THR & TKA Surgical Cases
Total Hip Replacement (THR) & Total Knee Arthroplasty (TKA) surgical cases.
A Samoyed’s Distal Femur Growing Bone: Deciphering Post-THR Periosteal Reaction Through Biomechanics
When young large-breed dogs undergo cementless total hip replacement (THR), postoperative imaging occasionally reveals a surprising phenomenon: periosteal new bone formation along the distal femur. In this case, an 18 kg male Samoyed underwent staged bilateral THR at 9 and 11 months of age due to severe hip laxity. One month after the second surgery, follow-up radiographs revealed marked periosteal reaction along the distal right femur and mild remodeling on the left. Some clinicians instinctively panic at the sight of periosteal changes, suspecting infection or implant failure. However, bone is a living, reactive sculpture. By analyzing Wolff's law, proximal stress shielding, active growth plates, and preoperative subchondral sclerosis, I break down why this distal bone growth represents a benign, mechanically driven adaptive remodeling rather than pathology—and how surgeons should objectively monitor it.
Total Knee Arthroplasty (TKA) in a 41 kg Doberman Pinscher: Overcoming End-Stage Osteoarthritis with a Biological Dual-Mobility System
When an owner drives hundreds of miles from outside the province to bring a 41 kg adult male Doberman Pinscher to Guangzhou Boss Animal Hospital, you know you are dealing with a severe, chronic crisis. The dog had suffered from recurrent bouts of severe knee swelling and lameness that temporarily waxed and waned, masking an insidious, chronic cranial cruciate ligament rupture. By the time he reached my operating table, the left stifle was in end-stage collapse—encased in massive osteophytes with complete destruction of both the femorotibial and patellofemoral articular cartilage. In a destroyed joint like this, standard TPLO is useless because it cannot heal eburnated, grinding bone. Using our VVV digital surgical planning software, I mapped out the reconstruction and implanted a Size 40 Vetmaster biological dual-mobility total knee replacement. Despite dense fibrous joint contractures that made joint space distraction an intense physical and technical battle, we achieved textbook alignment with an exact 12° posterior tibial slope. Today, this massive working dog has regained painless, powerful athletic function.
Salvaging a Disaster: Revision of a Four-Times Luxated Total Hip Replacement in a Border Collie Using a Dual-Mobility System
When this desperate owner drove over 1,000 kilometers to bring his 5.5-year-old, 22.5 kg Border Collie to Guangzhou Boss Animal Hospital, the dog was facing his fifth hip surgery in just over two months. Following an initial hybrid replacement at another clinic, the dog had suffered four consecutive dorsal hip luxations, each recurring within two to five days despite repeated attempts to alter cup angles down to an extreme 25°. Analyzing the patient's CT, I identified a striking biomechanical contradiction: an overly closed cup should cause ventral luxation, yet this dog kept popping out dorsally—proving the dorsal muscular and capsular envelope had been completely destroyed. My colleague Dr. Yu Jiezhou and I revised the joint using the Vetmaster cementless dual-mobility system reinforced with synthetic ligament suspension. By replacing mechanical friction with dual-mobility jump distance, we achieved rock-solid stability—demonstrated intraoperatively by gently lifting the dog off the table by the femoral neck without dislocation. Today, the dog walks soundly, free from the revision nightmare.
Sequential Bilateral Biological Total Hip Replacement in a British Shorthair Cat: Anatomy, Technique, and Overcoming Contralateral Artifacts
Feline hip dysplasia is vastly underdiagnosed because cats are masters at masking chronic orthopedic pain. In this case, a 2-year-old male British Shorthair weighing 5.8 kg presented with severe bilateral hip laxity, advanced articular wear, and marked lameness. Cats possess unique anatomy: an exceptionally tiny acetabulum paired with a straight, "stovepipe" femoral canal, along with explosive jumping biomechanics requiring extreme range of motion. To restore lifelong, pain-free athletic ability without dislocation, I performed sequential bilateral cementless total hip replacements (THR) using the Vetmaster dual-mobility system (12 mm cup, #3 stem). This report details the technical execution of both stages—including the specific intraoperative challenge during the second stage, where the contralateral metal prosthesis blocked lateral fluoroscopic cup measurement, requiring precise C-arm patient leveling and mechanical alignment guidance.