Accuracy of percutaneous pedicle screw insertion in thoracic and lumbar spine

English Keywords:Thoracic spine  Lumbar spine  Percutaneous pedicle screw  Accuracy of screw insertion

English Abstract:

  【Abstract】 Objectives: To analyze the accuracy of percutaneous pedicle screws in thoracic and lumbar spine. Methods: 53 patients treated with percutaneous pedicle screw instrumentation in thoracic and/or lumbar spine were retrospectively analyzed in our hospital from July 2010 to December 2012. The patients aged from 18 to 73 years(average, 51.2 years), there were 31 males and 22 females. Twenty-four patients suffered from degenerative lumbar diseases and the other 29 from spinal fractures. The segments of pedicle screw insertion ranged from T8 to S1. The pedicle screw accuracy was graded by CT axial scans, along with the occurrence of screw-related complications. Grade 0: screw within cortex of pedicle; grade 1: screw thread breach of pedicle wall ≤2mm; grade 2: significant breach >2mm with no neurological compromise; grade 3: screw related complications. Results: Totally 212 screws were inserted, with an average of 4.0 per case. Among all 212 screws, 175(82.5%) were graded into grade 0, 32(15.1%) into grade 1, 4(1.9%) into grade 2. Only one patient with grade 3 in one screw developed neurological compromises and relived after revision surgery. Twenty-four out of the 37 inaccurately placed pedicle screws encroached the pedicle from the medial wall, while 13 from the lateral wall. Conclusions: The inaccuracy rate of percutaneous pedicle screw insertion in thoracic and lumbar spine is relatively high, but inaccurate screws with grade 2 and above rarely occur.