Ultrasonically implanted PLA suture anchors are stable in osteopenic bone.
We compared the in vitro pullout strengths of a metallic screw-type suture anchor (5-mm Corkscrew) and a new ultrasonically implanted absorbable pin from cadaveric humeral heads with different bone densities. They were assessed quantitatively using microcomputed tomography. Pullout tests were done at four standardized sites and then correlated with the local bone density. The mean pullout strengths for the 5-mm Corkscrew and the 3.5-mm polylactic pin were similar in weak bone (76 +/- 24 N versus 104 +/- 46 N), intermediate quality bone (194 +/- 81 N versus 218 +/- 76 N), and strong bone (349 +/- 127 N versus 325 +/- 100 N). Pullout strength correlated with bone density for both implants (r = 0.76 and r = 0.86 for the Corkscrew and polylactic pin, respectively). The ultrasonically implanted absorbable 3.5-mm polylactic pin achieved equal pullout strength in weak bone as the larger 5-mm titanium Corkscrew. Bone density is highly variable in humeral heads and influenced the pullout strength of both implants.
Meyer
D C
DC
Department of Orthopaedics, University of Zürich, Switzerland.
Mayer
J
J
Weber
U
U
Mueller
A
A
Koch
P P
PP
Gerber
C
C
D020341:Absorbable Implants; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015519:Bone Density / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000503:physiopathology*; D001858:Bone Nails; D002102:Cadaver; D006801:Humans; D006811:Humerus / Q000601:surgery*; D008422:Materials Testing; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013314:Stress, Mechanical; D013536:Suture Techniques; D013537:Sutures; D014057:Tomography, X-Ray Computed / Q000379:methods; D014465:Ultrasonics