108293547
Influence of transfixation pinning and casting (TPC) configurations on treatment outcomes in bovine tibial fracture
The aim of this study was to examine the treatment outcomes of tibial fracture using different configurations of transfixation pinning and casting (TPC) in eight cattle. After pins were inserted to stabilize the fracture site, cast material was placed from the level of the stifle to the hoof (full TPC) in six cases and from the stifle to the proximal metatarsus (partial TPC) in two cases. Five cattle (three full TPC and two partial TPC cases) underwent TPC removal 36–86 days after surgery and resumed productivity. The other three cattle which underwent full TPC suffered from irreversible orthopedic complications within 5 weeks of surgery, while a prolonged healing process was observed in the partial TPC cases. Although TPC is an effective method for treating bovine tibial fracture, full TPC may result in a guarded prognosis in some cattle. However, partial TPC can delay healing. Surgeons should choose the optimal TPC configuration while considering the various factors that affect the healing process.
10420814
Management of fractures in field settings.
Limb fractures are common in farm animals, are most commonly found in young stock, and often occur subsequent to trauma during dystocia or handling. Cattle are excellent patients for treatment of orthopedic injuries because they spend a majority of time lying down, have a tremendous potential for bone healing, are more resistant than other animals to contralateral limb breakdown and stress laminitis, and usually do not resist having orthopedic devices on their limbs. This article describes management of fractures, especially for cattle, in field settings; explains how the principles of external skeletal fixation are adapted for cattle; discusses the application of external skeletal fixation to individual bones, and reviews potential complications in the use of external skeletal fixation.
2551937
External skeletal fixation of fractures in cattle.
External skeletal fixation (ESF) is a versatile method for rigid immobilization of long bone fractures in cattle. Traditional ESF devices may be used in young calves for clinical management of open fractures. Transfixation pinning and casting is an adaptation of ESF principles to improve versatility and clinical management of selected fractures.
6070872
External skeletal fixation in ruminants.
External skeletal fixation (ESF) techniques are increasingly being adapted for treatment of fractures in large animals. This article includes detailed information regarding decision making for ESF, biomechanics of ESF, interaction of the bone and implants, general surgical techniques for application of ESF (including traditional ESF, use of acrylic sidebars for ESF, and transfixation, pinning, and casting), discussions of application of ESF to specific bones, and complications associated with the use of ESF. Also, techniques for the management of open, infected fractures are presented. Future directions of ESF research and application also are presented.
10535791
Conservative and surgical treatment of tibial fractures in cattle
Ninety-five cattle with tibial fractures, all but one with a uni-lateral fracture, were examined between 1990 and 1994. The feasibility of repairing the fracture was assessed radiographi-caily, also taking into account the bodyweight and value of the animal. Twenty-two cattle were slaughtered. Conservative treatment with stall confinement and/or a splint or cast was applied in 18 cases, with satisfactory results in eight of them (44 per cent). They were fattened to normal bodyweight, but they all had a severe deformity of the affected leg. In 55 ani-mals, the fractures were fixed externally with Steinmann pins and methylmethacrylate bridges under image-intensi-fied fluoroscopy. Ten of them could not bear weight on the affected leg and were slaughtered before the pins were removed. In the remaining 45 animals the pins were removed after a mean (sd) period of 71 (14) days. Four ani-mals re-fractured the affected leg shortly after the pins were removed and six others were slaughtered prematurely because of inadequate weight bearing. The results were suc-cessful in 35 cases (64 per cent). Slight deviations of the affected leg and/or the contralateral leg were often observed. The overall survival rate of the cattle with tibial fractures was 45 per cent.
75743652
Management of long bone fractures in cattle
Fractures are encountered on a regular basis in large animal practice and managing them poses a challenge in the field. Cattle are excellent orthopaedic patients: they have great bone healing properties, most tolerate limb immobilisation well and they rarely suffer from contralateral limb disorders. However, the decision between treatment and euthanasia depends on the economic or genetic value of the animal, the cost of the treatment and the prognosis associated with the particular fracture. Treatment choices vary between stall rest, external coaptation, external fixation and open reduction with internal fixation, depending on the type of fracture and the bone involved. This article describes the different treatment options for common fractures encountered in cattle.
42909709
Transfixation pinning and casting of tibial fractures in calves: five cases (1985-1989).
Medical records of 5 calves with tibial fractures that were reduced and stabilized by transfixation pinning and casting were reviewed. Multiple Steinmann pins were placed transversely through proximal and distal fracture fragments, and the pin ends were incorporated in fiberglass cast material after fracture reduction. Cast material serves as an external frame to maintain pin position and fracture reduction. Calves were between 2 weeks and 6 months old and weighed between 40 and 180 kg. Three fractures were spiral in configuration and 2 were comminuted. One tibial fracture was open. After surgery, all calves were ambulatory within 24 hours. To improve tarsal flexion and achieve normal stance in 3 calves, cast revision was required on the caudal aspect of the limb. Good radiographic and clinical evidence of stability was observed in 5 to 10 weeks (mean 8 weeks), at which time the pis and cast were removed. Return to normal function was rapid and judged to be excellent at follow-up evaluation 3 to 12 months later. Advantages of transfixation pinning and casting in management of tibial fractures include flexibility in pin positioning, adequate maintenance of reduction, early return to weight-bearing status, joint mobility, and ease of ambulation. The inability to adjust fixation and alignment after cast application is a disadvantage of this technique compared with other external fixators.
41628917
JSBS classics. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones. Retrospective and prospective analyses.
In 673 open fractures of long bones (tibia and fibula, femur, radius and ulna, and humerus) treated from 1955 to 1968 at Hennepin County Medical Center, Minneapolis, Minnesota, and analyzed retrospectively, the infection rate was 12 per cent from 1955 to 1960 and 5 per cent from 1961 to 1968. In a prospective study from 1969 to 1973, 352 patients were managed as follows: debridement and copious irrigation, primary closure for Type I and II fractures and secondary closure for Type III fractures, no primary internal fixation except in the presence of associated vascular injuries, cultures of all wounds, and oxacillin-ampicillin before surgery and for three days postoperatively. In 158 of the patients in the prospective study the initial wound cultures revealed bacterial growth in 70.3 per cent and the infection rate was 2.5 per cent. Sensitivity studies suggested that cephalosporin is currently the prophylactic antibiotic of choice. For the Type III open fractures (severe soft-tissue injury, segmental fracture, or traumatic amputation), the infection rates were 44 per cent in the retrospective study and 9 per cent in the prospective study.
31351111
Problems in the management of type III (severe) open fractures: a new classification of type III open fractures.
Between 1976-1979, 87 Type III open fractures (in 75 patients) were treated at the Hennepin County Medical Center. Factors leading to increased morbidity in Type III fractures were: massive soft-tissue damage; compromised vascularity; severe wound contamination; and marked fracture instability. This study demonstrates, because of varied severity and prognosis, that the current designation of Type III open fracture is too inclusive. We recommend, therefore, that Type III open fractures be divided, in order of worsening prognosis, into three subtypes. Type IIIA--Adequate soft-tissue coverage of a fractured bone despite extensive soft-tissue laceration or flaps, or high-energy trauma irrespective of the size of the wound. Type IIIB--Extensive soft-tissue injury loss with periosteal stripping and bone exposure. This is usually associated with massive contamination. Type IIIC--Open fracture associated with arterial injury requiring repair. Wound sepsis in the three subtypes were: Type IIIA, 4%, IIIB, 52%; and IIIC, 42%; while amputation rates were, respectively, 0%, 16%, and 42%. Only two patients developed osteomyelitis, and 12 patients had delayed or nonunions. Five patients died, all as a result of multisystem trauma. The bacterial pathogens in infected open fractures have changed dramatically over the years. In the present series (1976-1979), 77% of infections were due to Gram-negative bacteria, compared with 24% previously (1961-1975). A change of antibiotic therapy from a first-generation cephalosporin alone to a combination of a cephalosporin and an aminoglycoside, or a third-generation cephalosporin, is currently indicated in Type III open fractures.
37897590
Ultrasound-guided anaesthetic blockade of the pelvic limb in calves.
This study aimed to describe a suitable acoustic window to facilitate access to the sciatic and femoral nerves in calves and to study the effects of their blockade with local anaesthetics. The neuroanatomical and ultrasound (US) study was performed on the cadavers of 10 calves, and the effects of 2% lidocaine with epinephrine (0.2 mL/kg) were determined in five healthy calves. The sciatic nerve in the cadavers was easily visualised as a hyperechoic band distal to the femoral greater trochanter and caudal to the femoral shaft. The femoral nerve in the cadavers was not easily identified, and was visualised as a hyperechoic oval structure situated immediately medial to the psoas major muscle and lateral to the femoral artery. The sciatic nerve was stained by methylene blue, injected under US guidance, in 9/10 cases, and the femoral nerve was stained in 6/10 cases. Sciatic nerve blockade under US guidance produced adduction of the limb with metatarsophalangeal joint flexion, while the femoral nerve blockade produced reduced weight bearing. The sciatic nerve blockade produced a reduced response to the noxious stimulus, mainly in the phalanges, proximal and distal metatarsus, tarsus and tibia and, following the femoral nerve blockade, in the medial subarea of the femur. However, femoral nerve blockade produced a more variable degree of blockade. In conclusion, US -guided anaesthetic blockade of the sciatic nerve in calves may be considered for surgery in the distal pelvic limb, although further studies are necessary to determine its clinical application.
68054479
Modified transfixation pinning of compound radius and ulna fracture in a heifer.
A 405-kg heifer sustained a compound fracture of the distal portion of the radius and ulna after being hit by a car. The fracture was thoroughly debrided, lavaged, and reduced with the heifer under general anesthesia. The fracture was immobilized with a modified walking cast, using 2 fully threaded 6.4-mm (outside diameter) Steinmann pins placed through the proximal portion of the radius. The pins were incorporated into a full-limb fiberglass cast, and a 0.5-cm X 2.25-cm aluminum walking bar was positioned medially and laterally on the limb. The modified walking cast was removed after 7 weeks, and the fracture healed without complication. The transfixation pins and aluminum walking bar helped reduce the strong compressive and rotational forces at the fracture site. The modified walking cast can potentially be used for fixation of a variety of fractures in large animals.
27822805
Wolff's Law and bone's structural adaptations to mechanical usage: an overview for clinicians.
Basic Multicellular Unit-based bone remodeling can lead to the removal or conservation of bone, but cannot add to it. Decreased mechanical usage (MU) and acute disuse result in loss of bone next to marrow; normal and hypervigorous MU result in bone conservation. Bone modeling by resorption and formation drifts can add bone and reshape the trabeculae and cortex to strengthen them but collectively they do not remove bone. Hypervigorous MU turns this modeling on, and its architectural effects then lower typical peak bone strains caused by future loads of the same kind to a threshold range. Decreased and normal MU leave this modeling off. Where typical peak bone strains stay below a 50 microstrain region (the MESr) the largest disuse effects on remodeling occur. Larger strains depress it and make it conserve existing bone. Strains above a 1500 microstrain region (the MESm) tend to turn lamellar bone modeling drifts on. By adding to, reshaping and strengthening bone, those drifts reduce future strains under the same mechanical loads towards that strain region. Strains above a 3000 microstrain region (the MESp) can turn woven bone drifts on to suppress local lamellar drifts but can strengthen bone faster than lamellar drifts can. Such strains also increase bone microdamage and the remodeling that normally repairs it. Those values compare to bone's fracture strain of about 25,000 microstrain.
44689025
Retrospective study of 99 cases of bone fractures in cattle treated by external coaptation or confinement
Between 2000 and 2003, 99 cattle with limb fractures were treated. Over 50 per cent were tibial fractures, with the femur and os calcis being the second and third most frequently affected bones. Eight of the cattle were slaughtered because of their poor prognosis, 10 were treated by stall confinement, 76 were treated by external coaptation with a Thomas splint-cast combination and three were treated with a simple or reinforced half limb cast; these 79 cattle were usually discharged immediately. One calf was treated with internal fixation, and another by amputation. Follow-up information was obtained by telephone, and the treatments were classified as either completely successful (return to previous production level), partially successful (return to lower production level) or failure. Forty (52·6 per cent) of the cattle treated with the Thomas splint-cast combination were classified as a complete success and 14 (18·4 per cent) as a partial success; the treatment failed in 19 of the cattle and three were lost to follow-up. The animals’ bodyweight, age and sex, and whether the fracture was open or closed, had no significant influence on the outcome. Among the 10 cattle treated for proximal fractures by stall confinement, there were five survivors, four non-survivors and one was lost to follow-up.
71085398
Mechanical Strength of Synthetic Casting Tape for Application to Fracture Treatment of Farm Animals
Mechanical strength of poly-urethane- impregnated synthetic casting tape was investigated to determine its adequate application to fracture treatment of farm animals. It was demonstrated that mechanical strength of cylindrically formed samples of the casting tape depended upon the layer number, and the six-layered sample tolerated a compressive load of 6630 N and a torsional load of 64 N • m when completely cured.
34306004
Principles of bone healing and biomechanics of external skeletal fixation.
External skeletal fixation is being used to treat an increasing number of orthopedic conditions in veterinary medicine. Study of the variables affecting the biomechanics of external fixation and bone healing is vital if patient morbidity is to be minimized. These are reviewed and incorporated into strategies that can be applied to decision making using external fixation in the clinical setting.
20636391
The biology of fracture healing.
The biology of fracture healing is a complex biological process that follows specific regenerative patterns and involves changes in the expression of several thousand genes. Although there is still much to be learned to fully comprehend the pathways of bone regeneration, the over-all pathways of both the anatomical and biochemical events have been thoroughly investigated. These efforts have provided a general understanding of how fracture healing occurs. Following the initial trauma, bone heals by either direct intramembranous or indirect fracture healing, which consists of both intramembranous and endochondral bone formation. The most common pathway is indirect healing, since direct bone healing requires an anatomical reduction and rigidly stable conditions, commonly only obtained by open reduction and internal fixation. However, when such conditions are achieved, the direct healing cascade allows the bone structure to immediately regenerate anatomical lamellar bone and the Haversian systems without any remodelling steps necessary. In all other non-stable conditions, bone healing follows a specific biological pathway. It involves an acute inflammatory response including the production and release of several important molecules, and the recruitment of mesenchymal stem cells in order to generate a primary cartilaginous callus. This primary callus later undergoes revascularisation and calcification, and is finally remodelled to fully restore a normal bone structure. In this article we summarise the basic biology of fracture healing.
15305068
Outpatient Treatment for Humeral Fractures in Five Calves
ABSTRACT Humeral fractures were treated in 5 calves using unilateral external fixation with epoxy putty fixator (type I). The surgeries were performed under sedation and analgesia, and it involved application of ultrasound-guided brachial plexus block. The surgical procedures were completed in 60 to 90 min, and each calf was returned to the farm on the same day. The fixation allowed each calf to remain with the dam and suckle without strict stall rest and was removed 11 to 62 days post-surgery. The clinical sign of diminished radial nerve function disappeared 40 days to 4 months post-surgery. These observations suggest that this repair technique represents a feasible outpatient treatment for humeral fractures in calves.
5481306
Plates, pins, and interlocking nails.
Evidence-based criteria that promise the best treatment outcome for bovine fracture patients have not been established. Internal fixation with plates and screws allows successful management of many long bone fractures in calves as well as in heavier cattle. Intramedullary pins may be better or equally suited for repair of humerus or femoral fractures in calves, respectively. In richly comminuted fractures in heavy cattle, methods of external fixation are still indicated. With newly introduced locking plates, treatment options for repair of long bone fractures in cattle have further improved, but high costs and a guarded prognosis limit their application.