Tibial tuberosity advancement for stabilization of the canine cranial cruciate ligament-deficient stifle joint: surgical technique, early results, and complications in 101 dogs

Objective— To describe the surgical technique, early results and complications of tibial tuberosity advancement (TTA) for treatment for cranial cruciate ligament (CrCL)-deficient stifle joints in dogs.
Study Design— Retrospective clinical study.
Animals— Dogs (n=101) with CrCL-deficient stifles (114).
Methods— Medical records of 101 dogs that had TTA were reviewed. Complications were recorded and separated into either major or minor complications based on the need for additional surgery. In-hospital re-evaluation of limb function and time to radiographic healing were reviewed. Further follow-up was obtained by telephone interview of owners.
Results— Complications occurred in 31.5% of the dogs (12.3% major, 19.3% minor). Major complications included subsequent meniscal tear, tibial fracture, implant failure, infection, lick granuloma, incisional trauma, and medial patellar luxation; all major complications were treated with successful outcomes. All but 2 minor complications resolved. The mean time to documented radiographic healing was 11.3 weeks. Final in-hospital re-evaluation of limb function (mean, 13.5 weeks), was recorded for 93 dogs with lameness categorized as none (74.5%), mild (23.5%), moderate (2%), and severe (1%). All but 2 owners interviewed were satisfied with outcome and 83.1% reported a marked improvement or a return to pre-injury status.
Conclusions— TTA is a procedure comparable with alternate methods of CrCL repair with expected good to excellent functional outcome.
Clinical Relevance— TTA procedure can be successfully used to obtain the dynamic stability of a CrCL-deficient stifle joint in dogs.     

Canine Total Knee Replacement: Surgical Technique and One-Year Outcome

Objective— To describe a surgical technique for total knee replacement (TKR) in dogs with severe osteoarthritis (OA) and report 1-year outcome.
Study Design— Prospective clinical case study.
Animals— Dogs (n=6) with severe stifle OA.
Methods— Preoperative and postoperative evaluations were compared after 6 dogs had TKR. Data gathered included radiographs, goniometric measures of passive range of motion, ground reaction forces, and girth measurements of the thigh before surgery and at 6 weeks, 3 months, 6 months, and 1 year.
Results— Stifle extension and excursion angles were significantly improved by 3 months after TKR. Mean peak vertical force and impulse were significantly improved by 6 months.
Conclusions— TKR is a viable treatment option for dogs with severe stifle OA.
Clinical Relevance— With continued refinement of surgical technique, instrumentation, and implants, TKR could become a reliable treatment for dogs with disabling, painful nonseptic stifle OA.     

Custom total knee replacement in a dog with femoral condylar bone loss

Objective— To report surgical planning, technique, and outcome of custom total knee replacement (TKR) performed to manage a medial femoral condylar nonunion in a dog.
Study Design— Clinical case report.
Animal— A 3-year-old, 20 kg Karelian Bear Hound.
Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.
Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.
Conclusion— Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.
Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients.     

Revision of Cemented Total Hip Arthroplasty with Cementless Components in Three Dogs

Objective— To report revision of cemented total hip arthroplasty failure with cementless components in 3 dogs.
Study Design— Clinical case reports.
Animals— Dogs with total hip arthroplasty failure (n=3).
Methods— Cementless total hip arthroplasty revision was performed in 3 dogs with previously cemented femoral and acetabular components. All dogs required revision of the femoral component and 1 dog also required revision of the acetabular component.
Results— Revisions resulted in a stable functional prosthesis with successful bone integration.
Conclusions— Use of cementless components may be a viable option for revision of loosened cemented prosthesis after explantation of failed cemented canine total hip replacements.
Clinical Relevance— Failed canine-cemented total hip arthroplasties can be successfully revised with cementless components.     

Pre- and postoperative force plate analysis of dogs with experimentally transected cranial cruciate ligaments treated using tibial plateau leveling osteotomy

Objective— Quantitative and objective assessment of hindlimb kinetics after cranial cruciate ligament (CrCL) transection and subsequent stifle stabilization using the tibial plateau leveling osteotomy (TPLO) in normal dogs.
Study Design— In vivo experimental biomechanical evaluation.
Animals— Six healthy adult foxhounds.
Methods— Dogs were screened by orthopedic and radiographic examination before study entry. Force plate analysis of gait was measured before extirpation of the right CrCL and TPLO and again at 8 and 18 weeks after surgery.
Results— There was a significant decrease in peak vertical forces (PVFs) and vertical impulse (VI) of the treated hindlimb at 8 weeks when compared with preoperative and 18-week measurements. When compared with preoperative values, there was no significant difference in 18 week PVF and VI in dogs that had TPLO.
Conclusion— TPLO can restore kinetic measures of limb function at 18-weeks after surgery when compared with preoperative values after experimental transection of the CrCL in dogs.
Clinical Relevance— TPLO induces lameness that returns to near normal at 18 weeks. The severity and duration of lameness was similar to that reported for other experimental models of stifle instability repaired by different techniques.     

Proximal tibial intraarticular ostectomy for treatment of canine cranial cruciate ligament injury

OBJECTIVE: To report a technique for surgical alteration of the slope of the tibial plateau by a proximal tibial intraarticular ostectomy (PTIO) after injury to the canine cranial cruciate ligament (CCL) and to determine the outcome. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=52) with CCL injury in 60 stifle joints. METHODS: CCL injury was treated by lateral stifle arthrotomy, removal of CCL remnants, and appropriate meniscal surgery. PTIO was performed to remove a wedge of bone from the proximal aspect of the tibia. The ostectomy site was reduced and stabilized using a bone plate and screws applied to the medial surface of the tibia as well as a craniocaudal positional screw. Dogs were evaluated at 6 weeks, 6, and 12 months by complication assessment, lameness scores, stifle range of motion (ROM), thigh circumference, radiographic assessment, degenerative joint disease (DJD) scores, and surgeon and owner evaluation of function. RESULTS: Lameness scores improved by 6 and 12 months in all but 1 dog. Thigh circumference and DJD were increased at 6 and 12 months. Complications occurred in 20% of dogs with all but 1 occurring perioperatively or within 6 weeks; most common were injury to the long digital extensor tendon (4 dogs) and plate failure (3); 2 other dogs required surgery to treat complications. Most owners (98%) reported that lameness had improved by 12 months; 90% were extremely or very satisfied with the procedure and 90% would have the same procedure performed on another dog. CONCLUSION: PTIO to level the tibial plateau provided a satisfactory clinical outcome in dogs >20 kg with CCL injury and the complication rate was similar to tibial plateau levelling osteotomy (TPLO). Stifle osteoarthritis continued to progress radiographically. CLINICAL RELEVANCE: PTIO represents an alternative to TPLO that does not require specialized surgical equipment.     

Unilateral Uniplanar External Skeletal Fixation for Isolated Diaphyseal Tibial Fractures in Skeletally Immature Dogs

Objective: To report and evaluate use of external skeletal fixation (ESF) for repair of isolated (fibula intact) diaphyseal tibia fractures in skeletally immature dogs.
Study Design: Case series.
Animals: Skeletally immature (mean age, 17 weeks; range, 12–23 weeks) dogs (n=5) with isolated diaphyseal tibial fractures.
Methods: Medical records (2006–2007) of 5 dogs with isolated diaphyseal tibial fractures treated with Type 1a ESF were reviewed and outcome assessed by clinical examination and telephone interviews.
Results: Dogs were evaluated ∼2 and 4 weeks after surgery. Limb function, muscle mass, and comfort level remained very good to excellent throughout healing. Bony union was confirmed radiographically and the ESF removed ∼4 weeks after surgery (mean, 31.4 days; range, 28–37 days). Owner satisfaction was high when contacted a minimum of 4 weeks after ESF removal.
Conclusions: Use of Type Ia ESF with positive profile threaded pins is a practical and biologic method for treatment of isolated tibial fractures in skeletally immature dogs
Clinical Relevance: ESF is an effective alternative treatment to external coaptation and internal fixation for isolated diaphyseal tibial fractures in skeletally immature dogs.     

Meniscal Release in Cruciate Ligament Intact Stifles Causes Lameness and Medial Compartment Cartilage Pathology in Dogs 12 Weeks Postoperatively

Objective— To evaluate after 12 weeks the effects of caudal medial meniscal release (MR) in the cranial cruciate ligament-intact canine stifle.
Study Design— Blinded, prospective in vivo study.
Animals— Purpose-bred hound dogs (n=10).
Methods— Either MR (n=5) or a sham (SH) surgery (n=5) was performed via arthroscopy. Orthopedic examination and subjective lameness evaluation were performed in each dog preoperatively and at 4, 8, and 12 weeks after surgery. Twelve weeks postoperatively, ultrasonographic, radiographic, and arthroscopic examinations were performed on the operated stifles. Gross pathology of the articular cartilage, cruciate ligaments, and menisci was assessed. India ink staining of the femoral and tibial articular surfaces was performed to determine the percent area of articular cartilage damage.
Results— At 8 and 12 weeks after surgery, MR dogs were lamer than SH dogs. At 12 weeks, the degree of radiographic OA was significantly higher in MR stifles than in SH stifles. Gross and sonographic meniscal pathology was more severe in MR stifles compared with SH stifles. MR stifles had significantly more severe articular cartilage pathology compared with SH stifles 12 weeks after surgery; pathology was most severe in the medial compartment.
Conclusions— MR alone is associated with articular cartilage loss, further meniscal pathology, degenerative joint disease, and lameness.
Clinical Relevance— Subsequent osteoarthritis and dysfunction of the stifle joint should be considered when making clinical decisions regarding MR in dogs.     

PREVALENCE,ASSOCIATION WITH STIFLE CONDITIONS,AND HISTOPATHOLOGIC CHARACTERISTICS OF TIBIAL TUBEROSITY RADIOLUCENCIES IN DOGS

A tibial tuberosity radiolucency is sometimes identified on lateral radiographs of canine stifle joints, however little is known about the cause or significance. The purpose of this study was to describe the prevalence, association with other stifle conditions, and histopathologic characteristics of tibial tuberosity radiolucencies in a group of dogs. Radiographs of all canine stifle joints over 5 years were evaluated. Presence or absence of a tibial tuberosity radiolucency was recorded by an observer who was unaware of clinical status. Patient signalment and presence of other stifle joint conditions were recorded from medical records. A tibial tuberosity radiolucency was found in 145/675 dogs (prevalence = 21.5%). Statistically significant associations were identified between tibial tuberosity radiolucency and stifle condition (P < 0.0001), breed size (P = 0.011), and younger age of presentation (P = 0.001), but not with gender (P = 0.513). Dogs with a tibial tuberosity radiolucency had higher odds of having a medial patellar luxation than dogs without (OR = 9.854, P < 0.0001, 95% CI 6.422–15.120). Dogs with a tibial tuberosity radiolucency had lower odds of having a cranial cruciate ligament rupture than dogs without (OR = 0.418, P < 0.0001, 95% CI 0.287–0.609). Four canine cadavers, two with normal stifles and two with tibial tuberosity radiolucencies, underwent radiographic, computed tomographic, and histologic examination of the stifles. Computed tomography revealed a hypoattenuating cortical defect in the lateral aspect of the proximal tibial tuberosity that corresponded histopathologically to a hyaline cartilage core. Findings indicated that the tibial tuberosity radiolucency may be due to a retained cartilage core and associated with medial patellar luxation in dogs.     

Intraoperative radiation for limb sparing of the distal aspect of the radius without transcarpal plating in five dogs

Objectives— To evaluate intraoperative irradiation (IORT) as a method of limb spare with preservation of the radiocarpal joint.
Study Design— Prospective case series.
Animals— Dogs (n=5) with stage II sarcoma of the distal aspect of the radius.
Methods— A bone segment containing the tumor was isolated surgically, treated by IORT, reimplanted, and secured by internal fixation. In 1 dog, the postradiation tumor bed was curetted and filled with bone cement. Dogs were administered alternating adriamycin and carboplatin starting 2 weeks after IORT and monitored at regular intervals.
Results— Four dogs had osteosarcoma and 1 had undifferentiated sarcoma. Implant failure (n=3), deep tissue infection (3), and pathologic fracture (3) resulted in amputation (3) or pancarpal plating (2). The dog with undifferentiated sarcoma was euthanatized because of suspected tumor recurrence 4 months postoperatively. Osteotomy healing was documented by radiography (1), histopathology (2), or by direct observation (2).
Conclusions— A technique for limb-sparing surgery of the distal portion of the radius in dogs using IORT had advantages include healing of the autograft and a source for a perfectly fitting autograft but did not appear to offer any advantage with respect to infection rate. Long-term preservation of the radiocarpal joint was not successful.
Clinical Relevance— It was not possible to preserve the function of the radiocarpal joint and so this technique cannot be recommended currently. Further study is needed to evaluate whether or not IORT can be considered in combination with pancarpal plating and possibly curettage and cementation of the tumor to prevent subchondral bone collapse.     

Radiographic, Densitometric, and Biomechanical Effects of Recombinant Canine Somatotropin in an Unstable Ostectomy Gap Model of Bone Healing in Dogs

Objective —To determine the effect of recombinant canine somatotropin (STH) on radiographic, densitometric, and biomechanical aspects of bone healing using an unstable ostectomy gap model.
Study Design —After an ostectomy of the midshaft radius, bone healing was evaluated over an 8–week period in control dogs (n = 4) and dogs receiving recombinant canine STH (n = 4).
Animals or Sample Population—Eight sexually intact female Beagle dogs, 4 to 5 years old. Methods—Bone healing was evaluated by qualitative and quantitative evaluation of serial radiographs every 2 weeks. Terminal dual-energy x-ray absorptiometry and three-point bending biomechanical testing were also performed.
Results —Dogs receiving STH had more advanced radiographic healing of ostectomy sites. Bone area, bone mineral content, and bone density were two to five times greater at the ostectomy sites of treated dogs. Ultimate load at failure and stiffness were three and five times greater in dogs receiving STH.
Conclusions —Using the ostectomy gap model, recombinant canine STH enhanced the radiographic, densitometric, and biomechanical aspects of bone healing in dogs. Clinical Relevance—Dogs at risk for delayed healing of fractures may benefit from treatment with recombinant canine STH.     

Limited open reduction and stabilization of sacroiliac fracture-luxations using fluoroscopically assisted placement of a trans-iliosacral rod in five dogs

Objective— To describe percutaneous fluoroscopically assisted placement of a trans-iliosacral rod to stabilize sacroiliac fracture-luxations after limited open reduction.
Study Design— Retrospective clinical case series.
Animals— Dogs (n=5) with sacroiliac fracture-luxations.
Methods— Medical records and radiographs were reviewed to evaluate implant placement, fracture reduction, pelvic canal diameter ratio, maintenance of reduction, implant stability, assessment of union, and to identify any complications. Owners were contacted to obtain long-term assessment of limb function.
Results— Dogs weighed between 6 and 31 kg. Trans-iliosacral rods were placed correctly traversing the sacral body. Mean (±SD) percent reduction of the sacroiliac joint was 92.9±6.6%. Pelvic canal diameter ratio did not differ significantly between time periods. With the exception of 1 dog, which died in the early postoperative period, all sacroiliac fracture-luxations healed without appreciable complications. Three dogs were sound and 1 dog had a subtle lameness at final physical and radiographic examination (mean±SD: 217±205 days). Owners assessed their dog's limb function (mean±SD: 355±205 days) as good or excellent.
Conclusions— Trans-iliosacral rods can be accurately placed using intraoperative fluoroscopy after limited open reduction of sacroiliac fracture-luxations. Trans-iliosacral rods provided bilateral secure fixation, allowed early weight-bearing and dogs consistently had good long-term clinical results.
Clinical Relevance— Trans-iliosacral rods are suitable implants for the stabilization of sacroiliac fracture-luxations, particularly in dogs with bilateral fracture-luxations and/or concurrent musculoskeletal injuries.     

Cervical Spine Locking Plate Fixation for Treatment of Cervical Spondylotic Myelopathy in Large Breed Dogs

Objective— To describe indirect decompression by means of cervical spine locking plate (CSLP) fixation with vertebral distraction, discectomy, and cancellous block bone grafting in large breed dogs with single caudal cervical dynamic spondylotic lesions diagnosed by myelography with linear traction to the cervical spine, and contrast-enhanced computed tomography.
Study Design— Prospective clinical study.
Animals— Dogs (n=12) with caudal cervical spondylotic myelopathy because of a single dynamic, traction-responsive lesion.
Methods— Single, traction-responsive, caudal cervical spondylotic lesions were treated by vertebral distraction, discectomy, cancellous block bone grafting, and CSLP fixation. Follow-up was obtained by sequential recheck examination by the author or referring veterinarian or by telephone inquiries.
Results— Ten dogs had neurologic improvement after surgery. Indirect decompression by maintained distraction with cancellous block grafting and CSLP fixation was readily accomplished with less risk of blood loss or iatrogenic spinal cord injury than that associated with direct (ventral) decompression. There were no complications of graft intrusion, extrusion or subsidence, implant loosening, foraminal impingement, or end-plate failure. Two dogs that had satisfactory short-term recoveries developed clinical signs associated with adjacent segment disease and were euthanatized. At long-term follow-up, 8 dogs had satisfactory function, either a normal gait or one with slight to moderate proprioceptive deficits.
Conclusions— CSLP fixation with cancellous block interbody grafting is an effective and perhaps safer method of treating single-level, traction-responsive cervical spondylosis in large breed dogs.
Clinical Relevance— CSLP fixation with interbody bone grafting is a viable alternative to other techniques for treatment of single-level, traction-responsive cervical spondylosis.     

Effect of Tibial Tuberosity Advancement on Femorotibial Contact Mechanics and Stifle Kinematics

Objective— To evaluate the effects of tibial tuberosity advancement (TTA) on femorotibial contact mechanics and 3-dimensional kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs.
Study Design— In vitro biomechanical study.
Animals— Unpaired pelvic limbs from 8 dogs, weighing 28–35 kg.
Methods— Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TTA-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test ( P <.05) was used for statistical comparison.
Results— Significant disturbances to all measured contact mechanic parameters were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and internal tibial rotation in the CrCL-deficient stifle. No significant differences in any contact mechanic and kinematic parameters were detected between normal and TTA-treated stifles.
Conclusion— TTA eliminates craniocaudal stifle instability during simulated weight-bearing and concurrently restores femorotibial contact mechanics to normal.
Clinical Relevance— TTA may mitigate the progression of stifle osteoarthritis in dogs afflicted with CrCL insufficiency by eliminating cranial tibial thrust while preserving the normal orientation of the proximal tibial articulating surface.     

Osteophytosis, subchondral bone sclerosis, joint effusion and soft tissue thickening in canine experimental stifle osteoarthritis: comparison between 1.5 T magnetic resonance imaging and computed radiography

Objective— To compare use of 1.5 T magnetic resonance imaging (MRI) and computed radiography (CR) for morphologic and temporal evaluation of osteophytosis, subchondral sclerosis, joint effusion, and synovial thickening in experimentally induced canine stifle osteoarthritis (OA).
Study Design— Prospective study.
Animals— Dogs (n=8).
Methods— CR (mediolateral and caudocranial projections) and MRI (dorsal 3D T1-weighted gradient echo, sagittal 3D SPGR and T2-weighted fast spin echo with fat saturation) were performed at baseline (n=8) and at week 4 (n=5), week 8 (n=8), and week 26 (n=5) after cranial cruciate ligament transection. Osteophytosis, subchondral bone sclerosis, and joint effusion were scored on CR and MRI, and synovial thickening on MRI.
Results— MRI was more sensitive than CR for detection of osteophytosis and could better discriminate joint effusion from soft tissue thickening, although scores for these variables strongly correlated between modalities (ρ=0.94 [osteophytosis] and 0.80 [effusion]; P <.001). Scores for subchondral bone sclerosis also correlated (ρ=0.54, P <.004), although this variable may have been over interpreted on CR. Joint effusion and synovial thickening peaked at week 8, before partially regressing at week 26. Conversely, osteophytosis and sclerosis progressed semi-linearly over 26 weeks.
Conclusion— MRI is more sensitive than radiography in assessing onset and progression of osteophytosis in canine experimental stifle OA and provides enhanced discrimination between joint effusion and synovial thickening.
Clinical Relevance— MRI is as a more powerful imaging modality that should be increasingly used in animals to assess the joint related effects of disease-modifying OA drugs.     

Effect of Tibial Plateau Leveling Osteotomy on Femorotibial Contact Mechanics and Stifle Kinematics

Objective— To evaluate the effects of tibial plateau leveling osteotomy (TPLO) on femorotibial contact mechanics and 3-dimensional (3D) kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs.
Study Design— In vitro biomechanical study.
Animals— Unpaired pelvic limbs from 8 dogs, weighing 28–35 kg.
Methods— Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TPLO-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test ( P <.05) was used for statistical comparison.
Results— Significant disturbances to all measured contact mechanical variables were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and increased internal tibial rotation in the CrCL-deficient stifle. No significant differences in 3D femorotibial alignment were observed between normal and TPLO-treated stifles; however, femorotibial contact area remained significantly smaller and peak contact pressures in both medial and lateral stifle compartments were positioned more caudally on the tibial plateau, when compared with normal.
Conclusion— Whereas TPLO eliminates craniocaudal stifle instability during simulated weight bearing, the procedure fails to concurrently restore femorotibial contact mechanics to normal.
Clinical Relevance— Progression of stifle osteoarthritis in dogs treated with TPLO may be partly the result of abnormal stifle contact mechanics induced by altering the orientation of the proximal tibial articulating surface.     

Use of a four pin and methylmethacrylate fixation in L7 and the iliac body to stabilize lumbosacral fracture-luxations: a clinical and anatomic study

Objectives— To describe the clinical outcome of a 4 pin lumbosacral fixation technique for lumbosacral fracture–luxations, and to refine placement technique for iliac pins based on canine cadaver studies.
Study Design— Retrospective and anatomic study.
Sample Population— Dogs (n=5) with lumbosacral fracture-luxations and 8 cadaveric canine pelvi.
Methods— Lumbosacral fracture–luxations were stabilized with a 4 pin (positive-profile threaded) and bone cement fixation. Caudal pins were inserted in the iliac body and cranial pins were inserted into the L7 or L6 pedicle and body. Follow-up examinations and radiographs were performed to assess patient outcome. Intramedullary pins were inserted into the iliac bodies of 8 cadaver pelvi. Radiographs were taken to measure pin insertion angles and define ideal insertion angles that would maximize pin purchase in the ilium.
Results— Follow-up neurologic examination was normal in 4 dogs. Radiographic healing of the fracture was evident in 5 dogs. One implant failure occurred but did not require re-operation. For cadaver iliac pins, mean craniocaudal insertion angle was 29° and mean lateromedial insertion angle was 20°.
Conclusions— Four pin and bone cement fixation effectively stabilizes lumbosacral fracture luxations. The iliac body provides ample bone stock, which can be maximized using an average craniocaudal pin trajectory of 29° and an average lateromedial pin trajectory of 20°.
Clinical Relevance— Lumbosacral fracture–luxations can be stabilized with 4 pin and bone cement fixation in the lumbar vertebrae and iliac body, using 29 and 20° as guidelines for the craniocaudal and lateromedial pin insertion angles in the ilium.     

Evaluation of a Collagenase Generated Osteoarthritis Biomarker in Naturally Occurring Canine Cruciate Disease

Objective— To determine the clinical value of a novel osteoarthritis (OA) biomarker in detecting canine cruciate disease.
Study Design— Cross sectional clinical study.
Animals— Dogs (n=22) with cranial cruciate ligament (CCL) rupture and 12 control dogs.
Methods— Concentrations of collagenase-generated cleavage epitope of type II collagen (Col2-3/4C_{long mono}, or C2C) in serum, urine, and joint fluid were compared between a group of dogs with CCL rupture and a control group. Correlation of C2C concentrations to the clinical stage of stifle OA was also evaluated.
Results— There were no significant differences in C2C concentrations in serum, urine, and joint fluid between groups ( P >.05). Subjective scores of lameness, joint effusion, osteophytosis were significantly more severe in the CCL rupture group compared with the control group ( P <.05). There was no significant correlation of C2C concentrations with clinical stage of stifle OA ( P >.05).
Conclusion— This OA biomarker did not detect pathology associated with CCL rupture. Our results suggest that collagenase-specific degradation of type II collagen in articular cartilage may not be involved in the early stage of naturally occurring canine cruciate disease, and that pathology associated with naturally occurring CCL rupture is different from that of experimental OA model.
Clinical Relevance— C2C is not clinically useful in detecting CCL rupture in dogs.     

Risk factors for ventral luxation in canine total hip replacement

Objective— To identify risk factors associated with ventral luxation (VL) of canine total hip replacement (THR), and outcome.
Study Design— Retrospective study.
Animals— Dogs (n=602) that had THR (563 cemented, 35 cementless, 4 hybrid).
Methods— Dogs (1999–2004) with VL after THR were compared with dogs with uncomplicated THR. Data included signalment, body weight, diagnosis, implant size, acetabular cup orientation, and femoral displacement ratio (FDR).
Results— VL was diagnosed in 11 (1.8%) dogs after primary THR. Including 2 other dogs that had VL after the study period, 10 (77%) of 13 dogs had VL within 7 days of surgery. Risk factors for VL included Saint Bernard-type dogs ( P =.0001), short neck extension ( P =.0005), and high angle of lateral opening in other breeds ( P =.018). There were trends toward higher risk of VL with lower FDR in Saint Bernardtypes ( P =.060), and with cementless implants ( P =.061). Twelve dogs had revision arthroplasty that was successful in all cementless and 2 cemented VL cases. Five dogs had recurrent VL and a poor outcome.
Conclusion— VL is generally an early complication of THR, with no single common risk factor identified.
Clinical Relevance— Saint Bernard types and short neck extensions are associated with increased risk of VL. Poor cup orientation is a determining factor for VL in some dogs, but a protective orientation of the acetabular cup was not found. Revision is successful in most dogs, but recurrent VL merits a guarded prognosis.