Clinical and radiological mid- to long-term investigation of anterior lumbar stand-alone fusion: Incidence of reoperation and adjacent segment degeneration.

Introduction: Anterior stand-alone fusion (ASAF) devices have been developed in an attempt to reduce adjacent segment degenerative changes observed with posterior instrumented fusion techniques. Research question: The purpose of this study was to assess mid- to long-term clinical and radiological results following ASAF at the lumbosacral junction with special emphasis on the assessment of adjacent level pathologies.Materials & Methods: Clinical outcome scores and radiological data were acquired within an ongoing single-center prospective cohort study. Progression of adjacent level degeneration was evaluated based on MRI scans according to the Pfirrmann and Weishaupt classification system by two independent radiologists. Results: The results from 37 patients (FU â€‹≥ â€‹5 years) demonstrated high satisfaction rates and significant improvements in VAS and ODI scores. N â€‹= â€‹8 patients (21.6%) had to undergo subsequent surgery at the cranially adjacent level. The incidence of adjacent level disc degeneration and adjacent facet joint degeneration was 24.3% and 35.1%, respectively. More pronounced degenerative changes of the adjacent level discs (p â€‹= â€‹0.005) and facet joints (p â€‹= â€‹0.042) prior to surgery and a lower segmental lordosis reconstruction at the lumbosacral junction (p â€‹= â€‹0.0084) were identified as potential risk factors for the development of subsequent adjacent level pathologies. Discussion & Conclusion: The study revealed satisfactory clinical results at a mid-to long-term FU of ≥5 years. The incidence of adjacent level degeneration was higher than initially expected. Patients with preexisting radiographic signs of degenerative adjacent level changes have a higher risk for subsequent deterioration necessitating reoperation at the adjacent segment at later stages. Furthermore, adequate intraoperative segmental lordosis reconstruction at the index segment is paramount as the present data reveal this to be a key protective factor for adjacent segment preservation.

[Minimally invasive stand-alone fusion of the lumbosacral junction]. / Minimal-invasive Stand-alone-Fusion des lumbosakralen Übergangs.

OBJECTIVE: Stable interbody fusion of the lumbosacral segment via an anterior retroperitoneal approach using an interbody spacer as an anterior stand-alone device which is fixed with four locking screws. INDICATIONS: Degenerative disc disease without instability or deformity; adjacent segment degeneration; pseudarthrosis. CONTRAINDICATIONS: Translational instabilities as in spondylolisthesis at the index segment; deformities; steep sacral slope. Challenging vascular situation with aortic bifurcation and/or venous confluence in front of L5/S1; osteoporosis. Relative: previous abdominal/gynecological surgery; infection/tumor/trauma. SURGICAL TECHNIQUE: Access to the lumbosacral junction via a mini-open laparotomy using a retroperitoneal approach, insertion of a retractor system, preparation of the lumbosacral segment and complete discectomy and endplate preparation, distraction of the disc space, assessment of the adequate implant size, packing of the device and the disc space with bone graft substitute, insertion of the device in the intervertebral space, fixation of the implant by inserting two screws each into the cranial and caudal vertebral body, X­ray control, withdrawal from the surgical site under constant assessment for possible lesions, wound closure. POSTOPERATIVE MANAGEMENT: Immediate full load-bearing mobilization within 4-6 h postoperatively, external brace optional, resumption of sporting activities 3-6 months postoperatively. RESULTS: From 2005-2012, of the original 77 patients who underwent surgery, 71 patients (26 men, 45 women; 92.2%) were followed up for an average of 35.1 months (range 12-85 months). The overall complication rate was 12.7%; the reoperation rate was 2.8%. At final follow-up, 77.5% of the patients were satisfied and 22.5% were not satisfied. The ODI and the VAS scores revealed significant improvements over the entire follow-up period. X­ray analysis demonstrated a significant improvement of segmental lordosis. Solid bony fusion (determined by CT) was observed in 97.3%.

Anterior stand-alone fusion revisited: a prospective clinical, X-ray and CT investigation.

PURPOSE: The purpose of this study was to assess the mid-term clinical and radiological results as well as patient safety in terms of complication and reoperation rates in patients treated with a novel anterior stand-alone fusion (ASAF) device (Synfix-LR, DePuy Synthes, West Chester, PA, USA) in a cohort of patients with predominant and intractable low back pain originating from monosegmental degenerative disc disease at the lumbosacral junction. METHODS: Clinical outcome scores visual analog scale (VAS), Oswestry disability index (ODI) and patient satisfaction rates were acquired within the framework of an ongoing single-center prospective clinical trial. Evaluation of radiological data included segmental and global lumbar lordosis, neuroforaminal height and width. Interbody fusion was assessed from post-operative CT scans. The minimum follow-up (FU) was 12 months. RESULTS: 71 out of an initial 77 patients were available for final FU (92.2 % FU rate) after a mean FU of 35.1 months (range 12.0-85.5 months). The overall results revealed a highly significant improvement from baseline VAS and ODI levels (p < 0.0001). 77.5 % (n = 55/71) of all patients reported a 'highly satisfactory' (n = 37/71; 52.1 %) or a 'satisfactory' (n = 18/71; 25.4 %) outcome; 22.5 % of patients were not satisfied. The overall complication rate was 12.7 % (n = 9/71). Two cases required post-operative revision surgery (2.8 %). Radiographical analysis demonstrated a highly significant increase of segmental lordosis from 16.1° to 26.7° (p < 0.0001). A high rate of solid interbody fusion was confirmed in 97.3 % of all cases (n = 36/37). CONCLUSION: The current study delineates satisfactory clinical results following ASAF at the lumbosacral junction. Patient safety was demonstrated with acceptable complication and low reoperation rates. Radiological data demonstrated a significant reconstruction of lordosis at the lumbosacral junction. Solid interbody fusion was achieved in 97.3 % of all cases in a highly selected cohort with optimal predisposition for fusion. ASAF may serve to avoid a variety of negative side effects for a considerable number of patients which, otherwise, would have been candidates for posterior instrumented fusion techniques.