DOS 2017

DOS Kongressen 2017 ·

Patients with anteromedial osteoarthritis achieve the

greatest improvement in patient reported outcome af-

ter total knee arthroplasty

Iben Rønne Jessing, Mette Mikkelsen, Kirill Gromov, Henrik Husted, Thomas Kal-

lemose, Anders Troelsen

Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital;

Background:

The osteoarthritic (OA) disease pattern of the knee is one of the

determinants for choice of arthroplasty concept when knee replacement is in-

dicated, but whether the disease pattern has a direct effect on postoperative

outcome has not previously been investigated.

Purpose / Aim of Study:

The aim was to investigate if different OA disease

patterns and severity of osteoarthritis had an effect on postoperative outcome

after receiving total knee arthroplasty (TKA).

Materials and Methods:

472 patients with complete pre- and 1-year postop-

erative patient reported outcome measures (PROM’s) undergoing TKA surgery

from January 2013 to November 2015 at one hospital were retrospectively

identified and classification of the OA disease pattern were made on preopera-

tive full weight bearing radiographs. During the investigated period no partial

knee replacements were performed and measured resection was the universal

technical approach. The outcome was development in PROM scores from pre-

to 1-year postoperatively.

Findings / Results:

The key findings showed the greatest improvement in

mean PROM scores for anteromedial OA (AMOA) compared with other OA dis-

ease patterns; 3.2 points (95 % confidence interval (CI) 1.5-4.9, p < 0.001) in

Oxford Knee score, 8.2 points (95 % CI 2.6-18.9, p = 0.135) in Forgotten Joint

score and 0.08 points (95 % CI 0.02-0.14, p = 0.002) in EQ-5D score. Similar

results were observed favoring bone-on-bone AMOA compared with AMOA

that had only partial thickness cartilage loss.

Conclusions:

Patients classified with AMOA achieve greater improvement in

PROM scores after TKA surgery compared with other OA disease patterns. This

finding has important implications for reporting, risk stratification and interpre-

tation in TKA outcome studies, including randomized trials.

No conflicts of interest reported

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