Medial patellar ligament reconstruction in combination with derotational distal femoral osteotomy for treating recurrent patellar dislocation in the presence of increased femoral anteversion: a systematic review.

BACKGROUND: Medial patellar ligament reconstruction (MPFL-R) in combination with derotational distal femoral osteotomy (DDFO) for treating recurrent patellar dislocation (RPD) in the presence of increased femoral anteversion is one of the most commonly used surgical techniques in the current clinical practice. However, there are limited studies on the clinical outcomes of MPFL-R in combination with DDFO to treat RPD in the presence of increased femoral anteversion. PURPOSE: To study the role of MPFL-R in combination with DDFO in the treatment of RPD in the presence of increased femoral anteversion. METHODS: A systematic review was performed according to the PRISMA guidelines by searching the Medline, Embase, Web of Science, and Cochrane Library databases through June 1, 2023. Studies of patients who received MPFL-R in combination with DDFO after presenting with RPD and increased femoral anteversion were included. Methodological quality was assessed using the MINORS (Methodological Index for Nonrandomized Studies) score. Each study's basic characteristics, including characteristic information, radiological parameters, surgical techniques, patient-reported outcomes, and complications, were recorded and analyzed. RESULTS: A total of 6 studies with 231 patients (236 knees) were included. Sample sizes ranged from 12 to 162 patients, and the majority of the patients were female (range, 67-100%). The mean age and follow-up ranges were 18 to 24 years and 16 to 49 months, respectively. The mean femoral anteversion decreased significantly from 34° preoperatively to 12° postoperatively. In studies reporting preoperative and postoperative outcomes, significant improvements were found in the Lysholm score, Kujala score, International Knee Documentation Committee score, and visual analog scale for pain. Postoperative complications were reported in all studies, with an overall reported complication rate of 4.7%, but no redislocations occurred during the follow-up period. CONCLUSION: For RPD with increased femoral anteversion, MPFL-R in combination with DDFO leads to a good clinical outcome and a low redislocation rate. However, there was no consensus among researchers on the indications for MPFL-R combined with DDFO in the treatment of RPD.

A novel extracellular vesicles production system harnessing matrix homeostasis and macrophage reprogramming mitigates osteoarthritis.

Osteoarthritis (OA) is a degenerative disease that significantly impairs quality of life. There is a pressing need for innovative OA therapies. While small extracellular vesicles (sEVs) show promising therapeutic effects against OA, their limited yield restricts clinical translation. Here, we devised a novel production system for sEVs that enhances both their yield and therapeutic properties. By stimulating mesenchymal stem cells (MSCs) using electromagnetic field (EMF) combined with ultrasmall superparamagnetic iron oxide (USPIO) particles, we procured an augmented yield of EMF-USPIO-sEVs. These vesicles not only activate anabolic pathways but also inhibit catabolic activities, and crucially, they promote M2 macrophage polarization, aiding cartilage regeneration. In an OA mouse model triggered by anterior cruciate ligament transection surgery, EMF-USPIO-sEVs reduced OA severity, and augmented matrix synthesis. Moreover, they decelerated OA progression through the microRNA-99b/MFG-E8/NF-κB signaling axis. Consequently, EMF-USPIO-sEVs present a potential therapeutic option for OA, acting by modulating matrix homeostasis and macrophage polarization.

Increased Risk of Rheumatoid Arthritis in Patients With Asthma: A Genetic Association Study Using Two-Sample Mendelian Randomization Analysis.

OBJECTIVE: Observational studies have explored the association between asthma and some types of arthritis, including rheumatoid arthritis and osteoarthritis, but the results are largely contradictory. We aimed to investigate the causal effects of asthma on arthritis, including osteoarthritis, rheumatoid arthritis, gout, and ankylosing spondylitis. METHODS: Two-sample Mendelian randomization (MR) analysis was used to investigate the causal effects of asthma on each arthritis. The genetic instruments for asthma were obtained from a large genome-wide association study of asthma. The inverse-variance weighted (IVW) method was used as the main analysis of MR. Bonferroni-adjusted P value threshold was used to account for multiple comparisons. RESULTS: MR-IVW analysis suggested that adult-onset asthma (AOA) was associated with increased risk of rheumatoid arthritis. The odds ratio for rheumatoid arthritis associated with AOA and childhood-onset asthma (COA) were 1.018 (95% confidence interval [95% CI], 1.011-1.025; P < 0.001) and 1.006 (95% CI 1.001-1.012; P = 0.046), respectively. For osteoarthritis, gout, or ankylosing spondylitis, all the MR analyses showed no significant causal effects of AOA or COA on them. We also performed a reverse MR analysis to explore the causal effects of rheumatoid on all asthma, allergic asthma, or nonallergic asthma and found no significant causal effects on them. CONCLUSION: Genetically predicted AOA predisposes patients to an increased risk of rheumatoid arthritis but has no causal effects on osteoarthritis, gout, and ankylosing spondylitis. The result of COA on rheumatoid arthritis is suggestive of potential causal relationship but needs to be confirmed in further studies.

Complications associated with single-level bone transport for the treatment of tibial bone defects caused by fracture-related infection.

BACKGROUND: The purpose of this study was to report the outcomes of single-level bone transport with a unilateral external fixator for treatment of proximal, intermediate and distal tibial bone defects caused by fracture-related infection (FRI) and compare their complications. METHODS: The clinical records and consecutive X-ray photographs of patients with tibial bone defects treated by single-level bone transport using a unilateral external fixator (Orthofix Limb Reconstruction System) were analyzed retrospectively, from January 2012 to December 2018. Patients were divided into the proximal group (P, n = 19), intermediate group (I, n = 25), and distal group (D, n = 18) according to the location of the tibial bone defect. The Association for the Study and Application of the Method of Ilizarov (ASAMI) standard was applied to assess the bone and functional outcomes and postoperative complications evaluated by the Paley classification. RESULTS: A total of 62 participants were included in this study, with a median age of 36 ± 7.14 years. Sixty patients with tibial bone defects caused by FRI were successfully treated by single-level bone transport using a unilateral external fixator, with a mean bone union time (BUT) of 7.3 ± 1.71 months. According to the ASAMI criteria, there were statistical differences in bone and function results between the three groups (P vs. I vs. D, P < 0.001). The excellent and good rate of bone result in the intermediate group was higher than the other (P vs. I vs. D, 73.6% vs. 84% vs. 66.7%), and the excellent and good rate of function result in the proximal group was the highest (P vs. I vs. D, 84.2% vs. 80% vs. 73.3%). Complications were observed in 29 out of 62 patients (46.7%), with pin tract infection being the most common (14.8%), followed by axial deviation (14.8%), muscle contractures (12.7%), joint stiffness (12.7%), and soft tissue incarceration (12.7%). Other complications included delayed consolidation (12.7%), delayed union (6.3%), nonunion (4.2%), and neurological injury (8.5%). Two patients (3.2%) required below-knee amputation due to uncontrollable infection and previous surgery failure. CONCLUSIONS: Pin tract infection was the most common complication in tibial bone transport using an external fixator. Complications of distal tibial bone transport are more severe and occur at a higher rate than in other parts. Axial deviation mostly occurred in the intermediate tibial bone transport.

Risk factors associated with tendon adhesions after hand tendon repair.

Background: Tendon adhesions after hand tendon repair are one of the most difficult complications of hand surgery and can cause severe disability. This study aimed to assess the risk factors associated with tendon adhesions after hand tendon repair to provide a theoretical foundation for the early prevention of tendon adhesions in patients with tendon injuries. Moreover, this study intends to increase doctors' awareness of the issue and serves as a reference for developing new prevention and treatment strategies. Methods: We retrospectively analyzed 1,031 hand trauma cases that underwent repair after finger tendon injury in our department between June 2009 and June 2019. Tendon adhesions, tendon injury zones, and other relevant information were collected, summarized, and analyzed. The significance of data was determined using a t-test or Pearson's chi-square test, and odds ratios (OR) were calculated using logistic regression tests to describe factors associated with post-tendon repair adhesions. Results: A total of 1,031 patients were enrolled in this study. There were 817 males and 214 females with an average age of 34.98 (2-82) years. The injured side included 530 left and 501 right hands. Postoperative finger tendon adhesions occurred in 118 cases (11.45%), including 98 males and 20 females, 57 left and 61 right hands. The risk factors for the total sample in the descending order were degloving injury, no functional exercise, zone II flexor tendon injury, time from injury to surgery >12 h, combined vascular injury, and multiple tendon injuries. The flexor tendon sample shared the same risk factors as the total sample. Risk factors for the extensor tendon sample were degloving injury, no functional exercise. Conclusions: Clinicians should pay close attention to patients with tendon trauma in hand having the following risk factors: degloving injury, zone II flexor tendon injury, lack of functional exercise, time from injury to surgery >12 h, combined vascular injury, and multiple tendon injuries. Due to the high risk of post-repair adhesions in patients with the conditions mentioned above, individualized treatment measures should be designed for the risk factors, and postoperative functional exercise of the hand is required.

High-fat diet causes undesirable bone regeneration by altering the bone marrow environment in rats.

Objective: Diet structure has changed greatly over the last few decades, and high-calorie diets have become an integral part of people's daily diet, as well as the important cause of obesity in society. Several organ systems, including the skeletal system, are seriously affected by high-fat-diets (HFD) in the world. There is, however, still a lack of knowledge about the effects of HFD on bone regeneration and the possible mechanisms involved. In this study, the difference in bone regeneration between rats under HFD and low-fat-diets (LFD) was evaluated by monitoring the process of bone regeneration in distraction osteogenesis (DO) model animals, as well as the possible mechanisms. Methods: A total of 40 Sprague Dawley (SD) rats (5 weeks old) were randomly divided into HFD group (n=20) and LFD group (n=20). Except for feeding methods, there were no differences between the two groups in terms of treatment conditions. All animals received the DO surgery eight weeks after starting to feed. After a delay of 5 days (latency phase), the active lengthening phase was performed for 10 days (0.25 mm/12 h), and the consolidation phase followed for 42 days. An observational study of bone included radioscopy (once a week), micro-computed tomography (CT), general morphology, biomechanics, histomorphometry, and immunohistochemistry. Result: The results showed that HFD group had a higher body weight than LFD group after 8, 14, and 16 weeks of feeding. Furthermore, at the final observation, there were statistically significant differences between LFD group and HFD group in terms of total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels. Additionally, observations on bone regeneration showed a slower regeneration and a lower biomechanical strength in HFD group than LFD group, based on radiography, micro-CT, general morphology, biomechanics, histomorphometry, and immunohistochemistry. Conclusion: In this study, HFD resulted in elevated blood lipids, increased adipose differentiation at the bone marrow level, and delayed bone regeneration. The pieces of evidence are beneficial to better understand the association between diet and bone regeneration and to adjust the diet optimally for fracture patients.

Diabetes mellitus impairs bone regeneration and biomechanics.

BACKGROUND: With the rise of high-calorie diets and the aging of populations, the incidence of diabetes was increased dramatically in the world and the number of people with diabetes was predicted to rise to 600 million by 2045. Numerous studies have confirmed that several organ systems, including the skeletal system, are seriously affected by diabetes. In that study, the bone regeneration and the biomechanics of the newly regenerated bone were investigated in diabetic rats, which may provide a supplement for previous studies. METHODS: A total of 40 SD rats were randomly divided into the type 2 diabetes mellitus (T2DM) group (n = 20) and the control group (n = 20). Beyond that high fat diet and streptozotocin (STZ) were jointly used in the T2DM group, there were no differences between the two groups in terms of treatment conditions. Distraction osteogenesis was used in all animals for the next experimental observation. The evaluation criterion of the regenerated bone was based on radioscopy (once a week), micro-computed tomography (CT), general morphology, biomechanics (including ultimate load, modulus of elasticity, energy to failure, and stiffness), histomorphometry (including von Kossa, Masson trichrome, Goldner trichrome, and safranin O staining), and immunohistochemistry. RESULTS: All rats in the T2DM group with fasting glucose levels (FGL, > 16.7 mmol/L) were allowed to complete the following experiments. The results showed that rats with T2DM have a higher body weight (549.01 g ± 31.34 g) than rats in the control group (488.60 g ± 33.60 g) at the end of observation. Additionally, compared to the control group, slower bone regeneration in the distracted segments was observed in the T2DM group according to radiography, micro-CT, general morphology, and histomorphometry. Furthermore, a biomechanical test showed that there was a worse ultimate load (31.01 ± 3.39%), modulus of elasticity (34.44 ± 5.06%), energy to failure (27.42 ± 5.87%), and stiffness (34.55 ± 7.66%) than the control group (45.85 ± 7.61%, 54.38 ± 9.33%, 59.41 ± 10.96%, and 54.07 ± 9.30%, respectively). Furthermore, the decreased expressions of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) were presented in T2DM group by immunohistochemistry. CONCLUSION: The present study demonstrated that diabetes mellitus impairs bone regeneration and biomechanics in newly regenerated bone, a phenomenon that might be related to oxidative stress and poor angiogenesis brought on by the disease.

Risk factors of transport gap bending deformity in the treatment of critical-size bone defect after bone transport.

BACKGROUND: The purpose of this study was to investigate the risk factors of transport gap bending deformity (TGBD) in the treatment of critical-size bone defect (CSBD) after the removal of the external fixator. METHODS: From January 2008 to December 2019, 178 patients with bone defects of the lower extremity caused by infection were treated by bone transport using a unilateral external fixator in our medical institution. TGBD was defined as the bone callus in the distraction area with a deviation to the force line of the femur (> 10°) or tibia (> 12°) after removal of the external fixator. The Association for the Study and Application of the Method of Ilizarov (ASAMI) standard was applied to assess the bone and functional outcomes. After the data were significant by the T-test or Pearson's Chi-square test was analyzed, odds ratios were calculated using logistic regression tests to describe factors associated with the diagnosis of TGBD. RESULTS: A total of 178 patients were enrolled in the study, with a mean follow-up time of 28.6 ± 3.82 months. The positive result of the bacteria isolated test was observed in 144 cases (80.9%). The rate of excellent and good in the bone outcomes (excellent/good/fair/poor/failure, 41/108/15/14/0) was 83.7%, and 92.3% in the functional results (excellent/good/fair/poor/failure, 50/98/16/14/0) according to the ASAMI criteria. TGBD after removal of external fixator occurred in twenty-two patients (12.3%), including 6 tibias, and 16 femurs. Age > 45 years, BMI > 25 kg/m2, femoral defect, diabetes, osteoporosis, glucocorticoid intake, duration of infection > 24 months, EFT > 9 months, EFI > 1.8 month/cm were associated significantly with a higher incidence of TGBD in the binary logistic regression analysis (P < 0.05). The incidence more than 50% was found in patients with femoral defect (76.1%), osteoporosis (72.7%), BMI > 25 kg/m2 (69.0%), diabetes (59.5%), glucocorticoid intake (54.7%). In the multivariate logistic regression analyses, the following factors were associated independently with TGBD, including age > 45 years, BMI > 25 kg/m2, femoral defect, diabetes, and osteoporosis. CONCLUSIONS: Bone transport using a unilateral external fixator was a safe and practical method in the treatment of CSBD caused by infection. The top five risk factors of TGBD included femoral defect, BMI > 25 kg/m2, duration of bone infection > 24 months, age > 45 years, and diabetes. Age > 45 years, BMI > 25 kg/m2, femoral defect, osteoporosis, and diabetes were the independent risk factors. The higher incidence of TGBD may be associated with more risk factors.

Bone Defects in Tibia Managed by the Bifocal vs. Trifocal Bone Transport Technique: A Retrospective Comparative Study.

Background: The purpose of this study is to evaluate the clinical effectiveness and determine the differences, if any, between the trifocal bone transport (TFT) technique and the bifocal bone transport (BFT) technique in the reconstruction of long segmental tibial bone defects caused by infection using a monolateral rail external fixator. Methods: A total of 53 consecutive patients with long segmental tibial bone defects caused by infection and treated by monolateral rail external fixator in our department were retrospectively collected and analyzed from the period January 2013 to April 2019, including 39 males and 14 females with an average age of 38.8 ± 12.4 years (range 19-65 years). Out of these, 32 patients were treated by the BFT technique, and the remaining 21 patients were managed by the TFT technique. The demographic data, operation duration (OD), docking time (DT), external fixation time (EFT), and external fixation index (EFI) were documented and analyzed. Difficulties that occur during the treatment were classified according to Paley. The clinical outcomes were evaluated by following the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria at the last clinical visit. Results: All patients achieved an infection-free union finally, and there was no significant difference between the two groups in terms of demographic data and both ASAMI bone and functional scores (p > 0.05). The mean defect size and OD in TFT (9.4 ± 1.5 cm, 161.9 ± 8.9 min) were larger than that in BFT (7.8 ± 1.8 cm, 122.5 ± 11.2 min) (p < 0.05). The mean DT, EFT, and EFI in TFT (65.9 ± 10.8 days, 328.0 ± 57.2 days, 34.8 ± 2.1 days/cm) were all less than those in BFT (96.8 ± 22.6 days, 474.5 ± 103.2 days, 60.8 ± 1.9 days/cm) (p < 0.05). Difficulties and complications were more prevalent in the BFT group than in the TFT group (p < 0.05). Conclusion: Both the trifocal and BFT techniques achieve satisfactory clinical outcomes in the reconstruction of long segmental tibial bone defects caused by infection using a monolateral rail external fixator. The TFT technique can significantly decrease the DT, EFT, EFI, difficulties, and complications compared with the BFT technique.

Enhanced Nerve Regeneration by Bionic Conductive Nerve Scaffold Under Electrical Stimulation.

Repair of peripheral nerve defect (PND) with a poor prognosis is hard to deal with. Neural conduit applied to nerve defect at present could not achieve the effect of autologous nerve transplantation. We prepared bionic conductive neural scaffolds to provide a new strategy for the treatment of PNDs. The highly aligned poly (L-lactic acid) (PLLA) fiber mats and the multi-microchannel conductive scaffolds were combined into bionic conductive nerve scaffolds, which were implanted into rats with sciatic nerve defects. The experimental animals were divided into the scaffold group (S), scaffold with electrical stimulation (ES) group (S&E), and autologous nerve transplantation group (AT). The regenerative effect of bionic conductive nerve scaffolds was analyzed. Compared with aligned PLLA fiber mats (APFMs), highly aligned fiber mats had a higher fiber orientation and did not change the tensile strength, Young's modulus, degradation rate, elongation at break of the fiber membrane, and biocompatibility. The bionic conductive nerve scaffolds were well matched with the rat sciatic nerve. The evaluations of the sciatic nerve in Group S&E were close to those in Group AT and better than those in Group S. Immunohistochemical results showed that the expression levels of neurofilament heavy polypeptide (NF-H) and protein S100-B (S100-ß) in Group S&E were higher than those in Group S, and the expression levels of low-density lipoprotein receptor-related protein 4 (LRP4), mitogen-activated protein kinase (MAPK) p38, extracellular signal-regulated kinase (ERK), and mitogen-activated protein kinase kinase (MEK) in Group AT were higher than those in Group S. Bionic conductive nerve scaffolds combined with ES could enhance peripheral nerve regeneration and achieve satisfactory nerve regeneration close to autologous nerve grafts. ERK, p38 MAPK, MEK, and LRP4 may be involved in peripheral nerve regeneration under ES.

Efficacy comparison of trifocal bone transport using unilateral external fixator for femoral and tibial bone defects caused by infection.

BACKGROUND: This study aimed to evaluate the clinical and functional outcomes of patients with femoral and tibial critical-sized bone defect (CSBD) treated by trifocal bone transport using the Ilizarov method. METHODS: From March 2011 and January 2017, clinical and radiographic data of patients with CSBD (> 6 cm) caused by infection were documented and analyzed. Patients were divided into the femur group (n = 18) and tibia groups (n = 21) according to the location of bone transport. The bone and functional outcomes were evaluated according to the Association for the Study and Application of the Method of the Ilizarov (ASAMI) criterion, and postoperative complications were evaluated by Paley classification. RESULTS: A total of 39 patients were managed by the trifocal bone transport for the femur (n = 18) or tibia (n = 21) bone defects with a mean follow-up time of 26.1 months (range 17-34 months). Eighteen femurs and 21 tibias with a mean distraction regenerate length (DRL) of 8.3 cm (range 6-13 cm) and 7.5 cm (range 6-11 cm) respectively. Infection was eradicated in all patients, and the total bone union was received in all cases (100%). Statistical difference of bone grade (excellent/good/fair/poor, 3/11/3/1 vs 2/13/4/2, P < 0.05), and function grade (excellent/good/fair/poor, 3/14/1/0 vs 4/13/3/1, P < 0.05) were respectively observed between the femur group and tibia group. The excellent and good rate of bone (femur vs tibia, 77.8% vs 71.4%), and function grade (femur vs tibia, 94.4% vs 80.9%) was higher in the femur group than the tibia. The rate of complication in the femur group was lower than in the tibia (femur vs tibia, 94.4% vs 76.2%). One femur and five tibias were performed additional surgery for delayed union and axial deviation. CONCLUSIONS: The trifocal bone transport using the unilateral external fixator was a practical method in the management of CSBD in the lower extremity. The BUT and EFI of the femur group were shorter than the tibia. Although the complications noted were more frequent on the femur, these were mostly minor.

Retrospective clinical outcomes in the definitive treatment of high-energy tibial diaphyseal fractures using hexapod external fixator versus monolateral external fixator.

BACKGROUND: External fixation, which can preserve the biomechanical microenvironment of fracture healing, plays an important role in managing the high-energy fractures with poor surrounding soft tissues. The purpose of this study was to determine the differences of clinical outcomes, if any, between hexapod external fixator and monolateral external fixator in the definitive treatment of high-energy tibial diaphyseal fractures. METHODS: A total of 53 patients with high-energy tibial diaphyseal fractures and definitively treated by the hexapod external fixator (HEF) or monolateral external fixator (MEF) were retrospectively collected and analyzed, from March 2015 to June 2019. There were 31 patients in the HEF treatment, and the other 22 patients were managed by the MEF. The demographic data, surgical duration, external fixation time, final radiological results, complications, and clinical outcomes were documented and analyzed. Difficulties that occurred during the treatment were classified according to Paley. The clinical outcomes were evaluated by the Association for the Study and Application of the Method of Ilizarov criteria (ASAMI) at the last clinical visit. RESULTS: The mean surgical duration in the HEF group (62.4 ± 8.3 min) was shorter than that in the MEF group (91.4 ± 6.9 min) (P < 0.05). All patients acquired complete bone union finally. Patients in the HEF group (24.2 ± 3.1 weeks) underwent a shorter average external fixation time than that in the MEF group (26.3 ± 3.8 weeks) (P < 0.05). Satisfactory alignment was achieved in all patients without the need for remanipulation. The residual sagittal plane deformities in the HEF group were all less than that in the MEF group (P < 0.05). The complication rate was 35.5% in the HEF group, while 45.5% in the MEF group. There was no statistically significant difference between the two groups in ASAMI scores (P > 0.05). CONCLUSION: There is no statistically significant difference in finally clinical outcomes between hexapod external fixator and monolateral external fixator in the definitive treatment of high-energy tibial diaphyseal fractures. The hexapod external fixation treatment is a superior effective method, including advantages of stable fixation, less surgical duration, postoperatively satisfactory fracture reduction, and fewer complications.

[V-Y plasty combined with gastrocnemius aponeurosis turndown repairing the Myerson type â ¢ chronic Achilles tendon rupture].

Objective: To investigate the clinical application and effectiveness of V-Y plasty combined with gastrocnemius aponeurosis turndown in the repair of Myerson type Ⅲ chronic Achilles tendon rupture combined with large tendon defect. Methods: Between February 2008 and July 2019, 25 patients underwent the V-Y plasty combined with gastrocnemius aponeurosis turndown to treat the Myerson type Ⅲ chronic Achilles tendon rupture. There were 21 males and 4 females. The age ranged from 17 to 56 years, with an average of 34.3 years. Achilles tendon rupture was caused by sports injury in all patients, and the duration from Achilles tendon rupture to operation was 31-70 days, with an average of 53.9 days. After resection of fibrous scar tissue, the distance of Achilles tendon defect was 7-12 cm, with an average of 9.04 cm. The clinical results were evaluated by the Achilles tendon total rupture score (ATRS), American Orthopaedic Foot and Ankle Society (AOFAS) score, dorsiflexion and heel raise height before and after operation. Results: The donor and recipient wounds of all 25 cases healed by first intention after operation. All patients were followed up 24 months. During the follow-up, 3 patients developed mild wound infection, which was cured after anti-infection treatment. One patient had Achilles tendon exposure, which was cured after local flap transfer and repair. Ultrasound and MRI reexamination at 3-12 months after operation showed no Achilles tendon elongation, adhesion, or re-rupture. At 24 months after operation, the ATRS score, AOFAS score, dorsiflexion and heel raise height of affected side significantly improved when compared with those before operation (P<0.05). However, the dorsiflexion and heel raise height of affected side were still significantly worse than those of the healthy side (P<0.05). Conclusion: V-Y plasty combined with gastrocnemius aponeurosis turndown to repair the chronic Achilles tendon rupture can achieve good effectiveness, and the Achilles tendon function significantly improved after repair. However, the procedure is more invasive and has a long duration of intraoperative wound exposure, causing an increased risk of infection, and the aesthetic is not good.

Treatment outcome of tardy ulnar nerve palsy associated with traumatic cubitus valgus by supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release.

BACKGROUND: Tardy ulnar nerve palsy is a common late complication of traumatic cubitus valgus. At present, the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus is still controversial, whether these two problems can be corrected safely and effectively in one operation is still unclear. To investigate the supracondylar shortening wedge rotary osteotomy combined with in situ tension release of the ulnar nerve in the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus. METHODS: Between 2012 and 2019, 16 patients who had traumatic cubitus valgus deformities with tardy ulnar nerve palsy were treated with simultaneous supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release. we compared a series of indicators of preoperative and postoperative follow-up for at least 24 months, (1) elbow range of motion; (2) the radiographic correction of the preoperative and postoperative humerus-elbow-wrist angles; (3) the static two-point discrimination and grip strength; and (4) the preoperative and postoperative DASH scores of upper limb function. The minimum follow-up was 24 months postoperative (mean, 33 months; range, 24 ~ 44 months). RESULTS: The mean ROM was improved from 107 ° preoperatively to 122 ° postoperatively (P = 0.001). The mean preoperative elbow wrist angle was 24.6 °, and the mean postoperative humerus-elbow wrist angle was 12.1 ° (P < 0.001). The average grip strength and static two-point discrimination improved from 21 kgf and 8 mm to 28 kgf and 4.0 mm (P < 0.001 and P < 0.001, respectively). The ulnar nerve symptoms were improved in all patients except one. The mean HASH score improved from 29 to 16 (P < 0.001). CONCLUSION: Supracondylar shortening wedge rotary osteotomy combined with in situ tension release of ulnar nerve is an effective method for the treatment of traumatic cubitus valgus with tardy ulnar nerve palsy, which restored the normal biomechanical characteristics of the affected limb and improved the elbow joint function.

Hypoxia During the Consolidation Phase of Distraction Osteogenesis Promotes Bone Regeneration.

Background: Hypoxia is the critical driving force for angiogenesis and can trigger the osteogenic-angiogenic coupling followed by the enhancement of bone regeneration. While lots of studies showed that hypoxia administration can accelerate bone formation during distraction osteogenesis (DO), the therapeutic timing for the osteogenic purpose was concentrated on the distraction phase. The outcomes of hypoxia administration in the consolidation phase stay uncertain. The purpose of this study was to determine the osteogenic effectiveness of hypoxia therapy during the consolidation phase, if any, to enhance bone regeneration in a rat femoral DO model. Methods: A total of 42 adult male Sprague-Dawley rats underwent right femoral mid-diaphysis transverse osteotomy and were randomly divided into Control (NS administration, n = 21) and Group1 (deferoxamine therapy, n = 21) after distraction. During the consolidation phase, Group1 was treated with local deferoxamine (DFO) injection into the distraction zone, while the Control underwent the same dosage of NS. Animals were sacrificed after 2, 4, and 6 weeks of consolidation. The process of bone formation and remodeling was monitored by digital radiographs, and the regenerated bone was evaluated by micro-computed tomography (micro-CT), biomechanical test, and histological analysis. The serum content of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) were measured by enzyme linked immunosorbent assay (ELISA) for further analysis. Results: Bone regeneration was significantly enhanced after hypoxia therapy during the consolidation phase. The digital radiograph, micro-CT, and biomechanical evaluation showed better effects regarding volume, continuity, and mechanical properties of the regenerated bone in Group1. The histomorphological evaluation also revealed the hypoxia treatment contributed to accelerate bone formation and remodeling during DO. The higher positive expression of angiogenic and osteogenic markers were observed in Group1 after hypoxia administration according to the immunohistochemical analysis. The serum content of HIF-1α and VEGF was also increased after hypoxia therapy as evidenced from ELISA. Conclusion: Hypoxia administration during the consolidation phase of distraction osteogenesis has benefits in enhancing bone regeneration, including accelerates the bone formation and remodeling.

A Novel Hepatectomy Model in Mice Using a Gutta Cutter Tool: A Feasibility Study and Preliminary Results.

BACKGROUND: A simple and reproducible model of hepatectomy provides an essential basis for the study of liver regeneration. However, current rodent models of hepatectomy involve lobectomy, which cannot simulate clinical liver resection with surgical margins. The main purpose of this study was to evaluate a novel murine modeling technique for hepatectomy using a gutta cutter. METHODS: Seventy-five C57BL/6 mice were randomly divided into 3 groups (n = 25 mice per group). Group 1 (control) underwent single ligature of the left lobe. Group 2 underwent left lobe local (5-mm diameter) hepatectomy by gutta cutter. Group 3 underwent partial left lobe resection (1.5 cm) by gutta cutter. Postoperative complications were analyzed. Serum aspartate transaminase, alanine aminotransferase, alkaline phosphatase, urea nitrogen, interleukin 6, and tumor necrosis factor-α were detected using an automatic biochemical analyzer. Hematoxylin-eosin and immunohistochemical staining was used to examine pathology, proliferating cell nuclear antigen, caspase-3, CD34, signal transducer and activator of transcription 3 (STAT-3), and phosphorylated STAT-3 (p-STAT-3). RESULTS: Major postoperative complications, hepatic enzymes, kidney function, interleukin 6, and tumor necrosis factor-α were similar among the groups (all P > .05). Histology showed little necrosis and a clear surgical boundary in groups 2 and 3. Groups 1 and 3 had higher positive cell levels (proliferating cell nuclear antigen, CD34, p-STAT-3) than group 2 (P < .05). There were no significant differences in caspase-3 and STAT-3 positive cells. CONCLUSIONS: Hepatectomy in mice using a gutta cutter to better mimic human liver resection shows potential as an alternative and safe animal model. This model may be useful in investigating methods of promoting liver regeneration.

Staged correction trajectory with hexapod external fixator for the satisfactory reduction of long bone shaft fracture.

BACKGROUD: When the reduction of long bone shaft fracture fragments is performed by a hexapod external fixator, the collision and interference between bony ends often results in an incomplete reduction and a time-consuming procedure. The purpose of this study was to present and determine the clinical effectiveness of staged correction trajectory with hexapod external fixator in the reduction of a long bone shaft fracture. METHODS: A total of 57 patients with tibial shaft fractures treated by hexapod external fixator were retrospectively analyzed from June 2016 to February 2020. Thirty-one cases (Group I) underwent a conventional one-step reduction trajectory from June 2016 to July 2018. Starting in September 2018, the other twenty-six patients (Group II) underwent staged correction trajectory (three key points reduction trajectory of "distraction-derotation-reduction"). The demographic data, residual deformities before and after correction, number of repeated X-rays after the first postoperative X-ray, duration of deformity correction process, and external fixation time were analyzed. Johner-Wruhs criteria were used to evaluate the final clinical outcomes. RESULTS: All the 57 patients achieved satisfactory fracture reduction and bone union. There were no significant differences between the two groups in demographic data, residual deformities before and after correction, external fixation time, and final clinical outcomes (p > 0.05). The average number of repeated X-rays after the first postoperative X-ray and mean duration of deformity correction process in Group II (1.3 times, 2.9 days) were all less than those in Group I (2.3 times, 5.1 days) (p < 0.05). CONCLUSION: Compared with the conventional one-step reduction trajectory, there is no differences in final clinical outcomes, but the staged correction trajectory provides less repeated X-rays and shorter reduction process duration.

Nine-year-long complex humeral nonunion salvaged by distraction osteogenesis technique: a case report and review of the literature.

BACKGROUND: Humeral nonunion with significant bone loss or shortening is uncommon and poses a complex clinical problem. We present a case of humeral nonunion with a large segmental bone defect treated with the distraction osteogenesis technique and remedy the radial nerve palsy produced during distraction osteogenesis by forearm tendon transfers. The reconstruction of upper limb function was achieved with satisfactory results. This case provides a referenceable alternative method for repairing large segmental bone defects due to complex nonunion of the upper extremity, as well as a remedy in the unfortunate event of radial nerve palsy, providing a reference and lessons learned for the treatment of similar cases and the management of possible complications. CASE PRESENTATION: A 31-year-old male patient experienced 9 years of hypertrophic nonunion due to an unreliable internal fixation. The radiographs showed the absence of bone bridging between the two fragments, loosening of the screws, and extensive osteolysis around the internal screws. The patient was treated with distraction osteogenesis. At the end of the distraction period, the patient unfortunately developed right radial nerve paresis, which was salvaged by forearm tendon transplantation, and finally reconstructed hand function and achieved bone union of the humerus. CONCLUSION: Distraction osteogenesis, although not a panacea for all humeral nonunions with significant segmental bone loss, does offer a viable salvage procedure in this unusual and often complex clinical problem. When irreversible radial nerve palsy occurs during distraction, forearm tendon transfers can have a good clinical effect.

Marker- three dimensional measurement versus traditional radiographic measurement in the treatment of tibial fracture using Taylor spatial frame.

BACKGROUND: The Taylor Spatial Frame (TSF) has been widely used for tibial fracture. However, traditional radiographic measurement method is complicated and the reduction accuracy is affected by various factors. The purpose of this study was to propose a new marker- three dimensional (3D) measurement method and determine the differences of reduction outcomes, if any, between marker-3D measurement method and traditional radiographic measurement in the TSF treatment. METHODS: Forty-one patients with tibial fracture treated by TSF in our institution were retrospectively analyzed from January 2016 to June 2019, including 21 patients in the marker-3D measurement group (experimental group) and 20 patients in the traditional radiographic measurement group (control group). In the experimental group, 3D reconstruction with 6 markers installed on the TSF was performed to determine the electronic prescription. In the control group, the anteroposterior (AP) and lateral radiographs were performed for the traditional parameter measurements. The effectiveness was evaluated by the residual displacement deformity (RDD) and residual angle deformity (RAD) in the coronal and sagittal plane, according to the AP and lateral X-rays after reduction. RESULTS: All patients achieved functional reduction. The residual RDD in AP view was 0.5 (0, 1.72) mm in experimental group and 1.74 (0.43, 3.67) mm in control group. The residual RAD in AP view was 0 (0, 1.25) ° in experimental group and 1.25 (0.62, 1.95) °in control group. As for the lateral view, the RDD was 0 (0, 1.22) mm in experimental group and 2.02 (0, 3.74) mm in control group, the RAD was 0 (0, 0) ° in experimental group and 1.42 (0, 1.93) ° in control group. Significant differences in all above comparisons were observed between the two groups (AP view RDD: P = 0.024, RAD: P = 0.020; Lateral view RDD: P = 0.016, RAD: P = 0.004). CONCLUSIONS: The present study introduced a marker-3D measurement method to complement the current TSF treatment. This method avoids the manual measurement error and improves the accuracy of fracture reduction, providing potential advantages of bone healing and function rehabilitation.