Survival and complications of total hip arthroplasty using third-generation dual-mobility cups with non-cross-linked polyethylene liners in patients younger than 55years

The use of both conventional and dual-mobility components in primary total hip arthroplasty is safe in a university hospital practice

Aims

Dislocation after total hip arthroplasty (THA) is a frequent cause of revision. Patients with intrinsic risk factors have been identified. The use of a dual-mobility (DM) acetabular component has shown great effectiveness in preventing dislocation, with questions regarding selective or absolute use. The aim of this study was to compare the outcome of conventional THA (C-THA) and DM-THA, when used for selected patients.

Methods

This retrospective continuous cohort study evaluated 531 patients, of whom 313 received C-THA and 218 DM-THA. There were 354 primary osteoarthritis (67%), 121 femoral neck fractures (FNFs) (23%), and 56 other indications (10%). The surgical approach was anterior (AA) in 75% cases (398) and posterior (PA) in 25% of cases (133). In the DM-THA group, 189 patients (87%) presented at least one dislocation risk factor compared to 151 patients (48%) in the C-THA group (p < 0.001). The primary outcome was major surgical complications within two years (including deep infection requiring surgery, dislocation requiring closed or open reduction, or revision surgery). Secondary outcomes included length of hospital stay and component positioning.

Results

There were no differences in major complications at two years' follow-up, with six patients (2.7%) in the DM-THA group and eight in the C-THA group (2.6%) (p = 0.301). There were four dislocations in the DM-THA group (three PA and one AA) and three in the C-THA group (three AA) (p = 0.402). The length of stay was significantly longer in the DM-THA group, with seven days (2 to 12) compared to four days (1 to 7) in the C-THA group (p = 0.001).

Conclusion

C-THA and DM-THA are complementary devices in the management of patients requiring primary THA. C-THA associated with AA is a safe option for patients with or without dislocation risk factors, excluding FNF. The selective implantation of the DM component was associated with a low rate of dislocation when THA was undertaken for FNF. The identification of dislocation risk factors is important to select patients requiring DM-THA and provide reproducible outcomes in a university hospital practice with various levels of surgeon experience.

What does the SOFCOT-RENACOT 2024 hip prosthesis register tell us?

INTRODUCTION

The French Society of Orthopedic and Traumatology Surgery (SOFCOT) multicenter register of hip prostheses (HP) has been collecting data from nearly 100 centers in France since 2006. After 18 years of collection, this analysis was carried out to deduce the main conclusions.

HYPOTHESIS

Despite its low representativeness (3%), this register provides instructive information on the evolution of hip arthroplasty techniques and implants in France.

MATERIAL AND METHODS

As of the 31st of December 2023, 58,314 primary HP were recorded, mainly for primary osteoarthritis (44,535 hips, 76.4%), followed by femoral neck fractures (4,880, 8.4%). The mean age was 71 years (SD, 11.6) with 57% (33,305) women. In total, 73% of the implants were uncemented and 170 brand names were listed. Over the same period, 5,853 first reoperations were recorded. Social security number matching identified 777 revisions of an already registered primary HP. The revision index for 100 components observed per year (RCOY) allows the performance of implants to be compared (alert threshold if >1.3).

RESULTS

The causes of these 777 early first revisions at a short mean follow-up (MF) of 1.4 years were: dislocation (191/777, 24.6%), peri-prosthetic fracture (175, 22.5%), aseptic loosening (103, 13.3%) and acute infection (101, 13%). The RCOY for all primary HP was 0.25 at 5.4 years of MF. This index: (i) Depended on the type of implant: 0.23 for HP with dual-mobility cups (DMC) at 4.7 years of MF; 0.25 for HP with short femoral stems at 4.4 years; and 0 for resurfacing after only 2.5 years (due to the creation of a specific mandatory register, since 2015, which put an end to the voluntary inclusion of resurfacing in this general register). (ii) Depended on the method of fixation: 0.21 for completely cemented HP at 7.8 years of MF and 0.29 at 4.9 years for completely uncemented HP. (iii) Based on the friction torque: 0.12 for conventional metal-metal HP at 9.7 years of MF and 0.29 at 5.1 years for alumina-alumina HP. (iv) Finally, 3 arthroplasties with 3 uncemented stems had an RCOY > 1.3.

DISCUSSION

Although the RCOY of HP with conventional cemented femoral stems is only 0.16 at 6.6 years of MF, while that of HP with conventional uncemented stems is 0.29 at 4.9 years, the trend towards uncemented femoral fixation has continued to intensify. Resurfacing gives good results following careful selection of implants but with a short MF of 2.5 years. Conventional metal-metal bearings continue to give excellent results at almost 10 years of MF. The 10-year survival of HP with short femoral stems is favorable compared to that of HP with conventional stems. There is no significant difference between the survival of HP with conventional versus highly cross-linked polyethylene liner.

CONCLUSION

Despite its low representativeness, this register provides information on the techniques and implants used in France. The addition of clinical monitoring and PROM within the new SOFCOT-RENACOT registry as well as re-certification obligations should help promote its development.

LEVEL OF EVIDENCE

III; prospective comparative study.

Change in spinopelvic mobility 3 months after THA using a direct anterior approach

INTRODUCTION

Spinopelvic kinematics, reflected by the change in spinopelvic tilt (ΔSPT) from a standing position to a flexed seated position, has been associated with the risk of prosthetic impingement and hip dislocation. Some studies have suggested changes in spinopelvic mobility after total hip arthroplasty (THA), but none have explored changes in mobility in the first three months following THA using a direct anterior approach.

HYPOTHESIS

Our hypothesis was that changes in spinopelvic mobility occur in the first 3 months postoperatively, leading to increased hip mobility and increased spinopelvic kinematic abnormalities.

METHODS

This retrospective analysis of a consecutive series included 109 patients treated with primary anterior THA by a single senior surgeon. Lateral radiographs taken in standing and flexed seated positions before and three months after surgery were examined to analyze ΔSPT, pelvic femoral angle (PFA), lumbar lordosis (LL), and abnormal spinopelvic mobility (ΔSPT ≥20 °). Secondary objectives included examining the relationship between changes in lumbar flexion and hip flexion, and then analyzing preoperative spinopelvic parameters involved in postoperative pelvic mobility changes.

RESULTS

Between the two periods of analysis, the ΔSPT increased on average by 9.53 ° (-34.4/50.3 °), the ΔPFA increased by 7.68 ° (-74/49 °), and lumbar flexion (ΔLL) decreased by 4.26 ° (-20.8/26 °). The rate of ΔSPT ≥20 ° was 22.9% before the operation and 47.7% after the operation (OR = 8.98; CI [2.82; 28.56]; p < 0.001). A strong positive correlation was found between changes in ΔSPT and ΔPFA (ρ = 0.76; r2 = 0.574; p < 0.001) and no correlation between changes in ΔSPT and ΔLL (ρ=-0.019; r2 = 0.005; p = 0.842). The multivariate analysis demonstrated independent predictors of change in ΔSPT were body mass index (BMI, β = -0.59, [-1.15; -0.03], p = 0.0386), ΔPFA (β = -0.46, [-0.59; -0.34], p < 0.001), and ΔLL (β = -0.36, [-0.53; -0.19], p < 0.001). No dislocation was observed.

CONCLUSIONS

Spinopelvic mobility changes occur early on, within 3 months, after anterior THA. Patients with preoperative lumbar stiffness, associated with a stiff hip and lower BMI, should prompt surgeons to the risk of worsening spinopelvic kinematic abnormalities postoperatively.

LEVEL OF EVIDENCE

IV; retrospective study.

Ten to 15-Year Outcomes of Monoblock Uncemented Dual Mobility Cups: Excellent Survival Rate and Outcome in Primary Total Hip Arthroplasty

Background

Dual mobility cups (DMCs) have effectively prevented dislocations after total hip arthroplasty (THA). However, use of these cups in primary THAs remains controversial, especially in young patients. This study aimed to determine the long-term survival rate and functional outcomes of a contemporary DMC used in primary THA.

Methods

This retrospective multicenter study identified a cohort of 614 primary THAs performed with the same uncemented monoblock DMC between 2007 and 2010. Survival analysis included 572 THAs, while clinical analysis involved 394 THAs at a minimal follow-up of 10 years. The mean follow-up was 11.1 ± 1.2 years. The mean age was 71.4 ± 11.7 years, with 4.2% of patients under 50 years old. The mean body mass index was 27.0 ± 5.3 kg/m2. The 10-year Kaplan-Meier survival rate was calculated based on cup removal for any reason or cup revision for an aseptic reason as the end point. Harris hip scores were collected at the last follow-up.

Results

The cup-revision-free survival rate was 98.6% at 10 years and 96.2% at 13 years. No cup revisions were reported due to aseptic loosening or dislocation. The cup revisions were due to infection (7 of 572; 1.2%), acetabular fracture (1 of 572; 0.17%), and psoas impingement due to cup malpositioning (n = 1 of 572; 0.17%). Only 3 dislocations (0.52%) were observed, and they did not require revision. The mean Harris hip score significantly improved from 54.1 ± 14.4 preoperatively to 88.0 ± 14.3 at the last follow-up (p < 0.0001). For patients under 50 years old at the time of surgery, the mean Harris hip score showed significant improvement from 53.0 ± 10.2 preoperatively to 89.7 ± 12.8 at the last follow-up (p < 0.0001), with no significant difference compared with the older patients (p = 0.50). No revision or complication was reported in the younger patient population at 13 years of follow-up.

Conclusions

The monoblock uncemented DMC demonstrated excellent survival rates with no DMC-specific complications during a minimum 10-year follow-up. The dislocation rate was very low, and a younger age was not identified as a risk factor for failure. Therefore, monoblock cementless DMCs can be safely used, even in primary THA.

Level of Evidence

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

Archetype analysis of the spine-hip relationship identifies distinct spinopelvic profiles

INTRODUCTION

The position of the pelvis in the sagittal plane can vary considerably between different functional positions. Adapting the position of the acetabular cup in relation to the alignment between the spine and the hip of each individual, prior to prosthesis placement, can prevent the risk of prosthetic impingement. Taken individually, risk factors for unfavorable spinopelvic kinematics can be difficult to interpret when trying to precisely predict which patients are at risk. Furthermore, the use of classifications or algorithms can be complex, most often associated with limited values and often difficult to apply in current practices of risk assessment.

HYPOTHESIS

We hypothesized that the deconstruction of the data matrix including age and spinopelvic parameters (SPT, LL, PI, LF and PI-LL) correlated with the analysis of spinopelvic kinematics could be used to define an individualized hip-spine relationship.

MATERIAL AND METHOD

We applied archetypal analysis, which is a probabilistic, data-driven and unsupervised approach, to a complete phenotype cohort of 330 patients before total hip arthroplasty to define the spinopelvic profile of each individual using the spinopelvic parameters without threshold value. For each archetype, we analyzed the spinopelvic kinematics, not implemented in the creation of the archetypes.

RESULTS

An unsupervised learning method revealed seven archetypes with distinct spinopelvic kinematic profiles ranging from -8.9 ° to 13.15 ° (p = 0.0001) from standing to sitting and -5. 35 ° to -10.81 ° (p = 0.0001) from supine to standing. Archetype 1 represents the "ideal" patient (A1); young patients without spinopelvic anomaly and the least at risk of mobility anomaly. Followed by 3 archetypes without sagittal imbalance according to their lumbar lordosis and pelvic incidence, from the highest to the lowest (archetypes 2-4), archetype 4 exposing a greater risk of spinopelvic kinematic anomaly compared to others. Then 2 archetypes with sagittal imbalance: archetype 5, with an immobile pelvis in the horizontal plane from standing to sitting position in anterior tilt and archetype A6, with significant posterior pelvic tilt standing, likely compensating for the imbalance and associated with the greatest anomaly of spinopelvic kinematics. Finally, archetype 7 with the stiffest lumbar spine without sagittal imbalance and significant unfavorable kinematics from standing to sitting.

CONCLUSION

An archetypal approach to patients before hip replacement can refine diagnostic and prognostic features associated with the hip-spine relationship and reduced heterogeneity, thereby improving spinopelvic characterization. This risk stratification of spinopelvic kinematic abnormalities could make it possible to target patients who require adapted positioning or types of implants before prosthetic surgery.

LEVEL OF EVIDENCE

IV retrospective study.

In silico analysis of the patient-specific acetabular cup anteversion safe zone

INTRODUCTION

Various computer-assisted surgical systems claim to improve the accuracy of cup placement in total hip arthroplasties after assessing spinopelvic mobility to prevent prosthetic impingement. However, no study has yet analyzed the extent of the patient-specific cup anteversion safe zones.

HYPOTHESIS

We hypothesized that most patients have a safe zone >10 °, except those with abnormal spinopelvic mobility, who have a much narrower safe zone.

MATERIALS AND METHODS

We simulated the risks of prosthetic impingement using the planned cup anteversion. The consecutive cohort included 341 patients who underwent total hip arthroplasty. Our primary endpoint was the patient-specific impingement-free zone for cup anteversion, which was then divided into four subgroups: 0 °, 1 ° to 5 °, 6 ° to 10 °, and >10 °. This data was then secondarily analyzed for abnormal spinopelvic mobility (the difference in the spinopelvic tilt [ΔSPT] from a standing to a flexed seated position >20 °).

RESULTS

The mean anteversion safe zone was 22.8 ° with 82.4% (281/341) of patients with a zone strictly >10 °. The mean safe zone was 8.9 ° (+/- 9 °) in patients with an ΔSPT ≥20 ° (18.2%), with 37.1% of these patients having a zone of 0 °, 16.13% a zone between 1 ° and 5 °, 8.06% a zone between 6 ° and 10 ° and 38.71% a zone >10 °. The mean safe zone was 25.9 ° (+/- 9 °) in patients with an ΔSPT <20 ° (81.8%), and the proportion of cases in each zone was 2.51%, 1.08%, 4.3%, and 92.11%, respectively (p < 0.001).

CONCLUSION

The safe zone for anteversion appears to be fairly wide in most patients. However, identifying patients at risk of abnormal spinopelvic mobility seems necessary to identify the two-thirds of patients with a narrow safe zone.

LEVEL OF EVIDENCE

IV; retrospective study.

Results of third generation dual mobility total hip arthroplasties with non-cross-linked polyethylene in patients under 60 years of age: comparative study of full pressfit vs. tripod cups after 8.6 years

BACKGROUND

The concept of dual mobility of total hip arthroplasties (THA) is a revolution in the prevention of dislocations and in the treatment of instability. Its use remains controversial in patients under 60 years old, providing poorer results with first generation cups coated with alumina. This study, carried out on modern dual mobility (DM) cups with a porous bilayer coating, in active patients under 60 years of age aimed to evaluate: (1) the mechanical survival of two latest generation DM THA, with failure defined as revision of acetabular or femoral implants for mechanical loosening, by comparing a tripod cup to a full pressfit cup, (2) to evaluate the complications, (3) to compare the rate of radiographic peri-prosthetic osteolysis between the 2 implants.

HYPOTHESIS

The hypothesis was that the medium-term survival of modern DM cups placed in young patients was the same regardless of the type of acetabular fixation used.

MATERIALS AND METHODS

This was a retrospective study of 119 latest generation DM THA with standard polyethylene, composed of 66 full pressfit cups and 53 tripod fixation cups, used in primary arthroplasty in 111 patients between 2005 and 2016. The survival study was carried out using medical records. The clinical evaluation was carried out using the modified Harris Hip Score (mHHS) as well as the self-administered Hip and Osteoarthritis Outcome Score (HOOS) and Oxford-12 questionnaires. Radiological analysis was carried out on radiographs looking for bone demineralization and acetabular and femoral lines.

RESULTS

At 8.6 years (5-16), no revision for mechanical loosening was observed regardless of the type of cup. The prosthesis dislocation rate (large joint) was 1.7%: 1 case in each group (p = 1), including one revision required in the full pressfit group. Three revisions for mechanical complications were recorded: a recurrent dislocating hip on a full pressfit cup that was not sufficiently anteverted, an acetabular peri-prosthetic fracture on a full pressfit cup and a case of iliopsoas impingement with a retroverted tripod cup. The survival rate for all-cause revision was 93.8% for pressfit (95% CI: 88.2%-99.9%) vs. 96.2% for tripod (95% CI: 91.1%-100%) (p = 0.63) and for revision due to any cause excluding infection, 96.9% for pressfit (95% CI: 92.8%-100%) vs. 98.1% for tripod (95% CI: 94.4%-100%) (p = 0.7). The rate of periacetabular osteolysis was 11%, significantly more present amongst tripod cups (24%, 9 cases) compared to full pressfit cups (2%, 1 case) (p < 0.01).

CONCLUSION

This series demonstrates good performance of 3rd generation DM cups with porous bilayer coating in patients under 60 years of age regardless of the type of acetabular fixation, at 8.6 years of follow-up. The rate of osteolysis around full pressfit cups remains very low, unlike that of tripod cups. The use of Double Mobility prostheses for primary hip osteoarthritis is possible in young patients, preferably with full pressfit cups (i.e., without any pegs or additional screws that may promote diffusion of polyethylene debris and osteolysis).

LEVEL OF EVIDENCE

III; comparative retrospective study.

Anterior-approach total hip arthroplasty in patients with poliomyelitis: Long-term outcomes

OBJECTIVE

In patients with residual poliomyelitis-related impairments, total hip arthroplasty (THA) is challenging due to the high frequency of risk factors such as hip dysplasia, dislocation, muscle weakness, and fracture. The objective of this study was to assess the long-term functional and radiographic outcomes of anterior-approach THA with a ceramic-ceramic, dual-mobility, or constrained implant in patients with poliomyelitis sequelae.

HYPOTHESIS

THA via the anterior approach with a ceramic-ceramic, dual-mobility, or constrained implant is a reliable technique that is not associated with excess risks of instability or aseptic loosening.

MATERIAL AND METHODS

This single-centre retrospective study included consecutive patients with poliomyelitis sequelae who underwent THA between January 1998 and September 2019 via the anterior approach, with implantation of a ceramic-ceramic, dual-mobility, or constrained implant. The Harris Hip Score (HHS), implant position, and complications (e.g., infection and loosening) were collected during the most recent in-person visit.

RESULTS

The study included 19 patients (23 hips). Mean follow-up was 5.2 ± 4.2 years (range, 2.0-10.6 years). Only six of the 23 procedures were done on the side with greater muscle weakness. The mean HHS at last follow-up was 80.4 ± 10.4. A single procedure (1/23, 4%) was followed by a complication, consisting in intra-prosthetic dislocation 2 years after implantation of a dual-mobility cup. At last follow-up, the HHS was not associated with psoas and gluteus muscle strength (rs = 0.35, p = 0.11 and rs = 0.37, p = 0.09, respectively) and was not significantly different between the weaker vs. stronger side (82.7 ± 8.0 vs. 79.5 ± 11.3, respectively; p = 0.53). Cup position was more horizontal, thereby optimising function, when the procedure was done on the weaker vs. the stronger side (39.9° ± 4.3 vs. 45.0° ± 6.8, respectively; p = 0.02).

CONCLUSION

THA is a good option for improving function in patients with poliomyelitis sequelae. THA via the anterior approach with a ceramic-ceramic, dual-mobility, or constrained implant is a reliable method that is not associated with an excess risk of instability or loosening.

LEVEL OF EVIDENCE

IV.

The RM Press fit cup™: an investigation in 182 hips at ten-year follow-up

INTRODUCTION

For over 10 years, the RM Pressfit cup™ has been used in our department. This is a one-piece, elastic, cementless implant designed with standard polyethylene (PE), covered with a thin coating of titanium particles. To date, there is no French study evaluating this cup after more than 10 years. Therefore, we conducted a retrospective study in order to: (1) evaluate the survival of the implant with a minimum follow-up of 10 years, (2) evaluate the functional scores at the last follow-up, (3) measure the wear of the PE, (4) identify radiological loosening, (5) search for risk factors for cup removal, (6) identify complications that required management in the operating theatre.

HYPOTHESIS

The working hypothesis was that the survival of this implant was greater than 95% at 10 years' follow-up, in accordance with the criteria of the National Institute for Health and Care Excellence (NICE).

MATERIALS AND METHODS

This was a retrospective monocentric study, including adult patients who underwent total hip arthroplasty (THA) with an RM Pressfit cup™ (28 mm friction size) for coxarthrosis (primary or secondary) or femoral head osteonecrosis. Exclusion criteria were a follow-up period of less than 10 years, the placement of an RM Pressfit cup™ as a secondary intention for a THA (n = 5) or following a trochanteric fracture (n = 1). In total, 163 patients (182 hips) with a median age (Q1-Q3) of 63 (56-68) years, and a sex ratio (M/F) of 1.7 were included. Functional scores were evaluated using the Harris and Oxford scores. Radiographs were analyzed in the immediate postoperative period and at the last follow-up.

RESULTS

The median follow-up was 10.5 (10-11.5) years. Of the 182 included hips, 7 cups were removed, corresponding to a 10-year survival rate of 96.1% (95% CI [93.3; 96.9]). The median Harris and Oxford scores at 10.5 years were 95 (90-98) and 19 (17-23) points, respectively. The median PE wear rate was 0.058 (0.039-0.087) mm/year. Univariate analysis showed that male gender was associated with PE wear (OR = 3.6; 95% CI [1.3; 12.9] [p = 0.012]). Ten cups (6%) showed radiological instability with migration greater than 3 mm and/or variation in inclination greater than 8 °, and only 9 hips (6%) showed bone resorption. No preoperative or perioperative factors analyzed were associated with cup removal. Dislocation accounted for 71% (n = 5) of the causes of cup removal. Additionally, 6 hips experienced at least one dislocation episode requiring reduction by external maneuvers in the operating room, bringing the overall dislocation rate in the series to 6% (n = 11). Increased cup inclination was the only risk factor for prosthetic dislocation (OR = 1.2; 95% CI [1.09; 1.4] [p = 0.0003]). Overall complications requiring surgical intervention included 15 (8.3%) implanted cups (7 removed cups, 6 dislocation episodes requiring reduction by external maneuvers in the operating room, and 2 hips reoperated for washing and changing of mobile components due to early infection).

CONCLUSION

The RM Pressfit cup™ gives good long-term clinical and radiological results with an overall survival of 96.1% and a low complication rate over 10 years. Over the last 2 years the RM Vitamys™ cup has been introduced allowing the use of 32 mm femoral head diameter for size 48 cups, to reduce the risk of dislocation.

LEVEL OF EVIDENCE

IV; retrospective cohort.

Monobloc dual-mobility acetabular component versus a standard single-mobility acetabular component

Aims

The benefit of a dual-mobility acetabular component (DMC) for primary total hip arthroplasties (THAs) is controversial. This study aimed to compare the dislocation and complication rates when using a DMC compared to single-mobility (SM) acetabular component in primary elective THA using data collected at a single centre, and compare the revision rates and survival outcomes in these two groups.

Methods

Between 2010 and 2019, 2,075 primary THAs using either a cementless DM or SM acetabular component were included. Indications for DMC were patients aged older than 70 years or with high risk of dislocation. All other patients received a SM acetabular component. Exclusion criteria were cemented implants, patients treated for femoral neck fracture, and follow-up of less than one year. In total, 1,940 THAs were analyzed: 1,149 DMC (59.2%) and 791 SM (40.8%). The mean age was 73 years (SD 9.2) in the DMC group and 57 years (SD 12) in the SM group. Complications and revisions have been analyzed retrospectively.

Results

The mean follow-up was 41.9 months (SD 14; 12 to 134). There were significantly fewer dislocations in the DMC group (n = 2; 0.17%) compared to the SM group (n = 8; 1%) (p = 0.019). The femoral head size did not influence the dislocation rate in the SM group (p = 0.702). The overall complication rate in the DMC group was 5.1% (n = 59) and in the SM group was 6.7% (n = 53); these were not statistically different (p = 0.214). No specific complications were attributed to the use of DMCs. In the DMC group, 18 THAs (1.6%) were revised versus 15 THAs in the SM group (1.9%) (p = 0.709). There was no statistical difference for any cause of revisions in both groups. The acetabular component aseptic revision-free survival rates at five years were 98% in the DMC group and 97.3% in the SM group (p = 0.780).

Conclusion

The use of a monobloc DMC had a lower risk of dislocation in a high-risk population than SM component in a low-risk population at the mid-term follow-up. There was no significant risk of component-specific complications or revisions with DMCs in this large cohort.

The Performance of Primary Dual-Mobility Total Hip Arthroplasty in Patients Aged 55 Years and Younger: A Systematic Review

Background

Dual-mobility (DM) total hip arthroplasty (THA) combines the stabilization advantage provided by large head articulation with the low friction advantage provided by small head articulation. There is momentum for DM to be used in a wider selection of patients, with some advocating for DM to be the routine primary total hip construct. Further investigation is needed to determine whether the use of DM in younger adults is validated by aggregate data. Our objective was to review the literature for the clinical performance of DM THA in patients aged 55 years and younger.

Methods

A systematic review of the literature was performed according to the guidelines of Preferred Reporting in Systematic Reviews and Meta-Analyses. Inclusion in the review required clinical outcome reporting for DM primary THA in ambulatory patients aged 55 years or younger. The risk of bias was appraised using the Cochrane risk of bias in nonrandomized studies of interventions and the quality of the evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation framework.

Results

Across a sample of 1048 cases, the frequency weighted term of follow-up was 87.7 months. The pooled rate of revision was 9.5%. The Harris Hip Score significantly improved from 49.1 preoperatively to 93 postoperatively. The Postel-Merle d'Aubigné score significantly improved from 10.5 preoperatively to 17.1 postoperatively.

Conclusions

The literature demonstrates satisfactory short-term outcomes with a mitigated risk of dislocation for DM used as primary THA in patients aged 55 years and younger. The current findings suggest that third-generation designs provide reduced rates of intraprosthetic dislocation and improved survivorship.

Single-use versus reusable ancillaries for dual mobility cup in total hip replacement. A prospective randomized short-term safety and feasibility comparison

BACKGROUND

Single-use (SU) ancillaries for cup preparation in total hip arthroplasty (THR) aim to reduce the costs of hip replacement surgery. These devices have been recently introduced, but their safety and feasibility have not been studied. Therefore, we performed a prospective randomized study aiming to assess the impact in our department of using these SU ancillaries versus standard reusable ancillaries for dual mobility THR regarding 1) the cost, 2) operative time, 3) quality of primary fixation.

HYPOTHESIS

We hypothesized that the use of SU ancillaries for acetabular preparation would reduce maintenance costs, and so optimise the operating procedure, reduce the overall cost of surgery, save time, while maintaining the same quality of prosthesis fitting.

METHOD

We conducted a randomised, controlled, open-label, two-arm, single-centre, prospective therapeutic trial with a medico-economic objective. Inclusions were made prospectively from patients hospitalised and surgically managed in our department for arthrosis over 18 years old treated with dual mobility THR.

RESULTS

In the current study, 18/20 (90%) of the cases required the use of one SU reamer when using SU ancillaries. Only two cases (10%) required a second SU reamer (without SU failure regarding the acetabular implant) because there was too much subchondral bone left and not enough cancellous bone allowing correct cup fitting. We also found that the test implant supplied in the SU kit had a less secure press-fit than the reusable metal test implants. There was one of primary press-fit failure in the SU group requiring a different cup with additional screws. The estimated cost to the supplier per procedure was 20,105 euros using single-use reamers versus 26,666 euros using conventional ancillary kits, a saving of 6561 euros (p<0.001). For the healthcare institution, the median price per intervention on the differentiating points was 2648 euros versus 2580 euros, with no significant difference (p=0.297). The results show an average societal cost of 52,199 euros using single-use and 53,572 euros using reusable ancillary equipment, with a significant difference between the two groups (p<0.003). The average cost of Healthcare Risk Waste (HCRW) disposal in the SU group was 5.2 euros per intervention against 5.1 euros in the RU group, without significant difference (p=0.910). We found a similar result for the cost of disposal of non-HCRW waste per procedure: 0.37 euros in the SU group versus 0.34 in the RU group, without significant difference (p=0.345).

CONCLUSION

SU ancillaries significantly reduce the table set up time and have the potential to facilitate time and cost savings but further research is needed in this direction. Our study shows that the daily workload, operating times, and the number of boxes of instruments to be sterilised are decreased. The associated environmental gain is significant. Nevertheless, the economic promise of these SU ancillaries is only partially supported in this trial owing to the small number of patients. Further work will be needed to obtain a more powerful medico-economic assessment of this promising ancillary product.

LEVEL OF EVIDENCE

II; prospective randomized study.

Total hip arthroplasty reduces the risk of dislocation after femoral neck fracture

INTRODUCTION

Femoral neck fracture in the elderly patient can either be managed using hemi-arthroplasty (HA) or total hip arthroplasty (THA). The aim of this study was to explore the rate of three selected complications in each procedure: is the dislocation rate higher with HA compared to THA? Is the blood transfusion rate higher with THA compared to HA? Do the patients who underwent THA require more ICU transfer than the patients who underwent HA? Is the ICU transfer correlated to the use of cement for stem fixation?

METHOD

Based on a national health-care database, a comparative and retrospective study was conducted. 96,184 patients were included after having a surgery for femoral neck fracture between 2014 and 2017. The mean follow up was 3.5 years (Min. 2 years-Max. 5 years). The population was divided into two groups: hemiarthroplasty (HA) and total hip arthroplasty (THA). The primary outcome was the dislocation rate and the secondary outcomes were the blood transfusion rate and the need for ICU after surgery.

RESULTS

At two years of follow up in the Hemiarthroplasty group, 3647 patients had a dislocation episode over 64,106 patients: 5.69%. In the Total Hip Arthroplasty group: 1904 patients had a dislocation episode over 32,078 patients: 5.94% (p=0.26711). The percentage of deceased patient without dislocation was 17.76% in the HA group and 11.56% in the THA group (p<0.001). The univariate hazard ratio for dislocation was higher in the THA group: HR 1.063 IC 95% (0.993-1.138) p=0.077. The multivariate analysis calculating competitive risk with death and dislocation found THA to be a protective factor of dislocation HR 0.926 IC 95% (0.866-0.991) p=0.0266. The rate of blood transfusion was 5.59% in the THA group and 7.03% in the HA group (p<0.001), The multivariate analysis found HR=1.062 IC 95% (0.99-1.139) p=0.0955. The need for ICU transfer after the surgery was 7.04% in the HA group and 8.08% in the THA group (p<0.001). The multivariate analysis found HR 0.995 IC 95% (0.921-1.076) p=0.9094. Finally, only cement was found as an independent risk factor of ICU transfer after surgery: HR 1.254 IC 95% (1.164-1.35) p<0.0001.

CONCLUSION

THA for femoral neck fracture allows to reduce the risk of dislocation compared to hemiarthroplasty. The multivariate analysis failed to prove the superiority of one procedure over the other regarding blood transfusion risk and the need for ICU transfer. The use of cemented stem appears to be a risk factor of ICU transfer after hip arthroplasty.

LEVEL OF EVIDENCE

III, Retrospective comparative study.

Comparing dislocation rates by approach following elective primary dual mobility total hip arthroplasty: a systematic review

BACKGROUND

Dual mobility components can be implanted during total hip arthroplasty (THA) for primary osteoarthritis via a direct anterior approach (DAA), anterolateral approach (ALA), direct lateral approach (DLA), or posterior/posterolateral approach (PLA). This review compares dual mobility hip dislocation rates using these approaches for elective primary THA.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for articles published after January 1, 2006 that reported dislocation rates for adult patients after primary THA with dual mobility implants. Articles were excluded if they reported revision procedures, nonelective THA for femoral neck fractures, acetabular defects requiring supplemental implants, prior surgery, or ≤ 5 patients. The primary outcome was hip dislocation rate. Secondary outcomes included infection, Harris Hip Score (HHS), and Postel-Merle d'Aubigné (PMA) score.

RESULTS

After screening 542 articles, 63 met inclusion criteria. Due to study heterogeneity, we did not perform a meta-analysis. Eight studies reported DAA, 5 reported ALA, 6 reported the DLA, and 56 reported PLA. Study size ranged from 41 to 2,601 patients. Mean follow-up time ranged from 6 months to 25 years. Rates of infection and dislocation were low; 80% of ALA, 87.5% of DAA, 100% of DLA, and 82.1% of PLA studies reported zero postoperative dislocations. Studies reporting postoperative HHS and PMA scores showed considerable improvement for all approaches.

CONCLUSIONS

Patients undergoing primary THA with dual mobility implants rarely experience postoperative dislocation, regardless of surgical approach. Additional studies directly comparing DAA, ALA, DLA, and PLA are needed to confirm these findings.

The Saturne cementless dual-mobility cup grants satisfactory long-term survival

Purpose

To report long-term survival and clinical outcomes of primary total hip arthroplasty (THA) using a Saturne cementless dual-mobility (DM) cup, and investigate whether patient demographics or surgical parameters affect clinical scores.

Methods

A consecutive series of primary THAs implanted with Saturne cementless DM cups between 01/09/2009–31/12/ 2011 was retrospectively assessed. Patients were postoperatively evaluated using modified Harris hip score (mHHS) and forgotten joint score (FJS). Complications, reoperations, and revisions were noted. Regression analyses were performed to determine associations of postoperative mHHS with preoperative and intraoperative variables. Ten-year Kaplan–Meier survival was calculated.

Results

Of 308 patients (308 hips), 111 (36%) had died with their original cups in place, 29 (9%) were lost-to-follow-up, and 5 (2%) required cup revision, leaving a final cohort of 163 (53%) with their original cup in place at a follow-up of ≥ 10 years. Ten-year survival was 98% considering cup revision for any reason as endpoint; 99% considering cup revision for aseptic loosening as endpoint; 96% considering stem revision for any reason as endpoint; and 96% considering any revision as endpoint. The final cohort of 163 patients was assessed at 11 ± 1 years (range, 10–13), mHHS was 85 ± 16 (range, 31–100) and FJS was 84 ± 24 (range, 0–100). Multivariable regression analysis revealed that postoperative mHHS significantly worsened with age (β = -0.48, p = 0.007) and BMI (β = -0.70, p = 0.008), as well as for 22 mm head sizes (β = -6.98, p = 0.046).

Conclusions

The Saturne DM cup granted satisfactory survival and clinical outcomes at a minimum follow-up of 10 years, and resulted in no cases of intra- or extra-prosthetic dislocations.