BACKGROUND: Failure of inserted anchors has been recognized as one of the major pathomechanisms of re-tearing after rotator cuff repair.
OBJECTIVE: To predict the inserted anchor failure using CT-based 3-dimensional finite element method (CT/3D-FEM).
METHODS: Among twenty patients who underwent rotator cuff repair, 5 had anchor failure (failed anchor group) and 15 had no anchor failure (stable anchor group). A 3D model of proximal humerus was developed for each patient based on the CT data. A virtual pullout testing of TWINFIX™ anchors inserted into bone at 6 different sites was performed using FEM. Then, mean failure load of 6 anchors for each patient was compared between two groups. Moreover, an optimal cut-off value of the mean failure load was determined for predicting anchor failure.
RESULTS: The mean failure load in the failed anchor group (70.3 N) was significantly lower than that in the stable anchor group (119.0 N; ). In our method, the optimum cut-off value of the mean failure load was 75.4 N.
CONCLUSIONS: Failure of the inserted TWINFIX™ anchor could be predicted using CT/3D-FEM. In this method, there seemed to be a high risk of anchor failure in shoulders with a mean failure load of <75.4 N.
BarberF.A. and HerbertM.A., Cyclic loading biomechanical analysis of the pullout strengths of rotator cuff and glenoid anchors: 2013 update, Arthroscopy29(5) (2013), 832–844.
2.
BarberF.A.HerbertM.A.BeavisR.C. and Barrera OroF., Suture anchor materials, eyelets, and designs: Update 2008, Arthroscopy24(8) (2008), 859–867.
3.
BensonE.C.MacDermidJ.C.DrosdowechD.S. and AthwalG.S., The incidence of early metallic suture anchor pullout after arthroscopic rotator cuff repair, Arthroscopy26(3) (2010), 310–315.
4.
CumminsC.A. and MurrellG.A., Mode of failure for rotator cuff repair with suture anchors identified at revision surgery, J. Shoulder Elbow Surg.12(2) (2003), 128–133.
5.
KaarT.K.SchenckR.C.Jr.WirthM.A. and RockwoodC.A.Jr., Complications of metallic suture anchors in shoulder surgery: A report of 8 cases, Arthroscopy17(1) (2001), 31–37.
6.
ParkH.B.KeyurapanE.GillH.S.SelhiH.S. and McFarlandE.G., Suture anchors and tacks for shoulder surgery, Part II: The prevention and treatment of complications, Am. J. Sports Med.34(1) (2006), 136–144.
7.
BesshoM.OhnishiI.MatsuyamaJ.MatsumotoT.ImaiK. and NakamuraK., Prediction of strength and strain of the proximal femur by a CT-based finite element method, J. Biomech.40(8) (2007), 1745–1753.
8.
BesshoM.OhnishiI.OkazakiH.SatoW.KominamiH.MatsunagaS.et al., Prediction of the strength and fracture location of the femoral neck by CT-based finite-element method: A preliminary study on patients with hip fracture, J. Orthop. Sci.9(6) (2004), 545–550.
9.
SanoH.TakahashiA.ChibaD.HattaT.YamamotoN. and ItoiE., Stress distribution inside bone after suture anchor insertion: Simulation using a three-dimensional finite element method, Knee Surg. Sports Traumatol. Arthrosc.21(8) (2013), 1777–1782.
10.
KellerT.S., Predicting the compressive mechanical behavior of bone, J. Biomech.27(9) (1994), 1159–1168.
11.
KeyakJ.H.RossiS.A.JonesK.A. and SkinnerH.B., Prediction of femoral fracture load using automated finite element modeling, J. Biomech.31(2) (1998), 125–133.
12.
BayraktarH.H.MorganE.F.NieburG.L.MorrisG.E.WongE.K. and KeavenyT.M., Comparison of the elastic and yield properties of human femoral trabecular and cortical bone tissue, J. Biomech.37(1) (2004), 27–35.
13.
McCaldenR.W.McGeoughJ.A.BarkerM.B. and Court-BrownC.M., Age-related changes in the tensile properties of cortical bone. The relative importance of changes in porosity, mineralization, and microstructure, J. Bone Joint Surg. Am.75(8) (1993), 1193–1205.
14.
TingartM.J.AprelevaM.LehtinenJ.ZurakowskiD. and WarnerJ.J., Anchor design and bone mineral density affect the pull-out strength of suture anchors in rotator cuff repair: Which anchors are best to use in patients with low bone quality?, Am. J. Sports Med.32(6) (2004), 1466–1473.
15.
ClavertP.BouchaibJ.SommaireC.FlurinP.H. and Hardy SfaP., Does bone density of the greater tuberosity change in patients over 70?, Orthop. Traumatol. Surg. Res.100(1) (2014), 109–111.
16.
KannusP.LeppalaJ.LehtoM.SievanenH.HeinonenA. and JarvinenM., A rotator cuff rupture produces permanent osteoporosis in the affected extremity, but not in those with whom shoulder function has returned to normal, J. Bone Miner. Res.10(8) (1995), 1263–1271.
17.
YamamotoA.TakagishiK.OsawaT.YanagawaT.NakajimaD.ShitaraH.et al., Prevalence and risk factors of a rotator cuff tear in the general population, J. Shoulder Elbow Surg.19(1) (2010), 116–120.
18.
GoradiaV.K.MullenD.J.BoucherH.R.ParksB.G. and O’DonnellJ.B., Cyclic loading of rotator cuff repairs: A comparison of bioabsorbable tacks with metal suture anchors and transosseous sutures, Arthroscopy17(4) (2001), 360–364.
19.
PietschmannM.F.FrohlichV.FicklschererA.GulecyuzM.F.WegenerB.JanssonV.et al., Suture anchor fixation strength in osteopenic versus non-osteopenic bone for rotator cuff repair, Arch. Orthop. Trauma Surg.129(3) (2009), 373–379.
20.
PietschmannM.F.FrohlichV.FicklschererA.HausdorfJ.UtzschneiderS.JanssonV.et al., Pullout strength of suture anchors in comparison with transosseous sutures for rotator cuff repair, Knee Surg. Sports Traumatol. Arthrosc.16(5) (2008), 504–510.
21.
TingartM.J.AprelevaM.ZurakowskiD. and WarnerJ.J., Pullout strength of suture anchors used in rotator cuff repair, J. Bone Joint Surg. Am.85(11) (2003), 2190–2198.
22.
YakackiC.M.PoukalovaM.GuldbergR.E.LinA.SaingM.GilloglyS.et al., The effect of the trabecular microstructure on the pullout strength of suture anchors, J. Biomech.43(10) (2010), 1953–1959.
23.
KirchhoffC.BraunsteinV.MilzS.SprecherC.M.FischerF.TamiA.et al., Assessment of bone quality within the tuberosities of the osteoporotic humeral head: Relevance for anchor positioning in rotator cuff repair, Am. J. Sports Med.38(3) (2010), 564–569.
24.
OhJ.H.SongB.W. and LeeY.S., Measurement of volumetric bone mineral density in proximal humerus using quantitative computed tomography in patients with unilateral rotator cuff tear, J. Shoulder Elbow Surg.23(7) (2014), 993–1002.
25.
SerhanM.AltinelL.ErogluM.VerimO.DemirT. and AtmacaH., Suture anchor fixation strength with or without augmentation in osteopenic and severely osteoporotic bones in rotator cuff repair: A biomechanical study on polyurethane foam model, J. Orthop. Surg. Res.9 (2014), 48.
26.
OshtoryR.LindseyD.P.GioriN.J. and MirzaF.M., Bioabsorbable tricalcium phosphate bone cement strengthens fixation of suture anchors, Clin. Orthop. Relat. Res.468(12) (2010), 3406–3412.
