The epidemiology of revision total hip arthroplasty in the United States

Economics of Total Hip Arthroplasty: Review

This review article focuses on issues of economic analysis in providing care to patients requiring total hip arthroplasty. A large number of factors affecting the final financial result force us to look at economic research in the field of arthroplasty with a certain degree of criticality. At the same time, the existing financing systems cannot fully take into account all the possible costs arising from total hip arthroplasty. For this reason, studies concerning revision total hip arthroplasty are of particular interest, where treatment costs can vary significantly depending on the etiology and complexity of the case. These differences are reflected in the works of authors from France, Germany and Great Britain, who compared the treatment costs of patients with septic and aseptic revisions. Very different data both between countries and within the same country well demonstrate the need for a critical approach to the results of cost-effectiveness studies, QALYs based on Markov and other models, as the quality of the original data can be highly variable and reproduce the error of the initially incorrect price structure. At the same time, the rapidly increasing number of operations of primary and revision hip arthroplasty and, accordingly, the increasing economic costs of these operations require clear and effective economic criteria for their evaluation. The formation and application of these criteria will be the purpose of further research.

Vital protocols for PolyWare™ measurement reliability and accuracy

Background and objective

PolyWare™ software (PW) has been exclusively used in the majority of polyethylene wear studies of total hip arthroplasty (THA). PW measurements can be significantly inaccurate and unrepeatable, depending on imaging conditions or subjective manipulation choices. In this regard, this study aims to shed light on the conditions needed to achieve the best accuracy and reliability of PW measurements.

Methods

The experiment looked at how PW fluctuated based on several measurement conditions. x-ray images of in-vitro THA prostheses were acquired under a clinical x-ray scanning condition. A linear wear rate of 6.67 mm was simulated in combination with an acetabular lateral inclination of 36.6° and anteversion of 9.0°.

Results

Among all the imported x-ray images, those with a resolution of 1,076 × 1,076 exhibited the best standard deviation in wear measurements as small as 0.01 mm and the lowest frequencies of blurriness. The edge detection area specified as non-square and off the femoral head center exhibited the most blurriness. The x-ray image that scans a femoral head eccentrically placed by 15 cm superior to the x-ray beam center led to a maximum acetabular anteversion measurement error of 5.3°.

Conclusion

Because PW has been the only polyethylene wear measurement tool used, identifying its sources of error and devising a countermeasure are of the utmost importance. The results call for PW users to observe the following measurement protocols: (1) the original x-ray image must be a 1,076 × 1,076 square; (2) the edge detection area must be specified as a square with edge lengths of 5 times the diameter of the femoral head, centered at the femoral head center; and (3) the femoral head center or acetabular center must be positioned as close to the center line of the x-ray beam as possible when scanning.

The prevalence and treatment of osteoporosis in patients undergoing total hip arthroplasty and the levels of biochemical markers of bone turnover

AIMS

Osteoporosis is common in total hip arthroplasty (THA) patients. It plays a substantial factor in the surgery's outcome, and previous studies have revealed that pharmacological treatment for osteoporosis influences implant survival rate. The purpose of this study was to examine the prevalence of and treatment rates for osteoporosis prior to THA, and to explore differences in osteoporosis-related biomarkers between patients treated and untreated for osteoporosis.

METHODS

This single-centre retrospective study included 398 hip joints of patients who underwent THA. Using medical records, we examined preoperative bone mineral density measures of the hip and lumbar spine using dual energy X-ray absorptiometry (DXA) scans and the medications used to treat osteoporosis at the time of admission. We also assessed the following osteoporosis-related biomarkers: tartrate-resistant acid phosphatase 5b (TRACP-5b); total procollagen type 1 amino-terminal propeptide (total P1NP); intact parathyroid hormone; and homocysteine.

RESULTS

The prevalence of DXA-proven hip osteoporosis (T-score ≤ -2.5) among THA patients was 8.8% (35 of 398). The spinal osteoporosis prevalence rate was 4.5% (18 of 398), and 244 patients (61.3%; 244 of 398) had osteopenia (-2.5 < T-score ≤ -1) or osteoporosis of either the hip or spine. The rate of pharmacological osteoporosis treatment was 22.1% (88 of 398). TRACP-5b was significantly lower in the osteoporosis-treated group than in the untreated group (p < 0.001).

CONCLUSION

Osteoporosis is common in patients undergoing THA, but the diagnosis and treatment for osteoporosis were insufficient. The lower TRACP-5b levels in the osteoporosis-treated group - that is, osteoclast suppression - may contribute to the reduction of the postoperative revision rate after THA.Cite this article: Bone Joint Res 2022;11(12):873-880.

Polyethylene liner cementation into a well-fixed metal acetabular shell for the management of periacetabular osteolysis: a systematic review

PURPOSE

Although various papers have reported on the clinical performance of cup retention with cementation of a new liner and bone grafting in the management of well-fixed cups with polyethylene wear and periacetabular osteolysis after total hip arthroplasty (THA), no systematic review of this topic has been published to date.

METHODS

Medline, EMBASE and Cochrane Library were searched for articles published from January 1999 to January 2019 using "osteolysis" AND "well-fixed", "osteolysis" AND "retro-acetabular", "bone graft" AND ("retention" OR "retained" OR "stable") AND "cup", and "cemented liner" AND "well-fixed".

RESULTS

Nine articles were selected for review (186 cases, 76.1 months mean follow-up). The overall revision rate was 11.3% (21 hips) most commonly due to aseptic loosening (9/186 hips), dislocation (8/186 hips), and liner wear progression (2/186 cases). The reported square size of osteolytic lesions ranged from a mean of 465.84 mm2 to a max of 4,770 mm2. Almost all reported lesions treated with bone grafts resolved or did not progress 97% (72/74). All studies indicated improved pain and functional scores at follow-up.

CONCLUSION

Cementation of a new liner with periacetabular bone grafting provides an alternative option to isolated liner exchange and cup revision for the management of periacetabular osteolysis in well-fixed cups with a disrupted locking mechanism or unavailable exchange liner. Further higher quality studies are required in order to examine if the use of highly cross-linked polyethylene, highly porous-coated cups, hydroxyapatite-coated cups, and small-diameter cups influence the clinical outcome of liner cementation in well-fixed cups with periacetabular osteolysis.

SuperPath® vs. direct anterior approach : A retrospective comparison between two minimally invasive approaches in total hip arthroplasty

OBJECTIVE

Minimally invasive approaches are subject to controversy in orthopedic surgery. The aim of the current study was to compare the radiographic parameters between two minimally invasive approaches in total hip arthroplasty.

MATERIAL AND METHODS

Between January 2018 and February 2019, the radiographic parameters of 80 patients undergoing total hip arthroplasty via minimally invasive approaches (DAA: n = 40; SuperPath® SP: n = 40) have been measured. The radiographic analysis was performed with digital software tool mediCad® (HECTEC™ GmbH, Landshut, Germany).

RESULTS

Patients treated with DAA showed significantly higher inclination (SP: 39.7° ± 7.3° vs. DAA: 44.7° ± 5.3°) and significantly lower cup anteversion values (SP: 31.2° ± 7.9° vs. DAA: 27. 5° ± 5.3°, p < 0.001) than patients undergoing THA via SP postoperatively. The horizontal femoral offset was neither preoperatively nor postoperatively higher in DAA than in SP cohort (preoperative: p = 0.71, postoperative: p = 0.25) (preoperative: SP:37.2 mm ± 7.3 vs. DAA 38.2 mm ± 7.5; postoperative: SP: 38.0 mm ± 7.2 vs. DAA: 40.5 mm ± 7.0). At both times, the acetabular offset was significantly higher in DAA cohort than in SP cohort (preoperative: SP: 32.9 mm ± 5.9 vs. DAA: 36.8 mm ± 4.9; postoperative: SP: 28.9 mm ± 4.2 vs. DAA: 33.4 mm ± 3.8) (preoperative: 0.001; postoperative: p < 0.001). The vertical height was preoperatively and postoperatively not significantly higher in SP cohort than in DAA cohort (preoperative: SP: 16.1 mm ± 4.1 vs. DAA: 15.5 mm ± 4.9; postoperative: SP: 16.6 mm ± 4.6 vs. DAA: 16.1 mm ± 4.6) (preoperative: p = 0.77; postoperative: p = 0.58). The preoperatively existing leg length discrepancy of the affected leg could be compensated via surgery without showing significant differences between the two cohorts (preoperative: SP: -3.2 mm ± 5.4 vs. DAA: 1.9 mm ± 4.9; postoperative: SP: 1.5 mm ± 5.4 vs. DAA: 4.8 mm ± 5.6) (preoperative: p = 0.34; postoperative: p = 0.09).

CONCLUSION

The current study demonstrates suitable cup positioning and stem alignment in the coronal plane using minimal-invasive approaches DAA and Superpath®.

Impact of Indication for Revision THA on Resource Utilization

BACKGROUND

Demographic variables play an important role in outcomes following revision total hip arthroplasty (rTHA). Surgical and in-patient variables as well as outcomes vary between indications for rTHA. The purpose of this study was to investigate the impact of the indication for the rTHA on costs and postoperative outcomes.

METHODS

This retrospective cohort analysis investigated all patients who underwent unilateral, aseptic rTHA at an academic orthopaedic specialty hospital who had at least 1-year postoperative follow-up. In total, 654 patients were evaluated and categorized based on their indication for aseptic rTHA. Demographics, direct and total procedure costs, surgical factors, postoperative outcomes, and re-revision rates were collected and compared between indications.

RESULTS

Younger patients had the greatest leg length discrepancy (LLD) and older patients had the highest incidence of periprosthetic fracture (PPF) (P = .001). The greatest proportion of full revisions were found for LLD (16.7%) and head/polyethylene liner-only revisions for metallosis/adverse tissue reaction (100%). Operative time was significantly longest for LLD revisions and shortest for metallosis/adverse tissue reaction revisions (P < .001). Length of stay was longest for periprosthetic fracture and shortest for LLD and stiffness/heterotopic ossification (P < .001). Re-revision rate was greatest for implant failure and lowest for LLD. Total cost was highest for PPF (148.9%) and lowest for polyethylene liner wear (87.7%).

CONCLUSIONS

Patients undergoing rTHA for indications such as PPF and aseptic loosening were associated with longer operative times, length of stay and higher total and direct costs. Therefore, they may need increased perioperative attention with respect to resource utilization, risk stratification, surgical planning, and cost-reducing measures.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BACKGROUND

Extended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs.

METHODS

We retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m² (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years).

RESULTS

The cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up.

CONCLUSIONS

EOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points.

LEVEL OF EVIDENCE

Level III.

Early Revision Rates of Total Hip Arthroplasty Using the Intellijoint HIP Computer Navigation System: A Study From the Australian National Joint Replacement Registry of 1911 Procedures

Background

Total hip arthroplasty (THA) is an effective treatment for symptomatic hip osteoarthritis. The aim of this study was to determine the revision outcome of commercially available navigation technologies.

Methods

Data from the Australian Orthopaedic Association National Joint Replacement Registry from January 2016 to December 2020 included all primary THA procedures performed for osteoarthritis. Procedures using the Intellijoint HIP navigation system were identified and compared to procedures using "other" computer navigation systems and to nonnavigated procedures. The cumulative percent revision (CPR) was compared between the 3 groups using Kaplan-Meier estimates of survivorship and hazard ratios from Cox proportional hazards models, adjusted for age and gender.

Results

There were 1911 procedures that used the Intellijoint system, 4081 used "other" computer navigation systems, and 160,661 were nonnavigated procedures. The all-cause 2-year CPR rate for the Intellijoint system was 1.8% (95% confidence interval [CI], 1.2-2.6), compared to 2.2% (95% CI, 1.8-2.8) for other navigated cases and 2.2% (95% CI, 2.1-2.3) for nonnavigated cases. A prosthesis analysis identified the Paragon/Acetabular Shell THAs combined with the Intellijoint system to have a higher (3.4%) rate of revision than nonnavigated THAs (hazard ratio = 2.00 [95% CI, 1.01-4.00], P = .048). When this combination was excluded, the Intellijoint group demonstrated a 2-year CPR of 1.3%. There was no statistical difference in the CPR between the 3 groups before or after excluding the Paragon/Acetabular Shell system.

Conclusions

The preliminary data presented demonstrate no statistical difference in all-cause revision rates when comparing the Intellijoint system with "other" navigation systems and "nonnavigated" approaches for primary THAs.

Level of evidence

III (National registry analysis).

Transfusion Rates in the Operative Treatment of Prosthetic Hip and Knee Infection

Surgery for prosthetic joint infection (PJI) can often lead to significant blood loss, necessitating allogeneic blood transfusion (ABT). The use of ABT is associated with higher rates of morbidity and death in revision total joint arthroplasty, particularly in the treatment of PJI. We compared ABT rates by procedure type among patients treated for PJI. We retrospectively reviewed 143 operative cases of hip and knee PJI performed at our institution between 2016 and 2018. Procedures were categorized as irrigation and debridement (I&D) with modular component exchange (modular component exchange), explantation with I&D and placement of an antibiotic spacer (explantation), I&D with antibiotic spacer exchange (spacer exchange), or antibiotic spacer removal and prosthetic reimplantation (reimplantation). Rates of ABT and the number of units transfused were assessed. Factors associated with ABT were assessed with a multilevel mixed-effects regression model. Of the cases, 77 (54%) required ABT. The highest rates of ABT occurred during explantation (74%) and spacer exchange (72%), followed by reimplantation (36%) and modular component exchange (33%). A lower preoperative hemoglobin level was associated with higher odds of ABT. Explantation, reimplantation, and spacer exchange were associated with greater odds of ABT. Antibiotic spacer exchange and explantation were associated with greater odds of multiple-unit transfusion. Rates of ABT remain high in the surgical treatment of PJI. Antibiotic spacer exchange and explantation procedures had high rates of multiple-unit transfusions, and additional units of blood should be made available. Preoperative anemia should be treated when possible, and further refinement of blood management protocols for prosthetic joint infection is necessary. [Orthopedics. 2022;45(6):353-359.].

Incidence, Timing, and Predictors of Hip Dislocation After Primary Total Hip Arthroplasty for Osteoarthritis

INTRODUCTION

Total hip arthroplasty (THA) may be complicated by dislocation. The incidence of and risk factors for dislocation are incompletely understood. This study aimed to determine the incidence and predictors of hip dislocation within 2 years of primary THA.

METHODS

The 2010 to 2020 PearlDiver MHip database was used to identify patients undergoing primary THA for osteoarthritis with a minimum of 2 years of postoperative data. Dislocation was identified by associated codes. Age, sex, body mass index, Elixhauser Comorbidity Index, fixation method, and bearing surface were compared for patients with dislocation versus control subjects by multivariate regression. Timing and cumulative incidence of dislocation were assessed.

RESULTS

Among 155,185 primary THAs, dislocation occurred within 2 years in 3,630 (2.3%). By multivariate analysis, dislocation was associated with younger age (<65 years), female sex, body mass index < 20, higher Elixhauser Comorbidity Index, cemented prosthesis, and use of metal-on-poly or metal-on-metal implants ( P< 0.05 for each). Among patients who experienced at least one dislocation, 52% of first-time dislocations occurred in the first 3 months; 57% had more than one and 11% experienced >5 postoperative dislocation events. Revision surgery was done within 2 years of index THA for 45.6% of those experiencing dislocation versus 1.8% of those who did not ( P < 0.001).

CONCLUSION

This study found that 2.3% of a large cohort of primary THA patients experienced dislocation within 2 years, identified risk factors for dislocation, and demonstrated that most patients experiencing dislocation had recurrent episodes of instability and were more likely to require revision surgery.

Systemic administration with melatonin in the daytime has a better effect on promoting osseointegration of titanium rods in ovariectomized rats

Aims

This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night.

Methods

In this study, a titanium rod was implanted in the medullary cavity of one femoral metaphysis in OVX rats, and then the rats were randomly divided into four groups: Sham group (Sham, n = 10), OVX rat group (OVX, n = 10), melatonin day treatment group (OVX + MD, n = 10), and melatonin night treatment group (OVX + MN, n = 10). The OVX + MD and OVX + MN rats were treated with 30 mg/kg/day melatonin at 9 am and 9 pm, respectively, for 12 weeks. At the end of the research, the rats were killed to obtain bilateral femora and blood samples for evaluation.

Results

Micro-CT and histological evaluation showed that the bone microscopic parameters of femoral metaphysis trabecular bone and bone tissue around the titanium rod in the OVX + MD group demonstrated higher bone mineral density, bone volume fraction, trabecular number, connective density, trabecular thickness, and lower trabecular speculation (p = 0.004) than the OVX + MN group. Moreover, the biomechanical parameters of the OVX + MD group showed higher pull-out test and three-point bending test values, including fixation strength, interface stiffness, energy to failure, energy at break, ultimate load, and elastic modulus (p = 0.012) than the OVX + MN group. In addition, the bone metabolism index and oxidative stress indicators of the OVX + MD group show lower values of Type I collagen cross-linked C-telopeptide, procollagen type 1 N propeptide, and malondialdehyde (p = 0.013), and higher values of TAC and SOD (p = 0.002) compared with the OVX + MN group.

Conclusion

The results of our study suggest that systemic administration with melatonin at 9 am may improve the initial osseointegration of titanium rods under osteoporotic conditions more effectively than administration at 9 pm. Cite this article: Bone Joint Res 2022;11(11):751–762.

Preventing Antibiotic-Resistant Infections: Additively Manufactured Porous Ti6Al4V Biofunctionalized with Ag and Fe Nanoparticles

Implant-associated infections are highly challenging to treat, particularly with the emergence of multidrug-resistant microbials. Effective preventive action is desired to be at the implant site. Surface biofunctionalization of implants through Ag-doping has demonstrated potent antibacterial results. However, it may adversely affect bone regeneration at high doses. Benefiting from the potential synergistic effects, combining Ag with other antibacterial agents can substantially decrease the required Ag concentration. To date, no study has been performed on immobilizing both Ag and Fe nanoparticles (NPs) on the surface of additively manufactured porous titanium. We additively manufactured porous titanium and biofunctionalized its surface with plasma electrolytic oxidation using a Ca/P-based electrolyte containing Fe NPs, Ag NPs, and the combinations. The specimen's surface morphology featured porous TiO2 bearing Ag and Fe NPs. During immersion, Ag and Fe ions were released for up to 28 days. Antibacterial assays against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa showed that the specimens containing Ag NPs and Ag/Fe NPs exhibit bactericidal activity. The Ag and Fe NPs worked synergistically, even when Ag was reduced by up to three times. The biofunctionalized scaffold reduced Ag and Fe NPs, improving preosteoblasts proliferation and Ca-sensing receptor activation. In conclusion, surface biofunctionalization of porous titanium with Ag and Fe NPs is a promising strategy to prevent implant-associated infections and allow bone regeneration and, therefore, should be developed for clinical application.

Laser projector method for measuring postoperative acetabular anteversion after total hip replacement

INTRODUCTION

For patients undergoing THR, measuring the postoperative acetabular anteversion precisely plays a pivotal role in the prognosis. However, using elliptical methods mandates computerized equipment that is frequently in shortage in remote areas and developing countries. We invented a laser projector utilizing the ellipse method to measure the acetabular anteversion directly. The aim is to examine the consistency and validity of the laser projector as compared to our original software, Elliversion.

MATERIALS AND METHODS

We retrospectively collected 50 postoperative pelvis radiographs including acetabulum from our institution. One investigator first measured the anteversion of included radiographs through Elliversion software as the control group. Subsequently, two operators independently used the laser projector for measurements in two separate periods with 1-day intervals as the experimental group. Our analysis was comprised of intra- and inter-observer comparisons and reliability, which investigated both the consistency and validity, by using two-sample student's t-test and intraclass correlation coefficient.

RESULTS

There was no significant difference in measuring the anteversion through laser projectors between two operators (p = 0.54), with excellent inter-observer reliability (ICC, 0.967). The estimated effect in the anteversion measurement between the Elliversion and laser projector was also comparable, with the ICC level of 0.984, indicating excellent reliability.

CONCLUSION

Our study reported the consistency and validity of this laser projector as there is no significant difference between Elliversion and Laser projector, notably with excellent intra- and inter-observer reliability. We look forward to helping elevate clinical acumen when doctors provide care to patients after THR, especially in remote areas.

Reduction of posterior dislocated hip prosthesis using a modified lateral position maneuver: a retrospective, clinical comparative, and follow-up study

BACKGROUND

Posterior dislocation (PD) is a common complication after total hip arthroplasty (THA), and the Allis maneuver is the most widely used method for reduction. However, this classic maneuver has some disadvantages. The aim of the present study was to investigate whether a modified lateral position (MLP) reduction maneuver provides an easier and safer method for PD reduction than the Allis maneuver.

METHODS

Between August 2019 and September 2021, a series of 88 consecutive PD patients who underwent THA were retrospectively evaluated. The patients were divided into the MLP reduction group and Allis reduction group according to the electronic health medical record. The success rate of closed reduction, Harris hip score (HHS), and radiographic outcomes were determined. Satisfaction scores, doctor safety events and complications were also determined and compared between the groups. The mean follow-up period was 1.66 ± 0.88 years.

RESULTS

The success rate of reduction in the MLP group was significantly 12.5% higher than that in the Allis group (P = 0.024). Periprosthetic fracture and implant loosening were retrospectively identified in 2 hips and 1 hip, which all occurred in the Allis group. The mean doctor and patient SAPS scores in the MLP group were 84.00 points and 76.97 points, respectively, which were significantly higher than those in the Allis group (72.12, P = 0.008 and 63.28 points, P = 0.001). Four adverse events were reported in the Allis group, compared with 0 in the MLP group.

CONCLUSIONS

For PD after THA, the MLP reduction maneuver can effectively increase the reduction success rate, satisfaction, and doctor safety without increasing the risk of complications compared with the traditional Allis supine reduction maneuver.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100054562) in December 19th 2021.

Administrative Data Use in National Registry Efforts: Blessing or Curse?

"Big data" refers to a growing field of large database research. Administrative data, a subset of big data, includes information from insurance claims, electronic medical records, and registries that can be useful for investigating novel research questions. While its use provides salient advantages, potential researchers relying on big data would benefit from knowing about how these databases are coded, common errors they may encounter, and how to best use large data to address various research questions. In the first section of this paper, Dr. Nicholas A. Bedard addresses the four major pitfalls to avoid with diagnosis and procedure codes in administrative data. In the next section, Dr. Jeffrey N. Katz et al. focus on the strengths and limitations of administrative data, suggesting methods to mitigate these limitations. Lastly, Dr. Elena Losina et al. review the uses and misuses of large databases for cost-effectiveness research, detailing methods for careful economic evaluations.

State and Government Administrative Databases: Medicare, National Inpatient Sample (NIS), and State Inpatient Databases (SID) Programs

The availability of large state and federally run administrative health-care databases provides potentially comprehensive population-wide information that can dramatically impact both medical and health-policy decision-making. Specific opportunities and important limitations exist with all administrative databases based on what information is collected and how reliably specific data elements are reported. Access to patient identifiable-level information can be critical for certain long-term outcome studies but can be difficult (although not impossible) due to patient privacy protections, while more easily available de-identified information can provide important insights that may be more than sufficient for some short-term operative or in-hospital outcome questions. The first section of this paper by Sarah K. Meier and Benjamin D. Pollock discusses Medicare and the different data files available to health-care researchers. They describe what is and is not generally available from even the most granular Medicare Standard Analytic Files, and provide an analysis of the strengths and weaknesses of Medicare administrative data as well as the resulting best and inappropriate uses of these data. In the second section, the Nationwide Inpatient Sample and complementary State Inpatient Database programs are reviewed by Steven M. Kurtz and Edmund Lau, with insights into the origins of these programs, the data elements that are recorded relating to the operative procedure and hospital stay, and examples of the types of studies that optimally utilize these data sources. They also detail the limitations of these databases and identify studies that they are not well-suited for, especially those involving linkage or longitudinal studies over time. Both sections provide useful guidance on the best uses and pitfalls related to these important large representative national administrative data sources.

Underweight Body Mass Index Is Associated With Increased In-Hospital Complications and Length of Stay After Revision Total Joint Arthroplasty

INTRODUCTION

The purpose of this study was to assess the impact of underweight status on in-hospital postoperative outcomes and complications after revision total joint arthroplasty (rTJA) of the hip and knee.

METHODS

Data from the National Inpatient Sample were used to identify all patients undergoing rTJA in the United States between 2006 and 2015. Patients were divided into two groups based on a concomitant diagnosis of underweight body mass index and a control normal weight group. Propensity score analysis was performed to determine whether underweight body mass index was a risk factor for in-hospital postoperative complications and resource utilization.

RESULTS

A total of 865,993 rTJAs were analyzed. Within the study cohort, 2,272 patients were classified as underweight, whereas 863,721 were classified as a normal weight control group. Underweight patients had significantly higher rates of several comorbidities compared with the control cohort. Underweight patients had significantly higher rates of any complication (49.98% versus 33.68%, P = 0.0004) than normal weight patients. Underweight patients also had significantly greater length of stay compared with normal weight patients (6.50 versus 4.87 days, P < 0.0001).

CONCLUSION

Underweight patients have notably higher rates of any complication and longer length of stay after rTJA than those who are not underweight. These results have important implications in preoperative patient discussions and perioperative management. Standardized preoperative protocols should be developed and instituted to improve outcomes in this patient cohort.

Survivorship of the retained femoral component after revision total hip arthroplasty: A systematic review and meta-analysis

Objective

This systematic review and meta-analysis aimed to estimate re-revision rates of retained femoral components after revision of total hip arthroplasty (THA).

Methods

Papers were searched in the PubMed, Embase, Web of Science, and Cochrane Library databases with predetermined keywords from January 2000 to January 2022. The studies reporting the re-revision rates of retained stems after revision THA were identified. Pooled rates of re-revision for any reason and aseptic loosening were calculated using a random-effects model or a fixed-effects model based on the results of heterogeneity assessment after the Freeman–Tukey double-arcsine transformation. A meta-regression was performed to explore potential sources of heterogeneity.

Results

There were 20 studies with 1,484 hips that received the isolated cup revision with the femoral component retained. The pooled re-revision rate of retained stems was 1.75% [95% confidence interval (CI) 0.43%–3.65%]. The re-revision rate of retained stems due to aseptic loosening was 0.62% (95% CI, 0.06%–1.55%). The meta-regression showed that the fixation type (cemented or cementless) was related to the re-revision rate for any reason and the re-revision rate for aseptic loosening.

Conclusion

Based on the existing evidence, the isolated cup revision with a stable stem in situ yields low re-revision rates. The cement status of retained stems may influence the survivorship of stems.

Ultrasonic bone cement removal efficiency in total joint arthroplasty revision: A computer tomographic-based cadaver study

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model. The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography. With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-four residues with a mean volume of 0.40 ± 4.95 mm³ were identified with only 4 exceeding 1 cm in length in at least one axis. Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations.

What Is the Normal Trajectory of C-Reactive Protein, Erythrocyte Sedimentation Rate, Plasma Fibrinogen and D-Dimer after Two-Stage Exchange for Periprosthetic Joint Infection?

Objective

C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), plasma fibrinogen and D‐Dimer are used as diagnostic biomarkers of prosthetic joint infection (PJI) after total joint arthroplasty (TJA). The purpose of the study was to investigate the normal trajectory of CRP, ESR, plasma fibrinogen and D‐Dimer at different time points after two‐stage exchange arthroplasty for PJI.

Methods

We studied 53 patients undergoing two‐stage exchange for PJI at five time points: preoperatively (T0), duration of hospital stays (T1), 30 days (T2), 30–90 days (T3), and 90–180 days (T4) after surgery. The medical records of all patients were well documented and carefully reviewed. The Shapiro–Wilk test was utilized to compare the normal distribution for continuous variables, and the nonnormally distributed data were used for Friedmann's one‐way repeat measures analysis of variances. Post hoc Dunnett's test was used to compare each pair of data to find differences from baseline.

Results

Compare with T0 point, the levels of CRP and ESR increased significantly and reached peak values at T1 point (all P < 0.001), with median values of 56.40 mg/L (range, 5.54–161.0 mg/L) and 49.00 mm/h (range, 13.00–113.0 mm/h), respectively. In addition, the levels of plasma fibrinogen and D‐Dimer increased significantly and reached peak values at T1 point (all P < 0.001), with median values of 4.13g/L (range, 2.27–6.80 mg/L) and 4.00 mg/L (range, 0.19–14.01 mg/L), respectively. CRP and ESR rapidly declined at the T2 point with significantly compared with T0 point (P = 0.001 and P < 0.001). The levels of CRP, ESR, plasma fibrinogen and D‐Dimer returned to preoperative levels of 5.23 mg/L (range, 1.01–21.70 mg/L), 19.00 mm/h (range, 6.00–60.00 mm/h), 3.38g/L (range, 1.71–5.10 g/L) and 2.33 mm/h (range, 0.19–6.87 mg/L) at T4 point, and there was no significant difference compared with T0 point (all P > 0.05).

Conclusions

The study demonstrated the normal trajectory of CRP, ESR, plasma fibrinogen and D‐Dimer at five time points in patients who underwent two‐stage exchange for PJI. Thus, the results have the possibility of providing signs of infection after the patient receives two‐stage exchange arthroplasty for PJI, which can benefit from early treatment.

Epidemiology of revision hip replacement in Italy: a 15-year study

Background

Over the past two decades, there has been an increase in the amount of primary total hip arthroscopies (THA) which in turn has increased the need for THA revision surgeries. The purpose of this study was to quantify the increase in THA revision in Italy, evaluate the causes and types of THA procedures performed.

Methods

The data regarding revision hip prosthetic replacements performed both in public and private structures between 2001 and 2015 was collected by the National Hospital Discharge reports (SDO) carried out by the Italian Ministry of Health.

Results

Overall, 109,746 Revision Hip Replacements (RHR) were performed in Italy from 2001 to 2015 in the adult population. The study shows a greater number of female patients underwent surgery between 2001 and 2015 and the 75- to 79-year age group had the highest incidence of THA revision. The main causes for THA revision were found to be “Mechanical complication of internal orthopedic device implant and graft” (31.5%), “Infection and inflammatory reaction due to internal joint prosthesis” (10.5%) and “Mechanical loosening of prosthetic joint” (8.3%).

Conclusions

Revision hip replacement is growing and heavily affecting the population between 65 and 89 years and the main causes of THA revision have been quantified. The average length of hospitalization (LOS) was found to have decreased over the 14-year study period. Understanding the causes and risk factors for revision is essential in identifying avoidable complications and improving preventative care for patients undergoing primary implantation to decrease the revision burden.

The Cost-Effectiveness of Extended Oral Antibiotic Prophylaxis for Infection Prevention After Total Joint Arthroplasty in High-Risk Patients

BACKGROUND

Extended oral antibiotic prophylaxis may decrease rates of prosthetic joint infection (PJI) after total joint arthroplasty (TJA) in patients at high risk for infection. However, the cost-effectiveness of this practice is not clear. In this study, we used a break-even economic model to determine the cost-effectiveness of routine extended oral antibiotic prophylaxis for PJI prevention in high-risk TJA patients.

METHODS

Baseline PJI rates in high-risk patients, the cost of revision arthroplasty for PJI, and the costs of extended oral antibiotic prophylaxis regimens were obtained from the literature and institutional purchasing records. These variables were incorporated in a break-even economic model to calculate the absolute risk reduction (ARR) in infection rate necessary for extended oral antibiotic prophylaxis to be cost-effective. ARR was used to determine the number needed to treat (NNT).

RESULTS

Extended oral antibiotic prophylaxis with Cefadroxil in patients at high risk for PJI was cost-effective at an ARR in baseline infection rate of 0.187% (NNT = 535) and 0.151% (NNT = 662) for TKA and THA, respectively. Cost-effectiveness was preserved with varying costs of antibiotic regimens, PJI treatment costs, and infection rates.

CONCLUSION

The use of extended oral antibiotic prophylaxis may reduce PJI rates in patients at high risk for infection following TJA and appears to be cost-effective. However, the current evidence supporting this practice is limited in quality. The use of extended oral antibiotic prophylaxis should be weighed against the possible development of future antimicrobial resistance, which may change the value proposition.

Periprosthetic joint infection rates across primary total hip arthroplasty surgical approaches: a systematic review and meta-analysis of 653,633 procedures

INTRODUCTION

Evidence demonstrates comparable clinical outcomes across the various surgical approaches to primary total hip arthroplasty (THA). However, high-quality contemporary data regarding periprosthetic joint infection (PJI) risk between direct anterior approach (DAA) and other (THA) approaches is lacking. This systematic review and meta-analysis evaluated PJI rates reported in the literature between the DAA and other approaches.

MATERIALS AND METHODS

Five online databases were queried for all studies published from January 1st, 2000 through February 17th, 2021 that reported PJI rates between DAA and other surgical approaches. Studies reporting on primary THAs for osteoarthritis (OA) and that included PJI rates segregated by surgical approach were included. Articles reporting on revision THA, alternative THA etiologies, or minimally invasive techniques were excluded. Mantel-Haenszel (M-H) models were utilized to evaluate the pooled effect of surgical approach on infection rates. Validated risk of bias and methodological quality assessment tools were applied to each study. Multiple sensitivity analyses were conducted to evaluate the robustness of analyses.

RESULTS

28 articles reporting on 653,633 primary THAs were included. No differences were found between DAA cohorts and combined other approaches (OR: 0.95; 95% CI 0.74-1.21; p = 0.67) as well as segregated anterolateral approach cohorts (OR: 0.82, 95% CI 0.64-1.06; p = 0.13). However, DAA patients had a significantly reduced risk of infection compared to those undergoing posterior (OR: 0.66, 95% CI 0.58-0.74; p < 0.0001) and direct lateral (OR: 0.56, 95% CI 0.48-0.65; p < 0.00001) approaches.

CONCLUSION

The DAA to primary THA had comparable or lower PJI risk when compared to other contemporary approaches. The results of the most up-to-date evidence available serve to encourage adult reconstruction surgeons who have already adopted the DAA. Additionally, orthopaedic surgeons considering adoption or use of the direct anterior approach for other reasons should not be dissuaded over theoretical concern for a general increase in the risk of PJI.

LEVEL OF EVIDENCE

Level III.

Preoperative Hypoalbuminemia Is Associated With Early Morbidity and Mortality After Revision Total Hip Arthroplasty

Hypoalbuminemia is associated with early morbidity and mortality in revision total knee arthroplasty. We evaluated the effect of preoperative hypoalbuminemia on 30-day morbidity and mortality in revision total hip arthroplasty (THA). The National Surgical Quality Improvement Program (NSQIP) database was queried from 2015 to 2018 to identify patients who underwent revision THA. Patients were stratified based on the presence or absence of preoperative hypoalbuminemia and their odds of a major complication or death within 30 days of revision THA with multivariate logistic regression. After Bonferroni correction for these 2 primary outcomes, statistical significance was defined as P<.025. A total of 2492 revision THAs with complete data were identified, of which 486 (20%) had preoperative hypoalbuminemia. Preoperative hypoalbuminemia increased the absolute risk of a major complication by 15.3% compared with patients with revision THA without hypoalbuminemia (30% vs 14.7%, P<.001). Patients with preoperative hypoalbuminemia also had nearly a 7-fold higher incidence of death (3.3%) compared with those with revision THA without preoperative hypoalbuminemia (0.5%, P<.001). After logistic regression, the odds of having a major complication after revision THA with preoperative hypoalbuminemia within 30 days were increased by 80% (odds ratio, 1.8; 95% CI, 1.4-2.3; P<.001), and the odds of death within 30 days were increased by 210% (odds ratio, 3.1; 95% CI, 1.2-7.8; P=.020). Hypoalbuminemia is associated with early morbidity and mortality after revision THA. [Orthopedics. 2022;45(5):281-286.].

Synthesis and Biomedical Applications of Zirconium Nanoparticles: Advanced Leaps and Bounds in the Recent Past

Many synthetic routes manufacture zirconium nanoparticles in metal oxide, nitride, and other combination forms. Coupled with other variables such as concentration, pH, and form of precursor used, the various synthetic methods support synthesizing the zirconium metal oxide nanoparticles with changed features. Various synthetic methods were studied, such as sol-gel, hydrothermal, laser ablation, and precipitation. All have different synthetic routes, different precursors and solvents were sued, and the product was characterized by SEM, TEM, photo luminance spectroscopy, UV-absorption spectroscopy, and powder X-ray diffraction. X-ray diffraction determined the crystal structure by identifying the crystal shape, arrangement of atoms, and spacing between them. SEM and TEM studied the particle size and morphology of nanoparticles. UV-visible absorption spectroscopy and PL spectroscopy were used for the determination of optical properties of nanoparticles. Zirconium oxide nanoparticles have many applications in the medical field. The review study primarily focuses on the efficient combination of zirconium dioxide with other additive materials and functionalization techniques used to improve the material's properties, assisting the use of the material in hip arthroplasty and bone tissue applications. The development of sophisticated near-infrared (NIR) absorbing small molecules for useful phototheranostic applications was discussed in this paper.

The accuracy of component positioning during revision total hip arthroplasty using 3D optical computer-assisted navigation

INTRODUCTION

Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA.

METHODS

A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position.

RESULTS

Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0 mm vs 9.13 ± 7.9 mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p =  0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84 mm vs 7.14 ± 4.8 mm, p = 0.68).

CONCLUSION

Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4 mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

The influence of nanotopography on cell behaviour through interactions with the extracellular matrix – A review

Nanotopography presents an effective physical approach for biomaterial cell manipulation mediated through material-extracellular matrix interactions. The extracellular matrix that exists in the cellular microenvironment is crucial for guiding cell behaviours, such as determination of integrin ligation and interaction with growth factors. These interactions with the extracellular matrix regulate downstream mechanotransductive pathways, such as rearrangements in the cytoskeleton and activation of signal cascades. Protein adsorption onto nanotopography strongly influences the conformation and distribution density of extracellular matrix and, therefore, subsequent cell responses. In this review, we first discuss the interactive mechanisms of protein physical adsorption on nanotopography. Secondly, we summarise advances in creating nanotopographical features to instruct desired cell behaviours. Lastly, we focus on the cellular mechanotransductive pathways initiated by nanotopography. This review provides an overview of the current state-of-the-art designs of nanotopography aiming to provide better biomedical materials for the future.

●

A comprehensive overview of nanotopography fabrication, and nanotopography regulates various cell behaviours.

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The interactive physical adsorption between nanotopography and extracellular matrix.

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Nanotopography initiates the cellular mechanotransductive pathways and downstream signalling cascades.

Use of a monoblock dual-mobility acetabular component in primary total hip arthroplasty in patients at high risk of dislocation

INTRODUCTION

Dislocation is amongst the most common complications following total hip arthroplasty (THA). Dual-mobility bearings have been suggested as one way to reduce the risk of dislocation, particularly among patients at increased risk. The purpose of this study was to determine the outcomes of a monoblock dual-mobility shell for patients at high risk for dislocation following primary THA.

METHODS

A total of 155 primary THAs with a monoblock, cementless dual-mobility acetabular component were performed in patients at high risk for dislocation. Two patients died prior to their two-year follow-up. The remaining 153 THAs were followed for a mean of 5.1 years (range: 2.1 to 9.3).

RESULTS

There were no dislocations; however, four patients underwent revision surgery: one for an early periprosthetic acetabular fracture, one for an early periprosthetic femoral fracture, one for a late periprosthetic femoral fracture, and one for leg-length discrepancy. Intraoperative complications included one periprosthetic acetabular fracture treated with protected weight-bearing and one intraoperative proximal femoral fracture treated with cerclage wiring. Harris Hip Scores improved from a mean of 42.4 points preoperatively to a mean of 82.4 points postoperatively (p < 0.001). No cups were radiographically loose. At a mean follow-up of 5.1 years, survivorship of the acetabular component was 99.3% (95% CI, 98.1-100%) and survivorship without any reoperation was 97.4% (95% CI, 95.9-100%).

DISCUSSION

Although there were no dislocations in this high-risk population, periprosthetic fractures of the femur and acetabulum were common with the implants utilised.

The Outcomes and Revision Rate of Total Hip Arthroplasty in a Single Tertiary Center: A Retrospective Study

Introduction

Total hip arthroplasty (THA) is a commonly performed and successful orthopedic practice procedure. However, failure of arthroplasty may require revision THA and pose substantial clinical challenges for orthopedic surgeons. Therefore, this retrospective study aimed to estimate the revision rate of THA and its risk factors at a tertiary care hospital.

Methods

A retrospective cohort study was conducted in 2021 of patients who had undergone THA during 2016-2020 in a tertiary care hospital. All patients above 18 years old who had a THA were included in the study. The data was collected from patients' medical charts/electronic databases.

Results

A total of 148 THAs were included in this study. In total, 77 (52%) were females, and 71 (48%) were males. The average age of our patients was 49±17 years old, and the mean recorded BMI was 29.6. A total of 62% (n=92/148) of our participants were shown to have at least one comorbid disease, with hypertension being the most common comorbidity. Our findings show that half of the patients, 74 (50%), had a THA due to both primary and secondary osteoarthritis, 37 (25%) patients had avascular necrosis of the hip, and 25 (17%) were due to trauma. The most performed surgical approach was Kocher-Langenbeck (posterior) approach on 128 (86%), followed by the Hardinge (lateral) approach on 20 (13.51%). The most observed complication in the patients was postoperative pain in 35 (23.65%), followed by UTIs in 5 (3.38%). Of the 148 patients, nine (6.08%) had revision surgery. Regarding the revision rate, male patients were associated with a significantly higher rate of revision (P=<0.001), and older patients had a significantly increased risk of revision (P=0.026). Patients who developed complications, such as UTI, were associated with a higher revision rate (P=0.035). Also, a posterior approach (Kocher-Langenbeck) of the procedure was significantly linked to an increased risk of revision (P=0.014).

Conclusion

All in all, there are multiple associated factors with an increased incidence of revision THA. For example, male patients, older patients, complication development during the hospital stay, and posterior surgical approach were all associated with a significantly higher rate of revision.

A Novel Osteoporosis Screening Protocol to Identify Orthopedic Surgery Patients for Preoperative Bone Health Optimization

Introduction

Osteoporosis is highly prevalent in elective orthopedic surgery. While preoperative bone health optimization decreases osteoporosis-related complications, there is an unmet need to establish who may benefit from preoperative dual-energy x-ray absorptiometry (DXA). This study assesses a novel, simple screening protocol to identify orthopedic surgical patients for preoperative DXA.

Materials/Methods

This retrospective cohort study included 628 patients undergoing total knee, hip, or shoulder arthroplasty or thoracolumbar spine fusion. Inclusion criteria were ≥40 years undergoing primary elective surgery. Screening criteria defining who should obtain DXA due to high osteoporosis risk included: female ≥65, male ≥70, fracture history when ≥50 years, or FRAX major osteoporotic fracture risk (without bone mineral density [BMD]-adjustments) ≥8.4%. Osteoporosis was defined by World Health Organization criteria [T-score ≤ -2.5], clinical National Osteoporosis Foundation (NOF) criteria [T-score ≤ -2.5, elevated BMD-adjusted FRAX risk, or prior hip/spine fracture], and modified clinical criteria [NOF criteria simplified to include any non-traumatic prior fracture and FRAX without BMD].

Results

The study included 100 TKAs, 100 THAs, 251 TSAs, and 177 spine fusions, average age 65.6 ± 9.8. DXA was available for 209 patients. Screening criteria recommending DXA was met by 362 patients. For those with DXA, screening sensitivity was .96 (CI: .78 to .99) and specificity was .19 (CI: .14 to .25) for identifying T-score osteoporosis. Similar sensitivity of .99 (CI: .91 to .99) and specificity of .61 (CI: .56 to .66) were found for modified clinical osteoporosis. For modified clinical osteoporosis, 192 patients with osteoporosis met criteria (true pos.), 1 patient with osteoporosis did not meet criteria (false neg.), 170 patients without osteoporosis met criteria (false pos.), and 265 patients without osteoporosis did not meet criteria (true neg.).

Discussion/Conclusion

A simple screening protocol identifies orthopedic surgical candidates at risk of T-score or clinical osteoporosis for preoperative DXA with high sensitivity.

Association between sagittal spinal alignment and mechanical complications after primary total hip arthroplasty: a systematic review

Objective

Total hip arthroplasty (THA) affects pelvic posture and spinal alignment. These postural changes may further predispose patients to mechanical complications (MCs) after THA. The aim of this study was to conduct a systematic review to investigate whether any high-quality studies have assessed the association between sagittal spinal alignment and MCs after primary THA.

Methods

Inclusion criteria for studies were adult patients (age ≥18 years), primary THA, pre- and postoperative spinopelvic standing sagittal radiographs acquired preoperatively and at a minimum of 6-month follow-up, measurements of spinopelvic parameters, and reporting of possible MCs after THA. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

Results

Six articles met the inclusion criteria. Although several studies confirmed the importance of spinal alignment when planning THA, these mainly investigated pelvic mobility as a risk factor for THA dislocation. Radiological follow-up imaging practices varied, and studies focused on different individual spinopelvic parameters.

Conclusion

Based on our study findings, no conclusions can be drawn regarding the association between sagittal spinal alignment and MCs after primary THA. Further research is needed to improve our knowledge of the connection between MCs after THA and sagittal spinal alignment.

[Contemporary indications for aseptic revision total hip arthroplasty]

BACKGROUND

Hip arthroplasties and revision procedures will continue to rise over the next decades. In 2020 in Germany, 75% of all revision surgeries involved an exchange of at least one component; exchanges of all components were carried out in 27.5% of the revisions. The most common failure modes were aseptic loosening, infections, periprosthetic fractures, instabilities, and metal-related pathologies.

INDICATIONS

Aseptic loosening remains the most common reason for revision. However, the indications for hip arthroplasty revisions have changed over time, with a decrease in revisions due to aseptic loosening and an increase in revisions due to infection and periprosthetic fracture. The rate of dislocations remained approximately constant over the past decade, with international differences. Metal-associated pathologies will continue to play a significant role in revision hip arthroplasty.

Minimal Clinically Important Difference (MCID) at One Year Postoperatively in Aseptic Revision Total Hip Arthroplasty

BACKGROUND

Outcomes after aseptic revision total hip arthroplasty (THA) are variable, and it is unknown whether the indication for aseptic revision THA influences postoperative clinical improvement. The minimal clinically important difference (MCID) assesses if changes in patient-reported outcome measure result in meaningful clinical benefit to patients. The purpose of this study was to quantify the 1-year postoperative MCID for aseptic revision THA and to assess the percentage of patients achieving the MCID for each revision diagnosis.

METHODS

A prospective, single-institution registry of revision total joint arthroplasties was used. Retrospective review of 413 first-time aseptic revision THAs was performed. Demographics, revision diagnosis, preoperative Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS Jr.), and 1-year postoperative HOOS Jr. were recorded. The MCID for the HOOS Jr. at one year postoperatively was calculated for each revision diagnosis using a distribution-based method. The percentage of patients exceeding the MCID with each diagnosis was determined.

RESULTS

There were 9 aseptic revision diagnoses, all with n ≥ 5. The 3 most common revision diagnosis were aseptic loosening (n = 114), dislocation or instability (n = 103), and polyethylene wear or osteolysis (n = 73). The MCID for all the aseptic revision THAs was 10.9. Seven of the nine revision diagnoses achieved the MCID. The highest percentage of patients achieving the MCID was for aseptic loosening (84.2%) and implant fracture (81.3%), whereas lowest was for adverse local tissue reaction (35.3%) and implant recall (20.0%).

CONCLUSION

The one-year revision THA MCID is 10.9 for the HOOS Jr. There is variability in the percentage of patients achieving the MCID based on diagnosis. Our data can be used to counsel patients undergoing revision THA for noninfectious etiologies.

Predictors of Success With Chronic Antibiotic Suppression for Prosthetic Joint Infections

BACKGROUND

Management of recurrent prosthetic joint infection (PJI) after attempted surgical eradication remains a challenge. Chronic antibiotic suppression (CAS) is regarded as a reasonable treatment option for select patients with persistent infection or multiple comorbidities. The study seeks to compare cohorts who succeed and fail with CAS.

METHODS

This retrospective cohort study assesses patients who were treated with CAS for a PJI. Patients were included if they had a culture-proven PJI and received chronic suppressive antibiotics. Failure of suppression was defined as reoperation after initiating CAS or death occurring as result of infection. A Cox proportional hazards multivariate regression model was used to estimate risk of reoperation as a function of risk factors related to patient comorbidities, surgical history, affected joint, and infecting organism.

RESULTS

We identified 45 PJIs (31 knees, 14 hips) managed with CAS with a median follow-up of 50 (95% confidence interval [CI] 33.61-74.02) months. The overall success rate of managing PJI with CAS was 67% (30/45). Controlling for body mass index and Gram status of the organism, total hip arthroplasty patients were less likely than total knee arthroplasty patients to require reoperation (hazard ratio 0.18, 95% CI 0.01-0.96, P = .04). Patients with Gram-positive infections were less likely than those with a Gram-negative infections to require reoperation (hazard ratio 0.22, 95% CI 0.05-0.88, P = .03). Severe antibiotic side effects were rare. Patients who experienced multiple changes to their antibiotic regimen were more likely to fail with CAS.

CONCLUSION

CAS is a reasonable strategy in patients with PJI who lack or refuse further surgical treatment options. Most hips and Gram-positive infections treated with CAS successfully avoided reoperation in this cohort.

Modern Proximal Femoral Replacement in Revision Total Hip Arthroplasty for Nononcologic Indications

BACKGROUND

Advances in surgical technique and prosthesis design have expanded the non-neoplastic indications for proximal femoral replacement (PFR) to include fracture nonunion, periprosthetic fracture, and severe bone loss in the setting of revision total hip arthroplasty (THA). The purpose of this study is to assess outcomes of PFRs used for nononcologic indications.

METHODS

A single-institution, retrospective, cohort survey study was conducted between August 2015-February 2020 of consecutive patients undergoing PFR for nononcologic indications in revision THA. Patient demographics, surgical variables, complications, and revision procedures were collected. Patient satisfaction and Oxford Hip scores were assessed via a telephone questionnaire. Implant survivorship was estimated using the Kaplan-Meier method.

RESULTS

In total, 24 patients (27 PFRs) were available for analysis with an average age of 69.3 ± 12.9 years (range: 37-90). The average number of operations prior to PFR implantation was 3.1 ± 2.1 (range: 0-7). At a mean follow-up of 2.4 years (range: 0.5-5.1), the mean Oxford Hip Score was 31.7 ± 10.2, and mean patient satisfaction was 4.9/5. Six patients (20.7%) experienced a postoperative complication, with dislocation occurring in three patients (10.3%). None of the patients with dual mobility articulations (n = 4) had dislocation. Three-year survivorship was 85.2% (95% CI 71.8%-98.6%) with all-cause reoperations as the endpoint and 100% (95% CI 100.0%-100.0%) with revision for aseptic loosening as the endpoint.

CONCLUSION

The current study demonstrates excellent short-term survivorship, satisfactory patient-reported outcomes, and high patient satisfaction following PFR for nononcologic indications during revision THA utilizing modern techniques. The most common mode of failure was dislocation requiring reoperation with revision to constrained acetabular components.

Limiting the Surveillance Period to 90 Days Misses a Large Portion of Infections in the First Year After Total Hip and Knee Arthroplasty

Background

In 2013, the Centers for Disease Control and Prevention reduced the periprosthetic joint infection (PJI) surveillance period from 1 year to 90 days for total hip (THA) and knee arthroplasty (TKA). Our aim was to determine how the reduced surveillance window impacts capture of PJIs.

Material and methods

Primary and revision THA and TKA cases were retrospectively identified in a statewide registry from October 1, 2015, to September 30, 2018. Infections were defined using the Periprosthetic Joint/Wound Infection measure (Centers for Medicare and Medicaid Services). We compared the cumulative incidence of infected primary and revision THA (pTHA/rTHA) and TKA (pTKA/rTKA) at 0-90 days and 91-365 days postoperatively.

Results

A total of 136,491 patients were included, 59.59% female, mean age 65.8 years, and mean body mass index 32.3 kg/m². The overall rate of PJI diagnosed by 1 year was 1.33%. The percent of infections diagnosed between 0-90 days and 91-365 days were pTHA 76.78% and 23.22%, rTHA 74.12% and 25.88%, pTKA 57.67% and 42.33%, and rTKA 53.78% and 46.22%, respectively. More infections were diagnosed after 90 days in pTKA than in pTHA and in rTKA than in rTHA (P < .0001). There was a higher risk of infection throughout the year when comparing rTKA to rTHA (P = .0374) but not when comparing pTKA to pTHA (P = .0518).

Conclusion

A substantial portion of infections are missed by the 90-day surveillance period. More infections are missed after TKA than after THA. Extension of the surveillance period would allow for identification of opportunities for quality improvement.

Hospital Volume as a Source of Variation for Major Complications and Early In-Hospital Mortality After Total Joint Arthroplasty

Background

Material and methods

Results

Conclusion

Diagnosis and Detection of Subtle Aseptic Loosening in Total Hip Arthroplasty

Aseptic loosening is a common cause of revision total hip arthroplasty (rTHA), and with the rising number of primary THAs, revisions for aseptic loosening represent a significant burden for arthroplasty surgeons. Aseptic loosening remains a diagnostic and management challenge. Loosening can occur as a result of inadequate initial fixation, mechanical loss of fixation over time, or a biological loss of fixation over time. However, in most cases, etiology is multifactorial, involving all 3 factors. The diagnosis of aseptic loosening involves a careful history, focused clinical exam, and thorough evaluation of imaging using several diagnostic modalities. The careful evaluation of serial radiographs remains the cornerstone of diagnosis with additional input from advanced imaging modalities such as FDG-PET, DEXA, MRI, and several others, each offering unique advantages and disadvantages. In certain patients, history and physical exam might be the only initial obvious signs of loosening, and thus, unexplained continuous pain augmented by imaging findings serves as an indication for revision surgery.

Neocortex Formation in a Tapered Wedge Stem is Not Indicative of Complications or Worse Outcomes

BACKGROUND

The formation of sclerotic bone, a neocortex, distally surrounding total hip arthroplasty (THA) stems may commonly be seen on radiographs around proximally porous coated stems but can be confused with loosening. The goal of this study was to determine the prevalence of the neocortex finding and whether it associated with worse outcomes after THA.

METHODS

A retrospective review of 825 patients with a single tapered wedge stem was performed. Radiographs at 1-year, as well as final follow-up were reviewed for evidence of sclerotic bone (neocortex) surrounding the stem in all 14 Gruen zones. The final attending radiology read of lucency was also recorded. Patients were grouped by the presence of the neocortex. PROMIS Physical Function scores and complications were compared between neocortex groups.

RESULTS

The neocortex group had 558 (68%) patients compared to 267 (32%) in the no neocortex group. The most common Gruen zones for evidence of neocortex were 10 (55%), 11 (52%), and 12 (51%). Seven percent of patients had a finding of lucency on radiology read. There was no difference between groups in terms of dislocations (P = .61), infection (P = .79), fracture rates (P = .54), revision surgery (P = .73), and reoperation for any cause (P = .62). PROMIS PF scores were significantly higher in the neocortex group (P < .0001).

CONCLUSION

The presence of a distal neocortex is a common finding on radiographs after THA with this proximally porous-coated tapered wedge stem and does not portend worse outcomes, nor is it a sign of aseptic loosening, increased revision rates, infection, dislocation, or periprosthetic fracture risk.

Effect of Alumina Particles on the Osteogenic Ability of Osteoblasts

Biomaterials are used as implants for bone and dental disabilities. However, wear particles from the implants cause osteolysis following total joint arthroplasty (TJA). Ceramic implants are considered safe and elicit a minimal response to cause periprosthetic osteolysis. However, few reports have highlighted the adverse effect of ceramic particles such as alumina (Al2O3) on various cell types. Hence, we aimed to investigate the effect of Al2O3 particles on osteoprogenitors. A comparative treatment of Al2O3, Ti, and UHMWPE particles to osteoprogenitors at a similar concentration of 200 μg/mL showed that only Al2O3 particles were able to suppress the early and late differentiation markers of osteoprogenitors, including collagen synthesis, alkaline phosphatase (ALP) activity and mRNA expression of Runx2, OSX, Col1α, and OCN. Al2O3 particles even induced inflammation and activated the NFkB signaling pathway in osteoprogenitors. Moreover, bone-forming signals such as the WNT/β-catenin signaling pathway were inhibited by the Al2O3 particles. Al2O3 particles were found to induce the mRNA expression of WNT/β-catenin signaling antagonists such as DKK2, WIF, and sFRP1 several times in osteoprogenitors. Taken together, this study highlights a mechanistic view of the effect of Al2O3 particles on osteoprogenitors and suggests therapeutic targets such as NFĸB and WNT signaling pathways for ceramic particle-induced osteolysis.

Role of serum and synovial procalcitonin in differentiating septic from non-septic arthritis- a prospective study

INTRODUCTION

Septic arthritis is a serious orthopaedic emergency that must be diagnosed and managed early to prevent devastating complications. The current gold standard for diagnosing septic arthritis is synovial fluid culture, but results are delayed by 48-72 h, and the sensitivity of the test is very low. Differentiating Septic from non-septic arthritis is vital to prevent unnecessary use of antibiotics and prevent complications. Serum Procalcitonin (PCT) is a useful marker in differentiating septic from non-septic arthritis but there are very few studies that have studied the role of synovial PCT for the same.

AIM

To determine the role of serum and synovial PCT in differentiating acute Septic from non-septic arthritis.

MATERIALS AND METHODS

Prospective clinical study in which 60 patients presenting with acute inflammatory arthritis (<2 weeks duration) were enrolled from May 2018 to May 2020. Serum and synovial fluid samples were drawn at presentation and routine blood investigations, synovial fluid culture sensitivity, and Procalcitonin levels were measured. Patients were divided into 3 groups, with group-1 having confirmed pyogenic, group-2 having presumed pyogenic, and group-3 having non -pyogenic patients, respectively. All data was tabulated and statistically analysed using appropriate tests.

RESULTS

Mean serum PCT values in groups 1, 2 and 3 were 1.06 ± 1.11, 0.85 ± 0.74, and 0.11 ± 0.24, respectively. Patients in the Pyogenic group (group1 and group 2) had significantly higher mean serum PCT as compared to group3 (p < 0.0001). Group 1 had higher serum PCT as compared to group 2, but the difference was not significant (p = 0.58). Mean synovial PCT in group 1, 2 and 3 were 2.42 ± 1.98, 1.89 ± 1.18, and 0.22 ± 0.40, respectively. Patients in the Pyogenic group (Group1 and Group2) had significantly higher mean synovial PCT as compared to Group 3 (p < 0.0001). Group 1 had higher mean synovial PCT as compared to group 2, but the difference was not significant (p = 0.54). The area under the ROC curve of the serum levels of PCT was 0.0.895, and the area under the ROC curve of the synovial fluid levels of PCT was 0.914, which was higher than the serum PCT level.

CONCLUSION

Serum and synovial Procalcitonin may be used as a diagnostic marker in differentiating septic from inflammatory arthritis and can help in reducing unnecessary use of antibiotics and early diagnosis and management of septic arthritis, thereby preventing complications.

Arthroscopic labral repair combined with less invasive open-shelf acetabuloplasty for patients with developmental dysplasia of the hip

Hip arthroscopy has become widely used for intra-articular lesions, such as labral tears and femoral acetabular impingement. However, its use in patients with developmental dysplasia of the hip (DDH) has been controversial and has historically demonstrated mixed results, as acetabular dysplasia may cause instability due to insufficient bony coverage of the femoral head, thus causing excessive stress on the repaired labrum and cartilage. We devised a combined hip arthroscopic labral repair and a less invasive open-shelf procedure using a small skin incision as an anterolateral portal in hip arthroscopy. This novel procedure may improve the stability of the repaired labrum with a bony covering in a minimally invasive manner. Moreover, the shelf procedure can be performed under direct vision in a comparatively safe and precise manner. In total, 13 hips with DDH underwent the procedure for labral tears. All patients were females, with a mean age of 30 years. The mean follow-up period was 33 months. The mean Harris hip score improved from 74.2 to 93.6, and Oxford Hip score improved from 32.4 to 19.3. According to the Tönnis classification, the grade of arthritis preoperatively was grade 0 for nine hips and grade I for four hips. No radiographic progression of osteoarthritis was observed. It is possible that this novel procedure could be an effective treatment for labral tears with DDH and may prevent the early onset of secondary osteoarthritis. In this technical tip, we describe hip arthroscopic labral repair combined with a less invasive open-shelf acetabuloplasty in further detail.

The Utility of Perioperative Products for the Prevention of Surgical Site Infections in Total Knee Arthroplasty and Lower Extremity Arthroplasty: A Systematic Review

Surgical site infections (SSIs) are among the most prevalent and devastating complications following lower extremity total joint arthroplasty (TJA). Strategies to reduce the rates can be divided into preoperative, perioperatives, and postoperative measures. A multicenter trial is underway to evaluate the efficacy of implementing a bundled care program for SSI prevention in lower extremity TJA including: (1) nasal decolonization; (2) surgical skin antisepsis; (3) antimicrobial incise draping; (4) temperature management; and (5) negative-pressure wound therapy for selected high-risk patients. The purposes of this systematic review were to provide a background and then to summarize the available evidence pertaining to each of these SSI-reduction strategies with special emphasis on total knee arthroplasty. A systematic review of the literature was conducted in accordance with the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. Five individual literature searches were performed to identify studies evaluating nasal decolonization temperature management, surgical skin antisepsis, antimicrobial incise draping, and negative-pressure wound therapy. The highest level of evidence reports was used in each product review, and if there were insufficient arthroplasty papers on the particular topic, then papers were further culled from the surgical specialties to form the basis for the review. There was sufficient literature to assess all of the various prophylactic and preventative techniques. All five products used in the bundled program were supported for use as prophylactic agents or for the direct reduction of SSIs in both level I and II studies. This systematic review showed that various pre-, intra-, and postoperative strategies are efficacious in decreasing the risks of SSIs following lower extremity TJA procedures. Thus, including them in the armamentarium for SSI-reduction strategies for hip and knee arthroplasty surgeons should decrease the incidence of infections. We expect that the combined use of these products in an upcoming study will support these findings and may further enhance the reduction of total knee arthroplasty SSIs in a synergistic manner.

Systematic Review and Meta-Analysis of Intrawound Vancomycin in Total Hip and Total Knee Arthroplasty: A Continued Call for a Prospective Randomized Trial

BACKGROUND

Periprosthetic joint injection (PJI) is a rare, but life-altering complication of total joint arthroplasty (TJA). Though intrawound vancomycin powder (IVP) has been studied in other orthopedic subspecialties, its efficacy and safety in TJA has not been established.

METHODS

PubMed and MEDLINE databases were used to identify studies utilizing IVP in primary and revision total hip (THA) and knee arthroplasty (TKA). Postoperative PJI data were pooled using random effect models with results reported as odds ratios (ORs) and 95% confidence intervals (CIs). Studies were weighted by the inverse variance of their effect estimates.

RESULTS

Overall, 16 of the 1871 studies identified were pooled for final analysis, yielding 33,731 patients totally. Of these, 17 164 received IVP. In aggregate, patients who received IVP had a decreased rate of PJI (OR 0.46, P < .05). Separately, TKA and THA patients who received IVP had lower rates of PJI (OR 0.41, P < .05 and OR 0.45, P < .05, respectively). Aggregate analysis of primary TKA and THA patients also revealed a decreased PJI rate (OR 0.44, P < .05). Pooled revision TKA and THA patients had a similar decrease in PJI rates (OR 0.30, P < .05). Although no publication bias was appreciated, these findings are limited by the low-quality evidence available.

CONCLUSION

While IVP may reduce the risk of PJI in primary and revision TJA, its widespread use cannot be recommended until higher-quality data, such as that obtained from randomized control trials, are available. This study underscores the continued need for more rigorous studies before general adoption of this practice by arthroplasty surgeons.

Modular dual-mobility articulations in patients with adverse spinopelvic mobility

AIMS

Adverse spinal motion or balance (spine mobility) and adverse pelvic mobility, in combination, are often referred to as adverse spinopelvic mobility (SPM). A stiff lumbar spine, large posterior standing pelvic tilt, and severe sagittal spinal deformity have been identified as risk factors for increased hip instability. Adverse SPM can create functional malposition of the acetabular components and hence is an instability risk. Adverse pelvic mobility is often, but not always, associated with abnormal spinal motion parameters. Dislocation rates for dual-mobility articulations (DMAs) have been reported to be between 0% and 1.1%. The aim of this study was to determine the early survivorship from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) of patients with adverse SPM who received a DMA.

METHODS

A multicentre study was performed using data from 227 patients undergoing primary total hip arthroplasty (THA), enrolled consecutively. All the patients who had one or more adverse spine or pelvic mobility parameter had a DMA inserted at the time of their surgery. The mean age was 76 years (22 to 93) and 63% were female (n = 145). At a mean of 14 months (5 to 31) postoperatively, the AOANJRR was analyzed for follow-up information. Reasons for revision and types of revision were identified.

RESULTS

The AOANJRR reported two revisions: one due to infection, and the second due to femoral component loosening. No revisions for dislocation were reported. One patient died with the prosthesis in situ. Kaplan-Meier survival rate was 99.1% (95% confidence interval 98.3 to 100) at 14 months (number at risk 104).

CONCLUSION

In our cohort of patients undergoing primary THA with one or more factor associated with adverse SPM, DM bearings conferred stability at two years' follow-up. Cite this article: Bone Joint J 2022;104-B(7):820-825.

Development of bony range of motion (B-ROM) boundary for total hip replacement planning

BACKGROUND AND OBJECTIVE

Pre-operative surgical planning using computer simulation is increasingly standard practice before Total Hip Arthroplasty (THA), in order to determine the optimal implant positions, and thereby minimise post-operative complications such as dislocation, wear and leg length discrepancy. One of the limitations of current methods, however, is the lack of information on the subject-specific reference range of motion (ROM) that could be used as targets for surgical planning. Only a limited number of hip motions are considered, which are neither subject-specific, nor representative of all the hip motions associated with all the activities of daily livings (ADLs). In this paper, therefore, a method was developed to calculate subject-specific representative bony range of motion (B-ROM) that would cover all the possible joint motions and presented in terms of pure joint motions.

METHODS

Only 3D bone geometries of femur and pelvis, constructed from personalised CT scan, were used as inputs for healthy hip joint whereas implant geometries and their positions on native bone geometries were required for planned treatment side or replaced side. Hip joint motion simulation was carried out using six different Tait-Bryan intrinsic rotation sequences of three pure joint motions - flexion-extension, abduction-adduction and internal-external rotation, and B-ROM was then identified for any of these six different sequences which caused earliest feasible impingement. The B-ROM could be used as a list of ROM data points or visualised as multiple 2D surface plots or a 3D envelop. Using the developed method, the B-ROM of a contralateral healthy hip joint of a patient can be used to define the subject-specific target ROM values to inform the surgical planning of the arthritic hip side so that the patient's natural ROM could be restored as closely as possible by the planned implant placements. This was demonstrated with a clinical verification study using 'non-dislocating' and 'dislocating' THA patients.

RESULTS

The results supported the study hypothesis that the percentage of intersected volume of the healthy and replaced side B-ROM was higher for the 'Non-Dislocator' patient (95%) compared to 'Dislocator' (78%). Also, the results showed that the only one sequence (first flexion-extension, then abduction-adduction and finally internal-external rotation) was not adequate to identify all the possible limiting B-ROM, and therefore, all the six rotation sequences should be considered.

CONCLUSIONS

The method encompasses every potential ADL, and as a result, more comprehensive surgical planning is possible, as the implant positions can be optimised in order to maximise impingement-free ROM, and consequently minimise clinical complications.

Current Trends in Revision Hip Arthroplasty: Indications and Types of Components Revised

BACKGROUND

The materials and techniques for both primary and revision total hip arthroplasty (THA) have changed over time. This study evaluated if the indications for revision THA, rates of components utilized (femoral or acetabulum, both, or head/liner exchange), length of stay (LOS), and payments to surgeons and facilities have also changed.

METHODS

A retrospective study, utilizing the PearlDiver database, of 38,377 revision THA patients from January 2010 through December 2018 was performed. Data included the indication for revision, components revised (femoral or acetabulum, both, or head/liner exchange), LOS, and payments. Indications and components were analyzed by logistic regression (Dunnett's post hoc test). Revision totals were analyzed with a linear regression model. Analysis of variance assessed changes in LOS and payments.

RESULTS

Patients' median age was 67 years (Q1-Q3: 59-74), and 58.7% were female. Revisions for dislocation decreased between 2010 and 2018 (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.68-0.98). Revisions for component loosening increased (OR 1.54, 95% CI 1.25-1.91). Dislocation remained the most common indication (19.3%), followed by PJI (17.3%) and loosening (17.1%). Both-component (OR:1.45; 95% CI:1.25-1.67) and femoral component only revisions increased; acetabular component only and head/liner exchanges decreased. Acetabular (OR 0.57, 95% CI 0.47-0.70) and head/liner exchange (OR 0.29, 95% CI 0.20-0.43) revisions decreased, while both component exchange (OR 1.45, 95% CI 1.25-1.67) and femoral revisions (OR 1.17, 95% CI 0.99-1.37) increased. Average LOS (-0.68 days; P < .001) and surgeon payments decreased (-$261.8; P < .001) while facility payments increased ($4,211; P < .001).

CONCLUSION

Indications for revision THA in this database study changed over time, with revision for dislocation decreasing and revision for loosening increasing over time. Both component and femoral revisions increased, and acetabular component and head/liner exchanges decreased. It is possible that these associations could be attributed to a number of details, the method of femoral fixation, surgical approach, and cementing, all of which require additional study.