Revision TKR: Isolated Liner Exchange

- Discussion:
    - may be indicated for patients with knee stiffness and pain with securely fixed and appropriately aligned components;
    - involves arthrolysis of adhesions and exchange to a thinner tibial polyethylene insert;
    - in the report by Babis GC, et al, the authors reviewed their experience with this technique;
          - from 1992 through 1998, 7 knees with marked stiffness after TKR were treated arthrolysis of adhesions and conversion to a 
                  thinner tibial polyethylene insert;
          - only patients in whom the TKR was well aligned, well fixed, and not associated with infection were included;
          - average time to revision was 12 months, and the mean arc of motion prior to revision was 38.6° (range, 15° to 60°);
          - duration of follow-up after the insert exchange averaged 4.2 years (range, two to eight years).
          - mean Knee Society pain and function scores changed from 44 and 36.4 points preoperatively to 39.6 and 46 points at the time of 
                  final follow-up;
          - 2 knees were rerevised, one because of infection and the other because of aseptic loosening of the components;
          - 5 remaining knees were painful and stiff at the time of final follow-up;
          - 4 of these five knees were severely painful, and one knee was moderately and occasionally painful;
          - mean arc of motion of these five knees was 58° (range, 40° to 70°) at the time of final follow-up;
          - the authors noted that isolated tibial insert exchange, arthrolysis, and débridement failed to provide a viable solution to the difficult and 
                   poorly understood problem of knee stiffness in a group of carefully selected patients following total knee arthroplasty;
    - in the report by Babis GC, et al, the authors assessed the results of isolated tibial insert exchange during revision TKR surgery;
          - authors performed 56 isolated tibial insert exchanges in fifty-five patients primarily because of wear or instability;
          - patients with loosening of any of the components, a history of infection, severe stiffness of the knee, recognized malposition of any
                   component, or problems with the extensor mechanism were excluded;
          - 12 knees had had one, two, or three prior revisions;
          - duration of follow-up averaged 8.3 years (range, 1.6 to 16.2 years) after the index arthroplasty and 4.6 years (range, two to fourteen years) after the revision;
          - mean Knee Society knee and function scores improved from 56 and 50.9 points prior to the revision to 76 and 59 points at the time of final follopcow-up;
          - 14 (25%) of the fifty-six knees subsequently required rerevision at a mean of only three years (range, 0.5 to 6.8 years) after the tibial insert exchange;
          - cumulative survival rate at 5.5 years was 63.5%;
          - of the 27 knees with preoperative instability, eight were rerevised and another four were considered failures because of severe pain;
          - of the 24 knees that were treated with the index revision because of wear of the insert, five were rerevised;
          - the authors conclude that isolated tibial insert exchange led to a surprisingly high rate of early failure;
                 - tibial insert exchange as an isolated method of total knee revision needs to be undertaken with caution even in circumstances
                       for which the modular insert was designed and believed to be of greatest value.

Poor Outcomes of Isolated Tibial Insert Exchange and Arthrolysis for the Management of Stiffness Following Total Knee Arthroplasty 

The Effectiveness of Isolated Tibial Insert Exchange in Revision Total Knee Arthroplasty 

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 10, 2012 4:13 pm