Presentation on theme: "The Role of Hip Resurfacing"— Presentation transcript:
1 The Role of Hip Resurfacing John R. Moreland, M.D.Transforming Orthopaedics: Advanced Outcomes and TechniquesJanuary 30-February 2,2008Vail, Colorado
2 Déjà VuResidency and fellowship at UCLA with Dr. Harlan Amstutz 1973 to 1978Fellowship with Mr. Michael Freeman in LondonRevised many of my own and other surgeons’ surface failuresRevised only one MOM surface
3 Is There a Role for Surfaces? When a stem can not be placed.How large a role otherwise?Probably surface replacement should currently have a small roll since for most patients the apparent disadvantages outweigh the advantages.Time will define the proper role for surface replacement since the experiment to determine its place has already begun.
4 Difficulty of SurgeryThere is general agreement that surface replacement is harder than using stems since the acetabular preparation must be done with the femoral head in place.
5 Minimally Invasive Issues Stem placementInvolves less soft tissue damageSurface placementFemoral head is in the way and young male patients with big muscles often request surfaceBone conservingFemoral side: more bone conserving than cemented stems, less so for cementlessAcetabular side: not more bone conservingEasier to remove for infection or malposition compared to an osseointegrated stem.
6 Revision for Acetabular Fixation StemsVery low, multiple designsSurfaceLow in early reportsLess exposure available to place acetabular componentNo adjuvant fixationMust use cobalt-chrome componentsNo apical holeIncreased frictional torque
7 Revision for Femoral Fixation StemsVery low, multiple designsCementless designs easy to revise if loose.SurfaceHigher rate than stems in early reports? Osteonecrosis of femoral headSmall surface area for fixationTechnical insertion issues
9 Dislocation Stems Surfaces Rates vary MOM with big heads can be used Promise of lower rates not realizedIncreased soft tissue damage necessary to get exposure is the probable reason
10 Range of Motion Stems Surfaces Big head diameters relative to neck size give greater ROM before neck impingementPostoperative ROM actually more dependent on other factorsSurfacesPoor head to neck diameter ratioMore susceptible to getting heterotopic bone formation and being impaired by it
11 Nerve DamageWill probably be higher with surfaces because of the extra retraction necessary to obtain exposureSome reports have already documented this
12 Metal on Metal Problems Metal ion issuesCancerMetabolic changesFetus exposureRenal failureMetal hypersensitivityClicking and squeaking
13 Other Surface Disadvantages The learning curve for the surgeon, the operating room personnel and the patientsRequires instrument purchases and storageRequires familiarity with two ways of doing THRRequires a more expensive prosthesis with insurance coverage issues and possible medical liability issues for a new operation without established indications.
14 Surface Replacement Advantages For patients with deformed proximal femursEasier to remove than osseointegrated stems for infection or malpositionEasy to market and build your practiceIntuitively attractiveOften confused with MIS and big headsDo surfaces allow better function?Might be true for high level activitiesFew of my stem patients ever return to distance running? Stress fractures of femoral neck
15 Is There a Role for Surfaces? Yes: when a stem can not be placedHow large a role otherwise?Probably a small role since for most patients the disadvantages outweigh the advantagesLong term follow-up will tell usNeed matched series since the differences are apparently not largeIs the function with surfaces better than stems for high level activities?