Orthotics and prosthetics by 3D-printing: Accelerating its fabrication flow.

Orthoses and socket prostheses are rarely used orthopaedic devices in veterinary medicine. Recently, more pet owners have sought these treatments for pets with orthopaedic conditions. However, veterinarians often lack substantial scientific evidence on device outcomes and may expect high costs, the main limiting factor, if human orthopaedic market prices are assumed. This discrepancy creates an imbalance between pet owners' expectations, veterinarians' recommendations, and actual patient benefits. To address economic constraints and enhance knowledge about these devices, this study used 3D technology-namely 3D scanning and printing via fused deposition modelling-to design, modify, and manufacture orthoses and socket prostheses for ten patients, including nine dogs and one calf. An equation was devised and applied to all printed devices to streamline the resizing process for sockets and orthoses. The 3D-printed devices were fitted to the patients, and their adaptation was assessed using three novel scales based on prior scientific literature in the small animal orthopaedic field. The orthoses were well-tolerated, with successful and straightforward adaptation. Although socket prostheses were tolerated, the dogs' adaptation was suboptimal, while the calf demonstrated excellent and immediate adaptation.

Why Owners Choose an Orthosis Over Stifle Surgery for Canine Cranial Cruciate Ligament Deficiency.

The objective of this study was to describe the patient population of dogs with cranial cruciate ligament (CrCL) deficiency that were prescribed a stifle orthosis. A total of 215 client-owned dogs with previously diagnosed CrCL deficiency were prescribed a stifle orthosis at a veterinary pain management and mobility clinic. Patient intake data collected included dog signalment, chief medical complaint, home environment and activity description, medical and surgical history, and diagnosing veterinarian. An orthopedic examination was conducted to assess pelvic limb function and determine pelvic limb morphologic measures. Spayed females (57.2%) were most common in our sample. Median age, body weight, and body condition score were 9.00 ± 3.23 years, 32.98 ± 13.37kg, and 6.00 ± 1.04, respectively. Most common breeds prescribed stifle orthoses included Labrador Retriever, Golden Retriever, and German Shepherd. Right and left limbs were equally affected, and 19.5% of dogs previously had stifle stabilization surgery. Primary reasons for seeking a stifle orthosis consultation were surgical concerns, advanced age, and surgery cost. Most common chief complaints included altered gait, decreased weight bearing, and pain following activity. Reduced stifle extension, increased cranial drawer score, and decreased 3-leg stance time characterized the CrCL-deficient stifle. Stifle orthosis represents an alternative approach to surgical stabilization and management of CrCL deficiency. CrCL-deficient dogs prescribed stifle orthoses were generally large breeds of advanced age with above ideal body condition score. Owners commonly sought a stifle orthosis for CrCL deficiency due to reservations regarding surgical management.

Biomechanics of an orthosis-managed cranial cruciate ligament-deficient canine stifle joint predicted by use of a computer model.

OBJECTIVE To evaluate effects of an orthosis on biomechanics of a cranial cruciate ligament (CrCL)-deficient canine stifle joint by use of a 3-D quasistatic rigid-body pelvic limb computer model simulating the stance phase of gait and to investigate influences of orthosis hinge stiffness (durometer). SAMPLE A previously developed computer simulation model for a healthy 33-kg 5-year-old neutered Golden Retriever. PROCEDURES A custom stifle joint orthosis was implemented in the CrCL-deficient pelvic limb computer simulation model. Ligament loads, relative tibial translation, and relative tibial rotation in the orthosis-stabilized stifle joint (baseline scenario; high-durometer hinge]) were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints. Sensitivity analysis was conducted to evaluate the influence of orthosis hinge stiffness on model outcome measures. RESULTS The orthosis decreased loads placed on the caudal cruciate and lateral collateral ligaments and increased load placed on the medial collateral ligament, compared with loads for the CrCL-intact stifle joint. Ligament loads were decreased in the orthosis-managed CrCL-deficient stifle joint, compared with loads for the CrCL-deficient stifle joint. Relative tibial translation and rotation decreased but were not eliminated after orthosis management. Increased orthosis hinge stiffness reduced tibial translation and rotation, whereas decreased hinge stiffness increased internal tibial rotation, compared with values for the baseline scenario. CONCLUSIONS AND CLINICAL RELEVANCE Stifle joint biomechanics were improved following orthosis implementation, compared with biomechanics of the CrCL-deficient stifle joint. Orthosis hinge stiffness influenced stifle joint biomechanics. An orthosis may be a viable option to stabilize a CrCL-deficient canine stifle joint.

Comparison of owner satisfaction between stifle joint orthoses and tibial plateau leveling osteotomy for the management of cranial cruciate ligament disease in dogs.

OBJECTIVE To compare owner satisfaction between custom-made stifle joint orthoses and tibial plateau leveling osteotomy (TPLO) for the management of medium- and large-breed dogs with cranial cruciate ligament disease (CCLD). DESIGN Owner survey. SAMPLE 819 and 203 owners of dogs with CCLD that were managed with a custom-made stifle joint orthosis or TPLO, respectively. PROCEDURES Client databases of an orthosis provider and veterinary teaching hospital were reviewed to identify potential survey respondents. An online survey was developed to evaluate owner-reported outcomes, complications, and satisfaction associated with the nonsurgical (orthosis group) and surgical (TPLO group) interventions. Survey responses were compared between groups. RESULTS The response rate was 25% (203/819) and 37% (76/203) for the orthosis and TPLO groups, respectively. The proportion of owners who reported that their dogs had mild or no lameness and rated the intervention as excellent, very good, or good was significantly greater for the TPLO group than for the orthosis group. However, ≥ 85% of respondents in both groups reported that they would choose the selected treatment again. Of 151 respondents from the orthosis group, 70 (46%) reported skin lesions associated with the device, 16 (11%) reported that the dog subsequently underwent surgery, and 10 (7%) reported that the dog never tolerated the device. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated high owner satisfaction rates for both interventions. Owners considering nonsurgical management with an orthosis should be advised about potential complications such as persistent lameness, skin lesions, patient intolerance of the device, and the need for subsequent surgery.

Effect of hoof boots and toe-extension shoes on the forelimb kinetics of horses during walking.

OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of both forelimb feet to determine the sole length in contact with the ground when barefoot, wearing HBs, and shod with toe-extension shoes. Stance duration, ground reaction force, and sole length were compared among the various walking sessions. RESULTS Compared with baseline findings, stance duration increased significantly when horses were fitted with HBs (7%) or toe-extension shoes (5%). Peak forelimb ground reaction force was similar among walking sessions; however, time of braking force peak was significantly greater during the stance phase only when horses wore HBs. Also, the sole length in contact with the ground was significantly longer in horses fitted with HBs (14.3 cm) or shod with the toe-extension shoes (17.6 cm), compared with that for one of the barefoot hooves (12.7 cm). CONCLUSIONS AND CLINICAL RELEVANCE In nonlame horses, use of HBs prolonged the stance time and time of braking force peak, which is indicative of a slower deceleration phase during limb impact with the ground. Also, the use of HBs prolonged the deceleration phase of the stride and increased the sole length in contact with the ground.

Orthoses and exoprostheses for companion animals.

Exoprostheses are devices that are secured to incomplete limbs to enable locomotion. By comparison, orthoses are devices externally applied to support or protect an injured body part. Orthoses also can be used to control, guide, protect, limit motion of, or immobilize an extremity, a joint, or a body segment. Exoprostheses and orthoses are a growing aspect of the physical rehabilitation of companion animals. They require precise design and fabrication. Patients and owners must be trained to use the devices. Exoprostheses and orthoses can have a profound beneficial impact on the mobility and the quality of life of companion animals.

The emerging role of veterinary orthotics and prosthetics (V-OP) in small animal rehabilitation and pain management.

In veterinary school, we learn much about how to repair bone fractures, ligament injuries, and neuropathies. The idea, of course, is to return some level of function to a damaged appendage and decrease pain. When a limb cannot be salvaged for medical or financial reasons, we are taught that dogs and cats do "great" on 3 legs. Three legs may mean a less functional limb or outright total amputation. We espouse this doctrine to our clients. Indeed, most of us have countless stories of triped patients acclimating to their disability with aplomb. Although it is true that many patients adapt, learning to ambulate and negotiate their environment, this is functional adaptation-not necessarily the highest quality of life. As a profession, we have come to expect-even accept-that limited mobility, limb breakdown, and chronic neck or back pain are unavoidable consequences. The short- and long-term consequences of limb loss or altered limb function are not benign as once thought. Furthermore, the quality of care demanded by clients is rising and the breadth of knowledge afforded by technology and global communication spawns innovative therapies readily accessible to the computer-savvy pet owner. Recent examples of therapeutic innovations include the following: dentistry, acupuncture, chiropractic, and rehabilitation. Often there is no precedent for these new therapies in animals, and the onus rests with the veterinary community to educate itself to provide best care for patients and clients and to establish evidence-informed best practice. The newest emerging therapeutic modality is veterinary orthotics and prosthetics. Like the previously mentioned modalities, the origin lies in human health care and subsequently leaps to veterinary health care.

Use of a custom orthotic boot for management of distal extremity and pad wounds in three dogs.

OBJECTIVE: To describe use of a custom orthotic boot for management of distal extremity and pad wounds in dogs. STUDY DESIGN: Clinical report. ANIMALS: Dogs (n = 3). METHODS: A custom orthotic boot made of lightweight copolymer plastic was used to immobilize the distal extremity and protect full-thickness wounds involving the medial or lateral aspect of the metatarsus including a portion of the metatarsal pad in 3 dogs. Boots were made in a bivalve design with closed-cell foam padding and adjustable straps that allowed for easy application. They were molded with the tarsocrural joint in slight hyperextension and the metatarsophalangeal joints in a neutral position so that the wounds and metatarsal pads were "off weighted" when the dogs were standing. In addition, a "window" was cut out directly over the wounds to minimize direct contact between the boot and the wound. RESULTS: Wounds healed by contraction and epithelialization in 21, 21, and 45 days. The only complication encountered was mild skin irritation at the top of the boot in 2 dogs that was managed with additional closed-cell foam padding. CONCLUSION: A custom orthotic boot was effective at immobilizing the distal extremity and reducing contact between the wound and the boot which allowed for complete healing by contraction and epithelialization.

Gastrocnemius tendon strain in a dog treated with autologous mesenchymal stem cells and a custom orthosis.

OBJECTIVE: To report clinical findings and outcome in a dog with gastrocnemius tendon strain treated with autologous mesenchymal stem cells and a custom orthosis. STUDY DESIGN: Clinical report. ANIMAL: A 4-year-old spayed female Border Collie. METHODS: Bone-marrow derived, autologous mesenchymal stem cells were transplanted into the tendon core lesion. A custom, progressive, dynamic orthosis was fit to the tarsus. Serial orthopedic examinations and ultrasonography as well as long-term force-plate gait analysis were utilized for follow up. RESULTS: Lameness subjectively resolved and peak vertical force increased from 43% to 92% of the contralateral pelvic limb. Serial ultrasonographic examinations revealed improved but incomplete restoration of normal linear fiber pattern of the gastrocnemius tendon. CONCLUSIONS: Findings suggest that autologous mesenchymal stem cell transplantation with custom, progressive, dynamic orthosis may be a viable, minimally invasive technique for treatment of calcaneal tendon injuries in dogs.

Use of a pressure plate to analyse the toe-heel load redistribution underneath a normal shoe and a shoe with a wide toe in sound warmblood horses at the walk and trot.

The objective of this study was to use a pressure plate to quantify the toe-heel load redistribution in the forelimbs of sound warmblood horses with normal shoes and shoes with a wide toe and narrow branches, used empirically in the treatment of superficial digital flexor tendon or suspensory ligament injuries. In a crossover-design study, six horses, randomly shod with normal shoes and shoes with a wide toe, were led over a dynamically calibrated pressure plate to record data from both forelimbs. There were no significant differences between both shoes in the toe-heel index of stance time, peak vertical force and vertical impulse. For the adapted shoe, the peak vertical pressure was slightly lower and was exerted slightly earlier in the stance phase, albeit not significantly. However, the significantly larger toe contact area of the adapted shoe resulted in a significantly lower total vertical pressure in the toe region. Hence, the pressure plate adequately visualised the individual loading of the toe and heel region, and clearly demonstrated the altered pressure distribution underneath the shoe with a wide toe. Although further research on a deformable surface is needed to confirm this hypothesis, the pressure redistribution from the toe to the heels could promote sinking of the heels in arena footing, thereby mimicking the biomechanical effects of a toe wedge and providing a rationale for its application in the treatment of SDFT or SL injuries. The pressure measuring equipment used in this study can offer to the clinician a diagnostic tool for the evaluation of the load distribution underneath the equine hoof and for the fine-tuning of corrective shoeing.

Pressure distribution between the deep digital flexor tendon and the navicular bone, and the effect of raising the heels in vitro.

The objectives of this study were to topographically map pressure distribution across the palmar surface of the navicular bone in response to forces applied by the deep digital flexor tendon (DDFT), and evaluate the effect of raising the heels in vitro . A rig was constructed to hold an equine cadaver limb and apply controlled pressure to the navicular bone from the DDFT. Pressure-sensitive paper was used to quantify and map the resultant pressure. Changes in response to heel wedges (5 degrees and 10 degrees ) were recorded. The areas subject to maximum pressure from the DDFT were: the central ridge, the paired symmetrical areas adjacent to the ridge and the distal edge of the palmar bone surface. These regions correspond to the known sites of navicular pathology. Heel wedges redistributed the pressure exerted on the palmar surface of the navicular bone, with measurements varying depending on fetlock angle and wedge angle. These in vitro results support the hypothesis that inappropriate forces exerted via the DDFT on the bone cause navicular disease. However, they throw doubt on the practice of shoeing such horses with heel wedges as the redistribution of pressure may increase the force exerted on regions predisposed to disease.

Comparación de las características mecánicas estáticas del fémur aislado de perro, con y sin la colocación de una placa de ortopedia fabricada en polipropileno / Compare the mechanical statistical characteristics of dog femur isolet, with or without placing to an orthopedic píate made of polypropylene

Los objetivos generales fueron: evaluar resistencia a la compresión del fémur derecho aislado y del fémur izquierdo osteotomizado transversalmente fijado con una placa ortopédica fabricada en polipropileno, y comparar las características mecánicas estáticas entre ambos. Este trabajo se realizó mediante la confección de un modelo experimental de carga constituido por un fémur de mamífero (perro) en condiciones aisladas. Se utilizaron los huesos fémur de 13 perros mestizos, adultos jóvenes, de talla mediana a grande. Para los pruebas se utilizó una máquina servohidráulica para ensayos estáticos y dinámicos Amsler Wolpert. Se utilizó para el tratamiento de los datos, el test estadístico de diferencias de medias para muestras pareadas dependientes. Como resultado del análisis de las curvas se obtuvo que: el fémur derecho soportó antes de la falla, entre 4,02 a 8,47 KN de carga (= 6,66 KN) con una deformación de 2,02 a 5,09 mm (= 3,66 mm). En tanto el conjunto fémur izquierdo + placa ortopédica soportó antes de la falla, entre 3,05 a 5,61 KN de carga (= 4,49 KN) con una deformación de 2 a 4.5 mm (= 3 mm). Como conclusión, es posible afirmar que hay diferencias en la resistencia a la carga compresiva entre el fémur derecho y su contralateral izquierdo + placa ortopédica.

The general aims were: to evaluate the resistance to compression of the right femur isolated and that of the left femur transversally osteotomized fixed to an orthopedic plate made of polypropylene and to compare the mechanical statistical characteristics between both. This work was carried out by performing an experimental charge pattern made of a mammal femur (dog) under isolated conditions. Femur bones of 13 hybrid young adult dogs of medium to large size were used. A servohydric engine was used for the Amsler Wolpert static and dynamic essays. The mean difference statistical test for depending paired samples was used for the evaluation of data. As a result of the curves analysis it was obtained that: before failure the right femur underwent a charge of 4.02 to 8.47 KN (= 6.66 KN) with a deformation of 2.02 to 5.09 mm (= 3.66mm) while the charge that the left femur + orthopedic plate underwent before de failure was of 3.05 to 5.61 KN ( = 4.49KN) with a deformation of 2 to 4.5 mm ( = 3mm). As a conclusion it might be stated that there are differences in the resistance to the compressive charge between right femur and its left contra lateral + the orthopedic plate.

Assistive devices, orthotics, and prosthetics.

Deciding on which supportive device, orthotic, or prosthetic is best suited for a given patient is a complex process involving many different factors. The ability to manage biomechanical abnormalities successfully may be enhanced by an understanding of the properties of the various materials that comprise these devices, their effect on functional performance, and other associated patient factors. Veterinary health care providers are faced with the challenge of effectively addressing the physiologic and fiscal needs of the patient in a rapidly changing patient care environment.

Use of an ankle-foot orthosis in a dog with traumatic sciatic neuropathy.

Traumatic unilateral sciatic neuropathy secondary to a gunshot wound was diagnosed in a seven-month-old, intact male golden retriever. Findings on neurological assessment, performed after cardiovascular stabilisation, were incompatible with a return to normal limb function. An ankle-foot orthosis was used to correct excessive flexion of the digits and tarsus. This device greatly improved the dog's willingness to ambulate and could serve as an alternative to amputation in companion animals with severe sciatic axonotmesis or neurotmesis. Complications associated with chronic tibiotarsal hyperflexion necessitated a pantarsal arthrodesis one year after initial presentation; the dog also developed cranial cruciate disease in the affected limb three years after the gunshot injury.

Calculated forelimb flexor tendon forces in horses with experimentally induced superficial digital flexor tendinitis and the effects of application of heel wedges.

OBJECTIVE: To calculate forces in the flexor tendons and the influence of heel wedges in affected and contralateral (compensating) forelimbs of horses with experimentally induced unilateral tendinitis of the superficial digital flexor (SDF) tendon. ANIMALS: 5 Warmblood horses. Procedure-Ground reaction force and kinematic data were obtained during a previous study while horses were trotting before and after induction of tendinitis in 1 forelimb SDF and after application of 6 degrees heel wedges to both forehooves. Forces in the SDF, deep digital flexor (DDF), and the suspensory ligament (SL) and strain in the accessory ligament (AL) of the DDF were calculated, using an in vitro model of the distal region of the forelimb. RESULTS: After induction of tendinitis, trotting speed slowed, and forces decreased in most tendons. In the affected limb, SL force decreased more than SDF and DDF forces. In the compensating limb, SDF force increased, and the other forces decreased. After application of heel wedges, SDF force in both limbs increased but not significantly. Furthermore, there was a decrease in DDF force and AL strain. CONCLUSIONS AND CLINICAL RELEVANCE: The increase in SDF force in the compensating forelimb of horses with unilateral SDF tendinitis may explain the high secondary injury rate in this tendon. The lack of decrease of SDF force in either limb after application of heel wedges suggests that heel wedges are not beneficial in horses with SDF tendinitis. Instead, heel wedges may exacerbate the existing lesion.

The effect of orthopaedic shoeing on the force exerted by the deep digital flexor tendon on the navicular bone in horses.

This study quantifies both the intended effect of orthopaedic shoeing to decrease the load on the navicular bone and the eventual undesired effects on gait performance. The compressive force exerted by the deep digital flexor tendon on the navicular bone and on the quality of the trot and redistribution of forces over the flexor tendons and the suspensory ligament were studied as a function of orthopaedic shoeing in 12 sound Dutch Warmblood horses. A modified CODA-3 gait analysis system and a force plate were used to quantify objectively the load on the lower limb. The quality of the trot was assessed using the same gait analysis system while the horses were trotting on the treadmill. The effects of shoes with heel wedges and egg-bar shoes were compared to flat shoes and unshod feet. When heel wedges were applied, the maximal force on the navicular bone was reduced by 24% (P<0.05) in comparison with flat shoes. Egg-bar shoes did not reduce the force on the navicular bone, but in unshod feet this force appeared to be 14% lower (P<0.05) compared to flat shoes. Egg-bar shoes cause the horse's trot to be slightly less animated (P<0.05), compared to flat shoes and shoes with heel wedges. It is concluded that shoes with heel wedges reduce the force on the navicular bone as a result of a decreased moment of force at the distal interphalangeal joint in combination with a decreased angle between the deep digital flexor tendon distally and proximally of the navicular bone. Therefore it can be expected that in horses suffering from navicular disease, heel wedges will have the expected beneficial effect on the pressure on the navicular bone, while the effect of egg-bar shoes remains doubtful.

Follow-up study of owner attitudes toward home care of paraplegic dogs.

A questionnaire was mailed to 30 owners of paraplegic dogs who had been caring for their dogs at home for 3 to 72 months. It was designed to collect information on demographic variables, duration of ownership and paralysis, age of the pet, pet/owner relationship, owner expectations and perceptions of the pet's quality of life, problems the pet experienced, effect that maintaining a paralyzed pet had on the owners' quality of life, and whether use of a cart was beneficial. Significant correlation was found between prior expectations that the pet would lead a high-quality life and perception that the pet, in fact, had a high quality of life during paralysis (r2 = 0.61, P = 0.01). Owners who had anticipated that extra work would be necessary to care for their paraplegic dog had a more positive attitude toward home care (r2 = 0.55, P = 0.03). Overall, owners involved in the study were satisfied with all aspects of maintaining paraplegic dogs at home. Our findings support the feasibility of dedicated owners successfully maintaining small (average body weight, 9 kg) paraplegic dogs at home for extended periods.