Total knee arthroplasty is safe for patients aged ≥80 years in Hong Kong.

INTRODUCTION: Total knee arthroplasty (TKA) is an efficacious operation that improves pain and function in patients with knee arthritis. Because of the population ageing trend in Hong Kong, there is a need to determine the safety profile of TKA in older patients. This study examined the age of patients who underwent TKA in the past 10 years in Hong Kong; the aim was to investigate the mortality safety profile and clinical outcomes of TKA in patients aged ≥80 years. METHODS: This study included all patients who underwent primary TKA in the Hospital Authority (HA) from 2010 to 2019. Incidences of 30-day, 90-day, and 1-year mortality were established. Clinical outcomes of patients aged ≥80 years in one cluster of HA hospitals were assessed. RESULTS: Between 2010 and 2019, 25 040 TKA procedures were conducted in all HA hospitals; 2491 were conducted in patients aged ≥80 years. The median age at operation was higher during 2015-2019 than during 2010-2014 (70 vs 69 years; P<0.001); furthermore, an increase was observed in the proportion of patients aged ≥80 years at the time of operation. Incidences of 30-day, 90-day, and 1-year mortality were 0.156%, 0.35%, and 1.09%, respectively. CONCLUSIONS: In this first study to examine the safety profile of TKA in older patients in Hong Kong, the mean age at the time of TKA and proportion of patients aged ≥80 years have steadily risen in the past decade. Even in older patients, TKA is a reasonably safe procedure.

Universal haemoglobin A1c screening reveals high prevalence of dysglycaemia in patients undergoing total knee arthroplasty.

INTRODUCTION: Diabetes mellitus is an established modifiable risk factor for periprosthetic joint infection (PJI). Haemoglobin A1c (HbA1c) is a glycaemic marker that correlates with diabetic complications and PJI. As diabetes and prediabetes are frequently asymptomatic, and there is increasing evidence to suggest a correlation between dysglycaemia and osteoarthritis, it is reasonable to provide HbA1c screening before total knee arthroplasty (TKA). The aim of the present study was to determine the prevalence of dysglycaemia in patients who underwent TKA and investigate whether HbA1c screening and optimisation of glycaemic control before TKA affects the incidence of PJI after TKA. METHODS: Patients who underwent primary TKA before and after routine HbA1c screening was introduced in our unit were reviewed. Prediabetes and diabetes were defined according to the American Diabetes Association. Patients with HbA1c ≥7.5% were referred to an endocrinologist for optimisation of glycaemic control before TKA. The incidence PJI, defined according to the Musculoskeletal Infection Society criteria, was recorded. RESULTS: A total of 729 patients (934 knees) had HbA1c screening before TKA. Of them, 17 (2.3%) and 184 (25.2%) patients had known prediabetes and diabetes, respectively, and 265 (36.4%) and 12 (1.6%) had undiagnosed prediabetes and diabetes, respectively. The incidence of PJI was significantly lower in all patients who received HbA1c screening compared with those who did not (0.2% vs 1.02%, P=0.027). CONCLUSION: Screening for HbA1c before TKA provides a cost-effective opportunity to identify undiagnosed dysglycaemia. Patients identified as having dysglycaemia receive modified treatment, significantly reducing the rate of PJI when compared with historical controls.

Blood transfusions in total knee arthroplasty: a retrospective analysis of a multimodal patient blood management programme.

PURPOSE: Transfusion is associated with increased perioperative morbidity and mortality in patients undergoing total knee arthroplasty (TKA). Patient blood management (PBM) is an evidence-based approach to maintain blood mass via haemoglobin maintenance, haemostasis optimisation, and blood loss minimisation. The aim of the present study was to assess the effectiveness of a multimodal PBM approach in our centre. METHODS: This was a single-centre retrospective study of patients who underwent primary TKA in Queen Mary Hospital in Hong Kong in 2013 or 2018, using data from the Clinical Data Analysis and Reporting System and a local joint registry database. Patient demographics, preoperative haemoglobin, length of stay, readmission, mean units of transfusion, postoperative prosthetic joint infection, and mortality data were compared between groups. RESULTS: In total, 262 and 215 patients underwent primary TKA in 2013 and 2018, respectively. The mean transfusion rate significantly decreased after PBM implementation (2013: 31.3%; 2018: 1.9%, P<0.001); length of stay after TKA also significantly decreased (2013: 14.49±8.10 days; 2018: 8.77±10.14 days, P<0.001). However, there were no statistically significant differences in readmission, early prosthetic joint infection, or 90-day mortality rates between the two groups. CONCLUSION: Our PBM programme effectively reduced the allogeneic blood transfusion rate in patients undergoing TKA in our institution. Thus, PBM should be considered in current TKA protocols to reduce rates of transfusions and related complications.

Pain Relief After Total Knee Arthroplasty with Intravenous and Periarticular Corticosteroid: A Randomized Controlled Trial.

BACKGROUND: Total knee arthroplasty (TKA) is a cost-effective procedure, but it is also associated with substantial postoperative pain. The present study aimed to compare pain relief and functional recovery after TKA among groups that received intravenous corticosteroids, periarticular corticosteroids, or a combination of both. METHODS: This randomized, double-blinded clinical trial in a local institution in Hong Kong recruited 178 patients who underwent primary unilateral TKA. Six of these patients were excluded because of changes in surgical technique; 4, because of their hepatitis B status; 2, because of a history of peptic ulcer; and 2, because they declined to participate in the study. Patients were randomized 1:1:1:1 to receive placebo (P), intravenous corticosteroids (IVS), periarticular corticosteroids (PAS), or a combination of intravenous and periarticular corticosteroids (IVSPAS). RESULTS: The pain scores at rest were significantly lower in the IVSPAS group than in the P group over the first 48 hours (p = 0.034) and 72 hours (p = 0.043) postoperatively. The pain scores during movement were also significantly lower in the IVS and IVSPAS groups than in the P group over the first 24, 48, and 72 hours (p ≤ 0.023 for all). The flexion range of the operatively treated knee was significantly better in the IVSPAS group than in the P group on postoperative day 3 (p = 0.027). Quadriceps power was also greater in the IVSPAS group than in the P group on postoperative days 2 (p = 0.005) and 3 (p = 0.007). Patients in the IVSPAS group were able to walk significantly further than patients in the P group in the first 3 postoperative days (p ≤ 0.003). Patients in the IVSPAS group also had a higher score on the Elderly Mobility Scale than those in the P group (p = 0.036). CONCLUSIONS: IVS and IVSPAS yielded similar pain relief, but IVSPAS yielded a larger number of rehabilitation parameters that were significantly better than those in the P group. This study provides new insights into pain management and postoperative rehabilitation following TKA. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

GDNF-treated acellular nerve graft promotes motoneuron axon regeneration after implantation into cervical root avulsed spinal cord.

UNLABELLED: It is well known that glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for motoneurons. We have previously shown that it greatly enhanced motoneuron survival and axon regeneration after implantation of peripheral nerve graft following spinal root avulsion. AIMS: In the current study, we explore whether injection of GDNF promotes axon regeneration in decellularized nerve induced by repeated freeze-thaw cycles. METHODS: We injected saline or GDNF into the decellularized nerve after root avulsion in adult Sprague-Dawley rats and assessed motoneuron axon regeneration and Schwann cell migration by retrograde labelling and immunohistochemistry. RESULTS: We found that no axons were present in saline-treated acellular nerve whereas Schwann cells migrated into GDNF-treated acellular nerve grafts. We also found that Schwann cells migrated into the nerve grafts as early as 4 days after implantation, coinciding with the first appearance of regenerating axons in the grafts. Application of GDNF outside the graft did not induce Schwann cell infiltration nor axon regeneration into the graft. Application of pleiotrophin, a trophic factor which promotes axon regeneration but not Schwann cell migration, did not promote axon infiltration into acellular nerve graft. CONCLUSIONS: We conclude that GDNF induced Schwann cell migration and axon regeneration into the acellular nerve graft. Our findings can be of potential clinical value to develop acellular nerve grafting for use in spinal root avulsion injuries.