Prospective randomised trial comparing unlinked, modular bicompartmental knee arthroplasty and total knee arthroplasty: A five years follow-up
Introduction
Osteoarthritis of the knee is a common disease in our population, whereby the medial, lateral and patellofemoral compartments are involved to varying degrees [1]. A large number of patients with debilitating osteoarthritis of the knee have articular degeneration that is limited to the medial and patellofemoral compartments with a relatively healthy lateral compartment. In addition, a significant subset of these patients has been found to have intact cruciate ligaments [2]. While the current standard of care is still total knee arthroplasty (TKA), there has been increasing interest in bicompartmental knee arthroplasty (BCA) as an alternative treatment option.
BCA can be performed using two philosophically different component designs, either with separate modular unlinked components or with a single monolithic design with a fixed relationship between the patello and tibiofemoral components [3]. The limited success of the bicompartmental prostheses has largely been associated with the monolithic designs, with several studies citing a relatively high incidence of patellofemoral complications and need for revision surgery [4], [5], [6]. This is likely related to challenges in sizing and orienting a linked femoral component, possibly resulting in a constrained articulation and abnormal stress transmission across the knee joint [7], [8], [9]. Conversely, a modular, unlinked trochlear and medial femoral condylar prosthesis allows for independent resurfacing of the medial and patellofemoral compartments. This allows for independent sizing and orientation of the separate components and avoids the problems faced when using the linked prostheses.
BCA provides a minimally invasive alternative to TKA that limits bony resection and spares the anterior and posterior cruciate ligaments, as well as the lateral compartment of the knee. These characteristics are essential to facilitating quicker postoperative recovery and increased stability with better restoration of normal knee kinematics and gait pattern [10], [11]. However, there has been little in the literature comparing the mid-term functional outcomes of patients undergoing BCA and TKA [12].
The purpose of this study is to compare the functional outcomes of patients with advanced osteoarthritis limited to the medial and patellofemoral compartments treated with either a modular, unlinked BCA or TKA and the intra-operative blood loss during BCA and TKA. We hypothesized that due to the bicompartmental prosthesis being inherently tissue conserving and bicruciate-retaining in design, it can better restore knee kinematics and result in a superior functional outcome as opposed to TKA. In addition, we hypothesized that the blood loss during BCA is less due to limited surgical dissection and bone cuts as opposed to TKA.
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Materials and methods
This study is a prospective, randomised, clinical trial comparing the functional outcomes and intra-operative blood loss of BCA and TKA in patients with advanced osteoarthritis limited to the medial and patellofemoral joints. Institutional Review Board approval was obtained prior to the commencement of this study in January 2007 (CIRB 2007/152/D). The patients were recruited from our specialist outpatient clinic from October 2007 to January 2009.
Patients diagnosed with primary knee
Results
One hundred and twenty-one patients were assessed for eligibility. Thirty-two patients were excluded based on pre-defined exclusion criteria while 41 patients declined to participate. A total of 48 patients enrolled in the study and were randomised to the BCA (n = 26) and TKA (n = 22) groups. Of the 48 patients randomised, six were lost to follow-up, of which two had passed away and four were not contactable at five years post surgery (Fig. 1).
The patient demographic information study showed no
Discussion
While minimally invasive techniques for total knee arthroplasty are commonly used today, bicompartmental arthroplasty has been advocated as an alternative to TKA for limited arthritis of the knee. It offers tissue sparing advantages including preservation of bone stock, retention of both the cruciate ligaments and restoring kinematics which more closely resemble that of the native knee [22], [23]. It also facilitates limited surgical exposure without having to enter the lateral knee joint.
Acknowledgments
The authors would like to thank the staff of the Orthopaedic Diagnostic Centre, Singapore General Hospital, in particular Ms. Chong Hwei Chi and Mr. William Yeo, for their help in the collation of the data presented.
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Cited by (30)
Ten year outcomes for the prospective randomised trial comparing unlinked, modular bicompartmental knee arthroplasty and total knee arthroplasty
2020, KneeCitation Excerpt :This study also forms the 10-year follow-up report of our previous prospective randomised trial [10]. This is a follow-up of a prospective, randomised clinical trial, comparing BCA and TKA in patients with advanced knee osteoarthritis affecting only the medial and patellofemoral compartments [10]. The outcomes reviewed were peri-operative functional scores, and radiographic alignment.
Systematic Review of Modular Bicompartmental Knee Arthroplasty for Medio-Patellofemoral Osteoarthritis
2020, Journal of ArthroplastyCitation Excerpt :Postoperative knee pain was found to be similar in most of the patients after BKA and TKA except in one study [21] which observed higher mean value for KOOS pain in BKA compared to TKA. The gain in movements after BKA was significantly greater over that in TKA in 3 studies (P < .05) [21–23] and comparable to TKA in 2 studies (P > .05) [20,24]. The improvement in quality of life scores was greater after BKA over TKA in one study (P < .05) [21] and comparable to that in TKA in 2 studies [20,23].
Change in Body Mass Index After Total Knee Arthroplasty and Its Influence on Functional Outcome
2018, Journal of ArthroplastyCitation Excerpt :Functional outcome scores collected include the Oxford Knee Score (OKS) and Knee Society Score as knee-specific outcome measures. The original OKS used in this study was devised by Dawson et al, a questionnaire comprising of 12 items on daily activities, which the patient must answer without help from healthcare personnel [21,22]. Each item was scored from 1 to 5, with 1 representing best outcome/least symptoms.