Current Management Trends for Surgical Site Infection After Posterior Lumbar Spinal Instrumentation: A Systematic Review

Objective: The objective of this systematic review is to determine the fate of spinal implants when patients develop postoperative wound infection after posterior instrumental fusion in a degenerative spine.

Methods: A systematic review of the English-language literature (published between January 2001 and July 2020) was undertaken to identify articles documenting the management strategy for surgical site infections (SSIs) after posterior lumbar spinal fusion. Studies on pedicle screw fixation after trauma, immunocompromised, metastatic spine disease, and combined anterior/posterior approach were excluded. Two independent reviewers assessed the level of evidence quality using the criteria set by the North American Spine Society, and disagreements were resolved by consensus.

Results: Of the 3071 citations identified, 49 met the criteria to undergo full-text review. Outcomes after SSIs were studied from a combined pool of 1150 patients who had undergone instrumental spinal fusion. The collected data showed that 456 patients (39.97%) had undergone spinal implant removal after SSI while 694 patients (60.03%) had their implants retained until the resolution of SSI. There was an absolute risk reduction (ARR) of 29% (-0.292) and a relative risk reduction (RRR) of 50.3% (-0.503) of implant removal if the patient underwent wound debridement following SSI. The number needed to treat (NNT) for wound debridement was calculated at 3.31 from our pooled cohort. The ARR in implant removal following vacuum-assisted closure (VAC) therapy was 16.6% and RRR was noted at 40.4%. This led to a high value of NNT at 6.0 patients. There was an ARR of 33.5% and a RRR of 70.7% was estimated in patients undergoing continuous irrigation.

Conclusions: Our review of the literature suggests that surgeons prefer early wound debridement with or without negative pressure wound therapy under antimicrobial coverage for eradication of SSI after posterior lumbar spinal fusion. Implant removal is generally reserved for cases refractory to the other treatment modalities.