Prevention of surgical infection following joint arthroplasty is preferable to treatment.

Prevention requires identification and control of the potential sources of microbial contamination. The purpose of this study was to determine whether the density of airborne particulate in the operating room during total joint arthroplasty could predict the density of viable airborne bacteria at the surgery site.

A standard particle analyzer was used to measure the number and diameters of airborne particulate during 22 joint arthroplasty surgeries performed in non-laminer flow rooms. An impact air sampler and standard culture plates were used to collect airborne particulate and were analysed to identify and count colony-forming units.

Particulate density averaged > 500,000 particles/ft3, and 1,786 colony-forming units were identified, primarily gram-positive cocci. The density of particles ≥10um explained 41% of the variation in colony-forming unit density. Colony-forming units and ≥10 um particle density increased with longer surgery duration and higher staff counts.

This is the first study to the authors knowledge that shows a correlation between the number of persons in the OR and CFUs at the surgical site during total joint arthroplasty procedures. Increasing surgical staff appear to produce both more particulate and more CFUs. These observations support the use of environmental controls that isolate and protect the surgical site from airborne particulate and microbial contamination.

Continuous monitering of particulate larger than 10 um during joint arthroplasty procedures may be warrented.

Background: Chronic compartment syndrome is well recognised. Patients present with exercise-induced pain, relieved by rest. The condition is caused by increased intracompartmental pressure due to inadequate muscle compartment fascial size. Cases of forearm chronic compartment are sporadic. Previous published case series affecting the upper limb have not used compartment pressure monitoring to aid diagnosis. In our chronic compartment pressure monitoring clinic we confirmed the diagnosis of four cases. Following these a review of the literature showed that there was no definition of normal pre or post-exercise pressure for the upper limb.

Aim: This study aimed to establish the normal pre and post-exercise forearm pressures in asymptomatic normal individuals to give a baseline upon which perceived raised pressures could be calculated against.

Methods: Ethical approval was obtained from Dorset Research and Ethics Committee. 41 participants underwent compartment pressure measurements of the superficial extensor and flexor forearm compartments before and after five minutes of exercise. A Stryker intracom-partmental pressure monitor was used.

Results: Normal ranges for pre-exercise extensor compartment (2–27mmHg, upper CI 18.8–25.2mmHg), post-exercise extensor compartment (2–24mmHg, upper CI 16.8–22.8mmHg), pre-exercise flexor compartment (1–19mmHg, upper CI 13.3–17.4mmHg) and post-exercise flexor compartment (0–19mmHg, upper CI 16–21.4mmHg) pressures were established. No significant difference was found between pressures before and after exercise (extensor pressures; p=0.41, flexor pressures; p=0.21). There was a significant difference between sexes (extensor pressures; p=0.04, flexor pressures; p=0.008)

Conclusion: This study has shown a significant difference in normal forearm compartment pressures between sexes. No difference between pre and post-exercise pressure could be established. A normal reference range of forearm compartment pressures to aid diagnosis of chronic compartment syndrome has been determined. This may also prove useful in aiding the diagnosis of acute forearm compartment syndrome.

Background: Functional outcome and patient satisfaction after total knee arthroplasty can be variable. Up to 20% of patients have been reported to not be entirely happy with their knee replacement. Psychological factors, in particular illness perception – a patient’s beliefs about their illness – have been found to predict recovery from a range of conditions. Few studies have examined their impact within the orthopaedic context.

Aim: The aim of this study was to investigate the impact of psychological factors, including illness perception, anxiety and depression, on postoperative recovery and functional outcome after total knee arthroplasty.

Patients and Methods: 100 patients from two centres, who underwent a primary total knee arthroplasty for osteoarthritis between 2004 and 2006, took part in this prospective cohort study.

Before surgery patients were asked to complete a psychological questionnaire consisting of Revised Illness Perception Questionnaire (IPQ-r), Hospital Anxiety and Depression Scale (HADS) and Recovery Locus of Control (RLOC). Knee function was assessed preoperatively, at six weeks and one year using Oxford Knee Score (OKS) and range of motion (ROM).

Results: The mean OKS improved significantly at six weeks and further at one year. The mean ROM showed little change in the first six weeks, but was significantly improved at the one-year follow-up.

The psychological factors Consequences, Illness Coherence, Emotional Representation and HADS Anxiety showed a statistically significant correlation with the OKS at six weeks, the factors Consequences and HADS Anxiety and HADS Depression with the OKS at one year. We found no correlation with range of motion at six weeks, but ROM at one year was statistically significantly correlated with the factors Consequences and HADS Depression.

This indicates that patients who believed that their illness had less impact on their personal lives and patients with lower scores on the anxiety and depression scale showed a lower OKS and higher ROM at one year, indicating a better functional outcome.

Hierarchical regression analysis showed that, after controlling for demographics and baseline scores, the factor consequences explained 7% of the variance in ROM at one year. HADS Anxiety and Depression had a significant impact on OKS and accounted for 13.7% of the variance of OKS at one year.

Discussion: Recovery from TKA surgery can be difficult to predict. This study showed that functional outcome can be significantly influenced by psychological factors. These should be taken into account when considering patients for TKA surgery. Improving patient education, looking at home environment and social network as well as addressing anxiety and depression may help to improve overall outcome after TKA surgery.

Aim: The aim of this study was to investigate how psychological factors and illness perception can influence the recovery and functional outcome after total knee arthroplasty (TKA).

Patients and Methods: 100 patients who underwent primary total knee arthroplasty were included in this study. Pre-operatively patients were asked to complete a psychological questionnaire consisting of the revised Illness Perception Questionnaire (IPQ-r), Hospital Anxiety and Depression scale (HADS) and Recovery Locus of Control scale (RLOC). Function was assessed using Oxford Knee Score (OKS) and range of motion (ROM) pre-operatively and at six weeks and one year after surgery.

Results: Early results show that individual phychological variables correlate with the post-operative OKS at six weeks. Beliefs that the condition has a major effect on life and less understanding of the illness are associated with a poorer recovery. Women were found to have a higher degree of personal control, but this was not correlated with functional outcome. Patients with higher pre-operative OKS were more likely to suffer from anxiety and depression.

None of the investigated parameters predicted ROM at six weeks.

Discussion: Recovery from TKA surgery can be difficult to predict. This study showed that several psychological variables influence early functional outcome. These should be taken into account when considering patients for TKA surgery. Improving patient education, looking at home environment and social network as well as adressing anxiety and depression may help to improve overall outcome after TKA surgery.

A high proportion of complications following TKR occur at the patellofemoral articulation secondary to delami-nation and adhesive/abrasive wear. Electron beam cross-linking and melting has been shown to substantially reduce delamination and adhesive/abrasive wear in polyethylene tibial inserts. A series of in-vitro patella wear and fatigue tests were developed to explore the benefits of this material at the patellofemoral articulation.

Patellae (NKII, Sulzer Orthopedics, Inc., Austin, TX) were tested on an AMTI (Watertown, MA) knee simulator articulating against the trochlear grove of the femoral component. The simulator controlled flexion/ extension and patellofemoral contact force. Each test included patellae manufactured from conventional and electron beam crosslinked and melted polyethylene. Three different simulations were created: i) normal gait (5 million cycles) with optimal component alignment, ii) stair climbing (2 million cycles) with optimal component alignment, iii) stair climbing (2 million cycles) with 4° of femoral component internal rotation to simulate a component malalignment condition. In the last two simulations all patellae were artificially aged for 35 days in 80°C air to simulate one aspect of the long term oxidative state of each material.

In normal gait, the unaged conventional and highly cross-linked materials demonstrated similar behaviour. In stair climbing with optimal component alignment, the aged conventional patellae developed cracks by 2 million cycles. In stair climbing with component malalign-ment the aged conventional patellae developed cracks and delamination by 1 million cycles. None of the highly cross-linked components showed cracks or delamination. These results demonstrate the potential advantage of highly cross-linked polyethylene for the patella.

Abstract: The importance of nerve root inflammation accompanying disc herniation and its contribution to symptomatology was first proposed in the 1950’s. This encouraged the widespread administration of (percutaneous) epidural steroid injections in the non-surgical treatment of acute and chronic lumbar Radicular pain. It also prompted the local application of steroid preparations directly onto the nerve root at the time of disc compression.

The literature supporting this latter practice however, is scant and equivocal. A randomised double blind prospective study was therefore carried out to evaluate the benefits of epidural steroid application at the time of lumbar disc decompression. 50 consecutive patients undergoing elective lumbar discectomy were enrolled. Patients in the study group (n=25) received 20mg of tri-amcinolone acetonide, applied directly to the decompressed nerve root. The control group (n=25) received an equal volume of saline. Intraoperative analgesia was standardised and postoperative pain was measured by a 10cm visual analog pain scale at 2, 6, 12, 25 and 72 hours. Standardised post-operative analgesic protocols were established and the amounts of consumed analgesics were determined.

Statistical analysis was performed using the Mann-Whitney test. No statistically significant difference was noted in either pain score, analgesic consumption at 24, 38 or 72 hours or length of hospital stay, between the steroid treatment or control groups. This suggests that local epidural steroid administration after lumbar disc decompression offers no therapeutic advantage over mechanical decompression alone.

In 1991 15% of the UK population that travelled abroad required medical assistance. We have been treating more patients with lower limb injuries requiring repatriation via aircraft. Recommendations from Airlines were unavailable. 357 Consultants replied to a questionnaire about transportation of patients with a lower limb injury wearing a plaster cast. There was no consensus on safe transportation of these patients. No scientific data is available on the dynamics of transportation of patients with lower limb trauma. In order to assess the safest method of transportation an experiment was conducted. Ethical committee approval was granted. Five volunteers wearing above leg plaster casts were placed in a decompression chamber. The effects on anterior compartment pressures, Doppler venous return, ambient pressure between plaster and skin were assessed in different positions with and without plasters being split. In the normal population we have shown a trebling of intracompartmental pressures from an average of under 10mmHg to 30mmHg. Intracompartmental pressures are more raised with 90 degrees of hip flexion rather than 45 degrees. We recommend patients be transferred with their legs at 45 degrees to the ground with a split plaster cast.

Aim: A prospective randomised clinical trial was performed to evaluate two forms of immobilisation in the treatment of colles fractures not requiring manipulation.

Methods: Patients were randomised to either plaster cast (PC) or a removable splint: wrist splint (FWS) according to date of presentation. Patients who had associated injuries to the same upper limb, previous wrist fracture, and open fractures, below 20 years or impaired cognitive function were excluded. The hospital ethical committee approved the study and informed consent was obtained from patients. Patients were reviewed at one week, two weeks, six weeks and twelve weeks following enrolment into the trial. Radiographs were performed on the first four visits. Subjective data was obtained using a patient questionnaire. Levels of pain, comfort in cast, swelling and any modifications to the cast were documented. Was used at six and twelve weeks to assess Clinical assessment was performed by a qualified physiotherapist using the demerit score of Sarmiento which combines range of motion, grip strength and functional assessment.

Results: There were thirty-seven patients in the PC group and thirty-four in the FWS group. They were well matched in terms of age and sex distribution One patient in the PC group required manipulation under anaesthesia due to loss of position at one week. There was no statistical difference between either treatment method in radiological position. Nine patients in the PC group required change of cast due to loosening or discomfort. A further eight patients in the PC group required cast trimming. Visual analogue scores for pain and cast discomfort were lower in the FS group (p< 0.05). Grip strength compared to the opposite side was higher in the FS group (55.9% Vs 47.8% at week six, 71.8% Vs 65% at week twelve). Functional assessment demonstrated a higher score in the FS group at six weeks. However the difference did not reach statistical significance at repeat examination at twelve weeks.

Conclusion: In this study there was no difference in either method in maintaining fracture position. However there was greater patient satisfaction and earlier rehabilitation in those patients treated in a futura wrist splint. Patients treated in plaster cast required a greater use of plaster room resources. We feel that the use of a removable wrist splint in suitable patients with either undisplaced or minimally displaced distal radial fractures is validated by this study.