Aim

Predicting success of a Debridement, Antibiotics and Implant Retention (DAIR) procedure for Periprosthetic Joint Infection (PJI) remains a challenge. A failed DAIR might adversely affect the outcome of any future revision surgery for PJI. Hence, the ability to identify and optimise factors predictive of DAIR success would help target the procedure to the appropriate patient cohort and avoid unnecessary surgery for patients where a DAIR is unlikely to eradicate infection.

The orientation of the acetabular component in metal-on-metal hip resurfacing arthroplasty affects wear rate and hence failure. Correct assessment of acetabular orientation is key in assessing the painful hip resurfacing. This study aimed to establish if interpretation of pelvic radiographs with TraumaCad software can provide a reliable alternative to computed tomography (CT) in measuring the acetabular inclination and version.

TraumaCad was used to measure the acetabular orientation on AP pelvis radiographs of 14 painful hip resurfacings. Four orthopaedic surgeons performed each measurement twice. These were compared with measurements taken from CT reformats performed by an experienced musculoskeletal radiologist. The correlation between TraumaCad and CT was calculated, as was the intra- and inter-observer reliability of TraumaCad.

There is strong correlation between the two techniques for the measurement of inclination and version (p<0.001). Intra- and inter-observer reliability of TraumaCad measurements are good (p<0.001). Mean absolute error for measurement of inclination was 2.1°. TraumaCad underestimated version compared to CT in 93% of cases, by 12.6 degrees on average.

When assessing acetabular orientation in hip resurfacing, the orthopaedic surgeon may use TraumaCad in the knowledge that it correlates well with CT and has good intra- and inter-observer reliability but underestimates version by 12° on average. This underestimation may be contributed to by the natural divergence of the X-ray beam, the short arc of the ellipse left exposed by the large diameter head, and the non-hemispherical resurfacing cup.

Informed consent is vital for good patient-surgeon communication. It allows the patient to be given an unbiased and accurate view of the procedure as well giving an opportunity for patients to gain trust in their surgical team. The consent form is written evidence of this discussion and a poor consent form implies a sub-standard consenting process. The General Medical Council (GMC) have issued guidelines for consent in surgical procedures. These state that all common risks and rare but serious risks should be disclosed as well as all information being given in clear simple and consistent language.

Currently, the consent form for a hip fracture operation is hand written. Our hypothesis was that the quality of consenting is variable and that many important complications may not be identified.

The British Orthopaedic Association (BOA) blue book, ‘The care of patients with fragility fractures,’ has given guidance of common and serious complications associated with operative management of hip fractures. In addition to these procedure specific complications, we have identified general complications from standardised joint arthroplasty consent forms in our trust, such as deep vein thrombosis. Our standards based on GMC guidance are that the consent form should be legible, free from jargon, without abbreviations and should include the specific and general complications.

We retrospectively identified and analysed 30 consecutive consent forms of patients that underwent operative management for hip fractures between March and April 2011. Of all consent forms, 59% were completely or partly illegible, 77% had used abbreviations and medical jargon. Inclusion of general complications on the consent form varied; infection 100%, bleeding 100%, deep vein thrombosis 82%, MI 18%, pneumonia 12%, death 12% and haematoma 0%. Specific operative complications were poorly included, with no patients undergoing hemiarthroplasty being advised of the risk of prosthetic loosening, acetabular wear or periprosthetic fractures. For consent of patients undergoing fracture fixation, 67% had been informed of re-operation and 40% had been told of non-union.

This data shows that consent forms are generally poorly written and subject to great variation in complications for the same surgical procedure. This data is likely to apply to some extent to all hospitals that use blank consent forms. This has implications for patient care and safety, as well as medicolegal implications for medical professionals. In our hospital, consent forms have been standardised for joint arthroplasty, with all complication pre-printed with plain English explanations below. Our proposal is that all common operations should have pre-printed consent forms. This would standardise consenting and provide a much improved documentary evidence of the consenting process.

This data has a number of lessons that can be applied to other hospitals. Firstly, we suggest that other hospitals consider standardised consent forms. Secondly, individual trainees should be clear that consent forms remain the documentary evidence of the consenting process, long after you forget the verbal details and you should ensure that you include all complications, write clearly and without jargon or abbreviations.

Urinary catheterization in the postoperative period is known to increase the risk of deep joint infection following arthroplasty. A number of studies have attempted to elucidate the individual patient factors and surgical procedural factors which predispose patients to postoperative urinary retention.

We conducted a retrospective observational study of three hundred patients to specifically determine the effect of the anaesthetic technique on the incidence of urinary retention following elective lower limb arthroplasty. One hundred consecutive patients were surveyed in each of three groups differing by the type of the anaesthetic technique and the drug administered; 1) general anaesthesia with femoral nerve block, 2) spinal anaesthesia with intrathecal fentanyl, and 3) spinal anaesthesia with intrathecal morphine.

The incidence of urinary retention requiring catheterisation in male patients receiving intrathecal morphine was 58% compared with 10% and 6% for those who had general anaesthesia with femoral nerve block and intrathecal fentanyl, respectively. This difference was statistically significant (p<0.01). The incidence of urinary retention in females across all groups was =2%. The average residual volume of urine following catheterisation was 750ml (460-1500ml).

Our findings show that the use of intrathecal morphine greatly increases the risk of postoperative urinary retention in male patients, whereas no significant increase was found amongst female patients. This risk should be carefully considered when choosing the type of intraoperative anaesthetic/analgesic combination employed in male patients and be rationalised against the intended benefits to the patient.

Purpose of study

To investigate possible advantages of uncemented over cemented femoral components in hip resurfacing.

We investigated the blood flow to the femoral head during and after Resurfacing Arthroplasty of the hip.

In a previous study, we recorded the intra-operative blood flow in 12 patients who had a posterior approach to the hip and 12 who had a trochanteric flip approach. Using a LASER Doppler flowmeter, we found a 40% drop in blood flow in the posterior group and an 11% drop in the trochanteric flip group (p<0.001). The aim of this current study was to find out whether the intra-operative fall in blood flow persists during the post-operative period.

We therefore conducted a Single Positron Emission Tomography (SPECT) scan on 14 of the same group of patients. The proximal femur was divided into four regions of interest. These were the mid-shaft, proximal shaft, inter-trochanteric and head-neck regions. The data was analysed for bone activity and comparisons made between the two groups for each region of the femur. We found that the bone activity in the mid-shaft, upper-shaft, and head-neck regions was the same eleven months after the surgery irrespective of the approach to the hip. However there was higher activity in the trochanteric flip group in the inter-trochanteric region.

We conclude that the intra-operative deficit in blood flow to the head-neck region of the hip associated with the posterior approach does not seem to persist in the late post-operative period. We believe the reason for increased bone activity in inter-trochanteric region to be due to the healing of the trochanteric flip osteotomy.

We used a laser Doppler flow-meter with high energy (20 m W) laser (Moor Instruments Ltd. Milwey, UK) to measure the blood flow to the femoral head during resurfacing arthroplasty.

Twenty-four hips were studied; 12 underwent a posterior approach and twelve a Ganz's trochanteric flip osteotomy. The approach was determined according to surgeon preference. Three patients were excluded, The exclusion criteria were previous hip surgery, history of hip fracture and avascular necrosis (AVN). All patients had the hybrid implant with cemented femoral component.

During surgery a 2.0mm drill bit was passed via the lateral femoral cortex to the superior part of the head neck junction. The position was confirmed using fluoroscopy. The measurements were taken during five stages of the operation: when the fascia lata was opened (baseline), at the end of soft tissue dissection, following dislocation of the hip, after relocation back into the socket, after inserting the implants prior to closing the soft tissues and, finally, at the end of soft tissue closure.

The results were analysed and the values were normalised to a percentage of the baseline value. We found a mean drop of 38.6 % in the blood flow during the posterior approach and a drop of 10.34% with the trochanteric flip approach. The significant drop occured between the baseline (1st stage) and the end of the soft-tissue dissection (2nd stage). In both groups the blood flow remained relatively constant afterwards.

Our study shows that there is a highly significant drop in blood flow (p<0.001) during the posterior approach compared with the trochanteric flip approach.