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Sacroiliac fracture-luxation is a common injury that is associated with ilial and acetabular fractures of the opposite hemipelvis. Sacroiliac fracture-luxation results in an unstable pelvis and potentially collapse of the pelvic canal. A minimally invasive approach to the reduction and insertion of a screw for fixation of sacroiliac fracture-luxation using fluoroscopic guidance is viable. The advantages of using this technique are that a small incision is made with minimal soft tissue disruption and the surgical time is short. Recent publications have documented that this technique provided superior repair of sacroiliac fracture-luxations.

Objective To classify the type of angular deformity affecting the radius and ulna in canine limbs using the center of rotation of angulation methodology. Study Design Retrospective case series. Animals Dogs (n=71) diagnosed with thoracic limb lameness attributable to antebrachial angular limb deformities. Methods Medical records from 2006–2013 were searched and cases with orthogonal radiographs or computed tomographic scans of the affected antebrachium were included. Classification of the deformity in the frontal plane and the presence of sagittal plane angulation, torsion, and adjacent joint radiographic disease were determined and compared. Results Chondrodystrophic (n=26; 44 limbs) and non-chondrodystrophic (n=45; 62 limbs) dogs were included. Thirty-five uniapical and 71 biapical or multiapical deformities in the frontal plane were identified. The incidence of biapical deformities was statistically higher in chondrodystrophic compared to non-chondrodystrophic dogs (P=.02). When breeds were combined, biapical deformities were associated with a significantly higher incidence of adjacent radiographic joint disease (P=.049), more frequently affecting the elbow (P=.022). Overall, 82% of the 106 limbs had radiographic evidence of either elbow or carpal joint disease at the time of presentation. Conclusion Biapical deformities are common in dogs with limb deformities, particularly chondrodystrophic dogs. Radiographic evidence of disease in adjacent joints should be evaluated in patients presenting for antebrachial deformities.

Objective To describe a radiographic method for determination of the mechanical axes and joint orientation lines in orthogonal planes for the canine humerus and establish a range of normal joint orientation angles in a population of large breed dogs. Study Design Radiographic study. Sample Population Humeri (n = 50) of skeletally mature, nonchondrodystrophic canine cadavers, weighing 20–40 kg with no evidence of orthopedic disease. Methods Mediolateral and craniocaudal digital radiographs were used to establish anatomic landmarks for determination of the mechanical axis in both frontal and sagittal planes, the joint orientation lines of both shoulder and elbow and measurement of the resulting mechanical lateral distal humeral angle (mLDHA) in the frontal plane, and the mechanical caudal proximal humeral angle (mCaPHA), and mechanical cranial distal humeral angle (mCrDHA) in the sagittal plane. Results Means (±SD) for the joint orientation angles were: mLDHA, 86.92 ± 1.24°, mCaPHA, 43.28 ± 5.44°, and mCrDHA, 71.86 ± 3.97°. The 95% CI ranges for the joint orientation angles were mLDHA, 86.58–87.86°, mCaPHA, 41.77–44.79°, and mCrDHA, 70.76°–72.96°. Conclusion A method for measurement of the mechanical axis and associated joint angles of the normal canine humerus in the frontal and sagittal planes was established and reference intervals reported. In the frontal plane, it was determined that the canine humerus is not perpendicular to the elbow joint; therefore, elbow mechanical axis deviation is normal and requires further assessment.

Objective To report pelvic limb joint reference angles, limb alignment, and mechanical axis deviation for the feline pelvic limb. Study Design Cadaveric radiographic anatomic study. Animals Skeletally mature, mixed breed cats (n = 50). Methods Extended pelvic limb radiography was performed and images analyzed to determine femoral anatomic joint reference angles, femoral and tibial mechanical joint reference angles, tibiofemoral angle, metatarsotibial angle, mechanical axis-femur and mechanical axis-metatarsus angles, and mechanical axis deviation of the stifle and tarsus. Mean ± SD and 95% confidence intervals (95% CI) were calculated. Results Mean ± SD angles and 95% CI were: anatomic lateral proximal femoral (103.9° ± 3.8°; 103.1° − 104.6°), anatomic lateral distal femoral (93.8° ± 2.5°; 93.3° − 94.3°), mechanical lateral proximal femoral (100.5° ± 3.7°; 99.8° − 101.2°), mechanical lateral distal femoral (97.2° ± 2.2°; 96.7° − 97.6°), mechanical medial proximal tibial (88.0° ± 3.2°; 87.3° − 88.6°), mechanical medial distal tibial (107.6° ± 4.8°; 106.6° − 108.5°), mechanical tibiofemoral (7.4° varus ± 2.5°; 6.9° − 7.9°), mechanical metatarsotibial (6.0° valgus ± 3.5°; 5.3° − 6.7°); mechanical axis-femur (3.2° ± 1.4°; 2.9° − 3.5°) and mechanical axis-metatarsus (2.4° ± 2.0°; 1.7° − 2.1°). Mechanical axis deviation of the stifle and of the tarsus were 2.0% ± 0.9% (95% CI: 1.9–2.2) and 0.8% ± 1.0% (95% CI: 0.7–1.0), respectively. Conclusions Mean pelvic limb joint reference and limb alignment angles can be used for diagnosing angular limb deformities of the feline pelvic limb and for planning corrective osteotomies in affected cats.

OBJECTIVE To determine which of 3 different plate angles (20°, 25°, 30°) used in double pelvic osteotomy (DPO) would result in the most similar acetabular angle (AA) achieved with a 20° triple pelvic osteotomy (TPO) technique in dogs. STUDY DESIGN Experimental anatomic study. ANIMALS Cadaveric canine pelves (n = 8). METHODS Transverse plane computed tomographic images of cadaveric pelves with intact sacroiliac joints, mounted in a custom jig, were made (baseline) and again after DPO (20°, 25°, 30°) and TPO (20°) and pelvic angles measured in 6 transverse planes. Pelvic angles of the 3 DPO techniques were compared with TPO using concordance correlation to determine which DPO angle resulted in an acetabular ventroversion angle closest to TPO. RESULTS Mean ± SD AAs were 32.89 ± 2.23 (baseline), 47.39 ± 4.39 (20° DPO), 51.43 ± 5.06 (25° DPO), 54.75 ± 4.38 (30° DPO), and 50.20 ± 5.76 (20° TPO). Concordance correlations for the AA compared with 20° TPO were 0.027 (baseline), 0.721 (20° DPO), 0.902 (25° DPO), and 0.593 (30° DPO). A concordance correlation of ≥ 0.8 indicates good correlation. CONCLUSIONS A 25° DPO is most similar in acetabular ventroversion to 20° TPO (concordance correlation, 0.902).

Large meniscal defects are a common problem for which treatment options are limited. Successful meniscal regeneration has been achieved by using grafts of small intestinal submucosa in posterior, vascular meniscal defects in a dog model. This study investigates the long-term effects of a tibial tunnel fixation technique and a clinically based meniscectomy defect on meniscal regeneration using this model. Eight mongrel dogs underwent medial arthrotomy and partial meniscectomy. The dogs were divided into groups based on defect treatment: small intestinal submucosa (n = 4) or meniscectomy (n = 4). Dogs were scored for lameness by subjective scoring postoperatively, sacrificed at 6 months, and assessed for articular cartilage damage, gross and histologic appearance of the operated meniscus, amount of new tissue in the defect, and relative compressive stiffness of articular cartilage. Dogs in the meniscectomy group were significantly (P = .002) more lame than dogs treated with small intestinal submucosa. Small intestinal submucosa-treated joints had significantly (P = .01) less articular cartilage damage than meniscectomy joints. Small intestinal submucosa meniscal implants resulted in production of meniscal-like replacement tissue, which was consistently superior to meniscectomy in amount, type, and integration of new tissue, chondroprotection, and limb function during the study period. Small intestinal submucosa implants may be useful for treatment of large posterior vascular meniscal defects in humans. The tibial tunnel technique used for fixation may have clinical advantages and therefore warrants further investigation.

A retrospective study was performed to evaluate a satisfactory/unsatisfactory (S/U) grading scheme in a didactic surgery laboratory during the first 3 years of implementation (2002-2004) and identity areas for improvement that might be adapted to this course or similar courses. Each instructor graded six students per session by assigning a descriptor of very good (G), acceptable (A), or unacceptable (U) in each of 11 assessment categories. A U in any category in one of the final two laboratories resulted in a failing grade for the course, unless the student performed acceptably in a make-up laboratory. A computerized course evaluation was used to solicit student feedback. Also, the numbers of G, A, and U grades were used to evaluate consistency of grading among instructors, to compare resident and faculty scores, and to track student progress. The return of course evaluations was low, but those available indicated favorable acceptance of S/U grading. There was little difference in assigned grades between faculty and residents, but some individual instructors seemingly graded more strictly than others. Student grades improved as the course progressed each year. No student received a final failing grade; however, two students required the make-up laboratory. Efforts to improve subjective grading should include planned acquisition of student feedback and establishment of more consistency of grading. While objective criteria may not be enough to adequately assess overall performance in didactic surgery laboratories, consistency of subjective evaluation requires adherence to well-defined assessment criteria.

OBJECTIVES To report a method for radiographic determination of the mechanical axis of the canine pelvic limb and its relationship to the joints and bone axes. To report reference ranges for the relationships between the axes of the pelvic limb and for joint position relative to the pelvic limb axis. STUDY DESIGN Cadaveric radiographic anatomic study. ANIMALS Pelvic limbs (n=101) from normal midsized to large breed dogs; tibiae (n=105) from dogs with cranial cruciate ligament disease (previous study). METHODS Extended full-limb radiography was performed and images analyzed to determine: mechanical joint reference angles (femur, tibia), pelvic limb axis, tibiofemoral and metatarsotibial angle, mechanical axis-femur/metatarsus angle, and mechanical axis deviation (MAD) of the stifle/tarsus. RESULTS Mean mechanical angles were: lateral proximal femoral (103.7 degrees +/-5.4 degrees ), lateral distal femoral (98.6 degrees +/-2.5 degrees ), medial proximal tibial (92.2 degrees +/-1.8 degrees ), medial distal tibial (95.9 degrees +/-2.2 degrees ), tibiofemoral (9.1 degrees varus +/-2.8 degrees ), metatarsotibial (0.6 degrees valgus +/-2.1 degrees ). Mean mechanical axis-femur and-metatarsus angles were 5.6 degrees (+/-1.7 degrees ) and 2.9 degrees (+/-1.5 degrees ), respectively. Mean MAD of the stifle and tarsus were 3.6% (+/-1.1%) and 1.2% (+/-0.6%), respectively. Tibial angles were not different between dogs with and without cranial cruciate ligament disease. CONCLUSIONS Mechanical axes of the canine pelvic limb and their relationship to the joints can be determined by full-limb radiography. CLINICAL RELEVANCE Techniques and reference ranges may be useful for diagnosis, surgical planning, and postoperative assessment of pelvic limb deformities.

Objective To describe a method for radiographic measurement of proximal and distal mechanical joint angles of the canine tibia. Normal ranges were established for a population of dogs, and specifically, Labrador retrievers, with cranial cruciate ligament rupture. Study design Retrospective study. Sample population Tibiae (n=105) of dogs evaluated for cranial cruciate ligament rupture; 70 tibiae were from Labrador retrievers, 35 tibiae were from other breeds. Methods Anatomic landmarks were established and craniocaudal radiographs were used to measure the mechanical medial proximal (mMPTA) and distal (mMDTA) tibial angles in the frontal plane. Results Means (+/-SD) for all tibiae were mMPTA, 93.30+/-1.78 degrees, and mMDTA, 95.99+/-2.70 degrees. For Labrador retrievers, means were mMPTA, 93.38+/-1.81 degrees, and mMDTA 96.34+/-2.51 degrees. No significant differences were detected between Labrador Retrievers and non-Labrador retrievers with respect to mMPTA (power=0.5) or mMDTA (power=0.342). Labrador Retrievers were significantly younger than non-Labradors (P=.003). Conclusion A method for measurement of the mechanical joint angles of the canine tibia in the frontal plane was established and reference ranges for a population of dogs and Labrador Retrievers with cranial cruciate ligament rupture are reported. Clinical relevance The established method of measurement and references ranges can be used to aid in diagnosis, determining indications, and surgical planning for angular limb deformities of the tibia, especially when affected bilaterally. The methodology and reference values may also be used for postoperative critique.

Background Large meniscal defects are a common problem for which current treatment options are limited. Hypothesis Treatment of posterior medial meniscal defects in dogs with small intestinal submucosa is superior to partial meniscectomy in terms of clinical limb function, chondroprotection, and amount and type of new tissue in the defect. Study Design Controlled laboratory study. Methods A total of 51 mongrel dogs underwent medial arthrotomy with creation of standardized meniscal defects. The dogs were divided into groups based on defect treatment: small intestinal submucosa meniscal implant (n = 29) or meniscectomy (n = 22). The dogs were assessed for lameness by subjective scoring after surgery and sacrificed at 3, 6, or 12 months and assessed for articular cartilage damage, gross and histologic appearance of the operated meniscus, amount of new tissue in the defect, equilibrium compressive modulus of meniscal tissue, and relative compressive stiffness of articular cartilage. Results Dogs in the meniscectomy groups were significantly (P Conclusion Small intestinal submucosa scaffolds placed in large meniscal defects resulted in production of meniscus-like replacement tissue, which was consistently superior to meniscectomy in amount, type, and integration of new tissue; chondroprotection; and limb function in the long term. Clinical Relevance Small intestinal submucosa implants might be useful for treatment of large posterior vascular meniscal defects in humans.

Objective— To describe the normal anatomic axis of the canine radius in 2 planes (frontal, sagittal), and report the use and efficacy of dome osteotomies for acute correction of canine antebrachial deformities. Study Design— Retrospective study. Sample Population— Normal antebrachii (n=20) radiographs were used as a reference, and 7 dogs with 9 radial angular limb deformities that were corrected by use of dome osteotomies. Methods— Orthogonal radiographs of 20 normal antebrachii were used to determine normal ranges of frontal (FPA) and sagittal plane anatomic axes (SPA). Pre and postoperative radiographs of 7 dogs (9 radii) that had surgical correction of radial angular limb deformities by dome osteotomies were reviewed. Success at deformity correction into established normal ranges and to the normal contralateral side, if present, was determined. Results— Normal ranges were FPA, 0–8° and SPA, 8–35°. There were 4 biapical and 5 uniapical deformities. FPA and SPA were corrected into normal range in 66% and 78% of affected limbs, respectively; however, only 44% of radii were corrected into normal ranges in both planes. Conclusions— Ranges for normal canine radial axes can be used as goals for angular limb correction when there is bilateral angular deformity. The dome osteotomy technique is advantageous in certain conditions for biplanar deformity correction. Clinical Relevance— Dome osteotomies can be used to correct radial deformities in the frontal and sagittal planes, with certain advantages, but are heavily reliant on appropriate preoperative planning.

Objective To report clinical findings and outcome in dogs diagnosed with medial shoulder instability (MSI) treated with radiofrequency-induced thermal capsulorrhaphy (RITC). Study design Retrospective study. Animals Dogs (n=43) with MSI. Methods Medical records from consecutive cases with MSI based on orthopedic examination, palpation of shoulder abduction angles, and arthroscopic findings were used to determine clinical findings and long-term (> or = 1 year) outcome of RITC. Results Forty-three dogs met the criteria for inclusion; 2 dogs had bilateral MSI. The most common clinical findings were chronic unilateral weight-bearing lameness, large (> 45 degrees) shoulder abduction angles, and spinatus muscle atrophy in the affected limb. Mean preoperative abduction angle (50.7 degrees +/- 4.8 degrees) in affected shoulders was significantly larger than in the unaffected shoulders (32.5 degrees +/- 2.1 degrees). Mean postoperative abduction angle in affected shoulders was not significantly different from unaffected shoulders when measured immediately, 8, 16-20 weeks, and approximately 1 year after surgery. Follow-up evaluation ranged from 1 to 6.2 years. RITC treatment resulted in improved clinical function in 40 cases (93%) with 34 cases (79%) considered excellent; 3 cases (7%) were considered failures. Conclusions RITC was a safe and effective method of treatment of MSI in most dogs studied. Clinical relevance RITC can be considered as a viable option for surgical treatment of selected cases of MSI in dogs.

It is critical to understand how radiotransmitters and their attachment techniques impact marked individuals. Many studies of transmitter effects assess only overt, deleterious effects. However, physiological effects caused by attachment techniques might compromise the integrity of resulting information. Our objectives, therefore, were to assess the efficacy of subcutaneous implants and determine the physiological effects on mourning doves (Zenaida macroura) using heterophil: lymphocyte (H:L) ratios, and fecal glucocorticoid measures. We conducted 2 trials with 60 mourning doves; 1 in summer-autumn (trial #1) and 1 in autumn-winter (trial #2). For each trial we assigned 15 male and 15 female doves to either a subcutaneous implant treatment or a control group. During the 2 trials, we observed no differences in body masses, H:L ratios or fecal corticosterone levels between mourning doves with subcutaneous implants and the control group. Given the ultimate use of the information obtained from teleme...

Objectives— To evaluate the effects of different cementing techniques on radiographic cement mantle grade and short-term aseptic loosening of the femoral component in canine total hip replacement (THR). Study Design— Retrospective study. Sample Population— Radiographs of 284 dogs that had THR. Methods— Immediate postoperative radiographs of 284 dogs that had cemented THR were reviewed by 4 surgeons and 1 radiologist and assigned a cement mantle grade using a 4-grade classification system. Dog age and weight at surgery, cementing technique (1st, 2nd, 3rd generation), complications (type and timing), and follow-up time were retrieved and analyzed. Results— Mean cement mantle score for 2nd generation technique was significantly higher than 3rd generation technique and both were significantly higher than 1st generation technique (P

Objective—To evaluate biocompatibility and effects of implantation of 3-dimensional chondrocyte-agarose autografts in tibial defects in rabbits and to compare in vitro and in vivo chondrocyte-agarose constructs with respect to cell viability, differentiation, and matrix production.Animals—24 adult New Zealand White rabbits.Procedure—Three-dimensional constructs with (grafted group) or without (control group) autogenous chondrocytes were implanted into tibial defects of rabbits and cultured in vitro. During an 8-week period, defects were evaluated radiographically, grossly, histologically, biochemically, and immunohistochemically. In vitro constructs were evaluated histologically, biochemically, and immunohistochemically.Results—Tibial defects had significantly higher radiographic densitometry values at 4 and 6 weeks after implantation in grafted group rabbits, compared with control group rabbits. Number of observed centers of endochondral ossification was significantly greater in defects of grafted group rabbits, compared with control group rabbits. On day 14, glycosaminoglycan concentration was significantly higher in tibial defects of grafted group rabbits, compared to defects of control group rabbits or in vitro constructs. At weeks 2, 4, and 8, glycosaminoglycan concentrations were significantly lower in the in vitro control constructs, compared with other groups. Collagen type I was present in bone and bony callous in defects of grafted and control group rabbits. Collagen type II was identified in cartilaginous tissues of grafted and control group rabbits. Collagen type X was associated with hypertrophic chondrocytes. Only type II collagen was found in the in vitro chondrocyte constructs.Conclusion and Clinical Relevance—Chondrocyte-agarose grafts are biocompatible in large tibial defects and appear to provide a cell source for augmenting endochondral ossification. (Am J Vet Res2003;64:12–20)

Objective To assess the effect of rotating the acetabulum 20 degrees and 30 degrees on percent coverage (PC) of the femoral head by the acetabulum and Norberg angle (NA) after triple pelvic osteotomy (TPO). Study design Retrospective study. Animal population Fifty-six client-owned dogs. Methods PC and NA were measured from preoperative, immediate postoperative, first recheck, and second recheck radiographs to compare the effects of 20 degrees and 30 degrees of rotation of the acetabulum after TPO for treatment of hip dysplasia. Results Within the 20 degrees rotation group, PC and NA values were significantly greater at each subsequent evaluation time starting at the preoperative measurement except for NA between the first and second recheck times. Within the 30 degrees rotation group, PC and NA values were significantly greater at each subsequent evaluation time starting at the preoperative measurement except for PC and NA between the first and second recheck times. No significant differences between the 20 degrees and 30 degrees rotation groups were found at any corresponding times for either PC or NA. Conclusions Acetabular rotation of 20 degrees provided the same degree of improvement in acetabular femoral head coverage as 30 degrees of rotation after TPO at the immediate postoperative, first recheck, and second recheck evaluation times. Clinical relevance Based on PC and NA, 20 degrees rotation of the acetabulum provides as much benefit as 30 degrees of acetabular rotation when performing a TPO.

OBJECTIVE To characterize chondrocytes from naturally occurring osteochondrosis (OC) lesions of the humeral head of dogs. SAMPLE POPULATION 15 cartilage specimens from 13 client-owned dogs with humeral head OC and 10 specimens from the humeral head of healthy dogs (controls). PROCEDURE Chondrocytes were isolated and cultured in a 3-dimensional system. On days 7, 10, 15, 20, and 25, glycosaminoglycan and hydroxyproline content and cytologic characteristics were evaluated. Expression of collagen types I, II, and X was assessed by use of immunohistochemistry. RESULTS Chondrocytes from OC lesions were less viable, compared with control chondrocytes. Glycosaminoglycan content in the OC group was significantly less than in the control group on all days except day 20. Hydroxyproline content was also significantly less in the OC group on days 10, 20, and 25. Expression of collagen type II was significantly less in the OC group, compared with the control group on all days, whereas expression of collagen type I was significantly greater in the OC group on days 20 and 25. Expression of collagen type X was significantly less in the OC group on all days except day 25. CONCLUSIONS AND CLINICAL RELEVANCE Chondrocytes from naturally occurring OC lesions of the humeral head of dogs cultured in a 3-dimensional system were less viable and less capable of producing appropriate extracellular matrix molecules than chondrocytes from unaffected dogs. Alterations in the synthetic capabilities of chondrocytes from OC-affected cartilage may be a cause or an effect of the disease process.

SummaryThe objective of this study was to evaluate the effects of [D-Ala2, Nme-Phe4, Gly5-ol] enkephalin (DAMGO), a μ-opioid receptor agonist, and β-funaltrexamine (β-FNA), a μ-opioid receptor antagonist, on the biosynthetic capabilities of canine chondrocytes cultured in the presence of interleukin-1 β (IL-1 β). Articular chondrocytes were harvested from the humeral heads of three adult dogs and cultured in a three-dimensional (3-D) gel medium made from low-melting agarose and cell culture medium. Chondrocytes in 3-D culture were exposed to IL-1 β (0 or 20 ng/ml), DAMGO (0,0.1,1.0, or 10 μM), and β-FNA (0 or 10 μM) by addition to the liquid media in all possible combinations. On days five and 15 of 3-D culture, liquid medium samples were harvested for subsequent analysis of glycosaminogly- can (GAG), prostaglandin E2 (PGE2) and matrix metalloprotease-3 (MMP-3) content. On the same days, gel plugs were also harvested and evaluated for GAG content.Incubation with IL-1 β decreased the amount of GAG in the gel plugs and caused an increase in PGE2 production on days five and 15 of 3-D culture. Treatment with DAMGO or β-FNA did not significantly modulate PGE2 production, MMP-3 production, GAG loss to the medium or GAG content of the gel plugs on either day five or 15 of 3-D culture in the presence or absence of IL-1 β. We concluded that DAMGO and β-FNA had neither protective nor detrimental effects on the biosynthetic capabilities of chondrocytes in the presence or absence of IL-1 β.

To classify the type of angular deformity affecting the radius and ulna in canine limbs using the center of rotation of angulation methodology.Retrospective case series.Dogs (n=71) diagnosed with thoracic limb lameness attributable to antebrachial angular limb deformities.Medical records from 2006-2013 were searched and cases with orthogonal radiographs or computed tomographic scans of the affected antebrachium were included. Classification of the deformity in the frontal plane and the presence of sagittal plane angulation, torsion, and adjacent joint radiographic disease were determined and compared.Chondrodystrophic (n=26; 44 limbs) and non-chondrodystrophic (n=45; 62 limbs) dogs were included. Thirty-five uniapical and 71 biapical or multiapical deformities in the frontal plane were identified. The incidence of biapical deformities was statistically higher in chondrodystrophic compared to non-chondrodystrophic dogs (P=.02). When breeds were combined, biapical deformities were associated with a significantly higher incidence of adjacent radiographic joint disease (P=.049), more frequently affecting the elbow (P=.022). Overall, 82% of the 106 limbs had radiographic evidence of either elbow or carpal joint disease at the time of presentation.Biapical deformities are common in dogs with limb deformities, particularly chondrodystrophic dogs. Radiographic evidence of disease in adjacent joints should be evaluated in patients presenting for antebrachial deformities.

Objective—To determine glycosaminoglycan (GAG) concentration and immunohistochemical staining characteristics of type-I, -II, and -X collagen from cartilage affected by osteochondritis dissecans (OCD) in dogs. Animals—31 dogs with OCD and 11 clinically normal purpose-bred dogs. Procedure—Cartilage samples were evaluated microscopically, and GAG content was determined. Immunohistochemical staining was performed for type-I, -II, and -X collagen. Sections were subjectively evaluated for location and intensity of staining. Results—Cartilage affected by OCD had a variety of pathologic changes and significantly lower GAG concentrations than did normal cartilage. Normal cartilage had no detectable type-I collagen. For dogs < 9 months of age, cartilage affected by OCD had significantly more type-I collagen but significantly less type- X collagen than did control cartilage. For dogs > 12 months of age, cartilage affected by OCD contained significantly more type-I collagen than did control cartilage. There was a significant negative correlation between immunoreactivity of type-I collagen and that of type-II and -X collagen. A significant positive correlation was found between immunoreactivity of type-II and -X collagen. Conclusions and Clinical Relevance—Cartilage affected by OCD contains less GAG, more type-I collagen, and less type-X collagen, compared with normal cartilage. A direct correlation between these changes and the etiopathogenesis of OCD was not established. (Am J Vet Res 2001;62:876–881)

Porcine small intestinal submucosa (SIS) was used to replace large, avascular defects in the medial menisci of dogs. Twelve dogs received SIS grafts and 3 dogs were left untreated as controls. Dogs were evaluated at 4, 8, and 12 weeks by means of lameness scoring and ultrasonography. Dogs were sacrificed at 1, 6, or 12 weeks after implantation, and the tissue at the site of meniscal resection was evaluated for gross and histologic appearance, cross-sectional and surface area, and collagen types I and II. The femoral and tibial condyles were assessed for articular cartilage damage. Control dogs were significantly more lame than grafted dogs 8 and 12 weeks after instrumentation. Grafted dogs' replacement tissue appeared meniscal-like when evaluated grossly and ultrasonographically 12 weeks after instrumentation. The amount of replacement tissue was significantly greater in both cross-sectional and surface area for grafted dogs than for controls at all time points. Histologically, the SIS biomaterial could be identified in all grafted dogs at 1 week post-implantation, but in none at 6 weeks post-implantation. Subjectively, grafted dogs' replacement tissue was histologically superior to that of controls with respect to tissue type, organization, and architecture. Collagen types I and II immunoreactivity in grafted menisci were similar to that of normal menisci. Control dogs had significantly more articular cartilage damage than grafted dogs. SIS appears to induce regeneration of meniscal-like tissue in large, avascular meniscal defects in dogs, resulting in superior clinical function and articular cartilage protection compared to ungrafted controls.

SummaryThe purpose of this study was to determine collagen type II and X immunohistochemical staining characteristics of naturally-occurring fragmented medial coronoid processes (FMCP) in order to help delineate potential pathophysiological events associated with FMCP.34 surgically excised FMCP from 21 client-owned dogs and 16 intact medial coronoid processes from 8 mongrel dogs were examined. The specimens were categorized by the dog's age: 24 months.The excised FMCP and normal medial coronoid processes were sectioned and stained with haematoxylin and eosin, safranin-O fast green, and toluidine blue. Sections were subjectively evaluated for tissue morphology, cell and matrix content, and proteoglycan staining. Immunohistochemical staining was performed for collagen types II and X. Sections were then subjectively evaluated for the location and intensity of staining.FMCP tissue demonstrated a wide variety of histological and immunohistochemical characteristics compared to normal medial coronoid processes. Significantly (P = 0.016) more normal dogs stained positive for collagen type X than dogs with FMCP in the Excised fragmented medial coronoid processes were examined to determine the collagen immunohistochemical staining characteristics when compared to intact processes.

Objective To report a technique for fluoroscopically guided closed reduction with internal fixation of fractures of the lateral portion of the humeral condyle (FLHC) and determine the long-term results in 10 clinical cases. Study Design Prospective clinical case study. Animals Ten dogs with 11 fractures. Methods Fractures of the lateral portion of the humeral condyle were stabilized with transcondylar screws and Kirschner wires. Closed reduction and implant placement were achieved using intraoperative fluoroscopic guidance. After fracture repair, postoperative radiographs were evaluated for articular alignment and implant placement. Dogs were evaluated after surgery by means of lameness scores, elbow range of motion (ROM), radiographic assessment, and owner evaluation of function. Results Postoperative reduction was considered anatomic in 6 fractures with all other fractures having

A unique biomaterial, porcine small intestinal submucosa, was used to construct grafts for implantation into surgically created medial meniscal defects in dogs. Five dogs received grafts and two were left untreated as controls. All dogs were evaluated at 4, 8, and 12 weeks by means of lameness scoring, force plate analysis, and ultrasonography. Twelve weeks after implantation the dogs were sacrificed and the replacement tissue was evaluated for gross and histologic appearance, amount, glycosaminoglycan content, and type II collagen immunoreactivity. Four weeks after instrumentation, both groups had lameness scores that were significantly higher than preoperative scores, but at the 8- and 12-week evaluations, scores for the grafted dogs were not different from preoperative values. The ultrasonographic appearance of replacement tissue in grafted defects resembled normal meniscus. In the untreated defects, only unorganized tissue was present. In control dogs, replacement tissue resembled fibrous tissue and cartilage erosions were visible on the medial femoral condyles. In four of the five grafted dogs, replacement tissue was grossly indistinguishable from normal meniscus. The amount of tissue in the defect was significantly greater for the grafted dogs. Histologically, replacement tissue in control dogs was composed of vascularized connective tissue with no evidence of chondroid differentiation. Replacement tissue in grafted dogs closely resembled normal meniscal tissue with respect to chondroid differentiation, collagen content, and zonal architecture. Porcine small intestinal submucosa appeared to have beneficial effects on meniscal regeneration.

Objective— To describe a technique for closed reduction and percutaneous insertion of a lag screw for fixation of sacroiliac fracture-luxations, and to report the success of this technique in stabilizing sacroiliac fracture-luxations. Study Design— A retrospective clinical study. Study Population— 13 consecutive client-owned dogs with sacroiliac fracture-luxations. Methods— Sacroiliac fracture-luxations were stabilized by using a closed reduction and percutaneous lag screw fixation technique. Preoperative, postoperative, and last re-examination radiographs were used to assess the location and number of pelvic injuries, other orthopedic injuries, percent reduction of the sacroiliac joint, percent sacral width screw depth, position of the screw, pelvic canal diameter ratio, hemipelvic canal width ratio, and complications. Information on signalment, weight, weight-bearing status, neurologic status, and complications was obtained from the medical record. Results— Mean percent reduction of the sacroiliac joint was 92.33%. All screws were placed within the sacral body with a mean screw depth/sacral width of 79.03%. No screw loosening occurred. Mean pelvic canal diameter ratios were 0.99, 1.20, and 1.14 preoperatively, immediately postoperatively, and at the last re-examination, respectively. Nine of 13 dogs were willing to walk on the ipsilateral rear leg the day after surgery. Conclusions— Closed reduction and percutaneous insertion of a lag screw for stabilization of fracture-luxation of the sacroiliac joint is an acceptable method of repair. Clinical Relevance— Sacroiliac fracture-luxations can be successfully reduced and stabilized using a minimally invasive technique.

Objective—To test a crimp clamp system designed to secure monofilament nylon leader (MNL) material commonly used as lateral fabellotibial sutures (LFS) in extra-articular stabilization of the canine stifle joint. Study Design—In vitro biomechanical tests of MNL loops secured with either the crimp clamp system or knots were performed. Suture loops (n = 94) were created from 27.3 kg tensile strength MNL and fastened with knots or crimp clamps. Tests were conducted on steam-sterilized, ethylene-oxide-sterilized, and nonsterilized MNL sutures. Loops were evaluated in single load tests and cycled tests. Values for load to failure, initial loop tension, loop elongation, mode of failure, and point of failure were determined. Results—Crimp-clamped loops were superior to knotted loops in all parameters tested in both cycled and noncycled tests. Loop failure generally occurred by breaking within 3 mm of the fixation in both clamped and knotted tests. Loop elongation after cycling was greater in the knotted loops compared with clamped loops (P < .001). Load to failure was greater in clamped tests than in knotted tests (P < .001), regardless of sterilization technique used. Significantly higher initial loop tension could be achieved with the clamp system compared with knot fixation (P < .001). Conclusions—The crimp clamp system provides superior in vitro loop fixation characteristics compared with knot fixation in 27.3 kg test MNL. Clinical Relevance—Based on the results of biomechanical testing and the known biocompatibility of the system's implant components, clinical trials using the crimp clamp system are warranted.

A retrospective study of canine scapular fractures diagnosed and treated from 1988 through 1994 at four veterinary teaching hospitals was performed. Dogs (n = 105) with 109 scapular fractures were included. Most scapular fractures occurred in young (i.e., less than four years of age), male, medium- to large-breed (i.e., greater than 10 kg) dogs as the result of vehicular trauma. Concurrent injuries (primarily thoracic trauma) occurred in approximately 70% of cases. In-house follow-up evaluations were considered adequate in only 17% of the cases. A classification system that includes biomechanical principles for categorization is described to avoid discrepancies between various traditional classification systems.

SummaryThree-dimensional (3-D) culture of chondrocytes has been shown to promote cell proliferation, differentiation, and production of matrix while providing for cell morphology and matrix characteristics that resemble normal articular cartilage (1-3). In a recently published study, enhanced glycosaminoglycan (GAG) production was demonstrated in canine chondrocytes in 3-D culture on cancellous bone substrate (3). The effects of growth factors known to be present in cryopreserved bone were suggested to be responsible. Various growth factors including epidermal growth factor (EGF), fibroblast growth factor (FGF), and plateletderived growth factor (PDGF) have been shown to enhance chondrocyte DNA production, mitotic activity, and matrix production (5-10). The objective of the study reported here was to evaluate the effects of one concentration of EGF, FGF, and PDGF on canine chondrocyte proliferation and production of normal matrix constituents in 3-D culture.Canine articular chondrocytes were cultured in three-dimensional medium for 25 days. EGF, FGF, and PDGF were added to the culture medium. Chondrocytes in 3-D culture maintained viability and differentiation. Cell morphology and matrix production resembled that of intact hyaline cartilage. Significant differences with respect to cell counts, glycosaminoglycan concentration, or collagen type II immuno-reactivity as the result of added growth factors were not found.

SummaryThe purpose of this study was to determine the degree of thermal conduction along the fixation pins associated with acrylic external fixators and to develop a means of minimizing the potential for thermal injury. The data suggest that the degree of temperature conducted with 1.9 cm diameter acrylic external fixators was of minimal clinical significance if maintained a distance of one centimeter from the patient’s tissues. Larger diameter columns increase the potential for injury, however, this can be minimized with the use of a constant saline drip at the pin-acrylic interface to facilitate heat loss.This article describes the evaluation of thermal properties of polymethylmethacrylate external skeletal fixators. The data demonstrate heat conduction along the fixation pins. Thermal injury is theoretically minimized if columns are maintained a distance of at least one centimeter from the patient’s tissue.Research supported in part by and presented for the University of Missouri Pi Chapter of the Honor Society of Phi Zeta in coordination with SmithKline Beecham Animal Health, April 7, 1994

Sacroiliac fracture-luxation is a common injury that is associated with ilial and acetabular fractures of the opposite hemipelvis. Sacroiliac fracture-luxation results in an unstable pelvis and potentially collapse of the pelvic canal. A minimally invasive technique for repair of sacroiliac-fracture luxation is a viable option for repair of this injury and has considerable benefits. Reduction and fixation using a minimally invasive technique provides results comparable to an open technique without the associated morbidity of an open technique. Exact screw placement is facilitated by fluoroscopy to make sure that the disk space or vertebral canal is not penetrated yet allows an adequate length of screw purchase in the sacrum.

To report pelvic limb joint reference angles, limb alignment, and mechanical axis deviation for the feline pelvic limb.Cadaveric radiographic anatomic study.Skeletally mature, mixed breed cats (n = 50).Extended pelvic limb radiography was performed and images analyzed to determine femoral anatomic joint reference angles, femoral and tibial mechanical joint reference angles, tibiofemoral angle, metatarsotibial angle, mechanical axis-femur and mechanical axis-metatarsus angles, and mechanical axis deviation of the stifle and tarsus. Mean ± SD and 95% confidence intervals (95% CI) were calculated.Mean ± SD angles and 95% CI were: anatomic lateral proximal femoral (103.9° ± 3.8°; 103.1° - 104.6°), anatomic lateral distal femoral (93.8° ± 2.5°; 93.3° - 94.3°), mechanical lateral proximal femoral (100.5° ± 3.7°; 99.8° - 101.2°), mechanical lateral distal femoral (97.2° ± 2.2°; 96.7° - 97.6°), mechanical medial proximal tibial (88.0° ± 3.2°; 87.3° - 88.6°), mechanical medial distal tibial (107.6° ± 4.8°; 106.6° - 108.5°), mechanical tibiofemoral (7.4° varus ± 2.5°; 6.9° - 7.9°), mechanical metatarsotibial (6.0° valgus ± 3.5°; 5.3° - 6.7°); mechanical axis-femur (3.2° ± 1.4°; 2.9° - 3.5°) and mechanical axis-metatarsus (2.4° ± 2.0°; 1.7° - 2.1°). Mechanical axis deviation of the stifle and of the tarsus were 2.0% ± 0.9% (95% CI: 1.9-2.2) and 0.8% ± 1.0% (95% CI: 0.7-1.0), respectively.Mean pelvic limb joint reference and limb alignment angles can be used for diagnosing angular limb deformities of the feline pelvic limb and for planning corrective osteotomies in affected cats.

To describe a radiographic method for determination of the mechanical axes and joint orientation lines in orthogonal planes for the canine humerus and establish a range of normal joint orientation angles in a population of large breed dogs.Radiographic study.Humeri (n = 50) of skeletally mature, nonchondrodystrophic canine cadavers, weighing 20-40 kg with no evidence of orthopedic disease.Mediolateral and craniocaudal digital radiographs were used to establish anatomic landmarks for determination of the mechanical axis in both frontal and sagittal planes, the joint orientation lines of both shoulder and elbow and measurement of the resulting mechanical lateral distal humeral angle (mLDHA) in the frontal plane, and the mechanical caudal proximal humeral angle (mCaPHA), and mechanical cranial distal humeral angle (mCrDHA) in the sagittal plane.Means (± SD) for the joint orientation angles were: mLDHA, 86.92 ± 1.24°, mCaPHA, 43.28 ± 5.44°, and mCrDHA, 71.86 ± 3.97°. The 95% CI ranges for the joint orientation angles were mLDHA, 86.58-87.86°, mCaPHA, 41.77-44.79°, and mCrDHA, 70.76°-72.96°.A method for measurement of the mechanical axis and associated joint angles of the normal canine humerus in the frontal and sagittal planes was established and reference intervals reported. In the frontal plane, it was determined that the canine humerus is not perpendicular to the elbow joint; therefore, elbow mechanical axis deviation is normal and requires further assessment.

Three different pin types (Ellis, enhanced threaded, and nonthreaded) were used in type 1 external skeletal fixation after transverse osteotomy of the radius and ulna in 12 skeletally mature dogs. Dogs were placed into three groups of four dogs based on the pin type used. Axial extraction forces were determined for each of the pin types after 8 weeks of weight bearing (chronic study). Nine contralateral radii were used to determine axial extraction forces for nine of each pin type not subjected to weight bearing forces (acute study). The force required for extraction of the enhanced threaded and Ellis pins in the chronic and acute studies was not significantly different. The force required to extract the nonthreaded pins was significantly less than that required for the other two pin types. Ground reaction forces had returned to levels measured before surgery by 2 weeks after surgery in the enhanced threaded and Ellis pin groups, however, dogs in the nonthreaded pin group required 4 weeks until normal ground reaction forces were measured. Radiographic evaluations 1, 2, 4, 6, and 8 weeks after surgery showed no difference among groups in the number of pin tract radiolucencies, however, the enhanced threaded pins had caused more trans-cortical chip fractures than the other two pin types. None of the pins broke during the eight-week chronic study.

Objective— To evaluate outcome by radiographic assessment after closed reduction and percutaneous screw fixation in lag fashion of sacroiliac fracture-luxations in dogs. Study Design— Retrospective study. Animals— Dogs (n=24) with sacroiliac fracture-luxations. Methods— Medical records (1999–2006) and radiographs of 24 dogs (29 fracture-luxations) that had stabilization of sacroiliac fracture-luxation by fluoroscopic-guided closed reduction and percutaneous screw fixation in lag fashion were reviewed. Signalment, body weight, number, and location of all concurrent injuries and implants used for repair were recorded. Radiographs were used to evaluate the accuracy of screw placement in the sacral body, screw depth/sacral width ratio, reduction of the sacroiliac joint, pelvic canal diameter, and hemipelvic canal width. Radiographic re-examination (range, 4 to >8 weeks postoperatively) was available for evaluation. Results— Mean screw depth/sacral width ratio on immediate postoperative and re-examination radiographs was 64% and 61%, respectively. Mean percentage reduction of the sacroiliac joint on immediate postoperative and re-examination radiographs were 91% and 87%, respectively. Pelvic canal diameter ratio demonstrated successful restoration of the pelvic canal. Hemipelvic canal width ratio documented successful closed reduction repair independent of concurrent pelvic injuries. Conclusion— Successful repair of sacroiliac fracture-luxations, determined by radiographic assessment, can be achieved by fluoroscopic-guided closed reduction and percutaneous screw fixation in lag fashion. Clinical Relevance— Fluoroscopic-guided closed reduction and percutaneous screw fixation in lag fashion of sacroiliac fracture-luxations is a minimally invasive technique that restores and maintains pelvic canal dimensions and should be considered as an alternative to open reduction or nonsurgical management of sacroiliac fracture-luxations.

Objective To describe a method for radiographic measurement of the mechanical joint angles of the tibia in the sagittal plane and report reference ranges for a population of dogs with cranial cruciate ligament disease, and specifically for Labrador Retrievers. Study design Retrospective evaluation of radiographs. Animals Canine tibia (n=150) of dogs evaluated for cranial cruciate ligament disease; 104 tibiae were from Labrador Retrievers, 46 tibiae were from other medium- to large-breed dogs. Methods Medial-lateral radiographs were used to establish anatomic landmarks and measure the mechanical cranial distal tibial angle (mCrDTA) and mechanical caudal proximal tibial angle (mCaPTA). Results For all tibiae mean mCrDTA was 81.6 degrees and mCaPTA, 63.6 degrees . For Labrador Retriever tibiae mean mCrDTA was 81.7 degrees and mCaPTA, 63.8 degrees . For non-Labradors, means mCrDTA was 81.5 degrees and mCaPTA, 63 degrees . Labrador Retrievers were significantly younger than non-Labradors in our study population. No significant differences were noted between Labrador Retrievers and non-Labradors for mCrDTA or mCaPTA and correlations between mCrDTA and mCaPTA were neither strong nor significant. Conclusion A method was established for radiographic measurement of mechanical joint angles of the canine tibia in the sagittal plane. Reference ranges are reported for a population of Labrador Retrievers and a population of non-Labradors with cranial cruciate ligament disease. Clinical relevance Measurement method and reference ranges provided for mechanical tibial angles may be used to aid in diagnosis, surgical planning, and postoperative critique for hindlimb angular deformities.

Case Description—A 1-year-old 7.4-kg (16.3-lb) castrated male mixed-breed dog was evaluated because of intermittent lameness and an antebrachial angular limb deformity. Clinical Findings—The left forelimb had gross antebrachial external rotation (approx 90°) and marked procurvatum. Radiography revealed a severe partially compensated biapical antebrachial angular limb deformity. Measurements of medial proximal radial angle (MPRA) and lateral distal radial angle (LDRA) were obtained from orthogonal radiographs of the proximal and distal segments of the radius, respectively. Elbow joint-to-carpus translation was quantified. Deformities were localized and quantified by the center of rotation of angulation (CORA) method. Computed tomographic 3-dimensional image reconstructions of the antebrachium and carpus were completed to create 3 life-size stereolithographic models. Treatment and Outcome—2 closing wedge radial osteotomies were performed at the level of the CORAs and stabilized with bone plates and screws. Results—Frontal and sagittal plane alignments were corrected to 8° and 15°, respectively (reference limits, 0° to 8° and 8° to 35°, respectively). The MPRA was corrected from 55° to 68°, and LDRA was corrected from 32° to 76° (values considered normal are approx 85° and 87°, respectively). Elbow joint-to-carpus translation was improved by 42.5%. After 8 weeks, radiography revealed bone union. Owners considered the outcome acceptable, on the basis of limb appearance and lack of lameness at 1 year after surgery. Conclusions and Clinical Relevance—A segmental radiographic planning technique combined with the CORA method, computed tomography, and stereolithography may be useful in the characterization of and planning corrective surgery for forelimb deformities in dogs.

Objective To develop a standard method of measurement for femoral angles and report values for normal Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers. Study design Retrospective evaluation of canine pelvis and femoral radiographs. Sample population Radiographs of Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers (n=100 for each breed). Methods Anatomic lateral distal and proximal femoral angle, mechanical lateral distal and proximal femoral angle, and femoral angle of inclination were measured from radiographs. Results For the 4 breeds (Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers, respectively) anatomic lateral distal femoral angles were 97 degrees , 97 degrees , 94 degrees , and 98 degrees ; mechanical lateral distal femoral angles were 100 degrees , 100 degrees , 97 degrees , and 100 degrees ; anatomic lateral proximal femoral angles were 103 degrees , 98 degrees , 101 degrees , and 96 degrees ; mechanical lateral proximal femoral angles were 100 degrees , 95 degrees , 97 degrees , and 93 degrees ; and inclination angles were 134 degrees , 134 degrees , 132 degrees , and 137 degrees . Labrador Retrievers, Golden Retrievers, and Rottweilers had significantly higher values for both anatomic and mechanical lateral distal femoral angle than German Shepherds. Anatomic and mechanical lateral proximal angles were greatest for Labrador Retrievers and lowest for Rottweilers. Conclusion Anatomic and mechanical femoral joint angles vary between breeds of dogs. Clinical relevance Values for femoral joint angles may be clinically useful for angular limb deformity diagnosis, treatment, and assessment.

Objective— To determine and compare rates of meniscal tears after tibial plateau leveling osteotomy (TPLO) among 3 groups of dogs based on treatment method: arthrotomy with meniscal release (openR), arthrotomy without meniscal release (openNR), arthroscopy without meniscal release (scopeNR), and compare long term owner-assessed outcomes for the same groups. Study Design— Retrospective cohort study. Sample Population— Stifles (n=254) of dogs that had TPLO. Methods— The three groups were compared for significant (P

Naturally occurring biomaterials, such as small intestine submucosa (SIS), are attractive as potential scaffolds for engineering various tissue types. The aim of this study was to determine whether acellular SIS scaffolds can support cell attachment and ingrowth in a diarthroadial joint without significant intraarticular hemorrhage. Disks of porcine SIS were arthoscopically implanted freely within a randomized knee joint of 21 dogs and harvested 1, 2, 3, and 6 weeks postoperatively. Harvested disks were assessed for gross and histologic appearance, cellular infiltration, and immunoreactivity of collagenase and collagen types I and II. Knee synovium and synovial fluid were also evaluated. All disks were thickened and opacified at harvest. Eleven disks (52%) had adhered to intraarticular tissues and cellular infiltration into the disks was positively correlated with tissue adherence. Further, tissue adherence was positively correlated with duration of intraarticular implantation. Five disks (24%) contained focal areas of homogeneous extracellular matrix. A trend toward more collagenase immunoreactivity was noted in the 3-week disks. Collagen type I was present in remaining SIS and extracellular matrix associated with infiltrated cells. Placed freely within a joint, acellular SIS disks underwent cellular and extracellular matrix modification resulting in fibrocartilage-like tissue. Utilization of SIS as a scaffold for intraarticular tissue-engineering applications is supported as cytoconductivity, appropriate residence time, and absence of untoward effects of implantation are desirable criteria for a tissue-engineering biomaterial.

Objective—To identify complications associated with tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament rupture in dogs and assess owner perceptions of outcome. Design—Retrospective study. Animals—193 dogs that underwent unilateral or bilateral TPLO (253 TPLOs total) between November 1997 and March 2001. Procedure—Complications associated with the surgical procedure were recorded. A questionnaire was sent to owners of all dogs to assess their perceptions of outcome. Results—Complications were identified in 47 of the 193 (24.4%) dogs and in association with 52 of the 253 (20.6%) TPLOs. Dogs that underwent bilateral TPLOs during a single anesthetic episode had a higher complication rate than did dogs that underwent unilateral TPLO and dogs that underwent bilateral TPLOs during separate anesthetic episodes. Body weight, surgery time, whether a meniscal release or meniscectomy was performed, and extent of cruciate ligament damage were not associated with whether complications occurred. One hundred forty-one of 151 (93%) owners who responded to the questionnaire were satisfied with the outcome of the surgery. Assessments of outcome were not significantly different between owners of dogs that had complications and owners of dogs that did not. Conclusions and Clinical Relevance—Results indicated that complications developed in approximately 25% of dogs undergoing TPLO for treatment of a cranial cruciate ligament injury but that most complications responded to appropriate treatment, and development of complications did not affect owner assessments of outcome. There was a higher incidence of complications when bilateral TPLOs were performed during a single anesthetic episode. (J Am Vet Med Assoc 2003; 222:1726–1732)

A 4-month-old Siberian husky was presented for a history of lameness of the left hind limb. Physical and radiographic examination revealed a 1-cm shortening of metatarsals III and IV, with subsequent hyperextension of the digits on the left hind paw. A circular external skeletal fixator was used to accomplish distraction osteogenesis in both metatarsals over a period of 15 days. Treatment was successful in restoring appropriate length of the metatarsals and in resolution of the lameness. At 6 and 12 months after surgery, the owner reported that the dog was ambulating normally and had no complications related to the surgery.

Objective—To determine effects of carprofen and dexamethasone on chondrocytes in a culture model of osteoarthritis (OA). Sample Population—Chondrocytes isolated from articular cartilage of the humeral head of 5 adult dogs. Procedure—Chondrocytes were harvested, cultured and subcultured in monolayer, and then cultured in a 3-dimensional (3-D) medium. Cells from each dog were distributed into 6 groups with differing content of liquid medium for each 3-D construct (agarose [AG], AG plus interleukin [IL]-1β, AG plus carprofen [4 μg/mL], AG plus dexamethasone [1 mg/mL], AG plus IL-1β [20 ng/mL] plus carprofen [4 μg/mL], and AG plus IL-1β (20 ng/mL) plus dexamethasone (1 mg/mL). On days 3, 6, 12, and 20 of culture, samples from all groups were collected. Liquid media were assayed for glycosaminoglycan, prostaglandin (PG)E2, matrix metalloprotease (MMP)-3, and MMP- 13 concentrations. All 3-D constructs were evaluated for viability, cell morphology, proteoglycan staining, and collagen type-II concentration. Total glycosaminoglycan content in each 3-D construct was quantitated by spectrophotometric assay. Results—Addition of IL-1β caused a significant loss of cell viability and matrix production. Addition of carprofen or dexamethasone caused significant decreases in PGE2 in the liquid media, and each was minimally effective in protecting chondrocytes against negative effects of IL-1β. Conclusions and Clinical Relevance—Human recombinant IL-1β resulted in loss of cell viability, alterations in extracellular matrix components, and production of PG and MMP. Carprofen and dexamethasone had little effect on cell and matrix variables but did decrease PGE2 concentrations and primarily affected the inflammatory pathway of osteoarthritis. (Am J Vet Res 2002;63:1363–1369)

Objective—To determine immunoreactivity of matrix metalloproteinase (MMP)-1, -3, and -13 in cartilaginous tumors of dogs, correlate expression of MMP with histologic grade of tumors and clinical outcome of dogs, and compare MMP immunoreactivity between chondrosarcomas and chondromas. Sample Population—Formalin-fixed, paraffin-embedded tissues obtained from samples of naturally occurring chondrosarcomas (n = 31) and chondromas (8) of dogs that were submitted to our veterinary medical diagnostic laboratory. Procedure—Histologic sections from each sample were stained with H&E and monoclonal antibody to MMP-1, -3, and -13 by use of an avidin-peroxidase immunohistochemical technique. For each section, histologic grade (I, II, or III) and immunohistochemical expression (0, 1, 2, or 3) were evaluated. Clinical outcome was obtained from medical records or interviews with referring veterinarians and scored as a good outcome, moderate outcome, or poor outcome. Correlations among variables and differences between chondrosarcomas and chondromas were analyzed. Results—Samples from chondrosarcomas had significantly higher immunoreactivity of MMP-1 and -13, compared with immunoreactivity in samples from chondromas. In chondrosarcomas, a significant positive correlation (r, 0.386) was found between MMP-1 and -13 immunoreactivities, and a significant negative correlation (r, –0.390) was detected between MMP-3 and -13 immunoreactivities. Conclusion and Clinical Relevance—A significant increase in expression of collagenases (MMP-1 and - 13) in chondrosarcomas, compared with expression in chondromas, suggests that collagenases may play an important role in tumor progression, and possibly metastasis, in chondrosarcomas of dogs. (Am J Vet Res 2002;63:1285–1291)

Osteochondrosis lesions in the tibiotarsal joint were treated arthroscopically in two dogs. One dog had unilateral osteochondrosis of the dorsal aspect of the lateral trochlear ridge of the talus. The second dog had bilateral osteochondrosis of the plantar aspect of the medial trochlear ridge of the talus. Removal of all osteochondral fragments (i.e., joint mice) and debridement and curettage of the remaining talar defects were accomplished arthroscopically. Both dogs had excellent short-term outcomes.

Objective—To report values for percentage coverage of the femoral head (PC) and Norberg angle (NA) in 4 common breeds of dogs and to determine values for each that distinguish between normal and dysplastic hip status on the basis of Orthopedic Foundation for Animals (OFA) hip evaluation. Animals—1,841 dogs 24 to 48 months of age that were Labrador Retrievers (455), Golden Retrievers (423), Rottweilers (545), or German Shepherd Dogs (418). Procedure—Retrospective analysis of NA and PC measured from standard OFA ventrodorsal pelvic radiographs from 4 breeds of dog. Results—Norberg angle ranged from 67.4 to 124.4° for Labrador Retrievers, 59.7 to 128.6° for Rottweilers, 70.2 to 119.4° for Golden Retrievers, and 55.3 to 121.3° for German Shepherd Dogs. The PC ranged from 6.5 to 79.9% for Labrador Retrievers, 5.7 to 79.5% for Rottweilers, 8.3 to 79.3% for Golden Retrievers, and 5.4 to 83.7% for German Shepherd Dogs. On the basis of logistic regression modeling for determining normal versus abnormal hip status for all 4 breeds, cutoff points for NA were < 105° and PC were < 50%. Conclusions and Clinical Relevance—Results of our study indicate that cutoff points of NA of 105° and PC of 50% do not differentiate normal versus dysplastic hip status. Each of the 4 breeds had different values for NA and PC that distinguished normal from dysplastic hip status. (Am J Vet Res 2000;61:1492–1500)

Despite the extensive amount of research conducted on mourning doves (Zenaida macroura), no biochemical reference values exist for this species. Our objective, therefore, was to establish base line clinical chemistry reference values for mourning doves to assist with establishing clinical diagnoses. Wild mourning doves were captured 19 March 1996 to 8 August 1996, and 6 February 1998 to 12 May 1998; blood samples were collected from 382 mourning doves. Plasma biochemical values were established for glucose, sodium, potassium, chloride, enzymatic CO2, albumin, total protein, globulin, calcium, phosphorus, cholesterol, magnesium, aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), lactate dehydrogenase (LDH), and uric acid. These reference values are invaluable for determining diagnosis of diseases of the gastrointestinal, hepatic, renal, cardiovascular, musculoskeletal, and endocrine systems.

Objective—To determine the effects of interleukin (IL)-1β on matrix synthesis and degradation by chondrocytes cultured in a 3-dimensional (3-D) gel medium. Sample Population—Chondrocytes from 7 dogs. Procedure—Articular chondrocytes were harvested and cultured in 3-D gel medium alone or with 10 or 20 ng IL-1βml that was added beginning on day 0, 3, 6, or 9. On days 3, 6, 12, and 20 of 3-D culture, samples of the liquid medium were evaluated for glycosaminoglycan (GAG), prostaglandin E2 (PGE2), and matrix metalloprotease (MMP)-3 content. The 3-D plug in each well was evaluated for histologic characteristics of viability, cell morphology, and proteoglycan staining, immunohistochemically stained for collagen type II, and spectrophotometrically analyzed for GAG content. Results—Significant differences for all variables were detected between controls and each IL-1β group, among groups with different IL-1β concentrations, and among groups with IL-1β added at various time points. Chondrocytes exposed to IL-1β had loss of GAG, increased PGE2 and MMP-3 concentrations, and lack of collagen type-II synthesis. These IL-1β effects appeared to be time and concentration dependent. Conclusions—Addition of IL-1β to chondrocytes in 3- D gel medium results in time- and concentrationdependent effects on matrix synthesis and degradation and provides an appropriate in vitro model for many of the pathophysiologic events associated with osteoarthritis. (Am J Vet Res 2000;61:766–770)

Biopsy and necropsy specimens, comprising 107 primary carcinomas and three mesenchymal tumours, were reviewed from 110 dogs with cancer of the bladder, urethra, or both. Histological classifications developed for the assessment of human bladder cancer were found to be readily applicable to the dog. These classifications are based on histological features, including the pattern of growth, the cell type, the grade of transitional tumour and the depth of invasion of the bladder wall. Features associated with localized disease in canine transitional cell carcinoma included papillary architecture, "in-situ" tumour, low tumour grade and a strong peritumoral lymphoid cell reaction. Features of tumours with metastasis included infiltrating and non-papillary architecture, increasing tumour grade, depth of invasion, vascular invasion and presence of peritumoral fibrosing reaction. Wide variability was found within single tissue samples, indicating that multiple sample sites are necessary for the adequate characterization of a given lesion. Statistically significant correlations were found between: tumour grade and depth of invasion (P < 0.0001); tumour grade and presence of metastases (P < 0.029); and peritumoral desmoplasia and metastases (P < 0.029). It was concluded that canine bladder cancer could be classified for the purpose of clinical management with a modified World Health Organization system as developed for human tumours.

The effects of three different techniques of intramedullary (IM) pin placement on pin location and incidence of stifle joint injury were evaluated using 70 cadaver canine tibiae after mid-disphyseal osteotomy. In 50 tibiae, pins were placed retrograde in either a nondirected (group A) or a craniomedially directed fashion (group B) with 25 tibiae in each group. Pins were driven normograde (group N) in 20 tibiae. All the stifles were dissected to qualitatively evaluate pin interference with different joint structures. End-on radiographs of the tibial plateaus were used to quantitatively evaluate pin location. Interference with the caudal cruciate ligament, medial meniscus, lateral meniscus, or meniscal ligaments was not observed in any group. There was a significant association between pinning technique and incidence of involvement of the cranial cruciate ligament (P < .005), patella (P < .001), patellar ligament (P < .005), and femoral condyle (P < .01). Pin location for group A was significantly different from either other group in a cranial-caudal direction (P = .003), and was significantly different from group N in a medial-lateral direction (P = .005). No significant difference was observed between pin location for groups B and N in either plane. It was concluded that although nondirected retrograde pinning cannot be recommended, retrograde pins directed craniomedially may be an acceptable technique for the repair of proximal to mid-diaphyseal tibial fractures if care is taken to properly seat the pins.