Expandable corpectomy cage with articulating endcap for correction of severe cervical kyphotic deformity: a case report.

Background: The treatment of cervical kyphotic deformities is challenging. In select cases, anterior corpectomy is required to obtain adequate correction. Most contemporary anterior column reconstruction involves titanium mesh cages or fixed-angle expandable systems, but there are limitations to those techniques. In this case, we present the use of an expandable titanium cage with an articulating endcap to provide controlled correction of a severe cervical kyphotic deformity. Case Description: A 63-year-old male with a history of C4-C7 decompression and fusion done elsewhere presented with several months of worsening neck pain, impaired posture, hand weakness, and inability to ambulate. Clinical exam was notable for a semi-rigid chin-on-chest deformity. Neurologic exam was notable for diffuse weakness and hyperreflexia. Imaging showed severe cervical kyphosis of over 70 degrees with circumferential ankylosis at the apex of deformity at C5, along with a grade 2 spondylolisthesis at C3/4 above the prior instrumented fusion. We concluded that he had a semi-rigid cervical deformity with tension myelopathy and recommended surgical intervention. He underwent preoperative halo gravity traction, followed by a posterior-anterior-posterior (P-A-P) approach. During the first posterior stage, the spine was instrumented C2 to T2 with posterior column osteotomies at C4/5 and C5/6. This was followed by C5 anterior corpectomy with use of an expandable titanium cage with articulating endcap. This allowed us to insert the graft in a neutral alignment, then carefully extend the neck to complete the deformity correction in a controlled manner by leveraging the flexibility of the articulating cage endcap. This was followed by a posterior approach for final C2 to T2 arthrodesis. Although appropriate correction was achieved, the patient's postoperative course was notable for C5 palsy and dysphagia, both of which resolved by 3 months. The patient's myelopathy symptoms improved, and deformity correction was maintained at last follow-up. Conclusions: In the surgical treatment of severe cervical kyphotic deformities where a corpectomy strategy is chosen, an expandable cage with articulating endcap can allow for controlled correction of kyphosis. Although not ideal for every scenario, we believe this is a valuable technique in appropriately selected patients.