Revision Surgery For Aseptic Loosening Research Articles

The Diagnostic Characteristic and Reproducibility of Bone Scintigraphy Single-Photon Emission Computed Tomography/Computed Tomography for Diagnosing Aseptic Loosening of Uncemented Total Knee Arthroplasty

BackgroundThe primary objective of this study was to investigate the diagnostic characteristics of bone scintigraphy single-photon emission computed tomography/computed tomography (BS-SPECT/CT) for diagnosing aseptic loosening after uncemented total knee arthroplasty (TKA), and to evaluate the following aspects: how to manage inconclusive results, the interobserver reliability, and the location of tracer uptake between symptomatic cases with and without aseptic loosening. MethodsIn this study, 180 patients who had uncemented TKA and persistent knee pain suspected of aseptic loosening were included. As part of routine medical care, BS-SPECT/CT was used, and its results were compared with the reference standard, which involved revision surgery for aseptic loosening or a 12-month follow-up without revision or imaging. Inconclusive BS-SPECT/CT results were considered either negative (best-case scenario) or positive (worst-case scenario). Sensitivity, specificity, positive/negative likelihood ratios (LRs), and positive/negative predictive values (PPV and NPV) were calculated. Sensitivity analyses were conducted by comparing the diagnostic characteristics between cases with a follow-up of less and more than 2 years of follow-up. The anatomical distribution of tracer uptake and interobserver reliability were also evaluated. ResultsOf the 180 BS-SPECT/CT scans conducted, 22 were determined positive, 113 negative, and 45 inconclusive. The best-case scenario showed a sensitivity of 66.7%, specificity of 93.8%, +LR 10.8, −LR 0.4, PPV 54.6%, and NPV 96.2%. In contrast, the worst-case scenario had a sensitivity of 94.4%, specificity of 69.1%, +LR 3.1, −LR 0.1, PPV 25.4%, and NPV 99.1%. Sensitivity analyses revealed no relevant differences in characteristics between the 2 TKA-interval groups. The interobserver reliability was fair-to-moderate (κ = 0.39; 95% confidence interval 0.18 to 0.60), with an estimated agreement of 79% (95% confidence interval 70 to 87). Four prosthetic zones had a notably higher proportion of cases with tracer uptake in those with aseptic loosening compared to those without. ConclusionsThe test characteristics of BS-SPECT/CT were deemed appropriate in patients who have complaints of uncemented TKA suspected of aseptic loosening. Inconclusive cases were best categorized as negative, especially in patients who have a short interval between TKA and the first BS-SPECT/CT. Increased tracer uptake in 4 prosthetic zones was observed in cases of aseptic loosening, although interobserver reliability was fair to moderate. Level of EvidenceLevel III, Diagnostic Retrospective Cohort Study.

Vancouver type B2 periprosthetic femoral fractures: clinical and radiological outcomes from a tertiary care center

IntroductionThe purpose of this study was to report mid-term clinical and radiographic results after hip arthroplasty revision in Vancouver type B2 femoral periprosthetic fractures (PPFx). Specifical focus of the paper is as follows: (1) the description of a standardized and reproducible surgical technique, (2) functional outcomes presentation and (3) type and number of complications and implants’ survival rate analysis.MethodsWe retrospectively reviewed all patients treated for hip revision with non-modular tapered fluted titanium stem in patients with Vancouver type B2 femur PPFx at a single institution. At least 18 months’ follow-up period was required. Harris Hip Scores and SF-12 were obtained, and radiographical follow-up was performed. Complications were reported and analyzed.ResultsThe authors included 114 patients (114 hips) with a mean follow-up of 62.8 ± 30.6 months. All patients were treated with Wagner SL revision hip stem (Zimmer-Biomet), metal cerclage wires ± trochanteric plate. The mean HHS and SF-12 score at the last follow-up evaluation were respectively 81.3 ± 9.7 and 32.5 ± 7.6. Seventeen (14.9%) complications occurred. We observed five cases of dislocations, two of periprosthetic joint infections and six cases of new PPFx. The stem-related revision rate for any cause at the final FU was 1.7%, due to PJI. No patients underwent stem revision surgery for aseptic loosening. Fracture healed in all the included patients with a union-rate of 100%. The re-operation rate for any cause was 9.6%, with an implant survival rate for overall failure of 96.5%.ConclusionThe presented standard and reproducible surgical technique obtains optimal clinical and radiological results with limited complication rate at mid-term follow up. Preoperative planning as well as careful intraoperative surgical technique is of a paramount importance.

DUAL-MOBILITY CUPS CEMENTED INTO CAGE IN COMPLEX REVISION TOTAL HIP ARTHROPLASTY PROVIDE A LOW REVISION RATE AT MORE THAN TEN YEARS

Instability and aseptic loosening are the two main complications after revision total hip arthroplasty (rTHA). Dual-mobility (DM) cups were shown to counteract implant instability during rTHA. To our knowledge, no study evaluated the 10-year outcomes of rTHA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for rTHA at 10 years, with few revisions for acetabular loosening and/or instability.This is a retrospective study of 77 rTHA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; SERF, DÉCINES-CHARPIEU, FRANCE) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation.With a mean follow-up of 10.7 years [2.1-16.2], 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years [7–12]. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients.The use of a DM cup cemented into a metal ring during rTHA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years. That's why we also recommend DM cup for all high risk of dislocation situations.

Classification and reconstruction of femoral bone defect in the revision of aseptic loosening of distal femoral endoprostheses: a 10-year multicenter retrospective analysis

ObjectiveThis study proposes a system for classifying the aseptic loosening of distal femoral endoprostheses and discusses reconstruction methods for revision surgery, based on different classification types.MethodsWe retrospectively analyzed the data of patients who received revision surgery for aseptic loosening in distal femoral tumor endoprosthesis from January 2008 to December 2020 at 3 bone tumor treatment centers in China. Based on the patient imaging data, we proposed a classification system for the aseptic loosening of distal femoral endoprostheses and discussed its revision surgery strategy for various bone defects.ResultsA total of 31 patients were included in this study, including 21 males and 10 females aged 15–75 y (average: 44.3 y). First-revision surgery was performed on 24 patients, whereas second-revision surgery was conducted on 7 patients. The 31 patients were classified into different types based on the degree of aseptic loosening: Type I, 12 patients (38.7%); Type IIa, 7 patients (22.5%); Type IIb, 7 patients (22.5%); Type III, 4 patient (12.9%); and Type IV, 1 patient (3.2%). For type I, 11 patients underwent revisions with standard longer-stem prostheses (one with the original prosthesis), and one patient had the original prosthesis plus cortical allograft strut. For type II (a and b), 10 patients underwent revisions with original prosthesis or longer-stem prosthesis and 4 patients combined with cortical allograft strut. For type III, one patient underwent revision with a longer-stem prosthesis and the other 3 patients with a custom short-stem prosthesis. For type IV, only one patient underwent revision with a custom short-stem prosthesis.ConclusionsAseptic loosening of the distal femoral prosthesis can be divided into 4 types: type I, type II (a, b), type III and type IV. The reconstruction methods of our centers for different types of bone defects can offer some reference value in the revision of aseptic loosening.

Outcome measures and survivorship following total hip arthroplasty in adolescent population.

The most frequent indication for total hip arthroplasty (THA) in adolescent patients has been juvenile idiopathic arthritis (JIA). However, in recent years, other causes have become more prevalent. (1) What is the survivorship following THA across the diagnostic spectrum in adolescent population? (2) How are quality of life results affected by systemic medical conditions? We retrospectively reviewed all consecutive THA in patients under 21years of age, performed at our Institution between 1993 and 2018. There were 34 prostheses implanted in 26 patients with a mean age of 18.4years (range 11 to 21). The most frequent diagnosis was JIA (14 hips), followed by avascular necrosis (10 hips). Patient reported outcomes were assessed using Harris and Oxford Hip Scores (HHS and OHS), Visual Analogue Scale (VAS) and EuroQol-5D. Survivorship for revision and aseptic loosening was determined with Kaplan Meier analysis. At final follow-up, the overall survival rate was of 89.3% at 12-year follow-up. Three acetabular components underwent revision surgery for aseptic loosening. Clinical HHS significantly improved from 37.5 to 90.6 points (p < 0.001). Mean OHH was 37.4 points, with a final VAS of 1.64 points. Mean 5Q-5D was 0.704 with an interquartile range of 0.4 to 1.0. JIA patients displayed worse pre-operative HHS scores, and at final follow-up had worse HHS, OHS, VAS and EQ-5D scores compared to the rest of the patients. Complications included three intra-operative femoral fractures, one sciatic nerve palsy and one adductor contracture. THA in adolescent patients provides improved functional outcomes with acceptable revision rates at mid-term follow-up.

Risk of Revision After Arthroplasty Associated with Specific Gene Loci: A Genomewide Association Study of Single-Nucleotide Polymorphisms in 1,130 Twins Treated with Arthroplasty.

The risk of revision surgery following total joint arthroplasty (TJA) may be influenced by genetic factors. Therefore, we sought to identify genetic variants associated with the risk of revision surgery in a genomewide association study. We investigated a cohort of 1,130 twins from the Swedish Twin Registry treated with TJA. During a mean of 9.4 years of follow-up, 75 individuals underwent revision surgery for aseptic loosening (the primary outcome) and 94, for any reason (the secondary outcome). Genetic information was collected using the Illumina OmniExpress and PsychArray panels, and the Haplotype Reference Consortium served as the reference for gene imputation. Adjusted Cox regression models were fitted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Nine single-nucleotide polymorphisms (SNPs) reached genomewide significance for aseptic loosening. The first SNP, rs77149046, located in the endosome-lysosome associated apoptosis and autophagy regulator family member 2 (ELAPOR2) gene, conferred an HR of 5.40 (CI, 3.23-9.02; p = 1.32×10 -10 ), followed by 4 SNPs within the region coding for sodium-dependent taurine and beta-alanine transporter (SLC6A6), with HRs ranging from 3.35 to 3.43. The sixth SNP, rs7853989 (HR, 3.46; CI, 2.33-5.13; p = 6.91×10 -10 ), was located in a region coding for the ABO blood group system. This SNP has been described as predictive for blood type B. Seven significant SNPs were found for the risk of revision for any reason, with the first 4 again being located in the SLC6A6 region. The leading SNP, rs62233562, conferred an HR of 3.11 (CI, 2.19-4.40; p = 1.74×10 -10 ) for revision surgery. Similar HRs were found for SNPs 3:14506680 (p = 1.78×10 -10 ), rs2289129 (p = 1.78×10 -10 ), and rs17309567 (p = 3.16×10 -10 ). The fifth SNP, rs11120968, was located in the calmodulin-binding transcription activator 1 (CAMTA1) gene (HR, 2.34; CI, 1.74-3.13, p = 1.45×10 -8 ). We identified 12 unique SNPs associated with an increased risk of revision surgery. Among these, 2 were in ELAPOR2, which is closely linked to bone formation. Another SNP is located in a gene region encoding for the ABO system, which merits further studies of causal relationships. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Proton Pump Inhibitors and the Risk of Early Aseptic Loosening in Hip and Knee Arthroplasty.

IntroductionThe use of proton pump inhibitors (PPIs) has been associated with a higher risk of osteoporotic fractures and non-unions rates. However, the relation between the use of PPIs and the development of aseptic loosening in arthroplasty procedures has not been studied. The objective of this study is to analyze the relation between the use of PPIs, and the risk of early aseptic loosening in total knee arthroplasty (TKA) and total hip arthroplasty (THA).Materials and methodsA nested case-control study was conducted on patients who were subjected THA or TKA in our center between 2010 and 2014. Cases were patients subjected to revision surgery due to early aseptic loosening during the study period. Cases were matched with controls who did not require any type of revision surgery by type of joint replacement (THA/TKA), gender, age (+/− 2 years), and follow-up time (±6 months). Odds Ratios were adjusted to potential confounders.ResultsThe crude and adjusted ORs (95% CI) of undergoing revision surgery for aseptic loosening following primary total knee arthroplasty or total hip arthroplasty, were 6.25 (2.04–19.23) and 6.10 (1.71–21.73), respectively, for any use PPIs compared with non-users. Crude and adjusted ORs, were 11.6 (2.93–45.88) and 17.1 (2.41–121.66), respectively, for patients with a Proportion of Days Covered (PDC) for PPIs <.5 (Table 2). In addition, the crude and adjusted ORs of undergoing revision surgery, were 5.05 (1.59–16.02) and 5.01 (1.36–18.44), respectively, for patients with a PDC for PPIs ≥.5.DiscussionThese results suggest that PPIs should be used with caution in patients with TKA and THA, and that the use of these drugs should not be prolonged unless there was a justifiable indication.ConclusionsThe use of PPIs and was associated with a higher risk of early aseptic loosening in patients subjected to THA and TKA.

Medium term outcome of Lancaster cortical window technique for extraction of femoral stem in revision hip arthroplasty

BackgroundThe extraction of a femoral stem during the revision hip arthroplasty can be a daunting task and can lead to catastrophic complications for the patient. A sound technique employed intraoperatively helps in the speedy recovery of the patient and reduces the risk of future surgical interventions. In this study, we present a medium-term outcome of our novel Lancaster cortical window technique which can be used for the removal of cemented or uncemented femoral stems.MethodsThe study was conducted at a specialist centre in the north-west of the UK from January 2014 to May 2019. This is a retrospective case series where patients were treated surgically using the Lancaster cortical window technique for removal of the femoral implant during a revision hip arthroplasty. Patient’s electronic notes and radiographs were used to evaluate the functional and radiological outcome.ResultsIn this study, 18 patients were managed surgically using the novel Lancaster window technique. The mean age of all the patients was 81.5 years, and the male to female ratio was 10:8. Fifteen patients underwent revision surgery for aseptic loosening of the femoral and acetabular components. The rest of the three patients had revision surgery for a broken femoral stem, intraoperative femoral canal perforation while implanting a total hip replacement femoral stem and infection. Twelve femurs were replanted with uncemented long femoral stems and six with long cemented stems. The cortical window osteotomy united in all the patients in 4.2 months (mean). The mean follow-up of these patients is 20.9 months, and none of them had any implant subsidence or loosening at the time of their last follow-up.ConclusionWe believe Lancaster cortical window technique can be safely used for the removal of cemented stems during revision hip arthroplasty without the need for expensive equipment.

Metaphyseal Stem Tip Location is a Risk Factor for Aseptic Loosening of Cemented Distal Femoral Replacements

BackgroundThe objective of this study was to describe the incidence of aseptic loosening (AL) of cemented stem distal femoral replacements (DFR) and to identify modifiable risk factors for its development. MethodsA retrospective review was performed of 245 consecutive primary, cemented stem DFRs implanted at a single institution over a 40-year period. The primary outcome was revision surgery for AL. A multivariate analysis was performed to identify risk factors for AL. Radiographs were reviewed to identify stem tip location, which was defined as diaphyseal or metaphyseal. Implant survival to AL was compared using Kaplan-Meier analysis. ResultsAL and structural failure were the most common causes of implant failure (incidence 11.8%, 29/245). Younger age (P = .002), male sex (P = .01), longer resection length (P = .04), and nonmodular implants (P = .002) were all significantly associated with AL. After 1:1 matching, stem tip location in metaphyseal bone was independently associated with AL (P = .04). 36% (9/25) of implants that loosened had a stem tip located in the metaphysis vs only 8% (2/25) of implants that did not fail. 30-year survival to AL was lower for implants with a metaphyseal stem tip than implants with a diaphyseal stem tip (22.7% vs 47.6%; P = .11). ConclusionA stem tip location in metaphyseal bone is associated with diminished survival to AL. When templating before DFR, stem tip location can assist in identifying high-risk reconstructions that may benefit from alternative or supplemental fixation techniques to prevent the development of AL.

Clinical and radiological outcomes of total hip arthroplasty using a highly porous titanium cup or a conventional hydroxyapatite-coated titanium cup: A retrospective study in Japanese patients

BackgroundA highly porous titanium cup has a unique structure that mimics human trabecular bone and is expected to achieve better outcomes due to rigid fixation and extensive bone ingrowth. Several manufacturers have developed a highly porous titanium cup; however, some have shown a high incidence of radiolucent lines (RLLs) on early postoperative radiographs. In this study, we compared the clinical and radiological outcomes of total hip arthroplasty (THA) using a highly porous titanium cup (OsseoTi, Zimmer Biomet) with those after THA using a conventional hydroxyapatite-coated titanium cup (Trident HA, Stryker). MethodsA total of 201 hips that underwent THA using an OsseoTi cup (n = 101) or Trident cup (n = 100) were enrolled in the study. Patient characteristics, cup alignment, clinical outcome (determined by the Japanese Orthopedic Association [JOA] score), and incidence of RLLs around the cup were evaluated at 3, 6, 12, and 24 months postoperatively. ResultsThe clinical outcome was excellent in both groups. The incidence of RLLs was 12.9% at 3 months, 20.8% at 6 months, 23.8% at 12 months, and 22.8% at 24 months after surgery in the OsseoTi group; there were no cases of RLL at any time after surgery in the Trident group. The RLLs were mainly distributed in zone 2. Despite the high rate of RLL in the OsseoTi group, the RLL were narrow and only 5% had a width of >1 mm at 24 months postoperatively. There were no cases with RLLs in all three zones. ConclusionsDespite excellent clinical outcomes in both study groups, the incidence of RLLs was higher in the OsseoTi group than in the Trident group. Although none of our cases with RLL have required revision surgery for aseptic loosening so far, these patients require careful follow-up.

Low Revision Rates at More Than 10 Years for Dual-Mobility Cups Cemented Into Cages in Complex Revision Total Hip Arthroplasty

BackgroundInstability and aseptic loosening are the two main complications after revision total hip arthroplasty (rTHA). Dual-mobility (DM) cups were shown to counteract implant instability during rTHA. To our knowledge, no study evaluated the 10-year outcomes of rTHA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for rTHA at 10 years, with few revisions for acetabular loosening and/or instability. MethodsThis is a retrospective study of 77 rTHA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; Serf, Décines-Charpieu, France) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation. ResultsWith a mean follow-up of 10.7 years [2.1-16.2], 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years [7-12]. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients. ConclusionThe use of a DM cup cemented into a metal ring during rTHA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years.

Long-term results of Zweymüller SLL femoral stem in revision hip arthroplasty for stage II and IIIA femoral bone defect: a 9-15-year follow-up study.

Loosening of femoral stem can be associated with a wide spectrum of bone loss that represents the most important factor for choosing the most appropriate revision implant. Positive outcomes in femoral revision were already observed with Zweymüller Alloclassic® SLL stem in short- and medium-term follow-up. The aim of the study is to analyse the clinical results of 31 patients who underwent prosthetic revision for aseptic loosening of femoral component with Zweymüller femoral stem and long follow-up. The series included 10 men and 21 women with a mean age of 66.24years at the time of revision surgery and a mean follow-up of 12.25years. Clinical and radiological evaluation was performed at 2months, 6months and yearly, using Harris Hip Score (HHS) and Engh's criteria and Brooker classification for heterotopic ossifications. At the last follow-up, the survival of the stem was observed in all patients (32 hips). The mean HHS was 77.83 ± 20.90. Clinical results were stated as excellent in 14 cases, good in 5 cases, fair in 4 cases and poor in 9 cases. Radiographic stability with fixation by bone ingrowth was observed in 15 cases and with fibrous ingrowth in 17 cases. Heterotopic ossifications grade III was observed in 4 cases and grade II in 3 cases. Zweymüller Alloclassic® SLL stem showed excellent or good results in about 59% of revision surgery for aseptic loosening. The survival rate of the stem at 9-15years of follow-up was satisfactory.

Middle term results of tantalum acetabular cups in total hip arthroplasty following pelvic irradiation

ObjectivesThe aim of this study was to evaluate the middle term cup survival, assess the functional implementation and the radiographic evolution of tantalum acetabular cups implanted on patients with a history of pelvic radiotherapy. MethodsFrom 2005 to 2013, we performed 12 THA replacements (4 males 8 females; mean age: 46.6 years (range 25–75)) on irradiated bone with Trabecular metal acetabular cups, 8 primary implants and 4 revision implants. The mean radiation dose delivered was 5500 cGy (range 3000 cGy–13,600 cGy). The mean follow-up was 68 months, ranging from 38 to 136. Postoperative follow-up time was assessed at 1, 3, 6 and 12 months, then annually. Double projection radiographs were requested at each control. Radiographic signs of loosening were investigated by X-rays looking for radiolucent lines. We used the Harris hip score for the clinical and functional evaluation. ResultsTo now none of the 12 patients in the series needed any revision surgery for aseptic loosening. In the revision group one patient have been revised for septic loosening, two patients have been treated by conservative procedure for hip dislocation. Post-operative Harris hip score improved from an average of 46 points to 85.3 points. At last follow-up we found only in one case radiographic signs of progressive lucent line, without clinical sign of failure. ConclusionIn a clinical setting, tantalum cup seems to provide a good stability due to the integration of the trabecular metal to the underline cancellous bone. The reported results, in agreement with literature data, propose the use of tantalum cups in irradiated bone. Level of evidenceLevel IV, therapeutic study.

Survival of Hydroxy Apatite-Coated Cups: Acetabular Screws Involve a Lower Rate of Revision Surgery due to Aseptic Loosening

It is believed that the path of acetabular screws may represent a shuttle between hydroxyapatite (HA) particles and the liner. The aim was to assess the relationship between acetabular screws and revision surgery for aseptic loosening in total hip arthroplasties (THAs). A retrospective multicentric study was performed. Patients older than 18 years and patients who underwent THA with both the stem and cup HA-coated were included. The rate of revision-surgery considering only aseptic loosening was calculated. The proportion of cases in which acetabular screws were used was registered, as well as the proportion of cups that showed osteolysis. The statistical relationship between acetabular screws and osteolysis, as well as acetabular screws and revision-surgery for aseptic loosening were assessed. There were 749 cases. Mean age 62.1 (45-84) years. Mean follow-up 14.19 (8.9-16.7) years. Revision surgery was performed in 12.8% (96/749) of the cups. 73.95% (71/96) of the revised cups showed aseptic loosening. The overall 15-year survival of the cups considering only aseptic loosening was 84.4%. Acetabular screws were used in 47.5% (356/749) of the cups. Acetabular screws were used in 40.44% (55/136) of the cups that showed osteolysis. The use of acetabular screws was associated with less osteolysis (p = 0.006). Acetabular screws were used in 35.21% (25/71) of the cups that were revised for aseptic loosening. The use of acetabular screws was associated with a lower rate of revision surgery (p = 0.020). In THA with the stem and cup HA-coated, the use of acetabular screws is associated with a lower rate of revision surgery.

Effectiveness of Constrained Liner Use During Harrington Hip Reconstruction in Oncology Patient

BackgroundPatients with destructive acetabular lesions are at high risk for morbidity. Harrington described reinforcing acetabular diseased bone with methylmethacrylate, supplemented by metal fixation, to allow total hip reconstruction. However, all published studies using this technique report dislocations. We believe that initial use of constrained liners would help alleviate dislocation risk, without increasing component loosening or polyethylene wear. MethodsSixty-eight patients who underwent Harrington hip arthroplasties for metastatic cancer from August 2005 to March 2015 were identified. All patients had a constrained acetabular liner implanted during their index procedure. Electronic medical records and radiographs were reviewed. A literature review of studies with similar technique was used as a historical control. ResultsForty-seven patients (69.2%) died 22.7 ± 22.7 months after surgery, at age 62.4 ± 17.2 years. At an average clinical follow-up of 9.9 ± 14.2 months (range 2-50 months), we found no incidents of dislocation. No patients had component failure requiring revision or evidence of loosening on x-ray. Thirteen papers, comprising 185 patients, demonstrated 39 patients (21.1%) with dislocations and 13 patients (7.0%) requiring revision surgery for aseptic loosening. ConclusionModified Harrington technique has demonstrated relative durability when reconstructing metastatic acetabular disease, although dislocation occurs in approximately 20% of patients. This study demonstrates that initial use of a constrained liner can alleviate postoperative dislocations without increasing risk of perioperative complications. Even modest reduction in complications during the limited lifespan of oncologic patients can have dramatic positive effects on quality of life.

STAR™ Ankle

Category: Ankle Arthritis. Introduction/Purpose: Over the past decade, total ankle arthroplasty (TAA) has become a mainstay in the treatment of end stage ankle arthritis. Currently in its fourth generation, the Scandanavian Total Ankle Replacement (STAR™) is the only 3-piece mobile bearing design available in the United States. Current studies show 89-94% survivorship of the STAR™ at 9-12 years follow-up. We report patient outcomes at a minimum of 15 years. Methods: 24 patients from the initial U.S. STAR™ FDA trial who had undergone no metal revision at 10 year follow-up were available for participation. Radiographic examinations were performed for all patients. Changes in prosthetic position, coronal and sagittal plane alignment, osteolysis, adjacent joint arthritis, and heterotopic ossification were documented. Clinical examinations were performed for 14 patients. Clinical findings, AOFAS ankle/hindfoot scores and SF-36 scores were recorded. All secondary procedures and complications were noted. Implant failure was defined as revision or explant of either the tibial or talar component. Results: 87.5% (21/24) of participants had metal survivorship at a minimum of 15 years. Two patients required revision surgery for aseptic loosening and one required a tibiotalocalcaneal fusion for a progressive coronal plane deformity. Of the 21 patients with metal survivorship, the AOFAS ankle/hindfoot rating scale improved from an average of 39.6 points preoperatively, to an average of 71.6 points at latest follow up (range 42-89). The average SF-36 score was 49.0. Postoperative range of motion averaged 17 degrees (range 5-30°). Adjacent joint arthritis was seen radiographically in 5 patients (23.8%), one which required a subtalar fusion. Two patients required exchange for a broken polyethylene spacer. 11/21 (52.4%) of patients required an additional surgical procedure, 3 of whom required two additional procedures. Average time to subsequent procedure was 10.2 years. Conclusion: Our data shows that if the STAR™ ankle has survived for 10 years, it will likely survive for 15 years. On the whole, patients reported good subjective outcomes, maintaining a near 30 point improvement in AOFAS scores. Revisions after 10 years were seen for aseptic loosening and coronal plane deformity. Patients should be counseled that it is common to have a subsequent procedure, which averaged 10 years postoperative from our experience. Further advancement in instrumentation, polyethylene wear characteristics, and revision implants will likely be the next stage in the advancement of TAA.

Migration pattern of a cobalt-chrome monoblock acetabular component after metal-on-metal hip resurfacing.

The purpose of this study was to study the initial fixation and migration pattern of a monoblock acetabular component used for a metal on metal hip resurfacing using Einzel Bild Roentgen Analyse (EBRA). 99 patients with a mean age of 49.6 years (range 28.5-66.3 years) of whom 14 were bilateral underwent a hip resurfacing (Conserve Plus®, MicroPort, Memphis, TN) for a total of 113 resurfacings. Acetabular component orientation was noted with 35 of the 113 components (31.0%) having a lucency &gt;2 mm on the immediate postoperative radiograph. The mean follow-up for our cohort of 113 hips is 50 months (2-79 months). When examining the 2-year migration mark, 37 of the 113 hips exceeded the threshold of 0.5 mm/year with a median total migration of 1.40 mm (range 1.02-4.24). 6 resurfacings underwent revision surgery for aseptic loosening of the acetabular component at a mean time of 43.6 months. Presence of initial lucency (OR 2.29, p = 0.05) was the only significant predictor of migration over threshold at 2-years. Those that had migrated over the threshold (1.0 mm) at 2 years were at significantly greater risk of continued migration at 4 years. The migration pattern of this component raises concerns about long term performance, with postoperative lucencies representing a significant factor for future migration.

Prosthesis Failure Within 2 Years of Implantation Is Highly Predictive of Infection

The outcome of revision surgery depends on accurate determination of the cause of prosthesis failure because treatment differs profoundly among aseptic loosening, mechanical failure, and prosthetic joint infections (PJI). We sought to determine (1) the predictive role of the interval from primary to revision surgery in determining the reason for prosthesis failure of a hip, knee, shoulder, or elbow arthroplasty, and (2) whether positive cultures during revision surgery for aseptic loosening were associated with shorter event-free survival of the prosthesis. All patients undergoing revision surgery between July 2010 and January 2012 were included in a prospective cohort of 112 patients, and were classified as having had failure from aseptic loosening (56%), mechanical failure (15%), or PJI (29%). To make the diagnosis of PJI, at surgery we used a standardized enhanced diagnostic approach in all patients including sampling of five periprosthetic tissue specimens, sonication of removed prosthetic components, prolonged incubation of aerobic and anaerobic cultures, and multiplex PCR of sonication fluid in aseptic loosening cases. Kaplan-Meier survival and Cox proportional hazards regression analysis were performed. The median time from primary to revision surgery was (p < 0.001) longer for patients with aseptic loosening (7.8 years) than for patients with mechanical failure (1.6 years) or PJI (2 years). No difference in the time to revision was observed for patients with aseptic loosening with positive or negative microbiological cultures (p = 0.594). Propionibacterium acnes was cultured below the established microbiological criteria for positivity in 12 (19%) procedures that had been presumed to have been revisions for aseptic loosening. PJI should be considered in all revisions performed within 2 years of implantation even in the absence of clinical or laboratory findings suggestive for infection. However, the growth of low-virulence microorganisms below the cut-off in revisions for apparent aseptic loosening is not associated with early prosthesis failure.

Increase of Cortical Bone After a Cementless Long Stem in Periprosthetic Fractures

Healing and functional recovery have been reported using an extensively porous-coated stem in Vancouver B2 and B3 periprosthetic fractures; however, loss of cortical bone has been observed when using these stems in revision surgery for aseptic loosening. However, it is unclear whether this bone loss influences subsequent loosening. We analyze the healing fracture rate and whether the radiographic changes observed around and extensively porous-coated stem used for periprosthetic fractures affect function or loosening. We retrospectively reviewed 35 patients with periprosthetic fractures (20 Vancouver B2 and 15 Vancouver B3). Patients' mean age at surgery was 80 years (range, 51-86 years). No cortical struts were used in this series. We evaluated radiographs for signs of loosening or subsidence. The cortical index and the femoral cortical width were measured at different levels on the immediate pre- and postoperative radiographs and at different periods of followup. The minimum followup was 3 years (mean, 8.3 years; range, 3-17 years). All fractures had healed, and all stems were clinically and radiographically stable at the end of followup. Nineteen hips showed nonprogressive radiographic subsidence during the first 3 postoperative months without clinical consequences. The cortical index and the lateral and medial cortical thickness increased over time. Increase of femoral cortex thicknesses was greater in cases with moderate preoperative osteoporosis and in cases with stems less than 16 mm in thickness. Our data suggest an extensively porous-coated stem for Vancouver B2 and B3 periprosthetic fractures leads to a high rate of union and stable fixation. Cortical index and lateral cortex thickness increased in these patients with periprosthetic fractures. Patients with moderate osteoporosis and those using thin stems showed a major increase in femoral cortex thickness over time.

Prosthetic hip revision: relationship between bone stock and quality of life in aseptic loosening of the femoral component

We evaluated the clinical and radiographic results in the medium and long term in patients undergoing revision surgery for aseptic loosening with different bone quality at the time of the operation. We investigated how different bone quality shapes for a good clinical result. A total of 33 patients who underwent revision surgery of the hip (for aseptic loosening of the stem) evaluated radiographically and clinically at 1,6,12 and 18 months. The evaluation of clinical status preoperatively and at the end of follow-up was be made as questionnaires SF-36, Harris Hip Score and WOMAC; radiographic assessment was made using the scale of Paprosky. The data thus obtained have been related to complications arising and the status of femoral bone-loss before the surgery time. The groups PI and PII (Paprosky) showed a high level of satisfaction with an average value of reference for the postoperative rated as excellent, the absence of complications and good functional recovery at the end of follow-up. The groups PIII and PIV showed increased incidence of complications and difficulties with rehabilitation clinics and SF-36 scores and HHS inferior to other classes. Our dates confirm that bone quality at the time of surgery affects the therapeutic target. All patients with good bone quality at the time of the revision surgery (groups PI and PII) showed a distinct advantage from surgical treatment. Revision surgery had not much effect in patients with high bone loss. Preservation of bone stock should be considered a good foundation for the success of a prosthetic reimplantation with better functional and radiographic out-come associated with greater satisfaction for the patient.