Arthroscopic-guided ulnar distraction for the correction of elbow incongruency in four dogs.

Four skeletally immature, small breed dogs (five elbows) with elbow incongruency were evaluated for forelimb lameness. Findings on clinical examination included pain, effusion and decreased range of motion of the affected elbow. Radiography, computed tomography and arthroscopy demonstrated elbow incongruency in all dogs. Fragmented medial coronoid process was diagnosed arthroscopically in three dogs (four elbows). Arthroscopic subtotal coronoidectomy was performed in all cases of fragmented medial coronoid process. Incongruency was corrected with acute ulnar lengthening under arthroscopic visualisation. The ulna was stabilised with a plate following correction. In two elbows an ostectomy of the anconeal process was performed to prevent impingement against the olecranon fossa. All dogs demonstrated improvement in lameness scores and client-scored visual analogue scale scores. Postoperative computed tomography showed significant improvement in elbow incongruency in all dogs. Arthroscopic-guided ulnar lengthening may be considered as a valid treatment in severe cases of elbow incongruency.

Inhibición del crecimiento longitudinal en hemiepifisiodesis: análisis experimental en conejos / Longitudinal growth inhibition in hemiepiphysiodesis: experimental analysis in rabbits

Introducción: La modificación del eje de un miembro mediante la detención parcial del crecimiento (hemiepifisiodesis), es un procedimiento habitual en la cirugía ortopédica pediátrica. Sin embargo no está bien establecido cuánto afecta este procedimiento al crecimiento final del hueso. El objetivo del presente trabajo fue determinar en forma experimental la inhibición del crecimiento longitudinal producido por una hemiepifisiodesis. Materiales y métodos: Se utilizaron, 10 conejos de 8 semanas de vida, a los que se les colocó una grapa en el fémur distal externo derecho. En la 8ª semana del estudio (16 semanas de vida) se realizó la comparación radiológica e histológica de ambos fémures. Resultados: La longitud final media de los fémures con grapas a las 8 semanas finalizado el experimento fue de 89,6mm (rango 87mm-95mm) versus 95,7mm (rango 91mm-100mm) de los fémures sanos. El porcentaje de inhibición media del crecimiento fisario al final del experimento fue de 6,58% (rango 3.2%-10%). Conclusiones: Se demostró experimentalmente la disminución global de la actividad de la fisis durante la hemiepifisiodesis. Esto debe ser tenido en cuenta cuando indicamos una hemiepifisiodesis unilateral en un niño con una discrepancia previa de longitud.

In vivo evaluation of intra-articular protection in a novel model of canine cranial cruciate ligament mid-substance elongation injury.

OBJECTIVES: To evaluate the effects of intra-articular protection (IAP) on the canine cranial cruciate ligament (CrCL) and stifle in a CrCL midsubstance elongation injury model. STUDY DESIGN: Experimental longitudinal cohort study. ANIMALS: Skeletally mature female mixed breed hounds (n=12; mean+/-SEM weight, 25.6+/-0.7 kg). METHODS: After CrCL elongation in 1 stifle of each dog, IAP was applied in 6 joints. In vivo assessment included radiographs, cranial-caudal joint translation, gait analysis, and synovial fluid levels of 3B3(-) (proteoglycan epitope) and C2C (collagen II neoepitope) up to 12 weeks after surgery. Joint translation and rotation were quantified at necropsy. CrCL midsubstance length was determined before and after elongation and at necropsy. CrCLs were subjectively assessed with light microscopy. Comparisons were made between stifles containing elongated CrCLs with and without IAP and unoperated controls. RESULTS: Four weeks after surgery, ground reaction forces were significantly decreased in operated limbs. Absolute C2C levels were significantly elevated in operated stifles 4 weeks post-surgery. C2C and 3B3(-) levels normalized to total protein were significantly elevated in IAP+ stifles 8 weeks after surgery. Protected CrCLs appeared to have decreased granulation tissue and better collagen fiber alignment. CONCLUSIONS: IAP has negligible effects on the canine stifle based on the response variables evaluated in this 12-week study. Protection of elongated CrCLs may promote reduced, organized scar formation. CLINICAL RELEVANCE: These results support the healing capacity of the canine CrCL midsubstance following elongation injury and IAP application to potentially reduce cicatrix formation in elongated CrCLs.

Prognostic factors in treating antebrachial growth deformities with a lengthening procedure using a circular external skeletal fixation system in dogs.

OBJECTIVE: To evaluate treatment of antebrachial growth deformities (AGD) with a lengthening procedure using a circular external skeletal fixation (CESF) system and to determine prognostic factors. STUDY DESIGN: Prospective clinical study. ANIMALS: Thirty-four dogs with unilateral AGD. METHODS: Length deficits, angular and rotational deformities, elbow incongruity (EI), osteoarthritis (OA) of the elbow and carpal joint, function, and cosmesis were determined before and after a CESF lengthening procedure. RESULTS: On admission, EI (21 dogs; 62%), OA of the elbow joint (17 dogs; 50%), carpal OA (12 dogs; 35%), and concomitant elbow and carpal OA (5 dogs; 7%) were common findings. Treatment significantly improved function (normal, 20 dogs; 60%) and cosmesis (normal, 22 dogs; 65%). Angular and rotational deformities were almost completely corrected with small remaining length deficits. Elbow and carpal OA increased significantly during the follow-up period. Significant correlations were demonstrated between initial elbow OA and final function (R=0.42, P=.02), initial function and final function (R=0.41, P=.02), and initial ulnar and radial deficit and final cosmesis (R=0.58, P=.0001 and R=0.45, P=.008). CONCLUSIONS: Treatment of AGD by a CESF lengthening procedure was successful despite small remaining length deficits. Initial elbow OA, function, and ulnar and radial length deficits are prognostic factors in the treatment of AGD. CLINICAL RELEVANCE: Initial elbow OA and initial function are prognostic factors in predicting the functional outcome of treatment of AGD with a CESF lengthening procedure in the dog.

Hinged Ilizarov external fixation for correction of antebrachial deformities.

OBJECTIVE: To evaluate hinged circular external fixation for correction of antebrachial deformities in dogs. STUDY DESIGN: Uncontrolled clinical trial. ANIMAL POPULATION: Seven client-owned dogs. METHODS: Six dogs had one radius corrected and one dog had both radii corrected. Preoperative planning included measurement of the craniocaudal and mediolateral angular deformities, rotational deformity, length deficit, origin of deformity, graphical or mathematical determination of the amplitude and direction of the actual limb deformity, and frame assembly. RESULTS: Preoperatively, function and cosmesis were assessed to be fair to poor in all dogs. Deformity correction started 48 to 60 hours postoperatively and ranged from 0.46 mm to 1.36 mm twice daily. Hospitalization time ranged from 4 to 6 days. Corrections were mostly made by the owners, at home. Lengthening and angular correction ranged from 3 to 38 mm and 18 degrees to 48 degrees. Mean residual deformities were 2.7% of radial length and 2.7 degrees. The time duration with the circular external fixators in place ranged from 29 to 71 days. Two additional surgeries were necessary in one dog because of wire breakage. Mean follow-up was 40 months. Long-term function and cosmesis were good to excellent in all dogs. CONCLUSION: Although complications were present in six of seven dogs, the outcome of hinged Ilizarov external fixation was successful in all dogs treated for deformities of the antebrachium. CLINICAL RELEVANCE: Despite complex preoperative planning, the placement of hinged circular external fixators is straightforward, and allows precise correction of complex antebrachial deformities with minimal tissue trauma.

Dual-energy x-ray absorptiometry and force-plate analysis of gait in dogs with healed femora after leg-lengthening plate fixation.

Dual-energy x-ray absorptiometry was used to measure bone mineral density of four regions in healed femora of nine dogs after fracture fixation with a leg-lengthening plate. Six to 85 months (mean, 46 months) after surgery, the bone mineral density of healed femora was not significantly different from the contralateral uninjured femora (P > .05; power = 0.8 at delta = 15%). Radiolucencies around the proximal screws, apparently associated with screw loosening, were seen on radiographic views of the healed femora of three dogs. In one of these dogs, one screw in the proximal metaphysis had broken. Force-plate analysis of gait was also performed on dogs at the time of bone mineral density measurement. Peak vertical force was decreased in the pelvic limb with the healed fracture compared with the contralateral unoperated limb (P < 0.05). Clinically apparent lameness in three dogs did not appear to be associated with altered bone mineral density and may have been caused by hip osteoarthritis, a nondisplaced hairline diaphyseal fracture, and screw loosening in conjunction with extensive post-traumatic soft tissue injury.

Distraction osteogenesis using modified external fixation devices in five dogs.

Distraction osteogenesis was used to treat five dogs with limb deformities or limb shortening. The affected bones underwent osteotomy, and modified external fixators were attached. Complications included pin loosening, implant breakage, and soft-tissue contracture. Adequate limb length was attained in all cases, but clinical results varied from poor to excellent. Two dogs were not lame after the procedure, two dogs had improved function but were still lame, and one dog had complications necessitating amputation.