Marcelo B. P. Siqueira

Chronic Suppression of Periprosthetic Joint Infections with Oral Antibiotics Increases Infection-Free Survivorship.

BACKGROUND The clinical benefit of chronic suppression with oral antibiotics as a salvage treatment for periprosthetic joint infection is unclear. The purpose of this study was to compare infection-free prosthetic survival rates between patients who received chronic oral antibiotics and those who did not following irrigation and debridement with polyethylene exchange or two-stage revision for periprosthetic joint infection. METHODS We reviewed the records on all irrigation and debridement procedures with polyethylene exchange and two-stage revisions performed at our institution from 1996 to 2010 for hip or knee periprosthetic joint infection. Of 625 patients treated with a total of 655 eligible revisions, ninety-two received chronic oral antibiotics for a minimum of six months and were eligible for inclusion in our study. These patients were compared with a matched cohort (ratio of 1:3) who did not receive chronic oral antibiotics. RESULTS The five-year infection-free prosthetic survival rate was 68.5% (95% confidence interval [CI] = 59.2% to 79.3%) for the antibiotic-suppression group and 41.1% (95% CI = 34.9% to 48.5%) for the non-suppression group (hazard ratio [HR] = 0.63, p = 0.008). Stratification by the type of surgery and the infecting organism showed a higher five-year survival rate for the patients in the suppression group who underwent irrigation and debridement with polyethylene exchange (64.7%) compared with those in the non-suppression group who underwent irrigation and debridement with polyethylene exchange (30.4%, p < 0.0001) and a higher five-year survival rate for the patients in the suppression group who had a Staphylococcus aureus infection (57.4%) compared with those in the non-suppression group who had a Staphylococcus aureus infection (40.1%, p = 0.047). CONCLUSIONS Chronic suppression with oral antibiotics increased the infection-free prosthetic survival rate following surgical treatment for periprosthetic joint infection. Patients who underwent irrigation and debridement with polyethylene exchange and those who had a Staphylococcus aureus infection had the greatest benefit.

Synovial Cytokines and the MSIS Criteria Are Not Useful for Determining Infection Resolution After Periprosthetic Joint Infection Explantation

BackgroundDiagnosing periprosthetic joint infection (PJI) requires a combination of clinical and laboratory parameters, which may be expensive and difficult to interpret. Synovial fluid cytokines have been shown to accurately differentiate septic from aseptic failed total knee (TKA) and hip (THA) arthroplasties. However, after first-stage explantation, there is still no reliable test to rule out PJI before a second-stage reimplantation procedure.Questions/purposes(1) Which synovial fluid cytokines have the highest diagnostic accuracy for PJI? (2) Which cytokine shows the greatest decrease associated with the resolution of infection in the same patient between explantation and subsequent reimplantation of an infected arthroplasty? (3) What is the accuracy of synovial fluid cytokines and the Musculoskeletal Infection Society (MSIS) criteria to rule out PJI after first-stage explantation? (4) What are the most studied synovial fluid cytokines for diagnosing PJI as reported in the literature and what are their cumulative diagnostic accuracy?MethodsBetween May 2013 and March 2014, 104 patients with painful THA and TKA evaluated for possible PJI were included in our study. Of these, 90 (87%) had cytokine levels measured from synovial fluid samples collected as part of this prospective study (n = 33 hips, n = 57 knees). A second group of 35 patients (n = 36 samples) who presented during the same time period with an antibiotic spacer also had synovial cytokines measured before second-stage reimplantation. For the first group of 90 patients, the MSIS definition classified each joint at the time of surgery as infected (n = 31) or not infected (n = 59) and was used as the standard to test the accuracy in diagnosing PJI. Of the 35 patients with synovial marker data before second-stage surgery, 15 patients had cytokine measurements both at explantation and reimplantation and were used to quantify the change between stages. The reimplantation group had a minimum 1-year followup (with four [11%] patients lost to followup) and was classified into successful or failed treatment based on Delphi-based consensus data and was used to test the accuracy in detecting infection resolution at reimplantation.ResultsInterleukin (IL)-1β and interferon-γ demonstrated the highest diagnostic utility (area under the curve 0.92, 0.91, respectively); IL-1β and IL-6 had the highest sensitivities (0.90 [95% confidence interval {CI}, 0.74–0.98] and 0.81 [0.63–0.93]). As a measure of infection resolution, IL-1β had the greatest decrease (12.4-fold; level at explantation: 232.4 [range, 23.1–1545.7]; level at reimplantation: 18.8 (range 1.2–298.9); mean difference: 325.5 [95% CI, 65.0–596.0]; p = 0.0001), and IL-6 had a nearly similar decrease (11.2-fold; level at explantation: 228.1 [range, 10,158.4–182,725.0]; level at reimplantation: 2518.2 [range, 10.4–41,319.3]; mean difference: 33,176.0 [95% CI, 7543.6–58,808.3]; p < 0.0001). Cytokines and MSIS criteria had low sensitivity to rule out infection in a joint treated for PJI.ConclusionsIL-6 and IL-1β demonstrated high sensitivities to diagnose PJI and showed the greatest decrease between first and second stages, which may potentially be used to monitor treatment response to PJI. However, cytokines and MSIS criteria had low sensitivity to rule out infection before reimplantation.Level of EvidenceLevel III, diagnostic study.

Modes of failure of total knee arthroplasty: registries and realities.

Revision knee arthroplasty places a major strain on the health care system and is associated with high rates of complications, readmissions, and reoperations. Determining the modes of failure of total knee arthroplasty (TKA) preoperatively is essential for a successful revision procedure. Nationwide arthroplasty registries have served as reliable quality control instruments and as data sources of clinical studies that can potentially help guide the investigation of a failed TKA. Modes of failure vary according to the setting of the procedure (primary vs revision arthroplasty) and the prosthesis level of constraint. This article reviews the most prevalent modes of failure of primary and revision TKA, and further quantifies rates and specific modes of failure of bicruciate retaining, posterior cruciate retaining, posterior stabilizing, varus-valgus constrained, and hinged implants.

Role of negative pressure wound therapy in total hip and knee arthroplasty

Negative-pressure wound therapy (NPWT) has been a successful modality of wound management which is in widespread use in several surgical fields. The main mechanisms of action thought to play a role in enhancing wound healing and preventing surgical site infection are macrodeformation and microdeformation of the wound bed, fluid removal, and stabilization of the wound environment. Due to the devastating consequences of infection in the setting of joint arthroplasty, there has been some interest in the use of NPWT following total hip arthroplasty and total knee arthroplasty. However, there is still a scarcity of data reporting on the use of NPWT within this field and most studies are limited by small sample sizes, high variability of clinical settings and end-points. There is little evidence to support the use of NPWT as an adjunctive treatment for surgical wound drainage, and for this reason surgical intervention should not be delayed when indicated. The prophylactic use of NPWT after arthroplasty in patients that are at high risk for postoperative wound drainage appears to have the strongest clinical evidence. Several clinical trials including single-use NPWT devices for this purpose are currently in progress and this may soon be incorporated in clinical guidelines as a mean to prevent periprosthetic joint infections.

Outcomes of Medial Collateral Ligament Injuries during Total Knee Arthroplasty

Intraoperative medial collateral ligament (MCL) disruption during total knee arthroplasty (TKA) is often managed with either primary repair or use of a constrained implant. A total of 23 patients with an MCL injury during TKA between 2003 and 2009 were compared with 92 matched controls. Of the 23 patients, 10 were treated with an unconstrained implant and primary MCL repair, 8 with constrained implants, 3 with constrained implants and MCL repair, and 2 with unconstrained implants and no MCL repair. After an average 5-year follow-up, patients had lower Knee Society Scores (KSS), 79 versus 87 (p = 0.03), but similar Knee Function Scores (KFS), 68 versus 72 (p = 0.35). The improvement between preoperative and postoperative KSS and KFS did not vary among the two groups (p = 0.88 and p = 0.77, respectively). Postoperative scores did not vary significantly among the four treatment modalities. Conservative treatment can provide satisfactory outcomes and avoid potential complications of increased constraint.

Current concepts in total femoral replacement

Total femoral replacement (TFR) is a salvage arthroplasty procedure used as an alternative to lower limb amputation. Since its initial description in the mid-20(th) century, this procedure has been used in a variety of oncologic and non-oncologic indications. The most compelling advantage of TFR is the achievement of immediate fixation which permits early mobilization. It is anticipated that TFR will be increasingly performed as the rate of revision arthroplasty rises worldwide. The existing literature is mainly composed of a rather heterogeneous mix of retrospective case series and a wide assortment of case reports. Numerous TFR prostheses are currently available and the surgeon must understand the unique implications of each implant design. Long-term functional outcomes are dependent on adherence to proper technique and an appropriate physical therapy program for postoperative rehabilitation. Revision TFR is mainly performed for periprosthetic infection and the severe femoral bone loss associated with aseptic revisions. Depending on the likelihood of attaining infection clearance, it may sometimes be advisable to proceed directly to hip disarticulation without attempting salvage of the TFR. Other reported complications of TFR include hip joint instability, limb length discrepancy, device failure, component loosening, patellar maltracking and delayed wound healing. Further research is needed to better characterize the long-term functional outcomes and complications associated with this complex procedure.

Comparison of Synovial Fluid Cytokine Levels between Traumatic Knee Injury and End-Stage Osteoarthritis

&NA; Degenerative osteoarthritis (OA) has been associated with elevated synovial fluid cytokines. It is unclear whether traumatic knee injuries are a trigger to the chemical process that leads to OA. The purpose of this study was to compare the synovial fluid cytokine levels between knees undergoing arthroscopy due to a documented inciting injury and knees undergoing primary arthroplasty due to end‐stage OA without a previous inciting injury. Synovial fluid samples were prospectively collected from knees undergoing arthroscopic surgeries due to ligamentous or meniscal knee injuries (knee injury group, n = 16) and primary arthroplasty due to OA (end‐stage OA group, n = 14). In the knee injury group, patients had none or minimal OA and at least 30 days from the inciting injury. Exclusion criteria for both groups included inflammatory arthropathy (n = 1) and insufficient fluid for analysis (n = 1). In addition to synovial fluid cytokines, preoperative demographic, clinical, and functional data (Knee Injury and Osteoarthritis Outcome Score [KOOS]) were collected and compared between the groups. The end‐stage OA group had higher age (p < 0.0001), body mass index (p = 0.0061), Charlson comorbidity index (<0.0001), and OA classification (p < 0.0001). Preoperative KOOS were similar between the groups. Interleukin‐6 (IL‐6) and IL‐8 were elevated in the end‐stage OA group compared with the knee injury group (p = 0.04 and 0.006, respectively). Granulocyte‐macrophage colony‐stimulating factor, interferon gamma, IL‐1&bgr;, IL‐12p70, IL‐2, IL‐10, and tumor necrosis factor alpha were not statistically different between the groups. A similar synovial fluid cytokine profile was found between the two groups. The elevation of IL‐6 and IL‐8 in the end‐stage OA group indicates the potential role that these proinflammatory cytokines may have in long‐term cartilage damage.

The Diagnostic Utility of Synovial Fluid Markers in Periprosthetic Joint Infection: A Systematic Review and Meta-analysis

Introduction: This study is a systematic review of all reported synovial fluid markers for the diagnosis of periprosthetic joint infection and a meta-analysis of the most frequently reported markers to identify those of greatest diagnostic utility. Methods: A search of six databases was conducted to identify all studies evaluating the utility of synovial fluid markers in the diagnosis of periprosthetic joint infection. Two observers assessed methodologic quality and extracted data independently. A meta-analysis of the most frequently reported markers was performed. Results: Twenty-three studies were included in the meta-analysis. The most common markers (and their respective area under the curve) were interleukin-17 (0.974), leukocyte esterase (0.968), &agr;-defensin (0.958), interleukin-6 (0.956), interleukin-1&bgr; (0.948), and C-reactive protein (0.927). Among these markers, &agr;-defensin had the highest diagnostic odds ratio but did not achieve statistically significant superiority. Conclusion: The most frequently studied synovial fluid markers for the diagnosis of periprosthetic joint infection are C-reactive protein, leukocyte esterase, interleukin-6, interleukin-1&bgr;, &agr;-defensin, and interleukin-17, all of which have high diagnostic utility. Level of Evidence: Level II

Does Gender Influence How Patients Rate Their Patient Experience after Total Knee Arthroplasty

Abstract The Centers for Medicare and Medicaid Services has implemented the Value‐Based Purchasing (VBP) score as a pay‐for‐performance reimbursement model. Patient experience, as measured by the Press Ganey (PG) survey, currently comprises 20% of total VBP score. It is therefore beneficial for the orthopaedist to become familiar with these changes to maximize profits. Currently, a paucity of data exists that elucidates which factors influence PG scores between men and women following total knee arthroplasty (TKA). Therefore, we asked: (1) which PG survey factors most influences hospital ratings among men and women patients post‐TKA and (2) is there a significant difference in overall hospital ratings among men and women cohorts post‐TKA? We queried the PG database for patients who received a TKA between November 2009 and January 2015, yielding 224 men (mean age 64 years, range: 39‐88) and 519 women (mean age 65 years; range, 25‐92). A multiple regression analysis was performed for each cohort with overall hospital satisfaction as the dependent variable to assess the influence (&bgr;‐weight) each PG domain imparted on overall hospital rating. A chi‐square analysis and t‐test were performed to assess categorical and continuous variables, respectively. For men, communication with nurses (&bgr; = 0.408, p = 0.016), followed by communication about medications (&bgr; = 0.261, p = 0.032), most influenced overall hospital rating. For women, communication with nurses (&bgr; = 0.479, p < 0.001) most influenced overall hospital rating. This was followed by staff responsiveness (&bgr; = 0.201, p = 0.046), pain management (&bgr; = 0.263, p = 0.015), and communication about medications (&bgr; = − 0.152, p = 0.029). It is of great advantage for the orthopaedist to focus on the PG domains most pertinent to each patient gender post‐TKA. For both genders, overall hospital rating was significantly influenced by communication with nurses and information about medication. However, staff responsiveness and pain control were of significant importance in determining overall hospital rating for women. Therefore, orthopaedists should consider focusing on these factors depending on the gender of the patient to optimize satisfaction.

Correction of Hammertoe Deformity With Novel Intramedullary PIP Fusion Device Versus K-Wire Fixation.

Background: K-wire fixation has been the most common method of fixation for hammertoe deformity. However intramedullary devices are gaining ground in both number of available choices and in procedures performed. This study aimed to compare the outcomes of hammertoe correction performed with K-wire fixation versus a novel intramedullary fusion device (CannuLink). Methods: A retrospective review of hammertoe correction by a single surgeon was performed from June 2011 to December 2013. Sixty patients (95 toes) underwent K-wire fixation and 39 patients (54 toes) underwent fusion with the CannuLink implant. Average age was 61.7 years and 61.4 years, respectively. Average length of follow-up was 12.9 and 12.3 months, respectively. Patients were evaluated for medical comorbidities, smoking status, inflammatory arthritis, peripheral vascular disease, peripheral neuropathy, pre- and postoperative visual analog pain scale, bony union percentage, revision rate, complications (hardware and surgery-related), and persistent symptoms at last follow-up. There was no significant difference in demographics or comorbidities between the 2 groups (P > .05). Results: In the K-wire group, 16 patients (18 toes) remained symptomatic at last follow-up (27%). Nine toes (9.5%) had recurrent deformity, 3 toes (3%) developed a late infection because of the recurrent deformity, and 1 toe (1%) developed partial numbness. One patient suffered a calf deep vein thrombosis (DVT) and peroneal nerve neuritis, 1 patient developed foot drop, and 3 patients continued to complain of pain. Five toes required revision surgery (5.3%). In the intramedullary group, 3 (7.7%) patients remained symptomatic and all were associated with a complication. One patient developed chronic regional pain syndrome in the foot, a calf DVT, and a nonfatal pulmonary embolus. A second patient developed a painless recurrent deformity. A third patient had wound dehiscence. Nobody had hardware failure or required a second operation. Conclusion: The CannuLink intramedullary device for hammertoe correction resulted in fewer complications, only 1 recurrent deformity, and no reoperations compared with K-wire fixation. Level of Evidence: Level III, retrospective comparative study.