Quasi-static mechanical evaluation of canine cementless total hip replacement broaches: effect of tooth design on broach and stem insertion.

BACKGROUND: Biomedtrix BFX® cementless total hip replacement (THR) requires the use of femoral broaches to prepare a press-fit envelope within the femur for subsequent stem insertion. Current broaches contain teeth that crush and remove cancellous bone; however, they are not particularly well-suited for broaching sclerotic (corticalized) cancellous bone. In this study, three tooth designs [Control, TG1 (additional V-grooves), TG2 (diamond tooth pattern)] were evaluated with a quasi-static testing protocol and polyurethane test blocks simulating normal and sclerotic bone. To mimic clinical broaching, a series of five sequential broach insertions were used to determine cumulative broaching energy (J) and peak loads during broach insertion. To determine the effect of broach tooth design on THR stem insertion, a BFX® stem was inserted into prepared test blocks and insertion and subsidence energy and peak loads were determined. RESULTS: Broach tooth design led to significant differences in broaching energy and peak broaching loads in test blocks of both densities. In low density test blocks, TG1 required the lowest cumulative broaching energy (10.76 ±0.29 J), followed by Control (12.18 ±1.20 J) and TG2 (16.66 ±0.78 J) broaches. In high density test blocks, TG1 required the lowest cumulative broaching energy (32.60 ±2.54 J) as compared to Control (33.25 ±2.16 J) and TG2 (59.97 ±3.07 J).  During stem insertion and subsidence testing, stem insertion energy for high density test blocks prepared with Control broaches was 14.53 ± 0.81 J, which was significantly lower than blocks prepared with TG1 (22.53 ± 1.04 J) or TG2 (19.38 ± 3.00 J) broaches. For stem subsidence testing in high density blocks, TG1 prepared blocks required the highest amount of energy to undergo subsidence (14.49 ± 0.49 J), which was significantly greater than test blocks prepared with Control (11.09 ±0.09 J) or TG2 (12.57 ± 0.81 J) broaches. CONCLUSIONS: The additional V-grooves in TG1 broaches demonstrated improved broaching performance while also generating press-fit envelopes that were more resistant to stem insertion and subsidence. TG1 broaches may prove useful in the clinical setting; however additional studies that more closely simulate clinical broach impaction are necessary prior to making widespread changes to THR broaches.

Fascia iliaca compartment block for postoperative pain after total hip arthroplasty: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Fascia iliaca compartment block (FICB) is one of the regional nerve blocks used to reduce pain after total hip arthroplasty (THA). We aim to assess the efficacy of FICB in reducing post-operative pain and opioid consumption. METHODS: We searched PubMed, Web of Science, Cochrane Library, Embase, and Scopus on February 19, 2023, and we updated our search in august 2023 using relevant search strategy. Studies were extensively screened for eligibility by title and abstract screening, followed by full-text screening. We extracted the data from the included studies, and then pooled the data as mean difference (MD) or odds ratio (OR) with a 95% confidence interval (CI), using Review Manager Software (ver. 3.5). RESULTS: FIBC significantly reduced analgesic consumption at 24 h (MD = -8.75, 95% CI [-9.62, -7.88] P < 0.00001), and at 48 h post-operatively. (MD = -15.51, 95% CI [-26.45, -4.57], P = 0.005), with a significant sensory block of the femoral nerve (P = 0.0004), obturator nerve (P = 0.0009), and lateral femoral cutaneous nerve (P = 0.002). However, FICB was not associated with a significant pain relief at 6, 24, and 48 h postoperatively, except at 12 h where it significantly reduced pain intensity (MD = -0.49, 95% CI [-0.85, -0.12], P = 0.008). FICB was also not effective in reducing post-operative nausea and vomiting (MD = 0.55, 95% CI [0.21, 1.45], P = 0.23), and was associated with high rates of quadriceps muscle weakness (OR = 9.09, % CI [3.70, 22.30], P = < 0.00001). CONCLUSIONS: FICB significantly reduces the total analgesic consumption up to 48 h; however, it is not effective in reducing post-operative pain, nausea and vomiting and it induced postoperative muscle weakness.

Comparison of acute outcomes from elective total hip replacements and after fragility femoral neck fractures in nonagenarians.

BACKGROUND: Hip hemiarthroplasty has traditionally been used to treat displaced femoral neck fractures in older, frailer patients whilst total hip replacements (THR) have been reserved for younger and fitter patients. However, not all elderly patients are frail, and some may be able to tolerate and benefit from an acute THR. Nonagenarians are a particularly heterogenous subpopulation of the elderly, with varying degrees of independence. Since THRs are performed electively as a routine treatment for osteoarthritis in the elderly, its safety is well established in the older patient. The aim of this study was to compare the safety of emergency THR to elective THR in nonagenarians. METHODS: A retrospective 10-year cohort study was conducted using data submitted to the National Hip Fracture Database (NHFD) across three hospitals in one large NHS Trust. Data was collected from 126 nonagenarians who underwent THRs between 1st January 2010 - 31st December 2020 and was categorised into emergency THR and elective THR groups. Mortality rates were compared between the two groups. Secondary outcomes were also compared including postoperative complications (dislocations, revision surgeries, and periprosthetic fracture), length of stay in hospital, and discharge destination. RESULTS: There was no significant difference in mortality between the two groups, with 1-year mortality rates of 11.4% and 12.1% reported for emergency and elective patients respectively (p = 0.848). There were no significant differences in postoperative complication rate and discharge destination. Patients who had emergency THR spent 5.56 days longer in hospital compared to elective patients (p = 0.015). CONCLUSION: There is no increased risk of 1-year mortality in emergency THR compared to elective THR, in a nonagenarian population. Therefore, nonagenarians presenting with a hip fracture who would have been considered for a THR if presenting on an elective basis should not be precluded from an emergency THR on safety grounds. TRIAL REGISTRATION: Not necessary as this was deemed not to be clinical research, and was considered to be a service evaluation.

Establishment and validation of a nomogram to predict postoperative anemia after total hip arthroplasty.

BACKGROUND: Anemia is a common complication of total hip arthroplasty (THA). In this study, we evaluated the preoperative risk factors for postoperative anemia after THA and developed a nomogram model based on related preoperative and intraoperative factors. METHODS: From January 2020 to May 2023, 927 THA patients at the same medical center were randomly assigned to either the training or validation cohort. The correlation between preoperative and intraoperative risk factors and postoperative anemia after THA was evaluated using univariate and multivariate logistic regression analysis. A nomogram was developed using these predictive variables. The effectiveness and validation for the clinical application of this nomogram were evaluated using the concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA). RESULTS: Through univariate and multivariate logistic regression analysis, 7 independent predictive factors were identified in the training cohort: Lower body mass index (BMI), extended operation time, greater intraoperative bleeding, lower preoperative hemoglobin level, abnormally high preoperative serum amyloid A (SAA) level, history of cerebrovascular disease, and history of osteoporosis. The C-index of the model was 0.871, while the AUC indices for the training and validation cohorts were 84.4% and 87.1%, respectively. In addition, the calibration curves of both cohorts showed excellent consistency between the observed and predicted probabilities. The DCA curves of the training and validation cohorts were high, indicating the high clinical applicability of the model. CONCLUSIONS: Lower BMI, extended operation time, increased intraoperative bleeding, reduced preoperative hemoglobin level, elevated preoperative SAA level, history of cerebrovascular disease, and history of osteoporosis were seven independent preoperative risk factors associated with postoperative anemia after THA. The nomogram developed could aid in predicting postoperative anemia, facilitating advanced preparation, and enhancing blood management. Furthermore, the nomogram could assist clinicians in identifying patients most at risk for postoperative anemia.

Surgeon handedness affects the acetabular cup positioning during primary total hip arthroplasty regardless of the surgical approach. a systematic review and metanalysis.

PURPOSE: The aim was to investigate the effect of surgeon handedness on acetabular cup positioning, functional outcomes, and dislocation incidence during primary THA. METHODS: A systematic review was conducted according to the PRISMA guidelines. Studies published in English were searched in three databases (PubMed, Embase, and Scopus). A dominant side is a right-handed (RHD) or left-handed (LHD) surgeon who operates on the right or left hip, respectively. The opposite is considered to be the non-dominant side. We used odds ratios for dichotomous data and mean differences for continuous data, with 95% confidence intervals for quantitative data synthesis. Heterogeneity was assessed using the I² test, with outcomes graphically represented in a forest plot and a p-value of < 0.05 considered statistically significant; analyses were performed using Review Manager 5.4 (RevMan 5.4.1). >. RESULT: Four observational studies were included out of 98 articles. Ten experienced surgeons participated (8 RHD and 2 LHD) and operated on 822 patients (1484 hips), divided equally between dominant and non-dominant sides, and the posterolateral approach was utilized in 80.9% of THAs. RHD surgeons operated on 1404 (94.6%) THAs. The pooled synthesis for inclination indicated no significant difference between either side [MD: 0.10 (95% CI -2.10 to 2.30, P = 0.93, I² = 91%)]. While the difference was significant for anteversion [MD: -2.37 (95% CI -3.82 to -0.93, P = 0.001, I² = 31%)]. The functional outcome was better on the dominant side [MD: 1.44 (95% CI 0.41 to 2.48, P = 0.006, I² = 0%)], and the dislocation incidence was significantly higher on the non-dominant side [OR: 0.45 (95% CI 0.25 to 0.81, P = 0.008, I² = 0%)]. CONCLUSION: Surgeon handedness and whether operating on the dominant or non-dominant side could affect the acetabular cup positioning and outcomes during primary THAs, even in the hands of high-volume surgeons.

Orthopaedic surgeons' attitude toward physical activity for people after total hip or knee replacement: Northern vs Southern European country.

BACKGROUND: Regular physical activity (PA) is a key factor of lifestyle behavior enhancing general health and fitness, especially in people after total hip or knee replacement (THR and TKR). Orthopaedic surgeons can play a primary role in advocating the benefits of an active lifestyle. Aim of the study was 1) to assess the attitude of orthopaedic surgeons towards PA for people after THR/TKR and 2) to compare the attitude between a Northern European (the Netherlands) and a Southern European (Italy) country and analyze which factors influence the attitude towards PA. METHODS: A cross-cultural study. An (online) survey was distributed among orthopaedic surgeons in Italy and the Netherlands. Chi-square and Mann-Whitney tests were used to compare surgeons' and clinics' characteristics, and questionnaires' scores, respectively. A linear regression analysis was conducted to assess which surgeon characteristics influence attitude towards PA. RESULTS: A cohort of 159 surgeons (103 Italians and 56 Dutch) was analyzed. The median score of overall orthopaedic surgeons' attitude towards PA was positive (57 out of 72). Dutch surgeons showed a more positive attitude compared to Italian surgeons (p < 0.01). Main difference was found in the "Physical activity concern" factor, where Italian surgeons showed more concern about the negative effects of PA on the survival of the prosthesis. The regression analyses showed that "Country" and "Type of clinic" were associated with the surgeons' attitude. CONCLUSIONS: Overall, the orthopaedic surgeons' attitude towards PA for people with THR and TKR was positive. However, Dutch surgeons seem to be more positive compared to the Italian. The country of residence was the item that most influenced attitude. Further investigations are needed to untangle specific factors, such as cultural, socioeconomic, or contextual differences within the variable "country" that may influence orthopaedic surgeons' attitudes towards PA.

Hip and knee replacement in lower limb amputees: a scoping review.

BACKGROUND: There are many consequences of lower limb amputation, including altered biomechanics of gait. It has previously been shown that these can lead to increased rates of osteoarthritis (OA). A common and successful treatment for severe OA is joint replacement. However, it is unclear whether amputees undergoing this surgery can expect the same outcomes or complication profile compared with non-amputees. Furthermore, there are key technical challenges associated with hip or knee replacement in lower limb amputees. This scoping review aimed to identify and summarise the existing evidence base. METHODS: This was a systematic scoping review performed according to PRISMA guidelines. An electronic database search of MEDLINE (PubMed), Cochrane Library, EMBASE and CINAHL was completed from the date of inception to 1st April 2023. All peer reviewed literature related to hip or knee replacement among lower limb amputees was included. RESULTS: Of the 931 records identified, 40 studies were included in this study. The available literature consisted primarily of case reports and case series, with generally low level of evidence. In total, there were 265 patients of which 195 received total hip replacement (THR), 51 received total knee replacement (TKR) and 21 received hip hemiarthroplasty. The most common reason for amputation was trauma (34.2%), and the main indication for joint replacement was OA (77.1%), occurring more frequently in the contralateral limb (66.7%). The outcomes reported varied widely between studies, with most suggesting good functional status post-operatively. A variety of technical tips were reported, primarily concerned with intra-operative control of the residual limb. CONCLUSION: There is a need for more observational studies to clearly define the association between amputation and subsequent need for joint replacement. Furthermore, comparative studies are needed to identify whether amputees can be expected to achieve similar functional outcomes after surgery, and if they are at higher risk of certain complications.

Satisfactory mid-term clinical outcomes of endoscopic tenotomy for iliopsoas tendinopathy following total hip arthroplasty.

PURPOSE: To report 5-year outcomes of endoscopic iliopsoas tenotomy in patients with iliopsoas tendinopathy following total hip arthroplasty (THA) and determine whether clinical scores are associated with cup position. METHODS: Patients who underwent endoscopic iliopsoas tenotomy for iliopsoas tendinopathy following THA (2014-2017) were contacted. Indications for endoscopic iliopsoas tenotomy after THA were groin pain during active hip flexion, exclusion of other causes of groin pain, and no pain relief after 6 months of conservative treatment. Pretenotomy cup inclination and anteversion were measured on radiographs; axial and sagittal cup overhang were measured on computed tomography (CT) scans. Oxford hip score (OHS), modified Harris hip score (mHHS), and groin pain were assessed. RESULTS: The initial cohort comprised 16 men (17 hips) and 31 women (32 hips), aged 60.7 ± 10.6 years. Cup inclination and anteversion were, respectively, 46.2 ± 6.2° and 14.6 ± 8.4°, while axial and sagittal cup overhang were, respectively, 4.4 ± 4.0 mm and 6.9 ± 4.5 mm. At ≥5 years follow-up, four hips underwent cup and stem revision, two underwent isolated cup revision and one underwent secondary iliopsoas tenotomy. OHS improved by 23 ± 10 and mHHS improved by 31 ± 16. Posttenotomy groin pain was slight in 20.0%, mild in 17.5% and moderate in 12.5%. Regression analyses revealed that net change in mHHS decreased with sagittal cup overhang (ß = -3.1; 95% confidence interval [CI] = -4.6 to -1.7; p < 0.001), but that there were no associations between cup position and net change in OHS. CONCLUSIONS: Endoscopic iliopsoas tenotomy provides good mid-term clinical outcomes in patients with iliopsoas tendinopathy following THA. Furthermore, improvements in mHHS were found to decrease with increasing sagittal cup overhang, in cases for which adequate preoperative imaging was available. LEVEL OF EVIDENCE: Level IV.

Risk factors for deep vein thrombosis of the lower extremity after total hip arthroplasty.

OBJECTIVE: To investigate the risk factors for deep vein thrombosis (DVT) following total hip arthroplasty (THA). METHODS: Patients who underwent THA in the Department of Joint Surgery at the Sixth Affiliated Hospital of Xinjiang Medical University from September 2020 to December 2022 were retrospectively selected based on inclusion criteria. They were divided into the DVT group (n = 65) and the non-DVT group (n = 397) according to the occurrence of postoperative DVT. The following variables were reviewed for both groups: age, sex, Body Mass Index (BMI), affected limb, previous history (smoking and drinking), diabetes, hypertension, operation time, total cholesterol, triglycerides, fibrinogen, hemoglobin, albumin, platelets, D-dimer, International Normalized Ratio (INR), and fibrin degradation products. Univariate analysis was conducted on these factors, and those with statistical significance were further analyzed using a binary logistic regression model to assess their correlation with DVT after THA. RESULTS: A total of 462 patients were included in the study, with the DVT group representing approximately 14% and the non-DVT group approximately 86%. The DVT group had an average age of 67.27 ± 4.10 years, while the non-DVT group had an average age of 66.72 ± 8.69 years. Univariate analysis revealed significant differences in diabetes mellitus, preoperative fibrinogen, preoperative D-dimer, preoperative INR, and preoperative and postoperative fibrin degradation products between the DVT and non-DVT groups. Binary logistic regression analysis identified diabetes mellitus, elevated preoperative fibrinogen, preoperative D-dimer, and preoperative INR (p < 0.05) as risk factors for DVT after THA. CONCLUSION: This study found that diabetes mellitus, elevated preoperative fibrinogen, preoperative D-dimer, and preoperative INR are independent risk factors for DVT following THA. Surgeons should thoroughly assess these risk factors, implement timely and effective interventions, and guide patients to engage in functional exercises as early as possible to reduce the incidence of DVT, thereby improving the outcomes of THA and improving patient quality of life.

The environmental impact of hip and knee arthroplasty: An analysis of carbon emissions and disposal costs.

BACKGROUND AND PURPOSE: The rise in hip and knee arthroplasty for osteoarthritis requires addressing healthcare system pollution to support Ireland's climate change goals. This research aimed to quantify waste generated and determine environmental and economic impacts to promote sustainable strategies in joint arthroplasty and shed light on the suboptimal waste management practices. METHODS: The study was conducted at National Orthopaedic Hospital Cappagh (NOHC), measuring waste generated during hip and knee arthroplasty. Clinical, domestic, and recycled waste weights were recorded, including the segregation of Central Sterile Supply Department (CSSD) Blue Wrap waste in ten operations. Kilograms of carbon dioxide emissions (kgCO2e) and disposal costs were calculated. RESULTS: In a sample of 100 joint arthroplasty operations, the study found that revision knees produced 23.58 â€‹kgCO2e per case, revision hips 23.50 â€‹kgCO2e, primary knees 15.82 â€‹kgCO2e, and primary hips 14.64 â€‹kgCO2e. CSSD Blue Wrap contributed on average 13.5% of OT waste. Extrapolating these findings to the estimated number of joint arthroplasties performed in 2022 â€‹at NOHC (1556 hip and knee joint arthroplasties), the emissions were estimated to be 24,576 kgCO2e, with the cost of disposal up to €29,228. Strategies to mitigate this waste have been identified and proposed. CONCLUSION: The research aimed to address the environmental impact of orthopaedic joint arthroplasties, offering strategies to reduce waste generation, carbon emissions, and cost. Utilising our methodology to calculate greenhouse gas emissions will empower sustainability offices to conduct their own waste audits and implementing our strategies for waste management practices can help minimise environmental waste.

Increased Rates of Late Periprosthetic Fractures in Larger Hydroxyapatite-Coated Cementless Stems: Are Collared Stems a Better Alternative for Total Hip Arthroplasty?

BACKGROUND: Cementless hip stems are widely used for total hip arthroplasty (THA) and have demonstrated excellent survivorship. This study aimed to investigate the effects of stem size and calcar collars on rates of revision due to periprosthetic fracture. METHODS: All primary THA procedures recorded by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from September 1999 to December 2021 for a diagnosis of osteoarthritis using a single cementless hip stem with modern bearings were included. The primary outcome measure was revision due to periprosthetic fracture. Stems were divided into 2 groups for comparison, large (size 14 to 20) and small-medium (6 to 13). A subanalysis was performed for collared stems. A total of 59,518 primary THA procedures were included. RESULTS: The cumulative percent revision for periprosthetic fracture was significantly higher for large stems compared to small-medium stems (hazard ratio [HR] = 1.57 [95% confidence interval {CI} 1.18, 2.09] P = .002). Furthermore, collared stems had significantly lower revision rates due to late periprosthetic fracture compared to collarless variants (2 week + HR = 4.55 [95% CI 3.23, 6.42], P < .001). Large collarless stems were found to have greater revision rates due to fracture compared to small-medium collarless stems (HR = 1.55 [95% CI 1.13, 2.12] P = .006), but no difference was found between collared groups (HR = 1.37 [95% CI 0.68, 2.78] P = .382). CONCLUSION: Large cementless hip stems have a higher rate of revision due to periprosthetic fracture compared to small-medium stems. Using a collared stem reduces the rate of periprosthetic fracture.

Characteristics and Quality of Online Searches for Direct Anterior Versus Posterior Approach for Total Hip Arthroplasty.

BACKGROUND: Online resources are important for patient self-education and reflect public interest. We described commonly asked questions regarding the direct anterior versus posterior approach (DAA, PA) to total hip arthroplasty (THA) and the quality of associated websites. METHODS: We extracted the top 200 questions and websites in Google's "People Also Ask" section for 8 queries on January 8, 2023, and grouped websites and questions into DAA, PA, or comparison. Questions were categorized using Rothwell's classification (fact, policy, value) and THA-relevant subtopics. Websites were evaluated by information source, Journal of the American Medical Association Benchmark Criteria (credibility), DISCERN survey (information quality), and readability. RESULTS: We included 429 question/website combinations (questions: 52.2% DAA, 21.2% PA, 26.6% comparison; websites: 39.0% DAA, 11.0% PA, 9.6% comparison). Per Rothwell's classification, 56.2% of questions were fact, 31.7% value, 10.0% policy, and 2.1% unrelated. The THA-specific question subtopics differed between DAA and PA (P < .001), specifically for recovery timeline (DAA 20.5%, PA 37.4%), indications/management (DAA 13.4%, PA 1.1%), and technical details (DAA 13.8%, PA 5.5%). Information sources differed between DAA (61.7% medical practice/surgeon) and PA websites (44.7% government; P < .001). The median Journal of the American Medical Association Benchmark score was 1 (limited credibility, interquartile range 1 to 2), with the lowest scores for DAA websites (P < .001). The median DISCERN score was 55 ("good" quality, interquartile range 43 to 65), with the highest scores for comparison websites (P < .001). Median Flesch-Kincaid Grade Level scores were 12th grade level for both DAA and PA (P = .94). CONCLUSIONS: Patients' informational interests can guide counseling. Internet searches that explicitly compare THA approaches yielded websites that provide higher-quality information. Providers may also advise patients that physician websites and websites only describing the DAA may have less balanced perspectives, and limited information regarding surgical approaches is available from social media resources.

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-weeks, 6-months, and 1-year Single Assessment Numeric Evaluation, Visual Analog Scale, Hip Disability and Osteoarthritis Outcome Score Joint Replacement, University of California, Los Angeles, and Patient-Reported Outcomes Measurement Information System mental and physical scores, as well as satisfaction scores. RESULTS: A total of 6,418 patients were included (55% women). Women were older (P < .001), had a lower body mass index (P < .001), and were more likely to have public insurance (P < .001). Fewer women were discharged to home or self-care (P < .001). Women had higher rates of cementation (P < .001) and fracture within 90 days (P < .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. CONCLUSIONS: 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.

Patient-Related Predictors of Treatment Failure After Two-Stage Total Hip Arthroplasty Revision for Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Periprosthetic joint infection (PJI) treatment has high failure rates even after 2-stage revision. Risk factors for treatment failure (TF) after staged revision for PJI are not well defined, nor is it well established how they correlate with the risks of developing an index PJI. Identifying modifiable risk factors may allow preoperative optimization, while identifying nonmodifiable risk factors can influence surgical options or advise against further surgery. We performed a systematic review and meta-analysis to better define predictors of TF in 2-stage revision for PJI. METHODS: The PubMed, Embase, and Scopus databases were searched from their inception in December 1976 to April 15, 2023. Studies comparing patient-related variables between patients successfully treated who had 2-staged revision total hip arthroplasty (THA) and patients with persistent infections were included. Studies were screened, and 2 independent reviewers extracted data, while a third resolved discrepancies. Meta-analysis was performed on these data. There were 10,052 unique studies screened, and 21 studies met the inclusion criteria for data extraction. RESULTS: There was good-quality evidence that obesity, liver cirrhosis, and previous failed revisions for PJI are nonmodifiable risk factors, while intravenous drug use (IVDU) and smoking are modifiable risk factors for TF after 2-stage revision for hip PJI. Reoperation between revision stages was also significantly associated with an increased risk of TF. Interestingly, other risk factors for an index PJI including male gender, American Society of Anesthesiology score, diabetes mellitus, and inflammatory arthropathy did not predict TF. Evidence on Charlson Comorbidity Index was limited. CONCLUSIONS: Patients with a smoking history, obesity, IVDU, previous failed revision for PJI, reoperation between stages, and liver cirrhosis are more likely to experience TF after 2-stage revision THA for PJI. Modifiable risk factors include smoking and IVDU and these patients should be referred to services for cessation as early as possible before 2-stage revision THA.

Detection of Total Hip Replacement Loosening Based on Structure-Borne Sound: Influence of the Position of the Sensor on the Hip Stem.

Accurate detection of implant loosening is crucial for early intervention in total hip replacements, but current imaging methods lack sensitivity and specificity. Vibration methods, already successful in dentistry, represent a promising approach. In order to detect loosening of the total hip replacement, excitation and measurement should be performed intracorporeally to minimize the influence of soft tissue on damping of the signals. However, only implants with a single sensor intracorporeally integrated into the implant for detecting vibrations have been presented in the literature. Considering different mode shapes, the sensor's position on the implant is assumed to influence the signals. In the work at hand, the influence of the position of the sensor on the recording of the vibrations on the implant was investigated. For this purpose, a simplified test setup was created with a titanium rod implanted in a cylinder of artificial cancellous bone. Mechanical stimulation via an exciter attached to the rod was recorded by three accelerometers at varying positions along the titanium rod. Three states of peri-implant loosening within the bone stock were simulated by extracting the bone material around the titanium rod, and different markers were analyzed to distinguish between these states of loosening. In addition, a modal analysis was performed using the finite element method to analyze the mode shapes. Distinct differences in the signals recorded by the acceleration sensors within defects highlight the influence of sensor position on mode detection and natural frequencies. Thus, using multiple sensors could be advantageous in accurately detecting all modes and determining the implant loosening state more precisely.

Pelvic flexion/extension and its impact on functional acetabular alignment and stability following total hip replacement.

PURPOSE: Dislocation following total hip arthroplasty (THA) remains a significant clinical problem and can occur even with optimal implant alignment. We hypothesized that different patterns of pelvic flexion/extension (PFE) during daily activities may influence acetabular alignment and contribute to impingement and instability following THA. Recently, there has been an increased interest in spinopelvic alignment and its impact on THA. Therefore, this study aimed to identify different patterns of PFE that could be predictive of instability following THA. METHODS: A range of motion (ROM) simulator was used to demonstrate the effects of different patterns of PFE on ROM and impingement. The findings were applied to PFE measurements obtained from 84 patients in standing and sitting positions. RESULTS: Three different categories of PFE were identified: normal, hypermobile, and stiff. ROM simulator revealed that changes in PFE had affected ROM and impingement significantly. Patients in the stiff pelvis category, even with "optimal" implant alignment, were more susceptible to implant impingement. CONCLUSIONS: The different patterns of PFE during daily activities could affect acetabular alignment and stability following THA. We propose a classification system that can identify different types of PFE and predict their effects on the stability of prostheses following THA. Hence, we believe that patients with unfavorable PFE may require modified cup alignment.

Over ten-year follow-up results of a prospective and consecutive series of primary total hip arthroplasty with an original cementless total hip prosthesis.

PURPOSE: High survival rates up to ten  years have been reported for non-cemented hip replacements. Publications beyond ten years have more diverse conclusions. To study the long-term survival of uncemented total hip replacement (THR), we examined a series of 125 THR, all with a minimum follow-up of ten  years. METHODS: This is a prospective study of 203 patients operated for coxarthrosis between 2007 and 2011, by six senior surgeons. The original ellipsoidal stem and the impacted acetabulum were systematically cementless; the acetabulum had either a fixed ceramic or polyethylene insert, or a dual-mobility insert. At the date of the follow-up check, 44 patients were deceased and 34 patients were lost to follow-up. This left 125 complete files for our study. RESULTS: They were a revision of the cup in four cases and a revision of the femoral stem in three cases (3.4%). The Kaplan-Meier cumulative survival rate of the THR, by considering revision for any reason as endpoint, at ten  years (120 months) is estimated at 96.6% (CI 92.7-98.7). Radiologically, on 86 analyses (68.8%) at ten  years and more reported, no significant evolution of the appearance of the cancellous bone around the acetabular cup was noted, nor any ossification. Some periprosthetic osteogenesis reactions were noted around the 1/3 distal but no periprosthetic edging. CONCLUSION: In this minimum ten-year follow-up study, a cementless THR with a straight ellipsoidal cementless stem and a press-fit cup provides excellent implant survival and high patient satisfaction. (Clinically felt minimal difference.).

Combined assessment of acetabular coverage and femoral head-neck shapes predicts osteoarthritis progression after periacetabular osteotomy.

INTRODUCTION: Postoperative osteoarthritis (OA) progression is a major determinant of failure after curved periacetabular osteotomy (CPO). A large postoperative combination angle, i.e., the combination of computed tomography-based anterior center edge and alpha angles, is associated with femoroacetabular impingement after CPO, but its association with postoperative OA progression is unclear. We aimed to identify the anatomical parameters that can lead to OA progression after CPO and the impact of the combination angle on the same. MATERIALS AND METHODS: We included 90 hips that were subjected to CPO at our center between March 2013 and March 2018. Seventeen hips showed OA progression with an increase in the Tönnis classification after surgery; 73 hips showed no progression. Radiographic anatomical parameters, including the lateral and anterior center edge angles, femoral and acetabular anteversion, and combination angle, and clinical outcomes, including modified Harris Hip Scores (mHHSs), postoperative anterior impingement, and range of motion, were compared between the two groups. Statistical significance was set at P < 0.05. RESULTS: Postoperative OA progression was significantly affected by preoperative OA evidence (P = 0.017), acetabular anteversion < 5.0° (P = 0.003), and a combination angle > 107.0° (P = 0.025). Patients with radiographic OA progression were associated with poor mHHSs (P = 0.017) and high frequencies of anterior impingement with a limited hip flexion and internal rotation angle. CONCLUSIONS: OA progression after CPO may be associated with preoperative evidence of OA and postoperative acetabular retroversion as well as a large combination angle. Surgeons should focus on the potential effects of preoperative OA grades, postoperative reduction in acetabular anteversion, and postoperative combination angle.

Motion acquisition of gait characteristics one week after total hip arthroplasty: a factor analysis.

INTRODUCTION: Clinical gait analysis can be used to evaluate the recovery process of patients undergoing total hip arthroplasty (THA). The postoperative walking patterns of these patients can be significantly influenced by the choice of surgical approach, as each procedure alters distinct anatomical structures. The aim of this study is twofold. The first objective is to develop a gait model to describe the change in ambulation one week after THA. The secondary goal is to describe the differences associated with the surgical approach. MATERIALS AND METHODS: Thirty-six patients undergoing THA with lateral (n = 9), anterior (n = 15), and posterior (n = 12) approaches were included in the study. Walking before and 7 days after surgery was recorded using a markerless motion capture system. Exploratory Factor Analysis (EFA), a data reduction technique, condensed 21 spatiotemporal gait parameters to a smaller set of dominant variables. The EFA-derived gait domains were utilized to study post-surgical gait variations and to compare the post-surgical gait among the three groups. RESULTS: Four distinct gait domains were identified. The most pronounced variation one week after surgery is in the Rhythm (gait cycle time: + 32.9 % ), followed by Postural control (step width: + 27.0 % ), Phases (stance time: + 11.0 % ), and Pace (stride length: -  9.3 % ). In postsurgical walking, Phases is statistically significantly different in patients operated with the posterior approach compared to lateral (p-value = 0.017) and anterior (p-value = 0.002) approaches. Furthermore, stance time in the posterior approach group is significantly lower than in healthy individuals (p-value < 0.001). CONCLUSIONS: This study identified a four-component gait model specific to THA patients. The results showed that patients after THA have longer stride time but shorter stride length, wider base of support, and longer stance time, although the posterior group had a statistically significant shorter stance time than the others. The findings of this research have the potential to simplify the reporting of gait outcomes, reduce redundancy, and inform targeted interventions in regards to specific gait domains.

Total hip arthroplasty in patients with colostomy: impact on inpatient complications, hospital costs, and length of stay.

INTRODUCTION: The presence of permanent end-colostomy is traditionally thought of as a risk factor for complications following orthopedic joint replacement; however, literature supporting this association is scarce. This study aims to discern how length of stay, cost of stay, and inpatient complications following total hip arthroplasty (THA) are impacted by presence of colostomy. METHODS: Data from the National Inpatient Sample was analyzed by International Classification of Diseases, 10th Revision, Clinical Modification regarding THA in patients with and without end-colostomy. Unmatched and matched analyses comparing length of stay, cost of stay, and post-operative adverse outcomes between the two groups were conducted. In the unmatched analysis, 445 THA patients with colostomy were compared to 367,449 THA patients without colostomy. The colostomy patients were then matched for age, sex, race, diabetes, obesity, and the matched groups consisted of 445 patients with and 425 patients without colostomy, respectively. RESULTS: Compared to the THA without colostomy group, the colostomy group was significantly older, had longer hospital stays, and greater cost of stay. When matched for age and comorbidities, length of hospital stay (p < 0.001) and cost of stay (p = 0.002) remained significantly higher. The colostomy group was at significantly increased risk for periprosthetic fracture, dislocation, and infection compared to all THA patients. When matched for age and common comorbidities, the colostomy group had significantly higher risk in only periprosthetic dislocation [p = 0.003, OR 11.8 (1.6-4.6, 95% CI)] and periprosthetic infection [p < 0.05, OR 2.7 (0.97-7.7 95% CI)]. CONCLUSION: Patients with colostomy are at risk of longer hospital courses and greater incurred costs following THA compared to patients without colostomy. They are additionally at significantly increased risk of periprosthetic dislocation and periprosthetic infection, warranting treatment as high-risk patients. STUDY DESIGN: Retrospective cohort study.