Trevor G. Murray

Predicting Patient Discharge Disposition After Total Joint Arthroplasty in the United States

The purpose of this study was to develop an easily administered tool to preoperatively predict patient discharge disposition after total joint arthroplasty in the United States. Data were collected in a retrospective review of 517 medical charts and analyzed using logistic regression to develop a model for predicting the likelihood that a patient will not be discharged directly home. The resulting regression model was the basis for the nomogram, named the Predicting Location after Arthroplasty Nomogram. This model demonstrated a bootstrap-corrected concordance index of 0.867, excellent calibration, and external validation as demonstrated by a concordance index of 0.861. Preoperative knowledge that a patient is likely to require an extended care facility allows the clinical care team to make appropriate arrangements and avoid potential delays in patient discharge.

Venous Thromboembolic Disease Reduction With a Portable Pneumatic Compression Device

This study compares a miniaturized, portable, sequential, pneumatic compression device (ActiveCare continuous enhanced circulation therapy [CECT] system) (Medical Compression Systems Ltd, Or Aqiva, Israel), with a nonmobile, nonsequential device on the ability to prevent postoperative deep venous thrombosis (DVT) after joint arthroplasty. All patients were treated with low-molecular-weight heparin, application of 1 of the 2 devices perioperatively, and routine duplex screening. The CECT system had better compliance (83% of the time vs 49%), lower rates of DVT (1.3% compared with 3.6%), reduction in clinically important pulmonary embolism (0 compared to 0.66%), and shorter length of hospital stay (4.2 vs. 5.0 days). The portable CECT system proved significantly more effective than the standard intermittent pneumatic compression when used in conjunction with low-molecular-weight heparin for DVT prevention in high-risk orthopedic patients.

Prospective Randomized Evaluation of the Need for Blood Transfusion During Primary Total Hip Arthroplasty with Use of a Bipolar Sealer

BACKGROUND Blood loss during total hip arthroplasty can be substantial and may lead to adverse patient outcomes and increased health-care costs. Many blood-management options are available for these procedures. The purpose of the present study was to test the hemostatic efficacy of a bipolar sealer used during total hip arthroplasty in order to determine whether its use results in significantly lower transfusion requirements and/or improved clinical, functional, and health-related quality-of-life outcomes in healthy patients. METHODS This prospective, single-center, randomized, double-blinded study was designed to enroll a total of 140 patients. Patients with a low preoperative hemoglobin level or a history of bleeding abnormalities and other medical conditions were excluded. Patients were randomized to either the treatment arm (radiofrequency energy with use of the Aquamantys 6.0 bipolar sealer) or control arm (standard Bovie electrocautery). The primary outcome measure was the transfusion requirement, and the secondary outcome measures were intraoperative estimated blood loss, postoperative hemoglobin levels, perioperative narcotic usage, length of hospital stay, postoperative pain scores, and postoperative function as measured with the Harris hip score and the Short Form-12 quality-of-life score. RESULTS Seventy-one patients were assigned to the treatment arm, and sixty-nine were assigned to the control arm. The mean number of units of blood transfused for all patients in the study and control arms were 0.38 and 0.44, respectively (p = 0.72). The transfusion requirements were similar in the two groups, with fifteen of seventy-one patients in the treatment arm and fourteen of sixty-nine patients in the control arm requiring a transfusion (p = 0.9). No significant differences were detected between the groups in terms of estimated blood loss, postoperative hemoglobin levels, perioperative narcotic usage, length of hospital stay, postoperative pain scores, Harris hip scores, or Short Form-12 scores. CONCLUSIONS In this patient population, there were no significant differences between the treatment and control groups in terms of the need for blood transfusions or overall blood loss. Given these findings, we have discontinued the use of this bipolar sealing device in uncomplicated primary total hip arthroplasty patients at our institution. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Extensor mechanism allograft reconstruction for extensor mechanism failure following total knee arthroplasty.

BACKGROUND Extensor mechanism disruption following total knee arthroplasty is a rare but devastating complication. The purpose of this study was to report our experience with extensor mechanism allograft reconstruction for chronic extensor mechanism failure. METHODS Fifty consecutive extensor mechanism allograft reconstructions were performed in forty-seven patients with a mean age of 67.6 years who were followed for a mean time of 57.6 months (range, twenty-four to 125 months). The operative technique included the use of a fresh-frozen, correctly sized full extensor mechanism allograft that was tensioned tightly in full extension. Patients were evaluated clinically with use of the Knee Society score, and reconstructions were considered failures if the patient had a score of <60 points or a recurrent extensor lag of >30° or if they required revision or removal of the allograft. RESULTS Nineteen reconstructions (38%) were considered failures, including four revised to a second extensor mechanism allograft due to failure of the allograft, five for deep infection, and ten considered clinical failures secondary to a Knee Society score of <60 points or an extensor lag of >30°. The mean Knee Society score improved from 33.9 to 75.9 points (p<0.0001). The estimated Kaplan-Meier survivorship with failure for any reason as the end point was 56.2% (95% confidence interval, 39.4% to 70.1%) at ten years. CONCLUSIONS Extensor mechanism disruption following total knee arthroplasty is a difficult complication to treat, with modest outcomes. Extensor mechanism allograft reconstruction is a reasonable option; however, patients must be informed regarding the substantial risk of complications, and although initial extensor mechanism function may be restored, expectations regarding longer-term outcomes are more guarded.

Influence of technique with distally fixed modular stems in revision total hip arthroplasty.

Distally fixed modular implants have seen a recent increase in use, to manage proximal femoral bone loss often encountered during revision total hip arthroplasty (THA). Forty-three distally fixed modular stems implanted at our institution between 1999 and 2006 were clinically and radiographically reviewed. These patients had either a minimum 2-year follow-up (average, 2.4 years; range, 2-5.6 years) or failure (ie, explant or rerevision required). Eleven stems subsided, and 4 were rerevised (n = 4), for a rate of 9.3%. All revised stems were radiographically undersized, emphasizing the importance of the technique. Although being a valuable option in revision THA, these stems are not free of complications. The high rate of subsidence encountered in our early experience shows that there is a learning curve. This complication is preventable by avoiding undersizing.

Rivaroxaban Use for Thrombosis Prophylaxis Is Associated With Early Periprosthetic Joint Infection

BACKGROUND Periprosthetic joint infection is a disastrous complication after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The use of certain agents to prevent deep vein thrombosis after arthroplasty has been linked to an increased risk of adverse effects including wound drainage and infection. Adverse effects of one alternative, rivaroxaban, was studied in a single community hospital. METHODS International Classification of Diseases, Clinical Modification 9 codes were used to identify primary THAs and TKAs in an administrative database at one large-volume community hospital performed in 2012. Patients were divided into 2 groups: the study group received rivaroxaban, whereas the control group received another form of chemical thromboprophylaxis for at least 2 weeks postoperative. Demographics, risk factors, and illness severity scores were collected for each group. The primary measured outcome was the incidence of deep surgical site infection (SSI) within 30 days postoperative. RESULTS A total of 639 TKA or THA patients were included, with 159 patients who received rivaroxaban and 480 who received another form of chemical thromboprophylaxis. There were no significant differences between groups regarding demographics, risk factors, or illness severity scores. Incidence of early deep SSI in the rivaroxaban group was higher than in the control group (2.5% vs 0.2%; P < .015). CONCLUSION The use of rivaroxaban for thromboprophylaxis led to a significantly increased incidence of deep SSI in a continuous series of patients undergoing primary THA and TKA in a single institution.

The use of abduction bracing for the prevention of early postoperative dislocation after revision total hip arthroplasty.

One potential strategy to decrease the risk of dislocation after revision total hip arthroplasty (THA) is the use of an abduction brace to limit flexion and adduction. The purpose of this study was to compare the dislocation rate after revision THA between patients treated with or without an abduction brace. Data were obtained from 1211 revision THAs performed in 610 women and 518 men who had a mean age of 64.7 years (range, 22-95 years) and were followed up for a minimum of 90 days. Five hundred two patients were braced, whereas 650 were not. The 90-day dislocation rate among patients who wore a brace was 5.2% compared with 5.7% in the nonbrace group (P = .70). Multivariate regression found no benefit to bracing (P = .37), while controlling for factors found to significantly affect dislocation rate in this population. Our data do not support the routine use of an abduction brace to aid in the prevention of dislocation.

Robotic Testing of Proximal Tibio-Fibular Joint Kinematics for Measuring Instability Following Total Knee Arthroplasty

Pain secondary to instability in total knee arthroplasty (TKA) has been shown to be major cause of early failure. In this study, we focused on the effect of instability in TKA on the proximal tibio‐fibular joint (PTFJ). We used a robotics model to compare the biomechanics of the PTFJ in the native knee, an appropriately balanced TKA, and an unbalanced TKA. The tibia (n = 5) was mounted to a six‐degree‐of‐freedom force/torque sensor and the femur was moved by a robotic manipulator. Motion at the PTFJ was recorded with a high‐resolution digital camera system. After establishing a neutral position, loading conditions were applied at varying flexion angles (0°, 30°, and 60°). These included: internal/external rotation (0 Nm, ±5 Nm), varus/valgus (0 Nm, ±10 Nm), compression (100 N, 700 N), and posterior drawer (0 N, 100 N). With respect to anterior displacement, external rotation had the largest effect (coefficient = 0.650; p < 0.0001). Polyethylene size as well as the interaction between polyethylene size and flexion consistently showed substantial anterior motion. Flexion and mid‐flexion instability in TKA have been difficult to quantify. While tibio‐femoral kinematics is the main aspect of TKA performance, the effects on adjacent tissues should not be overlooked. Our data show that PTFJ kinematics are affected by the balancing of the TKA.

Long-term outcomes of total knee arthroplasty following soft-tissue defect reconstruction with muscle and fasciocutaneous flaps

Background: Insufficient soft-tissue coverage following total knee arthroplasty jeopardizes prosthesis retention and may lead to significant complications. The aim of this study was to evaluate the natural history of total knee arthroplasty following flap reconstruction of soft-tissue defects. Methods: A retrospective review of patients treated with flaps after failed total knee arthroplasty between 1998 and 2013 was conducted. Patients with preexisting soft-tissue defects who required reactive flap reconstruction were included in group 1. Patients with no preexisting soft-tissue defects, but with extensive débridement during revision total knee arthroplasty requiring immediate proactive flap coverage, were included in group 2. Results: Fifty-eight patients in group 1 were treated with 86 flaps, and 15 patients in group 2 were treated with 17 flaps. Mean length of follow-up was 67.0 and 54.7 months, respectively (p = 0.21). Flap-related complications and number of subsequent flap revisions were comparable in both groups. Patients in group 1 had a higher rate of implant reinfection (58 percent versus 27 percent; p < 0.05), amputations (25 percent versus 0 percent; p < 0.05), and subsequent prosthesis revisions (2.2 versus 0.9; p < 0.05). Functional joint was preserved in 54 percent and 80 percent of cases, respectively. Mean gain in range of motion and quality of life were significantly better in group 2 (p < 0.05). Conclusions: Early proactive soft-tissue coverage of total-knee arthroplasty is critical to long-term success. In cases where reactive treatment is required, significantly worse outcomes and a high rate of complications should be expected. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Do resistant organisms affect success of two-stage reimplantation for prosthetic hip infections?

Background Infected total hip arthroplasty (THA) generates substantial personal, social, and economic burden. Revision procedures for infection are associated with longer operative times, more blood loss, and more complications compared with revisions for aseptic loosening or primary THA. Methods We retrospectively evaluated 44 patients who had THA and underwent a two-stage revision for prosthetic hip infection with methicillin-resistant or vancomycin-resistant organisms between 1995 and 2005. The minimum follow-up was 24 months (average, 45.2 months; range, 24–130 months). Treatment was considered a failure if a two-stage procedure failed to control the infection and required repeat surgery. Results A two-stage revision procedure with culture-specific antibiotics controlled the infection in 29 of the 44 patients (66%). Of the remaining 15 patients, 10 (23%) had a reinfection, and five (11%) had a relapse with the same organism. Conclusions Infection was controlled in two-thirds of the patients with resistant infections using a two-stage approach. These data highlight the importance of considering the virulence of infecting organisms when treating prosthetic hip infections. The likelihood of controlling the infection with a single two-stage procedure is inferior to that reported in the literature for susceptible organisms.