Comparison of distal and proximal centralising devices in hip arthroplasty

Radiological Comparison of Canal Fill between Collared and Non-Collared Femoral Stems: A Two-Year Follow-Up after Total Hip Arthroplasty

Collared femoral stems in total hip arthroplasty (THA) offer reduced subsidence and periprosthetic fractures but raise concerns about fit accuracy and stem sizing. This study compares collared and non-collared stems to assess the stem-canal fill ratio (CFR) and fixation indicators, aiming to guide implant selection and enhance THA outcomes. This retrospective single-center study examined primary THA patients who received Corail cementless stems between August 2015 and October 2020, with a minimum of two years of radiological follow-up. The study compared preoperative bone quality assessments, including the Dorr classification, the canal flare index (CFI), the morphological cortical index (MCI), and the canal bone ratio (CBR), as well as postoperative radiographic evaluations, such as the CFR and component fixation, between patients who received a collared or a non-collared femoral stem. The study analyzed 202 THAs, with 103 in the collared cohort and 99 in the non-collared cohort. Patients' demographics showed differences in age (p = 0.02) and ASA classification (p = 0.01) but similar preoperative bone quality between groups, as suggested by the Dorr classification (p = 0.15), CFI (p = 0.12), MCI (p = 0.26), and CBR (p = 0.50). At the two-year follow-up, femoral stem CFRs (p = 0.59 and p = 0.27) were comparable between collared and non-collared cohorts. Subsidence rates were almost doubled for non-collared patients (19.2 vs. 11.7%, p = 0.17), however, not to a level of clinical significance. The findings of this study show that both collared and non-collared Corail stems produce comparable outcomes in terms of the CFR and radiographic indicators for stem fixation. These findings reduce concerns about stem under-sizing and micro-motion in collared stems. While this study provides insights into the collar design debate in THA, further research remains necessary.

Comparison of canal fill and radiolucent line formation between two fully coated, hydroxyapatite tapered stems: a 2-year follow-up after total hip arthroplasty

INTRODUCTION

Comparison between fully hydroxyapatite (HA)-coated stems with differing geometry are lacking in the total hip arthroplasty (THA) literature. This study aimed to compare femoral canal fill, radiolucency formation, and 2-year implant survivorship between two commonly used, HA-coated stems.

METHODS

All primary THAs performed with two fully HA-coated stems (Polar stem, Smith&Nephew, Memphis, TN and Corail stem, DePuy-Synthes, Warsaw, IN) with a minimum 2-year radiographic follow-up were identified. Radiographic measures of proximal femoral morphology based on the Dorr classification and femoral canal fill were analyzed. Radiolucent lines were identified by Gruen zone. Perioperative characteristics and 2-year survivorship were compared between stem types.

RESULTS

A total of 233 patients were identified with 132 (56.7%) receiving the Polar stem (P) and 101 (43.3%) receiving the Corail stem (C). No differences were observed with respect to proximal femoral morphology. Femoral stem canal fill at the middle third of the stem was greater for P stem patients than for C stem patients (P stem; 0.80 ± 0.08 vs. C stem; 0.77 ± 0.08, p = 0.002), while femoral stem canal fill at the distal third of the stem and presence of subsidence were comparable between groups. A total of six and nine radiolucencies were observed in P stem and C stem patients, respectively. Revision rate at 2-year (P stem; 1.5% vs C stem; 0.0%, p = 0.51) and latest follow-up (P stem; 1.5% vs C stem; 1.0%, p = 0.72) did not differ between groups.

CONCLUSION

Greater canal fill at the middle third of the stem was observed for the P stem compared to the C stem, however, both stems demonstrated robust and comparable freedom from revision at 2-year and latest follow-up, with low incidences of radiolucent line formation. Mid-term clinical and radiographic outcomes for these commonly used, fully HA-coated stems remain equally promising in THA despite variations in canal fill.

Surgical interventions for treating intracapsular hip fractures in older adults: a network meta-analysis

BACKGROUND

Hip fractures are a major healthcare problem, presenting a considerable challenge and burden to individuals and healthcare systems. The number of hip fractures globally is rising rapidly. The majority of intracapsular hip fractures are treated surgically.

OBJECTIVES

To assess the relative effects (benefits and harms) of all surgical treatments used in the management of intracapsular hip fractures in older adults, using a network meta-analysis of randomised trials, and to generate a hierarchy of interventions according to their outcomes.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Web of Science, and five other databases in July 2020. We also searched clinical trials databases, conference proceedings, reference lists of retrieved articles and conducted backward-citation searches.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing different treatments for fragility intracapsular hip fractures in older adults. We included total hip arthroplasties (THAs), hemiarthroplasties (HAs), internal fixation, and non-operative treatments. We excluded studies of people with hip fracture with specific pathologies other than osteoporosis or resulting from high-energy trauma.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion. One review author completed data extraction which was checked by a second review author. We collected data for three outcomes at different time points: mortality and health-related quality of life (HRQoL) - both reported within 4 months, at 12 months, and after 24 months of surgery, and unplanned return to theatre (at end of study follow-up). We performed a network meta-analysis (NMA) with Stata software, using frequentist methods, and calculated the differences between treatments using risk ratios (RRs) and standardised mean differences (SMDs) and their corresponding 95% confidence intervals (CIs). We also performed direct comparisons using the same codes.

MAIN RESULTS

We included 119 studies (102 RCTS, 17 quasi-RCTs) with 17,653 participants with 17,669 intracapsular fractures in the review; 83% of fractures were displaced. The mean participant age ranged from 60 to 87 years and 73% were women.  After discussion with clinical experts, we selected 12 nodes that represented the best balance between clinical plausibility and efficiency of the networks: cemented modern unipolar HA, dynamic fixed angle plate, uncemented first-generation bipolar HA, uncemented modern bipolar HA, cemented modern bipolar HA, uncemented first-generation unipolar HA, uncemented modern unipolar HA, THA with single articulation, dual-mobility THA, pins, screws, and non-operative treatment. Seventy-five studies (with 11,855 participants) with data for at least two of these treatments contributed to the NMA. We selected cemented modern unipolar HA as a reference treatment against which other treatments were compared. This was a common treatment in the networks, providing a clinically appropriate comparison. In order to provide a concise summary of the results, we report only network estimates when there was evidence of difference between treatments. We downgraded the certainty of the evidence for serious and very serious risks of bias and when estimates included possible transitivity, particularly for internal fixation which included more undisplaced fractures. We also downgraded for incoherence, or inconsistency in indirect estimates, although this affected few estimates. Most estimates included the possibility of benefits and harms, and we downgraded the evidence for these treatments for imprecision.  We found that cemented modern unipolar HA, dynamic fixed angle plate and pins seemed to have the greatest likelihood of reducing mortality at 12 months. Overall, 23.5% of participants who received the reference treatment died within 12 months of surgery. Uncemented modern bipolar HA had higher mortality than the reference treatment (RR 1.37, 95% CI 1.02 to 1.85; derived only from indirect evidence; low-certainty evidence), and THA with single articulation also had higher mortality (network estimate RR 1.62, 95% CI 1.13 to 2.32; derived from direct evidence from 2 studies with 225 participants, and indirect evidence; very low-certainty evidence). In the remaining treatments, the certainty of the evidence ranged from low to very low, and we noted no evidence of any differences in mortality at 12 months.  We found that THA (single articulation), cemented modern bipolar HA and uncemented modern bipolar HA seemed to have the greatest likelihood of improving HRQoL at 12 months. This network was comparatively sparse compared to other outcomes and the certainty of the evidence of differences between treatments was very low. We noted no evidence of any differences in HRQoL at 12 months, although estimates were imprecise. We found that arthroplasty treatments seemed to have a greater likelihood of reducing unplanned return to theatre than internal fixation and non-operative treatment. We estimated that 4.3% of participants who received the reference treatment returned to theatre during the study follow-up. Compared to this treatment, we found low-certainty evidence that more participants returned to theatre if they were treated with a dynamic fixed angle plate (network estimate RR 4.63, 95% CI 2.94 to 7.30; from direct evidence from 1 study with 190 participants, and indirect evidence). We found very low-certainty evidence that more participants returned to theatre when treated with pins (RR 4.16, 95% CI 2.53 to 6.84; only from indirect evidence), screws (network estimate RR 5.04, 95% CI 3.25 to 7.82; from direct evidence from 2 studies with 278 participants, and indirect evidence), and non-operative treatment (RR 5.41, 95% CI 1.80 to 16.26; only from indirect evidence). There was very low-certainty evidence of a tendency for an increased risk of unplanned return to theatre for all of the arthroplasty treatments, and in particular for THA, compared with cemented modern unipolar HA, with little evidence to suggest the size of this difference varied strongly between the arthroplasty treatments.

AUTHORS' CONCLUSIONS

There was considerable variability in the ranking of each treatment such that there was no one outstanding, or subset of outstanding, superior treatments. However, cemented modern arthroplasties tended to more often yield better outcomes than alternative treatments and may be a more successful approach than internal fixation. There is no evidence of a difference between THA (single articulation) and cemented modern unipolar HA in the outcomes measured in this review. THA may be an appropriate treatment for a subset of people with intracapsular fracture but we have not explored this further.

Arthroplasties for hip fracture in adults

BACKGROUND

Hip fractures are a major healthcare problem, presenting a huge challenge and burden to individuals and healthcare systems. The number of hip fractures globally is rising rapidly. The majority of hip fractures are treated surgically. This review evaluates evidence for types of arthroplasty: hemiarthroplasties (HAs), which replace part of the hip joint; and total hip arthroplasties (THAs), which replace all of it.

OBJECTIVES

To determine the effects of different designs, articulations, and fixation techniques of arthroplasties for treating hip fractures in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, seven other databases and one trials register in July 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing different arthroplasties for treating fragility intracapsular hip fractures in older adults. We included THAs and HAs inserted with or without cement, and comparisons between different articulations, sizes, and types of prostheses. We excluded studies of people with specific pathologies other than osteoporosis and with hip fractures resulting from high-energy trauma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We collected data for seven outcomes: activities of daily living, functional status, health-related quality of life, mobility (all early: within four months of surgery), early mortality and at 12 months after surgery, delirium, and unplanned return to theatre at the end of follow-up.

MAIN RESULTS

We included 58 studies (50 RCTs, 8 quasi-RCTs) with 10,654 participants with 10,662 fractures. All studies reported intracapsular fractures, except one study of extracapsular fractures. The mean age of participants in the studies ranged from 63 years to 87 years, and 71% were women. We report here the findings of three comparisons that represent the most substantial body of evidence in the review. Other comparisons were also reported, but with many fewer participants. All studies had unclear risks of bias in at least one domain and were at high risk of detection bias. We downgraded the certainty of many outcomes for imprecision, and for risks of bias where sensitivity analysis indicated that bias sometimes influenced the size or direction of the effect estimate. HA: cemented versus uncemented (17 studies, 3644 participants) There was moderate-certainty evidence of a benefit with cemented HA consistent with clinically small to large differences in health-related quality of life (HRQoL) (standardised mean difference (SMD) 0.20, 95% CI 0.07 to 0.34; 3 studies, 1122 participants), and reduction in the risk of mortality at 12 months (RR 0.86, 95% CI 0.78 to 0.96; 15 studies, 3727 participants). We found moderate-certainty evidence of little or no difference in performance of activities of daily living (ADL) (SMD -0.03, 95% CI -0.21 to 0.16; 4 studies, 1275 participants), and independent mobility (RR 1.04, 95% CI 0.95 to 1.14; 3 studies, 980 participants). We found low-certainty evidence of little or no difference in delirium (RR 1.06, 95% CI 0.55 to 2.06; 2 studies, 800 participants), early mortality (RR 0.95, 95% CI 0.80 to 1.13; 12 studies, 3136 participants) or unplanned return to theatre (RR 0.70, 95% CI 0.45 to 1.10; 6 studies, 2336 participants). For functional status, there was very low-certainty evidence showing no clinically important differences. The risks of most adverse events were similar. However, cemented HAs led to less periprosthetic fractures intraoperatively (RR 0.20, 95% CI 0.08 to 0.46; 7 studies, 1669 participants) and postoperatively (RR 0.29, 95% CI 0.14 to 0.57; 6 studies, 2819 participants), but had a higher risk of pulmonary embolus (RR 3.56, 95% CI 1.26 to 10.11, 6 studies, 2499 participants). Bipolar HA versus unipolar HA (13 studies, 1499 participants) We found low-certainty evidence of little or no difference between bipolar and unipolar HAs in early mortality (RR 0.94, 95% CI 0.54 to 1.64; 4 studies, 573 participants) and 12-month mortality (RR 1.17, 95% CI 0.89 to 1.53; 8 studies, 839 participants). We are unsure of the effect for delirium, HRQoL, and unplanned return to theatre, which all indicated little or no difference between articulation, because the certainty of the evidence was very low. No studies reported on early ADL, functional status and mobility. The overall risk of adverse events was similar. The absolute risk of dislocation was low (approximately 1.6%) and there was no evidence of any difference between treatments. THA versus HA (17 studies, 3232 participants) The difference in the risk of mortality at 12 months was consistent with clinically relevant benefits and harms (RR 1.00, 95% CI 0.83 to 1.22; 11 studies, 2667 participants; moderate-certainty evidence). There was no evidence of a difference in unplanned return to theatre, but this effect estimate includes clinically relevant benefits of THA (RR 0.63, 95% CI 0.37 to 1.07, favours THA; 10 studies, 2594 participants; low-certainty evidence). We found low-certainty evidence of little or no difference between THA and HA in delirium (RR 1.41, 95% CI 0.60 to 3.33; 2 studies, 357 participants), and mobility (MD -0.40, 95% CI -0.96 to 0.16, favours THA; 1 study, 83 participants). We are unsure of the effect for early functional status, ADL, HRQoL, and mortality, which indicated little or no difference between interventions, because the certainty of the evidence was very low.  The overall risks of adverse events were similar. There was an increased risk of dislocation with THA (RR 1.96, 95% CI 1.17 to 3.27; 12 studies, 2719 participants) and no evidence of a difference in deep infection.

AUTHORS' CONCLUSIONS

For people undergoing HA for intracapsular hip fracture, it is likely that a cemented prosthesis will yield an improved global outcome, particularly in terms of HRQoL and mortality. There is no evidence to suggest a bipolar HA is superior to a unipolar prosthesis. Any benefit of THA compared with hemiarthroplasty is likely to be small and not clinically appreciable. We encourage researchers to focus on alternative implants in current clinical practice, such as dual-mobility bearings, for which there is limited available evidence.