Biomechanical Effects of Partial Decortication on All-Suture and Conventional Suture Anchors in Different Bone Densities

Summary

Here, we describe a protocol to evaluate biomechanical effects of partial decortication on all-suture anchors (ASAs) and conventional suture anchors (CAs) in Sawbones of varying densities.

Abstract

While biomechanical testing has shown a correlation between decortication and anchor failure load, the effects of partial decortication on the biomechanical properties of all-suture anchors remain unclear. We aimed to evaluate the biomechanical effects of partial decortication on all-suture anchors and conventional suture anchors in Sawbones of varying densities. Suture anchors were tested in nondecorticated, partially decorticated, and completely decorticated Sawbones. Two types of all-suture anchors and one type of conventional anchor were evaluated. Two types of biphasic polyurethane foam were used to mimic normal bone: 0.32 g/cm³ density (20 pounds per cubic foot, pcf 20) and osteoporotic bone: 0.16 g/cm³ density (10 pounds per cubic foot, pcf 10). Cyclic loadings were applied, and peak displacement was recorded. After cyclic loading tests, surviving anchors were subjected to pull-to-failure tests. The number of cycles, peak displacement, ultimate failure loads, and failure modes were determined.

First, peak displacement was significantly influenced by bone density and anchor type: normal bone models exhibited lower peak displacement than osteoporotic models, and conventional screw-type anchors consistently demonstrated reduced peak displacement compared to all-suture anchors. In contrast, the extent of bone decortication-whether non-decorticated, partially decorticated, or completely decorticated-showed no significant effect on peak displacement. Second, in osteoporotic bone models (10 pounds per cubic foot), no significant difference in failure load was observed between the partially and non-decorticated groups, but both exhibited significantly higher values than the completely decorticated group.

Introduction

Rotator cuff tears are the most common cause of shoulder pain, and arthroscopic rotator cuff repair is the primary treatment option owing to its satisfactory clinical outcomes. Suture anchors play a crucial role in this procedure. Advancements in suture anchors have contributed to improved anchoring stability and enhanced healing rates^1,2,3. All-suture anchors (ASAs) are a newer type of anchors that primarily consist of two components: the suture material and sheath^4,5. Upon insertion into the bone, anchors are deploy....

Protocol

This study utilized synthetic bone models. No human or animal subjects were involved, and ethical approval was not required.

1. Suture anchor preparation

NOTE: Store anchors in dry, room-temperature conditions until use. Commercial identifiers are provided in the Table of Materials.

1. Prepare three anchor types.
   1. Select the All-Suture Anchor 1 (ASA1 = UHT). To follow this protocol, ensure that ASA1 consists of a flat braided ultra-high molecular weight polyethylene (UHMWPE) tube threaded with the UHMWPE suture, with a predilatation drill diameter of 2.8 mm th....

Results

Cyclic testing
In the CD group, one UHT anchor and three Y-Knot anchors failed on being pulled out from the pcf 10 testing blocks. In the PD group, one Y-Knot anchor failed when pulled out from the pcf 20 testing blocks. In the ND group, all the anchors survived the cyclic testing.

The peak displacements during the cyclic testing are listed in Table 1. Notably, no significant differences in peak displacement were observed among the ND, PD, and CD groups, r.......

Discussion

This study analyzed the effects of decortication on the biomechanical performance of suture anchors by examining two types of ASAs and one type of CA in bone blocks of varying densities. Peak displacement was influenced by bone density (lower in normal bone models) and anchor type (lower in conventional screw-type anchors), while decortication extent showed no significant influence. In osteoporotic models, failure loads between partially decorticated and non-decorticated groups showed no significant difference, yet both .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Biocorkscrew	Arthrex, Naples, USA	AR-1927bcf-45	Conventional screw-type suture anchor (CA)
Bluehill Universal	Norwood, MA, USA	E10KNBL5086	Mechanical test console software
Computer Numerical Control 2030 Engraving Machine	JPX Technology Co., Shenzhen, China	JD2030F400W	Computer-assisted grinding tool
Instron, E10k,	Norwood, MA, USA	E10KNBL5086	Mechanical testing machine
Mach3Mill	ArtSoft Corporation, Sarasota, FL,USA	Mach3 R3.043.066	3-axis CNC control software
Pcf 10 Sawbone	Pacific Research Laboratories, Vashon, WA, USA	1522-319	Osteoporotic bone model
Pcf 20 Sawbone	Pacific Research Laboratories, Vashon, WA, USA	1522-315	Normal bone model
UHT	Star, Beijing, China	F19000001	All-suture anchors 2 (ASA 1)
Y-Knot RC	ConMed, New York, USA	YPRC02	All-suture anchors 1 (ASA 2)