A knowledge-based computer-aided system for closed diaphyseal fracture reduction.
BACKGROUND
We recently developed an algorithm to perform closed fracture reduction using unilateral external fixator. Although its validity has been verified experimentally, the whole reduction process was not evaluated owing to the lack of a device that could facilitate its implementation in clinical practice. The objective of this study is to develop a prototype of such a system, and quantify its reduction accuracy.


METHODS
The system consists of a custom-made unilateral external device and a self-contained software package. The device features 7 one degree of freedom joints, each allows for continuous adjustments and is equipped with measurement components to facilitate accurate positioning. A CT-based method was developed, which facilitates virtual reduction and calculates the adjustment requirements that reduce a fracture deformity. The device was adjusted off-the-site and reattached back in place to guide the reduction of the fracture fragments. Reduction accuracy was evaluated using eight phantoms of different types, sides and fracture patterns by calculating the rotation about a screw axis and the displacement between the origins of the distal and proximal local coordinate systems after the reduction.


RESULTS
The mean (SD) of the translational and rotational reduction errors were 1.73 (0.97)mm and 2.57 degrees (1.36 degrees), respectively, which demonstrated the accuracy and reliability of the system.


CONCLUSIONS
The system allows surgeons to perform fracture reduction in an objective, efficient, and accurate manner yet minimize the radiation exposure and lessens the extent of tissue disruption around the fracture site during the reduction process.
Koo
Terry K K
TK
Foot Levelers Biomechanics Research Laboratory, Department of Research, New York Chiropractic College, 2360 State Route 89, Seneca Falls, NY 13148-3204, USA. tkoo@nycc.edu
Mak
Arthur F T
AF
D001185:Artificial Intelligence; D004867:Equipment Design; D019544:Equipment Failure Analysis; D016267:External Fixators; D005592:Fracture Fixation / Q000295:instrumentation* / Q000379:methods*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*