Survivorship and Clinical Outcomes of Constrained Acetabular Liners in Primary and Revision Total Hip Arthroplasty: A Systematic Review

The choice of bearings in revision total hip arthroplasty : rationale, algorithm, and outcome

Aims

The aim of this study was to determine the success of an algorithm designed to guide the choice of bearing based on gluteus medius deficiency to be used in revision total hip arthroplasty (THA).

Methods

Dislocation following revision THA remains a leading cause of failure, and while bearings which offer enhanced stability are available, the indications for their use remain unclear. The integrity of the abductor muscles is a major contributor to stability. We describe the use of an algorithm based on gluteus medius deficiency to determine the choice of bearing in revision THA. The default choice in patients with no damage to gluteus medius was a large head, defined as one with a diameter of ≥ 36 mm. Those with gluteus medius deficiency but with preservation of the posterior muscle and tendon were treated with a dual-mobility bearing. A constrained acetabular liner was used in those with complete gluteus medius deficiency. This was a series of consecutive revision THAs undertaken by a single surgeon using this algorithm. The patients were followed to report the rates of dislocation, all-cause re-revision, and Oxford Hip Score (OHS).

Results

A total of 311 revision THAs were performed in 259 patients (26 were bilateral) with a mean age of 70 years (32 to 95). At a mean follow-up of 4.8 years (1.0 to 9.0), the dislocation rate for the whole cohort was 4.1% (95% CI 2.4 to 7.0), and Kaplan-Meier survival analysis revealed a 96.1% (95% CI 93.0 to 97.8) dislocation-free survival at 60 months. A large diameter head was the most commonly used bearing, in 164 revisions (53%). There was no significant difference in the dislocation-free survival between the bearings (p = 0.46). The survival free of all-cause re-revision for the whole cohort was 94.2% (95% CI 96.3 to 91.0). The mean OHS improved from 19.6 (2 to 47) preoperatively to 33.9 (4 to 48) at the final follow-up.

Conclusion

The findings suggest that the algorithm which we describe, based on soft-tissue deficiency at the time of surgery, can allow the successful choice of bearing to be used in revision THA.

Constrained Acetabular Liners Implanted Simultaneously at the Time of Acetabular Revision Utilizing Contemporary Components

INTRODUCTION

Concern for early acetabular component loosening may deter surgeons from utilizing a constrained acetabular liner (CAL) at the time of acetabular component revision. We have previously demonstrated this can be safely and effectively done with a highly porous tantalum shell, numerous screws, and a cemented constrained liner. It is not known, however, whether similar outcomes are achievable with contemporary modular acetabular components with a liner-locking mechanism.

METHODS

A retrospective review of our total joint registry from 2000 to 2021 identified 38 cases of revision total hip arthroplasties (THAs) in which a CAL was inserted into a contemporary revision acetabular component placed during the same surgery. All cases received supplemental screw fixation (mean of four screws). The mean age at revision total hip arthroplasty (THA) was 66 years, 74% of patients were women, and the mean body mass index was 31. The most common indications for index revision THA were recurrent dislocation (57%), aseptic loosening (20%), and two-stage reimplantation (26%). The mean follow-up was four years.

RESULTS

The 5-year survivorship free from acetabular re-revision for aseptic loosening was 97%, any acetabular re-revision was 94%, and any re-revision was 77%. There was only one acetabular component revised for aseptic loosening at two years. There were eight re-revisions performed for dislocation (4), periprosthetic joint infection (2), aseptic loosening (1), and periprosthetic fracture (1). Radiographic review did not identify any evidence of acetabular component loosening in unrevised cases.

CONCLUSION

Selective use of a CAL at the time of acetabular revision with a contemporary acetabular component and multiple screws had a low rate of aseptic loosening. These results suggest that a CAL can be utilized at the time of acetabular revision when a stable acetabular component is inserted with robust screw fixation.

LEVEL OF EVIDENCE

Level IV.

Constrained acetabular liners in total hip arthroplasty: analysis of 265 primary and revision cases from the Dutch Arthroplasty Register (2007-2022)

INTRODUCTION

Constrained acetabular liners (CALs) are predominantly used as a salvage procedure in patients with a severe risk for dislocation after total hip arthroplasty (THA). However, the constrained design of CALs bears the risk of impingement with subsequent loosening or failure of the integrity of the implant. We investigated the use and survival of CALs in primary and revision THA in the Dutch Arthroplasty Register (LROI).

METHODS

Use of CAL in THAs was extracted from the LROI in the period 2007-2022. 423,773 primary THAs and 52,706 revision THAs have been registered, of which 29 CALs were implanted in primary THA and 236 CALs in revision THA. Patient characteristics and survival of the CAL placed in primary and revision THA were separately analysed.

RESULTS

Of the CALs placed in primary THA, no revisions of the implant occurred during a median follow-up of 5.4 years (interquartile range [IQR] 4.0-12.4). The CALs in revision THA were most frequently used for cases with recurrent dislocation (183/236). Median follow-up was 4.8 (IQR 2.3-8.2) years. The re-revision rate was 10% (95% CI, 6.6-14) at 5-year follow-up and 12% (CI, 8.1-17) at 9-year follow-up. The most frequently registered reason for re-revision was dislocation (n = 19, 70%).

CONCLUSIONS

In the Netherlands there is a relatively low use of CALs in primary as well as revision THA. The survival rate of CALs is acceptable, with recurrent dislocation as the main reason for re-revision. The use of CALs should be reserved for specific cases with high risk for dislocation.

Does the Degree of Liner Constraint Increase Risk of Complications in Articulating Spacers in Two-stage Revision After THA?

BACKGROUND

Two-stage revisions for chronic periprosthetic joint infections (PJIs) often include antibiotic-loaded cement spacers to control for infection and preserve function. While studies have reported on complications (dislocations, readmissions, and reoperations) after static versus articulating spacer types, there is a paucity of evidence about whether the degree of spacer constraint in articulating spacers affects these complications. This study aims to address a key gap in understanding as to whether the level of spacer constraint affects complications in two-stage revision THA utilizing articulating spacers.

QUESTIONS/PURPOSES

(1) Among patients receiving nonconstrained versus constrained articulating antibiotic spacers during first-stage revision THA for PJI, are there differences in major complications, such as dislocation, loosening, periprosthetic fracture, reinfection, and unplanned revisions? (2) After second-stage reimplantation, do patients who received a nonconstrained versus constrained liner during the first stage show differences in the risk of complications, reoperations, and readmissions?

METHODS

This is a retrospective review of 539 patients who underwent two-stage revision THA for PJI at a single-specialty, urban academic referral center between July 2011 and March 2023. Of these 539 patients, 72% (388) were excluded for undergoing a full component revision (femoral or acetabular) for any reason before their first stage, 3% (15) for receiving static spacers, and 6% (35) for receiving prefabricated femoral mono-block stems as part of their first stage. Those who underwent only liner exchange were not excluded. The remaining 19% (101 of 539) of patients were included in the final analysis and categorized by degree of liner constraint: 32 were in the nonconstrained group and 69 were in the constrained group. All surgeons included in this study specialize in adult reconstruction and are fellowship trained, and the selected level of constraint was solely based on their routine practice for articulating spacer construct. Baseline characteristics and clinical data, including age, self-reported gender, race, BMI, American Society of Anesthesiologists score, smoking status, surgical history, and perioperative details, were collected. There were no differences in baseline characteristics between the groups except for smoking status. A priori power analysis determined that 150 patients (75 per group) would be needed to detect a statistical difference in the risk of dislocation between groups, assuming a 20% dislocation risk for the constrained group, at a 0.05 alpha level, and 80% power.

RESULTS

Between patients receiving nonconstrained versus constrained liners, there were no differences in complications after the first stage of revision. Three percent (1 of 32) of the nonconstrained liners developed dislocations compared with 3% (2 of 69) in the constrained group (relative risk [RR] 1.1 [95% confidence interval (CI) 0.09 to 12.3]; p > 0.99). Three percent (1 of 32) of the nonconstrained group developed periprosthetic fractures compared with 7% (5 of 69) in the constrained group (RR 0.4 [95% CI 0.05 to 3.69]; p = 0.72). Similarly, 3% (1 of 32) versus 7% (5 of 69) had persistent infection (RR 0.4 [95% CI 0.05 to 3.69]; p = 0.72). One incident of loosening occurred in the constrained group. There were also no differences in spacer revision incidence: 10% (3 of 32) of the nonconstrained group and 10% (7 of 69) of the constrained group underwent an unplanned revision after the first stage (RR 1.0 [95% CI 0.29 to 3.91]; p = 0.91). For the second stage, dislocation was 14% (3 of 21) in the nonconstrained group and 10% (5 of 52) in the constrained group (RR 1.1 [95% CI 0.2 to 5.9]; p > 0.99). When comparing periprosthetic fractures, 10% (2 of 21) of the nonconstrained group developed periprosthetic fractures compared with 4% (2 of 52) in the constrained group (RR 2.2 [95% CI 0.3 to 16.6]; p = 0.78). Nineteen percent (4 of 21) in the nonconstrained group had persistent infection compared with 12% (6 of 52) in the constrained group (RR 1.5 [95% CI 0.39 to 5.74]; p = 0.81). The occurrence of readmission after the second stage was 19% (4 of 21) in the nonconstrained group compared with 15% (8 of 52) in the constrained group (RR 1.1 [95% CI 0.3 to 3.9]; p > 0.99). Twenty-four percent (5 of 21) of patients in the nonconstrained group required a surgery-related emergency department visit compared with 13% (7 of 52) in the constrained group (RR 1.6 [95% CI 0.4 to 5.6]; p = 0.64). The incidence of reoperation was 14% (3 of 21) in the nonconstrained group and 13% (7 of 52) in the constrained group (RR 0.9 [95% CI 0.2 to 3.8]; p > 0.99).

CONCLUSION

Our results indicated no differences in the risk of dislocations, reinfections, reoperations, and readmissions between patients undergoing constrained versus nonconstrained articulating spacers for two-stage revision THA. Because constrained liners are typically preferred in patients at higher risk of instability, our findings suggest that their use does not necessarily increase the risk of complications. However, because of the small sample size, larger studies are needed to demonstrate whether there is superiority of liner constraint in this patient population.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Contemporary insights into spinopelvic mechanics

Understanding spinopelvic mechanics is important for the success of total hip arthroplasty (THA). Despite significant advancements in appreciating spinopelvic balance, numerous challenges remain. It is crucial to recognize the individual variability and postoperative changes in spinopelvic parameters and their consequential impact on prosthetic component positioning to mitigate the risk of dislocation and enhance postoperative outcomes. This review describes the integration of advanced diagnostic approaches, enhanced technology, implant considerations, and surgical planning, all tailored to the unique anatomy and biomechanics of each patient. It underscores the importance of accurately predicting postoperative spinopelvic mechanics, selecting suitable imaging techniques, establishing a consistent nomenclature for spinopelvic stiffness, and considering implant-specific strategies. Furthermore, it highlights the potential of artificial intelligence to personalize care.

Conventional single articulation constrained liners in revision hip arthroplasty: risk factors for failure and their combinations

BACKGROUND

Constrained liners (CLs) have been used in revision total hip arthroplasty (rTHA) with varying results. Relatively few studies have identified specific risk factors for failure. This study aimed to assess implant survivorship and complication rates, identify risk factors for constraint-related complications, and assess the effect of multiple factors present in a single case.

METHODS

We conducted a retrospective analysis of 101 rTHAs for various aseptic indications and as second-stage procedures for periprosthetic joint infection (PJI) utilising 2 models of conventional single-articulation CLs. We excluded 8 cases in which the liners were removed early due to PJI and assessed the risk factors for constraint-related complications in the remaining 93 cases. The mean follow-up duration for complication-free cases was 6.5 years (range 4.7-10.5 years).

RESULTS

The incidences of dislocation of a prosthetic head and loosening of the acetabular component were 19.8% and 5.0%, respectively. We also observed 8 cases where the locking ring of the liner was dislodged without dislocation (1 case required re-revision). The presence of factors related to impingement (cup retention, smaller internal diameter CLs, signs of probable impingement from the femoral side) was associated with higher rates of constraint-related complications. The presence of factors related to soft-tissue stabilisers did not increase the rate of complications. The simultaneous presence of multiple impingement-related risk factors resulted in worse outcomes.

CONCLUSIONS

CLs may be less effective for treating or preventing instability related to impingement. CLs should be used with caution or avoided when multiple impingement-related risk factors are present.

Cemented Constrained Liners Used as an Articulating Hip Spacer for the Treatment of Chronic Prosthetic Joint Infection

Background

Two-stage exchange arthroplasty remains the gold standard for treating chronic hip periprosthetic joint infections. However, controversy remains regarding the optimal spacer type, particularly among patients with increased dislocation risk. This study reports on the outcomes of articulating hip spacers utilizing a single constrained-liner design.

Methods

All patients who underwent treatment for hip periprosthetic joint infection at a single institution were screened. Patients were included if they received an articulating spacer utilizing a constrained liner of a single manufacturer design. Indications for constrained liner, demographic variables, and surgical variables were recorded. Patients were assessed for dislocation and component loosening prior to the second stage or at the final follow-up if the second stage was not undertaken. Comparative analysis was performed.

Results

Overall, 26 constrained liners were utilized in 25 patients. Indications for constrained liner included history of dislocation (n = 14), massive proximal femoral bone loss (n = 14), greater trochanteric deficiency (n = 12), and absent abductors (n = 7). Many patients had more than one indication. In total, 9 hips (34.6%) underwent a second stage at an average of 7.4 months, while 17 hips never underwent a second stage with an average follow-up of 27.6 months. One patient experienced failure of their constrained liner prior to the second stage due to pelvic discontinuity and massive acetabular bone loss.

Conclusions

Utilization of a constrained liner as an articulating spacer is a viable option for patients at high risk of instability. Meticulous cement technique, appropriate component position, and implant selection are crucial in achieving successful outcomes.

Treatment strategy and clinical outcomes of surgically managed hip periprosthetic fractures: analysis from a high-volume centre

BACKGROUND

Hip periprosthetic fractures (PPF) after total hip arthroplasty (THA) are becoming increasingly prevalent. Their management is secondary to the fracture type and the stability of the implant. This study aimed to provide the outcomes of operatively managed PPF from a high-volume centre to help guide future decision making.

METHODS

This was a retrospective study of prospectively collected data from January 2008 to January 2021. Patient demographics, implant specific details, and fixation strategy were collected. Complications including infection, reoperation, re-fracture, re-revision, were collected. Short-term mortality was evaluated at 3 months and 1 year. P-values <0.05 were considered significant.

RESULTS

282 surgically managed PPF were identified. Vancouver B2 were predominant in 52% of the cases. Revision alone and revision with additional fixation were the most frequent strategies in 168 cases (60%). Complications requiring reoperation occurred in 20% of the cases, with infection as the most frequent (8.5%). Mortality rate was 7.8% at 3 months and 15.7% at 1 year, with significantly lower rates in B2 type. B2 fractures treated with cemented stems had a significantly lower 1-year mortality than distal fit revisions.

CONCLUSIONS

PPF is associated with a high complication rate. Revision alone and revision with additional fixation remain the preferred method in B2/B3 type fractures, however, cemented revision can yield similar outcomes with lower short-term mortality. Considering the high-risk elderly and frail category of patients, a multidisciplinary team is necessary to improve outcomes and reduce mortality.

The Value of Computed Tomography Scan in Three-dimensional Planning and Intraoperative Navigation in Primary Total Hip Arthroplasty

Total hip arthroplasty (THA) is a frequently performed procedure; the objective is restoration of native hip biomechanics and achieving functional range of motion (ROM) through precise positioning of the prosthetic components. Advanced three-dimensional (3D) imaging and computed tomography (CT)-based navigation are valuable tools in both the preoperative planning and intraoperative execution. The aim of this study is to provide a thorough overview on the applications of CT scans in both the preoperative and intraoperative settings of primary THA. Preoperative planning using CT-based 3D imaging enables greater accuracy in prediction of implant sizes, leading to enhancement of surgical workflow with optimization of implant inventory. Surgeons can perform a more thorough assessment of posterior and anterior acetabular wall coverage, acetabular osteophytes, anatomical landmarks, and thus achieve more functional implant positioning. Intraoperative CT-based navigation can facilitate precise execution of the preoperative plan, to attain optimal positioning of the prosthetic components to avoid impingement. Medial reaming can be minimized preserving native bone stock, which can enable restoration of femoral, acetabular, and combined offsets. In addition, it is associated with greater accuracy in leg length adjustment, a critical factor in patients' postoperative satisfaction. Despite the higher costs and radiation exposure, which currently limits its widespread adoption, it offers many benefits, and the increasing interest in robotic surgery has facilitated its integration into routine practice. Conducting additional research on ultra-low-dose CT scans and examining the potential for translation of 3D imaging into improved clinical outcomes will be necessary to warrant its expanded application.

Custom three-dimensional printed implants for reconstruction of oncologic pelvic defects

The use of three-dimensional printed implants in the field of orthopedic surgery has become increasingly popular and has potentiated hip reconstruction in the setting of oncologic resections of the pelvis and acetabulum. In this review, we examine and discuss the indications and technical considerations for custom implant reconstruction of pelvic defects.

Fully constrained acetabular liner vs. dual mobility hip joint in the surgical treatment of metastatic bone disease of the hip: study protocol for a randomized, open-label, two-arm, non-inferiority trial evaluating the post-operative hip dislocation rate

BACKGROUND

Patients receiving total hip arthroplasty (THA) due to metastatic bone disease of the hip (MBD) are at an increased risk of post-operative joint dislocation compared to other populations. Different joint solutions have been developed with the purpose of reducing the dislocation risk compared to regular THAs. One of these solutions, the constrained liner (CL), has been used increasingly at our department in recent years. This design, however, is prone to polyethylene wear and higher revision rates. An alternative is the dual mobility cup (DM), which has been shown to reduce the risk of dislocation in other high-risk populations. Few studies have investigated DM for THA due to MBD, and no studies have directly compared these two treatments in this population. We therefore decided to conduct a trial to investigate whether DM is non-inferior to CL regarding the post-operative joint dislocation risk in patients receiving THA due to MBD.

MATERIALS AND METHODS

This study is a single-center, randomized, open-label, two-arm, non-inferiority trial. We will include 146 patients with MBD of the hip who are planned for THA at the Department of Orthopedic Surgery, Rigshospitalet. Patients with previous osteosynthesis or endoprosthetic surgery of the afflicted hip, or who are planned to receive partial pelvic reconstruction or total femoral replacement, will be excluded. Patients will be stratified by whether subtrochanteric bone resection will be performed and allocated to either CL or DM in a 1:1 ratio. The primary outcome is the 6 months post-operative joint dislocation rate. Secondary outcomes include overall survival, implant survival, the rate of other surgical- and post-operative complications, and quality of life and functional outcome scores.

DISCUSSION

This study is designed to investigate whether DM is non-inferior to CL regarding the risk of post-operative dislocation in patients receiving THA due to MBD. To our knowledge, this trial is the first of its kind. Knowledge gained from this trial will help guide surgeons in choosing a joint solution that minimizes the risk of dislocation and, ultimately, reduces the need for repeat surgeries in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05461313. Registered on July 15 2022. This trial is reported according to the items in the WHO Trial Registration Data Set (Version 1.3.1).

Cementless augmented versus cemented Dual Mobility cups: medium-term outcome of case series with a control group

BACKGROUND

Post-operative dislocation and reconstruction of acetabular defects are two challenging topics in revision Total Hip Arthroplasty (rTHA). Cemented Dual Mobility (DM) cups on top of Kerboull Cross and bone graft have been successfully employed to overcome these challenges. The cementless augmented DM cups were recently introduced. In this study medium term results of the augmented cementless DM Coptos cups are reported and compared to the established technique of cemented DM cups and Kerboull plate.

MATERIAL AND METHODS

This is a retrospective analysis of data collected on patients who received rTHA using DM cups in the period between June 2015 and September 2020. Two groups of patients were identified. The first group received cementless augmented DM-cups (NOVAE® Coptos TH-SERF) (Coptos TH cup group). The second comparable group who had Kerboull ring (KE ring group) and cemented DM cups (NOVAE® STICK). Demographic data, surgical technique, functional and radiological outcome as well as complications during the follow-up visits are reported.

RESULTS

Forty-two patients with a mean age at the time of revision 48.8 ± 13.6 years. 29 patients received Coptos TH DM-cup, while 13 patients had Bone Graft (BG), KE ring and cemented DM cups for acetabular reconstruction. Acetabular defects were Paprosky types IIB and IIC in 31 patients and IIIA and B in 11 patients. The follow-up was 52.8 ± 21 months (mean ± STD); and the mean Harris Hip Score (HHS) at last visit was 91 ± 5. Good stability of all cups was reported. Full integration of the impaction graft was observed in 94% of the Coptos and 92% of the KE groups. One of the Coptos cups was readjusted and one case of single dislocation was recorded in the KE group. None of the DM cups in both groups was revised or awaiting revision.

CONCLUSION

Coptos TH cups achieve similar results to the cemented DM on KE ring at the medium term but long term outcome remains to be seen.

Metal-on-Metal Hips: Ten-Year Clinical and Radiographic Outcomes of the ADEPT Metal-on-Metal Hip Resurfacing and Modular Total Hip Arthroplasty

BACKGROUND

The aim of this study is to update the 10-year follow-up survivorship and metal ions levels of a cohort of metal-on-metal (MoM) hip resurfacing (HR) and large-diameter-head (LDH) total hip arthroplasty (THA).

METHODS

The study is a retrospective analysis of prospectively collected data that compared the outcomes of 24 MoM HR (21 patients) and 15 (11 patients) modular LHD MoM THA at >10 years follow-up. Baseline characteristics as well as intraoperative and postoperative information were collected, including complications, revisions, clinical and radiographic outcomes, and serum metal ions level (Cobalt, Chromium). Metal ion levels were compared using a two-tailed unpaired t-test and Wilcoxon signed-rank test (jamovi v2.3.3.0, Sydney, NSW, AU).

RESULTS

No significant differences were detected in gender, BMI, and ASA score between the two groups. Patients in the modular THA group were significantly older (57 years vs. 46 years; p < 0.05). The HR overall survivorship was 91.7% (22 of 24 hips) with survivorship from implant failure and/or aseptic loosening and/or metal debris related 100% of problems. The modular THA overall survivorship was 86.7% (13 of 15 hips) with survivorship from implant aseptic loosening and metal ions complications of 93.4% (14 of 15 hips). No significant difference was noted when comparing clinical outcomes. Metal ions were significantly lower in the HR group (Co 25.8 nmol/L vs. 89 nmol/L; p < 0.001-Cr 33.5 nmol/L vs. 55.2 nmol/L; p = 0.026).

CONCLUSION

Both implants reported excellent and comparable clinical outcomes at >10 years follow-up. The Adept HR reported remarkable survivorship, in line with the registry data, proving once again its reliability in young active males. The modular LDH THA, despite being discontinued, presented higher reliability and a lower failure rate when compared with similar withdrawn MoM implants. Trunnionosis did not appear to be a significant problem in this particular modular design.

The exeter cemented stem provides outstanding long-term fixation and bone load at 15 years follow-up: A systematic review and meta-analysis

PURPOSE

Since its introduction in 1988, the double-tapered polished Exeter cemented stem has been widely adopted in primary total hip arthroplasty (THA). Despite the results coming from the arthroplasty registries have proven great survivorship, the aim of this study was to dig deeper and describe the modes of failure of the Exeter stem at 15 years follow-up while reporting the clinical and radiographic outcomes.

METHODS

A search of PubMed, MEDLINE, and Embase was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses since inception of database to January 2022. A meta-analysis was performed on stem's failure rates and clinical outcomes using random effects models. Publication bias was assessed with funnel plots.

RESULTS

Overall, ten studies met the inclusion criteria with 2167 hips at mean 14.8 ± 4.1 years follow-up. The meta-effect estimate for revision rate for stem-related reasons was 3.8% (CI 95% 2.1-5.6, p < 0.01). The meta-effect for revision rate for stem aseptic loosening (AL) was 0.22% (CI 95% 0-0.4, p = 0.048) and for periprosthetic fracture was 0.6% (CI95% 0.3-0.9, p < 0.001). The meta effect estimate for Oxford Hip Score (OHS) at final follow-up was 32.4 (moderate; CI 95% 23.2-41.6, p <0.001) with and heterogeneity among the studies of I² 0%. Radiolucent lines were reported in 5.5% of cases, with 1.0% of cases (21 hips) reported to be progressive.

CONCLUSION

Current evidence suggests that the Exeter cemented stem not only has proven long-term outstanding reliability with a revision rate of 3.8%, but also incredibly low revision rates for AL (0.22%) and periprosthetic fracture (0.6%). It is suitable for a variety of indications, and the consistent radiological appearances indicate durable fixation and load transmission while being associated with a remarkably low stem-related complication rate.

Constrained acetabular liners are a viable option in second-stage re-implantation for chronic infected total hip arthroplasty with abductor or greater trochanter deficiency and large acetabular bone defects

Background

Abductor mechanism deficiency is a clear indication for using constrained acetabular liners (CALs), and large acetabular bone defects are considered a relative contraindication to CALs. We report the results of using CALs in special cases in which abductor or greater trochanter deficiency was accompanied by large acetabular bone defects at second-stage re-implantation for chronic infected total hip arthroplasty (THA).

Methods

Between January 2010 and January 2018, 19 patients who used CALs at second-stage re-implantation and had abductor or greater trochanter deficiency and large acetabular bone defects were included in this study. We followed up with the clinical and radiological results of these patients. Complications and infection-related information were also recorded.

Results

Eight patients, 4 patients, and 7 patients had Paprosky type IIB, type IIC, and type IIIA acetabular bone defects at second-stage re-implantation, respectively. The indication for using CALs was abductor deficiency in 14 patients and greater trochanter deficiency in the other 5 patients. The mean follow-up was 74.4 months (range 50–96). The mean Harris Hip Score (HHS) was 76.3 points (range 62–86) at the last follow-up. Three patients presented acetabular radiolucent lines with no progress: zone 3, zone 3 and zone 2 and 3, respectively. One patient suffered transient sciatic nerve palsy. There was no dislocation, failure of the CALs, reoperation, or recurrence of infection.

Conclusion

Our results suggested that for screened patients, CALs are a viable option in second-stage re-implantation for chronic infected THA with abductor or greater trochanter deficiency and large bone defects.

Survivorship and clinical outcomes of proximal femoral replacement in non-neoplastic primary and revision total hip arthroplasty: a systematic review

BACKGROUND

Several studies have evaluated the survivorship and clinical outcomes of proximal femoral replacement (PFR) in complex primary and revision total hip arthroplasty with severe proximal femoral bone loss; however, there remains no consensus on the overall performance of this implant. We therefore performed a systematic review of the literature in order to examine survivorship and complication rates of PFR usage.

METHODS

A systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A comprehensive search of PubMed, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was conducted for English articles using various combinations of keywords.

RESULTS

In all, 18 articles met the inclusion criteria. A total of 578 PFR were implanted. The all-cause reoperation-free survivorship was 76.6%. The overall complication rate was 27.2%. Dislocation was the most common complication observed and the most frequent reason for reoperation with an incidence of 12.8 and 7.6%, respectively. Infection after PFR had an incidence of 7.6% and a reoperation rate of 6.4%. The reoperation rate for aseptic loosening of the implant was 5.9%. Overall, patients had improved outcomes as documented by postoperative hip scores.

CONCLUSION

PFR usage have a relatively high complication rate, however, it remains an efficacious treatment option in elderly patients with osteoporotic bone affected by severe proximal femoral bone loss. Modular designs have shown reduced dislocations rate and higher survivorship free from dislocation. However, PFR should only be used as salvage procedure when no other reconstruction options are available.