Editorial Commentary: Acellular Collagen Matrix Patch Augmentation of Large Rotator Cuff Tear Repair Results in Improved Healing

Despite a high retear rate, repair of large rotator cuff tendon tear repairs shows good clinical outcomes. Unfortunately, these results often deteriorate with time, and large tears, not to mention progressively symptomatic retears, especially in compromised rotator cuff tissue, remain a problem. The solution could include augmenting repair with a patch such as an acellular collagen matrix. Proper patient selection is needed to achieve a benefit justifying the added expense and operative time associated with adding a patch. Biomechanically, such patches are strong and increase suture retention, as well as repair construct strength and stiffness. Patches provide a significant healing effect. Recent research and meta-analysis support the use of patches on rotator cuff tendon tears 3 cm or larger, whereas smaller tears (1-2 cm in length) appear to heal without the need for a patch.

Editorial Commentary: Dasatinib With Quercetin Shows Promise in Decreasing Age-Related Senescence in the Rotator Cuff Tendon-Can It Work Elsewhere?

Cellular senescence is a fundamental mechanism seen in all age-related diseases. Human supraspinatus tendon and adjacent bursal specimens evaluated for cellular senescence by immunohistochemistry and gene expression show more senescent cells in older patients. This confirms the observation that older patients are more likely to have rotator cuff pathology, and older age is associated with lower rates of rotator cuff healing and more frequent tendon retears. Senolytic drugs can selectively eliminate senescent cells without a localized or systemic impact. Tendon and bursal specimens co-cultured and then incubated with dasatinib and quercetin for 48 hours show a significant decrease in senescent cells. This suggests that these drugs may slow biological aging in rotator cuff tendons and offer the possibility of a clinically effective treatment for the aging rotator cuff tendon. Moreover, this concept is promising for the development of future effective therapies addressing tissue senescence.

Single-row or Double-row Rotator Cuff Repair

Rotator cuff tears are potentially a career-ending injury for athletes. The surgeon must identify which patients will benefit from surgical repair. The factors to consider are age, type of sport, time since injury, athlete's level, and the patient's expectations. An essential and independent fact determining the surgical treatment is whether the damage is due to overuse or from a traumatic/collision injury. Some sports are more demanding than others resulting in different return-to-participation (RTP) rates. This RTP return rate can present a real challenge and more so by a desire to reach the pre-injury level of play. The incidence of rotator cuff tearing varies from one sport to another. In football players this can be 12% whereas for tennis players this incidence is 4% to 17%. The RTP rate must be considered when making treatment decisions and is influenced by the level of the athlete: for professional athletes, the rate is 61%, and for recreational 73%. When the surgeon and the patient decide on the surgical treatment, the surgeon must consider whether to perform a double-row or a single-row rotator cuff tendon repair. The decision-making and the surgical technique will be addressed.

Pivot Shift Syndrome of the Knee

The pivot shift test, in contrast to the Lachman or anterior drawer, is a manually subjective clinical test that simulates the injury mechanism. It is the most sensitive test to determine ACL insufficiency. This paper reviews the history, development, research, and treatment associated with the pivot shift phenomenon which is associated with tearing and loss of function of the knee anterior cruciate ligament. The pivot shift test most closely recapitulates what the symptomatic anterior cruciate ligament deficient patient feels is happening which is an abnormal translation and rotation of the injured joint during flexion or extension. The test is best conducted in the relaxed patient by applying knee flexion, tibial external rotation, and valgus stress. The pivot shift biomechanics and treatment measures are reviewed.

Editorial Commentary: Quadriceps Tendon Suture Anchor Repair Provides Better Patient-Reported Outcomes Than Transosseous Tunnel Repair: Defining the New Gold Standard

Quadriceps tendon suture anchor repair provides biomechanically greater and more consistent failure loads than transosseous tunnel repair, including less cyclic displacement (gap formation). Although satisfactory clinical outcomes are found with both repair techniques, few studies provide a side-to-side comparison. However, recent research demonstrates better clinical outcomes in using suture anchors, with equal failure rates. Suture anchor repair is minimally invasive requiring smaller incisions, less patellar dissection, and eliminates patellar tunnel drilling that can breach the anterior cortex, create stress risers, result in osteolysis from nonabsorbable intraosseous sutures and longitudinal patellar fractures. Suture anchor quadriceps tendon repair should now be considered the gold standard.

Editorial Commentary: Suture Type or Technique Has Little Influence on Outcome After Acute Lower-Extremity Tendon Rupture

Operative repair of Achilles tendon rupture significantly decreases the rerupture rate, regardless of type of surgical suture technique. Likewise, regarding repair of either the quadriceps or patellar tendon, surgical repair technique does not significantly influence the generally excellent outcomes achieved, whereas too-early mobilization should be avoided. In terms of the use of suture versus suture tape, load to failure is similar. Many factors impact tendon rupture repair success, including postoperative care, the quality of the tendon, underlying medical issues, and patient compliance, but suture type or technique has little influence on outcome after acute lower-extremity tendon rupture.

Editorial Commentary: Lateral Extra-Articular Tenodesis Results in Better Stability After Anterior Cruciate Ligament Reconstruction for Patients With High-Grade Pivot Shifts

Magnetic resonance imaging of the torn anterior lateral ligament (ALL) is inconsistent and subject to significant intra- and interobserver variability. Like that of an anterior cruciate ligament (ACL), an ALL tear can vary in degree (first, second, or third) and location (tibial or femoral side). These variations may impact the appropriate surgical intervention. Relevant biomechanical data indicate that the deep iliotibial band fibers are more important than the ALL in controlling pivot shift. Lateral compartment overconstraint after ALL reconstruction does not appear to be a biomechanical or clinical issue. An ALL reconstruction creates a nonisometric construct (tight in extension and lax in flexion), allowing physiologic internal tibial rotation at 90° flexion, whereas lateral extra-articular tenodesis (LET) is more isometric, limiting physiologic internal tibial rotation at 90° flexion. The indications for a combined ACL/ALL reconstruction are evolving, but a Segond fracture and ligamentous hyperlaxity of ≥5 using the modified Beighton system seem reasonable. An ACL/LET reconstruction results in better stability for patients with high-grade pivot shifts.

Arthroscopic Repair of Medium to Large Rotator Cuff Tears With a Triple-Loaded Medially Based Single-Row Technique Augmented With Marrow Vents

PURPOSE

The primary purpose of this study was to evaluate the repair integrity on magnetic resonance imaging (MRI), and secondarily, clinical outcomes, of medium to large (2-4 cm) rotator cuff tears treated using an arthroscopic triple-loaded medially based single-row repair technique augmented laterally with bone marrow vents.

METHODS

This is a retrospective outcomes study of patients with full-thickness medium to large (2-4 cm) rotator cuff tears repaired by 4 surgeons at a single institution over a 2-year period with a minimum of 24 months' follow-up. A single-row repair with tension-minimizing medially based triple-loaded anchors and laterally placed bone marrow vents was used. Patients completed a satisfaction and pain survey, the Western Ontario Rotator Cuff index questionnaire, and a Short Form-36 version 2 survey to evaluate clinical outcomes. MRI was obtained at a minimum of 24 months follow-up to assess repair integrity.

RESULTS

A total of 64 males and 27 females with a mean age of 59.7 (range, 34-82) were included. The mean tear size was 2.6 cm in anteroposterior dimension, treated with a mean of 2.2 anchors. Eighty-three of 91 shoulders (91%) reported being completely satisfied with their result. The median Western Ontario Rotator Cuff score was 95.2% of normal, with a significant difference found between those with an intact repair and those with a full-thickness recurrent defect (median, 95.9% vs. 73.8%; P = .003). Postoperative MRI obtained at a median of 32 months (range, 24-48) demonstrated an intact repair in 84 of 91 shoulders (92%), with failure defined as a full-thickness defect of the tendon.

CONCLUSIONS

Arthroscopic repair of medium to large rotator cuff tears using triple-loaded medially based single-row repair augmented with marrow vents resulted in a 92% healing rate by MRI and excellent patient-reported outcomes LEVEL OF EVIDENCE: Level IV, retrospective case series.

The Biomechanical Performance of the Latest All-Inside Meniscal Repair Devices

PURPOSE

To evaluate the biomechanical characteristics of recently introduced meniscal repair devices with a hand-tied, inside-out meniscal suture in a human meniscus model.

METHODS

In detached adult human menisci, vertical longitudinal cuts were created 3 mm from the synovial-meniscal junction, simulating a bucket-handle meniscal tear. Each cut was repaired using a single device. Group 1 received a vertical mattress suture of No. 2-0 OrthoCord; group 2, TrueSpan device with PEEK (polyether ether ketone) anchors containing No. 2-0 OrthoCord suture; group 3, TrueSpan device with biodegradable poly-lactide-co-glycolide (PLGA) anchors containing No. 2-0 OrthoCord suture; group 4, Meniscal Cinch II device; group 5, AIR meniscal repair device; and group 6, FasT-Fix 360 device. All samples were preloaded at 5 N and cycled 200 times between 5 and 20 N. The specimens that survived cyclic loading were destructively tested at 12.5 mm/s. Endpoints included maximum load, displacement, stiffness, and failure mode.

RESULTS

The mean failure loads were as follows: 95.8 N for OrthoCord suture, 87.1 N for TrueSpan with PEEK, 84.6 N for TrueSpan with PLGA, 48.6 N for Meniscal Cinch II, 72.3 N for AIR, and 68.1 N for FasT-Fix 360. Repairs performed with OrthoCord suture (P = .002) and both TrueSpan devices (P < .03) but not the FasT-Fix 360 device or AIR device were statistically significantly stronger than Meniscal Cinch II repairs. Mean cyclic displacement measured 1.1 mm for OrthoCord, 1.5 mm for TrueSpan with PEEK, 1.5 mm for TrueSpan with PLGA, 2.1 mm for Meniscal Cinch II, 1.1 mm for AIR, and 1.4 mm for FasT-Fix 360. The Meniscal Cinch II device showed more displacement than all other devices (P < .05). The FasT-Fix 360, AIR, and Meniscal Cinch II devices failed by anchor pullout from the peripheral meniscus. OrthoCord and both TrueSpan devices failed by suture pulling through the bucket-handle tissue.

CONCLUSIONS

OrthoCord suture is stronger than the AIR, FasT-Fix 360, and Meniscal Cinch II devices. The TrueSpan device with PEEK and TrueSpan device with PLGA are stronger than the Meniscal Cinch II device. The Meniscal Cinch II device failed during cyclic loading with greater cyclic displacement than the AIR device, FasT-Fix 360 device, OrthoCord, and TrueSpan device with PEEK. The Meniscal Cinch II, AIR, and FasT-Fix 360 devices failed by anchor pullout, whereas OrthoCord and both TrueSpan devices failed by suture pull-through.

CLINICAL RELEVANCE

Some newly introduced all-inside meniscal repair devices show inferior failure strength compared with earlier versions that might adversely impact clinical outcomes.

The Clinical and Biomechanical Performance of All-Suture Anchors: A Systematic Review

Purpose

This systematic review aimed to clarify the relative strengths and weaknesses of the all-suture anchors (ASAs) in both clinical and experimental studies. Our hypothesis was that there would be similar clinical and experimental data for ASAs regarding the biomechanical properties, clinical outcomes and complication rates.

Methods

A systematic review of MEDLINE and Embase databases was performed. The inclusion criteria for clinical studies were both retrospective or prospective study design and minimum 1-year follow-up; for biomechanical studies, the inclusion criteria were performance on either cadaver and animal bones or synthetic surfaces. Studies were excluded if the studies were not in English or if they were review articles, commentaries, letters, case reports, or technical notes. The risk of bias assessment was done using the Methodological Index for Non-randomized Studies (MINORS) tool.

Results

We included 13 experimental and 3 clinical studies. The least displacement under cyclic loading was recorded with Q-Fix. Failure mode was mostly by suture breaking for the Q-Fix, whereas anchor pullout was the most common for the others. Cadaver humerus’ greater tuberosity seemed to be less durable for the ASAs. Tests on cadaver glenoid showed similar biomechanical properties when compared to a control anchor. Studies investigating clinical and radiologic findings were very few, and only 3 case series were included in this review. Clinical findings of patients treated with ASAs for instability and rotator cuff repair showed satisfactory results and little increase in the complication rate (retear or revision surgery because of loose anchor).

Conclusions

ASAs have similar or better biomechanical properties compared to regular anchors. Low-profile design seems to be an important advantage. Case series can not distinguish between the possible clinical benefits and/or risks.

Clinical Relevance

ASAs have similar biomechanical properties when compared with other types of anchors. Their strength and performance vary with anatomic location, which may influence clinical success.

Biomechanical comparison of conventional double-row repair versus double row repair with the parachute configuration

INTRODUCTION

The rotator cuff tears are a very frequent condition. The rotator cuff repair is a procedure often perform by the orthopedic surgeon. There are multiple techniques and suture configurations for this type of repairs. The double row configuration is one of the most used and consider very effective for mid-size and large size rotator cuff tears. The parachute configuration for this repair is a novel technique that may be useful for mid-size and large size tears, for this repair two medial double row anchors are used and one knotless lateral anchor. Our porpoise was to compare biomechanical performance and footprint coverage of a conventional suture-bridge double-row rotator cuff repair configuration versus a double-row-parachute.

METHODS

This paper shows the biomechanical behavior on a cadaver model of the parachute configuration, and also compares this conformation with a double row in a suture-bridge fashion. Our hipothesis was that the Parachute configurations biomechanical performance is equivalent to the suture-bridging double-row technique.

RESULTS

The parachute configuration advantages show the advantage of using less anchors, which will decrease the surgical time and also the risks of using multiple hardware in the humeral head.

Editorial Commentary: Glenoid Track Instability Management Score or Instability Severity Index Score-Will This Decrease Latarjet Abuse?

Open treatment of anterior shoulder instability using a coracoid transfer, such as the Latarjet procedure, is associated with low recurrence rates but with significant complications such as nerve injury, arthrosis, and graft osteolysis. However, an arthroscopic Bankart procedure, although less invasive and with a low complication rate, has the possibility of a higher recurrent instability rate. Scoring systems such as the Instability Severity Index Score, created to select patients for an arthroscopic Bankart procedure or coracoid transfer, have varying levels of success. Often, the scoring system selects a relatively high percentage of patients for the coracoid transfer, possibly undermining its widespread adoption. The relation between glenoid and humeral bone loss has produced the concept of "on-track" and "off-track," which impacts recurrent instability rates. Merging the on-track and off-track concept with the new Glenoid Track Instability Management Score may produce an algorithm that more accurately assesses the need for the Latarjet procedure or arthroscopic stabilization.

Grafts and Patches in Rotator Cuff Surgery: Bioinductive Scaffolds, Augmentation, Interposition, and Superior Capsule Reconstruction

Rotator cuff repair can be challenging because of the compromised state of the tendon tissue. These challenges range from simply degenerative tendons to complete tendon loss in patients which can impair soft-tissue healing. Various grafts and patches are currently available to help address these challenges. The ideal solution for the treatment of irreparable rotator cuff tears or those prone to retear remains controversial. Sometimes augmentation with a patch is appropriate. However, at times a completely retracted and immobile tendon remnant is found. Reconstruction of the superior capsule has demonstrated promising results in several short-term series. The indications for these procedures, the optimal surgical technique, and their limitations are evolving. This chapter discusses the current literature related to bioinductive scaffolds, graft augmentation, graft interposition, and superior capsular reconstruction.

Suture-Based Debris Behavior in the Draining Lymph Nodes of a Porcine Knee: A Study of Silicone, Polyethylene and Carbon

Purpose

To determine whether debris from a silicone core suture has an observable intra-articular or extra-articular impact or can be shown to migrate into the lymphatic system.

Methods

Using a porcine stifle joint model, 2 study groups were created: 1 group used silicone-suture particles created by rupturing hand-tied knots of a nonabsorbable suture with an outer sheath of ultrahigh molecular-weight polyethylene, an inner polyester sheath and a medical-grade silicone/sodium chloride-filled core. The second group used a mixture of 3 vitreous carbon particles sizes. Twelve Yorkshire pigs were randomly assigned to each group. Only 1 type of study particle was used in a single animal to avoid cross-contamination. Half of the study materials were placed by arthrotomy into the joint and, after capsular closure, the remaining half were placed on the joint capsule before skin closure. Six weeks postimplantation, the stifle joints and regional lymph nodes were examined macroscopically and microscopically. The extracapsular and intra-articular tissue and the lymph nodes were examined.

Results

Macroscopically, none of the 12 silicone-suture particle group limbs had abnormal macroscopic observations. Of the 12 limbs in the carbon particle group, 8 demonstrated discoloration in the extracapsular, intra-articular and lymph node tissues; 6 limbs demonstrated joint discoloration (extracapsular and intra-articular). The silicone-suture particle group showed lymph node inflammation in 25% of the iliac lymph nodes and 42% of the inguinal lymph nodes but none in the popliteal lymph nodes. In the carbon particle group, 100% of the iliac lymph nodes, 75% of the inguinal lymph nodes and 8% of the popliteal nodes showed inflammation. No silicone-suture debris migration was observed microscopically. Visible carbon particle migration was present in 100% of the iliac lymph nodes and in 50% of the inguinal lymph nodes but in none (0) of the popliteal lymph nodes. The carbon particle group also showed inflammation in these areas.

Conclusions

Carbon particles in the porcine knee migrated into the lymph nodes (iliac 100%; inguinal 50%, popliteal 0); gross discoloration was observed in 8 of 12 specimens. Silicone-suture particles could not be found in the lymph nodes, and no macroscopic joint damage was observed.

Clinical Relevance

The clinical use of a suture containing a silicone/salt central core is common, and the porcine lymphatic model suggests that this type of suture material does not result in clinically significant silicone particulates.

Editorial Commentary: All-Suture Shoulder Glenoid Anchors: Can We Adequately Tension Them or Knot?

All-suture anchors require smaller drill holes (often under 2.0 mm) than comparable solid glenoid anchors (e.g., Gryphon: 2.5-mm drill). A smaller drill allows closer anchor approximation, but there is no indication that this improves repair biomechanics. In fact closely associated multiple fixation points are associated with glenoid fractures, and the same multiple fixation points can be achieved with double- or triple-loaded conventional anchors. All-suture anchors require deployment immediately adjacent to intact cortical bone. Without this, slack and pistoning of the suture ball anchor occur during cyclic loading and have been associated with bone cavitation, repair loosening, and gap formation. A mechanical tensioning mechanism more effectively removes the slack than hand tensioning by the surgeon. Drill length is another concern. All-suture anchor drills measure between 20 and 24 mm long. This length is commonly associated with far cortex penetration and places the suprascapular nerve and axillary nerve at increased risk of contact damage. Maximizing all-suture anchor performance is associated with mechanical deployment systems rather than hand traction applied by the surgeon. Finally, no current all-suture anchor is biodegradable, osteoconductive, or replaced by bone.

Editorial Commentary: Acetabular Labral Repair-Is A Knotless Anchor Better?

Knotless anchors have an important role in arthroscopic acetabular labral repair. Different anchors show 2 primary failure modes: suture breakage and suture pullout from the anchor ("eyelet failure"). Knotless anchors show minimal displacement at physiological loads and should perform well for arthroscopic labral repair. Surgeons should consider the suture-passing device size and use a device that creates as small of a labral hole as possible.

Development of a Porcine Lymph Drainage Model to Study Particle Migration

Background: Intra-articular wear particulate migration from the knee joint has been studied in various animal models as well as postmortem in patients who received total knee joint replacement. However, there still exists a need for a simple, yet analogous animal model for tracking the migration of wear debris from the knee joint, especially through the draining lymph nodes. Methods and Results: To fill this need, a proof-of-concept porcine model was developed for particle migration from the knee joint into the surrounding lymphatic system. Vitreous carbon particles were deposited both intra-articularly and extracapsularly in a bilateral manner to the hind limbs in pigs (n = 6). The regional/draining lymph nodes were qualitatively assessed weekly by a veterinarian by manual palpation to detect any enlargement or change in consistency when compared to the initial assessment before the surgical procedure. At 6 weeks, the draining lymph nodes were harvested and processed for histology. Microscopic evaluation showed carbon particle migration from the knee into 100% of the iliac lymph nodes, 50% of the inguinal lymph nodes, and 0% of the popliteal lymph nodes. Discussion: Overall, this study established a needed animal model for evaluating carbon particle migration to the draining lymph nodes from the knee joint.

Editorial Commentary: Polyurethane Meniscal Scaffold: A Perfect Fit or Flop?

The goal of using a synthetic scaffold to establish a biomechanically functioning meniscus or provide an equivalent meniscus substitute is not achieved by the polycaprolactone-polyurethane Actifit scaffold. Recent research, that did not include a control group, shows that the revision rate is significant, and any improvements in patient outcomes could reflect the associated reconstructive surgery. Based on these data and similar published reports, it is premature to conclude that this implant is clinically indicated. The technique is currently more flop than fit.

Editorial Commentary: Don't Pig Out When Selecting a Shoulder, Rotator Cuff Augmentation Graft! Xenografts Are Not the Way to Go

Porcine xenograft dermal onlay augmentation of rotator cuff repair does not provide improved cuff integrity or provide better clinical outcomes. The retear rate was actually higher in repairs augmented with a porcine xenograft than the control group. Adverse events occurred in 60% of the xenograft patients compared with 40% of the controls. The use of liquid platelet-rich plasma had no discernible impact. A total of 85% of the observed failures with the suture-bridging double-row repair were at the medial cuff (Cho type 2).

Editorial Commentary: Feeling the Pressure! A Biomechanical Analysis of All-Inside and Inside-Out Knee Meniscus Repair

A biomechanical, time-zero comparison found that both No. 2-0 UltraBraid inside-out sutures and FasT-Fix 360 all-inside devices used to repair a displaced bucket handle knee meniscus tear increased the contact area in deeper flexion angles (at 45°-60°) and reduced the peak contact pressure (at 45°-90°). No significance difference was observed between the inside-out and all-inside repair techniques.

All-Suture Anchors: Biomechanical Analysis of Pullout Strength, Displacement, and Failure Mode

PURPOSE

To evaluate the biomechanical and design characteristics of all-suture anchors.

METHODS

All-suture anchors were tested in fresh porcine cortical bone and biphasic polyurethane foam blocks by cyclic loading (10-100 N for 200 cycles), followed by destructive testing parallel to the insertion axis at 12.5 mm/s. Endpoints included ultimate failure load, displacement at 100 and 200 cycles, stiffness, and failure mode. Anchors tested included JuggerKnot (1.4, 1.5, and 2.8), Iconix (1, 2, and 3), Y-knot (1.3, 1.8, and 2.8), Q-Fix (1.8 and 2.8), and Draw Tight (1.8 and 3.2).

RESULTS

The mean ultimate failure strength of the triple-loaded anchors (564 ± 42 N) was significantly greater than the mean ultimate failure strength of the double-loaded anchors (465 ± 33 N) (P = .017), and the double-loaded anchors were stronger than the single-loaded anchors (256 ± 35 N) (P < .0001). No difference was found between the results in porcine bone and biphasic polyurethane foam. None of these anchors demonstrated 5 mm or 10 mm of displacement during cyclic loading. The Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix (P = .025) but not the Iconix and Draw Tight (P > .05). The most common failure mode varied and was suture breaking for the Q-Fix (97%), JuggerKnot (81%), and Iconix anchors (58%), anchor pullout with the Draw Tight (76%), whereas the Y-Knot was 50% suture breaking and 50% anchor pullout.

CONCLUSIONS

The ultimate failure load of an all-suture anchor is correlated directly with its number of sutures. With cyclic loading, the Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix but not the Iconix and Draw Tight. JuggerKnot (81%) and Q-Fix (97%) anchors failed by suture breaking, whereas the Draw Tight anchor failed by anchor pullout (76%).

CLINICAL RELEVANCE

All-suture anchors vary in strength and performance, and these factors may influence clinical success. Biphasic polyurethane foam is a validated model for suture anchor testing.

Editorial Commentary: Are All-Suture Anchors as Good as Conventional Anchors?

Research in this issue, like other biomechanical testing, suggests that the all-suture anchors studied here seem strong enough for glenoid and acetabular applications. Testing suture anchors in nonbiologic material may be problematic unless that material is validated or there is a control. The cyclic loads used influence the data, and oscillating between 10 and 50 N does not allow for sufficient anchor performance differentiation. The next question is whether there will be any adverse events associated with the use of all-suture anchors clinically.

Biomechanical Comparison of Standard and Linked Single-Row Rotator Cuff Repairs in a Human Cadaver Model

PURPOSE

The purpose of this study was to evaluate the time zero cyclic and failure loading properties of a linked single-row rotator cuff repair compared with a standard simple suture single-row repair using triple-loaded suture anchors.

METHODS

Eighteen human cadaveric shoulders from 9 matched pairs were dissected, and full-thickness supraspinatus tears were created. The tendon cross-sectional area was recorded. In each pair, one side was repaired with a linked single-row construct and the other with a simple suture single-row construct, both using 2 triple-loaded suture anchors. After preloading, specimens were cycled to 1 MPa of effective stress at 1 Hz for 500 cycles, and gap formation was recorded with a digital video system. Samples were then loaded to failure, and modes of failure were recorded.

RESULTS

There was no statistical difference in peak gap formation between the control and linked constructs (3.6 ± 0.9 mm and 3.6 ± 1.2 mm, respectively; P = .697). Both constructs averaged below a 5-mm cyclic failure threshold. There was no statistical difference in ultimate load to failure between the control and linked repair (511.1 ± 139.0 N and 561.2 ± 131.8 N, respectively; P = .164), and both groups reached failure at loads similar to previous studies. Constructs failed predominantly via tissue tearing parallel to the medial suture line.

CONCLUSIONS

The linked repair performed similarly to the simple single-row repair. Both constructs demonstrated high ultimate load to failure and good resistance to gap formation with cyclic loading, validating the time zero strength of both constructs in a human cadaveric model.

CLINICAL RELEVANCE

The linked repair provided equivalent resistance to gap formation and failure loads compared with simple suture single-row repairs with triple-loaded suture anchors. This suggests that the linked repair is a simplified rip-stop configuration using the existing suture that may perform similarly to current rotator cuff repair techniques.

Complex Medial Meniscus Tears Are Associated With a Biconcave Medial Tibial Plateau

PURPOSE

To determine whether an association exists between a biconcave medial tibial plateau and complex medial meniscus tears.

METHODS

A consecutive series of stable knees undergoing arthroscopy were evaluated retrospectively with the use of preoperative magnetic resonance imaging (MRI), radiographs, and arthroscopy documented by intraoperative videos. Investigators independently performed blinded reviews of the MRI or videos. Based on the arthroscopy findings, medial tibial plateaus were classified as either biconcave or not biconcave. A transverse coronal plane ridge, separating the front of the tibial plateau from the back near the inner margin of the posterior body of the medial meniscus, was defined as biconcave. The medial plateau slope was calculated with MRI sagittal views. General demographic information, body mass index, and arthroscopically confirmed knee pathology were recorded.

RESULTS

A total of 179 consecutive knees were studied from July 2014 through August 2015; 49 (27.2%) biconcave medial tibial plateaus and 130 (72.8%) controls were identified at arthroscopy. Complex medial meniscus tears were found in 103. Patients with a biconcave medial tibial plateau were found to have more complex medial meniscus tears (69.4%) than those without a biconcavity (53.1%) (P = .049) despite having lower body mass index (P = .020). No difference in medial tibial plateau slope was observed for biconcavities involving both cartilage and bone, bone only, or an indeterminate group (P = .47).

CONCLUSIONS

Biconcave medial tibial plateaus were present in 27.4% of a consecutive series of patients undergoing knee arthroscopy. A biconcave medial tibial plateau was more frequently associated with a complex medial meniscus tear.

LEVEL OF EVIDENCE

Level III, case-control study.

Biocomposite Implants Composed of Poly(Lactide-co-Glycolide)/β-Tricalcium Phosphate: Systematic Review of Imaging, Complication, and Performance Outcomes

PURPOSE

To determine the degradation and performance outcomes of poly(lactide-co-glycolide)/β-tricalcium phosphate (PLGA/β-TCP) implants.

METHODS

A MEDLINE and Embase search for randomized or nonrandomized controlled studies and prospective or retrospective case series that used biocomposite interference screws or suture anchors composed of PLGA/β-TCP was performed. Main outcomes included volume of implant resorption and incidence of osteoconductivity at implant sites, imaging findings, adverse events, and the frequency of reoperations.

RESULTS

A total of 13 studies representing 668 patients with either knee or shoulder implants were included. Median follow-up was 28 months (range: 12-37 months). Biocomposite implants lost 88% of their original volume during follow-up. Osteoconductivity at the implant site was identified in 63% of cases. Adverse events included tunnel widening (3%), effusion (5%), and cyst formation (4%). Synovitis was not reported.

CONCLUSIONS

Biocomposite interference screws or suture anchors composed of PLGA/β-TCP almost fully absorb over 3 years while promoting osteoconductivity with few reported adverse events.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Editorial Commentary: Musculotendinous Junction Mattress Sutures Are Inefficient

Medial row sutures placed at the musculotendinous junction are more likely to cut through the tendon than those sutures placed 10 mm lateral to the junction. Even if there is little tendon left, putting the stitches at the junction is a bad idea. In this instance, a single-row repair is better.

Biomechanical Strength and Elongation of the T-Block Modification for Bone-Patella Tendon-Bone Allografts

PURPOSE

To assess the biomechanical performance of 2 different T-block modifications of bone-patella tendon-bone (BPTB) allografts.

METHODS

The matched knee pairs from 10 human cadavers (mean age 49 years) were fashioned into 30 BPTB allografts and divided into 3 groups (10 each): group 1, standard patella tendon-tibial attachment; group 2, T-block tibial attachment with 10 mm of unattached bone proximal to the patella tendon insertion with 15 mm of tendon attached; group 3, T-block tibial attachment with 15 mm of unattached bone proximal to the patella tendon insertion and 10 mm of tendon attached. A biocomposite interference screw secured each graft into a 10-mm tunnel in 15 pcf polyurethane foam. A 10-N preload was applied followed by 500 cycles of 10- to 150-N loading at 0.5 Hz. Grafts completing cyclic loading were destructively tested at 200 mm/min. Failure load, stiffness, elongation, and failure mode were recorded.

RESULTS

Failure loads and elongation for groups 1, 2, and 3 (790, 729, and 700 N; 0.15, 0.16, and 0.19 mm, respectively) were not statistically different (P > .1). Graft stiffness for groups 1 and 2 (214 and 186 N/mm) were not statistically different, but group 3 (170 N/mm) was different from group 1. All group 1 and 2 tests failed by graft pullout as did 8 of 10 from group 3. The other 2 failed by tendon tearing from bone.

CONCLUSIONS

A T-block BPTB allograft harvested with 10 or 15 mm of unattached bone proximal to the tibial patella tendon insertion has no ultimate failure strength difference after cyclic loading compared with the standard BPTB allograft. The 15-mm T-block showed lower stiffness and more elongation at failure than the standard BPTB allograft whereas the 10-mm T-block exhibited comparable stiffness and elongation measurements to the standard BPTB allograft control specimens.

CLINICAL RELEVANCE

The T-block BPTB allograft construct should increase the availability of BPTB allografts for anterior cruciate ligament reconstruction and facilitate the use of grafts possessing longer tendon segments that are currently being discarded.

Triple-Loaded Single-Row Versus Suture-Bridge Double-Row Rotator Cuff Tendon Repair With Platelet-Rich Plasma Fibrin Membrane: A Randomized Controlled Trial

PURPOSE

To compare the structural healing and clinical outcomes of triple-loaded single-row with suture-bridging double-row repairs of full-thickness rotator cuff tendons when both repair constructs are augmented with platelet-rich plasma fibrin membrane.

METHODS

A prospective, randomized, consecutive series of patients diagnosed with full-thickness rotator cuff tears no greater than 3 cm in anteroposterior length were treated with a triple-loaded single-row (20) or suture-bridging double-row (20) repair augmented with platelet-rich plasma fibrin membrane. The primary outcome measure was cuff integrity by magnetic resonance imaging (MRI) at 12 months postoperatively. Secondary clinical outcome measures were American Shoulder and Elbow Surgeons, Rowe, Simple Shoulder Test, Constant, and Single Assessment Numeric Evaluation scores.

RESULTS

The mean MRI interval was 12.6 months (range, 12-17 months). A total of 3 of 20 single-row repairs and 3 of 20 double-row repairs (15%) had tears at follow-up MRI. The single-row group had re-tears in 1 single tendon repair and 2 double tendon repairs. All 3 tears failed at the original attachment site (Cho type 1). In the double-row group, re-tears were found in 3 double tendon repairs. All 3 tears failed medial to the medial row near the musculotendinous junction (Cho type 2). All clinical outcome measures were significantly improved from the preoperative level (P < .0001), but there was no statistical difference between groups postoperatively.

CONCLUSIONS

There is no MRI difference in rotator cuff tendon re-tear rate at 12 months postsurgery between a triple-loaded single-row repair or a suture-bridging double-row repair when both are augmented with platelet-rich plasma fibrin membrane. No difference could be demonstrated between these repairs on clinical outcome scores.

LEVEL OF EVIDENCE

I, Prospective randomized study.

Long-Term Degradation of Self-Reinforced Poly-Levo (96%)/Dextro (4%)-Lactide/β-Tricalcium Phosphate Biocomposite Interference Screws

PURPOSE

To evaluate the long-term in vivo degradation of biocomposite interference screws made with self-reinforced poly-levo (96%)/dextro (4%)-lactide/β-tricalcium phosphate [SR-PL(96)/D(4)LA/β-TCP].

METHODS

A study of the in vivo biologic behavior of an SR-PL(96)/D(4)LA/β-TCP biocomposite interference screw was initiated in 2011 using an anterior cruciate ligament (ACL) reconstruction model. Eight patients undergoing a bone-patellar tendon-bone ACL reconstruction fixed at both the femur and tibia with an SR-PL(96)/D(4)LA/β-TCP screw at least 36 months earlier were evaluated by physical, radiographic, and computed tomography (CT) evaluations. Lysholm, Tegner, Cincinnati, and International Knee Documentation Committee scores were obtained. After incomplete degradation was observed in these 8 patients, a subsequent series of 17 patients were evaluated at a minimum of 48 months after surgery. By use of CT scans, Hounsfield unit (HU) data were obtained at the femoral and tibial screw and other bone sites. An ossification quality score (range, 1 to 4) was used to determine osteoconductivity at the screw sites.

RESULTS

Eleven male and 6 female patients evaluated by CT scan and radiographs at a mean of 50 months (range, 48 to 61 months) after surgery showed bone plug healing to the tunnel wall and the SR-PL(96)/D(4)LA/β-TCP screws were replaced with material that was calcified and non-trabecular. Osteoconductivity was present in 24 of 34 tunnels (70.58%) and nearly complete or complete (type 3 or 4 ossification) in 11 of 34 (32.35%). Mean screw site densities (femoral, 242 HU; tibial, 240 HU) were consistent with cancellous bone density. One positive pivot-shift test was found. Lysholm, Cincinnati, Tegner, and International Knee Documentation Committee activity scores improved from 44.5, 40.7, 2.3, and 1.4, respectively, preoperatively to 92, 92.4, 5.7, and 3.3, respectively, at follow-up (P < .0001). The average postoperative Single Assessment Numeric Evaluation score was 92. The mean KT arthrometer (MEDmetric, San Diego, CA) difference was 1.25 mm.

CONCLUSIONS

The SR-PL(96)/D(4)LA/β-TCP interference screw was replaced with calcified, non-trabecular material 4 years after implantation in a bone-patellar tendon-bone ACL reconstruction model. Osteoconductivity was confirmed in 24 of 34 screw sites (71%), with nearly complete or complete filling in 11 of 34 (33%). The SR-PL(96)/D(4)LA/β-TCP biocomposite interference screw is osteoconductive.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Subtle lisfranc subluxation: results of operative and nonoperative treatment

Subtle Lisfranc instability is typically a low-energy, twisting, axial-loading injury. The present study evaluated the operative treatment of subtle Lisfranc injuries after nonoperative failure. The data from consecutive patients with subtle Lisfranc instabilities were reviewed. Those in whom initial nonoperative treatment had failed underwent surgery. The American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score was obtained initially, after nonoperative treatment, and, for those in whom nonoperative treatment had failed, after operative treatment. Of 36 patients enrolled, 16 (44.44%) were successfully treated nonoperatively, and 20 (55.56%) required surgery after nonoperative treatment had failed. Of those treated operatively, 9 (45%) were stabilized with dual screws and 11 (55%) with dual suture buttons. The mean follow-up period was 36 ± 12.2 months. The AOFAS scores significantly improved from the pre- to final post-treatment values. The overall mean pretreatment AOFAS score (62.8 ± 8.84) was significantly lower statistically than the mean overall post-treatment AOFAS score (91.3 ± 8.34; p < .0001). The mean AOFAS score before nonoperative treatment (61.9 ± 9.5) improved to a mean AOFAS score of 75.3 ± 15.8 after nonoperative treatment (p = .0029). The mean preoperative AOFAS score (63.5 ± 8.46) improved to a postoperative AOFAS score of 92.3 ± 8.43 (p < .0001). The mean AOFAS score before nonoperative treatment (61.9 ± 9.5) was not significantly different statistically from the mean preoperative AOFAS score (63.5 ± 8.46; p = .62). The mean AOFAS score after nonoperative treatment (75.3 ± 15.8) was lower than the mean postoperative AOFAS score (92.3 ± 8.43; p < .0001). Of the 9 feet stabilized with dual screws, 7 (77.78%) required screw removal during the observation period. Subtle Lisfranc injuries failing nonoperative treatment were successfully stabilized using either a dual screw or suture button technique.

Managing the pain of knee osteoarthritis

Pain from knee osteoarthritis creates a significant burden for symptomatic patients, who are often forced to change their lifestyle because of their symptoms. Activity modification, therapy, weight loss, nonsteroidal anti-inflammatory drugs, shoe orthotics, bracing, and injections are the nonoperative options available. New technologies are also emerging in the treatment of knee osteoarthritis. Ultimately, these therapeutic modalities should reduce pain and increase the overall functioning of patients. These nonoperative modalities give the clinician several effective options before surgical management is considered.

Adverse events associated with biodegradable lactide-containing suture anchors

PURPOSE

To evaluate the occurrence of adverse events and inflammatory reactions related to the use of biodegradable anchors.

METHODS

A retrospective review of a consecutive series of arthroscopic shoulder procedures using biodegradable suture anchors performed by a single surgeon was undertaken. The database was purged of patient identifiers. The blinded data were analyzed for procedure type, anchor type and composition, associated procedures, and general demographic data. Anchor composition and number were recorded. A shoulder procedure after the index operation was considered an adverse event. The nature of these procedures was evaluated using medical records, operative images, and video, looking specifically for inflammatory reactions. Any anchor-related issues were documented.

RESULTS

Three hundred sixty cases met the inclusion criteria. The procedure was a tendon repair (rotator cuff or biceps) in 265 cases and a labral repair (instability or SLAP) in 97, 2 of which were combined instability and tendon repairs. Nine different biodegradable anchors were identified, possessing 4 different polymer combinations. Adverse events (reoperations) were identified in 18 of 360 patients (5%): 13 tendon repairs and 5 labral/instability repairs. Only 2 were anchor related. In 1 tendon repair case, the anchor broke and an anchor fragment required removal. In 1 labral repair case, the anchor eyelet (a suture) loosened from the anchor body and eroded the humeral head. No cases of inflammatory synovitis were observed. No statistical difference in adverse event rates existed between tendon and labral repairs (P > .05).

CONCLUSIONS

Anchor-specific adverse events occurred in 2 of 360 procedures (0.5%). One was anchor design related (the prominent head containing the suture eyelet broke off) in a poly-L-lactic acid (PLLA) anchor. One was anchor material related and occurred when the poly-levo (70%)/dextro (30%)-lactide anchor body reabsorbed, loosening the encased eyelet suture and allowing this suture to migrate into the joint. No inflammatory reactions were documented in the slowly degrading pure PLLA or more rapidly degrading biocomposite PLLA/β-tricalcium phosphate-based anchors.

LEVEL OF EVIDENCE

Level IV, retrospective review, therapeutic study.

Meniscal cysts: treatment options and algorithm

Meniscal cysts are commonly seen in the knee. Symptomatic meniscal cysts tend to be located on the lateral side but magnetic resonance imaging studies indicate that medial cysts are more common. Meniscal cysts are commonly associated with horizontal meniscal tears. The arthroscopic management of symptomatic cysts should include debriding the horizontal meniscal tear (if nonrepairable) to fully decompress the cyst and the creation of a 5-mm channel from the joint into the cyst. If a vertical peripheral meniscal tear exists or is created, meniscal repair for appropriately selected cases should be performed.

Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger

PURPOSE

To compare clinical outcomes and revision rates for anterior cruciate ligament (ACL) reconstructions using bone-patellar tendon-bone (BPTB) allografts versus BPTB autografts in a population of patients aged 25 years and younger.

METHODS

A consecutive series of patients 25 years or younger undergoing ACL reconstruction with either a patient-selected BPTB allograft or BPTB autograft fixed with biocomposite interference screws was retrospectively reviewed. Multiligamentous and posterior cruciate ligament tears were excluded. All allografts were from a single source and not chemically processed or irradiated. Two graft-specific rehabilitation programs were used. The primary outcome measure was graft failure. Failure was defined as a subsequent ACL revision surgery, 2+ Lachman test, positive pivot-shift, or side-to-side KT difference of greater than 5 mm. Secondary outcome measures included Cincinnati, Lysholm, and International Knee Documentation Committee (IKDC) activity scores.

RESULTS

In 81 patients at least 24 months after surgery (28 allografts; 53 autografts), 7 failures were identified: 2 of 28 (7.1%) allografts and 5 of 53 (9.4%) autografts. Mean Cincinnati scores improved from 54.6 and 39.5 (allografts and autografts, respectively) to 86.2 and 85.1. Mean Lysholm scores improved from 60.3 and 44.8 (allografts and autografts, respectively) to 89.9 and 87.0. Average KT differences were 0.59 mm (allograft) and 0.34 mm (autograft group) (P = .58). IKDC activity scores were 2.9 (allografts) and 3.1 (autografts) postoperatively (P = .32).

CONCLUSIONS

Using a patient-choice ACL graft selection program after appropriate counseling and using graft-specific rehabilitation programs, not chemically processed or irradiated BPTB allograft reconstructions have no greater failure rate than autografts in patients aged 25 years and younger at a minimum 2-year follow-up. No significant differences in Cincinnati, Lysholm, and IKDC activity scores were found between these 2 groups.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Arthroscopic treatment of calcific tendonitis

Calcific tendonitis, or calcifying tendonitis, is a common disorder characterized by the multifocal accumulation of basic calcium phosphate crystals within the rotator cuff tendons. In most cases, the multifocal calcifications are located 1 to 2 cm from the insertion of the supraspinatus tendon on the greater tuberosity. The initial treatment should be nonoperative including oral anti-inflammatory medication and physical therapy. If this is unsuccessful, arthroscopic debridement of the deposit is effective. The technique used is an arthroscopic localization and debridement without associated subacromial decompression. The rotator cuff should be evaluated for partial- and full-thickness tears before and after the debridement of calcifications. If a partial- or full-thickness rotator cuff tendon tear is identified, it should be treated in a fashion consistent with those without associated calcium deposits. In our hands, tears 5 mm or greater in depth are repaired using a tendon-to-tendon or tendon-to-bone technique. Tears with less depth are debrided and then left alone. Arthroscopic debridement of calcific tendonitis can yield excellent functional results and high patient satisfaction.

Arthroscopic treatment of iliotibial band syndrome

Lateral knee pain in athletes is commonly seen in the sports medicine clinic, and the diagnosis of iliotibial band (ITB) syndrome is frequently made. Although conservative management including rest from activity, equipment modification, oral nonsteroidal anti-inflammatory drug use, and physical therapy is the mainstay of treatment initially, refractory cases do exist. Multiple surgical techniques have been described including an arthroscopic technique. Arthroscopic release of the ITB attachment to the lateral femoral epicondyle and resection of the lateral synovial recess for recalcitrant ITB syndrome comprise a valid option that can have a good outcome. This option avoids the complications associated with open surgery and allows for a complete arthroscopic knee examination. Division or lengthening of the ITB band itself is not a necessary step in this technique.

Poly L-lactide co-glycolide/β-tricalcium phosphate interference screw fixation for bone-patellar tendon bone anterior cruciate ligament reconstruction

The objective of this study was to prospectively evaluate the clinical effectiveness and radiographic response of a poly (l-lactide co-glycolide)/β-tricalcium phosphate (PlLA/PGA/β-TCP) interference screw used in bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. A prospective, consecutive series of 104 patellar tendon bone-tendon-bone ACL reconstructions fixed with PLLA/PGA/β-TCP biocomposite screws were studied. After receiving the approval from the Institutional Review Board, the following data were collected preoperatively from all patients: physical examination, Lysholm score, Cincinnati, and International Knee Documentation Committee (IKDC) activity scores, and standard knee radiographs. In addition to these, follow-up assessments included Lachman and pivot-shift tests, Tegner scores, and KT side-to-side differences. Surgical failure was defined by a 2+ Lachman test, positive pivot-shift test, side-to-side KT difference of greater than 5 mm or subsequent ACL revision surgery. Approximately 95% of patients (99 of 104) with an average follow-up of 36 months (range, 24 to 68) are reported. The average age was 30 years (range, 13 to 57 years). Postoperatively, four patients demonstrated +1 Lachman score and one patient demonstrated a +2 Lachman score. Postoperative pivot-shift tests were a trace positive in one patients and +1 in two patients. The average KT side-to-side difference was 0.65 mm. All, but five patients, demonstrated KT side-to-side measurements of 3 mm or less and those five demonstrated measurements of 5 mm or less. No revision reconstructions were performed. Significant improvements in Cincinnati score (41 to 85 postoperative) and Lysholm score (46 to 90) were observed. The average postoperative Tegner score was 7. IKDC activity score increased from 2.3 to 3.1. Approximately 4% of patients (4 of 99) met the criteria for failure. A PLLA/PGA/β-TCP biocomposite interference fixation screw provides good graft fixation, with good radiographic incorporation, without adverse events.The level of evidence of the study is IV.

The degradation outcome of biocomposite suture anchors made from poly L-lactide-co-glycolide and β-tricalcium phosphate

PURPOSE

The purpose of this study was to evaluate the long-term in vivo degradation of biocomposite suture anchors made of poly L-lactide-co-glycolide (PLLA/PGA) and β-tricalcium phosphate (β-TCP).

METHODS

Starting in 2008, the in vivo biological behavior of a biocomposite suture anchor was studied in a consecutive series of rotator cuff tendon repairs. Twenty patients undergoing rotator cuff repair secured with biocomposite PLLA/PGA-β-TCP suture anchors with at least a 36-month follow-up were evaluated by physical, radiographic, and computed tomographic (CT) evaluations of the operated shoulder. American Shoulder and Elbow Surgeons (ASES), Rowe, Simple Shoulder Test (SST), Constant, and Single Assessment Numeric Evaluation (SANE) scores were also obtained. CT scan data measured in Hounsfield units (HU) evaluated the material density at the anchor sites. Soft tissue and cancellous bone readings were also taken. Osteoconductivity scores were determined at the screw sites using an ossification quality score (range, 1 to 4).

RESULTS

Fifteen men and 5 women were evaluated an average of 37 months after surgery (range, 36 to 40). CT scans and radiographs showed no PLLA/PGA-β-TCP anchor material remaining. A total of 28 anchors were implanted in the 20 patients. The anchors were usually replaced with calcified, nontrabecular material. Osteoconductivity was present in 20 of 28 (71%) of the anchor sites and was nearly complete or complete (type 3 or 4 ossification) in 14 of 28 (50%). Mean anchor site density (94 HU) was not different from the mean cancellous bone density (99.8 HU). ASES, Rowe, SST, Constant, and SANE scores improved from 57.3, 64.5, 6.0, 51.7, and 45 preoperatively to 89.6, 86.5, 10.8, 78.6, and 84.3 at follow-up, respectively. All postoperative clinical outcome measures were statistically greater than the preoperative scores.

CONCLUSIONS

The PLLA/PGA-β-TCP (Healix BR, DePuy Mitek, Raynham, MA) suture anchor completely degraded and no remnant was present 3 years after implantation. Osteoconductivity was confirmed in 20 of 28 (71%) anchor sites and was nearly complete or complete in 14 of 28 (50%). The PLLA/PGA-β-TCP biocomposite suture anchor is osteoconductive.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Pullout strength of bone-patellar tendon-bone allograft bone plugs: a comparison of cadaver tibia and rigid polyurethane foam

PURPOSE

To compare the load-to-failure pullout strength of bone-patellar tendon-bone (BPTB) allografts in human cadaver tibias and rigid polyurethane foam blocks.

METHODS

Twenty BPTB allografts were trimmed creating 25 mm × 10 mm × 10 mm tibial plugs. Ten-millimeter tunnels were drilled in 10 human cadaver tibias and 10 rigid polyurethane foam blocks. The BPTB anterior cruciate ligament allografts were inserted into these tunnels and secured with metal interference screws, with placement of 10 of each type in each material. After preloading (10 N), cyclic loading (500 cycles, 10 to 150 N at 200 mm/min) and load-to-failure testing (200 mm/min) were performed. The endpoints were ultimate failure load, cyclic loading elongation, and failure mode.

RESULTS

No difference in ultimate failure load existed between grafts inserted into rigid polyurethane foam blocks (705 N) and those in cadaver tibias (669 N) (P = .69). The mean rigid polyurethane foam block elongation (0.211 mm) was less than that in tibial bone (0.470 mm) (P = .038), with a smaller standard deviation (0.07 mm for foam) than tibial bone (0.34 mm).

CONCLUSIONS

All BPTB grafts successfully completed 500 cycles. The rigid polyurethane foam block showed less variation in test results than human cadaver tibias.

CLINICAL RELEVANCE

Rigid polyurethane foam blocks provide an acceptable substitute for human cadaver bone tibia for biomechanical testing of BPTB allografts and offer near-equivalent results.

A comparison of lateral ankle ligament suture anchor strength

BACKGROUND

Lateral ankle ligament repairs increasingly use suture anchors instead of bone tunnels. Our purpose was to compare the biomechanical properties of a knotted and knotless suture anchor appropriate for a lateral ankle ligament reconstruction.

METHODS

In porcine distal fibulae, 10 samples of 2 different PEEK anchors were inserted. The attached sutures were cyclically loaded between 10N and 60N for 200 cycles. A destructive pull was performed and failure loads, cyclic displacement, stiffness, and failure mode recorded.

RESULTS

PushLock 2.5 anchors failed before 200 cycles. PushLock 100 cycle displacement was less than Morphix 2.5 displacement (p<0.001). Ultimate failure load for anchors completing 200 cycles was 86.5N (PushLock) and 252.1N (Morphix) (p<0.05). The failure mode was suture breaking for all PushLocks while the Morphix failed equally by anchor breaking and suture breakage.

CONCLUSIONS

The knotted Morphix demonstrated more displacement and greater failure strength than the knotless PushLock. The PushLock failed consistently with suture breaking. The Morphix anchor failed both by anchor breaking and by suture breaking.

Cyclic loading biomechanical analysis of the pullout strengths of rotator cuff and glenoid anchors: 2013 update

PURPOSE

The purpose of this study was to evaluate the biomechanical and design characteristics of newer suture anchors under cyclic loading.

METHODS

Suture anchors were tested in fresh porcine cortical and cancellous bone by cyclic loading (10 to 100 N for 200 cycles) followed by destructive testing parallel to the insertion axis at 12.5 mm per second. End points included ultimate failure load, displacement at 100 and 200 cycles, failure mode, and stiffness. Anchors tested included ReelX (Stryker Endoscopy, San Jose, CA); Footprint Ultra PK (4.5 and 5.5 mm) (Smith & Nephew, Andover, MA); TwinFix (4.5, 5.5, and 6.5 mm made from polyether ether ketone [PEEK], hydroxyapatite [HA], and titanium [Ti]) (Smith & Nephew Endoscopy, Andover, MA); Morphix (2.5 and 5.5 mm) (MedShape Solutions, Atlanta, GA); CrossFT BC (ConMed-Linvatec, Largo, FL); JuggerKnot (1.5 and 2.8 mm) (Biomet Sports Medicine, Warsaw, IN); Healicoil (Smith & Nephew Endoscopy, Andover, MA); Quattro (X, Link, and GL) (Cayenne Medical, Scottsdale, AZ); Healix (Biocryl Rapide [BR], PEEK, and Ti) (DePuy Mitek, Raynham, MA); Twin Loop (3.5 mm, PEEK) (Stryker Endoscopy, San Jose, CA); PressFT (2.1 and 2.6 mm) (ConMed Linvatec, Largo FL); Y-Knot (ConMed Linvatec, Largo FL); Gryphon (BR and PEEK) (DePuy Mitek, Raynham, MA); and Iconix (1, 2, and 3) (Stryker Endoscopy, San Jose, CA).

RESULTS

Rotator cuff anchors showed greater failure loads than did glenoid anchors in metaphyseal bone (rotator cuff anchors 448 N v glenoid anchors 296 N) (P = .001) and cancellous bone (rotator cuff anchors 435 N v glenoid anchors 225 N) (P < .001). No anchors reached 5 mm of displacement during cyclic loading. TwinFix anchors showed greater displacement at 100 (P = .014) and 200 cycles (P = .036) than did other rotator cuff anchors, although the ReelX and Morphix showed the greatest displacements. Rotator cuff anchors failed principally by eyelet breaking, whereas glenoid anchors failed more often by anchor pullout than by any other mode. No differences in stiffness were observed across the different rotator cuff and glenoid anchors tested.

CONCLUSIONS

Rotator cuff anchors showed higher failure strengths than did glenoid anchors, regardless of bone type. TwinFix anchors showed more cyclic displacement than did other rotator cuff anchors (except the ReelX and Morphix anchors) and the glenoid anchors tested. The failure mode was dependent on the specific anchor.

CLINICAL RELEVANCE

Suture anchor constructs tested showed that failure load is dependent on anchor type (rotator cuff anchor or glenoid anchor) but not on anchor location (cancellous or cortical bone).

Primary achilles tendon repair with mini-dorsolateral incision technique and accelerated rehabilitation

BACKGROUND

No consensus exists for the best primary repair of acute Achilles tendon ruptures. Problems with wound healing and nerve damage can occur. Prolonged immobilization leads to stiffness and calf atrophy. This study assesses the clinical outcome of acute Achilles tendon repairs using a mini-dorsolateral incision followed by a rapid rehabilitation program.

MATERIALS

A consecutive series of acute Achilles tendon ruptures repaired using a mini-dorsolateral incision were reviewed with a minimum 12 months follow up. Fifteen patients with an average age of 44 (range, 32 to 60) years were followed an average of 45 (range, 14 to 72) months. Two modified, buried core high strength sutures were placed in each torn end of the Achilles tendon reinforced with a running circumferential whip-stitch. Ankle Hindfoot scores, single toe raises, calf circumference, and adverse events were recorded. An accelerated postoperative rehabilitation protocol was followed.

RESULTS

Postoperative AOFAS Ankle Hindfoot scores averaged 98.3 [39 pain; 49.6 function; 9.3 alignment]. All patients could single heel raise. Eight of 15 demonstrated atrophy with an average calf circumference loss of 1.0 cm. The only postoperative complication was one case of superficial cellulitis successfully treated with oral antibiotics. There were no sural nerve injuries, wound break down, or re-ruptures at final followup.

CONCLUSION

The repair of acute Achilles tendon ruptures through a minimal lateral incision provided excellent functional outcomes, avoided complications including sural nerve injury, and allowed a return to sports between 4 to 6 months.

A biomechanical comparison of tendon-bone interface motion and cyclic loading between single-row, triple-loaded cuff repairs and double-row, suture-tape cuff repairs using biocomposite anchors

PURPOSE

To compare tendon-bone interface motion and cyclic loading in a single-row, triple-loaded anchor repair with a suture-tape, rip-stop, double-row rotator cuff repair.

METHODS

Using 18 human shoulders from 9 matched cadaveric pairs, we created 2 groups of rotator cuff repairs. Group 1 was a double-row, rip-stop, suture-tape construct. Group 2 was a single-row, triple-loaded construct. Before mechanical testing, the supraspinatus footprint was measured with calipers. A superiorly positioned digital camera optically measured the tendon footprint motion during 60° of humeral internal and external rotation. Specimens were secured at a fixed angle not exceeding 45° in reference to the load. After preloading, each sample was cycled between 10 N and 100 N for 200 cycles at 1 Hz, followed by destructive testing at 33 mm/s. A digital camera with tracking software measured the repair displacement at 100 and 200 cycles. Ultimate load and failure mode for each sample were recorded.

RESULTS

The exposed anterior footprint border (6.5% ± 6%) and posterior footprint border (0.9% ± 1.7%) in group 1 were statistically less than the exposed anterior footprint border (30.3% ± 17%) and posterior footprint border (29.8% ± 14%) in group 2 (P = .003 and P < .001, respectively). The maximal internal rotation and external rotation tendon footprint displacements in group 1 (1.6 mm and 1.4 mm, respectively) were less than those in group 2 (both 3.6 mm) (P = .007 and P = .004, respectively). Mean displacement after 100 cycles for group 1 and group 2 was 2.0 mm and 3.2 mm, respectively, and at 200 cycles, mean displacement was 2.5 mm and 4.2 mm, respectively (P = .02). The mean ultimate failure load in group 1 (586 N) was greater than that in group 2 (393 N) (P = .02). The suture-tendon interface was the site of most construct failures.

CONCLUSIONS

The suture-tape, rip-stop, double-row rotator cuff repair had greater footprint coverage, less rotational footprint displacement, and a greater mean ultimate failure load than the triple-loaded, single-row repair on mechanical testing. No double-row or single-row constructs showed 5 mm of displacement after the first 100 cycles. The most common failure mode for both constructs was suture tearing through the tendon.

CLINICAL RELEVANCE

Differences in cuff fixation influence rotational tendon movement and may influence postoperative healing. Stronger repair constructs still fail at the suture-tendon interface.

Biomechanical testing of suture-based meniscal repair devices containing ultrahigh-molecular-weight polyethylene suture: update 2011

PURPOSE

To evaluate the biomechanical characteristics of recently introduced ultrahigh-molecular-weight polyethylene suture-based, self-adjusting meniscal repair devices.

METHODS

Updating a prior study published in 2009, we made vertical longitudinal cuts 3 mm from the periphery in fresh-frozen adult human menisci to simulate a bucket-handle meniscus tear. Each tear was then repaired by a single repair technique in 10 meniscus specimens. Group 1 menisci were repaired with a vertical mattress suture of No. 2-0 Ethibond (Ethicon, Somerville, NJ). Group 2 menisci were repaired with a vertical mattress suture of No. 2-0 OrthoCord (DePuy Mitek, Raynham, MA). Group 3 menisci were repaired with a single OmniSpan device with No. 2-0 OrthoCord suture (DePuy Mitek). Group 4 menisci were repaired with a single Meniscal Cinch device with No. 2-0 FiberWire suture (Arthrex, Naples, FL). Group 5 menisci were repaired with a single MaxFire device inserted with the MarXmen gun (Biomet Sports Medicine, Warsaw, IN). Group 6 menisci were repaired with a Sequent device with No. 0 Hi-Fi suture (ConMed Linvatec, Largo, FL) in a "V" suture configuration. Group 7 menisci were repaired with a single FasT-Fix 360 device (Smith & Nephew Endoscopy, Andover, MA). By use of a mechanical testing machine, all samples were preloaded at 5 N and cycled 200 times between 5 and 50 N. Those specimens that survived were destructively tested at 5 mm/min. Endpoints included maximum load, displacement, stiffness, and failure mode.

RESULTS

Mean failure loads were as follows: Ethibond suture, 73 N; OrthoCord suture, 88 N; OmniSpan, 88 N; Cinch, 71 N; MarXmen/MaxFire, 54 N; Sequent, 66 N; and FasT-Fix 360, 60 N. Ethibond was stronger than MarXmen/MaxFire. The mean displacement after 100 cycles was as follows: Ethibond, 2.58 mm; OrthoCord, 2.75 mm; OmniSpan, 2.51 mm; Cinch, 2.65 mm; MarXmen/MaxFire, 3.67 mm; Sequent, 3.35 mm; and FasT-Fix 360, 1.13 mm. The MarXmen/MaxFire showed greater 100-cycle displacement than Ethibond and FasT-Fix 360. No difference in stiffness existed for these devices, and failure mode varied without specific trends.

CONCLUSIONS

The biomechanical properties of meniscal repairs using the OmniSpan, Cinch, Sequent, and FasT-Fix 360 devices are equivalent to suture repair techniques. However, the MarXmen/MaxFire meniscal repair device showed significantly lower failure loads and survived less cyclic loading in the human cadaveric meniscus than other tested repairs.

CLINICAL RELEVANCE

Most commercially available devices for all-inside meniscal repair using ultrahigh-molecular-weight polyethylene suture provide fixation comparable to the classic vertical mattress suture repair technique in human cadaveric meniscus.