Variation in Demographics, Hospital, and Patient-Reported Outcomes following Total Hip Arthroplasty According to Biological Sex.

BACKGROUND: The effect of biological sex on the outcomes of total hip arthroplasty (THA) remains unclear. Accounting for biological sex in research is crucial for reproducibility and accuracy. Average combined data may mask sex-related variation and obscure clinically relevant differences in outcomes. The aim of this study is to investigate hospital and patient-reported outcome measures (PROMs) after THA by biological sex to elucidate differences and ultimately provide more equitable care. METHODS: We performed a retrospective review of patients undergoing primary THA at a single large academic center between January 2013 and August 2020. Demographics, operative variables, hospital outcomes, and PROMs were compared between men and women patients. The PROMs included preoperative, 6-week, 6-month, and 1-year Single Assessment Numeric Evaluation (SANE), Visual Analog Scale (VAS), Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR), University of California, Los Angeles (UCLA), and Patient-Reported Outcomes Measurement Information System (PROMIS) mental and physical scores, as well as satisfaction scores. RESULTS: A total of 6,418 patients were included (55% women). Women were older (P < 0.001), had a lower body mass index (P < 0.001), and were more likely to have public insurance (P < 0.001). Fewer women were discharged to home or self-care (P < 0.001). Women had higher rates of cementation (P < 0.001) and fracture within 90 days (P < 0.001), and these associations remained significant with adjusted multivariable analyses. Women had significantly higher pain and lower functional scores preoperatively; postoperatively, most PROMs were equivalent. CONCLUSION: Important differences were observed in several areas. Demographic parameters differed, and a variable effect of biological sex was observed on surgical and hospital outcomes. Women had an increased incidence of cemented femoral components (indicated for osteoporotic bone) and postoperative fractures. Women's PROMs demonstrated globally lower functional scores and higher pain preoperatively. Differences attributed to sex should continue to be investigated and accounted for in risk-stratification models. Future studies are needed to elucidate the underlying causes of observed biological sex differences and are essential for equitable arthroplasty care.

A Systematic Review of Retracted Publications in Clinical Orthopaedic Research.

BACKGROUND: Retracted publications are an often-overlooked issue affecting the scientific community, and recent data confirms the overall number of retracted publications is rising. While this has previously been looked at within orthopaedic surgery, a contemporary understanding of retractions is required due to the rapid expansion in publications. Our study aimed to assess the retracted publications within clinical orthopaedic research to evaluate for characteristics and trends. METHODS: A systematic review was conducted on December 14, 2023, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. There were 4 databases that were queried to identify retracted publications in clinical orthopaedics that assessed operative and nonoperative orthopaedic interventions (excluding basic science). Articles were independently screened by 2 reviewers; those meeting the inclusion criteria were evaluated for various characteristics, including reasons for retraction based on Committee on Publication Ethics guidelines. RESULTS: There were 233 studies that met the inclusion criteria and were retracted between January 1, 1990, and December 14, 2023. Clinical orthopaedics represented 1.18% of all retracted publications identified through PubMed over this period. There were 87 articles that were retracted in 2023, up from 17 in 2022 (a 412% increase). Retracted studies were published in journals with 2022 impact factors up to 9.3, with an average of 3.1 (SD [standard deviation] 1.9). A total of 39.5% of the retracted studies were published in orthopaedic journals, and 60.9% of the retracted articles were published in exclusively open-access journals. The mean time from electronic publication to retraction was 2.1 years (SD 2.2). Retracted articles have been cited up to 180 times (mean 8.6; SD 20). Reasons for retraction included misconduct (45.9%), plagiarism (11.6%), redundant publication (11.6%), unethical research (10.3%), error (9.4%), and others (10.7%). CONCLUSIONS: The prevalence of retractions in the clinical orthopaedic literature is increasing. Clinical research is the basis for clinical practice guidelines, the gold standard for informing medical decision-making. Retractions may be one harbinger of lower-quality publications; researchers, institutions, and journals together play important roles in maintaining scientific integrity.

Bilateral Total Hip Arthroplasty: Outcomes of Staged Versus Simultaneous Procedures Performed Using an Anterior-Based Muscle-Sparing Approach.

BACKGROUND: The incidence of total hip arthroplasty (THA) in the United States continues to increase due to its ability to markedly improve patients' quality of life. This study investigated and compared the perioperative and postoperative outcomes of simultaneous (SI-THA) and staged (ST-THA) bilateral THA procedures using an anterior-based muscle-sparing (ABMS) approach. METHODS: This retrospective case control study evaluated perioperative and postoperative outcomes from primary bilateral SI-THA or ST-THA (within 365 days) performed with the ABMS approach by 3 surgeons at a single institution between January 2013 and August 2020. A total of 226 patients (113 in each cohort) were matched based on age, sex, body mass index, and comorbidity score. RESULTS: Compared to the ST-THA group, the SI-THA had shorter anesthesia duration (P < .001) and shorter length of stay (P < .001), but longer length of surgery (P = .002). There was no statistical significance between groups in blood transfusion rates, discharge dispositions, emergency department visits, hospital readmissions, or postoperative complications within one year. CONCLUSIONS: The results of this study demonstrate that SI-THA and ST-THA yield comparable results using the ABMS approach. Our perioperative and postoperative results suggest low rates of complications, emergency department visits, readmissions, and high rates of patient satisfaction scores. Therefore, both SI-THA and ST-THA can be considered by experienced surgeons as treatment for advanced bilateral hip arthritis.

High Incidence of Mechanically Assisted Crevice Corrosion at 10 Years in Non-Cemented, Non-Recalled, Contemporary Total Hip Arthroplasties.

BACKGROUND: One percent to 3% of contemporary non-cemented total hip arthroplasties (THAs) present with symptomatic mechanically assisted crevice corrosion (MACC). The incidence of this problem, however, as well as the rate of asymptomatic elevations in serum cobalt, is unknown. METHODS: Cobalt and chromium levels were obtained in conjunction with radiographs at routine 10-year surveillance follow-up of THAs from a single manufacturer with a titanium stem, cobalt alloy femoral head, and cross-linked polyethylene countersurface. RESULTS: Ten-year follow-up of patients with 162 consecutive THAs revealed that 17 patients with 18 hips had died of unrelated causes prior to metal ion testing. Two hips were revised for other reasons, and of the remaining 142 hips, 33 were in patients who were lost, leaving 109 hips (77% of those in alive patients and unrevised for other reasons and 67% of the entire cohort) for investigation. Sixty-three patients (58%) had a serum cobalt less than 1 ppb, and 35 (32%) a cobalt of ≥1 ppb, a cutoff consistent with MACC. Of the 32 hips with definite MACC, 15 of 32 (47%) patients were symptomatic, 16 of 30 (53%) patients had adverse local tissue reaction on magnetic resonance imaging, and 19 of 32 (59%) patients have undergone revision surgery for MACC to date. CONCLUSION: At 10-year follow-up, a minimum of 22% (35/162) of hips had a cobalt level more than 1 ppb, consistent with MACC. Symptoms and adverse local tissue reactions are each present about one-half of the time, and 59% of those with documented MACC have undergone revision.

No Consensus for Femoral Head Impaction Technique in Surgeon Education Materials From Orthopedic Implant Manufacturers.

BACKGROUND: Prior studies indicate that one factor that may contribute to total hip arthroplasty failure due to mechanically assisted crevice corrosion at the femoral head-trunnion junction is the method of femoral head fixation. METHODS: Up-to-date on-line surgical technique guides describing fixation of the prosthetic femoral head of common implants of the 4 largest manufacturers as well as 2 minor manufacturers were identified. The information given regarding preparation and fixation of the femoral head was evaluated and compared. RESULTS: A total of 24 surgical technique guides were evaluated. Most guides (22/24) addressed fixation technique; of these, 19 of 22 suggested cleaning and 20 of 22 suggested drying the trunnion prior to affixing the femoral head. The manner of fixation, however, varied widely and there was no single technique advocated. CONCLUSION: The majority of surgeon education materials do not specify a single technique for assembly of the head femoral component in total hip arthroplasty. If the method of fixation is indeed important, efforts should be made to identify the best technique, and improve and unify the surgical technique instructions.

High Early Major Complication Rate After Revision for Mechanically Assisted Crevice Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Failed total hip arthroplasty caused by mechanically assisted crevice corrosion (MACC) has serious consequences such as adverse local tissue reaction. Revision is currently indicated for significant hip pain, stiffness, and dysfunction; hip instability; progressive bone loss; and soft tissue destruction. Outcomes of this revision surgery are not yet completely understood. METHODS: We examined the surgical outcomes at a minimum of 6 months (average, 25; range, 7-68 months) in a cohort of 27 consecutive patients who underwent revision total hip arthroplasty for MACC associated with a single implant vendor and taper type. RESULTS: Major orthopedic complications occurred in 7 of 27 patients (25.9%), each after the original revision surgery. Five additional major complications occurred in subsequent surgeries. Postoperative hip dislocation occurred in 6 of 27 (22.2%), deep infection occurred in 3 of 27 (11.1%), and aseptic acetabular loosening, seroma requiring irrigation and debridement, pulmonary embolism, periprosthetic fracture, and reintubation each occurred in 1 of 27 (3.7%). Harris hip scores improved significantly with surgery (P = .0002), but overall, scores were lower for those who had major complications (70.9 vs 89.2), and only 20 of 27 patients (74.1%) had good or excellent outcomes. CONCLUSION: Symptomatic MACC is a potentially devastating diagnosis, because of decreased soft tissue and bone viability associated with adverse local tissue reaction. This leads to a high early major complication rate.

Ten-Year Cross-Sectional Study of Mechanically Assisted Crevice Corrosion in 1352 Consecutive Patients With Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Mechanically assisted crevice corrosion (MACC) in metal-on-polyethylene total hip arthroplasty (THA) is of concern, but its prevalence, etiology, and natural history are incompletely understood. METHODS: From January 2003 to December 2012, 1352 consecutive THA surgeries using a titanium stem, cobalt-chromium alloy femoral head, and highly cross-linked polyethylene liner from a single manufacturer were performed. Patients were followed at 1-year and 5-year intervals for surveillance, but also seen earlier if they had symptoms. Any patient with osteolysis >1 cm (n = 3) or unexplained pain (n = 85) underwent examination, radiographs, complete blood count, erythrocyte sedimentation rate, and C-reactive protein, as well as tests for serum cobalt and chromium levels. RESULTS: Symptomatic MACC was present in 43 of 1352 patients (3.2%). Prevalence of MACC by year of implant ranged from 0% (0 of 61, 2003; 0 of 138, 2005) to 10.5% (17 of 162; 2009). The M/L Taper stem had a greater prevalence (4.9%) of MACC than all other Zimmer (Zimmer, Inc, Warsaw, IN) 12/14 trunnion stem types combined (1.2%; P < .001). Twenty-seven of 43 (62.8%) patients have undergone revision surgery, and 16 of 43 (37.2%) patients have opted for ongoing surveillance. Comparing symptomatic THA patients with and without MACC, no demographic, clinical, or radiographic differences were found. MACC was significantly more common in 0 length femoral heads (compared with both -3.5 mm and +3.5 mm heads). CONCLUSION: The prevalence of MACC in metal-on-polyethylene hips is higher in this cross-sectional study than previously reported. A significantly higher prevalence was found in patients with M/L Taper style stem and THA performed both in 2009 and also between 2009 and 2012 with this manufacturer.

Elevated Intra-Articular Cobalt and Chromium Levels in Mechanically Assisted Crevice Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Failed total hip arthroplasty (THA) caused by mechanically assisted crevice corrosion (MACC) has serious consequences such as adverse local tissue reaction (ALTR). Serum cobalt (Co) and chromium (Cr) ion levels have been used to diagnose taper corrosion, but have not been shown to be an accurate measure of the severity of MACC or associated ALTRs. Additionally, elevated serum ions are not specific in patients with multiple artificial joints. METHODS: We examined the relationship between serum and intra-articular (IA) Co and Cr levels in a cohort of 20 patients undergoing revision THA, 16 who had symptomatic MACC. IA Co and Cr levels in MACC patients were compared with demographic, pre-operative, and operative findings. RESULTS: Serum and IA metal levels were found to be relatively low in THA patients undergoing revision surgery for isolated instability, aseptic loosening, or infection (average serum Co 0.03 ppb [parts per billion], IA Co 1.4 ppb, serum Cr 0.32 ppb, IA Cr 3.3 ppb). In patients with MACC, average IA Co (940 ppb) was significantly higher than serum Co (5.1 ppb) (P = .0003) and IA Cr (491 ppb) was significantly higher than serum Cr (1.3 ppb) (P = .0003). IA Co level was associated with shorter time of hip symptoms to revision surgery (P = .0043). CONCLUSION: Serum levels of Co and Cr correlated with joint levels in the entire cohort, but IA levels of MACC patients were 100 times greater than serum levels. IA Co and Cr levels may be useful in confirming MACC in a specific joint and the striking elevation may explain symptoms and ALTR with relatively low serum values.

Comparison of Pre-Revision Magnetic Resonance Imaging and Operative Findings in Mechanically Assisted Crevice Corrosion in Symptomatic Metal-on-Polyethylene Total Hip Arthroplasties.

BACKGROUND: Failed total hip arthroplasty (THA) caused by mechanically assisted crevice corrosion (MACC) has serious consequences-notably, adverse local tissue reactions. Metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) has been used to evaluate failed THA for other reasons but has not been assessed for the analysis of cases of MACC in the setting of metal-on-polyethylene arthroplasties. METHODS: We examined the correlation between preoperative MARS MRI and surgical findings in a cohort of 20 consecutive patients undergoing revision THA for symptomatic MACC without other associated orthopedic diagnoses. Surgical findings included soft tissue and bone evaluation, presence and location of fluid, abductor disruption, composite tissue damage grade, and prosthesis trunnion damage at the time of revision. RESULTS: MARS MRI complex synovitis, thickened pseudocapsule, and extra-articular fluid extension each strongly correlated with both the soft-tissue damage grade and trunnion damage noted at surgery. Bone marrow edema was also found to strongly correlate with bone necrosis intraoperatively. CONCLUSION: MARS MRI is an excellent diagnostic tool for evaluation of patients with elevated serum Co after metal-on-polyethylene THA. Patients with complex synovitis, a thick pseudocapsule, bone marrow edema, and extra-articular fluid should strongly consider revision surgery.

Treatment of Arthritis Associated With Legg-Calve-Perthes Disease With Modular Total Hip Arthroplasty.

Legg-Calve-Perthes (LCP) disease can result in morphological deformities and associated adult hip arthritis. Thirty-five consecutive total hip arthroplasties (THA) were performed in 28 patients with a history of LCP using a non-cemented modular femoral component. There was one revision for late hematogenous infection and no evidence of prosthesis failure. Harris hip scores, on average, improved from 49.8 (26-73) to 93.9 (82-100) (P<0.05) after a minimum of 2 years follow-up (average, 8.2 years, range 2-14 years). Clinically, patients demonstrated diminished or no limping (94%, 33/35) and improved leg length equality post-operatively (100%, 35/35). This style of stem accommodated metaphyseal/diaphyseal size mismatch in 80% (28/35), allowed for abnormal anteversion in 71% (25/35), and resulted in radiographic improvements in trochanteric height (P<0.05), body weight lever arm (P<0.05), and leg length (P<0.05).

A High Prevalence of Corrosion at the Head-Neck Taper with Contemporary Zimmer Non-Cemented Femoral Hip Components.

Mechanically assisted crevice corrosion (MACC) occurs at metal/metal modular junctions in which at least one of the components is fabricated from cobalt-chromium alloy and may lead to adverse local tissue reaction (ALTR) in patients with metal-on-polyethylene (MoP) total hip arthroplasty. This type of reaction has been previously described in hips with head/neck modularity, but the prevalence is unknown. We found a prevalence of 1.1 percent in a consecutive series of 1356 contemporary Zimmer non-cemented femoral hip components followed for a minimum of 2years. The average time to presentation was 3.7years (range, 9-105months); delay in treatment led to irreversible soft tissue damage in three patients. We recommend usage of ceramic heads until this problem is further understood.

Current Orthopaedic Surgeon Practices for Nonarthroplasty Treatment of Osteoarthritis of Adult Hip and Knee.

Evidence-based guidelines have recently been published for the nonarthroplasty treatment of osteoarthritis of the hip and knee and are becoming an expected part of comprehensive patient care. To understand how current treatment practices correlate with these guidelines, a survey was administered to 50 consecutive hip replacement and 50 consecutive knee replacement patients immediately before arthroplasty for osteoarthritis in one group practice. This article is a compilation of patients' usage of the modalities suggested in two such exemplary guidelines and demonstrates that patient and surgeon preferences, as well as factors such as preoperative Oxford score, body mass index, age, and joint involved, affect usage of one or more of the commonly employed preoperative modalities. This information provides orthopaedic surgeons and administrators with a compilation of responses that reflects surgeon and patient preferences for treatment before surgery.

Treatment of Postoperative Instability Following Total Knee Arthroplasty in Patients With Parkinson's Disease.

Acute postoperative posterior total knee arthroplasty (TKA) dislocation is rare in primary surgery but has been associated with Parkinson's disease (PD). We present a 77-year-old woman with knee arthritis and PD who sustained an acute, recurrent TKA posterior dislocation, recalcitrant to polyethylene upsizing. Transient stability was obtained for a period of 1 year after postoperative hamstring injection with botulinum toxin A and short-term immobilization. Spontaneous instability recurred after 1 year, and stability was obtained with revision to a more constrained construct and has been monitored over a period of 2 years. This is the first report demonstrating the use of botulinum toxin A for acute posterior TKA instability associated with PD. We endorse the necessity of increased constraint to maintain long-term stability in patients with Parkinson's disease.

The Association of Season of Surgery and Patient Reported Outcomes following Total Hip Arthroplasty.

Background: Understanding the impact of situational variables on surgical recovery can improve outcomes in total hip arthroplasty (THA). Literature examining hospital outcomes by season remains inconclusive, with limited focus on patient experience. The aim of this study is to investigate if there are differences in hospital and patient-reported outcomes measures (PROMS) after THA depending on the season of the index procedure to improve surgeon preoperative counseling. Methods: A retrospective chart review was performed on patients undergoing primary THA at a single large academic center between January 2013 and August 2020. Demographic, operative, hospital, and PROMs were gathered from the institutional electronic medical record and our institutional joint replacement outcomes database. Results: 6418 patients underwent primary THA and met inclusion criteria. Of this patient population, 1636 underwent surgery in winter, 1543 in spring, 1811 in summer, and 1428 in fall. PROMs were equivalent across seasons at nearly time points. The average age of patients was 65 (+/- 10) years, with an average BMI of 29.3 (+/- 6). Rates of complications including ED visits within 30 days, readmission within 90 days, unplanned readmission, dislocation, fracture, or wound infection were not significantly different by season (P > .05). Conclusion: Our findings indicate no differences in complications and PROMs at 1 year in patients undergoing THA during 4 distinct seasons. Notably, patients had functional differences at the second follow-up visit, suggesting variation in short-term recovery. Patients could be counseled that they have similar rates of complications and postoperative recovery regardless of season.

Outcomes of the Anterior-Based Muscle-Sparing Approach in Elective Total Hip Arthroplasty in Nonagenarians.

Background: As the population ages, total hip arthroplasty has become more common in elderly patients including patients over the age of 90 years. Efficacy in this age group has been established, though literature regarding safety of total hip arthroplasty in nonagenarians is mixed. The anterior-based muscle-sparing (ABMS) approach, which exploits the intermuscular plane between the tensor fasciae latae and the gluteus medius, has proposed benefits of fast recovery, excellent stability, and reduced bleeding and may be adventitious among elderly, more fragile patients. Methods: A total of 38 consecutive nonagenarians undergoing elective, primary total hip arthroplasty via the ABMS approach for any indication from 2013 to 2020 were identified, and information regarding operative outcomes and patient-reported outcomes was gathered from review of medical records and our institutional joint replacement outcomes database. Results: Included patients ranged from 90 to 97 years of age with the majority classified as American Society of Anesthesiologists score 2 (50%) or American Society of Anesthesiologists 3 (47.4%). The mean operative time was 74.6 minutes ± 13.6 minutes. Of all patients, 5 required a transfusion, 2 patients were readmitted within 90 days, and there were no major complications. The mean hospital length of stay was 2.8 days ± 0.8 days with 22 patients (57.9%) discharged to a skilled nursing facility. Limited patient-reported outcomes data showed statistically significant improvements in most outcomes scores at 6 months to 1 year postoperatively compared to preoperative scores. Conclusions: The ABMS approach is safe and effective in nonagenarians who may benefit from decreased amounts of bleeding and recovery times associated with the ABMS approach, which is evident from the low complication rates, relatively short hospital lengths of stay, and acceptable transfusion rates compared to previous studies.

Rural-Urban Differences in Hospital and Patient-Reported Outcomes Following Total Hip Arthroplasty.

Background: Rural patients have unique health-care factors influencing outcomes of arthroplasty, hypothetically putting these patients at increased risk for complications following total joint arthroplasty. The aim of this study is to better understand differences in patient outcomes and satisfaction between rural and urban patients receiving care in an urban setting and to provide more equitable care. Methods: A retrospective chart review was performed on patients undergoing primary total hip arthroplasty at a single large academic center between January 2013 and August 2020. Demographic, operative, and hospital outcomes were obtained from the institutional electronic medical record. Rurality was determined by rural-urban code (RUC) classifications by zip code with RUC codes 1-3 defined as urban and RUC 4-10 defined as rural. Results: Patients from urban areas were more likely to visit the emergency department within 30 days postoperatively (P = .006) and be readmitted within 90 days (P < .001). However, unplanned (P < .001) admissions were higher in the rural group. There was no statistical difference in postoperative complications (P = .4). At 6 months, rural patients had higher patient-reported outcome measures (PROMs) including Hip Disability and Osteoarthritis Outcome Score total (P = .05), Hip Disability and Osteoarthritis Outcome Score interval (P = .05), self-reported functional improvement (P < .05), improvements in pain (P < .05), and that the surgery met expectations (P < .05). However, these values did not reach minimal clinically important difference. Conclusions: There may be differences in emergency department visits, readmissions, and PROMs in rural vs urban populations undergoing total hip arthroplasty in an urban setting. Patient access to care and attitudes of rural patients toward health care may underlie these findings. Understanding differences in PROMs, satisfaction, and hospital-based outcomes based on rurality is essential to provide equitable arthroplasty care.

Comparison of surface characteristics of retrieved cobalt-chromium femoral heads with and without ion implantation.

Nitrogen ion implantation of CoCr is reported to produce increased surface hardness and a lower friction surface. Femoral heads with and without ion implantation retrieved from 1997 to 2003 were evaluated for surface roughness (average surface roughness [Ra], mean peak height [Rpm], and maximum distance from peak to valley [Rmax]), nanohardness, and the ion-treated layer thickness. The difference in average Rmax (P = .033) and average Rpm (P = .008) was statistically significant, but there was no correlation between the average or maximum roughness parameters (average surface roughness, Rmax, and Rpm) and time in vivo (P > .05). Overall, nanohardness was greater for the low-friction ion-treated heads (P < .001); and it decreased with increasing time in vivo (P = .01). Ion treatment produces an increased surface hardness, but the advantage of this increased hardness appears to dissipate over time in vivo.

Late Hematogenous Total Hip Infection After Revision for Mechanically Assisted Crevice Corrosion With Adverse Local Tissue Reaction.

Mechanically assisted crevice corrosion (MACC) at the trunnion-bore junction of a total hip arthroplasty may cause adverse local tissue reaction (ALTR) with inflammatory reaction and tissue necrosis. Complications, including acute infection, continued pain, and instability, are therefore common after a revision surgery for MACC. We now present 2 cases of late hematogenous bacterial infection years after revision for MACC and ALTR, a previously unreported outcome in this population. We hypothesize that MACC-induced tissue necrosis does not heal over time, and some patients with metal-on-polyethylene total hip arthroplasty treated for ALTR are at long-term risk of hematogenous bacterial infection.