Study design:

Systematic review OBJECTIVE: The objective of this systematic review is to determine the fate of spinal implants when the 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 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:

Out of the 3,071 citations identified, 49 met the criteria to undergo full-text review. Outcomes after surgical site infections were studied from a combined pool of 1,150 patients undergone instrumental spinal fusion. The collected data showed that 456 patients (39.97%) had undergone spinal implant removal following SSI while 694 patients (60.03%) had their implants retained until the resolution of SSI. There was an absolute risk reduction of 29% (ARR-0.292) and a relative risk reduction of 50.3% (RRR- 0.503) of implant removal if the patient underwent wound debridement following SSI. The NNT for wound debridement was calculated at 3.31 from our pooled cohort. The absolute risk reduction in implant removal following VAC therapy was 16.6% and relative risk reduction was noted at 40.4%. This led to a high value of NNT at 6.0 patients. There was an absolute risk reduction of 33.5% while a Relative Risk Reduction of 70.7% was estimated in patients undergoing continuous irrigation.

Conclusion:

Our review of the literature suggests that successful eradication of surgical site infection after posterior lumbar spinal fusion can be achieved by wound debridement or VAC therapy with appropriate antimicrobial coverage in most cases. Implant removal is generally reserved for cases refractory to the other treatment modalities.