Can a biomimetic osteochondral scaffold be a reliable alternative to prosthetic surgery in treating late-stage SPONK?

Background: This study aimed to assess the reliability of the Maioregen (R) biomimetic osteochondral scaffold (Finceramica Faenza SpA, Faenza, Italy) as a salvage and joint-preserving procedure in the treatment of late-stage osteonecrosis of the knee.Methods: Eleven active patients aged under 65 years and presenting with clinical and radiological signs of SPONK were treated with Maioregen. All were clinically evaluated pre-operatively and yearly thereafter for a minimum of two years. Subjective IKDC and Lysholm Knee Scale scores were used to assess clinical outcome. A VAS scale served to quantify pre-operative pain and post-operative pain. Activity levels were evaluated pre-operatively and at follow-up using the Tegner Activity Scale.Results: Subjective IKDC (40 +/- 15.0 to 65.7 +/- 14.8 (mean +/- SD)) and Lysholm Knee Scale (49.7 +/- 17.9 to 86.6 +/- 12.7 (mean +/- SD)) scores improved significantly from pre-operative evaluation (p < .01). VAS scores decreased from a pre-operative mean (+/- SD) of 6.3 +/- 2.5 to 1.6 +/- 2.7 at two years. The Tegner Activity Scale showed no significant differences between pre-injury and two-year follow-up.Two out of the 11 patients were symptomatic at 18 months post implant and progressed to condylar collapse. These patients required total knee arthroplasty.Conclusions: Use of a biomimetic scaffold can be a valid option in the surgical treatment of SPONK in relatively young active patients. Indeed, this surgical technique, originally developed for osteochondritis dissecans, has been found to give good clinical results at medium-term follow-up of late-stage osteonecrosis treatment and could postpone or even avoid the need for joint replacement procedures.