Summary

The study introduces a standardized procedure for BMAC injections and looks at minimum 2-year patient-reported outcomes of the procedure

Abstract

Purpose

There is considerable interest for the use of biologics in hip preservation and the treatment of hip osteoarthritis. Bone marrow aspirate concentrate (BMAC) has demonstrated significant osteochondral regeneration effects in in vivo animal experiments. Until now, however, the clinical efficacy of BMAC injections for patients with hip osteoarthritis and a standardized procedure for preparation and delivery of the injections remain poorly understood. The current case series looks at survivorship and minimum 2-year patient-reported outcomes (PROs) in 20 patients with early hip osteoarthritis who underwent needle-sized single use arthroscopic BMAC injections with the senior surgeon.

Methods

23 patients were retrospectively identified to have undergone BMAC injections for early hip osteoarthritis with the senior surgeon from 2018 – 2020. 3 patients declined to fill out 2-year prospectively collected patient-reported outcome scores and were excluded from the study, resulting in a final cohort of 20 patients (9 males, 11 females). The same preparation and delivery methods were used for the BMAC injections. For the BMAC injection, each patient had bone marrow aspirate concentrate extracted from the iliac crest and spun down utilizing a centrifuge to obtain 5 ml of bone marrow aspirate. A needle-sized single use arthroscope was percutaneously introduced into the hip joint. Under the guidance of the arthroscopic camera, the chondral wear was assessed, and the bone marrow concentrate was injected at the chondrolabral junction.

Results

The patients had mean pre-operative HOS-ADL of 51.0 ± 21.5, HOS-SS 35.2 ± 19.6, mHHS of 46.3 ± 14.7. Excluding the patients who required additional hip procedures, PROs were significantly improved from baseline with patients reporting reported a mean 2-year post-operative HOS-ADL of 80.1 ± 15.3 (p<0.01), HOS-SS 56.4 ± 32.8 (p<0.05), and mHHS 83.8 ± 11.5 (p<0.001). 2-year survivorship for the injections was 91% with 9% of patients requiring a THR within 2 years of the BMAC injection.

Conclusion

Minimum 2-year PROs are significantly improved in patients who received BMAC injections for early hip osteoarthritis. The current study provides further evidence that needle-sized single use arthroscopic BMAC injections are a promising treatment option for early hip osteoarthritis.