The Effect of Medial Release of the Distal Patellar Tendon Insertion on Lateral Patella Translation and Residual Insertion Strength: A Cadaveric Study

Patellar tendon avulsion is a risk with difficult exposure in a stiff knee, patella baja or previous tibial osteotomy. We sought to define a safe amount of release of the patellar tendon insertion for such cases. Eleven pairs of fresh frozen cadaveric lower limb specimens were acquired and randomized to either intact or partial release of the distal tibial insertion. Partial release of the tibial insertion of the tendon increased lateral exposure a mean 29% ± 15% (P = 0.002) while reducing ultimate strength to a mean of 80% that of the intact contralateral tendon. Measured patella release increased lateral patella translation and can be performed without risk of catastrophic rupture with basic activities of daily living following TKA.     

Synthesis of nanostructured powders and thin films of iron sulfide from molecular precursors

Iron(iii) xanthate single-source precursors [Fe(S₂COR)₃] (R = methyl, ethyl, isopropyl and 1-propyl) were used to deposit iron sulfide thin films and nanostructures by two simple, efficient and low-cost methods (spin coating and solid state deposition). The single-crystal X-ray structures of the iron(iii) n-propyl xanthate and iron(iii) iso-propyl xanthate have been determined. Thermogravimetric analysis (TGA) studies of the complexes shows that decomposition of the complexes produces iron sulfide, pyrite or trolite. The crystallinity of iron sulfide thin films and powder samples was studied using X-ray diffraction (XRD), and their morphology was studied by scanning electron microscopy (SEM).

Iron(iii) xanthate single-source precursors were used to deposit iron sulfide thin films and nanostructures by spin coating and solid state deposition.     

Sensory retraining is key to biofeedback therapy for formed stool fecal incontinence

OBJECTIVES: Biofeedback is a nonsurgical treatment that reportedly produces good results in 65-75% of fecally incontinent patients. However, previous studies have not ruled out nonspecific treatment effects. It is also unknown whether biofeedback works primarily by improving the strength of the striated pelvic floor muscles or by improving the rectal perception. We aimed to 1) evaluate the efficacy of biofeedback in formed-stool fecal incontinence, 2) assess the relative contribution of sensory and strength retraining to biofeedback outcomes, and 3) identify patient characteristics that predict a good response to treatment. METHODS: Twenty-four patients with frequent (at least once a week) solid-stool incontinence were provided with three to four biofeedback sessions. They were taught to squeeze in response to progressively weaker rectal distentions. Patients were re-evaluated by anorectal manometry and symptom diary 3 months after completing training and by diary and interview 6-12 months after training. RESULTS: Seventeen (71%) were classified responders; 13 became continent and four reduced incontinence frequency by at least 75%. Clinical improvements were maintained at 12-month follow-up. At 3-month follow-up, responders had significantly lower thresholds for perception of rectal distention and for sphincter contraction, but squeeze pressures did not significantly differ from those of nonresponders. Baseline measures that predicted a favorable response were sensory threshold (50 ml or less), urge threshold (100 ml or less), lower threshold for sphincter contraction, and lower threshold for the rectoanal inhibitory reflex; neither anal squeeze pressure nor severity of incontinence predicted treatment outcome. CONCLUSIONS: In solid-stool fecal incontinence biofeedback training effects are robust and seem not to be explained by expectancy or nonspecific treatment effect. Sensory retraining appears to be more relevant than strength training to the success of biofeedback.     

Adipose derived stem cells and nerve regeneration

Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts.