The required torque leading to an abrasion of the passive layer in the stem-head interface positively correlates to the assembly force. In order to limit the risk of fretting and corrosion a strong hammer blow seems to be necessary. Modular hip prostheses are commonly used in orthopaedic surgery and offer a taper connection between stem and ball head. Taper connections are exposed to high bending loads and bear the risk of fretting and corrosion, as observed in clinical applications. This is particularly a problem for large diameter metal bearings as the negative effects may be enhanced due to the higher moments within the taper connection. Currently, it is not known how much torque is required to initiate a removal of the passive layer, which might lead to corrosion over a longer period and limits the lifetime of prostheses. Therefore, the purpose of this study was to identify the amount of torque required to start an abrasion of the passive layer within the interface dependent on the assembly force and the axial load.Summary
Introduction
Single surgeon prospective cohort with radiological follow-up. Anjarwalla et al. have shown that the addition of posterior pedicle supplementation without posterolateral fusion during an ALIF procedure significantly increases the rate of interbody fusion when using a carbon fibre / PEEK cage packed with autogenous iliac crest graft. Stand alone ALIF cages which utilise screws passing through the interbody cage and into the vertebral bodies were designed to obviate the need for a posterior procedure by increasing the anterior construct stability and fusion rate.Study Design
Background
The purpose of this cohort study is to determine the incidence of all congenital vertebral anomalies detected antenatally through ultrasound. We also reported on the early mortality rate for this patient cohort, as well as the frequency and type of associated congenital anomalies. The East Midlands and South Yorkshire Anomalies Register consists of data on all voluntary reports of congenital anomalies, from an annual baseline birth rate of 67000 births. We analysed all registered congenital anomalies reported over a 10 year period. Between January 1997 and January 2007, 108 vertebral anomalies were reported, excluding spinal dysraphism (incidence 0.01%). 61 of these were detected antenatally (56%), 17 were detected postnatally (16%) and in 30 patients, the precise time of diagnosis was unclear (28%). At the time of analysis January 2007, 45 of 108 patients had died, either in utero or soon after delivery (42%). 12 fetuses remained in utero and 51 infants were alive. The mortality rate for antenatally diagnosed patients was 41% and the majority were electively terminated (72%). 2 fetuses electively terminated had vertebral anomalies in isolation. There is a relatively high incidence of elective termination of pregnancy as a result of antenatal anomaly ultrasound screening. We have evidence to suggest that foetuses with potentially minor congenital anomalies are being electively terminated at approximately 18 weeks gestation. A structured and timely spinal counselling should be offered once antenatal vertebral anomalies have been identified.
The purpose of this study was to ascertain whether early diagnosis through antenatal ultrasound screening and intervention lead to a reduction in morbidity associated with congenital scoliosis. Prospective cohort study All fetuses with vertebral body anomalies detected over a thirteen years period were included. Maternal risk factors, accuracy of antenatal diagnosis, associated fetal anomalies and ultimate outcome are described. Twenty-four fetuses with congenital hemivertebrae were identified from 39,000 antenatal scans (incidence 0.061%). The mothers' median age at conception was 26 years (range 18-40 years). The median fetal gestational age at diagnosis was 20 weeks (range 18-38 weeks). The median gestational age at delivery was 38 weeks (range 27-40). Antenatal ultrasound identified eighteen fetuses with a single hemivertebra, six fetuses with multiple hemivertebrae. Eleven patients (50%) have undergone early surgical intervention with median post-natal follow up was 4 years (range 0-9 years). The median age at surgery was 12 months (range 1.2 - 47 months). The median pre-operative Cobb angle was 33 degrees and the median Cobb angle at final follow up was 25 degrees. In this series 50% of patients required surgical intervention. We felt that pre-natal diagnosis of congenital vertebra abnormally has resulted in early surgical intervention using less complex surgical technique to halt progressive deformity. However, further studies are required to compare the results with the abnormally not detected antenatally.
The main objective of our study was to determine the treatment effect of corticosteroids in peri-radicular infiltration for radicular pain. We also examined whether there was any effect on the need for subsequent interventions such as additional root blocks and/or surgery. In a randomised, double blind controlled trial, 150 eligible patients with radicular pain and unilateral symptoms who failed conservative management were randomised for a single injection with bupivacaine and methylprednisolone (b+s) or bupivacaine (b) alone. The outcome measures used included the Oswestry Disability Index (ODI), Low Back Outcome Score (LBOS), Visual Analogue Score (VAS) for leg pain and back pain and patient's subjective level of satisfaction of the outcome.Objectives
Subjects and Method
Clinically useful improvements of greater than 10 points on the ODI occurred in 54%, deterioration of 10 points or more occurred in 17%. Visual analogue for leg improved by 2 or more in 63%. There was no statistically significant difference between the groups at 3 months (change in ODI [p=0.2], change in VAS [back pain, p=0.28; leg pain, p=0.67]. Subgroup analysis revealed no statistically significant difference in the change in scores between the stenotic group and disc herniation group at 3 months. At 1 year follow-up data was available for 86% of the patients. There was no statistically significant difference in the rate of further interventions.
To evaluate prognostic factors that influence outcome particularly those related to duration of symptoms in surgery for lumbar radiculopathy, #2 In primary care 75% of patients are pain free after the onset of sciatica within 28 days. The optimum timing of surgery for unresolved leg pain secondary to herniated lumbar disc is unclear. #2 We prospectively recruited 113 patients in this study and at one year, the follow up was available on 103 (91%). We investigated the prognostic value of a number of variables. These included the duration of sciatic symptoms, age at operation, Modified Zung Depression Score (MZD) and Modified Somatic Perception Score (MSP) using multiple regression analysis. The outcome was measured by the change of the Oswestry Disability Index (ODI), Low Back Outcome Score (LBOS) and of the Visual Analogue Scale (VAS). Patients with contained and non-contained herniated disc were compared. The change in ODI is statistically significantly associated with the duration of sciatica symptoms (p=0.05) with a one-month increase in the duration of symptoms being associated with a decrease in the change of ODI of 0.6% (95% CI, −1.014 to −0.187). The duration of sciatica and the MZD are associated with significant reduction in LBOS (p=0.034 and 0.028 respectively). VAS was not significantly associated with all the prognostic factors investigated. A shorter duration of sciatic symptoms was associated with a greater degree of patients’ outcome satisfaction. Non-contained herniated disc had a shorter duration of symptoms and a better functional outcome compared to contained herniated disc. Unemployment and smoking were not risk factors for poor surgical outcome.
This study investigates the efficacy of the AO Pi-plate in the treatment of complex, unstable, intra-articular fractures of the distal radius. A retrospective study of 17 patients was carried out who underwent open reduction and internal fixation for dorsally displaced, intra-articular fractures of the distal radius using the AO Pi-plate. All patients were assessed clinically and radiologically post-operatively. The final functional outcome was assessed using the Gartland &
Werley scoring system. The average follow-up period was 34.3 months. 94% (16 patients) of the fractures were classified as AO type C fractures. The wrist movement was restored to a near normal range in all cases. The mean grip strength was 67% of the uninjured hand. The functional outcome as measured by the Gartland &
Werley scoring system showed excellent and good results in 88% of the patients. Radiographic assessment revealed an average articular step-off of 0mm post-operatively. The implant removal rate was 29% (5 patients) and the main reason for that was extensor tenosynovitis.