Revision rates and cumulative financial burden in patients treated with hemiarthroplasty compared to cannulated screws after femoral neck fractures

Cold Welding of the Synthes Femoral Neck System Encountered at Conversion to Arthroplasty: A Case Report

CASE

The Synthes Femoral Neck System (FNS) is a relatively new device available to the market in 2019 designed to reduce complication and revision rates after femoral neck fracture stabilization. We present a 77-year-old man with Parkinson disease and avascular necrosis after femoral neck fracture initially managed with the FNS. Subsequent challenges in device removal occurred because of its propensity for bony integration, plate and locking screw welding, and screw head recess destruction.

CONCLUSION

Surgeons must recognize the need for additional available equipment (e.g., burr or broken screw removal set) for successful extraction when FNS removal is required.

A comparison of internal fixation and hemiarthroplasty in the management of un- or minimally displaced hip fractures in patients over 60 years old

BACKGROUND

The incidence of hip fractures in the elderly is increasing. Minimally displaced and undisplaced hip fractures can be treated with either internal fixation or hemiarthroplasty.

OBJECTIVES

To identify the revision rate of internal fixation and hemiarthroplasty in patients 60 years or older with Garden I or II hip fractures and to identify risk factors associated with each method.

METHOD

A retrospective analysis was conducted from 2 Major Trauma Centres and 9 Trauma Units between 01/01/2015 and 31/12/2020. Patients managed conservatively, treated with a total hip replacement and missing data were excluded from the study.

RESULTS

1273 patients were included of which 26.2% (n = 334) had cannulated hip fixation (CHF), 19.4% (n = 247) had a dynamic hip screw (DHS) and 54.7% (n = 692) had a hemiarthroplasty. 66 patients in total (5.2%) required revision surgery. The revision rates for CHF, DHS and hemiarthroplasty were 14.4%, 4%, 1.2% (p<0.001) respectively. Failed fixation was the most common reason for revision with the incidence increasing by 7-fold in the CHF group [45.8% (n = 23) vs. 33.3% (n = 3) in DHS; p<0.01]. The risk factors identified for CHF revision were age >80 (p<0.05), female gender (p<0.05) and smoking (p<0.05). The average length of hospital stay was decreased when using CHF compared to DHS and hemiarthroplasty (12.6 days vs 14.9 days vs 18.1 days respectively, p<0.001) and the 1 year mortality rate for CHF, DHS and hemiarthroplasty was 2.5%, 2% and 9% respectively.

CONCLUSIONS

Fixation methods for Garden I and II hip fractures in elderly patients are associated with a higher revision rate than hemiarthroplasty. CHF has the highest revision rate at 14.4% followed by DHS and hemiarthroplasty. Female patients, patients over the age of 80 and patients with poor bone quality are considered high risk for fixation failure with CHF. Hemiarthroplasty is a suitable alternative with lowest revision rates. When considering an internal fixation method, DHS is more robust than a screw construct.

Hybrid screw fixation for femoral neck fractures: Does it prevent mechanical failure?

INTRODUCTION

Traditionally, femoral neck fracture fixation has been performed using three partially threaded cancellous screws. However, fracture collapse with femoral neck shortening, and varus deformation frequently occurs due to posterior medial comminution and lack of calcar support. We hypothesize replacing the inferior neck/calcar screw with a fully threaded, length stable, screw will provide improved biomechanical stability, decrease femoral neck shortening and varus collapse.

METHODS

Ten matched cadaveric pairs (20 femurs) were randomly assigned to two screw fixation groups. Group 1 (Hybrid) utilized one fully threaded calcar screw & two partially threaded superior screws. Group 2 (PT) utilized all partially threaded screws. Specimens underwent standardized femoral neck osteotomies, 45° from the horizontal, with 5 mm posteromedial wedge removed to simulate posteromedial comminution. Screws were placed using fluoroscopic guidance. Specimens were biomechanically tested using two loading sequences: 1) Axial load applied up to 700 N, followed by cyclic loading at 2 Hz with loads of 700 to 1,400 N for 10,000 cycles. 2) All surviving constructs were cyclically loaded to failure in stepwise incremental manner with max load of 4,000 N. Paired t-tests used to compare stiffness, cycles to failure, and max load to failure (defined as 15 mm load actuator displacement).

RESULTS

Construct stiffness was 2848 ± 344 N/mm in PT vs. 2767 ± 665 for Hybrid (P = 0.628). Load to failure demonstrated, hybrid superiority with max cycles to failure (3797 ± 400 cycles) vs. (2981 ± 856 cycles in PT) (p = 0.010), and max load prior to failure (3290 ± 196 N) vs. (2891 ± 421 N in PT) (p = 0.010). No significant difference in bone mineral density was noted in any of the specimens.

CONCLUSIONS

Our study is the first to assess the biomechanical effects of hybrid fixation for femoral neck fractures. Hybrid screw configuration resulted in significantly stronger constructs, with higher axial load and increased cycles prior to failure. The advantageous mechanical properties demonstrated using a fully threaded inferior calcar screw provides a length stable construct which may prevent the common complication of excessive femoral neck shortening, varus collapse and poor functional outcome.

Long-Term Efficacy of Screw Fixation vs Hemiarthroplasty for Undisplaced Femoral Neck Fracture in Patients over 65 Years of Age: A Systematic Review and Meta-Analysis

Objective

To compare the long‐term efficacy of screw fixation and hemiarthroplasty in elderly patients with undisplaced femoral neck fractures.

Methods

We searched Cochrane Library, EMBASE, and MEDLINE from inception to 10 June 2020 to identify studies about undisplaced femoral neck fracture in elderly patients over 65 years of age. The included studies were assessed by two researchers according to the Cochrane risk‐of‐bias criteria and Newcastle–Ottawa Scale. Meta‐analysis was performed with Revman 5.3 software. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables.

Results

A total of 750 patients were included in this meta‐analysis. In elderly patients, undisplaced femoral neck fracture treated with hemiarthroplasty had a lower implant‐related complication rate (OR, 4.05 [95% CI, 2.38 to 6.89]; P < 0.00001; I² = 0), lower reoperation rate (OR, 4.88 [95% CI, 2.84 to 8.38]; P < 0.00001; I² = 0), and superior Harris score (WMD, −5.05 [95% CI, −7.30 to −2.80]; P < 0.0001; I² = 0) in the early postoperative period. Although screw fixation was associated with shorter operative time (WMD, −36.22 [95% CI, −50.72 to −21.73]; P < 0.00001; I² = 98%) and less blood loss (WMD, −165.84 [95% CI, −209.29 to −122.38]; P < 0.00001; I² = 96%), there was no significant difference in long‐term mortality (OR, 0.65 [95% CI, 0.28 to 1.48]; P < 0.31; I² = 75%) between these two treatments.

Conclusion

In elderly patients with undisplaced femoral neck fractures, hemiarthroplasty provided a lower implant‐related complication rate, lower reoperation rate, superior hip function without increased long‐term mortality. Hemiarthroplasty should be recommended as a better alternative in such patients compared with multiple cannulated screws.

Posterior tilt in nondisplaced femoral neck fractures increases the risk of reoperations after osteosynthesis. A systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review on the effect of posterior tilt on reoperations, patient reported outcome measures (PROM) and functional outcome following osteosynthesis of undisplaced FNFs (uFNF).

MATERIAL AND METHODS

A search string was developed with the aid of a scientific librarian and the search was performed in PubMed, CINAHL and Embase. The studies were screened independently by two authors using Covidence. Data were extracted by two authors and quality assessment was performed using Robins-I tool. The meta-analyses were performed in STATA IC 16 using Risk Ratio as the primary effect estimate.

RESULTS

In total, 617 studies were screened and ten studies were included with a total of 3,131 patients. The mean age ranged from 68.3 to 85.0 years and the prevalence of posterior tilt ≥20° in the studies ranged from 4.5% to 27.6%. There were 10.3% reoperations when posterior tilt was <20° whereas there were 24.5% when posterior tilt was ≥20° The meta-analysis therefore demonstrated an overall risk ratio of 0.11 (95% confidence interval; 0.04-0.18). Only one study investigated functional outcome, using ADL as measurement, but found no significant difference. No studies investigated PROM. In general, the studies were assessed to be of poor quality mainly due possible bias and confounding.

CONCLUSION

A posterior tilt ≥20° leads to a higher risk of reoperations in uFNF. Even though the studies were of poor quality, the results suggest that we should include the measurement of posterior tilt in national guidelines.

Screw Fixation Versus Hemiarthroplasty for Nondisplaced Femoral Neck Fractures in the Elderly: A Cost-Effectiveness Analysis

OBJECTIVE

To evaluate the cost-effectiveness of screw fixation versus hemiarthroplasty for nondisplaced femoral neck fractures in low-demand elderly patients.

METHODS

We constructed a Markov decision model using a low-demand, 80-year-old patient as the base case. Costs, health-state utilities, mortality rates, and transition probabilities were obtained from published literature. The simulation model was cycled until all patients were deceased to estimate lifetime costs and quality-adjusted life years (QALYs). The primary outcome was the incremental cost-effectiveness ratio with a willingness-to-pay threshold set at $100,000 per QALY. We performed sensitivity analyses to assess our parameter assumptions.

RESULTS

For the base case, hemiarthroplasty was associated with greater quality of life (2.96 QALYs) compared with screw fixation (2.73 QALYs) with lower cost ($23,467 vs. $25,356). Cost per QALY for hemiarthroplasty was $7925 compared with $9303 in screw fixation. Hemiarthroplasty provided better outcomes at lower cost, indicating dominance over screw fixation.

CONCLUSIONS

Hemiarthroplasty is a cost-effective option compared with screw fixation for the treatment of nondisplaced femoral neck fractures in the low-demand elderly. Medical comorbidities and other factors that impact perioperative mortality should also be considered in the treatment decision.

LEVEL OF EVIDENCE

Economic Level III. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of elderly patients with nondisplaced or minimally displaced femoral neck fractures treated with internal fixation: A systematic review and meta-analysis

BACKGROUND

Internal fixation remains the treatment of choice for non-displaced femoral neck fractures in elderly patients. Improved outcomes with arthroplasty following displaced femoral neck fractures may indicate that outcomes of non-displaced patterns should be reexamined. The aim of our study was to conduct a systematic review of the orthopaedic literature to determine the outcomes of internal fixation for the treatment of non-displaced and minimally displaced femoral neck fractures in elderly patients.

METHODS

Relevant articles were identified using PubMed, Embase, and CENTRAL databases. Manuscripts were included if they contained (1) patients 60 years or older with (2) nondisplaced or minimally displaced (Garden I or II) femoral neck fractures (3) treated with internal fixation (4) separately reported outcomes in this patient population. The primary outcome was reoperation. Secondary outcomes included mortality, patient-reported outcomes, length of hospitalization, infection, and transfusions. Fixed and random effects modeling was used to determine pooled estimates of the outcomes.

RESULTS

Twenty-seven studies were identified with a total of 21,155 patients, all of which were treated with internal fixation. The pooled risk of reoperation was 14.1% (95% CI: 10.6-18.2). The risk of one-year mortality was 14.6% (95% CI: 11.5-18.2) based on the reporting in 15 studies.

CONCLUSIONS

The risk of reoperation and mortality following the treatment of nondisplaced femoral neck fractures in the elderly with internal fixation exceeds 14%. This complication profile may be unacceptably high. Arthroplasty may offer improved short-term functional outcomes and a reduced risk of reoperation. However, there is currently little evidence to consider this treatment to be an alternative to internal fixation.

Osteosynthesis with Parallel Implants in the Treatment of Femoral Neck Fractures: Minimal Effect of Implant Position on Risk of Reoperation

BACKGROUND

The purpose of this study was to estimate the incidence of reoperation and the effect of implant position on the risk of reoperation within 12 months following osteosynthesis with use of parallel implants for femoral neck fractures.

METHODS

From cases registered in the Danish Fracture Database, 1,206 consecutive surgeries for a primary femoral neck fracture treated with use of parallel implants during the period of December 2011 to November 2015, and having available radiographs and follow-up data, were reviewed. Data included age, sex, time to surgery, fracture classification, and American Society of Anesthesiologists (ASA) score. Fracture displacement, posterior tilt, the number of implants, posterior distance, calcar distance, tip-cartilage distance, and angulation of implants were measured on pre- and postoperative radiographs. Data on secondary surgeries were collected from the Danish Civil Registration System. The effects of the included variables on the risk of reoperation were evaluated using Cox regression analysis.

RESULTS

The median age was 73 years (range, 21 to 102 years); in 69% of the cases, the patient was female. Two implants were used in 997 cases and 3 implants were used in 209. In 157 cases, the patient underwent reoperation within 1 year; in 228 cases, the patient died within 1 year. The median time to reoperation was 116 days. Patients <70 years of age were more likely to undergo reoperation (18.0% compared with 9.8%) but less likely to die (7.4% compared with 26.3%) than were patients ≥70 years of age. Female sex, higher ASA score, and displaced fractures were associated with increased risk of reoperation. Time to surgery was associated with increased risk of reoperation for displaced fractures only. Of the variables pertaining to the osteosynthesis, only insufficient fracture reduction, placement of the implants with an angle to the shaft of ≤125°, and femoral head perforation significantly increased the risk of reoperation. We found no effect of the posterior distance, the calcar distance, the tip-caput distance, or whether or not the implants were parallel.

CONCLUSIONS

Insufficient reduction, varus position of the implants, and perforation of the femoral head cartilage were the only surgical factors influencing the risk of reoperation. Sufficient fracture reduction is perhaps more important than focusing on an optimal position of the implants.

LEVEL OF EVIDENCE

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

Percutaneous image-guided screws meditated osteosynthesis of impeding and pathological/insufficiency fractures of the femoral neck in non-surgical cancer patients

AIM

To present percutaneous image-guided screw-mediated osteosynthesis (PIGSMO) for fixation of impending fractures (ImF) and non-displaced/mildly displaced pathological/insufficient fractures (PF/InF) of the femoral neck in non-surgical cancer patients.

MATERIALS AND METHODS

This is a double-centre single-arm observational study. Retrospective review of electronic records identified all oncologic patients who had undergone femoral neck PIGSMO. Inclusion criteria were: non-displaced or mildly displaced PF/InF, and ImF (Mirels' score ≥8); life expectancy ≥1 month; unsuitability for surgical treatment due to sub-optimal clinical fitness, refusal of consent, or unacceptable delay to systemic therapy.

RESULTS

Eleven patients were treated (mean age 63.7±13.5 years) due to ImF (63.6%, mean Mirels' score 10.1), PF (27.3%) or post-radiation InF (9.1%) under CT/fluoroscopy- (36.4%) or CBCT- (63.6%) guidance. Thirty-two screws were implanted and cement injection was added in 36.4% cases. Technical success was 90.9%. No procedure related complications were noted. At 1-month clinical follow-up (pain/walking impairment), 63.6% and 27.3% patients reported significant and mild improvement, respectively. Imaging follow-up (available in 63.6% cases) showed no signs of secondary fractures, neither of screws loosening at mean 2.8 months. Five patients (45.5%) died after PIGSMO (mean time interval 3.6 months).

CONCLUSIONS

PIGSMO is technically feasible and safe in cancer patients with limited life expectancy; it offers good short-term results. Further prospective studies are required to corroborate mid- and to prove long-term efficacy of the technique.

Diagnostic Imaging Strategies for Occult Hip Fractures: A Decision and Cost-Effectiveness Analysis

OBJECTIVE

Hip fractures cause significant morbidity and mortality. Determining the optimal diagnostic strategy for the subset of patients with potential occult hip fracture remains challenging. We determined the most cost-effective strategy for the diagnosis of occult hip fractures from the choices of performing only computed tomography (CT), performing only magnetic resonance imaging (MRI), performing CT and if negative performing MRI (MRI-selective strategy) or discharging the patient without advanced imaging.

METHODS

We developed a decision-analytic model to compare outcomes and costs of different diagnostic strategies for the diagnosis of an occult hip fracture from a societal perspective. Model inputs were derived from charge data, Medicare reimbursements, and the literature. Strategies with an incremental cost-effectiveness ratio (ICER) below $100,000 per quality-adjusted life-year (QALY) gained were considered cost-effective. We tested the robustness of our results using probabilistic sensitivity analysis.

RESULTS

Compared to a CT strategy, MRI provides an additional 0.05 QALY at an incremental cost of $1,227 and ICER of $25,438/QALY. For facilities without MRI capability, if the cost of transfer is below $1,228, transferring the patient to a MRI-capable facility is the most cost-effective strategy. Above this cost, employing a CT and if negative transfer to a MRI-capable facility strategy was more cost-effective. When the cost of a transfer reached more than $4,039, it became more cost-effective to only obtain a CT.

CONCLUSION

MRI is a cost-effective strategy for the diagnosis of an occult hip fracture. For facilities without MRI capability, the most cost-effective strategy depends on the cost of the interfacility transfer.