IN SITU POSTEROLATERAL FUSION FOR LOW GRADE LYTIC SPONDYLOLISTHESIS: LONG TERM RESULTS IN 75 ADULT PATIENTS

Abstract

Spondylolytic spondylolisthesis is one of the common causes of mechanical low back pain in adults. Conservative treatment of such cases, particularly for the low grade slips, remains the mainstay of management. When patients’ symptoms are marked and not responsive to conservative therapy, the surgical option can be considered. Up to the time of writing this abstract [January 2003], arthrodesis of the affected motion segment with or without instrumentation is the standard surgical option for treating mechanical low back pain. Results of different types of arthrodesis for treating such condition had been reported in literature, including posterior fusion, posterolateral fusion, and posterior and anterior interbody fusion.

Between 1993 and 1998, seventy- five adult patients with grade I or II lytic spondylolisthesis were treated by in situ posterolateral fusion and segmental instrumentation using the Oswestry Pedicle Screw System, with or without extended Gill’s procedure. The indications for surgical intervention in these cases were significant reduction in the quality of life with persistent low back pain and/or leg pain after a minimum of six months conservative therapy. Confirmatory imaging studies consistent with the clinical data should also be obtained before deciding the surgical option. The average operative time was 2.5 hours [range 2–4 hours). The average blood loss was 850 mls (range 300–2300 mls)

After an average follow-up of 60.7 months (range 24–95 months) clinical results were excellent and good in 92%, and radiological union was achieved in 94% of patients. Complications included 2 cases with superficial wound infection, one case with deep wound infection, and four of the patients went to non-union.

In conclusion, with a careful patient selection, patients with instrumental insitu posterolateral fusion gained a satisfactory clinical and radiological outcome and the results were maintained for an adequate postoperative period.