The Te Whatu Ora Southern catchment area covers the largest geographical region in New Zealand (over 62,000 km2) creating logistical challenges in providing timely access to emergency neck of femur (NOF) fracture surgery. Current Australian and New Zealand guidelines recommend that NoF surgery be performed within 48 hours of presentation. The purpose of this study was to compare the outcomes for patients with NoF fractures who present directly to a referral hospital (Southland Hospital) compared to those are transferred from rural peripheral centres. A retrospective cohort study identified 79 patients with NoF who were transferred from rural peripheral centres to a referral hospital for operative management between January 2011 to December 2020. This cohort was matched 1:1 by age and sex to patients with NoF who presently directly to the referral hospital over the same period. The primary outcome was to compare time to surgery between the groups and secondary outcomes were to compare length of hospital stay, complication rates and mortality rates at 30-days and 1-year.Introduction
Methods
The purpose of this study was to determine whether there have been changes in the complexity of femoral fragility fractures presenting to our Dunedin Orthopaedic Department, New Zealand, over a period of ten years. Patients over the age of 60 presenting with femoral fragility fractures to Dunedin Hospital in 2009 −10 (335 fractures) were compared with respect to demographic data, incidence rates, fracture classification and treatment details to the period 2018-19 (311 fractures). Pathological and high velocity fractures were excluded. The gender proportion and average age (83.1 vs 83.0 years) was unchanged. The overall incidence of femoral fractures in people over 60 years in our region fell by 27% (p<0.001). Intracapsular fractures (31 B1 and B2) fell by 29% (p=0.03) and stable trochanteric fractures by 56% (p<0.001). The incidence of unstable trochanteric fractures (31A2 and 31A3) increased by 84.5% from 3.5 to 6.4/10,000 over 60 years (p = 0.04). The proportion of trochanteric fractures treated with an intramedullary (IM) nail increased from 8% to 37% (p <0.001). Fewer intracapsular fractures were treated by internal fixation (p<0.001) and the rate of acute total hip joint replacements increased from 13 to 21% (p=0.07). The incidence of femoral shaft fractures did not change significantly with periprosthetic fractures comprising 70% in both cohorts. While there has been little difference in the numbers there has been a decrease in the incidence of femoral fragility fractures likely due to the increasing use of bisphosphonates. However, the incidence of unstable trochanteric fractures is increasing. This has led to the increased use of IM nails which are increasingly used for stable fractures as well. The increasing complexity of femoral fragility fractures is likely to have an impact on implant use, theatre time and cost.
Imageless computer navigation systems have the potential to improve acetabular cup position in total hip arthroplasty (THA), thereby reducing the risk of revision surgery. This study aimed to evaluate the accuracy of three alternate registration planes in the supine surgical position generated using imageless navigation for patients undergoing THA via the direct anterior approach (DAA). Fifty-one participants who underwent a primary THA for osteoarthritis were assessed in the supine position using both optical and inertial sensor imageless navigation systems. Three registration planes were recorded: the anterior pelvic plane (APP) method, the anterior superior iliac spines (ASIS) functional method, and the Table Tilt (TT) functional method. Post-operative acetabular cup position was assessed using CT scans and converted to radiographic inclination and anteversion. Two repeated measures analysis of variance (ANOVA) and Bland-Altman plots were used to assess errors and agreement of the final cup position. For inclination, the mean absolute error was lower using the TT functional method (2.4°±1.7°) than the ASIS functional method (2.8°±1.7°, A functional registration plane is preferable to an anatomic reference plane to measure intra-operative acetabular cup inclination and anteversion accurately. Accuracy may be further improved by registering patient location using their position on the operating table rather than anatomic landmarks, particularly if a tighter target window of ± 5° is desired.
Component positioning is of great importance in total hip arthroplasty (THA) and navigation systems can help guide surgeons in the optimal placement of the implants. We report on a newly developed navigation system which employs an inertial measurement unit (IMU) to measure acetabular cup inclination and anteversion. To assess the accuracy of the IMU when used for acetabular cup placement and compare this with an established optical navigation system (ONS).Introduction
Aims
The pelvis is known to undergo significant movement during Total Hip Replacement (THR). We developed a 4D-tracking device employing an inertial measurement unit (IMU) to track changes in pelvic orientation during THR. The IMU was mounted on the iliac crest in 39 cases with tracking initiated at the commencement of surgery and digital logging of significant intra-operative milestones (i.e. acetabular impaction). The system was validated by videoing a select number of cases and the 4D model linked in real-time. Data were processed using a custom Java-based infrastructure to calculate roll (left/right) and tilt (flexion/extension). 19 patients underwent direct anterior approach (DAA) and 20 posterior approach (PA). Comparing DAA to PA, at acetabular impaction there was mean pelvic roll seen of 3.7°(range 0.5–10.1°) in the DAA group, and 5.6°(range 0.1–16.2°) in the PA group. Mean tilt in the DAA group was 3.7°(range: 0.2–7.1°) and in the PA group was 1.7°(range: 0.2–4.3°). Mean BMI in the DAA group was 25.2(range: 18.4–34.2) and 29.1(range: 21.5–42.4). There was no direct correlation between BMI and the amount of roll or tilt recorded for individual patients. The IMU tracking device provided a useful and real-time method of assessing pelvic orientation during THR via both the DAA and posterior approach. Specific variations in tilt and roll are consistent with previous literature. Significant variation in the pattern of pelvic movement was noted to be dependent on the approach and the position of the patient on the operating table.
Carpal tunnel syndrome (CTS) is said to be a condition of middle-aged women. Our experience is that it more commonly occurs in older people and also in a younger working population. The aim of this study is to describe the epidemiology of CTS requiring carpal tunnel decompression (CTD). Over a 10.5 year period 3073 CTD were performed on 2309 patients aged 15 – 93 years. This included all public, private and ACC funded cases in our region. During this period we had no restriction to access to CTD as all publicly funded cases were performed under local anaesthetic in a day surgery unit. Neurophysiological studies were performed pre-operatively by the same neurophysiologist. Population data from the national census (2006) was used to calculate the annual incidence of patients requiring CTD for each 5 year age band. There were 1418 females (61.4%) and 891 males (38.6 %). In contrast females comprised 116 of 306 (37.8%) patients who had their surgery funded by ACC. The mean age at surgery was 45 years for ACC cases compared with 56 years for non-ACC funded cases. The incidence of males having surgery funded by ACC was 1.7 times higher than females. There was a biphasic pattern in females with an incidence of 3.0/1000 at age 50–54 years, and a second higher peak of 3.1 to 3.4/1000 from 70 to 5 years. Males had a linear increase in incidence peaking at 3.1/1000 for age 65–69 years declining slightly to 2.8/1000 for age 70–85 years. The incidence was significantly higher in females than males overall (1.8 v 1.1/1000) and in patients under 65 years (1.4 v 0.8/1000). In patients over 65 years there was no significant difference in incidence (female 2.8, male 2.5/1000). Within our region, the incidence of surgically treated carpal tunnel syndrome increases with age. The highest rates are seen over the age of 70 in women and 65 years in men with no significant difference in rates between men or women over 65 years.
Tibial eminence fractures were historically thought of as a condition of skeletal immaturity. Increasingly this injury has been recognized in adults. The aim was to report on the demographics, mechanism, treatment and outcomes of this injury in adult and paediatric patients. A retrospective review of all patients presenting to Dunedin Hospital, for management of a displaced tibial eminence fracture, between 1989 and 2009. 19 cases were identified, 10 skeletally mature and 9 skeletally immature. Alpine skiing with a forced flexion and rotation injury accounted for 7 cases, primarily adult females (5 cases). A hyper-extension and rotation injury accounted for 7 cases, primarily in skeletally immature males (4 cases), while direct trauma accounted for 5 cases, primarily males (4 cases). Associated injuries were more commonly seen in adults and those with high energy trauma. Stiffness was the most common complication (10 cases). Tibial spine fractures are more common in adults than previously thought. Female skiers appear to be a group at particular risk. Our most common complication was stiffness. Early range of motion is essential to reduce the problem of stiffness and extension impingement. Laxity is an infrequent problem in adults and children.
Retrospective review of fusion rates using Grafton DBM/allografts only in AIS. Medical records of 30 consecutive patients at an average age of 19(18-24)were reviewed. All patients had segmental fixation with dual rod and pedicle screw construct followed by decortication supplemented with matrix strips/allograft chips. Minimum follow up 1.5 years, average of 2 years (1.5-3). First follow up at 3 months postoperatively and than 6 months subsequently. All patients were evaluated using criteria described by Betz et al for “possible pseudoarthrosis” which included persistent back pain, defects in the fusion mass, loosening of pedicle screws, junctional kyphosis and curve progression of more than 10 degrees from initial standing postoperative PA views. There were no infections. Average time to clinically and radiographically evident fusion was 12 months (range 10-16). Radiographically visible unfused facet joints were encountered in 3 patients towards the end of the construct. One patient had extension of the construct to treat junctional kyphosis. Other two remained asymptomatic. None had Progression of deformity. One patient developed pars defect at level below construct and was treated with extension of fusion.Purpose
Methods
Carpal tunnel decompression is common at the world's largest lamb processing plant. The purpose of this study was to establish whether lamb boning caused carpal tunnel syndrome, whether expeditious rehabilitation was possible and current New Zealand Orthopaedic practice. The incidences/relative risks of carpal tunnel syndrome were calculated. Kaplan-Meier survival analysis was performed examining six seasons. Comparison with a standard idiopathic population was performed. Retrospective review of five seasons established rate of return to work/complications using an accelerated rehabilitation programme. A prospective study qualified pre/postoperative symptoms using validated techniques. An email survey of the NZOA was also performed. Medical statistician advice was provided throughout.Introduction/aims
Method
This study aims to evaluate the accuracy of sheer off self limiting screw drivers and to assess repeatability with age. It has been reported that overzealous tightening of halo pins is associated with co-morbidity. Our unit has recently received a tertiary referral where the patient over tightened a pin leading to intracranial haematoma, hence our interest in this subject. The torque produced by six new and nine old screw drivers was tested using an Avery Torque Gauge and a Picotech data recorder. These devices are designed to produce a torque of 0.68 Nm, any greater than this is potentially hazardous. Accepted error for each device was +/− 10%. The average torque produced by the new screw drivers was 0.56 Nm with a range of 0.35–0.64 Nm (SD 0.120). The older screw drivers produced an average torque of 0.67 Nm ranging from 0.52–0.85 Nm (SD 0.123). In conclusion, sheer off self limiting screw drivers are not accurate devices. The older devices are more likely to produce a torque exceeding a safe range and therefore we would recommend the use of new devices only.
In January 2000 we introduced identical guidelines for the more rapid rehabilitation of Achilles tendon ruptures, whether treated operatively or non-operatively. A relaxed equinus cast was used to four weeks, then a CAM walker to eight weeks with supervised mobilisation. The aims of this study were to compare the outcomes of the operative and non-operative groups treated with the same rehabilitation program and audit the effectiveness of these guidelines. The audit was retrospective from January 2000 till January 2008. The patients were identified from the Emergency Department admissions database, the hospital clinical coding system, the department’s surgical audit data and the hospital physiotherapy appointment system. The audit system was used to identify patients that had complications of their operative treatment, re-ruptures or readmissions. This study focused on the end points of re-rupture, readmission, complications including wound complications and infection. Five hundred and eighty seven presentations were recorded as Achilles tendon injuries. One hundred and eighty patients were treated operatively and 407 patients were treated conservatively. Seventy five patients (42%) treated operatively and 126 patients (30%) of the non-operative group were rehabilitated in our hospital physiotherapy department. The remaining 386 patients (65.7% of all patients) received physiotherapy elsewhere or did not attend for further treatment. In the operative group there were two re-ruptures (1.1%) both treated in our hospital physiotherapy department. There were 2 wound complications (1.1%), one requiring re-operation. In the non operative group there were 15 re-ruptures (3.7%). Of these three had attended the hospital physiotherapy department (rerupture rate of 2.4%) In the non-operative group treated elsewhere there were 12 re-ruptures from 281 patients (4.2%). Comparable results were found between operative and non-operative treatment when combined with close physiotherapy guidance. Non-operatively treated patients treated in the community may have higher re-rupture rates. The results are comparable to those in the literature suggesting that the guidelines are effective.
The use of MRI scanning has been described after open reduction of the hip in DDH to check hip position but has not previously been reported after open reduction with femoral osteotomy and the use of metalwork. We performed a prospective study utilising MRI to document the adequacy of reduction. An MRI scan was performed on the second postoperative day in order to confirm the satisfactory reduction of the hip following surgery. Previously a CT scan was performed. 10 consecutive cases were scanned and all gave diagnostic information of satisfactory reduction. Sedation was not required. The mean scanning time was 3 minute 45 seconds and the total time in the MRI suite ranged from 7 to 10 minutes. Satisfactory images, the lack of need of sedation, comparable time and cost to CT scanning and most importantly the lack of exposure of the child to ionising radiation make MRI a most appealing method of imaging. We therefore recommend it as the investigation of choice in this patient group. Demographic data reviewed included gender, MP at time of primary surgery, GMFCS level, age at time of surgery, type of adductor release procedure performed, and experience of surgeon. Outcome variables assessed were type of subsequent failure, time of failure after primary procedure, and length of follow-up. Three hundred and thirty children underwent hip adductor surgery. The number of children per GMFCS Level was 33 Level II, 55 level III, 103 level IV, and 139 level V. The average age at time of primary surgery was 4.19 years, mean MP at time of primary surgery 43.16%, and mean length of post-operative follow-up was 7.10 years. Eighty two children had adductor longus and gracilis lengthening alone, 97 also had an iliopsoas release, 97 had psoas tenotomy and phenolisation of the obturator nerve, and 54 had a psoas tenotomy and neurectomy of the anterior branch of the obturator nerve (in addition to longus &
gracilis lengthening). At time of audit 106 children did not require further surgery (‘surgery success’ of 32%). Thirty one were in children of GMFCS level II (94%), 27 level III (49%), 28 level IV (27%), and 20 level V (14%). A Cox proportional hazards survivorship analysis was constructed to chart the time course of progression to further surgery over time to reveal statistically significant ‘surgery success’ rates according to GMFCS. Differences in the success rates according to GMFCS become more apparent beyond 3 years post-surgery. The most important determinant for predicting the success of hip adductor surgery in preventing hip displacement is GMFCS at the time of primary surgery. Current treatment strategies need to be re-evaluated with the context of undertaking long-term post-operative follow up, particularly for children GMFCS levels VI and V.
In a high-risk technically advanced speciality like spine surgery, detailed information about all aspects of possible complications could be frightening for the patients, and thereby increase anxiety and distress. Therefore, aim of this study was to
Analyze written evidence of the consenting procedure pertaining to (a) nature of operation (b) benefits intended as a result of the operation (c) risks specific to the particular type of operation (c) general risks of spine surgery and anaestheia. Patients’ experiences of information regarding the risk of such complications and how the information affects the patients.
The study had a non-randomized design and patients divided into TWO groups Group A and group B. The patients in the group A received standard information and were consented in a routine way without being given written proforma with all complications. The patients in the group B were given the same information as patients in the control group, with written information about common and rare complications. Patients in both groups were assessed on an ‘impact of events scale’ and hospital anxiety and depression scale immediately before ad after the consent process and again after surgery when they were discharged from the hospital. For comparison of the proportion of Yes and No answers in 2 groups, Fisher’s exact test was used, and for comparison of more than 2 groups, the Chi-square test was used. For graded answers and other ordinal scales, the Mann–Whitney U-test was used for comparison of 2 groups and the Kruskal–Wallis test for comparison of more than 2 groups. Spearman’s test was used when assessing the correlation between 2 variables measured on an ordinal scale.
Work supported by Fondation Cotrel
Physical activity is a key determinant of bone mass and health, however during adulthood and ageing there appears to be a decrease in the ability to respond positively to exercise which is variable between individuals. While exercise is known to protect against the osteopo-rotic process with modest increases in BMD the exact cellular and molecular responses are poorly understood. We have studied the effect of mechanical stimulation on bone histomorphometric parameters, osteocyte viability and gene expression in human trabecular bone maintained in a 3D bioreactor. Trabecular bone cores were prepared from femoral head tissue removed from patients undergoing total hip arthroplasty and maintained in the bioreactor system for 3 (n= 4 patients), 7 (n=5 patients) or 28 days (n=1 patient). Cores (n=3 per patient) were either frozen directly on preparation (T0), placed in the bioreactor system and subjected to Mechanical stimulation (3000 μstrain in jumping exercise waveform repeated at 1Hz for 5 minutes daily) or maintained in the bioreactor system with no mechanical stimulation as control. After the experimental period total cell numbers, cell viability and apoptosis were determined in un-decalcified cryosections at specific distances throughout the bone cores by nuclear staining (DAPI), lactate dehydrogenase activity (LDH) and Nick Translation Assay respectively. Consecutive sections were collected and RNA extracted for gene expression analysis. Mechanical stimulation was shown to increase Bone Formation Rate (BFR) as determined by Calcein label/ distance to bone surface in the 28 day experiment (BFR mcm/day Control 0.01 ± 0.0035 vs Load 0.055 ± 0.0036 p=0.0022). Expression of bone formation markers such as Alkaline Phosphatase and Collagen Type I was shown to increase in all patients however there was an individual variation in the response of Osteopontin to mechanical stimulation as determined by quantitative real time PCR expression analysis. Numbers of viable osteocytes at T0 varied between individual patients however viability was significantly increased and apoptosis decreased in association with mechanical stimulation compared to control in all patient samples examined (p to 0.021). Our data tend to support animal model findings relating to the osteocyte saving effects of exercise and provide an insight into the molecular detail of the exercise response in human bone.
Normal acetabular development in developmental dysplasia of the hip (DDH) depends upon early and maintained congruent reduction. Computed tomography is an accepted method for evaluating this and attempts to quantify hip reduction, by various angular and linear measurements, have been reported. The aim of this study was to assess initial CT scans, following open reduction in the older child with DDH, with comparison of outcome to evaluate prognostic value.
In conclusion, despite the significant differences noted between DDH and normal hips they did not predict acetabular development or persistent acetabular dysplasia.
Surgical treatment of complex deformities necessitates a detailed appreciation of the complex three dimensional abnormal anatomies involved. Preoperative planning for these complex cases traditionally involves x-ray and computerised tomography (CT). These modalities offer only two-dimensional images to represent three-dimensional anatomy. Advances in digital imaging have allowed three-dimensional reconstructions to be derived from CT images. These greatly improve understanding of complex deformities, but will never be able to replace the intuitive understanding that is gained by handling a physical model. The Rapid Prototyping technique Selective Laser Sintering (SLS) is used in the industrial setting to manufacture prototype models from Computer Aided Designs (CAD). This technology can be utilised to convert CT images into accurate three-dimensional physical models of the human bony anatomy. We present the use of SLS modelling to aid in the preoperative planning of complex reconstructive surgery in children. Cases include bladder exstrophy, developmental dysplasia of the hip and reconstruction of a complex elbow malunion. The models provide invaluable visual and tactile information to the operating surgeon, accurately demonstrating the abnormal anatomy in an easily comprehensible manner. They allow estimation of the magnitude and degree of corrections necessary and evaluation of bony deficiencies.
Accurate and relevant patient chart notes are a key component in successful patient care. Hospital charts also constitute an important medicolegal record. The key to defensibility of at least 40% of medical claims rests with the quality of the medical records. With this in mind, we decided to assess the quality of chart note keeping in our unit. A retrospective review of fifty randomly chosen charts was performed. A scoring system was devised to audit ten key criteria comprising patient details, admission note, daily progress notes, signature clarity, consent form, operation note, post-operative plan, post-operative x-ray review, specification of right or left side and discharge letter. Members of the orthopaedic surgical staff were then informed of the chart review and the nature and purpose of the study was explained in detail. They were also told that there would be another chart audit at some random time over the following three months. Subsequently, a further fifty charts were assessed using the same criteria and scoring system. Overall, charts scored poorly in the areas of patient details, clarity of signatures, post-operative x-ray review and left-right specification. Criteria that scored satisfactorily included admission note, consent form, operation note, post-operative plan an discharge letter. Meticulous hospital notes are vitally important in the day-to-day management of patients for successful continuity of care and also for protection of the medical staff should any adverse outcomes arise. In this litigious society consultants and junior medical staff need to be reminded of the importance of optimal note keeping.
Traditional osteotomies are posterior or horizontal. A technique of an oblique osteotomy from the sciatic notch to the iliac crest has been developed at Great Ormond Street since 1996, along with a system of external fixation. It is undertaken concurrently with urological reconstruction. The system of external fixation is relatively simple compared with other published work.
Also children with classical exstrophy were divided into 4 groups on the basis of continence. The mean post-operative percent reduction in the amount of the original diastasis was determined for all age groups. Comparison of pubic approximation was made between the two types of post-operative immobilisation
The average improvement in pubic approximation was 37% for the whole series. Chidren who were older at the time of surgery (18–60 months) were found to maintain better correction over time (76%). Children immobilised with an external fixator maintained better closure of the pelvis than those treated with plaster cast alone. (51% and 12.2% respectively). Maintenance of pubic approximation was associated with a higher level of bladder continence. Complications included 3 cases of infection and loosening of the external fixator requiring early removal. There were no neurovascular complications.
It is a reliable operation and the technique is applicable to all age groups.
Initially the Urologist will make an infra-umbilical incision then identify and mobilise the anatomical structures intended for their subsequent reconstruction and repair. This wound is then temporarily closed. The Orthopaedic surgeon will then approach the ilial crest through bilateral oblique incisions made inferior to the anterior superior ilial spine as described for the Salter osteotomy The interval is developed distal to the anterior superior ilial spine after identification and protection of the lateral femoral cutaneous nerve which is taken medially. After the interval between sartorious and tensa fascia lata are identified the iliac apophysis is split and reflected off the inner and outer ilial crests. The exposure may be improved by also developing the interval between rectus femorus and gluteus medius. Each side of the pelvis is exposed sub-periosteally from the iliac crest extending into the sciatic notch. A Gigli saw is then passed through the sciatic notch. The line of the osteotomy is from the posterior part of the sciatic notch extending anteriorly and superiorly to exit the iliac crest 2cm posterior to the anterior superior iliac spine (figure 2). The most anterior 1.5cm of iliac crest from the distal pelvic fragment is trimmed to allow closure of the iliac apophysis after rotation. The size of the half pin utilised is determined by the age of the patient. A baby under 18 months old will have a 3.5mm pin from the AO wrist external fixator frame and an older child over 2 years, a 4.5mm half pin. One half pin is inserted on each side of the pelvis. The half pin is placed in the distal fragment from anterior and lateral to posterior and medial with the tip of the screw just exiting the cortical bone of the medial aspect of the sciatic notch (figure 3a). Consideration of pin placement must take into account rotation of the distal fragment and preventive skin pressure areas. The iliac apophysis is repaired and the skin wounds are closed. The Urologist completes the reconstruction procedure planned via their infra-umbilical approach. The final stage involves the medial and superior rotation of both distal pelvic fragments and subsequent closure of the symphyseal diastasis. This position is maintained with the application of an anterior A-shaped frame from the wrist, AO fixation set in the younger infant or the AO pelvic fixator in the older child (figure 3b). Symphyseal approximation is confirmed intra operatively by palpatation. Bilateral above knee front slabs casts are applied to prevent kicking the hips or knees. The post-operative management involves pin site care on alternate days. The front slab casts are removed at 3 weeks and the anterior A-frame is removed at 6 weeks after union is confirmed on a pelvic radiograph. Depending on the social situation the children may go home during the post-operative period.
Our results, apart from showing the deleterious effects of low nutrient concentrations, also indicate that isolated cells may metabolise differently from cells in the tissue; at low pO2 we observed a fall in lactate production, the opposite effect to that seen in tissue previously. The mechanism for this difference is as yet unknown.
This poster describes the separation of a pair of conjoined twins, aged 3 months. They were joined at the pelvis, shared a common hindgut and each had bladder exstrophy. The operation to separate them, done over a weekend, involved paired teams of anaesthetists, Paediatric Surgeons and Paediatric Urologists and one Orthopaedic Surgeon. The surgeons mobilised and divided the hindgut, giving one twin the distal half and the other the caecum and proximal colon. Two Urologists reconstructed the bladder exstrophies. The orthopaedic contribution was bilateral oblique pelvic osteotomy to allow midline closure, along with extensive hip releases to deal with severe flexion and abduction contractures. Both twins survived and are thriving. They have little neurological impairment in the lower limbs and therefore have great potential to walk.
Introduction: Complications of homologous blood transfusion include transmission of infection and development of antibodies. Autologous pre-donation, acute normo-volaemic haemodilution and cell salvage have been used to reduce the use of homologous transfusions. Surgery for spinal deformities often requires blood transfusion. In February 1999, we started an autologous pre-donation programme for children undergoing spinal deformity surgery. Methods and results: The case records of the first 15 patients who took part in the programme have been scrutinised and data about pre-donation, haemoglobin, pre- and post-operative hameoglobin, blood loss, blood transfusions, use of blood products, and complications related to pre-donation of blood were obtained and analysed. Similar data from case records of 15 patients, who had surgery for spinal deformities before start of the programme, were used as control. In the autologous pre-donation group, four received homologous transfusion and 11 escaped exposure to homologous blood or blood products. In comparison in control group 14 out of 15 received homologous transfusion. There was no significant difference between the two groups in terms of diagnosis, operating time, postoperative haemoglobin, body weight and age. Mean operative blood loss in autologous group was less (1190 mls) than in that of the control group (1529 mls). Of the four patients who received homologous transfusion, two were transfused outside the hospital protocol. Complications from pre-donation of blood occurred in three patients and were minor. They included minor bruising in two and difficult and painful venous cannulation in one. Conclusion: In our practice autologous pre-donation resulted in avoidance of homologous blood transfusion in three quarters of patients undergoing spinal deformity surgery. By adopting strategies such as acute normo-volaemic haemodilution, cell salvage and strictly adhering to protocols for prescribing transfusion, we believe that the need for homologous transfusion could be obviated except in extreme cases.
The purpose of this study was to audit screening and treatment programmes for Developmental Dysplasia of the Hip (DDH) over a 12-year period from 1989 to 2000 with respect to late presentation and treatment rate and duration. All babies born in Queen Mary Hospital are clinically screened for DDH by a consultant orthopaedic surgeon. Unstable hips are treated by Pavlik Harness and attend an ultrasound clinic run by an orthopaedic surgeon within 2 weeks. High-risk babies or those with suspected instability can also be referred for ultrasound. Serial ultrasound exams assisted with determining the duration of splintage. Radiographs are taken at 4 to 6 months. Late presenters were identified and analysed. Over the 12-year period 13 cases of late presenting DDH were identified (0.6 per 1000). Half of these had not been screened. None had ultrasound screening. Our treatment rate was approximately 4 per 1000 live births. Our screening programme can be improved by increased capture of patients for clinical screening. Ultrasound is a useful tool in managing neonatal hip instability allowing duration of splintage to be tailored to the individual and allows early detection of treatment failure.
The aim of the study was to review the role of Magnetic Resonance Imaging of the spine in discitis in the toddler age group (one to three years). Discitis presents differently in different age groups of children. It is most difficult to diagnose in the uncommunicative non-compliant toddler. The clinical features are often non-specific and laboratory and microbiological tests can be unhelpful. A highly sensitive test is required to aid in making the diagnosis. Although MR Imaging has been used in discitis for several years, we reviewed its actual effectiveness in this specific difficult age group. At a mean of 21 months at follow-up (range 10 to 40), MR imaging of the disc was variable, with partial recovery after 15 months and complete recovery after 34 months. Routine follow-up MR imaging was not recommended. We reviewed the role of Magnetic Resonance Imaging in eleven consecutive cases, both at presentation and at a follow-up clinic. MR imaging was diagnostic in all cases, reduced the diagnostic delay, and often avoided a disc biopsy. It demonstrated any paravertebral inflammatory collection, which helped in determining the duration of the oral therapy given after the initial intravenous antibiotics.
In the reconstruction of the exstrophy/epispadias complex pelvic osteotomy has a role in helping the urologist close the anterior defect thereby improving appearance and helping to achieve continence. In the neonate and infant, we have traditionally used an oblique osteotomy coupled with plastering of the legs until the osteotomy shows signs of healing. Plastering has significant disadvantages in respect of nursing care. We have therefore looked to external fixation in this age group. In the past year we have used the A.O. wrist fixator to stabilise the osteotomised pelvis of ten babies with bladder exstrophy ranging in age from neonates to two years. All have achieved soft tissue closure with improved appearance. However, because of the foreshortened anterior pelvis in the exstrophy patients, it is not possible to reconstruct to normality. The results to date are promising and the patients remain under follow up.
There is great confusion in the literature on mechano-transduction in osteoblasts. This is partly due to the use of hyper and hypophysiological systems for applying forces to cells. We only find evidence for the role of ion channels at hyper-physiological levels of strain. The cells are far more sensitive to tension than compression indicating that structures within the cell are decisive in determining response and that there is no tensegrity within the cell. Single cell mechanical measurements using an adapted atomic force microscope built in our lab, also does not show any evidence for a tensegrity structure. Analysis of the dimension of stretch and the amount of force needed to activate cells indicates that stretch activated ion channels are not involved as the force required is extremely high in relation to the activation energy of an ion channel. The force required to activate at the mechanosensing system is more in line with the forces generated inside a cell by the actin-myosin structure of several hundred thousand piconewtons. We find no evidence for any other pathway than a PLC-PKC-Calcium pathway involved in any of the signal transduction pathways, but other pathways are involved in hyperphysiological stretch. One of these induces ICAM-1 and thus can induce inflammatory pathways through cell-cell binding of macrophages and other cells. Due to the very high energies involved in activating the mechano-transduction pathways we do not see any graviception mechanism of single cells. Indeed many microgravitx flights of 25 seconds duration and a flight of 6 minutes did not show any effect in intracellular calcium. The cellular response to microgravity, if it is not an artefact, is not related to mechanosensing. This work was supported by the German Space Agency (DLR)
Using the trabecular bone bioreactor (ZETOS) developed in our laboratories we have investigated the formation of bone using the fluorescent bone seeking markers calcein and alizarin red. And the association of bone formation with the increase in stiffness with mechanical loading. 10 mm diameter bone cores 5 mm thick were obtained from the distal radius /ulna of cows obtained at the slaughter house. by precision cutting with diamond saws and keyhole cutters (our pattern) in sterile 7–10°C phosphate buffered saline (PBS) and cultured in a variation of DMEM containing fructose HI GEM.
We gratefully acknowledge support by the German Arthrose Foundation (DAH) and the AO in Davos, CH. DJ is a recipient of a Fork award from the AO
Intervertebral disc cells exsist in a precarious nutritional environment. Local concentrations depend on both nutritional supply and demand. Little is known about the metabolism of disc cells; existing data focuses on intact tissue, where the local metabolic environment is unknown. We have thus developed a closed chamber to study the metabolism of isolated cells under controlled conditions. Bovine disc cells were isolated from coccygeal discs and transferred to the sealed chamber, in which embedded electrodes measured pH, pO2 and glucose concentration, and a port allowed sampling and addition of metabolic reagents. Metabolic rates were assessed from concentration changes. Cell viability was assessed and intracellular ATP measured at completion of each experiment. Under standard conditions, metabolic rates were similar to those measured in tissue, with a glucose:lactic acid ratio of approximately one to two. We have also examined the effect of extracellular pH on nucleus pulposus cell metabolism. Between pH 7.4–6.8, metabolism is insensitive to extracellular pH, and lactic acid production agrees with the literature
These results show a fall in lactic acid production with extracellular acidification, which in vivo arises mainly from lactic acid produced by the cells. This may be protective. However the decrease in metabolism, and hence loss of ATP, may have a detrimental effect on the cells. There is thus a complex interplay between different components of the nutritional environment. Investigating these in combination should give valuable information about disc cell metabolism, as changes in cells metabolism can affect nutrient availability and hence cellular activity and viability.
Scoliosis is a disease characterised by vertebral rotation, lateral curvature and changes in sagittal profile. The role of mechanical forces in producing this deformity is not clear. It is thought that abnormal loading deforms the disc, which becomes permanently wedged. Modelling and in vitro studies suggest that such deformations should increase intradiscal pressure. Intradiscal pressure has been measured previously in a variety of clinical environments. The aim of this study is to measure pressure profiles across scoliotic discs to provide further information on the role of mechanical forces in scoliosis. Pressure readings were obtained in consented patients with ethical approval using a needle-mounted sterilised pressure transducer (Gaeltec, Dunvegan, Isle of Skye) calibrated as described previously. The transducer needle was introduced into the disc of an anaesthetised patient during routine anterior scoliosis surgery and pressure profiles measured. Signals were collected, amplified and analysed using Power-lab and a laptop computer. Pressure profiles across 10 human scoliotic discs from 3 patients have been measured to date. Pressures varied from 0.1 to 1.2 MPa. Annular pressures showed high pressure, non-isotropic regions on the concave but not convex side of these discs. Nuclear pressures recorded from the discs of these scoliotic patients were higher than those recorded previously in non-scoliotic recumbent individuals.
One of the mechanisms which controls bone growth, repair remodeling and absorption is mechanical loading. There exists no long-term in vitro model to study bone cells together with their matrix, nor a model that can apply quantitative mechanical forces of physiological amplitudes and frequencies. The analysis of the mechanical properties of bone (Young’s modulus and visco-elastic moduli) on small pieces of bone is also difficult with present devices. We have built a device that can maintain full viability and physiological response of bone for a period of several weeks and integrates all three functions. 10mm diameter bone cores 5 mm thick were obtained from the trabecular bone of the distal ulna of a 24 months old cow by precision cutting with diamond saws and keyhole cutters (our pattern) in sterile 7–10°C phosphate buffered saline (PBS) and cultured in a variation of DMEM containing fructose HI GEM.
We gratefully acknowledge support by the German Arthrose Foundation (DAH) and the AO in Davos, CH.