Pedicular dynamic stabilization system. Functional outcomes and implant-related complications for the treatment of degenerative lumbar disc disease with a minimum follow-up of 4 years

摘要

Introduction: The Dynesys® system is a non-fusion pedicular dynamic stabilization system. Theaim of our study is to evaluate the clinical outcomes in patients with degenerative disc diseaseand/or stenosis, and to measure the prevalence of screw loosening and breakage after 4 yearsof follow up.Material and methods: All patients who underwent surgery with Dynesys® system in 2008 werereviewed. The surgery was performed in cases of low back pain of more than 6 months durationand a positive MRI for degenerative disc disease and/or stenosis.Results: A total of 22 patients (11 females, 11 males) with a mean age of 44.40 ± 11 years wereincluded, 20 patients (91%) underwent Dynesys® without any associated decompression maneuver.The evaluation of back and leg pain (0---10 mm) showed a mean decrease of 2.4 ± 2.06 mm(P = .0001). The preoperative value of the Oswestry disability index was 52.36 ± 16.56% (severefunctional limitation). After surgery, this value was 34.27 ± 17.87% (moderate functional limitation)(P = .001) with a decrease of 18.09 ± 16.03% (P = .001). A total of 4 (18%) patients showedsigns of loosening screws. One patient (4.5%) had a screw breakage.Conclusions: Surgery with Dynesys® shows favorable long term clinical results, however therange of improvement in our series is lower than those reported in other studies. Comparativestudies between Dynesys® and decompression need to be performed in order to isolate thebenefit of the dynamic stabilization system. Implant-related complications are not uncommon.