A biomechanical comparison of lateral and posterior approaches to sacroplasty.
METHODS
Biomechanical cadaveric bench study.


OBJECTIVE
To measure the augmentation effect and extravasation risk of posterior and lateral approaches to sacroplasty.


BACKGROUND
The biomechanical stabilizing effect of sacroplasty is unknown.


METHODS
Using a sacral insufficiency fracture model, we performed sacroplasty in 15 osteoporotic cadaveric pelves. Five served as controls, and 10 were each injected with 4 mL of a polymethylmethacrylate cement (5 via a posterior approach, 5 via a lateral approach). Cement extravasation was assessed using computed tomography. Restored strength and stiffness were defined as the ratios of treatment to initial strength and to stiffness, respectively. Between-group differences in restoration parameters were checked for significance (P < 0.05) using an analysis of variance followed by Tukey's test.


RESULTS
We found no significant differences between groups in terms of restored strength ( approximately 61%) and stiffness ( approximately 77%). Both injection methods produced extravasation into the anterior sacrum, the posterior sacrum, the sacroiliac joint, and the neural foramens.


CONCLUSIONS
Sacroplasty with 4 mL of cement does not restore the strength or stiffness of the sacrum in a cadaveric model, regardless of the approach used.
Waites
Matthew D
MD
International Center for Orthopaedic Advancement, Department of Orthopaedic Surgery, The Johns Hopkins Bayview Medical Center, Baltimore, MD, USA.
Mears
Simon C
SC
Richards
Andrew M
AM
Mathis
John M
JM
Belkoff
Stephen M
SM
D000369:Aged, 80 and over; D001843:Bone Cements / Q000627:therapeutic use; D015519:Bone Density / Q000502:physiology; D001863:Bone Screws; D002484:Cementation / Q000009:adverse effects; D004548:Elasticity; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000000981:diagnostic imaging; D005592:Fracture Fixation / Q000379:methods*; D006801:Humans; D010024:Osteoporosis / Q000378:metabolism / Q000503:physiopathology; D019904:Polymethyl Methacrylate; D011475:Prosthesis Failure; D012447:Sacrum / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed; D054854:Vertebroplasty
D001843:Bone Cements; D019904:Polymethyl Methacrylate