Introduction

National Institute for Health and Clinical Excellence (NICE) guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractured neck of femur (NOF) in cognitively intact patients who were independently mobile prior to the injury. The National Joint Registry for England and Wales (NJR) has collected data on THRs performed since 2003. This retrospective cohort study explores risk factors independently associated with implant failure and perioperative mortality.

Unstable fractures of the distal tibia are being increasingly treated by open reduction and internal fixation using pre-contoured locking plates. Functional outcome following this type of fixation has not been reported previously.

The aim of this study was to functionally assess patients following MIPO fixation of distal tibial fractures.

Case notes of 26 patients treated at a single centre were reviewed. The fracture type, fixation technique, complications, time to union and subsequent treatment were documented. All patients returned for functional scoring using the validated American Academy of Orthopedic Surgeons (AAOS) foot and ankle core score.

Twenty-six consecutive patients were treated between 2002-2005. The majority were male, and 5 were open fractures. There were 13 AO type A, 4 type B and 9 type C fractures. Mean follow up was 20 months. Average time from injury to surgery was 2.5 days. All fractures were treated by a MIPO technique. A pre-contoured distal locking plate was used for the distal tibial reconstruction. Secondary surgical procedures e.g. 2nd look, delayed primary closure, or skin grafting were necessary in 3 cases. The fibula was plated in 60% of cases. Four patients developed wound infections requiring antibiotics, and all resolved. The commonest rehabilitation regime was 6 weeks non weight bearing in plaster. Mean time to union was 18 weeks. There were 3 cases of delayed union, requiring bone grafting. One patient required removal of the plate due to local irritation, and one required a broken screw to be removed. Mean range of movement was 10 degrees dorsiflexion, 30 plantarflexion. The mean normalised AAOS foot and ankle core score was 41 (SD +/− 8).

We conclude that MIPO fixation of distal tibial fractures is a safe and effective method of treatment. Functional outcome does not significantly differ from that of the general population.

Objective

To compare clinical parameters associated with medial parapatellar and midvastus approaches for total knee arthroplasty in the early post-operative period.

Introduction: The recent UK national comparative audit of the use of blood in primary, elective, unilateral THR found that 25% of patients required a peri-operative transfusion. We felt this figure was higher than should be expected, especially of surgeons with a dedicated arthroplasty subspecialty. We therefore audited our own practice with particular emphasis on the relationship between surgeon volume, implant and the need for transfusion.

Methods: A retrospective review of 508 consecutive primary, elective, unilateral hip and knee arthroplasties performed over a 12 month period. Pre- and post- operative haemoglobin levels, need for transfusion, and the timing and volume of any transfusion were recorded for each patient. Analysis determined the overall rate of transfusion, the details of any such transfusion, and the effects of surgeon volume upon the transfusion rate.

Results: The transfusion rate following THR (10%) was significantly lower than those found in the national audit. The transfusion rate following TKR was 7%. Multivariate analysis demonstrated that surgeon volume (< 50 THRs/yr Vs > 50 THRs/yr) and a preop-erative Hb < 12g/dl were the only significant determinants of a need for post operative transfusion (Both p< 0.05) following both THR and TKR. Other variables (age, gender, anaesthetic type, ASA, indication, surgeon grade and experience, implant, approach) were not significant. A preoperative haemoglobin of < 12g/dl was associated with a 6 fold and 3 fold increased risk of needing a transfusion following hip and knee replacement respectively.

Discussion: The need for allogenic blood transfusion following primary arthroplasty is influenced by both patient and surgeon related factors. Surgeons who have a dedicated arthroplasty practice and perform a high volume of procedures have significantly lower transfusion rates when compared to nationally accepted figures. This has implications for both patient care and resource management.

Introduction: Uncemented sockets have been used for revision with good results in the literature. Tantalum coated acetabular uncemented implant is the next generation implant. We used Tritanium (Stryker Corp. Kalamazoo, USA) for revision of acetabulum and present the early results.

Aim: To determine early results of porous tantalum coated modular acetabular cups in revision hip arthroplasty.

Patients and methods:41 acetabular revisions in 41 patients were performed using Tritanium acetabular uncemented sockets between March 2007 and March 2008. Posterior approach was used for all procedures. AAOS system for acetabular bone deficiency and Harris hip score for function was used for assessment.

Results: Mean age of the patients was 67 yrs (range 45–88). 95% of cups were fixed with screws for initial stability. AAOS classification showed there were 17 % Type 1, 49 % Type 2, 24% Type 3 and 5% Type 4 defects and 5 % had no defect. Bone graft was used to in 70% of patients, mostly autograft from the reamings. Mean Harris Hip Score improved from 68 pre-operatively to 84 at the last follow-up. Cup integration was seen in 93% patients. In two patients with pelvic discontinuity there was migration and in one loosening of the implant. One patient was treated for deep vein thrombosis and one patient for infection.

Conclusion: Early results of tantalum coated acetabular socket are encouraging, in providing adequate initial stabilisation for biologic fixation in segmental, cavitatory and combined defects. Facility to use locking screws in multiple directions may help in addressing pelvic discontinuity.

Introduction: Periprosthetic infection with extensive bone loss is a complex situation. The appropriate management of large bone defects has not been established. Without reconstruction amputation/disarticulation is the likely outcome.

Aim: To Analyse preliminary results of direct exchange endoprosthetic reconstruction for periprosthetic knee infection associated with segmental bone defects.

Methods: Study of patients with periprosthetic knee infection and severe osteolysis treated by direct exchange tumour prostheses between June, 2005 and May, 2008 (4 - Distal femoral & 2 - Total femoral Replacements). Exclusion criteria included polymicrobial infection, resistant organisms, depressed immunity and poor peripheral perfusion. At each clinical visit they were monitored for clinical, microbiological, haematological and radiological evidence of infection. Community based antibiotic therapy was provided by specialist microbiologists. All patients were counselled and consented by the operating surgeon and specialist microbiologist prior to surgery.

Results: The mean age and follow up were 70.2 years and 30.5 months respectively. The most common infecting organism was Staphylococcus epidermidis (four), followed by Streptococcus species. Mean duration of antibiotics was 6 weeks intravenous(community based) and 8 weeks oral. 1 patient required intervention by plastic surgeons at index procedure. Radiographs showed no changes at final followup. One patient had superficial wound infection, which was successfully debrided. Knee range of movements averaged full extension to 95 degrees. The mean oxford knee scores pre and post operatively were 58 and 39.4 respectively.

Conclusion: Salvage direct exchange endoprosthetic reconstruction has provided effective pain relief, stability and improved mobility in our experience. Isolation of sensitive organism, specialist microbiologist input, availability of specialist physiotherapy and plastic surgery service, appropriate community care, good patient compliance and surgeon’s experience are key to success in these patients. Morbidity was significantly reduced due to early mobilisation.

Introduction: The commonest surgical approach for total knee arthroplasty is medial parapatellar approach. This involves splitting the quadriceps tendon, potentially destabilising the extensor mechanism. The midvastus approach involves splitting the vastus medialis muscle instead of entering the quadriceps tendon, therefore, minimising interruption of the extensor mechanism without compromising the exposure of the knee.

Objective: To compare clinical parameters associated with medial parapatellar and midvastus approaches for total knee arthroplasty in the early postoperative period.

Methods: and Results: We present a prospective observational study of 77 patients undergoing primary total knee arthroplasty using medial parapatellar or midvastus approach (37 midvastus approach, 40 medial parapatellar approach). Ethical approval was obtained for the study. The prosthetic design and physical intervention was standardised in all the patients. The Oxford Knee Score, pain scale, knee flexion, unassisted straight leg raise, standing and walking were compared at 3rd, 5th and 7th day postoperatively, then at 6 weeks and at 3 months. The patients and physiotherapist were blinded to the type of approach used. The average age was 67 years (range 42 to 88). There were 49 women and 39 men. The average hospital stay was 7 days (range 2 to 15). There was statistically significant difference in duration of hospital stay, unassisted straight leg raise and standing at 3 days (p=0.001) all in favour of midvastus approach. There was no statistically significant difference in Oxford Knee Scores, pain scale and range of motion. The average duration to achieving straight leg raise for the midvastus group was 5 days and for the medial parapatellar approach group was 8 days

Conclusion: The study shows that total knee arthroplasty performed through the midvastus approach resulted in less postoperative pain, earlier unassisted straight leg raise and ambulation, therefore, shorter hospital stay as compared to medial parapatellar approach. This may be of benefit to the patients due to less discomfort after surgery and to the healthcare system due to shorter hospital stay for patients.

Periprosthetic infection with extensive bone loss is a complex situation. The appropriate management of large bone defects has not been established. Without reconstruction amputation/disarticulation is the likely outcome.

Aim of the study was to Analyse preliminary results of direct exchange endoprosthetic reconstruction for periprosthetic infection associated with segmental bone defects.

Study of patients with periprosthetic infection and severe osteolysis treated by direct exchange tumour prostheses between June, 2005 and May, 2008 (4 – Distal femoral & 2 – Total femoral Replacements). Microbiological evidence of infection was confirmed with regular monitoring of radiograph, crp, esr and wcc. Community based antibiotic therapy was provided by infectious disease team based in our institution.

The mean age and follow up were 74.2 years and 26.5 months respectively. Mean duration of antibiotics was 6 weeks intravenous(community based) and 3.5 months oral. 1 patient required intervention by plastic surgeons at index procedure. Radiographs at 6, 12 & 24 months showed no changes from immediate post-op. CRP, ESR and WBC count were within normal limits at the end of antibiotic therapy. One patient required prolonged pain relief with poor mobility due to instability in the opposite knee. One patient had infection recurrence. Knee range of movements averaged full extension to 95 degrees. The mean oxford knee scores pre and post operatively were 58 and 39.4 respectively.

We conclude that salvage endoprosthetic reconstruction has provided effective pain relief, stability and improved mobility in our experience. It has provided an oppourtunity to avoid amputation. Multidisciplinary support from plastic surgeons and specialist microbiologists is essential.

Purpose: To compare clinical parameters associated with medial parapatellar and midvastus approaches for total knee arthroplasty in the early postoperative period.

Method: We present a prospective observational study of 77 patients undergoing primary total knee arthroplasty using medial parapatellar or midvastus approach (37 midvastus approach, 40 medial parapatellar approach). Ethical approval was obtained for the study. The prosthetic design and physical intervention was standardised in all the patients. The Oxford Knee Score, pain scale, knee flexion, unassisted straight leg raise, standing and walking were compared at 3rd, 5th and 7th day postoperatively, then at 6 weeks and at 3 months. The patients and physiotherapist were blinded to the type of approach used.

Results: The average age was 67 years (range 42 to 88). There were 49 women and 39 men. The average hospital stay was 7 days (range 2 to 15). There was statistically significant difference in duration of hospital stay, unassisted straight leg raise and standing at 3 days (p=0.001) all in favour of midvastus approach. There was no statistically significant difference in Oxford Knee Scores, pain scale and range of motion. The average duration to achieving straight leg raise for the midvastus group was 5 days and for the medial parapatellar approach group was 8 days.

Conclusion: The study shows that total knee arthroplasty performed through the midvastus approach resulted in less postoperative pain, earlier unassisted straight leg raise and ambulation, therefore, shorter hospital stay as compared to medial parapatellar approach. This may be of benefit to the patients due to less discomfort after surgery and to the healthcare system due to shorter hospital stay for patients.

Segmental bone defects with complex fractures or chronic infections comprise a very special subset of patients. Modular endoprosthetic reconstruction is an operative solution. Without reconstruction amputation/disarticulation is the likely outcome.

Aim of the study was to analyse preliminary results of modular endoprosthetic reconstruction in nonneoplastic limb salvage.

11 patients(9 – distal femoral replacement, 2 – total femoral replacement) underwent salvage reconstruction between January 2005 and March 2008 for chronic periprosthetic infections(6 – single stage revision; 2 – two stage revision) and complex periprosthetic fractures(3) with segmental bone defects. Microbiological and haematological evidence of infection was confirmed in the infection group and treated with concomitant community based antibiotic therapy as per guidance from specialist team.

The mean age and follow up were 74.2 years and 27.5 months respectively. No intraoperative complications identified. Average post operative mobilisation was with frame at 5 days, 2 sticks at 2 weeks. 1 patient required plastic surgical intervention at index operation. 1 patient had recurrence of infection.

Radiographs at 6, 12 & 24 months showed no changes from immediate post-op. Microbiological and haematological evidence of infection eradication was considered as successful treatment. Knee range of movements averaged full extension to 95 degrees. Oxford knee scores showed maximal improvement in the single stage revision group.

We conclude that salvage endoprosthetic reconstruction has provided an oppourtunity to avoid amputation. A significant improvement in overall range of motion, knee scores, pain relief and stability was achieved in this highly complex subset of patients. Multidisciplinary support from plastic surgeons and specialist microbiologists is essential.

Resurfacing arthroplasty is advantageous over conventional total hip arthroplasty in that femoral bone stock is preserved. However, there has been controversy over the preservation of acetabular bone stock in resurfacing arthroplasty, with the concern that it may result in excess reaming compared with total hip replacement. This is of concern as the prosthesis is primarily advocated in the young patient, who is likely to face future revision surgery.

We prospectively identified a cohort of 68 patients with primary hip osteoarthritis undergoing conventional total hip arthroplasty. During surgery, the excised femoral head and neck diameter was measured, along with the diameter of the final acetabular reamer used to achieve a bed of bleeding cancellous bone. The measured neck diameter was then used to calculate the minimum possible resurfacing head and cup sizes, with corresponding final reamer sizes that could have been used in each patient without neck notching for both Birmingham Hip Resurfacing (BHR, Smith & Nephew, 3rd Generation) and Articular Surface replacement (ASR, De Puy, 4th Generation). Reaming diameter and volume was compared for all 3 groups.

Mean reaming diameters for the THR, ASR and BHR groups were 51, 52 and 56mm respectively. Mean reaming volumes were 39, 40 and 47cc. There was a statistically significant difference between the THR and BHR groups for both reamed diameter and volume (p< 0.001). There was also a significant difference between the ASR and BHR groups for both reamed diameter and volume (p< 0.001). This difference was more pronounced with larger neck diameters.

Our data shows that the BHR results in more ace-tabular bone loss compared to total hip replacement. An implant with a lower profile acetabular cup and a larger variety of sizes such as the ASR may allow better preservation of acetabular bone stock.

MRSA infections are a current concern in the elderly orthopaedic patient, with colonisation rates of between 417% reported in these patient groups. In our institution there has been concern regarding MRSA surgical site infection and cross contamination of elective and emergency patients. This prompted the unit to consider a screening programme to identify MRSA carriers. We undertook the following project to assess the feasibility and effectiveness of implementing such a screening programme.

The aim was to to ascertain the incidence of colonisation with MRSA, rate of wound infection and associated risk factors in patients admitted with a fractured proximal femur.

This was a prospective, blinded case series of 100 consecutive patients admitted to the trauma ward with a fractured proximal femur. Three swabs (axilla, nasal and perineum) were taken within 24 hours of admission. Data from each patient was collated and each patient was followed until discharge to assess for surgical site infection.

The age range was 60–97 years. 26% were admitted from institutional care. Four patients were colonised with MRSA on admission. An association was seen between patients colonised on admission and long term or recent residence in institutional care. One of these patients went on to develop colonisation of the surgical wound however this did not lead to surgical site infection and the patient was successfully treated with MRSA eradication therapy only. In these 4 patients all wounds healed satisfactorily with no evidence of infection.

While MRSA continues to be a growing concern in the press we found that rates of colonisation and subsequent infection were not high. There were no documented cases of MRSA wound infection in colonised individuals. Given the cost to detect these low levels of colonisation we do not feel that a screening regime would be cost effective or justified.

Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.

Background: In recent years an increased trend in MRSA infection has been seen in hospitals and the community, with colonisation rates of between 4 – 17% reported in these patient groups. There is also an association between carriage of Staph. Aureus and staphylococcal surgical wound infection.

In our institution there has been concern regarding MRSA surgical site infection and possible cross contamination of elective and emergency patients. There would be implications for implant related infections if this were to occur. This had prompted the unit to consider adopting a screening programme to identify and treat MRSA carriers. This would aim to minimise risk of post operative infection and cross infection. As little was actually known about the MRSA colonisation rates of admissions to our hospital we undertook the following project to assess the feasibility and effectiveness of implementing such a screening programme.

Aim: To ascertain the incidence of colonisation with MRSA, rate of wound infection and the associated risk factors in patients admitted to the trauma ward with a fractured neck of femur.

Method: A prospective, blinded case series of 100 consecutive patients admitted to the trauma ward with a fractured neck of femur. Three swabs (axilla, nasal and perineum) were taken within 24 hours of admission. Data from each patient was collected to ascertain the presence of risk factors linked to MRSA colonisation and each patient was followed until discharged to assess for surgical site infection.

Results: 304 swabs were taken from 100 patients. Age range 60–97. 26% admitted from institutionalised care and 74% admitted from their own home. Four patients were colonised with MRSA on admission (2 nasal, 2 perineal). An association was seen between patients colonised on admission and long term or recent residence in institutionalised care. One of these patients went on to develop colonisation of the surgical wound however this did not lead to surgical site infection and the patient was successfully treated with MRSA eradication therapy only. In these 4 patients all wounds healed satisfactorily with no evidence of infection.

There were three superficial surgical site infections postoperatively, all in individuals who were clear on their admission screening. Of these two were due to MRSA and one was due to MSSA. There were no cases of deep infection requiring further surgery.

Conclusion:While MRSA continues to be a growing concern we found that, in our hospital, rates of MRSA colonisation and subsequent infection were not high. There were no documented cases of MRSA wound infection in colonised individuals. Given the cost involved in swabbing all patients to detect these low levels of colonisation we do not feel that an expensive screening regimen would be cost effective or justified in our institution.

Introduction: There is a recent trend of using a raft of small diameter 3.5 mm cortical screws instead of the large diameter 6.5mm screws in depressed tibial plateau fractures. Our aim was to compare the biomechanical properties of these two constructs in the normal and osteoporotic synthetic bone model.

Methods: 20 rigid polyurethane foam blocks with a density simulating osteoporotic bone and normal bone were obtained. A Schatzker type 3 fracture was created in each block. The fracture fragments were then elevated and supported using 2, 6.5mm cancellous screws or 4, 3.5mm cortical screws.

The fractures were loaded using a Lloyd’s machine and a load displacement curve was plotted.

Results: Osteoporotic model. The mean force needed to produce a depression of 5mm was 700.8N with the 4-screw construct and 512.4N with the 2 screw construct (p=0.007).

Non-osteoporotic model. The mean force requires to produce the same depression was 1878.2N with the 2-screw construct and 1938.2N with the 4 screw construct (p=0.42).

An increased fragmentation of the synthetic bone fragments was noticed with the 2-screw construct but not with the 4-screw construct.

Conclusion: A raft of 4, 3.5 mm cortical screws is biomechanically stronger than two, 6.5mm cancellous screws in resisting axial compression in osteoporotic bone.

Introduction and aims: There is a recent trend of using a raft of small diameter 3.5 mm cortical screws instead of the large diameter 6.5mm screws in depressed tibial plateau fractures (Schatzker type 3). Our aim was to compare the biomechanical properties of these two constructs in the normal and osteoporotic sawbone model.

Methods: 10 sawbone (solid rigid polyurethane foam) blocks with a density simulating that of an osteoporotic bone and 10 blocks of a density simulating normal bone were obtained. A Schatzker type 3 fracture was created in each block. The fracture fragments were then elevated and supported using 2, 6.5mm cancellous screws in 10 blocks and 4, 3.5mm cortical screws in the remaining.

The models were loaded to failure using a Lloyd’s machine. A displacement (depression) of 5mm was taken to be the point of failure. A load displacement curve was plotted using Nexygen software and the force needed to cause a depression of 5mm was calculated in each block. Mann Whitney U test was used for statistical analysis.

Results: Osteoporotic model

The mean force needed to produce a depression of 5mm was 700.8N with the 4-screw construct and 512.4N with the 2 screw construct. This difference was statistically significant (p=0.007).

Non-osteoporotic model

The mean force requires to produce the same depression was 1878.2N with the 2-screw construct and 1938.2N with the 4 screw construct. The difference was not statistically significant (p=0.42).

An increased fragmentation of the sawbone fragments was noticed with the 2-screw construct but not with the 4-screw construct.

Conclusion: A raft of 4, 3.5 mm cortical screws is biomechanically stronger than 2, 6.5mm cancellous screws in resisting axial compression in osteoporotic bone.

Aim: 1. To assess the role of the CT scan in management of intra-articular fractures of the calcaneum. 2. Does the scan makes any difference to the management decision, obtained from assessing the plain radiograph?.

Methodology: This study involved 24 patients with intra-articular fracture of the calcaneum who had both a plain radiograph and a CT scan as a part of their assessment. Three consultants who were blinded to the actual management and names of the subjects were independently asked to grade the radiographs and CT scans, as operative or non-operative, on different occasions. The data was matched to the actual management and was subjected to statistical analysis.

Results: The data was non-parametric and related. The SIGN test was used to analyse the agreement between the three observers and if the decisions made in each of the groups were significantly different from the actual management. There was no statistically significant difference, between the management decision from the radiographs or CT and the actual management.

The change in management that the CT scan brought about was also assessed for each of the observers using the McNemars test. The CT scan did not make any significant difference to the decision made based on the plain radiographs, on whether to operate or not.

A Cochran Q test used to assess the variability of the decisions, showed that there was more inter-observer variability in decision making, using the CT based assessment (Q=9.50, p=0.009) as compared to plain radiographs (Q=3.84, p=0.14).

Conclusion: We conclude that, the CT scan should only be requested when a decision is made to operate on the fracture, based on plain radiographs. This may help with pre-operative planning of fracture fixation. It does not have to be obtained as a routine to assess all intra-articular fractures of the calcaneum.

Introduction The effect of hip rotation on the measurement of femoral offset is determined firstly using artificial bones in an anatomical study and then in a patient population. Its effect on the choice of femoral component in total hip arthroplasty is discussed

Methods Radiographs were taken of a series of saw bone models rotated through a range of angles. The resultant offset was then measured Standardised and Control (unstandardised) radiographs of the pelvis were taken of patients presenting to orthopaedic outpatients. Femoral offset was measured from each radiograph

Results In the anatomical study angles of rotation differed significantly with respect to measurement of offset (p< 0.0001 Friedman 2-way analysis of variance by ranks). The greatest measurement of offset was at 15 degrees internal rotation. Offset decreased with external rotation. The clinical study had power of 80%. Femoral offset was increased in all the standardised x-rays compared with their controls (n=108, mean=7.64, SD=5.55, 95% CI (6.58,8.70)). A one-sample t-test was performed to see if the standardised and control films were greater than 5mm different (t=14.30 (107df), p< 0.01).

Conclusions The clinical study confirmed the findings of the anatomical study. A standardised AP radiograph of the pelvis improves the measurement of femoral offset. For surgeons using the Exeter hip system failure to account for offset could lead to the selection of a stem two sizes too small with regards to offset. Lesser degrees of rotation, not readily identified by looking at the radiograph, could still lead to the selection of an incorrectly sized stem. Offset has been shown to increase the range of movement, abductor strength and stability of the hip joint whilst decreasing the rate of wear. It therefore benefits patients to account for offset, ensuring a correctly sized hip replacement.