Use of Patient-specific Interbody Cages through a Minimally Invasive Lateral Approach for Unstable Lumbar Spondylodiskitis

Introduction: Patients with diskitis/osteomyelitis who do not respond to medical treatment or develop spinal instability/deformity may warrant surgical intervention. Irregular bony destruction due to the infection can pose a challenge for spinal reconstruction. Previous reports have demonstrated that personalized interbody implants improve endplate-implant contact and achieve predictable alignment correction in patients with degenerative spinal disease. However, the use of patient-specific devices to correct deformity in osteomyelitis cases has not been reported. This study aims to report a lateral approach using patient-specific interbody cages combined with posterior or lateral instrumentation to achieve spinal reconstruction for spinal deformity/instability from spondylodiskitis.

Methods: This is a retrospective review of four cases undergoing debridement, lateral lumbar interbody fusion using patient-specific interbody cages, and supplemental lateral or posterior instrumentation for spinal instability/deformity following spondylodiskitis. The surgical technique is reported, as are the clinical and imaging outcomes.

Results: Four male patients with a mean age of 69 comprise this study. The mean hospital stay was 5.8 days. The mean follow-up was six months. There were no approach-related neurological injuries or complications. The mean visual analog scale (VAS) pain scores improved from 8.3 to 2.5, and the mean Oswestry disability index (ODI) improved from 68.6 to 33 at the end of the follow-up. The mean lumbar lordosis increased from 18 to 49 degrees. The segmental angle increased from 6.5 to 18 degrees. The coronal shift was 2.8 cm preoperatively and 1.2 cm postoperatively. The coronal Cobb angle reduced from 8.8 degrees preoperatively to 5 degrees postoperatively. Based on postoperative CT, all patients had interval development of bridging bone across the surgical level through or around the cage. None of them developed cage migration or subsidence.

Conclusion : Patients with irregular bony destruction due to diskitis/osteomyelitis may benefit from patient-specific cages for spinal reconstruction to address spinal instability and deformity.