Development, validation and initial outcomes of a questionnaire to examine human factors in postgraduate surgical objective structured clinical examinations.

BACKGROUND: Human factors including stress, repetition, burnout and fatigue are associated with possible sources of error. Objective structured clinical examinations (OSCEs), where examiners concentrate for long periods, would benefit from a human factors approach to see whether these factors affect consistency of examiner behaviour, attitude and marking. Little has been published for OSCEs, in part due to the lack of a validated tool for collecting data in this setting. METHODS: A 46-item questionnaire was developed based on the Human Factors Analysis and Classification System (HFACS) domains and completed by examiners in the Intercollegiate Membership of the Royal College of Surgeons (MRCS) examination. To refine the questionnaire, an initial analysis focused on response patterns of each item. Cronbach's α was used to assess internal consistency, and a factor analysis was performed to uncover different domains emerging from the data. RESULTS: A total of 108 examiners completed the questionnaire (90·0 per cent response rate). The questionnaire, refined to 38 items based on an initial analysis of response patterns, showed good reliability for internal consistency (Cronbach's α = 0·76) and test-retest reliability (r = 0·85, n = 48, P < 0·001). Four factors had a close themed resemblance to the original HFACS domains, but were associated with different items, suggesting that the four human-factor domains might be linked to different behaviours and attitudes in an examination setting. Analyses according to sex, professional background and experience highlighted additional stress levels in examiners from one of the surgical Royal Colleges (P <0·001), matching evidence from the situation in that College at the time of this study. CONCLUSION: The recognition and further investigation of human factors in OSCEs is needed to improve examiner experience and behaviour in order to influence delivery, candidate experience and quality assurance of these examinations.

Computer-assisted total knee arthroplasty using patient-specific templating.

Current techniques used for total knee arthroplasty rely on conventional instrumentation that violates the intramedullary canals. Accuracy of the instrumentation is questionable, and assembly and disposal of the numerous pieces is time consuming. Navigation techniques are more accurate, but their broad application is limited by cost and complexity. We aimed to prove a new concept of computer-assisted preoperative planning to provide patient-specific templates that can replace conventional instruments. Computed tomography-based planning was used to design two virtual templates. Using rapid prototyping technology, virtual templates were transferred into physical templates (cutting blocks) with surfaces that matched the distal femur and proximal tibia. We performed 45 total knee arthroplasties on 16 cadaveric and 29 plastic knees, including a comparative trial against conventional instrumentations. All operations were performed using patient-specific templates with no conventional instrumentations, intramedullary perforation, tracking, or registration. The mean time for bone cutting was 9 minutes with a surgical assistant and 11 minutes without an assistant. Computer-assisted analyses of six random computed tomography scans showed mean errors for alignment and bone resection within 1.7 degrees and 0.8 mm (maximum, 2.3 degrees and 1.2 mm, respectively). Patient-specific templates are a practical alternative to conventional instrumentations, but additional clinical validation is required before clinical use.

Radiation exposure to the hands of orthopaedic surgeons: are we underestimating the risk?

INTRODUCTION: Previous studies reported that the radiation exposure to the hands of orthopaedic surgeons was far below the acceptable limit. However, the risk could have been underestimated as some factors were overlooked, namely monitoring trainees during average workload, placing dosimeters over the most susceptible locations, measuring the cumulative dosage of radiation and considering the dose limit for non-classified workers. MATERIALS AND METHODS: We performed a prospective study in two centres to estimate the radiation dose to the hands of two consultant trauma surgeons and two trainees (one assisting and one operating) while performing 47 fluoroscopy-assisted procedures. We used validated thermoluminescent dosimeters (TLDs) rings and fingerstalls for monitoring the cumulative dosage. RESULTS: Trainees were at higher risk while performing intramedullary nailing and during assistance. Higher radiation doses were recorded from dominant index fingers and particularly fingertips. CONCLUSION: The risk of radiation exposure appears to be higher than previously reported. Fingertips are more susceptible to radiation exposure and should therefore be monitored in forthcoming studies.

A virtual fluoroscopy system and its use for image guidance in unicompartmental knee surgery.

The C-arm fluoroscope is an indispensable intraoperative 2D imaging device for orthopaedic surgery. However, its frequent use in an operation presents a significant radiation hazard to the theatre staff and patient. A recent technique known as virtual fluoroscopy (VF) enhances the fluoroscope's capability for image guided surgery by tracking optically the position of the C-arm, surgical instruments and the patient. Virtuality is achieved by overlay of surgical instruments onto one or more previously captured fluoroscopic images. A key benefit of VF is that it reduces considerably the radiation hazard. This paper reports on a new VF technique for tracking and calibration of the fluoroscopic C-arm. Also reported is the use of our VF system to provide a new image guided technique for the accurate placement of the femoral component of unicompartmental knee prosthesis.

A generic arthroscopy simulator architecture.

Virtual Environments offer considerable potential to improve training for arthroscopic surgery. However, current systems are developed for individual joints, which requires healthcare providers to purchase and maintain multiple environments with differing interfaces and capabilities. This paper describes a generic arthroscopy system architecture that allows the fast development of training environments for any joint, each sharing a common user-interface. The use of the architecture in developing a simple ankle simulator is also described.

Surgical trainee assessment using a VE knee arthroscopy training system (VE-KATS): experimental results.

Previous work has described the development of a Virtual Environment Knee Arthroscopy Training System (VE-KATS): a collaborative project between the Orthopaedic Department, Hull and East Yorkshire Hospitals NHS Trust, Hull, U.K., and the Department of Computer Science, University of Hull, U.K. This work describes the initial results obtained by Orthopaedic Surgical Trainees using VE-KATS. The results showed that differences between individual trainees could be measured using the scoring system incorporated within VE-KATS. There was a weak correlation with the seniority of the surgical trainees.

Use of polymerase chain reaction in diagnosis of occult tuberculosis of the fibula.

An unusual case of tuberculosis of the lower end of the fibula in a young patient is reported. The patient presented with symptoms of pain and swelling over the outer aspect of the right ankle with full range of painless ankle movements. The plain radiographs of the ankle were normal but MRI scan showed increased signals within the lower end of the fibula on T2-weighted images. The histology of the lesion showed only a few Langhans giant cells and culture failed to grow any organism. Polymerase chain reaction analysis of the biopsy specimen, however, showed growth of Mycobacterium tuberculosis. The patient responded to antitubercular treatment with complete resolution of symptoms. Polymerase chain reaction analysis should be considered in atypical presentations with bone pain to rule out an occult infectious pathology.

Computer and robotic assisted osteotomy around the knee.

The outcome variability and failures of conventional osteotomy have been attributed to lack of preoperative planning and inaccuracy in performing the correction. We present a computer and robotic assisted surgery system that can aid in accurate surgical planning for realignment, and in precisely implementing the plan in theatre. The approach seeks to avoid the cost and risks associated with the use of CT, and the insertion of fiducial markers, which are characteristic of existing computer assisted surgical systems. The paper details the architecture of the system as a whole, placing particular emphasis on planning technique. It is anticipated that the increased accuracy possible with the system will prove particularly useful for correcting multi-plane deformities, which are more problematic with conventional techniques.

A portable virtual environment knee arthroscopy training system with objective scoring.

We have developed a Virtual Environment Knee Arthroscopy Training System (VE-KATS). Formative analysis indicated several features which surgical trainees indicated were necessary for a system to be useful. We have addressed this need by incorporating both rigid and deformable objects, simultaneous use of camera and surgical instrument, improved optical modeling, portability and low cost. A major advance has been the incorporation of automated objective scoring of performance. VE-KATS has now progressed to a viable training system which will be of practical benefit to trainee orthopaedic surgeons.

A technique for very high accuracy image intensifier calibration.

Accurate characterisation of the image distortion within a fluoroscopic image intensifier is critical if it forms the vision component of an image guided surgical system. By considering non-linear dynamic distortion it is possible to greatly increase the accuracy of the image intensifier, although at the cost of some image quality.

Review of orthopaedic manipulator arms.

Trajectory planning and implementation forms a substantial part of current and future orthopaedic practice. This type of surgery is governed by a basic orthopaedic principle [1] which involves the placement of a surgical tool at a specific site within a region, via a trajectory which is planned from X-ray based 2D images and governed by 3D anatomical constraints. The accuracy and safety of procedures utilising the basic orthopaedic principle depends on the surgeon's judgement, experience, ability to integrate images, utilisation of intra-operative X-ray, knowledge of anatomical-biomechanical constraints and eye hand dexterity. The surgeon must remain as the responsible medical expert in charge of the overall system. At the same time the surgeon covets the accuracy offered by Computer Assisted Surgery including a manipulator. A summary of current inadequacies of manipulators indicates that the main drivers for future work are that accuracy is critical in close contact with the environment, safety concerns dictate manipulator geometry and technological limitations are many. In any effort to develop an optimal manipulator to guide surgical instruments and tools it is an obvious first step to review and categorise current manipulators. The aim of this paper is to review all aspects of manipulator design against the five main criteria of ergonomics; safety; accuracy; sterility and measurable benefits such as reduced operative time, reduced surgical trauma and improved clinical results.

A computer assisted orthopaedic surgical system for distal locking of intramedullary nails.

This paper presents a prototype system for computer assisted surgery, the purpose of which is to assist orthopaedic surgeons when performing distal locking of intramedullary nails. This system comprises three components, namely: an Intelligent Image Intensifier, a Trajectory Tactician and an Intelligent Trajectory Guide. The Intelligent Image Intensifier is an X-ray vision system that provides accurate X-ray images. Such images enable the Trajectory Tactician software to analyse the operation site and calculate the trajectory required for a screw to lock an intramedullary nail. This involves the capture of two X-ray images from which are extracted the projections of the nail's edge boundaries and its distal locking holes. Using an analytical mathematical model of the nail, the position and orientation of the nail is determined. The trajectory is then implemented by the surgeon using the Intelligent Trajectory Guide. Evaluation in the laboratory suggests that the system is capable of reliably inserting a locking screw into an intramedullary nail. The rapidity with which this computer assisted method achieves locking should benefit both patient and surgeon by reducing radiation dosage and the length of time required to lock a nail.

The use of semipermeable dressings in fingertip injuries.

A randomised prospective trial was carried out to compare the use of semipermeable and petroleum gauze dressings in fingertip injuries. The results demonstrate advantages in the use of semipermeable dressings.

Unicompartmental Oxford Meniscal knee arthroplasty.

Unicompartmental knee arthroplasty is an attractive concept, but some reports on its use are unfavorable. A meniscal bearing prosthesis has many advantages in this mode of arthroplasty. The authors present preliminary results of 25 unicompartmental knee replacements done with the Oxford Meniscal knee, with a follow-up period of 12-54 months (mean, 21 months). They discuss the scientific basis of unicompartmental knee arthroplasty, which they conclude may be the most appropriate treatment for selected cases of degenerative arthritis of the knee.

A simple adjustable functional brace for tibial fractures.

The use of an adjustable functional brace for fractures of the tibia has several practical and theoretical advantages. The high cost of commercially available braces has limited their use until now. We describe a simple, inexpensive orthosis which has given good results in a clinical study for 32 unselected fractures. The fractures' alignment was well maintained. The brace was comfortable to wear and there were few complications. It is hoped that the low cost of this simple custom-made brace will encourage more widespread use of this technique.

Bilateral Oxford Meniscal Knee arthroplasty.

Thirty-two patients who underwent bilateral bicompartmental Oxford Meniscal Knee arthroplasty have been followed up prospectively for a mean period of 51 months from the time of their first operation. Pain relief was obtained in all but one knee; walking ability was improved in more than two-thirds. Overall patient satisfaction with the results was good. Two knees failed. The results demonstrate that bilateral knee arthroplasty can be expected to give good functional results.