Patient-Specific Rods vs Traditional Rods in Surgical Correction of Adult Spinal Deformities: A Case-Matched Study.

Aim: Patient specific pre-contoured rods (PSRs) represent a relatively new technological development aimed at improving surgical outcomes and reducing complications in adult spinal deformity surgery. To date, only a limited number of studies have been published comparing PSRs with traditional spinal rods. In this paper, we compare the surgical, imaging, and clinical outcomes of PSRs and traditional spinal rods in a single-center case-matched study.

Methods: Thirty cases of adult spinal deformities (ASD) were retrospectively analysed. These included 10 patients who were operated on using UNiD™ (Adaptive Spine Intelligence, MedTronic, Minneapolis, MN, USA) PSRs and 20 operated on using traditional rods from January 2023 to August 2023. Minimum post-surgical follow-up was 6 months. General demographics and standard radiographic parameters, as well as Scoliosis Research Society (SRS)-22, Oswestry Disability Index (ODI) and Short Form Health Survey (SF-12) Scores, were measured at pre-operative examination and at 6-month follow-up. Follow-up imaging data were compared with software-planned correction goals. Intra-operative data and complications were also recorded.

Results: Patients in the two groups were matched in terms of age, body mass index (BMI), sex, type and severity of spinal deformity. The magnitude of the coronal deformity (p = 0.812) and preoperative sagittal imbalance (p = 0.845) were similar between the two groups. The number of fused levels (p = 0.439), osteotomies (p = 0.188), implant density (p = 0.880), and surgery duration (p = 0.299) were similar between the two groups. Sagittal correction goals set during preoperative planning were achieved in the PSRs group, with the exception of pelvic tilt (PT) (p = 0.042). In contrast, PT (p = 0.040), L1-S1 lordosis (p = 0.032) and global tilt (GT) (p = 0.001) remained significantly undercorrected in the control group at 6-month follow-up. Clinical outcomes (ODI and SF-12 Scores) and complication rates were similar between the two groups.

Conclusions: The use of PSRs improves the achievement of better post-operative spinopelvic alignment in adult spinal deformity surgery. Moreover, no significant differences were noted in terms of complications, operative times, and clinical outcomes compared to traditional spinal rods at 6-month follow-up.