Introduction

Metacarpal and metatarsal fractures account for approximately 3.3% of reported skeletal traumas in the feline population. Although management may vary depending on the lesion configuration, surgical intervention is established as the therapeutic standard whenever there is significant displacement, involvement of more than two bones, or comminuted fracture patterns. The clinical objective is then to restore biomechanical stability while optimising the biological environment of the fracture site.

In this context, the use of bioactive biomaterials is generating increasing interest. Calcium phosphate ceramics are widely favoured for their excellent biocompatibility and structural homology with the bone mineral matrix, acting as an osteoconductive scaffold. In parallel, platelet-rich fibrin (PRF), a second-generation platelet concentrate, offers an autologous reservoir of cytokines and growth factors (such as TGF-β, PDGF and VEGF), crucial for angiogenesis and osteoinduction. The hypothesis of this study is based on the biological synergy between the osteoconductive potential of calcium phosphate and the regenerative properties of PRF.

This work aims to evaluate the clinical and radiographic efficacy of a protocol combining Kirschner wire osteosynthesis and the local application of a PRF-calcium phosphate composite in ten cats. The objective is to analyse bone consolidation kinetics and functional recovery in order to validate the benefit of this combined approach in veterinary orthopaedic surgery.

Methodology

This prospective clinical study involved a cohort of 10 felines of various breeds, sexes and ages, presenting with fractures of the metacarpals (n=5; Cases 1, 4, 6, 7, 8) or metatarsals (n=5; Cases 2, 3, 5, 9, 10). The diagnosis was established through a rigorous clinical evaluation supplemented by a standardised radiographic examination. Inclusion criteria comprised displaced fractures, multiple bone involvement (more than two bones) or comminuted fracture patterns requiring surgical intervention.

The surgical protocol consisted of reduction and osteosynthesis by intramedullary pinning using Kirschner wires (K-wires). In order to optimise bone healing kinetics, a composite biomaterial was applied in situ at the fracture site. This composite was composed of platelet-rich fibrin (PRF), serving as an autologous matrix concentrated in cytokines and growth factors, combined with a calcium phosphate powder for its bioactivity and mineral conduction properties.

Longitudinal postoperative follow-up was conducted up to the 45th day. The evaluation criteria for therapeutic efficacy were based on the functional recovery of weight-bearing, the radiographic resolution of the fracture line and the quality of osteo-tissue regeneration. The data were analysed descriptively to validate the biological synergy of the PRF-calcium phosphate complex in the management of bone continuity defects in cats.

Results

The study involved a cohort of 10 felines presenting with unstable fractures (displaced, comminuted or multiple > 2). The anatomical distribution was balanced: 50% metacarpal fractures (n = 5; Cases 1, 4, 6, 7, 8) and 50% metatarsal fractures (n = 5; Cases 2, 3, 5, 9, 10).

Primary Outcome: Radiographic Consolidation

Standardised radiographic evaluation at the end of the follow-up (post-operative day 45) demonstrated a complete resolution of the fracture line in 100% of cases (n = 10/10). The combination of Kirschner wire osteosynthesis and the biological composite (PRF + calcium phosphate) achieved cortical continuity with no signs of delayed union or non-union.

Secondary Outcomes: Functional Recovery

• Weight-bearing: At D45, all patients (100%) demonstrated full weight-bearing capacity on the operated limb, correlated with restored biomechanical stability.
• Clinical evaluation: Functional recovery was deemed satisfactory for the entire cohort. No clinical signs of biomaterial rejection or infectious complications were documented during the follow-up period.

Summary of clinical data at D45