A Review of Treatment for Acute and Chronic Pars Fractures in the Lumbar Spine

Abstract

Purpose of review: Spondylolysis remains one of the most common causes of lower back pain in the pediatric and adolescent populations and is particularly prevalent in young sporting individuals. Despite this, approaches to diagnostic imaging and both conservative and surgical treatment vary widely among surgeons. The current review investigates recent literature on the etiology, clinical presentation, diagnosis, and treatment of spondylolysis. In particular, it interrogates the use of various advanced imaging modalities (CT, MRI, SPECT) in diagnosis as well as common surgical approaches to the condition.

Recent findings: Recent data has provided more information on how pars defect laterality, stage, and presence or absence of bone marrow edema impact healing potential. Other studies have highlighted the advantages of using MRI for spondylolysis diagnosis. Other data has provided more clarity on which adults may benefit from direct pars repair, while other studies have compared the various techniques for direct repair of pars defects. While the exact cause of spondylolysis remains unclear, there is growing understanding of the behavioral, genetic, and biomechanical risk factors that predispose individuals to the condition. MRI may be emerging as the advanced imaging modality of choice for diagnosis due to its lack of radiation and comparable sensitivity to other advanced imaging techniques. Conservative treatment remains the first step in management due to excellent outcomes in most patients, with surgical intervention rarely necessary. In patients that do require surgery, direct repair using a pedicle screw-based approach is preferred over spinal fusion and other direct repair techniques.

Keywords: Athletics; Pars Defect; Spine surgery; Spondylolisthesis; Spondylolysis.

Fig. 1

Sagittal limited z-axis CT scan, optimized to decrease radiation dose, demonstrating a complete fracture of the left-sided L5 pars interarticularis. Courtesy of Fadell et al. ⁶⁸. Published with permission from Springer Nature Inc.

Fig. 2

Buck method of direct repair using a direct pars lag screw. A,B Postoperative AP (A) and lateral (B) plain X-rays showing placement of the pars screw through the pars defect (black arrow). C,D Sagittal (C) and axial (D) CT scans depicting a well fused pars defect 26 months after the operation (black arrows). Figure 2 labeled for reuse according to Creative Commons Attribution Non-Commercial 3.0 Unported License (From Shin MH, Ryu KS, Rathi NK, Park CK. Direct pars repair surgery using two different surgical methods: a pedicle screw with universal hook system and direct pars screw fixation in symptomatic lumbar spondylolysis patients. J Korean Neurosurg Soc. 2013. 51(1): p. 14-9, https://dx.doi.org/10.3340%2Fjkns.2012.51.1.14)

Fig. 3

Scott method of direct repair using segmental wire fixation. Courtesy of Yamamoto et al. ¹²⁵. Published with permission from Springer Nature Inc.

Fig. 4

Morscher method of direct repair using a screw hook. Courtesy of Hefti et al. ¹²⁶. Published with permission from Springer Nature Inc.

Fig. 5

Pedicle screw-hook-rod method of direct repair depicted in A schematic view, B AP plain X-ray, and C lateral plain X-ray. (Adapted with permission from Elsevier: Spondylolysis repair, in Vaccaro A, Baron E [eds]: Spine Surgery. Third edition. Philadelphia, PA: Elsevier, 2018. pp 322-328.)