Megaprosthesis data collection forms

Our new suite of forms to support the accurate capture of data for megaprosthesis procedures has been launched on the 29 January 2026. These forms are designed to reflect various clinical scenarios and therefore the form to use for each should be selected carefully to ensure submission of the correct data. You can access these forms here or by clicking the image on this page.

Please read the guidance below before completing a megaprosthesis record.

Overview of the purpose of each new ‘M’ form

A megaprosthesis is a specialised implant used to replace a joint and a large segment of bone, typically following tumour resection or significant bone loss due to trauma or infection.

There are three NJR megaprosthesis-specific forms:

M1: Primary megaprosthesis in a native joint.
M2: Revision of an existing megaprosthesis to another megaprosthesis.
MS: Revision of a conventional joint replacement to a megaprosthesis.

The choice of form depends on the patient’s implant history and on the procedure being undertaken.

M1: Primary megaprosthesis in a native joint

Use the M1 form when a megaprosthesis is implanted as the first replacement in a joint that has not previously had any joint replacement surgery.

Typical scenarios include:

Primary tumour resection with reconstruction using a megaprosthesis.
Non-oncological indications where no prior arthroplasty has been performed.

Do not use M1 if the joint has previously undergone any type of joint replacement.

M2: Revision of a megaprosthesis to another megaprosthesis

Use the M2 form when an existing megaprosthesis is revised and replaced with another megaprosthesis.

This applies regardless of:

the reason for revision.
whether the revision involves partial or total replacement of the megaprosthesis.

Do not use M2 if the previous implant was a conventional joint replacement.

MS: Revision of a conventional joint replacement to a megaprosthesis

Use the MS form when a conventional joint replacement is revised and replaced with a megaprosthesis.

This includes revision of:

Primary conventional joint replacement.
Previously revised conventional joint replacement.

The MS form captures the conversion to a megaprosthesis and must always be completed in conjunction with an additional joint specific revision form.

Mandatory additional forms for MS submissions

When completing an MS form, you must also complete the relevant joint specific revision form to capture details of the removal of the original conventional implant.

One of the following forms must be submitted alongside the MS form:

H2 for hip revisions
K2 for knee revisions
S2 for shoulder revisions
E2 for elbow revisions
A2 for ankle revisions

Failure to submit both forms will result in incomplete data capture.

Key points to remember

Select the form based on the patient’s implant history, not by just the current procedure.

M1 is only for first time joint replacement with a megaprosthesis.
M2 is only for megaprosthesis-to-megaprosthesis revision.
MS must always be accompanied by the appropriate H2, K2, S2, E2, or A2 form.

If you are unsure which form to use, you should review the patient’s previous NJR records before proceeding.

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