Comparison of a minimally invasive osteosynthesis technique with conventional open surgery for transverse patellar fractures.

PURPOSE: The study aims to compare the efficacy and safety of a new minimally invasive osteosynthesis technique with those of conventional open surgery for transverse patellar fractures. METHODS: It was a retrospective study. Adult patients with closed transverse patellar fracture were included, and with open comminuted patellar fracture were excluded. These patients were divided into minimally invasive osteosynthesis technique (MIOT) group and open reduction and internal fixation (ORIF) group. Surgical time, frequency of intraoperative fluoroscopy, visual analogue scale score, flexion, extension, Lysholm knee score, infection, malreduction, implant migration and implant irritation in two groups were recorded and compared. Statistical analysis was performed by the SPSS software package (version 19). A p < 0.05 indicated statistical significance. RESULTS: A total of 55 patients with transverse patellar fractures enrolled in this study, the minimally invasive technique was performed in 27 cases, and open reduction was performed in 28 cases. The surgical time in the ORIF group was shorter than that in the MIOT group (p = 0.033). The visual analogue scale scores in the MIOT group were significantly lower than those in the ORIF group only in the first month after surgery (p = 0.015). Flexion was restored faster in the MIOT group than that in the ORIF group at one month (p = 0.001) and three months (p = 0.015). Extension was recovered faster in the MIOT group than that in the ORIF group at one month (p = 0.031) and three months (p = 0.023). The recorded Lysholm knee scores in the MIOT group were always greater than those in the ORIF group. Complications, such as infection, malreduction, implant migration, and implant irritation, occurred more frequently in the ORIF group. CONCLUSION: Compared with the ORIF group, the MIOT group reduced postoperative pain and had less complications and better exercise rehabilitation. Although it requires a long operation time, MIOT may be a wise choice for transverse patellar fractures.

Indirect reduction technique using a distraction support in minimally invasive percutaneous plate osteosynthesis of tibial shaft fractures.

PURPOSE: To describe an indirect reduction technique during minimally invasive percutaneous plate osteosynthesis (MIPPO) of tibial shaft fractures with the use of a distraction support. METHODS: Between March 2011 and October 2014, 52 patients with a mean age of 48 years (16-72 years) sustaining tibial shaft fractures were included. All the patients underwent MIPPO for the fractures using a distraction support prior to insertion of the plate. Fracture angular deformity was assessed by goni- ometer measurement on preoperative and postoperative images. RESULTS: Preoperative radiographs revealed a mean of 7.6°(1.2°-28°) angulation in coronal plane and a mean of 6.8°(0.5°-19°) angulation in sagittal plane. Postoperative anteroposterior and lateral radio- graphs showed a mean of 0.8°(0°-4.0°) and 0.6°(0°-3.6°) of varus/valgus and apex anterior/posterior angulation, respectively. No intraoperative or postoperative complications were noted. CONCLUSIONS: This study suggests that the distraction support during MIPPO of tibial shaft fractures is an effective and safe method with no associated complications.

Per- and polyfluoroalkyl substances exposure and bone mineral density in the U.S. population from NHANES 2005-2014.

BACKGROUND: Environmental exposures such as perfluoroalkyl substances (PFASs) were considered potential risks for bone mineral density (BMD). OBJECTIVE: To examine the associations between PFASs and BMD among the U.S. population. METHODS: This study included a total of 6416 participants from the National Health and Nutrition Examination Survey (NHANES 2005-2014). Multiple linear regression models were used to analyze the associations between serum PFASs and BMD and the coefficient ß with 95% confidence intervals (95% CI) was calculated as the effect estimate. Covariates such as age, race, BMI, smoking, alcohol intake, milk intake, and physical activity were adjusted in these models. Additionally, gender and menopausal period were considered in further subgroup analyses. RESULTS: Based on the combined data of NHANES 2005-2014, the effects from exposure to PFASs on BMD were found with gender and menopausal status differences. Positive associations were found in PFOA (ß = 0.010; 95% CI: 0.003, 0.016), PFHxS (ß = 0.007; 95% CI: 0.003, 0.012), and PFNA (ß = 0.001; 95% CI: 0.001, 0.017) in total population. Negative associations for PFOA (ß = -0.020; 95% CI: -0.029, -0.012), PFOS (ß = -0.011; 95% CI: -0.028, -0.011), PFHxS (ß = -0.019; 95% CI: -0.025, -0.013), PFDE (ß = -0.010; 95% CI: -0.016, -0.005), and PFNA (ß = -0.011; 95% CI: -0.021, -0.002) were found in women, while no significant association was found in men. In further subgroup analyses, women in pre-menopause status showed consistent negative associations. SIGNIFICANCE: PFASs exposure may be associated with BMD and gender and menopausal status confound the associations.

[Cause of micromotion in distal femoral prosthesis].

OBJECTIVE: To investigate possible causes of micromotion in distal femoral prosthesis. METHODS: Based on the assumption that the femur and prosthesis were considered as concentric cylinders with completely bonded interface, a theoretical model simulating the interfacial stress transfer was established. The distributions of the interfacial shear and radial stresses with the changing of z were obtained through mathematics and mechanics deducing. RESULTS: The maximum interfacial shear stress occurred at the position of z=0, namely, the cross section of the femur neck. The interfacial shear stress sharply decreased with the increasing of z and came to nearly zero at the range of z> 0.1 m. While the interfacial radial stress increased with the increasing of z,at the range of z >0.05 m it was constant and reached the maximum. CONCLUSION: The micromotion in distal prosthesis is caused by the interfacial radial stress.

[Minimally-invasive internal fixation for mid-lateral 1/3 clavicle fracture with distal clavicular anatomic locking plate].

OBJECTIVE: To investigate clinical effects of minimally-invasive internal fixation for mid-lateral 1/3 clavicle fracture with distal clavicular anatomic locking plate. METHODS: From February 2016 to March 2017, 32 patients with mid-lateral 1/3 clavicle fractures treated by minimally-invasive internal fixation with distal clavicular anatomic locking plate, including 24 males and 8 females with an average of (42.3±12.7) years old (ranged from 22 to 68 years old). According to Robinson classification, 6 patients were type 2A2, 18 patients were type 2B1 and 8 patients were type 2B2. No vessel and nerve injury occurred before operation. The time from injury to operation ranged from 0 to 6 days with an average of (3.1±1.4) days. Length of bilateral clavicule were compared before and after operation to evaluate fracture reduction. Constant score at 6 months after operation was applied to assess recovery of shoulder function. RESULTS: Thirty patients were followed up from 11 to 18 months with an average of (13.3±2.2 ) months. No vessel and nerve injury, implant failure, nonunion or delayed union occurred after operation, and facture wound healed at stage I, the time ranged from 8 to 12 weeks with an average of(10.2±1.1) weeks. Shortened length of clavicle decreased from(11.2±3.6) % before operation to (0.4±0.3)% after operation at 2 days. Ten patients removed internal fixation at 8 months after operation without re-fracture occurred after remove plate. Constant score increased from 23.53±5.21 before operation to 94.30±5.60 after operation at 6 months, and 26 patients got excellent results, and 4 good. Patients were satisfied aesthetic degree of scar and shoulder joint function. CONCLUSIONS: Minimally-invasive internal fixation for mid-lateral 1/3 clavicle fracture with distal clavicular anatomic locking plate, which has advantages of less trauma, rapid recover, less scar, could receive good clinical effects and not effect beauty.

[Descending branch of anterior lateral malleolar artery based anterograde island flaps for reconstruction of foot and ankle defects].

OBJECTIVE: To explore surgical method and clinical effects of descending branch of the anterior lateral malleolar artery based anterograde island flap for repairing foot and ankle wounds. METHODS: Nine patients with skin defects of foot and ankle repaired by descending branch of the anterior lateral malleolar artery based anterograde island flap were studied from June 2015 to January 2017, including 6 males and 3 females aged from 32 to 63 years old. The wound were located on foot and ankle and associated with exposure of bone, tendon, blood vessels or nerves. The surface of wound located on foot in 6 patients, and 3 patients in ankle joint. The area of defect ranged from 1.5 cm×2.0 cm to 6.0 cm×13.0 cm, and the area of flap ranged from 2.0 cm×3.0 cm to 7.0 cm×15.0 cm. The donor site was skin grafted with split-thickness skin from abdomen. Appearance, texture, condition of donor site of island flaps after operation were observed, satisfied degree of clinical effects were evaluated by ZHANG Hao's evaluation, and AOFAS score were used to evaluate function. RESULTS: Circulations of flaps in 9 cases were stable without blockage, and healed well at 2 weeks after operation. All patients were followed up from 2 to 18 months with an average of(8.0±2.3) months. All flap were survived at stage I, pedicles looked smooth and tidy, no cat-ear formed, the texture of flap was soft with satisfied appearance, the color was near to surrounding skin. The surface of wound were tidy after skin graft of donor sites without scar hypertrophy. Nine patients got satisfied results according to ZHANG Hao's evaluation, and AOFAS score was excellent. CONCLUSIONS: Descending branch of the anterior lateral malleolar artery based anterograde island flap for repairing foot and ankle wounds, which has advantages of protect main vessel, thin flap, is a simple and effective method.

Identification of CHD1L as an Important Regulator for Spermatogonial Stem Cell Survival and Self-Renewal.

Chromodomain helicase/ATPase DNA binding protein 1-like gene (Chd1l) participates in chromatin-dependent processes, including transcriptional activation and DNA repair. In this study, we have found for the first time that Chd1l is mainly expressed in the testicular tissues of prepubertal and adult mice and colocalized with PLZF, OCT4, and GFRα1 in the neonatal mouse testis and THY1+ undifferentiated spermatogonia or spermatogonial stem cells (SSCs). Knockdown of endogenous Chd1l in cultured mouse undifferentiated SSCs inhibited the expression levels of Oct4, Plzf, Gfrα1, and Pcna genes, suppressed SSC colony formation, and reduced BrdU incorporation, while increasing SSC apoptosis. Moreover, the Chd1l gene expression is activated by GDNF in the cultured mouse SSCs, and the GDNF signaling pathway was modulated by endogenous levels of Chd1l; as demonstrated by the gene expression levels of GDNF, inducible transcripts Etv5, Bcl6b, Pou3f, and Lhx1, but not that of GDNF-independent gene, Taf4b, were significantly downregulated by Chd1l knockdown in mouse SSCs. Taken together, this study provides the first evidence to support the notion that Chd1l is an intrinsic and novel regulator for SSC survival and self-renewal, and it exerts such regulation at least partially through a GDNF signaling pathway.

[Treatment of complete acromioclavicular joint dislocation with transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament].

OBJECTIVE: To explore the operation methods and clinical effects of transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament in treating complete acromioclavicular joint dislocation. METHODS: From January 2006 to June 2012,26 patients with acute complete acromioclavicular joint dislocation underwent surgery. Transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament, additional clavical hoot plate and Kirschner wires fixation, were performed in all the patients. Among the patients, 18 patients were male and 8 patients were female, with an average age of 36.7 years old (ranged from 25 to 51 years). The duration from injury to operation was from 3 to 12 days with an average of 5 days. According to the Rockwood classification, 4 cases were grade III and 22 cases were grade V . Clinical manifestation included local swelling, tenderness with snapping, limitation of shoulder joint motion. In preoperative bilateral shoulder joint X-rays, the injured coracoclavicular distance was (16.2 ± 5.0) mm which was significantly wider than that of uninjured sides (7.6 ± 1.0) mm. Clinical results were evaluated according to X-rays and Constant-Murley score. RESULTS: All incisions obtained primary healing after operation without complication of infection, internal fixation breakage, redislocation. All the patients were followed up from 12 to 30 months with an average of 18 months. Kirschner wires and internal fixation plate were removed at 1 month and 8-10 months after operation, respectively. At final follow-up, the motion of shoulder joint recovered to normal and a no pain joint was obtained. According to Constant-Murley score, 24 cases got excellent results and 2 cases good. There was no significant difference after operation between the injured coracoclavicular distance and the uninjured contralateral side [(7.7 ± 1.2) mm vs (7.6 ± 1.0) mm), P > 0.05]. CONCLUSION: Transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament, additional fixation using hook plate and Kirschner wires is the effective surgical method in treating complete acute acromioclavicular joint dislocation.