Subchondral stem cell therapy versus contralateral total knee arthroplasty for osteoarthritis following secondary osteonecrosis of the knee.

Purpose: Total knee arthroplasty (TKA) implanted in patients with secondary osteonecrosis (ON) related to corticosteroids have relatively poor outcome (20% revision rate) at a mean follow-up of only eight years. With the hypothesis that subchondral bone marrow injection might improve knees in these patients, we evaluated 30 patients who had bilateral knee osteoarthritis with severe joint space narrowing and received TKA in one knee and subchondral bone marrow concentrate injection in the contralateral knee.

Material And Methods: A prospective randomized controlled clinical trial was carried out in 60 knees of 30 patients (mean age 28 years, 18-41) who presented bilateral osteoarthritis secondary to knee ON related to corticosteroids in relation with different severe medical conditions. During the same anesthesia, one knee received TKA; for the other knee, a bone marrow graft containing an average of 6500 MSCs/mL (counted as CFU-F, range 3420 to 9830) was delivered to the subchondral bone of the femur and tibia. The length of anesthesia related to each procedure (bone marrow aspiration and subchondral injection of concentrated bone marrow versus total knee arthroplasty) was measured. Peri-operative outcomes, morbidity, complications, and safety of the two procedures were compared. Subsequent admissions for revision surgery were identified. At the most recent follow-up (average of 12 years, range 8 to 16 years), clinical outcomes of the patient (Knee Society score) were obtained along with radiological imaging outcomes (MRIs for knees with subchondral bone marrow injection).

Results: Anesthesia related to the TKA side was longer than for the cell therapy group. Medical and surgical complications were more frequent after TKA. A higher number of thrombophlebitis was observed on the side with TKA (15%) versus none on the side with cell therapy (0%). At the most recent follow-up (average of 12 years, range 8 to 16 years), six (out of 30) TKA knees needed subsequent surgery versus only one with cell therapy. The Knee Score had improved and remained similar in the TKA and cell therapy groups (respectively 80.3 points ± 11 versus 78.3 ± 23); 21 patients preferred the knee with cell therapy and 9 preferred the knee with TKA. Knees with cell therapy had improvement on cartilage and bone marrow lesions observed at the site of bone marrow subchondral injection.

Conclusions: Subchondral autologous bone marrow concentrate was an effective procedure for treating young patients with knee osteoarthritis following secondary ON of the knee related to corticosteroids with a lower complication rate and a quicker recovery as compared with TKA.