Frequency of Early Fusion of Bone in the Lumbosacral Spine: Radiographic Evidence of Bridging Bones Following Pedicle Screw Fixation

Hafiz Kabeer  Ahmed; Aamir  Saghir; Amna  Ghouri

doi:10.54112/bcsrj.v6i6.1958

Authors

Hafiz Kabeer Ahmed Department of Neurosurgery, Liaquat National and Medical College, Karachi, Pakistan
Aamir Saghir Department of Neurosurgery, Liaquat National and Medical College, Karachi, Pakistan
Amna Ghouri Department of Neurosurgery, Liaquat National and Medical College, Karachi, Pakistan

DOI:

https://doi.org/10.54112/bcsrj.v6i6.1958

Keywords:

ASA Physical Status, Bone Fusion, Lumbosacral Vertebrae, Pedicle Screws, Smoking, Spinal Fractures

Abstract

Pedicle screw fixation is a widely used surgical procedure for the management of lumbosacral fractures. Despite its frequent application, limited evidence exists regarding its effectiveness in achieving early bone fusion. Objective: To determine the rate of early bone fusion following pedicle screw fixation of lumbosacral fractures and to evaluate the impact of patient factors, including ASA class and smoking status, on fusion outcomes. Methods: A descriptive cross-sectional study was conducted at a tertiary care hospital in Karachi, Pakistan, from January to May 2025 after ethical approval. Patients aged 18–65 years with ASA class <IV who underwent pedicle screw fixation of the lumbosacral spine were included. Participants were followed for three months to assess early bone fusion radiographically. Descriptive statistics were presented as mean (SD) for continuous variables and frequency (%) for categorical variables. Binary logistic regression was performed to adjust for confounders, with adjusted odds ratios (aOR) and 95% confidence intervals (CI) reported. Results: A total of 139 patients were enrolled, with a mean age of 40.70 ± 8.97 years. The cohort comprised 84 females (60.43%) and 55 males (39.57%). Early bone fusion was achieved in 124 patients (89.21%). Smoking status was independently associated with reduced odds of early bone fusion, with lower fusion rates observed among current smokers (aOR: 0.12, 95% CI: 0.03–0.45) and ex-smokers (aOR: 0.14, 95% CI: 0.04–0.51) compared with non-smokers. Similarly, patients with ASA class II (aOR: 0.16, 95% CI: 0.04–0.63) and class III (aOR: 0.04, 95% CI: 0.01–0.32) had significantly lower odds of early fusion compared to ASA class I. Conclusion: Pedicle screw fixation demonstrated a high rate of early bone fusion in lumbosacral fractures. However, smoking and higher ASA class were identified as independent risk factors for reduced fusion, emphasizing the importance of patient optimization and smoking cessation in improving postoperative outcomes.

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References

Yang S, Xia H, Cong M, Guo A, Ma K, Song M. Unilateral pedicle screw fixation of lumbar spine: A safe internal fixation method. Heliyon. 2022;8(11):e11621. https://doi.org/10.1016/j.heliyon.2022.e11621

Matsukawa K, Yato Y. Lumbar pedicle screw fixation with cortical bone trajectory: A review from anatomical and biomechanical standpoints. Spine Surg Relat Res. 2017;1(4):164-73. https://doi.org/10.22603/ssrr.1.2017-0006

Berman D, Oren JH, Bendo J, Spivak J. The effect of smoking on spinal fusion. Int J Spine Surg. 2017;11(4):29. https://doi.org/10.14444/4029

Lau D, Chou D, Ziewacz JE, Mummaneni PV. The effects of smoking on perioperative outcomes and pseudarthrosis following anterior cervical corpectomy: Clinical article. J Neurosurg Spine. 2014;21(4):547-58. https://doi.org/10.3171/2014.6.SPINE13762

Zhang H, Dial B, Brown C. Early fusion rates after direct lateral lumbar interbody fusion with bone-morphogenetic protein. Int J Spine Surg. 2021;15(3):423-8. https://doi.org/10.14444/8063

Goel A. Is evidence of bone "formation" and "fusion" in the spinal segment evidence of segmental spinal instability? J Craniovertebral Junction Spine. 2022;13(4):365-7. https://doi.org/10.4103/jcvjs.jcvjs_139_22

Scott-Young M, Nielsen D, Rathbone E, Riar S, Gantt M. Efficacy of stand-alone anterior lumbar interbody fusion with PEEK cages, BMP-2, and allografts for treating discogenic low back pain: Assessing clinical and radiographic outcomes. Int J Spine Surg. 2024;18(5):502-13. https://doi.org/10.14444/8679

Koenders N, Rushton A, Verra ML, Willems PC, Hoogeboom TJ, Staal JB. Pain and disability after first-time spinal fusion for lumbar degenerative disorders: A systematic review and meta-analysis. Eur Spine J. 2019;28(4):696-9. https://doi.org/10.1007/s00586-018-5680-3

Wu J, Li J, Zhang H, Wu L, Shen X, Lv W. Predicting functional outcome after open lumbar fusion surgery: A retrospective multicenter cohort study. Eur J Radiol. 2025;182:111836. https://doi.org/10.1016/j.ejrad.2024.111836

Kernc D, Strojnik V, Vengust R. Early initiation of a strength training-based rehabilitation after lumbar spine fusion improves core muscle strength: A randomized controlled trial. J Orthop Surg Res. 2018;13(1):151. https://doi.org/10.1186/s13018-018-0853-7

Yang S, Yi YG, Kim Y, Jang DS, Chang MC. Postoperative rehabilitation for pain and functional recovery following anterior cervical discectomy and fusion: A narrative review. J Pain Res. 2025;18:4173-83. https://doi.org/10.2147/JPR.S533252

American Diabetes Association. Understanding A1C Diagnosis. 2023 [cited 2025 Sep 11]. Available from: https://diabetes.org/diabetes/a1c/diagnosis

American Family Physician. JNC 8 guidelines for the management of hypertension in adults. 2014 [cited 2025 Sep 11]. Available from: https://www.aafp.org/pubs/afp/issues/2014/1001/p503.html

Wu C, Hu X, Liu R, Xu C, Jiang Y, Ge Z, et al. Comparison of the clinical and radiographic outcomes of cortical bone trajectory and traditional trajectory pedicle screw fixation in transforaminal lumbar interbody fusion: A randomized controlled trial. Eur Spine J. 2024;33(3):1069-80. https://doi.org/10.1007/s00586-023-08086-5

Lee GW, Ahn M-W. Comparative study of cortical bone trajectory-pedicle screw (cortical screw) versus conventional pedicle screw in single-level posterior lumbar interbody fusion: A 2-year post hoc analysis from prospectively randomized data. World Neurosurg. 2018;109:e194-2. https://doi.org/10.1016/j.wneu.2017.09.137

Wang J, He X, Sun T. Comparative clinical efficacy and safety of cortical bone trajectory screw fixation and traditional pedicle screw fixation in posterior lumbar fusion: A systematic review and meta-analysis. Eur Spine J. 2019;28(7):1678-89. https://doi.org/10.1007/s00586-019-05999-y

Ding H, Hai Y, Liu Y, Guan L, Pan A, Zhang X, et al. Cortical trajectory fixation versus traditional pedicle-screw fixation in the treatment of lumbar degenerative patients with osteoporosis: A prospective randomized controlled trial. Clin Interv Aging. 2022;17:175-84. https://doi.org/10.2147/CIA.S349533

Zheng L-m, Zhang Z-w, Wang W, Li Y, Wen F. Relationship between smoking and postoperative complications of cervical spine surgery: A systematic review and meta-analysis. Sci Rep. 2022;12(1):9172. https://doi.org/10.1038/s41598-022-13198-x

Li Y, Zheng LM, Zhang ZW, He CJ. The effect of smoking on the fusion rate of spinal fusion surgery: A systematic review and meta-analysis. World Neurosurg. 2021;154:e222-35. https://doi.org/10.1016/j.wneu.2021.07.011

Somani S, Capua JD, Kim JS, Phan K, Lee NJ, Kothari P, et al. ASA classification as a risk stratification tool in adult spinal deformity surgery: A study of 5805 patients. Global Spine J. 2017;7(8):719-26. https://doi.org/10.1177/2192568217700106

Lynch CP, Cha EDK, Geoghegan CE, Jadczak CN, Mohan S, Singh K. Higher American Society of Anesthesiologists classification does not limit safety or improvement following minimally invasive transforaminal lumbar interbody fusion. Neurospine. 2022;19(3):533-43. https://doi.org/10.14245/ns.2142088.044

Hartman TJ, Nie JW, MacGregor KR, Oyetayo OO, Zheng E, Singh K. Impact of gender on outcomes following single-level anterior lumbar interbody fusion. J Clin Orthop Trauma. 2022;34:102019. https://doi.org/10.1016/j.jcot.2022.102019

Ciobanu-Caraus O, Grob A, Rohr J, Stumpo V, Ricciardi L, Maldaner N, et al. Sex differences in patient-rated outcomes after lumbar spinal fusion for degenerative disease: A multicenter cohort study. Spine. 2025;50(13):924-31. https://doi.org/10.1097/BRS.0000000000005183

Ibrahim JM, Singh P, Beckerman D, Hu SS, Tay B, Deviren V, et al. Outcomes and Quality of Life Improvement After Multilevel Spinal Fusion in Elderly Patients. Global Spine J. 2020;10(2):153-9. https://doi.org/10.1177/2192568219849393

Reis RC, de Oliveira MF, Rotta JM, Botelho RV. Risk of complications in spine surgery: A prospective study. Open Orthop J. 2015;9:20-5. https://doi.org/10.2174/1874325001509010020

Hartman TJ, Nie JW, MacGregor KR, Oyetayo OO, Zheng E, Singh K. Impact of gender on outcomes following single-level anterior lumbar interbody fusion. J Clin Orthop Trauma. 2022;34:102019. https://doi.org/10.1016/j.jcot.2022.102019

Salamanna F, Contartese D, Tschon M, Borsari V, Griffoni C, Gasbarrini A, et al. Sex and gender determinants following spinal fusion surgery: A systematic review of clinical data. Front Surg. 2022;9:983931. https://doi.org/10.3389/fsurg.2022.983931

Liu C, Guo C, Meng F, Zhu Z, Xia W, Liu H. Perioperative risk factors related to complications of lumbar spine fusion surgery in elderly patients. BMC Musculoskelet Disord. 2023;24(1):573. https://doi.org/10.1186/s12891-023-06689-z