The function of the popliteal muscle and tendon in horses remains undescribed. In humans, it is considered a stabilizer of the posterior-lateral region of the knee; its function is closely related to that of the lateral collateral ligament (LCL) and meniscus. The popliteal tendon (PopT) constitutes the main proximal attachment of the popliteus muscle to the femur, and in humans, insertional variations have been described. Knowledge of anatomical variations is needed for the correct interpretation of diagnostic images and arthroscopic findings. To elucidate further the anatomy of the equine PopT, both hind limbs of 30 horses were dissected. Similar to humans, the equine PopT has 3 variants (types I, II, and III) depending on the number of components forming the tendon. Additionally, the area of insertion varies; the location can be either cranial, underneath, or caudal to the proximal insertion of the LCL. Furthermore, the PopT has a constant attachment to the lateral meniscus. The results of the present study are useful for clinicians working with equine orthopedics, as the tendon and insertional variants could affect the interpretation of diagnostic images and arthroscopic examinations.
Anatomic Variation ; Extremities ; Femur ; Horses ; Humans ; Knee ; Lateral Ligament, Ankle ; Menisci, Tibial ; Orthopedics ; Stifle ; Tendons

Cranial cruciate ligament (CCL) rupture is one of the most common orthopedic conditions in dogs. The pathogenesis of CCL rupture is not fully described and remains to be elucidated fully. Several hypotheses have been proposed to explain the etiology of these changes. The objective of this study was to investigate structural changes in the CCL in relation to the tibial plateau angle (TPA) and the intercondylar notch (ICN) width in dogs. Fifty-five skeletally mature dogs were included in this study. ICN width and TPA measurements were obtained from intact CCL stifles. Samples of the CCL, caudal cruciate ligament (CaCL), and femoral head ligament (FHL) were harvested and stained for routine histological and immunohistochemical analysis. Microscopic changes in the ligaments were observed and were found to correlate with the TPA and ICN width values. The degree of structural changes within the CCL was observed to correlate with an increasing TPA and a narrowing ICN width. Changes in the CCL are likely to be caused by excessive forces acting through the ligament in stifles with a high TPA. Chondroid metaplasia of the CCL is an adaptation to abnormal mechanics within the stifle joint caused by altered bone morphology.
Animals ; Anterior Cruciate Ligament ; Arthritis ; Dogs ; Head ; Joints ; Ligaments ; Mechanics ; Metaplasia ; Orthopedics ; Rupture ; Stifle

Arthroscopy has become an attractive modality in the diagnosis and treatment of joint diseases in toy breed dogs. However, the application of arthroscopy is limited by small joint space. Our objective was to evaluate the efficacy of a stifle lever for joint distraction during stifle arthroscopy in toy breed dogs. Paired stifles (n = 32 each) collected from 16 cadavers of toy breed dogs were randomly assigned to one of two groups: the stifle lever group or the external manipulation group. All stifles underwent arthroscopic cranial cruciate ligament transection, and the visualization of the medial meniscus was evaluated. Medial meniscal release (MMR) was then performed. Following arthroscopic examination, the success rates of MMR and damages of tibial and femoral cartilages were evaluated. Visualization of the medial meniscus was significantly better, and meniscal probing was significantly easier, in the stifle lever group than in the external manipulation group (p = 0.001). There were no significant differences between groups for MMR success or articular cartilage damage. Using the stifle lever on arthroscopic examination improved visualization and probing on the medial meniscus in toy breed dogs. The stifle lever can be used as a good modality in assessing medial meniscal pathology in toy breed dogs.
Animals ; Anterior Cruciate Ligament ; Arthroscopy ; Cadaver ; Cartilage ; Cartilage, Articular ; Diagnosis ; Dogs ; Joint Diseases ; Joints ; Menisci, Tibial ; Pathology ; Play and Playthings ; Stifle

Age-related involution in dogs involves loss of muscle mass and changes in connective tissue and articular cartilage. The aim of this study was to examine whether an age-related influence on joint mobility can be detected in the absence of disease. Five young (mean age 2.0 years) and five old (mean age 10.4 years) healthy and sound Beagle dogs underwent computer-assisted gait analysis during locomotion on a treadmill. Shoulder, elbow, carpal, hip, stifle, and tarsal joint angles including joint angle progression curves, minimum and maximum joint angles, and range of motion (ROM) in degrees were analyzed. The old group had a smaller maximum joint angle (p = 0.037) and ROM (p = 0.037) of the carpal joint; there were similar tendencies in the shoulder, elbow, and carpal joints. Descriptive analysis of the progression curves revealed less flexion and extension of the forelimb joints. The results indicate restricted joint mobility of the forelimb in old dogs, primarily of the carpal joint. Results in the joints of the hindlimb were inconsistent, and the contrasting alterations may be due to a compensatory mechanism. As most alterations were found in the distal joints, these should receive particular attention when examining elderly dogs.
Aged ; Animals ; Carpal Joints ; Cartilage, Articular ; Connective Tissue ; Dogs* ; Elbow ; Forelimb ; Gait* ; Geriatrics ; Hindlimb ; Hip ; Humans ; Joints ; Locomotion ; Range of Motion, Articular ; Shoulder ; Stifle ; Tarsal Joints

The goal of the present study was to evaluate the diagnostic value of a joint distractor in arthroscopy in small-breed dogs. Sixty stifle joints, which were collected from thirty cadavers, were used in this study. To simulate different injuries, no medial meniscal tear, a full-thickness vertical longitudinal tear, a partial-thickness vertical longitudinal tear, full- and partial-thickness vertical longitudinal tears, or a peripheral detachment were created on the caudal horn of the medial meniscus of each stifle joint along with rupture of the cranial cruciate ligament. Each stifle joint then underwent arthroscopy with and without a joint distractor. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and correct classification rate (CCR) for the diagnosis of each type of medial meniscus pathology were calculated. For arthroscopy with and without a joint distractor, the Sn was 85% and 60%, the Sp was 96% and 92%, the PPV was 85% and 65%, the NPV was 96% and 90%, and the CCR was 94% and 86%, respectively. Arthroscopy is an effective diagnostic method for the assessment of medial meniscal pathologies in small-breed dogs, especially when performed with the aid of a joint distractor.
Animals ; Anterior Cruciate Ligament ; Arthroscopy ; Cadaver ; Classification ; Diagnosis ; Dogs* ; Horns ; Joints* ; Menisci, Tibial ; Methods ; Pathology ; Rupture ; Sensitivity and Specificity ; Stifle ; Tears

In November 2013, the US Food and Drug Administration (FDA) sent a warning letter to 23andMe, Inc. and ordered the company to discontinue marketing of the 23andMe Personal Genome Service (PGS) until it receives FDA marketing authorization for the device. The FDA considers the PGS as an unclassified medical device, which requires premarket approval or de novo classification. Opponents of the FDA's action expressed their concerns, saying that the FDA is overcautious and paternalistic, which violates consumers' rights and might stifle the consumer genomics field itself, and insisted that the agency should not restrict direct-to-consumer (DTC) genomic testing without empirical evidence of harm. Proponents support the agency's action as protection of consumers from potentially invalid and almost useless information. This action was also significant, since it reflected the FDA's attitude towards medical application of next-generation sequencing techniques. In this review, we followed up on the FDA-23andMe incident and evaluated the problems and prospects for DTC genetic testing.
Classification ; Genetic Testing* ; Genome ; Genomics ; Human Rights ; Humans ; Marketing ; Stifle ; United States Food and Drug Administration

Thirty-one dogs with patellar luxation (grades 2 and 3) were categorized into three groups. Group 1 (G.1; n = 12) had sodium hyaluronate (SHA) intra-articularly injected into the stifle joint that received surgery. Group 2 (G.2; n = 10) received SHA twice: first after surgery and then 1 week later. Group 3 (G.3; n = 9) served as a control, without injection. Blood was collected before injection and then once a week for 4 weeks after injection for evaluation of chondroitin sulfate (CS-WF6) and hyaluronan (HA). The results revealed significantly (p < 0.05) improved clinical scores by the end of week 4 in G.1 and G.2 relative to G.3; however, there was no significant difference between G.1 and G.2. There was a significant decrease (p < 0.05) in serum CS-WF6 levels beginning at week 2 in G.1 and G.2. At weeks 3 and 4, serum HA in G.1 and G.2 differed from that in G.3 (p < 0.05). No significant difference (p > 0.05) was observed in serum biomarkers between G.1 and G.2. In conclusion, intra-articular injection with SHA after joint surgery may improve homeostasis of the joint, retarding the process of OA.
Animals ; Blood Chemical Analysis/veterinary ; Chondroitin Sulfates/metabolism ; *Dogs ; Dose-Response Relationship, Drug ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Hyaluronic Acid/*administration & dosage/metabolism ; Injections, Intra-Articular/veterinary ; Male ; Osteoarthritis, Knee/drug therapy/prevention & control/*veterinary ; Stifle/*surgery ; Viscosupplements/*administration & dosage

A-7-month-old, intact male Shih-Tzu dog was referred with facial dermatitis and stifle pain with 7 days duration. Erythema, hemorrhage, and crusted nodular lesions of the face, swollen eyelids, and otitis externa were observed. A painful response was noted on palpation of the right stifle joint. Impression smears and skin biopsies revealed pyogranulomatous inflammation consistent with canine juvenile cellulitis (CJC). Skin lesions and pain were greatly improved following immunosuppressive corticosteroid therapy. This report firstly describes clinical and histopathological findings as well as treatment responses of CJC in a 7-month-old, domestic dog.
Animals ; Biopsy ; Cellulitis* ; Dermatitis ; Dogs* ; Erythema ; Eyelids ; Hemorrhage ; Humans ; Infant* ; Inflammation ; Joints ; Male ; Otitis Externa ; Palpation ; Skin ; Stifle

The purpose of this study was to evaluate a new extracapsular surgical technique for the treatment of cranial cruciate ligament rupture in small breed dogs. Nine small breed dogs (seven females and two males) weighing < or = 15 kg were treated with biceps femoris muscle transposition (BFT). The duration of the BFT procedure was 20 min. Each patient underwent a standard clinical protocol and a questionnaire for the owners. Follow-up (at 1, 3, and 12 months postoperative) confirmed significant improvement in all patients, especially at 1 month postoperatively (p < 0.01) and again after complete stifle joint assessment at 3 months postoperatively. After 12 months, only two patients showed a slight increase in osteoarthritis. According to our results, BFT is a simple extracapsular surgical technique that can be used for the treatment of cranial cruciate ligament rupture in small breed dogs.
Animals ; Anterior Cruciate Ligament/*injuries/*surgery ; Dog Diseases/*surgery ; Dogs ; Female ; Male ; Muscle, Skeletal/*transplantation ; Questionnaires ; Rupture/veterinary ; Stifle/*surgery

The levels of tartrate resistant acid phosphatase (TRAP), matrix metalloproteinase-2 (MMP-2), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in synovial fluid (SF) and serum in cases of canine osteoarthritis (OA) were measured. OA was induced by a surgically-created medial patellar luxation in the left stifle of 24 dogs. SF and blood samples were collected at 1.5- and 3-month intervals, respectively. Every 3 months, one dog was euthanatized to collect tissue samples from both stifles. TRAP levels in SF and serum were measured using a spectrophotometer, and TRAP-positive cells in joint tissues were identified by enzyme histochemistry. MMP-2 and TIMP-2 in SF and serum were detected by Western blotting and ELISA, respectively. TRAP in SF from the stifles and serum was significantly increased (p < 0.05) after 3 months. TIMP-2 in SF and serum was significantly decreased (p < 0.05), whereas MMP-2 in SF was significantly increased (p < 0.05) during the progression of OA. Histochemistry revealed an increased number of TRAP-positive cells in tissues from OA-affected joints. Assays measuring TRAP, MMP-2, and TIMP-2 in SF and serum, and methods that detect increased numbers of TRAP-positive cells in the joint tissues can play an important role in identifying the early phases of degenerative changes in canine joint components.
Acid Phosphatase/analysis/blood ; Animals ; Arthritis, Experimental/enzymology/etiology/veterinary ; Biological Markers/*analysis/*blood ; Blotting, Western/veterinary ; Dislocations/complications/*veterinary ; Dog Diseases/*enzymology/etiology ; Dogs ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Isoenzymes/analysis/blood ; Male ; Matrix Metalloproteinase 2/analysis/blood ; Osteoarthritis/enzymology/etiology/*veterinary ; Spectrophotometry/veterinary ; Stifle/physiopathology ; Synovial Fluid/*enzymology ; Tissue Inhibitor of Metalloproteinase-2/analysis/blood