Ph Hernigou (Creteil, France)
The benefits after TKA are theoretically comparable between octogenarians and younger patients. However, the life expectancy of an 85-year-old patient is approximately 6 years, and 2 to 3 months are necessary for recovery and rehabilitation after TKA. With a life expectancy of 6 years, this negatively impacts 1/12th of their remaining life to recovery for two knees if performed sequentially. Therefore, many elderly patients who planned to undergo staged-bilateral TKA elect to forego the second arthroplasty.
Methods: We conducted a study on 40 patients who had surgery after they were 85 years old (mean: 89 years; range 85 to 92) and who planned to undergo staged-bilateral TKA and elected to forego the second arthroplasty. With the hypothesis that subchondral bone marrow injection might improve knees in elderly patients, bone marrow concentrate injection was performed from 2000 to 2011 in the second knee. Osteoarthritic knee received after concentration, a graft containing an average of 3950 CTP/mL (counted as CFU-F, range 1240 to 6540). Subsequent admissions for revision surgery were identified. At the most recent follow up (end of 2016) 14 of 40 patients had died after a mean follow up of 6 years (range 3 to 10 years) and none of these patients had another surgery on both knees. The follow up for the 26 living patients in 2016 was an average of 9 years (range 5 to 16 years) with the older patient at 101 years old (still autonomous and walking). Thus, the status of the knee was known for all patients either at the time of death or at final follow up. At the most recent followup (average of 8 years FU, range 5 to 16 years), clinical outcome of the patient (Knee Society score), radiological and imaging (with MRI for the knee with subchondral bone marrow injection) outcomes were obtained.
Results: The duration of anesthesia and the time in the operating room were on average 1.5 times (range 1.2 to 1.9) longer for patients having TKA compared with cell therapy. The length of hospital stay with TKA averaged 8 days in the hospital versus 1 day for cell therapy. The length of anticoagulation was lower for cell therapy procedures (1 week) than for TKA procedures (4 weeks). The period for use of crutches averaged 3 days (range none to 7 days) for cell therapy, and three weeks (range 2 to 6 weeks) for two crutches with TKA. With regards to the post-operative period (6 months), the number of adverse events were higher (p = 0.04) in the TKA group. The TKA group had a higher rate of blood transfusion (30% versus 0%), and a higher number of thrombophlebitis (15% versus 0%).Three (among 40) TKA knees needed subsequent surgery versus only 1 with cell therapy. The Knee Score had improved and remained similar in both groups (respectively 80.3 points ± 11 versus 78.3± 23). Among the 40 patients, 28 preferred the knee with cell therapy and 12 the knee with TKA (P < 0.05). In the group of knees treated with BMC injection, the percentage cartilage volume measured with MRI increased in the medial compartment (that received BMC) compared to baseline (2.3± 2.1% at 2 years and 3.8± 2.5 at 5 years); during the same period a percentage cartilage volume loss (-2.1 ± 2.9% at 2 years and -3.5 ± 3.8% at 5 years) was observed in the lateral (considered as not involved at the baseline) compartment.
Conclusions: In conclusion, this study showed that subchondral bone marrow concentrate was an effective procedure for knee osteoarthritis in patients aged 85 years or more, with a lower complication rate and a quicker recovery as compared with TKA during the remaining lifetime of this elderly population.