Development and Validation of a Low-Cost Drilling Model.

Background: Simulation models enable learners to have repeated practise at their own time, to master the psycho-motor and sensory acuity aspects of surgery and build their confidence in the procedure. The study aims to develop and evaluate the feasibility of a low-cost drilling model to train surgeons in the drilling task. The model targets three aspects of drilling - (1) Reduce plunge depth, (2) Ability to differentiate between bone and medullary canal and (3) Increase accuracy drilling in various angles. Methods: This cross-sectional study was conducted after obtaining ethics approval. We invited Consultants in the field of Orthopaedic or Hand Surgery to form the 'expert' group, and the 'novice' group consisted of participants who had no prior experience in bone drilling. We developed a drilling simulator model made from a polyvinyl chloride (PVC) pipe filled with liquid silicone. This model cost less than US$5. An electric Bosch drill (model GBM 10 RE) with a 1.4 mm K-wire 10 cm in length (6.5 cm outside the drill) was used for drilling. The main outcomes of the study were time taken for drilling, plunge depth, ability to penetrate the far cortex and accuracy. Results: Thirty-one participants were recruited into the study, of which 15 were experts and 16 were novices. The experts performed significantly better for plunge depth (t = -3.65, p = 0.0003) and accuracy (t = -2.07, p = 0.04). The experts required 20% less time to complete the drilling tasks, but it was not statistically significant (t = -0.79, p = 0.43). Conclusions: The low-cost drilling model could be useful in training Residents in the drilling task. It will allow Residents to practise independently at their own time and assess their own performance.

Post-Reduction Stability of the Proximal Interphalangeal Joint after Dorsal Fracture Dislocation-A Cadaveric Study.

BACKGROUND: Proximal interphalangeal joint (PIPJ) dorsal fracture dislocations (DFD) are challenging injuries. Treatment aims to achieve stability of the PIPJ after reduction so that early motion can be initiated. We studied how increasing articular destruction would affect post reduction stability and investigate the amount of traction and PIPJ flexion needed to maintain the reduction. METHODS: Increasing amounts (20%, 40% and 60%) of damage to the volar lip of the middle phalanx in cadaveric specimens were created to represent PIPJ DFD that were stable, of tenuous stability and frankly unstable. Traction forces and PIPJ flexion needed to maintain the reduction were then measured. RESULTS: The PIPJ DFD with 20% damage were stable and did not subluxe while the one with 40% articular involvement was stable after reduction. For unstable the PIPJ with 60% involvement, the more the PIPJ was flexed, the less traction force was needed to hold the joint in reduction. For PIPJ flexion of 20 degrees, a minimum 4.4N of force is needed to maintain reduction while PIPJ flexion of 10 degrees required a minimum 5.0N of force. No amount of force could maintain PIPJ reduction if traction was performed in full extension. CONCLUSIONS: In our model, PIPJ DFD with less than 30% articular damage are stable while those with 30% to 50% of involvement have tenuous stability. For the unstable PIPJ DFD, traction obviates the need for excessive flexion of the PIPJ to maintain joint reduction. This information should be considered in treatment modalities for PIPJ DFD, as well in the design of external traction devices for the treatment of PIPJ DFD.

Causes and assessment of subacute and chronic wrist pain.

Wrist pain is a common presentation to the general practitioner and emergency department. Most cases are simple to treat, and pain frequently resolves with conservative treatment. However, there are certain conditions, such as scaphoid nonunion and Kienböck's disease, where delayed diagnosis and treatment can result in long-term deformity or disability. This article covers the various causes of wrist pain, recommendations on how wrist pain should be assessed, as well as details some of the common conditions that warrant specialist referral.