Abstract

Aims

Postoperative delirium (POD) and postoperative cognitive decline (POCD) are common surgical complications. In the UK, the Best Practice Tariff incentivizes the screening of delirium in patients with hip fracture. Further, a National Hip Fracture Database (NHFD) performance indicator is the reduction in the incidence of POD. To aid in its recognition, we sought to determine factors associated with POD and POCD in patients with hip fractures.

The burden of metastatic bone disease (MBD) in our Canadian cancer population continues to increase. MBD has a significant effect on patient morbidity, mortality, and health-related quality of life (HRQOL). There are various technical options used to surgically stabilize MBD lesions, surgical decision-making is variable and largely dependent on anatomic and surgeon-based factors. There is a paucity of research examining how surgical decision-making for MBD can be modified or individualized to improve quality of life (QOL) and functional outcomes, while more accurately aligning with patient-reported goals and expectations. The objective of this study was tosurvey MBD patients, support persons, physicians, and allied health care providers (HCP) with the goal of identifying 1) important contributors to HRQOL, 2) discordance in peri-operative expectations, and 3) perceived measures of success in the surgical management of MBD.

This project is a longitudinal patient-engaged research initiative in MBD. A survey was developed based on HRQOL themes in the literature and based on feedback from our patient research partners. Participants were asked to identify 1) important contributors to HRQOL and 2) perceived measures of success relevant to the surgical management of MBD. Participants were asked to rank themes from ‘extremely important’ to ‘not important at all’. Using open-ended questions, participants were asked to identify areas of improvement. Responses from the open-ended questions were analyzed by an experienced qualitative researcher using conventional content analysis. Participant's demographics were calculated using descriptive statistics. Concordance or discordance of perceived measure of success was assessed via a Chi-Square test of independence. All statistical analyses were performed using IBM SPSS® software.

Nine patients, seven support persons, 23 orthopaedic surgeons, 11 medical oncologists, 16 radiation oncologists, 16 nurses, and eight physiotherapists completed the survey. Regarding perceived measures of success, increased life expectancy (p Two main themes emerged around the timeliness of surgical care and the coordination of multidisciplinary care from patients and support persons. Patients and support persons expressed a sense of urgency in progressing to surgery/treatment, and frustration at perceived delays in treatment. Within coordination of care, patients and support persons would like clearer communication from the health care team.

There is discordance between patient/support person goals compared to physicians/HCP goals in the surgical management of MBD. Surgical decision-making and operative techniques that minimize disease progression and improve survival are important to MBD patients. Timely access to surgery/surgical consultation and improved multidisciplinary communication is important to patients. This data suggests improved peri-operative communication and education is needed for MBD patients. Furthermore, future research evaluating how modern orthopaedic surgical techniques influence survival and disease progression in MBD is highly relevant and important to patients with MBD.

Aims

The aim of this study was to assess the feasibility of conducting a full-scale, appropriately powered, randomized controlled trial (RCT) comparing internal fracture fixation and distal femoral replacement (DFR) for distal femoral fractures in older patients.

Introduction

The performance of total hip replacement (THR) devices can be affected by the quality of the tissues surrounding the joint or the mismatch of the component centres during hip replacement surgery. Experimental studies have shown that these factors can cause the separation of the two components during walking cycle (dynamic separation) and the contact of the femoral head with the rim of the acetabular liner (edge loading), which can lead to increased wear and shortened implant lifespan¹. There is a need for flexible pre-clinical testing tools which allow THR devices to be assessed under these adverse conditions. In this work, a novel dynamic finite element model was developed that is able to generate dynamic separation as it occurs during the gait cycle. In addition, the ability to interrogate contact mechanics and material strain under separation conditions provides a unique means of assessing the severity of edge loading. This study demonstrates these model capabilities for a range of simulated surgical translational mismatch values, for ceramic-on-polyethylene implants.

Introduction

Enhanced Recovery Protocol (ERP) for elective total hip or total knee replacement has become the gold standard. The main principles are to reduce bleeding, both with a tranexamic acid infusion and local injection of adrenaline, and to reduce the risk of postoperative thrombo-embolic complications by early mobilisation, enabled by local anaesthetic infiltration at time of surgery. The aim of this study is to evaluate the impact of the ERP.

Introduction

Segmental tibia fractures are high-energy injuries that are difficult to treat. We report on the use of the Ilizarov Method to treat 40 consecutive AO42C (35) and AO42B3 (5) fractures by a single surgeon. Fractures with bone loss requiring transport were excluded, as were fractures initially treated with nail or plate.

We report on the use of the Ilizarov method to treat 40 consecutive fractures of the tibial shaft (35 AO 42C fractures and five AO 42B3 fractures) in adults. There were 28 men and 12 women with a mean age of 43 years (19 to 81). The series included 19 open fractures (six Gustilo grade 3A and 13 grade 3B) and 21 closed injuries. The mean time from injury to application of definitive Ilizarov frame was eight days (0 to 35) with 36 fractures successfully uniting without the need for any bone-stimulating procedure. The four remaining patients with nonunion healed with a second frame. There were no amputations and no deep infections. None required intervention for malunion. The total time to healing was calculated from date of injury to removal of the frame, with a median of 166 days (mean 187, (87 to 370)). Minor complications included snapped wires in two patients and minor pin-site infections treated with oral antibiotics in nine patients (23%). Clinical scores were available for 32 of the 40 patients at a median of 55 months (mean 62, (26 to 99)) post-injury, with ‘good’ Olerud and Molander ankle scores (median 80, mean 75, (10 to 100)), ‘excellent’ Lysholm knee scores (median 97, mean 88, (29 to 100)), a median Tegner activity score of 4 (mean 4, (0 to 9)) (comparable to ‘moderately heavy labour / cycling and jogging’) and Short Form-12 scores that exceeded the mean of the population as a whole (median physical component score 55 (mean 51, (20 to 64)), median mental component score 57 (mean 53, (21 to 62)). In conclusion, the Ilizarov method is a safe and reliable way of treating complex tibial shaft fractures with a high rate of primary union.

The relationship between hindfoot and forefoot kinematics is an important factor in the planning of ankle arthrodesis and ankle arthroplasty surgery. As more severe ankle deformities are corrected, improved techniques are required to assess and plan hindfoot to forefoot balancing.

Gait analysis has previously been reported in patients with ankle arthritis without deformity. This group of patients have reduced intersegment motion in all measured angles. We have looked at a small group of patients with hindfoot deformity and ankle arthritis awaiting fusion or replacement.

Using the Oxford Foot Model we have assessed lower limb kinematics with a focus on hindfoot to forefoot relationships. The results of our pilot study are in variance to previous studies in that we have shown that in the presence of hindfoot/ankle deformity, the forefoot range of motion increases. We feel that these data may impact on surgical planning.

Controversy exists whether to treat unstable pertrochanteric hip fractures with either intra-medullary or extra-medullary devices. A prospective randomised control trial was performed to compare the outcome of unstable pertrochanteric hip fractures stabilised with either a sliding hip screw or long Gamma Nail. The hypothesis was that there is no difference in outcome between the two modes of treatment.

Over a four year period, 210 patients presenting with an unstable pertrochanteric hip fracture (AO/OTA 31 A2) were recruited into the study. Eligible patients were randomised on admission to either long Gamma Nail or sliding hip screw. Follow-up was arranged for three, six, and twelve months. Primary outcome measures were implant failure or ‘cut-out’. Secondary measures included mortality, length of hospital stay, transfusion rate, change in mobility and residence, and EuroQol outcome score.

Five patients required revision surgery for implant cut-out (2.5%), of which three were long Gamma Nails and two were sliding hip screws (no significant difference). There were no incidences of implant failure or deep infection. Tip apex distance was found to correlate with implant cut-out. There was no statistically significant difference in either the EuroQol outcome scores or mortality rates between the two groups when corrected for mini mental score. There was no difference in transfusion rates, length of hospital stay, and change in mobility or residence. There was a clear cost difference between the implants.

The sliding hip screw remains the gold standard in the treatment of unstable pertrochanteric fractures of the proximal femur.

Introduction

Anterior cruciate ligament (ACL) rupture is a common sporting injury, often managed surgically with patella-tendon or hamstrings autograft. Surgeons are under increasing pressure for open transparent assessment of their performance. Scoring systems can be used to assess outcome. More than 50 different scoring systems have been identified to assess the ACL deficient knee.

Background

Traditional measurements of hindfoot alignment are based on the tibio-calcaneal angle and do not take the forefoot into account. We have developed an algorithm based on standard radiographs to calculate calcaneal offset using Ground Reaction Force (GRF).

Purpose

Investigate the functional outcome of medial patellofemoral ligament (MPFL) surgery for patella instability.

Compare functional outcome of direct MPFL repair and reconstruction using hamstring graft.

Background

The Plantaris Longus Tendon (PLT) may be implicated in Achilles (AT) tendinopathy. Different mechanical characteristics may be the cause. This study is designed to measure these.

Introduction

Trochanteric bursitis is described as pain over the lateral side of the hip and thigh. The usual treatment is rest, administration of NSAIDs and injection of local anaesthetic and corticosteroid. Occasionally it is resistant to these measures.

Aim: The purpose of this study was to evaluate the results of transphyseal ACL reconstruction technique in skeletally immature patients.

Material & Methods: Between 2002 and 2008, twenty knees in twenty skeletally immature patients with a mean chronological age of 13.2 years (range, 7 to 16.2 years) underwent transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft with metaphyseal fixation. Ten knees had additional meniscal surgery. The functional outcome, graft survival, radiographic outcome, and any growth disturbance were evaluated at a mean of 2.2 years (range, 1.0 to 5.9 years) after the surgery.

Results: No patient underwent revision anterior cruciate ligament reconstruction. The mean International Knee Documentation Committee subjective knee score (SD) was 90.5 (10.0) points and the mean Lysholm knee score was 92.2 (10.0) points. The result of the Lachman examination was normal in 18 knees and nearly normal in two; it was not abnormal or severely abnormal in any knee. The mean increase in total height was 7.2 cm (range, 1.2 to 20.4 cm) from the time of surgery to the time of final follow-up. No angular deformities of the lower extremity were measured radiographically, and no lower-extremity length discrepancies were measured clinically. Complications included one case of knee stiffness requiring physiotherapy, one case of persistent pain leading to medial menisectomy for tear and one case of re-injury five months post ACL reconstruction requiring medial meniscus repair.

Conclusion: Excellent functional outcome was noted in skeletally immature patients after transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft with metaphyseal fixation. There were very few complications and no growth disturbance.

Controversy exists whether to treat unstable pertrochanteric hip fractures with either intramedullary or extramedullary devices. A prospective randomised control trial was performed to compare the outcome of unstable pertrochanteric hip fractures stabilised with either a sliding hip screw (SHS) or Long Gamma Nail (LGN). The hypothesis was that there is no difference in outcome between the two modes of treatment.

Over a four year period, 210 patients presenting with an unstable pertrochanteric hip fracture (AO/OTA 31 A2.1/A2.2/A2.3) were recruited into the study. Eligible patients were randomised on admission to either LGN or SHS. Follow-up was arranged for three, six, and twelve months. Primary outcome measures were implant failure and implant ‘cut-out’. Secondary measures included mortality, length of hospital stay, and EuroQol outcome score.

Five patients required revision surgery for implant cutout, of which three were LGNs and two were SHSs (no significant difference). There was a significant correlation between tip apex distance and the need for revision surgery. There were no incidences of implant failure or deep infection. Mortality rates between the two groups were similar when corrected for mini mental score. There was no difference between the two groups with respect to tip apex distance, hospital length of stay, blood transfusion requirement, and EuroQol outcome score.

The sliding hip screw remains the gold standard in the treatment of unstable pertrochanteric fractures of the proximal femur.

Introduction: Computational modelling of the spine offers a particularly difficult challenge to analysts due to its complex structure and high level of functionality. Previous studies [Wijayathunga, 2008; Jones, 2007] have shown that finite element (FE) predictions of vertebral stiffness are highly sensitive to the applied boundary conditions and therefore validation requires careful matching between the experimental and simulated situation. The aim of this study was to develop and experimentally validate specimen specific FE models of porcine vertebrae in order to accurately predict the stiffness of single vertebra specimens.

METHOD: Nine single vertebra specimens were excised from the thoracolumbar region of two porcine spines. The specimens were mounted between two parallel PMMA housings and each specimen was imaged using a micro computed tomography (μCT) system (μCT80; Scanco Medical, Switzerland). In order to accurately match the experimental conditions, a radio-opaque marker was positioned on the specimen housing at the point of load application. The vertebrae were separated into two groups: a development set (set 1) consisting of three specimens and a validation set (set 2) of six specimens. Specimens from set 1 were used to establish the optimum method of conversion from image greyscale, to element material properties. The models in set 2 were used to assess the accuracy of the stiffness predictions for each model. The vertebrae were tested in a materials testing machine (AGS-10kNG; Shimadzu Corp., Japan) under axial compression and the stiffness for each specimen was calculated. The μCT data was imported into an image processing package (Scan IP, Simpleware, UK). The software enabled the images to be segmented and the vertebra, cement housings and position of load application to be identified. The segmented images were down-sampled to 1mm voxels, enabling a FE mesh to be generated (Scan FE; Simpleware, UK) based on direct voxel to element conversion. The Young’s modulus of each bone element was assigned, based on the greyscale of the corresponding image voxel. The PMMA housing plates were assigned homogeneous material properties (E = 2.45 GPa). Abaqus CAE 6.8 (Simula, Providence, Rhode Island, USA) was used for the processing and post-processing of all the models.

Results: The mean experimental stiffness was 4321 N/ mm (standard deviation = 415 N/mm). The optimum conversion factor was calculated for set 1, which yielded a root mean squared (RMS) percentage error of 7.5% when compared with the experimental stiffness. Using this optimised scale factor, FE models of specimens from set 2 were created. The predicted stiffnesses for set 2 were compared to the corresponding experimental values and yielded an RMS error of 10.1%.

Conclusion: The results indicate that specimen specific models can provide good agreement with the corresponding experimental specimen stiffness. In addition, the method employed in this study proved robust enough to be applied to vertebral tissue obtained from different animals of the same species. This method will now be developed to assess treatments for traumatic spinal injuries.

The main objective of our review was to access the inter-net websites providing information on non operative treatment of scoliosis and to assess the evidence for each treatment in the medical literature.

Methods: We identified top five search engines at the site www.searchengines.com. The search term “scoliosis treatment” was entered into each search engine. The websites were reviewed and each search engine produced from 145,354 to 5460,000 results. We identified twenty non operative treatments for scoliosis. We further evaluated and studied these non operative treatments by using each treatment as a search term. The accuracy of these treatments was checked by doing a medical literature review. We used Medline 1950 to November 2008 and Embase 1980 to November 2008.

Results: 260 websites were duplicated in the five search engines, 103 websites only mentioned surgical treatment of scoliosis, and 10 websites could not be accessed at the time of the study. We evaluated the remaining 127 websites using the key words “scoliosis treatment” to generate a list of twenty unique non operative scoliosis treatments. These treatments when entered individually into the search engines enabled us to produce a list of these treatments in decreasing order of frequency. This was based on the number of results that each treatment generated.

These treatments were then entered for search in Medline and Embase, only 45% (9/20) of these treatments were found to have been described in the medical literature.

Conclusion: Our study did reveal that information on non operative treatment of scoliosis leaves much to be desired. Based on this study we recommend that it is the duty of the treating surgeon to warn the patients of the potential danger of misinformation that is abundant on the internet.

Ethics approval: None

Interest Statement: None

Spinal lipomatosis is seldom reported in spinal literature and although the condition occurs commonly, we seldom recognise it in reviewing spinal MRI scans. We aim to highlight the condition and show MRI signs to allow easier recognition. We also introduce a new method of evaluation of the severity of the condition using T1 MRI axial views to evaluate the area of the spinal canal involved in the pathological process.

We have evaluated 30 patients with a diagnosis of spinal lipomatosis made on sagittal MRI scanning of the spine. The T1 and T2 axial images have been evaluated using standard digital software which allows calculation of the surface area occupied by fat and allows representation of this as a ratio to total canal diameter. This has then been correlated to the traditional method of classifying lipomatosis on sagittal MRI sequences.

We have found this method useful and believe it provides a more accurate representation of how fat in the canal may produce symptoms of nerve compression. This shows that the condition behaves more like our traditional understanding of spinal stenosis with symptoms more likely when the relationship of fat to canal reaches greater than 50%. This approach to spinal lipomatosis has not been described before but we feel produces a better understanding of the condition than we have had before by using a classification based on purely on sagittal MRI sequences.

Ethics approval: None Audit

Interest Statement: No conflict of interest

To identify changes in curve magnitude in patients with degenerative scoliosis between the lying and standing positions.

Thirty five patients who underwent surgical correction of a degenerative scoliosis were identified. The pre-operative standing antero-posterior radiographs were compared with the coronal MRI images and Cobb angles measured.

The mean patient age was 64 years old. The mean increase in Cobb angle in the degenerative curve on standing was ten degrees. This was not associated with age or magnitude of curve.

A degenerative scoliosis is often considered inflexible. These results show that such curves do retain some flexibility and therefore patients may present with dynamic symptoms not represented on supine MRI images. Furthermore, pre-operative supine radiographs will identify the degree of flexibility that can be expected intra-operatively.

Ethics approval: none

Interest statement: none

Theatre discipline remains a vital adjunct in the fight against infection in joint replacement surgery. The aim of this audit was to compare local theatre practise in two hospitals with that which is recommended in the literature. Factors assessed included the correct use of the ‘plenum’, the application of hats and masks, the opening of theatre doors intra-operatively, and the number of staff in the theatre.

Results suggest that basic principles and practises of theatre antisepsis are not being adhered to during joint replacement surgery. Suggestions are made as to how theatre behaviour may be improved in order to optimise the operating environment.

Introduction: Radial shortening has been associated with a poor functional outcome following a fractured distal radius. Traditionally, outcome has been measured using doctor-based scores such as the Gartland and Werley Scoring System or modifications thereof.

Aims: The aim of this study is to compare patient based outcome scores with the Frykman class of the fracture and radial shortening both at injury and fracture union.

Methods: We followed up 60 patients over 55 who underwent closed reduction and k-wire fixation of distal radial fractures. Outcome was recorded by the Patient Rated Wrist Evaluation (PRWE) score, a validated subjective outcome measure.

Results: No association was found between radial shortening either at injury or fracture union with subjective outcome score but there was a significant association between Frykman Classification and outcome (p< 0.05).

Discussion: Our results showed that for distal radius fractures that united with a moderate degree of radial shortening, increasing Frykman Class was associated with a worse functional score.

Introduction: Displaced Colles’ fractures are usually managed by closed reduction and cast immobilisation. They are reduced initially but frequently lose position because cast immobilisation is an inefficient means of stabilisation. This results in malunion. If position is lost after reduction and cast immobilisation or the fracture is unstable, closed reduction and cast immobilisation is often supplemented by longitudinal k-wire fixation. There is a paucity of literature examining the incidence of unacceptable malunion after closed reduction and k-wire stabilisation.

Aim: The aim of this study was to determine whether closed reduction, longitudinal k-wire fixation and cast immobilisation of displaced fractures of the distal radius avoids unacceptable malunion. A secondary aim was to define the type of fracture best treated by this method.

Methods: 53 patients underwent closed reduction and longitudinal k-wiring of displaced Colles’ fractures and were reviewed after a mean of 26 months. Radiographs taken at the time of injury, after reduction and k-wiring, and at fracture union were compared for radial shortening and dorsal angulation.

Results: Manipulation significantly improved fracture position (p< 0.001). Dorsal angulation was successfully corrected by manipulation in 98%, and this position was maintained to fracture union in all cases. 73% of fractures manipulated for radial shortening > 2mm were adequately reduced, but 41% of these fractures subsequently lost position to malunite. The mean shortening between reduction and fracture union was 1.6mm. This did not correlate with Frykman Class or radial shortening at injury.

Discussion: Closed Reduction and k-wire stabilisation is an attractive technique because it is relatively non-invasive compared with plating or external fixation. However, a degree of radial shortening between reduction and fracture union must be anticipated. Fractures not reduced to allow for this later loss of radial length are more likely to malunite. This may compromise functional outcome.

Purpose: To review long-term outcome following knee arthrodesis, and compare this with patient outcome following revision knee arthroplasty.

Methods: Case notes and radiographs of patients who underwent arthrodesis using the Mayday nail were reviewed retrospectively for evidence of clinical and radiological union. Patients also completed an SF12 health survey and Oxford knee score in the form of postal questionnaires. Each patient was matched with patients who had undergone revision knee arthoplasty and the outcomes were compared.

Results: 19 patients were reviewed who underwent knee arthrodesis using a Mayday nail in two centres between 1993 and 2004. 18 cases had united clinically and radiologically with one case lost to follow-up. Mean SF12 scores of patients following knee arthrodesis indicated severe physical (28.8) but only mild mental (43.3) disabilities. The mean Oxford knee score in this group was 41.0. These results were comparable with matched patients following revision knee arthroplasty who scores 27.2 (physical) and 41.1 (mental) on the SF12, and a mean of 38.8 on the Oxford knee score.

Conclusion: Outcome scores following knee arthrodesis were similar to those following revision knee arthroplasty making it an option worth considering in selected patients requiring revision surgery.

Discussion: The Mayday nail provides a method of knee arthrodesis with a high union rate and an acceptable complication rate. Outcome scores following arthrod-esis were not dissimilar to those following revision total knee replacement. These results suggest that knee arthrodesis may be considered as an acceptable alternative to complex knee revision surgery.

Hip and knee arthroplasty has been associated with relatively high rates of thromboembolic events and the majority of UK orthopaedic surgeons use at least one form of prophylaxis. Of the many different subgroups of thromboembolic rates that are commonly presented in the literature, symptomatic proximal deep vein thrombosis (spDVT) and fatal pulmonary embolism (fPE) are perhaps the most important clinical outcomes.

To determine the effectiveness of common chemical and mechanical prophylactic methods in preventing spDVT and fPE in patients undergoing primary hip and knee arthroplasty. A systematic review of the literature from 1981 to December 2002 was performed. Predetermined inclusion and exclusion criteria were applied. Studies where more than one method of prophylaxis was used were excluded from analysis. For each individual method of prophylaxis, data was extracted, combined and converted to give estimates of the rates of spDVT, fPE and major bleeding events. Absolute risk reduction estimates for spDVT, fPE and major bleeding events were calculated by comparing the thromboembolic rates for each method of prophylaxis with using no prophylaxis of any kind.

992 studies were identified of which 162 met the inclusion criteria. No method of prophylaxis was statistically significantly more effective at preventing spDVT and fPE than using nothing. There were at least as many major bleeding complications as spDVTs. The number of fPEs prevented was very small.

When complications such as major bleeding are considered, the evidence behind the use of any prophylaxis is unconvincing.

53 patients underwent closed reduction and longitudinal k-wiring of displaced Colles’ fractures and were reviewed after a mean of 26 months. Radiographs taken at the time of injury, after reduction and k-wiring, and at fracture union were compared for radial shortening and dorsal angulation. Manipulation significantly improved fracture position (p< 0.001). Dorsal angulation was successfully corrected by manipulation in 98%, and this position was maintained to fracture union in all cases. 73% of fractures manipulated for radial shortening > 2mm were adequately reduced, but 41% of these fractures subsequently lost position to malunite. The mean shortening between reduction and fracture union was 1.6mm. This did not correlate with Frykman Class or radial shortening at injury.

Closed Reduction and k-wire stabilisation is an attractive technique because it is relatively non-invasive compared with plating or external fixation. However, a degree of radial shortening between reduction and fracture union must be anticipated. Fractures reduced inadequately to allow for this loss of radial length, are more likely to malunite.

This may compromise functional outcome.

Introduction: The anterior drawer test for anterior cruciate ligament (ACL) deficiency, requires a subjective assessment of joint movement, as the tibia is pulled forward. The aim of this study was to objectively quantify this movement using a magnetic tracking device.

Materials and Methods: Ten patients aged 24 to 44 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then re-assessed using a magnetic tracking device (Polhemus Fastrak). Patients had magnetic sensors attached around their femurs and tibias using elasticated Velcro straps. The Anterior Drawer test was then performed with the patient lying within range of the system’s magnetic source. The test was performed three times on the normal and injured knees of each patient, using a spring balance to apply a standard 20 lb (=89 N) force. During the tests, sensor position and orientation data was collected with an accuracy better than 1 mm and 1 degree, respectively. The data was sampled at 10Hz and stored on a computer for post-test analysis. This analysis deduced the tibial displacement resulting from each anterior drawer.

Results: During the anterior drawer test the supine patient’s knee is in 90 degrees flexion, with the foot planted on the examination couch. As the tibia is pulled anteriorly, it rotates upwards from the foot and the femur experiences a corresponding rotation from the hip. These complex coupled movements are best quantified in terms of absolute displacement of the tibia from the femur. In the normal knees, the mean displacement of the tibia from the femur was 4.2 mm (SD=1.6). In comparison the ACL deficient knees had a mean displacement of 6.3 mm (SD=2.9). This is 50 % more. A paired t test of this data showed a highly significant difference, with P = 0.005.

Conclusion: This study has quantified the movement produced during the Anterior Draw test for ACL deficiency. The tracker’s lightweight sensors caused minimal disturbance to the established clinical test. The system therefore provides objective measurement data to augment the clinicians subjective assessment.

Introduction: Spinal cord injury (SCI) continues to challenge the healthcare and the adjunct social welfare systems. Significant advances have been made in our understanding of the pathological cascade following the initial insult. However, this has yet to be translated into clinically significant treatments and one possible reason for this is that little is known about the actual interaction between the cord and the spinal column at the moment of impact; a factor that is becoming increasingly recognised as important. Burst fractures are a common cause of SCI and are sufficiently well defined to allow significant advances to be made in developing laboratory models of the fracture process. Following on from these advances an in-vitro model of the interaction between the cord and burst fracture fragment was developed and used to perform preliminary experiments to establish those factors that are important in determining the extent of probable cord damage.

Methods: A rig was developed that reliably reproduced a range of fragment-cord impact scenarios previously observed in the development of a model of the burst fracture process. In summary, a simulated bone fragment of mass 7.2 g was fired, transversely, at explanted bovine cord (within 3 hours of slaughter) with a velocity of 2.5, 5.0 or 7.5 ms-1. The cords were mounted in a tensile testing machine using a novel clamping system and held at 8 % strain. A surrogate posterior longitudinal ligament (PLL) was included and simulated in three biomechanically relevant conditions: absent, 0 % strain and 14 % strain. The posterior elements were represented by an anatomically correct surrogate. The impacts were recorded by using either a high speed video camera (4500 frames/s) or a series of fine pressure transducers.

Results: The fragments were recorded to undergo the same occlusion profile as previously reported in the burst fracture model, except that the cord itself reduced the level of maximum occlusion possible. All tests displayed the fragment recoiling following maximum occlusion. The maximum occlusion and the time to this position were found to be significantly dependent on both the fragment velocity and the condition of the PLL. Similar results were observed for peak pressure. One surprising result was that maximum occlusion or time to this event did not change with or without the cord being encased in the dura mater; a structure that is thought to protect the cord from external impacts.

Discussion: The model developed here of the cord-column interaction for the burst fracture produced useful initial insights into the factors that affect the impact on the cord. The PLL has a significant role to play in both reducing the peak pressures and the spreading the energy imparted over a longer period. The model has several areas in which it could be improved and these include 1) the incorporation of the perfusion pressure which tends to hydraulically stiffen the cord and 2) the inclusion of the cerebrospinal fluid, which may operate in unison with the dura in protecting the cord from impacts. Future work includes the incorporation of the CSF into the model, the development of surrogate cords and the generation of computational models using novel programming techniques.

Introduction: The Lachman test for anterior cruciate ligament (ACL) deficiency, requires a subjective assessment of joint movement, as the tibia is pulled anteriorly. This study has objectively quantified this movement using a magnetic tracking device.

Materials and Methods: Ten patients aged 21 to 51 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then reassessed using a magnetic tracking device (Polhemus Fastrak). Patients had magnetic sensors attached around the femoral and tibial mid-shafts using elasticated Velcro straps. The Lachman test was then performed with the patient lying within range of the system’s magnetic source. The test was performed three times on the normal and injured knees of each patient. During the tests, sensor position and orientation data was collected with an accuracy better than 1 mm and 1 degree, respectively. The data was sampled at 10Hz and stored on a computer for post-test analysis. This analysis deduced the tibial displacement resulting from each Lachman pull.

Results: The main Lachman movement is an anterior displacement of the tibia with respect to the femur. The mean anterior movement for the normal knees was 5.6 mm (SD=2.5). By comparison the ACL deficient knees had a mean anterior movement of 10.2 mm (SD=4.2). This is 82 % more. A paired t test of this data showed it to be highly significant with P = 0.005. In addition to the anterior movement, there was also a small proximal tibial movement. In the normal knees the mean movement was 0.7 mm (SD=1.9). In the injured knees the mean movement was 2.1 mm (SD=3.4). However, this difference was not significant (P = 0.12).

Conclusion: This study has quantified the movement produced during the Lachman test for ACL deficiency. The results compare well with reported results from similar arthrometer tests[1]. The main advantage of the magnetic tracker is that its lightweight sensors cause minimal disturbance to the established clinical test. It therefore offers a convenient and non-invasive method of investigation.

Purpose: To evaluate the clinical results after meniscal repair using Bionx arrows.

Methods: The study reports the clinical results of 50 patients who had meniscal repair.

The meniscal repairs were carried out by a single surgeon over a period of 4 years.

30 patients ( 1st set) had isolated meniscal repairs. 9 patients ( 2nd set) had meniscal repairs and ACL reconstruction at the same time. 11 patients (3rd set) had meniscal repair followed by ACL reconstruction few months later. The patients were seen in the clinic at 2, 6, 24 weeks post surgery and then kept under surveillance.

Results: In the 1st set , there were only 2 failures who needed partial menisectomy at 7 months and 2 years respectively after the initial repair. So, the failure rate is only 6.6%.

There was only 1 failure in the 2nd set who needed partial menisectomy 19 months post repair. This gives it a failure rate of 11.1%. In the 3rd set, there were 2 failures out of whom one needed partial menisectomy and other needed re-repair using the arrows at 3 and 7 months respectively post repair at the time of ACL reconstruction, a failure rate of 18.8%.

There has been speculation as to whether the outcome of revision total knee arthroplasty (TKA) is as successful as primary TKA. The purpose of this study was to assess patient outcomes following revision TKA and compare them to patient outcomes following primary TKA.

This study collected data prospectively from patients operated upon by one surgeon using one prosthesis in each group. Patients completed SF12 and WOMAC questionnaires pre-operatively and at six and twelve months post-operatively. In the primary TKA group there were 84 patients. In the revision TKA group there were 60 patients. Statistical analysis was performed using paired and unpaired t-tests.

Results showed that the improvements in SF12 physical scores and WOMAC pain, stiffness and function scores in both primary TKA and revision TKA patients were statistically significant (p < 0.0001). There was no significant difference in the magnitude of the improvement in SF12 physical (p = 0.7145) and WOMAC pain (p = 0.0902), stiffness (p = 0.1557) and function (p = 0.3152) scores between the primary and revision patients following surgery.

The mental scores of patients in both groups showed no significant difference following surgery (Primary p = 0.823, Revision p = 0.7095).

The findings show that primary and revision TKA lead to a comparable improvement in patient perceived outcomes of physical health parameters.

However, there is no significant improvement in patient perception of mental health.

There has been speculation as to whether the outcome of revision total knee arthroplasty (TKA) is as successful as primary TKA, this study was designed to compare the outcomes of primary and revision TKA in order to address this question.

The study collected data prospectively from patients operated upon by one surgeon using one prosthesis design in each group. All patients undergoing revision TKA between 1997 and 2000 were included in the study. 100 consecutive patients undergoing primary TKA between 1997 and 1999 were included in the study. All surgery was performed by the senior author.

Patients completed SF-12 and WOMAC questionnaires pre-operatively and at six and twelve months post-operatively. Mean scores were calculated for the different areas within both outcome measures (WOMAC pain, stiffness and function; SF-12 – physical constant score [PCS] and mental constant score [MCS])

The results were entered into a database and analysed using a combination of two way and simple repeated measures analysis of variance (ANOVA) and t-tests. Only if the result of the ANOVA was significant were post-hoc adjusted t-tests performed on the data values.

WOMAC scores did not differ between the two groups pre-operatively. Both patient groups showed a significant improvement in WOMAC scores at six months (P< 0.0005). In the primary group the pain and function scores improved significantly between six and twelve months (P=0.0258 and P=0.0019 respectively). This was not the case in revision patients.

SF-12 PCS scores were significantly better in the primary patients pre-operatively (P< 0.0005). Both groups showed a significant improvement at six months assessment (P< 0.0005). Neither group demonstrated an improvement between six and twelve months. SF-12 MCS scores did not show any difference between the two groups pre-operatively. No significant change in MCS score occurred during the study in either the primary or revision patients.

The SF-12 and WOMAC health questionnaires are valid, reliable and responsive outcome measures. The study has collected data prospectively from patients operated upon by one surgeon using one prosthesis design in each group. These findings support the concept that revision TKA leads to a comparable improvement in patient perceived outcomes of physical parameters as does primary TKA in both generic health outcome measures and disease specific outcome measures.

There has been speculation as to how the outcome of revision total knee arthroplasty (TKA) compares with that of primary TKA. We have collected data prospectively from patients operated on by one surgeon using one prosthesis in each group. One hundred patients underwent primary TKA and 60 revision TKA. They completed SF-12 and WOMAC questionnaires before and at six and 12 months after operation.

The improvements in the SF-12 physical scores and WOMAC pain, stiffness and function scores in both primary and revision TKA patients were highly statistically significant at six months. There was no statistically significant difference in the size of the improvement in the SF-12 physical and WOMAC pain, stiffness and function scores between the primary and revision patients at six months after surgery. The SF-12 mental scores of patients in both groups showed no statistically significant difference after surgery at the six- and 12-month assessments.

Our findings show that primary and revision TKA lead to a comparable improvement in patient-perceived outcomes of physical variables in both generic and disease-specific health measures at follow-up at one year.

Acute fractures of the scaphoid were randomly allocated for conservative treatment in a Colles’-type plaster cast with the wrist immobilised in either 20° flexion or 20° extension. The position of the wrist did not influence the rate of union of the fracture (89%) but when reviewed after six months the wrists which had been immobilised in flexion had a greater restriction of extension. We recommend that acute fractures of the scaphoid should be treated in a Colles’-type cast with the wrist in slight extension.

We carried out a prospective randomised study comparing medial epicondylectomy with anterior transposition for the treatment of ulnar neuropathy at the elbow. The mean follow-up period was 4.5 years and we assessed the patients neurologically and orthopaedically.

Neither procedure appeared to have a significant effect on elbow function. Our study showed better results after medial epicondylectomy; in particular patient satisfaction was higher than after ulnar nerve transposition. There were no significant differences in motor power or nerve-conduction rates and sensory fibres appeared to be more vulnerable to devascularisation.

We have assessed the results of 34 simple excisions of the trapezium, with no additional soft-tissue procedures, in 30 patients. At a median follow-up of five years (2 to 22), 16 thumbs (47%) were completely painfree and a further 10 (29%) were slightly painful after use. Nineteen thumbs (56%) had no functional disability, but thumb-pinch strength was reduced by about 20%. No patient had painful degeneration at the scaphotrapezial pseudarthrosis.

Fracture of the tuberosity of the scaphoid is common and usually heals without incident because of the good blood supply. We report four cases of nonunion of this fracture. Three of them were symptomatic and two required operative treatment.

Four patients with pectoralis major ruptures underwent clinical and dynamometric assessment and one patient underwent late surgical repair. The operation is described. Dynamometry proved a useful and objective method of estimating the loss of strength and indicating patients who might benefit from surgical repair.

Immobilisation of the thumb is widely believed to be important in the management of fractures of the carpal scaphoid. To assess the need for this, we randomly allocated 392 fresh fractures for treatment by either a forearm gauntlet (Colles') cast, leaving the thumb free, or by a conventional 'scaphoid' plaster incorporating the thumb as far as its interphalangeal joint. In the 292 fractures which were followed for six months, the incidence of nonunion was independent of the type of cast used.

Twenty observers reported independently on the presence or absence of a fracture of the scaphoid on 60 sets of radiographs; these included initial and 2- to 3-week views in patients in whom the outcome was known, normal scaphoids and random copies of these. Analysis of variance of the accuracy of observations revealed that the 2- to 3-week radiographs did not improve diagnostic ability and that this was independent of the experience or seniority of the observer. For normal radiographs, 20% of the observations reported a fracture. Reproducibility of opinion improved with experience but this did not help with accuracy. Radiographs without accurate clinical observation should not determine the management of the suspected scaphoid fracture.

Twenty-four cases of complete division of median or ulnar nerves were assessed on two occasions after direct suture, with an interval of three years between assessments. Clinical, electrophysiological and timed functional tests were used. All the operations had been performed by one surgeon, using the operating microscope for approximately half the cases but not for the other half. The results were analysed, and the patient's age, any delay between injury and suture, and the duration of follow-up were all found to exert strong and consistent effects on the scores obtained. After controlling for these factors, there was no consistent difference between the results of the two surgical methods. It is concluded that, at least in the hands of one particular surgeon, the use of the operating microscope gives no better results than careful epineural suture performed without it.

1. The results of arthroplasty of the forefoot in thirty-eight patients with polyarthritis have been analysed in detail. Sixty-five feet had been operated on by one of three different techniques–Kates-Kessel-Kay, Fowler or Clayton–though sometimes with modifications.

2. The subjective results were remarkably good. The patients were completely satisfied with forty-two operations, satisfied in most respects with twenty-one, and dissatisfied with only two.

3. The commonest cause of persistent pain was prominence of one metatarsal stump; great care must be taken at the time of operation to ensure that the metatarsals are trimmed to equal length.

4. The objective results were less satisfactory. The lateral four toes were usually functionless, the gait was never normal and the walking distance was still restricted, though often by other factors. The operation, therefore, should be carried out only in patients with severe pain and disability.

5. A comparison of the results of the three different techniques of operation showed no major differences.