Limb length discrepancy and impact on patient reported outcome measures in individuals with rotationplasty (ROTMAT).

Rotationplasty is a reconstructive procedure after bone tumor removal in kids with a growing skeleton, usually below the age of 10 – 12. Removal of tumor involves removal of the part of bone that has the growth plate, which lead to that limb being ’short’ as the normal limb keeps growing. Conventional reconstruction with a prostheses that is used for adults leads to significant limb length discrepancy as the normal limb continues to grow and the leg with endoprosthesis does not.

An expandable prosthesis, is prohibitively expensive, costs around 30 lakhs just for the prosthesis, not counting the need for future revisions.

Rotationplasty is a single procedure, where the operated knee is kept longer than the ‘unaffected’ knee, such that they are expected to be near equal at adulthood. These predictions of limb length discrepancy are made from algorithms that predict the growth of both the operated limb and ‘unaffected’ limb. Despite best efforts, these predictions may err on either side, leaving the operated knee a little short or a little longer than the ‘normal’ knee. The effect this ‘knee’ length discrepancy has on functional outcome is not well known.

This prospective study will measure ‘knee’ length difference in patients who have reached adulthood, where further increase in height is not expected, its effect on their function as measured by their treating doctor (physician reported functional outcome measures) and as noted by patients themselves (patient reported functional outcome measures), and gait analyses to compare outcomes with similar age patients who have had an amputation.

Patients of Rotationplasty who have reached at least 1 year of follow up shall be seen at their usual follow up appointment. Knee difference will be measured on an X-ray. All patients shall be requested to fill test scores.