A NEW RADIOLOGICAL ALIGNMENT JIG TO OVERCOMING THE CHALLENGES OF INSERTING DISTAL LOCKING SCREWS

Abstract

Introduction: The current techniques used for locking the distal end of intramedullary nails with cross screws remain a technical operative challenge for many clinicians. The surgeon uses his/her experience and judgement to locate the distal holes in the intramedullary nail, relying heavily on the use of two dimensional intra operative X-ray images (fluoroscopy) to undertake a three dimensional task. As a result, a large number of X-ray images are frequently required, significantly increasing the radiation exposure to both the patient and the operative team. Also there is an overall proportional increase in the operating time.

Aim: We aimed to develop a simple new radiological alignment jig that would allow the accurate placement of distal locking cross screws during intramedullary nailing, with minimal radiation exposure and without having to visualise the distal screw holes.

Materials and method: Laboratory tests were conducted using plastic femora (Sawbones Limited) fixed with intramedullary nails. Tests were performed three times using each of the different femoral intramedullary nails (Russell-Taylor, Smith & Nephew) investigating whether the length or diameter of the nail had any influence upon the accuracy of distal screw insertion. After successfully concluding the laboratory tests, a limited clinical study was conducted using the new alignment jig to insert distal locking screws in patients.

Results: Both the bench tests and limited clinical study were 100% successful and permitted the clinician to identify the distal holes correctly without needing to visualise the distal screw holes radiologically.

Conclusion: Our initial bench tests and clinical study show that the new alignment jig allows simple and accurate insertion of the distal locking screws with minimal radiological guidance. It also has considerable potential to reduce the overall operating time.