Intra- and extra-articular primary synovial chondromatosis (SC) was observed in a five-year-old, entire male German Shepherd. Thousands of small cartilaginous nodules were removed from the stifle joint as well as from several adjacent muscles. Diagnosis of SC was established based on clinical, radiographic and biopsy results. The owner declined to have a new surgery performed for complete nodule removal and partial synovectomy. Nine months after the initial presentation, a proximal pathological intra- articular tibial fracture was observed and malignant transformation to chondrosarcoma was diagnosed after limb amputation. No metastasis was observed after 1.5 years of follow-up.

In the 1990s, the AO (Arbeitsgemeinschaft für Osteosynthesefragen) Hand Study Group developed several anatomically bent plates (standard and short) for wrist panarthrodesis in humans. However, only straight plates have been used for carpal panarthrodesis (CP) in animals to date. The primary purpose of this study was to determine if precontoured plates are more anatomical for CP in dogs. Measurement of several of the bones that are implicated in CP, as well as the relationship between their surfaces and the surface of a straight plate, were performed in a radiographic and computed tomographic cadaveric study. Axial and transverse measurements taken at different levels of the metacarpal bones 2, 3 and 4 were also included. The second objective of this study was to develop a more anatomical CP plate according to the results obtained. The measurements and images obtained in this study show that, as in human orthopaedics, bent or stepped plates are more anatomically correct than straight plates for CP in dogs.

Fifty-two carpal panarthrodeses (CP) were carried out in 44 dogs (eight bilateral), in a multicentre study using a single (n = 47) or double (n = 5) stepped hybrid CP plate. Of these 44 cases, 39 were between 20-55 kg in bodyweight , 26 were males , and the carpometacarpal was the most common joint involved. Falling and other impact trauma were the most common aetiology. Pain of unknown origin, carpal luxation, chronic accessory carpal bone fracture, distal comminuted intra-articular radial fracture, bone tumour, degenerative joint disease, canine erosive idiopathic polyarthritis, avascular necrosis of the radial carpal bone and fractures of several metacarpal bones were some of the pathologies reported. Fracture of the third metacarpal bone during screw insertion was the only intrasurgical complication. Malpositioning of the plate or screws and over-tightened screws were technical errors observed in seven of the procedures. The radial carpal bone was not fixed with a screw in two cases due to bone deformity. Concurrent plate breakage and bending in the same patient operated on bilaterally was observed during the follow-up period, which represented a major complication rate of 3.8% for all procedures. Minor complications were: low grade infection, lick granuloma, digit hyperextension, screw loosening or failure, incomplete fusion of some joints and a fracture of the third metacarpal bone at the distal screw hole of the plate; which represented a rate of 44.2% on all procedures. Complete carpal healing was observed radiographically in 94.2% of all procedures. Limb function was excellent to good, and all of the owners, except for one, were satisfied with the procedure.

The clinical use of beta-tricalcium phosphate (beta-TCP) as a synthetic cancellous bone graft in veterinary orthopaedics is herein reported. The retrospective study was based on 13 clinical cases belonging to 11 dogs and one cat. The weights of the dogs ranged from 3.4 to 48 kg. One female cat weighing 3.5 kg completed the study. The clinical cases were six arthrodeses (four carpal, two tarsal), one hypertrophic non-union (femur), one atrophic non-union (metacarpal bones) and five long-bone fractures (two femurs, one tibia, two radii) possessing subcritical-sized bone defects. The beta-TCP used in this study was presented as irregular interconnected- porous granules and was placed in the bone defects after mixing it with fresh blood. Bone healing was achieved at between eight and 12 weeks in all clinical cases except for the case of the chronic atrophic nonunion in which only one of the four metacarpal bones healed. In the 12 successful cases, the bone defect grafted with beta-TCP showed a radiological bone ingrowth of 100% (10 cases), 90% (one case) and 75% (one case). The complete lack of tissue adverse effects in our series, and the good defect healing, allows us to hypothesise that beta-TCP can be successfully used as a synthetic bone graft in bone defects with good local biological conditions and where osteoconduction is especially needed for assuring a structural scaffold for new-bone ingrowth. When, in addition to osteoconduction, osteoinduction and osteogenesis are necessary for defect healing, the fresh cancellous bone graft remains the gold standard in veterinary orthopaedics.