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Fulltext Deep-Freezing Temperatures During Irradiation Preserves the Compressive Strength of Human Cortical Bone Allografts: A Cadaver Study

Yang Harmony TC, Yusof N, Ramalingam S, Baharin R, Syahrom A, Mansor A

Clin Orthop Relat Res, 2022 Feb 01;480(2):407-418.
PMID: 34491235 DOI: 10.1097/CORR.0000000000001968

BACKGROUND: Gamma irradiation, which minimizes the risk of infectious disease transmission when human bone allograft is used, has been found to negatively affect its biomechanical properties. However, in those studies, the deep-freezing temperature during irradiation was not necessarily maintained during transportation and sterilization, which may have affected the findings. Prior reports have also suggested that controlled deep freezing may mitigate the detrimental effects of irradiation on the mechanical properties of bone allograft.
QUESTION/PURPOSE: Does a controlled deep-freezing temperature during irradiation help preserve the compressive mechanical properties of human femoral cortical bone allografts?
METHODS: Cortical bone cube samples, each measuring 64 mm3, were cut from the mid-diaphyseal midshaft of five fresh-frozen cadaver femurs (four male donors, mean [range] age at procurement 42 years [42 to 43]) and were allocated via block randomization into one of three experimental groups (with equal numbers of samples from each donor allocated into each group). Each experimental group consisted of 20 bone cube samples. Samples irradiated in dry ice were subjected to irradiation doses ranging from 26.7 kGy to 27.1 kGy (mean 26.9 kGy) at a deep-freezing temperature below -40°C (the recommended long-term storage temperature for allografts). Samples irradiated in gel ice underwent irradiation doses ranging from 26.2 kGy and 26.4 kGy (mean 26.3 kGy) in a freezing temperature range between -40°C and 0°C. Acting as controls, samples in a third group were not subjected to gamma irradiation. The mechanical properties (0.2% offset yield stress, ultimate compression stress, toughness, and the Young modulus) of samples from each group were subsequently evaluated via axial compression loading to failure along the long axis of the bone. The investigators were blinded to sample group during compression testing.
RESULTS: The mean ultimate compression stress (84 ± 27 MPa versus 119 ± 31 MPa, mean difference 35 [95% CI 9 to 60]; p = 0.005) and toughness (3622 ± 1720 kJ/m3 versus 5854 ± 2900 kJ/m3, mean difference 2232 [95% CI 70 to 4394]; p = 0.009) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than in those irradiated at deep-freezing temperatures (below -40°C). The mean 0.2% offset yield stress (73 ± 28 MPa versus 109 ± 38 MPa, mean difference 36 [95% CI 11 to 60]; p = 0.002) and ultimate compression stress (84 ± 27 MPa versus 128 ± 40 MPa, mean difference 44 [95% CI 17 to 69]; p < 0.001) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than the nonirradiated control group samples. The mean 0.2% offset yield stress (73 ± 28 MPa versus 101 ± 28 MPa, mean difference 28 [95% CI 3 to 52]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to those irradiated at deep-freezing temperature. The mean toughness (3622 ± 1720 kJ/m3 versus 6231 ± 3410 kJ/m3, mean difference 2609 [95% CI 447 to 4771]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to the non-irradiated control group samples. The mean 0.2% offset yield stress, ultimate compression stress, and toughness of samples irradiated in deep-freezing temperatures (below -40°C) were not different with the numbers available to the non-irradiated control group samples. The Young modulus was not different with the numbers available among the three groups.
CONCLUSION: In this study, maintenance of a deep-freezing temperature below -40°C, using dry ice as a cooling agent, consistently mitigated the adverse effects of irradiation on the monotonic-compression mechanical properties of human cortical bone tissue. Preserving the mechanical properties of a cortical allograft, when irradiated in a deep-freezing temperature, may have resulted from attenuation of the deleterious, indirect effects of gamma radiation on its collagen architecture in a frozen state. Immobilization of water molecules in this state prevents radiolysis and the subsequent generation of free radicals. This hypothesis was supported by an apparent loss of the protective effect when a range of higher freezing temperatures was used during irradiation.
CLINICAL RELEVANCE: Deep-freezing temperatures below -40°C during gamma irradiation may be a promising approach to better retain the native mechanical properties of cortical bone allografts. A further study of the effect of deep-freezing during gamma radiation sterilization on sterility and other important biomechanical properties of cortical bone (such as, tensile strength, fracture toughness, and fatigue) is needed to confirm these findings.
Fulltext Improving knowledge of doctors and paramedics through effective bone procurement workshop: A cognitive approach

Mohd S, Yusof N, Lai LL, Hossain MG, Ramalingam S, Hamid SSA, et al.

BMC Med Educ, 2019 Jul 01;19(1):238.
PMID: 31262281 DOI: 10.1186/s12909-019-1685-9

BACKGROUND: Procurement of bone allograft must be performed by trained personnel. Improper handling and lack of knowledge during bone procurement will lead to contamination hence jeopardizing quality of the procured bones and expose bone recipients to risks of infection in post-operative phase. Bone procurement workshop is the fundamental training programme to enhance skill among personnel who has been or will be involved in bone procurement. This study evaluated the effectiveness of the workshop contents including teaching materials by assessing the knowledge on bone procurement among the participants before and after the workshop.
METHODS: Bone procurement workshop was held for 2 days for doctors and paramedics. The knowledge on bone procurement was evaluated in pre- and post-assessments by answering self administration questionnaire before and after the workshop, respectively.
RESULTS: A total of 50 participants comprised of doctors and paramedics attended the workshop however only 15 (55.6%) doctors and 12 (44.4%) paramedics completed the assessments. Overall, the mean total score for the post-assessment (61.4%) was significantly higher (p
Fulltext COVID-19 Collateral Damage: Management of Periprosthetic Joint Infection in Malaysia

Anwarali Khan MH, Kow RY, Ramalingam S, Ho JPY, Jaya Raj J, Ganthel Annamalai K, et al.

Cureus, 2021 Oct;13(10):e18820.
PMID: 34804677 DOI: 10.7759/cureus.18820

Background and objective Periprosthetic joint infection (PJI) is one of the dreaded complications in patients after arthroplasty surgeries, owing to the risk of morbidity and arduous investigations and management associated with it. Nevertheless, as Malaysia is currently battling against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 (COVID-19) pandemic head-on, the treatment for other non-life-threatening diseases including PJI has taken a backseat. In this study, we present a case series of 11 patients with PJI who were managed surgically at the largest tertiary hospital in Malaysia and we hope to shed some light on the difficulties we have encountered during this trying period. Patients and methods Patients with PJIs who underwent surgical intervention during the ongoing COVID-19 pandemic (March 1, 2020, to June 30, 2021) were reviewed and included in this study. The demographic profile of the patients, presenting complaints, prosthesis topography, biochemical investigative findings, surgical interventions, and short-term outcomes were summarized. Results A total of 11 patients were treated surgically at Hospital Kuala Lumpur for PJI. Among them, five patients are still awaiting their second-stage surgeries despite the completion of their antibiotic regimes, and they are fit for the procedure. Conclusion The COVID-19 pandemic has wreaked havoc on the treatment of patients with PJI. In a setting with scarce resources, surgeons should strongly consider single-stage revision surgeries for the treatment of patients with PJI.
Outcomes of Geriatric Hip Fractures in a Tertiary Referral Center in Malaysia During the COVID-19 Pandemic

Anwarali Khan MH, Kow RY, Ramalingam S, Sofian A, Ho JPY, Jaharan Singh KS, et al.

Cureus, 2023 Jun;15(6):e40479.
PMID: 37456372 DOI: 10.7759/cureus.40479

Introduction With the advancing age of the population, there are an increasing number of patients with geriatric hip fractures. Despite the advancement of surgical knowledge and improvement of implant designs to treat geriatric hip fractures, mortality and morbidity remain high among these frail patients. In conjunction with the COVID-19 pandemic, the collateral damage dealt to these patients remains unknown as scarce resources are funneled to deal with the pandemic. This study is geared to investigate the surgical outcomes of patients with geriatric hip fractures who were admitted during the initial phase of the COVID-19 pandemic. Methods This retrospective study was carried out at Hospital Kuala Lumpur, the largest public hospital in the capital of Malaysia, from March 1, 2020, to March 1, 2021. All patients of age 60 years and above were screened for suitability. Only patients who had undergone surgical intervention during the study period were included in this study. Patients' demographic data, mechanism of injury, waiting time for surgery, type of surgery, complications and ambulatory status were obtained from the medical records. Univariate analysis was performed to determine the factors associated with complications as well as the post-operative ambulatory status of the patients. Results A total of 52 patients were included in this study, with a median age of 72 years. The majority of the patients were Chinese (n=21, 40.4%). This was followed by Malay and Indian (n=14, 26.9% each) and other ethnicity (n=3, 5.8%). More than three-quarters of the patients had a trivial injury such as a fall due to a miss-step (n=16, 30.8%) and slip (n=16, 30.8%) and a fall due to dizziness (n=8, 15.4%). Only 12 patients (23.1%) sustained hip fractures due to trauma. The median time to surgery for these patients was 5 days (interquartile range: 4 days). Most of these patients underwent total hip replacement (n=30, 57.7%). This was followed by unipolar hemiarthroplasty (n=11, 21.2%), bipolar hemiarthroplasty (n=10, 19.2%) and internal fixation (n=1, 1.9%). Among these patients, six of them had documented complications. There were periprosthetic joint infection (n=2, 3.8%), dislocation (n=2, 3.8%), hematoma formation (n=1, 1.9%) and seroma (n=1, 1.9%). Six months after the surgery, most of the patients were able to ambulate, albeit some patients required walking aid such as walking stick and walking frame. Univariate analysis showed that all the factors were not associated with the complications and the post-operative ambulatory status of the patients. Conclusion The incidence of geriatric hip fractures remains high during the COVID-19 pandemic despite the movement control order (MCO) being enforced in Malaysia. With prompt surgical intervention, most of the patients can regain ambulatory status, albeit with a walking aid.
The readiness of the Asian research ethics committees in responding to the COVID-19 pandemic: A multi-country survey

Karbwang J, Torres CE, Navarro AM, Wongwai P, Jimenez EB, Shetty Y, et al.

F1000Res, 2024;13:19.
PMID: 39165349 DOI: 10.12688/f1000research.143138.1

BACKGROUND: COVID-19 is a highly challenging infectious disease. Research ethics committees (RECs) have challenges reviewing research on this new pandemic disease under a tight timeline and public pressure. This study aimed to assess RECs' responses and review during the outbreak in seven Asian countries where the Strategic Initiative for Developing Capacity in Ethical Review (SIDCER) networks are active.
METHODS: The online survey was conducted in seven Asian countries from April to August 2021. Two sets of online questionnaires were developed, one set for the chairs/secretaries and another set for the REC members.The REC profiles obtained from the REC members are descriptive in nature. Data from the chairs/secretaries were compared between the RECs with external quality assessment (SIDCER-Recognized RECs, SR-RECs) and non-external quality assessment (Non-SIDCER-Recognized RECs, NSR-RECs) and analyzed using a Chi-squared test.
RESULTS: A total of 688 REC members and 197 REC chairs/secretaries participated in the survey. Most RECs have standard operating procedures (SOPs), and have experience in reviewing all types of protocols, but 18.1% had no experience reviewing COVID-19 protocols. Most REC members need specific training on reviewing COVID-19 protocols (93%). In response to the outbreak, RECs used online reviews, increased meeting frequency and single/central REC. All SR-RECs had a member composition as required by the World Health Organisation ethics guidelines, while some NSR-RECs lacked non-affiliated and/or layperson members. SR-RECs reviewed more COVID-related product development protocols and indicated challenges in reviewing risk/benefit and vulnerability (0.010), informed consent form (0.002), and privacy and confidentiality (P = 0.020) than NSR-RECs.
CONCLUSIONS: Surveyed RECs had a general knowledge of REC operation and played a significant role in reviewing COVID-19-related product development protocols. Having active networks of RECs across regions to share updated information and resources could be one of the strategies to promote readiness for future public health emergencies.