Clinical efficacy of smiley face rod technique in the treatment of lumbar spondylolysis with grade Ⅰ spondylolisthesis

English Keywords:Lumbar spine  Spondylolysis  Smiley face rod technique

English Abstract:

  【Abstract】 Objectives: To investigate the clinical efficacy of the smiley face rod(SFR) technique in treating lumbar spondylolysis with grade Ⅰ spondylolisthesis. Methods: A total of 22 patients(18 males, 4 females) with lumbar spondylolysis and grade I spondylolisthesis treated with the SFR segmental fixation technique in our department from January 2019 to December 2024 were retrospectively analyzed. The age of the patients was 12-55(28.7±12.6) years old, the body mass index(BMI) was 18-29kg/m2(22.7±3.4kg/m2), and preoperative symptom duration was 6-60(12.3±14.3) months. The patients were followed up for 6-19(9.1±4.5) months. The operative time and intraoperative blood loss volume were recorded. Before opearation, at 3 months and 6 months after operation, visual analogue scale(VAS) for low back pain, Oswestry disability index(ODI), and Japanese Orthopaedic Association(JOA) scores were recorded to evaluate the clinical outcomes. Imaging examinations(X-ray, CT) were performed before operation and at 6 months after operation to measure preoperative and postoperative disc height(DH), slip distance(SD), slip rate, lumbar lordosis angle, and range of motion(ROM) at the surgical and adjacent segments to assess the improvement of spondylolisthesis and ROM, as well as the pars defect healing status. The correlations between age, BMI, preoperative disease duration and isthmus bone healing rate were studied. Results: The operative time was 131.8±32.8min(range: 86-200min), and intraoperative blood loss was 86.4±41.4mL(range: 50-150mL). Significant improvements in VAS, ODI and JOA scores were observed at 3 months and 6 months versus preoperative values(P<0.05). Slip distance, slip percentage, and lumbar lordosis angle significantly decreased at 6 months versus preoperatively(P<0.05). No significant differences were observed in DH ratio or ROM between the surgical and adjacent segments preoperatively and at 6 months(P<0.05). At 6-month follow-up, complete bilateral pars bony union was achieved in 18 cases(81.82%), partial union(including unilateral or other types) in 3 cases(13.63%), and nonunion in 1 case(4.55%). Age, BMI, and preoperative symptom duration showed potential influence on bone healing. Conclusions: In the treatment of lumbar spondylolysis with grade Ⅰ spondylolisthesis, SFR can effectively enhance postoperative lumbar stability, significantly alleviate low back pain symptoms, preserve lumbar mobility, and mitigate disc height collapse to a certain extent.