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Suture locking of isolated internal locking knotless suture anchors is not affected by bone quality.

Woodmass JM, Matthewson G, Ono Y, Bois AJ, Boorman RS, Lo IK, Thornton GM - Open Access J Sports Med (2015)

Bottom Line: Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism.Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors.In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Section of Orthopaedic Surgery, McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.

ABSTRACT

Purpose: The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i) interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock), ii) internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew), or iii) a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S).

Methods: Anchors were tested in foam blocks representing normal (20/8 foam) or osteopenic (8/8 foam) bone, using standard suture loops pulled in-line with the anchor to isolate suture locking. Mechanical testing included cyclic testing for 500 cycles from 10 N to 60 N at 60 mm/min, followed by failure testing at 60 mm/min. Displacement after 500 cycles at 60 N, number of cycles at 3 mm displacement, load at 3 mm displacement, and maximum load were evaluated.

Results: Comparing 8/8 foam to 20/8 foam, load at 3 mm displacement and maximum load were significantly decreased (P<0.05) with decreased bone quality for anchors that, even in part, relied on an interference fit suture locking mechanism (ie, 4.5 mm PushLock, 5.5 mm SwiveLock, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism.

Conclusion: The mechanical performance of anchors that relied, even in part, on interference fit were affected by bone quality. Isolated internal locking knotless suture anchors functioned independently of bone quality. Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors.

Clinical relevance: In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone.

No MeSH data available.


Mechanical performance of 5.5 mm SwiveLock (interference fit), 5.5 mm MultiFIX S (interference fit and internal locking) and 5.5 mm SpeedScrew (internal locking) anchors.Notes: (A) Displacement after 500 cycles at 60 N, (B) cycles at 3 mm, (C) load at 3 mm, (D) maximum load. Cycles at 3 mm were 500 cycles for all but one 5.5 mm SwiveLock anchor. ^8/8 foam (osteopenic bone) different than 20/8 foam (normal bone) for same anchor (P<0.05); +SwiveLock different than MultiFIX S and SpeedScrew in same material (P<0.05); ~MultiFIX S different than SwiveLock and SpeedScrew in same material (P<0.05). The diamond symbol on the boxplot indicates an outlier. SwiveLock, Arthrex Inc., Naples, FL, USA. MultiFIX S, ArthroCare Corp., Austin, TX, USA. SpeedScrew, ArthroCare Corp.
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f1-oajsm-6-201: Mechanical performance of 5.5 mm SwiveLock (interference fit), 5.5 mm MultiFIX S (interference fit and internal locking) and 5.5 mm SpeedScrew (internal locking) anchors.Notes: (A) Displacement after 500 cycles at 60 N, (B) cycles at 3 mm, (C) load at 3 mm, (D) maximum load. Cycles at 3 mm were 500 cycles for all but one 5.5 mm SwiveLock anchor. ^8/8 foam (osteopenic bone) different than 20/8 foam (normal bone) for same anchor (P<0.05); +SwiveLock different than MultiFIX S and SpeedScrew in same material (P<0.05); ~MultiFIX S different than SwiveLock and SpeedScrew in same material (P<0.05). The diamond symbol on the boxplot indicates an outlier. SwiveLock, Arthrex Inc., Naples, FL, USA. MultiFIX S, ArthroCare Corp., Austin, TX, USA. SpeedScrew, ArthroCare Corp.

Mentions: In 20/8 foam (normal bone), all of the 5.5 mm anchors completed cyclic loading without failing (Figure 1A to D and Table 1). Displacement after 500 cycles at 60 N was significantly different comparing all three anchors to each other: 5.5 mm SwiveLock, 5.5 mm MultiFIX S, and 5.5 mm SpeedScrew (P<0.05; Figure 1A). Load at 3 mm displacement (Figure 1C) and maximum load (Figure 1D) were greater for MultiFIX S compared with SwiveLock and SpeedScrew anchors (P<0.05).


Suture locking of isolated internal locking knotless suture anchors is not affected by bone quality.

Woodmass JM, Matthewson G, Ono Y, Bois AJ, Boorman RS, Lo IK, Thornton GM - Open Access J Sports Med (2015)

Mechanical performance of 5.5 mm SwiveLock (interference fit), 5.5 mm MultiFIX S (interference fit and internal locking) and 5.5 mm SpeedScrew (internal locking) anchors.Notes: (A) Displacement after 500 cycles at 60 N, (B) cycles at 3 mm, (C) load at 3 mm, (D) maximum load. Cycles at 3 mm were 500 cycles for all but one 5.5 mm SwiveLock anchor. ^8/8 foam (osteopenic bone) different than 20/8 foam (normal bone) for same anchor (P<0.05); +SwiveLock different than MultiFIX S and SpeedScrew in same material (P<0.05); ~MultiFIX S different than SwiveLock and SpeedScrew in same material (P<0.05). The diamond symbol on the boxplot indicates an outlier. SwiveLock, Arthrex Inc., Naples, FL, USA. MultiFIX S, ArthroCare Corp., Austin, TX, USA. SpeedScrew, ArthroCare Corp.
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Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4482379&req=5

f1-oajsm-6-201: Mechanical performance of 5.5 mm SwiveLock (interference fit), 5.5 mm MultiFIX S (interference fit and internal locking) and 5.5 mm SpeedScrew (internal locking) anchors.Notes: (A) Displacement after 500 cycles at 60 N, (B) cycles at 3 mm, (C) load at 3 mm, (D) maximum load. Cycles at 3 mm were 500 cycles for all but one 5.5 mm SwiveLock anchor. ^8/8 foam (osteopenic bone) different than 20/8 foam (normal bone) for same anchor (P<0.05); +SwiveLock different than MultiFIX S and SpeedScrew in same material (P<0.05); ~MultiFIX S different than SwiveLock and SpeedScrew in same material (P<0.05). The diamond symbol on the boxplot indicates an outlier. SwiveLock, Arthrex Inc., Naples, FL, USA. MultiFIX S, ArthroCare Corp., Austin, TX, USA. SpeedScrew, ArthroCare Corp.
Mentions: In 20/8 foam (normal bone), all of the 5.5 mm anchors completed cyclic loading without failing (Figure 1A to D and Table 1). Displacement after 500 cycles at 60 N was significantly different comparing all three anchors to each other: 5.5 mm SwiveLock, 5.5 mm MultiFIX S, and 5.5 mm SpeedScrew (P<0.05; Figure 1A). Load at 3 mm displacement (Figure 1C) and maximum load (Figure 1D) were greater for MultiFIX S compared with SwiveLock and SpeedScrew anchors (P<0.05).

Bottom Line: Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism.Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors.In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Section of Orthopaedic Surgery, McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.

ABSTRACT

Purpose: The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i) interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock), ii) internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew), or iii) a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S).

Methods: Anchors were tested in foam blocks representing normal (20/8 foam) or osteopenic (8/8 foam) bone, using standard suture loops pulled in-line with the anchor to isolate suture locking. Mechanical testing included cyclic testing for 500 cycles from 10 N to 60 N at 60 mm/min, followed by failure testing at 60 mm/min. Displacement after 500 cycles at 60 N, number of cycles at 3 mm displacement, load at 3 mm displacement, and maximum load were evaluated.

Results: Comparing 8/8 foam to 20/8 foam, load at 3 mm displacement and maximum load were significantly decreased (P<0.05) with decreased bone quality for anchors that, even in part, relied on an interference fit suture locking mechanism (ie, 4.5 mm PushLock, 5.5 mm SwiveLock, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism.

Conclusion: The mechanical performance of anchors that relied, even in part, on interference fit were affected by bone quality. Isolated internal locking knotless suture anchors functioned independently of bone quality. Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors.

Clinical relevance: In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone.

No MeSH data available.