Hee Nee Pang

Intravenous versus intra-articular tranexamic acid in total knee arthroplasty: A double-blinded randomised controlled noninferiority trial.

BACKGROUND Despite the proven efficacy of both intravenous (IV) and intra-articular (IA) tranexamic acid (TXA) in reducing blood loss during total knee arthroplasty (TKA), the ideal route of administration remained debatable. This study aimed to compare the effect of IV versus IA TXA on transfusion incidences, perioperative blood loss and postoperative lower limb swelling during TKA. METHODS One hundred patients were prospectively randomised into two groups: 1) IV TXA; and 2) IA TXA. In both groups, TXA was administered intraoperatively after cementing the prostheses. The perioperative blood loss was calculated using the haemoglobin balance method. The thigh, suprapatellar, and calf girths were measured preoperatively and on postoperative day (POD) 4. RESULTS Two patients in the IV group and one patient in the IA group required blood transfusion (p=0.500). The median and interquartile range (IQR) of perioperative blood loss on POD1 and POD4 was 530 (IQR 386,704) and 730 (IQR 523,925) ml for the IV group, compared with 613 (IQR 506,703) and 799 (IQR 563,1067) ml for the IA group (p=0.090 and p=0.232 respectively). The median increment in thigh, suprapatellar, and calf girths were 1.5 (IQR 0, 3.0), 2.0 (IQR 0.5, 4.0) and 0 (IQR 0, 1.0) cm for the IV group, compared to 2.0 (IQR 1.0, 4.0), 2.0 (IQR 0, 4.5) and 0 (IQR 0, 1.5) cm for the IA group (p=0.246, p=0.562, and p=0.937 respectively). CONCLUSIONS Both IV and IA TXA had comparable effect on transfusion incidences, perioperative blood loss, and postoperative lower limb swelling during TKA. IA TXA is an alternative to IV TXA. LEVEL OF EVIDENCE I.

Computer navigation is a useful intra-operative tool for joint line measurement in total knee arthroplasty

BACKGROUND Restoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead suboptimal outcomes. The purpose of this study was to analyze the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA). METHODS One hundred sixty-eight patients (168 knees) underwent CAS TKA by two surgeons at a single institution with 2 years follow-up. The final change in joint line was calculated from the verified tibial resection and distal femoral cuts. Group A patients had joint line changes of less than 4mm and Group B patients had joint line changes of more than 4mm. Post-operative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at 6 months and 2 years post TKA. RESULTS There was significant linear correlation between joint line changes and Oxford scores (P=0.0001), Function scores (P=0.0001) and Knee scores (P=0.0001) at 6 months and Oxford scores (P=0.0001) alone at 2 years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients demonstrated better Oxford scores (P=0.0001), Function scores (P=0.0001), Knee scores (P=0.0001) and total SF-36 scores (P=0.003) at 6 months as well as better Oxford scores (P=0.0001) and Knee scores (P=0.014) at 2 years. CONCLUSIONS CAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥4 mm are associated with poorer clinical outcome scores. LEVEL OF EVIDENCE Prognostic Study, Level II-1.

Low Infection Rates in Total Knee Arthroplasty in End Stage Renal Failure Patients

End stage renal failure is considered a risk factor for postoperative infection and many surgeons are cautious in offering this group of patients total knee arthroplasty for symptomatic osteoarthritis. In this retrospective study, 16 total knee arthroplasties were performed in 13 patients and each case was followed up for an average of 5.1 years. We report no cases of infection and also an overall improvement in multiple validated outcome measures. There were, however, 2 cases of periprosthetic loosening. As the patients in our series were generally younger and none was diagnosed with stroke or peripheral vascular disease at the time of surgery, we believe that careful patient selection is key to reducing infection rates in this challenging group of patients.

THINK surgical TSolution-One® (Robodoc) total knee arthroplasty

THINK Surgical TSolution-One® is an active-autonomous, image-based, robotic milling system which enables the surgeon to attain a consistently accurate implant component positioning. The TSolution-One® system is capable of achieving this through an image-based preoperative planning system which allows the surgeon to create, view and analyse the surgical outcome in 3D. The accuracy and precision of component positioning have been attributed to the following factors: customized distal femoral resection, accurate determination of the femoral rotational alignment, minimization of errors and maintenance of bone temperature with robotic milling. Despite all these advantages, there is still a paucity of long-term, high-quality data that demonstrates the efficacy of robotic-assisted total knee arthroplasty (TKA). Questions regarding radiation risks, prolonged surgical duration and cost-effectiveness remain unanswered. This paper aims to describe: (1) TSolution-One® surgical technique; (2) limitations and complications; (3) clinical and radiological outcomes.

Identifying an Ideal Time Frame for Staged Bilateral Total Knee Arthroplasty to Maximize Functional Outcome

Abstract Compared with staged bilateral total knee arthroplasty (TKA), simultaneous bilateral TKA carries a higher risk of cardiac complications, pulmonary complications, and mortality, especially in patients with preexisting cardiopulmonary disease or advanced age. However, the period of time between staged TKAs that would eliminate these increased risks has yet to be determined. The purpose of this study is to evaluate complication rates and functional outcome in patients who underwent staged bilateral TKA and to determine an optimal time frame for the second knee. The authors retrospectively reviewed 306 patients who underwent staged bilateral TKA between 2002 and 2013. Patients were grouped into 31 to 90, 91 to 180, 181 to 270, and 271 to 365 days interval, where complication and 90‐day readmission rates for the second TKA were identified. Patients were also assessed preoperatively and 2 years postoperatively using the Oxford knee score (OKS) and Short‐Form (SF)‐36. There was no significant difference in complication and 90‐day readmission rates between the various groups. The functional outcome of the knees scored 2 years postoperatively using OKS and SF‐36 showed comparable results across all four groups. Thus, the authors could not identify an ideal time frame for performing the second TKA with the objective of maximizing functional outcome.

No Difference in Functional Outcomes after Total Knee Arthroplasty with or without Pinless Navigation

&NA; This study aims to investigate the functional outcomes of pinless navigation (BrainLAB VectorVision Knee 2.5 navigation system; Munich, Germany) as an intraoperative alignment guide in total knee arthroplasty (TKA). A prospective, 24‐month follow‐up study of 100 patients who were scheduled and randomized into two groups, the pinless navigation and conventional surgery, was conducted. All TKAs were performed with the surgical aim of achieving neutral coronal alignment with the 180‐degree mechanical axis. The outcomes measured in this study were Oxford Knee Score (OKS), Knee Society Score (KSS), Short Form‐36 (SF‐36), and range of motion (ROM). At 24‐month postoperatively, four and two patients were lost to follow‐up from the pinless navigation group and conventional group, respectively. There were no significant differences in absolute scores of the OKS, KSS, and ROM, as well as changes from preoperative baseline, between pinless navigation and conventional groups at both 6 and 24 months postoperatively. Pinless navigation results in comparable functional outcomes as conventional TKA at 6 and 24 months postoperatively.