How to Minimize Complications of Classic Decompression and Fusion in Lumbar Spinal Stenosis: is a Complemental Interspinous Fusion an Alternative?

Abstract

IntroductionLumbar spinal stenosis (LSS) is the most common reason for back surgery in patients over 50 years. LSS decompression may cause an instability or deteriorate it. A classic fusion with pedicle screws enhances the hazard of the surgery in geriatric patients. The goal of the study was to find out, if the additional interspinous fusion (partly combined with interbody fusion) with a rigid intespinous device can minimize the risk of classic procedure. Material and Methods94 patients (44 men and 46 women) in age of 49- 88 years (mean 69) underwent LSS decompression with interspinous fusion, some of them additionally with intervertebral cages. Interspinous rigid fusion device were used to provide fusion. Demographic data, indications, operated levels, results in terms of approval of ODI, VAS back and legs, walking distance and satisfaction were analyzed. Blood loss, OP-, fluoroscopy time and complications were registered. Fusion was determined by CT performed at least 6 months post OP and X- rays. Results78 patients (83%) were operated with stand alone interspinous fusion device and 16 (17%) received additionally an intervertebralcCage. The follow- up was 6 to 36 months (mean 20). Indications: LSS with instability 41, LSS 28, LSS with disc herniation 19, deformity 3 and adjacent segment disease 3. The Op time ranged from 35 to 209 minutes (mean 82). The blood loss was between 10 to 450 ml (mean100ml). The fluoroscopy time reached from 2 to 18 seconds (mean 6). Mean values for ODI and VAS are presented in Table 1. pre OP3 months6 months12 months24 monthsODI5432202424VAS back5,82,02,12,92,9VAS legs7.91,93,22,32,22 years post OP the improvement of ODI was 54%. VAS back 50% and VES legs 72% respectively. The walking distance increased at least at 50% in 86 patients (91,5%). Concerning the satisfaction 90 patients (96%) would undergo the surgery once more, 4 of them (4%) not. Following complications were observed: cage subsidence (3), cage dislocation (1), epidural hematoma (2), wound infection (1), deep infection (1), dural tears (7), seroma (4). It means all in all 19 adverse events (20%). Only in 10 patients (11%) they had a consequence with revision surgery. Radiological criteria of the fusion had 59% of the patients with 6 months follow up, in 94% patients with 12, 98% with 24 and 100% with 36. ConclusionThe results of the study show, that the LSS decompression can be supplemented using an interspineous rigid device to provide a fusion without significant extending the Op time. More extended surgeries with pedicle screw fixation can be avoided and thus the complication rate reduced. 11% of complications, which require a repeat surgery are acceptable in population of aged patients with comorbidities. The advantage is the less invasive technique with less blood loss and only 0,1 minutes fluoroscopy time. We found no real liminations in decision making for the surgery. There were 22 drop outs.