Brantley, Justin

Clark, James

Hoblet, Aaron

Mercer, Deana

Mikola, Elizabeth

Salas, Christina

English

University of New Mexico

University of New Mexico 
UNM Digital Repository 
Hand and Wrist Orthopedics 
4-16-2013 
Pullout strength and stiffness of a non-metallic suture anchoring 
system for repair of the central slip of the extensor mechanism at 
the proximal interphalangeal joint 
Aaron Hoblet 
Christina Salas 
Justin Brantley 
James Clark 
Deana Mercer 
See next page for additional authors 
Follow this and additional works at: https://digitalrepository.unm.edu/hand_wrist 
Recommended Citation 
Aaron Hoblet, Christina Salas, Justin Brantley, James Clark, Deana Mercer, Elizabeth Mikola. Pullout 
strength and stiffness of a non-metallic suture anchoring system for repair of the central slip of the 
extensor mechanism at the proximal interphalangeal joint. Poster presented at: 2013 New Mexico Shared 
Knowledge Conference; April 16-18 2013; Albuquerque, NM. 
This Poster is brought to you for free and open access by the Orthopedics at UNM Digital Repository. It has been 
accepted for inclusion in Hand and Wrist by an authorized administrator of UNM Digital Repository. For more 
information, please contact amywinter@unm.edu, lsloane@salud.unm.edu, sarahrk@unm.edu. 
Authors 
Aaron Hoblet, Christina Salas, Justin Brantley, James Clark, Deana Mercer, and Elizabeth Mikola 
This poster is available at UNM Digital Repository: https://digitalrepository.unm.edu/hand_wrist/15 
 Studies have used metallic bone anchors and 
suturing techniques to repair acute rupture of the 
central slip of the extensor mechanism at the 
proximal interphalangeal joint of the hand which can 
lead to Boutonnière deformity. (Fig. 1)  
Pullout Strength and Stiffness of a Non-Metallic Suture Anchoring System for Repair 
of the Central Slip of the Extensor Mechanism at the Proximal Interphalangeal Joint 
Aaron Hoblet, MD1; Christina Salas, MS1,2; Justin Brantley, BS1,2; James Clark, MD1; Deana Mercer, MD1; Elizabeth Mikola, MD1  
1. Department of Orthopaedics and Rehabilitation  
2. Center for Biomedical Engineering 
 The University of New Mexico, Albuquerque, USA 
 We present a biomechanical study investigating 
pullout strength and stiffness of the non-metallic 
JuggerKnotTM Soft Anchor system with MaxBraidTM 
suture for repair of the central slip of the extensor 
mechanism at the proximal interphalangeal joint. We 
compare our results with pure tensile testing of 
MaxBraidTM suture as controls on the contralateral 
limb. 
 Ten matched pairs of cadaveric hands were used in 
this study: 
 
 Two fingers (index, middle) from each hand were used 
 One hand from each donor was randomized to Group 
1; the contralateral limb from the same donor 
assigned to Group 2 
 Group 1:  Prepared with 1.0mm mini JuggerKnot 
anchor with #2-0 MaxBraid suture (n=20) (Fig. 2) 
 Group 2: Prepared with #2-0 MaxBraid suture through 
transverse bone tunnel (n=20) in the contralateral 
limb 
 
 Prior to testing, areal bone mineral density (BMD) of 
the distal radius was obtained using dual-energy X-
ray absorptiometry 
 The distal phalanx is potted in bone cement and fixed 
to the base of the servohydraulic testing machine 
 The suture is fixed to the linear actuator using flat 
grips (Fig. 3) 
 Specimens are loaded using a displacement 
controlled protocol at a rate of 100mm/min until 
failure 
INTRODUCTION 
PURPOSE 
METHODS 
RESULTS 
 METHODS 
CONCLUSIONS 
RESULTS 
 Failure of the soft anchor system would occur 
through pullout from bone prior to suture breakage 
 Suture repair through bone tunnels provide higher 
strength and stiffness than the soft anchor system, 
but require more bone and soft tissue disruption 
 Results of this study are favorable when compared 
with published results of ultimate load using metallic 
anchors (UL=22.3+-4.7N) or horizontal mattress 
suture (UL=24.7+-5.5N) techniques[1] 
 No significant difference in ultimate load (UL) or 
stiffness was found between index and middle finger 
specimens for the anchor (p=0.68 UL and 0.62 
stiffness) or suture groups (p=0.38 UL and p=0.64 
stiffness) 
 Mean UL and stiffness for the anchor group was 
52.6+-18.3N and 10.4+-2.6N/mm, respectively 
 Mean UL and stiffness for the suture group was 
90.5+-18.7N and 16.2+-3.1N/mm, respectively 
 All anchors failed by pullout and all sutures failed by 
breakage 
 Regression analysis showed no correlation between 
anchor pullout and BMD 
REFERENCES 
 UL of the soft anchor is higher than the UL found in 
published studies which show failure is likely to 
occur at the suture/tendon interface before soft 
anchor pullout occurs – making it a viable alternative 
to metallic anchor repair 
ACKNOWLEDGEMENTS 
FIG. 3 
FIG. 5 
FIG. 4 
 This project was supported in part by the National 
Center for Advancing Translational Sciences of the 
National Institutes of Health through grant number 
UL1 TR000041. The content does not necessarily 
represent the official views of the NIH. 
 Special thanks to Biomet® for donation of the soft 
anchor systems 
A B 
Figure 1: A. Boutonnière deformity preventing full extension of the 
finger. B. Top image shows normal central slip attachment to proximal 
interphalangeal joint. Bottom image shows torn central slip.  
A B C 
Figure 2: A. JuggerKnotTM Soft Anchor System. Anchor sleeve is made 
from polyester suture loaded with MaxBraidTM polyethylene suture. B. 
Anchor is seated with a custom guide and inserter. C. Once fully seated, 
suture is pulled until the anchor sleeve is fully engaged against the 
cortical surface.  
A B 
C D 
Figure 4: Force-displacement plots of middle and index fingers 
prepared with JuggerKnot anchor plus suture (anchor) and suture only 
(suture) through transverse bone tunnels. A. anchor middle, B. suture 
middle, C. anchor index, and D. suture index. 
CLINICAL RELEVANCE 
 [1] Cluett J, Milne AD, Yang D, Morris SF.  J Hand Surg 
Br. 1999;24(6):679-682. 
 A paired t-test was used to analyze ultimate load to 
failure and construct stiffness between fingers (index 
vs. middle) and between fixation group (anchor vs. 
suture) 
 Regression analysis was used to determine whether 
BMD was a predictor of ultimate load 
Figure 3: Experimental testing fixture showing specimen in bone 
cement fixed to the base of the testing machine. Suture attached to 
vertical actuator grips for tensile loading at a rate of 100mm/min. 


Pullout strength and stiffness of a non-metallic suture anchoring system for repair of the central slip of the extensor mechanism at the proximal interphalangeal joint

https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1014&context=hand_wrist

Pullout strength and stiffness of a non-metallic suture anchoring system for repair of the central slip of the extensor mechanism at the proximal interphalangeal joint

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