RESUMEN

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.

RESUMEN

Acute penetration of a total hip arthroplasty into the pelvic cavity is a grave and potentially catastrophic scenario. Fortunately, this complication is uncommon and rarely encountered during a surgical career. Currently, a two-stage procedure is favoured by most surgeons, but the evidence for this is unconvincing and may expose the patient to unnecessary risks. Furthermore, a two-stage approach may be more suitable for the more common chronic migration of a loose acetabular shell, which fundamentally differs from acute pelvic penetration. We present the case of a 76-year-old man referred to our institution for reconstructive surgery following acute pelvic penetration of the acetabular shell during total hip arthroplasty. We used a single-stage Hardinge approach to retrieve the shell and successfully reconstruct the acetabulum. Specific indications for using this method are proposed. In carefully selected cases of intrapelvic implants, a single-stage method can improve patient outcomes while minimising unnecessary risks associated with the conventional two-stage approach.

Asunto(s)

RESUMEN

Charcot arthropathy is a rapidly progressive and destructive form of arthropathy caused by various neurological diseases. Total hip arthroplasty (THA) is usually contraindicated in patients with Charcot arthropathy; however, recent studies have reported good results following THA in this patient population. Herein, we report a case of Charcot arthropathy secondary to syphilis in a patient who was successfully treated with constrained THA, a new type of THA. A 56-year-old man was injured in a car accident, and a displaced acetabular fracture was revealed three weeks later. He was treated conservatively but soon developed greater displacement of the fracture and femoral head destruction. The patient was referred to our hospital for further treatment. The patient had pelvic pseudarthrosis secondary to Charcot arthropathy at the time of the first visit to our hospital. First, THA was performed with the acetabular reconstruction of the deficient bone. However, the acetabular implant was displaced one week postoperatively. THA revision was performed using a constrained cup. Postoperatively, the patient exhibited good hip stability without dislocation. However, displacement of the acetabular cup occurred one year after the second surgery. We performed a re-revision of THA using a new type of constrained cup that offers a high level of constraint to maintain range of motion (ROM) and prevent dislocations. The patient was able to walk with a T-cane one year postoperatively. Herein, we report a difficult case of revision THA in a patient with Charcot arthropathy concomitant with syphilis. THA is usually contraindicated in patients with Charcot arthropathy; however, we propose that THA using constrained cups that offer a wider ROM may be a useful therapeutic strategy for the treatment of Charcot arthropathy.

RESUMEN

Background: The objective of this study was to assess the long-term survival rate, complications, as well as the clinical and radiological outcomes of hemiarthroplasty and total hip arthroplasty using constrained polyethylene liners in patients with ischemic stroke. Methods: This study was a retrospective cohort study that included patients with ischemic stroke who underwent hip arthroplasty from March 2010 to September 2017. In the Constrained Acetabular Liners (CAL) group, patients received an uncemented acetabular shell with a constrained polyethylene liner. The Dual Mobility (DM) group underwent hemiarthroplasty (HA). Additionally, hip function, range of motion, quality of life, the incidence of clinical complications, and prosthesis stability were investigated. Results: 96 patients with unilateral femoral neck fractures who underwent hip replacement with CAL were included in the CAL group, while 103 patients who underwent hip replacement with a dual mobility head were included in the DM group. VAS, and SF-36 data were available for both CAL and DM groups. At the 1-year postoperative follow-up, the HHS in the CAL group was significantly lower than that in the DM group (80.83 ± 3.91 vs. 83.17 ± 4.15, P < 0.05). The VAS score in the CAL group peaked at the 1-year follow-up (2.07 ± 0.91 vs. 1.49 ± 0.85, P < 0.05). However, there were no significant differences between the two groups in terms of HSS, VAS, and SF-36 at the last follow-up after surgery. Operative time and the amount of bleeding in the DM group were significantly lower than those in the CAL group (105.30 ± 29.68 vs. 94.85 ± 31.07; 355.11 ± 123.95 vs. 302.22 ± 107.68, P < 0.05). Additionally, there was no significant difference in the mean leg length discrepancy between the two groups. Conclusion: The clinical, imaging, and postoperative complications of the CAL and DM groups were analyzed. The prognosis for DM appears to be more beneficial for early patient recovery, but a higher likelihood of recurrent dislocation is observed. CAL offers excellent stability for primary THA in high-risk patients; however, attention should be given to preventing aseptic loosening.

RESUMEN

Articulating hip spacers for periprosthetic joint infection (PJI) offer numerous advantages over static spacers such as improved patient mobilization, hip functionality, and soft tissue tension. Our study aimed to determine complication rates of a functional articulating spacer using a constrained liner to determine the role of acetabular cementation mantle and bone loss on the need for second-stage surgery. A retrospective review of 103 patients was performed and demographic information, spacer components and longevity, spacer-related complications, reinfection rates, and grade of bone loss and acetabular cement mantle quality were determined. There was no significant difference in spacer-related complications or reinfection rate between PJI and native hip infections. 33 of 103 patients (32.0%) elected to retain their spacers. Between patients who retained their initial spacer and those who underwent reimplantation surgery, there was not a significant difference in cement mantle grade (p = 0.52) or degree of bone loss (p = 0.78). Functional articulating antibiotic spacers with cemented constrained acetabular liners demonstrate promising early results in the treatment of periprosthetic and native hip infections. The rate of dislocation events was low. Further efforts to improve cement fixation may help decrease the need for second-stage reimplantation surgery.

RESUMEN

In the setting of chronic instability following total hip arthroplasty, implantation of a constrained acetabular liner may be warranted. We report on a patient who sustained a posterior prosthetic hip dislocation out of the constrained acetabular liner component (Stryker Trident [Kalamazoo, MI]), which had been previously replaced 2 months prior, and underwent a successful closed reduction in the emergency department. At 2-year follow-up, the patient's prosthetic hip has remained stable with no reported issues. To our knowledge, this is the first reported closed reduction of a revised constrained total hip arthroplasty with this implant system, size, and length of follow-up.

RESUMEN

PURPOSE: Preventing dislocation with large head (≥ 36 mm), dual mobility, or constrained acetabular liner is another option than a standard (≤ 32 mm). Many other dislocations risk factors than size of the femoral head exist after hip arthroplasty revision. Predicting dislocation with a calculator according to the implant, to the indication of revision, and to patient's risks could allow a better surgery decision. METHODS: Our search method covers the period from 2000 to 2022. A total of 470 relevant citations on hip major revision (cup or stem or both revisions) were identified with artificial intelligence comprising 235 publications of 54,742 standard heads comprising 142 publications of 35,270 large heads, comprising 41 publications of 3945 constrained acetabular components, and 52 publications of 10,424 dual mobility implants. We considered four implant types (standard, large head, dual mobility, or constrained acetabular liner) as the entry layer of the artificial neural network (ANN). Indication for revision THA was the second hidden layer. Demographics, spine surgery, and neurologic disease were the third layer. Implant revision, reconstruction process as next input (hidden layer). Surgery-related factors, and so on. The output was a postoperative dislocation or not. RESULTS: Of the 104,381 hips that underwent a major revision, a second revision for dislocation was performed for 9234 hips. In each implant group, dislocation remained the first cause of revision. The rate of second revision for dislocation as a percentage of first revision procedures was significantly higher in the standard head group (11.8%) than in the constrained acetabular liner group (4.5%), the dual mobility group (4.1%), and the large head group (6.1%). Instability of a previous THA, infection, or periprosthetic fracture as the indication for revision was increased risk factors as compared with aseptic loosening. One hundred variables were used to create the calculator with the best parameter combination of data and ranking the different factors, according to the four implant types (standard, large head, dual mobility, or constrained acetabular liner). CONCLUSION: The calculator can be used as a tool to identify patients at risk for dislocation after hip arthroplasty revision and individualize recommendations to select another option than a standard head size.

Asunto(s)

RESUMEN

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).

Asunto(s)

RESUMEN

BACKGROUND: The outcomes of constrained liners (CLs) in total hip arthroplasty (THA) remain inconclusive. We evaluated the mid-term performance of CLs in a consecutive series of high-risk dislocation patients undergoing primary or revision THA performed by a single surgeon. The survival, dislocation rate, complications, and functional patients' scores were assessed. Surgical tips to enhance outcomes were reviewed. METHODS: 45 patients who received the Trident Tripolar CL between 2010 to 2019 were retrospectively evaluated from Arthroplasty Registry Thessaloniki. There were 17 primary and 28 revision THAs. The primary indications for using CL were severe abductor insufficiency or comorbidities, increasing the dislocation risk in primary, and recurrent dislocation or abductor insufficiency in revision THAs. The mean patient's age was 68.5 (±14.5) years, and the mean follow-up 3.81 (±1.66) years. RESULTS: There were 2 dislocations and 1 deep infection in the revision group. For any reason, the cumulative 6-year survival rate was 93.3%, 100% for primary, and 89.3% for revision THAs. The mean overall CL survival was 76.3 months for any reason (95% CI, 68.1-84.5) and 80.5 months for dislocation (95% CI, 75.8-85.2). The mean postoperative functional scores were significantly improved (p < 0.001) at the latest follow-up. CONCLUSIONS: CLs can provide hip stability and durable fixation in selected low-demand patients with high-risk for dislocation after primary and revision THA at mid-term follow-up. Careful patient selection and the refined surgical technique aiming at the neutral liner position and considering the high CLs' offset relative to stem-neck impingement are necessary to maximise outcomes.

Asunto(s)

RESUMEN

PURPOSE: This paper aims to provide an overview of the possibility regarding the artificial intelligence application in orthopaedics to predict dislocation with a calculator according to the type of implant (hemiarthroplasty, standard total hip arthroplasty, dual mobility, constrained cups) after primary arthroplasty. MATERIAL AND METHODS: Among 75 results for primary arthroplasties, 26 articles were reviews on dislocation after hemiarthroplasty, 40 after standard total hip arthroplasty, seven about primary dual-mobility arthroplasty (DM THA), and two reviews about constrained implants. Although our search method for systematic reviews covers ten years (2012-2022), none for dual mobility was published before 2016, showing a recent explosion of original articles on this subject. A total of 1,069,565 implants and 26,488 dislocations in primary arthroplasties are included in these 75 reviews. We used a supervised learning model in which models assign objects to groups as input and artificial neural network (ANN) with nodes, hidden layers, and output layers. We considered only four implant types as the input layer. We considered the patient's factors (indication for THA, demographics, spine surgery, and neurologic disease) as the second input values (hidden layer). We considered the implant position as the third input (hidden layer) property including head size, combined anteversion, or spinopelvic alignment. Surgery-related factors, approach, capsule repair, etc. were the fourth input values (hidden layer). The output was a post-operative dislocation or not within three months. RESULTS: The accuracy for predicting dislocation with this systematic review was 95%. Dislocation risk, based on the type of implant, was wide-ranging, from 0 to 3.9% (mean 0.31%) for the 3045 DM THA, from 0.2 to 1.2% (overall 0.91%) for the 457 constrained liners, from 1.76 to 4.2% (mean 2.1%) for 895,734 conventional total hip arthroplasties, and from 0.76 to 12.2% (mean 4.5%) for 170,329 hemiarthroplasties. In the conventional THA group, many factors increase the risk of dislocation according to the calculator, and only a few (big head, anterior approach) decrease the risk, but not very significantly. In the hemiarthroplasty group, many factors can increase the risk of dislocation until 30%, but none could decrease the risk. According to the calculator, the DM THA and the constrained liner markedly decreased the risk and were not affected by implant position, spine surgery, and spinopelvic position. CONCLUSION: To our knowledge, this study is the first to yield an implant-specific dislocation risk calculator that incorporates the patient's comorbidities, the position of components, and surgery factors affecting instability risk.

Asunto(s)

RESUMEN

INTRODUCTION: Recurrent dislocation represents the third most common cause of revision surgery after total hip arthroplasty (THA). However, there is a paucity of information on the outcome of revision total hip arthroplasty for recurrent dislocation. In this study, we investigated (1) clinical outcomes of patients that underwent revision THA for recurrent dislocation, and (2) potential risk factors associated with treatment failure in patients who underwent revision total hip arthroplasty for recurrent dislocation. METHODS: We retrospectively reviewed 211 consecutive cases of revision total hip arthroplasty for recurrent dislocation, 81 implanted with a constrained liner and 130 with a non-constrained liner with a large-diameter femoral head (> 32 mm). Patient- and implant-related risk factors were analyzed in multivariate regression analysis. RESULTS: At 4.6-year follow-up, 32 of 211 patients (15.1%) underwent re-revision surgery. The most common causes for re-revision included infection (14 patients) and dislocation (10 patients). Kaplan-Meier analysis demonstrates a 5-year survival probability of 77% for patients that underwent revision THA for recurrent dislocation. Osteoporosis, obesity (BMI ≥ 40), spine disease and abductor deficiency are independent risk factors for failure of revision surgery for recurrent dislocation. Liner type (constrained vs. non-constrained) was found not to be associated with failure of revision THA for recurrent dislocation (p = 0.44). CONCLUSION: This study suggests that THA revision for recurrent dislocation is associated with a high re-revision rate of 15% at mid-term follow-up. Osteoporosis, obesity (BMI ≥ 40) spine disease and abductor deficiency were demonstrated to be independent risk factors for failure of revision THA for recurrent dislocation. LEVEL OF EVIDENCE: Level III, case-control retrospective analysis.

Asunto(s)

RESUMEN

A 75-year-old woman who had previously undergone a left revision total hip arthroplasty with the use of a constrained acetabular liner presented with recurrent dislocation of the hip. Intraoperatively, there was metallic staining of the hip capsule and significant notching of the femoral neck, consistent with impingement of the intact locking ring, necessitating stem revision. Constrained acetabular liners have high failure rates due to intraprosthetic impingement, but to our knowledge, failure due to notching of the femoral component and metallosis from repeated impingement has not been described. Surgeons should be aware of this potential mode of failure.

RESUMEN

INTRODUCTION: The aim of this study was to determine number and type of failures and revisions after usage of a constrained tripolar acetabular liner in patients with high risk of dislocation. Potential correlations between these failures and the factors included were analyzed. MATERIALS AND METHODS: In this retrospective study 55 participants in 68 cases were included after treatment with constrained tripolar acetabular liner. Patient specific data as well as surgery and implant specific data were collected. Radiological images were assessed. Furthermore, the gluteal function was analyzed. The parameters were statistically verified with regard to their influence on the failure of the constrained tripolar liner. RESULTS: This study included 16 cases (in nine participants) of postoperative failure. This results in a survival rate of 76.5% regarding the number of cases after 17 months. The statistical analysis of the different parameters considered that the number of previous surgeries has a significant (p = 0.027) influence on the failure. CONCLUSIONS: This retrospective study shows that treatment with constrained tripolar acetabular liners is a satisfactory method of treatment in cases with a high risk of dislocation. However, in cases with an increasing number of previous surgeries, an increased risk of failure was found. Therefore, in such cases, this type of supply treatment should be treated critically.

RESUMEN

BACKGROUND: Several studies have evaluated the survivorship and clinical outcomes of constrained acetabular liners (CALs) in complex primary and revision total hip arthroplasty with hip instability; however, there remains no consensus on the overall performance of this constrained implant. We therefore performed a systematic review of the literature to examine survivorship and complication rate of CAL usage. METHODS: A systematic review of the literature in accordance with 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, 37 articles met the inclusion criteria. A total of 4152 CALs were implanted. The all-cause reoperation-free survivorship was 79.9%. The overall complication rate was 22.2%. Dislocation was the most common complications observed and the most frequent reason for reoperation with an incidence of 9.4% and 9.2%, respectively. Infection after CAL placement had an incidence of 4.6%. The reoperation rate for aseptic acetabular component loosening was 2.9%. Overall, patients had improved outcomes as documented by postoperative hip scores. CONCLUSION: CALs usage have a relatively high complication rate, particularly when compared with current bearing alternatives (dual mobility cups and large diameter femoral heads), however, it remains a valuable salvage procedure in complex patients affected by recurrent dislocation and implant instability. Newer designs have shown reduced impingement and higher survivorship free from dislocation. However, CALs should only be used when the reasons of instability have been correctly recognized and optimized.

Asunto(s)

RESUMEN

Dual-mobility and constrained cups can stabilise most recurrent dislocations of total hip arthroplasty (THA), but may fail in case of hip abductor mechanism loss. For such complex situations, we developed an original artificial iliofemoral and ischiofemoral ligament reconstruction technique using a polyglactin 910 mesh (Vicryl ™) associated to repositioning of a Lefèvre constrained liner adapted to hip range of motion to prevent cam effects. The technique was implemented in 2 patients showing recurrent dislocation after THA, associating total femur replacement and cemented constrained liner in a metal reinforcement ring. In one of the 2 cases, the abductor mechanism had been entirely sacrificed. This simple and accessible salvage technique prevented recurrence of dislocation at 12 months' follow-up in these complex cases, previously subject to several episodes per year.

Asunto(s)

RESUMEN

INTRODUCTION: Recurrent dislocation after total hip arthroplasty (THA) using the dual mobility cup system can present challenges, while dual-mobility THA bearings can improve stability in both primary and revision total hip arthroplasties. PRESENTATION OF CASE: A 72-year-old woman with a history of schizophrenia underwent a left primary THA using the G7 dual mobility system. Two postoperative posterior dislocations occurred within 2 months post-surgery. The patient underwent revision surgery in which the metal liner and dual mobility head were exchanged using the Freedom constrained liner system without revision of the cup and stem. As of this writing, 28 months after the revision surgery, no further dislocations have occurred. The implants are stable, and the patient has good range of motion. DISCUSSION: Dual-mobility bearings are utilized to improve stability in both primary and revision total hip arthroplasties, but even if the dual mobility system is chosen, it sometimes fails to prevent postoperative dislocation. Although a relatively high failure rate has been reported in THA using the constrained liner system, this patient's clinical course suggests that the G7 Freedom constrained liner system can be an efficacious option for some patients with unstable hip joints who undergo THA using the dual mobility system. CONCLUSION: A modern constrained liner system such as the G7 Freedom liner may provide an improved salvage solution for joint instability in dual mobility THA.

RESUMEN

The treatment of a patient with schizophrenia suffering a subcapital hip fracture may be challenging, mainly due to the high risk of postoperative medical and surgical complications. Mechanical complications from the implant are also frequently encountered following hip arthroplasty in patients with schizophrenia. We report the case of a 57-year-old male patient with schizophrenia who underwent hip hemiarthroplasty for a displaced femoral neck fracture. During the initial postoperative period, the patient developed a cascade of surgical and mechanical complications, leading to multiple revision procedures and a suboptimal outcome. The ideal type of treatment of patients with schizophrenia with subcapital hip fracture is still missing. It is, therefore, important to highlight the high risk of postoperative complications in patients with schizophrenia who present with subcapital fractures subsequently treated with hemiarthroplasty.

RESUMEN

BACKGROUND: Treatment of adverse local tissue reaction (ALTR) is challenging owing to high complications and poor outcomes after a revision surgery. As dislocation is the most common cause of reoperation, it is often necessary to use advanced articulations such as dual mobility. This study aims to evaluate the outcome and complication rates after revision surgery with dual mobility constructs, compared to constrained and conventional articulations in the setting of significant abductor deficiency due to ALTR. METHODS: Out of a total of 338 revision total hip arthroplasties for ALTR, 234 patients with a significant tissue necrosis and abductor muscle insufficiency (grade 3) were evaluated. The complication rates after revisions were compared between 42 hips with dual mobility implants, 24 hips with constrained liners, 104 hips with large diameter heads (36-40 mm), and 64 hips with small diameter heads (≤32 mm). RESULTS: After an average of 4 years of follow-up (2.8-8.6), the dual mobility articulation had no dislocation, compared to 4.1% and 15.5% for constrained liner and conventional articulations, respectively (P < .001). Utilization of dual mobility and constrained liner cup also did not increase the risk of nondislocation complications, including periprosthetic joint infection and periprosthetic fracture (P = .18 and .52). CONCLUSIONS: This study demonstrates significantly lower dislocation rates for dual mobility when compared to conventional articulations and comparable to constrained liners in cases of severe abductor deficiency due to ALTR, suggesting that dual mobility implants are viable surgical treatment alternatives to constrained liners to minimize dislocation during revision total hip arthroplasty in the setting of significant abductor deficiency due to ALTR.

Asunto(s)

RESUMEN

BACKGROUND: Recurrent instability after total hip arthroplasty is a difficult complication. In certain cases, a constrained acetabular device is needed to address these issues. The purpose of this study is to report the midterm outcomes and survivorship of a single novel constrained liner device. METHODS: A retrospective review as performed on all procedures (except first stage exchange for infection) in which a Freedom Constrained (Zimmer Biomet, Warsaw, IN) liner was used between December 2003 and November 2016. Patients with 2-year minimum follow-up or failure were included, yielding a cohort of 177 patients. Procedures were 130 aseptic revisions, 40 reimplantations following infection eradication, and 7 complex primaries. The constrained mechanism was implanted in 46 hips (26%) to treat active instability and 131 hips (74%) for increased risk of instability and intraoperative instability. Patients had on average 3.4 previous surgeries. RESULTS: With an average 7.1-year follow-up, 11 hips dislocated (6.2%), and 13 hips (7.3%) were revised for acetabular aseptic loosening, resulting in an overall constrained aseptic or mechanical failure rate of 13.6%. Nineteen hips (10.7%) failed from infection with 58% of these having had a previous infection. Patients with active instability had significantly higher failure for dislocation than patients who were at risk (15.2% vs 3%, P = .01). All-cause survival rate at 7 years was 74.8%, aseptic survival was 83.6%, and survival for instability was 91.8%. CONCLUSION: Revision for instability remains challenging as many patients have had numerous previous surgeries and at-risk anatomy. Constrained inserts are one option to manage instability, but a high rate of recurrence can still occur.

Asunto(s)

RESUMEN

AIMS: We investigated the long-term performance of the Tripolar Trident acetabular component used for recurrent dislocation in revision total hip arthroplasty. We assessed: 1) rate of re-dislocation; 2) incidence of complications requiring re-operation; and 3) Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain and functional scores. PATIENTS AND METHODS: We retrospectively identified 111 patients who had 113 revision tripolar constrained liners between 1994 and 2008. All patients had undergone revision hip arthroplasty before the constrained liner was used: 13 after the first revision, 17 after the second, 38 after the third, and 45 after more than three revisions. A total of 75 hips (73 patients) were treated with Tripolar liners due to recurrent instability with abductor deficiency, In addition, six patients had associated cerebral palsy, four had poliomyelitis, two had multiple sclerosis, two had spina bifida, two had spondyloepiphyseal dysplasia, one had previous reversal of an arthrodesis, and 21 had proximal femoral replacements. The mean age of patients at time of Tripolar insertions was 72 years (53 to 89); there were 69 female patients (two bilateral) and 42 male patients. All patients were followed up for a mean of 15 years (10 to 24). Overall, 55 patients (57 hips) died between April 2011 and February 2018, at a mean of 167 months (122 to 217) following their tripolar liner implantation. We extracted demographics, implant data, rate of dislocations, and incidence of other complications. RESULTS: At ten years, the Kaplan-Meier survivorship for dislocation was 95.6% (95% confidence interval (CI) 90 to 98), with 101 patients at risk. At 20 years, the survivorship for dislocation was 90.6% (95% CI 81.0 to 95.5), with one patient at risk. Eight patients (7.2%) had a dislocation of their constrained liners. At ten years, the survival to any event was 89.4% (95% CI 82 to 93.8), with 96 patients at risk. At 20 years, the survival to any event was 82.5% (95% CI 71.9 to 89.3), with one patient at risk. Five hips (4.4%) had deep infection. Two patients (1.8%) developed dissociated constraining rings with pain but without dislocation, which required re-operation. Two patients (1.8%) had periprosthetic femoral fractures, without dislocation, that were treated by revision stems along with exchange of the well-functioning constrained liners. CONCLUSION: Constrained tripolar liners used at revision hip arthroplasty provided favourable results in the long term for treatment of recurrent dislocation and for patients at high risk of dislocation. Cite this article: Bone Joint J 2019;101-B(6 Supple B):123-126.

Asunto(s)