In vitro biomechanical investigation of the screw-holding capacity.
Objective. To evaluate the effect of repetitive screw-hole use on the insertional torque and retentive strength of vertebral system screws.
Summary and Background Data. Placement and removal of vertebral system screws is sometimes necessary during the surgical procedures in order to assess the walls of the pilot hole. This procedure may compromise the holding capacity of the implant.
Methods. Screws with outer diameter measuring 5, 6, and 7 mm were inserted into wood, polyurethane, polyethylene,
and cancellous bone cylindrical blocks. The pilot holes selleck chemicals llc were made with drills of a smaller, equal, or wider diameter than the
inner screw diameter. Three experimental groups were established based on the number of insertions and reinsertions of the screws and subgroups were created according to the outer diameter SRT1720 cost of the screw and the diameter of the pilot hole used.
Results. A reduction of screw-holding capacity was observed between the first and the following insertions regardless the anchorage material. The pattern of reduction of retentive strength was not similar to the pattern of torque reduction. The pullout strength was more pronounced between the first and the last insertions, while the torque decreased more proportionally from the first to the last insertions.
Conclusion. Insertion and reinsertion of the screws of the vertebral fixation system used in the present
study reduced the insertion torque and screw purchase.”
“Objective-To evaluate outcome after intralesional injection of insulin-like growth factor-I (IGF-I) for treatment of superficial digital flexor (SDF) tendonitis in Thoroughbred racehorses.
Design-Retrospective case series.
Animals-40 Thoroughbred racehorses.
Procedures-Medical records of racehorses with SDF tendonitis treated within 13 weeks after injury by intralesional injection of IGF-I (25 or 50 jig every other day for 4 or 5 treatments) were reviewed. Outcome was determined via analysis of race records, owner follow-up, and examination.
Results-Mean age of the horses was 3.1 years (range, 2 to 7 years), and time from injury to treatment ranged from www.selleckchem.com/products/pf-562271.html 8 to 90 days. Mean +/- SD approximate lesion length on admission was 15.6 +/- 6.0 cm, and mean percentage cross-sectional area of the tendon affected was 26 +/- 18%. Twenty-six of the 40 horses underwent desmotomy of the accessory ligament of the SDF tendon. Echolucency was reduced in 23 of 26 horses by the end of the treatment period. Twenty-one of 34 (62%) horses for which race data were available raced at least once after treatment, including 10 (30%) horses that raced between 1 and 4 times and 11 horses (32%) that raced >= 5 times. Thirteen of 28 (46%) horses had a recurrence of tendonitis or developed tendonitis elsewhere.