Fibrotic myopathy and contracture of the caudal thigh musculature: a prospective study of 41 dogs (2019-2022).

OBJECTIVE: To determine the presentation, diagnosis, progression, and family risk of fibrotic myopathy, a disease with marked breed predisposition in the German Shepherd Dog (GSD). ANIMALS: 41 dogs prospectively recruited to the University of Wisconsin-Madison Comparative Genetics and Orthopedic Laboratory between November 2019 to August 2022. METHODS: Medical records of dogs diagnosed with fibrotic myopathy were reviewed upon referral. The following data were recorded: sex, age, weight, regio interscapularis (withers) height, date of neutering, coat color and length, and age at fibrotic myopathy diagnosis. A pedigree was also obtained. RESULTS: In the study population, breeds included 37 GSDs, a Belgian Malinois, a Belgian Malinois cross, and 2 dogs with a GSD phenotype and no pedigree. Mean age at fibrotic myopathy diagnosis was 5.9 ± 2.0 years, and duration of lameness before diagnosis was 5.6 months and ranged from 0.75 to 18 months. Males were overrepresented at 61% of the study population. Inherited familial risk for fibrotic myopathy in the GSD was supported by pedigree analysis. CLINICAL RELEVANCE: This was the largest case series of fibrotic myopathy to date, providing a more comprehensive look at presentation and progression of the disease. The longer duration of lameness in bilaterally affected dogs likely represents disease progression rather than a more severe phenotype. Family history data support a genetic contribution to fibrotic myopathy, suggesting that further genetic investigation is warranted.

Outcome of rest with or without bandaging for treatment of carpal flexural contracture deformities in puppies: 47 puppies and 75 joints (2000-2018).

OBJECTIVE: To review outcome of dogs with carpal flexural contracture deformities treated with rest alone or with rest and bandaging. ANIMALS: 47 dogs (75 joints). PROCEDURES: Medical records of dogs with unilateral or bilateral carpal flexural contracture deformities were reviewed, and dogs were grouped according to deformity severity grade (graded on a scale from 1 to 3) at the time of diagnosis. Two treatment groups were compared: rest only and rest with a modified Robert-Jones bandage. All dogs were reevaluated weekly until recovery (ie, resolution of the deformity and lameness). RESULTS: All dogs responded to conservative management, with all dogs regaining full extension of the antebrachiocarpal joint and ambulating normally at the time of the final visit. Mean ± SD time from initial diagnosis to recovery (ie, resolution of the deformity and lameness) was 2.9 ± 2.2 weeks (median, 2 weeks; range, 1 to 9 weeks). For dogs with grade 1 or 2 severity, mean time to recovery did not differ significantly between treatment groups. For dogs with grade 3 severity, however, mean time to recovery was significantly shorter for dogs treated with rest and bandaging than for dogs treated with rest alone. CLINICAL RELEVANCE: Results suggested that conservative management (rest alone or rest and bandaging) was a successful treatment option for puppies with carpal flexural contracture deformity and that bandaging resulted in a shorter time to recovery for dogs that were severely affected.

Hind limb ossification centre hypoplasia and deformities induced by quadriceps contracture: Radiographic and Computed Tomographic study in 13 Doberman Pinscher littermates.

Quadriceps contracture (QC) is reported in dogs mainly as a complication of trauma or parasitic infection. QC causes progressive hind limb deviation, muscular hypotrophy and degenerative joint disease and, in puppies, bone hypoplasia. The aim of this clinical case series is to describe the radiographic and computed tomographic (CT) changes in hind limb ossification centres in thirteen 55 to 57-days-old Doberman Pinscher related littermates induced by QC after repeated intramuscular injections. The presence, size, and shape of ossification centres of affected and unaffected hind limbs were compared. Affected limbs were hyperextended and externally rotated, with genu recurvatum and proximo-medial patellar luxation. QC had no influence on the time of appearance of ossification centres however, it was associated with femoral head flattening, hip subluxation, flattening of the femoral distal epiphysis. The tibial plateau was tilted caudoproximally-craniodistally and wedged into the growth plate. Thirty-two out of fifty-five ossification centres (including diaphyseal and epiphyseal centres, such as femoral head and tibial plateau) were significantly smaller in affected limbs (p < 0.05). Lack of weight-bearing could account for the smaller size of ossification centres in affected tarsi and metatarsi. Progressive limb hyperextension and external rotation might have induced gradual loading withdrawal on the medial aspect of the foot justifying the reduced size observed only for the medial ossification centres of the digits of affected limbs. To the best of our knowledge, this is the first study describing CT findings of hind limb ossification centre changes in puppies with QC contracture.

CT findings in a dog with subacute myopathy and later fibrotic contracture of the infraspinatus muscle.

A 5-year-old Norwegian elkhound was referred due to an acute onset of lameness and persistent shoulder pain over a period of 3 weeks. Computed tomography demonstrated an enlarged, hypoattenuating right infraspinatus muscle with peripheral contrast enhancement and a nonenhancing center, without concurrent lesions in superficial structures or bones. The right infraspinatus muscle showed progressive atrophy on consecutive CT studies. The dog developed clinical symptoms compatible with fibrotic infraspinatus contracture 2 months after the initial presentation, and was treated with infraspinatus tenotomy. Histopathological diagnoses based on intraoperative biopsy samples were fibrotic muscle atrophy and muscle hypertrophy with regeneration.

Digital flexor musculotendinous contracture in two Devon Rex cats.

Clinical summary: A 13-year-old, spayed Devon Rex with unilateral digital flexor musculotendinous contracture of the forelimb was treated by surgical tenotomy. The condition improved transiently, but recurred rapidly and became bilateral. Histopathologic analysis of necropsy tissues resulted in a morphologic diagnosis of fibromyositis of the antebrachial muscles causing contracture and flexural deformity of the carpi and phalanges of both thoracic limbs. A search for similar cases yielded the clinical notes of a second cat, a 10-year-old, spayed Devon Rex, also with bilateral disease. This second case responded well to surgical tenotomy but tissue biopsies were not obtained to permit microscopic assessment of the underlying pathologic process. Relevance and novel information: Acquired and permanent contracture of the digital flexor muscles and/or tendons of the forelimbs is a rare and poorly described condition of cats. The very limited number of documented cases describing disease affecting one or more digits (but not the carpus) infers a causal link with onychectomy, but reported histopathologic changes have been limited to the tendons. The two cases described in this report suffered contracture of the carpus and all digits bilaterally, one without previous onychectomy and the other 9 years after onychectomy. There were novel histopathologic findings in the muscles of the one case for which biopsy material was available. Information gained from these two cases provides a new perspective for the investigation and treatment of future cases. Specifically, consideration should be given to an underlying immune-mediated myopathic process and a possible genetic predisposition in the Devon Rex breed. Currently, the poorly understood etiopathogenesis hinders our ability to definitively recommend treatment options, which might include corticosteroids and other forms of immunosuppressive therapy.

Heating produced by therapeutic ultrasound in the presence of a metal plate in the femur of canine cadavers / Aquecimento gerado pelo ultrassom terapêutico em presença de placa óssea metálica no fêmur de cadáveres caninos

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 t1 were 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...

O objetivo deste estudo foi avaliar o aquecimento gerado pelo ultrassom terapêutico (UST) na placa óssea metálica e estruturas adjacentes após a fixação no fêmur de cadáveres caninos. Foram utilizados dez pares de membros pélvicos, distribuídos igualmente entre os grupos que utilizaram as frequências de 1 e 3 MHz. Cada frequência testou as intensidades de 1 e 2 W/cm², sendo que o membro pélvico direito foi definido grupo controle (ausência da placa óssea metálica) e o membro pélvico esquerdo o grupo teste (presença da placa óssea metálica). Portanto, os grupos controles foram denominados GCI, com UST na frequência de 1 MHz e intensidade de 1 W/cm²; GCII, com 1 MHz e 2 W/cm²; GCIII, com frequência de 3 MHz e intensidade de 1 W/cm²; e GCIV, com 3 MHz e 2 W/cm². Para cada grupo controle, seu respectivo grupo teste foi denominado GTI, GTII, GTIII e GTIV. O UST foi aplicado na face lateral da coxa, utilizando o modo contínuo, transdutor de 3,5cm², em uma área de 6,25cm², durante dois minutos. Foram utilizados sensores acoplados a termômetros digitais que mediram a temperatura em diferentes locais antes (t0) e após (t1) a aplicação do UST. Pode-se verificar que as temperaturas em t1 foram maiores em todos os grupos testados. Os grupos que testaram a frequência de 3 MHz demonstraram que a temperatura intramuscular foi significativamente maior (P<0,05) na presença da placa óssea metálica. O ultrassom terapêutico no modo contínuo de 1 e 3 MHz e intensidades de 1 e 2 W/cm2 durante dois minutos promove o aquecimento da placa óssea metálica e estruturas adjacentes após a fixação no fêmur de cadáveres caninos...

Diseases of the tendons and tendon sheaths.

Contracted flexor tendon leading to flexural deformity is a common congenital defect in cattle. Arthrogryposis is a congenital syndrome of persistent joint contracture that occurs frequently in Europe as a consequence of Schmallenberg virus infection of the dam. Spastic paresis has a hereditary component, and affected cattle should not be used for breeding purposes. The most common tendon avulsion involves the deep digital flexor tendon. Tendon disruptions may be successfully managed by tenorrhaphy and external coaptation or by external coaptation alone. Medical management alone is unlikely to be effective for purulent tenosynovitis.

Prevalence and effect of oxytetracycline on congenital fetlock knuckling in neonatal dairy calves.

Musculoskeletal system deformities were observed in 24 (34.3%) of 70 neonatal dairy calves that presented with different congenital abnormalities. Among them, 19 calves (27.1%), the majority of which were crossbred Jersey calves of either gender with mean (± s.e.) body weight 22.00 kg ± 1.17 kg and aged 7.11 ± 1.16 days, were presented for treatment of congenital knuckling. Five of the knuckling calves had additional concurrent congenital conditions and were excluded from the present study. All of the remaining 14 calves showing moderate, bilateral fetlock knuckling had a wooden or polyvinyl chloride (PVC) splint applied to the palmar or plantar aspect of the affected limbs. All of the animals received a dose of the analgesic tolfenamic acid intramuscularly, and were randomly allocated to two equal groups. Calves of Group I additionally received oxytetracycline (20 mg/kg intravenous daily for 3 days). The condition resolved satisfactorily in 83.3% and 80.0% calves from the two groups, respectively. The left and right fetlock angle (mean ± SE) reduced significantly (p ≤ 0.01) from 50.57° ± 4.20° to 4.00° ± 2.27° and 48.71° ± 2.37° to 5.33° ± 3.03°, respectively in animals of Group I. In Group II calves, the angles showed reduction from 50.86° ± 2.94° to 4.20° ± 2.75° and from 48.71° ± 3.14° to 6.80° ± 3.34°, respectively. From the present study, it was concluded that bilateral moderate fetlock knuckling in the neonatal dairy calves can be managed satisfactorily with early application of splints. Supplementary use of oxytetracycline at repeated doses of low toxicity had only a marginally beneficial effect.

Bilateral carpal contracture in a neonatal addax (Addax nasomaculatus).

A neonate male addax calf displayed an inability to extend its forelimbs bilaterally (range of motion restricted to 45 degrees-50 degrees on full extension) with resultant inability to stand. Based on examination and radiographs, the congenital defect was attributed to contracted soft tissue structures (joint capsule and/or intercarpal ligaments). Splinting, support of the limbs, and physical therapy resulted in moderate improvement of the angle of contraction (full flexion to approximately 120 degrees on extension at day 10). The animal was able to walk with splints but died at 10 days from acute head trauma, presumably related to a traumatic fall caused by challenges with ambulation. Postmortem examination confirmed soft-tissue contracture of the forelimbs. Malposition of the calf in utero was considered a possible cause of the defect.

Sub-acute and chronic MRI findings in bilateral canine fibrotic contracture of the infraspinatus muscle.

A six-year-old, 30-kg female German pointer dog was presented for examination with a history of pre-existing right-forelimb lameness and more recent (3 months) persistent lameness in the left-forelimb. Physical examination revealed mild left-forelimb lameness and a mild circumduction movement. There were no signs of pain or crepitation detected during manipulation of the shoulders, but the animal was unable to fully flex both glenohumeral joints. Magnetic resonance imaging, using fast recovery fast spin echo T2-weighted and fat saturated proton density sequences, revealed abnormal heterogeneous hypointensity in the right infraspinatus muscle and a heterogeneous hyperintense area in the left infraspinatus muscle. Surgical treatment consisting of a bilateral infraspinatus tenectomy resulted in improved limb function. Histopathological examination demonstrated tissue changes in the right infraspinatus, characterised by myofibre degeneration and fibrosis, compatible with a chronic degenerative process, while changes in the left infraspinatus muscle were characterised by variable degrees of fibre degeneration, haemorrhage and interstitial oedema.

Bilateral iliopsoas muscle contracture and spinous process impingement in a German Shepherd dog.

OBJECTIVE: To report diagnosis and treatment of bilateral iliopsoas muscle contracture in a dog with spinous process impingement. STUDY DESIGN: Case report. ANIMALS: German Shepherd dog. METHODS: A dog with chronic progressive lameness, flexion contracture of the coxofemoral joints, severe pain, and decreased femoral reflexes had severe spondylosis bridging the vertebral bodies from L1 to L4 and enlarged dorsal spinous processes from T8 to L6 with impingement and bony proliferation. Ultrasonographic and magnetic resonance imaging (MRI) findings were consistent with fibrosis, mineralization, and atrophy of the iliopsoas muscles bilaterally which was treated by staged tenectomy of the insertions of the iliopsoas muscles. RESULTS: Because of severe perivascular fibrosis, the femoral vessels required ligation. Bilateral iliopsoas muscle tenectomy improved gait and provided pain relief. Histologic findings were consistent with fibrotic myopathy. CONCLUSIONS: Slow progression of severe clinical signs observed bilaterally in this dog differs from previous reports of iliopsoas myopathy. Findings were similar to the fibrotic myopathy of the gracilis or semitendinosus muscles described in dogs. CLINICAL RELEVANCE: Iliopsoas muscle abnormalities should be considered in dogs with limited hip extension and pain. MRI is useful for diagnosing muscle fibrosis. Iliopsoas tenectomy may improve clinical function in dogs with fibrotic myopathy.

Management of quadriceps contracture in a dog using a static flexion apparatus and physiotherapy.

A four-month-old golden retriever developed quadriceps contracture following management of a comminuted femoral fracture with an intramedullary pin and cerclage wire. Management involved surgical release of the quadriceps, rigid stabilisation of the fracture, use of a static stifle flexion apparatus and postoperative physiotherapy. The dog returned to full activity with normal stifle function.

Simultaneous bilateral contracture of the infraspinatus muscle.

A case of bilateral fibrotic contracture of the infraspinatus muscles in a five-year-old Belgian Shepherd dog is described. The dog was presented with progressive forelimb lameness with postural and gait abnormalities three months after an episode of overexertion. When walking, the lower part of both forelimbs swung in a lateral arc causing a circumduction movement and in the standing position, the dog showed elbow adduction with external rotation of the distal part of both front limbs. Orthopaedic examination revealed bilateral atrophy of both infraspinatus and supraspinatus muscles and restriction in the range of motion of both shoulders, especially when attempting abduction and flexion. No specific findings were observed in the shoulder or elbow radiographs but hyperechogenic areas were evident in the ultrasonographic examination of both infraspinatus muscles. A diagnosis of fibrotic contracture of both infraspinatus muscles was established and bilateral tenectomy of the insertion tendons of the infraspinatus muscles was performed. Complete recovery of the animal was achieved after the surgery, which was confirmed in a long-term follow-up (10 months). In conclusion, physical examination and ultrasonography allowed a proper diagnosis of the condition, and tenectomy of the infraspinatus muscles resulted in a complete recovery of the patient even with bilateral involvement.

Sartorius muscle contracture in a German shepherd dog.

OBJECTIVE: To report sartorius muscle contracture in a dog. STUDY DESIGN: Case report. ANIMALS: A 5-year-old, male, German Shepherd dog. METHODS: After a 2-month history of right hindlimb lameness was treated by tenectomy of the caudal sartorius muscle for sartorius muscle contracture. RESULTS: One month after surgery there was complete remission of clinical signs; however, after 12 months, there was partial reunion of sartorius caudal belly and onset of gracilis muscle contracture. CONCLUSIONS: Contracture of the sartorius muscle in dogs is seemingly rare and similar to gracilis muscle contracture with which it may be confused. Differentiation requires knowledge of muscular anatomy, careful palpation, and surgical inspection. CLINICAL RELEVANCE: Sartorius muscle contracture can be treated by tenectomy or removal of contracted muscle tissue, however, long-term outcome suggests the need to develop approaches that prevent recurrence caused by scarring of transected tissues.

Long-term follow-up of laminin alpha2 (merosin)-deficient muscular dystrophy in a cat.

Progressive muscle weakness beginning at 6 months of age was observed in a male Persian-mix cat. Muscle atrophy and joint contracture progressed over the next 3 years. The cat had developed gait difficulty at 8 months of age. The cat died at age of 5 years and 3 months due to an acute respiratory disorder. The clinical, laboratory, necropsy and histopathological findings of the cat were consistent with those of muscular dystrophy. The cat was diagnosed as having laminin alpha2 (merosin)-deficient muscular dystrophy on the basis of immunohistochemical findings. The cat was born in an inbred colony, and another related cat exhibited similar clinical signs. Few cases of laminin alpha2-deficient muscular dystrophy have been reported in cats, and this report provides additional information about the disease.

Surgical treatment of simple syndactylism with secondary deep digital flexor tendon contracture in a Basset Hound.

A five-month-old, female Basset Hound was presented for lameness associated with a fused 3rd and 4th digital pad on the left hind limb (simple incomplete syndactyly), and secondary contracture of the deep digital flexure tendon of the 3rd and 4th digit. An onychectomy of the third phalanx of the third and fourth digits was performed. Following the operation, the dog gained good use of the affected limb for one month until intermittent non-weight bearing lameness developed. A second surgery was performed six months later, partially removing the second phalanx of digits three and four. Follow-up reports indicate that the dog is doing well and is without lameness. This is the first report of deep digital flexor tendon contracture and surgical treatment of this complication in canine simple syndactylism.

Acquired muscle contractures in the dog and cat. A review of the literature and case report.

Canine and feline muscle contracture is reported to affect several different muscles, is associated with a number of predisposing factors, and a varying prognosis depending upon which muscle is affected. Most patients suffer some form of trauma weeks to months before the contracture is present. The clinical signs include: lameness, pain, weakness, decreased range of motion, a firmness noted throughout the entire muscle, and usually a characteristic gait. Pre-disposing factors for muscle contracture include: compartment syndrome, infection, trauma, repetitive strains, fractures, infectious diseases, immune-mediated diseases, neoplasia, and ischaemia. There does appear to be some breed and age predilection, however, the sex of the animal does not have an appreciable influence. In general, muscle contractures of the forelimb respond better to treatment and carry a better prognosis than muscle contractures of the hindlimb.

Fibrotic contracture of the canine infraspinatus muscle: pathophysiology and prevention by early surgical intervention.

Fibrotic contracture of the canine infraspinatus muscle (FCIM) is considered a rare musculotendineous disorder mainly affecting hunting dogs. After an acute onset of a painful non-weight bearing lameness, the initial pain and lameness improve over a period of one to four weeks, after which a characteristic circumducted gait abnormality develops in the forelimb. The initial injury to the infraspinatus muscle is not fully recognized or correctly interpreted in most cases, at least not with regard to its potential as a precursor of myopathy and FCIM. A mixed breed hunting dog developed an acute and extremely painful swelling of the infraspinatus muscle. The injury was easily recognized during clinical examination. The clinical signs were interpreted as an osteo-fascial compartment syndrome (OFCS) of the infraspinatus muscle. Immediate surgical decompression of the osteo-fascial compartment to prevent development of FCIM was undertaken. The histopathological and immunohistochemical examinations of the injured infrapinatus muscle revealed tissue changes that indicated acute muscle rupture, without any signs of an initiating degenerative process. On the day following surgery the dog was fully weight bearing. Restriction of activity for four weeks was recommended. Eight months after the initial injury, the dog had completely recovered and had full days of vigorous exercise and hunting activity without any apparent lameness. The findings in this case suggested that the infraspinatus muscle may be considered to be an osteo-fascial compartment in dogs and must be added to the list of compartments that may pose a potential risk for OFCS in the canine extremity.