TKR after posttraumatic and primary knee osteoarthritis: a comparative study

Ong-Art Phruetthiphat,Sebastiano Vasta,Yubo Gao,Biagio Zampogna,John J Callaghan,Benyapa Tassanawipas

doi:10.1186/s13018-021-02322-8

Abstract

BackgroundA few literatures reported that the outcomes of total knee replacement (TKR) in posttraumatic osteoarthritis (PTOA) were lower compared to TKR in primary osteoarthritis (primary OA). The study’s purpose was to compare the comorbidity and outcome of TKR among fracture PTOA, ligamentous PTOA, and primary OA. The secondary aim was to identify the effect of postoperatively lower limb mechanical axis on an 8-year survivorship after TKR between PTOA and primary OA.MethodsSeven hundred sixteen patients with primary OA, 32 patients with PTOA (knee fracture subgroup), and 104 PTOA (knee ligamentous injury subgroup) were recruited. Demography, comorbidities, Charlson Comorbidity Index (CCI), operative parameters, mechanical axis, functional outcome assessed by WOMAC, and complications were compared among the three groups.ResultsPTOA group was significantly younger (p<0.0001) with a higher proportion of men (p=0.001) while the primary OA group had higher comorbidities than the PTOA group, including anticoagulant usage (p=0.0002), ASA class ≥3 (p<0.0001), number of diseases ≥ 4 (p<0.0001), and CCI (p<0.0001). Both the fracture PTOA group (p<0.0001) and ligamentous PTOA group (p = 0.009) had a significantly longer operative time than the primary OA group. The fracture PTOA group had significantly lower pain components and stiffness components than the primary OA group. There was no significant difference in the rate of an aligned group, outlier group, and an 8-year survivorship in both groups.ConclusionThe outcome following TKR in the fracture PTOA was poorer compared to primary knee OA in the midterm follow-up. However, no difference was detected between the ligamentous PTOA and primary knee OA. The mechanical axis alignment within the neutral axis did not affect the 8-year survivorship after TKR in both groups.Level of evidenceLevel III; retrospective cohort study

Highlights

Fracture around the knee can lead to posttraumatic osteoarthritis of the knee (PTOA) [1,2,3,4]
Patients affected by posttraumatic Primary osteoarthritis (OA) were approximately 10 years younger than those affected by primary knee osteoarthritis of the knee (Primary knee OA) [5, 6]
A few literatures reported that surgical challenges and outcomes of total knee replacement (TKR) in PTOA patients were lower compared to TKR in primary OA [8,9,10,11,12]

Summary

Introduction

Fracture around the knee (distal femoral and tibial plateau fracture) can lead to posttraumatic osteoarthritis of the knee (PTOA) [1,2,3,4]. Patients affected by posttraumatic OA were approximately 10 years younger than those affected by primary knee osteoarthritis of the knee (Primary knee OA) [5, 6]. A few literatures reported that surgical challenges and outcomes of TKR in PTOA patients were lower compared to TKR in primary OA [8,9,10,11,12]. Not much data investigated the patient’s comorbidities, functional outcome, and complication between TKR after PTOA (fracture around the knee and ligamentous injury of the knee) and TKR after primary knee OA. A few literatures reported that the outcomes of total knee replacement (TKR) in posttraumatic osteoarthritis (PTOA) were lower compared to TKR in primary osteoarthritis (primary OA). The secondary aim was to identify the effect of postoperatively lower limb mechanical axis on an 8-year survivorship after TKR between PTOA and primary OA

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Conclusion