Radiological Decision Aid to determine suitability for medial unicompartmental knee arthroplasty: development and preliminary validation.
OBJECTIVE
An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre.


METHODS
Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty; TKA) by a single-surgeon were assessed. Suitability for UKA was determined using the Decision Aid, with the assessor blinded to treatment received, and compared with actual treatment received, which was determined by an experienced UKA surgeon based on history, examination, radiographic assessment including stress radiographs, and intra-operative assessment in line with the recommended indications as described in the literature.


RESULTS
The sensitivity and specificity of the Decision Aid was 92% and 88%, respectively. Excluding knees where a clear pre-operative plan was made to perform TKA, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.4%) with all affected patients readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKA, the five-year survival was 99% (95% confidence intervals (CI) 97 to 100). The false negatives (3.5%), who received UKA but did not meet the criteria, had significantly worse functional outcomes (flexion p < 0.001, American Knee Society Score - Functional p < 0.001, University of California Los Angeles score p = 0.04), and lower implant survival of 93.1% (95% CI 77.6 to 100).


CONCLUSIONS
The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKA and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKA. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):3-10.
University of Oxford, Oxford, UK.
T W
TW
Hamilton
Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, Oxford University NHS Foundation Trust, Oxford, UK.
H G
HG
Pandit
Joint Implant Surgeons, 7277 Smith's Mill Road, Suite 200 New Albany, Ohio 43054, USA.
A V
AV
Lombardi
Joint Implant Surgeons, 7277 Smith's Mill Road, Suite 200 New Albany, Ohio 43054, USA.
J B
JB
Adams
Wilgeheuwel Hospital, Amplifier St, Roodepoort, 1724, South, Africa.
C R
CR
Oosthuizen
Université de Bretagne-Occidentale, Faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France.
A
A
Clavé
Nuffield Orthopaedic Centre, Oxford University NHS Foundation Trust, Oxford, UK.
C A F
CA
Dodd
Joint Implant Surgeons, 7277 Smith's Mill Road, Suite 200 New Albany, Ohio 43054, USA.
K R
KR
Berend
Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, Oxford University NHS Foundation Trust, Oxford, UK.
D W
DW
Murray
D000368:Aged; D001175:Arthrography / Q000379:methods; D019645:Arthroplasty, Replacement, Knee / Q000379:methods* / Q000534:rehabilitation; D003661:Decision Support Techniques; D019317:Evidence-Based Medicine / Q000379:methods; D005260:Female; D062785:Hemiarthroplasty / Q000379:methods* / Q000534:rehabilitation; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D018579:Patient Selection; D020127:Recovery of Function; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
Functional outcome; Implant survival; Indications; Patient selection; Total knee arthroplasty; Unicompartmental knee arthroplasty
J Bone Joint Surg Am. 2006 Nov;88(11):2348-55
17079390
Int Orthop. 2013 May;37(5):833-8
23503637
J Arthroplasty. 1998 Dec;13(8):890-5
9880181
J Bone Joint Surg Br. 1986 Aug;68(4):608-9
3733839
Knee. 2009 Dec;16(6):473-8
19464898
Bone Joint J. 2015 Jun;97-B(6):793-801
26033059
Br J Cancer. 1977 Jan;35(1):1-39
831755
J Arthroplasty. 2004 Aug;19(5):590-7
15284980
Bone Joint J. 2015 Nov;97-B(11):1493-500
26530651
J Arthroplasty. 2013 Oct;28(9 Suppl):184-6
23770043
J Bone Joint Surg Br. 2007 Dec;89(12):1597-601
18057359
J Bone Joint Surg Br. 2006 Jan;88(1):54-60
16365121
Clin Orthop Relat Res. 1991 Dec;(273):157-64
1959265
J Bone Joint Surg Br. 2007 Dec;89(12 ):1602-7
18057360
J Bone Joint Surg Am. 2012 Sep 5;94(17 ):e126
22992855
J Knee Surg. 2010 Sep;23 (3):131-5
21329254
J Bone Joint Surg Br. 1999 Jul;81(4):632-5
10463735
Clin Orthop Relat Res. 1989 Nov;(248):13-4
2805470
J Arthroplasty. 2001 Dec;16(8):970-6
11740750
J Bone Joint Surg Br. 2012 Aug;94(8):1071-6
22844048
J Arthroplasty. 2013 Oct;28(9 Suppl):168-71
24099572
J Bone Joint Surg Br. 2011 May;93(5):622-8
21511927
Knee. 2011 Jun;18(3):168-71
20627734
Arch Orthop Trauma Surg. 2015 Aug;135(8):1169-75
25940127
J Bone Joint Surg Br. 1988 Nov;70(5):692-701
3192563
J Surg Orthop Adv. 2015 Winter;24(4):252-6
26731390
Lancet. 2014 Oct 18;384(9952):1437-45
25012116
Clin Orthop Relat Res. 2013 Jan;471(1):181-8
22864617
J Bone Joint Surg Br. 2010 Mar;92 (3):374-9
20190308
J Bone Joint Surg Am. 2005 Sep;87(9):1985-94
16140813
Acta Orthop Scand. 1992 Oct;63(5):497-501
1441942