Arthroscopic debridement combined with intra-articular bone marrow aspirate concentrate for early knee osteoarthritis: a prospective observational study with mean 19-month follow-up

BACKGROUND: Arthroscopic debridement for degenerative knee disease has uncertain benefit; orthobiologics such as bone marrow aspirate concentrate (BMAC) may modulate the joint microenvironment and improve symptoms in selected patients. This study evaluated clinical effectiveness and safety of intra-articular BMAC combined with arthroscopic debridement in patients with early degenerative knee pathology. METHODS: Prospective, single-center observational cohort (consecutive patients, January 2023 – January 2025) conducted in a university hospital using a single BMAC device and institutional protocol. Sixty-one patients were treated; 9 underwent bilateral procedures (70 knees). Knees with Kellgren-Lawrence (KL) 2-3 on weight-bearing radiographs were eligible and all patients also underwent preoperative magnetic resonance imaging (MRI) to document treatable intra-articular pathology. Outcomes (Visual Analogue Scale [VAS] 0-10, Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] 0-96) were collected prospectively at baseline, 3, 6 and 12 months, and at a final contact (range 12-26 months; mean 19.0±5.0). Safety was assessed by chart review and standardized interviews. Responders were prespecified as >30% improvement on either scale; exploratory analyses examined correlations between clinical change and age, Body Mass Index (BMI), and preoperative hematologic indices (hematocrit, platelet count, mean platelet volume [MPV]). RESULTS: Knees were classified KL 2-3 (KL 2: 52-85.2%; KL 3: 9-14.8%). Mean VAS improved from 8.0 to 2.9 and mean WOMAC from 62.6 to 23.4 (both P<0.001). As percent change, VAS improved by 51.1±22.9% and WOMAC by 40.8±18.4%. Overall, 61/70 knees (87.1%) achieved >30% VAS improvement, 52/70 (74.2%) achieved >30% WOMAC improvement, and 50/70 (71.4%) exceeded >30% on both scales. BMI showed a weak positive correlation with %ΔVAS (r=0.27; P=0.022), whereas age was not associated with outcome; no significant differences were observed for hematocrit or platelet count, and MPV showed a non-significant trend among WOMAC responders (P=0.119). No serious treatment-related adverse events were recorded; minor donor-site ecchymosis/hematoma and transient pain resolved with conservative measures. CONCLUSIONS: In patients with early degenerative knee disease, arthroscopic debridement combined with intra-articular BMAC was associated with substantial and clinically meaningful improvements in pain and function at a mean of 19 months of follow-up months, with an excellent safety profile. Controlled trials are warranted to isolate BMAC’s specific contribution and refine patient selection.