Proximal Junctional Kyphosis After Vertical Expandable Prosthetic Titanium Rib Insertion

Abstract

Study DesignRetrospective review of patients who had undergone vertical expandable prosthetic titanium rib (VEPTR) treatment at a single institution. ObjectivesTo evaluate whether clinically significant proximal junctional kyphosis (PJK) occurs after VEPTR insertion. Summary of Background DataPJK is a potential problem after posterior spinal instrumentation and fusion. PJK after VEPTR insertion has not been well-described. MethodsA total of 68 patients underwent VEPTR treatment between 1999 and 2009. Diagnosis, age at time of VEPTR insertion, location of VEPTR anchors, preoperative and postoperative scoliosis, T2–T12 kyphosis and PJK, time from VEPTR insertion to development of PJK, revision procedure for significant PJK, change in PJK after the revision procedure, and PJK at final follow-up were recorded. ResultsFour patients developed PJK (6%). One patient had congenital scoliosis with rib fusions, 1 had scoliosis associated with a syndrome, and 2 had neuromuscular scoliosis. Mean follow-up was 5.7 years. Average T2–T12 kyphosis and PJK before VEPTR insertion were 77° and 14°, respectively. Mean T2–T12 kyphosis and PJK after VEPTR insertion were 63° and 33°, respectively. Average T2–T12 kyphosis and PJK before the recommended revision procedure for treatment of PJK were 89° and 53°, respectively. All patients developed PJK within the first year after VEPTR insertion. Two patients underwent revision to growing rods. One of these patients had preoperative halo-gravity traction. Mean PJK in these 2 patients improved from 39° to 18° after revision and remained stable at 19° at an average follow-up of 2.9 years. ConclusionsPJK after VEPTR insertion can occur. Patients with preoperative thoracic hyperkyphosis may be at higher risk. PJK can develop within the first year of VEPTR treatment, and can become progressive and severe enough to require complex interventions. In this small case series, patients were revised to growing rods.