[Analysis of the effectiveness of sequential plate internal fixation in correction of Madelung deformity after ulnar osteotomy and shortening].

Objective: To investigate the effectiveness of sequential plate internal fixation in the correction of Madelung deformity after ulnar osteotomy and shortening. Methods: The clinical data of 13 patients with Madelung deformity admitted between September 2015 and July 2021 were retrospectively analyzed. There were 5 males and 8 females with an average age of 18.3 years ranging from 17 to 23 years. The disease duration ranged from 12 to 24 months, with an average of 17 months. Three cases had a clear history of trauma. All patients had external radial deviation deformity and limited movement of the ulnar deviation, and the ulnar impact pain was significant during ulnar deviation movement; 9 patients had limited wrist joint supination movement, and the supination movement was normal. In the first stage, ulnar osteotomy and shortening combined with external fixator were used to correct wrist deformity in 13 patients. After operation, bone transfer was performed 6 times per day, with adjustments made every 4 hours, which was 1 mm per day. After the osteotomy was in place, the ulnar plate internal fixation was performed to reconstruct the ulnar stability in the second stage. The Cooney wrist joint score was used to assess the pain, function, range of motion, flexion and extension range of motion, and grip strength of the wrist joint before operation and before the removal of internal fixator. The subjective feeling and appearance satisfaction of patients were recorded. Results: After the second-stage operation, all the 13 patients were followed up 10-22 months, with an average of 15 months. The deformity of wrist joint disappeared after operation, and the flexion, extension, and ulnar deviation were basically normal. There was no complication such as ulnar impingement sign, nonunion or infection. Wrist function, pain, and range of motion were significantly improved after operation, except for 1 patient who had no significant improvement in rotation and pain. The ulnar internal fixator was removed at 10-18 months after the second-stage operation. The scores of pain, function, range of motion, flexion and extension range of motion, and grip strength in the Cooney wrist score before removal of internal fixator significantly improved when compared with those before operation ( P<0.05). Subjective and appearance satisfaction of patients were excellent in 9 cases, good in 3 cases, and fair in 1 case. Conclusion: Ulnar osteotomy and shortening with sequential plate internal fixation for correction of Madelung deformity, with mild postoperative pain, can effectively avoid bone nonunion, improve wrist joint function, and have significant effectiveness.

[Advances on research of physical environment affecting stem cell differentiation in ligament tissue engineering].

Ligament tissue engineering is currently a novel approach to the treatment of ligament injury, which can replace the deficiency of autografts. Ligament tissue engineering consists of four basic elements:seed cells, nanoscaffolds, growth factors, and mechanical stimulation. At present, the main problem in ligament tissue engineering is how to control seed cells to ligament cells more controllly. The study found that each physical property of the natural bio ligament and mechanical stimulation (uniaxial stretching) plays an important role in the differentiation of stem cells into ligament cells. Therefore, the design of nanofiber scaffolds must consider the elastic modulus of the material and the material. Structure(material arrangement, porosity and diameter, etc.), elastic modulus and material structure in different ranges will guide cells to differentiate into different lineages. Considering that the ligament is the main force-bearing tissue of the human body, mechanical stimulation is also essential for stem cell differentiation, especially uniaxial stretching, which best meets the stress of the ligament in the body. A large number of studies have found the frequency and amplitude of stretching. And time will also lead the cells to differentiate in different directions. RhoA/ROCK plays a regulatory role in cytoskeletal remodeling and cell differentiation. It is also found that RhoA/ROCK protein participates in the process of nanofiber arrangement and uniaxial stretching to guide stem cells to differentiate into ligament cells, specifically how to influence stem cell differentiation. It is not clear at present that understanding the effects of physical properties on stem cell differentiation and understanding the mechanism of action of RhoA/ROCK protein will provide a new theoretical basis for further optimization of ligament tissue engineering.

Masquelet induced membrane technique for treatment of rat chronic osteomyelitis.

The application value of Masquelet induced membrane technique for the treatment of rat chronic osteomyelitis was explored. A total of 180 male Sprague-Dawley (SD) rats were randomly divided into sham operation group (control group), chronic osteomyelitis model group (model group) and Masquelet induced membrane therapy + chronic osteomyelitis model group (observation group); 60 rats in each group. A rat model of traumatic osteomyelitis was established using a modified blunt trauma method in model and observation group. All rats in observation group were treated with membrane induction technology while in the control group they were not. Postoperative complications, bone healing time and functional status of the affected limbs were recorded. After surgery, no obvious perioperative complications occurred in most of the rats, except that 5 rats experienced partial necrosis at the edge of the flap, and 3 experienced superficial infection around the incision site in the ilium. Primary bone healing was achieved in 50 rats with an average healing time of 15 weeks. Among them, 38 rats restored weight-bearing function after 20 weeks. Seven rats experienced infection after surgery, but complete bone healing was achieved after treatment with induced membrane technique again. Following treatment with induced membrane technique, the rat body weight, body temperature and the number of bacteria in the wound decreased over time. In conclusion, Masquelet induced membrane technique is effective for the treatment of large bone defects in rats after traumatic osteomyelitis. This technique significantly shortens the treatment cycle. The surgical procedure is simple, and the incidence of postoperative complications is low.

[Effectiveness of wide fascial and doubly vascularized pedicle posterior cnemis flap in repair of soft tissue defect of forefoot].

Objective: To investigate the effectiveness of wide fascial and doubly vascularized pedicle posterior cnemis flap in repair of the soft tissue defect of forefoot. Methods: Between March 2011 and March 2017, 18 cases with severe soft tissue defects of forefeet were repaired with the wide fascial and doubly vascularized pedicle posterior cnemis flaps. There were 13 males and 5 females with an average age of 33 years (range, 11-49 years). Of 18 cases, the defects were caused by trauma in 16 cases with an average disease duration of 15 hours (range, 3-72 hours), by infection after correction of spastic clubfoot in 1 case, and by infection after open fracture fixation in 1 case. The defects were on the planta of forefoot in 11 cases and on the dorsum of forefoot in 7 cases. The size of soft tissue defects ranged from 6 cm×4 cm to 15 cm×9 cm. All defects combined with the bone, joint, and tendon exposures and 4 defects combined with fractures. The size of flaps ranged from 8 cm×5 cm to 17 cm×10 cm. All wounds of donor sites were repaired by skin grafting. Results: The operation time was 100-190 minutes (mean, 140 minutes). Seventeen flaps survived and wounds healed by first intention. One flap had partial necrosis and cured after dressing change. Seventeen cases were followed up 5-24 months (mean, 16 months). Both the color and texture of the flaps were satisfactory. But the pedicles of flaps were swollen. The functions of foot and ankle returned to normal. Conclusion: The wide fascial and doubly vascularized pedicle posterior cnemis flap has reliable blood supply and sufficient venous reflux to ensure its survive, which can be used to repair severe soft tissue defect of forefoot.