Biomechanical evaluation of different suture anchors for the stabilization of anterior labrum lesions.
OBJECTIVE
The aim of the study was to investigate the biomechanical performance of different devices for anterior shoulder reconstruction in a clinically relevant human cadaver shoulder model.


METHODS
Biomechanical cadaveric study.


METHODS
The soft tissue, except for the joint capsule, was dissected from 28 fresh-frozen human shoulder specimens. A Bankart lesion was created and repaired with 3 suture anchors. The devices tested were the 2.4-mm Fastak (Arthrex, Karlsfeld, Germany) with either Ethibond (Ethicon, Westwood, MA) no. 2 or 3, the 2.8-mm Fastak with Ethibond no. 2, the Panalok (Mitek, Norwood, MA) with Ethibond no. 2 with a modified setting technique, and the 8-mm Suretac (Acufex Microsurgical, Mansfield, MA). The specimens were anteriorly dislocated in 60 degrees glenohumeral abduction and 90 degrees external rotation. Load was measured continuously and failures were noted. The experimental groups were compared with each other and with a control group with intact shoulders.


RESULTS
Bankart repair with 2.4-mm Fastaks and Ethibond no. 2 and 3 failed at a mean load of 342.0 N and 692.2 N, respectively, predominantly by suture rupture at the eyelet of the anchor. Shoulder reconstruction with 2.8-mm Fastaks failed at an average load of 722.8 N, mostly by suture rupture at the knot. The difference to the 2.4-mm Fastak with Ethibond no. 2 was significant (P < .05). The mean load to failure was 983.8 N in the Panalok group, and the most frequent failure mode was suture rupture at the knot. Bankart repair with Suretac failed at an average load of 468.4 N, typically by capsular damage at the repair site. Capsular injuries in the control group occurred at a mean load of 958.2 N. Anterior shoulder reconstruction with 2.4-mm Fastak with Ethibond no. 2 and with Suretac were statistically significantly inferior to the control group (P < .05).


CONCLUSIONS
All tested devices allow stable anterior shoulder reconstruction, but we recommend the Panalok and the 2.8-mm Fastak because they provided greater stability than either the 2.4-mm Fastak or the Suretac in our experiments. Suretac can possibly cause additional capsular damage in redislocations after Bankart repair.


CONCLUSIONS
This cadaveric study gives an insight into the biomechanical performance of a Bankart repair with different devices directly postoperative and shows possible failure modes and additional injuries in case of early traumatic redislocation.
Mueller
Michael B
MB
Department of Trauma Surgery, University Hospital of Regensburg, Regensburg, Germany.
Fredrich
Helmut H
HH
Steinhauser
Erwin
E
Schreiber
Ulrich
U
Arians
Achim
A
Imhoff
Andreas B
AB
D001696:Biomechanical Phenomena; D015519:Bone Density; D001863:Bone Screws; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000601:surgery*; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery*; D017211:Treatment Failure; D016896:Treatment Outcome