We currently do not perform or recommend primary bicompartmental replacement using the OUKA. This may seem surprising considering the success of bicompartmental OUKA with an intact ACL achieved in the past (see Chapter 1) and as other surgeons are regularly performing bicompartmental replacement with fixed bearing UKA (Parratte et al, 2010). Bicompartmental replacement is commonly a medial and lateral UKA or a medial UKA and patellofemoral replacement (PFR).
In patients with AMOA, neither the state of the PFJ nor the presence of anterior knee pain influence the outcome. Therefore, a combined OUKA and PFR could not be expected to improve the outcome whatever the state of the PFJ or wherever the pain. Indeed, it could only make it worse by adding the relatively high failure rate of the PFR. The only exception might be in patients with severe lateral damage with grooving and subluxation. This is however so rare (<1%) that we would do a TKA in this situation.
In patients with medial compartment OA with an intact ACL, it is rare to find that the lateral compartment is not acceptable for a medial UKA (full thickness joint space on valgus stress and ignoring medial ulceration of the lateral condyle). If there is narrowing of the lateral compartment with full thickness medial loss, this is suggestive of an inflammatory condition so a TKA is probably best. The presence of a central lateral ulcer of full thickness on a valgus stress radiograph is a potential indication for bicompartmental surgery but this is rare. Therefore in general we see little role for a primary medial and lateral UKA. As discussed in Chapter 11, we would do lateral OUKA for arthritis progression after medial OUKA or a medial OUKA for arthritis progression after lateral OUKA.
