Effect of heel elevation on breakover phase in horses with laminitis.

BACKGROUND: In a laminitic horse, the maximal loading of the toe region occurs during the breakover phase. To date, no kinetic data demonstrates the effect of supportive orthopaedic therapy in horses with laminitis on breakover phase. Thus, the purpose of this study was to examine the effect of heel elevation on the breakover phase. Eight horses with acute laminitis treated medically as well as with application of a hoof cast with heel wedge (HCHW) were included in this study. Immediately following cessation of clinical signs of acute laminitis, two measurements using the Hoof™ System were taken: the first with HCHW and the second immediately following removal of the HCHW, i.e. in barefoot condition (BFC). The hoof print was divided into three regions: toe, middle hoof, and heel. Kinetic parameters included vertical force (VF), stance duration, contact area (CA) for all hoof regions during stance phase, duration of breakover, VF in the toe region at onset of breakover and location of centre of force. RESULTS: The VF and CA were higher in the heel region (63 and 61%, respectively) and decreased significantly after removal of the HCHW (43 and 28% after removal, respectively). The breakover phase in horses with HCHW lasted 2% of stance phase and was significantly shorter than that in BFC, which lasted 6% of stance phase. The VF at onset of breakover for the toe region in horses with HCHW was significantly lower than that in BFC. The centre of the force was located at the heel region in all horses with the HCHW, and at the middle the hoof region in BFC. CONCLUSIONS: Heel elevation in horses with laminitis as examined on a concrete surface significantly shortens breakover phase and decreases the vertical force in the toe region during breakover. HCHW provides adequate support to the palmar hoof structures by increasing the contact area in the heel region and incorporating the palmar part of frog and sole into weight bearing, thus decreasing the stress on the lamellae. Hoof cast with heel elevation could be a beneficial orthopaedic supportive therapy for horses suffering from acute laminitis.

Aluminium Splint Incorporated Fibreglass Cast Preserves Limb Function in Bovines with Olecranon Fracture.

OBJECTIVE: Olecranon process fractures are rare in bovines. The aim of the study was to put on record satisfactory limb usage in cattle and buffaloes suffering from olecranon fractures and treated conservatively, primarily for carpal contracture or to prevent it, using aluminum splints incorporated within a fiberglass cast along with stall confinement. STUDY DESIGN: This one year study included 19 olecranon fractures in bovines (15 buffaloes and 4 cattle). Out of 19, 12 bovines (9 buffaloes and 3 cattle) were treated primarily to manage the associated carpal contracture, using external coaptation of aluminium splints incorporated within a fiberglass cast for 6 to 8 weeks. The owners of the remaining 7 bovines (6 buffaloes and 1 bullock) were only advised to keep their animal in stall-confinement, due to various reasons. RESULTS: Slipping and falling on hard surfaces was the primary aetiology of olecranon fractures (17/19). Most of the fractures (14/19) were presented more than 10 days after a traumatic event, with a mean duration of 24.0 ± 26.6 days. On follow up, all the treated bovines showed satisfactory limb usage whereas all stall-confined buffaloes showed no improvement. CONCLUSION: Slipping and falling on hard surfaces is a common cause of olecranon fracture in bovines. Olecranon fractures associated carpal contracture can be successfully treated/prevented by applying full limb cast (if possible including elbow) along with aluminum splints leading to satisfactory limb usage in bovines. Further it is concluded that stall confinement alone is insufficient to prevent limb contracture (which usually develops with olecranon fracture in bovines) leading to permanent non-weight bearing disability.

Standing MRI for surgical planning of equine fracture repair.

OBJECTIVE: To report the feasibility of standing MRI (sMRI) and document the value of sMRI in surgical planning for surgical repair of limb fractures in the horse. STUDY DESIGN: Retrospective case series. ANIMALS: Thirty-one horses with preoperative sMRI. METHODS: Medical records were reviewed for fracture type, application of a polyester cast, sMRI sequences performed, technical variables, and image quality. Fracture geometry and concomitant lesions were compared between sMRI and radiography. The relative value of sMRI with regard to surgical planning was classified as minor (sMRI did not provide additional findings), intermediate (additional lesions found or slight modification to surgical plan), or major (sMRI led to significant alternations in surgical plan). RESULTS: Standing MRI provided good studies in all horses. Standing MRI was classified as having major relevance in 12 of 31 horses, intermediate relevance in 14 of 31 horses, and minor relevance in 5 of 31 horses. CONCLUSION: Preoperative sMRI produced good studies in all horses and influenced the surgical planning in the majority of fractures in this study. Application of a polyester cast seemed to improve comfort without appreciable loss of image quality. CLINICAL SIGNIFICANCE: Standing MRI can be considered as an adjunct to plan the repair of equine fractures, and a polyester cast does not impair image quality.

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.

Evaluation of the effects of initial water temperature and curing time on fiberglass cast strength.

OBJECTIVE: To determine the effects of water temperature and cure time on cast strength. STUDY DESIGN: Prospective randomized experimental study. METHODS: Two water temperatures were tested, 23°C (cold) and 42°C (warm). Cast constructs were made of 4-inch fiberglass casting material over a rubber mandrel. Each construct was divided into 3 segments and tested in 4-point bending at 0.5, 1, and 24 hours. Stiffness and bending moment, cumulative energy, and angular deformation at yield and failure were recorded and analyzed by using repeated measures ANOVA. RESULTS: Mean time ± SD to complete the construct was 2.2 ± 0.8 and 2.3 ± 0.6 minutes for warm and cold water, respectively. Warm water and longer cure times produced constructs with greater stiffness (23.05 vs 20.88 newton-meter degrees [Nm°] at 0.5 hours), bending moment (121.75 vs 107.31 Nm° at 0.5 hours), and cumulative energy (557.33 vs 428.89 Nm° at 1 hour) at yield and failure. Longer cure time significantly increased angular deformation of rods at failure; however, water temperature did not. In general, the strongest casts were produced with warm water and after curing for 24 hours. CONCLUSION: Fiberglass casts continued to gain strength for at least 24 hours. Use of warm water increased the rate of curing, resulting in stronger constructs at earlier time points. CLINICAL SIGNIFICANCE: Use of warm water is recommended to initiate fiberglass cast curing, especially if the casted limb will be loaded soon after cast application.

Short- and long-term success of transfixation pin casts used to stabilize long bone fractures in ruminants.

Transfixation pin casts (TPC) may be useful in management of fractures in ruminants. A retrospective study was conducted to report the uses, complications, and outcomes of TPC in ruminant fracture stabilization. Twenty-five cattle, 7 goats, and 7 sheep with long bone fractures managed with TPC met the inclusion criteria. Long-term outcome was assessed from telephone interviews with owners. Thirty-one animals (79%) survived to removal of external coaptation and return to the farm. Common complications included pin-hole osteitis and disuse osteopenia. Common complications resulting in death or euthanasia included osteomyelitis and non-union and pin tract fracture. Animals with increased body weight had a greater odds of dying or being euthanized. Cattle had a decreased odds of dying or being euthanized compared with goats and sheep. Long-term follow-up was available for 20 patients, 17 of which returned to intended use and 12 of which had no residual lameness.

Succès à court et à long terme des plâtres à broche transfixiante utilisés pour stabiliser les fractures d'os longs chez les ruminants. Les plâtres à broche transfixiante (PBT) peuvent être un outil utile pour la gestion des fractures des ruminants. Une étude rétrospective a été réalisée afin de faire rapport sur les utilisations, les complications et les résultats des PBT pour la stabilisation des fractures des ruminants. Vingt-cinq bovins, 7 chèvres et 7 moutons avec des fractures d'os longs gérée par PBT ont satisfait aux critères d'inclusion. Les résultats à long terme ont été évalués par entrevue téléphonique avec les propriétaires. Trente-et-un (79 %) animaux ont survécu à l'enlèvement de la coaptation externe et sont retournés à la ferme. Les complications communes incluaient l'ostéite du trou de la broche et l'ostéopénie par inaction. Les complications communes se traduisant par la mort ou l'euthanasie incluaient l'ostéomyélite, la non-union et la fracture causée par la broche. Les animaux ayant un poids supérieur présentaient plus de risques de mortalité ou d'euthanasie. Les bovins présentaient des risques réduits de mortalité ou d'euthanasie comparativement aux chèvres et aux moutons. Le suivi à long terme était disponible pour 20 patients et 17 d'entre eux sont retournés à leur usage prévu et 12 n'avaient pas de boiterie résiduelle.(Traduit par Isabelle Vallières).

Use of pressure mapping for quantitative analysis of pressure points induced by external coaptation of the distal portion of the pelvic limb of dogs.

OBJECTIVE To quantitatively measure the amount of pressure induced at the calcaneus and cranial tibial surface of dogs by use of 2 cast configurations. ANIMALS 13 client- or student-owned dogs. PROCEDURES Pressure sensors were placed over the calcaneus and cranial tibial surface. Dogs then were fitted with a fiberglass cast on a pelvic limb extending from the digits to the stifle joint (tall cast). Pressure induced over the calcaneus and proximal edge of the cast at the level of the cranial tibial surface was simultaneously recorded during ambulation. Subsequently, the cast was shortened to end immediately proximal to the calcaneus (short cast), and data acquisition was repeated. Pressure at the level of the calcaneus and cranial tibial surface for both cast configurations was compared by use of paired t tests. RESULTS The short cast created significantly greater peak pressure at the level of the calcaneus (mean ± SD, 0.2 ± 0.07 MPa), compared with peak pressure created by the tall cast (0.1 ± 0.06 MPa). Mean pressure at the proximal cranial edge of the cast was significantly greater for the short cast (0.2 ± 0.06 MPa) than for the tall cast (0.04 ± 0.03 MPa). CONCLUSIONS AND CLINICAL RELEVANCE A cast extended to the level of the proximal portion of the tibia caused less pressure at the level of the calcaneus and the proximal cranial edge of the cast. Reducing the amount of pressure at these locations may minimize the potential for pressure sores and other soft tissue injuries.

Modified Thomas splint-cast combination for the management of limb fractures in small equids.

OBJECTIVE: To describe the management and outcome of limb fractures in small domestic equids treated with a modified Thomas splint-cast combination (MTSCC). STUDY DESIGN: Retrospective case series. ANIMALS: Client owned horses and donkeys. METHODS: Medical records, including radiographs, were reviewed for details of animals diagnosed with a limb fracture and treated by external coaptation using a MTSCC (2001-2012). Follow-up >6 months after discharge was obtained via telephone consultation with owners or veterinarians. RESULTS: Nine horses and 4 donkeys were identified with fractures of the tibial diaphysis (n = 4), ulna (n = 3), distal metatarsus (n = 2), proximal metacarpus (n = 1), radial diaphysis (n = 1), calcaneus (n = 1), and distal femoral physis (n = 1). Follow-up was available for 12 equids, of which 8 (67%) recovered from the fracture and became pasture sound. Six equids developed obvious external deformation of the affected limb. CONCLUSION: Selected small equids with long bone fractures, and without athletic expectations, can be managed with external coaptation using an MTSCC. The owner should be informed that the treatment is considered a salvage procedure.

Comparison of 2 equine transfixation pin casts and the effects of pin removal.

OBJECTIVE: To (1) compare strain on the dorsal aspect of the proximal phalanx (P1) between 2 types of transfixation pin casts (TPC) and (2) evaluate the change in strain as the pins are removed. STUDY DESIGN: Experimental. ANIMALS: Equine cadaver forelimbs (n = 10 pair). METHODS: Each limb of a pair was assigned to 1 of 2 TPC constructs. Construct 1 consisted of a TPC with 2 positive profile, centrally threaded pins placed in the distal aspect of the third metacarpus (MC3) and construct 2 had 4 smooth Steinmann pins placed similarly. A strain gauge was mounted on P1 and axial compression (444.8-5337.9 N) applied. One forelimb of each pair was tested as a control with no construct in place. The 2 TPC groups were retested after removal of 1 proximal (n = 5 limbs) or distal (n = 5) pin from construct 1, and 2 proximal (n = 5) or distal (n = 5) pins from construct 2. Limb specimens were retested after all pins had been removed. RESULTS: There was a significant decrease in strain between both TPC constructs and the non-casted control at all loads except 444.8 N. There was no significant difference in strain reduction between the 2 TPC constructs. After proximal pin removal there was a 7% (construct 1) and 10% (construct 2) increase in strain. When distal pins were removed there was a 0.5% (construct 1) and 1% (construct 2) increase in strain. The difference between proximal and distal pin removal was only statistically different from each other at high loads. CONCLUSION: Both constructs provided equivalent reduction in strain. Removal of the proximal pin(s) increased the strain.

Transfixation pinning and casting of a comminuted metacarpal fracture in a 870 kg bull.

OBJECTIVE: To report metacarpal fracture repair in a bull. STUDY DESIGN: Clinical report. ANIMALS: Simmental bull (n = 1; 870 kg). METHODS: A comminuted right metacarpal fracture was repaired using 2 transfixation pins (6 mm diameter) through the distal metaphysis and diaphysis of the radius and a full limb synthetic resin cast. RESULTS: Slight bending of both pins occurred 1 day after surgery. Both pins were loose and removed at 31 days and a full-limb cast reapplied. The cast was changed at approximately -4 week intervals. On day 50, the right carpus had moderate overextension and a valgus deformity. An exercise program was started on day 62, and on day 110, the cast was replaced with a Robert-Jones-bandage. At 130 days there was circumferential callus formation and the bull was discharged. At 6.5 months, overextension of the right carpus had resolved and carpal valgus had improved. The bull returned to at 7.5 months after surgery, and was successfully used for 4 years. CONCLUSION: For highly valuable cattle like this breeding bull, a surgical treatment of such a fracture should be attempted despite a primarily poor prognosis.

Indications and limitations of splints and casts.

Long bone fractures are relatively common in cattle, whether they result from a self-inflicted trauma or from external actors (herd mate or farm machinery). Various advanced orthopedic techniques have been described to stabilize and treat fractures in cattle with success. Unfortunately the use of most of those techniques remains unrealistic in a field setting, rendering the realization of splints and casts still accurate for the treatment of long bone fracture in cattle. This article refers to the use of all external coaptation and their specific indications as well as their limitations.

Use of the Thomas splint and cast combination, walker splint, and spica bandage with an over the shoulder splint for the treatment of fractures of the upper limbs in cattle.

Many tibial and radial-ulnar fractures in cattle and small ruminants may be treated successfully with Thomas splint and cast combinations (TSCC). The Walker splint has been specifically designed for treating tibial fractures and stifle injuries in cattle.It usually fits better in rear limbs of cattle than the TSCC and thus can provide more stability. Spica bandages combined with lateral splints placed over the dorsum of the affected limb and down the contralateral shoulder may be used for partial immobilization of humeral fractures in calves and small ruminants when surgical repair is not an option.

Use of a modified transfixation pin cast for treatment of comminuted phalangeal fractures in horses.

OBJECTIVES: To (1) report a modified transfixation pin cast technique, using dorsal recumbency for fracture reduction, distal positioning of the pins in the epiphysis and distal metaphysis, and a hybrid cast, combining plaster of Paris (POP) and fiberglass casting, and (2) report outcome in 11 adult horses. STUDY DESIGN: Case series. ANIMALS: Adult horses (n = 11) with comminuted phalangeal fractures. METHODS: Horses were anesthetized and positioned in dorsal recumbency. The phalangeal fracture was reduced by limb traction using a cable attached to the hoof. Screw fixation in lag fashion of fracture fragments was performed when possible. Transfixation casting was performed using two 6.3 mm positive profile centrally threaded pins with the 1st pin placed in the epiphysis of the metacarpus/tarsus at the center of, or slightly proximal to, the condylar fossa and the 2nd one 3-4 cm proximal. A hybrid cast was applied. RESULTS: Forelimbs were involved in 9 horses and the hind limb in 2. Pins were maintained for a minimum of 6 weeks. No pin loosening was observed at the time of removal (6-8 weeks). A pony fractured the distal aspect of the metacarpus at the proximal pin. Nine horses survived (82%); none of the horses developed septic arthritis despite the distal location of the distal pin, close to the fetlock joint. CONCLUSION: This modified transfixation pin casting technique was associated with good pin longevity and could reduce the risk of secondary pin hole fractures and pin loosening.

Risk factors associated with cast complications in horses: 398 cases (1997-2006).

OBJECTIVE: To determine the frequency of and risk factors for complications associated with casts in horses. DESIGN: Multicenter retrospective case series. ANIMALS: 398 horses with a half-limb or full-limb cast treated at 1 of 4 hospitals. PROCEDURES: Data collected from medical records included age, breed, sex, injury, limb affected, time from injury to hospital admission, surgical procedure performed, type of cast (bandage cast [BC; fiberglass tape applied over a bandage] or traditional cast [TC; fiberglass tape applied over polyurethane resin-impregnated foam]), limb position in cast (flexed, neutral, or extended), and complications. Risk factors for cast complications were identified via multiple logistic regression. RESULTS: Cast complications were detected in 197 of 398 (49%) horses (18/53 [34%] horses with a BC and 179/345 [52%] horses with a TC). Of the 197 horses with complications, 152 (77%) had clinical signs of complications prior to cast removal; the most common clinical signs were increased lameness severity and visibly detectable soft tissue damage Cast sores were the most common complication (179/398 [45%] horses). Casts broke for 20 (5%) horses. Three (0.8%) horses developed a bone fracture attributable to casting Median time to detection of complications was 12 days and 8 days for horses with TCs and BCs, respectively. Complications developed in 71%, 48%, and 47% of horses with the casted limb in a flexed, neutral, and extended position, respectively. For horses with TCs, hospital, limb position in the cast, and sex were significant risk factors for development of cast complications. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that 49% of horses with a cast developed cast complications.

Accessory carpal bone luxation in two gray wolves (Canis lupus).

Two sibling male castrated gray wolves (Canis lupus) developed acute onset right forelimb lameness, one at 8 and the other at 11 yr of age. In both cases, the right carpus was swollen, carpal hyperextension was notable, and the wolves exhibited significant intermittent lameness of the affected limb. Radiographs revealed right accessory carpal bone luxation in both cases, with type III fracture of the accessory carpal bone in one wolf. Although carpal bone luxation in domestic dogs is frequently treated surgically, conservative medical management resolved the lameness in both wolves with no further complications.

External coaptation of rostral mandibular fractures in calves.

Six cases of rostral mandibular fracture with considerable displacement were treated successfully by external coaptation. Four cases were simple and two were compound fractures. After xylazine sedation and manual reduction of the fractures, the casting tape was laminated to make a rigid splint below the mandibles and then the splint was secured using the casting tape passing the nasal bridge and cranial and/or caudal to the ears as it encircled the head. During application of the tape, a PVC pipe 25 mm in diameter was held in its jaws to keep the mouth open so that the calf could suckle. Simple rostral mandibular fractures were cured after two weeks of cast immobilisation and compound fractures after about three weeks. This method is easy and non-stressful and provided a good prognosis in the present cases.

Comparison of hydroxyapatite-coated and uncoated pins for transfixation casting in horses.

OBJECTIVE: To determine the extent to which a hydroxyapatite coating promotes pin stability in the third metacarpal bone during transfixation casting in horses. ANIMALS: 14 adult horses. PROCEDURES: 7 horses each were assigned to either an uncoated or hydroxyapatite-coated pin group. Three transcortical pins were placed in the third metacarpal bone of each horse and incorporated into a cast for 8 weeks. Insertion and extraction torque were measured, and torque reduction was calculated. Radiography was performed at 0, 4, and 8 weeks. Lameness evaluation was performed at 2, 4, 6, and 8 weeks. Bacteriologic culture of pins and pin holes was performed at pin removal. RESULTS: All horses used casts without major complication throughout the study. Insertion torque was higher in uncoated pins. There was no effect of group on extraction torque. Hydroxyapatite-coated pins had lower torque reduction. Five of 15 hydroxyapatite-coated pins maintained or increased stability, whereas all uncoated pins loosened. Pin hole radiolucency, lameness grades, and positive bacteriologic culture rates were not different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Hydroxyapatite coating increased pin stability within the third metacarpal bone of horses during 8 weeks of transfixation casting but did not improve pin performance on clinical assessments. Clinical use of hydroxyapatite-coated transfixation pins may result in greater pin stability; however, further research is necessary to improve the consistency of pin osteointegration and elucidate whether clinical benefits will ultimately result from this approach in horses.