Randomised controlled trials (RCTs) of instrumented posterolateral fusion and circumferential fusion in adult patients who underwent spinal fusion surgery for degenerative disease of the lumbar spine were eligible for inclusion. Trials had to follow patients up for at least one year after surgery. Patients with acute spinal fracture, infection, tumour, osteoporosis or rheumatoid arthritis were excluded.
The primary outcomes of interest were global assessment of clinical outcomes and complication rate. Secondary outcomes were fusion rate, blood loss, operating time and reoperation time. Trials were excluded if they did not report on at least one relevant outcome.
Included trials compared posterolateral fusion combined with titanium CD-horizon, posterolateral fusion combined with variable screw placement or instrumented posterolateral fusion versus circumferential fusion plus an anterior lumbar interbody fusion Brantigan cage plus posterior instrumentation, posterolateral fusion plus transforaminal lumbar interbody fusion, posterolateral fusion plus posterior lumbar interbody fusion, or posterolateral fusion combined with variable screw placement and interbody fusion. The mean age of patients ranged from 42 to 58.6 years.
Two reviewers independently performed study selection; disagreements were resolved by discussion or consultation with a third reviewer.