Ulnar Ostectomy Research Articles

Ulnar osteosarcoma in dogs: 30 cases (1992–2008)

To examine the biological behavior of ulnar osteosarcoma and evaluate predictors of survival time in dogs. Retrospective case series. 30 dogs with primary ulnar osteosarcoma. Medical records were reviewed. Variables recorded and examined to identify predictors of survival time were signalment, tumor location in the ulna, tumor length, serum alkaline phosphatase activity, surgery type, completeness of excision, tumor stage, tumor grade, histologic subtype, development of metastases, and use of chemotherapy. 30 cases were identified from 9 institutions. Eleven dogs were treated with partial ulnar ostectomy and 14 with amputation; in 5 dogs, a resection was not performed. Twenty-two dogs received chemotherapy. Median disease-free interval and survival time were 437 and 463 days, respectively. Negative prognostic factors for survival time determined via univariate analyses were histologic subtype and development of lung metastases. Telangiectatic or telangiectatic-mixed subtype (n = 5) was the only negative prognostic factor identified via multivariate analysis (median survival time, 208 days). Dogs with telangiectatic subtype were 6.99 times as likely to die of the disease. The prognosis for ulnar osteosarcoma in this population was no worse and may have been better than the prognosis for dogs with osteosarcoma involving other appendicular sites. Partial ulnar ostectomy was associated with a low complication rate and good to excellent function and did not compromise survival time. Telangiectatic or telangiectatic-mixed histologic subtype was a negative prognostic factor for survival time. The efficacy of chemotherapy requires further evaluation.

Traumatic fragmented medial coronoid process in a Chihuahua

Fragmented medial coronoid process (FMCP) is a disease process that has not previously been reported in toy-breed dogs. This report describes a presumptive case of FMCP in a 14-month-old Chihuahua that was presented for evaluation approximately four weeks following acute onset of moderate lameness in the left forelimb. Definitive diagnosis of a fragmented medial coronoid process was based upon computed tomography (CT) scan. A CT scan also demonstrated moderate joint incongruity in the affected elbow. Surgical removal of the fragment and subtotal coronoidectomy were performed via a medial arthrotomy. An ulnar ostectomy was also performed to address joint incongruity. Histology of specimens removed at surgery did not demonstrate evidence of microdamage as characteristic of FMCP in large breed dogs, and instead, suggested that the fracture was acute and traumatic in nature. Rapid return to function was observed following surgery.

Effects of autologous platelet rich plasma gel and calcium phosphate biomaterials on bone healing in an ulnar ostectomy model in dogs

The aim of the study was to evaluate the bone healing properties of an osteopromotive platelet rich plasma (PRP) gel in combination with osteoconductive calcium phosphate (CaP) ceramic granules in a long-bone critical size defect in dogs. A standardised 2 cm long ulnar ostectomy was performed bilaterally in four dogs to compare new-bone formation by CaP matrix with and without association with PRP. Radiographic and histological evaluations were performed blindly. Radiographic evaluation was performed at three, six, nine, 12 and 16 weeks postoperatively. Quantitative measurements of new-bone formation were compared using statistical analysis. At explantation 16 weeks after surgery, no significant ossification was present, neither with CaP granules alone nor in association with PRP gel, and there was no difference of radiodensity between the groups. Qualitative histological evaluation demonstrated for both types of implants the presence of non-mineralised fibrous connective tissue around the CaP granules. New-bone formation was only present to a very small extent within the macropores of the CaP granules at the distal bone-implant interface. In our model which exhibited very limited osteoconduction, neither the CaP granules alone nor in association with PRP were sufficient to stimulate bone healing. In this canine model employing a critical size ulnar gap, the combination of CaP granules and PRP did not effectively promote bone regeneration.

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

To determine effects of incremental radial shortening and subsequent ulnar ostectomies on joint surface contact patterns in a canine elbow joint model. Paired forelimbs from 9 adult dogs. 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. 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. 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.

An alternative technique for revision arthrodesis of the rheumatoid wrist: A case report

Few studies address the problem of failed rheumatoid wrist arthrodesis. We report a case of this difficult complication that was treated with a new technique of arthrodesis, which includes both the ulnocarpal and radiocarpal sites with 2 intramedullary nails and an ulnar ostectomy.

Vascular Injury and Delayed Hemorrhage after Antebrachial External Skeletal Fixation in a Dog

SummaryA seven-month-old female Saluki was diagnosed with angular limb deformity due to premature closure of the left distal ulnar physis. Corrective radial osteotomy and ulnar ostectomy were performed, and the radius was stabilized with external skeletal fixation. Profuse haemorrhage occurred from the second medioproximal pin site two weeks after surgery. Removal of the pin resolved the hemorrhage. Early recognition and treatment of vascular injury secondary to vessel erosion after external skeletal fixation is necessary, as this is a serious complication. Appropriate pin placement in the radius will prevent this complication.Two weeks after application of an external skeletal fixator to the antibrachium of a seven-month-old Saluki profused haemorrhage occurred from one pin site. Surgical removal of the pin was necessary to arrest haemorrhage.

Antebrachial deformities in the dog: treatment with external fixation.

The results of 12 dogs with antebrachial deformity treated by ulnar ostectomy, radial osteotomy and external skeletal fixation are presented. Postoperative complications were seen in only one dog; a delayed union requiring placement of autogenous cancellous bone graft at a second surgery to achieve healing. Postoperatively, owners reported limb function was good in almost all cases, although they were less pleased with the cosmetic appearance.

Osteotomy for Correction of Premature Growth Plate Closure in 24 Dogs

SummaryTwenty-four dogs (27 limbs) were evaluated after surgery for correction of forelimb angular limb deformities. Partial ulnar ostectomies or definitive corrective osteotomies were performed depending upon the age of the dog. According to owner assessment nine of fourteen limbs were considered functionally good, or excellent, after partial ulnar ostectomies. Younger dogs appeared to have better functional results after dynamic correction with the mean age at surgery of dogs with good to excellent results being 6.5 months contrasted to the mean age at surgery of dogs with fair to poor results being 9.75 months. Ten of fourteen limbs were considered functionally good or excellent after definitive corrective osteotomy. One dog had definitive osteotomy after partial ulnar ostectomy in order to further correct a residual angular deformity. However, 58% of the limbs with radiographic follow-up had signs of degenerative joint disease (DJD). There were not significant differences between neither degree of angulation remaining after surgery and the functional result nor the degree of angulation remaining after surgery and the development of DJD. A prospective study is warranted to more objectively assess the efficacy of surgical correction of angular limb deformities in dogs.Twenty-four dogs were evaluated after surgery for correction of forelimb angular limb deformities. The results are described.

Radio-Ulnar Synostosis Complicating Partial Mid-Diaphyseal Ulnar Ostectomy in Growing Dogs

SummaryRadio-ulnar synostosis developed in two dogs that had partial mid-diaphyseal ulnar ostectomies performed to correct asynchronous growth of the radius and ulna. The synostosis was apparently painful and caused lameness in one dog, and exacerbated humero-ulnar subluxation in the other dog. Periosteal and interosseous ligament trauma, together with the location of the ulnar ostectomy, radial overstrain and radial hypertrophy were considered to be important factors in the pathogenesis of synostosis formation in these cases.Radio-ulnar synostosis was a complication of mid-diaphyseal ulnar ostectomy in two young dogs.

Development of small-cell osteogenic sarcoma after ulnar ostectomy in a dog

Development of small-cell osteogenic sarcoma after ulnar ostectomy in a dog

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.

Autogenous Fat Grafts to Prevent Recurrence following Surgical Correction of Growth Deformities of the Radius and Ulna in the Dog

The use of autogenous fat grafts as interpositional material to prevent the regrowth of bone is discussed. Four cases from a series of ten are presented to illustrate the use of autogenous fat grafts as an aid in preventing recurrence following surgical correction of growth deformities of the radius and ulna. Surgery consisted of removing a segment of ulna and filling the defect with an autogenous fat graft to prevent the ulna from reuniting. Partial ulnar ostectomy was combined with radial osteotomy when indicated.

Functional adaptation of bone to increased stress. An experimental study.

In young pigs walking normally, we recorded the principal compressive strains (epsilon 2) as revealed by strain gauges attached to the shaft of the radius. We found no correlation between the mean principal compressive strain and either age or weight in normal animals over the three-month time span of the experiment. Directly after unilateral removal of the ulnar diaphysis, the principal compressive strain on the radial shaft increased by two to two and one-half times its normal value. The increased level of strain in the radius caused by ulnar ostectomy resulted in a rapid and substantial remodeling response in the radius, but three months after ulnar ostectomy, the area of bone enclosed by the periosteal perimeter of the overstrained radius approached the value for the radius and ulna together in the contralateral limb, as did the cross-sectional area of the bone tissue in the mid-shaft of that radius. Three months after unilateral ostectomy, the principal compressive strain was not significantly different in the left and right radii and approached normal values.