Incision.

METHODS & MATERIALS: Retrospective analysis of a Single Surgeon practise where it was documented in operation notes whether the nerve was seen to ‘Blushed’ at the time of surgery.They were assessed postoperatively from notes for complete resolution of symptoms and whether there was any recurrence of symptoms.

RESULTS: n=330 Carpal Tunnel Decompressions were reviewed. It was noted that those who had complete resolution of symptoms had ‘Blushing’ noted at the time of surgery compared to those who had partial or incomplete resolution of symptoms wher ‘No BUSHING’ was noticed. Average time of follow up = 6 weeks. Blushing Noted at the time of decompression 192, Recovery/ improvement of symptoms 189, Blushing not noted at the time of surgery 38, NO documentation about Blushing in 100

CONCLUSION: Blushing of Median Nerve intraoperatively is a reliable sign for complete decompression of the nerve and is correalted with good final outcome.

Improvised Explosive Device (IED) attacks on vehicles have been a significant feature of recent conflicts. The Dynamic Response Index (DRI), developed for predicting spinal injury in aircraft ejection, has been adopted for testing vehicles in underbelly blast. Recent papers suggest that DRI is not accurate in blast conditions. We suggest that the distribution of blast and ejection injuries is different.

A literature review identified the distribution of spinal fractures in aircraft ejection incidents. A Joint Theatre Trauma Registry search identified victims of mounted IED blast with spinal fractures. The distribution of injuries in the two groups was compared using the Kruskall Wallis test.

329 fractures were identified in ejector seat incidents; 1% cervical, 84% thoracic and 16% lumbar. 245 fractures were identified in victims of mounted blast; 16% cervical, 34% thoracic and 50% lumbar. There was no significant similarity between the two (p=1). There was no statistically significant difference between the distribution of fractures in blast survivors versus fatalities.

The difference between blast and ejection injury patterns suggests that injury prediction models for ejection should not be extrapolated to blast mechanisms and that new models need to be developed.

Introduction

Displaced distal radius fractures in children have been treated in above elbow plaster casts since the last century. Cast index has been calculated previously, which is a measure of the sagittal cast width divided by the coronal cast width measurement at the fracture site. This indicates how well the cast was moulded to the contours of the forearm. We retrospectively analysed the cast index in post manipulation radiographs to evaluate its relevance in redisplacement or reangulation of distal forearm fractures.

Aims

The primary aim of this study was to assess whether patient satisfaction one year after total knee arthroplasty (TKA) changed with longer follow-up. The secondary aims were to identify predictors of satisfaction at one year, persistence of patient dissatisfaction, and late onset dissatisfaction in patients that were originally satisfied at one year.

The aim was to evaluate the Intraobserver and Interobserver reliability of Pelvic Incidence as a fundamental parameter of sagittal spino-pelvic balance in patients with spondylolisthesis compared to controls with Idiopathic Adolescent Scoliosis.

A blinded test retest study including multi-surgeon assessment of Pelvic Incidence in patients with spondylolisthesis and Idiopathic Adolescent Scoliosis was carried out. We assessed the agreement between the pelvic incidence measurements using the Bland and Altman method and mean differences (95% confidence interval) are reported.

Forty patients seen at Starship Children’s Hospital between 1992 – 2003 by two spinal surgeons were retrospectively identified. The main group had 20 patients with spondylolisthesis (Isthmic and/or Dysplastic types) and the control group consisted of 20 patients with Idiopathic Adolescent Scoliosis. Five observers with different levels of experience included the two orthopaedic surgeons, one fellow, one senior trainee and one non-trainee registrar. Prior to the initial test phase, a consensus-building session was carried out. All five observers arrived at a standardised method for measuring the Pelvic Incidence. In the test phase randomly ordered lateral lumbosacral radiographs were independently evaluated by the five observers and pelvic incidence was measured. Assessment of the Pelvic Incidence was repeated one week later in the re-test phase. The radiographs were presented in a randomly pre-assigned order. Bland and Altman plots were constructed and mean differences (95% confidence interval) reported to evaluate the agreement between the Pelvic Incidence measurements among the five independent observers. All analysis was performed on the statistical software package SAS. P-value of 0.05 was considered statistically significant.

The spondylolisthesis group had 11 (55%) males and 9 (45%) females with an average age of 14 ± 4.2. 2 patients had high-grade (Meyerding Class III, IV, V) and 16 had low-grade (Meyerding Class I, II) spondylolisthesis. 2 patients were post-reduction of spondylolisthesis. In the Scoliosis group there were 2 (10%) males and 18 (90%) females with an average age of 15 ± 2.9. There was no significant difference between male and females pelvic incidence measurement (60° ± 18.7° vs. 57° ± 14.6°, p=0.540) or age (15 ± 2.9 vs. 14 ± 3.8, p=0.181). There was no difference in pelvic incidence across the Meyerding groups, p=0.257. There was a significant difference between spondylolisthesis and scoliosis pelvic incidence measurements 65° ± 15.6° vs. 51° ± 12.8°, p=0.003. In the Spondylolisthesis Group the interobserver reliability between five clinicians, expressed as the mean difference in pelvic incidence measurement was 0.6° (95%CI −0.81, 1.91) and was not significantly different from zero p=0.423. The agreement limits were from −12.8° to 13.9°. The intraobserver reliability of pelvic incidence showed the mean difference ranging from −2.1° to 1.4° (p=0.129 and 0.333 with 95% CI). One had marginal evidence of a significant difference of 3.3° (95% CI 0.05° to 6.55°, p=0.047). In the Scoliosis Group the interobserver reliability was 0.3° (95% CI −0.81, 1.49) and was not significantly different from zero p=0.726. The agreement limits were from −11.0° to 11.6°. The intraobserver reliability among four observers ranged from −1.7° to 0.5° (p=0.178 and 0.661). One had a significant difference in readings of 4.1° (95% CI of 0.70° to 7.40°, p= 0.020).

Scoliosis patients had a significantly smaller pelvic incidence than spondylolisthesis patients. The interobserver reliability of the pelvic incidence measurement was excellent across both groups. The intraobserver reliability was good with only one observer in each group demonstrating a marginally significant difference. Pelvic incidence is therefore a reliable measurement which can be used as a predictor in progression of spondylolisthesis.

Introduction

The role of soft tissue balancing in optimising functional outcome and patient satisfaction after total knee arthroplasty surgery is gaining interest. Consistent soft tissue balancing has been aided by novel technologies that can quantify loads across the joint at the time of surgery. Based on free body diagram theory, compressive load equilibrium should be correlated with ligamentous equilibrium between the medial and lateral collateral ligaments. The authors propose to use the Collateral Ligaments Strain Ratio (CLSR) as a functional tool to quantify and track the effectuated surgical change in laxity of the medial and lateral collateral ligaments and correlate this ratio to validated functional scores and patient reported outcomes. The relationship with intra-operative balancing of compartmental loads can then be scrutinised.

Introduction The accuracy of ultrasonography has been reported to be high in diagnosing full thickness rotator cuff tears if measurements are made in both in the coronal and sagital planes. The purpose of this study is to determine how well pre-operative shoulder ultrasound rotator tear measurements when performed only in the coronal plane, the common practice in Israel, predicts the intra-operative surgical findings.

Materials and Methods Fifty consecutive patients who underwent open rotator cuff repairs were included in the study. All patients underwent a pre-operative ultrasound by the same experienced musculoskeletal ultrasoundist. Rotator cuff tears were measured in the coronal plane only. This was compared with the tear size measured intra-operatively. Regression analysis was done between the two variables.

Results The mean size of rotator cuff tears as determined by ultrasonography was 15.56±8.07mm and the measure size of the tears intraoperatively was 27.94±9.8 mm. The result of the regression analysis of the two variables was R2= 0.268405 for the first 25 patients and R2= 0.310309 for the second 25 patients.

Discussion Using ultrasound it is easy to visualize the extent of rotator tears in the coronal plane, but more time consuming to measure the extent in the sagital plane, where the tear may have its greatest extension. Ultrasound measurements tear measurements in this study, made only in the coronal plane correlated poorly with intraoperative findings and only minimally improved over the time course of the study.

Conclusion Proper assessment of a possible candidate for a rotator cuff repair should include an ultrasound with the tear size measured specifically in both the coronal and sagital planes.

Introduction and Aims: Recurrent disc herniation or sciatica is one of the major complications of discectomy, often leading to a cascade of surgical procedures of increasing magnitude, but decreasing surgical outcome. We undertook a study to see if prolapsed disc fragment type can predict the possibility of recurrence of disc herniation or sciatica.

Method: We looked at the records of patients who had a discectomy operation during a 10-year period from 1992–2002. We excluded from the study patients who had a concomitant fusion operation, patients with multiple level disc operations and those who have diabetes. We went through the operation records, looking for the type of the disc fragment, i.e. whether it was contained, extruded or sequestrated disc. In the follow-up notes we recorded the patients that complained of leg pain, starting three months after the operation and continuing despite treatment. We recorded the length of follow-up.

Results: Sixty-five patients were entered for the study. There were 31 males and 34 females. The age range at surgery was 16–61 years (average 42.1 year). The follow-up ranged from 18 months to 10 years (average 30 months). We divided the patients into two groups. Group A, those patients with recurrent leg pain; and group B, those patients with no leg pain.

There were 18 patients in group A – they were all subjected to further examination with MRI scan. In five of the patients, the scan showed recurrence of disc herniation. It was an ipsilateral reherniation in four patients and contralateral in one patient. Eight of these 18 patients required repeat surgery.

In the five patients with reherniation (7.69% of whole series), the repeat surgery was a discectomy. In another three patients the surgery was a wide decompression and fusion. On further analysing the pathology found at the initial discectomy, in the group A patients, six (33%) had extruded discs and 12 (66%) had contained discs. In group B, 34 (72%) had extruded discs and 13 (27%) had contained discs. The statistical significance in this small series is debatable.

Conclusion: Patients with extruded discs do much better than those with contained discs. Recurrent disc herniation is more common in contained discs and less common in extruded discs. If we could select pre-operatively those patients with contained disc herniations, we could elect to persist with conservative treatment for longer in this group.

The aim of this study was to assess whether the pro-lapsed disc fragment type was predictive of recurrent disc herniation or sciatica after discectomy. The records of 39 patients treated by lumbar discectomy only were reviewed. Within two months of surgery, the type of disc fragment prolapse and state of the annulus were assessed on CT scans or MRI. Patients who presented later with recurrent sciatica or disc prolapse were reviewed with MRI. All other patients were contacted and asked whether they had had recurrent sciatica or had undergone repeat surgery elsewhere. The follow-up period was three years.

The results suggest that patients in whom discs required annulotomy at surgery had poorer results than those with extrusion through an annular fissure. The degree of annular competence can be used to assess the risk of recurrence of herniation or sciatica.

Background: Hip fractures in the elderly have epidemic character. Although hip fractures have been considered as a single, homogeneous condition, there are two major anatomic types of proximal femoral fractures: intertrochanteric and femoral neck.

Aim: The purpose of our study is determining if patients suffering from these two types of hip fracture have different characteristics. Are demographics predictor factors of the type of hip fracture following fall in the elderly?

Patients and Methods: A retrospective study of patients admitted to a tertiary referral hospital for a hip fracture between 2003 and 2007 was conducted A total of 652 patients participated in the study, aged between 64–97 years old. 159 patients were men and 493 women.

Patients were divided into two groups according to the type of hip fracture. Group 1 included 299 patients with subcapital fractures, 61 men and 238 women and the second group 353 patients with intertrochanteric fractures, 98 men and 298 women. Patients’ demographics concerning age, sex, weight, height on admission at the hospital were compared between groups.

Results: The mean age (79± 9,4) of the patients with intertrochanteric fracture was statistically significant greater(Mann-Whitney test, p=0,001) than this of the patients with femoral neck fractures (76± 11,5).The sex ratio between the two groups seem to be significant different (x2 test, p=0,029) However following stratification of the data the effect of sex on the type of fracture disappeared. Mean height (Mann-Whitney test, p=0,765) and weight (Mann-Whitney test, p=0,448) did not differ significantly between the two groups. The mean time of hospitalization for the group of intertrochanteric fractures was significantly greater than this of the subcapital group(Mann-Whitney test. p=0,001).

Conclusions: It appears that intertrochanteric fracture patients have intrinsic factors (older age and consequently poor health) impacting upon their risk of fracture and ability to recover. Differences in patient characteristics and sequelae do exist between femoral neck and intertrochanteric hip fracture patients that impact upon recovery. However somatometric characteristics as height and weight did not differ significantly between the two types of fractures.

Introduction: In postmenopausal female patients with hip osteoarthritis, osteoporosis as well as altered local trabecular bone architecture may lead to a increased migration of uncemented hip prostheses.^1,2 The aim of this study was to determine whether 3D bone architecture and mechanical properties of intertrochanteric cancellous bone in the proximal femur predict RSA migration of uncemented femoral stems.

Materials and Methods: The study population consisted of 61 female patients with primary hip osteoarthritis. Informed consent was obtained prior to any study-related procedures. The Ethical Committee approved the study protocol.

All patients underwent a total hip replacement (ABG II, Stryker) with uncemented proximally hydroxyapatite-coated femoral stem with tantalum RSA markers. Ceramicceramic bearing surfaces were used. A uniplanar type of RSA setup was applied. The RSA examinations were performed postoperatively and at 3, 6, and 12 months.

During surgery, cancellous bone biopsy was taken from the proximal femur from the site of stem implantation. The specimens were scanned with micro-CT. 3D analysis of trabecular bone geometry and BMD was performed using CTAn software. After micro-CT imaging, the trochanteric cancellous bone specimens were subjected to a destructive compression test. Maximum force and stiffness were calculated. Linear regression analysis was applied to study correlations between different parameters investigated.

Results: The patients exhibited major differences in the density and structural quality of intertrochanteric cancellous bone. Significant correlations were found between the measured biomechanical parameters and the structural parameters calculated from micro-CT data.

Unexpectedly, the quality of intertrochanteric cancellous bone did not predict RSA migration of the femoral stems. The femoral stems reached high stability within 3 months and there were no significant differences in the axial and rotational migration of the femoral stems between the patients with normal or poor quality of the intertrochanteric cancellous bone.

Discussion: The 3D bone architecture, mineral density and mechanical properties of the local intertrochanteric cancellous bone do not seem to serve as predictors of femoral stem migration. The observation suggests that the significance of cancellous bone quality for the initial stability of uncemented femoral stems has been over-emphasized.

Introduction: Rotational alignment of the femoral component is widely believed to be crucial for the ultimate success of total knee arthroplasty (TKA). However there is a paucity of normative data on femoral component rotation in ‘perfect’ TKA.

Methods: Femoral component rotation in well-functioning TKA was assessed by means of axial radiography as described by Kanekasu et al. Well-functioning TKA were defined by three criteria at 5-year follow-up:

Knee Society objective and functional score of 190 or above

Thirty TKA of 29 patients (9 male, 20 female) with a median age of 70 years (range, 31–87) at time of surgery fulfilled the study criteria. All TKA were implanted at a single high-volume joint replacement center in 2002. In all cases both the condylar twist angle (CTA) using the clinical epicondylar axis (CEA) and the posterior condylar angle (PCA) using the surgical epicondylar axis (SEA) were used to assess rotational alignment of the femoral component.

Results: Overall, the mean CTA was 3.6+−3.5° of internal rotation (IR) (range, 4.1° of external rotation (ER) to 8.6° of IR) for the femoral component. For females, the CTA had a mean value of 4 +/−3.7° of IR (range, 7.6° of IR to 4.1° of ER) compared to 2.3 +/−3° of IR (range, 5.3° of IR to 2.5° of ER) in males. Overall, the mean PCA was 1.5 +/−3.5° of ER (range, 8.4° of ER to 5.1° of IR). In females, the mean PCA was 1 +/−3.9° ER (range, 2.3° of IR to 5.8° of ER) compared to 2.8 +/−2° ER (range, 0.4° of ER to 5.7° of ER) in males. The mean angle between CEA and SEA was overall 5.1 +/−1.8° (range, 3.3° to 9.1°), in females 5.1 +/−1.6° (range, 3.5° to 9.0°) compared to 5.0 +/−2.4° (range, 3.2° to 9.1°) in males.

Conclusion: Well-functioning TKA demonstrated a highly variable rotational alignment of the femoral component ranging from excessive external rotation to excessive internal rotation. These findings challenge current reference values for optimal femoral component rotation.

Slipped upper femoral epiphysis (SUFE) is an uncommon condition with potentially severe complications including avascular necrosis (AVN) and chondrolysis. Children with a ‘slip’ are at a significantly higher risk of a contralateral slip. Controversy remains as to when to undertake prophylactic pinning. The primary aim of this study was to assess the Posterior Sloping Angle (PSA, as described by Barrios et al in 2005) as a predictor for contralateral slip in a large, multi ethnic cohort.

All consecutive patients treated for SUFE presenting to Waikato Hospital between January 2000 and December 2009 were identified via medical coding. Patients without radiographs and those with bilateral slips on presentation were excluded. Clinical records were reviewed to document demographic data, slip characteristics and follow up outcomes. Radiographic analysis of the PSA in the unaffected hip was performed by a single author. Statistical analysis was performed using a student's t-test with Microsoft Excel 2003.

182 patients were identified, 50 were excluded [26 bilateral slips, 24 no radiograph available] to total a study population of 132 patients. 93 patients were male [72%]. Mean age was 11.8 years [6.2–15.6 years]. 72% were of Maori ethnicity and 26% were of New Zealand European descent. 90 patients [69%] had a unilateral slip, 42 [32%] had a contralateral slip. 48% were not followed until physeal closure and 50% did not attend at least one scheduled appointment Mean PSA of those with a unilateral slip was 10.8° [2–21°]. Patients who subsequently developed a contralateral slip had a statistically significantly higher mean PSA of 17.2° [6–36°] [p<0.0001]. Children with a contralateral slip were significantly younger 11.1 years than those with a unilateral slip 12.2 years (p<0.0001). No significant differences in PSA were found between Maori and NZ European children.

If a PSA of 14° was used as an indication for prophylactic fixation in this population 35/42 [83.3%] of contralateral slips would have been prevented. 19/90 hips would have been pinned unnecessarily. The number needed to treat demonstrates that 1.79 hips are prophylactically pinned to prevent one slip in this population.

This large retrospective cohort study demonstrates that a PSA of 14° in an unaffected hip after one sided SUFE could warrant prophylactic pinning in an unaffected hip to prevent subsequent slip and the complications associated with this, potentially protecting a population that can be difficult to follow up.

Back ground:

Previous studies have stated that presence of concomitant back pain has a negative effect on the outcome of lumbar decompression/microdiscectomy but none have actually defined what level of back pain should be considered as significant. This is a study of consecutive patients who underwent a primary single level lumbar micro decompression /microdiscectomy performed by thirty nine surgeons at a single tertiary spinal centre between August 2011 and December 2014. The aim was to determine the differential effect of the intensity of back pain and leg pain as a predictor of outcome.

Background

There are no published studies investigating predictive values of psychological distress on effectiveness of epidural injection.

Inflammatory changes in synovial tissues occur commonly in knee osteoarthritis (OA) and are termed “inflammatory OA”. The pathogenic significance of this inflammatory OA is uncertain. It is also not known whether inflammatory changes in the synovial membrane are reflected in the synovial fluid (SF) and whether the SF contains a similar inflammatory cell infiltrate.

This study examined 34 cases of knee joint OA and cytologically and immunohistochemically characterised inflammatory cells in the synovial membrane and SF. Specimens of SF and synovial membrane were taken at the time of knee arthroplasty.

All cases of inflammatory OA synovium contained (CD68+) macrophages; several cases also contained a scattered, focally heavy (CD3+) lymphocytic infiltrate and occasional lymphoid aggregates. Inflammatory changes in OA SF reflected this cell composition with numerous CD68+ macrophages and CD3+ lymphocytes being noted in inflammatory OA cases. The SF volume was greater (> 5ml) in cases of inflammatory OA. Non-inflammatory OA knee joints contained very few inflammatory cells, which were mainly macrophages, in both the synovial membrane and SF.

Our findings indicate that inflammatory changes in the synovial membrane of OA knee joints are reflected in the SF and that the volume of SF is commonly increased in cases of inflammatory OA. Both macrophages and lymphocytes in the inflammatory infiltrate of knee joint SF may contribute to joint destruction in OA by providing mononuclear phagocyte osteoclast precursors and the production of inflammatory cytokines and growth factors that promote osteoclastogenesis.

In conclusion, the cytology of SF and synovitic membrane are similar in inflammatory OA. With knee effusions of greater than 5mls and inflammatory synovitic membrane consideration of total knee arthoplasty in the presence of single compartment disease should be considered because of the risk of further joint destruction.

Introduction: Re-operations after intertrochanteric fractures (ITF) are often caused by fracture displacement following postoperative mobilisation. The biomechanical complexity of the fracture, implant position, and the patient’s characteristics are known to influence postoperative outcome significantly. We investigated the importance of an intact lateral femoral wall (LFW) for the postoperative displacement after fixation by a sliding compression hip screw (SHS).

Methods: Two hundred and fourteen consecutive patients with ITF fixated by 135° SHS mounted on four hole lateral plates were included between 2002 and 2004. The fractures were preoperatively classified according to the AO/OTA classification system. The status of the greater and lesser trochanter, the integrity of the LFW and implant positioning were assessed postoperatively. Re-operations due to technical failure were recorded for six months.

Results: Only three percent of patients (5/168) with postoperatively intact LFW’s were re-operated within six months, while twenty-two percent (10/46) of patients with fractured LFW’s had been re-operated (p < 0.001). In multivariate logistic regression analyses combining demographic and biomechanical parameters, a compromised LFW was a significant predictor for reoperation (p = 0.010). Seventy-four percent (34/46) of the LFW fractures occurred during the operative procedure itself. Peri-operative LFW fractures only occurred in three percent (3/103) of the AO/OTA type 31A1–A2.1 ITF fractures, compared to thirty-one percent (31/99) of the AO/OTA type 31A2.2–A2.3 fractures (p < 0.001).

Conclusions: A postoperative fractured LFW was found to be the main predictor for reoperation after ITF. Consequently we conclude that patients with pre- or potential postoperative LFW fractures are not treated adequately by SHS. ITF should therefore be classified according to the integrity of the LFW, especially in regard to randomized trials comparing fracture implants.

Introduction: The recent BOA blue book on blood conservation in elective orthopaedic surgery highlighted the need for blood saving strategies to be implemented. Perioperative management guidelines of oral anti-coagulation and anti-thrombosis medication have to date concentrated on warfarin use. Information and guidelines on aspirin usage in elective orthopaedics and its effects post operatively are limited.

Methods: Data was collected prospectively from 1936 patients who underwent 2024 primary unilateral total hip replacement in a single institution. All patients were treated with the same postoperative transfusion regime and thromboembolic prophylaxis. Preoperative medication, haemoglobin levels and patient demographics were recorded by a standard assessment. Post op transfusion requirements and haemoglobin levels were noted throughout the postoperative period.

Results: Multivariate analysis revealed that preoperative aspirin use was a significant independent predictor of postoperative transfusion requirement (p< 0.001).

Discussion: Expanding indications for the use of aspirin for primary and secondary cardiovascular disease prevention have meant that large numbers of our patients undergoing total hip replacement are concurrently taking the drug. With increasing and emerging evidence of the risks involved in blood transfusion, including vCJD transmission and immune related reactions coupled with reduced supplies of donor blood further measures to reduce transfusion requirement are needed. We recommend that in the absence of absolute contraindications to stopping aspirin therapy, it should be omitted for 1 week prior to total hip replacement.

Study Design: Prospective observational study.

Objectives: To score the severity of injury to (a) vertebrae and (b) intervertebral discs following thoraco-lumbar fracture, and compare the two in their ability to predict clinical outcome at 1–2 years.

Methods: 44 patients with fractures between T11 and L5 without neurological deficit were treated conservatively. All had plain X-rays and MRI scans immediately and at one year post-injury. Bony injury severity was scored on a seven-point ordinal scale based on a) comminution, b) apposition and c) kyphosis. Disc injury severity was scored on a six-point ordinal scale based on a) change in signal, b) change in height, c) indentation /herniation. Outcome was assessed at one to two years from injury (av. 18.1 + 5.6 months) Non-parametric correlation coefficients were calculated between injury severity variables and outcome variables.

Outcome measures: Modified Oswestry disability questionnaires, SF-36 questionnaires (physical and mental component summary scores – PCS and MCS), verbal and numeric rating scale of ability to perform pre-morbid activities/work. Detailed analysis of a.) pain (intensity, duration, character, distribution, etc.), b.) early morning stiffness (severity, frequency, and duration).

Results: According to the AO classification, 25% of the fractures were A1 (wedge), 9% were A2 (split), 45% were A3 (burst) and 20% were B1 (flexion-distraction with posterior ligament injury). Disc injuries scored as: grade 3 (mild) in 14%, grade 4 in 36%, grade 5 in 36% and grade 6 (very severe) in 14%. The spearman correlation coefficients between injury severity and outcome were consistently higher with disc injury severity than bony. For the Oswestry disability score the correlation coefficients for disc and bone injury severity respectively were 0.50 (p< .0001) and 0.40 (p< .05), for SF36-PCS: 0.43 (p< .005) and 0.32 (p< .05), for SF36-MCS: 0.43 (p< .005) and 0.06 (NS), for return to pre-morbid activities and work: 0.32 (p< .05) and 0.25 (p< .5), for pain intensity by numeric rating scale: 0.69 (p< .0001) and 0.41 (p< .01), and for pain intensity by verbal rating scale: 0.65 (p< .0001) and 0.28 (p< 0.1).

Conclusion: In all clinical outcomes assessed, there was consistently better prediction by measures of injury severity to the disc than the bone. This study offers possible explanation for previously low or conflicting evidence of correlation between clinical outcome and bony injury in thoraco-lumbar spine fractures uncomplicated by neurological injury. It implies that in selected patients with severe disc injury, treatment focused on eliminating the effects of the disc injury may result in better clinical outcome.

Radiographic evaluation of the anterolateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. Alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion.

The aim of our study was to analyse the reliability of frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Thirty two patients who presented with femoroac-etabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate prediction of alpha angle.