Background Many patients experience bilateral knee osteoarthritis and require bilateral total knee replacement (TKR). Same-stage, bilateral TKR is proposed to be a cost-effective and safe solution compared to two-stage, but conflicting results in the literature are reported. We aim to compare the costs, safety, and rehabilitation performance of patients in same-stage versus two-stage, bilateral TKR with our centre’s perioperative protocol. Materials and methods We retrospectively reviewed 175 patients (95 same-stage, 80 two-stage) who had undergone bilateral TKR in our centre. Patient selection for same-stage, bilateral TKR was strictly protocol-driven and required fulfilment of all criteria, including age < 75 years, American Society of Anesthesiologists (ASA) grade 1 or 2, body mass index (BMI) < 40, and having non-complex arthritis. All patients followed a standardised pre-operative, intra-operative, and post-operative Enhanced Recovery After Surgery (ERAS) protocol. The cost, safety profiles, and rehabilitation outcomes were compared between the same-stage and two-stage groups. Results The same-stage, bilateral TKR reduced the length of hospital stays by 5.71 days per patient, decreased the operation time by 27.4 min, saved 3.34 (18.6%) physiotherapy sessions, and 3.78 (51.5%) occupational therapy sessions. The same-stage group experienced a higher haemoglobin drop but no significant difference in transfusion percentage, transfusion volume, complication rate, and readmission rate. The two-stage subgroup with anaesthetic risk, age, and BMI similar to the same-stage group showed the same results. Same-stage, bilateral TKR patients experienced no significant difference in final post-operative pain levels and rehabilitation outcomes as two-stage TKR patients. Conclusion This study showed that same-stage, bilateral TKR can reduce costs, with similar safety profiles and rehabilitation outcomes compared to the two-stage, bilateral TKR.

Cement arterio-venogram is a rare event with cement extrusion into femoral nutrient vessels. In literature it is known to be benign with no significant clinical sequelae. It is postulated that it is due to high cement implantation pressure, that results in optimal cement filling quality. All previously reported cases were female patients, and it is thought to be a female only phenomenon due to the relatively narrow femoral canal leading to higher pressures during cementation. In this case series we report 3 cases different to existing literature. All 3 patients showed a cement arterio-venogram together with bone cement implantation syndrome and hypotension intraoperatively. It was also observed that during implantation the cement was of low viscosity. We postulate low cement viscosity during implantation with pressurization is also a contributing factor to these phenomena. This case series also demonstrates the first 2 male cases, showing this the even can occur in males too. The cement arteriovenogram is located at 41%–42% femur length which is within the ‘third sixth’ of the length of the femur. Good cementation techniques and prevention is also highlighted in this report.