2017 ISAKOS Biennial Congress ePoster #1213
Total Knee Arthroplasty After Varus Distal Femoral Osteotomy: A Case Control Study
Romain Gaillard, MD, Lyon, Rhône-Alpes FRANCE
Timothy Lording, MBBS, FRACS, Malvern East, VIC AUSTRALIA
Sebastien Lustig, MD, PhD, Lyon, Rhône Alpes FRANCE
Elvire Servien, MD, PhD, Prof., Lyon, Rhône Alpes FRANCE
Philippe Noel Neyret, MD, PhD, Prof., Lyon La Tour De Salvagny FRANCE
Centre Albert Trillat, Hopital de la Croix-Rousse, Lyon, Rhône-Alpes, FRANCE
FDA Status Cleared
Summary
We studied the results of total knee arthroplasty (TKA) performed after varus distal femoral osteotomy (VrDFO), in comparison to a control group of TKA performed as the primary intervention for arthritis.
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Abstract
PUROPOSE AND HYPOTHESIS: The aim of this study was to study the results of total knee arthroplasty (TKA) performed after varus distal femoral osteotomy (VrDFO), in comparison to a control group of TKA performed as the primary intervention for arthrosis. Our hypothesis was that the medium term results for the two groups would be similar.
Materials And Methods
All TKA performed after VrDFO were extracted from a single centre, prospective database of 4046 arthroplasties. A control group was created comprising two TKA performed as the primary intervention for each TKA after VrDFO and matched for sex, age at intervention, body mass index (BMI), the type of arthrosis and the type of implant. All prostheses used a system of posterior stabilisation by a third median condyle (Laboritoire Tornier-Wright). The primary outcome measure was the post-operative Knee Society Score (KSS).
Results
14 TKA after VrDFO were identified, with a mean follow-up of 42 months (12-102 months). The control group comprised 28 patients. There were no significant differences between groups in terms of the matching criteria. Pre-operatively, there were no differences between groups in terms of KSS (knee and function scores), range of motion (fixed-flexion and maximum flexion), and mechanical axes on long leg films. Operative duration was identical for the two groups. In the VrDFO group there was more lateral intra-operative laxity (p=0.006), more intra-operative complications (patella tendon injuries, p=0.0008), and a more frequent need for screw support for the tibial component due to more severe lower limb deformity (p<0.0001). No significant difference was found between groups with regards the post-operative KSS; mean knee score was 91.7 in the VrDFO group compared to 82.3 in the control group (p=0,12), and function score 70.6 compared to 77.8 (p=0.46). Range of motion was comparable between groups mean maximum flexion in the VrDFO group of 115.7° and 110.9° in the control group (p=0.52).
Conclusion
TKA after VrDFO is uncommon. The procedure is technically difficult, on an often multi-operated knee, and carries an increased risk of intra-operative complications. Despite this, the medium term results are comparable to arthroplasty performed as a primary intervention.