Open vs. Minimally Invasive Pedicle Screw Instrumentation: Differences in Technique and Tools

Two surgical teams can run the exact same pedicle screw system and still need two completely different case carts, depending on whether the case is open or minimally invasive. The implant might stay constant, but minimally invasive pedicle screw instrumentation calls for a different dilation and retraction set, a different insertion sequence, and often a different imaging setup than an open tray requires. Getting the tray wrong doesn’t just slow the case down. It can force a mid-procedure scramble for tools that should have been on the table from the start. Here’s what actually changes in the instrument set and workflow between the two approaches, tool by tool and step by step.

The Access Method Sets the Tray From the Start

Before a screw ever gets placed, the access technique already dictates which instruments need to be on the back table. Open and MIS approaches start from two different physical realities, and the tray reflects that difference from the first incision onward.

Open Access Instruments

An open pedicle screw placement approach calls for a standard exposure set: self-retaining retractors, Cobb elevators, and periosteal instruments to strip and hold back the paraspinal musculature. Because the surgeon works under direct visualization, there’s no dilation sequence to stage and no tube system to dock. The tray is comprehensive but not particularly specialized, since most of what it needs overlaps with general posterior spine exposure sets the OR staff already knows.

MIS Access Instruments

A percutaneous approach replaces that exposure set with a sequential dilation system: an initial access needle, a guidewire, and a series of graduated dilators that expand the tract without cutting muscle. A tubular or expandable retractor then docks over the final dilator to hold the working channel open. Understanding how MIS pedicle screw placement works starts with this dilation sequence, not with the screw itself, which is why an MIS tray can’t simply be an open tray with a few items pulled out. It’s a separate build with its own components from the first step.

Screw Insertion Tools Differ by Approach

Once access is established, the tools used to actually place the screw diverge just as sharply as the access method did.

Open Insertion Tools

In an open case, the surgeon typically uses a pedicle probe or awl to establish the starting point, confirms the tract with a ball-tip probe, and taps the pilot hole before driving the screw with a straight or low-profile driver under direct view. Because the surgeon can see and feel the entry point throughout, the instrument set stays relatively simple and each step can be verified visually before moving to the next.

MIS Insertion Tools

A percutaneous pedicle screw insertion technique requires every one of those steps to happen over a guidewire, through the docked retractor, without direct sightlines to the bone. That means a cannulated tap, a cannulated probe, and an extended tower-based driver that reaches from the screw head to the skin surface. Eminent Spine’s pedicle screw prep sets for open and MIS procedures bundle the approach-specific instruments together so the OR team isn’t assembling a percutaneous tray piece by piece from a general set.

Rod Passage and Reduction Instruments

Getting the screw into bone is only half the procedure. Passing and seating the rod is where the two approaches’ toolsets look the most different from each other.

Open Rod Passage

Under direct visualization, rod passage is largely a hands-on task. The surgeon bends or contours the rod as needed, seats it into the tulip heads by hand or with a simple rod holder, and reaches for a persuader or reduction instrument only when a screw sits noticeably proud of the rod’s path.

MIS Rod Passage

Through a percutaneous tower system, none of that is hands-on. A specialized rod inserter passes the contoured rod down through the tower assemblies to the tulip heads without the surgeon ever seeing the rod directly. Blind reduction instruments then seat the rod and manage any height mismatch between screw heads, a task the tower system depends on since the surgeon can’t confirm seating by eye the way an open procedure allows.

Matching the wrong prep set to a case wastes OR time before the first screw ever goes in. Eminent Spine’s approach-specific instrumentation keeps the right tools staged and ready, whether the case is planned open or percutaneous.

Talk Through Your Tray Setup

Imaging and Guidance Equipment Requirements

The instrument tray isn’t the only thing that changes between approaches. What gets rolled into the room for imaging depends heavily on which technique is planned.

Open Imaging Needs

Open cases can often proceed with intermittent fluoroscopy or, at straightforward levels, minimal imaging altogether, since direct visualization and tactile feedback supply most of the confirmation the surgeon needs. A single C-arm typically covers an open pedicle screw case without requiring a dedicated navigation setup.

MIS Imaging Needs

Percutaneous cases can’t lean on that same tactile feedback, which makes fluoroscopy or image-guided pedicle screw navigation a requirement rather than an option. That usually means more C-arm time per level, a registered navigation system where the program uses one, and OR staff trained to run guidance equipment efficiently so imaging doesn’t become the rate-limiting step in the case.

Closure and Case Wrap-Up Differences

The instrumentation gap narrows again once fixation is complete, but a few differences carry through to closure.

Open Closure

Open cases close in layers, fascia, subcutaneous tissue, and skin, using standard closure instruments already present on a general spine set. The larger incision means more closure time and more suture or staple volume per level compared to a percutaneous case.

MIS Closure

Percutaneous incisions close with minimal suturing since each access point is only as large as the final instrumentation required, often a single subcuticular stitch or adhesive closure per site. The tradeoff for a lighter closure tray is the additional access equipment used earlier in the case.

Standardizing a Tray Strategy Across Both Approaches

Programs that run a mix of open and MIS cases don’t need two unrelated implant systems. They need a plan for the instrumentation that supports each approach.

One Screw Platform, Two Access Paths

Because Eminent Spine’s 3D Titanium Pedicle Screw System is available in both cannulated and non-cannulated configurations on the same platform, a program can standardize its implant choice and vary only the instrument set by approach. That keeps inventory, sterilization logistics, and staff training simpler than running two unrelated systems side by side.

Matching Prep Sets to the Planned Approach

How a program chooses screw sizing and overall fixation strategy is a broader planning question, one covered in more depth in pedicle screw design considerations for lumbar spinal fusion. The instrumentation question here is narrower: once the approach is confirmed preoperatively, matching the correct prep set to it reduces the odds of an intraoperative switch, which is disruptive regardless of which system is on the table.

Build a Tray That Matches How You Actually Operate

The instrumentation differences between open and minimally invasive pedicle screw placement aren’t a footnote to the technique decision. They’re a direct consequence of it. Once the approach is set, the tray, the imaging plan, and the closure supplies all follow from that choice, and getting each piece staged correctly is what keeps a case moving instead of pausing to hunt for the right tool.

Eminent Spine builds its pedicle screw platform and approach-specific prep sets to work as one system rather than two disconnected product lines, so your OR doesn’t have to reinvent its setup every time the technique changes. If you’re mapping out what your program’s tray strategy should look like across both approaches, reach out to the Eminent Spine team to talk through what that looks like for your cases.

Open vs. Minimally Invasive Pedicle Screw Instrumentation: Differences in Technique and Tools

The Access Method Sets the Tray From the Start

Open Access Instruments

MIS Access Instruments

Screw Insertion Tools Differ by Approach

Open Insertion Tools

MIS Insertion Tools

Rod Passage and Reduction Instruments

Open Rod Passage

MIS Rod Passage

Imaging and Guidance Equipment Requirements

Open Imaging Needs

MIS Imaging Needs

Closure and Case Wrap-Up Differences

Open Closure

MIS Closure

Standardizing a Tray Strategy Across Both Approaches

One Screw Platform, Two Access Paths

Matching Prep Sets to the Planned Approach

Build a Tray That Matches How You Actually Operate

Share This Post

More Like This

Pedicle Screw Fixation in Long Construct Scoliosis

MIS Pedicle Screw vs. Open Screw Placement: What Drives the Decision?

Cannulated vs. Non-Cannulated Pedicle Screws: A Clinical Design Comparison

How Triple-Lead Thread Technology Advances Pedicle Screw Performance

How Eminent Spine’s 3D Pedicle Screw Passed FDA 510(k) Clearance

What Is a Pedicle Screw and How Is It Used in Spinal Fusion?

When Bone Won’t Hold: The Real Challenges of Pedicle Screw Fixation in Osteoporotic Patients

Treatment for Loose Pedicle Screws: Why It Happens and What It Costs

Products

Resources

Contact