Promising outcomes of hip mosaicplasty by minimally invasive anterior approach using osteochondral autografts from the ipsilateral femoral head

Purpose: Recent studies demonstrated promising results of mosaicplasty for femoral head osteochondral lesions using posterior and lateral approaches. This study aimed to evaluate outcomes of mosaicplasty using ipsilateral femoral head autografts by minimally invasive anterior approach. The hypothesis was that this surgical technique would grant satisfactory clinical outcomes with considerable improvement of clinical scores. Methods: A consecutive series of 27 mosaicplasties, to treat osteochondral lesions of the femoral head measuring 1.6 +/- 0.7 cm(2) (range 0.8-4.0) in patients aged 28.7 +/- 7.4 years (range 19-44), was evaluated using the mHHS and WOMAC scores at minimum follow-up of 12 months. All patients were operated by minimally invasive anterior (Hueter) approach and osteochondral plugs were harvested from the non-weight-bearing portion of the femoral head. Adjuvant osteoplasty was necessary for some patients at the acetabulum (n = 3), femur (n = 14) or both (n = 2). Results: Three patients were excluded due to concomitant periacetabular osteotomies or shelf procedures, one patient could not be reached, and another was revised to THA. This left 22 patients for clinical assessment at 39.4 +/- 23.2 months (12.0-90.2). Their mHHS improved from 56.3 +/- 12.6 to 88.4 +/- 9.9, and WOMAC improved from 45.1 +/- 16.9 to 80.6 +/- 13.0. Two patients (8.4%) underwent arthroscopy at 13 and 30 months to remove painful residual cam-type deformities. Regression analyses revealed that net improvement in WOMAC decreased with lesion size (p = 0.002) and increased with follow-up (p = 0.004). Conclusions: Hip mosaicplasty using autografts from the ipsilateral femoral head, performed by minimally invasive anterior approach, granted satisfactory outcomes and functional improvements. Caution is, however, advised for lesions > 2 cm(2) (diameter > 16 mm) which may be a threshold limit for this procedure.