No differences in histopathological degenerative changes found in acute, trauma-related rotator cuff tears compared with chronic, nontraumatic tears

Protective and Regenerative Effects of Reconstituted HDL on Human Rotator Cuff Fibroblasts under Hypoxia: An In Vitro Study

Hypoxia and hypo-high-density lipoproteinemia (hypo-HDLemia) are proposed risk factors for rotator cuff tear. HDL is recognized for its potential benefits in ischemia-driven angiogenesis and wound healing. Nevertheless, research on the potential benefits of reconstituted HDL (rHDL) on human rotator cuff fibroblasts (RCFs) under hypoxia is limited. This study investigates the cytoprotective and regenerative effects of rHDL, as well as N-acetylcysteine (NAC), vitamin C (Vit C), and HDL on human RCFs under hypoxic conditions. Sixth-passage human RCFs were divided into normoxia, hypoxia, and hypoxia groups pretreated with antioxidants (NAC, Vit C, rHDL, HDL). Hypoxia was induced by 1000 µM CoCl2. In the hypoxia group compared to the normoxia group, there were significant increases in hypoxia-inducible factor-1α (HIF-1α), heme oxygenase-1 (HO-1), and Bcl-2/E1B-19kDa interacting protein 3 (BNIP3) expressions, along with reduced cell viability, elevated reactive oxygen species (ROS) production, apoptosis rate, expressions of cleaved caspase-3, cleaved poly ADP-ribose polymerase-1 (PARP-1), vascular endothelial growth factors (VEGF), and matrix metalloproteinase-2 (MMP-2), as well as decreased collagen I and III production, and markedly lower cell proliferative activity (p ≤ 0.039). These responses were significantly mitigated by pretreatment with rHDL (p ≤ 0.046). This study suggests that rHDL can enhance cell proliferation and collagen I and III production while reducing apoptosis in human RCFs under hypoxic conditions.

Factors associated with healing failure after early repair of acute, trauma-related rotator cuff tears

BACKGROUND

Healing failure after rotator cuff repair is a challenging problem. Acute, trauma-related tears are considered a separate entity and are often treated surgically. The aim of this study was to identify factors associated with healing failure in previously asymptomatic patients with trauma-related rotator cuff tears treated with early arthroscopic repair.

METHODS

This study included 62 consecutively recruited patients (23% women; median age, 61 years; age range, 42-75 years) with acute symptoms in a previously asymptomatic shoulder and a magnetic resonance imaging-verified full-thickness rotator cuff tear after shoulder trauma. All patients were offered, and underwent, early arthroscopic repair, during which a biopsy specimen was harvested from the supraspinatus tendon and analyzed for signs of degeneration. Of the patients, 57 (92%) completed 1-year follow-up and underwent assessment of repair integrity on magnetic resonance images according to the Sugaya classification. Risk factors for healing failure were investigated using a causal-relation diagram where age, body mass index, tendon degeneration (Bonar score), diabetes mellitus, fatty infiltration (FI), sex, smoking, tear location regarding integrity of the rotator cable, and tear size (number of ruptured tendons and tendon retraction) were included and analyzed.

RESULTS

Healing failure at 1 year was identified in 37% of patients (n = 21). A high degree of FI of the supraspinatus muscle (P = .01), a tear location including disruption of rotator cable integrity (P = .01), and old age (P = .03) were associated with healing failure. Tendon degeneration as determined by histopathology was not associated with healing failure at 1-year follow-up (P = .63).

CONCLUSION

Older age, increased FI of the supraspinatus muscle, and a tear including disruption of the rotator cable increased the risk of healing failure after early arthroscopic repair in patients with trauma-related full-thickness rotator cuff tears.

Editorial Commentary: Repair Is Efficacious for Acute Rotator Cuff Tears in Patients Over 65 Despite Advanced Age, and Early Repair Is Better

Although indications for rotator cuff repair are still controversial, common practice is to be more aggressive with surgery as a first-line treatment in patients with acute rotator cuff tears. Both functional outcomes and healing are better with earlier repair, and a healed tendon limits the progression of permanent degenerative changes, including tear progression, fatty infiltration, and progression to cuff tear arthropathy. But what about elderly patients? For those that are physically and medically fit for surgery, there may still be benefit to earlier surgical repair. For those not physically or medically fit for surgery, or those who decline, a short trial of conservative care and repair for those who fail with conservative treatment is still efficacious.

Capsular remnant in the rotator cuff footprint is a novel arthroscopic finding may indicate the etiology of the tear

PURPOSE

The aim of the study was that the capsule remnant is a common indicator of sub-acromial impingement syndrome and bursal side onset rotator cuff tears.

METHODS

Sixty-three patients with capsule remnants in the rotator cuff footprint (Study group) were detected, while the 53 patients did not have any remnant on the tendon footprint (Control group) between 2015 and 2020 were included. Demographic data of patients, such as age, gender, and operated side information were obtained from the archive files. Acromion type, presence of osteophytes in the acromioclavicular joint, Acromiohumeral Distance (AHD), Acromial Index (AI), Critical Shoulder Angle (CSA), and Coracoacromial Ligament (CAL) degeneration values were evaluated from preoperative MRI, radiographic images, and arthroscopic video recordings.

RESULTS

Severe stages of CAL degeneration were observed in 82.5% of the patients who had capsule remnant (p: 0.001). While type 2 acromion was found in 61.9%, and also acromioclavicular joint osteophyte was found in 58.7% of the patients in the study group. The mean AHD was 8.22 ± 1.56 mm in the study group and 9.2 ± 1.3 mm in the control group. The mean CSA was 43.3 ± 4.9 in the study group and 40.8 ± 4.2 in the control group. The AI was measured as 0.8 ± 0.1 in the study group and 0.8 ± 0.01 in the control group. As a result of these measurements, a statistical difference was found between the two groups in terms of type 2 acromion ratio (p < 0.001), presence of osteophytes in the acromioclavicular joint (p < 0.001), mean acromio-humeral distance (p < 0.001), critical shoulder angle (p = 0.004), and acromial index values (p < 0.001).

CONCLUSION

The findings of sub-acromial impingement syndrome were found to be more prominent in patients with full-thickness degenerative tear and findings of capsular remnant in the footprint. If the presence of the current finding is detected during glenohumeral arthroscopy, sub-acromial impingement syndrome should be examined in more detail to reveal the underlying cause and prevent a recurrence.

Arthroscopic Repair Benefits Reparable Rotator Cuff Tear Patients Aged 65 Years or Older With a History of Traumatic Events

PURPOSE

To evaluate the clinical outcomes of arthroscopic rotator cuff repair at 2-year follow-up in patients aged 65 years or older with a history of traumatic events divided into groups based on symptom duration (<3 months, 3-6 months, and >6 months from injury to surgery) and to compared patient-reported outcomes among the 3 groups.

METHODS

Between 2015 and 2020, 110 patients who met the inclusion criteria were enrolled in this study; these patients were divided into 3 groups according to symptom duration: less than 3 months (group A), 3 to 6 months (group B) and more than 6 months (group C). Preoperative and 2-year postoperative clinical outcomes were compared, including American Shoulder and Elbow Surgeons, Constant-Murley, University of California, Los Angeles, Simple Shoulder Test, and visual analog scale scores; forward elevation; external rotation; and internal rotation. The minimal clinically important difference (MCID), patient acceptable symptom state, substantial clinical benefit, and maximum outcome improvement were also compared among the groups.

RESULTS

The American Shoulder and Elbow Surgeons score, as the primary outcome, improved significantly from 41.0 ± 18.5 to 85.4 ± 8.1 in group A, from 53.7 ± 14.3 to 86.3 ± 11.7 in group B, and from 49.7 ± 18.5 to 83.9 ± 11.9 in group C. All the other parameters showed statistically significant improvements at 2-year follow-up in each group (all P < .05). There was no significant difference in each parameter among the 3 groups except the visual analog scale score, which did not achieve the MCID. Overall, 86 patients (78.2%) exceeded the MCID, 87 patients (79.1%) achieved the patient acceptable symptom state, 77 patients (70.0%) achieved substantial clinical benefit, and 62 patients (56.4%) achieved maximum outcome improvement without significant differences among the 3 groups.

CONCLUSIONS

In rotator cuff tear patients aged 65 years or older with a history of traumatic events, arthroscopic rotator cuff repair significantly improves clinical outcomes at 2-year follow-up regardless of symptom duration if the tear is fully reparable.

LEVEL OF EVIDENCE

Level III, prognostic retrospective study.

Absorbable suture knots on the supraspinatus tendon prevent adverse effects of nonabsorbable suture knots in a rat model

PURPOSE

To compare the absorbable and nonabsorbable suture knots on the tendon on bone-to-tendon healing during the early phase in a rat rotator cuff tear (RCT) model.

METHODS

Fifty-two male Sprague-Dawley rats (10 weeks old; mean weight, 380 g) were used in this study, and 51 of them were randomly assigned into three groups: absorbable suture group (ASG, n = 22), nonabsorbable suture group (NSG, n = 22), and sham surgery group (SSG, n = 7), and the remaining rat was used to take surgical pictures. Bilateral supraspinatus tendon tears were created and repaired immediately in ASG and NSG. Three rats from ASG and NSG were killed for Western blot and histological evaluation at 3 days, 1 week, and 4 weeks after surgery. At 4 weeks, four rats from each group were killed for biomechanical test, and three rats from SSG were used for histological evaluation.

RESULTS

Absorbable suture knots on the tendon completely degraded at 4 weeks. However, nonabsorbable suture knots remained intact between the tendon and articular side. ASG showed a stronger inflammatory reaction at 3 days and 1 week, but a weaker reaction at 4 weeks as confirmed by gross observation and Western blot. Besides, ASG showed superior biomechanical properties in terms of maximum load to failure and stiffness at 4 weeks. Modified Bonar score revealed superior maturity for tissue healing in ASG to that in NSG at 4 weeks. Furthermore, inferior bone-to-tendon interface and weakest link formation were observed in NSG on histologic images.

CONCLUSION

Absorbable suture knots on the tendon contributed to better mechanical properties compared with the nonabsorbable one after rotator cuff repair.

Rotator Cuff Health, Pathology, and Repair in the Perspective of Hyperlipidemia

Rotator Cuff Injuries (RCI) are prevalent cause of shoulder pain affecting over 20% of the population in the USA. Surgical repair of the torn rotator cuff helps in relieving the pressure on the rotator cuff tendon and from symptoms, however tendon-to-bone healing after rotator cuff surgery still has a high failure rate. Hyperlipidemia has been strongly associated with RCI although the cellular and molecular mechanisms are largely unknown. The focus of this critical review is to further explore the role of hyperlipidemia in RCI and rotator cuff tissue repair to determine its implication as a risk factor for tears, repair, and retears. A literature review was conducted to elucidate the role of hyperlipidemia as an inflammatory mediator and catalyst for structural instability within the shoulder. The results from various studies were critically reviewed to summarize the relationship between hyperlipidemia and rotator cuff pathology. Hyperlipidemia induces LDL-particle entrapment within the dense regular collagen of rotator cuff tendons resulting in foam cell aggregation and macrophage recruitment. Subsequent inflammatory pathways including the JAK2/STAT3 pathway and NLRP3 inflammasome pathway led to persistent inflammation and Extracellular Matrix (ECM) degradation within the rotator cuff. While arthroscopic repair remains the most common treatment modality, nonsurgical treatment including statins, vitamin D, and targeting miRNA are also of therapeutic benefit. Hyperlipidemia interferes with arthroscopic repairs by inducing inflammation and stiffness within tendons and increases the risk of retears. Most notably, targeting underlying mechanisms influencing inflammation has large therapeutic value as a novel treatment strategy for the management of rotator cuff pathology.