patients ≥ 60 years old than in younger patients. 24 The rate of osteoporosis in older patients is reported to be higher than that of the general population, with a rate of 50% in older female patients. 5 Pedicle screw fixation is a common procedure used in the surgical treatment of lumbar degenerative diseases, while the osteoporotic lumbar spine has created great challenges in maintaining the stability of lumbar fixation. Pedicle screw loosening is one of the main reasons for secondary surgical interventions after lumbar surgery, and osteoporosis, or low bone mineral
Da Zou, Aikeremujiang Muheremu, Zhuoran Sun, Woquan Zhong, Shuai Jiang and Weishi Li
Jau-Ching Wu, Wen-Cheng Huang, Hsiao-Wen Tsai, Chin-Chu Ko, Ching-Lan Wu, Tsung-Hsi Tu and Henrich Cheng
The long-term outcome of lumbar dynamic stabilization is uncertain. This study aimed to investigate the incidence, risk factors, and outcomes associated with screw loosening in a dynamic stabilization system.
The authors conducted a retrospective review of medical records, radiological studies, and clinical evaluations obtained in consecutive patients who underwent 1- or 2-level lumbar dynamic stabilization and were followed up for more than 24 months. Loosening of screws was determined on radiography and CT scanning. Radiographic and standardized clinical outcomes, including the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, were analyzed with a focus on cases in which screw loosening occurred.
The authors analyzed 658 screws in 126 patients, including 54 women (42.9%) and 72 men (57.1%) (mean age 60.4 ± 11.8 years). During the mean clinical follow-up period of 37.0 ± 7.1 months, 31 screws (4.7%) in 25 patients (19.8%) were shown to have loosened. The mean age of patients with screw loosening was significantly higher than those without loosening (64.8 ± 8.8 vs 59.3 ± 12.2, respectively; p = 0.036). Patients with diabetes mellitus had a significantly higher rate of screw loosening compared with those without diabetes (36.0% vs 15.8%, respectively; p = 0.024). Diabetic patients with well-controlled serum glucose (HbA1c ≤ 8.0%) had a significantly lower chance of screw loosening than those without well-controlled serum glucose (28.6% vs 71.4%, respectively; p = 0.021). Of the 25 patients with screw loosening, 22 cases (88%) were identified within 6.6 months of surgery; 18 patients (72%) had the loosened screws in the inferior portion of the spinal construct, whereas 7 (28%) had screw loosening in the superior portion of the construct. The overall clinical outcomes at 3, 12, and 24 months, measured by VAS for back pain, VAS for leg pain, and ODI scores, were significantly improved after surgery compared with before surgery (all p < 0.05). There were no significant differences between the patients with and without screw loosening at all evaluation time points (all p > 0.05). All 25 patients with screw loosening were asymptomatic, and in 6 (24%) osseous integration was demonstrated on later follow-up. Also, there were 3 broken screws (2.38% in 126 patients or 0.46% in 658 screws). To date, none of these loosened or broken screws have required revision surgery.
Screw loosening in dynamic stabilization systems is not uncommon (4.7% screws in 19.8% patients). Patients of older age or those with diabetes have higher rates of screw loosening. Screw loosening can be asymptomatic and presents opportunity for osseous integration on later follow-up. Although adverse effects on clinical outcomes are rare, longer-term follow-up is required in cases in which screws become loose.
Vincent Prinz, Simon Bayerl, Nora Renz, Andrej Trampuz, Marcus Czabanka, Johannes Woitzik, Peter Vajkoczy and Tobias Finger
reducing reoperation rates and further exposure to radiation and anesthesia. 6 , 8 Loosening of pedicle screws associated with cage dislocation or vertebral fracture at the level of the screw is one of the most common complications after spinal posterior instrumentation. 7 , 14 The percentage of pedicle screw loosening and instrumentation-associated vertebral fracture is estimated to range from less than 1% to 15% in nonosteoporotic patients; in osteoporotic patients, the rate of pedicle screw loosening is even higher, reaching up to 60%. 1 , 5 , 7 , 12 Spinal surgery
Tsai-Sheng Fu and Yun-Da Li
P osterior instrumentation with pedicle screws is widely used to stabilize the thoracolumbar spine for a variety of indications, such as the promotion of bony fusion, the correction of deformity, and the stabilization of vertebral fracture. 1 The pedicle screw offers immediate and strong fixation with a low rate of device-related complications. 2 , 5 , 12 However, possible complications do include pedicle screw loosening and vertebral fracture at the level of the screw or adjacent to the surgical material. 7 , 21 The percentage of cases of pedicle screw
Martin H. Pham, Vivek A. Mehta, Neil N. Patel, Andre M. Jakoi, Patrick C. Hsieh, John C. Liu, Jeffrey C. Wang and Frank L. Acosta
described the occurrence of either pedicle screw loosening or pedicle screw fracture after use of the Dynesys system ( Table 4 ). Ninety-six of 822 patients (11.7%) had pedicle screw loosening and 13 of 822 patients (1.6%) had pedicle screw fracture over a mean follow-up period of 30.0 months (range 16.4–54.0 months). TABLE 4. Studies reporting pedicle screw loosening or fracture after use of the Dynesys system Authors & Year Total No. of Pts No. of Pts w/Screw Loosening No. of Pts w/Screw Fracture Stoll et al., 2002 83 7 0
spinal surgery. Sarcopenia may be a useful clinical measure of perioperative risk in spine surgery patients. Neurosurg Focus Neurosurgical Focus FOC 1092-0684 American Association of Neurological Surgeons 10.3171/2016.4.FOC-LSRSabstracts 2016.4.FOC-LSRSABSTRACTS Abstracts Paper #25. Transforaminal Lumbar Interbody Fusion Protects Against Early Pedicle Screw Loosening David Kim , MD 1 , Riya Joshi , MPH, MBBS 2 , Kevin Baker , Ph.D 3 , Gyu Ho Lee , BA 4 , Daniel Park , MD 5
healed. There were no instrumentation failures, although one patient had pedicle screw loosening at 2 years post-operatively. Ten patients underwent elective instrumentation removal. Conclusions Sacral fractures with spinopelvic dissociation patterns are severe injuries. This is the first reported series of patients treated with a percutaneous lumbopelvic instrumentation technique. Percutaneous lumbopelvic instrumentation can be performed safely with limited blood loss and within a reasonable surgical duration, theoretically minimizing the physiological burden of
Yu-Wen Cheng, Peng-Yuan Chang, Jau-Ching Wu, Chih-Chang Chang, Li-Yu Fay, Tsung-Hsi Tu, Wen-Cheng Huang and Henrich Cheng
conditions of the lumbar spine . J Neurosurg Spine 25 : 332 – 338 , 2016 27104286 10.3171/2016.2.SPINE151018 9 Wu JC , Hsieh PC , Mummaneni PV , Wang MY : Spinal motion preservation surgery . Biomed Res Int 2015 : 372502 , 2015 26881197 10.1155/2015/372502 10 Wu JC , Huang WC , Tsai HW , Ko CC , Wu CL , Tu TH , : Pedicle screw loosening in dynamic stabilization: incidence, risk, and outcome in 126 patients . Neurosurg Focus 31 : 4 E9 , 2011 10.3171/2011.7.FOCUS11125 21961872
Type II odontoid fractures Marcus D. Mazur M.D. Michael L. Mumert M.D. Erica F. Bisson M.D. Meic H. Schmidt M.D. 10 2011 31 4 E7 10.3171/2011.7.FOCUS11135 0310007 Clinically relevant complications related to pedicle screw placement in thoracolumbar surgery and their management: a literature review of 35,630 pedicle screws Oliver P. Gautschi M.D. Bawarjan Schatlo M.D. Karl Schaller M.D. Enrico Tessitore M.D. 10 2011 31 4 E8 10.3171/2011.7.FOCUS11168 2011.7.FOCUS11168 Pedicle screw loosening in dynamic stabilization: incidence, risk, and outcome in 126 patients
Shinya Okuda, Takenori Oda, Ryoji Yamasaki, Takamitsu Haku, Takafumi Maeno and Motoki Iwasaki
) Instrumentation failures were observed in 7 patients (7%) ( Table 2 ); pedicle screw loosening was observed in 4 patients, and pedicle screw breakage was seen in 3. All pedicle screw loosening was observed at the cranial side. These patients did not report back pain or radicular pain, but nonunion was detected in 1 asymptomatic patient. In the other 3 patients, bony union was observed at the final follow-up. All pedicle screw breakages were observed at the caudal side. Of the 3 patients with pedicle screw breakage, 2 had no complaints, and bony union was observed at the final