Unloading the osteoarthritic knee: osteotomy and joint distraction

Abstract

In the young and active population results after knee replacement are less satisfactory with higher rates of revision due to mechanical, aseptic loosening. Therefore, in case of persisting, painful, conservative treatment-resistant knee osteoarthritis at relative young age, alternative, joint preserving, treatments strategies are a necessity. In this population the surgical treatment should focus on reversing the mechanical factors associated with the development and progression of knee osteoarthritis. An option in this respect is (temporarily) unloading the knee joint. Depending on the severity of the osteoarthritis (unicompartmental or bicompartmental) and malalignment, unloading of the knee joint is possible by performing an osteotomy (partial unloading) or by knee joint distraction (temporarily unloading). In this way a better understanding of what the optimal treatment will be in relatively young patients withconservative treatment-resistant knee osteoarthritis may be found. This thesis has given new insights in the use of distal femoral osteotomies and knee joint distraction. We have shown that a distal lateral closed-wedge valgus osteotomy of the femur for the treatment of varus deformity of the knee is a valuable procedure when the deformity is localized in the femur and using a biplane technique shortens bone healing time. In the cadaveric study we found that the periosteal vascularization of medial and lateral aspect of the distal femur is highly constant, safely can be cauterized, and can serve as a landmark for orthopaedic surgeons in determining the height of the osteotomy cuts in distal femoral osteotomies. In the field of knee joint distraction (KJD) we demonstrated that KJD results in prolonged clinical relevant benefit, even five years after distraction, with a high survival rate of 83%. Starting with KJD (when compared with total knee arthroplasty) is cost-effective, specifically in the younger age categories (45-54 years), a shorter distraction period (six instead of eight weeks) does not influence short-term outcome but with six weeks seeming the minimal duration, and higher Kellgren & Lawrence grade and male gender were predictive for radiographic determined cartilaginous thickness one year after distraction treatment. Furthermore, in case of unicompartmental osteoarthritis KJD was non-inferior to high tibial osteotomy one year after treatment, and thus KJD can be considered as alternative treatment option. Even more impressive, in end-stage knee osteoarthritis, treatment with KJD resulted in comparable clinical benefit after one year when compared with total knee arthroplasty (TKA). Combined with the high five-year survival rate and the established cost-effectiveness in the younger age categories, it can be concluded that KJD is a promising joint-preserving surgical treatment, which can effectively postpone a TKA and revision TKA burden in young patients with conservative treatment-resistant end-stage knee osteoarthritis.