The clinical and radiographic degenerative spondylolisthesis classification and its predictive value.

INTRODUCTION: The clinical and radiographic degenerative spondylolisthesis (CARDS) classification is a new classification that has been introduced for degenerative spondylolisthesis (DS). It has four categories. Our study aimed to analyse the functional and radiographic outcome following DS surgery based on the preoperative CARDS classification.

METHODS: A retrospective study of the prospectively collected Australian Spine Registry database was performed. Data on demographics, patient reported outcome measures including the Oswestry Disability Index (ODI) and EQ-5D-3 L scores, and changes in radiographic measurements were analysed. Based on the preoperative findings all x-rays were classified applying the CARDS classification.

RESULTS: Between 2018 and 2021 a total of 54-patients were identified as having had surgery for DS at L4/5. The mean age was 65.3 ± 11.3years and females were predominantly affected (61%). Most cases were of CARDS type C (46%), followed by type B (29%). CARDS type A and D were observed in 18% and 6% respectively. Preoperatively, the L4/5 lordosis was 19.8 ± 6.3° and lumbar lordosis 43.9 ± 12.8°. Postoperatively the L4/5 lordosis alignment changed significantly to 23.5 ± 8.8° (p < 0.05). Preoperatively, the CARDS classification was 34.8 ± 17.4 (type A), 40.5 ± 11.0 (type B), 43.8 ± 12.9 and 50.0 ± 14.4 for type D (Pearson-coefficient 0.284, p = 0.041). Postoperatively this changed to 22.7 ± 16.1, 28.7 ± 21.2, 12.5 ± 13.1, and 6.5 ± 2.1 respectively. Similar improvements were observed for the EQ-5D-3 L.

CONCLUSION: This study shows that the CARDS classification correlates with preoperative functional scores as well as helping to predict response to surgery. CARDS will likely assist in operative planning and prognostication.

LEVEL OF EVIDENCE: III, therapeutic and prognostic study.