The treatment of periprosthetic fractures with locking plates: effect of drill and screw type on cement mantles: a biomechanical analysis.
BACKGROUND
Periprosthetic fractures after cemented hip replacement are a challenging problem to manage. Biomechanical studies have suggested the benefit of using locking screws for plate fixation, but there are concerns whether screws damage the cement mantle and promote crack propagation leading to construct failure.


METHODS
In this biomechanical study, different screw types were implanted into the cement mantle after pre-drilling holes of different sizes, in unicortical and bicortical configuration. The presence of cracks and the pull-out resistance of these screws were then evaluated.


RESULTS
No unicortical screw induced cracks. Screws with a shortened tip, smaller flutes and double threads were significantly better for pull-out resistance. Bicortical screws were associated with a risk of local cement mantle damage, but also with a significantly greater holding power. By increasing the drill diameter, the onset of cracks decreased, but so does the pull-out resistance.
Kampshoff
Jorg
J
Department of Orthopaedic Surgery, Fremantle Hospital, P.O. Box 480, Fremantle, WA 6160, Australia. Kampshoff@gmail.com
Stoffel
Karl K
KK
Yates
Piers J
PJ
Erhardt
Johannes B
JB
Kuster
Markus S
MS
D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D001843:Bone Cements; D001863:Bone Screws / Q000009:adverse effects*; D004867:Equipment Design; D006620:Hip Fractures / Q000209:etiology*; D006801:Humans; D011183:Postoperative Complications
D001843:Bone Cements