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Failing to regenerate native tendon tissue in chronic massive rotator cuff tears (CMRCTs) results in high retear rates after surgery. Gelatin is a hydrolyzed form of collagen which is bioactive and biocompatible. This study intends to investigate the suitability of integrating gelatin to poly (l‐lactic acid) (PLLA) fibrous membranes for promoting the healing of CMRCTs. PLLA/Gelatin electrospun membranes (PGEM) are fabricated using electrospinning technology. The fourier transform infrared, static contact angles are tested sequentially. Cytocompatibility is evaluated with rat tendon fibroblasts and human umbilical endothelial cells (HUEVCs) lines. CMRCTs rat models are established and assigned into three groups (the sham group, the repaired group, and the augmentation group) to perform histomorphological and biomechanical evaluations. Gelatin is successfully integrated into PLLA fibrous membranes by the electrospinning technique. In vitro studies indicate that PGEM shows a great cytocompatibility for rat tendon fibroblasts and HUEVCs. In vivo studies find that applications of PGEM significantly promote well‐aligned collagen I fibers formation and enhance biomechanical properties of the repaired tendon in CMRCTs rat models. In summary, gelatin promotes tendon fibroblasts and HUEVCs adhesion, migration, and proliferation on the PLLA fibrous membranes, and PGEM may provide a great prospect for clinical application.

Background Wang successfully replanted the severed fingers of 2 patients after cryopreservation in 2002 and 2003, which has enabled us to share our own experience for the knowledge interests of our colleagues and to further develop this technology. Methods Fifteen healthy adult male Sprague-Dawley rats were selected and divided into 5 groups (group 1: normal control, group 2: cryopreservation with protectant, group 3: cryopreservation without protectant, group 4: 6-hour postoperative, and group 5: 72-hour postoperative). After harvesting the hind limbs, cryoprotectant was applied to 20 limbs, and the rest were cryopreserved without cryoprotectant for 15 days. After being thawed, the amputated limb was replanted in situ. Nerves, skins and gastrocnemius muscles were collected for hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and transmission electron microscopy observation. Results Muscle and skin tissues treated with cryoprotectant restored a better outline after being frozen than those not treated, whereas nerves were not significantly different between the 2 groups. After replantation, some of the myofibrils of the muscle were in disarray, but the sarcomere structure remained intact at approximately 6 hours postoperatively. At 72 hours, a transmission electron microscopy scan showed that the myofibrillar arrangement was disorderly, with segmental myofilament breakage, and the sarcomere structure was destroyed in some cases. In addition, the scan revealed increased apoptotic cells and collapse of basic structures in the skin and nerves. Conclusions Relative to that of skin and neuronal tissue, the replantation of muscle tissues through the cryopreservation method is more difficult.

BackgroundCyamella,the sesamoid bones of the popliteus muscle, are rare in humans. Snapping knee is an uncommon problem which can be difficult to diagnose.Case presentationIn this case, we report a 24-year-old male with snapping knee caused by symptomatic cyamella in the popliteus tendon. A large cyamella was identified upon surgery and was removed. Postoperatively, the patient had immediate relief of preoperative symptoms, and there were no signs of recurrence after 1 years of follow-up.ConclusionsAlthough not previously suggested, symptomatic cyamella in the popliteus tendon should be considered as part of the differential diagnosis of the snapping knee.

At the Summit on Organ Banking through Converging Technologies held recently in Boston, tissue and organ cryopreservation technology was a topic of considerable interest. Although cryopreservation has been widely used in clinical practice, it currently remains limited to bloodless tissues with simple structures and functions that are small or thin, for example, ultra-thin skin, ovarian tissue slices, and other similar tissues. For whole organs, except for successful cryopreservation of rat ovaries ( 2002) and hind limbs (August 2002), successful cryopreservation of vascularized animal tissues or organs and their replantation have not yet been reported. We conducted histological and electron microscopic examinations on muscle after blood supply restoration to explain this problem and describe our experience with the goal of informing our colleagues to further develop the technology. To achieve broad application of vascularized tissue and organ cryopreservation, we have summarized our experience and established a clinical application scope for vascularized composite tissue cryopreservation.