Rotator Cuff Delamination Is Associated With Increased Tendon Retraction and Higher Fatty Muscle Infiltration: A Comparative Study on Arthroscopy and Magnetic Resonance Imaging

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.

Mechanical strength of the rotator cuff and cable interface: a complete histological and biomechanical study

PURPOSE

This study sought to evaluate the biomechanical properties of the interface between the rotator cuff and the semicircular humeral ligament or rotator cable (RCa) using histological and biomechanical techniques.

METHODS

Out of 13 eligible cadaver specimens, 5 cadaver shoulders with an intact rotator cuff were included, 8 were excluded due to an injured rotator cuff. The histological study enables us to describe the capsule-tendon interface between the infraspinatus tendon (IST) or supraspinatus tendon (SST) and RCa, and to detect loose connective tissue layers to determine their precise location and measure their length along the interface. The biomechanical study sought to characterize and compare the mechanical strength of the IST-RCa versus SST-RCa interfaces.

RESULTS

The average thickness of the RCa was 1.44 ± 0.20 mm. The histological study revealed a loose connective tissue layer at the IST-RCa interface, a finding not observed at the SST-RCa interface. The biomechanical study showed that the rigidity of the SST-RCa interface (72.10-2 N/mm) was 4.5 times higher than for the IST-RCa interface (16.10-2 N/mm) and the average maximum forces reached were 19.0 N and 10.6 N for the SST-RCa and IST- RCa interfaces, respectively.

CONCLUSION

The IST-RCa interface consists of a loose connective tissue layer contrary to the SST-RCa interface. In parallel, two different groups in terms of the mechanical response were identified: the IST-RCa interface group had less rigidity and ruptured more quickly than the SST-RCa interface, therefore emerging as the most vulnerable interface and explaining a potential extension of rotator cuff tears.

The Zipknot Technique: A Modified Tension Band Repair Technique for Isolated Supraspinatus Tears

Tension band repair frequently is used for small rotator cuff tears. This Technical Note describes a variation using a single knotless suture anchor but with a specific lark's head knot technique to pass the sutures through the tendon that improves bone-tendon contact and tendon healing while preventing a dog-ear deformity.

Delamination of rotator cuff tears impairs healing after repair: a systematic review and meta-analysis

PURPOSE

To compare the clinical outcomes and retear rates after rotator cuff repair (RCR) between delaminated and non-delaminated tears.

METHODS

This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines using the PubMed, Cochrane Library, the Web of Science and Embase databases. Only articles on arthroscopic RCR with clinical outcome scores and data on the number of rotator cuff retears and complete healing were included. This study's relevant data were extracted and statistically analyzed. The methodological index for nonrandomized studies was used to assess the risk of bias in the included studies. After conducting a heterogeneity test and sensitivity analysis to determine whether the samples were heterogeneous, the study also detected publication bias. A sub-group test was used to evaluate the influences of the imaging follow-up period on retear rates.

RESULTS

Ten eligible articles were identified with 2,061 patients (925 in the delaminated group and 1,136 in the non-delaminated group). The meta-analysis demonstrated that delamination was significantly associated with higher retear rates (P = 0.026; odds ratio = 1.873, 95% confidence interval 1.079-3.252; I2 = 51.6%) with an imaging follow-up period of > 1 year and lower rates of complete healing (P = 0.036; odds ratio = 0.659, 95% confidence interval 0.446-0.973; I2 = 9.0%) in patients after rotator cuff repair. However, no significant differences were observed between the two groups based on American Shoulder and Elbow Surgeons score, Constant score, visual analog scale score, external rotation, internal rotation, or forward elevation.

CONCLUSIONS

This meta-analysis found that delamination was significantly associated with higher retear rates with imaging follow-up period of > 1 year, and lower rates of complete healing. In addition, the preoperative and postoperative clinical scores and shoulder joint range of motion were similar between patients with delaminated and non-delaminated tears.

LEVEL OF EVIDENCE

Level IV.

Comparison of Outcomes After Arthroscopic Superior Capsule Reconstruction Versus Arthroscopic Partial Repair or Arthroscopic Debridement for Irreparable Rotator Cuff Tears

Background

Arthroscopic superior capsule reconstruction (SCR), arthroscopic partial repair (PR), and arthroscopic debridement (DB) are valid treatment options for irreparable rotator cuff (RC) tears.

Purpose/Hypothesis

The purpose of this study was to compare clinical, functional, and radiological outcomes of arthroscopic SCR with arthroscopic PR and arthroscopic DB in patients with irreparable posterosuperior RC tears. It was hypothesized that SCR would lead to superior clinical and functional outcomes compared with PR or DB.

Study Design

Cohort study; Level of evidence, 3.

Methods

Clinical and functional outcomes of this single-center retrospective study included range of motion, strength, and the age- and sex-adjusted Constant-Murley score. Patient-reported outcome measures (PROMs) involved the quick Disabilities of the Arm, Shoulder and Hand score, the Subjective Shoulder Value, and the visual analog scale for pain. Graft and repaired tendon integrity was evaluated by magnetic resonance imaging (MRI) at 12 months of follow-up.

Results

In total, 57 patients treated with SCR (n = 20), PR (n = 17), and DB (n = 20) were included. The mean clinical follow-up was 33.8 ± 17.9 months. Preoperative clinical and functional characteristics were comparable among the 3 groups. The range of motion and clinical and functional scores of all 3 groups significantly improved from pre- to postoperatively. Postoperative PROMs showed no differences among all 3 study groups. SCR revealed significantly higher postoperative strength compared with PR (P = .001) and DB (P = .004). Postoperative MRI revealed a rerupture in 4 patients with SCR (20%). Postoperative MRI showed a rerupture in 9 patients with PR ( 53%). Fatty muscle infiltration of the supraspinatus and infraspinatus significantly progressed within all 3 study groups in postoperative MRI scans. No clinical and functional differences were observed between intact and reruptured PR.

Conclusion

Patients who underwent SCR had better postoperative strength recovery than patients who underwent PR or DB.

Interpositional scaffold anchor rotator cuff footprint tear repair: excellent survival, healing, and early outcomes

PURPOSE

Shoulder function limitation duration after a full-thickness rotator cuff tendon (RCT) tear may influence post-repair healing and outcomes. A suture anchor was developed to improve footprint repair fixation and healing through biological fluid delivery and scaffold augmentation. The primary multicenter study objective was to evaluate RCT repair failure rate based on 6-month MRI examination, and device survival at 1-year follow-up. The secondary objective was to compare the clinical outcomes of subjects with shorter- and longer-term shoulder function limitation duration.

METHODS

Seventy-one subjects (46 men) with moderate-to-large RCT tears (1.5-4 cm), at a median 61 years of age (range = 40-76), participated in this study. Pre-repair RCT tear location/size and 6-month healing status were confirmed by an independent radiologist. Subjects with shorter- (Group 1: 17.8 ± 21 days, n = 37) and longer-term (Group 2: 185.4 ± 89 days, n = 34) shoulder function limitation durations were also compared over 1 year for active mobility, strength, American Shoulder and Elbow Surgeon's Shoulder Score (ASES score), Veterans RAND 12 Item Health Survey (VR-12), and visual analog scale (VAS) pain and instability scores.

RESULTS

Three of the 52 subjects [5.8%] who underwent 6-month MRI experienced a re-tear at the original RCT footprint repair site. By the 1-year follow-up, overall anchor survival was 97%. Although Group 2 displayed lower ASES and VR-12 scores pre-repair (ASES = 40.1 ± 17 vs. 47.9 ± 17; VR-12 physical health (PH) = 37.2 ± 9 vs. 41.4 ± 8) (p ≤ 0.048), at 3-month post-RCT repair (ASES = 61.3 ± 19 vs. 71.3 ± 20; VR-12 PH = 40.8 ± 8 vs. 46.8 ± 9) (p ≤ 0.038), and at 6-month post-RCT repair (ASES = 77.4 ± 18 vs. 87.8 ± 13; VR-12 PH = 48.9 ± 11 vs. 54.0 ± 9) (p ≤ 0.045), by 1-year post-RCT repair, groups did not differ (n.s.). Between-groups VR-12 mental health score differences were not evident at any time period (n.s.). Shoulder pain and instability VAS scores also did not differ (n.s.), displaying comparable improvement between groups from pre-RCT repair to 1-year post-RCT repair. Groups had comparable active shoulder mobility and strength recovery at each follow-up (n.s.).

CONCLUSION

At 6-month post-RCT repair, only 3/52 of patients [5.8%] had a footprint re-tear, and at 1-year follow-up, overall anchor survival was 97%. Use of this scaffold anchor was associated with excellent early clinical outcomes regardless of shoulder function impairment duration.

LEVEL OF EVIDENCE

II.

Delaminated Tears of the Rotator Cuff: MRI Interpretation with Clinical Correlation

(1) Background: A delaminated tear is described as a horizontal split in the tendon substance. This review summarizes the clinical and radiologic characteristics of delaminated tears of the rotator cuff. (2) Methods: Initial radiological characteristics of a delaminated tear include the horizontal component of a partial-thickness tear determined using magnetic resonance (MR) arthrography. As demonstrated using indirect MR arthrography, the tear gradually progresses to be defined as either horizontal intrasubstantial splitting of the bursal and articular layers or differential retraction of the bursal and articular layers. (3) Results: The existence of delaminated tears is a poor prognostic factor in functional and morphologic outcomes after the repair of rotator cuff tendons and many surgical techniques have been introduced to solve this problem. Although the presence of a delaminated tear does not affect the arthroscopic repair outcome, the presence of medium-to-large, retracted delaminated tears may be an adverse negative prognostic factor after single-row repair. (4) Conclusion: Advances in imaging and surgical techniques have improved the detection of delaminated rotator cuff tears. Preoperative identification of delaminated tears on magnetic resonance imaging is clinically important because tailored surgical repair techniques must be chosen for successful outcomes.

A Step-by-Step Approach to Arthroscopic Repair of Massive Rotator Cuff Tears

Arthroscopic repair of massive rotator cuff tears can be technically challenging but is achievable in many cases. Performing adequate releases are important for successful tendon mobility and avoiding excessive tension in the final repair, thus restoring the native anatomy and biomechanics. This Technical Note provides a step-by-step approach to release and mobilize massive rotator cuff tears to or near anatomical tendon footprints.

Muscle-Specific Micro-Ribonucleic Acids miR-1-3p, miR-133a-3p, and miR-133b Reflect Muscle Regeneration After Single-Dose Zoledronic Acid Following Rotator Cuff Repair in a Rodent Chronic Defect Model

BACKGROUND

Zoledronic acid improves bone microarchitecture and biomechanical properties after chronic rotator cuff repair (RCR) in rats. Besides the positive effects of zoledronic acid on bone mineral density and bone microarchitecture, bisphosphonates have positive effects on skeletal muscle function.

PURPOSES/HYPOTHESIS

The purposes of this study were to (1) longitudinally evaluate circulating bone- and muscle-specific serum micro-ribonucleic acids (miRNAs) and (2) investigate supraspinatus muscle tissue after tenotomy and delayed RCR in a rat model. It was hypothesized that zoledronic acid would improve muscle regeneration after chronic RCR in rats.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 34 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy (time point 1) with delayed transosseous RCR after 3 weeks (time point 2). All rats were sacrificed 8 weeks after RCR (time point 3). Animals were randomly assigned to 2 groups. One day after RCR, the control group was given 1 mL of subcutaneous saline solution, and the intervention group was treated with a subcutaneous single-dose of 100 µg/kg body weight of zoledronic acid. All 34 study animals underwent miRNA analysis at all 3 time points. In 4 animals of each group, histological analyses as well as gene expression analyses were conducted.

RESULTS

Circulating miRNAs showed significantly different expressions between both study groups. In the control group, a significant downregulation was observed for muscle-specific miR-1-3p (P = .004), miR-133a-3p (P < .001), and miR-133b (P < .001). Histological analyses showed significantly higher rates of regenerating myofibers on the operated side (left) of both study groups compared with the nonoperated side (right; P = .002). On the nonoperated side, significantly higher rates of regenerating myofibers were observed in the intervention group compared with the control group (P = .031). The myofiber cross-sectional area revealed significantly smaller myofibers on both sides within the intervention group compared with both sides of the control group (P < .001). Within the intervention group, significantly higher expression levels of muscle development/regeneration marker genes embryonal Myosin heavy chain (P = .017) and neonatal Myosin heavy chain (P = .016) were observed on the nonoperated side compared with the operated side.

CONCLUSION

An adjuvant single-dose of zoledronic acid after RCR in a chronic defect model in rats led to significant differences in bone- and muscle-specific miRNA levels. Therefore, miR-1-3p, miR-133a-3p, and miR-133b might be used as biomarkers for muscle regeneration after RCR.

CLINICAL RELEVANCE

Adjuvant treatment with zoledronic acid may improve muscle regeneration after chronic RCR in humans, thus counteracting fatty muscle infiltration and atrophy.