Amir Kamali

Cervical disc arthroplasty (CDA) has emerged as a surgical solution for patients with degenerative compressive cervical myelopathy but faces limitations, particularly in achieving stable integration. One of the primary challenges with current artificial discs is the risk of migration and dislocation due to insufficient osseointegration with the adjacent vertebrae. While CDA is an established treatment in human medicine, dogs with cervical myelopathy are routinely treated with decompressive surgeries. In veterinary medicine, there is particular interest in innovative therapies, such as disc arthroplasty. Recently, a novel biomimetic artificial intervertebral disc (BioAID) was developed. This artificial disc replicates key features of the natural disc, incorporating a viscoelastic core and a tensile fiber jacket mimicking the nucleus pulposus and annulus fibrosus, respectively. Titanium endplates with keels secure fixation, and the fiber jacket facilitates osseointegration with the adjacent vertebrae to minimize the risk of migration over time.Since goats are a commonly used and readily available animal model for spine research, this study presents a comprehensive, hands-on guide (including the design and fabrication of the implant, selection and enrollment of experimental animals, preoperative management, anesthesia protocols, and postoperative care) for the implantation of the artificial disc device in the goat cervical spine. A detailed, step-by-step surgical methodology is provided, along with the design of custom surgical instruments and the use of imaging techniques required both intra- and post-operatively. This approach bridges the gap between experimental research and clinical application. The surgical procedure was successfully performed in four goats, with post-implantation monitoring over 21 days confirming no migration or complications. These findings suggest that the implantation technique ensures primary stability, supporting its feasibility for further evaluation. Future studies are needed to assess long-term osseointegration and biomechanical performance before translating this approach to clinical applications in both humans and dogs.

Cervical disc arthroplasty (CDA) has emerged as a surgical solution for patients with degenerative compressive cervical myelopathy but faces limitations, particularly in achieving stable integration. One of the primary challenges with current artificial discs is the risk of migration and dislocation due to insufficient osseointegration with the adjacent vertebrae. While CDA is an established treatment in human medicine, dogs with cervical myelopathy are routinely treated with decompressive surgeries. In veterinary medicine, there is particular interest in innovative therapies, such as disc arthroplasty. Recently, a novel biomimetic artificial intervertebral disc (BioAID) was developed. This artificial disc replicates key features of the natural disc, incorporating a viscoelastic core and a tensile fiber jacket mimicking the nucleus pulposus and annulus fibrosus, respectively. Titanium endplates with keels secure fixation, and the fiber jacket facilitates osseointegration with the adjacent vertebrae to minimize the risk of migration over time.Since goats are a commonly used and readily available animal model for spine research, this study presents a comprehensive, hands-on guide (including the design and fabrication of the implant, selection and enrollment of experimental animals, preoperative management, anesthesia protocols, and postoperative care) for the implantation of the artificial disc device in the goat cervical spine. A detailed, step-by-step surgical methodology is provided, along with the design of custom surgical instruments and the use of imaging techniques required both intra- and post-operatively. This approach bridges the gap between experimental research and clinical application. The surgical procedure was successfully performed in four goats, with post-implantation monitoring over 21 days confirming no migration or complications. These findings suggest that the implantation technique ensures primary stability, supporting its feasibility for further evaluation. Future studies are needed to assess long-term osseointegration and biomechanical performance before translating this approach to clinical applications in both humans and dogs.

The acetabular rim extension (ACE-X) implant is a custom-made three-dimensionally printed titanium device designed for the treatment of canine hip dysplasia. In this study, 34 dogs (61 hips) underwent ACE-X implantation, and assessments were conducted using computed tomography, force plate analysis, Ortolani’s test, and the Helsinki chronic pain index (HCPI) questionnaires at five intervals: the pre-operative day, the surgery day, and the 1.5-month, 3-month, and 12-month follow-ups. Statistically significant increases in femoral head coverage with a negative Ortolani subluxation test were observed immediately after surgery and persisted throughout the study. Osteoarthritis (OA) scores remained stable, but osteophyte size significantly increased between the surgery day and the 12-month follow-up, especially in hips with a baseline OA score of 2 compared to those with a score of 1. The force plate data showed no significant changes during the study. The HCPI demonstrated a significant decrease in pain score from pre-operative value to six-week follow-up and gradually decreased over time. Major complications were identified in six hips (9.8%) of four dogs. In conclusion, the ACE-X implant effectively increased femoral head coverage, eliminated subluxation, and provided long-term pain relief with minimal complications, benefiting over 90% of the study population. The study supports the ACE-X implant as a valuable alternative treatment for canine hip dysplasia.

The ACEtabular rim eXtension (ACE-X) implant is a custom-made 3-dimensional-printed titanium device designed for the treatment of canine hip dysplasia. Thirty-four dogs (61 hips) underwent ACE-X implantation, and assessments were conducted using computed tomography, force plate analysis, Ortolani’s test, and Helsinki Chronic Pain Index (HCPI) questionnaires at five intervals: pre-operative day, surgery day, 1.5-month, 3-month, and 12-month follow-up. Statistically significant increases in femoral head coverage with negative Ortolani subluxation test were observed immediately after surgery and persisted throughout the study. Osteoarthritis (OA) scores remained stable, but osteophyte size significantly increased between the surgery day and the 12-month follow-up, especially in hips with a baseline OA score of 2 compared to those with a score of 1. Force plate data showed no significant changes during the study. The HCPI demonstrated a significant decrease in pain score from pre-operative value to 6-week follow-up and gradually decreased over time. Major complications were identified in 6 hips (9.8%) of 4 dogs. In conclusion, the ACE-X implant effectively increased femoral head coverage, eliminated subluxation, and provided long-term pain relief with minimal complications, benefiting over 90% of the study population. The study supports the ACE-X implant as a secure and valuable treatment for canine hip dysplasia.