Rehabilitation of fractures in small animals: Maximize outcomes, minimize complications

Treatment options, complications and long-term outcomes for limb fractures in pet rabbits

BACKGROUND

Limb fractures represent the most common orthopaedic disease in pet rabbits. However, only a few studies have evaluated therapeutic details of limb fractures. There are no data available for long-term outcomes of limb fracture treatment.

METHODS

The medical records of six institutions were reviewed retrospectively to identify cases of traumatic limb bone fractures in pet rabbits between 1999 and 2020. The medical records (n = 387) were analysed for details of fracture prevalence, aetiology, therapy protocols, treatment complications, outcome and long-term effects. In addition to the retrospective data evaluation, 13 rabbits were re-evaluated in person in recent clinical analyses, including orthopaedic examination, radiography and computed-tomographic imaging. Details of long-term effects of fracture treatment were requested over the telephone for a further 232 animals using a standardised questionnaire.

RESULTS

Long bone fractures accounted for the majority of all fractures (296/387; 76.5%). Hindlimb fractures (301/387; 77.7%) were more common than forelimb fractures (86/387; 22.2%), and tibial fractures and combined fractures of the tibia and fibula (119/387; 30.8%) were observed most frequently. Most fracture treatments were based on osteosynthesis procedures (243/328; 74.1%). Treatment complications occurred in 130 out of 328 (39.6%) cases. A high bodyweight (p = 0.047) and an older age (p = 0.01) were found to be significant risk factors for the emergence of therapy complications. Overall, 75.4% of animals (175/232) had a satisfactory long-term outcome. Limb posture anomalies were evaluated in 61 cases (26.3%).

LIMITATIONS

The multi-centre approach led to the inclusion of various institutions, veterinarians, treatment protocols and rabbit populations that might have influenced the results. The medical records were reviewed retrospectively, so there were some data that were lacking or could not be collected in a standardised manner. Furthermore, rabbit owners' evaluation of long-term outcomes might be prone to error, despite the use of a standardised interview questionnaire.

CONCLUSION

Limb fractures are a common orthopaedic issue in pet rabbits. The patient's bodyweight and age are significant risk factors for the emergence of complications during the fracture treatment process. Long-term orthopaedic effects, such as abnormal limb posture and permanent lameness of the affected limb, were observed regularly.

Rehabilitation of companion animals following orthopaedic surgery

Physical therapy and rehabilitation following orthopaedic surgery in companion animals have become more common and new advancements in this field have been made in recent years. Surgery alone may not return the animal to its previous physical activity or work-related tasks, whether due to concurrent soft tissue trauma, arthrogenic muscle inhibition or osteoarthritis. Rehabilitation therapies following surgery can restore function as well as strength, coordination and balance. Many simple techniques such as cryotherapy and passive range of motion exercises have been shown to improve outcomes following musculoskeletal procedures and may help restore function as well as reduce pain and facilitate healing. Some techniques are more useful during different stages in order to achieve optimum tissue healing and recovery of function. During the first 72 hours, rehabilitation should focus on reduction of inflammation and pain, maintaining joint nutrition and range of motion, and stimulating vascularisation and healing; and may include cryotherapy, passive range of motion exercises, massage and therapeutic exercises. Following the initial recovery period, the goals of rehabilitation also include restoring strength, balance and normal gait patterns, as well as recovery of function. During this period the focus of therapy may shift toward therapeutic exercises, aquatic therapy and increasing activity in the animal. Therapeutic modalities such as neuromuscular electrical stimulation, photobiomodulation (laser therapy), therapeutic ultrasound and extracorporeal shock wave therapy have been reported to reduce pain and inflammation, enhance healing and reduce recovery time in the early and late stages following orthopaedic surgery.

Electrical stimulation-based bone fracture treatment, if it works so well why do not more surgeons use it?

BACKGROUND

Electrical stimulation (EStim) has been proven to promote bone healing in experimental settings and has been used clinically for many years and yet it has not become a mainstream clinical treatment.

METHODS

To better understand this discrepancy we reviewed 72 animal and 69 clinical studies published between 1978 and 2017, and separately asked 161 orthopedic surgeons worldwide about their awareness, experience, and acceptance of EStim for treating fracture patients.

RESULTS

Of the 72 animal studies, 77% reported positive outcomes, and the most common model, bone, fracture type, and method of administering EStim were dog, tibia, large bone defects, and DC, respectively. Of the 69 clinical studies, 73% reported positive outcomes, and the most common bone treated, fracture type, and method of administration were tibia, delayed/non-unions, and PEMF, respectively. Of the 161 survey respondents, most (73%) were aware of the positive outcomes reported in the literature, yet only 32% used EStim in their patients. The most common fracture they treated was delayed/non-unions, and the greatest problems with EStim were high costs and inconsistent results.

CONCLUSION

Despite their awareness of EStim's pro-fracture healing effects few orthopedic surgeons use it in their patients. Our review of the literature and survey indicate that this is due to confusion in the literature due to the great variation in methods reported, and the inconsistent results associated with this treatment approach. In spite of this surgeons seem to be open to using this treatment if advancements in the technology were able to provide an easy to use, cost-effective method to deliver EStim in their fracture patients.

Modalidades fisioterapêuticas na reabilitação de cães com doença do disco intervertebral toracolombar submetidos à cirurgia descompressiva: 30 casos (2008-2016)

RESUMO Este estudo retrospectivo teve como objetivo demonstrar as modalidades fisioterapêuticas empregadas no tratamento de cães com doença do disco intervertebral (DDIV) toracolombar após descompressão cirúrgica da medula espinhal, bem como relatar os fatores que determinaram as alterações das modalidades. Foram incluídos 30 cães que apresentavam sinais neurológicos desde paraparesia ambulatória a paraplegia com dor profunda na primeira sessão de fisioterapia. As modalidades utilizadas nos protocolos de todos os pacientes foram a crioterapia, massagem, alongamento passivo, movimentação passiva articular, estímulo do reflexo flexor e estimulação elétrica neuromuscular. A inclusão ou exclusão de exercícios terapêuticos, como a tipoia corporal, a plataforma proprioceptiva circular, a natação, a hidroesteira, os obstáculos e a caminhada em colchão, foi de acordo com a evolução clínica e a adaptação de cada paciente. Oitenta por cento (80%) dos cães alteraram o grau de disfunção neurológica antes de iniciar a fisioterapia e 93% retornaram à habilidade de caminhar (paraparesia ambulatória) ao final da fisioterapia. O número de sessões e o tempo de recuperação foram maiores quanto pior foi o grau de lesão do paciente.

Heating produced by therapeutic ultrasound in the presence of a metal plate in the femur of canine cadavers

The present study aimed to assess the heat generated by a therapeutic ultrasound (TUS) in a metal bone plate and adjacent structures after fixation to the femur of canine cadavers. Ten pairs of hind limbs were used, and they were equally distributed between groups that were subjected to 1- and 3-MHz frequencies, with each frequency testing 1- and 2-W/cm² intensities. The right hind limb was defined as the control group (absence of the metal plate), and the left hind limb was the test group (presence of the metal plate). Therefore, the control groups (CG) were denominated CGI, using TUS with 1-MHz frequency and 1-W/cm² intensity; CGII, using 1-MHz frequency and 2-W/cm² intensity; CGIII, using 3-MHz frequency and 1-W/cm² intensity; and CGIV, using 3-MHz frequency and 2-W/cm² intensity. For each control group, its respective test group (TG) was denominated TGI, TGII, TGIII and TGIV. The TUS was applied to the lateral aspect of the thigh using the continuous mode and a 3.5-cm² transducer in a 6.25-cm² area for 2 minutes. Sensors were coupled to digital thermometers that measured the temperature in different sites before (t0) and after (t1) of the TUS application. The temperatures in t1were higher in all tested groups. The intramuscular temperature was significantly higher (P<0.05) in the groups used to test the 3-MHz frequency in the presence of the metal plate. The therapeutic ultrasound in the continuous mode using frequencies of 1 and 3 MHz and intensities of 1 and 2 W/cm2 for 2 minutes caused heating of the metal plate and adjacent structures after fixation to the femur of canine cadavers.

Use of a graft of demineralized bone matrix along with TGF-β1 leads to an early bone repair in dogs

Tibia fractures are common in small animal practice. Over the past decade, improvements to animal internal fracture fixation have been developed. TGF-β1 has been shown to be crucial in the development, induction and repair of bone. In present study, we investigate the effect of local application of a graft demineralized bone matrix (DBM) along with TGF-β1 in a model of open osteotomy induced experimentally in dogs. Tibia fracture was brought about by using an open osteotomy model in young male dogs. Fracture repair was evaluated by a histological and biochemical analysis. Collagen content, proteolytic activity and urokinase-type plasminogen activator (uPA) expression were analyzed at the end of the study. Radiographic analysis, alkaline phosphatase and hematological evaluation were performed weekly. At the fifth week, there was an improvement and restoration of bone architecture in animals treated with a graft containing TGF-β1 (5 ng/ml) compared with the control and graft groups, as was evidenced by the presence of an early formation of wide callus and bone regeneration. In addition, local application of TGF-β1 led to an increase in collagen and proteolytic activity. More immunopositive osteoclast and mesenchymal cells were found in bone tissue from animals treated with TGF-β1 as compared with the control group. No changes in alkaline phosphatase, hematological and clinical parameters were observed. This study shows that the combined use of DBM along with TGF-β1 is able to improve and accelerate the bone repair.

Assessment of impulse duration thresholds for electrical stimulation of muscles (chronaxy) in dogs

OBJECTIVE

To determine the electrical impulse duration thresholds (chronaxy) for maximal motor contraction of various muscles without stimulation of pain fibers in dogs.

ANIMALS

10 healthy adult Beagles.

PROCEDURES

The dogs were used to assess the minimal intensity (rheobase) required to elicit motor contraction of 11 muscles (5 in the forelimb [supraspinatus, infraspinatus, deltoideus, lateral head of the triceps brachii, and extensor carpi radialis], 5 in the hind limb [gluteus medius, biceps femoris, semitendinosus, vastus lateralis, and tibialis cranialis], and the erector spinae). The rheobase was used to determine the chronaxy for each of the 11 muscles in the 10 dogs; chronaxy values were compared with those reported for the corresponding muscles in humans.

RESULTS

Compared with values in humans, chronaxy values for stimulation of AA motor fibers in the biceps femoris and semitendinosus muscles and muscles of the more distal portions of limbs were lower in dogs. For the other muscles evaluated, chronaxy values did not differ between dogs and humans.

CONCLUSIONS AND CLINICAL RELEVANCE

Application of the dog-specific chronaxy values when performing electrical stimulation for strengthening muscles or providing pain relief is likely to minimize the pain perceived during treatment in dogs.

Determinants of passive hip range of motion in adult Greyhounds

OBJECTIVE

To determine the ranges of normal pelvic limb range of motion in adult Greyhound dogs, and to explore which factors influence hip range of motion in a population bred to meet the specific demands of racing. Design A cross-sectional study design.

METHOD

Thirty-two dogs (17 male and 15 female) 13 to 81 months old were randomly selected from a local pool of 160 Greyhounds. Goniometric measurements of hip, stifle and hock range of motion were recorded in triplicate. Signalment information collected included sex, weight and age of each Greyhound. The outcome factors for the study were range of hip flexion and hip extension. The theorised exposures, age, sex, weight, racing history and hock and stifle range of motion, were modelled against the outcome variables by linear regression analysis.

RESULTS

Male dogs were significantly heavier (P < 0.001) and older (P < 0.002) than female dogs. Mean hip flexion was 71.75 degrees and mean hip extension 128.10 degrees. The determinants of hip flexion were sex (P = 0.008) and range of stifle flexion (P = 0.002). Race training did not influence the range of hip flexion in the sample. Determinants of hip extension included range of stifle extension (P = 0.015), history of race training (P = 0.004) and hock flexion. The mean hip extension of raced Greyhounds was 134.95 degrees compared with 121.25 degrees for unraced Greyhounds (mean difference -13.70, 95% confidence interval -18.12, -9.29; P < 0.001).

CONCLUSIONS

This study has reported isolated pelvic limb joint range of motion in the racing Greyhound. Hip range of motion was affected by stifle range of motion, sex and race training. Dogs that had received race training had greater flexibility, possibly due to training having an active stretching role on muscles, tendons and other structures limiting the hip range of motion.