7.6 Testing Forceps & Clamps

Two Families, Two Test Routines

The word forceps covers two mechanically different instruments:

• Spring / thumb forceps — two arms joined at a proximal spring; no ratchet. Tested for tip alignment and spring return.
• Ring-handled forceps and clamps — box-locked and usually ratcheted. Tested with the four hinged-instrument tests in Section 7.5, plus jaw-pattern-specific checks.

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Testing Thumb Forceps

Procedure

1. Hold the forceps up to a light source.
2. Close the tips gently with the fingers — the pressure a surgeon would use, not a squeeze.
3. Evaluate the tips, under magnification for fine and micro patterns.
4. Release and observe the arms returning.
5. Sight down the length of the instrument from the spring toward the tips.

Pass / fail criteria by pattern

Spring test: release the arms and confirm they spring fully open, briskly. A forceps that stays partly closed, opens slowly, or feels soft has a fatigued or bent spring and is a repair item. A forceps whose arms are out of plane will show as tips that deviate laterally when sighted from the spring end.

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Testing Toothed Clamps

Allis, Kocher/Ochsner, tenacula, and towel clips grip by interlocking teeth, so the test is about the teeth.

1. Close to the first ratchet tooth and inspect the jaw under magnification.
2. Confirm every tooth is present, full height, and straight.
3. Confirm the teeth interlock rather than meeting point-to-point or riding past each other.
4. Confirm the remaining serrated portion of the jaw meshes (Kocher has serrations behind its 1x2 teeth).
5. Apply the standard ratchet, box-lock, and shank tests.

A single bent or missing tooth is a failure. The instrument grips and then releases unpredictably, which on an Allis holding bowel or on a tenaculum holding a cervix is a tissue-injury event.

For Foerster sponge forceps, the equivalent test is ring alignment: the two fenestrated rings must register exactly, or a clamped sponge can be released into the wound.

For towel clips, confirm both points are sharp, matched in length, and not bent, and that the ratchet holds — a clip that releases mid-case drops the drape.

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Testing Atraumatic Vascular Clamps

This group requires a different mindset because the working surface is delicate by design.

Do:

• Inspect the inserts under magnification: the fine longitudinal double rows must be sharp, complete, and aligned row-to-row across the closed jaw.
• Check jaw closure along the full length by holding to light.
• Check ratchet and box lock normally.
• Check Fogarty-type soft inserts for suppleness, splits, hardening, and correct seating.
• Check spring force on bulldogs by closing and releasing — the jaws must meet fully under spring pressure alone.

Do not:

• Clamp them on gauze, a fingernail, a pen, or any hard object. The shallow rows flatten and the clamp is destroyed.
• Use them as general graspers, or use them to hold a needle.

A vascular clamp with flattened or polished rows is a repair item — the inserts are replaceable — and routing it correctly rather than scrapping it is part of the specialist's cost-stewardship role.

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Testing Micro-Clamps and Approximators

Micro-vascular clamps hold a vessel of a millimetre or two, and both too little and too much closing force are failures — excessive force crushes the intima. Practically, the department checks that:

• The jaws meet fully along their length under spring pressure.
• The jaws are aligned, not crossed or offset.
• The spring is intact and the frame of an approximator slides freely.
• No burrs are present on any surface that contacts vessel wall.

Where the manufacturer supplies a closing-force gauge, it is used per its instructions. Otherwise, clamps showing any deformation are removed, because a sprung micro-clamp cannot be restored at the assembly table.

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Common Failure Fingerprints

Documenting these fingerprints is how a specialist converts individual repairs into a conversation about handling practice — which is exactly what the exam's Ethics content area expects.

Overriding Jaws, Guide Pins and Alignment Aids

Several clamp and forceps patterns carry features specifically intended to preserve alignment, and knowing them sharpens your inspection.

Guide pins or alignment pins are small posts on one jaw that seat into a corresponding hole on the other as the instrument closes. They exist because the pattern demands precise tip meeting — common on heavy toothed clamps and some bone-holding instruments. A bent guide pin, or a pin that no longer seats, means the jaws will offset under pressure, and the instrument goes to repair.

Interlocking terminal teeth, as on a Kocher or Ochsner, must mesh cleanly. Inspect the teeth for wear, blunting, and — critically — for one tooth riding beside rather than into its counterpart, which indicates the box lock has worn or the jaws have sprung.

Overriding is the general failure to look for on any clamp: closed jaws in which one tip passes the other rather than meeting it. It is easiest to see by holding the closed instrument at eye level and sighting along the jaws from the tip end.

Testing Thumb Forceps Systematically

Non-ringed forceps have no ratchet and no box lock, so the whole test is about the tips and the spring.

Close the forceps with light finger pressure and confirm the tips meet first and meet exactly. Toothed forceps must have teeth that interdigitate fully — the 1x2 arrangement means the single tooth must drop between the pair, not sit alongside them. Serrated forceps must show serrations that meet along the working surface. Then examine the tips under magnification for bending, for burrs, and for missing or broken teeth.

Check the spring by compressing fully and releasing: the arms should separate to their rest position cleanly. Forceps that stay partly closed have lost temper and are not repairable by bending.

Recognising the Fingerprint of Specific Abuses

Failures on this group usually carry a signature that tells you what happened, and reporting the cause is more valuable than reporting the defect.

Tips bent outward or splayed on a fine forceps almost always means it was used to grasp something too heavy, or it was crushed under other instruments in a tray. Flattened serrations on a vascular clamp mean it was over-tightened or clamped on something harder than a vessel. A snapped or chipped tooth on a heavy clamp usually means it was applied to bone or hardware. Corrosion concentrated in the box lock means the instrument was cleaned closed.

Each of these has a corrective action upstream — point-of-use handling, tray configuration, in-service education — and the specialist who names the pattern lets the department fix the cause rather than repeatedly funding the repair.