Object: The authors assessed the late outcome of patients with Meyerding Grade I and II isthmic spondylolisthesis (IS) who underwent posterior instrumentation and posterolateral fusion (PLF). Decompression and posterior internal fixation with PLF is the classic surgical treatment for painful low-grade IS. Nevertheless, outcome data are scarce and of limited value mainly because they represent small numbers of patients, short follow-up periods, or both.
Methods: The authors obtained data in the cases of 132 consecutive adult patients (mean age 40.6 years, range 15.2-69.9 years) with IS who underwent treatment between 1984 and 2003. Assessment involved analysis of responses to mailed questionnaires, clinical charts and, in cases in which unsatisfactory results were suspected, results of clinical reevaluations. Spondylolisthesis was present at L3-4 in three patients, L4-5 in 14, L3-4 in one, L3-5 in one, L5-S1 in 113, and S1-2 in one. Signs and symptoms included back and leg pain (65.3%), leg pain alone (26.3%), back pain alone (8.4%), and neurological dysfunction (18%). At a mean follow-up duration of 9.9 years (range 0.5-19.4 years), favorable results were reported for back and leg pain in 91.7 and 87.1% of patients, respectively. The mean visual analog scale scores were 2.13 for back and 1.59 for leg pain. Eighty-four patients resumed full- or part-time work, and 56.8% were capable of performing housework more easily. In 45.5% of the patients analgesic medications were not required, and 43.9% required them sporadically. The majority (63.6%) of patients reported they would undergo surgery again and recommended it to others. Thirteen (9.9%) suffered adjacent-segment morbidity, and in seven (5.3%) pseudarthrosis was documented. There were two deep and one superficial infections (2.3%).
Conclusions: Posterior instrumentation and PLF, with possible neurodecompression, yielded favorable long-term results in this retrospective study of 132 patients with low-grade IS.