[Perioperative morbidity of lumbar stabilisation with Dynesys]

Several non-fusion technologies have been developed as an alternative to fusion procedures in the past decades, in order to avoid typical problems related to fusion. The Dynesys (Zimmer, USA), which was inaugurated 7 years ago, consists of pedicle screws, flexible spacers and cords and is intended to control segmental motion and to realign the lumbar spine. Since this device is new, it was the goal of this study to analyse the perioperative morbidity of lumbar stabilisation with Dynesys retrospectively.

136 patients (74 men and 62 women) underwent posterior stabilisation of the lumbar spine with Dynesys between January 2002 and April 2006. We acquired retrospectively several patient-related variables, e.g. the number of instrumented and decompressed segments, the perioperative blood loss, the operation duration, prior surgeries and technical and general complications.

The average age of the patients was 61.2 years (range: 33-84). 1.6 segments (range: 1-3) were instrumented and 1.2 segments (range: 0-3) were decompressed on average. The mean perioperative blood loss was 1100 ml (range: 50-3400) and the mean operation duration was 127.1 minutes (range: 30-270). Eighteen patients (13.2 %) had a urinary tract infection and 5 patients (3.7 %) had cardiovascular complications. Dura lesions were seen in 11 patients (8.1 %) with 1 patient having persistent bladder symptoms. Revision surgery was necessary in 3 patients (2.2 %) due to screw malposition with neurological deficits and radicular pain. Five patients (3.7 %) were revised due to postoperative seroma, 2 of them developing superficial infection.

The perioperative morbidity of lumbar stabilisation with Dynesys seems to be similar to posterior fusion techniques. However, an additional morbidity due to interbody fusion, which may necessitate also autogenous bone, is avoided.