SLR - July 2022 - Brett A. Albert, DPM, MPH
Reference: Kantor AH, Uffmann W, Marchand LS, Haller JM, Higgins TF, Rothberg DL. What Happens on the Back Table? Viability and Osteogenic Potential of Reamed Autogenous Bone Graft as a Function of Time and Temperature—A Pilot Study. Journal of Orthopaedic Trauma. 2022;36(2):S28-S31. doi:10.1097/bot.0000000000002310Level of Evidence: II
Scientific Literature Review
Reviewed by: Brett A. Albert, DPM MHA
Residency Program: Hennepin Healthcare, Minneapolis, MN
Podiatric Relevance: Autogenic bone graft is widely accepted as the gold standard for supplementing bone healing as it retains osteoconductive, osteoinductive, and osteogenic properties that promote bone formation. There are several factors that drive a surgeon’s choice between allograft and autograft (cost, availability, scope of practice, patient comorbidities, surgeon skillset, reimbursement, amongst others). An important yet difficult to measure factor is viability/effectiveness of the graft used. The osteogenic potential of reamed autogenous bone graft (R-ABG) has already been established; the present study is the first to examine the graft viability under ex-vivo storage conditions (i.e. on the back table).
Methods: In 10 patients, 10 cm3 of R-ABG was harvested from the femur and divided into seven samples. One sample of R-ABG was processed and analyzed immediately (baseline); the remainder of the samples were stored at 0 degrees Celsius, 15 degrees Celsius (proposed ambient temperature of an operating room), and 37 degrees Celsius after 60 and 120 minutes. The samples were processed in the following manner after their respective holding times in the assigned temperatures: cells were detached with trypsin, flushed twice, washed in phosphate-buffered saline, filtered, and labeled for CD34 and CD45 markers. At that time, the mononuclear cells were analyzed utilizing flow cytometry to determine the percentage of viable cells present within the sample. The percent change in viability from baseline was calculated for each sample and then averaged across the 10 samples.
Results: Ten (10) samples were collected from 10 patients. Mean age was 44 years, 9 males and 1 female. There were no statistically significant differences in mean cell viability between all storage temperatures and all storage durations. While not statistically significant, the authors did note a relative decrease in cell viability in samples stored at 15 degrees Celsius and 37 degrees Celsius for 120 minutes.
Conclusions: R-ABG provides viable progenitor cells when stored at 0 degrees Celsius, 15 degrees Celsius, and 37 degrees Celsius after 60 and 120 minutes. These data can serve as reassurance to surgeons utilizing R-ABG as the osteogenic properties to not appear to be diminished with prolonged storage at OR ambient temperature during an operation. While this specific harvest technique is not commonly used by podiatric foot and ankle surgeons, these data can be extrapolated to more commonly used harvest sites and techniques. This study does have a small sample size and is underpowered, which warrants additional study of this subject with a larger sample size. In conclusion, there may be less of an effect on osteogenic properties of harvested autograft based on storage duration and temperature than previously thought.