Evaluation of Elastic Stiffness in Healing Achilles Tendon After Surgical Repair of a Tendon Rupture Using In Vivo Ultrasound Shear Wave Elastography.

BACKGROUND There has been no published report assessing the mechanical properties of a repaired Achilles tendon after surgery using shear wave elastography (SWE). The aim of this study was to investigate the changes in mechanical properties of the healing Achilles tendon after surgical repair of a tendon rupture using ultrasound SWE and how these changes correlate with tendon function. MATERIAL AND METHODS Twenty-six patients who underwent surgical repair for Achilles tendon rupture were examined with ultrasound SWE coupled with a linear array transducer (4-15 MHz). The elasticity values of the repaired Achilles tendon in a longitudinal view were measured at 12, 24, and 48 weeks postoperatively. Functional outcomes were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system at 12, 24, and 48 weeks postoperatively. General linear regression analysis and correlation coefficients were used to analyze the relationship between elasticity and the AOFAS score. RESULTS There were significant differences with respect to the mean elasticity values and functional scores of the repaired Achilles tendon at 12, 24, and 48 weeks postoperatively (all P<0.05). Tendon function was positively correlated with the elasticity of the repaired Achilles tendon (P=0.0003). CONCLUSIONS Our findings suggest that SWE can provide biomechanical information for evaluating the mechanical properties of healing Achilles tendon and predict Achilles tendon function.

Experimental study on treatment of acetabular anterior column fractures: applyment of a minimally invasive percutaneous lag screw guide apparatus.

BACKGROUND: The aim of this study was to design a new minimally invasive percutaneous lag screw guide apparatus and to verify its adjuvant treatment of acetabular anterior column fracture on pelvis specimens. METHODS: This guide apparatus was self-developed based on the principles of "two points form a line" and "Rectangle". Using C-arm fluoroscopy, this guide apparatus was used to conduct minimally invasive percutaneous lag screw internal fixation of acetabular anterior column fractures. Ten hollow lag screws were placed into 5 pelvis specimens. RESULT: Result showed no sign of any screws puncturing the cortex or entering into the hip joint on radiological assessment. The cross-section reconstructed vertical distance to the screw, on the cross-section acetabular notch and the cross-section of the screw where the distance of between the screw and the iliopectineal line's arc roof was at its shortest, indicate that at all points (T, R-r) under the line with an inclination of 1 (namely T = R-r) the screw is within the cortex and does not puncture the acetabula anterior column or enter into the hip joint. CONCLUSIONS: We may conclude that this self-developed guide apparatus solves the screw precision problem during the treatment of acetabular anterior column fractures through a minimally invasive percutaneous lag screw.

Outcome of posterior cruciate ligament reconstruction using the single- versus double bundle technique: a meta-analysis.

OBJECTIVE: To test the hypothesis that double bundle posterior cruciate ligament (PCL) reconstruction yields better improvement in stability and functional recovery of the knee than the single bundle technique. METHODS: PubMed®, Embase®, the Cochrane Library, CNKI, Wanfang and CBM disc databases were searched for comparative trials of PCL reconstruction using the single- versus double bundle technique. Data were extracted and meta-analysis was performed for stability improvement and functional recovery. RESULTS: The meta-analysis included 435 patients in three randomized controlled trials (RCTs) and eight non-RCTs. Double bundle reconstruction provided significantly better 90° posterior stability than the single bundle technique (weighted mean difference 0.81, 95% confidence interval, [CI] 0.2, 1.42). Double bundle reconstruction resulted in a significantly higher likelihood of International Knee Documentation Committee (IKDC) examination grade A than the single bundle technique (odds ratio 0.41, 95% CI 0.24, 0.72). CONCLUSIONS: The small amount of data available indicates that double bundle reconstruction is superior to the single bundle technique after isolated PCL injury. These findings should be interpreted with caution due to the low quality and limited sample size of the studies concerned.

[New research progress on atrophic nonunion].

Occurance of atrophic nonunion is a complex process. Previous studies suggested that atrophic nonunion was mainly due to lack of blood supply of fracture fragments, but recent studies found that blood supply was not deficiency in middle and late stages, indicating that decreased osteogenic factors and blood supply in early stages might play an important role in morbidity. Current effective treatment measures for atrophic nonunion mainly include bone graft and fixation,physical therapy, local injection therapy. All-round preventive could reduce incidence of atrophic nonunion. Atrophic nonunion is still a troublesome complication of fractures in orthopaedics, and more attention should be paid for its effective prevention and treatment. The paper summarized recent original articles about atrophic nonunion and reviewed the occurrence mechanisms, diagnosis, prevention and treatment measures of this disease.