Pars Interarticularis Fractures Treated with Minimally Invasive Surgery: A Literature Review

Abstract

Recurrent stress on the isthmic pars interarticularis often leads to profound injury and symptom burden. When conservative and medical management fail, there are various operative interventions that can be used. The current review details the common clinical presentation and treatment of pars injury, with a special focus on the emerging minimally invasive procedures used in isthmic pars interarticularis repair. PubMed and Google Scholar database literature reviews were conducted. The keywords and phrases that were searched include but were not limited to; "history of spondylolysis", "pars interarticularis", "pars defect", "conventional surgical repair of pars", and "minimally invasive repair of pars". The natural history, conventional presentation, etiology, risk factors, and management of pars interarticularis injury are discussed by the authors. The surgical interventions described include the Buck's repair, Morscher Screw-Hook repair, Scott's Wiring technique, and additional pedicle screw-based repairs. Minimally invasive techniques are also reviewed, including the Levi technique. Surgical intervention has been proven to be safe and effective in managing pars interarticularis fractures. However, minimally invasive techniques often provide additional benefit to patients such as reducing damage of surrounding structures, decreasing postoperative pain, and limiting the time away from sports and other activities.

Keywords: minimally invasive; pars interarticularis; percutaneous pedicle screws.

Figure 1

Oblique plain lumbar radiograph. Normal pars interarticularis denoted by black arrow. Pars interarticularis defect with “Scottie dog” sign demonstrated by white arrow. (“Contributed by J Taylor Mansfield, DO” [1,33]) “Reproduced with permission from Mansfield, J.T.; Wroten, M. Pars Interarticularis Defect; published by StatPearls Publishing: Treasure Island, FL, USA, 2023”.

Figure 2

CT of L5 vertebral body and posterior elements. White arrow indicates spondylolysis of right pars interarticularis. Reactive sclerosis in the left pars demonstrated by white arrowhead [34]. “Reprinted from Neural arch bone marrow edema and spondylolysis in adolescent cheerleaders: A case series. J. Chiropr. Med. 2019, 18, 335–342; with permission from Elsevier”.

Figure 3

An illustration showing the different surgical techniques for direct pars repair. (A) Buck’s repair technique. A screw is passed across the pars defect. (B) Scott’s repair technique. The wire is passed around the transverse process and spinous process. (C) Morscher repair technique using pedicle screw with laminar hooks. (D) Pedicle screw-based technique with a U-shaped rod. “Used with permission from The University of Miami Department of Neurological Surgery, Miami, FL, USA”.

Figure 4

Buck’s repair technique. (A) Preoperative radiograph in lateral projection. (B) CT scan of pars defect. (C) Postoperative radiographs after surgery using Buck’s repair technique. “Reproduced with permission from Sri Vijay Anand, K.S.; Eamani, N.; Shetty, A.; Rajasekaran, S. Spondylolysis and pars repair technique: A comprehensive literature review of the current concepts. Indian Spine J. 2021, 4, 29” [38].

Figure 5

Oblique radiographs showing a bilateral pars defect in the L5 of a 17 year old patient [45]. The arrows depict the specific sites of the defect. “Used with permission of Springer Nature BV, from Hefti, F.; Seelig, W.; Morscher, E. Repair of lumbar spondylolysis with a hook-screw. Int. Orthop. 1992, 16, 81–85; permission conveyed through Copyright Clearance Center, Inc.”.

Figure 6

Radiographs showing solid fusion of L5 in the same patient one-year post-op [45]. The arrows depict the site of fusion. “Used with permission of Springer Nature BV, from Hefti, F.; Seelig, W.; Morscher, E. Repair of lumbar spondylolysis with a hook-screw. Int. Orthop. 1992, 16, 81–85; permission conveyed through Copyright Clearance Center, Inc.”.

Figure 7

Bilateral L5 intralaminar threaded guidewire placement in the lateral (left) and AP (right) projections demonstrated by intraoperative fluoroscopic views. Lateral laminar entry and bisect the pedicle is demonstrated by the guidewires on the AP projection. The lateral projection shows appropriate clearance of the L5–S1 neural foramen, and the rostral endplate or foramen is not violated [68]. “Reproduced with permission from Ghobrial, G.M.; Crandall, K.M.; Lau, A.; Williams, S.K.; Levi, A.D. Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature; published by Neurosurg. Focus 2017, 43, E6”.

Figure 8

Bilateral placement of cannulated pars screws over threaded guidewires (left) and subsequent bilateral exposure of the pars fracture demonstrated by intraoperative fluoroscopic views in the AP (left) and lateral (right) projection. Tubular-based retractors (right) provide visualization of pars fracture for decortication [68]. “Reproduced with permission from Ghobrial, G.M.; Crandall, K.M.; Lau, A.; Williams, S.K.; Levi, A.D. Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature; published by Neurosurg. Focus 2017, 43, E6”.

Figure 9

Postoperative upright standing radiographs in AP (left) and lateral (right) projections demonstrating bilateral placement of lag screws [68]. “Reproduced with permission from Ghobrial, G.M.; Crandall, K.M.; Lau, A.; Williams, S.K.; Levi, A.D. Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature; published by Neurosurg. Focus 2017, 43, E6”.

Figure 10

Case 8. Chronic L-4 pars defect in a 15-year-old girl. Sagittal CT of the lumbar spine, illustrating left L-4 pars fracture (left). CT obtained at 3 months follow up demonstrating fusion across the fracture (right). “Reproduced with permission from Ghobrial, G.M.; Crandall, K.M.; Lau, A.; Williams, S.K.; Levi, A.D. Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature; published by Neurosurg. Focus 2017, 43, E6”.