Is the Revision Rate for Femoral Neck Fracture Lower for Total Hip Arthroplasty Than for Hemiarthroplasty?: A Comparison of Registry Data for Contemporary Surgical Options

Symptomatic Acetabular Erosion After Hip Hemiarthroplasty: Is It a Major Concern? A Retrospective Analysis of 2477 Hemiarthroplasty Cases

Background/Objectives: Acetabular erosion is a postoperative condition that can occur after hip hemiarthroplasty (HA), potentially leading to pain and requiring conversion to total hip arthroplasty (THA). Given the discrepancy in its incidence and impact in the literature, this study aims to report the incidence of symptomatic acetabular erosion and the subsequent conversion to THA in all HA cases performed in a single health system. Methods: A total of 2477 HA cases had their clinical notes and serial radiographs examined for this retrospective study. Outcome measures included any records of hip or groin pain and conversion to THA that were attributed to acetabular erosion as documented in the clinical notes. Results: Two thousand four hundred and seventy-seven HA cases were reviewed in this study. The mean age for all patients in the study was 81.5 years and the mean follow up was 3.7 years. Out of the 2477 HA cases, only 12 HA cases (0.48%) in 12 patients had data records of chronic hip pain, attributable to acetabular wear in the clinical notes, of variable severity and presentations. The mean duration until the clinical documentation of acetabular wear-induced pain was 25.6 months (range, 1.4-146.4 months), with most symptomatic hip erosion cases presented within the first year (50% presented within the first 6 months) after the index HA surgery. Despite that, only five cases underwent conversion to THA (0.2%) while seven patients received conservative management. Conclusions: In patients older than 65 years of age who are candidates for HA, the incidence of symptomatic hip erosion and the subsequent conversion to THA is low and hence HA remains a viable treatment option. Based on the duration until clinical presentation of acetabular erosion, this study suggests that the state of acetabular cartilage during surgery may influence the development of early acetabular wear in most symptomatic patients. On the other hand, hip hemiarthroplasty is a rare treatment option for displaced femoral neck fractures in patients younger than 65 years of age, and its use in this patient subset depends on conditional and patient-related factors such as the activity level, cognitive function, and medical comorbidities.

No Difference in Revision Rates or Patient-Reported Outcome Measures Between Surgical Approaches for Total Hip Arthroplasty Performed for Femoral Neck Fracture: An Analysis of 5,025 Primary Total Hip Arthroplasties From the New Zealand Joint Registry

BACKGROUND

Total hip arthroplasty (THA) for femoral neck fracture (FNF) can be performed through different surgical approaches. This study compared the revision rates and patient-reported outcome measures by surgical approach.

METHODS

Data from the New Zealand Joint Registry were analyzed for patients undergoing primary THA for FNF from January 2000 to December 2021. A total of 5,025 THAs were performed for FNF; the lateral approach was used in 2,499 (49.7%), the posterior in 2,255 (44.9%), and the anterior in 271 (4.3%). The primary outcome measure was the all-cause revision rate. Secondary outcome measures included revision rates for: dislocation, aseptic femoral component loosening, periprosthetic fracture, and infection. Oxford Hip Scores (OHS) were also collected. Age, sex, body mass index, American Society of Anesthesiologists score, femoral head size, dual mobility use, femoral fixation, and surgeon experience were assessed as potential confounding variables.

RESULTS

There was no difference in the revision rates between lateral and posterior (P = .156), lateral and anterior (P = .680), or posterior and anterior (P = .714) approaches. There was no difference in the reasons for revision between the lateral and posterior approaches or 6-month OHS (P = .712). There was insufficient data to compare the anterior approach.

CONCLUSIONS

There is no difference in the overall revision rates, reasons for revision, or OHS between the lateral and posterior surgical approaches for THA performed for FNF. Insufficient data on the anterior approach is available for an accurate comparison.

LEVEL OF EVIDENCE

Level III.

A Comparison of Surgical Approaches for Hip Hemiarthroplasty Performed for the Treatment of Femoral Neck Fracture: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

BACKGROUND

Multiple hemiarthroplasty (HA) approaches exist for femoral neck fracture (FNF) treatment. However, there is no consensus on the superiority of one approach for postoperative outcomes. This study assessed outcomes among randomized controlled trials (RCTs) comparing the posterior approach (PA), direct lateral approach (DLA), anterolateral approach (ALA), and the direct anterior approach (DAA) in HA for FNF.

METHODS

PubMed, Ovid/MEDLINE, Scopus, Cochrane Central Registry of Controlled Trials, and Cochrane Database of Systematic Reviews were queried in February 2024. A frequentist model network meta-analysis of eligible prospective RCTs compared outcomes among approaches using P-scores.

RESULTS

Of 1,481 retrieved studies, 11 RCTs totaling 1,513 FNF patients who underwent HA through a PA (n = 446; 29.5%), DLA (n = 481; 31.8%), ALA (n = 296; 19.6%), or DAA (n = 290; 19.2%) with median (interquartile range) follow-up of 6 (4.5-12.0) months were included for meta-analysis. DAA was associated with statistically increased operative duration (mean difference [MD], 1.89 minutes; 95% CI, 0.08 to 3.69 minutes; p < 0.001) compared with a PA, whereas an ALA was associated with statistically greater blood loss compared with a PA (MD, 5.81 mL; 95% CI, 4.11 to 7.50 mL; p < 0.001). There were no differences in the incidence of fracture, dislocation, infection, complications, revision, nor 1-year mortality among approaches. There were also no differences in hip nor pain score improvement at latest follow-up, although with high heterogeneity (I2 = 85.7% and 94.2%, respectively).

CONCLUSION

This study found no clinical difference in improvement in pain, function, nor in revision outcomes and operative characteristics among HA approaches for FNF, and each approach had a similar adverse event profile. Despite limited randomized evidence, these findings suggest comparable short-term efficacy and safety of all approaches.

LEVEL OF EVIDENCE

Therapeutic, Level I. See Instructions for Authors for a complete description of levels of evidence.

The Reverse Fragility Index for Mortality End Points in Randomized Trials Comparing Uncemented and Cemented Hemiarthroplasty for Intracapsular Hip Fractures

BACKGROUND

Interpreting clinical relevance of randomized clinical trials (RCTs) is challenging when P-values are marginally above or below the P = .05 threshold. This study examined the robustness of statistically insignificant mortality events from RCTs comparing hemiarthroplasty femoral fixation for displaced intracapsular hip fractures through the reverse fragility index (RFI).

METHODS

RCTs were identified using Pubmed, OVID/Medline, and Cochrane databases. Mortality endpoints were stratified into 3 categories: (1) within 30-days, (2) within 90-days, and (3) at latest follow-up. The RFI was derived by manipulating reported mortality events utilizing a contingency table while maintaining a constant number of participants. The reverse fragility quotient (RFQ) was quantified by dividing the RFI by the study sample.

RESULTS

Eight RCTs (2,494 participants) were included. The median RFI and RFQ within 30-days was 3.0 (interquartile range [IQR]: 3.0 to 6.0) and 0.016 (IQR: 0.015 to 0.021), suggesting nonsignificant findings were contingent on 1.6 mortality events/100 participants. The median RFI and RFQ within 90-days was 6.0 (IQR: 4.0 to 7.0) and 0.028 (IQR: 0.024 to 0.038), suggesting nonsignificant findings were contingent on 2.8 mortality events/100 participants. At latest follow-up, the median RFI and RFQ was 7.0 (IQR: 6.0 to 12.0) and 0.038 (IQR: 0.029 to 0.054), suggesting nonsignificant findings were contingent on only 3.8 mortality events/100 participants. Median loss to follow-up was 16.0 (IQR: 11.0 to 58.0; 228% greater than RFI), and exceeded the RFI in 6/7(85.7%) studies.

CONCLUSIONS

A small number of events (median of 7) was required to convert a statistically nonsignificant finding to one that is significant for the endpoint of mortality. The median loss to follow-up exceeded the median RFI by greater than 200%, suggesting methodological limitations such as patient allocation could alter conclusions.

Predicting Instability Risk Following Hemiarthroplasty for Femoral Neck Hip Fractures in Geriatric Patients

BACKGROUND

Although a rare complication, dislocation following hemiarthroplasty (HA) for a femoral neck hip fracture is associated with increased mortality, readmission, and possible revision surgery. To date many of the specific risk factors have been difficult to demonstrate. Patient factors, surgical factors, as well as morphological factors need to be assessed. Therefore, the purpose of this study was to elucidate the risk factors for dislocation of HA following femoral neck hip fractures in the geriatric population.

METHODS

This was a retrospective review of 270 patients who had hip fractures. Medical records between the years 2016 and 2022 informed binomial regression predictive models. The discriminative ability of variables in the final model and acetabular anteversion to predict dislocation was assessed with area under the curve (AUC) estimates.

RESULTS

Center edge angle (odds ratio 1.23), abduction angle (odds ratio 1.17), and depth width ratio (2.96e-11) were significant predictors of dislocation (P = .003, .028, and <.001, respectively). Center edge angle and depth width ratio (<44.1 ° and .298), respectively, were cut scores for risk. Dementia had a high discriminative of ability, as did men (AUC = 0.617, 0.558, respectively). Acetabular anteversion was not predictive of dislocation (P = .259) and theorized anteversion safe zones had poor discriminative ability with AUCs of 0.510 and 0.503, respectively.

CONCLUSIONS

Morphological factors related to hip dysplasia and a shallow acetabulum, which can be assessed with a radiograph alone, were found to be predictors of instability following HA in the elderly. Hemiarthroplasty implant design and manufacturer, and also acetabular version did not contribute to instability risk.

Extended trochanteric osteotomy is a safe procedure in two-stage hip revision: a systematic review of the literature

BACKGROUND

Extended trochanteric osteotomy (ETO) has proved to be an effective technique in complicated stem removal in femoral aseptic loosening or periprosthetic fracture. Debate remains about its safety in periprosthetic joint infection (PJI). The primary aim of this study is to analyze the ETO reinfection and union rate in two-stage hip revision.

MATERIAL AND METHODS

A systematic literature review was performed regarding all studies reporting ETO outcomes in the two-stage revision for hip PJI up to October 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. A literature search was conducted in the following databases: MEDLINE/EMBASE, Scopus, Web of Science, and Cochrane. Quality assessment of the articles was performed using the Methodological Index for Non-Randomized Studies. This systematic review was registered in the International Prospective Registry of Systematic Reviews. Patient demographic, clinical, and surgical data were collected.

RESULTS

This systematic review included and analyzed nine clinical studies with a total of 382 ETO PJI hips in two-stage revision. The overall ETO reinfection rate was 8.9% (34 hips), consistent with the reinfection rate after two-stage revision in patients without ETO. The overall ETO union rate was 94.8% (347 hips), comparable to the ETO union rate in non-septic patients. Compared between a group of patients with ETO PJI and a group of patients with non-PJI ETO, there were no significant differences in postoperative complications, both septic and aseptic, and for postoperative HHS.

CONCLUSION

ETO proved to be a safe and effective procedure in PJI revisions. It may be a viable option in challenging femoral stem removal during the two-stage hip revision in PJI.

LEVEL OF EVIDENCE

IV.

Is outcome of total hip arthroplasty for hip fracture inferior to that of arthritis in a contemporary arthroplasty practice?

INTRODUCTION

Outcome of total hip arthroplasty (THA) for femoral neck fractures (FNF) has been associated with higher complication rates. However, THA for FNF is not always performed by arthroplasty-surgeons. This study aimed to compare THA outcomes for FNF to osteoarthritis (OA). In doing so, we described contemporary THA failure modes for FNF performed by arthroplasty surgeons.

METHODS

This was a retrospective, multi-surgeon study from an academic center. Of FNF treated between 2010 and 2020, 177 received THA by an arthroplasty-surgeon [mean age 67 years (range, 42 to 97), sex: 64.4% women]. These were matched (1:2) for age and sex with 354 THAs performed for hip OA, by the same surgeons. No dual-mobilities were used. Outcomes included radiologic measurements (inclination/anteversion and leg-length), mortality, complications, reoperation rates and patient-reported outcomes including Oxford Hip Score (OHS).

RESULTS

Post-operative mean leg-length difference was 0 millimeters (mm) (range, -10 to -10 mm), with a mean cup inclination and anteversion of 41 and 26° respectively. There was no difference in radiological measurements between FNF and OA patients (p=0.3). At 5 years follow-up, mortality rate was significantly higher in the FNF-THA compared to the OA-THA group (15.3 vs. 1.1%; p<0.001). There was no difference in complications (7.3 vs. 4.2%; p=0.098) or reoperation rates (5.1 vs. 2.9%; p=0.142) between groups. Dislocation rate was 1.7%. OHS at final follow-up was similar [43.7 points (range, 10 to 48) vs. 43.6 points (range, 10 to 48); p=0.030].

CONCLUSION

Total hip arthroplasty for the treatment of FNF is a reliable option and is associated with satisfactory outcomes. Instability was not a common reason of failure, despite not using dual-mobility articulations in this at-risk population. This is likely due to THAs being performed by the arthroplasty staff. When patients live beyond 2-years, similar clinical and radiographic outcomes with low rates of revision can be expected, comparable to elective THA for OA.

Elucidation of target implant orientations with the safety range of hip rotation with adduction or abduction during squatting: Simulation based on in vivo replaced hip kinematics

Objectives: The study aimed to elucidate target cup orientation and stem anteversions to avoid impingement between the liner and stem neck even at hip rotation with adduction during the deeply flexed posture.

Methods: A computer simulation analysis was performed on 32 total hip arthroplasty patients applying patient-specific orientation of the components and in vivo hip kinematics obtained from three-dimensional analysis of the squatting motion. The anterior/posterior liner-to-neck distance and impingement were evaluated based on a virtual change in internal/external rotation (0°–60°) and adduction/abduction (0°–20°) at actual maximum flexion/extension during squatting. Cutoff values of cup orientations, stem anteversion, and combined anteversion to avoid liner-to-neck impingements were determined.

Results: The anterior liner-to-neck distance decreased as internal rotation or adduction increased, and the posterior liner-to-neck distance decreased as external rotation or adduction increased. Negative correlations were found between anterior/posterior liner-to-neck distances at maximum flexion/extension and internal/external rotation. Anterior/posterior liner-to-neck impingements were observed in 6/18 hips (18/56%) at 45° internal/external rotation with 20° adduction. The range of target cup anteversion, stem anteversion, and combined anteversion to avoid both anterior and posterior liner-to-neck impingements during squatting were 15°–18°, 19°–34°, and 41°–56°, respectively.

Conclusion: Simulated hip rotations caused prosthetic impingement during squatting. Surgeons could gain valuable insights into target cup orientations and stem anteversion based on postoperative simulations during the deeply flexed posture.