7.4 Testing Scissors

Why Scissors Get Their Own Test

A dull scissor does not announce itself. It looks identical to a sharp one, and the surgeon discovers the problem by tearing tissue rather than cutting it. Sharpness is therefore one of the few instrument properties that must be actively tested rather than visually assessed, and the CBSPD outline names scissors first in its list of instruments to test.

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The Gauze Test

The widely taught protocol, consistent with the way the test is described in the sterile processing literature and derived from the international scissors test standards:

Procedure

1. Start with a clean, dry scissor — soil or lubricant film changes the result.
2. Fold gauze to the required number of layers.
3. Position the gauze at the tips of the blades — the tip is where scissors dull first and where a failing scissor pushes material instead of cutting it.
4. Close the blades in a single smooth stroke.
5. Evaluate the cut.

Pass: a clean, complete cut of every layer, with no dragging.

Fail: any snagging, bending, folding, or pushing of the test material at any point along the cut, including at the very tips. Partial cutting is a failure. A scissor that cuts the first three layers and drags the fourth is a failure.

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Fine, Delicate and Specialty Scissors

Gauze is too coarse a challenge for very fine scissors, and forcing a micro-scissor onto four layers of gauze can damage it. For those instruments, use the manufacturer's or the department's validated alternative:

The governing principle is use the material specified for that scissor, at the specified number of layers, at the tips — and use the same method consistently, so results are comparable over time.

Specialty scissors have their own considerations:

• Supercut scissors (black handles) have one razor-honed blade; they are sharpened only by the manufacturer's process, so a failed supercut is routed to the vendor, not to a general sharpening service.
• Tungsten carbide scissors (gold handles) hold their edge far longer and can be re-inserted rather than replaced.
• Laparoscopic scissors are tested as inserts per IFU and are frequently designed as limited-life or single-use cutting elements.

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Mechanical Checks That Accompany the Sharpness Test

Sharpness is only one of several ways a scissor fails. Before or alongside the cutting test:

1. Edge condition under magnification — look for nicks, rolled edges, and chips. A nick partway along a blade is the fingerprint of the scissor having been used on wire or suture.
2. Blade alignment — the blades must meet along their whole length; hold to light with the blades closed.
3. Screw or box-lock tension — the pivot must be firm enough that the blades shear against each other, but free enough to move smoothly. Loose blades ride over each other and will not cut regardless of edge sharpness.
4. Tips — matched, intact, and meeting. A bent or broken tip fails the instrument outright.
5. Ring handles and shanks — no sprung shanks, no cracks.
6. Surface — no pitting, cracks, or corrosion at the pivot.

A scissor that fails alignment or pivot tension will fail the gauze test as well, and sharpening it will not fix it. Diagnosing which fault you are looking at is what routes the instrument to the right repair.

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Documentation and Disposition

A failed scissor is removed from the set and routed for sharpening, re-insertion, or replacement, with the failure documented in the repair record. Two department-level practices follow:

• Track repeat offenders. A scissor that returns from sharpening and fails again within weeks is either at end of life or being abused in the OR.
• Track patterns. Repeated notched Metzenbaums point to tissue scissors being used on suture or wire — an instrument abuse issue that belongs in the Ethics content area and must be reported rather than absorbed as a repair cost.

Test Media, Repair and the Sharpening Decision

The gauze test is performed with the material the protocol specifies, and consistency is what makes it a test rather than an impression. Departments use standard cotton gauze sponges of a known ply, and some use commercial sharpness-test materials — coloured latex or silicone strips of a defined thickness — which have the advantage of being uniform between batches and of showing a clean cut or a snag unambiguously.

Whatever the medium, the technique is fixed: cut with the tips, using the full closing stroke, and observe the cut rather than merely feeling it. A serviceable scissor cuts through all the way to the tip in a single smooth pass with no snag, no push, and no fold. A scissor that cuts partway and then pushes the material out of the blades has failed.

When to Sharpen and When to Replace

A dull scissor is usually repairable, and sharpening by a qualified vendor is routine and economical. What is not repairable in the department is any of it: scissors are never sharpened in-house by staff on a bench grinder or stone, because the blade geometry, the bevel angle, and the set of the blades relative to each other are precision characteristics that hand sharpening destroys.

Route to repair when the instrument is dull, when the screw or joint has loosened, or when the blades have lost their set and no longer shear correctly. Route to replacement when there is a crack, when the blade is chipped or notched deeply, when corrosion has pitted the cutting edge, or when the instrument has been repaired repeatedly and returns dull quickly — a pattern that usually indicates soft, floor-grade stock.

Tungsten-carbide-insert scissors, identified by their gold rings, have replaceable inserts and are almost always worth repairing rather than replacing.

Recording the Result and Closing the Loop

A failed scissor that is simply set aside will find its way back into a tray. The disposition must be physical and documented: tag the instrument, remove it from the tray immediately, place it in the designated repair or quarantine location — never back on the assembly table — and record the removal against the set so the count sheet shortage is known.

Then close the loop. Note the shortage on the count sheet, inform the operating room if the set is needed before a replacement arrives, and, where the department uses instrument-level tracking, record the repair against that instrument so its history accumulates. An instrument that has been sharpened three times in a year is telling you something that only the record will reveal.