BACKGROUND:Slow growth of peripheral nerve, muscle denervation atrophy and fossilization of motor end plate fol owing sciatic nerve injury cause irreversible limb function disorders. Umbilical cord mesenchymal stem cells have been widely used in multi-disciplinary research, but studies concerning umbilical cord mesenchymal stem cells delaying denervated muscle atrophy in rats fol owing peripheral nerve injury are rarely reported.
OBJECTIVE:To observe the value of human umbilical cord mesenchymal stem cells transplantation to delay denervated muscle atrophy of rats after sciatic nerve injury.
METHODS:Umbilical cord blood was col ected from healthy parturient woman after ful-term delivery. In the experimental group, the rat’s Sunderland IV degree sciatic nerve injury model was established by 5 mm denervation, epineurial repair, and 5 mm smal gap transplantation of umbilical cord mesenchymal stem cells. In the control group, after modeling, the same volume of normal saline was injected into the smal gap. The main outcome measures included the sciatic nerve function index, the wet weight of triceps surae,sciatic nerve latency, action potential conduction velocity and amplitude,and skeletal muscle fiber cross section area maintenance rate.
RESULTS AND CONCLUSION:After 4, 8 and 12 weeks of modeling, the sciatic nerve function index values, the wet weight of triceps surae and skeletal muscle fiber cross section area maintenance rates in the experimental group were significantly higher than those in the control group (P<0.05). After 12 weeks of modeling, electromyography results showed sciatic nerve latency was significantly lower, but action potential conduction velocity and amplitude were dramatical y higher in the experimental group than the control group (P<0.05, P<0.001). Human umbilical cord mesenchymal stem cells transplantation in denervated muscle atrophy rats after sciatic nerve promotes nerve growth, delays denervated muscle atrophy, maintains the denervatied neuromusle’s morphology and function.

Objective:To evaluate the surgical effect of repairing soft tissue defect of hand and foot with medial gastrocnemius fascia flap combined with skin graft.Methods:From January, 2018 to June, 2019, 10 patients were treated with transfers of free medial gastrocnemius fascia flaps combined with skin graft to repair soft tissue defect of hand and foot. The size of free fascial flap was 5.0 cm×8.0 cm-12.0 cm×15.0 cm. After successful transfer on the wound, the skin was grafted onto the fascial flap, and the donor site was sutured directly. The appearance and function of the recipient and donor sites were observed and the effect of the operation was evaluated. Sensory recovery was assessed by the standard set by British Medical Research Council (BMRC) at the last follow-up.Results:All the free medial gastrocnemius fascia flap survived. After 6-10 days of granulation tissue growing, the skin grafts were transferred and all survived. All patients entered follow-up for 3-9 months, with an average of 7.5 months. The tissue at the recipient sites were soft and wear-resistant without swelling or ulceration. According to the self-designed evaluation system of soft tissue defect reconstruction, 10 patients had score from 68 to 92 (average, 75.2) . At the last follow-up, sensory recovery was assessed by BMRC, 7 cases were excellent and 3 cases were good.Conclusion:The repair of hand and foot soft tissue defect by the free medial gastrocnemius fascia flap combined with skin graft has advantages in constancy of vascular anatomy of free fascia tissue, long vascular pedicle and for repair of various types of hand and foot defects. Skin of the recipient area is soft with good appearance without swelling after the reconstruction of fascia flap. It is a method of treatment in repair of soft tissue defect of hand and foot by avoiding the thinning of a flap in the second procedure.