Cadaveric specimens that have been fresh-frozen and then thawed for use have historically been considered to be the gold standard for biomechanical studies and the closest surrogate to living tissue. However, there are notable issues related to specimen rapid decay in the thawed state as well as infectious hazard to those handling the specimens. Cadaveric specimen preparation using a new phenol-based soft-embalmed method has shown considerable promise in preserving tissue in a prolonged fresh-like state while mitigating the infection risk. In this study, we evaluated the ability of soft-embalmed specimens to replace fresh-frozen specimens in the biomechanical study of flexor tendon repair.

An ex-vivo study was conducted on six cadaveric hands in both a fresh-frozen, thawed state and following embalming with a phenol-based solution. Six different combinations of flexor digitorum profundus (FDP) tendons, from D2 to D5, and flexor pollicis longus (FPL) tendons were used to create two groups of similar composition with 15 tendons each, one group to be tested fresh and the other following embalming. A 5cm length of each flexor tendon was harvested from zone 2 and transversely cut at the mid-section. A modified-Kessler repair was performed on each specimen using 4–0 Fiberwire, with two core sutures and 1cm purchase on each end. Incisions were closed with a running stitch to prepare the specimen for embalming. The same protocol was used to repair and harvest the second group of tendons one month following the perfusion of a phenol-based solution through the vasculature of the hand and forearm. Tendon repair biomechanics were characterised through a ramp loading to failure (rate 1mm/sec), incorporating the 12 mm travel distance of the testing machine. A video-extensometry technique was used to validate machine recordings for the repair site for force at the 2mm gap distance, the ultimate strength, and the mode of failure. Characteristics of the two groups were tested for equivalency using inferential confidence intervals (ICI).

Both fresh and embalmed groups were indistinguishable in both force at 2mm gap (fresh 17.9±4.7N; embalmed 18.1±5.1) and ultimate strength (fresh 43.93±10.0; embalmed 43.7±9.4). With the exception of one specimen with complete suture pull-out, all specimens exhibited partial pull-out as the final mode of failure.

Our study demonstrated that tendon repair characteristics of phenol-embalmed specimens were equivalent to fresh specimens. Post-mortem chemical preservation can indeed preserve both visual and biomechanical characteristics of soft tissues. This study opens new avenues in support of the use of embalmed specimens in medical curricula and surgical training.

The inmate population is a unique cohort with several healthcare-related challenges. International studies have demonstrated higher rates of infectious diseases, chronic diseases and psychiatric disorders in inmates when compared to general population. However, little is known about the outcomes following total joint arthroplasty in this population. This retrospective chart review aims to outline the differences in clinical outcomes after hip and knee total joint arthroplasty in the Kingston inmate population compared to the national population standard.

A list of all inmate inpatient hospital visits with diagnostic/procedure codes pertaining to total joint arthroplasty within the last ten years was obtained through a computer-based search of the Kingston General Hospital Discharge Abstract Database(DAD). The patient charts were reviewed and demographic and outcome data pertinent to our study was collected. Data was compiled using Excel and imported into IBM SPSS for descriptive analysis.

Twenty male inmate patients underwent 24 primary Total Hip Arthroplasties(THA) or Total Knee Arthroplasties(TKA) and one medial unicompartmental knee arthroplasty from May 2003 to January 2013. The average age was 58 with mean Body Mass Index(BMI) of 34. Median American Society of Anesthesiologist(ASA) score was 3 and mean Charlston Comorbidity Index was 3.92. The rates of HCV and HIV were 35%(n=5) and 0%, respectively. Average length of stay from time of initial procedure was 4.2 days. The overall revision rate was 24% (n=6). Reasons for revision included deep prosthetic infection (50%, n=3), aseptic loosening (17%, n=1), arthrofibrosis (17%, n=1) and late periprosthetic fracture (17%, n=1). Infection rates were reported at 16% (n=4); 75% of which were deep prosthetic infections requiring revision surgery. Other complications included ST-elevation myocardial infarction(STEMI) (n=1), and postoperative knee stiffness requiring manipulation under anesthesia(MUA) (n=1).

Compared to Correctional Services Canada(CSC) data on male inmate health in 2012, our study population demonstrated a higher rate of HCV (35% vs. 9.4%), diabetes (30% vs. 4.2%) and overall cardiovascular and respiratory comorbidities. This may reflect the higher rate of comorbidities associated with osteoarthritis, such as BMI>25, which was evident in 95% of our study population vs. 64.5% in Canadian inmates. Total joint revision rates in our inmate study population was 24%, which is higher than the 2014 Canadian Joint Replacement Registry's yearly revision rate of 8.7% in THA and 5.2% in TKA. Our study population also demonstrated infection as the leading cause for revision at 50%, compared to 14.5% for THA and 19.6% for TKA in the general Canadian population. Further study of the complex biopsychosocial risk factors in the inmate population is warranted to better define pre-surgical risk assessment criteria.