Role of Routine Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infections.

Background: The first-line management strategy for acute periprosthetic joint infections (PJIs) is debridement, antibiotics, and implant retention (DAIR). Suppressive antibiotic therapy (SAT) after DAIR is proposed to improve outcomes, yet its efficacy remains under scrutiny. Methods: We conducted a multicenter retrospective study in patients with acute PJI of the hip or knee who were treated with DAIR in centers from Europe and the United States. We analyzed the effect of SAT using a Cox model landmarked at 12 weeks. The primary covariate of interest was SAT, which was analyzed as a time-varying covariate. Patients who experienced treatment failure or were lost to follow-up within 12 weeks were excluded from the analysis. Results: The study included 510 patients with 66 treatment failures with a median follow-up of 801 days. We did not find a statistically significant association between SAT and treatment failure (hazard ratio, 1.37; 95% CI, .79-2.39; P = .27). Subgroup analyses for joint, country cohort, and type of infection (early or late acute) did not show benefit for SAT. Secondary analysis of country cohorts showed a trend toward benefit for the US cohort (hazard ratio, 0.36; 95% CI, .11-1.15; P = .09), which also had the highest risk of treatment failure. Conclusions: The utility of routine SAT as a strategy for enhancing DAIR's success in acute PJI remains uncertain. Our results suggest that SAT's benefits might be restricted to specific groups of patients, underscoring the need for randomized controlled trials. Identifying patients most likely to benefit from SAT should be a priority in future studies.

Positive Intraoperative Cultures in Cup Revisions of THA: What Happens to the Stem?

BACKGROUND: Positive intraoperative cultures (PICs) are encountered in some patients undergoing revision of the acetabular cup after a previous THA. It is unknown whether PIC of the cup indicates whether the stem is infected as well and what happens to the stem during follow-up. QUESTIONS/PURPOSES: (1) What proportion of patients undergoing THA who undergo cup revision have PICs? (2) What is the survival of the stem during follow-up in cup revisions with PICs versus that of those with negative cultures? (3) Does antibiotic treatment of PIC of the cup prevent revision THA during follow-up? METHODS: In this retrospective, comparative multicenter study, five surgeons at four centers performed 338 acetabular cup revisions between January 2015 and December 2017. After evaluating the data, we excluded one patient because of an incomplete dataset and 77 patients because fewer than three intraoperative cultures were obtained during surgery, leaving 260 patients for analysis. Follow-up was 2 years. Patients were stratified into three cohorts: no PIC, one PIC, and two or more PICs. RESULTS: The proportion of patients with one or more PIC was 15% (39 of 260). A total of 8% (21 of 260) had one and 7% (18 of 260) had two or more PICs. Stem survival was lower in patients with two or more PICs, but stem revision for periprosthetic joint infection was similar between groups. Two-year survival, which was defined as freedom from revision for any cause or infection, was 97% (95% confidence interval 95% to 99%) in the group without PICs, 100% (95% CI 95% to 100%) in the group with one PIC, and 86% (95% CI 68% to 100%; p = 0.08) in the group with two or more PICs. None of the patients in the no PIC and one PIC groups were treated with antibiotics. In the two or more PICs cohort, 12 of 18 patients were treated. The stem survived in one of 12 patients treated with antibiotics versus two of six patients who were not treated with antibiotics. CONCLUSION: When treated with antibiotics, more than two PICs isolated during cup revision surgery do not have a major impact on survival of the stem during follow-up. A larger cohort of patients with PICs during cup revision might confirm these findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

The learning curve of the direct anterior approach is 100 cases: an analysis based on 15,875 total hip arthroplasties in the Dutch Arthroplasty Register.

BACKGROUND AND PURPOSE: In the last decade, the direct anterior approach (DAA) for total hip arthroplasty (THA) has become more popular in the Netherlands. Therefore, we investigated the learning curve and survival rate of the DAA in primary THA, using data from the Dutch Arthroplasty Register (LROI). PATIENTS AND METHODS: We identified all patients who received a primary THA using the DAA in several high-volume centers in the Netherlands between 2007 and 2019 (n = 15,903). Procedures were ordered per surgeon, using date of operation. Using the procedure number, operations were divided into 6 groups based on the number of previous procedures per surgeon (first 25, 26-50, 51-100, 101-150, 151-200, > 200). Data from different surgeons in different hospitals was pooled together. Revision rates were calculated using a multilevel time-to-event analysis. RESULTS: Patients operated on in group 1-25 (hazard ratio [HR] 1.6; 95% CI 1.1-2.4) and 26-50 (HR 1.6; CI 1.1-2.5) had a higher risk for revision compared with patients operated on in group > 200 THAs. Between 50 and 100 procedures the revision risk was increased (HR 1.3; CI 0.9-1.9), albeit not statistically significant. From 100 procedures onwards the HR for revision was respectively 1.0 (CI 0.6-1.6) and 0.8 (CI 0.5-1.4) for patients in operation groups 101-150 and 151-200. Main reasons for revision were loosening of the stem (29%), periprosthetic infection (19%), and dislocation (16%). INTERPRETATION: We found a 64% increased risk of revision for patients undergoing THA using the DAA for the first 50 cases per surgeon. Between 50 and 100 cases, this risk was 30% increased, but not statistically significant. From 100 cases onwards, a steady state had been reached in revision rate. The learning curve for DAA therefore is around 100 cases.

MRI Assessment of Muscle Damage After the Posterolateral Versus Direct Anterior Approach for THA (Polada Trial). A Randomized Controlled Trial.

BACKGROUND: There is controversy in literature whether the direct anterior approach (DAA) results in less muscle damage compared with the posterolateral approach (PLA) for total hip arthroplasty. The aim of this randomized controlled trial was to assess muscle damage between these two approaches. METHODS: Forty-six patients were included. Muscle atrophy, determined with the Goutallier classification, and muscle surface of twelve muscles were analyzed on magnetic resonance imaging images made preoperatively and one year postoperatively. Differences in component placement after DAA or PLA were assessed on radiographs. Harris hip scores and Hip disability and Osteoarthritis and Outcome Score were used as functional outcomes. RESULTS: External rotator musculature was damaged in both approaches. After PLA, the obturator muscles showed significantly more atrophy and a decrease in muscle surface. After DAA, the tensor fascia latae showed an increased muscle atrophy and the psoas muscle showed a decreased muscle surface. An increase in muscle surface was seen for the rectus femoris, sartorius, and quadratus femoris after both approaches. The muscle surface of the gluteus medius and iliacus was also increased after PLA. No difference in muscle atrophy was found between the approaches for these muscles. The inclination angle of the cup in PLA was significantly higher. No differences were found in functional outcomes. CONCLUSION: Different muscle groups were affected in the two approaches. After PLA, the external rotators were more affected, whereas the tensor fascia latae and psoas muscles were more affected after DAA.

Patient satisfaction in different approaches for total hip arthroplasty.

BACKGROUND: At present, the posterolateral, the direct lateral and direct anterior approach (DAA) are the most frequently used techniques for total hip arthroplasty (THA), however there is no clear superiority of one of the approaches based on clinical outcome measures. The goal of this study is to lead the patient and the surgeon to an optimal treatment by providing them with relevant information based on patient reported outcome measures (PROMs). METHODS: Patient satisfaction and hip function one year postoperatively were investigated retrospectively in a cohort of patients who underwent hip replacement surgery by DAA on one hip and by posterolateral or direct lateral approach on the contralateral hip. Additionally, a control group who underwent the DAA bilaterally was used for comparison. RESULTS: No difference in hip function was found between the DAA and the posterolateral or direct lateral approach, measured with the Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire at least one year postoperatively to the last THA in the study group. Also in the control group no difference was found between the hips. However, the overall scores of the control group were higher, although not statistically significant, than those of the study group (p=0.055). And a majority of the study group preferred the DAA (68%), with the reasons reported being faster recovery, less sleeping disturbance and earlier mobilization. CONCLUSION: As expected, the postoperative hip function is similar, but patients' preference is not. The latter result might be true or possibly influenced by preoperative psychological factors and mental health. The DAA and the posterolateral or direct lateral approaches have shown to lead to a similar hip function, but a majority of patients subjectively prefer the DAA. LEVEL OF EVIDENCE: III.

Flow cytometric assessment of leukocyte kinetics for the monitoring of tissue damage.

Leukocyte populations quickly respond to tissue damage, but most leukocyte kinetic studies are not based on multiparameter flow cytometry. We systematically investigated several blood leukocyte populations after controlled tissue damage. 48 patients were assigned to either an anterior or posterolateral total hip arthroplasty. Peripheral blood was collected pre-operatively and at 2 h, 24 h, 48 h, 2 and 6 weeks postoperatively and assessed by flow cytometry for absolute counts of multiple leukocyte populations using standardized EuroFlow protocols. Absolute counts of leukocyte subsets differed significantly between consecutive time points. Neutrophils increased instantly after surgery, while most leukocyte subsets initially decreased, followed by increasing cell counts until 48 h. At two weeks all leukocyte counts were restored to pre-operative counts. Immune cell kinetics upon acute tissue damage exhibit reproducible patterns, which differ between the leukocyte subsets and with "opposite kinetics" among monocyte subsets. Flow cytometric leukocyte monitoring can be used to minimally invasively monitor tissue damage.

Similar Superior Patient-Reported Outcome Measures for Anterior and Posterolateral Approaches After Total Hip Arthroplasty: Postoperative Patient-Reported Outcome Measure Improvement After 3 months in 12,774 Primary Total Hip Arthroplasties Using the Anterior, Anterolateral, Straight Lateral, or Posterolateral Approach.

BACKGROUND: Patient-reported outcome measures (PROMs) are used to evaluate the outcome of total hip arthroplasty (THA). We determined the effect of surgical approach on PROMs after primary THA. METHODS: All primary THAs, with registered preoperative and 3 months postoperative PROMs were selected from the Dutch Arthroplasty Register. Based on surgical approach, 4 groups were discerned: (direct) anterior, anterolateral, direct lateral, and posterolateral approaches. The following PROMs were recorded: Hip disability and Osteoarthritis Outcome Score Physical function Short form (HOOS-PS); Oxford Hip Score; EQ-5D index score; EQ-5D thermometer; and Numeric Rating Scale measuring pain, both active and in rest. The difference between preoperative and postoperative scores was calculated (delta-PROM) and used as primary outcome measure. Multivariable linear regression analysis was performed for comparisons. Cohen's d was calculated as measure of effect size. RESULTS: All examined 4 approaches resulted in a significant increase of PROMs after primary THA in the Netherlands (n = 12,274). The anterior and posterolateral approaches were associated with significantly more improvement in HOOS-PS scores compared with the anterolateral and direct lateral approaches. Furthermore, the posterolateral and anterior approaches showed greater improvement on Numeric Rating Scale pain scores compared with the anterolateral approach. No relevant differences in delta-PROM were seen between the anterior and posterolateral surgical approaches. CONCLUSION: Anterior and posterolateral surgical approaches showed more improvement in self-reported physical functioning (HOOS-PS) compared with anterolateral and direct lateral approaches in patients receiving a primary THA. However, clinical differences were only small.

Posterolateral vs Direct Anterior Approach in Total Hip Arthroplasty (POLADA Trial): A Randomized Controlled Trial to Assess Differences in Serum Markers.

BACKGROUND: The direct anterior approach (DAA) for total hip arthroplasty has claimed to be a true tissue-sparing minimally invasive approach that has less tissue damage and a faster recovery when compared to the posterolateral approach (PLA). The aim of this randomized controlled trial is to measure the differences in serum markers and functional outcomes between the DAA and PLA for total hip arthroplasty. METHODS: Forty-six patients were prospectively included and randomized for either the DAA (n = 23) or PLA (n = 23). All surgical procedures were performed by 3 well-trained orthopedic surgeons. The degree of tissue damage was assessed by measuring creatine kinase (CK) and C-reactive protein levels (CRP) preoperatively and 2 hours, 1 day, 2 weeks, and 6 weeks postoperatively. Generalized linear mixed models analyses were used to assess differences between serum markers over time; correction for possible confounding factors was performed. The Hip disability and Osteoarthritis Outcome Score and the Harris Hip Score were assessed preoperatively and 6 weeks postoperatively. RESULTS: There were no differences in patient demographics. The DAA had a longer operative time (P = .001). CK and CRP levels increased postoperatively, but no significant differences between the groups were found on any of the time points. Functional outcomes were also similar in both approaches. CONCLUSION: No difference in tissue damage measured with serum markers CK and CRP were found between the DAA and PLA for total hip arthroplasty.

The push-through total femoral prosthesis offers a functional alternative to total femoral replacement: a case series.

PURPOSE: Oncologic resections or complications of segmental femoral prostheses can result in severe bone loss of the femur for which a total femoral prosthesis (TFP) is required. This study assesses whether the loss of stability and function caused by the loss of muscle attachments can be improved by using a push-through total femoral endoprosthesis (PTTF), because it saves parts of the femur and its muscle attachments. METHODS: In this retrospective case series, ten patients aged 25-77 (mean 54) who received a PTTF between 2005 and 2014 were included for baseline, complications and survival analysis with a mean follow-up of 5.3 (1.1-9.6) years. Functional outcome was assessed in six patients using the Musculoskeletal Tumor Society (MSTS) score, WHO performance scale, Toronto Extremity Salvage Score (TESS), SF36, EQ-5D, NRS pain score, fatigue score and satisfaction score. RESULTS: The mean MSTS score was 64% (23-93%). Five patients had a WHO performance scale of 1, one patient of 3. Mean TESS was 69% (13-90%). SF36 was most notably limited by physical functioning (mean 48), vitality (68) and general health (67). NRS score was 1.9, 1.8 and 8.3 for pain, fatigue and satisfaction, respectively. There were four failures: two infections (one resulting in amputation and one in a minor revision) and two mechanical failures (which required one revision to a TFP and one minor revision). Patient survival was 100%, limb survival 90%, and prosthesis survival 80%. CONCLUSION: The push-through total femoral endoprosthesis allows preservation of muscle attachments and offers a good alternative to total femoral prostheses.

Validity and Reliability of the Dutch Version of the International Hip Outcome Tool (iHOT-12NL) in Patients With Disorders of the Hip.

STUDY DESIGN: Clinical measurement. OBJECTIVES: To translate and culturally adapt the international Hip Outcome Tool (iHOT-12) into Dutch and to determine its validity and reliability. BACKGROUND: The iHOT-12 for measuring health-related quality of life and physical functioning in younger, active patients with hip pathology is available in English and Swedish. The tool is scored on a 0-to-100-point scale, with higher scores reflecting better function. A Dutch version of the questionnaire, with demonstrated high validity and reliability, is needed for both clinical and research purposes. METHODS: The iHOT-12 was translated and culturally adapted from English into Dutch (iHOT-12NL). Subsequently, the iHOT-12NL, RAND 36-Item Health Survey, Hip disability and Osteoarthritis Outcome Score (HOOS), and Tegner activity scale were completed by 117 patients with hip pathologies. Structural validity was analyzed using exploratory principal-component factor analysis. To determine construct validity, 12 hypotheses were predefined regarding relationships between the iHOT-12NL and subscales of the RAND 36-Item Health Survey, Hip disability and Osteoarthritis Outcome Score, and Tegner activity scale. To determine test-retest reliability, 61 patients completed the iHOT-12NL on a second occasion within a 2-week period. Intraclass correlation coefficient (ICC), Cronbach alpha, standard error of measurement (SEM), and minimal detectable change (MDC) were calculated to assess reliability. Bland-Altman analysis was conducted to assess bias between test and retest. RESULTS: Factor analysis revealed that the iHOT-12NL has 1 component. Construct validity was good, as 83% of the hypotheses were confirmed. Internal consistency was good, with a Cronbach alpha of .96. The ICC was 0.93 (95% confidence interval: 0.88, 0.96), demonstrating good test-retest reliability. The SEM was 7.3 points. Individual- and group-level MDC values were 20.2 and 2.6 points, respectively. Bland-Altman analysis showed an absence of bias. CONCLUSION: The iHOT-12NL is a reliable and valid instrument for measuring physical functioning and health-related quality of life in younger, physically active patients with hip pathology.