Implant survival and patient-reported outcome following total hip arthroplasty in patients 30 years or younger: a matched cohort study of 1,008 patients in the Swedish Hip Arthroplasty Register

Assessing the Effects and Challenges of Total Hip Arthroplasty before Pregnancy and Childbirth: A Systematic Review

Total hip arthroplasty is indubitably one of the most performed operations worldwide. On the other hand, especially in the western world, the average age that women get pregnant has raised confoundedly. Consequently, a steadily increasing number of women become pregnant after they had hip arthroplasty surgery, with copious potential implications. The amount of knowledge on this particular field is considered inadequate in the existing literature. This paper aims to augment clinicians understanding surrounding this topic. A systematic literature review was conducted in accordance with the PRISMA guidelines. Papers from various computerized databases were scrutinized. Article selection was carried out by three authors independently employing specific pre-determined inclusion and exclusion criteria, while disagreements were elucidated with the contribution of other authors. A patently limited number of research articles were detected from our rigorous literature review, with only 12 papers meeting the inclusion criteria. The vast majority of studies were small-scale and examined confined population groups. Most studies had been performed in Finland, utilizing data from nationwide registries. Women with previous history of total hip arthroplasty feature increased rates of c-section delivery, although vaginal labor can be attempted with certain precautions. Hip implants' survival does not appear to be affected from gestation, which is predominately well-tolerated from these women. Metal ion circulation in mothers' blood has not been proven to trigger substantial complications concerning either mothers or offspring. It can be considered safe for women with such medical history to get pregnant; however, further multinational studies and pertinent research on this field are vital to attain more solid inferences.

Patient-Reported Outcome Measures in High-Risk Medical Device Registries: A Scoping Review

Little is known about the methods and outcomes of patient-reported outcome measure (PROM) use among high-risk medical device registries. The objective of this scoping review was to assess the utility and predictive ability of PROMs in high-risk medical device registries. We searched Ovid Medline, Embase, APA PsychINFO, Cochrane Library, and Scopus databases for published literature. After searching, 4323 titles and abstracts were screened, and 262 full texts were assessed for their eligibility. Seventy-six papers from across orthopedic (n = 64), cardiac (n = 10), penile (n = 1), and hernia mesh (n = 1) device registries were identified. Studies predominantly used PROMs as an outcome measure when comparing cohorts or surgical approaches (n = 45) or to compare time points (n = 13) including pre- and postintervention. Fifteen papers considered the predictive ability of PROMs. Of these, 8 treated PROMs as an outcome, 5 treated PROMs as a risk factor through regression analysis, and 2 papers treated PROMs as both a risk factor and as an outcome. One paper described PROMs to study implant survival. To advance methods of PROM integration into clinical decision-making for medical devices, an understanding of their use in high-risk device registries is needed. This scoping review found that there is a paucity of studies using PROMs to predict long-term patient and clinical outcomes in high-risk medical device registries. Determination as to why PROMs are rarely used for predictive purposes in long-term data collection is needed if PROM data are to be considered suitable as real-world evidence for high-risk device regulatory purposes, as well as to support clinical decision-making.

Level of Evidence 4

Ten Year Outcomes of Contemporary Total Hip Arthroplasty in Adolescent and Young Adult Patients are Favorable

BACKGROUND

The purpose of this study was to assess 10-year patient-reported outcome measures, complications, polyethylene wear-rates, and implant survivorships in patients ≤30 years of age treated with contemporary total hip arthroplasty (THA).

METHODS

We retrospectively assessed 121 patients (144 hips) who underwent THA at age ≤30 years (mean 23 [range, 11 to 30]) at an average follow-up duration of 10.7 years (range, 8 to 17). Highly-crosslinked polyethylene acetabular liners were used in all cases. Femoral heads were ceramic (74%) or cobalt-chrome (26%). There were 52 hips (36%) that had previous surgery and 31 hips (22%) were in patients who had associated major systemic comorbidities. We analyzed the modified Harris Hip scores, University of California Los Angeles Activity Scores, major complications, polyethylene wear-rates, and implant survivorships.

RESULTS

At final follow-up, the average modified Harris Hip scores improved from 47 (±15.1) to 81 (±19.5) with an average 34-point improvement. The University of California Los Angeles scores improved from 4.0 (±2.3) to 6.0 (±2.4). The major complication rate was 5.6%. There were 6 hips (4.2%) that were revised. Indications for revision included instability (3, 2.1%), late infection (1, 0.7%), liner dissociation (1, 0.7%), and acetabular loosening (1, 0.7%). Mean linear (0.0438 mm/y) and volumetric (29.07 mm3/y) wear rates were low. No periprosthetic osteolysis was detected in any hip. Survivorship free from revision for any reason was 97.2, 95.8, and 95.8% at 5, 10, and 15 years.

CONCLUSIONS

Contemporary THA in patients ≤30 years of age is associated with marked clinical improvements at 10-year follow-up and encouraging survivorship estimates at 15 years.

Cellular senescence is associated with osteonecrosis of the femoral head while mesenchymal stem cell conditioned medium inhibits bone collapse

Osteonecrosis of the femoral head (ONFH) is a type of ischemic osteonecrosis that causes pain, loss of function, and femoral head collapse. Here, we analyzed samples of femoral heads excised from patients with ONFH to clarify the relationship between ischemic osteonecrosis and cellular senescence. X-gal staining was strong and p16INK4a-positive cells were abundant in the transitional region of ONFH. The β-galactosidase-positive cells in the transitional region were also positive for nestin, periostin, or DMP-1. In contrast, no β-galactosidase-positive cells were detected in the healthy region. The senescence-associated p16INK4a, p21, and p53 were upregulated in ONFH tissue. We also examined and analyzed a mouse ischemic femoral osteonecrosis model in vivo to verify the association between ONFH and cellular senescence. Human mesenchymal stem cell-conditioned medium (MSC-CM) was administered to determine its therapeutic efficacy against cellular senescence and bone collapse. MSC-CM reduced the number of senescent cells and downregulated the aforementioned senescence-related genes. It also decreased the number of empty lacunae 4 weeks after ischemia induction and promoted bone formation. At 6 weeks post-surgery, MSC-CM increased the trabecular bone volume, thereby suppressing bone collapse. We conclude that cellular senescence is associated with ONFH and that MSC-CM suppresses bone collapse in this disorder.

Intertrochanteric curved varus osteotomy for subchondral fracture of the femoral head: a case series

Although favorable results have been reported with total hip arthroplasty, joint-preserving treatment should be the first choice for subchondral fracture of the femoral head (SFF) in young patients. This study reviewed four young male patients with SFF who underwent intertrochanteric curved varus osteotomy (CVO). The patients had a mean age of 32.3 years (range: 18-49 years). Conservative treatment was initially attempted in all cases, but failed to alleviate the pain, leading to surgical intervention at an average time of 6 months (range: 4-10 months) after symptom onset. As the fracture sites were located medial to the lateral edge of the acetabulum in all cases, CVO was performed to achieve a postoperative intact ratio of ≥ 34% in the weight-bearing region of the femoral head. The average follow-up period after surgery lasted 4.3 years (range: 2-7 years). Clinical and radiographic assessments were performed pre- and postoperatively. At the latest follow-up, the mean Harris hip score improved from 67.3 preoperatively to 99.5 postoperatively. The average preoperative intact ratio of the weight-bearing region of the femoral head was 12.3%, which increased to 44.3% postoperatively. No progression to femoral head collapse or joint space narrowing was observed on the plain radiographs. CVO is a simple, less-invasive, and beneficial approach for treating SFF in young patients whose fractures occur medial to the lateral edge of the acetabulum.

Early Total Hip Arthroplasty is a Cost-Effective Treatment for Severe Radiographic Slipped Capital Femoral Epiphysis Over an Individual's Lifetime

BACKGROUND

Slipped capital femoral epiphysis (SCFE) causes degenerative changes warranting total hip arthroplasty (THA) in approximately 50% of patients by age 60 years. For severe SCFE, a reorienting intertrochanteric osteotomy (ITO) following in situ pinning (ISP) can decrease impingement with hip flexion, but by altering proximal femoral geometry, complicates subsequent conversion THA. We hypothesized that increasing implant survivorship would affect the most cost-effective treatment strategy (ISP followed by ITO [ISP + ITO] with later THA versus ISP alone [ISPa] with earlier THA) over a patient's lifetime.

METHODS

A state-transition Markov model was constructed to analyze the cost-effectiveness of either ISPa or ISP + ITO over a 60-year time horizon for children who have severe, stable SCFE. Transition probabilities associated with implant and native hip survivorship, state utilities, and costs were derived from the literature. Sensitivity analyses assessed the model robustness. Incremental cost-effectiveness ratios (ICERs) were compared to a societal willingness to pay (WTP) of $100,000 per quality-adjusted life year (QALY).

RESULTS

Over a 60-year horizon, ISPa was costlier ($291,836) than ISP + ITO ($75,227) but achieved overall better outcomes (51.4 QALYs ISPa versus 48.7 QALYs ISP + ITO), rendering ISPa cost-effective with an ICER of $80,980/QALY. Implant survivorship and time horizon were sensitive variables.

CONCLUSION

Based upon current implant performance, ISPa with subsequent earlier THA is cost-effective when considering an individual's life expectancy and thereby deserves consideration in patients who have severe SCFE. Without clear level 1 clinical data, our economic model considers a difficult problem, while providing families and clinicians with a framework for understanding treatment options.

LEVEL OF EVIDENCE

Economic and decision analysis, Level III.

Outcome measures and survivorship following total hip arthroplasty in adolescent population

BACKGROUND

The most frequent indication for total hip arthroplasty (THA) in adolescent patients has been juvenile idiopathic arthritis (JIA). However, in recent years, other causes have become more prevalent.

QUESTIONS/PURPOSES

(1) What is the survivorship following THA across the diagnostic spectrum in adolescent population? (2) How are quality of life results affected by systemic medical conditions?

METHODS

We retrospectively reviewed all consecutive THA in patients under 21 years of age, performed at our Institution between 1993 and 2018. There were 34 prostheses implanted in 26 patients with a mean age of 18.4 years (range 11 to 21). The most frequent diagnosis was JIA (14 hips), followed by avascular necrosis (10 hips). Patient reported outcomes were assessed using Harris and Oxford Hip Scores (HHS and OHS), Visual Analogue Scale (VAS) and EuroQol-5D. Survivorship for revision and aseptic loosening was determined with Kaplan Meier analysis.

RESULTS

At final follow-up, the overall survival rate was of 89.3% at 12-year follow-up. Three acetabular components underwent revision surgery for aseptic loosening. Clinical HHS significantly improved from 37.5 to 90.6 points (p < 0.001). Mean OHH was 37.4 points, with a final VAS of 1.64 points. Mean 5Q-5D was 0.704 with an interquartile range of 0.4 to 1.0. JIA patients displayed worse pre-operative HHS scores, and at final follow-up had worse HHS, OHS, VAS and EQ-5D scores compared to the rest of the patients. Complications included three intra-operative femoral fractures, one sciatic nerve palsy and one adductor contracture.

CONCLUSION

THA in adolescent patients provides improved functional outcomes with acceptable revision rates at mid-term follow-up.

Effect of trochanter displacement on impingement and bone contact in total hip arthroplasty performed after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head: a simulation study

Background

Curved intertrochanteric varus osteotomy (CVO) is a useful treatment option for osteonecrosis of the femoral head (ONFH). However, the effect of proximal femoral deformity in cases of CVO converted to total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate the effect of trochanter displacement on impingement and the contact state of the implant and femur in THA.

Methods

Thirty-eight hips that had undergone CVO for ONFH were reviewed and compared with a control group of 30 contralateral hips that had not undergone surgery. The range of motion (ROM) and impingement patterns and the percentage of cortical bone in the stem placement within the femur were measured by simulation using CT-based three-dimensional template software. We also measured the ROM and the number of joints that achieved the ROM required for activities of daily living when the upward displaced apex of the greater trochanter with osteotomy was resected and compared the findings with those obtained when the apex was not resected.

Results

The CVO group showed a significantly greater bony impingement in external rotation (68.4% vs. 43.3%, p = 0.033) and abduction (78.9% vs. 33.3%, p < 0.001) than in the control group. The CVO group showed a significantly smaller range of external rotation (19.0° [interquartile range; 4.0–28.8] vs. 38.0° [interquartile range; 36.0–41.8], p < 0.001) and abduction (23.0° [interquartile range; 8.5–38.8] vs. 56.0° [interquartile range; 50.3–60.0], p < 0.001) than in the control group. Significantly more joints achieved the ROM necessary for activities of daily living when the apex was resected than when it was not (10.5% vs. 63.2%, p < 0.001). The percentage of cortical bone in the stem placement position was significantly higher in the CVO group than in the control group in the proximal portion of the stem (25.5% vs. 0.0%, p < 0.001).

Conclusion

In cases requiring conversion to THA, we recommend resecting the upward displaced apex to achieve a sufficient ROM and carefully resecting the bone to avoid malignment of the stem.

Comparing uncemented, hybrid and cemented primary total hip arthroplasty in young patients, a New Zealand Joint Registry study

BACKGROUND

Despite increasing use of uncemented implants in young patients undergoing total hip arthroplasty (THA), there is minimal evidence for specific implant combinations in this group. We analysed the most commonly used uncemented (Corail-Pinnacle), hybrid (Exeter-Trident/Tritanium), and fully cemented (Exeter) implant combinations in the New Zealand Joint Registry (NZJR) in patients aged under 40 and between 40 and 55 years.

METHODS

All THAs recorded in the NZJR between 1999 and 2018 were included. The 40-55 and < 40 age groups were analysed separately. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. The primary outcome was revision for any reason.

RESULTS

We identified 4152 THAs in the 40-55 group and 422 in the < 40 group. In the 40-55 group, revision rates and patient-reported outcome measure scores were comparable between the uncemented implant combination (0.70/100 component years) and the hybrid implant combination (0.62/100 component years), whereas the cemented implant combination exhibited a statistically significant higher revision rate (1.75/100 component years) (p < 0.001). In the < 40 group, revision rate for the hybrid implant combination (0.46/100 component years) was significantly lower than the uncemented implant combination (1.54/100 component years).

CONCLUSION

The most commonly used hybrid and uncemented implant combinations provided equivalent survival and functional outcomes in patients aged 40-55 years. More research is required to guide implant selection in patients aged < 40 years. The authors suggest a transition away from comparing classes of implants (cemented, uncemented, hybrid) given the diverse product range within these categories.

Preoperative predictors of health-related quality of life changes (EQ-5D and EQ VAS) after total hip and knee replacement: a systematic review

BACKGROUND

Patient-reported outcomes are of ever-increasing importance in medical decision-making. The EQ-5D is one of the generic instruments measuring health-related quality of life (HRQoL) in arthroplasty. This review aimed to identify possible predictors of HRQoL changes for patients undergoing total knee replacements (TKR) or total hip replacements (THR).

METHODS

A systematic literature review according to the PRISMA guidelines was conducted, searching several databases. Preoperative to postoperative HRQoL changes were evaluated in patients undergoing THR or TKR, using the EQ-5D visual analog scale (VAS) or the preference-based EQ-5D Index were evaluated. Articles were considered with prospectively or retrospectively collected data, as well as registry data, each with statistical analyses of patient-related factors.

RESULTS

Eight hundred eighty-two articles were found, of which 21 studies met the inclusion criteria. Predictors were distinguished in alterable and non-alterable ones. The EQ-5D Index indicated a tendency towards beneficial improvements for patients with a high body mass index (BMI) (> 40) and no significant results for the VAS. Additionally, one study found that patient education and preoperative physiotherapy appeared to enhance HRQoL. Some evidence indicated that male gender was negatively associated with changes in the VAS and the EQ-5D Index, but one study reported the opposite. Changes in VAS and EQ-5D Index were lower for older patients, whereas a higher educational level seemed to be advantageous. A high Charnley class led to deteriorating changes in VAS, although a high Kellgren Lawrence classification was positively associated with the EQ-5D Index, in a limited number of studies. For all results, clinical relevance was calculated differently and mainly reported as uncertain or small.

CONCLUSIONS

The literature on this topic was weak and offers only limited guidance. Results for alterable predictors, such as the BMI, indicated valuable improvements for highly obese patients. Further, high-quality research is required to support medical decision-making.

LEVEL OF EVIDENCE

Level IV, according to the OCEBM Levels of Evidence Working Group.

Effectiveness of ankle fusion in patients with hemophilia, advanced ankle degeneration, and unbearable pain for whom nonsurgical and surgical treatments have been ineffective

Introduction: In underdeveloped countries, patients with hemophilia often experience repetitive ankle joint hemorrhages due to a shortage of coagulation factors (factor VIII [FVIII] and factor IX [FIX] for hemophilia A and B, respectively).Areas covered: This is a narrative literature review in which we searched the Cochrane Library and PubMed for articles related to ankle arthrodesis in patients with hemophilia. The searches covered the period from the databases´ inception to 28 February 2021. In the event of unsuccessful hematologic prophylaxis and conservative measures (e.g. analgesics, cyclooxygenase-2 inhibitors, taping, intra-articular injections of hyaluronic acid and corticosteroids, physical and rehabilitation medicine, orthoses, radiosynovectomy, and joint-preserving surgery (e.g. removal of the distal tibia by open surgery or by arthroscopic surgery, joint debridement by arthroscopic surgery), the classical surgical solution is ankle arthrodesis, which does not preserve the ankle joint.Expert opinion: Ankle pain is reduced after ankle arthrodesis (75% of patients experience no pain). Approximately 5% of patients require reoperation due to lack of fusion, and deep infection occurs in 2.5%. After tibiotalar fusion, a self-reported activity scale shows that approximately 12% of patients improve, 9% worsen, and 79% show no improvement. The results of ankle arthrodesis therefore appear to be poor.Therefore, although 75% of the patients stopped having ankle pain after arthrodesis, according to a self-reported activity scale 88% of them did not improve or worsened.

Long-term outcomes of curved intertrochanteric varus osteotomy combined with bone impaction grafting for non-traumatic osteonecrosis of the femoral head

AIMS

We compared the clinical outcomes of curved intertrochanteric varus osteotomy (CVO) with bone impaction grafting (BIG) with CVO alone for the treatment of osteonecrosis of the femoral head (ONFH).

METHODS

This retrospective comparative study included 81 patients with ONFH; 37 patients (40 hips) underwent CVO with BIG (BIG group) and 44 patients (47 hips) underwent CVO alone (CVO group). Patients in the BIG group were followed-up for a mean of 12.2 years (10.0 to 16.5). Patients in the CVO group were followed-up for a mean of 14.5 years (10.0 to 21.0). Assessment parameters included the Harris Hip Score (HHS), Oxford Hip Score (OHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), complication rates, and survival rates, with conversion to total hip arthroplasty (THA) and radiological failure as the endpoints.

RESULTS

There were no significant differences in preoperative and postoperative HHS or postoperative OHS and JHEQ between the BIG group and the CVO group. Complication rates were comparable between groups. Ten-year survival rates with conversion to THA and radiological failure as the endpoints were not significantly different between groups. Successful CVO (postoperative coverage ratio of more than one-third) exhibited better ten-year survival rates with radiological failure as the endpoint in the BIG group (91.4%) than in the CVO group (77.7%), but this difference was not significant (p = 0.079).

CONCLUSION

Long-term outcomes of CVO with BIG were favourable when proper patient selection and accurate surgery are performed. However, this study did not show improvements in treatment results with the concomitant use of BIG. Cite this article: Bone Joint J 2021;103-B(4):665-671.

A retrospective analysis of trends in primary knee arthroplasty in Germany from 2008 to 2018

Unicompartimental and total knee arthroplasty is one of the most successful and most performed operations worldwide. In the last years the number of primary knee arthroplasty increased constantly. The aim of this study is to analyze the rising numbers of primary knee arthroplasty and to see how it is used in Germany. In this retrospective study data, provided by the Federal Statistical Office of Germany from 2008 to 2018 was analyzed, using operation codes from the German procedure classification system and characteristics like age, sex and type of the prosthesis. We found a slight increase of unicompartimental and total knee arthroplasty over the investigated 10 years from 150.504 in 2008 up to 168.479 procedures in 2018, with a maximum of 169.334 in 2017. Most patients were female and over 65 years old. Interestingly, there was an obvious decrease of regular TKA in the year 2013, with a relevant impact on the total number of procedures. In the following years the number rised again reaching the former level in 2015 and is still increasing. The highest increase was found in partial knee arthroplasty, with a constant rise every year, starting with 7988 in 2008 up to 21.072 in 2018. In contrast, we found a relevant reduction of constrained prosthesis in primary TKA, whereas the number of semi-constrained prosthesis in primary TKA is again rising after a decrease in 2015. We found that the number of bicondylar TKA and especially UKA increased from 2008 to 2018. Regarding an aging population, we can expect a rising number for Primary knee arthroplasty and in consequence a rising number of revision arthroplasty in the future. This will be a challenging cost factor for the healthcare system in Germany.

The Prevention of Periprosthetic Joint Infection in Primary Total Hip Arthroplasty Using Pre-Operative Chlorhexidine Bathing

Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is a devastating complication. The aim of this study was to investigate whether preoperative bathing using chlorhexidine gluconate (CHG) before THA can effectively reduce the postoperative PJI rate. A total of 933 primary THA patients, with the majority being female (54.4%) were included in the study. Primary THA patients who performed preoperative chlorhexidine bathing were assigned to the CHG group (190 subjects), and those who did not have preoperative chlorhexidine bathing were in the control group (743 subjects). The effects of chlorhexidine bathing on the prevention of PJI incidence rates were investigated. Differences in age, sex, and the operated side between the two groups were not statistically significant. Postoperative PJI occurred in four subjects, indicating an infection rate of 0.43% (4/933). All four infected subjects belonged to the control group. Although the PJI cases were significantly more in the control group than in the CHG group, statistical analysis revealed no statistical significance in the risk of PJI occurrence between the two groups (p = 0.588). Preoperative skin preparation by bathing with a 2% chlorhexidine gluconate cleanser did not produce significant effects on the prevention of postoperative PJI in primary THA.

Favourable clinical outcomes following cemented arthroplasty after metal-on-metal total hip replacement: a retrospective study with a mean follow-up of 10 years

BACKGROUND

Given the unexpected high rate of failure following metal-on-metal total hip replacement (MoM-THR), it is expected that more MoM-THR patients will experience revision. The long-term outcomes regarding the primary MoM-THR revised to cemented THR (CTHR) remain controversial. The purpose of this retrospective review was to evaluate the long-term outcomes of patients who underwent conversion from MoM-THR to CTHR.

METHODS

A total of 220 patients (220 hips) who underwent a conversion of primary MoM-THR to CTHR from March 2006 to October 2016 were retrospectively reviewed. The primary outcomes were the functional outcomes assessed using the Harris hip scores (HHS) and major radiographic outcomes. Follow-ups occurred at 3 months, 6 months, 1 year, 2 years, and then every two years after revision.

RESULTS

Mean follow-up was 10.1 years (5-13 years). Distinct improvements were detected in the mean HHS between the preoperative and last follow-up analysis (62.35[±8.49] vs. 84.70[±14.68], respectively, p < 0.001). The key orthopaedic complication rate was 18.2% (27/148). Seven (4.7%) cases experienced a CTHR failure at a mean of 3.4 (±1.2) years after revision MoM-THR, mostly attributed to recurrent dislocation.

CONCLUSION

CTHR might yield an acceptable functional score and a low rate of the key orthopaedic complications.

Association of NLRP3 and CARD8 Inflammasome Polymorphisms With Aseptic Loosening After Primary Total Hip Arthroplasty

Our aim was to investigate the association of inflammasome polymorphisms NLRP3 rs35829419 (p. Q705K) and CARD8 rs2043211 (p. C10X) with aseptic loosening of total hip endoprostheses. We asked whether patients with the loosening of total hip arthroplasty earlier than 15 years after primary implantation had a higher proportion of the polymorphisms Q705K and C10X in comparison to subjects without loosening. A retrospective case-control study compared 36 patients with total hip endoprosthesis loosening earlier than 15 years after primary implantation and 51 control subjects with unloosened total hip endoprostheses, matched for gender, age, and follow-up period. Buccal mucosa samples were used for genomic DNA analysis and genotyped for NLRP3 rs35829419 and CARD8 rs2043211 using a fluorescence-based competitive allele-specific real-time polymerase chain reaction. The proportion of subjects with both wild-type NLRP3 and CARD8 (i.e., without Q705K or C10X) was considerably higher in the control group when compared with patients with early total hip arthroplasty loosening (49% vs. 28%; p = 0.05). After adjustment for gender, age, and follow-up, patients with combined wild type of both NLRP3 and CARD8 had significantly smaller odds for early implant loosening (odds ratio 0.33, p = 0.02). Investigated polymorphisms may influence several inflammatory pathways and contribute to the loosening of artificial implants with potential clinical significance for the appropriate selection of patients and endoprostheses when planning elective total hip arthroplasty. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:417-421, 2020.

No effect of delivery on total hip replacement survival: a nationwide register study in Finland

Background and purpose - Previous small studies have suggested that delivery does not adversely affect the survivorship of total hip replacement (THR). We investigated whether delivery after primary THR affects hip implant survivorship in a large population-based study sample Patients and methods - In this register-based nationwide cohort study, all women aged 15-45 who underwent primary THR in Finland from 1987 to 2007 were included from the Finnish Arthroplasty Register. Data on deliveries were obtained from the medical birth register. After primary THR, 111 women (133 THRs) delivered and formed the delivery group. In the reference group, 1,878 women (2,343 THRs) had no deliveries. We used Kaplan-Meier analysis with 95% confidence intervals (CI) to study implant survivorship at 6 and 13 years, and Cox multiple regression to assess survival and hazard ratios (HRs), with revision for any reason as an endpoint with adjustment for age, rheumatoid arthritis, and stem and cup fixation. Results - 51 (38%) revisions were recorded in the delivery group and 645 (28%) revisions in the reference group. The 6-year implant survivorship was 91% (CI 85-96) in the delivery group and 88% (CI 87-90) in the reference group. The 13-year survival rates were 50% (CI 39-62) and 61% (CI 59-64). The adjusted HR for revision after delivery was 0.7 (CI 0.4-1.2) in ≤ 6.8 years' follow-up and 1.1 (CI 0.8-1.6) in > 6.8 years' follow-up. Interpretation - Based on the findings in this nationwide study of hip replacement in fertile-aged women, delivery does not seem to decrease THR implant survivorship; women should not be afraid of or avoid becoming pregnant after THR.