Cage Retropulsion after Posterior Lumbar Interbody Fusion by Unilateral stand-alone Carbon Cage

Abstract

Background Data: Posterior lumbar interbody fusion (PLIF) becomes widely used surgical procedure to reduce pain and spinal instability resulting from some spinal diseases. Although this procedure is widely used, postoperative conditions such as good clinical outcome and spinal instability are still a matter of controversy. Maintenance of disc height and solid fusion significantly increased with PLIF with cage. Cage migration to the spinal canal is one of the most common cause of implant failure in mono-segmental lumbar interbody fusion.Purpose: to evaluate the efficacy of unilateral stand-alone carbon cage in patients with degenerated lumbar disc diseaseStudy Design: A prospective follow-up study.Patients and Methods: A prospective follow-up study was carried out on 40 patients (24 males and 16 females). All patients had single level lumbar disc prolapse, diagnosed clinically and radiologically, who admitted to Neurosurgery Department, Mansoura University Hospital and on Private work during the period from March 2013 to March 2015. On admission demographic data as age, gender, job and body mass index (BMI) were obtained for all patients. All patients were examined on admission clinically and radiologically by MRI lumbosacral spine and dynamic study plain x-ray films in extension and flexion views. Disc height was measured for all patients at the herniated level only, by MRI using Dabbs method. The outcome was measured according to modified Mac-Nab’s criteria.Results: Six cases out of 40 (15%) developed cage retropulsion. There was a lower significant mean age (38.3+2.96) for cases with cage retropulsion compared to (42.4+5.7) for those cases without cage retropulsion (P 0.05). The majority of cases with cage retropulsion were obese (66.7%), while those without cage retropulsion were overweight (64.7%). L4-5 was the most common affected level (66.6%) among cases with cage retropulsion, and those without retropulsion were (70.6%). The majority of cases (5) with cage retropulsion (83.3%) had wide disc space height. Workers and carriers represented the majority of cases with cage retropulsion (33.3%). All cases (100%) with cage retropulsion had a poor outcome. However, the majority of cases with no cage retropulsion had excellent (50%) and good (11.8%) outcome according to the modified Mac-Nab’s criteria.Conclusion: Our data suggest that strenuous work, early heavy physical activities, large disc height may be contributing factors for cage retropulsion. Cage retropulsion has a negative impact on patients’ outcome. (2017ESJ146)