Assessment of BFX cup version in a three-dimensional model simulating the ventrodorsal radiographic view.

OBJECTIVE: To measure truncated face and open face versions of the biological fixation (BFX) cup in a three-dimensional (3D) model simulating the ventrodorsal radiographic projection with different cup and pelvis positions. STUDY DESIGN: Computer simulation. METHODS: Simulated ventrodorsal views were generated in silico using 3D models of a BFX cup and a medium-sized canine pelvis. Truncated face and open face versions of the BFX cup were defined and measured with various angles of cup version, cup inclination, and pelvic extension. RESULTS: Truncated face version was different from and underestimated open face version by 12° to 22° (p < .001). Open face version varied with inclination while truncated face version was unaffected by inclination. Open face version was dependent on the degree of pelvic extension while truncated face version was unaffected. CONCLUSION: Open face version differed from truncated face version. Changes in open face version were not consistently matched by a change in truncated face version. CLINICAL SIGNIFICANCE: The open face of the cup may be excessively retroverted without this being reflected by truncated face retroversion as seen on a ventrodorsal radiographic view. However, in this study, BFX cups placed with truncated face version and inclination in the normal range and an ALO of 45° yielded predictable open face version.

Lumbosacral intervertebral disk extrusions in 13 dogs.

OBJECTIVE: To describe the clinical presentation, magnetic resonance imaging (MRI) findings, and outcome of dogs treated surgically for lumbosacral intervertebral disk extrusion (IVDE). STUDY DESIGN: Retrospective study. ANIMALS: Thirteen dogs. METHODS: Records and MRI studies of dogs with intraoperatively confirmed lumbosacral IVDE were reviewed. MRI features of thoracolumbar IVDE were applied to all cases. Postoperative outcome was subjectively assessed as excellent, good, or poor. RESULTS: All dogs had an acute or subacute onset of lumbosacral pain and nerve root signature. Seven dogs had neurological deficits. MRI revealed lateralized herniated disk material and partial to complete disk degeneration in all cases; the extradural material extended cranial and/or caudally from the disk space in 10 cases. All dogs underwent L7-S1 dorsal laminectomy and removal of extruded disk material. In six dogs, surgery was complicated by inflammatory changes, including one case of epidural steatitis. On reexamination 4-6 weeks postsurgery, outcome was judged as excellent in 11 dogs and poor in the remaining 2 due to contralateral nerve root signature in one case and nonambulatory paraparesis and urinary incontinence in the case with steatitis. CONCLUSION: Lumbosacral IVDE in dogs was characterized by acute/subacute onset of lumbosacral pain and nerve root signature and lateralized and often dispersed extradural material over a degenerated L7-S1 intervertebral disk on MRI. Early decompressive dorsal laminectomy generally resulted in excellent clinical outcome. CLINICAL SIGNIFICANCE: Observation of these clinical and imaging features in dogs should prompt clinical suspicion of lumbosacral IVDE.

Medial Bone Plating for Management of Type V Central Tarsal Bone Fractures in Six Dogs.

OBJECTIVE: The aim of this study was to report the surgical technique and outcomes of dogs with type V central tarsal bone (CTB) fractures stabilized with a bone plate applied to the medial aspect of the tarsus and metatarsus. STUDY DESIGN: This study was a retrospective review of dogs with type V CTB fractures diagnosed with computed tomography and stabilized using a medial bone plate. Follow-up included clinical examination and radiography 8 to 10 weeks postoperatively and/or a long-term owner questionnaire. RESULTS: Six dogs were identified. All fractures occurred during exercise without external trauma and all dogs had additional tarsal fractures. Five dogs returned for clinical follow-up; all had no or mild lameness and evidence of fracture healing on radiography. A suspected surgical site infection occurred in one dog and resolved with medical management. Suspected contact between the plate and medial malleolus in one dog, and loosening of a talar screw in another, were identified, though not treated. Five owners completed the questionnaire, a median of 88 months postoperatively. No further complications were reported, limb function was reportedly acceptable, and all owners were very satisfied with the surgery. CONCLUSION: Medial bone plate stabilization of highly comminuted CTB fractures resulted in evidence of fracture healing, and a low incidence of complications in six non-racing dogs.

Long-term outcomes after pantarsal arthrodesis with medial plate fixation without external coaptation in 30 dogs.

OBJECTIVE: To report long-term outcomes of dogs treated with pantarsal arthrodesis (PTA) with medial plate fixation without external coaptation. STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned dogs (n = 30). METHODS: Medical records of dogs that had undergone a PTA with a medially applied plate without adjunctive rigid external coaptation were reviewed. Data collected included signalment, complications, and assessment of function at last physical examination. Follow-up information was obtained by phone conversations with owners. Complications were classified as minor, major II, major I, and catastrophic. RESULTS: Thirty-six PTA were performed in 30 dogs. Recorded complications included eight (22.2%) minor complications, 11 (30.6%) major II complications and 11 (30.6%) major I complications. One (2.8%) dog required amputation because of catastrophic complication. Owners provided follow-up for 26 dogs at a median duration of 1215 days (range, 325-3495) after surgery. The outcome was reported as full function in 12 dogs and acceptable function in 14 dogs, with no owners reporting unacceptable function. The owner of the dog in which amputation was required was not contacted. Incorrect contact details prevented owner follow-up in the other three dogs, but all had acceptable function at last veterinary follow up. CONCLUSION: Dogs treated with PTA by medially applied plate had a high incidence of complications requiring surgical or medical management, although full or acceptable function was achieved in 29 of 30 dogs. CLINICAL SIGNIFICANCE: Pantarsal arthrodesis offers a predictably good medium to long-term outcome in spite of a high risk of complications.

Accuracy of three-dimensional printed patient-specific drill guides for treatment of canine humeral intracondylar fissure.

OBJECTIVE: To determine the accuracy of three-dimensional printed patient-specific drill guides (3D-PDG) as treatment of humeral intracondylar fissures (HIF) in dogs. STUDY DESIGN: Retrospective consecutive case series. ANIMALS: Client-owned dogs with HIF treated with a 5-mm transcondylar screw (TCS) placed from medial to lateral with a 3D-PDG. METHODS: The proposed TCS entry point and trajectory were planned using computed tomography (CT) data and computer-aided design software (CAD), and a 3D-PDG was produced. During surgery the 3D-PDG was used to drill the pilot hole from medial to lateral; the guide was then removed, the pilot hole was overdrilled, and a 5-mm TCS was placed. Postoperative CT data were imported into CAD software, and the entry points, exit points, and trajectories were compared between the planned and actual screw locations. RESULTS: Sixteen elbows from 11 dogs were included. Mean (SD) entry point translation was 1.3 mm (0.64), with all screws entering cranial to the proposed location. Mean maximum screw angulation was 5.2° (2.10°), with most screws directed caudodistal to the desired trajectory. Mean (SD) exit point translation was 1.8 mm (0.89) from the planned location. There was no intra-articular screw placement. CONCLUSION: Use of a 3D-PDG permitted accurate placement of a mediolateral 5-mm locking TCS within the humeral condyle. CLINICAL SIGNIFICANCE: Three-dimensional printed patient-specific drill guides should be considered as accurate and consistent for placing TCS for treatment of HIF in dogs.

Tuberculosis joint infections in four domestic cats.

CASE SERIES SUMMARY: This paper describes the clinical presentation, diagnostic imaging findings and outcome in four cats with confirmed joint-associated tuberculosis. The cats were 2-6 years of age, and immune competent. Three cases had tuberculosis affecting only one joint, whereas one case had at least three joints affected. Two cases were caused by Mycobacterium bovis, and the other two were caused by Mycobacterium microti. Radiological findings included osteolysis, periosteal reaction and associated soft tissue swelling. Two cases were euthanased and two cases responded well to amputation and follow-on antibiotic therapy. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the first publication of a series of cats with joint-associated tuberculosis. Although tuberculosis is not common, a high degree of suspicion is needed to avoid delayed diagnosis. This case series highlights the importance of considering mycobacterial disease as a differential for joint disease in cats.

Cement plug technique for the management of disc-associated cervical spondylopathy in 52 Dobermann Pinscher dogs.

OBJECTIVES: To report the radiographic and clinical outcome of an intervertebral bone cement plug technique for the management of disc-associated cervical spondylopathy in Dobermann Pinscher dogs. METHODS: Retrospective study of 52 Dobermann Pinscher dogs. RESULTS: A variable degree of cement plug subsidence with loss of vertebral distraction was evident in all dogs (n = 40) that were radiographed >6 weeks postoperatively. In no case was there definitive evidence of vertebral body fusion. Eight dogs had a sudden deterioration in neurological status, cervical hyperaesthesia, or both between three days and 12 weeks following surgery that was considered to be implant-associated; six of these dogs were euthanatized. Following surgery, 43/52 dogs were considered to be neurologically normal or to have improved, however, nine of 43 subsequently deteriorated due to adjacent segment disease. At the long-term follow-up, 34 dogs were considered to be neurologically normal or to have improved. Twenty-nine dogs were dead by the end of the study period. CLINICAL SIGNIFICANCE: Intervertebral bone cement plug surgery results in an initial improvement in clinical signs in the majority of Dobermann Pinschers with disc-associated cervical spondylopathy. However, it fails to maintain vertebral distraction or achieve vertebral body fusion, and is associated with acute implant complications, additional cervical disc protrusions or mortality in a significant proportion of cases.

Highly Comminuted, Articular Fractures of the Distal Antebrachium Managed by Pancarpal Arthrodesis in 8 Dogs.

OBJECTIVE: To describe the surgical management by pancarpal arthrodesis for highly comminuted articular fractures of the distal antebrachium in 8 dogs. STUDY DESIGN: Retrospective clinical case series. ANIMALS: Eight dogs. METHODS: Medical records (2001-2014) of dogs with antebrachial fractures were reviewed and dogs with highly comminuted distal antebrachial fractures were identified. The nature of the injury, surgical management by pancarpal arthrodesis, outcome, and complications were recorded. RESULTS: Nine fractures occurred in 8 dogs. Seven dogs were ex-racing greyhounds (8 fractures) and of these, 6/7 dogs had fractures of the right thoracic limb. Compared with the hospital population of dogs with antebrachial fractures, greyhounds were over-represented for the antebrachial injury (odds ratio 117, 95% confidence interval 13-1022). Five dogs sustained injury during exertional exercise or with relatively minor trauma. Submitted bone samples (n = 4) showed no evidence of underlying neoplasia. Mean followup was 15.5 months with 11 complications recorded in 7/8 dogs, including 1 catastrophic, 5 major, and 5 minor complications. Pancarpal arthrodesis allowed a full functional outcome in 3 dogs and an acceptable outcome in 3. CONCLUSION: Comminuted articular fractures of the distal radius and ulna are complex injuries and have a similar presentation to pathologic fractures. Surgical management by pancarpal arthrodesis is associated with a high risk of complication and a guarded prognosis for a full functional outcome.

Precision of a novel computed tomographic method for quantification of femoral varus in dogs and an assessment of the effect of femoral malpositioning.

OBJECTIVE: To assess the precision of a novel protocol for determination of femoral varus angle (FVA) using computed tomography (CT) in dogs, and to quantify the effect of femoral rotational and sagittal plane malpositioning on measured FVA. STUDY DESIGN: Cross-sectional study. SAMPLE POPULATION: Femora (n = 66) from dogs that had pelvic limb CT examination for patellar instability (26) or other reasons (10). METHODS: Three observers measured FVA of each of 66 femora on three separate occasions. Standardized orientation of a volume rendered image was achieved by superimposition of the caudal and distal aspects of the femoral condyles on a lateral projection, definition of a sagittal plane axis, and finally rotation through 90° to yield a cranial projection. Intra- and inter-observer variability were estimated using the intra-class correlation coefficient. The effect of variation in rotational and sagittal plane orientation on measured FVA was subsequently quantified using 6 femora with FVAs between -0.4° and 19°. RESULTS: Intra-class correlation coefficients for the 3 observers, indicating intra-observer variation, were 0.982, 0.937, and 0.974. The intra-class correlation coefficient of the means of the results from each observer, indicating inter-observer variation, was 0.976. Consistent linear variations in measured FVA occurred as a result of rotational malpositioning in all 6 tested femora, and as a result of sagittal plane malpositioning in femora with FVAs ≥ 7.9°. CONCLUSIONS: The reported protocol for the measurement of FVA in dogs is repeatable and reproducible. Small variations in femoral orientation, as might be expected with conventional radiography, lead to clinically significant alterations in measured FVA.

Hybrid cemented/cementless total hip replacement in dogs: seventy-eight consecutive joint replacements.

OBJECTIVE: To evaluate the use of hybrid total hip replacement (THR), using a cementless acetabular component and a cemented femoral component. STUDY DESIGN: Prospective case series. SAMPLE POPULATION: Client-owned dogs (n = 71). MATERIALS AND METHODS: Consecutive clinical cases that had hybrid THR were studied. Radiographic features, pain scores, and lameness scores were recorded pre- and postoperatively. Longer term outcome was assessed by owner questionnaire. RESULTS: Hybrid THRs (n = 78) were performed in 71 dogs. Four cases (5%) had major postoperative complications; 3 were resolved after revision surgery, and 1 owner requested an explantation. No other major complications were identified on follow-up radiographs (67 THR) at 12 weeks. On clinical follow up (77 THR) at 4 weeks, lameness had improved in 68, was unchanged in 8, and was worse in 1. Pain had decreased in 72, was unchanged in 4, and was worse in 1. At 12 weeks (69 THR) compared with preoperative status, lameness had improved in 67 and was unchanged in 2. Pain had improved in 68 and was unchanged in 1. Longer term follow-up (mean, 16 months) was available for all hips. No further complications were reported. Owner satisfaction was good for 76 THRs and reasonable for 2. CONCLUSIONS: Hybrid THR can be performed successfully with a low complication rate and represents an alternative to either entirely cemented or cementless implantation.

Radiographic evaluation of BFX acetabular component position in dogs.

OBJECTIVE: To assess the reliability of radiographic measurement of angle of lateral opening (ALO) and angle of version of BFX acetabular cups. STUDY DESIGN: In vitro radiographic study. SAMPLE POPULATION: BFX cups (24, 28, and 32 mm). METHODS: Total hip replacement constructs (cups, 17 mm femoral head and a #7 CFX stem) were mounted on an inclinometer. Ventrodorsal radiographs were obtained with ALO varying between 21° and 70° and inclination set at 0°, 10°, 20°, and 30°. Radiographs were randomized using a random sequence generator. Three observers blinded to the radiograph order assessed ALO using 3 methods: (1) an ellipse method based on trigonometry; (2) using a measurement from the center of the femoral head to the truncated surface of the cup; (3) by visual estimation using a reference chart. Version was measured by assessing the ventral edge of the truncated surface. RESULTS: ALO methods 2 and 3 were accurate and precise to within 10° and were significantly more accurate and precise than method 1 (P < .001). All methods were significantly less accurate with increasing inclination. Version measurement was accurate and precise to within 7° with 0-20° of inclination, but significantly less accurate with 30° of inclination. CONCLUSIONS: Methods 2 and 3, but not method 1, were sufficiently accurate and precise to be clinically useful. Version measurement was clinically useful when inclination was ≤ 20°.