Biomechanical Comparison of Modified Suture Bridge Using Rip-Stop versus Traditional Suture Bridge for Rotator Cuff Repair

A Combined Rip-Stop and Double-Pulley Technique in Arthroscopic Suture-Bridge Repair

Rotator cuff tear is one of the most common upper-extremity pathologies and often requires repair. The pursuit of optimal arthroscopic rotator cuff repair has spurred numerous technical innovations and stitch-pattern refinements. First, the double-pulley construct can increase tendon-bone compression and provide a joint seal. Second, the rip-stop configuration can reduce the possibility of tendon cut-through and improve the biomechanical properties of the fixation. Thus, an alternative method is introduced by incorporating both techniques simultaneously into arthroscopic suture-bridge repair, in which the medial double-pulley construct assumes the function of a rip-stop. This method may improve the biology of tendon healing and reduce the retear rate after rotator cuff repair.

Arthroscopic Suture Bridge Combined All-Inside Fixation for Delaminated Rotator Cuff Tears

The anatomic repair of delaminated rotator cuff tears presents a surgical challenge, necessitating innovative solutions for optimal outcomes. This Technical Note describes the arthroscopic suture bridge combined with all-inside fixation, a novel approach tailored for small yet deep-layer dominant delaminated tears. The method involves addressing the upper-layer tear beneath the acromion and employing all-inside suturing in the glenohumeral joint for the lower-layer tear, decoupling the outer tear size from limiting the treatment of the deeper tear. Accurate tear identification and preoperative planning are critical for success. This technique offers advantages in overcoming the outer tear's impact on lower tear repair, potentially reducing patient costs. Proficiency in tear identification and surgical planning is essential for successful execution. Considerations include reserving sutures as a precaution and inapplicability to posteriorly located delaminated tears. This approach provides a valuable contribution to arthroscopic techniques, especially for smaller delaminated tears.

Double-Row Achilles Insertional Repair With Rip-Stop Increases Construct Strength Compared to Traditional Techniques: A Biomechanical Study

BACKGROUND

Although double-row suture-anchored (DRSA) techniques for Achilles insertional tendinosis has proven successful, a reoccurring failure mode not yet addressed is suture tearing through the tendon. This study aims to address suture tearing by incorporating a rip-stop element. Authors hypothesized that the Rip-Stop group would demonstrate increased strength compared with more traditional techniques.

METHODS

12 paired cadaveric feet were used in this study (n = 24). One sample from each pair was assigned to receive the standard double-row (SDR) Achilles repair with 4.75-mm knotless anchors (n = 12). The control's matched sides were divided between 2 DRSA bridge groups: modified double-row (MDR) bridge with 3.9-mm anchors or rip-stop double-row (RS-DR) bridge repair with soft proximal anchors and 3.9-mm anchored distal row. In neutral position, specimens underwent 1000 cycles (20-100 N) followed by load to failure. Displacements, stiffness, ultimate load, and failure mode were recorded.

RESULTS

RS-DR had the lowest initial displacement values followed by SDR and MDR (1.3 ± 0.4, 2.7 ± 1.4, and 3.2 ± 1.3 mm, respectively). Significance was detected when comparing initial displacement of RS-DR to MDR (P = .038). Cyclic displacement was lowest for RS-DR, followed by MDR and SDR (1.6 ± 0.9, 2.2 ± 1.1, and 4.5 ± 3.2 mm, respectively). Cyclic stiffness was similar for RS-DR and MDR (89.1 ± 24.6 and 81.9 ± 5.6 N/mm, respectively). RS-DR ultimate load (1116.8 ± 405.7 N) was statistically greater than SDR (465.6 ± 352.7, P = .003).

CONCLUSION

RS-DR-repaired specimens demonstrated a decrease in displacement values and increased ultimate load and stiffness when compared to other groups. Results of this cadaveric model suggest that the addition of a rip-stop to DRSA Achilles repair is more impactful than anchor size. Limitations include that this was a time-zero biomechanical study, which cannot simulate the performance of the repairs during postoperative healing and recovery.

CLINICAL RELEVANCE

A rip-stop technique for Achilles repair effectively improves dynamic mechanical characteristics and may mitigate suture tearing through tendon in a patient cohort.

H-loop Knotless Double-Row Repair Versus Knotted Suture Bridge for Rotator Cuff Tears: A Biomechanical and Histological Study in an Animal Model

BACKGROUND

Knotted suture bridge repair (KSBR) has been widely proven to be an effective method for rotator cuff repairs. However, the occurrence of type 2 failure after suture bridge repair remains a frequent problem because of the stress concentration and disturbance of tendon perfusion in the medial row. The authors have developed the H-loop knotless double-row repair (HLDR) to counteract these problems.

PURPOSE

To compare the biomechanical and histological outcomes of HLDR and KSBR for rotator cuff tear in the rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Acute bilateral supraspinatus tears were created on the shoulders of 46 New Zealand White rabbits. HLDR and KSBR were randomly performed on the left side or right side. Thirteen animals each were sacrificed at 2, 4, and 8 weeks after surgery (n = 39), with 6 rabbits used for histological evaluation and the other 7 rabbits for biomechanical testing. The remaining 7 animals from the original 46 were only used for initial biomechanical evaluation at week 0.

RESULTS

Macroscopically, all repaired tendons were connected to their footprint on the greater tuberosity without postoperative complications at 8 weeks after surgery. The HLDR group had significantly better histological bone-to-tendon integration compared with the KSBR group in terms of fibrocartilage regeneration, collagen composition, and fiber organization. The biomechanical outcomes in the HLDR group were demonstrated to be better than those of the KSBR group at time 0 and 8 weeks after surgery.

CONCLUSION

Both repair techniques were effective for rotator cuff tears in a rabbit rotator cuff tear model; however, HLDR demonstrated more advantages in improving biomechanical properties and histological tendon-to-bone healing compared with KSBR.

CLINICAL RELEVANCE

This animal study suggested that HLDR might be an alternative choice for rotator cuff tears in humans to increase tendon-to-bone healing and reduce the rate of failure to heal.

Knotted Versus Knotless Medial-Row Transosseous-Equivalent Double-Row Rotator Cuff Repairs Have Similar Clinical and Functional Outcomes

Purpose

To retrospectively investigate the clinical and functional outcomes of patients who underwent knotted medial-row rotator cuff repair (KT-RCR) compared with patients who underwent knotless medial-row rotator cuff repair (KL-RCR).

Methods

A retrospective chart review of patients who underwent double-row transosseous-equivalent rotator cuff repair in 2016 was performed at a single institution with 2-year follow-up. Information regarding demographic characteristics, preoperative tear size (magnetic resonance imaging), surgical variables (including method of suture stabilization), preoperative and postoperative American Shoulder and Elbow Surgeons (ASES) scores, and all complications (e.g., cuff failure, adhesive capsulitis, and persistent pain) was compiled.

Results

A total of 189 patients met the inclusion criteria: 72 in the KL-RCR group and 117 in the KT-RCR group. No significant difference in preoperative ASES scores was found between the KL-RCR and KT-RCR groups (48.3 vs 45.4, P = .327). Postoperative ASES scores did not differ between the groups (82.4 for KL-RCR vs 78.8 for KT-RCR, P = .579). We found no significant difference in cuff failure rates after 2 years, determined by magnetic resonance imaging (5.6% for KL-RCR vs 6.1% for KT-RCR, P > .999), or complication rates (11.1% for KL-RCR vs 8.6% for KT-RCR, P = .743).

Conclusions

The knotted approach and knotless approach to double-row rotator cuff repair showed similar outcome scores, cuff failure rates, and complication rates at minimum 2-year follow-up.

Level of Evidence

Level III, retrospective therapeutic comparative trial.

Knotted Transosseous-Equivalent Technique for Rotator Cuff Repair Shows Superior Biomechanical Properties Compared With a Knotless Technique: A Systematic Review and Meta-analysis

PURPOSE

To compare the biomechanical properties of the knotted versus knotless transosseous-equivalent (TOE) techniques for rotator cuff repair (RCR).

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using PubMed, Embase, and the Cochrane Library to identify studies that compared the biomechanical properties of knotted and knotless TOE RCR techniques. The search phrase used was as follows: (Double Row) AND (rotator cuff) AND (repair) AND (biomechanical). Evaluated properties included ultimate load to failure, cyclic displacement, stiffness, footprint characteristics, and failure mode.

RESULTS

Eight studies met the inclusion criteria, including a total of 67 specimens in each group. Of 6 studies reporting on ultimate load to failure, 4 found tendons repaired with the knotted TOE technique to experience significantly higher ultimate load to failure compared with knotless TOE repairs (knotted range, 323.5-549.0 N; knotless range, 166.0-416.8 N; P < .05). Of 6 studies reporting on failure stiffness, 2 found knotted TOE repairs to have significantly higher failure stiffness compared with knotless TOE repairs (knotted range, 30.0-241.8 N/mm; knotless range, 28.0-182.5 N/mm; P < .05), whereas 1 study found significantly higher failure stiffness in knotless TOE repairs compared with knotted TOE repairs (P = .039). Cyclic gap formation favored the knotted TOE group in 2 of 3 studies (knotted range, 0.6-5.2 mm; knotless range, 0.4-9.1 mm; P < .05). The most common mode of failure in both groups was suture tendon tear.

CONCLUSIONS

On the basis of the included cadaveric studies, rotator cuff tendons repaired via the knotted TOE technique display superior time-zero biomechanical properties, including greater ultimate load to failure, compared with rotator cuffs repaired via the knotless TOE technique. Suture tearing through the tendon remains a common failure method for both techniques.

CLINICAL RELEVANCE

The results of this systematic review provide helpful insight into the biomechanical differences between 2 popular techniques for RCR. Although these results should be carefully considered by surgeons who are using either of these techniques in the operating room, they should not be mistaken for direct clinical applicability because cadaveric studies may not directly correlate to clinical outcomes.

The "Greenhouse" Technique Using Knotless Single-Row Suture Bridge Combined With Bone Marrow Stimulation for the Arthroscopic Treatment of Rotator Cuff Tears

To simplify the arthroscopic rotator cuff repair technique and improve tendon healing, we have developed a method named the "Greenhouse" technique to repair rotator cuff. With bone marrow stimulation combined with knotless single-row suture bridge fixation, we provide a technique for reliable cuff fixation with enhanced biological features.

A biomechanical comparison of a mesh suture to a polyblend suture in a porcine tendon model

Background

The suture-tendon interface turned out to be the weak point of a repaired rotator cuff. A double rip-stop (DRS) technique was developed to enhance the strength of the suture-tendon interface. The first aim of this study was to compare the suture-tendon interface strength between mesh suture and the No. 2 FiberWire (FW), which is commonly used in the clinic. The second aim was to compare the biomechanical properties of rotator cuff repair between mesh suture and No. 2 FiberWire using a typical suture-bridge (SB) and DRS techniques.

Methods

Eighteen porcine subscapularis tendon (SST) was randomly assigned to the Mesh-tendon group and FiberWire-tendon group. A single suture loop was passed through the SST with a Mesh suture or FiberWire. Thirty-two infraspinatus tendons (ISTs) were randomly assigned to four groups: SB-Mesh group: SB technique with Mesh suture, SB-FW group: SB technique with FiberWire, DRS-Mesh group: DRS technique with Mesh suture, and DRS-FW group: DRS technique with FiberWire. All repaired specimens were underwent failure testing. Failure modes, load to create a 3-mm gap, failure load, and stiffness were compared.

Results

There were no significant differences between the Mesh-tendon group and FiberWire-tendon group regarding the failure load, stiffness, and ultimate stress. When the same technique was used, the rotator cuff repaired with a mesh suture had the similar load to create a 3-mm gap, failure load, and stiffness compared with FiberWire. When the same suture was used, the DRS technique had a significantly higher load to create a 3-mm gap formation and failure load compared with the SB technique.

Conclusions

The repair failure strength and stiffness using the mesh suture were similar to the FiberWire suture regardless of the repair techniques. However, the repair strength in the DRS technique was significantly stronger than the SB technique when the same suture material was used.

Biomechanical evaluation of a novel double rip-stop technique with medial row knots for rotator cuff repair: an in vitro study

Aims

Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots.

Methods

A total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded.

Results

The mean load to create a 3 mm gap formation in the DRSK and DRS groups was significantly higher than in the SB group. The DRSK group had the highest load to failure with a mean ultimate failure load of 395.0 N (SD 56.8) compared to the SB and DRS groups, which recorded 147.1 N (SD 34.3) and 285.9 N (SD 89.8), respectively (p < 0.001 for both). The DRS group showed a significantly higher mean failure load than the SB group (p = 0.006). Both the DRS and DRSK groups showed significantly higher mean stiffness than the SB group.

Conclusion

The biomechanical properties of the DRS technique were significantly improved compared to the SB technique. The DRS technique with medial row knots showed superior biomechanical performance than the DRS technique alone.

Modified Double-Row Suture Bridge Technique With Double-Row Biceps Tenodesis for Massive Rotator Cuff Tear

This article aims to describe a modification of the arthroscopic suture bridge technique for repair of a massive (>3 cm) rotator cuff tear. The method uses 2 medial anchors and 2 lateral anchors for rotator cuff repair, as well as double-row biceps tenodesis. This operative modification may impart better tendon healing and fewer rupture complications than the traditional double-row repair techniques.

A Modified SpeedBridge Technique for Retracted or Delaminated Rotator Cuff Repairs

Treatment of full-thickness rotator cuff tears vary in surgical technique dependent on the amount of retraction of the rotator cuff and/or delamination of the soft tissue. The described technique addresses both of those concerns. We present a modification of the SpeedBridge technique used to address retracted or delaminated repairs and effectively expand the indications for use of the double-row knotless technique. In this modification, the reduction is performed by an initial anchor with several stay sutures providing provisional reduction of the tissue in a controlled fashion. This is followed by compression through a standard double-row technique.

Biomechanical analysis of four different medial row configurations of suture bridge rotator cuff repair

BACKGROUND

Rotator cuff tendon rupture after suture bridge repair occasionally occurs at the medial row, with remnant tendon tissue remaining at the footprint. While concentrated medial row stress is suspected to be involved in such tears, the optimal suture bridge technique remains controversial.

METHODS

This study aimed to investigate the construct strength provided by suture bridge techniques having four different medial row configurations using artificial materials (n = 10 per group): Group 1, four-hole (two stitches per hole) knotless suture bridge; Group 2, eight-hole (one stitch per hole) parallel knotless suture bridge; Group 3, eight-hole non-parallel knotless suture bridge; and Group 4, eight-hole knot-tying suture bridge. Each construct underwent cyclic loading from 5 to 30 N for 20 cycles, followed by tensile testing to failure. The ultimate failure load and linear stiffness were measured.

FINDINGS

Group 2 had the highest ultimate failure load (mean 160.54 N, SD 6.40) [Group 4 (mean 150.21 N, SD 9.76, p = 0.0138), Group 3 (mean 138.80 N, SD 7.18, p < 0.0001), and Group 1 (mean 129.35 N, SD 4.25, p < 0.0001)]. The linear stiffness of Group 2 (mean 9.32 N/mm, SD 0.25) and Group 4 (mean 9.72 N/mm, SD 0.40) was significantly higher (p = 0.0032) than that of Group 1 (mean 8.44 N/mm, SD 0.29) and Group 3 (mean 8.61 N/mm, SD 0.31).

INTERPRETATION

In conclusion, increasing the number of suture-passed holes, arranging the holes in parallel, and a knotless technique improved the failure load following suture bridge repair.

Biomechanical Strength of Rotator Cuff Repairs: A Systematic Review and Meta-regression Analysis of Cadaveric Studies

BACKGROUND

Biomechanical cadaveric studies of rotator cuff repair (RCR) have shown that transosseous equivalent and double-row anchored repairs are stronger than other repair constructs.

PURPOSE

To identify technical and procedural parameters that most reliably predict biomechanical performance of RCR constructs.

STUDY DESIGN

Systematic review.

METHODS

The authors systematically searched the EMBASE and PubMed databases for biomechanical studies that measured RCR performance in cadaveric specimens. The authors performed a meta-regression on the pooled data set with study outcomes (gap formation, failure mode, and ultimate failure load) as dependent variables and procedural parameters (eg, construct type, number of suture limbs) as covariates. Stratification by covariates was performed. An alpha level of .05 was used.

RESULTS

Data from 40 eligible studies were included. Higher number of suture limbs correlated with higher ultimate failure load (β = 38 N per limb; 95% CI, 28 to 49 N) and less gap formation (β = -0.6 mm per limb; 95% CI, -1 to -0.2 mm). Other positive predictors of ultimate failure load were number of sutures, number of mattress stitches, and use of wide suture versus standard suture. When controlling for number of suture limbs, we found no significant differences among single-row anchored, double-row anchored, transosseous equivalent, and transosseous repairs. Higher number of suture limbs and transosseous equivalent repair both increased the probability of catastrophic construct failure.

CONCLUSION

This study suggests that the number of sutures, suture limbs, and mattress stitches in a RCR construct are stronger predictors of overall strength than is construct type. There is a need to balance increased construct strength with higher risk of type 2 failure.