Popliteus impingement after TKA may occur with well-sized prostheses.
To determine the mechanisms and extents of popliteus impingements before and after TKA and to investigate the influence of implant sizing. The hypotheses were that (1) popliteus impingements after TKA may occur at both the tibia and the femur, and (2) even with an apparently well-sized prosthesis, popliteal tracking during knee flexion is modified compared to the preoperative situation.



The location of the popliteus in three cadaver knees was measured using computed tomography, before and after implantation of plastic TKA replicas, by injecting the tendon with radiopaque liquid. The pre- and post-operative positions of the popliteus were compared from full extension to deep flexion using normosized, oversized, and undersized implants (one size increments).



At the tibia, TKA caused the popliteus to translate posteriorly, mostly in full extension: 4.1 ± 2 mm for normosized implants, and 15.8 ± 3 mm with oversized implants, but no translations were observed when using undersized implants. At the femur, TKA caused the popliteus to translate laterally at deeper flexion angles, peaking between 80° and 120°: 2 ± 0.4 mm for normosized implants and 2.6 ± 0.5 mm with oversized implants. Three-dimensional analysis revealed prosthetic overhang at the posterosuperior corner of normosized and oversized femoral components (respectively, up to 2.9 mm and 6.6 mm).



A well-sized tibial component modifies popliteal tracking, while an undersized tibial component maintains more physiologic patterns. Oversizing shifts the popliteus considerably throughout the full arc of motion. This study suggests that both femoro- and tibio-popliteus impingements could play a role in residual pain and stiffness after TKA.
Centre Orthopédique Santy, 24 Av Paul Santy, Lyon, France. bonnin.michel@gmail.com.|Hopital Privé Jean Mermoz, 55 Av Jean Mermoz, 69008, Lyon, France. bonnin.michel@gmail.com.
Michel P
MP
Bonnin
Department of Orthopaedics, Ghent University, De Pintelaan, 185, Ghent, Belgium.
Arnoud
A
de Kok
Department of Orthopaedics, Ghent University, De Pintelaan, 185, Ghent, Belgium.
Matthias
M
Verstraete
Department of Orthopaedics, Ghent University, De Pintelaan, 185, Ghent, Belgium.
Tom
T
Van Hoof
Department of Orthopaedics, Ghent University, De Pintelaan, 185, Ghent, Belgium.
Catherine
C
Van Der Straten
Accelerate Innovation Management, Rue de Hollande 4-6, 1204, Geneva, Switzerland.
Mo
M
Saffarini
Department of Orthopaedics, Ghent University, De Pintelaan, 185, Ghent, Belgium.
Jan
J
Victor
D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D002102:Cadaver; D006801:Humans; D007593:Joint Instability; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D007720:Knee Prosthesis / Q000009:adverse effects*; D008023:Ligaments, Articular; D011183:Postoperative Complications; D016059:Range of Motion, Articular; D014057:Tomography, X-Ray Computed
Popliteus tendon; TKA impingement; TKA pain; TKA sizing
Knee Surg Sports Traumatol Arthrosc. 2014 Aug;22(8):1887-94
24917536
Clin Orthop Relat Res. 2011 Jan;469(1):76-81
20809169
Knee. 2016 Oct;23 (5):796-800
27039135
Bone Joint J. 2016 Jan;98-B(1):49-57
26733515
Knee. 2014 Aug;21(4):810-4
24827697
Am J Sports Med. 2009 Mar;37(3):534-41
19088056
J Biomech. 2005 Feb;38(2):269-76
15598453
J Bone Joint Surg Br. 2000 Nov;82(8):1196-8
11132286
Knee. 2013 Dec;20(6):466-70
23274066
Knee Surg Sports Traumatol Arthrosc. 2002 Mar;10(2):86-90
11914765
J Bone Joint Surg Am. 2008 Jul;90(7):1464-72
18594094
Clin Orthop Relat Res. 2014 Jan;472(1):121-5
23653101
Knee Surg Sports Traumatol Arthrosc. 2013 Oct;21(10 ):2314-24
23404515
Am J Sports Med. 2010 Aug;38(8):1674-81
20675651
J Bone Joint Surg Am. 1987 Jul;69(6):873-80
3597501
J Bone Joint Surg Am. 2010 Jan;92 (1):98-104
20048101
Knee Surg Sports Traumatol Arthrosc. 2011 Sep;19(9):1418-32
21833512
J Arthroplasty. 2008 Sep;23(6 Suppl 1):104-9
18722310
Clin Orthop Relat Res. 2013 May;471(5):1465-71
23361931
Knee Surg Sports Traumatol Arthrosc. 2014 Dec;22(12):2911-23
25217314
Knee Surg Sports Traumatol Arthrosc. 2016 Aug;24(8):2532-40
25605560
Knee Surg Sports Traumatol Arthrosc. 2015 Nov;23(11):3368-74
25038883
Knee Surg Sports Traumatol Arthrosc. 2014 Aug;22(8):1778-85
24797810
J Arthroplasty. 1995 Aug;10(4):543-5
8523017
Arthroscopy. 1990;6(3):209-20
2206184
Knee Surg Sports Traumatol Arthrosc. 2015 Jun;23(6):1763-9
25552404
J Knee Surg. 2014 Dec;27(6):485-8
24474167
J Biomech. 2005 Feb;38(2):277-84
15598454
Arthroscopy. 2005 Jul;21(7):826-33
16012496
Bone Joint J. 2014 Dec;96-B(12):1623-30
25452364
J Bone Joint Surg Am. 2010 May;92(5):1115-21
20439656
Knee Surg Sports Traumatol Arthrosc. 2013 May;21(5):1005-10
23269474
J Arthroplasty. 2011 Feb;26(2):260-7.e1-2
20452177
J Bone Joint Surg Am. 1989 Jun;71(5):714-6
2732260
J Arthroplasty. 1997 Apr;12(3):353-5
9113555
Knee Surg Sports Traumatol Arthrosc. 2015 Oct;23(10):3049-54
24839040
J Bone Joint Surg Am. 2011 Mar;93 Suppl 1:10-20
21411682
J Biomech. 1983;16(5):351-61
6885837
Knee Surg Sports Traumatol Arthrosc. 2014 Dec;22(12):3113-20
25069569
Knee Surg Sports Traumatol Arthrosc. 2014 Dec;22(12):2931-40
25026932
J Arthroplasty. 2005 Sep;20(6):777-83
16139716
J Arthroplasty. 2014 Aug;29(8):1677-80
24768545
Sports Med Arthrosc. 2015 Mar;23(1):2-9
25545644
Joints. 2015 Jun 08;3(1):15-9
26151034
Int Orthop. 2012 Oct;36(10):2061-5
22851125
Am J Sports Med. 2003 Sep-Oct;31(5):701-7
12975189
Clin Orthop Relat Res. 1975 Oct;(112):231-41
1192638
AJR Am J Roentgenol. 2008 Feb;190(2):442-8
18212231
Orthop Traumatol Surg Res. 2011 May;97(3):272-5
21315677
Acta Orthop Belg. 2013 Apr;79(2):191-6
23821971
Knee Surg Sports Traumatol Arthrosc. 2004 Sep;12(5):429-33
14634721