Effects of pilot hole preparation technique on pedicle screw fixation in different regions of the osteoporotic thoracic and lumbar spine

Abstract

<jats:p content-type="fine-print"><jats:italic>Object.</jats:italic> The authors evaluated the effects of pilot hole preparation technique on insertional torque and axial pullout resistance in osteoporotic thoracic and lumbar vertebrae.</jats:p> <jats:p content-type="fine-print"><jats:italic>Methods.</jats:italic> Using a probe technique and fluoroscopy, 102 pedicle screws were placed in 51 dual-energy x-ray absorptiometry—proven osteoporotic thoracic and lumbar levels. Screws were inserted using the same-size tapping, one-size-under tapping, or no-tapping technique. Insertional torque and axial pullout resistance were measured. Analysis of variance, Fisher exact test, and regression analysis were performed.</jats:p> <jats:p content-type="fine-print">Same-size tapping decreased pullout resistance in the lumbar spine. There was no effect on pullout resistance in the thoracic spine. Pullout resistance values were lower for all insertion techniques in the upper thoracic spine. Insertional torque and bone mineral density correlated with pullout resistance in the thoracic and lumbar spine.</jats:p> <jats:p content-type="fine-print"><jats:italic>Conclusions.</jats:italic> Tapping decreased pedicle screw pullout resistance in the osteoporotic human lumbar spine, although it did not affect pullout strength in the thoracic spine. Tapping decreased insertional torque in upper thoracic levels. Surgeons should optimize overall construct rigidity when placing thoracic pedicle screws in patients with spinal segment osteoporosis.</jats:p>

Effect of pilot hole on biomechanical and in vivo pedicle screw–bone interface

“…Despite technological advances, implant failures, such as screw bending, breakage, and loosening still occur [2,10,40]. It is well established in the literature that the holding power of the pedicle screw is influenced by bone mineral density [5], geometry of the screw [1,20,[25][26][27] and the screw insertion technique employed by the surgeon [5,14,33,38]. It has been reported that the holding power of the pedicle screw is significantly influenced by the size and technique of the pilot hole [5,7,14,15,33].…”

Efeito do macheamento do orifício piloto na resistência ao arrancamento e no torque de inserção dos parafusos pediculares com alma cônica

“…to, no âmbito da cirurgia da coluna vertebral tem sido demonstrado que o macheamento do orifício piloto não aumenta a resistência ao arrancamento dos parafusos (2) e que poderia reduzir essa resistência nos ossos esponjosos e na coluna lombar (6,7) , sem alterar essa propriedade nos parafusos inseridos na coluna torácica (4) .…”

In vivo preclinical evaluation of the influence of osteoporosis on the anchorage of different pedicle screw designs

“…Due to the demographic development and the increasing average age of the population, treatment of these conditions often involves instrumentation of osteoporotic spinal segments and the indications for placing instrumentation in patients with osteoporosis will likely continue to broaden [11]. Cancellous bone is more affected by osteoporosis than cortical bone, and it is not surprising that pedicle screw fixation is significantly less effective in patients with low bone mineral density, as its anchorage relies also on the properties of the cancellous bone within the vertebral body [12].…”