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Objective: To report the technique and outcome of proximal ulnar autograft transplantation to achieve ipsilateral radial lengthening in a dog with premature closure of both proximal and distal radial physes., Study Design: Case report., Animals: An 8-month-old female spayed Border Collie., Methods: The dog was presented for a grade III/IV left thoracic limb lameness localized to the elbow. Orthogonal radiographs of both forelimbs revealed a 7% length deficit of the left radius and elbow subluxation indices indicative of left elbow incongruity due to suspect premature closure of both radial physes. Radial lengthening consisted of a proximal ulnar ostectomy, a radial osteotomy, and transplantation of the ulnar autograft into the radial osteotomy site secured with an eight-hole dynamic compression plate. Orthopedic examinations were conducted at 2 weeks, 4 weeks, and 3 years postoperatively. Radiographic examinations were completed preoperatively, immediately postoperatively, and at 4 weeks and 3 years postoperatively., Results: Lameness improved with a grade II/IV lameness at 4 weeks postoperatively and complete resolution at 3 years postoperatively. Radiographic examination at 4 weeks showed persistent radial lengthening of 1 cm, and a decreased humeroradial index (HRI), humeroulnar index (HUI), and radioulnar index (RUI) compared with preoperative values. At the 3 year examination, the HRI and HUI had increased indicating progression of elbow incongruity. The patient remained clinically unaffected., Conclusion: In dogs with radial shortening and elbow incongruity, use of an ipsilateral proximal ulnar autograft with rigid internal fixation can be an effective treatment for radial lengthening to improve elbow congruity and resolve lameness., (© 2024 American College of Veterinary Surgeons.)

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., (© 2013 British Small Animal Veterinary Association.)

Radial agenesis was diagnosed in a nine-week-old boxer. An ulnocarpal arthrodesis was performed when six months of age to improve limb alignment and enable weight bearing. When the dog was 10 months old, a hinged circular fixator was applied to the limb to gradually lengthen the ulna and correct angular and rotational deformity. The fixator was removed at 16 months of age. At this time, there was 1.7 cm (6 per cent) shortening of the affected antebrachium-metacarpus and 2.6 cm (15 per cent) compensatory overgrowth of the humerus compared with the contralateral limb. Inability to extend the digits was a complication that improved with physiotherapy. Follow-up at 23 months of age showed good limb use when walking and running. Radiographs of the elbow showed periarticular osteophytes and subcoronoid sclerosis of the ulna.

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.

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.

The effect of glucocorticoids (dexamethasone) on circulating concentrations of insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBPs) was examined in young (2-week-old) chickens. Increasing dosages (6, 60, and 600 microg/kg) of dexamethasone resulted in progressive growth retardation as evidenced by decreased body-weight gain, reduced bone growth, and breast muscle weights, together with immunosuppression as indicated by decreased thymus and bursa weights. Plasma concentrations of IGF-I were progressively reduced with increased doses of dexamethasone. There were no changes in circulating IGFBPs except on Day 7 when binding activity of the 36-kDa IGFBP was increased by dexamethasone (6 microg/kg). It is speculated that similarities exist between the 36-kDa IGFBP and the mammalian IGFBP-1 based on the response to dexamethasone treatment.

The effect of dietary protein restriction (5% and 10% compared to control 20%) on circulating concentrations of insulin-like growth factor (IGF)-1 and IGF binding proteins (IGFBPs) was examined in young (18-day-old) chickens during a 2-week period. Reductions in dietary protein caused progressive growth retardation as evidenced by decreased body-weight gain and reduced bone growth. The decrease in plasma concentrations of IGF-I appeared to be directly related to dietary protein levels (i.e., the lower the amount of dietary protein, the greater the reduction in the circulating concentrations of this growth factor). Three IGFBPs with MWs of 30, 36, and 40 kDa were detected by radioligand assay following separation by SDS-electrophoresis. Binding activity of the 30-kDa IGFBP was transiently increased on Day 3 by protein restriction (both 5% and 10%). The 36-kDa IGFBP was also affected by protein restriction with binding activity of this IGFBP decreased throughout the study. The binding activity of the 40-kDa IGFBP was transiently increased on Days 3 and 7 but subsequently decreased on Days 10 and 14 in the 10% protein group. In the 5% protein group, binding activity of the 40-kDa IGFBP was decreased throughout the study. The decrease in circulating concentrations of IGF-I appeared to be inversely related to the initial increase in the binding activity of the 30-kDa IGFBP on Day 3 (5% and 10% protein) and to the increased binding activity of the 40-kDa IGFBP on Days 3 and 7 (10% protein). This may suggest that bioavailability of plasma IGF-I is decreased initially due to increased binding with these IGFBPs. However, binding activity of all three IGFBPs then decreased in a manner directly related to the decreasing IGF-I plasma concentrations for the remainder of the experiment. The initial increase in binding activity observed with the 30-kDa IGFBP is similar to that observed with IGFBP-1 in mammals in that both of these IGFBPs respond rapidly to nutritional deprivation. Decreased protein intake would certainly have an impact on the amount of available proteins required for the synthesis of these growth factors.

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 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 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.