Fixation of Cancellous Bone and Physeal Fractures in Dogs and Cats. A Comparison of the Use of Self-reinforced Biodegradable Devices to the Use of Metallic Devices and External Fixations

The use of self-reinforced biodegradable devices made of polyglycolide in the cancellous bone and physeal fractures of dogs and cats was compared to the use of metallic devices and external fixations on similar fractures. The series consisted of 64 dogs and 22 cats divided into 6 comparable groups. The patients in the 2 groups fixed with biodegradable devices started to use their operated limbs earlier than in the other groups. The same 2 groups also healed clinically (showed no lameness) earlier than the other groups. Radiographically there was no statistical difference between the 6 groups.On the basis of this study it may be concluded that the fixation with self-reinforced biodegradable devices is as suitable for the fixation of cancellous bone and physeal fractures of dogs and cats as the fixation with metallic devices or external fixation. This biodegradable technique has additional benefits allowing the patients to feel less pain in their operated limbs and making secondary operations to remove the devices unnecessary.     

The use of small (2.7 mm) screws for arthroscopically guided repair of carpal chip fractures

Reasons for performing the study: Removal of large chip fractures of the carpal bones and the osteochondral deficits that result, have been associated with a worse prognosis than removal of small fragments in similar locations. Hypothesis: Reducing the articular defects by repair of large osteochondral fragments may have advantages over removal. Methods: Horses with osteochondral chip fractures that were of sufficient size and infrastructure to be repaired with small (2.7 mm diameter) AO/ASIF cortex screws were identified and repair effected by arthroscopically guided internal fixation. Results: Thirty‐three horses underwent surgery to repair 35 fractures of the dorsodistal radial carpal bone (n = 25), the dorsal margin of the radial facet of the third carpal bone (n = 9) and the intermediate facet of the distal radius (n = 1). There were no surgical complications and fractures healed satisfactorily in 26 of 28 horses and 23 horses returned to racing performance. Conclusion: Arthroscopically guided repair of carpal chip fractures with small diameter cortex screws is technically feasible and experiences with 33 cases suggest that this may have advantages over fragment removal in managing such cases. Potential relevance: Surgeons treating horses with large chip fractures of the carpal bones should consider arthroscopically guided internal fixation as an alternative to removal.     

Patterns of scintigraphic uptake in the fetlock joint of Thoroughbred racehorses and the effect of increased radiopharmaceutical uptake in the distal metacarpal/tarsal condyle on performance

Reasons for performing study: The effect of palmar osteochondral disease lesions on performance of Thoroughbred (TB) racehorses is unclear. There is a need to describe patterns of radiopharmaceutical uptake (IRU) in fetlock joints of TB racehorses and to evaluate post scintigraphy performance. Hypotheses: IRU in the metacarpal (MC) and metatarsal (MT) condyles is more common than IRU in the parasagittal grooves and is associated with poorer post diagnosis performance than controls. Methods: Location of IRU within the fetlock region was identified and graded subjectively in TB racehorses. Performance variables were determined from race records for horses with moderate/marked MC/MT condylar IRU (cases), other horses undergoing scintigraphy (scintigraphy controls) and age/sex matched controls from the last race in which a case participated (controls). Statistical analyses included quantile regression, Fisher's exact test, Kaplan‐Meier survival curves, log‐rank test and Cox regression. Results: Metacarpal/MT condylar IRU was identified in 103/220 horses with only 3/220 having parasagittal IRU. Moderate/marked IRU was identified in the MC and MT condylar regions in 62 and 39 horses, respectively, with palmaromedial and plantarolateral IRU most common. Fore‐ and hindlimb cases had fewer starts, reduced earnings (P<0.001) and reduced earnings/start than controls respectively. Cases were more likely to return to racing later than controls following a rest period. Cases were older than scintigraphy controls. Conclusions: In TB racehorses presenting for lameness MC/MT condylar IRU is the most common abnormality identified within the fetlock joint. Racehorses with moderate/marked condylar IRU have a shortened racing career, are less successful than age/sex matched controls and are older than other racehorses presented for scintigraphy. Potential relevance: Overload of the MC/MT condyles is a common and significant problem in TB racehorses that is readily identified with scintigraphy. Scintigraphy of horses that are lame or performing poorly is less useful for screening for potential condylar fractures.     

Dick与Steffee手术治疗胸腰椎骨折脱位椎弓根钉定位方法的改进

目的：寻找治疗胸腰椎骨折脱位更安全、更完善的椎弓根钉定位方法。方法：在标准定位法的基础上,设计一种综合定位法进行椎弓根钉定位。结果：综合定位法可显著提高椎弓根钉定位的准确性、安全性,且解决了标准定位法所不能解决的定位问题。结论：综合定位法效果良好,无１例感染及神经损伤、症状加重等并发症发生。     

骨折对大鼠凝血指标的影响

Wistar大鼠160只,随机分为8组,正常对照组、6h组、12h组、24 h组、3d组、5d组、7d组、14d组,每组各20只,除对照组外其他各组大鼠均手术使其一侧后肢股骨粉碎性骨折,各时段组大鼠采血测凝血指标:凝血酶原时间(PT)、凝血活酶时间(TT)、纤维蛋白原(FBG)后取患肢血管做病理学检查.两项检查结果表明,大鼠粉碎性骨折后,12 h至3d内的时间段是肢体深静脉血栓(DVT)形成的关键期,此后进入静脉血栓脱落导致肺栓塞的危险期,在骨折前或骨折后的前3d采取积极措施预防DVT可取得较理想的效果.动态监测创伤骨折大鼠凝血指标的变化,对早期预防创伤后深静脉血栓形成具有诊断价值.     

Magnetic resonance imaging findings of bone marrow lesions in the equine distal tarsus

Three horses with sudden onset severe lameness were admitted for further diagnostic investigation. All horses had variable changes on radiographs in the distal tarsal region. Because of the sudden onset and severe degree of lameness, a magnetic resonance imaging (MRI) examination was performed. All horses showed areas of increased signal intensity in short tau inversion recovery (STIR) images involving the central and/or third tarsal bones. These lesions involved both the subchondral bone and bone marrow and are currently defined as bone marrow lesions (BML). Two horses were treated with shockwave therapy, one received intra‐articular medication. Two of the horses returned to previous athletic level and one is still in rehabilitation.     

壮筋补骨丸促进家兔人工骨折愈合的组织学观察

为客观评价壮筋补骨丸促进骨折愈合的作用,选用30只雄性新西兰兔造成右侧桡骨3 mm完全缺损的骨折模型,随机分为模型组、伤科组和壮筋组,分别给予生理盐水、伤科接骨片和壮筋补骨丸灌胃,连续4周.各组动物每周处死3只,取样进行HE染色、Masson染色和PAS染色观察,并于术后28 d取右侧桡骨(骨折骨)进行扫描电镜观察.结果表明,壮筋组较模型组及伤科组提前1周PAS和Masson染色呈阳性,于2周后观察到胶原纤维大量出现,成骨过程明显快于模型组.电镜观察显示模型组术后4周骨痂生长,胶原纤维交错排列,未出现成熟的骨细胞,而伤科组及壮筋组术后4周胶原纤维平行簇状排列,出现了板质骨和骨细胞,与模型组比较差异明显,表明壮筋补骨丸能促进新西兰兔骨折愈合.     

Delivery of growth factors using gene therapy to enhance bone healing

OBJECTIVE: To review the delivery of growth factors using gene therapy for enhancing long-bone fracture healing. STUDY DESIGN: Literature review. METHODS: MEDLINE and CAB Abstracts literature search (1980-2004). RESULTS: Non-union and infected non-union are relatively common complications of long-bone fractures in human and veterinary patients. Growth factors are cytokines that regulate many cell functions important in fracture healing. Exogenous growth factors can be delivered to the fracture site as recombinant proteins or using gene therapy. Recombinant human bone morphogenetic protein-2 and -7 (rhBMP-2 and -7), in particular, enhance fracture healing in numerous experimental and clinical studies. Some limitations with use of recombinant proteins may be overcome by use of gene therapy. Gene therapy involves delivery of the growth factor gene to cells at the fracture site using a viral or non-viral vector. The gene is then expressed (protein synthesis) by cells at the fracture site. Delivery of the BMP gene to the fracture site using gene therapy has been evaluated in laboratory animal models of non-union, with favorable results and without complications. CONCLUSION: Delivery of growth factors, particularly members of BMP family, to the fracture site using gene therapy may be a method to enhance fracture healing. Use of this technology may improve the prognosis for patients with long-bone fractures. CLINICAL RELEVANCE: Clinical application of gene therapy could improve the prognosis for human and veterinary patients with long-bone fractures, but has not been evaluated clinically.     

Use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture in a dog

OBJECTIVE: To describe the clinical use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture. STUDY DESIGN: Case report. ANIMALS: A 5-year-old castrated male Labrador retriever with a grade IIIB open tibial fracture. METHODS: A myocutaneous flap was created by elevating the origin of the semitendinosus muscle and the associated overlying skin. The flap was rotated distally based on the distal vascular pedicle into a soft-tissue defect overlying the central and distal third of the tibia. RESULTS: The flap allowed one-stage reconstruction of a severe soft-tissue defect overlying denuded bone in a grade IIIB open tibial fracture. The muscular portion of the flap survived; however, there was necrosis of 3 cm of skin extending distally beyond the muscular portion of the flap. CONCLUSION: Distal rotation of the semitendinosus muscle and overlying skin can be used in the treatment of severe soft-tissue defects of the canine crus. CLINICAL RELEVANCE: Complex soft-tissue injuries to the canine crus can be treated with a myocutaneous flap as a reasonable alternative to other reconstructive techniques.     

Assessment of stiffness and strength of 4 different implants available for equine fracture treatment: a study on a 20 degrees oblique long-bone fracture model using a bone substitute

OBJECTIVE: To compare the mechanical properties of 4 stabilization methods for equine long-bone fractures: dynamic compression plate (DCP), limited contact-DCPlate (LC-DCP), locking compression plate (LCP), and the clamp-rod internal fixator (CRIF--formerly VetFix). STUDY DESIGN: In vitro mechanical study. SAMPLE POPULATION: Bone substitute material (24 tubes) was cut at 20 degrees to the long axis of the tube to simulate an oblique mid-shaft fracture. METHODS: Tubes were divided into 4 groups (n=6) and double plated in an orthogonal configuration, with 1 screw of 1 implant being inserted in lag fashion through the "fracture". Thus, the groups were: (1) 2 DCP implants (4.5, broad, 10 holes); (2) 2 LC-DCP implants (5.5, broad, 10 holes); (3) 2 LCP implants (4.5/5.0, broad, 10 holes) and 4 head locking screws/plate; and (4) 2 CRIF (4.5/5.0) and 10 clamps in alternating position left and right of the rod. All constructs were tested in 4-point bending with a quasi-static load until failure. The implant with the interfragmentary screw was always positioned on the tension side of the construct. Force, displacement, and angular displacement at the "fracture" line were determined. Construct stiffness under low and high loads, yield strength, ultimate strength, and maximum angular displacement were determined. RESULTS: None of the implants failed; the strength of the bone substitute was the limiting factor. At low loads, no differences in stiffness were found among groups, but LCP constructs were stiffer than other constructs under high loads (P=.004). Ultimate strength was lowest in the LCP group (P=.01), whereas yield strength was highest for LCP constructs (409 N m, P=.004). CRIF had the lowest yield strength (117 N m, P=.004); no differences in yield strength (250 N m) were found between DCP and LC-DCP constructs. Differences were found for maximum angular displacement at the "fracture" line, between groups: LPC相似文献