Surgical outcome in patients with cervical ossified posterior longitudinal ligament: A single institutional experience

OBJECTIVE: Ossification of the posterior longitudinal ligament (OPLL) is a complex multi-factorial disease process having both metabolic and biomechanical factors. The role of surgical intervention as well as the choice of approach weather anterior or posterior is ambiguous. The objective of this study was to assess the surgical out come and post operative functional improvement in patients with cervical OPLL at a tertiary care centre. PATIENTS AND METHODS: This prospective study included 63 patients of cervical OPLL who underwent either anterior and/or posterior surgeries in Department of Neurosurgery, Nizam's Institute of Medical Sciences, Hyderabad between June 2009 to May 2011. Patient's data including age, sex, pre and post operative functional status, radiographic findings and OPLL subtypes were recorded and analyzed over a follow up ranging up to minimum two years. RESULTS: The mean age of the patients was 51.1 (range 30-80 years) involving 14 women and 49 men. Out of 63 patients, 14 patients underwent surgery by anterior approach (corpectomy and fusion) and all of them improved (P = 0.52). 49 patients underwent surgery by posterior approach where decompressive laminectomy was performed in 40, laminectomy with instrumentation was done in 5, laminoplasty was done in 3 and 1 patient underwent both anterior and posterior surgeries. Of those who underwent posterior surgery, 40 patients improved, 7 remained the same as their preoperative status (who were having signal intensity changes on T2W MRI) and 2 patients deteriorated in the immediate post operative period and then showed gradual improvement. All the patients were followed up for 24 months. The mean pre-operative Nurick grade was 2.82 which later on improved to 2.03 post surgery (P < 0.05). Minor complications included wound infections in two patients (1.26%). CONCLUSIONS: Anterior cervical decompression and reconstruction is a safe and appropriate treatment for cervical spondylitic myelopathy in the setting of single or two level OPLL. Laminectomy or laminoplasty is indicated in patients with preserved cervical lordosis having three or more levels of involvement. Younger patients with good pre operative functional status and less than 2 levels of involvement have better outcome following anterior surgery.