TKR Group Research Articles

Unicompartmental versus computer-assisted total knee replacement for medial compartment knee arthritis: a matched paired study

Patients older than 60 with unicompartmental knee arthritis can be treated with total or unicompartmental knee replacement. The aim of this study was to compare the results of matched paired groups of patients with isolated medial compartment knee arthritis replaced with either UKR (group A) or computer-assisted TKR (group B). The results included 68 knees at a minimum follow-up of 3 years. All patients had a varus deformity no greater than 8 masculine and a BMI lower than 30. Patients were matched in terms of preoperative arthritis severity, age, gender and preoperative range of motion. In the computer-assisted TKR group, all the implants were positioned within 4 masculine of the correct hip-knee-ankle angle and frontal tibial component angle. The surgical time and hospital stay were statistically longer in the CA TKR group. During the study no implant required revision. The results showed higher scores for a UKR in the treatment of isolated primary unicompartmental knee arthritis in patients older than 60 compared to a computer-assisted TKR. In this study a computer-assisted alignment system for TKR with optimal implant positioning did not produce equivalent clinical results compared to a UKR, but did increase the financial costs.

Do we really need to routinely crossmatch blood before primary total knee or hip arthroplasty?

A maximum surgical blood ordering schedule may lead to wastage of valuable resources due to over-ordering of blood and/or under-utilisation. We audited the results of a group-and-save (GS) policy for primary hip (THR) and knee (TKR) arthroplasty to evaluate its safety and practicality. We conducted a retrospective review of consecutive patients attending for THR (177) or TKR (137) over a period of 8 months (phase 1). Following introduction of a limited GS policy, 205 THR and 147 TKR were reviewed prospectively over a corresponding period of 8 months (phase 2). Corresponding THR and TKR groups in each phase were comparable with respect to age, gender, length of stay, operating surgeon, pre- and lowest postoperative hemoglobin, reason for and timing of transfusion. Quantities (units) of blood requested pre- and postoperatively, transfused and returned to the blood bank, were recorded. 77 and 62% of all blood requested for THR and TKR, respectively, in phase 1 was not used. 58 and 21% of patients undergoing THR and TKR, respectively, in phase 2 underwent preoperative GS, with 92% and 100% of all blood requested being used for transfusion. Overall, the quantity of blood returned was reduced by 25% for the THR group. Transfusion rates fell by 9% and 5% for the TKR and THR groups, respectively. We found no adverse events associated with blood from a GS sample. Cost savings of 37 800 euro were calculated estimated for the study period (phase 2). For routine primary THR/TKR, GS policy is a safe procedure. Reduction in non-utilisation of blood has economic and cost-saving implications for limited healthcare resources. Having subsequently introduced a group-and-save policy for all patients undergoing routine THR/TKR, considerable savings have been identified after only 2 months.

Poster 71: Preventing venous thromboembolism after total joint replacement. A multifactorial approach

Objective: To investigate the efficacy of a comprehensive protocol encompassing hypotensive epidural anesthesia, aspirin, intermittent compression devices, along with early mobilization and postoperative exercises in patients after noncemented total hip (THR) and knee (TKR) replacements. Design: Prospective observational 2-group study. Setting: University hospital. Participants: 360 consecutive patients after noncemented THR and TKR. Interventions: All patients were allowed full weight bearing on the first postoperative day. Ankle-high pneumatic boots (foot pumps) were used early after surgery. Aspirin (325mg/d every day) was given to all patients as a pharmacologic measure to prevent thromboembolic events. Most patients were transferred to an acute rehabilitation center and received physical therapy sessions on postoperative day 1. Main Outcome Measures: The presence of deep vein thrombosis (DVT) was determined with the use of venous duplex scans on a regular basis from postoperative day 5 to day 10 (mean, 6.8). The duration of follow-up was 3 months. No patients were lost to follow-up. Results: 6 patients (3%) developed DVT in the THR group and 4 patients (2.4%) in the TKR group. None of the patients developed symptomatic pulmonary embolism during the follow-up period. Conclusion: The use of epidural anesthesia, foot pumps, early full weight-bearing ambulation, aspirin, and systematic duplex ultrasonography surveillance constitutes an effective combination to prevent DVT (2%–3%) after total joint replacements.