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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_15 | Pages 11 - 11
7 Aug 2024
Warren JP Khan A Mengoni M
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Objectives

Understanding lumbar facet joint involvement and biomechanical changes post spinal fusion is limited. This study aimed to establish an in vitro model assessing mechanical effects of fusion on human lumbar facet joints, employing synchronized motion, pressure, and stiffness analysis.

Methods and Results

Seven human lumbar spinal units (age 54 to 92, ethics 15/YH/0096) underwent fusion via a partial nucleotomy model mimicking a lateral cage approach with PMMA cement injection. Mechanical testing pre and post-fusion included measuring compressive displacement and load, local motion capture, and pressure mapping at the facet joints. pQCT imaging (82 microns isotropic) was carried out at each stage to assess the integrity of the vertebral endplates and quantify the amount of cement injected.

Before fusion, relative facet joint displacement (6.5 ± 4.1 mm) at maximum load (1.1 kN) exceeded crosshead displacement (3.9 ± 1.5 mm), with loads transferred across both facet joints. After fusion, facet displacement (2.0 ± 1.2 mm) reduced compared to pre-fusion, as was the crosshead displacement (2.2 ± 0.6 mm). Post-fusion loads (71.4 ± 73.2 N) transferred were reduced compared to pre-fusion levels (194.5 ± 125.4 N). Analysis of CT images showed no endplate damage post-fusion, whilst the IVD tissue: cement volume ratio did not correlate with the post-fusion behaviour of the specimens.


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Osteoporosis can cause significant disability and cost to health services globally. We aim to compare risk fractures for both osteoporosis and fractures at the L1-L4 vertebrae (LV) and the neck of femurs (NOFs) in patients referred for DEXA scan in the North-West of England.

Data was obtained from 31546 patients referred for DEXA scan in the North-West of England between 2004 and 2011. Demographic data was retrospectively analysed using STATA, utilising chi-squared and t-tests. Logistical models were used to report odds ratios for risk factors included in the FRAX tool looking for differences between osteoporosis and fracture risk at the LV and NOFs.

In a study involving 2530 cases of LV fractures and 1363 of NOF fractures, age was significantly linked to fractures and osteoporosis at both sites, with a higher risk of osteoporosis at NOFs compared to LV. Height provided protection against fractures and osteoporosis at both sites, with a more pronounced protective effect against osteoporosis at NOFs. Weight was more protective for NOF fractures, while smoking increased osteoporosis risk with no site-specific difference. Steroids were unexpectedly protective for fractures at both sites, with no significant difference, while alcohol consumption was protective against osteoporosis at both sites and associated with increased LV fracture risk. Rheumatoid arthritis increased osteoporosis risk in NOFs and implied a higher fracture risk, though not statistically significant compared to LV. Results summarised in Table 1.

Our study reveals that established osteoporosis and fracture risk factors impact distinct bony sites differently. Age and rheumatoid arthritis increase osteoporosis risk more at NOFs than LV, while height and steroids provide greater protection at NOFs. Height significantly protects LV fractures, with alcohol predicting them. Further research is needed to explore risk factors’ impact on additional bony sites and understand the observed differences’ pathophysiology.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 69 - 69
1 Mar 2021
Ghani R Usman M Salar O Khan A Karim J Davis E Quraishi S Ahmed M
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Abstract

Objectives

Up to 19% of patients who undergo surgery for an acute hip fracture are readmitted to the hospital within three months of the index operation. We aimed to identify risk factors for unplanned clinic attendance, readmission, and mortality within the first 12 months postoperatively and subsequently determine if there is a role for routine follow-up.

Methods

Patients greater than 65 years old who underwent hip hemiarthroplasty using an uncemented Thompson implant for treatment of a traumatic non-pathological hip fracture were identified from a prospectively maintained database at a single institution between August 2007 and February 2011. Patient demographics, comorbidities, place of residence, mobility status, unplanned attendance to an orthopaedic clinic with symptoms relating to the respective limb, readmission, and mortality were recorded.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_1 | Pages 8 - 8
1 Jan 2019
Guiot L Spence S Bradman H Khan A Holt G
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Hip fractures in young adults are rare but represent an important cohort of patients, of which relatively limited data exists. The aim of this study was to evaluate this distinct subgroup of hip fractures from an epidemiological perspective and assess their subsequent outcomes.

Patients aged 18–50 were identified across an 8 year period from a total of 5326 hip fractures. 46 hip fractures met the inclusion criteria and a retrospective case series analysis was conducted.

25/46 (54%) of fractures were intracapsular and 21/46 (46%) were extracapsular. Only 15/46 (33%) of fractures were sustained from a high energy mechanism and 31/46 (67%) low energy. The low energy cohort was significantly more comorbid with a mean Elixhauser comorbidity score of 1.5 compared to the high energy cohort 0.3 (p<0.0005, unpaired t-test). Alcohol excess was the most prevalent comorbidity present in 24% of patients and was a positive predictor in complication (p=0.006, binary regression). Failure of fixation (non-union/avascular necrosis) in displaced intracapsular fractures sustained following low energy trauma managed by internal fixation 5/11 (45%) was markedly higher than the high energy cohort 0/6 (0%). 5 year mortality was 9% for all hip fractures, six times higher than an aged matched cohort of non-hip fractures (p=0.007, Wilcoxon test).

Representing only 0.86% of all hip fractures in the study period, hip fractures in young adults are rare. A clear sub-division of patients is observed between patients with a low and high energy mechanism, both in terms of level of comorbidity and surgical outcome.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_18 | Pages 26 - 26
1 Dec 2014
Haque S Umar M Khan A Osei N
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The aim of our study was to assess the outcome of caudal epidural injection for patients with low back pain in relation to fatty infiltration of spinal muscle. This is a prospective study. The spinal muscles were graded on sagittal section T1 MRI at the lower border of lumber 4 vertebra from 3 to 12 depending on the severity of fatty infiltration. The outcome of the intervention was assessed by improvement in pre and post intervention oswestry disability index score as well as visual analog pain score. Patients with significant fatty changes don't respond well to the caudal epidural injection.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_17 | Pages 19 - 19
1 Nov 2014
Yousaf S Lee C Khan A Hossain N Edmondson M
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Introduction:

Early stabilization has the potential to expedite early return to function and reduce hospital stay thus reducing cost to health care. A clinical audit was performed to test the hypothesis that early surgical stabilization lowers the rate of soft tissue complications and is not influenced by choice of distal fibular implants used for stabilization of ankle fractures.

Methods:

All surgically treated adult patients with isolated unstable ankle fracture were included from April 2012 to April 2013 at a MTC in UK. Patients with poly-trauma were excluded.

All patients underwent a standard surgical protocol: aim for early definitive surgical fixation (ORIF) within 24 hours however if significantly swollen than temporary stabilization with an external fixation followed by a staged definitive fixation.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_4 | Pages 11 - 11
1 Feb 2014
Lee KC Khan A Longworth S Sell P
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Introduction

There has been a recent surge in the interest of the role of vitamin D in chronic musculoskeletal pain however there are limited studies that have investigated the link of vitamin D hypovitaminosis with low back pain. The aim of our study was to determine the prevalence of low vitamin D levels in patients who present with low back pain in an outpatient setting in the UK.

Methods

Data was collected retrospectively from computerised databases of all patients who presented with low back pain from a single spinal consultant's outpatient clinic and have had serum levels of 25-hydroxycholecalciferol (25-OH vitamin D) requested. Data of these patients were collected from hospital electronic and paper records and analysed against their serum 25-OH vitamin D levels.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_3 | Pages 9 - 9
1 Feb 2014
Halai M Gupta S Gilmour A Bharadwaj R Khan A Holt G
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Leg length discrepancy (LLD) can adversely affect functional outcome and patient satisfaction after total hip arthroplasty. We describe a novel intraoperative technique for femoral component insertion.

We aimed to determine if this technique resulted in the desired femoral placement, as templated, and if this was associated with a reduced LLD.

A series of fifty consecutive primary total hip replacements were studied. Preoperative digital templating was performed on standardised PA radiographs of the hips by the senior surgeon. The preoperative LLD was calculated and the distance from the superior tip of the greater trochanter to the predicted shoulder of the stem was calculated (GT-S). Intraoperatively, this length was marked on the rasp handle and the stem inserted to the predetermined level by the surgeon. This level corresponded to the tip of the greater trochanter and formed a continuous line to the mark on the rasp handle. Three independent blinded observers measured the GT-S on the postoperative radiographs. We assessed the relationship between the senior author's GT-S (preoperative) and the observers' GT-S (postoperative) using a Person correlation. The observers also measured the preoperative and postoperative LLD, and the inter-observer variability was calculated as the intra-class correlation coefficient.

There was a strong correlation of preoperative and postoperative GT-S (R=0.87), suggesting that the stem was inserted as planned. The mean preoperative and postoperative LLD were −4.3 mm (−21.4–4) and −0.9 mm (−9.8–8.6), respectively (p<0.001).

This technique consistently minimised LLD in this series. This technique is quick, non-invasive and does not require supplementary equipment.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 572 - 572
1 Sep 2012
Khan A Ebreo D El Meligy M Armstrong C Peter V
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Introduction

The advantages of metal on metal (MOM) hip replacement are decreased wear rate, preservation of bone stock, anatomical restoration and enhanced stability. Large amounts of metal wear particles and metal ions are released which may induce adverse reactions including local soft tissue toxicity, hypersensitivity reactions, bone loss and risk of carcinogenesis. Aseptic loosening can be the result of a peri prosthetic osteolysis generated as a result of a biological response to particulate wear debris.

Our aim in this study was to determine whether a steeply inclined acetabular component would give rise to a higher concentration of metal ions.

Patients and methods

Between April 2003 and June 2006, 22 patients had MOM hip replacement for osteoarthritis by a single Surgeon. There were 12 male and 10 female patients. The average age at the time of surgery was 56 years (Range: 44–69 years). We divided the 22 patients into 2 groups, one group (A) of 11 patients with the acetabular inclination angle more than 50 degrees and the other group (B) of 11 patients with the angle less than 50 degrees. The inclination of the acetabular cup was measured using a standard AP radiograph of the pelvis.

The patients had metal ion levels (blood chromium and serum cobalt) measured at an average follow up of 3.2 years (Range 2.4 to 5 years).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 224 - 224
1 Sep 2012
Ebreo D Khan A El-Meligy M Armstrong C Peter V
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INTRODUCTION

The advantages of large diameter metal on metal total hip arthroplasty (MoM THA) and hip resurfacing arthroplasty are decreased wear rate, preservation of bone stock, anatomical restoration and enhanced stability. Large amounts of metal wear particles and metal ions are released which may induce adverse reactions including local soft tissue toxicity, hypersensitivity reactions, bone loss and risk of carcinogenesis. Aseptic loosening can be the result of a peri-prosthetic osteolysis generated as a result of a biological response to particulate wear debris.

No reports in the literature exist as to whether circulating levels of Chromium (Cr) and Cobalt (Co) decrease upon removal of a symptomatic large diameter MoM implant or whether levels remain high due to the effect of metal ions debris left behind in the soft tissues after revision surgery.

PATIENTS AND METHODS

Between June 2006 and June 2009 we undertook 44 revision surgeries of both large head MoM THAs (femoral head diameter 38mm) and metal-on-metal hip resurfacings for suspected metallosis. Mean time from original implant to revision was 4 years, 8 months (1yr 4mo–7yr 9mo).

The mean follow up evaluation was 2 years and 2 months (1yr 2mo–4 years). Blood samples were taken for whole blood Cr and serum Co according to a recognised protocol and compared with reference levels indicated by the Medicines and Healthcare Regulatory Agency recommendation of less than 7ppb for Cr (130nM/L) and Co (119nM/L).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVI | Pages 21 - 21
1 Aug 2012
Khan A Surrao D Waldman S
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Bioreactors used in tissue engineering are mostly batch-fed with media added and removed periodically. Continuous flow bioreactors help increase ECM accumulation and cell proliferation, due to continuous flow of fresh media, thus, maintaining a steady extracellular nutrient environment. In previous work, we found chondrocytes cultured in continuous flow bioreactors with 20mM HEPES, accumulated considerably more matrix than static cultures. Hence, the objective of this study is to determine if NaHCO3 helps maintain a more physiological extracellular pH in the bioreactor, thus, enhancing ECM accumulation.

Cartilaginous tissue constructs were generated from isolated chondrocytes harvested from the metacarpal joints of 12-18 month old calves. Cells were seeded in high-density 3D cultures (2 million cells/construct). Constructs were cultivated in a continuous flow bioreactor, with and without 14 mM NaHCO3 supplemented media, for 5 weeks, at 37 degrees Celsius, 95% relative humidity and 5% CO2. After 5 weeks of culture the tissue weight, thickness, pH and ECM deposition were determined.

From the results obtained (Table 1), it is evident that chondrocytes cultured in the continuous flow bioreactor with 14mM NaHCO3 and 20mM HEPES, proliferated more extensively and produced more ECM than chondrocytes cultured in only 20mM HEPES. Additionally, the NaHCO3 constructs accumulated ECM in both the vertical (thickness) and horizontal (outgrowth) planes. The question then arises, are the effects mediated by improved buffering, or by addition of NaHCO3 itself. There was a significant difference between the pH of media with (pH 7.41) and without NaHCO3 (pH 6.95) supplementation, with no exposure to cells or tissue; when allowed to equilibrate with 5% CO2 at 37 degrees Celsius. However, there was little difference between the media after exposure to cells; after five weeks of culture in the bioreactor (Table 1). Thus, in the bioreactor with bicarbonate present, because of increased cell number and activity, the pH fell 0.54 pH units during the 7 hour residence time in comparison to the bioreactor with no bicarbonate supplementation. With no NaHCO3 supplementation, the extracellular pH of the medium fed to the cells was never above pH 7.0 (Table 1); low pH could account, at least in part, for lower ECM and cell numbers.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 199 - 199
1 Jun 2012
Ryan M Fait J Khan A Barnes G
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Purpose

In revision hip surgery, Type IIIB femurs have presented the greatest historical challenge to achieving stable fixation and osseous integration. This study evaluated the intermediate term outcome of a modular, tapered, distal fixation revision femoral component used in a consecutive revision hip series with special attention to its performance in the defective Type IIIB femur.

Methods

Between February 2002 and January 2005, 51 consecutive revision hip arthroplasties were performed using modular, tapered, distal fixation femoral components. The femoral defects at the time of revision surgery were classified using a system previously described by Paprosky. The most recent radiographs were reviewed and clinic notes examined to assess femoral component stability.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_X | Pages 125 - 125
1 Apr 2012
Oliver W Khan A Fender D Gibson M
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Patients with peripheral primary bone tumours are often identified and referred at an early stage to a regional tumour service according to established guidelines. In patients with primary bone tumours of the spine, however, the definitive management or outcome of such patients is being prejudiced by preliminary intervention from non-specialist services prior to their referral.

Objective: To audit the standards of management of patients with primary bone tumours of the spine referred to a regional tumour service.

Retrospective review of case notes and radiology.

Subjects: Patients with primary bone tumour of the spine managed at the Orthopaedic Spine Unit with the Regional Bone Tumour Service in Newcastle Upon Tyne Hospitals NHS Trust.

Referral to tumour service, prior intervention, operative treatment, survival, factors affecting definitive management

31 of 39 (16 benign, 23 malignant) patients were initially referred from primary care to services other than the regional tumour service, most commonly neurosurgery (11/39) and paediatric oncology (4/39). Seven of 39 of these patients had undergone interventions prior to their referral to the tumour service, which may have negatively impacted their definitive management or curative surgery.

These tumours present complex issues regarding their definitive management to optimise outcome. Closer links between departments are required to enable the multidisciplinary management of primary bone tumours of the spine. Prior surgical intervention may compromise cure. Those involved in their management should be encouraged to liaise with their regional bone tumour service to improve outcome.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 297 - 297
1 Jul 2011
Jameson S Khan A Andrew L Sher L Angus W Reed M
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Background: From August 2009, all doctors were subject to the European Working Time Directive (EWTD) restrictions of 48 hours of work per week. Changes to rota patterns have been introduced over the last two years to accommodate for these impending changes, sacrificing ‘normal working hours’ training opportunities for out-of-hours service provision. We have analysed the elogbook data to establish whether operative experience has been affected.

Methods: A survey of trainees (ST3-8) was performed in February 2009 to establish shift patterns in units around the UK. All operative data entered into the elogbook during 2008 at these units was analysed according to type of shift (24hr on call with normal work the following day [traditional on call], 24hr on call then off next working day, or shifts including nights).

Results: 66% of units relied on traditional 24hrs on call in February 2009. When compared with these units, trainees working shifts had 18% less operative experience (564 to 471 operations) over the six years of training, with a 51% reduction in elective experience (288 to 140 operations). In the mid years of training, between ST3-5, operative experience fell from 418 to 302 operations (25% reduction) when shifts were introduced.

Discussion: The eLogbook is a powerful resource that provides accurate data for the purpose of supporting orthopaedic training. This national data reflects the situation in UK hospitals in 2009, prior to the implementation of a maximum of 48 hours. It is expected that most hospitals will need to convert to shift-type working patterns to fall within the law. This could have significant implications for elective orthopaedic training in the UK.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 296 - 296
1 Jul 2011
Gupta S Khan A Jameson S Reed M Wallace A Sher L
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Introduction: In August 2007, the Department of Health initiative Modernising Medical Careers was implemented. This was a system of reform and development in postgraduate medical education and training. In preparation for the changes, the SAC for T& O outlined a new curriculum. The emphasis of early training, StR years 1 and 2, was to be trauma. We aim to identify how effectively the SAC proposals are being applied, and what difference this makes to the trainees’ operative experience? Furthermore, how do the new posts compare to the historic SHO models?

Methods: A survey carried out by BOTA allowed us to assess post compliance with the SAC recommendations. A compliant job was defined as trauma based for 50% or more of working time. Consent was obtained to evaluate the eLogbooks of trainees in compliant and non-compliant jobs, along with registrars who had previously held traditional SHO grade posts. Overall operative experience over a specified 4 month time period was examined, with focus on routine trauma procedures.

Results: The results of the BOTA and SAC survey revealed that 45% of the new orthopaedic posts were compliant with curriculum guidelines. The eLogbooks of 92 individuals were analysed; 28 historical posts, 34 compliant and 30 non-compliant. The mean total number of recorded entries by trainees in the 4 month period was 73.2 in the historic group, 90.5 in the compliant and 87.3 in the non-compliant job group. The corresponding numbers of trauma operations were 35.7, 48.4 and 41.5.

Conclusions: Operative experience has improved since the introduction of the new curriculum. The new posts are offering more operative and in particular trauma exposure than traditional SHO jobs. If jobs can be restructured such that they all comply with the SAC, educational opportunities in the early years will be maximised.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 288 - 288
1 Jul 2011
Shariff R Khan A Sampath J Bass A
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Introduction: Majority of children with cerebral palsy patients suffer from fixed flexion contractures of their knees. Procedures commonly used to correct knee flexion deformities include hamstring release, anterior femoral hemiepiphyseodesis and femoral extension osteotomies. The latter procedure can cause neurovascular complications. Femoral stapling procedures are not very popular because of a theoretical risk of permanent physeal closure. We present our initial experience in correction of knee flexion deformity by using the 8-plate technique. This uses guided growth in the distal femoral physis to achieve gradual correction of the knee flexion deformity.

Materials and Methods: We reviewed a consecutive series of 25 children with fixed flexion deformity of the knee who underwent anterior femoral hemiepiphysiodesis using a two-hole plate (8-plate) between April 2005 and April 2008. The pre-operative and postoperative knee flexion deformity (in degrees) and complication rates were also recorded. Paired t-Test was undertaken to assess the correction in the fixed flexion deformity post-operatively

Results: Total number of patients – 25, male:female = 19:6. Total number of limbs – 46

The mean age of the patients was 11.04 years (range between 4–16). Mean follow up time for the patients after they had undergone the procedure was 16.2 months (range 3 – 34). The Mean correction achieved − 21.52 degrees (range 5 – 40). Mean correction per month − 2.05 degrees. A paired ‘t’ test showed the correction was found to be highly statistically significant (p value < 0.001).

Conclusion: We conclude that this is a simple technique with few complications to date. The learning curve for this procedure is 1 case. All patients in our series have shown promising results, with sustained gradual correction to date.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 261 - 261
1 Jul 2011
Upadhyay V Mahajan RH Sahu A Butt U Khan A Dalal RB
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Purpose: To assess moderate-term outcomes of silastic joint replacements of the first metatarsophalangeal joint.

Method: The thirty-two patients (37 feet) that had silastic implants inserted were reviewed at an average of 2 years and 4 months (ranging 7 months to 5 years and 4 months). The mean patient age was 63 years. These patients answered a subjective questionnaire, had their feet examined clinically and radiographically and a pre-operative and post-operative AOFAS score was calculated for each.

Results: The follow-up assessment revealed that every patient described that their pain had decreased after surgery and 17 feet (46%) were completely pain free. There was a significant improvement in patients’ subjective pain scores after surgery (t value = < 0.0001). Pre-operatively, the mean pain score for all 37 feet was 8.14, whereas post-operative the mean pain score was 1.32. The mean AOFAS score before surgery was 39.97. This increased to a mean score of 87.40 after surgery (P = < 0.0001). This again is a significant improvement. No patient was dissatisfied with the outcome with their surgery.

Conclusion: These moderate term results are encouraging, with good subjective and objective results. However, long-term follow-up will be required to assess the longevity of this implant.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 21 - 21
1 Jan 2011
Khan A Khan A Wallace W Marx C
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An online survey has been carried out to evaluate the compliance with the OCAP learning tools, and the availability of clinical experience to early years’ trainees in Trauma and Orthopaedics in 2007–8. Three surveys were planned over the year, and we present the results from the first two surveys. Over the initial eight month period, 335 trainees in Trauma and Orthopaedic posts responded. There was considerable variation in the proportion of responses from different deaneries, and it was felt this reflected differences in the use of the two logbooks available (FHI or ISCP).

Respondents were FTSTAs (50%), ST1s (11%) and ST2s (29%). The respondents reported their operative experience was poor with low numbers of index procedures – the median values being 2 DHS, 1 Hemiarthroplasty and 0 for Ankle ORIFs performed as the lead surgeon in the first 4 months, rising to 3, 1 and 1 respectively in the second. As an assistant the numbers were 3, 4 and 3. FTSTAs had done more procedures as lead surgeon. It is not clear whether this reflects motivation, or whether they are trainees who were unable to secure training posts due to seniority and were already more experienced. Many posts were entirely ward based.

Improvements in meetings with Assigned Educational Supervisors were noted, as was the use of the learning agreements, and with registration rates with the ISCP. There was considerable variation between posts, hospitals and deaneries, and a tool was developed to summarise this data to be post-, trainee-, and duration-specific. Summaries of each post were distributed to Training Program Directors, Heads of School, and the SAC. Although some improvement has occurred, further rounds of the survey are necessary to ensure that this continues. The next round will commence in September 2008 to complete twelve months of data.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 565 - 565
1 Oct 2010
Khan A Fender D Gibson M Sanderson P
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Background: Although needle tip position has been correlated with outcome with respect to pain relief, and to complication rate, to our knowledge, no previous study assesses the location of the needle tip with respect to its ability to isolate injectate around the exiting nerve root without blocking the traversing nerve root to the next caudal level.

Aim: To study the location of injectate when diagnostic selective nerve root blockade is performed.

Method: 87 consecutive selective nerve root blocks performed by a single surgeon were assessed. A consistent surgical technique was utilised. Antero-Posterior fluoroscopy films were analysed to determine the location of injectate in relation to the foraminal and pedicle anatomy. A pro-forma operation note ensured all necessary data was collected prospectively.

Results: Of needle tips positioned lateral to the middle third of the superior pedicle on the AP view, 45 of 51 flowed into the nerve sheath alone, and 6 flowed into both the nerve sheath, and spinal canal. Of these 6, 2 were due to a larger volume of contrast injected, and 2 were due to abnormal anatomy from marked lumbar degenerative scoliosis. Of tips located below the middle third of the pedicle, 2 of 29 flowed into the nerve sheath alone, 2 flowed into the canal alone, and 27 flowed into both. Of those placed medial to zone below the middle third of the pedicle, all seven flowed into the canal only. Analysis using Fisher’s Exact test yielded an extremely statistically significant result, with p < 0.001 comparing needle tip positions in the lateral position with the mid-zone and medial tip positions, and their relationship with injectate reaching the traversing nerve root.

Discussion: For a nerve root block to be truly selective, no injectate must flow past the exiting root to the traversing root. Low volumes of injectate must be placed predictably and accurately. This paper demonstrates the importance of needle tip location in preventing flow beyond the foramen. It is also recommended that contrast be used when significant deformity is present. In cases where there is a therapeutic rather than diagnostic intention, such accuracy is unnecessary. This study does not address the efficacy of the selective nerve root block as a non-operative intervention, nor does it assess the ability of the block to predict operative benefit. It does, however, provide a benchmark for accuracy achievable in patients without significant spinal deformity.

Conclusion: Care must be taken to ensure that the needle tip is positioned lateral to the zone below the middle third of the pedicle if a selective nerve root block is to be used for diagnostic purposes, particularly if there is significant deformity or no contrast is used. In the absence of deformity, however, selective nerve root block may be performed reliably, with a location accuracy of 96%.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 292 - 292
1 May 2010
Khan A Powell R Tredgett M Field J
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Aim: Subtle intra-articular screw penetration of the distal radius during fracture fixation is difficult to determine using standard PA and lateral radiographs. The purpose of our study was to determine which radiographs most reliably identify penetration into the joint.

Methods: A distal volar locking plate was applied to an isolated cadaveric radius bone and a series of plain radiographs taken. The radius, fixed along its long axis, was allowed to rotate through 180 degrees and inclined, in increments, to 40 degrees. In the control group the distal screws did not breach the articular surface. In the study group the screws penetrated the articular surface by 1mm. In each group 65 plain radiographs were taken and the presence or absence of screw penetration scored by two blinded observers.

Results: Using Weighted Kappa analysis the overall inter-observer agreement for all views was 0.5 (CI 0.39 –0.63). However in 7 radiographs there was complete inter-observer agreement correctly identifying screw penetration of the articular surface. The articular surface was correctly identified as intact in 13 views. Only a 75 degrees pronated view, without inclination, was 100% sensitive and specific for identifying the absence or presence of screw penetration through the articular surface.

Conclusion: The intra-operative use of a 75 degrees pronated view may reduce the need for repeated use of the image intensifier and excessive irradiation during plate fixation of distal radius fractures.