meaning acceptable and useful, but not outstanding.

If you want it to go from “decent” to “strong” or even “excellent,” here are three simple upgrades you could make:

Clarify Bias Handling: Explicitly state how you minimized bias — for example, “two independent reviewers performed the selection and data extraction.” Right now, it's not clear.

Discuss Heterogeneity: Mention that different studies measured deviation differently (2D vs 3D, tip vs entry point, etc.) and that no meta-analysis was performed because of this heterogeneity.

Tone Down the Conclusion Slightly: Instead of affirming strongly that deviations don't affect spinal fusion, you could say:

“Minor deviations appear not to significantly compromise screw placement accuracy, although direct evidence linking deviation to fusion outcomes remains limited.”

That way, your conclusion sounds solid and cautious — like in a top-tier systematic review.