Comparative endurance testing of the Biomet Matthews Nail and the dynamic compression screw, in simulated condylar and supracondylar femoral fractures.
BACKGROUND
The dynamic compression screw is a plate and screws implant used to treat fractures of the distal femur. The Biomet Matthews Nail is a new retrograde intramedullary nail designed as an alternative surgical option to treat these fractures. The objective of this study was to assess the comparative endurance of both devices.


METHODS
The dynamic compression screw (DCS) and Biomet Matthews Nail (BMN) were implanted into composite femurs, which were subsequently cyclically loaded using a materials testing machine. Simulated fractures were applied to each femur prior to the application of load. Either a Y type fracture or a transverse osteotomy was prepared on each composite femur using a jig to enable consistent positioning of cuts.


RESULTS
The Biomet Matthews Nail demonstrated a greater endurance limit load over the dynamic compression screw in both fracture configurations.


CONCLUSIONS
The distal locking screws pass through the Biomet Matthews Nail in a unique "cruciate" orientation. This allows for greater purchase in the bone of the femoral condyle and potentially improves the stability of the fracture fixation. As these fractures are usually in weak osteoporotic bone, the Biomet Matthews Nail represents a favourable surgical option in these patients.
O'Connor-Read
Laurence M
LM
Department of Trauma and Orthopaedics, Buckinghamshire Hospitals NHS Trust, High Wycombe, UK. laurenceoconnorread@yahoo.com
Davidson
Jerome A
JA
Davies
Benjamin M
BM
Matthews
Michael G
MG
Smirthwaite
Paul
P
D032701:Biomimetics / Q000295:instrumentation / Q000379:methods; D001858:Bone Nails; D001863:Bone Screws; D019544:Equipment Failure Analysis; D005264:Femoral Fractures / Q000503:physiopathology* / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D011474:Prosthesis Design; D011475:Prosthesis Failure