Part IV

Amy L. McIntosh, MDPediatric Orthopedic Surgeon

Mayo ClinicRochester, Minnesota

Joint Replacement

Total = Ball + Socket

CHARNLEY THA: 30 YEAR MINIMUM F/U

Results

CP1046688-1Years since THAYears since THA

Survival Survival free (%)free (%)Survival Survival free (%)free (%)

0

20

40

60

80

100

0 3 6 9 12 15 18 21 24 27 30

30 Year Survivorship Free of Any Component

Removal or Revision For Any Reason: 81.4%

Specific Issues in Hip Surgery for Younger Patients

• “Minimally Invasive Surgery”

• Resurfacing Operations

• Bearing Surfaces

M.I.S. Surgery

• Marketing rather than a scientific term

• Effort to perform joint surgery through smaller incisions– Goal of speeding patient

recovery

Proceed with Caution• You’re in this for the 20 year rather than

the 20 day outcome– Very subtle differences in artificial hip and

knee alignment have a big impact in how long they last

– Scientific studies of MIS surgery have shown less predictable alignment than standard surgery

– Equal or greater damage to underlying muscles

– Computer assistance may erase this difference