A New Generation of Osteochondral Autograft Transfer System for the Treatment of Osteochondritis Dissecans of the Femoral Condyle: Clinical Experience in 18 Dogs.

OBJECTIVES: The aim of this study was to describe the clinical application and outcome of osteochondral autograft transfer using the COR system (COR; DePuy Synthes, Warsaw, Indiana, United States) for the treatment of osteochondritis dissecans (OCD) of the femoral condyle in dogs. METHODS: Medical records of dogs that were treated for OCD of the femoral condyle using the COR system between February 2013 and March 2020 were retrospectively reviewed. The results of pre- and postoperative clinical and radiographic examinations were evaluated. RESULTS: Twenty stifles (18 dogs; 15 lateral and 5 medial femoral condyles) met the inclusion criteria. A single graft transfer was done in six stifle joints and mosaicplasty in 14 (2 grafts in 9/14 stifles; 3 grafts in 5/14 stifles). Proper anatomic reconstruction was confirmed intraoperatively and radiographically in all dogs. There were no major and three minor postoperative complications. At 3 months, 15 of 20 stifles (14 of 18 dogs) had no lameness or radiographic signs of inflammation. At 6 months, 12 of 13 dogs had no lameness or discomfort, and four of 13 stifles had radiographic evidence of moderate osteoarthritis. CLINICAL SIGNIFICANCE: Treatment of OCD of the femoral condyle using the COR system is feasible in dogs, with low complications and provides a satisfactory short-term outcome.

Postoperative Complications of Double Pelvic Osteotomy Using Specific Plates in 305 Dogs.

OBJECTIVE: The aim of this clinical retrospective study was to describe the postoperative complications and associated factors of double pelvic osteotomy (DPO) using DPO plates. MATERIALS AND METHODS: Medical records were searched for dogs that underwent unilateral or bilateral DPO using DPO plates from February 2009 to October 2018 and were re-evaluated for a minimum of 1 to 2 months postoperatively. A variety of commercially available, specific DPO plates were used. Complications were determined during the immediate postoperative period and at the time of the clinical and radiographic re-evaluations done 1 and/or 2 months postoperatively. RESULTS: A total of 458 DPO (226 right, 232 left) performed in 305 dogs satisfied the inclusion criteria. Double pelvic osteotomy plates from eight different manufacturers were used: Fixin (n = 160), Kyon (n = 154), New Generation Device (n = 63), Hofmann (n = 61), Veterinary Instrumentation (n = 12), DePuy Synthes (n = 4), Porte (n = 3) and Koenigsee (n = 1). Mean age of the dogs was 6.2 months (range: 5-8 months), and the body weight ranged from 10 to 47 kg. Overall, a total of 42 complications occurred in 38 DPO (8.2%). Complications included greenstick fracture of the ischium in 14 DPO (3%), isolated screw loosening in 13 DPO involving 16 of a total of 2,947 screws (0.5%), isolated screw breakage in 4 DPO involving 5 of 2,947 screws (0.1%), incomplete ilium fracture in 3 DPO (0.6%), partial caudal plate avulsion in 3 DPO (0.6%), iatrogenic sciatic neuropraxia in two DPO (0.4%), suspected surgical site infection (SSI) in 1 DPO (0.2%) and persistent pain and lameness caused by the implant in 2 DPO (0.4%). The case of suspected SSI and the two cases of persistent pain were classified as major complications (3 DPO, 0.6%), requiring medical and surgical intervention, respectively, whereas other 39 complications in 35 DPO were classified as minor, not requiring treatment (7.6%). CONCLUSION: Double pelvic osteotomy using DPO plates appears to be a safe surgical option for the treatment of hip dysplasia in growing dogs; no catastrophic complications were reported and the incidence of complications (0.6% major complications and 7.6% minor complications) was low. This study showed that DPO using DPO plates and proper technique was safe in 92% of cases. The only two factors found to be significantly associated with the development of complications after DPO were the laterality (left-sided or right-sided) and body weight.

Hemiepiphysiodesis for the Correction of Distal Femoral Valgus in Growing Dogs.

OBJECTIVES: The aim of this study was to describe hemiepiphysiodesis for the treatment of distal femoral valgus in immature dogs and to evaluate its effect on the anatomical lateral distal femoral angle (aLDFA). METHODS: Skeletally immature dogs with distal femoral valgus deformities that had undergone hemiepiphysiodesis between November 2012 and March 2020 at two private veterinary practices were included. Criteria for inclusion in the study were a preoperative aLDFA below the previously published reference range (94 ± 3.3 degrees) and radiographs of the femur taken preoperatively and at growth plate closure. RESULTS: A total of 11 dogs fulfilled the inclusion criteria, and a total of 17 limbs were treated. The mean aLDFA was 82.1 ± 3.2 degrees (range: 76-87 degrees) preoperatively and 93.1 ± 5 degrees (range: 76-99 degrees) at the final re-evaluation. The mean difference between the preoperative and final aLDFA was +11 degrees, which was significant. Undercorrection occurred in 2/17 cases, whereas overcorrection was not recorded. The implants were removed in 12/17 cases, and rebound growth occurred in 3 of these. CLINICAL SIGNIFICANCE: Hemiepiphysiodesis for the treatment of distal femoral valgus is a technique that allows for increase in aLDFA and should be considered as an early treatment in affected immature dogs. Monitoring for possible overcorrection using serial radiography is important. Implant removal when the desired aLDFA has been achieved is recommended because the incidence of rebound growth is uncommon in dogs.

Comparison of tibial anatomical-mechanical axis angles and patellar positions between tibial plateau levelling osteotomy (TPLO) and modified cranial closing wedge osteotomy (AMA-based CCWO) for the treatment of cranial cruciate ligament disease in large dogs with tibial plateau slopes greater than 30° and clinically normal Labradors retrievers.

BACKGROUND: The objective of this study was to evaluate tibial anatomical-mechanical axis angles (AMA-angles) and proximodistal and craniocaudal patellar positions following tibial plateau levelling osteotomy (TPLO) and AMA-based modified cranial closing wedge osteotomy (CCWO) in large dogs with tibial plateau angle (TPA) > 30°, to compare these postoperative positions with those of a control group of healthy normal dogs, and to assess which procedure yields postoperative morphology of the tibiae and stifles that is most consistent with that of the unaffected group. This study also investigated whether the occurrence of patellar ligament thickening (PLT), which is commonly observed 2 months postoperatively after TPLO, is associated with misplacement of the osteotomy. A total of 120 dogs weighing more than 20 kg, 40 of which were control animals, were enrolled in this retrospective study. Stifles were radiographically evaluated preoperatively and postoperatively on the side with CCLR and on the healthy contralateral side and compared with clinically normal stifles. PLT was reassessed after 2 months. RESULTS: Significant decreases in median patellar height ratio were found after both procedures (TPLO 0.24 (0.05-0.8); CCWO 0.22 (0.05-0.4)). The postoperative craniocaudal patellar position and the median AMA angle differed significantly among the groups (P = 0.000) (TPLO 87.5% caudal to the AA and 3.12° (0.76-6.98°); CCWO 100% cranial to the AA and 0° (- 1.34-0.65°); control group 5% caudal to the AA and 0.99° (0-3.39°)). At 8 weeks, PLT grade differed significantly in the two operated groups (P = 0.000) (TPLO 40% 0-2, 20% 2-4, 40% > 4; CCWO 98.8% 0). CONCLUSIONS: TPLO and AMA-based CCWO are associated with significant decreases in patellar height; however, the PLT results 2 months postoperatively differed between the two groups; the decrease in patellar height and PLT were independent of osteotomy position in the TPLO group. Compared to TPLO, CCWO results in reduced postoperative AMA angles and craniocaudal patellar positions that more closely resemble those of unaffected dogs, suggesting that the CCWO procedure allows us to better correct the caudal bowing of the proximal tibia that is often associated with deficient stifles in large dogs with TPA > 30°.

Zürich cementless total hip arthroplasty as a treatment option for capital physeal fractures in dogs: Outcome in 53 cases.

OBJECTIVE: To review the outcome of dogs that underwent Zürich cementless total hip arthroplasty (Z-THA) for the repair of acute and chronic capital physeal fractures (CPF) and document the CPF-related hip remodeling. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Fifty-three Z-THA in 53 dogs. METHODS: Medical records of dogs (2006-2019) that underwent Z-THA for CPF management were reviewed. Dogs were divided into two groups on the basis of the days elapsed between CPF diagnosis and Z-THA, acute (≤30 days) and chronic (>30 days). Hip remodeling variables were determined from preoperative radiographs or intraoperatively. Descriptive statistics were performed, and the complication rates, outcome, and coxofemoral remodeling were recorded. Comparisons of remodeling variables and rates between groups were performed by using Fisher's exact test. RESULTS: In total, 23 of 53 (43.4%) cases were acute, and 30 of 53 (56.6%) cases were chronic. There was no difference in the femoral remodeling rates between the acute and chronic groups (P = .184), whereas acetabular remodeling was more prevalent in the chronic group (P < .001). Intraoperative complications occurred in four of 53 (7.5% [1/23 acute, 3/30 chronic]) cases, and postoperative complications occurred in six of 53 (11.3% [2/23 acute, 4/30 chronic]) cases. Good clinical outcomes were achieved in 51 of 53 (96.2% [21 acute, 30 chronic]) cases. CONCLUSION: Complication rates of Z-THA for CPF repair were similar to the complication rates reported for Z-THA of dysplastic hips. Hip remodeling was common regardless of CPF chronicity. CLINICAL SIGNIFICANCE: Zürich cementless total hip arthroplasty is viable for surgical management of CPF. There is a high likelihood that hip remodeling will be encountered, even in fractures treated within 30 days of presenting for hind limb lameness.

A Modification of the Cheli Craniolateral Approach for Minimally Invasive Treatment of Osteochondritis Dissecans of the Shoulder in Dogs: Description of the Technique and Outcome in 164 Cases.

OBJECTIVE: The aim of this study was to describe a novel minimally invasive surgical approach for the treatment of shoulder osteochondritis dissecans (OCD) in dogs and to retrospectively review our clinical cases treated with this approach. STUDY DESIGN: The study describes a modification of Cheli surgical approach (1985), developed to reduce the degree of invasiveness as well as the incidence of postoperative complications observed in other surgical approaches to the shoulder joint. Medical records of dogs that underwent our minimally invasive approach to the scapulohumeral joint for treatment of OCD from May 2001 to May 2019 were retrospectively reviewed for intraoperative findings and complications. Clinical outcome and complications were also evaluated in the operated dogs with a minimum of a 2-month-follow-up evaluation. RESULTS: A total of 164 shoulders in 141 dogs (23 bilateral), 103 males and 38 females, were examined and treated with our modified craniolateral approach for the treatment of OCD of the humeral head. In all cases, the modified craniolateral approach allowed visibility and adequate exposure of the caudal humeral head surface. Radiographic and clinical follow-up evaluations were available in 123/164 (75%) cases. The clinical outcome was consistent with other reports using different surgical approaches for OCD lesions of the humeral head in dogs. CLINICAL SIGNIFICANCE: This technique provided a reliable approach for surgical treatment of canine shoulder OCD and can be considered a valid alternative to other surgical approaches including arthroscopy.

Use of a Modified Tibial Plateau Levelling Osteotomy with Double Cut and Medial Crescentic Closing Wedge Osteotomy to Treat Dogs with Cranial Cruciate Ligament Rupture and Tibial Valgus Deformity.

OBJECTIVE: The aim of this study was to report efficacy of a modified tibial plateau levelling osteotomy (TPLO) with double cut and medial crescentic closing wedge osteotomy (TPLO/MCCWO) to treat dogs with cranial cruciate ligament rupture and concurrent tibial valgus. STUDY DESIGN: This study was a cases series. MATERIALS AND METHODS: Medical records of dogs that had TPLO with medial crescentic closing wedge osteotomy were reviewed. Data collected included signalment, body weight, pre- and postoperative tibial valgus angle, tibial plateau angle (TPA), surgical planning, corrective osteotomy technique, method of fixation, complications, and length of time to radiographic healing. RESULTS: Fifty-two surgical procedures performed in 45 dogs (7 bilateral) were included in the study. Mean age at surgery was 54 months, and body weight ranged from 5 to 63 kg (mean: 36.5 kg). Mean pre- and postoperative mechanical medial proximal tibial angle were 101° (98°-107°) and 92.80° (88°-97°) respectively. The mean pre- and postoperative TPA were 27.80° (16-35°) and 6.50° (3-11°) respectively. Intraoperative complications occurred in two stifles: in one stifle over-rotation of the proximal tibial segment resulted in a TPA of -8°, with immediate revision to a 5° TPA; in the second stifle a fissure of the lateral tibial cortex developed during insertion of a screw and required adjunctive fixation. No postoperative complications were recorded and all osteotomies healed uneventfully. CONCLUSIONS: Tibial plateau levelling osteotomy/medial crescentic closing wedge osteotomy is an effective treatment for dogs with cranial cruciate ligament rupture and tibial valgus allowing accurate correction of the tibial deformity with a low complication rate.

Kirschner wire fixation of Salter-Harris type IV fracture of the lateral aspect of the humeral condyle in growing dogs. A retrospective study of 35 fractures.

OBJECTIVES: To evaluate the use of Kirschner wires for treatment of fractures of the lateral aspect of the humeral condyle in growing dogs. METHODS: Retrospective analysis of 35 elbow fractures (33 dogs) of the lateral aspect of the humeral condyle treated by insertion of multiple transcondylar and one anti-rotational Kirschner wires. Radiographic and clinical re-evaluations were carried out immediately after surgery, at four weeks and, when required, at eight weeks postoperatively. Long-term follow-up was planned after a minimum of six months. The relationship between different implant configurations and clinical outcome was analysed statistically. RESULTS: Complete functional recovery was seen in 31 elbows (30 dogs), three elbows (2 dogs) had reduction in the range of motion, and one elbow (1 dog) had persistent grade 1 lameness two months postoperatively. Major complications occurred in eight elbows (8 dogs) and all were resolved by implant removal. Implant configuration did not affect outcome. Long-term evaluation in 12 cases with a mean follow-up of four years showed absence of lameness, normal function and no or mild radiographic evidence of osteoarthritis in 11 cases. CLINICAL SIGNIFICANCE: Fracture of the lateral aspect of the humeral condyle in growing dogs can be successfully treated by multiple transcondylar convergent or parallel Kirschner wires, resulting in adequate fracture healing.

Revision of a BFX total hip replacement stem using a Kyon stem and a head adaptor in two dogs.

OBJECTIVE: To report revision of BFX cementless press-fit stem loosening with a Kyon cementless stem and a head adaptor in two dogs. METHODS: Total hip arthroplasty stem revision was performed in two dogs with loosening of a previously implanted Biomedtrix press-fit BFX stem. Both dogs had a well-integrated BFX cup and single stage revision was performed using a standard Kyon stem and a head adaptor in order to couple with a 17 mm head and maintain the BFX cup. RESULTS: Revisions resulted in a stable functional prosthesis with successful bone integration at the one-year postoperative re-evaluation. CONCLUSIONS: Use of a Kyon stem with a head adaptor may be a successful option to provide immediate stem stability for revision of a loosened BFX stem with a properly osseointegrated cup.

Hemiepiphysiodesis for the correction of proximal tibial valgus in growing dogs.

OBJECTIVES: To describe the use of hemiepiphysiodesis for the treatment of proximal tibial deformities in immature dogs and evaluate the effect on the mechanical medial proximal tibial angle (mMPTA). METHODS: Skeletally immature dogs with proximal tibial deformities from three institutions treated with hemiepiphysiodesis between March 2006 and January 2015 were included. All dogs were required to have an mMPTA outside the previously published reference range (93.3 ± 1.78°) preoperatively. Dogs were required to have radiographs or computed tomography performed preoperatively and at least eight weeks postoperatively. RESULTS: A total of 19 dogs (n = 31 limbs) fulfilled the inclusion criteria. The mean mMPTA was 102.5° ± 5.3° preoperatively and 92.4° ± 7.2° at the final re-evaluation. The mean difference in mMPTA was -10 ± 5.1° (range, -1 to -19°; p <0.001). Overcorrection was observed in 16 limbs and mMPTA remained above the reference range in nine limbs. Rebound growth was observed in eight limbs where implant removal was performed. CLINICAL SIGNIFICANCE: Hemiepiphysiodesis for the treatment of proximal tibial valgus is a technique that allows for reduction in mMPTA and should be considered as an early treatment for immature animals that are presented with proximal tibial deformities. Serial radiographs to monitor for overcorrection should be performed. Implant removal should be considered if overcorrection occurs, taking into consideration that rebound growth may be observed.

Central tarsal bone fracture in a cat.

Fracture of the central tarsal bone is an uncommon injury in dogs and occurs predominantly in racing Greyhounds. To the authors' knowledge, this type of fracture has not been described previously in cats. This case report describes a five-year-old Domestic Shorthair cat referred to the Centro Veterinario Luni Mare because of lameness, swelling and signs of pain in the right hindlimb caused by trauma. Clinical examination and diagnostic imaging revealed a right central tarsal bone fracture. Open reduction and internal fixation with a 2.0 mm position screw and two 0.8 mm Kirschner wires were carried out. The last follow-up examination three years postoperatively found the cat in good health with normal range of motion and function, and no signs of lameness in the right hindlimb.

Long-Term Outcome of Zürich Cementless Total Hip Arthroplasty in 439 Cases.

OBJECTIVE: To review complications in dogs with the Zürich cementless total hip arthroplasty (Z-THA) with ≥ 2 year followup, and compare complications between juvenile and adult dogs classified by age (≤ 11 and > 11 months) at the time of original surgery. STUDY DESIGN: Retrospective case series. ANIMALS: Three hundred and twenty-one dogs with 439 total hip arthroplasties. METHODS: Medical records were reviewed from January 2002 to December 2007. Signalment, body weight and body condition score, implant size and positioning, and any complications were recorded. A step-up logistic regression analysis was performed for an outcome of any complication (yes/no). Predictors included were implant size, implant position, weight and body condition score before surgery, weight and body condition score change after surgery, breed, sex, and age. RESULTS: Four hundred and thirty-nine Z-THA were performed in 321 dogs. Mean (standard deviation) age was 8.5 (1.5) months, range 4.5-11 and 53.3 (31.2) months, range 12-132, for juvenile and adult dogs, respectively. Followup extended for a mean 47.8 (20.0) and 42.0 (13.5) months for juvenile and adults dogs, respectively, with complications recorded in 20% and 13% of Z-THA, respectively. All hips were successfully revised except for 2 explants in juvenile dogs and 2 in adult dogs. There were no statistical differences in the frequency of complications between juveniles or adult dogs, but the type of complication did appear to be different. From the logistic model, the probability of a complication increased with an increase in body condition score after surgery (P < .0001) and with an increase in the pre-surgery body condition score (P = .05), and decreased with an increase in weight after surgery (P = .05). CONCLUSION: The frequency of complications was less than 20% in juvenile and adult dogs and the frequency was not different across age groups. Complications were primarily related to the change (increase) in body condition score after surgery. Revision was successful in almost all dogs.

Lateral caudal axial pattern flap in 13 dogs.

OBJECTIVE: To describe the frequency and extent of complications associated with lateral caudal axial pattern flaps used to cover large traumatic or excision skin defects on the dorsum, gluteal, and perineal region in 13 dogs. STUDY DESIGN: Case series. ANIMALS: Thirteen client-owned dogs. METHODS: Medical records from 8 institutions were reviewed for dogs treated with a lateral caudal axial pattern flap, including cases in which the procedure was combined with other reconstructive techniques. The flap length relative to the tail length, location of tail skin incision, size and cause of the defect, and short- and long-term complications were recorded. RESULTS: Thirteen dogs were included, 11 with tumors and 2 with traumatic skin loss. The mean estimated length of the flap relative to tail length was 51% (range 33-70%). Four dogs had wound complications. This included 2 dogs with minor postoperative wound complications (mild distal dehiscence) that did not require surgical revision and 2 dogs with major complications that required surgical revision. Two of these 4 dogs had distal flap necrosis, one was revised surgically and one was managed conservatively. In these 2 dogs, the flap length was estimated as 80% and 65% of the tail length, respectively. At 30 days, flaps in all dogs were completely healed. No long-term complications were recorded in any dog. For some dogs, the reconstruction was not obvious, with only the change in hair direction and color noticeable. CONCLUSION: Lateral caudal axial pattern flap is a reconstructive option for gluteal, dorsal, and perineal skin defects in dogs. Distal flap necrosis and dehiscence due to wound infection occurred in 4 dogs that required additional wound care but not always surgical revision.

Limitations of the cancer stem cell theory.

Cancer stem cells (CSCs) can be operationally defined as a subset of neoplastic cells which are responsible for the growth and re-growth of primary and metastatic tumors. Although the existence of perpetually dividing cells is a logical necessity to explain the malignant properties of human tumors, experimental data supporting their existence have only recently been obtained. New knowledge in basic stem cell biology and the availability of several cell surface markers for the definition and isolation of small subsets of immature cells coupled to the use of the classical model of xenotransplantation in immune deficient mice has identified putative CSCs in several solid tumors such as mammary, colon, brain, pancreas, prostate, melanoma and others. However, the theory must be considered as still in its infancy, since tumors grown in mice only partially recapitulate the biology of human cells. In addition, whether the "transformed" cell is the neoplastic counterpart of a normal stem cell or whether complete malignant behaviour can occur in a more differentiated cell has still to be demonstrated. In spite of these difficulties, the CSC hypothesis could be of clinical relevance, especially in the definition of new ways to assay drug sensitivity of primary human tumors.