A Novel Technique for Spondylolysis Repair With Pedicle Screws, Rod and Polyester Band

Case Report With Technical Note and Systematic Literature Review

Pedro Berjano, MD, PhD; Gabriele Ristori, MD; Maryem-Fama Ismael Aguirre, MD; Francesco Langella, MD; Marco Damilano, MD; Riccardo Cecchinato, MD; Alvin Pun, MD; Claudio Lamartina, MD

Disclosures

Spine. 2020;45(24):E1682-E1691. 

In This Article

Materials and Methods

Case Report: Screw-Rod-Band (SRB) Technique

In July 2016, a 14-year-old male (50 kg, 155 cm) affected by L5 spondylosis with history of persistent low back pain (Oswestry Disability Index (ODI) 24, Visual Analog Scale (VAS)-back 6, and VAS-leg 0) underwent a L5 isthmic reconstruction. The patient gave an informed consent for the modified procedure aimed to preserve the spinal mobility, reduce the surgical invasiveness and the potential risks of neurological injury. The procedure combines the use of pedicle screws, a rod and a polyester band to repair the spondylolysis. The pedicle screws serve as anchors in the anterior part of the vertebra. A horizontal rod connects the pedicle screws. The polyester band links to the rod and passes below the spinous process of the spondylolytic vertebra. Tensioning of the band compresses the pars defect to create stability and promote fusion.

Intraoperatively, the patient was placed under general anesthesia in a prone position. Through a median longitudinal posterior approach, with limited paravertebral muscle splitting, the pars interarticularis is exposed bilaterally. The pars defect is prepared by removing the interposed soft tissue and curetting the bony ends. Two polyaxial pedicle screws of 6 to 6.5 mm in diameter and of appropriate length are inserted into the lytic vertebra utilizing a standard technique. A rod is inserted horizontally connecting the two screws and piercing the interspinous ligament above the lytic vertebra, and the nuts are locked definitively. A commercially available polyester band is passed from the right under the base of the spinous process of the lytic vertebra, around to the left side of the rod, again under the base of the spinous process from left to right, and finally connected to the right side of the rod. The tensioning of the band results in a compressive force across the pars interarticularis. This step is completed when the gap, created by Gill body resection, is completely closed. If a minimal residual gap is still present, it can be filled with autologous bone graft, which is also used when the opposed bone surfaces are sclerotic (in such case, the end surfaces are refreshed with a sharp curette or a low speed burr). The band is locked after tensioning, providing stability (Figure 1). The final positioning of the implants is checked by intraoperative radiography. The wound is thoroughly washed and closure performed as per routine.

Figure 1.

Case example. This is a case of L5 Isthmic spondylolysis. The image shows the surgical field after (A) the implant of L5 pedicle screw with polyaxial tulip and (B) after the isthmus fixation using Screw-Rod-Band (SRB) Technique. The Sawbones model (C) illustrates the SRB Technique.

Pre and postoperative radiographs of the patient are shown in Figure 2. The drain is removed on the first postoperative day. The patient is allowed to stand up 2 days after surgery. No brace is required but extension and torsion movements are to be avoided for 4 months after the procedure. To confirm bone union, a low-dose Conventional Tomography scan 3D reconstruction[18] and a lateral radiograph is performed at the 4-month follow-up. At the 4-year follow-up, no complications occurred, the patient was satisfied good clinical (ODI 4, VAS-Back 1, VAS-Leg 0) and radiographic outcome achieved (Figure 3).

Figure 2.

Case example. Screw-Rod-Band (SRB) Technique. Preoperative coronal (A) and Sagittal (B) x-ray. Postoperative coronal (C), and sagittal (D) x-ray. X-ray, 4 years follow-up (E) coronal and sagittal (F).

Figure 3.

Case example. Screw-Rod-Band (SRB) Technique. Preoperative CT scan, (A) left and (B) right side. Low dose CT scan at 4-month follow-up, (C) left, and (D) right side. CT scan at 4 years follow-up, (E) left and (F) right side.

Systematic Literature Review

Study Design. A computer-based literature search was performed to identify all studies examining original techniques for surgical spondylolysis repair. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed during the design, search, and reporting stages of this systematic review.[19]

The PubMed database was searched from its inception point to June 2020. The search terms were "spondylolysis," "pars interarticularis," "surgery," "repair," "fixation," or "reconstruction."

The search string was: ((((((((((spondylolysis) AND surgery)) OR spondylolysis) AND repair)) OR spondylolysis) AND fixation)) OR ((((((((spondylolysis[MeSH Terms]) AND surgery)) OR spondylolysis[MeSH Terms]) AND repair)) OR spondylolysis[MeSH Terms]) AND fixation)) OR ((((((((pars interarticularis) AND surgery)) OR pars interarticularis) AND repair)) OR pars interarticularis) AND fixation). Similar search strategies were used in MEDLINE, EMBASE, Cochrane-Register, and ScienceDirect database.

Two authors (M.I. and G.R.) performed the search and evaluated the abstracts independently for potential eligibility and subsequently full-text publications for eligibility. A third author (F.L.) resolved discrepancies. Each researcher reviewed the title and abstract of all the articles and selected the relevant ones according to inclusion and exclusion criteria. The list of references of each article was screened in order to find any additional original articles. In addition to the computer search, an independent hand search including scanning of reference lists from other studies was performed.

Study Selection. The following criteria were applied for article inclusion to ensure that the question was addressed: articles presenting original research (observational studies or clinical trials) or technical note in peer-reviewed journals without language restriction. The patients included were both male and female and underwent primary surgery for a lumbar spondylolysis. After identification and removal of duplicates, studies were excluded in the screening process (title and abstract) if (1) no abstract was available, (2) if title and abstract indicated that the focus of the article was outside the scope of the article, (3) the patients were not affected by spondylolysis, or (4) the authors proposed spinal arthrodesis. When screening for eligibility (full text), articles were excluded if the authors proposed a non-original procedure. Additional subject definition and exclusion criteria were applied to allow for the most homogeneous comparisons across studies. We excluded editorials and commentaries, review articles and meta-analysis, cervical spondylolysis, spondylolisthesis cases. Figure 4 shows the search strategy used according to PRISMA guidelines to generate the final study list.

Figure 4.

Flow diagram of studies through the different phases of the review. Literature review search algorithm performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After the application of all exclusion criteria, 21 studies were identified for the final analysis.

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