Custom-made titanium 3D printed interbody cages for treatment of osteoporotic fracture related spinal deformity

BACKGROUND: Advances in minimally invasive interbody fusion have greatly enhanced surgeons' capability to correct adult spinal deformity with reduced morbidity. However, the feasibility of such approaches is limited in patients with previous osteoporotic fractures as the resultant vertebral deformity renders the endplate geometry incongruous with conventional interbody implants. Current 3D printing technology offers a novel solution by fabricating custom-made implants tailored to individual anatomy. We present the results of a patient with osteoporotic lumbar fractures treated by such technology.

CASE DESCRIPTION: A 74-year-old woman, with previous osteoporotic fractures at L2 and L3 resulting in concave deformity of the endplates, presented with intractable radiculopathy secondary to lateral recess and foraminal stenosis (L2-3 and L3-4). A minimally invasive lateral lumbar interbody fusion at L2-3 and L3-4 was considered favorable but due to the associated vertebral collapse, off-the-shelf implants were not compatible with patient anatomy. In silico simulation based on preoperative CT imaging was thus conducted to design customized cages to cater for the depressed recipient endplates and vertebral loss. The design was converted to implantable titanium cages through 3D additive manufacturing. At surgery, a tight fit between the implants and the targeted disc space was achieved. Postoperative CT scan confirmed excellent implant-endplate matching and restoration of lost disc space. The patient began to ambulate from postoperative day one and at six-month follow-up resolution of radicular symptoms and CT evidence of interbody fusion were recorded.

CONCLUSIONS: 3D printed custom-made interbody cages can help overcome the difficulties in deformity correction secondary to osteoporotic fractures.