Acetabular fractures present a challenge. Anatomical reduction can be achieved by open reduction and internal fixation (ORIF). However, in elderly patients with complex fracture patterns and osteoporotic bone stock, “fix and replace” has become an option in the management of these injuries. This involves ORIF of the acetabulum to enable insertion of a press fit cup and subsequent cemented femoral stem at the index surgery.

A Retrospective analysis of all operatively managed acetabular fractures by a regional Pelvic and Acetabular Trauma service (01/01/2018-30/05/2023) STATA used for analysis. 34 patients undergoing “fix and replace” surgery. Of the 133 patients managed with ORIF, 21 subsequently required Total Hip Arthroplasty (THA). Mean follow up was 2.7 years versus 5.1. There was no statistical significance between the two groups with regards to BMI or sex. Mean age in the “fix and replace” group was 68 compared to 48 in the ORIF and subsequent THA group. This reached statistical significance between the two groups (p=0.001).ASA and Charlson Comorbidity Index (3 and 3 in “fix and replace” and 2 and 1.2 in ORIF to THA group) and Charlson Comorbidity Index both were statistically significantly different (p=0.006 and p=0.027, respectively). High energy mechanism of injury accounted for 56% of the “fix and replace” group compared to 48% in the ORIF to THA. 74% of “fix and replace” were associated fractures compared to 53% of ORIF to THA. Wait to surgery was 3 days for “fix and replace” while 186 days was the mean wait time from listing to THA for the ORIF to THA group. Complication rate was 41% versus 43% in the two groups. 14% in the ORIF to THA group developed PJI versus 6% in “fix and replace”.

Fix and replace allows early mobilisation in frailer, elderly patients. Our results show fewer returns to theatre and less PJI in patients having arthroplasty as part of “fix and replace” than subsequent to Open reduction internal fixation.

Aims

Global literature suggests that female surgical trainees have lower rates of independent operating (operative autonomy) than their male counterparts. The objective of this study was to identify any association between gender and lead/independent operating in speciality orthopaedic trainees within the UK national training programme.

Australian Football (AF) is a popular sport in Australia, with females now representing one-third of participants. Despite this, the injury profiles of females versus males in largely unknown. The current study investigated fractures, dislocations and tendon ruptures in females versus males presenting to emergency departments (ED) with an AF injury.

All patients, regardless of age, presenting to one of 10 EDs in Victoria, Australia, with an AF injury were included. Data were prospectively collected over a 10-month period, coinciding with a complete AF season. Data were extracted from patient medical records regarding injury-type, body-part injured and treatments required. Female and male data were compared with chi-squared tests.

Of the 1635 patients presenting with an AF injury, 595 (36.0%) had a fracture, dislocation or tendon rupture, of whom 85 (14.3%) were female and the average age was 20.5 years (SD 8.0). Fractures accounted for most injuries (n=478, 80.3% of patients had a fracture), followed by dislocations (n=118, 19.8%) and tendon ruptures (n=14, 2.4%). Upper limb fractures were more common than lower limb fractures (71.1% v 11.5% of fractures). Females were more likely to fracture their hands or fingers than males (45.7% v 34.3%). Males were more likely to fracture ribs (5.4% v 0%). Most fractures (91.2%) were managed in the ED, with the remainder being admitted for surgery (GAMP/ORIF). Males were more likely to be admitted for surgery than females (11.2% v 5.9%). Regarding dislocations (n=118), females were more likely to dislocate the patella (36.8% v 8.1% of dislocations). Only males sustained a tendon rupture (n=14): finger extensor or flexor (57.1%), achilles tendon (28.6%) and patella tendon (14.3%).

Orthopaedic AF injuries are common presentations to EDs in Victoria, though few require specialist orthopaedic intervention. Injury profiles differed between genders suggesting that gender specific injury prevention and management might be required.

Osteoarthritis (OA) is a disease of the synovial joint with synovial inflammation, capsular contracture, articular cartilage degradation, subchondral sclerosis and osteophyte formation contributing to pain and disability. Transcriptomic datasets have identified genetic loci in hip and knee OA demonstrating joint specificity. A limited number of studies have directly investigated transcriptional changes in shoulder OA. Further, gene expression patterns of periarticular tissues in OA have not been thoroughly investigated. This prospective case control series details transcriptomic expression of shoulder OA by analysing periarticular tissues in patients undergoing shoulder replacement for OA as correlated with a validated patient reported outcome measure of shoulder function, an increasing (clinically worsening) QuickDASH score. We then compared transcriptomic expression profiles in capsular tissue biopsies from the OA group (N=6) as compared to patients undergoing shoulder stabilisation for recurrent instability (the control group, N=26). Results indicated that top ranked genes associated with increasing QuickDASH score across all tissues involved inflammation and response to stress, namely interleukins, chemokines, complement components, nuclear response factors and immediate early response genes. Some of these genes were upregulated, and some downregulated, suggestive of a state of flux between inflammatory and anti-inflammatory signalling pathways. We have also described gene expression pathways in shoulder OA not previously identified in hip and knee OA, as well as novel genes involved in shoulder OA.

In Australia nearly two-thirds of arthroplasty procedures are performed in the private setting, which is disproportionate to the dimensioning 43.5% of the population with private health cover. The rapid growth of shoulder arthroplasty surgery will be absorbed by both private and public sectors. This study aimed to assess the influence of healthcare setting on elective shoulder arthroplasty outcomes, defined by revision rate, and functional measures.

Data was collected on all primary procedures performed from 2004 – 2019 within a regional area of Victoria, Australia. Patients were categorised into private or public settings. Trauma cases for acute proximal humerus fractures were excluded. The primary outcome of revision surgery was recorded as a cumulative percentage, and survival analysis conducted to calculate a hazard ratio (HR). Functional outcomes were measured through range-of-motion (ROM) and multiple validated patient-reported-outcome-measures (PROMs).

458 patients were identified in the study: 290 private and 168 public. There was no difference in the revision rate (3.8% private, 4.8% public), with an adjusted HR of 1.25 (p=0.66) for public compared to private. Baseline and post-operative functional measures were significantly greater in the private setting for ROMs and PROMs analysis, in particular post-operative QuickDASH (15.9±14.7 to 32.7±23.5; p<0.001) and Oxford Shoulder Score (42.6±6.3 to 35.7±11.2; p<0.001). However, there was no significant difference for any of the functional measures in the amount of change from baseline to 12-months between settings.

Although healthcare setting does not appear to influence revision rate for shoulder arthroplasty, clear differences were demonstrated for functional measures both pre and post operatively. This may be attributed to factors such as access to perioperative rehabilitation and should be an area to target future investigations.

Global surgical literature suggests that female trainees have less operative autonomy than their male counterparts. This pilot study had the primary objective to identify difference in autonomy by gender, and to power a national study to carry out further quantitative and qualitative research on this.

This was a retrospective, cross-sectional study utilising eLogbook data for all orthopaedic trainees (ST2-8) and consultants with CCT date 2016–2021 in a single Scottish deanery. The primary outcome measure was percentage of procedures undertaken as lead surgeon. 15 trainees and four recent consultants participated, of which 12 (63%) were male (mean grade 5.2), and 7 (37%) were female (mean grade 4.3). Trainees were lead surgeon on 64% of procedures (17595/27558), with autonomy rising with grade (37% ST1 to 85% ST8, OR 9.4). Operative autonomy was higher in male vs female trainees (66.5% and 61.4% respectively, p=<0.0001), with female trainees more likely to operate with a supervisor present (STU/S vs P/T, f 48%:13%, m 45%:20%).

This pilot study found that there was a significant difference in operative autonomy between male and female trainees, however this may be explained by differences in mean grade of male vs female trainees. Five trainees took time OOT, 4/5 of whom were female. Extension to a national multi-centre study should repeat the quantitative method of this study with additional qualitative analysis including assessing effect of time OOT to explore the reason for any gender discrepancies seen across different deaneries in the UK.

Background

Carbon fibre (CF) instrumentation is known to be radiolucent and has a tensile strength similar to metal. A specific use could be primary or oligometastatic cancer where regular surveillance imaging and Stereotactic Radiotherapy are required.

CT images are inherently more prone to artefacts which affect Hounsfield unit (HU) measurements. Titanium (Ti) screws scatter more artefacts. Until now it has been difficult to quantify how advantageous the radiolucency of carbon fibre pedicle screws compared to titanium or metallic screws actually is.

A previously fit and well 58 year old male suffered from a bilateral psoas haematoma (PH) following 52 days of veno-venous extracorporeal membranous oxygenation (VV-ECMO) for severe Coronavirus disease (COVID-19), refractory to all non-invasive and medical therapies. He developed multiple complications, including inability to walk or weight-bear, due to lumbar plexopathy triggered by bilateral PH compression, compounded by COVID-19-related mononeuritis multiplex. The patient was referred to our institution with a known diagnosis of bilateral PH and after spinal multidisciplinary team (MDT) input, was deemed not for surgical or interventional radiology treatments. The patient received extensive neurorehabilitation, coordinated by multiple MDTs. Although PH has been correlated to COVID-19, to the best of our knowledge this is the first reported case of such a complex presentation resulting in a dramatic bilateral PH.

Health records from 3 large UK teaching hospitals were collected regarding treatment and follow up appointments, following patient's written informed consent. Patient's comorbidities, duration in hospital units, MDT inputs, health assessments, mobilisation progress and neurologic assessments, were all recorded. Data was collected retrospectively then prospectively due to lengthy in-patient stay. The literature review was conducted via PubMed and open access sources, selecting all the relevant studies and the ECMO guidelines.

Patient received treatment from 3 different units in 3 hospitals over 212 days including 103 days in neurorehabilitation. Involvement of physiotherapy, dietitians, speech and language teams, neurologist, neurophysiotherapists, occupational therapists was required. The patient progressed from a bed-bound coma and inability to walk, to standing with lower limb backslab at discharge. Additionally, he was referred for elective exploratory surgery of the psoas region for scar debridement and potential nerve graft repair of the lumbosacral plexus. The surgery outcome is cautiously optimistic, with some improvement in nerve conduction studies, however is currently unknown regarding recovery progress and return to premorbid functional baseline.

The novelty of this presentation yields significant learning points regarding early recognition of PH, requirements for vast MDT input and specialist use of VV-ECMO in severe COVID-19 patients. It also highlights the broad pathophysiology of SARS-CoV-2 causing neuropathy and coagulopathy; understanding this will optimise robust anticoagulation guidelines, required in VV-ECMO.

Training time in Trauma & Orthopaedics is pressured. In this action research project, we develop a feedback/self-reflection model for trainers and trainees, emphasising the contribution both groups make to training, to maximise cohesion and efficacy.

Starting in 2013, trainees completed anonymous feedback forms after each 6-month post. The 18-point quantitative questionnaire covers four training domains: WBA engagement, teaching/feedback, research/audit, operative training.

Consultant trainers completed a once-off corresponding 18-point self-reflection questionnaire. Additionally, trainers were asked for their expectations of and advice for trainees.

Individual trainer profiles were generated from trainee feedback questionnaires, allowing comparison between trainer-group-average, trainer-specific and trainer-self-reflection scores across 18 fields. Trainer profiles were uploaded to ISCP and used for recognition of trainer status for SOAR. This data provided basis for local service provision review with amendments to maximise training efficacy.

Results of thematic analysis of trainer feedback was shared with the trainee group. This and subsequent group self-reflection formed the basis of our ‘Trainee Charter’.

Trainee feedback illustrates high levels of satisfaction with local training (average global score 4.2/5). Strengths included ‘feedback’ and ‘operative teaching’; relative weaknesses included ‘research time’ and ‘OPD teaching’.

The ‘Trainee Charter’ details specific desirable behaviours that embody eight trainee-qualities consistently identified by trainers as important, including ‘honesty’ and ‘being organised’. The charter emphasises trainee contribution to training.

For the first time, trainers have the benefit of serial and individualised feedback. Trainees are better informed and empowered in relation to maximising their own training. Most importantly, both halves of the training-team are explicitly acknowledged.

Functional scores are used to clinically assess total hip arthroplasty (THA) and for comparative purposes in orthopaedic literature. Previous pilot work has highlighted patient comorbidity as a potential source of bias in addition to the often-examined factors of age, gender and underlying diagnosis.

We analysed prospectively collected data relating to 217 primary THAs (Tayside Arthroplasty Audit Group database). Sample size was calculated from previous pilot data (significance level 5%, power 80%, effect size 0.25). Proportional stratified sampling was performed including all patient age groups (≤40, 41–55, 56–65, >65) and four fixation classes (cemented, hybrid, uncemented and Birmingham resurfacing). Five year Harris Hip Function Score (HHFS) was the dependent variable; age, sex, underlying diagnosis, BMI, pre-operative HHFS and comorbidity (Functional Comorbidity Index; range 0–8) were co-variates/co-factors.

In univariate analysis, FCI accounted for 11% of the variation in HHFS at 5 years. Regarding patients with FCI 0–1 as a reference group, patients with greater comorbidity had lower HHFS at 5 years (FCI 2–3: −3.95; FCI 4–5: −7.21, FCI ≥6: −6.92). In a multivariable model of HHFS at 5 years, FCI group, diagnosis, pre-operative HHFS, patient age and BMI were significant. HHFS at 5 years was significantly higher in FCI group 0–1 than any other category (2–3 P=0.006, 4–5 P<0.001, ≥6 P=0.002). In total, the model accounted for 29% of variability in HHFS at 5 years.

This is the first statistically robust study to examine the effect of comorbidity on THA function. These results strongly suggest that increasing patient comorbidity is associated with poorer THA function when measured using HHS.

Two significant conclusions can be drawn:

Patient comorbidity should be taken into account pre-operatively when considering potential future THA function.

Introduction

Functional scores are used to clinically assess total hip arthroplasty (THA) and for comparative purposes in the orthopaedic literature. Previous research has highlighted patient age, gender and underlying diagnosis as potential sources of bias but comorbidity has not been considered. The Functional Comorbidity Index (FCI) is a published epidemiological tool which correlates disease with associated physical function deficit. It scores 18 conditions: one point for each, total score 0–18.

Pain produced by the tourniquet is a common source of complaint for patients undergoing carpal tunnel decompression. Practice varies as to tourniquet position. There is little evidence to suggest benefit of one position over another. Our aim was to compare the experience of both the patient and the surgeon with the tourniquet placed either on the arm or the forearm.

Ethical approval was granted. Following power calculation and a significance level set at 0.05, 100 patients undergoing open carpal tunnel decompression under local anaesthetic were randomised to arm or forearm group. Visual Analogue Scores (VAS) (0–100) for pain, blood pressure and heart rate were taken at 2 minute intervals. The operating surgeon provided a VAS for bloodless field achieved and obstruction caused by the tourniquet.

The demographics of the groups was similar. There were no statistically significant differences in any measure between the groups.

Average tourniquet times were 8.8 minutes (forearm) and 8.2 minutes (arm). The average VAS score for forearm and arm was 13 and 11 respectively for bloodless field, 9 and 2 for obstruction. Average overall VAS for pain was 27 in each group, however interval VAS scores for pain were higher in the arm group. The average change Mean Arterial Pressure was −5 mmHg (forearm) −2 mmHg (arm) pulse rate was −1 bpm (forearm) and −2 bpm (arm).

Tourniquet placement on the arm does not result in significant difference in patient pain, physiological response or length of operation. Surgeons reported less obstruction and better bloodless fields with an arm tourniquet, however there was a trend for forearm tourniquet to result in less pain for the patient.

Management of open tibial fractures remains controversial. We hypothesised that unreamed intramedullary nail offers inherent advantages of nail as well as external fixation. We undertook a prospective randomised study to compare the results of management of open tibial fractures with either an external fixator or an undreamed intramedullary nail until fracture union or failure.

Our study included 30 consecutive open tibial fractures (Gustilo I, II & IIIA) between 4 cm distal to knee and 4 cm proximal to ankle in skeletally mature adults, who presented to a level-1 trauma centre. Alternate patients were treated by either external fixation and unreamed nailing i.e. 15 in each group. Standard protocol for debridement and fixation was followed in all cases. All external fixators were removed at 6 weeks. All cases were followed up until fracture union, the main outcome measurement. 26 (87%) were males and 4 (13%) females; age range was 20-60 years (average 33.8).

All fractures in both groups united. Time to union averaged 7.9 months for both groups. Incidence of wound problems, infection, hardware failure and delayed union were comparable. However, there was higher incidence of angular deformities and stiffness of knee and ankle in external fixation group, although not statistically significant.

We found no statistically significant difference between unreamed intramedullary nailing and external fixation for the management of open tibial diaphyseal fractures, although ease of weight bearing as well as absence of angular deformities and joint stiffness were distinct advantages in the nail group. Therefore we recommend unreamed nail for Gustilo I, II and IIIA open tibial fractures.

Femoral head fractures i.e. Pipkin fractures are uncommon injuries and there are very few large series in literature with reported outcomes. There remain many controversies regarding diagnosis and management. This study, which is the largest single surgeon experience, is an attempt to get answers to some of these controversies.

This series is an analysis of 51 patients with femoral head fractures. There were 44 males and seven females. The right side was involved in 36 and left in 16 patients. According to Pipkin classification these were 13 Pipkin-I, 27 Pipkin-11, three Pipkin-111 and eight Pipkin-IV fractures. Thirty-two patients were managed by surgical intervention. The surgical approach was posterior in Pipkin-I and in seven cases of Pipkin-II fractures. Another eight Pipkin II cases were managed surgically by anterior Smith-Peterson approach while another eight fractures were accessed by posterior approach with flip osteotomy. The Pipkin III and IV cases were managed using surgical approaches that varied depending on the pattern of associated acetabular injury. The fractured fragment, if small, was excised and, if large, was re-fixed using small fragment partially threaded cancellous screw. Follow-up of two to eight years was available in 39 cases.

Using Thompson and Epstein criteria, 26 patients were rated as having good results, eight fair and five poor results. Early osteoarthritic changes were seen in five patients, avascular necrosis of the femoral head in three patients and one patient had re-fracture in same hip during an epileptic fit with subsequent fixation problems. Of four patients with sciatic nerve injury, two had persisting motor deficit. There was one case of heterotopic ossification.

Most Pipkin-I fractures can be managed by closed reduction, Pipkin-II fractures usually require ORIF. The best results have been obtained by a Smith-Peterson approach if the hip has already been reduced, but posterior approach with flip osteotomy offers the best exposure if the hip is still unreduced. Pipkin III patients need hip replacement if presentation is late, while ORIF gives acceptable outcome in Pipkin IV fractures.

As management of open tibial fractures remains controversial, we hypothesised that unreamed intramedullary nail offers inherent advantages of a nail as well as external fixation, while limiting the morbidity of external fixation.

We undertook a prospective randomised study to compare management of open tibial fractures with external fixator or intramedullary nail until fracture union or failure. Our study included 30 consecutive open tibial fractures (Gustilo I, II & IIIA) between 4 cm distal to knee and 4 cm proximal to ankle in skeletally mature adults, who presented to a level-1 trauma centre. Alternate patients were treated by external fixation or unreamed nail i.e. 15 in each group. Standard protocol for debridement and fixation was followed. External fixators were removed at 6 weeks. All cases were followed until fracture union, the main outcome measurement.

26 (87%) males and 4 (13%) females; age 20–60 years (Mean 33.8). All fractures in both groups united. Time to union averaged 7.9 months for both groups. Incidence of wound problems, infection, hardware failure and delayed union were comparable. However, there was higher incidence of angular deformities and stiffness of knee and ankle in external fixation group, although not statistically significant.

We found no statistically significant difference between unreamed intramedullary nailing and external fixation for the management of open tibial diaphyseal fractures. Ease of weight bearing as well as absence of angular deformities and joint stiffness were distinct advantages in the nailing group. Therefore we recommend unreamed nail for Gustilo I, II & IIIA open tibial fractures.

Introduction A prospective, randomised, controlled study has been conducted to compare the clinical outcomes of patients treated with a Presige® artificial cervical disc (Medtronic Sofamor Danek, Memphis, TN) to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purposes of the study are to (1) prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion; and (2) to asses the ability of the prosthesis to maintain motion. Enrolment has closed and this is a report of the data with 50 cases with 6 month follow-up and 9 cases having reached 24 month final follow-up.

Methods In four centres, 52 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy were randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc replacement. The patients were evaluated with pre and postoperative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients had pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function.

Results At 6 weeks the neck disability index reduced by 34.1 for the investigational group compared to 35.2 for the fusion group. The improvement seen in the treatment groups was statistically equivalent (p < 0.05, non-inferiority margin = 10) up to the 24-month follow-up interval. The pain score had reduced by 7.7 for the investigational group and by 9.7 for the control group. Both groups improved statistically from preoperatively though statistical equivalence could not be shown. This improvement appeared to be maintained until the 12 month follow-up. Mean arm pain scores improved in both groups with statistical equivalence being demonstrated (p < 0.05, non-inferiority margin = 10). The adverse events in both groups were similar. Analysis of range motion showed a mean preoperative range of motion in the arthroplasty group of 5.9 degrees and 6.3 degrees in the fusion group. At twelve months the arthroplasty group had a mean range of motion of 5.9 degrees and the fusion group had a mean range of motion of 1.1 degrees

Discussion Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesised that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that, in the short to medium term, the clinical outcomes appear to be equivalent to fusion. And that range of motion is maintained.

Introduction: A prospective, randomized, controlled study has been conducted to compare the clinical outcomes of patients treated with an artificial cervical disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion. Enrolment has closed and this is a report of the data with 50 cases with 6 month follow-up and 9 cases having reached 24 month final follow-up.

Methods: In four centres, 52 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy were randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc replacement. The patients were evaluated with pre- and post-operative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients had pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function.

Results: At 6 weeks the neck disability index reduced by 34.1 for the investigational group compared to 35.2 for the fusion group. The pain score had reduced by 7.7 for the investigational group and by 9.7 for the control group. This improvement appeared to be maintained until the 12 month follow-up. The mean pain scores at 24 months were similar (4.3 and 5.6 respectively) In general there appeared to be a slightly better outcome for the investigational group, though the investigational group showed slightly less preoperative pain (p=0.091) and disability (p=0.055) than the fusion group. Both pain score and disability scores improved statistically significantly compared to the pre op scores (p< 0.001 all comparisons). Analysis of non-inferiority of outcome for the investigational group using ANCOVA with the preoperative score as the covariate and a non-inferiority margin of 5 points (5%) showed statistical significance at 12 weeks for Neck Disability Index.

Discussion: Anterior cervical discectomy and fusion has a good short-term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesized that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Though there is insufficient power to prove equivalence with a clinical margin of 5%.

Introduction: A prospective, randomized, controlled study has been conducted to compare the clinical outcomes of patients treated with an Artificial Cervical Disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion.

Methods: In four centers, 60 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy are randomized prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc placement. The patients are evaluated with pre and postoperative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients have pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function.

Results: Data is presented for the first 47 patients. At 6 weeks the neck disability index reduced by 36.1 for the investigational group compared to 34.8 for the fusion group. The pain score had reduced by 8.2 for the investigational group and by 9.9 for the control group. This improvement appeared to be maintained until the 12 month followup. In general there appeared to be a slightly better outcome for the investigational group. Both pain score and disability scores improved statistically significantly compared to the pre op scores (p< 0.001 all comparisons). Analysis of non inferiority of outcome for the investigational group using ANCOVA with the preoperative score as the covariate and a non inferiority margin of 5 points showed statistical significance at 6 and 12 weeks for Neck disability index. Operative time appeared slightly less (2.3 hrs) for the investigational group compared to the fusion group(2.5hrs). Blood loss also appeared higher in the fusion group (165 mls compared to 91 mls). Hospital stay was equivalent (2.8 days and 2.9 days).

Discussion: Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesized that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term followup studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Early statistical evidence is available for some of the outcome measures at early post op followup. Further statistical power will be available when the full 60 cases are available for study and this may give further weight to the hypothesis of equivalence of outcome.

INTRODUCTION: A prospective, randomised, controlled study has been conducted to compare the clinical outcomes of patients treated with an Artificial Cervical Disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesised that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion.

METHODS: In four centres, 60 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy are randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc placement. The patients are evaluated with pre- and post-operative serial flexion-extension cervical X-rays at six weeks, three, six, 12, and 24 months. At the same intervals, the patients have pre- and post-operative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function.

RESULTS: Data are presented for the first 47 patients. At six weeks the neck disability index reduced by 36.1 for the investigational group compared to 34.8 for the fusion group. The pain score had reduced by 8.2 for the investigational group and by 9.9 for the control group. This improvement appeared to be maintained until the 12 month follow-up. In general there appeared to be a slightly better outcome for the investigational group. Both pain score and disability scores improved statistically significantly compared to the pre-operative scores (p< 0.001 all comparisons). Analysis of non inferiority of outcome for the investigational group using ANCOVA with the pre-operative score as the covariate and a non inferiority margin of five points showed statistical significance at six and 12 weeks for Neck disability index. Operative time appeared slightly less (2.3 hours) for the investigational group compared to the fusion group (2.5 hours). Blood loss also appeared higher in the fusion group (165 mls compared to 91 mls). Hospital stay was equivalent (2.8 days and 2.9 days).

DISCUSSION: Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesised that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the meantime, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Early statistical evidence is available for some of the outcome measures at early post-operative follow-up. Further statistical power will be available when the full 60 cases are available for study and this may give further weight to the hypothesis of equivalence of outcome.

To evaluate the mechanism of dislocation of the navicular in complex foot trauma; we hypothesize this is similar to lunate/perilunate dislocations.

Our experience with 6 cases of total dislocation of navicular without fracture, and an analysis of 7 similar cases reported world-wide was used as the basis for this hypothesis. Radiographs of our patients and the published cases were analyzed in detail, and associated injuries/instablilities were assessed. The position of the dislocated navicular and the mechanism of trauma was considered and correlated, and this hypothesis was propounded.

When the navicular dislocates without fracture, it most frequently comes to lie medially, with superior or inferior displacement, depending upon the foot position at injury. It is hypothesized that the forefoot first dislocates laterally (perhaps transiently) at the naviculocunieform joint by an abduction injury; in all cases we recorded significant lateral injury (either cuboid fracture, or lateral midfoot dislocation). The relocating forefoot subsequently pushes the unstable navicular from the talonavicular joint, and depending upon the residual attachments of soft tissues, this bone comes to lie at different places medially. This is a similar mechanism to the lunate dislocation in the wrist, where the relocating carpus push the lunate volarly. Our clinical experience with these complex injuries has shown that the whole foot is extremely unstable. For reduction, the talonavicular joint has to be reduced first, and then the rest of the forefoot easily reduces on to the navicular. An understanding of injury mechanics allows us to primarily stabilize both the columns of the foot, and subsequent subluxation and associated residual pain are avoided.

Pure navicular dislocations are not isolated injuries, but are complex midfoot instabilities, and are similar to perilunate injuries of the wrist.