Comparison of First- and Second-Generation Fixed-Bearing Total Ankle Arthroplasty Using a Modular Intramedullary Tibial Component.

BACKGROUND: This series reviews the clinical and radiographic outcomes of patients who underwent total ankle replacement (TAR) using first- and second-generations of a modern fixed-bearing prosthesis utilizing a modular intramedullary stem. METHODS: A consecutive series of first- and second-generation primary TARs with modular intramedullary stems were identified. Clinical outcome data were collected prospectively--including visual analog scale for pain, American Orthopaedic Foot & Ankle Society hindfoot-ankle, Short Musculoskeletal Function Assessment, and Short Form-36 scores. Preoperative coronal plane deformity and correction of deformity after TAR were assessed. Complications, subsequent procedures, and failure rates were compared. A total of 193 first- and 56 second-generation patients were identified with a mean follow-up of 3.7 and 2.1 years, respectively. RESULTS: Clinical outcome data reflected significant improvements at 1 year postoperatively, and improvements were maintained at 2-year follow-up for each group. Improvement in visual analog scale scores were significantly better in the second-generation group at 1 year postoperatively, but this was not maintained at 2 years. Mean coronal tibiotalar angles for ankles with preoperative varus or valgus deformities were significantly improved. Correction was maintained until final follow-up, with no significant differences in deformity improvement between groups. The rate of reoperation at 2 years postoperatively on the affected foot or ankle subsequent to the index ankle replacement for patients in the first-generation group (18.5%) was higher compared to the second-generation group (15.9%), but the time until reoperation was not statistically significant (P = .376). The implant failure rate was higher in the first-generation group (6.0%) compared to the second-generation group (2.6%) at 2 years postoperatively, but the time until failure was not significantly different (P = .295). CONCLUSION: Patients who underwent TAR with a first- or second-generation fixed-bearing prosthesis with an intramedullary tibial component demonstrated significant improvements in all measures of pain and function with sustained improvements in coronal plane alignment. The second-generation prosthesis demonstrated slightly better improvements at 1 year and was associated with lower reoperation and implant failure rates. LEVEL OF EVIDENCE: Level II, comparative series.

Impact of perioperative allogeneic and autologous blood transfusion on acute wound infection following total knee and total hip arthroplasty.

BACKGROUND: Patients undergoing total hip or knee arthroplasty frequently receive blood transfusions. The relationship between transfusion and the risk of infection following total joint arthroplasty is unclear. In this study, we sought to examine the impact of allogeneic and autologous transfusion on the risk of acute infection following total hip and total knee arthroplasty. METHODS: We performed a retrospective study of consecutive primary total knee arthroplasties and total hip arthroplasties. Patients who had a reoperation for suspected infection within three months after the arthroplasty were identified. Differences in risk factors were assessed across transfusion groups: no transfusion, autologous only, and allogeneic exposure (allogeneic with or without additional autologous transfusion). Backward-stepwise logistic regression analysis was used to compare reoperations (as outcomes) between cases with and those without allogeneic exposure. Prespecified covariates were body mass index, diabetes, an American Society of Anesthesiologists (ASA) score of >2, preoperative hematocrit, and total number of units transfused perioperatively. RESULTS: We identified 3352 patients treated with a total hip or knee arthroplasty (1730 total knee arthroplasties and 1622 total hip arthroplasties) for inclusion in the study. Transfusion was given in 1746 cases: 836 of them had allogeneic exposure, and 910 had autologous-only transfusion. There were thirty-two reoperations (0.95%) for suspected infection. Between-group risk-factor differences were observed. The mean age and the rates of diabetes, immunosuppression, ASA scores of >2, and bilateral surgery were highest in the allogeneic group, as were estimated blood loss, surgery duration, and total number of units transfused (p < 0.001). In the unadjusted analyses, the rate of reoperations for suspected infection was higher in the cases with allogeneic exposure (1.67%) than in those without allogeneic exposure (0.72%) (p = 0.013). Autologous-only transfusion was not associated with a higher reoperation rate. However, multivariable logistic regression demonstrated that the total number of units transfused (p = 0.011) and an ASA score of >2 (p = 0.008)-but not allogeneic exposure-were significantly predictive of a reoperation. CONCLUSIONS: Perioperative allogeneic transfusion was associated with a higher rate of reoperations for suspected acute infection. However, patients with allogeneic exposure had increased infection risk factors. After adjustment for the total number of units transfused and an ASA score of >2, allogeneic exposure was not significantly predictive of a reoperation for infection.

Genetic and cellular evidence of decreased inflammation associated with reduced incidence of posttraumatic arthritis in MRL/MpJ mice.

OBJECTIVE: To examine the relationship between inflammation and posttraumatic arthritis (PTA) in a murine intraarticular fracture model. METHODS: Male C57BL/6 and MRL/MpJ "superhealer" mice received tibial plateau fractures using a previously established method. Mice were killed on day 0 (within 4 hours of fracture) and days 1, 3, 5, 7, 28, and 56 after fracture. Synovial tissue samples, obtained prior to fracture and on days 0, 1, 3, 5, and 7 after fracture, were examined by reverse transcription-polymerase chain reaction for gene expression of proinflammatory cytokines and chemokines. Synovial fluid and serum samples were collected to measure cytokine concentrations, using enzyme-linked immunosorbent assay. Whole joints were examined histologically for the extent of synovitis and cartilage degradation, and joint tissue samples from all time points were analyzed immunohistochemically to evaluate the distribution of interleukin-1 (IL-1). RESULTS: Compared to C57BL/6 mice, MRL/MpJ mice had less severe intraarticular and systemic inflammation following joint injury, as evidenced by lower gene expression of tumor necrosis factor α and IL-1ß in the synovial tissue and lower protein levels of IL-1α and IL-1ß in the synovial fluid, serum, and joint tissues. Furthermore, after joint injury, MRL/MpJ mice had lower gene expression of macrophage inflammatory proteins and macrophage-derived chemokine (CCL22) in the synovial tissue, and also had reduced acute and late-stage infiltration of synovial macrophages. CONCLUSION: C57BL/6 mice exhibited higher levels of inflammation than MRL/MpJ mice, indicating that MRL/MpJ mice are protected from PTA in this model. These data thus suggest an association between joint tissue inflammation and the development and progression of PTA in mice.