Surgical repair of recurrent anterior shoulder instability requires se
cure fixation of the separated inferior glenohumeral complex to bone.
Many techniques of fixation are in use for both arthroscopic and open
repair. The specific aim of this study was to compare the initial fail
ure strength of eight repair techniques using a previously described c
anine model of Bankart repair. Intact capsule-to-bone complexes failed
at the bony interface at 236 N. Traditional Bankart repair failed at
122.1 N (2 sutures) and 74.7 N (1 suture), Acufex TAG rod (Acufex Micr
osurgical, Mansfield, MA) at 143.5 N (2 sutures) and 79.8 N (1 suture)
, transglenoid suture technique (2 sutures) at 166.6 N, Mitek GII (Mit
ek, Norwood, MA) (1 suture) at 96.4 N, Zimmer Statak (Zimmer Inc, Wars
aw, IN) (1 suture) at 95.2 N, and Acufex bioabsorpable Suretac at 82.2
N. The two-suture repairs were statistically equivalent in strength t
o each other, as were the one-suture repairs and the Suretac device. T
wo-suture repairs were significantly stronger than the one-suture repa
irs (P < .01) failure. In the single-suture specimens, failure occurre
d by suture breakage in 46% (18 of 39) of specimens and soft-tissue fa
ilure around the suture in 54% (21 of 39), Failure in the two-suture t
echniques primarily occurred by soft-tissue failure (23 of 25) and thi
s proved a statistically significant difference (P < .003). No device
broke or pulled out of bone. Our results indicate that in a soft-tissu
e-to-bone repair model (1) pullout of suture anchors is a rare event a
nd suggests that pullout strength of suture anchors should not be the
sole basis of comparison of one device to another in Bankart repairs;
(2) suture techniques and anchor devices that allow for two sutures ex
hibit a stronger initial pullout strength than one-suture techniques a
nd devices; (3) suture anchor techniques are equivalent in strength to
suture-alone techniques; and (4) all repair techniques are significan
tly weaker than undisturbed (control) specimens indicating that the ul
timate outcome of a Bankart repair, open or arthroscopic, is dependent
on physiological repair of soft-tissue to bone. Further study is requ
ired to document the strength of soft-tissue-to-bone repair with time.
These results are repair specific. Soft-tissue-tobone repair in other
areas, i.e., rotator cuff, may show different failure mechanics.