Background: The purpose of the study was to compare the morphomechanical and functional characteristics during maximal isometric, concentric, and eccentric contractions in the legs of patients that underwent unilateral Achilles tendon repair with those in their noninjured control legs. Methods: Twenty participants (median age = 38.2 years; range, 21.1-57.3 years) who underwent Achilles repair between 3 and 12 months ago were recruited with the following measures: (1) mechanical stiffness of the aponeurosis and (2) electromyography and medial gastrocnemius fascicle angle and length, standing muscle and tendon length, and height of heel rise with isometric contraction. Results: Compared to the noninjured legs, the repaired legs showed less resting fascicle length, standing muscle length, isometric plantarflexion torque, and heel raise distance ( Ps ranged between .044 and <.001). During the concentric and eccentric phases of the raising and lowering test, the repaired legs demonstrated less fascicle length ( P ≤ .028) but greater tendinous tissue length ( Ps ranged between .084 and <.001) and fascicle angle ( Ps ranged between .247 and .008) and fewer change magnitudes of the fascicle length and tendinous tissue length ( P ≤ .003). The change magnitudes of the morphological characteristics showed correlations with the torque or distance. Conclusion: Selecting the appropriate surgical repair and rehabilitation for Achilles tendon ruptures is recommended for restoring the length and mechanical strength of the muscle-tendon unit of plantar-flexion muscles. Level of Evidence: Level III, comparative study.

Background: The Lumbar sagittal parameters might be related to modic changes (MCs). However, studies on this topic have rarely been reported. The aim of this study was to identify the relationships between the lumbar sagittal parameters and the development of MCs. Methods: The lumbar sagittal parameters of 321 patients with chronic low back pain from May 2016 to August 2018 were measured on X-ray by using Surgimap surgical planning software. Univariable analyses were used to test the potential variables of interest. Logistic regression models were then performed for the significant parameters to identify the independent factors associated with the development of MCs. Results: More patients in the MCs group were older with more number of female than in the disc degeneration group (p < 0.05). In the univariate analysis, significant differences were detected for the parameters of lumbar lordosis, sacral slope, intervertebral height index, endplate concave angle, and intervertebral angle only at the L5/S1 level between the two groups. The results of logistic regression analysis showed that a smaller intervertebral height index was positively associated with the development of MCs at the level of L3/4 (p < 0.05). However, the positive role of gender was only for MCs at the L5/S1 level (p < 0.05). Conclusions: The results of this study revealed that there were negative relationships between the lumbar sagittal parameters and MCs. Furthermore, being female and having a narrow intervertebral space were the independent risk factors for the development of MCs at the corresponding lumbar levels. Interestingly, body mass index might be not associated with MCs for the Chinese population.

Experimental autoimmune-orchitis (EAO), a rodent model of chronic testicular inflammation and fibrosis, replicates pathogenic changes seen in some cases of human spermatogenic disturbances. During EAO, increased levels of pro-inflammatory and pro-fibrotic mediators such as TNF, CCL2, and activin A are accompanied by infiltration of leukocytes into the testicular parenchyma. Activin A levels correlate with EAO severity, while elevated CCL2 acting through its receptor CCR2 mediates leukocyte trafficking and recruits macrophages. CCR2 + CXCR4 + macrophages producing extracellular matrix proteins contribute widely to fibrogenesis. Furthermore, testicular macrophages (TMs) play a critical role in organ homeostasis. Therefore, we aimed to investigate the role of the activin A/CCL2-CCR2/macrophage axis in the development of testicular fibrosis. Following EAO induction, we observed lower levels of organ damage, collagen deposition, and leukocyte infiltration (including fibronectin+, collagen I+ and CXCR4+ TMs) in Ccr2−/− mice than in WT mice. Furthermore, levels of Il-10, Ccl2, and the activin A subunit Inhba mRNAs were lower in Ccr2−/− EAO testes. Notably, fibronectin+ TMs were also present in biopsies from patients with impaired spermatogenesis and fibrotic alterations. Overexpression of the activin A antagonist follistatin reduced tissue damage and collagen I+ TM accumulation in WT EAO testes, while treating macrophages with activin A in vitro increased the expression of Ccr2, Fn1, Cxcr4, and Mmp2 and enhanced migration along a CCL2 gradient; these effects were abolished by follistatin. Taken together, our data indicate that CCR2 and activin A promote fibrosis during testicular inflammation by regulating macrophage function. Inhibition of CCR2 or activin A protects against damage progression, offering a promising avenue for therapeutic intervention.

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