Treatment of L5-S1 Spondyloptosis via Posterior-Only L5 Partial Spondylectomy and Reduction of L4 Onto S1: Surgical Technique and Case Series.

Objective: Spondyloptosis (Grade-V spondylolisthesis) is the most severe form of spondylolisthesis and presents significant surgical challenges due to its rarity and complexity. This study aimed to outline the key aspects of posterior-only L5 partial spondylectomy and reduction of L4 onto S1 for spondyloptosis, as well as evaluate the clinical outcomes and prospects of this technique.

Methods: Three patients diagnosed with L5/S1 spondyloptosis between July 2022 and June 2023 were assessed. All these patients underwent posterior-only L5 partial spondylectomy with L4-S1 reduction, using a modified Kebaish's technique. The surgical approach was described in detail, and patient outcomes were assessed through postoperative imaging and clinical measures.

Results: The mean age of the patients was 28.7 years (range, 13-41). Preoperative assessments showed a mean Visual Analog Scale (VAS) score for low back or lower limb pain of 5.3 (range 5-6), an Oswestry Disability Index (ODI) of 57.3% (40%-74%), and a Japanese Orthopedic Association-29 (JOA-29) score of 15.7 (13-19). The mean operative time was 469 min (455-483), with a mean estimated blood loss of 1400 mL (1200-2000). The average follow-up duration was 14 months (12-18). At the final follow-up, all the patients achieved solid fusion, confirmed via computed tomography. Postoperative VAS, ODI, and JOA-29 scores improved to 2 (0-3), 17.3% (6%-26%), and 23 (22-25), respectively. All the patients reported high satisfaction with the treatment.

Conclusions: Posterior-only L5 partial spondylectomy with L4-S1 reduction is a feasible and effective treatment for lumbar spondyloptosis. Although technically demanding and associated with a high risk of nerve palsy, this approach can yield favorable clinical outcomes when applied appropriately in these challenging cases.