Connexin 43 Is Necessary for Murine Tendon Enthesis Formation and Response to Loading

The enthesis is a mineralized fibrocartilage transition that attaches tendon to bone and is vital for musculoskeletal function. Despite recent studies demonstrating the necessity of muscle loading for enthesis formation, the mechanisms that regulate enthesis formation and mechanoresponsiveness remain unclear. Therefore, the current study investigated the role of the gap junction protein connexin 43 in these processes by deleting Gja1 (the Cx43 gene) in the tendon and enthesis. Compared with their wild-type (WT) counterparts, mice lacking Cx43 showed disrupted entheseal cell alignment, reduced mineralized fibrocartilage, and impaired biomechanical properties of the supraspinatus tendon entheses during postnatal development. Cx43-deficient mice also exhibited reduced ability to complete a treadmill running protocol but no apparent deficits in daily activity, metabolic indexes, shoulder muscle size, grip strength, and major trabecular bone properties of the adjacent humeral head. To examine enthesis mechanoresponsiveness, young adult mice were subjected to modest treadmill exercise. Gja1 deficiency in the tendon and enthesis reduced entheseal anabolic responses to treadmill exercise: WT mice had increased expression of Sox9, Ihh, and Gli1 and increased Brdu incorporation, whereas Cx43-deficient mice showed no changes or decreased levels with exercise. Collectively, the results demonstrated an essential role for Cx43 in postnatal tendon enthesis formation, function, and response to loading; results further provided evidence implicating a link between Cx43 function and the hedgehog signaling pathway. © 2020 American Society for Bone and Mineral Research.     

Giant pseudoaneurysm of the innominate artery late after surgical repair of type-A aortic dissection

A 49-year-old man was admitted to our department 6 months after emergent surgery for type-A acute aortic dissection. A chest computed tomography-scan revealed a huge aneurysm originating from the proximal aortic arch, strongly adherent to the upper part of the sternum. Extracorporeal circulation was instituted first, and chest was reopened in circulatory arrest. The mass was a giant pseudoaneurysm originating from a laceration at the base of the innominate artery. Due to tissue fragility and complete distortion of the origin of right carotid and subclavian arteries, we performed an extra-anatomic ascending aorta-to-right carotid artery bypass, followed by Teflon-reinforced suture of the proximal artery stumps. The postoperative course was uneventful.     

Mixed sex cord stromal tumor and incidental findings of perineural and intravascular extraparenchymal Leydig cells: a potential diagnostic pitfall

International Urology and Nephrology -     

Donor-recipient age interaction and the impact on clinical results after heart transplantation

To evaluate the impact of donor-recipient age matching on clinical outcomes after heart transplantation, a total of 509 patients (January 1990-December 2018, mean follow-up 111 ± 80 months) were stratified into 4 groups (young-R/young-D, young-R/old-D, old-R/young-D, old-R/old-D) according to the recipient (young-R < 60, old-R ≥ 60 years) and the donor (young-D < 50, old-D ≥ 50 years) age. No difference was found among 30-day mortality (P = .11) and postoperative complications between groups. Both unadjusted and adjusted survival was significantly higher for group young-R/young-D than that of other groups, in which survival was similar [adjusted HR for mortality of 2.0(1.2-3.4), 2.1(1.4-3.8) and 2.5(1.6-4.1) for groups old-R/young-D, young-R/old-D, old-R/old-D, respectively]. Compared to other groups, the incidence of grade ≥ 2 CAV was significantly lower in old-R/young-D group [adjusted HR 0.4(0.2-0.7)]. Among young recipients, the rate of acute grade ≥ 2 rejection episodes was higher in those receiving an old donor graft (P = .04). Old recipient groups were more affected by neoplasms and severe renal failure than young recipient groups (P < .01). Employment of hearts from donors ≥50 years of age adversely affects survival in recipients <60 years of age but does not influence outcomes in older recipients. Also, donor and recipient ages seem to have opposite effects on incidence of rejections and CAV of high grade.     

Postpneumonectomy bronchopleural fistula: analysis of risk factors and the role of bronchial stump coverage

Surgery Today - Bronchopleural fistula (BPF) is a potentially fatal complication of pneumonectomy. We analyze its occurrence rate, risk factors, and the methods used for its prevention. We reviewed...     

Are our expectations bigger than the results we achieve? A comparative study analysing potential advantages of ankle arthroplasty over arthrodesis

Purpose

Prior studies have reported improved gait performance and kinematics after total ankle arthroplasty (TAR) compared to ankle arthrodesis (AAD). Given these findings, AAD has been primarily considered as a salvage procedure that may lead to adjacent joint degeneration.

Methods

A total of 101 TAR and 40 screw arthrodeses were enrolled in a retrospective study with a prospectively designed follow-up examination that included gait analysis and outcome assessment with the AOFAS hindfoot score and FAOS questionnaire.

Results

Significant asymmetry in gait and reduced range of motion compared to normal remained after both procedures. Subjective outcome improved after both procedures, and pain was significantly better after TAR. Limited functional gains after TAR and joint degeneration to the same degree after both procedures was seen in the mid-term. Hindfoot fusion seemed to have a greater impact on postoperative function than ankle arthrodesis.

Conclusion

Considering only minor functional gains of TAR compared to AAD the implantation of current TAR designs in large patient series may be questioned.     

Autologous protein solution prepared from the blood of osteoarthritic patients contains an enhanced profile of anti‐inflammatory cytokines and anabolic growth factors

The objective of this clinical study was to test if blood from osteoarthritis (OA) patients (n = 105) could be processed by a device system to form an autologous protein solution (APS) with preferentially increased concentrations of anti‐inflammatory cytokines compared to inflammatory cytokines. To address this objective, APS was prepared from patients exhibiting radiographic evidence of knee OA. Patient metrics were collected including: demographic information, medical history, medication records, and Knee Injury and Osteoarthritis Outcome Score (KOOS) surveys. Cytokine and growth factor concentrations in whole blood and APS were measured using enzyme‐linked immunosorbent assays. Statistical analyses were used to identify relationships between OA patient metrics and cytokines. The results of this study indicated that anti‐inflammatory cytokines were preferentially increased compared to inflammatory cytokines in APS from 98% of OA patients. APS contained high concentrations of anti‐inflammatory proteins including 39,000 ± 20,000 pg/ml IL‐1ra, 21,000 ± 5,000 pg/ml sIL‐1RII, 2,100 ± 570 pg/ml sTNF‐RI, and 4,200 ± 1,500 pg/ml sTNF‐RII. Analysis of the 82 patient metrics indicated that no single patient metric was strongly correlated (R² > 0.7) with the key cytokine concentrations in APS. Therefore, APS can be prepared from a broad range of OA patients. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1349–1355, 2014.