PRP-NPWT in DSWI with osteomyelitis: sternal stability and albumin predict healing failure

Background Deep sternal wound infection with osteomyelitis (DSWI-OM) is a severe complication after median sternotomy. This study aimed to identify key determinants of wound healing after initial combined platelet-rich plasma (PRP) and negative-pressure wound therapy (NPWT) in DSWI-OM patients, to guide individualized management. Methods In a single-center retrospective cohort, 75 DSWI-OM patients treated with PRP-NPWT (2013–2021) were stratified by healing status at 2 weeks into Healed ( n = 33) and Nonhealed ( n = 42) groups. Univariate and multivariable logistic regression analyses identified risk factors from baseline characteristics, wound-specific factors (e.g., debridement history), and laboratory parameters. ROC curves established cut-off values. A novel sternal stability classification (Type A: stable, B: loosened, C: defective) integrated anatomical severity. Results The primary closure failure rate was significantly higher in DSWI-OM than DSWI-alone patients (56.0% vs 22.5% P = 0.0006). Multivariable analysis identified prior debridement (OR 3.648, 95% CI 1.097–12.126) and serum albumin level (analyzed as a continuous variable, OR 0.838 per 1 g/L increase, 95% CI 0.746–0.941) as independent risk factors (all P < 0.05). In addition, an albumin threshold of < 31.5 g/L was predictive of failure (AUC 0.763). Sternal stability grading strongly correlated with healing (Type A: 42.4% vs Type C: 30.3% P = 0.037). Failed pre-admission debridement was associated with greater sternal instability/defects ( P = 0.043). Conclusions Sternal structural integrity and nutritional status are critical for PRP-NPWT success in DSWI-OM. Integrating sternal stability classification and an albumin threshold (≥ 31.5 g/L) into preoperative assessment can optimize timing and procedure selection, potentially avoiding futile primary closure in high-risk patients. These findings require prospective validation.