DEFINITION

Arthroscopic surgical techniques in sports medicine have significantly advanced as a result of the development of various implants to repair ligaments, tendons, and meniscus cartilage. These anchoring devices are currently combined with ultra-high-molecular-weight polyethylene (UHMWPE)-containing suture.

These anchors and their sutures are used in the glenohumeral joint for labral and ligamentous attachment to the dense glenoid bone, in the bursa for rotator cuff and biceps tendon attachment to the greater or lesser tuberosity, and in the knee to repair tears in torn menisci.

Anchor designs are procedure specific because of the different repair requirements and techniques. Some designs contain multiple sutures and are most suitable for osteoporotic bone (rotator cuff repairs). Others contain fewer sutures and are better in denser cortical bone (glenoid repairs). Meniscal repair devices have smaller sutures, and implants are designed to approximate and hold torn meniscal tissue.

 

 

ANATOMY

 

The principal application of all repair implants is to secure the tissue (tendon, ligament, or meniscus) to the appropriate site without excessive tension, in a way that resists loosening, and which allows for physiologic healing.

 

Rotator cuff

 

 

Repair concepts for the rotator cuff that have facilitated the goal of an effective repair include an appreciation of margin convergence,19,31 the deadman angle for anchor insertion,18 orthogonial repair orientation,34 and understanding appropriate anchor location. Controversy exists about the clinical effectiveness of complete footprint coverage and the posterior interval slide.28,36

 

Several options exist for placing anchors regarding the footprint attachment. These include locating the anchors at the edge of the humeral articular cartilage to reduce the tension on the tendon, locating the anchors more lateral to the articular cartilage but still on top of the tuberosity, locating the anchors on the

lateral side of the humerus in the cortical bone shaft (referred to as orthogonal)24,25,32,33 and using

bridging sutures to compress the cuff tendon to the prepared tuberosity,20,21 and using a double row of anchors to secure the tendon adjacent to the articular cartilage and at the peripheral greater tuberosity.

 

The direction or angle of anchor insertion is especially important for rotator cuff repairs. The commonly

recommended angle for anchor insertion is the deadman angle (45 degrees).18 However, the 45-degree angle is actually the maximum acceptable angle for insertion rather than the ideal. More acute insertion angles are often better. The humerus adjacent to a chronic cuff tear often has an osteoporotic (“hollow”) humeral head with fewer trabeculae than normal. Directing the anchor in a more tangential, superior angle places the anchor into the denser subchondral bone.

 

Anchor depth is important. Anchors inserted too deep fail by the suture cutting through the bone or by anchor displacement by rotating and translating toward the cortical surface. An anchor that stands “proud” is more likely to fail at the eyelet.

 

Glenoid

 

 

Glenoid bone is denser than that in the greater tuberosity. Also, working in the restricted space of the glenohumeral joint places limits on the size of implants. As with rotator cuff repair, various portals are used to reach different anchor insertion locations, and careful consideration of proper portal positioning is important. For insertion angles, one should keep in mind the anatomy of the glenoid to avoid breaking through inferiorly, avoiding injury to the axillary nerve about 1 cm from the 6 o'clock position and avoiding placing the anchors too medially on the anterior face of the glenoid. Anchor placement should be on the articular cartilage near the edge and not down on the neck.

 

Meniscus

 

 

The anatomic features related to meniscus repair deal with both the blood supply and the tear type.

 

 

The meniscal blood supply comes from the periphery, which is more vascular than the more central areas.2 A good vascular supply is essential for healing; therefore, selection of a meniscus tear for repair must realize that repairs in the more central area are unlikely to heal. The meniscus has been divided into three

zones based on vascularity.3 The peripheral third (“red/red zone”) has the most vascularity. The less vascular (“red/white zone”) middle third is an area where repairs may be considered if no degenerative changes are observed in the meniscus. The avascular inner third of the meniscus is called the white/white zone and will not heal.

 

Tear type also plays a role. Degenerative tears will not heal. Indications of degeneration include fraying of the meniscus, multiple tear planes, rolling of the inner fragment when probed, and a chronically locked displaced bucket handle.

 

The most common location of repairable meniscus tears is the posterior third. Reaching this area in a tight medial compartment can be a challenge and lead to chondral excoriation with repeated passes of the device.

 

As the popliteal tendon passes behind the posterior lateral meniscus, a hiatus is created with no attachments to the

 

P.669

lateral meniscus. This creates a challenge for repair should the tear extend into and through this region. Placing sutures through the meniscus and into the popliteal tendon is not advised.

 

Risks associated with meniscal repair include vascular damage to the popliteal artery, chondral injury, and soft tissue entrapment.22,23

MATERIAL PROPERTIES

 

Suture anchors

 

 

Historically, anchors were made from various metals, including stainless steel and titanium. More recently, nonmetallic anchor have been introduced made from plastic (PEEK), biodegradable (PLLA, PDLLA, or PLA-PGA), and biocomposite (containing beta-tricalcium phosphate or hydroxyapatite) material.6,10,12

Biodegradable anchors demonstrate comparable pullout strength, degrade completely over time, and avoid

revision surgery or postoperative imaging problems. Recently introduced biocomposite materials offer

osteoconductive behavior, leading to anchor replacement by bone at the end of the degradation process.10

 

Biodegradable and biocomposite suture anchors are just as effective as nonabsorbable anchors. Degradable polymers commonly used in suture anchors include polyglycolic acid (PGA), poly-L-lactic acid (PLLA), stereoisomers of lactide such as poly-D-L-lactic acid (PDLLA), and combinations (copolymers) of lactide and glycolide (PLA-PGA). The slowest degrading polymer used in implants is PLLA, which takes

years to reabsorb.9 In an effort to reduce the time needed for an implant to degrade, various stereoisomer combinations of PLLA (PD[96%]L[4%]LA or PD[70%]L[30%]LA) have been introduced as well as copolymers (PLLA co-PGA), which as yet have not been associated with a lytic response.

 

Polyetheretherketone (PEEK) is a nonabsorbable, biologically inert polymer. PEEK is a chemically resistant organic crystalline thermoplastic polymer adaptable to a wide pH range from 60% sulfuric acid to 40% sodium hydroxide which can resist deformation even at high temperatures. It can be combined with carbon fiber for reinforcement and has many current applications in orthopaedic surgery beyond suture anchors.

 

Although a PEEK anchor can be drilled through during a revision procedure, this process would create many small plastic shavings, which could be thrown into the joint and become difficult to remove. Such PEEK shavings will never degrade and create an abrasive, which could injure the articular cartilage.

 

Patient age is a factor. Older patients may be better choices for nonabsorbable devices, but the patient typically undergoing shoulder instability surgery is young. Using a degradable anchor is attractive because of the patient's anticipated longevity.

 

Biocomposite anchors reflect a significant advance in material technology. Biocomposite materials are combinations of a degradable polymer with a bioceramic. Combining biodegradable polymers and beta-tricalcium phosphate (β-TCP) creates a blend, possessing attractive properties of both materials. For instance, the compressive strength and stiffness of β-TCP is very high and, when blended, imparts these characteristics to the biocomposite. The resulting material degrades over time and stimulates

osteoconductive ingrowth of bone into the space previously occupied by the anchor.8,10

 

These nonmetallic materials are radiolucent and can be drilled through during a revision procedure. Those which do not absorb over time present the same concerns as any metal anchor.

 

Recently, anchors composed entirely of suture have been introduced.12 One or more strands of braided UHMWPE suture is joined with a short sleeve of braided polyester or UHMWPE material, which creates an anchor after being inserted into the bone. Traction on the suture bunches the sleeve, creating a ball of material that forms the anchor within the bone.

 

Meniscal repair devices

 

 

Common characteristics of the latest generation of all-inside devices include the use of UHMWPE suture material and a self-adjusting, locking knot, which does not require the addition of half hitches for knot security. Although some previous versions of these devices used small anchors made from biodegradable polymer, most of all the current versions use anchors made from PEEK. The exception is a completely suture based repair device which inserts two parallel tubular needles into the torn meniscus after which a small shuttling needle transfers the repair suture between these two parallel needles to create a horizontal repair stitch.

 

Sutures

 

 

Sutures can be physically described as monofilament, braided, or blended and absorbable, nonabsorbable, or partially absorbable. The most common completely biodegradable monofilament suture used is

polydioxanone (PDS). It is frequently used in glenohumeral instability surgery. Although any type of suture can also be used to shuttle braided sutures through tissue, the monofilament characteristic of PDS allows it to work with suture hook devices in a way that braided sutures cannot. It also can be used as a marker stitch to facilitate the identification of a rotator cuff tear in the bursa. PDS suture degrades quickly; it retains only 60% of its original strength 2 weeks after implantation, 40% by 6 weeks, and is almost completely reabsorbed by 9 weeks.

 

Nonabsorbable braided polyester sutures, such as Ethibond, were, until the development of UHMWPE sutures, the suture of choice for most soft tissue repairs and in suture anchors. However, braided polyester has been replaced in most arthroscopic applications and in all current suture anchors by high-strength UHMWPE-containing suture. FiberWire (Arthrex, Inc., Naples, FL) was the first high-strength suture and consists of a braided polyester coat surrounding a central core of multiple strands of UHMWPE.

 

The commercial availability of FiberWire redefined expected suture strength. This lead to the subsequent introduction by competitors of sutures made from pure braided UHMWPE. A single manufacturer provides braided UHMWPE suture for other companies, and it is currently marketed under several different brand names. The pure braided UHMWPE suture has almost twice the ultimate strength of FiberWire (which is partially braided polyester) and a 500-fold increase in resistance to fraying compared to pure braided

polyester suture.15

 

 

P.670

 

OrthoCord (DePuy Mitek, Raynham, MA) is the most recently introduced high-strength suture and is used in DePuy Mitek suture anchors. OrthoCord combines both UHMWPE suture with degradable PDS suture. No. 2 OrthoCord consists of 32% UHMWPE and 68% PDS and is coated with polyglactin 910. OrthoCord has a PDS core with a UHMWPE sleeve and leaves a lower profile after the PDS reabsorbs while retaining the outer sleeve strength.

 

Suture Anchors

 

Many ways exist to classify shoulder suture anchors. For this chapter, they will be classified as medial row anchors, lateral row anchors, and glenoid instability anchors.

 

Medial row anchors

 

 

Medial row anchors tend to be more robust and have higher load to failure strengths than the other two types. These anchors are often also used for biceps tenodesis. These anchors withstand the higher biomechanical stresses found at the medial side of the rotator cuff footprint, which can measure over 900 N in some instances in the infraspinatus. Medial row anchors are usually screwin anchors and require knot tying.

 

Lateral row anchors

 

 

In contrast, lateral row anchors are usually knotless designs.6,29 The knotless designs have been shown to be clinically effective by themselves. Recently, their principal application relates to their use for a suture bridge technique in which sutures from medial row anchors, after being passed through the tendon in a mattress stitch fashion, are tied and then fixed laterally in the knotless anchor to compress the remaining tendon to the greater tuberosity, creating a more expansive footprint of attachment. This configuration applies pressure on the rotator cuff tendon and compresses the tendon against the greater tuberosity bone bed during healing. Some advocate placing the lateral row anchors “over the top” on the lateral side of the greater tuberosity parallel to the cuff tendon. This “orthogonal” or “anatomic” anchor position is felt by its proponents to be superior to placing the anchor in a “deadman angle” at the edge of the greater

tuberosity.18,34

 

Glenoid instability anchors

 

 

Glenoid instability anchors are principally designed for shoulder stabilization procedures in younger patients with better bone quality than those undergoing a rotator cuff repair.

 

Instability rehabilitation programs generally call for a period of immobilization, which allow the capsule and glenohumeral ligaments to be well on the way to healing before the stresses of rehabilitation are applied. The capsulolabral tissue and bone at a shoulder instability repair are younger and healthier than that encountered in rotator cuff tendon repairs. Consequently, the biomechanical properties and design features of an acceptable glenoid anchor will be different from one used in the humeral tuberosity.

 

Glenoid anchors are smaller, have lower profiles, and are designed to be inserted into cortical bone. Glenoid anchors range in size from under 2 mm in diameter up to 3.5 mm. This smaller size meets the requirements of the confined space and dense glenoid rim. Toggle anchor designs generally ineffective for a decorticated osteoporotic greater tuberosity are applicable in the glenoid. Smaller and shorter anchors can be accommodated in the glenohumeral joint's smaller space. Shorter anchors avoid overpenetration at the inferior glenoid, which could lead to breaking out of the bone into the axillary space and potentially injuring the axillary nerve.

 

However, these smaller anchors have lower failure loads than the larger rotator cuff tendon anchors. Smaller glenoid anchors cannot accommodate as many sutures as the larger cuff anchors, and this must be considered in selecting the appropriate anchor for glenoid capsule-ligamentous repair. Both knotless and knot-tying glenoid anchor designs are available.

 

Meniscal Repair Devices

 

The latest generation of meniscal repair devices allow for an all-inside technique. The initial generation of all-inside devices provided rigid fixation (ie, tacks, staples, and screws) and lower load to failure strength and carried risks of chondral abrasion because a portion of these devices remained exposed on the meniscal surface.

 

The development of “self-adjusting” all-inside meniscal repair devices offered greater strength and safety, but using braided polyester suture material were still subject to breaking.

 

The current generation suture-based, all-inside, self-adjusting meniscal repair devices containing UHMWPE suture provide a stronger all-arthroscopic technique, which is less likely to break, avoids the need for additional incisions about the knee, and decreases the potential for injury to the neurovascular structures

about the knee.16

 

Common characteristics of all these devices include the use of UHMWPE suture material and a self-adjusting, locking knot, which does not require the addition of half hitches for knot security. All of these devices are inserted into the meniscus using a needle, and then once at least two passes of the suture are in position, the knot is tensioned and the repair secured.

 

Differences exist in the instrumentation, design, suture size, implant size, and type of knot deployed for the different devices. Comparisons of these devices often evaluate load to failure strength, mode of failure, and other mechanical properties.

 

Sutures and Knots

 

Arthroscopic sutures should possess good handling characteristics, good strength, good loop and knot

security, and, when appropriate, be biodegradable. If degradation should occur, the suture should not create a significant inflammatory response. Furthermore, a superior arthroscopic suture offers greater strength for its size while maintaining a low-friction surface conducive to tying in the wet, arthroscopic environment.

 

Concerns exist about knots tied with these UHMWPE sutures. Reports exist that such knots are susceptible to

slipping before breaking at loads below expected failure loads.1,13 This is due to the physical properties of UHMWPE suture and the type of knot being tied.

 

Some knots are more susceptible to slipping when tied using UHMWPE suture than others.1,13 The Duncan knot and Weston knot were reported to slip at submaximal loads in 97% and 86% of the time, respectively. In contrast, the SMC knot and the Revo knot slipped only 1% and 3%, respectively, at a submaximal load. The San Diego knot and the Tennessee slider knot were reported to slip less than 10% of the time in that same

study.13 Therefore, using UHMWPE

 

P.671

suture may provide a higher strength suture but not necessarily a higher strength knot. This greater risk of knot slippage can be mitigated by choosing the right knot.

 

Knot types and uses

 

 

There are two types of arthroscopic knots: sliding knots and nonsliding knots. As surgeons, we should be familiar with knot security and loop security.

 

Knot security is the ability of the knot to resist slipping when a load is applied. Three factors can affect this: friction, internal interference, and slack between throws.

 

Loop security is the ability of maintaining the size and tension on the loop during knot tying.

 

It is possible to have a loose knot on a secure loop (poor knot security) and it is possible to have a secure knot on a loose loop (poor loop security). Either construct will be ineffective in tissue repair.

 

Sliding and nonsliding knots

 

 

All arthroscopic knots (both sliding and nonsliding) start with a foundational knot that removes any slack at the tissue interface. This is then secured by several additional half hitches. Sliding knots start with a specific locking hitch (created outside the joint), whereas nonsliding knots create that locking hitch with a series of half hitches (created inside the joint).

 

To counter the problem that arthroscopically only asymmetric tension can be applied to the two suture strands creating a less secure knot (not square throws), complex sliding locking knots have been developed. These knots develop internal resistance and then lock, resulting in better knot and loop security.

 

Locking and nonlocking knots

 

 

Nonlocking knots (Duncan loop) are held in place by the friction of the suture as the knot is tightened. The UHMWPE suture has less friction, and this holding requirement is not consistently met.

 

Locking knots (such as the SMC, Tennessee slider, San Diego, and Weston) have an internal locking mechanism such that when the non-post limb of suture is tensioned, the knot changes its configuration and locks in place. The surgeon will feel the knot locking by a snapping or clunking sensation in the sutures. Once locked, the knot cannot be moved. It is important to make certain that the knot is correctly positioned before locking it.

FAILURE MECHANISMS

 

Suture anchors

 

 

Biomechanical failure can occur because of anchor failure (anchor pullout, breaking, eyelet failure), suture failure (breaking or knot slipping), or tissue failure (suture cutting out).6,14

 

Repair construct failure can occur at the tissue-suture interface, the suture knot (loop insecurity, knot slipping, or suture breaking), suture-anchor interface, or at the anchor-bone interface (anchor pulling out, anchor breaking, or anchor moving in the bone).

 

However, clinically, the principal mode for rotator cuff tendon repair failure is at the suture-tendon interface.

 

Anchor pullout

 

 

Current suture anchors provide high resistance to pullout from the bone. Anchor pullout strength is a function of contact surface (between bone and anchor) and the friction resisting pullout between the bone and the anchor. A greater anchor surface area or the denser the bone, the higher the load needed before the anchor pulls out.

 

Several biomechanical studies are in the literature that provide these data.6,11 These report that the smaller non-screw design glenoid anchors exhibit lower pullout strengths than the larger screw-in rotator cuff anchors. This is not unexpected because a larger anchor with deeper threads is more likely to hold to a higher load. However, a comparison of 5.5- to 6.5-mm treaded rotator cuff anchors does not demonstrate a significant difference in failure loads. This suggests that the design (fully threaded rather than push in) may be more important to screw-in anchor pullout strength than anchor size.

 

Bone density and anchor location also play a role. Another study showed that a 50% increase in trabecular bone density resulted in a 53% increase in pullout strength. Both bone density and anchor configuration can play a part in increasing pullout strength.37,38

 

Anchor insertion failure

 

 

The anchor insertion depth relative to the cortical bone, the angle of insertion, and anchor rotation during insertion can result in failure. An anchor placed too deeply into the bone may fail in one of two ways depending on the bone density. A deep anchor in good bone can result in the suture wearing against the adjacent cortical bone. With cyclic loading, the suture will rub over this bony edge, resulting in suture failure. Second, placing an anchor too deep in an osteoporotic bone can result in the suture wearing a channel through the adjacent cortex, leading to anchor migration.

 

The angle and rotation of the anchor are also critical. Ideal anchor insertion places the anchor eyelet parallel to the direction of suture pull. An anchor aligned against the pull causes the suture to lever and rub over the eyelet. Eyelet rotation away from the suture places strain on the suture as it levers over the eyelet opening. Both anchor angulation and rotation can lead to suture abrasion and failure.

 

Anchor breaking

 

 

Although anchor breaking may occur during insertion, once implanted, it is rare.

 

Anchor breaking during installation is linked to the anchor material. Biodegradable anchors are more likely to break than metal or PEEK anchors.

 

Misalignment during anchor insertion, undersized drill holes in dense bone, placing excessive pressure on an insertion tool, and poor visualization of the anchor insertion orientation from inadequate exposure or

bleeding can result in anchor breaking.

 

Failure to tap the hole for a screw-in anchor can result in increased sheer stress and torque, especially in very hard bone, and result in breaking.

 

Anchor eyelet failure

 

 

Current anchor eyelet designs have moved away from the prominent proximal post to eyelets located in the main anchor body and a more distal crossbar eyelet reached through the anchor's hollow central core.

Some anchors offer independent eyelets for two separate sutures completely within the anchor body. Each design has strengths and weaknesses.

 

The distal crossbar eyelet allows for a consistent anchor failure at the crossbar. This serves as a protective measure because the crossbar breaks before the anchor body can be pulled from the bone.

 

 

P.672

 

Recent studies have demonstrated that anchor eyelet failure is increasingly common as the principal

mechanism of failure. The increased strength of UHMWPE suture attached to the anchors may contribute to this observation.

 

Suture breakage

 

 

Because of the significant strength of UHMWPE suture, suture breaking today is usually iatrogenic. Despite high strength, poor surgical technique can weaken the suture and result in suture breakage during knot tying or after anchor implantation. A clamp or knot pusher if used incorrectly can abrade the suture, weakening it. Nicks on the suture have an immediate effect on the suture's integrity.

 

Suture breaking bailouts

 

 

If an area of suture damage is identified, the surgeon should adjust the suture length or knot choice to remove the damaged suture section from the stresses of knot tying.

 

If a suture does break during knot tying, and the anchor is loaded with multiple sutures, the surgeon may choose to rely on the remaining sutures. Alternately, if the anchor eyelet permits, a remaining intact suture can be used as a shuttling device to insert a replacement suture and therefore actually reload the anchor arthroscopically.

 

MENISCAL REPAIR DEVICES

 

Biomechanical failure of a meniscal repair device can occur because of anchor failure (anchor pullout of the peripheral rim or a failure to be fully inserted), suture failure (breaking of the suture or knot slipping, creating a loose loop), or tissue failure (suture cutting out of the inner fragment).5,16,17,26

 

We recently evaluated the latest generation of suture-based, all-inside, self-adjusting meniscal repair devices in cadavers. Several failure issues were observed. Five different devices were tested: CrossFix II, Fast-Fix 360, Meniscal Cinch, OmniSpan, and Sequent meniscal stitcher (FIGS 1,2,3,4 and 5). These were evaluated for ease of use and adverse events during insertion into a meniscus posterior horn. The data reflects the modes of failure or potential problems encountered.

 

Suture looseness was observed with varying frequency.

 

 

The Fast-Fix 360 did not demonstrate any suture looseness (0 of 8). The OmniSpan demonstrated only 1 (1 of 8) loose suture. The Meniscal Cinch had loose sutures after

 

P.673

insertion in 3 of 8, the CrossFix II in 3 of 10, and the Sequent meniscal stitcher in 4 of 8.

 

 

 

 

FIG 1 • The CrossFix II meniscal repair device is completely suture based with a 16-mm depth limiter and needs 8 mm of tissue penetration for the internal Nitinol shuttling needle to be clear of the clear plastic sheath to function. The pretied sliding locking knot is seen within the clear plastic sheath. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

 

FIG 2 • The Fast-Fix 360 meniscal repair device has a braided UHMWPE suture connecting two PEEK arrow-shaped anchors (A), which are inserted with two separate passes and secured with a sliding locking knot. The rounded handle insertion device (B) allows needle orientation control during insertion, and there is an adjustable depth limiter which can be set by the surgeon for depths up to 20 mm. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

 

FIG 3 • The Meniscal Cinch device has a no. 2-0 suture, which is a blend of UHMWPE and braided polyester connected to two hollow tubular PEEK anchors (A) which are each loaded on separate needles in a 15-degree curved gun (B). (Courtesy of F. Alan Barber, MD, 2013.)

 

 

 

 

 

FIG 4 • The OmniSpan has one no. 2-0 OrthoCord (combination of PDS and UHMWPE) suture doubled between two PEEK anchors (A) and a sliding locking knot located on the outside of the first PEEK anchor.

Once inserted, the repair positions two vertically oriented sutures parallel on the meniscus surface without an apparent knot. The OmniSpan device is inserted using a disposable gun (B). Curved or straight needles are available. The larger black trigger deploys the anchors and the smaller red trigger advances the second anchor into the ready position. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

Scuffing of the articular cartilage

 

 

Scuffing was noted in one test for the CrossFix II and Fast-Fix 360.

 

Repair stitch orientation

 

 

The desirable meniscal repair orientation is vertical. All tested devices except the CrossFix II achieved a vertical mattress suture.

 

The CrossFix II was only able to achieve a horizontal mattress.

 

Proper stitch spacing (enough of a bite)

 

 

 

All devices except the CrossFix II were able to achieve at least a 5-mm bite. The CrossFix II is limited to a 3-mm stitch.

 

Surface structures

 

 

These can cause articular cartilage abrasion during knee motion.

 

The CrossFix II, Fast-Fix 360, and OmniSpan had minimal suture structures left in these tests.

 

The Meniscal Cinch had a large knot in four of eight tests, and the Sequent had an anchor lying on the surface in one of eight tests.

 

 

 

 

FIG 5 • The Sequent meniscal repair device has one no. 0 Hi-Fi suture with either four or seven 1.3- × 5.1-mm PEEK anchors. A three-implant repair is the minimum and starts with the first anchor placed at the meniscus periphery, a second implant placed centrally, and a third implant again at the periphery spaced about 1 cm from the first. This continuous stitching technique can be continued until all the anchors are deployed. The

associated stitcher has straight and curved needles. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

Accurate and successful device insertion

 

 

The Fast-Fix 360 and Sequent were eight for eight (although one Sequent had to be removed and reinserted).

 

 

The OmniSpan was successful in 8 of 9 and the Cinch was successful in 8 of 10. The CrossFix II had only 6 successful insertions despite 10 attempts.

SURGICAL IMPLANTS

Suture Anchors

 

Arthrex (Naples, FL)

 

 

Corkscrew family (medial row anchor) (FIG 6): Corkscrew anchors are fully threaded (FT) and are made of PLLA (BioCorkscrew FT), PEEK (PEEK Corkscrew FT), β-TCP PLLA blend (Biocomposite Corkscrew FT), or

 

P.674

titanium (Corkscrew FT). The Corkscrew eyelet is made from a large braided polyester suture loop that is molded into the anchor body. Two braided no. 2 sutures (polyester or FiberWire) come with the anchor, and three sizes (4.5, 5.5, and 6.5 mm) are available.

 

 

 

FIG 6 • The Arthrex anchors shown on the top row from left to right include the BioComposite SutureTak,

PEEK SutureTak, Titanium Corkscrew FT, BioCorkscrew FT (made with PLLA), BioComposite Corkscrew FT (made with a blend of β-TCP-PLLA), knotless BioComposite SwiveLock (β-TCP-PLLA blend), and knotless BioSwiveLock PLLA (with a distal PEEK eyelet). At the bottom are the knotless Bio-PushLock (PLLA body and PEEK eyelet) without sutures and the knotless PushLock (PEEK body and eyelet) with two sutures in the eyelet. The Corkscrew anchors have eyelets made from a large braided polyester suture loop that is molded into the anchor body best seen in the BioCorkscrew FT. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

SwiveLock (lateral row anchor) (see FIG 6): The knotless SwiveLock anchors are designed for lateral row constructs. They are made of PLLA, PEEK, or β-TCP-PLLA blend. A separate distal eyelet is made of PEEK. These anchors are available in 2.9, 3.5, and 4.5 mm sizes. Although not preloaded with sutures, these fully threaded twist-in knotless anchors are designed for use with suture, tapes, and soft tissue grafts.

 

SutureTak (glenoid anchor) (see FIG 6): The SutureTak is made from PLLA, PEEK, or β-TCP-PLLA. The smaller sizes allow for use in the glenoid (2.0, 2.4, 3.0, and 3.7 mm). The 2-mm anchor is single loaded with no. 1 FiberWire. The 2.4- and 3.7-mm anchors are single or double loaded with no. 2 FiberWire. The 3-mm anchor comes either single or double loaded with either no. 2 FiberWire or no. 2 TigerTail sutures.

 

Biomet Sports Medicine (Warsaw, IN)

 

 

JuggerKnot (glenoid anchor) (FIG 7): This is one of a new type of anchor composed completely of suture. It is currently provided in three different sizes: 1.4, 1.5, and 2.8 mm. The two smaller anchors are glenoid anchors and the larger is a rotator cuff anchor. The 1.4-mm anchor has a no. 1 MaxBraid suture, which passes through a no. 5 polyester suture sleeve which is inserted into the bone tunnel in a “V” shape. The 1.5-mm anchor is composed of a single strand of no. 2 MaxBraid suture, which passes through a 25-mm long flexible sleeve of no. 6 braided suture. The 2.8-mm anchor (designed for rotator cuff tendon repairs) is inserted with a 2.9-mm drill composed of two no. 2 MaxBraid sutures passed through a 2-mm wide and 25-mm long flexible tube of braided polyester material. All these anchors compresses the associated sleeve into a ball with traction on the sutures, which anchors it against the adjacent intact cortex.

 

 

 

FIG 7 • The JuggerKnot anchors are composed completely of suture. From left to right are the white 2.8-mm anchor composed of two no. 2 UHMWPE sutures passing through a 2- × 25-mm braided polyester tube, the white 1.5-mm anchor composed of one no. 2 UHMWPE suture passed through a 25 mm long no. 6 braided suture, and the blue 1.4-mm anchor composed of no. 1 UHMWPE suture passed through a no. 5 braided polyester sleeve. After these anchors are inserted into a drilled bone tunnel in a V shape, they compress into a ball against the adjacent intact cortex with traction. The two smaller anchors are glenoid anchors and the larger is a rotator cuff anchor. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

 

FIG 8 • From left to right are the Titanium Healix, biocomposite Healix made from β-TCP/PLGA, and the PEEK Healix. The two smaller anchors are on the right, the much smaller biocomposite Gryphon (β-TCP/PLGA) and the PEEK Gryphon. These anchors are loaded with no. 2 OrthoCord and have a distal crossbar eyelet accessed through a central hollow core. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

DePuy Mitek (Raynham, MA)

 

 

Healix Advance (medial or lateral row anchor) (FIG 8): This anchor is available in PEEK, titanium, or as a β-TCP/PLGA biocomposite. β-TCP is osteoconductive and promotes bone ingrowth into the anchor location after degradation. Available in 4.5, 5.5, and 6.5 mm diameters, these anchors are double or triple loaded with no. 2 OrthoCord. The Healix Advance screw threads extend to the anchor tip and protect the distal crossbar eyelet to avoid breaking during insertion. A knotless version exists that can be used for a lateral row repair.

 

Gryphon BR (glenoid anchor) (see FIG 8): This push-in anchor is ribbed and composed of Biocryl rapide: 30% β-TCP/70% PLGA. It comes with one or two no. 2 OrthoCord sutures. It has a distal crossbar eyelet accessed through a central hollow core.

 

Smith & Nephew (Andover, MA)

 

 

TwinFix Ultra (medial row) (FIG 9) anchors are fully threaded screw-in anchors made of PEEK, titanium, or PLLA/HA (poly-L-lactic acid and hydroxyapatite) which can accommodate two or three no. 2 UltraBraid

sutures. They have distal eyelets accessed through a hollow central anchor core. They are available in 4.5, 5.5, and 6.5 diameters.

 

Footprint anchor (lateral row anchor) (FIG 10): The Footprint is a knotless anchor intended for the lateral row or other knotless applications. It is made from PEEK and is either 5.5 or 6.5 mm in diameter. Sutures are loaded through the eyelet while the anchor is still in the inserter and the anchor is then advanced into a predrilled hole. The sutures are tensioned and then, as the knob at the end of the applicator is rotated clockwise, a central plug inside the anchor is deployed and advanced to pinch the sutures and maintain the tension.

 

 

P.675

 

 

 

FIG 9 • TwinFix Ultra anchors are fully threaded screw-in anchors made of PLLA/HA (white), PEEK (brown), or titanium (gray). These are intended for medial row fixation and can accommodate two or three no. 2 UHMWPE sutures. They have distal eyelets accessed through a hollow central anchor core. They are available (from left to right) in 4.5, 5.5, and 6.5 mm diameters. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

Raptor anchor (glenoid anchor) (see FIG 10): This push-in anchor comes in 2.3 and 2.9 mm diameters and is single or double loaded with no. 2 UltraBraid sutures. A single eyelet is set transversely in the midportion of the anchor. The numbers associated with the anchor name are deceptive because they relate only to the minor diameter of the anchor. The BioRaptor 2.9 is actually 3.7 mm in diameter and the BioRaptor 2.3 is actually 3.0 mm. The BioRaptor 2.3 is not biodegradable as its name suggests but is actually made from PEEK. A biocomposite version, the OsteoRaptor, is available made of a blend of PLLA/HA.

 

Healicoil anchors (see FIG 10) differ from conventional solid-core implants by eliminating part of the central core material. The concept is to allow bone ingrowth between the anchor threads. This reduces the amount of PEEK material in an anchor this size. The Healicoil is a fully threaded anchor with a distal crossbar “eyelet” over which two or three UltraBraid (UHMWPE) sutures can pass. The sutures pass down the center open core of the anchor loop over the crossbar and return up the central core. A new

osteoconductive Healicoil (the Regenesorb Healicoil) is available made from PGLA (65%), β-TCP (15%), and calcium sulfate (20%) and is fully degradable.

 

 

 

FIG 10 • These Smith & Nephew anchors are (from left to right) the OsteoRaptor (a blend of PLLA and HA), BioRaptor made from PEEK, the fully threaded PEEK Healicoil anchors (4.5 and 5.5 mm), and the allsuture SutureFix Ultra 1.7 mm. At the bottom of the image is the knotless PEEK Footprint threaded with two sutures. All anchors are loaded with no. 2 UHMWPE sutures. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

SutureFix Ultra (see FIG 10) is another suture-based anchor. It is based on a single strand of no. 2 UltraBraid suture, which is woven six times through a sleeve of no. 5 UltraBraid. The anchor is inserted into a hole drilled in a bone, which has a 1.7 mm diameter. A positive activation mechanism deploys the sleeve into an opened pattern inside the bone before traction is applied. The traction pulls the suture/suture sleeve configuration against the intact cortical bone, creating the anchor.

 

ConMed Linvatec (Largo, FL)

 

 

Super Revo FT (medial row anchor) (FIG 11): This anchor is a fully threaded, self-drilling titanium screw-in anchor with an internal independent suture-sliding eyelet and holds two or three no. 2 Hi-Fi sutures.

 

CrossFT (medial row anchor) (see FIG 11): This is a fully threaded, PEEK or biocomposite, 5.5-mm-diameter screw-in anchor with a distal crossbar eyelet that holds up to three no. 2 Hi-Fi sutures.

 

PopLok (lateral row) (see FIG 11): The PopLok PEEK 4.5 is an expanding bolt anchor that is 4.5 mm in

diameter and 15.5 mm long. It can accommodate up to four strands of no. 2 high-strength suture. Its two wings deploy when activated to hold the anchor into position, and once deployed, the diameter across the wing tips measures 9 mm and the overall length shortens to 11 mm.

 

Y-Knot (glenoid anchor) (see FIG 11): This all-suture anchor has a single no. 2 Hi-Fi suture, which passes through a flat braided 3- × 25-mm UHMWPE sheath. It is inserted into a 1.3-mm hole and, when tensioned, bunches the sheath into a ball against the cortical bone, providing the anchor for the construct.

 

 

 

FIG 11 • These ConMed Linvatec anchors are (from left to right) the allsuture Y-Knot anchor made from a single no. 2 UHMWPE suture passed through a flat braided 3- × 25-mm UHMWPE sheath, the fully threaded PEEK CrossFT 5.5-mm triple loaded with no. 2 UHMWPE suture, the triple-loaded Titanium Super Revo FT, and the knotless PopLok 4.5 mm showing its two wings deployed. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

P.676

 

 

 

FIG 12 • From left to right are the Iconix 1 (deployed in its clover leaf pattern), Iconix 1 (not deployed), Iconix 2, and Iconix 3 anchors. The names reflect the number of strands of no. 2 UHMWPE suture they possess. These sutures pass through a flat flexible braided polyester tube. At the bottom is an Iconix 2 anchor demonstrating its two sutures passing several times through the braided polyester sleeve. This results in the clover leaf configuration after tensioning. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

Stryker Endoscopy (San Jose, CA)

 

 

Iconix anchors (FIG 12): These all-suture anchors are provided in three different versions (Iconix 1, 2, and 3) reflecting the number of strands of no. 2 Force Fiber suture they possess. The sutures of the anchor are woven three times through a flat, flexible braided polyester tube. Delivery is by pushing the anchor into a predrilled hole. When tensioned, the braided tube collapses into a “clover leaf” shape rather than a ball like other suture-based anchors. This clover leaf is compressed against the adjacent intact cortical bone, creating an anchor.

 

Meniscal Repair Devices

 

Fast-Fix 360 (Smith & Nephew)

 

 

The Fast-Fix 360 (see FIG 2) has a 25-degree curved 17-gauge needle and no. 2-0 braided UHMWPE suture, which is inserted with two separate passes. The suture connects two PEEK arrow-shaped anchors and is secured with a pretied sliding locking knot. The device has an adjustable depth limiter on the handle controlled by a button which can be adjusted up to 20 mm. The rounded handle allows control of the needle

orientation during insertion. The device is inserted into the joint with use of a slender slotted metal cannula. The sliding locking knot is inserted with the second PEEK anchor, and as the suture is pulled to tighten, the repair is embedded into the portion of the meniscus where that anchor is placed. A curved disposable knot cutter is provided which leaves a single strand of suture on the surface of the meniscus.

 

MaxFire MarXmen (Biomet Sports Medicine) (FIG 13)

 

 

The MaxFire MarXmen is an all-suture implant consisting of no. 0 MaxBraid PE suture with two separate anchors created from sleeves of braided polyester suture. This meniscal repair device is very similar to the JuggerKnot suture anchor (see FIG 7) also provided by Biomet Sports Medicine. The MarXmen gun uses a needle to insert the MaxFire sutures with their anchors through the meniscus in two separate passes. Both straight and curved needles are available. The sliding, self-locking knot is activated by tensioning the suture.

 

 

 

 

FIG 13 • The MaxFire MarXmen is an all-suture implant made from no. 0 UHMWPE suture with two separate anchors created from sleeves of braided polyester suture. Very similar to the JuggerKnot suture anchor, the MaxFire repair device is inserted by the MarXmen gun in two separate passes. Both straight and curved needles are available. The sliding, self-locking knot is activated by tensioning the suture, which balls up the braided polyester sleeves, creating anchors. (Courtesy of F. Alan Barber, MD, 2013.)

 

 

CrossFix II (Cayenne Medical, Scottsdale, AZ)

 

The CrossFix II (see FIG 1) creates an all-suture repair with no implanted anchors. The dual-pronged delivery device (with either 12-degree upward-curved or straight needles) has two hollow 15-gauge needles parallel to one another. These two parallel insertion needles create a 3-mm mattress stitch when the internal Nitinol shuttling needle carries the single no. 0 braided UHMWPE suture from one insertion needle to the other. The device has a 16-mm depth limiter and needs 8 mm of tissue penetration to function. A pretied sliding Weston knot is tightened by pulling on the suture. There is no suture anchor with this system. The insertion gun is inserted with a malleable metal-slotted introducer. The knot disposable pushersuture cutter leaves a 2- to 3-mm tail.

 

Care must be taken to release the handle completely to avoid placing torque on the two parallel needles before squeezing the trigger to activate the shuttling needle. Torque in the system will result in the needles not aligning, and the shuttling needle will not enter to opposite needle to transfer the suture.

 

Meniscal Cinch (Arthrex)

 

 

The Meniscal Cinch (see FIG 3) device has a 15-degree curved gun loaded with two separate trocar needles. The gun has an adjustable depth limiter on the handle. Each needle is loaded with a hollow tubular PEEK anchor and the two anchors are connected with a strand of no. 2-0 suture, which is a blend of UHMWPE and braided polyester (FiberWire). A 6-mm-diameter, slotted, “shoehorn” cannula facilitates device insertion. After insertion of the

 

P.677

first needle and deploying the PEEK anchor, that needle is removed and the second needle is pushed in for insertion in the same manner. This creates a vertical mattress stitch which is secured with a pretied, sliding locking knot.

 

OmniSpan (DePuy Mitek)

 

 

The OmniSpan device (see FIG 4) is inserted using a disposable gun. Curved or straight needles are available. The no. 2-0 OrthoCord suture is doubled between two PEEK anchors. A sliding locking knot is located on the outside of the first PEEK anchor inserted and creates a repair with two sutures crossing between the two anchors without a knot on the meniscal surface. The device is introduced into the knee using a malleable metal retractor. During needle insertion, a silicone tube on the needle provides a “soft stop” at 13 mm. The first anchor is deployed by pulling the large trigger on the gun while providing some forward pressure to avoid kick back. The needle is then repositioned appropriately to create a vertical stitch. Before inserting the needle a second time, the red trigger on the gun is pulled several times to advance the second anchor into view on the insertion needle. Once the second anchor is in the correct advanced position for deployment, the needle is advanced to the appropriate depth and the large trigger on the gun is pulled again. The gun with the needle is removed and a probe is inserted under the first loop that moves when pulling on the free suture end. The probe is used to pull that loop until the second loop lies flush against the meniscal surface, then the probe is removed and the suture is pulled to tighten the second loop. This avoids having one loose loop and creates a repair construct with two sutures across the meniscus surface. A nondisposable knot pusher-suture cutter cuts the suture flush with the meniscus surface, leaving no visible knot.

 

Sequent meniscal stitcher (ConMed Linvatec)

 

 

The Sequent meniscal stitcher (see FIG 5) has straight and curved needles, and the no. 0 Hi-Fi suture has either four or seven PEEK anchors measuring 1.3 mm in diameter and 5.1 mm long. A three-implant repair is the minimum and starts with the first anchor placed at the meniscus periphery, a second implant placed centrally, and a third implant again at the periphery spaced about 1 cm from the first. This continuous

stitching technique creates a V-shaped repair, with the anterior and posterior arms decreasing the shear stress across the tear as well as capturing the meniscal collagen fibers for tissue compression like a purely vertical stitch. A single strand of the no. 0 Hi-Fi suture is left on the meniscal surface between each anchor. To secure the suture and PEEK anchors, a complex manipulation of the insertion device is required. Two full clockwise rotations of the suture using the insertion device are performed followed by tensioning the suture to lock it into slots in the PEEK anchor. The insertion device has a sleeve, which when cut to the appropriate length serves as a depth limiter and also serves as an insertion cannula. A side-loading disposable suture cutter is associated with this device.

 

USING IMPLANTS FOR REPAIRS

Suture Anchors

 

Rotator cuff repairs: single row versus double row

 

 

In general, there are two different approaches to repairing a rotator cuff tendon. These focus either on attaching the tendon close to the articular cartilage or maximizing the amount of footprint that is covered. Firmly fixing the cuff footprint using a double row of suture anchors and possibly crossing the sutures to create a suture bridge is one approach. The other is to attach the cuff tendon at a location that places the tendon under minimal tension and then creating marrow vents in the adjacent lateral tuberosity to stimulate a healing response. It is thought that this bleeding marrow response will encourage the extension of the tendon laterally over the remainder of the greater tuberosity during the subsequent healing.

 

The mechanical stresses on single-row and double-row constructs are different.

 

 

With a single row, all the stress is taken by that row of anchors equally and shared between them.

 

 

With a double-row repair, there is an uneven distribution of the load. Khoury et al27 recently reported that medial row anchors are subjected to two-thirds of the total stress seen by a double-row cuff repair. In comparison, the lateral row anchors see only 33% of that load.

 

Because the medial row receives twice as much loading as the lateral row, the medial row may be the first to fail both clinically and biomechanically. It therefore seems prudent to place strong anchors in the medial row.

 

A suture bridge technique uses knotless lateral anchors. Considering that UHMWPE-containing sutures tend to cyclically elongate and can slip at submaximal loads, knotless lateral row anchors must have a very effective suture-locking mechanism when used in conjunction with UHMWPE suture.

 

Adding more and larger sutures creates a biomechanically stronger construct (no. 5 suture or suture tape). However, larger sutures place pressure over a larger area of an already degenerative cuff tendon, potentially compromising its vascular supply. The potential that crossing sutures will strangulate rotator cuff tendon tissue exists.

 

Increasing the number of UHMWPE sutures also increases the repair strength. However, the weakest link in the repair is the suture-tissue interface, not the suture. Placing more and more sutures in a repair will reach the point where the increased strength is irrelevant and physiologic healing is impaired.

 

Cuff tendon repairs fail at the musculotendinous junction or the tendon-bone interface. There is increasing evidence that secure fixation over a larger footprint area leads to repair failure at the musculotendinous junction in younger healthier rotator cuffs with less fatty degeneration or muscle atrophy.

 

 

Two different cuff repair failure modes exist: Cho type 1 (failure at the original repair site) and Cho type 2

(failure around the medial row)20,21

 

Voigt et al39 also reported that 13% of all suture bridge cuff repairs demonstrated medially ruptured tendons with a healed footprint (Cho type 2 failure). Ruptures at the musculotendinous junction leave very few options for a revision.

 

Musculotendinous junction tears (Cho type 2 failure) occurred with double-row repairs in 59% of Cho's failure cases. The percentage of Cho type 1 tears increased with the severity of fatty degeneration or muscle atrophy. This underscores the concern that healthier tissue may be more likely to tear in the more catastrophic type 2 manner.

 

 

 

Meniscal Repair Devices

P.678

 

Meniscal repair is only possible with properly selected tears. The principal requirement is a good blood supply. Young (usually younger than 40 years of age), active individuals, especially those undergoing a concurrent anterior cruciate ligament reconstruction or articular cartilage-resurfacing procedures, are the best candidates.

 

Meniscal repairs can be performed four ways: open, insideout, outside-in, and all-inside. The suture-based, self-locking devices are the current state of the art for this technique. These avoid a posterior capsular exposure, reduce the potential for neurovascular damage, and decrease operating time.

 

The best candidate for a meniscal device repair is a fresh, vertical, longitudinal, peripheral tear in the posterior horn of the meniscus.

 

Good blood supply is anticipated in the red/red and red/white zones. Degenerative changes (meniscus rolls when probed, delamination is present, multiple bucket-handle tears) and a chronically locked displaced bucket-handle tear decrease the likelihood of healing.

 

Proper preparation of both sides of the meniscus tear (inner fragment and meniscal rim) by rasping and possibly trephination is extremely important.

 

Stimulation of the perimeniscal synovium on both the top and bottom of the meniscus also promotes a vascular healing response. A vertically oriented meniscal repair suture that captures at least 5 mm of the circumferential collagen bundles is considered the gold standard for meniscal device repair.

 

The long-term success of meniscal repair appears to decline over time. This has been true for earlier versions of meniscal repairs and, unless proven otherwise, should be expected with the latest generation of all-inside devices.

 

Controversy exists about the appropriate postoperative rehabilitation protocol. No long-term randomized control studies exist comparing more aggressive to less aggressive protocols.

 

The three main variables with a rehabilitation program are when to start and the amount of knee motion, the nature of the weight-bearing status, and when to allow a return to weight-loaded and pivoting sports.

Accelerated rehabilitation programs have been advocated, but many authors are hesitant to allow knee flexion beyond 90 degrees in the first 2 months.4,7,30,35

 

Biologic enhancement of meniscal healing is being explored but is not currently in widespread use.

 

 

PEARLS AND PITFALLS

Suture Anchors

 

 

 

Anchor advances

• Multiple high-strength (UHMWPE) sutures, fully threaded designs, knotless lateral row designs, and distal suture “eyelets”

   

   

   

  Anchor insertion angle

• Deadman angle (45 degrees) is the maximum. More acute angles will advance the rotator cuff anchor into denser subchondral bone. Orthogonal (anatomic) angles are more acute and allow for better tendon compression of the sutures.

   

   

   

  Anchor insertion depth

• Anchors inserted too deep fail by the suture cutting through the bone or by anchor displacement by rotating and translating toward the cortical surface. An anchor that stands “proud” is more likely to fail at the eyelet.

   

   

   

  Anchor material

• Recently released nonmetallic anchors are made from plastic (PEEK), biodegradable (PLLA, PDLLA, or PLA-PGA), and biocomposite materials.

• Biocomposite materials offer osteoconductive behavior leading to anchor replacement by bone at the end of the degradation process.

 

 

 

Repair failure ▪ The most likely failure is at the suture-tendon interface. Additionally, cuff tendon repairs can fail at either the musculotendinous junction or at the tendon-bone interface.

 

 

 

Double-row failure

• Double-row repair failure occurs much more often at the musculotendinous junction in younger healthier rotator cuffs with less fatty degeneration or muscle atrophy.

   

   

   

  Single-row failure

  • Single-row repair failure occurs more often at the tendon-bone interface, leaving little tendon on the greater tuberosity.

     

     

     

    Meniscal Repair Devices

     

     

     

    Meniscal healing

    • A good vascular supply is essential. Proper preparation including rasping both sides of the tear and the adjacent synovium will enhance healing.

 

 

 

Blood supply is essential

• The peripheral third (red/red zone) has the most vascularity. Degenerative tears will not heal. Indications of degeneration include fraying of the meniscus, multiple tear planes, rolling of the inner fragment when probed, and a chronically locked displaced bucket handle.

   

   

   

  Meniscal repair devices

  • The latest generation of all-inside devices include a UHMWPE suture and a self-adjusting, locking knot, which does not require the addition of half hitches for knot security.

     

     

     

    Meniscal repair device material

• Most of the current versions use peripheral anchors made from PEEK.

 

 

 

 

 

	Postoperative ▪ No long-term randomized control studies exist comparing more aggressive to rehabilitation less aggressive protocols; however, most authors avoid knee flexion beyond 90 degrees in the first 2 months postsurgery.

 

 

 

P.679

 

 

CONCLUSIONS

Advances in sutures and suture anchors offer improved techniques for arthroscopic glenohumeral instability surgery and arthroscopic rotator cuff repair.

The newer released anchors are not metallic. Instead, the trend is clearly to use anchors made of bioabsorbable, biocomposite, and PEEK materials. The biocompatible absorbable anchors are just as strong and durable as the metallic and plastic anchors and facilitate easier postoperative imaging and revision surgery.

The larger cuff anchors tolerate higher loads, hold more sutures, and work better in osteoporotic bone of the greater tuberosity than the smaller anchors designed for glenoid fixation.

Of the all-inside, suture-based, self-locking meniscal repair devices, the Fast-Fix 360 and OmniSpan seem to be the easiest to insert, whereas the Sequent meniscal stitcher and the CrossFix II are the most challenging.

All but the Fast-Fix 360 demonstrated at least one loose suture. Successful placement was achieved most consistently in the Fast-Fix 360, Sequent, and OmniSpan.

 

REFERENCES

1. Abbi G, Espinoza L, Odell T, et al. Evaluation of 5 knots and 2 suture materials for arthroscopic rotator cuff repair: very strong sutures can still slip. Arthroscopy 2006;22(1):38-43.

    

    

2. Arnoczky SP, Warren RF. Microvasculature of the human meniscus. Am J Sports Med 1982;10(2):90-95.

    

    

3. Arnoczky SP, Warren RF. The microvasculature of the meniscus and its response to injury. An experimental study in the dog. Am J Sports Med 1983;11(3):131-141.

    

    

4. Barber FA. Accelerated rehabilitation for meniscus repairs. Arthroscopy 1994;10(2):206-210.

    

    

5. Barber FA. Meniscus repair: results of an arthroscopic technique. Arthroscopy 1987;3(1):25-30.

    

    

6. Barber FA, Bava ED, Spenciner DB, et al. Cyclic biomechanical testing of biocomposite lateral row knotless anchors in a human cadaveric model. Arthroscopy 2013;29(6):1012-1018.

    

    

7. Barber FA, Click SD. Meniscus repair rehabilitation with concurrent anterior cruciate reconstruction. Arthroscopy 1997;13(4):433-437.

    

    

8. Barber FA, Dockery WD. Long-term absorption of beta-tricalcium phosphate poly-L-lactic acid interference screws. Arthroscopy 2008;24(4):441-447.

    

    

9. Barber FA, Dockery WD. Long-term absorption of poly-L-lactic Acid interference screws. Arthroscopy 2006;22:820-826.

    

    

10. Barber FA, Dockery WD, Hrnack SA. Long-term degradation of a poly-lactide co-glycolide/beta-tricalcium phosphate biocomposite interference screw. Arthroscopy 2011;27(5):637-643.

     

     

11. Barber FA, Hapa O, Bynum JA. Comparative testing by cyclic loading of rotator cuff suture anchors containing multiple high-strength sutures. Arthroscopy 2010;26(suppl 9):S134-S141.

     

     

12. Barber FA, Herbert MA. Cyclic loading biomechanical analysis of the pullout strengths of rotator cuff and glenoid anchors: 2013 update. Arthroscopy 2013;29(5):832-844.

     

     

13. Barber FA, Herbert MA, Beavis RC. Cyclic load and failure behavior of arthroscopic knots and high strength sutures. Arthroscopy 2009;25(2):192-199.

     

     

14. Barber FA, Herbert MA, Beavis RC, et al. Suture anchor materials, eyelets, and designs: update 2008. Arthroscopy 2008;24(8): 859-867.

     

     

15. Barber FA, Herbert MA, Coons DA, et al. Sutures and suture anchors —update 2006. Arthroscopy 2006;22(10):1063.e1-1063.e9.

     

     

16. Barber FA, Herbert MA, Schroeder FA, et al. Biomechanical testing of new meniscal repair techniques containing ultra high-molecular weight polyethylene suture. Arthroscopy 2009;25(9):959-967.

     

     

17. Becker R, Starke C, Heymann M, et al. Biomechanical properties under cyclic loading of seven meniscus repair techniques. Clin Orthop Relat Res 2002;(400):236-245.

     

     

18. Burkhart SS. Suture anchor insertion angle and the deadman theory. Arthroscopy 2009;25(12):1365; author reply 1365-1366.

     

     

19. Burkhart SS, Athanasiou KA, Wirth MA. Margin convergence: a method of reducing strain in massive rotator cuff tears. Arthroscopy 1996;12(3):335-338.

     

     

20. Cho NS, Lee BG, Rhee YG. Arthroscopic rotator cuff repair using a suture bridge technique: is the repair integrity actually maintained? Am J Sports Med 2011;39(10):2108-2116.

     

     

21. Cho NS, Yi JW, Lee BG, et al. Retear patterns after arthroscopic rotator cuff repair: single-row versus suture bridge technique. Am J Sports Med 2010;38(4):664-671.

     

     

22. Cohen SB, Anderson MW, Miller MD. Chondral injury after arthroscopic meniscal repair using bioabsorbable Mitek Rapidloc meniscal fixation. Arthroscopy 2003;19(7):E24-E26.

     

     

23. Cohen SB, Boyd L, Miller MD. Vascular risk associated with meniscal repair using Rapidloc versus FasT-Fix: comparison of two all-inside meniscal devices. J Knee Surg 2007;20(3):235-240.

     

     

24. Cole BJ, ElAttrache NS, Anbari A. Arthroscopic rotator cuff repairs: an anatomic and biomechanical rationale for different suture-anchor repair configurations. Arthroscopy 2007;23(6):662-669.

     

     

25. Dierckman BD, Goldstein JL, Hammond KE, et al. A biomechanical analysis of point of failure during lateral-row tensioning in transosseous-equivalent rotator cuff repair. Arthroscopy 2012;28(1): 52-58.

     

     

26. Fisher SR, Markel DC, Koman JD, et al. Pull-out and shear failure strengths of arthroscopic meniscal repair systems. Knee Surg Sports Traumatol Arthrosc 2002;10(5):294-299.

 

 

27 Khoury LD, Kwon YW, Kummer FJ. A novel method to determine suture anchor loading after rotator cuff repair—a study of two doublerow techniques. Bull NYU Hosp Jt Dis 2010;68(1):25-28.

 

 

1. Lo IK, Burkhart SS. The interval slide in continuity: a method of mobilizing the anterosuperior rotator cuff without disrupting the tear margins. Arthroscopy 2004;20(4):435-441.

    

    

2. Lorbach O, Bachelier F, Vees J, et al. Cyclic loading of rotator cuff reconstructions: single-row repair with modified suture configurations versus double-row repair. Am J Sports Med 2008;36(8):1504-1510.

    

    

3. Mariani PP, Santori N, Adriani E, et al. Accelerated rehabilitation after arthroscopic meniscal repair: a clinical and magnetic resonance imaging evaluation. Arthroscopy 1996;12(6):680-686.

    

    

4. Mazzocca AD, Bollier M, Fehsenfeld D, et al. Biomechanical evaluation of margin convergence. Arthroscopy 2011;27(3):330-338.

    

    

5. Park MC, Elattrache NS, Ahmad CS, et al. “Transosseous-equivalent” rotator cuff repair technique. Arthroscopy 2006;22(12):1360. e1-1360.e5.

    

    

6. Park MC, Peterson A, Patton J, et al. Biomechanical effects of a 2 suture-pass medial inter-implant mattress on transosseous-equivalent rotator cuff repair and considerations for a “technical efficiency ratio.” J Shoulder Elbow Surg 2013;23(3):361-368.

    

    

7. Park MC, Tibone JE, ElAttrache NS, et al. Part II: biomechanical assessment for a footprint-restoring transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique. J Shoulder Elbow Surg 2007;16(4):469-476.

    

    

8. Shelbourne KD, Patel DV, Adsit WS, et al. Rehabilitation after meniscal repair. Clin Sports Med 1996;15(3):595-612.

    

    

9. Tauro JC. Arthroscopic repair of large rotator cuff tears using the interval slide technique. Arthroscopy 2004;20(1):13-21.

    

    

10. Tingart MJ, Apreleva M, Zurakowski D, et al. Pullout strength of suture anchors used in rotator cuff repair. J Bone Joint Surg Am 2003;85-A(11):2190-2198.

     

     

11. Tingart MJ, Lehtinen J, Zurakowski D, et al. Proximal humeral fractures: regional differences in bone mineral density of the humeral head affect the fixation strength of cancellous screws. J Shoulder Elbow Surg 2006;15(5):620-624.

     

     

12. Voigt C, Bosse C, Vosshenrich R, et al. Arthroscopic supraspinatus tendon repair with suture-bridging technique: functional outcome and magnetic resonance imaging. Am J Sports Med 2010;38(5):983-991.