A comparative study of effect of autograft compared with allograft anterior cruciate ligament reconstruction on expressions of LOXs and MMPs

Differential MMP 1 and MMP 13 expression in proliferation and ligamentization phases of graft remodeling in anterior cruciate ligament reconstruction

Purpose: Graft remodeling in anterior cruciate ligament reconstruction (ACLR) demonstrates three distinct phases: necrosis, proliferation and ligamentization. Biological enhancement involves modulating these processes, but the cellular activities related to extracellular matrix remodeling have not been investigated. We hypothesized that changes in matrix metalloproteinases (MMPs) 1 and 13 expression are involved in the transition of proliferation phase to ligamentization phase of graft remodeling.Materials and methods: Thirty-three rats underwent ACLR. Tendon grafts were harvested at week 1 (necrosis), 2 (proliferation), or 12 (ligamentization) post-operation for histological examination (n = 3), or for isolation of graft-derived cells (n = 8) for flow cytometry, proliferation assay, cell invasion assay, measurement of gene expression related to matrix remodeling (Col1A1, Col3A1, MMP1, tissue inhibitor of marix metalloproteinase 1 (TIMP1), and MMP13) and total MMP activities.Results: Increased cellularity in tendon graft was contributed by active cell proliferation and migration at week 2 post-operation, while decreased cellularity were paralleled by increased apoptosis at week 12. All genes measured (Col1A1, Col3A1, MMP1, TIMP1, and MMP13) increased significantly in week 2 cells compared to week 1 cells. MMP1 expression subsided at week 12, while MMP13 expression kept increasing till 12 weeks post-operation. Total MMP activities was 3-fold higher in cultured graft-derived cells from week 2 as compared to cells from week 12. Two distinct processes of graft remodeling were identified, characterized by increased MMP1 expression with cell proliferation and increased MMP13 expression with cell apoptosis.Conclusions: Unfavorable matrix remodeling during the proliferation phase is found with increased MMP1, while remodeling leading to ligamentization is associated with increased MMP13 expression.

Complications of Superior Capsule Reconstruction for the Treatment of Functionally Irreparable Rotator Cuff Tears: A Systematic Review

PURPOSE

The purpose of this systematic review is to characterize the complications associated with superior capsule reconstruction (SCR) for the treatment of functionally irreparable rotator cuff tears (FIRCTs).

METHODS

This systematic review was completed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Two independent reviewers completed a search of PubMed, Embase, and Medline databases. Studies were deemed eligible for inclusion if they reported postoperative outcomes of arthroscopic SCR for FIRCTs and considered at least 1 postoperative complication. Statistical heterogeneity was quantified via the I² statistic. Due to marked heterogeneity, pooled proportions were not reported. All complications and patient-reported outcomes were described qualitatively.

RESULTS

Fourteen studies met the inclusion/exclusion criteria. The overall complication rate post-SCR ranged from 5.0% to 70.0% (I² = 84.9%). Image-verified graft retear ranged from 8% to 70%, I² = 79.4%), with higher rates reported when SCR was performed using allograft (19%-70%, I² 76.6%) compared to autograft (8%-29%, I² = 66.1%). Reoperation (0%-36%, I² = 73.4%), revision surgeries (0%-21%, I² = 81.2%), medical complications (0%-5%, I² = 0.0%), and infections (0%-5%, I² = 0.0%) were also calculated.

CONCLUSIONS

SCR carries a distinct complication profile when used for the treatment of FIRCTs. The overall rate of complications ranged from 5.0% to 70.0%. The most common complication is graft retear with higher ranges in allografts (19%-70%) compared to autografts (8%-29%). The majority of studies reported at least 1 reoperation (range, 0%-36%), most commonly for revision to reverse shoulder arthroplasty.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV or better investigations.

Association of chemokine expression in anterior cruciate ligament deficient knee with patient characteristics: Implications for post-traumatic osteoarthritis

BACKGROUND

Stromal cell-derived factor-1a (SDF-1α) and high mobility group box chromosomal protein 1 (HMGB1) are chemokines that can drive post-traumatic osteoarthritis (PTOA) induced by anterior cruciate ligament (ACL) injury. However, the influence of patient characteristics on expression of those chemokines remains unclear. Our aim was to determine the relationship between chemokine expression in synovial fluid (SF) of the ACL-deficient (ACL-D) knee and patient characteristics including time from injury, sex, and age.

METHODS

SF samples were collected immediately prior to the first-time ACL reconstruction (ACLR) from 82 patients. Expression of SDF-1α and HMGB1 was measured with human-specific solid phase sandwich enzyme-linked immunosorbent assays. The expression levels between groups divided by time from injury, or age, or sex was compared using Student's t-test. The association of SDF-1α or HMGB1 levels with those variables was determined using regression analysis and Pearson product-moment correlation coefficient.

RESULTS

Regression and correlation analysis indicated significant correlation between SDF-1α expression and time from injury in the cohort (r = -0.266, P = 0.016, n = 82) and in females (r = -0.386, P = 0.024, n = 34). Significant correlation was also observed between SDF-1α expression and age in the cohort (r = -0.224, P = 0.043, n = 82) and in males (r = -0.289, P = 0.046, n = 48). No significant correlation between HMGB1 expression and patient characteristics was detected.

CONCLUSIONS

SDF-1α rather than HMGB1 might serve as a protein marker for monitoring the development of PTOA in the ACL-D knee, especially in female patients.

Superior capsule reconstruction using dermal allograft: early outcomes and survival

BACKGROUND

Superior capsule reconstruction (SCR) has shown promising outcomes in its initial description, but lacks additional reports analyzing outcomes. This study analyzes early outcomes of SCRs in patients with massive irreparable rotator cuff tears.

METHODS

A retrospective analysis of all SCRs at our institution from January 1, 2015, to August 31, 2017, was performed with a minimum 6-months follow-up. A total of 34 patients were included with a mean age of 60 years. SCR was performed by 1 of 6 fellowship trained surgeons.

RESULTS

At an average follow-up of 12 months, 22 patients were identified as failures after modified Neer classification. Furthermore, 8 of these patients have undergone a reoperation, whereas an additional 14 patients were considered clinical failures experiencing continued pain and a lack of shoulder function. Of note, 2 of the 3 patients with a subscapularis tear had a failure. In addition, revision cases, female gender, increased fatty infiltration in the infraspinatus and low surgeon volume were associated with a higher rate of failure. There was no significant improvement in range of motion or functional scores.

CONCLUSION

SCR performed for large-to-massive irreparable rotator cuff tears has a high rate of persistent pain and poor function leading to clinical failure in 65% of patients. Risk factors predicting clinical failure included revision cases, female gender, increased Goutallier fatty infiltration of the infraspinatus, and low surgeon volume (n ≤ 10).

The protective effect of anterior cruciate ligament reconstruction on articular cartilage: a systematic review of animal studies

OBJECTIVE

It is unclear if anterior cruciate ligament (ACL) reconstruction can prevent the onset of degenerative changes in the knee. Previous studies were inconclusive on this subject. The aim of this study was to systematically review all studies on the effect of ACL reconstruction on articular cartilage in animals.

DESIGN

Pubmed and Embase were searched to identify all original articles concerning the effect of ACL reconstruction on articular cartilage compared with both its positive (ACL transection) and negative (sham and/or non-operated) control in animals. Subsequently a Risk of bias and meta analysis was conducted based on five outcomes (gross macroscopic assessment, medical imaging, histological histochemical grading, histomophometrics and biomechanical characterization) related to articular cartilage.

RESULTS

From the 19 included studies, 29 independent comparisons could be identified which underwent ACL reconstruction with an average timing of data collection of 23 weeks (range 1-104 weeks). Due to limited data availability meta-analysis could only be conducted for gross macroscopic damage. ACL reconstruction caused significant gross macroscopic damage compared with intact controls (SMD 2.0 [0.88; 3.13]). These findings were supported by individual studies reporting on histomorphometrics, histology and imaging. No significant gross macroscopic damage was found when ACL reconstruction was compared with ACL transection (SMD -0.64 [-1.85; 0.57]).

CONCLUSION

This systematic review with an average follow up of included studies of 23 weeks (range 1-104 weeks) demonstrates that, in animals, ACL reconstruction does not protect articular cartilage from degenerative changes. The consistency of the direction of effect, provides some reassurance that the direction of effect in humans might be the same.