9.4 Set Configuration of Loaner Instruments

Configuration Is Part of the Validated Process

When a manufacturer validates a sterilization cycle for a loaner tray, it validates it for a specific configuration: those instruments, in that tray, in those positions, with that mat, in that container, at that weight. Rearranging the set changes the mass distribution, the air removal, the steam penetration path, and the drying behaviour — which means the validated parameters no longer describe what is in the sterilizer.

That is why loaner assembly is not a matter of fitting everything in neatly. It is reproducing a documented configuration.

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Working Without a Familiar Count Sheet

A loaner set has no in-house count sheet, so the authority is:

1. The manufacturer's IFU, which specifies configuration, container, weight limits, and cycle.
2. The vendor's inventory sheet or tray map, which specifies each item and its position.
3. Photographs or diagrams supplied by the vendor or captured by the department at receipt — these are extremely valuable for a set that will return.

The vendor representative may explain the configuration; they do not perform the assembly and they do not release the set.

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Assembly Steps

1. Lay out the tray to the vendor's map. Verify each position is filled with the correct item, size, and quantity.
2. Inspect and function-test as you place (Sections 9.2 and 9.3).
3. Verify screw and implant caddies position by position — a caddy verified by total count can still be missing a specific length, which is the size the surgeon will ask for.
4. Keep trials and implants clearly separated. Trials are reusable sizing components processed with the instruments; implants remain in the patient and carry their own documentation and sterilization requirements. Confusing the two is a serious event.
5. Place instruments open and unlocked on stringers, racks, or the designed silicone brackets.
6. Use the manufacturer's mats, brackets, dividers, and inserts as designed — they exist to hold items apart for steam contact and to prevent damage.
7. Protect tips and delicate items with vented, correctly sized protectors on dry instruments.
8. Position concave items to drain.
9. Verify weight, and split or repack if over the limit.
10. Select packaging per IFU — the specified rigid container with the correct filters and valves, or the specified wrap and wrap technique.
11. Place the internal chemical indicator in the least accessible area per policy.
12. Label clearly with the set identity, the case, and the date.

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The Weight Problem

Vendor trays are among the heaviest items a department handles, and the widely applied guidance limits a wrapped set to 25 pounds (11.4 kg) including the tray or container.

When a delivered tray exceeds the limit:

• Do not simply extend the dry time. Mass is the cause of wet packs, and a longer cycle does not fix an overloaded tray.
• Split the set into two, each with a documented configuration, and label them clearly as a pair ("1 of 2", "2 of 2") so the OR receives the whole system.
• Document the split and communicate it to the OR and to the vendor.
• Escalate repeat offenders — a vendor whose trays are always overweight is a programme issue to be resolved with purchasing and the OR, not a problem to be re-solved by every assembler.

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Container and Wrap Selection

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Do Not Improvise

The recurring temptation with loaner sets is to improve on the manufacturer's arrangement — consolidating two trays into one, removing an unused instrument, swapping the mat, or substituting a familiar container. Each of these changes the conditions the cycle was validated for. If the configuration genuinely cannot be reproduced — a missing mat, a damaged bracket, a container that does not close — the correct response is to contact the vendor and resolve it, not to build something similar and proceed.

Reconstructing a Configuration You Did Not Design

Assembling a loaner set is different from assembling a facility set because the correct configuration is defined by someone else and must be reproduced exactly.

Your references, in order of authority, are the manufacturer's instructions for use, the tray's own moulded brackets, silicone fingers, and labelled positions, and the vendor's inventory sheet. The tray itself is usually the most reliable practical guide: these cases are designed so each item has a defined position, and an item that does not seat easily in a bracket is usually in the wrong place.

Photographing the set at receipt, before disassembly, is a widely used and genuinely effective technique. It gives you an accurate record of the intended configuration for a set you have never handled and may never handle again.

Where the configuration is genuinely unclear, contact the vendor rather than improvising. A guessed configuration can leave sterilant unable to reach a surface, can allow instruments to shift and damage each other, and can produce a set the surgeon cannot work from.

Why Configuration Is a Sterilization Requirement

The configuration described in the instructions is not a suggestion about tidiness; it is part of what the manufacturer validated when establishing the cycle parameters.

The validation was performed on the set assembled in a specific way, in a specific container, at a specific mass, with items disassembled and positioned as described. Changing any of that invalidates the basis on which the cycle is claimed to work. Adding items, consolidating two trays into one, substituting a different container, or leaving an item assembled that should be taken apart all move the set outside the validated condition.

This is why you may not add your facility's instruments to a loaner tray, and why a loaner tray must not be split or combined to save a cycle.

Weight, Density and the Wet-Pack Problem

Loaner orthopaedic sets are the classic source of wet packs, and the reasons are structural.

They are dense metal in rigid cases, frequently at or above the weight limit, often stacked in multiple levels, and made of materials with high thermal mass that hold condensate. If the instructions specify a maximum weight or a maximum number of trays per load, observe it. If they specify an extended dry time, use it — reducing dry time to fit the schedule is the direct cause of most loaner wet packs.

Load the sterilizer so loaner cases are not stacked in a way that blocks drainage, keep the load light enough to dry, and follow the cool-down requirements. A wet pack is a contaminated pack, and a loaner wet pack usually means the entire set must be reprocessed on a cycle that leaves no time before the case.