Primary Total Hip Arthroplasty Research Articles

THE COMBINED USE OF SINGLE- AND DUAL-MOBILITY CUPS IN PRIMARY TOTAL HIP ARTHROPLASTY IS SAFE IN A UNIVERSITY HOSPITAL PRACTICE

Dislocation after Total Hip Arthroplasty (THA) is a frequent cause of revision and patients with intrinsic risk factors have been identified. The use of dual mobility (DM) cup has shown great efficiency in preventing dislocation, with questions regarding selective or absolute use. The aim of this study was to compare the outcome of single mobility THA (SM-THA) and DM-THA, when used for selected patients.This retrospective continuous cohort study evaluated 490 patients of whom 275 received SM-THA and 215 received DM-THA. There were 304 primary osteoarthritis (62%), 121 femoral neck fractures (24%) and 65 other indications (14%). The surgical approach was anterior (AA) in 79% and posterior (PA) in 21% of cases. In the DM-THA group, 189 patients (87%) presented at least one dislocation risk factor compared to 128 patients (46%) in the SM-THA group. The primary outcome was revision for all causes, with or without implant removal. Secondary outcomes included length of hospital stay.There was no difference in all cause revision at two years follow up with 9 procedures (3.2%) in SM-THA group and 11 in DM-THA group (5.1%) (p=0.3). There were 3 dislocations in SM-THA group (3 AA) and 3 in DM-THA group (2 PA and 1 AA) (p=0.4).The length of stay was significantly longer in DM-THA group with 7 days (2–12) compared to 4 days (1–7) in SM-THA group (p=0.001).SM-THA and DM-THA are two complementary devices in the management of patients requiring primary THA. SM-THA is a safe option for patients without dislocation risk factors, especially when using AA. The identification of such factors is important to select patients requiring DM-THA and provide reproducible outcomes in a University Hospital practice including various levels of surgeon experience.

A RANDOMIZED CONTROLLED TRIAL OF A CONVENTIONAL VERSUS MODULAR DUAL-MOBILITY BEARING: ARE SERUM METAL LEVELS A CONCERN?

The purpose of this randomized controlled trial was to evaluate serum metal levels in patients undergoing total hip arthroplasty (THA) with a conventional compared to a modular dual-mobility bearing.Patients undergoing primary THA for osteoarthritis were randomized to receive either a modular dual-mobility or conventional polyethylene bearing. All patients received the same titanium acetabular and femoral component and a ceramic femoral head. Serum metal levels were drawn pre-operatively then annually for a minimum of two years postoperatively. An a priori power analysis determined that 40 patients (20 per cohort) were needed to identify a clinically relevant difference in serum cobalt of 0.35 ng/ml (ppb) at 90% power.Forty-six patients were randomized to a modular dual-mobility (n=25) or conventional bearing (n=21) with 40 at a minimum follow-up of two years. No differences in serum cobalt (mean 0.14 ppb [range, 0.075–0.29] vs. 0.20 ppb [range, 0.075–0.57], p=0.39) or chromium levels (mean 0.14 ppb [range, 0.05–0.50] vs. 0.12 ppb [range, 0.05–0.35], p=0.65) were identified between the modular dual-mobility and conventional cohorts, respectively.There was no statistically significant difference in serum Co or Cr at two years postoperatively in subjects implanted with a ceramic head and this particular dual mobility bearing in comparison to a ceramic head and a conventional acetabular component. While modest expected elevations in serum Co and Cr were observed in the dual mobility group, in no case did the Co level exceed the laboratory reference range nor the threshold of one part per billion that has been associated with adverse local tissue reactions to mechanically-assisted crevice corrosion.

Lower Extremity Arterial Calcification Predicts Referral to a Closed Unit After Primary Total Hip Arthroplasty

BackgroundWe aimed to determine the association between lower extremity arterial calcification (LEAC) and referral to a closed unit (CU), length of stay, 90-day readmissions, and 1-year mortality in primary total hip arthroplasty (THA) patients. MethodsWe retrospectively analyzed 705 patients who underwent primary THA, identifying 64 patients (9.13%) who had LEAC and 641 who did not have LEAC. Patients who had LEAC were older (77 ± 10.0 versus 67 ± 11.5 years; P < 0.001) and had more comorbidities, except for a history of thromboembolic and oncologic diseases (P > 0.05). A preoperative antero-posterior pelvic radiograph was used to assess the presence of LEAC. Admission to CU, length of stay, 90-day readmissions, and 1-year mortality were recorded. A logistic regression model was used to identify risk factors for referral to CU. ResultsPatients who had LEAC had a higher incidence of admission to the intensive care unit (8 of 64 [12.5%] versus 8 of 641 [1.09%]; P < 0.001), a longer hospital stay (4.7 ± 1.8 versus 4.2 ± 1.3 days; P = 0.006), more readmissions (16 of 64 [25%] versus 33 of 641 [5.15%]; P < 0.001), and a higher 1-year mortality rate (6 of 64 [9.3%] versus 0 of 641 [0%]; P < 0.001) than patients who did not have LEAC. Of the patients who had LEAC admitted to CU, only 3 of 8 had a previous indication to do so in the preoperative assessment performed by the Department of Anesthesiology, while all non-LEAC ones referred to CU did so. Logistic regression analysis showed that LEAC was a risk factor for admission to CU (odds ratio = 4.77; 95% confidence interval: 1.12 to 20.25; P = 0.034). ConclusionsThe presence of LEAC was a risk factor for transfer to CU, longer in-hospital stays, more readmissions, and a higher 1-year mortality rate. Identifying patients who have LEAC can aid in the preoperative assessment and risk stratification of patients planned for primary THA.

Prevalence, risk factors, microbiological results and clinical outcome in unexpected positive intraoperative cultures in unclear and presumed aseptic hip and knee revision arthroplasties – A ten-year retrospective analysis with a minimum follow up of 2 years

BackgroundThe aim of this study was to assess the prevalence, microbiological spectrum, risk factors, and clinical outcomes of unexpected-positive-intraoperative-cultures (UPIC) in presumed aseptic and unclear revision-total-hip-/knee-arthroplasties (rTHA and rTKA) compared to culture-negative (CN) revisions. MethodsThis study reviewed all International-consensus-meeting-2018 (ICM 2018) negative or inconclusive rTHA (n = 751) and rTKA (n = 679) performed at our institution from 2011 to 2020 with a minimum follow-up of two years. A Kaplan-Meier-analysis was performed to determine the septic and aseptic-free implant survival in cases with UPIC's and matched culture-negative cases. Patient demographics, risk factors, microbiological spectrum and clinical outcomes were evaluated. ResultsThere were significantly more UPIC cases in rTHA 196/751 (26.1 %) compared to rTKA 113/679 (16.6 %); (p < 0.001). UPICs in rTKA and rTHA have a lower septic and aseptic implant-free-survival compared to CN revisions. Patients with a history of nickel allergy have a higher risk of an UPIC in rTHA and rTKA (p < 0.001). Septic re-revisions after UPIC had a significantly (H: p = 0.004; K: p = 0.030) shorter time period to the primary/previous surgery (H: 84 (IQR:41–797); K: 115 (IQR:55–446)) compared to patients with aseptic re-revisions after UPIC (H:1248 (IQR:178-3534); K: 827 (IQR:361-1183)). ConclusionUPICs have a higher rate of septic and aseptic failure than CN outcomes. UPICs are twice as common in rTHA compared to rTKA. Preoperative PJI workup reduces the UPIC rate. Nickel allergy is a risk factor for UPIC. Early revisions with UPICs after primary THA or TKA have a higher risk of septic failure. The translational potential of this articleThis article provides new information on revision rates for UPIC and potential risk factors for UPIC and its treatment failure.

Is it feasible to develop a supervised learning algorithm incorporating spinopelvic mobility to predict impingement in patients undergoing total hip arthroplasty?

Precise implant positioning, tailored to individual spinopelvic biomechanics and phenotype, is paramount for stability in total hip arthroplasty (THA). Despite a few studies on instability prediction, there is a notable gap in research utilizing artificial intelligence (AI). The objective of our pilot study was to evaluate the feasibility of developing an AI algorithm tailored to individual spinopelvic mechanics and patient phenotype for predicting impingement. This international, multicentre prospective cohort study across two centres encompassed 157 adults undergoing primary robotic arm-assisted THA. Impingement during specific flexion and extension stances was identified using the virtual range of motion (ROM) tool of the robotic software. The primary AI model, the Light Gradient-Boosting Machine (LGBM), used tabular data to predict impingement presence, direction (flexion or extension), and type. A secondary model integrating tabular data with plain anteroposterior pelvis radiographs was evaluated to assess for any potential enhancement in prediction accuracy. We identified nine predictors from an analysis of baseline spinopelvic characteristics and surgical planning parameters. Using fivefold cross-validation, the LGBM achieved 70.2% impingement prediction accuracy. With impingement data, the LGBM estimated direction with 85% accuracy, while the support vector machine (SVM) determined impingement type with 72.9% accuracy. After integrating imaging data with a multilayer perceptron (tabular) and a convolutional neural network (radiograph), the LGBM's prediction was 68.1%. Both combined and LGBM-only had similar impingement direction prediction rates (around 84.5%). This study is a pioneering effort in leveraging AI for impingement prediction in THA, utilizing a comprehensive, real-world clinical dataset. Our machine-learning algorithm demonstrated promising accuracy in predicting impingement, its type, and direction. While the addition of imaging data to our deep-learning algorithm did not boost accuracy, the potential for refined annotations, such as landmark markings, offers avenues for future enhancement. Prior to clinical integration, external validation and larger-scale testing of this algorithm are essential.

Polyethylene liner dissociation in total hip arthroplasty: a retrospective case–control study on a single implant design

BackgroundModular acetabular components for total hip arthroplasty (THA) provide intraoperative flexibility; however, polyethylene liner dissociation may occur. This study aimed to examine the incidence and causes of liner dissociation associated with a specific acetabular component design at a single centre.Materials and methodsA retrospective analysis of 7027 patients who underwent primary THA was performed to identify isolated liner dislocations. Patient demographics, clinical presentations, surgical and implant details, and both radiographic and computed tomography (CT) findings were analysed. Patients with liner dislocation were matched to a control group via 2:1 propensity score matching, and a logistic regression analysis was employed to identify associated risk factors.ResultsA total of 32 patients (0.45%) experienced liner dislocation at a mean 71.47 ± 60.10 months post surgery. Significant factors contributing to dislocations included the use of a conventional compared with a highly crosslinked polyethylene component (p = 0.049) and screw fixation (p = 0.028). Radiographic and CT analysis highlighted the importance of proper component orientation, revealing that patients experiencing dislocations demonstrated significantly lower acetabular cup anteversion angles (p = 0.001) compared with the control group. Impingement and malposition, identified in 41% and 47% of the cases, respectively, further underscored the multifactorial nature of dislocation risks.ConclusionsWhile the overall rate of polyethylene liner dislocation was low, the findings of this study highlight the importance of appropriate cup placement to decrease the risk of dissociation. It further substantiates the influence of impingement and malposition in liner displacement, with increased mechanical stress exerted on the locking mechanism under adverse conditions and the potential risk increase due to screw placement.

Impact of Intraoperative Femoral Fractures During Cemented Hemiarthroplasty for Femoral Neck Fractures

BackgroundThere have been several studies on intraoperative femoral fractures (IFFs) during primary total hip arthroplasty, but it is not well understood how this complication affects the patient population undergoing cemented hemiarthroplasty. This study aimed to analyze the impact of IFFs sustained during cemented hemiarthroplasty for the treatment of femoral neck fractures. MethodsA retrospective review was conducted of all patients who were treated for Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association 31B fractures with cemented hemiarthroplasty between January 1, 2000 and December 31, 2021, at a single academic level 1 trauma center. An initial cohort was constructed of all patients who sustained an IFF during their surgery, yielding 31 patients after excluding those who sustained a pathologic fracture or had incomplete data. These patients were matched 1:2 on age, sex, and body mass index to patients in a control cohort. The primary outcome measure was implant failure. Secondary outcome measures included complications, all-cause mortality, and radiographic outcomes (subsidence, femoral component loosening, acetabular wear, and heterotopic ossification) postoperatively. ResultsSubsequent implant revision was required in 3.2% (n = 1) of patients who sustained an IFF and 1.6% (n = 1) of patients who did not. After adjusting for comorbidities, there was no observed excess risk of implant failure in the fracture cohort when compared to the control cohort (hazard ratio [HR] = 0.30, P = 0.740). There was no observed excess risk of morbidity (HR = 0.69, P = 0.621) or all-cause mortality (HR = 0.23, P = 0.330). Radiographic outcomes also did not significantly differ between the 2 cohorts (P > 0.05). ConclusionsIntraoperative fractures during cemented hemiarthroplasty do not contribute to an increased risk of secondary surgery, morbidity, or mortality after surgery. They also do not adversely affect radiographic outcomes postoperatively. Level of EvidenceLevel III, Retrospective Comparative Study.

Clinical outcomes of total joint arthroplasty in patients with bowel ostomies.

The influence of prior colostomy or ileostomy on patients undergoing joint arthroplasty remains poorly understood. Our study aimed to assess whether patients with an ostomy undergoing hip and knee arthroplasties have worse postoperative outcomes and increased rates of revisions. A single-center, retrospective review of patients with a history of bowel ostomy who underwent a primary total hip arthroplasty (THA), hemiarthroplasty (HA), and total knee arthroplasty (TKA) from 2012 to 2021. A total of 24 THAs, 11 HAs, and 25 TKAs in patients with open small or large bowel stoma were identified. A ten-to-one propensity score match was utilized to establish cohorts with comparable demographics but no prior ostomy procedure. Patients with stomas undergoing elective THA showed greater 90-day ED visits (20.0 vs. 5.0%, P = 0.009), 90-day all-cause readmissions (20.0 vs. 5.0%, P = 0.009), 90-day non-orthopedic readmissions (10.0 vs. 0.5%, P < 0.001), 90-day readmissions for infection (5.0 vs. 0.5%, P = 0.043), all-cause revisions (15.0 vs. 0.5%, P < 0.001), revisions for PJI (5.0 vs. 0%, P = 0.043), and revisions for peri-prosthetic fracture (10.0 vs. 0%, P < 0.001). Patients with stomas undergoing non-elective hip arthroplasties exhibited a longer mean LOS (12.1 vs. 7.0 days, P < 0.001) and increased 90-day all-cause readmissions (40.0 vs. 17.3%, P = 0.034), 90-day orthopedic readmissions (26.7 vs. 6.0%, P = 0.005), all-cause revisions (13.3 vs. 2.0%, P = 0.015), revisions for peri-prosthetic fracture (6.7 vs. 0%, P = 0.002), and revisions for aseptic loosening (6.7 vs. 0%, P = 0.002). There were no significant differences in readmission or revision rates between ostomy patients undergoing TKA and a matched control group. Patients undergoing hip arthroplasties with an open stoma are at an increased risk of hospital encounters and revisions, whereas TKA patients with stomas are not at increased risk of complications. These findings emphasize the importance of recognizing and addressing the unique challenges associated with this patient population.

Local Infiltration Analgesia Is Superior to Regional Nerve Blocks for Total Hip Arthroplasty: Less Falls, Better Mobility, and Same-Day Discharge.

Background: Multimodal analgesia in total hip arthroplasty (THA) provides better pain control, mobility, and reduced side effects compared to monotherapies. Local infiltration analgesia (LIA) and regional nerve blocks (RNBs) are commonly used throughout these protocols. This study aimed to compare these procedures as part of a multimodal analgesia protocol for patients undergoing THA. Materials and Methods: A retrospective review of 1100 consecutive elective primary THAs was performed in 996 patients between June 2018 and December 2021. The RNB consisted of a preoperative continuous femoral nerve catheter and single-shot obturator nerve block, and LIA consisted of the intraoperative infiltration of weight-based bupivacaine. Results: A total of 579 (52.6%) patients received RNB, and 521 (47.4%) received LIA. Mean oral morphine equivalents (OMEs) during the first four hours postoperatively were significantly lower for LIA group (p < 0.001). However, the numeric pain rating scale in the post-anesthesia care unit (PACU) was similar between groups. Patients with LIA had significantly greater first ambulation distance in the PACU (p < 0.001), higher successful same-day discharge rate (p = 0.029), fewer falls (p = 0.041), and less refill OMEs post-discharge (p < 0.001) than RNB. Conclusions: In the setting of similar pain management between groups and better functional outcomes for LIA, the use of minimally invasive procedures like LIA for pain control following THA is favorable.

Multicenter survey about leg length discrepancy and total hip arthroplasty: postoperative management.

We created a Multicenter Survey for Italian orthopedics surgeons on how they approach leg length discrepancy when dealing with primary total hip arthroplasty. Aim of the study was to show how surgeons manage LLD and follow literature recommendations during clinical practice. The Survey was composed of 25 questions divided in 4 sections: surgeon's profile, preoperative and intraoperative evaluation, postoperative management. In this paper, we report the absolute and relative frequencies of answers to section on "postoperative management." Then, regarding the treatment of residual LLD, we reported whether trauma surgeons and experts in replacement surgery had higher odds ratios for providing "literature-based" answers compared to orthopedics physicians. Only four questions received more than 70% agreement on one of the answers. The OR for giving the "literature-based" answer, taking OP as the reference group was 1.57 for TR and 1.72 for RS for 10mm LLD at first follow-up (FU) and 1.23 TR and 1.32 RS when 20mm. When 10mm LLD at 3months FU the OR was 0.88 TR and 1.15 RS. The OR for treatment of LLD after the first examination of a new patient was 2.16 TR and 1.85 RS. LLD is a debated topic with no definitive recommendations. Many decisions still depend on tradition. Treatment of LLD during clinical practice often differs from literature recommendations.

Return to surfing following hip arthroplasty.

To date, no previous studies have explored return to surfing after hip arthroplasty. The objective of this study is to analyse return to a risky activity following hip arthroplasty. A retrospective chart review was conducted on all primary total hip arthroplasties (THA) and hip resurfacing arthroplasties (HRA) performed by the senior author from 2014 to 2021. Patients identified as surfers were contacted to complete a survey including surfing history and patient-reported outcomes. 83 hips in 67 patients were contacted. There were 66 THAs and 17 HRAs. 81 hips were performed through a posterior approach and 2 through an anterior approach. At an average of 67 months, there were no dislocations and no patients reported hip pain while surfing. Time to resume surfing was a median of 16 (range 8-144) weeks. Among 13 patients who did not return to surfing, 8 cited new lifestyle restrictions, 4 attributed it to other arthritic joints, and only 1 patient attributed their limitation to the replaced hip. This group had taken significantly more time off from surfing prior to surgery. Return to surfing following THA and HRA is common and safe in our study population with no complications and specifically no dislocations. Patients with other sites of arthritis and patients who have more extensive time away from surfing prior to surgery are less likely to return to sport. While surfing is clearly not without risk, patients can generally expect a high rate of successful return to surfing after hip arthroplasty.

No differences in clinical and radiographic outcomes between standard versus high offset collared stems for primary total hip arthroplasty at fiveyears follow-up.

To compare clinical and radiographic outcomes of propensity-matched patients undergoing THA using standard versus high offset stems at fiveyears. The authors retrospectively reviewed a consecutive series of primary THAs performed between 01/09/2015-31/12/2017 using a fully-hydroxyapatite coated collared stem, with either a standard (n = 365) or high (n = 110) offset. Outcomes collected included: modified Harris Hip Score (mHHS), Oxford Hip Score (OHS), Forgotten Joint Score (FJS), and radiographic measurements including limb length discrepancy (LLD), stem subsidence, and stem radiolucencies. Propensity score matching resulted in 80 hips per group. Preoperatively there were no significant differences in patient demographics, surgical data and radiographic measurements, except the standard offset group had significantly smaller femoral (40.0 ± 7.5 vs 48.4 ± 6.2, p < 0.001), acetabular (92. ± 6.3 vs 94.8 ± 7.3, p = 0.011) and global (132.0 ± 10.3 vs 143.2 ± 8.2, p < 0.001) offsets compared to the high offset group. At a minimum fiveyears follow-up, there were no significant differences in mHHS (93.2 ± 11.0 vs 93.1 ± 10.6, p = 0.553), OHS (45.1 ± 4.1 vs 45.3 ± 4.6, p = 0.623), and FJS (85.1 ± 19.3 vs 82.7 ± 23.0, p = 0.910). There were also no differences in radiographic measurements, including LLD (1.5 ± 4.8 vs 1.1 ± 3.5, p = 0.537), stem subsidence (0% vs 0%, p = 1.000), and stem radiolucencies (severe: 6% vs 1%, p = 0.152). The present matched-cohort study found no significant differences between standard versus high offset straight fully-hydroxyapatite coated collared stems for primary THA in terms of clinical and radiographic outcomes at fiveyears. These findings may suggest that uncemented collared high offset stems are not associated with an increased risk of radiolucencies and loosening compared to uncemented collared standard offset stems.

What Are the Relative Associations of Surgeon Performance and Prosthesis Quality With THA Revision Rates?

Many factors, including some related to the patient, implant selection, and the surgeon's skill and expertise, likely contribute to the risk of THA revision. However, surgeon factors have not been extensively analyzed in national joint replacement registries, and there is limited insight into their potential as a confounding variable for revision outcomes; for example, if surgeons with higher revision rates choose more successful prostheses, would this alone reduce their revision rate? This study used Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) data for patients receiving primary THA for a diagnosis of osteoarthritis to answer the following questions: (1) Will the difference in revision rates among surgeons change or disappear when only procedures performed with the best prostheses or prostheses that have been identified as having higher revision rates are considered? (2) Is the benefit associated with using the best-performing prostheses different among surgeons with different revision rates? (3) Do the reasons for revision differ between surgeons with higher rates of revision compared with surgeons with lower rates of revision? All primary THA procedures performed and recorded in the AOANJRR for osteoarthritis from September 1, 1999, to December 31, 2022, were considered for inclusion. Each THA prosthesis used was categorized per the AOANJRR as superior-performing, middle-performing, or identified as having a higher rate of revision by the AOANJRR benchmarking process. Surgeons who had performed at least 50 procedures and had a recorded 2-year cumulative percent revision (CPR) were included. After applying these restrictions, the study consisted of 302,066 procedures performed by 476 known surgeons. For the primary outcome measure of all-cause revision, we examined the variation in all-cause revision rates across individual surgeons when different classes of devices were used to assess whether differences between surgeons persisted when accounting for prosthesis selection. For the purposes of descriptively comparing reasons for revision between surgeons with higher-than-average or lower-than-average risk of revision, surgeons were classified into quartiles and outcomes compared when these surgeons used the same class of prosthesis. The difference in rates of revision among surgeons remained even after accounting for the effects of the prosthesis used. For any given surgeon, identified prostheses were associated with higher revision rates compared with both superior-performing prostheses (HR 1.73 [95% CI 1.57 to 1.92]; p < 0.01) and medium-performing prostheses (HR 1.31 [95% CI 1.20 to 1.43]; p < 0.01). All surgeons demonstrated a lower revision rate when using a superior-performing prosthesis, but the difference was greatest for surgeons with the highest rates of revision. Surgeons with the lowest rates of revision had a 19-year CPR of 3.9% (95% CI 3.0% to 5.0%) when using a superior-performing prosthesis compared with 5.4% (95% CI 4.0% to 7.3%) for procedures in which an identified prosthesis was used. Surgeons with the highest rates of revision had a 19-year CPR of 10.9% (95% CI 8.6% to 13.8%) when using a superior-performing prosthesis, and this increased to 20.4% (95% CI 18.0% to 23.1%) for procedures in which an identified prosthesis was used. The reasons for revision differ between surgeons, with causes of revision likely preventable and not related to the prosthesis choice being apparent for surgeons with high revision rates. The choice of implant and the surgeon performing the index procedure both affected the risk of revision as well as the reasons for revision. Surgeons could improve the survivorship of the arthroplasties they perform by choosing implants identified by registries as having lower revision rates. Acceptance of the fact that surgeons have different revision rates is needed, and detailed analysis is required to explain why surgeons with high revision rates have increased rates of likely preventable revisions, and outside of prosthesis choice, how revision rates can be lowered. The influence of training, fellowship completion, ongoing education, patient selection, indications for surgery, and factors underlying prosthesis decision-making should be assessed. The surgeon performing THA is an important confounder that should be considered in future registry analyses. Level III, therapeutic study.

Functional Outcome after Direct Anterior Approach Total Hip Arthroplasty (DAA-THA) for Coxa Profunda and Protrusio Acetabuli-A Retrospective Study.

Objective: The direct anterior approach (DAA) is a recognized technique for total hip arthroplasty (THA) that spares soft tissue. Functional and clinical outcomes following THA via the DAA in patients with complex acetabular deformities, specifically coxa profunda (CP) and protrusio acetabuli (PA), have yet to be determined. Methods: A retrospective analysis was conducted on 188 primary THA cases, including 100 CP hips and 88 PA hips, performed via the DAA. Functional and clinical outcomes were evaluated by means of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Harris Hip Score (HHS) preoperatively and at a mean follow-up of 46 ± 14 months. Furthermore, potential complications were assessed. Results: From the preoperative to the latest postoperative visit, a significant improvement in the WOMAC total score was observed (CP: -34.89 ± 20.66; PA: -40.38 ± 21.11). The length of stay (LOS) was the only parameter predictive of the postoperative WOMAC total score, with each day of LOS increasing the postoperative WOMAC by a mean of 1.77 points (p < 0.01). The HHS improved by 38.37 ± 14.23 (PA-group) and 32.79 ± 14.89 points (CP-group). No significant difference in the patient-reported outcome measures (PROMs) between the CP- and PA-group was found. The survival rate for any revision was 97.70% (PA-group) and 92.80% (CP-group). Conclusion: The results of this study indicate that the minimally invasive DAA was not predictive of the functional and clinical outcome following DAA-THA in patients with CP and PA. Improvements in the mean WOMAC and HHS scores were above or within the reported MCID. Additionally, revision rates were well below those reported in the literature for short and intermediate follow-up periods.

Enhancing the Tribological Properties of Bearing Surfaces in Hip Arthroplasty by Shot-Peening the Metal Surface

Total hip arthroplasty (THA) is a surgical procedure for patients with pain and difficulty walking due to hip osteoarthritis. In primary THA, the acetabulum and femoral head are replaced by a prosthesis where the modular femoral head and inner liner of the acetabulum form the bearing surface. The most popular bearing surface used in the United States, metal-on-polyethylene, consists of a cobalt–chromium molybdenum (CoCrMo) alloy femoral head that articulates with a polyethylene acetabular liner, typically made of highly cross-linked polyethylene. While successful in most cases, THA sometimes fails, commonly from aseptic loosening due to the wear debris of polyethylene. Fine-particle shot peening (FPSP) is a simple method for enhancing the mechanical properties and surface properties of metal, including reducing friction and enhancing the lubrication properties of the metal surface. In this study, we applied FPSP to the CoCr in the femoral head of a hip prosthesis to improve its surface properties and conducted experiments with pin-on-disc tribometers using CoCr as a pin and highly cross-linked polyethylene as a disc to mimic the THA implant. The results show that FPSP significantly enhances the tribological properties of the CoCr surface, including lubrication; decreases the friction coefficient; and decreases the polyethylene wear volume.

Mid-term outcomes of total hip arthroplasty in patients younger than 30 years.

Total hip arthroplasty (THA) has predominantly been utilized to treat older patients with primary osteoarthritis. However, recent improvements in surgical technique and implant materials have increased implant longevity, making THA a viable option for younger patients (< 30years old). While trend analyses indicate an expanding utilization of THA in younger patients with non-OA diagnoses, current data on mid- and long-term THA outcomes in this population are limited. This study aims to describe the demographics, perioperative data, and implant survivorship of patients younger than 30years undergoing THA. A retrospective study across two large urban academic medical institutions identified 135 patients aged < 30years who underwent 155 primary THAs between 2012 and 2017, with up to 10-year clinical follow-up. Baseline demographics, surgical indications, intraoperative details, and postoperative outcomes were analyzed. The mean age at surgery was 24.9 years (range 18-29). Osteonecrosis of the femoral head (55.5%), developmental hip dysplasia (28.3%), and arthritis (15.5%) were the primary indications. Most surgeries utilized the posterior approach (64.5%), manual technique (65.8%), and Ceramic-on-Polyethylene articulation (71.6%). Seven patients (4.5%) were readmitted within 90-days of surgery, including three non-orthopedic-related readmissions (1.9%) and four orthopedic-related readmissions (2.6%). Dislocations were reported in two patients (1.3%). There were six all-cause revisions (3.9%), four aseptic (2.6%) and two septic (1.3%). Kaplan-Meier analysis showed 10-year survival from implant retaining reoperation was 98.7%, 10-year survival from all-cause revision was 96.1%, and 10-year survival from aseptic revision was 97.4%. With a 10-year aseptic implant survivorship rate of 97.4%, THA is a reliable surgical intervention for patients younger than 30 years of age who have severe hip pathology. Further studies are warranted for a more comprehensive understanding of mid- and long-term survivorship risk factors in this demanding population, facilitating improved risk assessment and informed surgical decisions.

Total Hip Arthroplasty Outcomes in Patients with Gout: A Retrospective Analysis of Matched Large Cohorts.

Gout is the most prevalent form of inflammatory arthritis in the world. Total hip arthroplasty (THA) has emerged as a widely sought-after and highly effective surgical procedure for advanced hip diseases. However, there is a lack of research on the impact of gout on primary THA outcomes in large cohorts. This study aimed to address this gap by primarily investigating complications following THA in patients with or without gout. Patients with records of gout in the 2 years leading up to their primary THA and who also have at least 2 years of follow-up were identified using a national insurance database and compared to a 5:1 matched control. A total of 32,466 patients with gout and 161,514 patients without gout undergoing THA were identified. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. In addition, 90-day emergency department (ED) visits and inpatient readmission were also documented. Patients with gout demonstrated higher rates of medical complications including deep vein thrombosis, transfusion, acute kidney injury, and urinary tract infection than non-gout patients (p < 0.001). Gout patients also showed higher rates of pulmonary embolism (p = 0.017). Increased incidences of surgical complications were identified in gout patients, specifically wound complications and periprosthetic joint infection (p < 0.001). There was an increased risk of revision for gout patients up to 90 days (p = 0.003), 1 year (p = 0.027), and 2 years (p = 0.039). There was also an increased risk of dislocation for gout patients up to 90 days (p = 0.022) and 1 year (p = 0.047), but not at 2 years. No significant difference was observed in aseptic loosening or periprosthetic fracture. Additionally, gout patients also demonstrated a higher likelihood of 90-day ED visits and readmission (p < 0.001). Primary THA in gout patients is associated with increased risks of multiple medical and surgical complications. Our findings provide insights into the planning and expectation of THA for patients with gout. These insights have the potential to benefit the decision-making process for gout patients considering THA.

Favourable mid-term isokinetic strength after primary THA combined with a modified enhanced recovery after surgery concept (ERAS) in a single blinded randomized controlled trial

PurposeMuscular deficits as part of severe osteoarthritis of the hip may persist for up to two years following total hip arthroplasty (THA). No study has evaluated the mid-term benefit of a modified enhanced-recovery-after-surgery (ERAS) concept on muscular strength of the hip in detail thus far. We (1) investigated if a modified ERAS-concept for primary THA improves the mid-term rehabilitation of muscular strength and (2) compared the clinical outcome using validated clinical scores.MethodsIn a prospective, single-blinded, randomized controlled trial we compared patients receiving primary THA with a modified ERAS concept (n = 12, ERAS-group) and such receiving conventional THA (n = 12, non-ERAS) at three months and one year postoperatively. For assessment of isokinetic muscular strength, a Biodex-Dynamometer was used (peak-torque, total-work, power). The clinical outcome was evaluated by using clinical scores (Patient-Related-Outcome-Measures (PROMs), WOMAC-index (Western-Ontario-and-McMaster-Universities-Osteoarthritis-Index), HHS (Harris-Hip-Score) and EQ-5D-3L-score.ResultsThree-months postoperatively, isokinetic strength (peak-torque, total-work, power) and active range of motion was significantly better in the modified ERAS group. One year postoperatively, the total work for flexion was significantly higher than in the Non-ERAS group, whilst peak-torque and power did not show significant differences. Evaluation of clinical scores revealed excellent results at both time points in both groups. However, we could not detect any significant differences between both groups in respect of the clinical outcome.ConclusionWith regard to muscular strength, this study supports the implementation of an ERAS concept for primary THA. The combination with a modified ERAS concept lead to faster rehabilitation for up to one-year postoperatively, reflected by significant higher muscular strength (peak-torque, total-work, power). Possibly, because common scores are not sensitive enough, the results are not reflected in the clinical outcome. Further larger randomized controlled trials are necessary for long-term evaluation.

Readmissions at 30 Days and 1 Year for Implant-Associated Complications Following Primary Total Hip and Knee Arthroplasty: A Population-Based Study of 34,392 Patients Across Austria

BackgroundThe primary aim of this study was to assess 30-day and 1-year rates for unplanned readmission due to implant-associated complications following total hip (THA) or total knee arthroplasty (TKA) in Austria. Secondary endpoints were reasons for readmission and differences in revision risk depending on demographics and hospital size. MethodsData on patients receiving THA (n = 18,508) or TKA (n = 15,884) in orthopaedic and trauma units across Austria within a 1-year period (January 2021 to December 2021) were retrieved from a government-maintained database. The absolute and relative frequencies of unplanned readmissions were calculated. Risk factors for 30-day and 1-year readmission following THA or TKA due to implant-associated complications were investigated. ResultsThe 30-day and 1-year readmission rates for any implant-associated complication were 1.0% (339 of 34,392) and 3.0% (1,024 of 34,392), respectively. Relative to the overall readmission rate for any complication at 30 days (n = 1,952) and 1 year (n = 12,109), readmission rates for implant-associated complications were 17.4 and 8.5%, respectively. The 30-day readmission rates were higher in THA (1.2%) than TKA patients (0.8%; P = 0.001), while it was the opposite at 1 year (THA, 2.7%; TKA, 3.3%; P < 0.001). Mechanical complications (554 of 1,024) were the most common reason for 1-year readmission. Prolonged length of in-hospital stay independently associated with increased 1-year readmission risk in THA and TKA patients. Treatment at large-sized hospitals was associated with a higher 1-year readmission risk in TKA patients. ConclusionsThe 30-day and 1-year readmission rates for implant-associated complications following THA or TKA in Austria are lower than reported in other countries, with similar risk factors and reasons for readmission. Considering that almost 20% of unplanned hospital readmissions following total joint arthroplasty are attributable to implant-associated complications, optimization of in-hospital and postdischarge medical care for these patients is warranted.

The worldwide survival rate of total hip arthroplasties is improving: a systematic comparative analysis using worldwide hip arthroplasty registers.

The aim of this study was to evaluate the development of the worldwide survival rate of primary total hip arthroplasty (THA). The hypothesis was that survival improved over the last decade in worldwide arthroplasty registers. THA registers were screened in 2022 and compared between different countries with respect to the number of primary implantations per inhabitant, age, fixation type, and survival rate, and compared to similar data from 2009. The data from these reports were analyzed in terms of number, age distribution, and procedure type of primary THAs. Survival curves and a comparative analysis with respect to the development over time were calculated. We identified nine hip arthroplasty registers that contained sufficient data to be included. A large variation was found in the annual number of primary THA implantations per inhabitant, with more than the factor 4 for all age groups across regions. The procedure type varied strongly as well, e.g. in Sweden, 50% were cemented THAs, whereas in Emilia-Romagna (Italy), 96% of THAs were implanted cementless. We found an improved survival rate of 5%, with 90% of survival after 15 years in the cohorts from 2021 compared to 85% in the cohorts from 2009. The present study revealed a significant improvement in the survival of THA in worldwide arthroplasty registers within different countries and regions over the period of one decade. We believe that it is safe to state that the success of THA is still rising with respect to this main outcome.