1737 elective foot and ankle cases were prospectively audited from Dec 2005 to end June 2010. All cases were brought back to a specialist nurse dressing clinic between 10 and 17 days post op. Data was collected at the dressing clinic with a standardised proforma on the type of surgery, the state of the wound and any additional management required. Those patients with a pre-existing infection were excluded.

Of the 1737 cases 201 (11.6%) had a minor wound problems such as excessive post op bleeding into the dressings, suture problems, early removal of K wires, delayed wound healing and minor infection. 42 patients required antibiotics (2.4%) 8 patients had a deep wound infection (0.5%) requiring intravenous antibiotics and or further surgery.

There were 1185 forefoot procedures 36 of which developed an infection (3%), overall infections of the mid/hindfoot was 6 (1%).

Practice has changed as a result of the audit (reviewed annually). We have changed our closure techniques (reducing suture problems). For the past 2 years all of our elective foot and ankle patients now go to an ultra clean ward (Joint Replacement Unit) and we have shown a reduction in infection rates by over 50% since. Our infection rate before the JRU was 3.3% with 0.7% deep infection rate (818 procedures) and after the introduction of the JRU our infection rate has ped to 1.6% superficial and 0.3% deep infection p<.001.

This large series prospective study sets a benchmark for infection rates in elective foot and ankle surgery. It also highlights the benefit of a dedicated orthopaedic elective unit with rigorous infection control policy and the need to regularly review our results.

This study evaluated the biologic fixation of two different titanium porous coatings: a clinically successful sintered spherical bead coating [1] and a new sintered asymmetric particle coating (STIKTITE™, Smith & Nephew). The spherical bead coating has a porosity of about 50% and an average pore size of about 220 μm, whereas the STIKTITE coating has greater porosity (about 62%) and slightly smaller average pore size (about 200 μm). Biologic fixation was assessed using a load-bearing ovine model in which coated semi-circular disc implants were inserted into a defect created in the cancellous bone parallel to and approximately 3 mm below the medial tibial plateau [2] similar to the method reported by Ignatius [3]. The implants were slightly thicker than the defect created, producing a 0.2-mm overall pressfit. Initial implant stability was assessed using mechanical push-out (n = 3) immediately after implantation into cadaveric ovine bone. Quantitative mechanical push-out testing and qualitative histology (n = 9 and n = 2, respectively, per group per time point) was performed after six and 26 weeks in vivo.

The time-zero average peak push-out load (±S.D.) of the STIKTITE group (95±3 N) was found to be significantly greater (p < 0.02) than that of the spherical bead group (36±5 N). By six weeks in vivo, the average peak push-out load for the STIKTITE group was up to 1001±362 N, and that for the spherical bead group was up to 985±425 N, both representing a significant increase compared to their time-zero results (p < 0.0005). From six to twenty-six weeks in vivo, there was again a significant increase in the peak push-out load irrespective of group (p < 0.0005), with the average peak push-out loads up to 1620±406 N and 1444±446 N for the STIK-TITE and spherical bead groups, respectively. Histology revealed bone ingrowth in both groups that confirmed the findings of the mechanical push-out testing. While the STIKTITE group showed a trend toward greater biologic fixation, overall there was insufficient evidence to support differences between the two groups (p = 0.47) irrespective of the amount of time in vivo.

The results of this study confirm the ability of the STIK-TITE coating to achieve superior initial stability. This improved initial stability reduces the reliance on adjunct fixation (such as screws) or large amounts of press-fit to prevent micromotion and create an environment suitable for long-term bone ingrowth. The results also suggest that the STIKTITE coating had a tendency to initiate and maintain bone ingrowth under load-bearing conditions to a level greater than that of a clinically successful sintered bead coating. Because loading of the implant can cause micromotion at the bone/implant interface, models like the one used in this study likely provide a more challenging and realistic representation of anticipated clinical conditions than models with minimal implant loading.

Introduction: Femoroacetabular impingement (FAI) is an important cause of hip pain in young adults and a precursor to osteoarthritis. Genetic factors are important in the aetiology of osteoarthritis of the hip. From a research perspective, FAI is an example of how subtle morphological abnormality results in a predictable pattern of cartilage damage, and thereby offers great potential as a model to study early degenerative disease.

Although many causes of FAI are described, the vast majority of patients give no history of previous hip disease. The purpose of this study was to investigate the extent to which FAI has an underlying genetic basis, by studying the siblings of patients undergoing surgery for FAI and comparing them with controls.

Methods: 66 patients (probands, 29 male, 37 female, mean age 39.1 years) treated surgically for FAI provided siblings for the study. These patients were classified as having cam, pincer or mixed FAI. 101 siblings (55 male, 56 female, mean age 38.2 years) were recruited. The control group consisted of the 77 partners of those siblings (40 male, 37 female, mean age 41.9 years). All subjects underwent clinical (interview, examination, and hip scores) and radiological assessment (standardised AP Pelvic and cross-table lateral radiographs of each hip). Radiographs were scored for the presence of osteoarthritis, and cam- and pincer-type abnormalities.

Results: Participants were classified as a) Normal morphology with no clinical features, b) Abnormal morphology but no clinical features c) Abnormal morphology with clinical signs but no symptoms, and d) Abnormal morphology with symptoms and signs. The sibling relative risks were significant for groups b, c, and d, supporting the hypothesis of an underlying genetic predisposition to FAI. Siblings usually demonstrated the same type of abnormal morphology as the proband. Gender specificity was apparent however, with pincer abnormalities which were usually apparent in female probands being common in sisters but less common in brothers. The brothers of probands with cam deformities almost universally demonstrated the same deformity, although only 50% of sisters did so.

Discussion: Genetic influences are important in the aetiology of FAI. Whether the morphological abnormality is determined at conception or by an inherited predisposition to an acquired event during maturity warrants further study. We have identified a spectrum of disease with a proportion of siblings with abnormal morphology currently asymptomatic. These cohorts present an opportunity to prospectively study the natural history of the condition, improve our understanding of the mechanisms and pathology in early degenerative disease, and potentially to be recruited into clinical trials of surgical and adjuvant treatments.

We report results using the hydroxyapatite coated, distally locking Cannulok revision hip prosthesis. The component was used to treat periprosthetic and pathological fractures, often in the presence of aseptic loosening or infection in a group of elderly patients. 16 patients with a mean age of 78 years underwent surgery by a single surgeon over a period of 3 years. They were followed up clinically and radiologically for an average of 24 months.

The mean modified Merle D’Aubigne and Oxford Hip Scores were 14 and 23.6 respectively. These results are comparable to the published results for the previous version of the Cannulok hip, and other revision hip revision series.

We believe the implant provides a relatively simple and effective reconstructive option that can be used as an alternative to more extensive surgical options in elderly patients with periprosthetic fractures.

Introduction: Vertebroplasty (VP) is a relatively new procedure to treat osteoporotic compression fractures of vertebral bodies. During this procedure polymethyl-methacrylate (PMMA) is injected into vertebral bodies. However there is the concern, that fat embolism (FE) and acute hypotension could occur as in a variety of other orthopaedic procedures.

Aim: To investigate whether FE and acute hypotension are potential complications of VP using an animal model.

Methods: In six sheep, 6.0 ml PMMA were injected unilaterally into the L1 vertebral body. Transœsophageal echocardiography was used to monitor the pulmonary artery for bone marrow and fat particles until 30 minutes post-operatively. Pulse, arterial and venous pressures were also recorded. The lumbar spine and the lungs were harvested post mortem. The histopathologic score, (percentage of lung fields occupied by intravascular fat globules as seen through the microscope), was calculated.

Results: The first showers of echogenic material were visible approximately seven seconds after the beginning of the cement injection and lasted for about 2.5 minutes. The injection of bone cement caused a very rapid decrease in the heart rate after two seconds followed by a fall in the mean arterial pressure after 6.0 seconds. A maximum fall in heart rate was accompanied by a delayed fall in mean arterial pressure of 33.0 mmHg (P=0.0003) at 36seconds. The heat rate had returned to the baseline by 89 seconds and had increased by 10 beats/min (P=0.02) at 25 minutes. Mean arterial pressure had recovered by 209 seconds and was not different from the baseline at 25 minutes. Post mortem examination showed that no leakage of cement into the spinal cord had occurred. The histology revealed fat globules and bone marrow cells in the smaller and larger vessels throughout the lungs. The histopathologic score was 5.2 ± 0.9%.

Conclusions: This study clearly showed that VP resulted in FE with a two-phase decrease in heart rate and arterial blood pressure. The first phase was probably due to an autonomic reflex and the second phase was due to the passage of fat emboli through the right heart and obstructing the lungs.

Vertebroplasty (VP) is a new prophylactic treatment for preventing osteoporotic compression fractures of vertebral bodies. During this procedure polymethylmethacrylate (PMMA) is injected into several vertebral bodies. However, there is the concern, that fat embolism (FE) and acute hypotension could occur as in a variety of other orthopaedic procedures.

This study was undertaken to investigate whether FE and acute hypotension are potential complications of VP using an animal model.

In six sheep 6.0 ml PMMA were injected unilaterally into L1. Transesophageal echocardiography was used to monitor the pulmonary artery for bone marrow and fat particles until 30 minutes postoperatively. Pulse, arterial and venous pressure were also recorded. Post mortem the lumbar spine and the lungs were harvested. The lungs were subjected to histological evaluation.

The first showers of echogenic material were visible approximately 7.0 seconds after the beginning of the cement injection and lasted for about 2.5 minutes.

Injection of bone cement elicited a very rapid decrease in heart rate after 2.0 seconds followed by a fall in mean arterial pressure after 6.0 seconds. A maximum fall in heart rate was accompanied by a delayed fall in mean arterial pressure of 33.0 mmHg (P=0.0003) at 36.0 seconds. Heat rate had returned to baseline by 89.0 seconds and had increased by 10.0 beats/min (P=0.02) at 25 minutes. Mean arterial pressure had recovered by 209.0 seconds and was not different to the baseline at 25 minutes.

The post mortem inspection revealed disseminated haemorrhages on the lung surface and throughout the parenchyma mainly in the caudal lobes of all six animals. No leakage of cement into the spinal cord was detected. In histology fat globules and bone marrow cells were observed in both the smaller and larger vessels throughout the lung.

This study clearly shows that VP resulted in a two-phase decrease in heart rate and arterial blood pressure. The first phase was probably due to an autonomic reflex and the second phase was due to the passage of fat emboli through the right heart and obstructing the lungs.

We studied 1162 consecutive total hip replacements (THR) to establish the incidence of fatal pulmonary embolism (PE), clinical non-fatal PE and deep-vein thrombosis (DVT) in the six months after surgery. Chemical thromboprophylaxis had not been routinely used. We used a validated questionnaire supplemented by post-mortem records and a review of the clinical notes. Follow-up was 100%. The death rate from PE was 0.34% (95% CI 0.09 to 0.88), with one fatal PE after discharge 40 days after operation. The clinical PE rate confirmed by imaging was 1.20% (CI 0.65 to 2.02), with 0.7% of patients readmitted. The venographically-confirmed clinical DVT rate was 1.89% (CI 1.11 to 2.76), with 1.13% readmitted. The total thromboembolic morbidity was 3.4% (95% CI 2.5% to 4.7%); prophylaxis to reduce this would be justifiable if the complications of such prophylaxis did not produce an alternative morbidity. The fatal PE rate after THR without routine chemical prophylaxis was low; a very large randomised clinical trial would be required to demonstrate directly whether any prophylactic measure could reduce this. There is a large discrepancy between the high DVT rate reported in clinical trials using universal screening venography and the symptomatic DVT rate shown in this study. We found insufficient evidence to recommend continuing thromboprophylaxis after discharge from hospital.