A personalized three-dimensional printed knee splint for mechanical mitigation of canine knee osteoarthritis and adjunctive nonsteroidal anti-inflammatory drug therapy

Introduction Canine knee osteoarthritis (OA) involves pain, inflammation, altered joint loading, and restricted motor function. Because nonsteroidal anti-inflammatory drugs (NSAIDs) do not directly correct abnormal joint mechanics, this study evaluated a personalized three-dimensional (3D)-printed polylactic acid knee splint, used alone or with short-term NSAID treatment, in a monosodium iodoacetate-induced beagle knee OA model. Methods Twelve dogs were assigned to four groups ( n = 3 per group): OA without continued treatment (OA), splint alone (OA/Spt), NSAIDs alone (OA/NSAIDs), and combined NSAIDs plus splint treatment (OA/NSAIDs/Spt). In vivo outcomes included static hindlimb weight-bearing symmetry, knee joint range of motion (ROM), and Liverpool Osteoarthritis in Dogs (LOAD), The Canine Brief Pain Inventory (CBPI), and The CanineOrthopedic Index (COI) pain and function scores. Finite element analysis using representative healthy and OA knee models was used as descriptive, model-based mechanical support. Results The splint remained belowthe polylactic acid (PLA) yield threshold under simulated loading and reduced several model-predicted mechanical indices in the OA model, including peak stress, equivalent elastic strain, femoral condylar contact pressure, and cartilage total deformation. In vivo , splint treatment alone was associated with better short-term functional outcomes than no continued treatment, whereas the OA/NSAIDs/Spt group showed the greatest overall improvement in weight-bearing symmetry, ROM, and clinical scores. Discussion Because no formal interaction analysis was performed, the combined-treatment findings should be interpreted as broader short-term functional benefit rather than evidence of an interaction effect. These preliminary results support personalized 3D-printed splinting as a potential mechanical adjunct to NSAID therapy for canine knee OA.