Correlation between gross anatomical topography, sectional sheet plastination, microscopic anatomy and endoanal sonography of the anal sphincter complex in human males.

This study elucidates the structure of the anal sphincter complex (ASC) and correlates the individual layers, namely the external anal sphincter (EAS), conjoint longitudinal muscle (CLM) and internal anal sphincter (IAS), with their ultrasonographic images. Eighteen male cadavers, with an average age of 72 years (range 62-82 years), were used in this study. Multiple methods were used including gross dissection, coronal and axial sheet plastination, different histological staining techniques and endoanal sonography. The EAS was a continuous layer but with different relations, an upper part (corresponding to the deep and superficial parts in the traditional description) and a lower (subcutaneous) part that was located distal to the IAS, and was the only muscle encircling the anal orifice below the IAS. The CLM was a fibro-fatty-muscular layer occupying the intersphincteric space and was continuous superiorly with the longitudinal muscle layer of the rectum. In its middle and lower parts it consisted of collagen and elastic fibres with fatty tissue filling the spaces between the fibrous septa. The IAS was a markedly thickened extension of the terminal circular smooth muscle layer of the rectum and it terminated proximal to the lower part of the EAS. On endoanal sonography, the EAS appeared as an irregular hyperechoic band; CLM was poorly represented by a thin irregular hyperechoic line and IAS was represented by a hypoechoic band. Data on the measurements of the thickness of the ASC layers are presented and vary between dissection and sonographic imaging. The layers of the ASC were precisely identified in situ, in sections, in isolated dissected specimens and the same structures were correlated with their sonographic appearance. The results of the measurements of ASC components in this study on male cadavers were variable, suggesting that these should be used with caution in diagnostic and management settings.

Virtual reality assessment of technical skill using the Bonedoc DHS simulator.

The Bonedoc DHS simulator is a virtual reality simulator of screw and plate fixation of hip fractures which runs on a standard PC. We hypothesised that the simulator would be able to discriminate between subjects with different levels of operative experience. Three groups (medical students (MSs), basic trainees (BTs), and advanced trainees (ATs)) performed six virtual operations. Measurements included: reduction position, incision length, misplaced drill-holes, final screw placement, X-rays taken, surgical time as well as computer and operative experience. The accuracy, number of X-rays and speed were significantly different between novices and trainee surgeons (p<0.01, p<0.05, p<0.05). Intra-articular screw penetration by the medical students occurred 12 times, basic trainees 6 times and advanced trainees twice (p<0.01, MS vs. trainees). Amongst trainees, the advanced trainees placed the lag screw more accurately and took less X-rays (ns). The basic trainees performed the complete procedure fastest at 6 min compared to ATs at 9 min (p<0.05) but were not as accurate. The Bonedoc DHS simulator provides a means to discriminate between novices and trainee surgeons.

A simulation-based training system for hip fracture fixation for use within the hospital environment.

We report development of a PC-based virtual reality training system for hip fracture fixation that comprises a surgical simulator and an assessment component. The simulator allows hip fracture fixation to be performed on a virtual hip model using two-dimensional radiographic images to guide fracture reduction and implant placement. Ten operative scenarios with increasing complexities of fracture type are available. The face validity of the simulator was tested using a 26 item feedback questionnaire, with answers on a 5 cm visual analogue scale from 'disagree strongly' to 'agree strongly'. Ten study participants, aged 20-50, and with variable levels of surgical skills, each performed six operative scenarios on the simulator before completing the questionnaire. The results showed that the simulator had good face validity, with the majority of subjects stating it provided a realistic view of the operating environment (median score 8.2/10) and that the three-dimensional view provided was all that was required (median score 7.8/10). The subjects considered the simulator was able to test problem solving ability (median score 8.0/10). These results confirm that this simulator achieves good face validity without computationally intensive touch feedback (haptics). Overall, this study demonstrates that non-haptic simulators have a larger role to play in virtual simulation than is currently recognised.

Trauma and co-morbidity--a pilot study.

AIMS: To study the adult trauma patient population at the Auckland Hospital in order to determine the age distribution of trauma, the prevalence and importance of co-morbid conditions and any effect of the latter on the length of stay in the hospital. METHODS: Data were collected on 78 consecutive patients admitted to the Auckland Hospital under the Trauma team between December 1999 and January 2000. Data were collected by interviewing the patient, as well as reviewing patient's medical notes and the Trauma Registry. RESULTS: The prevalence of co-morbidities was 14.7%. No co-morbidity was found below the age of 40 years, but the prevalence of co-morbidity increased with age. The average length of stay for patients with no comorbidities and an Injury Severity Score (ISS) >15 was 19 days while for those with co-morbidities was 24.5 days--an increase of 29%. CONCLUSION: This pilot study has found that a significant number of trauma patients being admitted to Auckland Hospital have a pre-existing co-morbid condition that may alter their length of stay. It is an important issue that warrants further investigation, in order to devise a more accurate prognostic scoring system.

Lumbar transverse process fractures--a sentinel marker of abdominal organ injuries.

Fractures of lumbar vertebrae may be associated with abdominal organ injuries. Lumbar transverse process fractures are commonly thought of as minor injuries compared with body, pedicle and lamina fractures. To determine the significance of transverse process fractures as opposed to other lumbar vertebral fractures in relation to abdominal organ injury, a retrospective study was performed. One hundred and ninety-one patients with lumbar spine fractures were reviewed. One hundred and thirty-five (71%) of these had non-transverse process (NTP) fractures only (including vertebral body, pedicle, or spinous process fractures). Fourty-two patients (22%) had transverse process fractures only. Fourteen patients (7%) had both transverse process and NTP fractures. Twenty (48%) of the 42 patients with transverse process fractures had abdominal organ injuries identified. This was a significantly (P<0.05) higher rate than for the patients with NTP fractures, eight of 135 (6%). Patients with transverse process fractures and abdominal organ injuries had a median injury severity score (ISS) of 29 compared with a median ISS of 17 for patients with NTP fractures and abdominal organ injuries. If a transverse process has been fractured, there is likely to have been very large forces involved in the incident. The data strongly suggest that lumbar transverse process fractures should not be thought of as minor injuries but regarded as a significant marker for abdominal organ injuries and should alert the doctor caring for the injured patient of the high probability of these injuries.

Recurrence of gout after total knee arthroplasty.

The existence of gout in a total knee arthroplasty (TKA) may be more common than is currently recognized. We report 2 cases of acute recurrence of gout in knees after TKA, 1 with coexistent infection.