Outcomes of bicompartmental knee arthroplasty: a review

Abstract

Introduction

Isolated unicompartmental knee arthroplasty (UKA) and patellofemoral arthroplasty (PFA) are effective for localized arthritis. It becomes more controversial if the arthritis is present in two compartments of the knee.Total knee arthroplasty (TKA) offers high survival and high functional scores when arthritis is affecting the three compartments of the knee; however, TKA does not preserve the bone stock and the ligaments and these points can represent theoretical disadvantages, particularly for young patients with higher demand and higher risk for potential revision. BKA is a type of resurfacing surgery where two of the three compartments of the knee (medial tibiofemoral, lateral tibiofemoral or patellofemoral) joint are replaced with preservation of the third. Smaller implant sizes, less operative trauma, preservation of both cruciate ligaments and bone stock, and a more ‘‘physiological’’ knee are reported advantages over TKA. bicompartmental knee arthroplasties have been proposed to bridge the gap between UKA and TKA. There are two philosophically different BKA femoral component designs, modular unlinked components or single monolithic with a fixed relationship between the patello- and tibiofemoral components. Early clinical results of BKA have shown excellent pain relief, knee function, restoration of appropriate knee alignment, less bloodloss, shorter hospital stay and rapid return to normal activity. But opponents stated that these advantages do not persist after 1 year postoperatively.The younger, more active patient may be eligible for this type of resurfacing surgery: is a minimally invasive surgery because it is a tissue sparing knee surgery with multiple goals, such as avoid complications (fat embolism, blood loss), use smaller incisions, shorter hospital stay, lower risk of infection, lower risk of venous thromboembolism (VTE), faster return to daily activity, improving range of motion, obtain faster rehabilitation, less pain, obtain a highly functional implant and easier revision surgery, if required, at a later date.

This review discuss the clinical results, the kinematics, the proprioceptive function, the revision rate and the survivorship curve of BKA.

METHODS

A systematic literature search was conducted during May and June 2014. The electronic databases searched were: MEDLINE and Cochrane Library. No language or data restrictions were used. The search keyword was bicompartmental knee artroplasty, BKA, unicompartmental knee arthroplasty AND patellofemoral arthroplasty, unicompartmental knee arthroplasty AND patellofemoral joint, UKA AND PFJ, which appeared in the title, abstract or keyword fields. Initially, 129 articles were found: based on abstract and after removal of duplicates, 102 articles remained. The full text of each of these articles was read and another 13 articles were considered non-relevant and removed. The final number of articles included in this review was 89.

Conclusion.

advantages of a bone-sparing, ligament-sparing, such as BKA, are clearly evident. It seems intuitive that a knee reconstruction that maintains the proprioceptive and kinematic benefits of retaining the cruciate ligaments would be ideal for the treatment of advanced OA of the medial and patellafemoral compartments.

Choice of monolithic or modular components remains in debate but the use of single femoral components can lead to early revision.

There is a need for a prospective, randomized, long-term outcomes studies comparing BKA with TKA before definitive treatment recommendations can be made.