The Effect of Hypotensive Anesthesia on Hemoglobin Levels during Total Knee Arthroplasty

Introduction: Hypotensive epidural anesthesia (HEA) is used in total joint arthroplasty as a safe and effective blood-saving modality. In order to maintain the blood pressure and heart rate patients, receive 1000 to 1500 mL of lactated Ringer’s solution during surgery. While HEA reduces the intraoperative blood loss, the effect of intravenous fluid loading on hemoglobin levels is not fully understood. The current study investigates the effect of HEA on perioperative hemoglobin levels. Materials and Methods: The study included 35 patients operated on by a single surgeon undergoing primary total knee arthroplasty under HEA. Intraoperatively, at least 300 mL of intravenous fluid were given every 15 min over the first 60 min after HEA. Blood samples were drawn before entering the operating room, after HEA, as well as after inflation of the tourniquet, every 15 min thereafter, as well as in the recovery room and on postoperative days one and two. In addition, fluid in- and outtake was recorded. Results: Patients received a mean 1275 mL during the 60 min of tourniquet time. The mean arterial pressure (MAP) 5 min after HEA dropped to 60 mmHg and reached a constant level of around 58 mmHg 15 min after HEA. The average hemoglobin level dropped from 13.9 g/dL prior to HEA, to 12.5 g/dL immediately after HEA (p < 0.001). Intraoperatively the hemoglobin level dropped further and reached 11.8 g/dL at 60 min in the absence of blood loss. Conclusions: Hypotensive epidural anesthesia and the resulting fluid substitution resulted in an average hemoglobin drop of 2.1 g/dL within the first 60 min. This needs to be taken into account when evaluating the need for blood transfusions after primary joint replacement surgery under HEA

Dislocation rates with combinations of anti-protrusio cages and dual mobility cups in revision cases: Are we safe?

BACKGROUND:Due to the increasing numbers of revision total hip arthroplasty (THA) procedures being carried out, the frequency of major acetabular defects is also rising. A combination of an anti-protrusio cage and a dual mobility cup has been used in our department since 2007 in order to reduce the dislocation rate associated with complex defects. Although both implants have an important place in endoprosthetics, there are as yet limited data on the dislocation and complication rates with this combination. METHODS:This retrospective study included all patients in whom a Burch-Schneider cage and a dual mobility cup were implanted in our department between 2007 and 2014 and who had a minimum follow-up period of 24 months. RESULTS:The study included 79 patients with a mean follow-up period of 5.3 years. The implant survival rate was 85% at 65 months. Postoperative dislocation occurred in two cases (2.1%), with the first dislocation taking place within the first 3 weeks in both of these patients. CONCLUSIONS:The present study shows a promising dislocation rate with a combination of an anti-protrusio cage and a dual mobility cup. Particularly in the medium-term follow-up, no further dislocations occurred in the study. A maximum cup inclination of 45° in revision cases was associated with a lower dislocation rate in this group of patients

Revision TKA with a distal femoral replacement is at high risk of reinfection after two-stage exchange for periprosthetic knee joint infection

Purpose!#!Megaprosthetic distal femoral reconstruction (DFR) is a limb-salvage procedure to address bone loss following two-stage revision for periprosthetic knee joint infection (PJI). The purpose of this study was to analyze the survival of DFR compared to hinged total knee arthroplasty (TKA). It was hypothesized that DFR was associated with a poorer survival.!##!Methods!#!In this retrospective single-center study, 97 subjects who underwent two-stage revision of chronic knee PJI were included. Among these, 41 were DFR. The diagnosis of PJI was established using the Musculoskeletal Infection Society (MSIS) criteria. Implant survival was calculated using Kaplan-Meier method and compared with the log-rank test as well as multivariate Cox regression at a minimum follow-up period of 24 months.!##!Results!#!The median follow-up period was 59 (interquartile range (IQR) 45-78) months. Overall, 24% (23/97) of patients required revision surgery for infection. The infection-free survival of rotating hinge revision TKA was 93% (95% Confidence Interval (CI) 86-100%) at five years compared to 50% (95% CI 34-66%) for DFR. In multivariate analysis, the risk factors for reinfection were DFR reconstruction (HR 4.7 (95% CI 1-22), p = 0.048), length of megaprosthesis (HR 1.006 (95% CI 1.001-1.012), p = 0.032) and higher BMI (HR 1.066, 95% CI 1.018-1.116), p = 0.007). 10% (4/41) of patients undergoing DFR underwent amputation to treat recurrent infection.!##!Conclusion!#!Megaprosthetic DFR as part of a two-stage exchange for PJI is a salvage treatment that has a high risk for reinfection compared to non-megaprosthetic TKA. Patients must therefore be counseled accordingly.!##!Level of evidence!#!Retrospective observational study, Level IV

Implant Survival, Clinical Outcome and Complications of Megaprosthetic Reconstructions Following Sarcoma Resection

Megaprosthetic reconstruction of segmental bone defects following sarcoma resection is a frequently chosen surgical approach in orthopedic oncology. While the use of megaprostheses has gained popularity over the last decades and such implants are increasingly used for metastatic reconstructions and in non-tumor cases, there still is a high risk of long-term complications leading to revision surgery. This article investigates current implant survivorship, frequency and types of complications as well as functional outcomes of upper and lower limb megaprosthetic reconstructions