Bioabsorbable tricalcium phosphate bone cement strengthens fixation of suture anchors.
BACKGROUND
Failure of suture anchor fixation in rotator cuff repair can occur at different interfaces. Prior studies show fixation at the bone-anchor interface can be augmented using polymethylmethacrylate (PMMA) cement, and screw fixation into bone can be strengthened using bioabsorbable tricalcium phosphate cement.


OBJECTIVE
We wished to determine whether augmentation of suture anchor fixation using bioabsorbable tricalcium phosphate cement would increase pullout strength of suture anchors from bone and the number of cycles to failure, to determine the mode of failure after cement augmentation, and to compare strength and mode of failure with those after augmentation with PMMA.


METHODS
We used 10 matched pairs of cadaveric proximal humeri and implanted a metal screw-type suture anchor in one side and on the other side injected tricalcium phosphate cement into the anchor holes before anchor placement. We tested all specimens to failure using a ramped cyclic loading protocol.


RESULTS
Tricalcium phosphate cement augmentation increased the final load to failure by 29% and the number of cycles to failure by 20%. Visual inspection confirmed that failure occurred at the cement-bone interface.


CONCLUSIONS
Tricalcium phosphate cement appears to augment suture anchor fixation into bone, reducing the risk of anchor pullout and failure.


CONCLUSIONS
When relying on suture anchor fixation in bone of questionable quality, we suggest considering augmentation of suture anchor fixation with bioabsorbable cement. This method also provides potential for bioabsorbability and may be more amenable to arthroscopic application.
VA Bone and Joint Rehabilitation Research and Development Center, Palo Alto, CA, USA. droshtory@gmail.com
Rayshad
R
Oshtory
Derek P
DP
Lindsey
Nicholas J
NJ
Giori
Faisal M
FM
Mirza
D000368:Aged; D000369:Aged, 80 and over; D001843:Bone Cements / Q000737:chemistry*; D002102:Cadaver; D002130:Calcium Phosphates / Q000737:chemistry*; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D013314:Stress, Mechanical; D053441:Suture Anchors
D001843:Bone Cements; D002130:Calcium Phosphates; D019904:Polymethyl Methacrylate; C018392:tricalcium phosphate