Not Every Draining Wound is Infection: Vicryl Reaction after Total Knee Arthroplasty Mimicking Prosthetic Joint Infection - A Case Series and Diagnostic Insights.

Introduction: Vicryl reaction, also known as suture-related pseudo-infection (SRPI) or suture granuloma, is a rare but important differential diagnosis of post-operative wound complications following total knee arthroplasty (TKA). It mimics prosthetic joint infection, often leading to diagnostic confusion and potential overtreatment. Given the widespread use of braided absorbable sutures like polyglactin 910, recognizing this entity is essential to avoid unnecessary interventions. Materials and Methods: We present a case series of four patients who developed delayed wound complications following TKA. Clinical evaluation included assessment of fever, range of motion (ROM), and local wound findings. Laboratory investigations (total leukocyte count, C-reactive protein, erythrocyte sedimentation rate), radiological assessment, microbiological cultures (wound swab, knee aspirate, intra-operative samples), and histopathological examination were performed. Three patients underwent surgical debridement with tissue sampling, while one patient was managed conservatively. Discussion: All patients presented with localized wound complications, most commonly over the infra-patellar region along the suture line, with preserved and painless knee ROM. Systemic signs were minimal, with fever present in only one case. Laboratory markers showed variable elevation, while radiology was normal in all cases. Microbiological cultures were largely negative or inconsistent. Histopathology revealed a foreign body granulomatous reaction with giant cells, confirming Vicryl reaction/SRPI. Patients who underwent debridement with removal of suture material showed complete recovery, whereas the conservatively managed patient had persistent sinus, highlighting the importance of surgical management. Conclusion: Vicryl reaction or SRPI should be suspected in patients with delayed wound complications after TKA, especially in the absence of joint involvement. Early recognition, histopathological confirmation, and timely debridement can prevent unnecessary antibiotic use and avoid radical procedures such as two-stage revision arthroplasty.