The epidemiology of revision total hip arthroplasty in the United States

Radiographic Accuracy of Malseated Dual-Mobility Liners Varies Based on Implant Design

BACKGROUND

Dual-mobility constructs have gained popularity to mitigate dislocations after high-risk primary and revision total hip arthroplasties. Contemporary data have indicated that malseating of modular dual-mobility liners occurs in up to 6% of cases. The purpose of this cadaveric-based radiographic study was to determine the ability to accurately determine if modular dual-mobility liners were seated.

METHODS

There were 10 hips (5 cadaveric pelvic specimens) used to implant modular dual-mobility liners of 2 designs. One had a liner that seated flush and the other had an extended rim. There were 20 constructs that were well-seated and 20 constructs were intentionally malseated. A comprehensive series of radiographs was reviewed by 2 blinded surgeons. Statistical analyses included Chi-squared testing, logistic regressions, and kappa statistics.

RESULTS

Radiographic assessment of liner malseating was not accurate with an elevated rim design with misdiagnosis in 40% (16 of 40). The flush design had diagnostic errors in 5% (2 of 40; P = .0002). Logistic regressions demonstrated a significantly higher risk of misdiagnosing a malseated liner in the elevated rim group (odds ratio 13). There were 12 of 16 misdiagnoses in the elevated rim group failing to recognize a malseated liner. Each surgeon had almost perfect agreement for intraobserver reliability for flush designs (k 0.90) and fair agreement in the elevated rim design (k 0.35).

CONCLUSION

A comprehensive series of plain radiographs can reliably detect a malseated modular dual-mobility liner with a flush rim design in 95% of cases. However, elevated rim designs are more difficult to accurately identify malseating on plain radiographs.

Total Hip Arthroplasty in Patients with Bilateral Upper-Limb Amelia: A Report of 2 Cases

CASE

We report two patients, a 43-year-old man and a 26-year-old woman, with bilateral absence of the upper extremity and severe hip osteoarthritis. The involved hip was the dominant extremity for both patients. Total hip arthroplasty (THA) was performed using a posterior approach with dual-mobility implants. Both patients report satisfactory outcomes including the ability to perform the significant range of motion required for daily activities such as toe-to-head motion.

CONCLUSION

In patients with extreme range of motion requirements such as those affected with bilateral upper-limb amelia, a posterior THA with a dual-mobility implant may be safely and successfully performed to treat disabling hip osteoarthritis.

Readmission rate and healthcare utilization outcomes of computer-assisted fluoroscopy-based hip navigation versus manual total hip arthroplasty

INTRODUCTION

The study evaluates the technology of fluoroscopy-based hip navigation that has shown to improve implant positioning in total hip arthroplasty (THA).

METHODS

Premier Healthcare data for patients undergoing manual THA or fluoroscopy-based hip navigation THA between 1 January 2016-30 September 2021, were analyzed 90- and 365-day post-THA. The primary outcome was inpatient readmission. Secondary outcomes were operating room (OR) time, length of stay, discharge status, and hospital costs. Baseline covariate differences were balanced using fine stratification and analyzed using generalized linear models.

RESULTS

Among 4,080 fluoroscopy-based hip navigation THA and 429,533 manual THA balanced patients, hip-related readmission rates were statistically significantly lower for the fluoroscopy-based hip navigation THA cohort vs. manual THA for both 90-day (odd ratio [95% CI]: 0.69 [0.52 to 0.91] and 365-day (0.63 [0.49 to 0.81] follow-up. OR time was higher with fluoroscopy-based hip navigation THA vs. manual THA (134.65 vs. 132.04 minutes); however, fluoroscopy-based hip navigation THA patients were more likely to be discharged to home (93.73% vs. 90.11%) vs. manual THA. Hospital costs were not different between cohorts at 90- and 365-day post-operative.

CONCLUSIONS

Fluoroscopy-based hip navigation THA resulted in fewer readmissions, greater discharge to home, and similar hospital costs compared to manual THA.

Pneumatic Compression Combined with Standard Treatment after Total Hip Arthroplasty and Its Effects on Edema of the Operated Limb and on Physical Outcomes: A Pilot Clinical Randomized Controlled Study

Total hip arthroplasty (THA) is one of the most successful orthopedic procedures and is highly effective at improving function and quality of life. However, patients commonly experience edema immediately after hospitalization and also after discharge, which can lead to health consequences and a lower quality of life. For these reasons, the aim of this study (NCT05312060) was to evaluate the effectiveness of a specific intermittent leg pneumatic compression on lower limb edema and physical outcomes in patients after total hip arthroplasty, compared to standard conservative treatment. A total of 47 patients were enrolled and randomly allocated into two groups: the pneumatic compression group (PG = 24) and the control group (CG = 23). The CG performed the standard venous thromboembolism therapy, which included pharmacological prophylaxis, compressive stockings, and electrostimulation, while the PG combined pneumatic compression with standard VTE therapy. We evaluated thigh and calf circumferences, knee and ankle ranges of motion, pain, and walking autonomy. Our results showed a greater reduction in thigh and calf circumferences for PG (p < 0.001), while other outcomes were similar for the two groups (p > 0.05). The combination of standard therapy with pneumatic leg compression was more effective at reducing lower limb edema and thigh and calf circumferences than standard treatment. Our results suggest that pressotherapy treatment is a valuable and efficient option for managing lower limb edema after THA.

Direct Anatomic Registration in Computer-Assisted Total Hip Arthroplasty Improves Accuracy of Acetabular Cup Alignment

Background

Computer-assisted total hip arthroplasty using direct anatomic registration (DAR) with acetabular center axis software is an alternative method to the indirect anterior pelvic plane method. The software maps the center of hip rotation and orientation of the native acetabulum in 3 dimensions. This study aimed to evaluate the accuracy of acetabular cup alignment using DAR navigation combined with a mechanical guide device (MGD).

Methods

This prospective nonrandomized controlled study included 106 patients who underwent primary cementless total hip arthroplasty through the posterolateral approach. Fifty-four patients in the study group underwent DAR combined with MGD, whereas 52 patients underwent MGD only for acetabular cup positioning. Plain radiographs of both hips and computerized tomographic scans were obtained 2 months postoperatively for the evaluation of acetabular cup inclination and anteversion, respectively.

Results

The acetabular cup alignment in the study group was within the Lewinnek safe zone more than that in the control group (81.5% vs 59.6%, P < .05). The study group had a mean inclination angle of 43.88°° (standard deviation [SD] 5.38) and anteversion angle of 12.82° (SD 5.99), whereas the control group had 41.10° (SD 6.79) and 12.82° (SD 9.53), respectively. There were no significant differences in estimated blood loss, length of stay, and Harris hip scores at preoperative and 3 and 6 months postoperatively, except for the operative time, which was longer in the study group (P < .01). There was 1 posterior hip dislocation in each group.

Conclusions

DAR navigation combined with MGD provides better accuracy for acetabular cup positioning within the Lewinnek safe zone compared with the conventional technique.

Polyethylene Dual Mobility Liners Show Minimal Polyethylene Changes in Early Retrievals

BACKGROUND

Dual mobility (DM) liners were introduced to reduce instability in total hip arthroplasty. They were found to allow for motion predominantly at the femoral head and the inner bearing of the acetabular liner; however, little is known if this motion is sufficient to alter polyethylene material characteristics. We assessed cross-link (XL) density and oxidation index (OI) measurements of the inner and outer bearing articulations.

METHODS

Thirty-seven DM liners were collected with a duration of implantation greater than 2 years. Clinical and demographic data were collected from a chart review. A cylinder was cored from the apex of each liner and cut into 4.5 mm long inner and outer diameter segments for XL density swell ratio testing. The OI was measured from sagittal 100 μm microtome slices using Fourier transform infrared spectroscopy. Student's t-tests were used to determine differences in OI and XL density between the bearings. Spearman's correlation assessed relationships between patient demographics, OI, and XL density. Duration of implantation for the cohort was a mean of 35 (range, 24-96) months.

RESULTS

The inner and outer bearing had similar median XL densities (0.17 mol/dm3 versus 0.17 mol/dm3, P = .6). The inner bearing had an increased OI when compared to the outer bearing (0.16 versus 0.13, P = .008). The OI was inversely correlated with XL density (r = -0.50, P = .002).

CONCLUSION

Small differences were found in oxidation between the inner and outer bearing of the DM construct. Failures at an average of 3 years indicate low levels of oxidation, unlikely to impact the mechanical properties of the material.

Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2040-2060

Background

National projections of future joint arthroplasties are useful in understanding the changing burden of surgery and related outcomes on the health system. The aim of this study is to update the literature by producing Medicare projections for revision total joint arthroplasty procedures from 2040 through 2060.

Methods

The study uses 2000-2019 data from the CMS Medicare Part-B National Summary and combines procedure counts using CPT codes for revision total joint arthroplasty procedures. In 2019, revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA) procedures totaled 53,217 and 30,541, respectively, forming a baseline from which we generated point forecasts between 2020 and 2060 and 95% forecast intervals (FI).

Results

On average, the model projects an annual growth rate of 1.77% for rTHAs and 4.67% for rTKAs. By 2040, rTHAs were projected to be 43,514 (95% FI = 37,429-50,589) and rTKAs were projected to be 115,147 (95% FI = 105,640-125,510). By 2060, rTHAs was projected to be 61,764 (95% FI = 49,927-76,408) and rTKAs were projected to be 286,740 (95% FI = 253,882-323,852).

Conclusions

Based on 2019 total volume counts, the log-linear exponential model forecasts an increase in rTHA procedures of 42% by 2040 and 101% by 2060. Similarly, the estimated increase for rTKA is projected to be 149% by 2040 and 520% by 2060. An accurate projection of future revision procedure demands is important to understand future healthcare utilization and surgeon demand. This finding is only applicable to the Medicare population and demands further analysis for other population groups.

Does Prednisone Dose Affect Rates of Periprosthetic Joint Infection Following Primary Total Hip and Total Knee Arthroplasty?

BACKGROUND

Prednisone use is associated with higher rates of periprosthetic joint infection (PJI) following total joint arthroplasty (TJA). However, the relationship between prednisone dosage and infection risk is ill-defined. Therefore, this study aimed to assess the relationship between prednisone dosage and rates of PJI following TJA.

METHODS

A national database was queried for all elective total hip (THA) and total knee arthroplasty (TKA) patients between 2015 and 2020. Patients who received oral prednisone following TJA were matched in a 1:2 ratio based on age and sex to patients who did not. Univariate and multivariate regression analyses were performed to assess the 90-day risk of infectious complications based on prednisone dosage as follows: 0 to 5, 6 to 10, 11 to 20, 21 to 30, and >30 milligrams. Overall, 1,322,043 patients underwent elective TJA (35.9% THA, 64.1% TKA). Of these, 14,585 (1.1%) received prednisone and were matched to 29,170 patients who did not.

RESULTS

After controlling for confounders, TKA patients taking prednisone were at increased risk for sepsis (adjusted odds ratio [aOR] 2.76, P < .001), PJI (aOR 2.67, P < .001), and surgical site infection (aOR: 2.56, P = .035). THA patients taking prednisone were at increased risk for sepsis (aOR: 3.21, P < .001) and PJI (aOR: 1.73, P = .001). No dose-dependent relationship between prednisone and infectious complications was identified when TJA was assessed in aggregate.

CONCLUSION

Patients receiving prednisone following TJA were at increased risk of PJI and sepsis. A dose-dependent relationship between prednisone and infectious complications was not identified. Arthroplasty surgeons should be aware of these risks and counsel TJA patients who receive prednisone therapy.

Revision hip arthroplasty dislocation risk calculator: when to select dual mobility, large heads, constrained liners, or a standard head size? Testing one hundred thousand hip revisions with artificial intelligence

PURPOSE

Preventing dislocation with large head (≥ 36 mm), dual mobility, or constrained acetabular liner is another option than a standard (≤ 32 mm). Many other dislocations risk factors than size of the femoral head exist after hip arthroplasty revision. Predicting dislocation with a calculator according to the implant, to the indication of revision, and to patient's risks could allow a better surgery decision.

METHODS

Our search method covers the period from 2000 to 2022. A total of 470 relevant citations on hip major revision (cup or stem or both revisions) were identified with artificial intelligence comprising 235 publications of 54,742 standard heads comprising 142 publications of 35,270 large heads, comprising 41 publications of 3945 constrained acetabular components, and 52 publications of 10,424 dual mobility implants. We considered four implant types (standard, large head, dual mobility, or constrained acetabular liner) as the entry layer of the artificial neural network (ANN). Indication for revision THA was the second hidden layer. Demographics, spine surgery, and neurologic disease were the third layer. Implant revision, reconstruction process as next input (hidden layer). Surgery-related factors, and so on. The output was a postoperative dislocation or not.

RESULTS

Of the 104,381 hips that underwent a major revision, a second revision for dislocation was performed for 9234 hips. In each implant group, dislocation remained the first cause of revision. The rate of second revision for dislocation as a percentage of first revision procedures was significantly higher in the standard head group (11.8%) than in the constrained acetabular liner group (4.5%), the dual mobility group (4.1%), and the large head group (6.1%). Instability of a previous THA, infection, or periprosthetic fracture as the indication for revision was increased risk factors as compared with aseptic loosening. One hundred variables were used to create the calculator with the best parameter combination of data and ranking the different factors, according to the four implant types (standard, large head, dual mobility, or constrained acetabular liner).

CONCLUSION

The calculator can be used as a tool to identify patients at risk for dislocation after hip arthroplasty revision and individualize recommendations to select another option than a standard head size.

A Novel Method to Calculate Functional Pelvic Tilt Using a Standing Anteroposterior Pelvis Radiograph

Background

Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT.

Methods

A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT.

Results

There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r = 0.785, r² = 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r = 0.864, r² = 0.747, P < .001). Using regression analysis, a linear equation was created (PT = 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio.

Conclusions

There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component.

Which Combination is Best? A Comparison of the Predictive Potential of Serum Biomarker Combinations to Diagnose Periprosthetic Joint Infection

BACKGROUND

Without a gold standard test, recent periprosthetic joint infections (PJI) literature has explored the utility of combining serological results, with promising findings. However, previous studies evaluated fewer than 200 patients and often studied only 1 to 2 test combinations. The purpose of this study was to accumulate a large single institution cohort of revision total joint arthroplasty (rTJA) patients to determine the diagnostic utility of combination serum biomarkers to identify PJI.

METHODS

A single institution longitudinal database was assessed to identify all patients who underwent rTJA from 2017 to 2020. There were 1,363 rTJA patients (715 rTKA patients and 648 rTHA patients) including 273 PJI cases (20%) analyzed. The PJI was diagnosed post-rTJA utilizing 2011 Musculoskeletal Infection Society (MSIS) criteria. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), D-dimer, and interleukin 6 (IL-6) were systematically collected for all patients.

RESULTS

The rTKA combination markers of CRP+ESR (sensitivity: 78.3%, specificity: 88.8%, positive predictive value (PPV): 70.0%, negative predictive value (NPV): 92.5%), CRP+D-dimer (sensitivity: 60.5%, specificity: 92.6%, PPV: 63.4%, NPV: 91.7%), and CRP+IL-6 (sensitivity: 38.5%, specificity: 100.0%, PPV: 100.0%, NPV: 92.9%) all yielded higher specificity than CRP alone (sensitivity: 94.4%, specificity: 75.0%, PPV: 55.5%, NPV: 97.6%). Similarly, the rTHA combination markers of CRP+ESR (sensitivity: 70.1%, specificity: 88.8%, PPV: 58.1%, NPV: 93.1%), CRP+D-dimer (sensitivity: 57.1%, specificity: 90.1%, PPV: 43.2%, NPV: 94.1%), and CRP+IL-6 (sensitivity: 21.4%, specificity: 98.4%, PPV: 60.0%, NPV: 91.7%) all yielded higher specificity than CRP alone (sensitivity: 84.7%, specificity: 77.5%, PPV: 45.4%, NPV: 95.8%).

CONCLUSIONS

Overall, in diagnosing PJI for both rTKA and rTHA, two marker combinations yielded higher specificity, while three marker combinations yielded higher sensitivity compared to CRP alone. However, compared to all two and three marker combinations, CRP demonstrated superior overall diagnostic utility. These findings suggest that routine combination testing of markers for PJI diagnosis may be excessive and an unnecessary use of resources, especially in resource-limited situations.

Combining deep learning and machine learning for the automatic identification of hip prosthesis failure: Development, validation and explainability analysis

AIM

Revision hip arthroplasty has a less favorable outcome than primary total hip arthroplasty and an understanding of the timing of total hip arthroplasty failure may be helpful. The aim of this study is to develop a combined deep learning (DL) and machine learning (ML) approach to automatically detect hip prosthetic failure from conventional plain radiographs.

METHODS

Two cohorts of patients (of 280 and 352 patients) were included in the study, for model development and validation, respectively. The analysis was based on one antero-posterior and one lateral radiographic view obtained from each patient during routine post-surgery follow-up. After pre-processing, three images were obtained: the original image, the acetabulum image and the stem image. These images were analyzed through convolutional neural networks aiming to predict prosthesis failure. Deep features of the three images were extracted for each model and two feature-based pipelines were developed: one utilizing only the features of the original image (original image pipeline) and the other concatenating the features of the three images (3-image pipeline). The obtained features were either used directly or reduced through principal component analysis. Both support vector machine (SVM) and random forest (RF) classifiers were considered for each pipeline.

RESULTS

The SVM applied to the 3-image pipeline provided the best performance, with an accuracy of 0.958 ± 0.006 in the internal validation and an F1-score of 0.874 in the external validation set. The explainability analysis, besides identifying the features of the complete original images as the major contributor, highlighted the role of the acetabulum and stem images on the prediction.

CONCLUSIONS

This study demonstrated the potentialities of the developed DL-ML procedure based on plain radiographs in the detection of the failure of the hip prosthesis.

Invasive Gastrointestinal Endoscopy Following Total Joint Arthroplasty Increases the Risk for Periprosthetic Joint Infection

BACKGROUND

The safety of postoperative colonoscopy and endoscopy following total joint arthroplasty (TJA) remains largely unknown. The objective of this study was to characterize the effect of gastrointestinal endoscopic procedures after TJA on the risk of postoperative periprosthetic joint infection (PJI).

METHODS

Using a large national database, patients who underwent an endoscopic procedure (colonoscopy or esophagogastroduodenoscopy (EGD)) within 12 months after primary TJA were identified and matched in a 1:1 fashion based on procedure (primary total knee arthroplasty (TKA) vs. total hip arthroplasty (THA), age, sex, Charlson Comorbidity Index (CCI), and smoking status with patients who did not undergo endoscopy. A total of 142,055 patients who underwent endoscopy within 12 months following TJA (96,804 TKA and 45,251 THA) were identified and matched. The impact of timing of endoscopy relative to TJA on postoperative outcomes was assessed. Pre-operative comorbidity profiles and 1-year complications were compared. Statistical analyses included Chi-squared tests and multivariate logistic regressions with outcomes considered significant at P <0.05.

RESULTS

Multivariate analyses revealed that endoscopy within 2 months following TKA and 1 month of THA was associated with a significantly increased odds of periprosthetic joint infection (Odds Ratio (OR): 1.29 [1.08-1.53]; P=.004; OR: 1.41 [1.01-1.90]; P=0.033, respectively). Patients who underwent endoscopy greater than 2 months from the timing of their TKA and 1 month from THA were not at significantly greater risk of developing PJI.

CONCLUSION

This data suggests that invasive endoscopic procedures should be delayed if possible by at least 2 months following TKA and 1 month following THA to minimize the risk of PJI.

Taking a Deeper Dive into Malnutrition and Revision Arthroplasty: When do Nutritionists Get Involved?

BACKGROUND

Perioperative malnutrition is associated with increased complications and mortality following revision total joint arthroplasty (TJA). Nutritional consultations are useful in characterizing patient nutritional status, but are inconsistently utilized post-revision TJA. We sought to describe 1) the prevalence of nutritional consultations post revision TJA, 2) determine if septic revision TJA patients needed consultations more often, and if 3) a diagnosis of 'malnutrition' from the nutritionist conferred increased readmission rates.

METHODS

A retrospective study of 2,697 rTJAs performed in a single institution over a 4-year period was performed. Patient demographics, reasons for revision TJA, occurrences of nutritional consultation (indicated if body mass index (BMI)<20, Malnutrition Screening Tool (MST) score > 2, or poor oral intake postoperatively), specific nutritional diagnosis (according to 2020 Electronic Nutrition Care Process Terminology (eNCPT) and 90-day readmission rates were recorded and analyzed. Rates of consultations and adjusted logistic regressions were calculated.

RESULTS

There were 501 patients (18.6%) who required nutritional consultations, with 55 (11.0%) of these patients receiving a 'malnutrition' diagnosis. Septic rTJA patients required significantly more nutritional consultations (P<0.01) and were significantly more likely to have 'malnutrition' (P=0.49). A diagnosis of malnutrition was associated with highest odds of all-cause readmission (Odds Ratio (OR)=3.89, P=0.01), which was even higher than undergoing a septic revision TJA.

CONCLUSION

Nutritional consultations occur frequently following revision TJA. Patients who receive a diagnosis of 'malnutrition' through consultation are at significantly higher risk for re-admission and require close follow-up. Future efforts are needed to further characterize these patients in order to identify as well as optimize them preoperatively.

Dislocation and survival rate of dual mobility cups in revision total hip arthroplasty in patients with high risk of instability

PURPOSE

Instability remains as an unsolved complication after revision total hip arthroplasty (rTHA). Dual mobility (DM) cups have decreased dislocation rate in rTHA; however, there are few clinical studies that evaluate the risk of dislocation after rTHA in patients with high risk of instability.

METHODS

Between 2007 and 2019, 95 consecutive rTHA using a DM cup, in 93 patients with instability risk factors were retrospectively reviewed. Instability risk factors were defined as follows: deficient abductor mechanism (22.1%), previous dislocation (68.4%), Paprosky 3 acetabular bone defect (21.1%), neuromuscular disease (4.2%), lumbar spine arthrodesis (6.3%), and more than one previous surgery (33.6%). Mean follow-up was 4.3 ± 2.4 years. Clinical and radiographic parameters were reported. DM cup survival was determined using a Kaplan-Meier analysis with re-revision for any cause as the end-point. Surgical complications and re-dislocation rate was recorded.

RESULTS

Seven DM cups were re-revised; three due to aseptic loosening, three due to peri-prosthetic joint infection (PJI), and one due to instability. At seven years follow-up, the survival rate of the DM cup using re-revision for any reason as the end-point was 82.4% (95% confidence interval, 66.4-98.4%). There were 12 (12.6%) complications: two (2.1%) dislocations, six (6.3%) PJI, four (4.2%) peri-prosthetic fractures.

CONCLUSION

Our findings suggest DM cups are effective reducing dislocation rate in rTHA in patients with a high risk of instability, without increasing early aseptic loosening and with a low rate of dislocation. Nevertheless, longer follow-up is needed to confirm implant stability and dislocation rates in the long term.

Monocyte Differentiation on Atomic Layer-Deposited (ALD) Hydroxyapatite Coating on Titanium Substrate

Hydroxyapatite (HA; Ca₁₀(PO₄)₆(OH)₂) coating of bone implants has many beneficial properties as it improves osseointegration and eventually becomes degraded and replaced with new bone. We prepared HA coating on a titanium substrate with atomic layer deposition (ALD) and compared monocyte differentiation and material resorption between ALD-HA and bone. After stimulation with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL), human peripheral blood monocytes differentiated into resorbing osteoclasts on bovine bone, but non-resorbing foreign body cells were observed on ALD-HA. The analysis of the topography of ALD-HA and bone showed no differences in wettability (water contact angle on ALD-HA 86.2° vs. 86.7° on the bone), but the surface roughness of ALD-HA (Ra 0.713 µm) was significantly lower compared to bone (Ra 2.30 µm). The cellular reaction observed on ALD-HA might be a consequence of the topographical properties of the coating. The absence of resorptive osteoclasts on ALD-HA might indicate inhibition of their differentiation or the need to modify the coating to induce osteoclast differentiation.

Complication Rate after Primary Total Hip Arthroplasty Using the Posterior Approach and Enabling Technology: A Consecutive Series of 2,888 Hips

BACKGROUND

Total hip arthroplasty (THA) is a safe and effective procedure, however, complications such as dislocation, fracture, and infection still occur. It is still unclear whether the dislocation rate via the posterior approach (PA) is better, equal, or worse than the direct anterior approach. Our aim was to report the primary THA dislocation rate via the PA using enabling technology in a large consecutive series of patients.

METHODS

A retrospective cohort of 2,888 primary THAs were reviewed at a single, high volume, academic institution from January 2018 to September 2021. All patients underwent a THA by four fellowship-trained orthopaedic surgeons through the PA with enabling technology. Overall dislocation and readmission rates within 90 days and up to 3 years were analyzed.

RESULTS

Of the 2,888 procedures, a total of 39 patients had complications related to the surgery during the 3-year follow-up period. There were 10 patients (0.35%) who experienced a dislocation, with half undergoing surgical revision. Of the 39 patients who experienced complications, 37 (1.3%) were readmitted and 2 underwent revision during their hospital stay. Post-operative periprosthetic fractures were the most common cause for readmission and reoperation at a rate of 0.52 and 0.52%, respectively.

CONCLUSION

The dislocation rate of 0.35% is one of the lowest reported rates via the PA at a mean follow up of 2.1 years and is comparable to previously published rates using alternate approaches. Using contemporary THA with enabling technology, the PA is a reliable approach with respect to dislocation and complication rates after primary THA.

"Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population"

BACKGROUND

Instability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships.

METHODS

Using the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk for instability.

RESULTS

Instability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by peri-prosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders.

CONCLUSION

Instability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

Evaluation of Mechanically-Assisted Crevice Corrosion of Different Modular Dual Mobility Constructs

BACKGROUND

Modular dual mobility (MDM) acetabular component use is rising in total hip arthroplasty. However, concern of mechanically-assisted crevice corrosion (MACC) at the shell-liner interface remains. We investigated shell-liner corrosion using retrieval analyses and corrosion chamber testing.

METHODS

We analyzed fretting and corrosion on 10 matched pairs of two commercial modular dual mobility constructs (MDM1 and MDM2). Also, pristine pairs of Ti6Al4V shells and CoCrMo liners from three commercial dual mobility systems (MDM1, MDM2, MDM3) were tested in vitro to model MACC performance. Three pairs of each were placed into an electrochemical chamber with stepwise increasing cyclic compression loads, while measuring currents generated at the shell-liner taper. Onset fretting loads and fretting currents were calculated.

RESULTS

Corrosion damage scores on retrieved components were low, but higher in the MDM2 to MDM1 liners (P = 0.006), specifically outside the taper region (P = 0.00003). Fretting currents were higher in the MDM2 than in MDM1 or MDM3 (P = 0.011). Onset loads were also higher in the MDM2 (P = 0.001).

CONCLUSION

Among retrieved liners, MDM2 tapers seem prone to non-mechanical corrosion modes. Higher onset loads and fretting currents in MDM2 tapers indicate greater MACC resistance, but higher severity once corrosion begins. Differences among the devices were likely due to taper design and surface finish. Currents in all three were <5 μA, much lower than those observed with head-neck tapers. Our findings suggest that among the types of corrosion observed in these MDM designs, mechanically driven corrosion may not be the most significant.

Does Acetabular Bone Loss Severity Associate with Patient Reported Outcome Measures and Reoperation Rate in Revision Total Hip Arthroplasty?

INTRODUCTION

Acetabular bone loss is a challenging clinical problem when performing revision total hip arthroplasty (rTHA). This study aimed to evaluate how acetabular bone loss severity influences (1) clinical outcomes and (2) patient reported outcome measures (PROMs) in rTHA patients.

METHODS

Patients who underwent rTHA with acetabular component revision from January 2016 to February 2022 were included. Treating surgeons determined Paprosky acetabular bone loss classification intraoperatively. Patients were grouped based on numeric classification (PI, PII, or PIII) to categorize severity. Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR.) and Lower Extremity Activity Scale (LEAS) score were collected preoperatively and one year postoperatively. There were 197 patients included. Paprosky classification was PI for 47 patients (23.9%), PII for 113 patients (57.4%), and PIII for 37 patients (18.8%). Mean clinical follow-up was 29 months (range, 1 to 69).

RESULTS

Reoperation rate was 0% (0 patients), 6.2% (7 patients), and 10.8% (4 patients) for PI, PII and PIII groups respectively (p=0.052). Mean preoperative HOOS, JR. and LEAS for PI, PII and PIII groups were significantly different, but one-year postoperative HOOS, JR. and LEAS did not differ significantly. Rates of HOOS, JR. minimal clinically important difference (MCID) achievement differed significantly between bone loss groups.

CONCLUSION

In this study of rTHA patients, greater acetabular bone loss severity was associated with worse preoperative PROMs and trended towards higher reoperation rate. Postoperative PROMs for bone loss severity groups were statistically similar. Patients who had worse acetabular bone loss were more likely to achieve HOOS, JR. MCID postoperatively.

Malseating of Modular Dual Mobility Liners: High Prevalence in Revision Total Hip Arthroplasty

BACKGROUND

Modular dual mobility (MDM) acetabular components have become increasingly more popular in total hip arthroplasty (THA). Uncertainty remains regarding liner malseating and its consequences after 5 to 10 years, especially in patients who undergo revision THA. The objective of this study was to analyze the prevalence of malseating and implant survivorship of patients who underwent revision THA using an MDM liner.

METHODS

We retrospectively identified patients who had a minimum 2-year follow-up and underwent revision THA using an MDM liner. Patient demographics, implant details, mortality, and all-cause revisions were recorded. Patients who had radiographic follow-up were assessed for malseating. Kaplan Meier survival was used to determine implant survivorship. We included 143 hips in 141 patients. Mean age was 70 years (35 - 93 years) and 86 patients (60.1%) were female.

RESULTS

Overall implant survival was 89.3% (95% Confidence Interval (CI) 0.843 - 0.946) at a mean follow-up of 6 years (range 2 to 10) years. There were eight patients excluded from malseating assessment. Upon radiological review, 15 liners (11.1%) were malseated. Survival for all-cause revision for patients with malseated liners was 80.0% (12/15, 95% CI 0.62 - 0.99, P= 0.15) versus 91.5% in patients who had non-malseated liners (110/120, 95% CI 0.86 - 0.96). There were no intraprosthetic dislocations and 3.5% of the patients were revised due to instability. No liners were revised due to malseating, and no patients who had malseated liners were revised due to instability.

CONCLUSIONS

Using MDM components in our cohort comprised of revision THA was associated with a high prevalence of malseating and an overall survival of 89.3% at a mean follow up of 6 years. Malseating does not appear to impact implant survival at a mean follow-up of 6 years.

A dual-functional PEEK implant coating for anti-bacterial and accelerated osseointegration

Polyetheretherketone (PEEK) has been widely applied in biomedical engineering. However, the unsatisfactory bioactivity essentially limits the clinical application of PEEK. In this study, a simply immersing method was proposed to fabricate a dual-functional PEEK with antibacterial properties and enhanced bone integration. Firstly, the surface of PEEK was modified with a polydopamine (PDA) coating by incubating at dopamine solution. Afterward, the PEEK-PDA was modified with manganese (Mn) and silver (Ag) ions by the soaking method to fabricate the PEEK-PDA-Mn/Ag. The physicochemical capabilities of PEEK-PDA-Mn/Ag were further explored in the ions release, wettability, morphology, and element distributions. PEEK-PDA-Mn/Ag obviously accelerated the adhesion and distribution of MC3T3-E1 cells, indicating favorable biosafety in vitro. Meanwhile, the osteogenic properties of PEEK-PDA-Mn and PEEK-PDA-Mn/Ag were proved by the increased expression of osteogenic genes, alkaline phosphatase (ALP), and mineralization in vitro. Additionally, the wide antibacterial capabilities of PEEK-PDA-Mn/Ag were proved in both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in vitro. Furthermore, the PEEK-PDA-Mn/Ag was antibacterial with capability in enhancing osseointegration in vivo. Overall, the simply immersing method can modify the surface of PEEK, giving the bioactivity, biocompatibility, and antibacterial ability to the composited PEEK, which could be applied as an orthopedic implant in clinical.

Global Cluster Analysis and Network Visualization in Prosthetic Joint Infection: A Scientometric Mapping

OBJECTIVE

Prosthetic joint infection (PJI) is the main reason of failure of total joint arthroplasty (TJA). This study aimed to investigate the global trends and network visualization in research of PJI.

METHODS

Publications in PJI search during 1980-2022 were extracted from the Science Citation Index-Expanded of Web of Science Core Collection database (WoSCC). The source data was investigated and analyzed by bibliometric methodology. For network visualization, VOS viewer and R software was used to perform bibliographic coupling, co-citation, co-authorship and co-occurrence analysis and to predict the publication trends in PJI research.

RESULTS

There were 7288 articles included. The number of publications and relative research interests increased gradually per year globally. The USA made the highest contributions in the world and with the highest H-index and the most citations. Journal of Arthroplasty published the highest number of articles in this area. The Mayo Clinic, Thomas Jefferson University (Rothman Institute), Hospital Special Surgery and the Rush University were the most contributive institutions by network visualization. Included studies were divided into four clusters: bacterial pathogenic mechanism and antibacterial drugs study, TJA complications, risk factors and epidemiology of PJI, diagnosis of PJI, and revision surgical management. More articles in PJI could be published over the next few years.

CONCLUSION

The number of publications about PJI will be increasing dramatically based on the global trends and network visualization. The USA made the highest contributions in PJI. Diagnosis and revision management may be the next hot spots in this field.

The Top Three Burning Questions in Total Hip Arthroplasty

Total hip arthroplasty (THA) for end-stage osteoarthritis is one of the most effective surgical treatments in medicine. Impressive outcomes have been well documented in the literature with patients gaining ambulation and recovery of hip joint function. Nevertheless, there are still debatable issues and controversies that the orthopedic community has not been able to provide a definitive answer for. This review is focused on the current three most debatable issues surrounding the THA procedure: (1) new cutting-edge technology, (2) spinopelvic mobility, and (3) fast-track protocols. The scope of the herein narrative review is to analyze the debatable issues surrounding the three aforementioned topics and conclude the best contemporary clinical approaches regarding each issue.

Increased Dislocation Rates After Total Hip Arthroplasty in Patients With Prior Isolated Sacroiliac Joint Arthrodesis

BACKGROUND

While stiffness of the lumbosacral spine is a known predictor of instability following total hip arthroplasty (THA), little is known about the medical- and surgical-related outcomes following THA in patients who have prior isolated sacroiliac (SI) joint arthrodesis.

METHODS

197 patients who had a history of isolated SI joint arthrodesis who subsequently underwent elective primary THA for a diagnosis of osteoarthritis (THA-SI) from 2015 to 2021 were identified in a national administrative database. Using propensity score matching and logistic regression analyses, this cohort was compared to two groups of patients: patients who did not have any history of lumbar or SI arthrodesis and patients undergoing primary THA who had a history of lumbar arthrodesis without extension into the SI joint (THA-LF).

RESULTS

The THA-SI group had a significantly higher incidence of dislocation (odds ratio 2.06, 95% confidence interval 1.04-4.04, P = .037) with no increased incidence of medical complications or other surgical complications when compared to patients without a history of SI or lumbar arthrodesis. There were no significant differences in any complications in THA-SI patients when compared to THA-LF patients.

CONCLUSION

Patients who had prior isolated SI joint arthrodesis undergoing primary THA demonstrated a two-fold increased incidence of dislocation when compared to those who did not have prior SI arthrodesis, although the risk of complications in this population was similar to that observed in patients who had prior isolated lumbar spine arthrodesis.

Impact of three-dimensional printed planning in Paprosky III acetabular defects: a case-control and cost-comparison analysis

PURPOSE

The main challenges in revision total hip arthroplasty (rTHA) are the treatment of the bone loss and the pre-operative planning. 3D-printed models may enhance pre-operative planning. The aim of the study is to compare the intra- and peri-operative results and costs for Paprosky type 3 rTHAs planned with 3D-printed models to ones accomplished with the conventional imaging techniques (X-rays and CT scan).

METHODS

Seventy-two patients with Paprosky type 3 defect underwent rTHA between 2014 and 2021. Fifty-two patients were treated with standard planning and 20 were planned on 3D-printed models. Surgical time, intra-operative blood loss, number of transfused blood units, number of post-operative days of hospitalization, and use of acetabular rings were compared between the two groups. A costs comparison was also performed.

RESULTS

The 3D-printed group showed reduced operative time (101.8 min (SD 27.7) vs. 146.1 min (SD 49.5), p < 0.001) and total days of hospitalization (9.3 days (SD 3.01) vs. 12.3 days (SD 6.01), p = 0.009). The cost of the procedures was significantly lower than the control group, with an adjusted difference of 4183 euros (p = 0.004). No significant differences were found for the number of total transfused blood units and blood loss and the number of acetabular rings.

CONCLUSION

The use of 3D-printed models led to a meaningful cost saving. The 3D-printed pre-operative planning for complex rTHAs seems to be effective in reducing operating time, hospital stay and overall costs.

Perioperative Complications after Hip and Knee Revision Arthroplasty in the over 80 Years Old Population: A Retrospective Observational Case-Control Study

BACKGROUND

The number of joint revision arthroplasties has increased in the elderly population, which is burdened by several perioperative risks.

METHODS

Patients who underwent hip and knee revision arthroplasty were retrospectively included, and they were divided into two groups by age: <80 years old (Group 1) and ≥80 years old (Group 2). The primary outcome was to compare perioperative complication rates. The secondary outcome was to compare the 30-day, 90-day, and 1-year readmission rates.

RESULTS

In total, 74 patients in Group 1 and 75 patients in Group 2 were included. Postoperative anemia affected 13 patients in Group 1 (17.6%) and 25 in Group 2 (33.3%, p 0.027); blood units were transfused in 20 (26.7%) and 11 (14.9%, p 0.076) patients, respectively. In Group 1, two (2.7%) patients reported wound infection. In Group 2, eight (10.7%) patients presented hematomas, and two (2.7%) patients reported dislocations. No significant differences in the two groups were observed for 30-day (p 0.208), 90-day (p 0.273), or 1-year readmission rates (p 0.784).

CONCLUSION

The revision arthroplasty procedure in patients over 80 years old is not associated with a higher risk of perioperative complications, or higher readmission rate compared with younger patients undergoing hip and knee revision surgery.

Dislocation Rates of Primary Total Hip Arthroplasty in Patients With Prior Lumbar Spine Fusion and Lumbar Degenerative Disk Disease With and Without Utilization of Dual Mobility Cups: An American Joint Replacement Registry Study

INTRODUCTION

Patients undergoing primary total hip arthroplasty (THA) with a previous history of lumbar spine fusion (LSF) are at increased risk of dislocation. The purpose of this study was to compare the 90-day and 1-year dislocation rates of patients with LSF or lumbar degenerative disk disease who underwent primary THA with and without dual mobility (DM) constructs.

METHODS

An American Joint Replacement Registry data set of patients aged 65 years and older undergoing primary THA with minimum 1-year follow-up with a history of prior LSF or a diagnosis of lumbar degenerative disk disease was created. DM status was identified, and dislocation and all-cause revision at 90 days and 1 year were assessed.

RESULTS

A total of 15,572 patients met study criteria. The overall dislocation rates for the non-DM and DM groups were 1.17% and 0.68%, respectively, at 90 days, and 1.68% and 0.91%, respectively, at 1 year ( P = 0.005). The odds of 90-day (OR = 0.578, [ P = 0.0328]) and 1-year (OR = 0.534, [ P = 0.0044]) dislocation were significantly less with DM constructs, compared with non-DM constructs. No statistically significant difference was observed in revision rates between groups.

DISCUSSION

This large registry-based study identified a reduced risk of dislocation in patients at risk for spinal stiffness when a DM compared with non-DM construct was used in primary THA at 90-day and 1-year follow-up intervals. Our data support the use of DM constructs in high-risk patients with stiff spines and altered spinopelvic mobility as a promising option to mitigate the risk of postoperative hip instability after primary THA.

LEVELS OF EVIDENCE

Level III. Therapeutic retrospective cohort.

Stability analysis of tranexamic acid in the presence of various antiseptic solutions

Tranexamic acid (TXA) effectively reduces blood loss and transfusion risk during total joint arthroplasty. Additionally, intraoperative irrigation with various antiseptic solutions is often utilized for the management and prevention of surgical site infection. However, interactions between various antiseptic solutions and TXA have not been investigated. The purpose of this in vitro study is to evaluate the stability of TXA in the presence of common orthopedic antiseptic solutions. Five antiseptic solutions-0.1% chlorhexidine (CHX) gluconate, 10% povidone-iodine (BTD), 0.5% sodium hypochlorite (Dakin's), 3% hydrogen peroxide (H₂ O₂ ), and 1.5% H₂ O₂ -and a 0.9% normal saline (NS) control were obtained. A stock 100 mg/ml TXA solution was diluted in each antiseptic solution to a concentration of 10.0 mg/ml to generate reference standard and stability samples. TXA stability in each solution was measured using high performance liquid chromatography at t = 0 and t = 120 min and reported as mean percent of theoretical concentration (MPT) with associated relative standard deviation (RSD). All experiments were performed in triplicate at room temperature. At t = 0 min, TXA remained stable when mixed with 0.9% NS, 0.1% CHX, 10% BTD, 3% H₂ O₂ , and 1.5% H₂ O₂ (MPT range: 102.0%-105.0%, RSD range: 0.80%-2.92%). Only 0.5% Dakin's led to significant degradation of TXA at t = 0 min (MPT: 14.3%, RSD:1.28%). At t = 120 min, TXA stability persisted for all compounds except Dakin's 0.5% (MPT: 18.4%, RSD: 28.7%). TXA efficacy may be significantly diminished when 0.5% Dakin's is used as an intraoperative irrigation solution. CHX, BTD, and H₂ O₂ do not degrade TXA.

Patient-specific femoral implant design using metamaterials for improving load transfer at proximal-lateral region of the femur

Loading configuration of hip joint creates resultant bending effect on femoral implants. So, the lateral side of femoral implant which is under tension retracts from peri‑implant bone due to positive Poisson's ratio. This retraction of implant leads to load shielding and gap opening in proximal-lateral region, thereby allowing entry of wear particle to implant-bone interface. Retraction of femoral implant can be avoided by introducing auxetic metamaterial to the retracting side. This allows the implant to push peri‑implant bone under tensile condition by virtue of their auxetic (negative Poisson's ratio) nature. To develop such implants, a patient-specific conventional solid implant was first designed based on computed-tomography scan of a patient's femur. Two types of metamaterials (2D: type-1) and (3D: type-2) were employed to design femoral meta-implants. Type-1 and type-2 meta-implants were fabricated using metallic 3D printing method and mechanical compression testing was conducted. Three finite element (FE) models of the femur implanted with solid implant, type-1 meta-implant and type-2 meta-implant were developed and analysed under compression loading. Significant correlation (R² = 0.9821 and R² = 0.9977) was found between the experimental and FE predicted strains of the two meta-implants. In proximal-lateral region of the femur, an increase of 7.1% and 44.1% von-Mises strain was observed when implanted with type-1 and type-2 meta-implant over the solid implant. In this region, bone remodelling analysis revealed 2.5% bone resorption in case of solid implant. While bone apposition of 0.5% and 7.7% was observed in case of type-1 and type-2 meta-implants, respectively. The results of this study indicates that concept of introduction of metamaterial to the lateral side of femoral implant can prove to provide higher osseointegration-friendly environment in the proximal-lateral region of femur.

Prevalence of groin pain after primary dual-mobility total hip arthroplasty

BACKGROUND

Instability remains a challenging problem following total hip arthroplasty (THA). Dual-mobility (DM) components are used with increasing frequency to mitigate this potential complication. As has been shown with larger metal-on-metal (MoM) THA, the larger size femoral head may pose an increased risk of groin pain. This study aims to evaluate the prevalence of groin pain following primary DM THA compared to other THA constructs.

METHODS

We identified 190 primary THAs (183 patients) performed with DM components at a single academic institution from 2008 to 2017. We retrospectively reviewed standardised patient questionnaires and the electronic medical record to determine the prevalence of groin pain. DM patients were compared to historical controls of 39 MoM hip resurfacing, 26 large-head MoM THA, and 217 conventional THA. Mean age was 64 years, 58% were female, mean body mass index was 30 kg/m², and mean follow-up was 3.5 years (range 2-8 years).

RESULTS

The prevalence of groin pain in patients with DM components was 5%, similar to the prevalence reported by patients with conventional THA (7%). There was a decreased prevalence of groin pain in DM patients compared to hip resurfacing (18%) and MoM THA (15%). Among the 9 DM patients with groin pain, 1 was treated with iliopsoas injection, and 1 underwent radiofrequency ablation of the articular nerve.

CONCLUSIONS

This study documents a relatively low prevalence of groin pain among primary DM THA patients. This is comparable with historical controls of conventional THA and decreased compared to hip resurfacing and large head MoM THA.

Do polyethylene wear particles affect the development of pseudotumor in total hip arthroplasty? A minimum 15-year follow-up

BACKGROUND

Adverse local tissue reactions have been problematic as an implant-related complication in total hip arthroplasty (THA). Despite the absence of significant metal wear and corrosion, granulomatous pseudotumor has been reported to be caused by polyethylene wear. We performed a long-term follow-up study investigating the relationship between polyethylene wear and pseudotumor formation in THA.

METHODS

This study included 57 patients (64 hips) that underwent primary THA with metal-on-polyethylene or ceramic-on-polyethylene bearing over a minimum follow-up of 15 years. They were stratified into pseudotumor and non-pseudotumor groups and their linear wear rates of polyethylene liner and serum cobalt (Co) and chromium (Cr) ion levels were compared. Pseudotumor was diagnosed on metal artifact reduction sequence-MRI according to its composition and wall thickness using the Hauptfleisch classification.

RESULTS

The incidence of pseudotumor was 34% (22/64 hips) at the mean follow-up of 16.9 years. Metal ion levels did not differ between the pseudotumor and non-pseudotumor groups, and none of the patients exceeded the Co/Cr ratio of 2.0 μg/L. Moreover, the wear rate in the pseudotumor group was 1.8 times greater than in the non-pseudotumor group (0.14 vs. 0.08 mm/year, P < 0.001). According to an analysis of the receiver operating characteristic curves, the cutoff level of the wear rate to discriminate between pseudotumor and non-pseudotumor patients at 15 years was 0.11 mm/year (area under the curve = 91%; sensitivity = 95%; specificity = 78%; accuracy = 87%).

CONCLUSIONS

Our results might provide new insights into excessive polyethylene wear potentially leading to the future development of both pseudotumor and osteolysis. Further studies are needed to clarify the direct relationship between polyethylene wear and pseudotumor and the mutual effects of osteolysis and pseudotumor in particle reactions.

Large Femoral Heads and Select Dual-Mobility Bearings Are Associated With Reduced Instability in Contemporary Posterior Approach Total Hip Arthroplasty

BACKGROUND

Postoperative dislocation is considered the main drawback of posterior approach total hip arthroplasty (THA). Thinner highly cross-linked polyethylene and dual-mobility bearings allow maximizing femoral head diameter per a given cup size. This study evaluated dislocation rates as large femoral head bearings were introduced into a practice over an 11-year period.

METHODS

A total of 1,511 consecutive primary THAs were retrospectively reviewed. Demographics, implant sizes, femoral head-acetabular cup ratio, and dislocation status were collected from the electronic medical record. Data were evaluated using time series analysis techniques as larger femoral heads, thinner polyethylene liners, and dual-mobility bearings were introduced. The cohort was 57% women with mean age and body mass index of 62 years (range, 13 to 93) and 31 kg/m² (range, 13 to 54), respectively.

RESULTS

The overall dislocation rate was 0.98%. Use of femoral head sizes ≥ 40 millimeters increased from 4% in the years 2010 to 2016 to 51% in the years 2017 to 2021, correlating with a 50% reduction in dislocation rate from 1.4% to 0.7% (P = .279). Also, no dislocations occurred in patients who had dual-mobility bearings or ≥ 40-millimeter femoral heads (P = .007). Twelve of 14 dislocations occurred in cases with head-cup ratio < 0.7 (P = .013). Thirteen of 14 dislocations were in women (P = .005).

CONCLUSION

Maximizing the femoral head diameter per given cup size correlated with a decrease in dislocation rate in modern posterior approach THA. Furthermore, these results suggest that dual-mobility articulations should be reserved for high-risk patients or patients in whom a 40-millimeter femoral head is not possible.

LEVEL OF EVIDENCE

IV-consecutive case series; no control group.

Metal Augments Used in Revision Hip Arthroplasty: A Systematic Review and Single-Arm Meta-Analysis

BACKGROUND

Porous metal augments are used in complex hip arthroplasty; however, few studies have assessed their efficacy and safety. This systematic review analyzed the use of augments in revision hip arthroplasty and summarized the clinical research findings.

METHODS

We used combinations of "revision," "replacement," "arthroplasty," "augment," "acetabular," and "hip" to search PubMed, Web of Science, EMBASE, Cochrane Library databases, and clinical trial registration platform "Clinicaltrials" for relevant literature. The functional score, restoration of hip center of rotation, revision of implants, and complications were analyzed. Patients were divided into 3 subgroups according to the mean follow-up period. Overall, 19 reports involving 647 patients (655 hips) were selected. The mean age at the time of surgery was 63 years (range, 24-106) and the mean follow-up duration was 66 months (range, 11-204).

RESULTS

Harris Hip Score increased from approximately a mean of 40 points preoperatively to a mean of 84 points postoperatively. The vertical distance between hip center of rotation and teardrop was restored from a preoperative distance of 41.9 to 21.7 mm postoperatively. The overall acetabular revision rate was 4.7%, and the incidence of complications was 8.2%. There were significant differences in the reoperation, acetabular revision, and complication rates among the subgroups.

CONCLUSION

Metal augments used in revision hip arthroplasty are a safe and effective treatment option to correct acetabular defects.

Does acetabular robotic-assisted total hip arthroplasty with femoral navigation improve clinical outcomes at 1-year post-operative? A case-matched propensity score study comparing 98 robotic-assisted versus 98 manual implantation hip arthroplasties

INTRODUCTION

Despite the optimization of implant positioning, the clinical benefit of the use of robotic assistance during THA remains uncertain. In this case-control study (robotic versus manual technique) we made a retrospective short-term comparison of: (1) the functional results, (2) the complications, (3) and the influence of radiological symmetrization of the hips on the functional result.

HYPOTHESIS

The use of a robotic arm improved the functional results of a THA.

MATERIALS AND METHOD

A retrospective case-control study was performed, including patients with unilateral hip osteoarthritis who underwent a robotic arm-assisted THA (THA-R). The controls (THA-C) were matched according to age, sex, body mass index and surgical approach. The Harris (HHS), Oxford (OHS) and Forgotten Joint (FJS) scores were collected preoperatively and 1 year postoperatively. At each review, complications were categorized into minor events, revision surgery with and without implant change. Radiographic analysis was performed on weight-bearing images of the pelvis 3 months postoperatively. The objective of the surgery was symmetrization of the THA in the contralateral healthy hip. For each measured parameter of the hip joint center of rotation (COR), global offset (GO) and articular leg length discrepancy (aLLD), the difference between the two sides corresponding to the delta symmetrization was compared.

RESULTS

Ninety-eight patients were included in the THA-R group and matched to 98 controls in the THA-C group. At 1 year postoperatively, the FJS and OHS scores were statistically higher in the THA-R group, respectively 82.1±22.3 [8.3; 100] and 40.8±8.8 [6; 48] vs. 71.2±27.8 [0; 100] and 38.1±9.7 [12; 48] in the THA-C group (p=0.004 and p=0.043). There was no difference in HHS (THA-R: 85.9±15.8 [31; 100] vs. THA-C: 85.8±13.3 [49-100] (p=0.962)). The implant revision rate at 1 year was significantly higher in the THA-C group (0% vs. 5.1% (p=0.025)). There was no difference in the reoperation without component exchange despite 3 dislocations (3.1%) in the THA-R group (5 (5.1%) vs. 9 (9.2%) (p=0.273)). The rate of abarticular pathologies (ilio-psoas irritation and greater trochanteric bursitis) was higher in the THA-C group (10 (10.8%) vs. 2 (2%) (p=0.016). Robotic acetabular assistance allowed a significantly better restitution of the horizontal position (THA-R: 1mm±4.8 [-11.7; 12.6] vs. THA-C: 4.1mm±7 [-29.6; 28] (p=0.0005)) and vertical COR (THA-R: 0.5mm±3.1 [-6; 8.3] vs. THA-C: 2mm±4.1 [-6; 14.6] (p=0.0068)). Navigated assistance of the femur did not significantly optimize the restitution of the Global Offset (THA-R: +2mm±6.4 [-16.4; 27.6] vs. THA-C: +0.5mm±7 .7 [-34; 30.2] (p=0.145)), or lower limb length (THA-R: +1.1mm±5 [-8.2; 13.5] vs. THA-C: +0.3mm±6 [-14.1; 22.5] (p=0.344). The FJS was statistically correlated with the restoration of the symmetry of the COR and the aLLD. A post-hoc power analysis confirmed sufficient potency (1-β=0.85).

CONCLUSION

Robotic acetabular assistance combined with femoral navigation improves clinical outcomes of THAs with fewer short-term complications. The precision of the positioning of the implants, optimized by the computer-assisted surgery system, is correlated with the missed joint score.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Increased Risk of Hospital Readmissions and Implant-Related Complications in Patients Who Had a Recent History of Fragility Fracture: A Matched Cohort Analysis

BACKGROUND

With the increasing utilization of total knee arthroplasty (TKA) in a continually aging US population, the number of patients who have low bone mineral density who undergo TKA may concomitantly increase. This study aimed to assess the rates of short-term complications following TKA in patients who did and did not have a recent history of a prior fragility fracture.

METHODS

A matched retrospective cohort study analyzing 48,796 patients was performed using a national database to determine the impact of a preceding fragility fracture on rates of short-term complications following TKA. The rates of complications at 1 and 2 years post-TKA were analyzed using multivariate logistic regressions.

RESULTS

Prior fragility fracture was associated with increased rates of 1-year hospital readmissions (hazard ratio = 1.30, 95% CI, 1.22-1.38), periprosthetic fractures (odds ratio [OR] = 2.72, 95% CI, 1.89-3.99), non-infection-related revisions (OR = 1.32, 95% CI, 1.09-1.60), secondary fragility fractures (OR = 4.62, 95% CI, 4.19-5.12), prosthesis dislocations (OR = 1.76, 95% CI, 1.22-2.56), prosthesis instabilities (OR = 1.64, 95% CI, 1.25-2.15), and periprosthetic infections (OR = 1.49, 95% CI, 1.29-1.71), with similar trends in implant-related complications also seen at the 2-year mark. Patients who filled a prescription for osteoporosis pharmacotherapy had clinically similar rates of these complications compared to those who did not.

CONCLUSION

Sustaining a fragility fracture prior to TKA is associated with an increased risk of hospital readmission and significant implant-related postoperative complications, potentially increasing the morbidity and mortality of TKA in these patients.

Ceramic Femoral Heads Exhibit Lower Wear Rates Compared to Cobalt Chrome: A Meta-Analysis

BACKGROUND

Wear between the femoral head and acetabular liners continues to limit the longevity of total hip arthroplasty implants despite advances in implant materials. The purpose of this meta-analysis was to compare linear wear rates of cobalt-chromium (CoCr) and fourth-generation ceramic femoral heads on highly cross-linked polyethylene (XLPE) liners.

METHODS

A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted to identify all studies between 2003 and 2020 that examined in vivo wear rates of either fourth-generation ceramics or CoCr femoral heads on XLPE liners. Studies were analyzed in a weighted means analysis of wear rates and a random effects meta-analysis.

RESULTS

A total of 36 studies met inclusion criteria (1,657 CoCr and 659 ceramic patients). The pooled, weighted mean wear rate was 0.063 mm/year (standard deviation [SD]: 0.061, confidence interval [CI]: 0.049-0.077) for CoCr and 0.047 mm/year (SD: 0.057, CI: 0.033-0.062; P < .01) for ceramic (P < .01). A meta-analysis of 4 studies directly comparing ceramic and CoCr found that CoCr heads demonstrated 0.029 mm/year more wear than ceramic heads (95% CI: 0.026-0.059, P = .306). Mean wear for 32-mm heads was significantly higher for ceramic (P < .01), while mean wear for 36-mm heads was significantly higher for CoCr (P < .01).

CONCLUSION

Fourth-generation ceramic femoral heads were found to have significantly lower wear rates than CoCr heads. Unlike previous studies, this meta-analysis included only in vivo studies and those with the same generation of highly XLPE liners.

C-reactive protein/albumin and C-reactive protein/fibrinogen ratios for the diagnosis of periprosthetic joint infection in revision total joint arthroplasty

AIM

Testing for systemic inflammation markers is considered a simpler method for diagnosing periprosthetic joint infection (PJI). Changes in the C-reactive protein/albumin ratio (CRP/Alb ratio) and C-reactive protein/fibrinogen ratio (CRP/Fib ratio) are associated with PJI. This study aimed to evaluate the application of CRP/Alb and CRP/Fib ratios as novel inflammation-based markers for the diagnosis of PJI.

METHODS

We retrospectively evaluated 445 patients who underwent total hip and knee revision arthroplasties between January 2010 and February 2021. Of these, 129 patients were also independently evaluated for PJI with coagulation-related comorbidities. The patients were divided into two groups: the aseptic revision (268 patients) and PJI revision groups (187 patients). Subsequently, we evaluated the diagnostic value of the CRP/Alb and CRP/Fib ratios compared to other inflammation-based diagnoses using the area under the curve (AUC) values.

RESULTS

The AUC values of the CRP/Alb and CRP/Fib ratios were 0.880 and 0.872, respectively, suggesting similar diagnostic potentials for PJI. The CRP/Alb and CRP/Fib ratios were better than the erythrocyte sedimentation rate (ESR), Alb, and Fib, whose AUC values were 0.765, 0.352, and 0.730, respectively, for the diagnosis of PJI. The optimal cut-off for the CRP/Alb ratio was 0.13, with good sensitivity (85.0%) and specificity (78.4%). The optimal cut-off CRP/Fib ratio was 2.04, with good sensitivity (81.3%) and specificity (80.6%). Notably, the CRP/Alb and CRP/Fib ratios had the highest sensitivity, followed by four conventional inflammatory markers, namely, CRP, ESR, Alb, and Fib, which had sensitivities of 80.2%, 67.4%, 50.8%, and 54.0%, respectively. Similar findings were observed in patients with coagulation-related comorbidities.

CONCLUSION

Both the CRP/Alb and CRP/Fib ratios were significantly higher in patients with PJI than in those with aseptic failure and showed better sensitivity and specificity for diagnosing PJI than classical inflammatory markers.

Achieving Precise Cup Positioning in Direct Anterior Total Hip Arthroplasty: A Narrative Review

Malpositioned implants in total hip arthroplasty are associated with impingement, increased wear, and dislocations, thus precise cup positioning is crucial. However, significant deviations between targeted and actually achieved cup positions have been found even in patients operated by experienced surgeons. When aiming for higher accuracy, various methods based on freehand positioning lead by anatomic landmarks, C-arm fluoroscopy, imageless navigation, or robotic-assisted-surgery have been described. There is a constant development of new products aiming to simplify and improve intraoperative guidance. Both the literature and expert opinions on this topic are often quite controversial. This article aims to give an overview of the different methods and systems with their specific advantages and potential pitfalls while also taking a look into the future of cup positioning in anterior hip replacements.

Menthone Exerts its Antimicrobial Activity Against Methicillin Resistant Staphylococcus aureus by Affecting Cell Membrane Properties and Lipid Profile

Objective

The characteristic constituents of essential oils from aromatic plants have been widely applied as antimicrobial agents in the last decades. However, their mechanisms of action remain obscure, especially from the metabolic perspective. The aim of the study was to explore the antimicrobial effect and mechanism of menthone, a main component of peppermint oil, against methicillin resistant Staphylococcus aureus (MRSA).

Methods

An integrated approach including the microbiology and the high-coverage lipidomics was applied. The changes of membrane properties were studies by the fluorescence and electron microscopical observations. The lipid profile was analyzed by ultra-high performance liquid chromatography coupled with quadruple Exactive mass spectrometry (UHPLC-QE-MS). The lipid-related key targets which were associated with the inhibitory effect of menthone against MRSA, were studied by network analysis and molecular docking.

Results

Menthone exhibited antibacterial activities against MRSA, with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 3,540 and 7,080 μg/mL, respectively. The membrane potential and membrane integrity upon menthone treatment were observed to change strikingly. Further, lipids fingerprinting identified 136 significantly differential lipid species in MRSA cells exposed to menthone at subinhibitory level of 0.1× MIC. These metabolites span 30 important lipid classes belonging to glycerophospholipids, glycolipids, and sphingolipids. Lastly, the correlations of these altered lipids, as well as the potential metabolic pathways and targets associated with menthone treatment were deciphered preliminarily.

Conclusion

Menthone had potent antibacterial effect on MRSA, and the mechanism of action involved the alteration of membrane structural components and corresponding properties. The interactions of identified key lipid species and their biological functions need to be further determined and verified, for the development of novel antimicrobial strategies against MRSA.

Disparities in Elective and Nonelective Total Hip Arthroplasty

BACKGROUND

Prior studies have shown disparities in utilization of primary and revision total hip arthroplasty (THA). However, little is known about patient population differences associated with elective and nonelective surgery. Therefore, the aim of this study was to explore factors that influence primary utilization and revision risk of THA based on surgery indication.

METHODS

Data were obtained from 7,543 patients who had a primary THA from 2014 to 2020 in a database, which consists of multiple health partner systems in Louisiana and Texas. Of these patients, 602 patients (8%) underwent nonelective THA. THA was classified as "elective" or "nonelective" if the patient had a diagnosis of hip osteoarthritis or femoral neck fracture, respectively.

RESULTS

After multivariable logistic regression, nonelective THA was associated with alcohol dependence, lower body mass index (BMI), women, and increased age and number of comorbid conditions. No racial or ethnic differences were observed for the utilization of primary THA. Of the 262 patients who underwent revision surgery, patients who underwent THA for nonelective etiologies had an increased odds of revision within 3 years of primary THA (odds ratio (OR) = 1.66, 95% Confidence Interval (CI) = 1.06-2.58, P-value = .025). After multivariable logistic regression, patients who had tobacco usage (adjusted odds ratio (aOR) = 1.36, 95% CI = 1.04-1.78, P-value = .024), alcohol dependence (aOR = 2.46, 95% CI = 1.45-4.15, P-value = .001), and public insurance (OR = 2.08, 95% CI = 1.18-3.70, P-value = .026) had an increased risk of reoperation.

CONCLUSION

Demographic and social factors impact the utilization of elective and nonelective primary THA and subsequent revision surgery. Orthopaedic surgeons should focus on preoperative counseling for tobacco and alcohol cessation as these are modifiable risk factors to directly decrease reoperation risk.

Effect of Total Hip Arthroplasty with Ceramic Acetabular Component on Clinical, Radiographic and Functional Parameters in Older Patients with Hip Osteoarthritis: Two-Year Follow-Up

Background: Total hip arthroplasty (THA) is a widely used surgical procedure to reduce pain and improve function and quality of life in patients with hip disorders. The most common condition that leads to THA is osteoarthritis, with most surgeries being performed to treat severe osteoarthritis with pain and functional limitations. Despite the evident success of THA, the search for its improvement and better results, especially in the long term, continues, especially in older patients, for which there is still little scientific evidence. Objective: To evaluate the clinical, radiological, and functional aspects preoperatively and two years after THA with a ceramic acetabular component device in older patients with hip osteoarthritis. Methods: A retrospective cohort study was conducted to evaluate 65 older individuals who underwent THA of the hip with an acetabular component (MD® ceramic head with a ceramic acetabular insert) associated with the MD6® Phenom® femoral rod type, in Hospital of the Luz, São Paulo/SP, between 2018 and 2019. Anthropometric and clinical information about the operative procedure and two years follow-up were collected from the patients’ medical records. For the clinical-functional evaluation, the Harris Hip Score (HHS) questionnaire and hip movement goniometry were applied. For the radiographic parameters, the following were evaluated: the positioning of the acetabular component, the Zone of DeLee and the offset of the femoroacetabular component. Results: There was a higher prevalence of performing THA in males (53.8%). Preoperative and two-year postoperative radiographic parameters of surgical treatment for THA showed maintenance of the acetabular (p = 0.083) and femoral (p = 0.102) positioning angles and increased functionality (p < 0.001) and joint mobility of the hip (p = 0.001) with reduced pain after two years of THA. Complications related to dislocation, loosening, infection, and inadequate positioning of the implant were low, ranging from 1.5 to 3%. Conclusion: Older people who underwent cementless THA with an ceramic acetabular component device, in a two-year follow-up, showed effectiveness in improved clinical, radiological, and functional aspects.

The combined evaluation of fibrinogen and D-dimer levels are a helpful tool to exclude periprosthetic knee infection

This retrospective study was undertaken to (i) define the most appropriate thresholds for serum d-dimer and fibrinogen for differentiating aseptic failure from periprosthetic joint infection (PJI) and (ii) evaluate the predictive value of our d-dimer and fibrinogen threshold compared to previously proposed thresholds. This observational cohort study included consecutive patients who had undergone total knee arthroplasty (TKA) revision between January 2019 and December 2020. International Consensus Meeting diagnostic criteria were used to identify patients affected by the prosthetic infection. Receiver operating characteristic curve analyses assessed the predictive value of the parameters, and the areas under the curves were evaluated. We included 125 patients with a median age of 69 years (53-82) affected by painful TKA. Fifty-seven patients (47%) had PJI. Patients with PJI had higher median d-dimer, fibrinogen, ESR, and CRP when compared to patients believed to be free of PJI. The best threshold values for d-dimer and fibrinogen were 1063 ng/ml (sensitivity 0.72, specificity 0.74) and 420 mg/dl (sensitivity 0.67 and specificity 0.82), respectively. A d-dimer level >1063 ng/ml combined with a fibrinogen level >420 mg/dl had a sensitivity of 0.52, and a specificity of 0.90. We found that an increased d-dimer beyond 1063 ng/ml showed a better predictive value than the previously proposed threshold. The combined determination of d-dimer and fibrinogen displayed high specificity and should be considered an excellent tool to rule out an infection. The accuracy of the proposed cutoffs is more effective than previously reported.

A low dislocation rate after revision total hip arthroplasty performed through the anterior approach

BACKGROUND

Dislocation is a major complication in revision total hip arthroplasties. This study aimed to evaluate the dislocation rate, complications, and functional scores of revision total hip arthroplasty performed through the direct anterior approach.

METHODS

Between January 2014 and March 2020, 84 patients undergoing revision total hip arthroplasty were retrospectively reviewed. All operations were performed through the direct anterior approach. At the final follow-up, incidences of dislocation, reoperation, acute deep infections, periprosthetic fractures and psoas impingement were assessed. The median postoperative Oxford Hip Score was also calculated.

RESULTS

At revision surgery, the mean age was 66 ± 12 years (range, 28-91). During an average follow-up of 4.2 ± 1.2 years, reoperation rate for major complications in the non-infected revisions was 15% (n = 11), including five acute deep infections (7%), four periprosthetic fractures (5%), one dislocation and one psoas impingement (1%). The median postoperative Oxford Hip Score was 39 (interquartile range = 14).

CONCLUSION

In our series, revision total hip arthroplasty through direct anterior approach was associated with a very low dislocation rate, acceptable complication rates and good functional results. Our results suggest that this procedure is safe and reliable.

TRIAL REGISTRATION

Ethical approval for this study was obtained, before enrollment of the first participant, by CUB Erasme's research ethics committee (P2020/323) and C.H.U Ambroise Paré's research ethics committee.

Proposed bone health screening protocol to identify total knee arthroplasty patients for preoperative DXA

This study evaluates a novel, simple bone health screening protocol composed of patient sex, age, fracture history, and FRAX risk to identify total knee arthroplasty patients for preoperative DXA. Findings supported effectiveness, with sensitivity of 1.00 (CI 0.92-1.00) and specificity of 0.54 (CI 0.41-0.68) when evaluating for clinical osteoporosis.

PURPOSE

Bone health optimization is a process where osteoporotic patients are identified, evaluated via modalities such as dual-energy X-ray absorptiometry (DXA), and treated when indicated. There are currently no established guidelines to determine who needs presurgical DXA. This study evaluates the effectiveness of a simple screening protocol to identify TKA patients for preoperative DXA.

METHODS

This prospective cohort study began on September 1, 2019, and included 100 elective TKA patients. Inclusion criteria were ≥ 50 years and primary TKA. All patients obtained routine clinical DXA. The screening protocol defining who should obtain DXA included meeting any of the following: female ≥ 65, male ≥ 70, fracture history after age 50, or FRAX major osteoporotic fracture risk without bone mineral density (BMD) adjustments ≥ 8.4%. Osteoporosis was defined by the World Health Organization (WHO) criteria (T-score ≤  - 2.5) or clinically (T-score ≤  - 2.5, elevated BMD-adjusted FRAX risk, or prior hip/spine fracture). Sensitivity and specificity were calculated.

RESULTS

The study included 68 females and 32 males, mean age 67.2 ± 7.7. T-score osteoporosis was observed in 16 patients while 43 had clinical osteoporosis. Screening criteria recommending DXA was met by 69 patients. Screening sensitivity was 1.00 (CI 0.79-1.00) and specificity was 0.37 (CI 0.27-0.48) for identifying patients with T-score osteoporosis. Similar sensitivity of 1.00 (CI 0.92-1.00) and specificity of 0.54 (CI 0.41-0.68) were found for clinical osteoporosis.

CONCLUSIONS

A simple screening protocol identifies TKA patients with T-score and clinical osteoporosis for preoperative DXA with high sensitivity in this prospective cohort study.

The dual role of autophagy in periprosthetic osteolysis

Periprosthetic osteolysis (PPO) induced by wear particles is an important cause of aseptic loosening after artificial joint replacement, among which the imbalance of osteogenesis and osteoclastic processes occupies a central position. The cells involved in PPO mainly include osteoclasts (macrophages), osteoblasts, osteocytes, and fibroblasts. RANKL/RANK/OGP axis is a typical way for osteolysis. Autophagy, a mode of regulatory cell death and maintenance of cellular homeostasis, has a dual role in PPO. Although autophagy is activated in various periprosthetic cells and regulates the release of inflammatory cytokines, osteoclast activation, and osteoblast differentiation, its beneficial or detrimental role remains controversy. In particular, differences in the temporal control and intensity of autophagy may have different effects. This article focuses on the role of autophagy in PPO, and expects the regulation of autophagy to become a powerful target for clinical treatment of PPO.

Complications of primary total hip arthroplasty in human immunodeficiency virus-positive patients with femoral head osteonecrosis

BACKGROUND

Femoral head osteonecrosis (FHON) is a well-recognised complication in patients with human immunodeficiency virus (HIV) infection. Total hip arthroplasty (THA) is a reliable solution to FHON and has provided functional improvement and pain relief in these patients. Higher complication rates, in particular infections, have been reported in the series of THAs done in the HIV-positive patients. The purpose of this study was to evaluate the complication rate of THA for FHON in HIV-positive patients managed with the highly active antiretroviral therapy (HAART) protocols.

METHODS

A retrospective review was performed of HIV-positive patients with FHON who underwent THAs over a 10-year period at a single institution.

RESULTS

A total of 56 THAs (44 patients) met the inclusion criteria. The mean age at the time of THAs was 47 (range 34-60) years. Of the 44 patients, 39 (88.6%) were males. The mean follow-up was 6.6 (range 2.0-11.3) years. The overall complication rate was 12.5%, with 2 (3.6%) cases of deep periprosthetic infections.

CONCLUSIONS

HIV-positive patients with FHON undergoing THAs do have a considerable complication rate (12.5%). The deep periprosthetic infection rate (3.6%) in these patients, however, has decreased with contemporary disease modification protocols.

Is the routine use of local antibiotics in the management of periprosthetic joint infections justified?

Periprosthetic joint infection (PJI) following total hip and total knee arthroplasty continues to be a leading cause of re-operation and revision arthroplasty. Not only is the treatment of PJI notoriously challenging, but success rates are variable. Regardless of the surgical strategy used, successful management of PJI requires a comprehensive surgical debridement focused at eradicating the underlying biofilm followed by appropriate antimicrobial therapy. Although systemic antimicrobial delivery continues to be a cornerstone in the treatment of PJI, many surgeons have started using local antibiotics to deliver higher concentrations of antibiotics directly into the vulnerable joint and adjacent soft tissues, which often have compromised vascularity. Available evidence on the use of topical powder, bone cement, and calcium sulphate carriers for local delivery of antibiotics during the initial treatment of PJI is limited to studies that are extremely heterogeneous. There is currently no level-1 evidence to support routinely using these products. Further, appropriately powered, prospective studies are needed to quantify the safety and efficacy of antibiotic-located calcium-sulphate carriers to justify their added costs. These products should not encourage surgeons to deviate from best practice guidelines, such as those recommended during the International Consensus Meeting on Musculoskeletal Infections.

Empiric antibiotic therapy in early periprosthetic joint infection: a retrospective cohort study

PURPOSE

Periprosthetic joint infection (PJI) is a devastating complication following total knee or total hip arthroplasty (TKA/THA). Appropriate empiric antibiotic treatment, initiated directly after debridement and implant retention (DAIR), is suggested to contribute to treatment success. The aim of this study was to describe the microbiology and the antibiotic susceptibility in early PJI to guide future empiric treatment in a region with a low incidence of methicillin-resistant Staphylococcus aureus (MRSA).

METHODS

Consecutive patients who underwent DAIR within 3 months after primary unilateral TKA or THA between January 2011 and December 2018 were retrospectively identified from the hospital electronic health records. Data on causative pathogens, antimicrobial susceptibility and the number of post-operative days until cultures demonstrated bacterial growth were collected.

RESULTS

One hundred and eleven early PJIs were identified of which 65 (59%) were monomicrobial and 46 (41%) polymicrobial. Among all isolated pathogens, Staphylococcus aureus (n = 53; 29%) was the most commonly identified pathogen in early PJI without any involvement of MRSA. 72% of PJIs were susceptible to vancomycin which could be increased to around 90% by adding gram-negative coverage. On the 5th postoperative day, bacterial growth was observed in 98% of cases. All gram-negative bacteria demonstrated positive tissue cultures on the 4th postoperative day.

CONCLUSION

Vancomycin combined with ciprofloxacin or a third generation cephalosporin provided the highest antimicrobial coverage of all responsible pathogens identified in early PJI. Empiric treatment of gram-negative treatment can be safely terminated in the absence of gram-negative pathogens after 4 days of culturing in cases without preoperative antibiotic treatment.