Modular Knee Arthrodesis as Definitive Treatment for Periprosthetic Infection, Bone Loss, and Failure of the Extensor Mechanism After Total Knee Arthroplasty.

Background: Periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) can result in bone and soft-tissue loss, leg length discrepancies, and dysfunctional extensor mechanisms. While above-knee amputation (AKA) is an established salvage treatment, modular knee arthrodesis (MKA) is a viable option that provides rigid stability and maintains leg length even in patients with severe bone and soft-tissue loss. We sought to report the outcomes of patients with an MKA as the definitive treatment. Methods: We retrospectively reviewed 8 patients implanted with an MKA at 2 institutions between 2016 and 2022. The mean age was 69.63 years, and 50.0% of patients were women. All patients were indicated for conversion to an MKA as the definitive treatment in the setting of treated chronic PJI after TKA, severe bone loss, and failure of the extensor mechanism not amenable to repair. Medical records and radiographs were reviewed. Results: No patients required incision and drainage or exchange of their MKA for PJI at mean 2-year follow-up. One patient required 2 revisions for mechanical failure of his implant at 5.0 and 6.4 years postoperatively. Conclusions: MKA is a viable permanent alternative to AKA for patients with treated chronic PJI and dysfunctional extensor mechanism after TKA. The procedure restores leg lengths in the setting of severe bone and soft-tissue loss, therefore allowing patients to ambulate independently. Still, surgeons should be aware of the potential for mechanical failure requiring revision.

Proximal radiolucent lines around fully hydroxyapatite-coated tapered femoral stems: should we be concerned?

INTRODUCTION: Radiolucent lines occasionally develop around the proximal aspect of fully hydroxyapatite (HA)-coated tapered femoral stems after total hip arthroplasty (THA). It was hypothesised that distal wedging of stems may predispose to proximal radiolucent line formation, which may negatively impact clinical outcome. METHODS: All primary THA performed with a collarless fully HA-coated stem that had a minimum of 1 year of radiographic follow-up were identified in a surgical database (n = 244). Radiographic measures of proximal femoral morphology and femoral canal fill at the middle and distal thirds of the stem were analysed for association with the presence of proximal radiolucent lines. Linear regression was used to explore any association between radiolucent lines and patient reported outcome measures (PROMs), available in 61% of patients. RESULTS: Proximal radiolucent lines developed in 31 cases (12.7%) at final follow-up. Dorr A femoral morphology and increased canal-fill at the distal ⅓ of the stem correlated with the development of radiolucent lines (p < 0.001). No correlation was observed between pain or PROMs and the presence of proximal radiolucent lines. DISCUSSION: We observed an unexpectedly high incidence of proximal femoral radiolucent lines about collarless fully HA coated stems. Distal-only implant wedging in Dorr A bone may compromise proximal fixation. Although this finding did not correlate with short-term outcomes, the long-term clinical impact requires further study.

Uncemented Hemiarthroplasty in Displaced Femoral Neck Fractures is associated with Higher Perioperative Surgical Complications but Lower Medical Complications: Analysis from the National Inpatient Database.

Objectives: This study aimed to analyze and compare the perioperative outcomes of cemented and uncemented hemiarthroplasty in elderly patients with displaced femoral neck fractures by utilizing the data from the National Inpatient Sample database. Methods: Data from the National Inpatient Sample Database was analyzed to identify patients who underwent hemiarthroplasty following a displaced femoral neck fracture (cemented and uncemented. Demographic data, comorbidities, length of stay, total charges, and perioperative complications were analyzed. Results: 27390 patients were identified in the cemented group and 29406 in the uncemented group. The patients who underwent uncemented hemiarthroplasty demonstrated a higher incidence of prosthetic dislocation (Odds Ratio (OR) 3.348, p < 0.001), periprosthetic mechanical complications (OR 2.597, p < 0.001), wound dehiscence (OR 2.883, p < 0.001), superficial surgical site infection (OR 2.396, p = 0.043), deep surgical site infection (OR 1.686, p < 0.001), and periprosthetic fractures (OR 2.292, p < 0.001) as compared with patients who underwent cemented hemiarthroplasty. However, patients with uncemented fixation demonstrated a lower incidence of death (OR 0.567, p < 0.001), pulmonary embolism (OR 0.565, p < 0.001), deep vein thrombosis (DVT) (OR 0.746, p < 0.001), myocardial infarction (OR 0.772, p = 0.025) and blood loss anemia (OR 0.869, p < 0.001) as compared with cemented fixation. Conclusion: Our study on displaced femoral neck fractures utilizing the National Inpatient database found that uncemented hemiarthroplasty was associated with a higher incidence of perioperative surgical complications. Cemented hemiarthroplasty, however, was associated with a statistically significant higher rate of death, pulmonary embolism, deep vein thrombosis, and myocardial infarction.

Use of a Retrograde Guidewire to Direct an Antegrade Femoral Nail.

Antegrade intramedullary nailing for the treatment of diaphyseal femur fractures may present challenges in obtaining appropriate positioning of the distal tip of the nail. Known mismatch between the radius of curvature of commonly used nails and the anatomic bow of the femur may result in impingement or perforation of the anterior cortex of the distal femur. Additionally, some unique scenarios may arise that complicate traditional antegrade wire passage. We report our surgical technique and clinical experience using a retrograde guidewire to direct an antegrade femoral nail to aid in obtaining a desired central location of the distal nail tip. [Orthopedics. 2023;46(2):e132-e135.].

Risk Factors for Periprosthetic Femoral Fracture in Non-cemented Total Hip Arthroplasty Through the Direct Anterior Approach.

Background: Although total hip arthroplasty (THA) performed through the direct anterior (DA) approach is frequently marketed as superior to other approaches, there are concerns about increased risks of intraoperative and early postoperative femoral fracture. Purpose: We sought to assess patient-specific and radiographic risk factors for intraoperative and early postoperative (90-day) periprosthetic femoral fracture (PPFx) following DA approach THA. Methods: We retrospectively reviewed 1107 consecutive, primary, non-cemented DA THAs, performed between April 2009 and January 2015, for intraoperative and early postoperative PPFx. Patients lost to follow-up before 90 days (63), cemented or hybrid THA (52), or early femoral failure for another indication (3) were excluded, yielding 989 hips for analysis. Demographic variables and patient comorbidities were analyzed as risk factors for PPFx. Continuous variables were initially compared with 1-way analysis of variance (ANOVA) and categorical variables with chi-square test. A demographic matched-paired radiographic analysis was performed for femoral stem canal fill and compared using univariate logistic regression. Results: The incidence of perioperative PPFx was 2.02%, including 10 intraoperative and 10 early postoperative fractures. Sustaining a postoperative PPFx was associated with being 70 years old or older with a body mass index (BMI) of less than 25, or with having either osteoporosis or Parkinson disease. Radiographs demonstrated that intraoperative PPFx was associated with stems that filled greater proximally rather than distally. Conclusion: Our cohort study found older age, age over 70 with BMI of less than 25, osteoporosis, and Parkinson disease were associated with increased risk for early postoperative PPFx following DA approach THA. Intraoperative fractures may occur with disproportionate proximal femoral canal fill. Further study can evaluate whether cemented femoral components may mitigate risk in these patient populations.

Cemented Femoral Fixation in a High-Risk Cohort Diminishes Risk of Early Postoperative Periprosthetic Fracture.

BACKGROUND: Early periprosthetic fractures (PPFx) following primary total hip arthroplasty (THA) create significant morbidity. Established risk factors for early PPFx include age, gender, body mass index, surgical approach, and implant fixation. We investigated the role of femoral fixation on early PPFx (<90 days postoperatively) in a high-risk cohort undergoing direct anterior approach (DAA) THA. METHODS: The final cohort comprised 344 consecutive patients (390 hips) with risk factors for PPFx (age >68 years and body mass index <25 kg/m2) who underwent primary DAA THA between May 4, 2009 and December 31, 2019 and had 90-day follow-up. Noncemented fixation was used in 229-hips, while cemented fixation was used in 161 hips. The primary outcome was early PPFx. Fisher's exact test was used for categorical variables, while t-tests were used to compare continuous variables. RESULTS: We observed 8 early PPFx (2.1%), all fractures occurring in the noncemented group. Baseline demographics were similar but not equal, with the cemented group being older (78.0 versus 76.3 years; P = .004) with a greater proportion of females (91.9% versus 69.4%; P < .001). The rate of early PPFx was significantly higher with noncemented fixation compared to cemented fixation (3.5% versus 0.0%; P = .023). A post hoc power analysis confirmed sufficient power (1-ß = 0.81). CONCLUSION: Although baseline risk factors for early PPFx are not easily modifiable, surgical factors can be modified. Cemented fixation has the potential to markedly reduce the risk of early PPFx in high-risk patients undergoing DAA THA.

Transfusion Avoidance in Severely Anemic Total Hip and Total Knee Arthroplasty Patients: An Analysis of Risk.

Background: Allogenic blood transfusions increase the risk of multiple complications. We evaluated the influence of restricting transfusions in adults with osteoarthritis that underwent total hip or knee arthroplasty (THA/TKA) with severe postoperative anemia. Material and methods: Patients that underwent THA/TKA for osteoarthritis with postoperative hemoglobin (Hb) ≤ 8 g/dl were retrospectively identified. We evaluated characteristics and adverse postoperative outcomes of patients not transfused and compared them to those of patients who received postoperative transfusion. Adverse outcomes were 90-day readmission, reoperation, infection, and falls, as well as inpatient cardiovascular events and deaths. Results: One thousand eighty-seven patients meeting inclusion criteria underwent THA and TKA. The 399 patients (36.7%) who did not undergo transfuion were younger (67.4 vs 69.5 years, P = .008), healthier (American Society of Anesthesiologist ≤ 2: 64.2% vs 56%, P = .006), comprised a lower proportion of cardiovascular disease patients (13.8% vs 24.7%, P < .001), a lower proportion of patients with Medicare/Medicare Managed Care (57.2% vs 65.5%, P = .05), received tranexamic acid more frequently (66.4% vs 52.9%, P < .01), had a shorter procedure time (92.7 vs 103.1, P < .01), a lower postoperative drop in Hb (4.0 vs 4.2 g/dl, P = .022), a later drop in Hb (2.6 vs 2.2 days, P = .003), and a shorter length of stay (3.5 vs 4.8, P < .01). TKA patients underwent transfusion more frequently than THA patients (67.5% vs 59%, P = .004). There were no postoperative deaths. Adverse events were similar between the 2 groups. Conclusion: Findings suggest that younger and healthier patients that have lower Hb later during their hospital stay need not undergo transfusion solely based on Hb levels. Routine transfusion triggers can be avoided even in more anemic patients.

Risk of Instability After Revision Total Knee Arthroplasty for Periprosthetic Joint Infection.

Periprosthetic joint infection (PJI) remains a major source of morbidity after total knee arthroplasty (TKA). The risk of recurrent infection has been more extensively studied than the risk of mechanical failure. We sought to define the incidence of instability after revision TKA for PJI and to compare this incidence with that for revision TKA for instability. We retrospectively reviewed patients treated by 4 arthroplasty surgeons at 1 institution. The primary outcome was a new diagnosis of clinical instability after index revision. We analyzed potential risk factors that may contribute to postoperative instability after PJI, including demographic characteristics, implant alignment, number of previous procedures, level of constraint during index revision, and type of spacer used. Patients were matched 1:1 with patients undergoing revision TKA for instability. Continuous variables were compared with Student's t test for normally distributed variables and Mann-Whitney U test for non-normal variables. Categorical variables were compared with Fisher's exact test. Thirty-seven patients who underwent revision TKA for PJI were identified. Twelve (32.4%) had clinical instability after revision, compared with only 3 (8.1%) in the matched cohort (P=.019). Use of a revision, midlevel constraint device in the PJI cohort did not correlate with a lower risk of instability (P=.445). A greater number of previous surgical procedures increased the likelihood of instability (P=.041). Revision TKA for PJI is associated with a high risk of subsequent instability. Midlevel constrained implants may not be sufficient to prevent instability. A focus on soft tissue tension and a lower threshold for increasing constraint may be prudent in this cohort. [Orthopedics. 2022;45(3):145-150.].

Knee-Spanning External Fixation for Recurrent Traumatic Anterior Prosthetic Knee Dislocation With Associated Vascular Injury.

Traumatic anterior prosthetic knee dislocation after total knee arthroplasty is a rare event. We report the case of an 88-year-old female who presented with right traumatic anterior knee dislocation and concurrent popliteal artery injury requiring an emergent bypass graft. Postoperatively, the patient had redislocated her prosthetic knee, requiring urgent re-reduction and stabilization with an external fixator. We review her case, as well as additional reported cases of anterior knee dislocation. We also review the clinical considerations surrounding arterial injury, vascular bypass, and external fixation as a proposed management in unstable cases refractory to bracing.

Aseptic Tibial Implant Loosening After Total Knee Arthroplasty: Preventable?

Aseptic loosening is a considerable complication that affects the longevity of total knee arthroplasty (TKA) implants. Surgeon technique may help minimize aseptic loosening after TKA. Meticulous cementation of the prosthesis and the bone surface during various stages of cement polymerization will maximize cement adherence to the prosthesis and the bone, respectively. Pressurization of the cement in the canal and at the cut surface to achieve at least 2 mm of cement depth penetration has been reported to increase TKA implant longevity.

Equivalent VTE rates after total joint arthroplasty using thromboprophylaxis with aspirin versus potent anticoagulants: retrospective analysis of 4562 cases across a diverse healthcare system.

BACKGROUND: Guidelines support aspirin thromboprophylaxis for primary total hip and knee arthroplasty (THA and TKA) but supporting evidence has come from high volume centers and the practice remains controversial. METHODS: We studied 4562 Medicare patients who underwent elective primary THA (1736, 38.1%) or TKA (2826, 61.9%) at 9 diverse hospitals. Thirty-day claims data were combined with data from the health system's electronic medical records to compare rates of venous thromboembolism (VTE) between patients who received prophylaxis with: (1) aspirin alone (47.3%), (2) a single, potent anticoagulant (29%), (3) antiplatelet agents other than aspirin or multiple anticoagulants (21.5%), or (4) low-dose subcutaneous unfractionated heparin or no anticoagulation (2.2%). Sub-analyses separately evaluating THA, TKA and cases from lower volume hospitals (n = 975) were performed. RESULTS: The 30-day VTE incidence was 0.6% (29/4562). VTE rates were equal in patients receiving aspirin and those receiving a single potent anticoagulant (0.5% in both groups). Patients with VTE were significantly older than patients without VTE (mean 76.5 vs. 73.1 years, P = 0.04). VTE rate did not associate with sex or hospital case volume. On bivariate analysis considering age, aspirin did not associate with greater VTE risk compared to a single potent anticoagulant (OR = 2.1, CI = 0.7-6.3) with the numbers available. Odds of VTE were increased with use of subcutaneous heparin or no anticoagulant (OR = 6.4, CI = 1.2-35.6) and with multiple anticoagulants (OR = 3.6, CI = 1.1-11.2). THA and TKA demonstrated similar rates of VTE (0.5% vs. 0.7%, respectively, P = 0.43). Of 975 cases done at lower volume hospitals, 387 received aspirin, none of whom developed VTE. CONCLUSIONS: This study provides further support for aspirin as an effective form of pharmacological VTE prophylaxis after total joint arthroplasty in the setting of a multi-modal regimen using 30-day outcomes. VTE occurred in 0.7% of primary joint arthroplasties. Aspirin prophylaxis did not associate with greater VTE risk compared to potent anticoagulants in the total population or at lower volume hospitals.

Risk Factors for Wound Complications After Periprosthetic Fractures.

The number of hip and knee arthroplasties performed annually continues to rise. Revision rates are projected to increase by 137% to 601%, with periprosthetic fractures to be among the leading cause of revision. Wound complications following surgical treatment of periprosthetic fractures are a major source of patient morbidity and health care costs. This study evaluated risk factors for wound healing complications in patients undergoing surgical management of periprosthetic fractures around the hip and knee. This was a retrospective analysis of 67 consecutive lower-extremity periprosthetic hip and knee fracture surgeries. Descriptive data, comorbidities, dressing type, and rates of wound complications treated nonoperatively and operatively were collected. Logistic regression analysis was performed to calculate odds ratios (ORs) of having a wound complication. There was an overall wound complication rate of 22%; the majority of these complications (16%) were treated operatively. On multivariate analysis, prior bariatric surgery (OR, 12.02; 95% confidence interval [CI], 1.24-116.71; P=.03), peripheral vascular disease (OR, 6.84; 95% CI, 1.32-35.39; P=.02), and pulmonary disease (OR, 11.23; 95% CI, 1.85-68.31; P=.01) were all associated with an increased risk of developing a wound complication. Closed-incision negative-pressure therapy was associated with a decreased risk of developing a wound complication (OR, 0.04; 95% CI, 0.00-0.49, P=.01). Surgery to treat hip and knee periprosthetic fractures is associated with a high rate of wound complications. History of bariatric surgery, peripheral vascular disease, and pulmonary disease are all associated with an increased risk of developing a wound complication. Future payment models should reflect this elevated level of complications and risk. [Orthopedics. 2020;43(4):e258-e262.].

Aseptic Loosening at the Tibia in Total Knee Arthroplasty: A Function of Cement Mantle Quality?

BACKGROUND: Aseptic loosening remains one of the leading causes for failure of total knee arthroplasty (TKA). We sought to identify early radiographic measures that may associate with aseptic tibial component loosening, emphasizing systematic evaluation of the cement mantle. METHODS: All TKA revisions from 2007 to 2015 with the primary indication of tibial aseptic loosening were identified using in an institutional implant retrieval database. After exclusion criteria, 61 TKAs comprised the study group. A matched control group of 59 TKAs that had not failed at a minimum of 3 years was identified for comparison. Radiographic analysis on all 6-week postoperative radiographs included angulation of components, cement penetration depth, and presence of radiolucency at the implant-cement and bone-cement interfaces. Groups were compared with Student's t-test, chi-squared test, and Mann-Whitney U-test. A final multivariable logistic regression model was formed for the outcome of aseptic loosening. RESULTS: On multivariable analysis, failure was associated with a greater number of zones with cement penetration <2 mm (5.6 vs 3.4 zones, odds ratio [OR] 1.89, P < .001), increasing percent involvement of radiolucency at the implant-cement interface (8.7% vs 3.1%, OR = 1.15, P = .001), and increased varus alignment of the tibial component (1.5° vs 0°, OR = 1.35, P = .014). A greater number of zones with a radiolucent line at the bone-cement interface did not significantly associate (1.1 vs 0.3, P = .091). CONCLUSION: Our results suggest that radiographic indicators of poor cement mantle quality associate with later aseptic loosening. This emphasizes the need for surgeons to perform careful cement technique in order to reduce the risk of TKA failure. LEVEL OF EVIDENCE: III (Case-control).

Survivorship and Radiographic Analysis of Highly Porous Acetabular Cups Designed for Improved Osseointegration Potential.

INTRODUCTION: A variety of highly porous materials have been used to obtain biological acetabular fixation after total hip arthroplasty (THA). Due to their improved surface-coated properties, new highly porous titanium metal implants have shown potential to promote prosthesis osseointegration. Therefore, the purpose of this multicenter study was to evaluate: 1) overall acetabular cup survivorship; 2) postoperative complications; and 3) radiographic signs of loosening and radiolucencies in patients who received a new highly porous titanium metal cup. MATERIALS AND METHODS: A total of 81 patients who underwent primary THA and received a new porous acetabular cup between May 16, 2013 and January 27, 2016 at three academic centers were included for analysis. There were 40 women (49%) and 41 men (51%) who had a mean age of 65 years (range, 38 to 95 years) and a mean body mass index (BMI) of 28 kg/m2 (range, 16 to 43 kg/m2). The minimum follow up time was two years and seven months (range, 2 to 4 years). The cup was engineered with fully interconnected porosity designed for potential long-term biologic fixation. Medical records were reviewed to assess for any revision surgeries and postoperative complications, and the most recent radiographs were reviewed for signs of loosening or radiolucencies. RESULTS: Overall, acetabular component survivorship, free of fixation failure or aseptic loosening, was 100%. Two patients underwent revision due to dislocations; however, revisions were performed because no constrained or dual mobility liners were available for the shell at the time. Both patients had successful outcomes and were doing well at final follow up with no further episodes of dislocation. There was one open reduction internal fixation for a periprosthetic femoral fracture, and three polyethylene revisions were performed for instability. In all of these cases, the acetabular cup was retained. On radiographic evaluation of antero-posterior pelvis radiographs, there was one patient who had radiolucencies of <1mm in Zone 1 and Zone 2 at 15 months after surgery, and another patient demonstrated radiolucencies of <1mm in Zone 2 and 3 at one-year follow up. At a minimum of two-year follow up, both patients had non-progressive and stable findings. CONCLUSION: The results of this study demonstrated excellent survivorship, and there were no radiographic failures of this acetabular cup in primary total hip arthroplasty patients. Although two patients were found to have minimal (<1mm) radiolucencies, these were not progressive. Longer follow-up studies are needed to further assess the survivorship and outcomes of this new acetabular cup; however, based on the results of this study, these are expected to be favorable.

Failure of a Unidirectional Barbed-Suture Device at the Arthrotomy Repair Site Following Total and Unicondylar Knee Arthroplasty: A Case Report.

CASE: We report the failure of a routine arthrotomy repair following knee arthroplasty. Five additional cases of arthrotomy failure occurred within a 14-month period during which a specific unidirectional knotless barbed suture device had been used for arthrotomy closure. CONCLUSION: Additional study on larger cohorts may be useful to understand the effectiveness of barbed suture for arthrotomy closure in knee arthroplasty.

Variation in Treatment Patterns Correlate With Resource Utilization in the 30-Day Episode of Care of Displaced Femoral Neck Fractures.

BACKGROUND: We evaluated which treatment decisions in the management of displaced femoral neck fractures (FNFs) may associate with measures of resource utilization relevant to a value-based episode-of-care model. METHODS: A total of 1139 FNFs treated with hip arthroplasty at 7 hospitals were retrospectively reviewed. Treatment choices were procedure (hemiarthroplasty vs total hip arthroplasty [THA]), surgeon training status, admitting service, and time to surgery. Dependent variables were length of stay, discharge disposition, 30-day readmission, and in-hospital mortality. Variation across hospitals was evaluated with analysis of variance and chi-square tests. Treatment choices were evaluated for the dependent variables of interest with univariable and multivariable regression. RESULTS: There was significant variation between hospitals regarding proportion of cases treated with THA (range = 3.0%-73.2%, P < .001), proportion treated by arthroplasty fellowship-trained surgeons (range = 0%-74.9%, P < .001), proportion admitted to the orthopedic service (range = 2.8%-91.3%, P < .001), mean time to surgery (range = 0.9-2.1 days, P < .001), and proportion of discharge home (range = 63.9%-97.8%, P < .001). Multivariable analysis adjusting for age, gender, and Charlson Comorbidity Index demonstrated correlations between (1) decreased length of stay and admission to orthopedics (B = -1.256, P < .001); (2) lower 30-day readmission and THA (odds ratio [OR] = .376, P = .004), and (3) decreased discharge to a care facility and admission to orthopedics (OR = 0.402, P = <.001), THA (OR = 0.435, P = .002), and treatment by an arthroplasty fellowship-trained surgeon (OR = 0.572, P = .016). None of the treatment variables tested associated with in-hospital mortality. CONCLUSION: We observed significant variation in the treatment of displaced FNF patients across 7 hospitals and identified treatment choices that associated with resource utilization within the episode of care. Future, prospective study is necessary to understand whether care pathways that adapt some combination of these characteristics may result in more value-based care.

In-Hospital Acute Kidney Injury After TKA Revision With Placement of an Antibiotic Cement Spacer.

BACKGROUND: There is mounting evidence that treatment of periprosthetic joint infection of the knee with an antibiotic cement spacer (ACS) may increase risk for acute kidney injury (AKI). We sought to determine the incidence, as well as potential risk factors, of in-hospital AKI in this cohort. METHODS: We retrospectively identified 75 patients that received either a static or articulating ACS at a single institution. In-hospital AKI was defined by a more than 50% rise in serum creatinine from preoperative baseline to at least 1.4 mg/dL. Our secondary outcome was percent change in creatinine from preoperative to peak postoperative value. Variables were analyzed for the outcome of AKI with univariate logistic regression. A final multivariate model for percent change in creatinine was formed while controlling for age, gender, body mass index, and baseline creatinine. RESULTS: The incidence of AKI was 14.6%, occurring at a mean of 6.3 days (2-8 days). A lower preoperative hemoglobin (odds ratio = 1.82, P = .015) significantly increased risk for AKI on univariate analysis. Diagnosis of either hypertension or diabetes also showed a strong statistical trend (P = .056). On multivariate regression, lower preoperative hemoglobin significantly correlated with a greater percent rise in creatinine postoperatively (ß = 0.30, P = .015). CONCLUSION: The incidence of AKI in patients who receive ACS is relatively high, raising clinical concern in the care of periprosthetic joint infection patients. Our results suggest that a lower baseline hemoglobin may be involved in the etiology of AKI in this population. Therefore, it may be clinically appropriate to monitor anemic patients for AKI when implanting an ACS.

Closed incision negative pressure therapy decreases complications after periprosthetic fracture surgery around the hip and knee.

INTRODUCTION: Periprosthetic fractures (PPFXs) are becoming increasingly common following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients sustaining PPFXs face considerable perioperative morbidity, with relatively increased rates of surgical site infection. We sought to evaluate the efficacy of closed-incision negative-pressure wound therapy (ciNPT) in decreasing perioperative wound complications following lower extremity periprosthetic fracture surgery. METHODS: We performed a retrospective review of 69 consecutive patients who underwent surgery to address lower extremity periprosthetic fractures around hip or knee implants performed over a 6.5-year period. The population was divided into two groups based on the surgical dressing used at the conclusion of the procedure: (1) a sterile, antimicrobial hydrofiber dressing, or (2) ciNPT. There were no baseline demographic differences between the two groups. Rates of wound complications, surgical site infection, and reoperation related to the surgical site were compared between groups. Continuous variables were analyzed using a student's t-test, and categorical variables using either chi-square or fisher's exact test. RESULTS: Patients treated with ciNPT developed fewer wound complications (4% vs. 35%; p=0.002), fewer deep infections (0% vs. 25%; p=0.004), and underwent fewer reoperations related to the surgical site (4% vs. 25%; p=0.021) compared to patients treated with standard of care. CONCLUSIONS: Our findings suggest that ciNPT may reduce wound complications, SSIs, and reoperations in patients undergoing lower extremity periprosthetic fracture surgery. This is the first study to investigate ciNPT as a treatment for periprosthetic fracture surgery, and has the potential to change the postoperative management of these patients.

Pin Site Complications Associated With Computer-Assisted Navigation in Hip and Knee Arthroplasty.

BACKGROUND: There has been a great increase in the use of navigation technology in joint arthroplasty. In most types of navigation-assisted surgery, several temporary navigation pins are placed in the patient. Goals of this study are (1) to identify complications and (2) risk factors associated with placement of these pins. METHODS: This is a retrospective cohort study of all navigation-assisted hip and knee arthroplasty performed a single institution over a 3-year period. Records were reviewed and outcome measures were tabulated in a database. Complications included in the database were pin site infection, deep prosthetic joint infection, neurologic injury, vascular injury, and fracture through a pin site. RESULTS: A total of 3136 pin sites in 839 patients were included in the study. Five pin site complications were reported with a complication rate of 0.16% per pin site and 0.60% per patient. The complications-per-procedure were slightly higher for unicondylar knee arthroplasty (0.64%) compared with patellofemoral arthroplasty (0%) and total hip arthroplasty (0.46%), but not statistically significant. There were three infections, one neuropraxia, and one suture abscess. No periprosthetic fractures through a pin site were reported. All complications were resolved with nonoperative treatment. The infections required oral antibiotics, and were associated with transcortical drilling in two cases and juxtacortical drilling in the third. CONCLUSION: Pins required for navigation-assisted arthroplasty have a low complication rate. Transcortical or juxtacortical drilling may be a risk factor for pin site infection; future studies should be directed at quantifying this effect.

Management of Vancouver Type-B2 and B3 Periprosthetic Femoral Fractures: Restoring Femoral Length via Preoperative Planning and Surgical Execution Using a Cementless, Tapered, Fluted Stem.

INTRODUCTION: Periprosthetic femoral fractures, which are likely to increase as the population ages and total hip arthroplasty becomes more prevalent1, can be effectively managed by restoring femoral length via preoperative planning and surgical execution using a cementless, tapered, fluted stem. STEP 1 PREOPERATIVE PLAN: Template the contralateral, uninjured side. STEP 2 TEMPLATE THE FRACTURED SIDE: Identify the ideal COR on the injured side and template the femoral stem. STEP 3 ESTABLISH DEPTH OF REAMING: Use stem templates to establish a reference point on the reamer for use intraoperatively, and identify the distance from that point to an identifiable distal landmark. RESULTS: We report on 14 (12 Vancouver type-B2 and 2 Vancouver type-B3) periprosthetic femoral fractures treated with the described method15.