Ulnar interlocking intramedullary nail stabilization of a proximal radio-ulnar fracture in a dog

Objective: To report use of an ulnar interlocking intramedullary nail for repair of an open highly comminuted fracture of the proximal third of the antebrachium in a dog, caused by gunshot. Study Design: Case report. Animals: 1.5‐year old, 60 kg, neutered male Mastiff. Methods: An ulnar interlocking intramedullary nail was used to stabilize an open comminuted proximal antebrachial fracture and a cast applied for 4 weeks. Results: Union by secondary bone healing occurred in 8 weeks. At 16 weeks, there was advanced remodeling of the radial and ulnar bony callus and fracture lines were no longer evident. Limb use was normal with normal pain free range of motion of the right elbow. Conclusion: Ulnar interlocking nail is a viable alternative treatment for highly comminuted fracture of the proximal third of the antebrachium in dogs.     

Partial Ulnar Osteotomy With Free Autogenous Fat Grafting for Treatment of Radius Curvus in the Dog

The efficacy of free autogenous fat grafts in inhibiting healing of partial ulnar ostectomies was investigated. Fat grafts did impede or prevent bone union in the treated ulnar ostectomies. Protection from forced weight bearing on the operated limb by splinting minimized varus deformity of the radius and ulna, and enhanced the survival of the fat graft and the formation of an ulnar nonunion. The procedure was then applied to treatment of radius curvus resulting from surgically induced premature distal ulnar physeal closure. Partial ulnar ostectomy with free autogenous fat grafting released the ulnar restraint on radial growth and allowed partial correction of the degree of radial curve associated with premature distal ulnar physeal closure.     

Bilateral wedge ostectomy on an 18-month-old llama with severe bilateral carpal valgus.

An 18-month-old llama was admitted with severe (45 degrees and 40 degrees) bilateral carpal valgus. The llama had grown normally until it was 6 months old, when the carpal deviations had commenced. Radiography revealed abnormalities at the distal ulnar physes. Premature closure of these physes or abnormal distal ulnar growth may have been the cause of the carpal valgus. The owners requested surgical correction of the condition. Medial wedge osteotomies of each radius were performed 3 weeks apart. Internal fixation of the osteotomized radial bones was accomplished with small right-angled T plates, and the limbs were placed in full-limb casts for 3 weeks and tube casts for 3 more weeks. Both limbs healed in straight alignment, and the llama was able to walk and run normally. Dorsal subluxation of the right radiocarpal joint was noticed after the operation. This was believed to be caused by the uncorrected dorsal bowing of the distal portion of the radius, which had occurred secondary to the severe carpal valgus.     

A RADIOGRAPHIC STUDY OF THE DEVELOPMENT OF THE SHEEP CARPUS FROM BIRTH TO 18 MONTHS OF AGE

Osseous development of the carpus of six clinically normal lambs was studied radiographically from birth to 18 months of age with the aim of forming a standard radiographic evaluation and reference for the sheep carpus.
Radiographic data consisted of 200 radiographs. Dorsopalmar and lateromedial projections were made daily during the first week, then weekly until the sixth month, and finally monthly until 18 month of age. Ten radiographs were selected to illustrate normal development of the carpus.
The distal ulnar epiphysis reached the ulnar carpal bone at the third week, but remained separate from the ulnar diaphysis until six months of age. The ulnar epiphysis was radiographically fused with the ulnar diaphysis at thirteen months of age.     

In vitro experimental study of the effect of radial shortening and ulnar ostectomy on contact patterns in the elbow joint of dogs

OBJECTIVE: To determine effects of incremental radial shortening and subsequent ulnar ostectomies on joint surface contact patterns in a canine elbow joint model. SAMPLE POPULATION: Paired forelimbs from 9 adult dogs. PROCEDURE: Joint casting was performed by placement of colored polymethylmethacrylate in the elbow joint cavity and loading in a materials testing system at physiologic angle and load. Joint casting was performed in unaltered specimens, after radial shortening, and after subsequent distal ulnar ostectomy, proximal ulnar ostectomy, and proximal ulnar ostectomy with intramedullary pinning. Computer-aided analysis of photographs of proximal radial and ulnar articular surfaces without joint casts was performed before and after each casting procedure. RESULTS: All increments of radial shortening changed the size and location of radial and ulnar contact areas. The radial contact area became smaller, the anconeal contact area disappeared, the medial coronoid contact area migrated craniolaterally, and the lateral projection of the coronoid process became a contact area. A proximal ulnar ostectomy stabilized with an intramedullary pin restored normal contact area size and location and restored continuity of the radial and coronoid contact areas across the radioulnar articulation in 6 of 10 specimens. A midshaft ulnar ostectomy, distal to the level of the radioulnar ligament, had no effect on contact patterns. A proximal ulnar ostectomy without stabilization resulted in varus deformity during loading. CONCLUSIONS AND CLINICAL RELEVANCE: Proximal radial shortening, which creates articular step incongruity, changes the location and size of the radioulnar contact areas. Dynamically stabilized ulnar ostectomies proximal to the radioulnar ligament restore contact patterns in vitro.     

Surgical management of premature closure of the distal ulnar growth plate in a growing dog

Surgical management of deformity due to premature closure of the distal ulnar growth plate in a growing dog is discussed. The method of management selected was ulnar diaphyseal ostectomy with transphyseal wiring of the distal radius. Elbow subluxatin and degenerative joint disease as a consequence of premature ulnar closure are also discussed.     

Effect of surgical technique on radiographic fusion of the anconeus in the treatment of ununited anconeal process

O bjectives : The aim of this study was to determine if internal fixation of the anconeus combined with a proximal ulnar osteotomy was more likely to result in fusion of the anconeus to the ulna compared with a proximal ulnar osteotomy alone.
M ethods : A total of 12 orthopaedic referral clinics reviewed their clinical databases for cases of ununited anconeal process. Demographic and clinical parameters were collected along with radiographic follow-up at a minimum of four weeks. Cases treated with proximal ulnar osteotomy alone were compared with those treated with proximal ulnar osteotomy + internal fixation. Both groups were compared for background and disease variables. We tested for an association between treatment method and whether radiographic anconeal union had occurred.
R esults : A total of 47 elbows (44 dogs) were identified. Of these, 28 cases (average age 7·6 months) were treated with proximal ulnar osteotomy (of which eight were stabilised with an intramedullary pin) alone. Nineteen cases (average age 7·1 months) were treated with proximal ulnar osteotomy + internal fixation. The two groups were not significantly different in age (P=0·638, Mann-Whitney U test). Fourteen of 28 cases with proximal ulnar osteotomy alone displayed anconeal union at follow-up compared with 16 of 19 cases of proximal ulnar osteotomy + internal fixation, and this difference was statistically significant (P=0·029, Fisher's exact test).
C linical S ignificance : These data suggest that use of a lag screw to stabilise and compress the ununited anconeal process in addition to proximal ulnar osteotomy produces a better radiographic outcome. It is argued that radiographic union of the anconeus is likely to be associated with better long-term clinical outcome but further studies are required to confirm this.     

Abnormal canine bone development associated with hypergravity exposure.

Chronic centrifugation of 85- to 92-day-old Beagles at 2.0 X g and 2.6 X g for 26 weeks during the time of active skeletal growth caused skeletal abnormalities in the radius and the ulna of ten of 11 dogs. The pattern of change mimicked that found in naturally occurring and experimentally induced premature distal ulnar physeal closure or delayed growth at this physis. Minimal changes in bone density were detected by sensitive photon absorptiometric techniques. Skeletal abnormalities also were found in five of the six cage-control dogs, although the run-control dogs were radiographically normal.     

Dysostosis Enchondralis of the Ulnar Bone in the Basset Hound

Ninety-four Basset Hounds were examined for the clinical features, the radiographical changes and the nutritional and hereditary possibilities connected with the development of decreased longitudinal growth of the ulnar bone. In six puppies the possibility was examined of the development of the disease being due to overloading of the foreleg. Ten of the dogs were examined for gross pathology and 4 by histology post mortem.Clinical symptoms and radiographical changes were not seen until the age of 31/2 months. In all cases there were broadening of the joint space in the elbow joint and degeneration of the articular cartilage at the semilunar notch. An abnormally broad and irregular growth plate was seen in the affected young dogs, and histology revealed obvious abnormalities in the growth plate located in the zone of resting cartilage indicating degenerative disturbances in the cartilage. There were no signs of rickets, and it was not possible to demonstrate that the disease was caused by misleading.It is concluded that the disease corresponds to similar anomalies found in the other chondrodystrophic breeds of dogs, and it is suggested that the decreased growth of the ulnar bone may be hereditary.     

Distal Humeral Salter Harris (Type II) Fracture Repair by an Ulnar Osteotomy Approach in a Horse

Objectives: To report repair of a comminuted distal humeral type II Salter–Harris fracture using an ulnar osteotomy approach and locking compression plates (LCP). Study Design: Case report. Animal: A 3‐month‐old Standardbred filly with a type II Salter–Harris fracture of the distal humerus. Methods: Radiographic and computed tomography examinations were performed to assist surgical planning. The distal humeral fracture was approached by an ulnar osteotomy and repaired using a 7‐hole broad LCP and screws inserted in lag fashion. The osteotomy was subsequently repaired using a 7‐hole narrow LCP. Results: The distal humeral fracture was successfully approached and stabilized by an ulnar osteotomy approach. At 6‐month follow‐up, the filly was ambulating comfortably with a normal cosmetic appearance. Conclusions: An ulnar osteotomy approach was readily performed and allowed for repair of a type II Salter–Harris fracture of the distal humerus. Clinical Relevance: The equine distal humerus can be accessed readily using an ulnar osteotomy approach. LCPs allow for repair of complicated fractures that have previously been associated with a grave prognosis.     

Comparison of the radius of curvature of the ulnar trochlear notch of Rottweilers and Greyhounds

OBJECTIVE: To compare radius of curvature along the ulnar trochlear notch of Rottweilers and Greyhounds to determine whether morphologic differences exist that may contribute to the cause and pathogenesis of fragmented coronoid process in Rottweilers. SAMPLE POPULATION: Paired elbow joints from 13 Rottweilers and 14 Greyhounds. PROCEDURE: Elbow joints were radiographically scored on the basis of severity of osteoarthritic lesions. The articular contour of each ulnar trochlear notch was digitized. The radius of curvature at defined points along the ulnar trochlear notch was compared between breeds. RESULTS: Radius of curvature of the ulnar trochlear notch was not a constant function of arc length in either breed but had a consistent characteristic appearance in both breeds. Radius of curvature was greatest at each end of the ulnar trochlear notch and had 2 peaks in the midportion of the notch in both breeds. These peaks occurred farther distally in the notch and were larger in Rottweiler ulnae than Greyhound ulnae. A significant difference in mean radius of curvature was detected between breeds at these peaks. Greyhounds had significantly greater mean radius of curvature at the end of the medial coronoid process, compared with Rottweilers. CONCLUSIONS AND CLINICAL RELEVANCE: Radius of curvature of the ulnar trochlear notch is a complex function of arc length in Rottweilers and Greyhounds. The waveform has a consistent characteristic appearance in both breeds. Although significant differences were identified between breeds, associations between these differences and cause or pathogenesis of fragmented coronoid process in Rottweilers were not apparent.     

Effectiveness of intraoperative somatosensory evoked potential monitoring during cervical spinal operations on animals with spinal cord dysfunction

We conducted somatosensory evoked potential (SEP) monitoring on 3 dogs with cervical spinal cord dysfunction caused by various diseases throughout operative procedures to examine whether the intraoperative SEP monitoring was effective for prediction of spinal cord conductive function. The SEP was recorded on the scalp via stimulation of the ulnar nerve. Stable SEP was recorded in all animals examined. Its amplitude was decreased by surgical manipulations of the regio vertebralis, but the amplitude gradually recovered once the manipulations were halted. The latency showed small variation throughout the operations. This evidence suggests that intraoperative SEP monitoring may provide continuous and instantaneous information regarding the functional integrity of the central nervous system.     

Ulnar ostectomy decreases the stability of canine cadaver carpi as assessed with stress radiography

Distal ulnar ostectomy may be performed palliatively in patients with distal ulnar osteosarcoma. Concurrent arthrodesis of the carpus has been proposed to counteract joint instability following transection of carpal ligaments associated with removal of the distal ulna. The objective of this prospective one group pretest, posttest study was to assess stability of the carpus following distal ulnar ostectomy using pre‐ and postoperative stress radiographic views in a group of canine cadaver limbs. Seven thoracic limbs from six canine cadavers weighing more than 20 kg were obtained. Lateral and dorsopalmar, extended lateral, medial stress, and lateral stress radiographs were made before and after distal ulnar ostectomy. Presurgical canine cadaver carpal angle measurements were as follows (mean ± standard deviation): extension 205.9° ± 5.4; medial stress 25.1° ± 5.7; and lateral stress 13.3° ± 5.2°. Cadaver limb joint angles exceeded those previously reported in live dogs. A significant increase in carpal angle was noted following ulnar ostectomy. The mean increases in carpal angle were as follows: (mean ± standard deviation (95% confidence interval)): extension 6.2° ± 4.9 (2.6–9.8) (P = 0.007); medial stress 3.2° ± 3.0 (1.0–5.5) (P = 0.015); lateral stress 6.2° ± 5.2 (2.4–10.1) (P = 0.010). Findings from this cadaver study support the use of supplementary stabilization for clinical patients undergoing distal ulnar ostectomy. Future studies are needed in clinical patients to evaluate changes in limb positioning and gait associated with distal ulnar ostectomy.     

Transverse ulnar bone transport osteogenesis: a new technique for limb salvage for the treatment of distal radial osteosarcoma in dogs

Objective— To develop instrumentation and a technique for transverse ulnar bone transport osteogenesis in dogs.
Study Design— Cadaveric study and in vivo validation (1 dog).
Sample Population— Paired cadaveric antebrachii (n=10 dogs) and 1 live dog.
Methods— Circular fixator constructs were applied and fitted with reeling or linear motors designed to transport an ulnar segment transversely into a defect created by excising the distal 50% of the ipsilateral radius. A longitudinal osteotomy of the adjacent ulna was created and the segment was transported across the radial defect. Pre- and post-distraction CT scans were used to compare the efficacy of each construct. The procedure was performed unilaterally in a live dog using the reeling motor (RM) construct.
Results— Both constructs effectively transported the ulnar segment into the defect. Subjectively, the RMs were easier to apply and operate. No significant differences were observed in the objective measures of efficacy between the 2 construct types. The live dog produced viable regenerate bone after transverse ulnar bone transport.
Conclusions— Transverse ulnar bone transport should be considered a potential method for limb salvage in dogs with osteosarcoma (OSA) of the distal radius. The RMs were effective and clinically applicable.
Clinical Relevance— Transverse ulnar bone transport osteogenesis affords the benefits of longitudinal radial bone transport osteogenesis, allowing resolution of large longitudinal radial defects in a substantially less time as a result of shortening the transport distance. This would be beneficial when treating conditions such as OSA where minimizing convalescence and maximizing quality of life is a priority.     

Correction of angular deformities caused by premature closure of the distal ulnar epiphyseal plate in dogs

Surgical correction of angular deformities caused by premature closure of the distal ulnar growth plate in dogs. Correction of angular deformities in 14 cases of premature closure of the distal ulnar growth plate is described. Angular deformities were most frequently seen in large breeds during the most active phase of growth at 3-5 months of age. Preoperative axial deviations measured on radius were from 7 to 38 degrees in valgus and 0 to 35 degrees in antecurvation compared with the contralateral leg. According to the kind of treatment, the dogs were divided into two groups: In group I which consisted of cases with sufficient remaining growth potential of the radius, segmental ostectomy of ulna with insertion of an autologous fat graft in the ostectomy diastasis was performed to allow spontaneous correction by asymmetrical epiphyseal growth. In group II reconstructive osteotomy and stable, internal fixation with a plate was accomplished. The cosmetic result was judged as excellent in 10 cases, good in 3 and less favourable in 1. Postoperative follow up time was in average 33 months. On control 43% of the dogs showed no lameness, 57% were slightly lame after exercise or rest. None of the cases turned out to be permanently lame at the end of the follow up investigation.     

Establishment of a Method to Measure Length of the Ulnar Nerve and Standardize F-wave Values in Clinically Normal Beagles

We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve.     

Radiographic changes in elbow dysplasia following ulnar osteotomy--a case report and review of the literature

This case report describes the results of bilateral elbow arthrotomy and a unilateral ulnar osteotomy in a 10-month-old dog with bilateral elbow dysplasia. Fragmented coronoid processes were removed from both joints via bilateral medial arthrotomies. On the right side an ulnar osteotomy was also performed using a caudolateral approach. Bilateral flexed lateral elbow radiographs taken before surgery and 5 months postoperatively were assessed for changes in osteophyte size on the anconeal process, caudal epicondylar ridge and radial head. Osteophytes on the anconeal process and caudal epicondylar ridge disappeared over the postoperative period in the joint that received an ulnar osteotomy. In the contralateral joint the size of the oesteophytes on the anconeal process and caudal epicondylar ridge increased in size during the same period.     

Repair of an Ulnar Fracture With Radial Luxation in a Horse

An ulnar fracture with radial luxation (Monteggia fracture) was repaired in a horse. Reduction of the radial luxation was difficult, requiring 2 incisions, limb traction, neuromuscular blockade, and direct radial manipulation. The ulnar fracture was repaired by use of a dynamic compression plate. Three months postoperatively, the horse was free of any apparent lameness.     

Unilateral congenital elbow luxation in a dachshund

Congenital elbow luxation was diagnosed in a 12-week-old, intact male, dachshund with a lateral elbow prominence and mild lameness of the right forelimb. Closed reduction of the radial head, ulnar ostectomy, and external stabilization of the joint were performed. Function was returned to the limb, but radial head and ulnar subluxation persisted.     

MOTOR AND SENSORY NERVE CONDUCTION STUDY IN THE FERRET

Ferrets are considered a popular small mammal pet, and like other companion animals they are reported to suffer from diseases affecting the neuromuscular system. There currently is a lack of comprehensive electrodiagnostic study regarding the appendicular nerves of ferrets. In this research investigation, 25 domestic ferrets were used for electromyography and motor nerve conduction studies of the tibial, fibular, ulnar, and radial nerves, including H reflexes of the tibial and ulnar nerves, as well as sensory conduction of the fibular nerve. Mean and standard deviations for motor and sensory nerve studies were established. The hypothesis that weight would be correlated with all distal and proximal compound muscle action potential latencies was tested and confirmed for the tibial, fibular, and radial nerves but not the ulnar nerve.