The Clinical Frailty Scale is a Strong Predictor of 1-Year Mortality in Surgically Managed Hip Periprosthetic Fracture: An Analysis From a High-Volume Institution.

BACKGROUND: Hip periprosthetic fractures (PPFs) after primary total hip arthroplasty are increasing with the number of primary implants and aging population. Mortality has been reported up to 34% at 1-year. The aim of this study was to evaluate the association of Clinical Frailty Scale (CFS) and 1-year mortality, complication rate, and length of stay (LOS) in surgically managed hip PPFs. METHODS: This was a retrospective study of prospectively collected data from January 2008 to January 2021. A total of 282 surgically managed hip PPFs were identified. Mean age was 79 years (range, 42 to 106). Preoperative scores were analyzed through linear regression to identify significant association with mortality, complication and LOS. Receiver operating characteristic curve and Area Under the Curve (AUC) were generated to evaluate the quality of the models and the discriminatory ability of each clinical score. Significance was considered at P values < .05. RESULTS: Mortality was 7.8% at 3-months and 15.7% at 1-year. Complication rate requiring surgery was 19.5% and mean LOS was 8.9 ± 7 days. The CFS was significantly associated with 3-month (odds ratio 2.23, P < .001) and 1-year mortality (odds ratio 2.01, P < .001). The receiver operating characteristic curve test for 1-year mortality showed a greater AUC for the CFS when compared with American Society for Anesthesiologists score and age-adjusted Charlson Comorbidity Index (AUC 0.80 versus 0.68 versus 0.72, respectively). CONCLUSIONS: Frailty is a syndrome with increased risk of mortality after surgically managed PPF. The CFS can be easily assessed at the time of admission and could be considered as a strong and reliable predictor of 1-year mortality with a greater AUC than the conventionally used American Society for Anesthesiologists score.

Prevalence and Impact of Unexpected Positive Intraoperative Cultures in Total Hip or Knee Revision Surgery.

BACKGROUND: Our aim was to evaluate the prevalence and impact of unexpected positive intraoperative cultures (UPICs) on the outcome of presumed aseptic total knee and hip revision surgery. METHODS: Data regarding patients who underwent elective total hip or knee revision surgery from January 2003 to July 2017 due to preoperatively presumed aseptic reasons was retrospectively reviewed. Partial revisions and patients who had follow-ups below 60 months were excluded from the study. In all surgeries, at least 3 intraoperative samples were taken for microbial culture. Failure was defined as the need for rerevision due to any cause at 5 years and/or the need for antibiotic suppressive therapy. Overall, 123 total hip and 431 total knee revisions were eligible for the study. All cases had at least a 5 years follow-up. RESULTS: There were 420 cases (75.8%) that had all cultures negative, 108 (19.5%) had a single UPIC, and 26 (4.7%) had either ≥2 UPICs for the same microorganism or 1 UPIC for a virulent microorganism. This latter group was not associated with a significantly higher failure rate (2 of 26, 7.7%) compared to those in the aseptic group (54 of 528, 10.2%). Revisions performed within the first 24 months after primary implantation had a higher 5-years rerevision rate (19.3 versus 8.4%, P = .01), mainly attributable to aseptic causes. CONCLUSIONS: Total hip and knee revisions with UPICs were not significantly associated with a higher rerevision risk at 5 years. Those revisions performed within the first 24 months after primary arthroplasty had a higher rate of any-cause failure.

Impact of fixation method on femoral bone loss: a retrospective evaluation of stem loosening in first-time revision total hip arthroplasty among two hundred and fifty five patients.

PURPOSE: Implant loosening represent the most common indication for stem revision in hip revision arthroplasty. This study compares femoral bone loss and the risk of initial revisions between cemented and uncemented loosened primary stems, investigating the impact of fixation method at primary implantation on femoral bone defects. METHODS: This retrospective study reviewed 255 patients who underwent their first revision for stem loosening from 2010 to 2022, receiving either cemented or uncemented stem implants. Femoral bone loss was preoperatively measured using the Paprosky classification through radiographic evaluations. Kaplan-Meier analysis estimated the survival probability of the original stem, and the hazard ratio assessed the relative risk of revision for uncemented versus cemented stems in the first postoperative year and the following two to ten years. RESULTS: Cemented stems showed a higher prevalence of significant bone loss (type 3b and 4 defects: 32.39% vs. 2.72%, p < .001) compared to uncemented stems, which more commonly had type 1 and 2 defects (82.07% vs. 47.89%, p < .001). In our analysis of revision cases, primary uncemented stems demonstrated a 20% lower incidence of stem loosening in the first year post-implantation compared to cemented stems (HR 0.8; 95%-CI 0.3-2.0). However, the incidence in uncemented stems increased by 20% during the subsequent years two to ten (HR 1.2; 95%-CI 0.7-1.8). Septic loosening was more common in cemented stems (28.17% vs. 10.87% in uncemented stems, p = .001). Kaplan-Meier analysis indicated a modestly longer revision-free period for cemented stems within the first ten years post-implantation (p < .022). CONCLUSION: During first-time revision, cemented stems show significantly larger femoral bone defects than uncemented stems. Septic stem loosening occurred 17.30% more in cemented stems.

Femoral revision in total hip arthroplasty using a cementless modular stem: clinical and radiological results with a 8-year follow-up.

INTRODUCTION: Modular femoral components allow for patient-specific restoration of hip joint geometry and the reconstruction of extensive bone defects in revision total hip arthroplasty (THA); however, potential problems of modular implants such as taper corrosion and the risk of implant fracture continue to be of concern. The aim of the present study was to evaluate the clinical and radiological results of a cementless modular revision stem following revision surgery due to aseptic loosening and periprosthetic fracture and to assess patient-reported outcome measures (PROMs) in these patients at mid-term follow-up. MATERIALS AND METHODS: In this study, a consecutive cohort of 75 patients who underwent primary revision THA at our institution using a modular cementless stem design (MRP-TITAN stem) was retrospectively evaluated at a mean follow-up of 7.7 years. Kaplan-Meier survivorship analyses were performed with revision of the femoral component for any reason as the end point. The Harris-Hip Score, the UCLA Activity Score, the Forgotten Joint Score and the SF-12 Score were used for clinical assessment. We used the Wilcoxon signed rank test to compare pre- and postoperative clinical scores. RESULTS: Overall stem survival with the endpoint stem re-revision for any reason was 85.4% at a mean follow-up of 7.7 years (range 2.4-14 years). Stem survival was 89.5% in the aseptic loosening group and 78.3% in the periprosthetic fracture group with no statistically significant difference between both groups (p = 0.107). One patient had to be revised due to taper fracture. PROMs improved significantly up to the latest follow-up, and radiographic evaluation showed full osseointegration of all stems in this cohort. CONCLUSIONS: Revision THA using a modular cementless titanium revision stem demonstrated adequate clinical and radiological results at mid- to long-term follow-up in this cohort. Cementless revision stems are a useful treatment option to restore the anatomy, especially in deformed hips and in complex revision hip arthroplasty. However, there are some significant disadvantages related to an increased risk of mechanical failure such as corrosion/fretting damage and implant fracture. Future high-quality prospective studies with longer follow-up are necessary to confirm the supposed advantages.

Cemented vs cementless stems for revision arthroplasties due to Vancouver B2 periprosthetic hip fracture.

PURPOSE: According to Vancouver classification, B2 type fractures are most often treated with removal of the loose stem and implantation of a long stem that bypasses the fracture site. However, there is a controversy about the stem fixation that should be used: cemented or cementless. Hence, this study aims to compare cemented and cementless stems in prosthetic revision due to Vancouver B2 (VB2) periprosthetic hip fracture. METHODS: A retrospective study was done including all the patients treated with stem exchange due to VB2 periprosthetic hip fracture in a tertiary hospital between 2015 and 2022. Patients were divided into two groups according to the stem fixation used: cemented or cementless. Functional outcomes, hospital stay, surgical time, complication rate, and mortality were compared between the two groups of patients. RESULTS: Of the 30 included patients, 13 (43.4%) were treated with cementless stems and 17 (56.7%) with cemented stems. There were no statistically significant differences in age, gender, anesthesia risk scale (ASA) or functional capacity prior to the intervention. Patients treated with cementless stems had a higher complication and reintervention rate than those treated with cemented stems: 62 and 45% versus 34 and 6% (p = 0.035; p = 0.010), respectively. Furthermore, in the group of cementless stems a higher proportion of non-union was found (53.8% vs. 17.6%; p = 0.037). Also, the hospital stay (33 vs. 24 days; p = 0.037) and the time to full weight-bearing (21 days vs. 9 days; p < 0.001) were longer in the cementless stem group. CONCLUSION: Cemented fixation in stem revision due to Vancouver B2 periprosthetic hip fracture could be an optimal option with faster recovery which could decrease the rate of complications and reintervention, without compromising the fracture healing and patient mortality. Thus, this option can be considered when an anatomical reduction can be obtained, especially in elderly patients with multiple comorbidities in which a less aggressive surgical option should be considered.

Risk Factors Associated With Femorotomy or Fracture During Cementless Stem Removal and Generation of an Individual Predictive Risk Score.

BACKGROUND: Femorotomy is a commonly used technique during cementless stem removal but should be preferred in selective revision cases to prevent intraoperative femoral fracture associated with deteriorated clinical outcome. Our aim was to assess the risk factors for fracture or femorotomy and develop a predictive risk stratification score. METHODS: A monocentric retrospective cohort including 202 patients was analyzed. Thirty six candidate prognostic factors were assessed. RESULTS: The following independent predictors of fracture or femorotomy were identified: presence of a "bracket sign" (Odds Ratio [OR]: 10.857; 95% Confidence interval [CI]: 2.613-45.115; P = .001) defined as a distal spot weld between the surface of the implant and closest endosteum, bone contact in zone 2 (OR: 4.700; 95% CI: 1.827-12.089; P = .001), 6 (OR: 4.966; 95% CI: 1.823-13.530; P = .002), 12 (OR: 9.660; 95% CI: 3.715-25.116; P < .0001), 13 (OR: 2.958; 95% CI: 1.009-8.021; P = .033), and global hypertrophy (OR: 0.170; 95% CI: 0.036-0.806; P = .026). The prognostic score, named Femorotomy INcidence Numeric scoring system, had good performance and discriminability; the area under the curve of the model was 0.924 (95% CI: 0.878-0.969). CONCLUSION: The only independent risk factors were those assessed on X-ray (eg, bracket sign, bone contact in zones 2, 6, 12, and 13), while global hypertrophy was protective. We noticed the importance of differentiating pedestals and "bracket signs"; the latter is an indicator of fixation of the stem. We developed a risk prediction score (Femorotomy INcidence Numeric score) of fracture or femorotomy that can be used as a companion tool to assess the risk for doing an early osteotomy of the femur.

Contribution of the BioballTM head-neck adapter to the restoration of femoral offset in hip revision arthroplasty with retention of a well-fixed cup and stem.

PURPOSE: Failure to restore the femoral offset of the native hip is a potential cause of dysfunctional hip arthroplasty. The aim of this study was to report our experience of using a modular head-neck adapter in revision THA, specifically analyzing its usefulness as a tool to correct a slightly diminished femoral offset. MATERIALS AND METHODS: This was a retrospective single-center study including all hip revisions performed at our institution from January 2017 to March 2022 where the BioBallTM head-neck metal adapter was used. The preoperative and one year follow-up modified Merle d'Aubigné hip score was used to evaluate functional outcomes. RESULTS: Of a total of 34 cases included for revision, the head-neck adapter system was used specifically in six patients (17.6%) to increase femoral offset, retaining both the acetabular and femoral components. In this subgroup of patients, mean offset decrease after primary THA was 6.6 mm (4.0-9.1), equivalent to a mean 16.3% femoral offset reduction. The median modified Merle d'Aubigné score went from 13.3 preoperatively to 16.2 at one year follow-up. CONCLUSION: The use of a head-neck adapter is a safe and reliable procedure that may allow the surgeon to easily correct a slightly diminished femoral offset in a dysfunctional THA without the need to revise well-fixed prosthetic components.

Revision hip arthroplasty dislocation risk calculator: when to select dual mobility, large heads, constrained liners, or a standard head size? Testing one hundred thousand hip revisions with artificial intelligence.

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.

Gram negative periprosthetic hip infection: nearly 25% same pathogen infection persistence at a mean of 2 years.

PURPOSE: While gram negative (GN) periprosthetic joint infections (PJI) have previously been described as difficult to treat pathogens with high rates of reinfection, limited investigations have addressed midterm outcomes and risk of infection persistence by the same pathogen. This study analyzed (1) baseline demographics, treatment strategy, and midterm outcomes of GN PJIs, as well as (2) differences in reinfection and relapse rates compared to gram positive (GP) PJIs. METHODS: We identified 29 patients that were revised for 30 GN PJIs of total hip arthroplasties (THAs) between 2010 and 2020 using a university-based hip registry. Mean age was 77 years, 63% were females (19), and mean BMI was 27 kg/m2. Major causative pathogens included Escherichia coli (12), Klebsiella pneumoniae (5), Pseudomonas aeruginosa (5), and Enterobacter cloacae complex (5). Mean follow-up was 3.5 years. Study outcomes included (1) Kaplan-Meier survivorship analyses of all 30 GN PJIs, and (2) comparison of 18 two-stage exchanges for GN PJIs and 104 two-stage exchanges for GP PJIs, performed during the time from 2013 to 2017. RESULTS: (1) The 5-year survivorship free of recurrent PJI was 69%, and there were 7 recurrent PJIs at a mean of 2 years. There were 2 further suprafascial wound infections, resulting in a 61% survivorship free of any infection at 5-years. At a mean of 2 years, there were 7 patients with reinfection by the same GN pathogen (6 PJIs, one wound infection) as at index revision (23%). (2) Following two-stage exchange, the 5-year survivorship free of recurrent PJI (GN: 74%; GP: 91%; p = 0.072), any infection (GN: 61%; GP: 91%; p = 0.001), and reinfection by the same pathogen was significantly lower among GN PJIs (GN: 73%; GP: 98%; p < 0.001). CONCLUSIONS: Patients revised for GN PJIs are at increased risk of reinfection as opposed to GP infections. Affected patients must be counseled on the exceptionally high risk of infection persistence with one in four developing relapses. LEVEL OF EVIDENCE: Therapeutic Level III.

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

INTRODUCTION: The 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. METHODS: We 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. RESULTS: The 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%. CONCLUSION: The 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.

Spacer exchange in persistent periprosthetic joint infection: microbiological evaluation and survivorship analysis.

PURPOSE: The purposes of this study were to determine demographics and characteristics of patients who underwent spacer exchange for persistent infection in the setting of two-stage arthroplasty for periprosthetic joint infection, to describe the microbiology of pathogens involved, to analyze survivorship free from infection in these patients. METHODS: The institutional prospectively collected database was reviewed to enroll patients with minimum 2 years follow-up. Patients who underwent two-stage procedure for septic arthritis were excluded, as were patients who had spacer fracture or dislocation. RESULTS: A total of 34 patients (41 procedures) were included. Mean age was 65.0 ± 12.8 years. Mean follow-up was 53.4 ± 24.8 months. Mean number of previous procedures was 3.6 ± 1.2. A total of 27 (79.4%) patients underwent final reimplantation. The most frequently isolated pathogen in spacer exchange was Staphylococcus epidermidis (10 cases, 28.6%). Polymicrobial cultures were obtained from 9 (25.71%) patients, 10 (28.6%) presented culture-negative infections. A total of 11 (32.4%) resistant pathogens were isolated, and 16 (47.0%) difficult to treat pathogens were detected. Eradication rate was 78.8%. Overall survivorship of implants after final reimplantation was 72.8% at 51.8 months. CONCLUSION: Surgeons should be aware that subjects necessitating spacer exchange often present multiple comorbidities, previous staged revision failures, soft-tissue impairment and difficult to treat infection. In these patients, spacer exchange provides good clinical results and infection eradication, preventing arthrodesis or amputation.

The iliac stemmed cup in reconstruction of the acetabular defects secondary to tumor resection: a systematic review of literature.

INTRODUCTION: Stemmed acetabular cups are suitable for reconstruction in case of important bone loss. Nevertheless, their use is not so common, because generally judged very invasive and technically difficult to implant. The aim of the present review is to verify the results of their use and to evaluate indications and complications. MATERIALS AND METHODS: Literature research was performed in the main healthcare databases; indications, surgical technique, related complications, functional results and implant survival were valued and analyzed for every selected paper. RESULTS: 13 studies were selected, for a population of 424 patients and 428 hips. The main indication was reconstruction after tumor removal; the primary non-oncologic indication was revision for aseptic loosening. The most frequent complications were aseptic loosening and implant failure (16.2%), followed by deep infection (11.3%) and dislocation (9.8%). The average MSTS score was 65.9%; while data regarding functional results for degenerative cases are quite fragmented. The 5-years implant survival was 73.6%. CONCLUSIONS: Data regarding SAC prostheses are quite rare in the literature; no prospective studies with comparisons with other reconstruction techniques are available so their use is mainly based on the experience of single centers. While data for tumors are more consistent and supported by studies, information on revisions of hip prosthesis implanted for degenerative problems is quite scarce. Preliminary results on the SAC prosthesis as a valid alternative both for tumoral and degenerative revision cases are encouraging. Prospective randomized studies are advocated to value results compared to alternative techniques.

What is the rate of successful closed reduction of dislocated dual mobility cups following complex revision hip arthroplasty?

PURPOSE: The aim of this study was to assess the difference in success rates of closed reduction in septic and aseptic revision total hip arthroplasty (THA) performed with a dual mobility (DM) implant. Our objective was to answer the following questions: (1) Is there a difference in success rates of closed reduction between septic and aseptic revision THA with a DM implant? (2) Is closed or open reduction more successful in preventing re-dislocation? METHODS: Between January 2009 and October 2021, 924 revisions were performed with a DM implant. All patients presenting to our institution with a dislocation following septic or aseptic revision THA using a cemented DM cup were included in this study. We analyzed 106 cases of dislocation in 74 patients. For all patients, we collected reason for revision, and classified index surgery as septic or aseptic. RESULTS: Overall, 106 dislocations occurred (106/924, 11.5%). Thirty-nine cases (52.7%) had a dislocation after a septic exchange THA, while in 35 patients (47.3%), a dislocation occurred after an aseptic rTHA. In 29 patients (39.2%), successful closed reduction under general anesthesia was feasible, while the majority of cases required open reduction. In 31 of these patients (67.4%), open reduction was combined with a revision arthroplasty. CONCLUSIONS: In case of DM cup dislocation, there is a low success rate of closed reduction. To prevent re-dislocation, total revision leads to a significantly reduced risk compared to open or closed reduction alone. Careful X-ray analysis for a halo sign showing intra-prosthetic DM cup dislocation is mandatory to avoid futile reduction attempts. LEVEL OF EVIDENCE: III.

Dual mobility cup in hip arthroplasty: An in-depth analysis of joint registries.

Although total hip arthroplasty (THA) has shown successful results, instability remains a major complication. In recent years, dual mobility cups (DMC) have gained interest among clinicians thanks to its low rate of dislocation and good clinical results. The main aim of this work was to describe the accuracy of data on DMC from national and regional joint registries (JRs) and the available worldwide literature. We identified topics on DMC among JRs to propose a new harmonized and standardized section for DMC with the aim to understand its surveillance over the time. We extracted survival and implant data for a separate analysis. After performing a critical exclusion process, nine JRs were considered eligible and included for final synthesis; these were the results from the available worldwide data from JRs. In our study, eight analyzed JRs reported a slight increase in DMC use in the last decade. In all the JRs evaluated and the available articles, dislocation remains one of the main reasons for revision and re-revision in hip arthroplasties. DMC is considered to be a valid construct increasingly used worldwide in primary and revision THA with the primary aim of reducing dislocation rates. Annual reports from JRs collect heterogeneous and low-quality information about outcomes and surveillance of DMC, creating a burden for clinicians to extract comparable data from different JRs. Longer follow-up and a systematic registering of DMCs with international registry harmonization are needed to monitor DMC outcomes.

Reliability and validity test of a novel three-dimensional acetabular bone defect classification system aided with additive manufacturing.

BACKGROUND: Accurate assessment of acetabular defects and designing precise and feasible surgical plans are essential for positive outcomes of hip revision arthroplasty. Additive manufacturing (AM) is a novel technique to print physical object models. We propose a three-dimensional acetabular bone defect classification system aided with AM model, and further assess its reliability and validity under blinded conditions. METHODS: We reviewed 104 consecutive patients who underwent hip revision arthroplasty at our department between January 2014 and December 2019, of whom 45 had AM models and were included in the reliability and validity tests. Three orthopedic surgeons retrospectively evaluated the bone defects of these 45 patients with our proposed classification, made surgical plans, and repeated the process after 2 weeks. The reliability and validity of the classification results and corresponding surgical plans were assessed using the intra-class correlation coefficient or kappa correlation coefficient. RESULTS: The reliability and validity of the classification results were excellent. The mean initial intra-class correlation coefficient for inter-observer reliability was 0.947, which increased to 0.972 when tested a second time. The intra-observer reliability ranged from 0.958 to 0.980. Validity of the classification results also showed a high kappa correlation coefficient of 0.951-0.967. When considering corresponding surgical plans, the reliability and validity were also excellent, with intra-class correlation coefficients and kappa correlation coefficients measuring all over 0.9. CONCLUSIONS: This three-dimensional acetabular defect classification has excellent reliability and validity. Using this classification system and AM models, accurate assessment of bone defect and reliable surgical plans could be achieved. This classification aided with AM is a promising tool for surgeons for preoperative evaluation.

Hip Arthroplasty With the Use of a Reconstruction Cage and Porous Metal Augment to Treat Massive Acetabular Bone Loss: A Midterm Follow-Up.

BACKGROUND: Acetabular reconstruction in the context of massive acetabular bone loss is challenging. In rare scenarios where the extent of bone loss precludes shell placement (cup-cage), reconstruction at our center consisted of a cage combined with highly porous metal augments. This study evaluates survivorship, complications, and functional outcomes using this technique. METHODS: Patients with minimum 2-year follow-up were included. Baseline characteristics were collected. Preintervention and postintervention ambulatory scores were collected. Kaplan-Meier (KM) survival analysis for cage failure requiring revision surgery was conducted. Binomial regression analysis was performed to assess for correlation of aseptic cage failure with baseline characteristics. Preintervention and postintervention ambulatory aid requirements were compared. RESULTS: A total of 41 patients were identified. Mean follow-up was 6.4 years (range 2.8-11.0). Four (9.8%) aseptic cage revisions were identified. Aseptic KM survival analysis was 87.4% (95% confidence interval 75.3-99.6) at 10 years. Aseptic KM survival was 45.0% versus 92.8% at 9 years (P = .14) for patients with vs without pelvic discontinuity. KM survival for all-cause failure was 61.6% (95% confidence interval 44.0-79.2) at 10 years. Binomial regression did not demonstrate correlation of cage failure with baseline characteristics. Wilcoxon signed-rank test demonstrated a significant reduction in ambulatory aide requirement after surgery (mean rank 11.47 vs 9.00, Z = -2.95, P = .003). CONCLUSION: In scenarios of massive acetabular bone loss where a cup-cage is not a viable option, good survivorship free from aseptic cage failure can be expected at mid-term follow-up using an antiprotrusio cage combined with porous metal augments. Success requires extensive experience in revision surgery.

Survivorship and Risk Factors for Re-Revision after Aseptic Revision Total Hip Arthroplasty in Patients Aged ≤55 Years.

BACKGROUND: There is a relative paucity of literature on the outcomes after revision total hip arthroplasty (rTHA) in young patients. This study reports the survivorship and risk factors for re-revision in patients aged ≤55 years. METHODS: We identified 354 patients undergoing aseptic nononcologic rTHA at mean follow-up of 5 years after revision, with mean age of 48 years, body mass index of 28 kg/m2, and 64% female. Thirty-five (10%) patients underwent at least 1 previous rTHA. The main indications for rTHA included wear/osteolysis (21%), adverse local tissue reaction (21%), recurrent instability (20%), acetabular loosening (16%), and femoral loosening (7%); and included acetabular component-only rTHA in 149 patients (42%), femoral component-only rTHA in 46 patients (13%), both component rTHA in 44 patients (12%), and head/liner exchanges in patients 115 (33%). The Kaplan-Meier method was used to measure survivorship free from re-revision THA, and multivariate regression was used to identify risk factors for re-revision THA. RESULTS: Sixty-two patients (18%) underwent re-revision THA at the mean time of 2.5 years, most commonly for instability (37%), aseptic loosening (27%), and prosthetic joint infection (15%). The rTHA survivorship from all-cause re-revision and reoperation was 83% and 79% at 5 years, respectively. Multivariate analysis demonstrated that patients undergoing femoral component only (hazard ratio 4.8, P = .014) and head/liner exchange rTHA (hazard ratio 2.5, P = .022) as risk factors for re-revision THA. CONCLUSION: About 1 in 5 patients aged ≤55 years undergoing rTHA required re-revision THA at 5 years, most commonly for instability. The highest risk group included patients undergoing head/liner exchanges and isolated femoral component revisions.

Extended Trochanteric Osteotomy Closure Performed Before or After Canal Preparation and Stem Impaction Does Not Affect Axial Stability.

BACKGROUND: An extended trochanteric osteotomy (ETO) safely addresses femoral component removal during challenging revision total hip arthroplasty. However, no prior study has evaluated whether a difference in axial stability exists between ETO closure performed before (reconstitution) or after (scaffolding) canal preparation and stem impaction. We hypothesized that given the absence of clinical reports of outcome differences despite the wide use of both practices, no significant difference in the initial axial stability would exist between the 2 fixation techniques. METHODS: ETOs were performed and repaired using the reconstitution technique for the 6 right-sided femora and the scaffolding technique for the six left-sided femora. The 195-mm long, 3.5°-tapered splined titanium monobloc stems were impacted into 6 matched pairs of human fresh cadaveric femora. Three beaded cables were placed in a standardized fashion on each specimen, 1 for prophylaxis against osteotomy propagation during reaming/impaction and 2 to close the ETO. Stepwise axial loading was performed to 2600 N or until failure, which was defined as subsidence >5 mm or femoral/cable fracture. RESULTS: All specimens successfully resisted axial testing, with no stem in either ETO repair group subsiding >2 mm. The mean subsidence for the reconstitution group was 0.9 ± 0.4 mm, compared to 1.2 ± 0.5 mm for the scaffolding group (P = .2). CONCLUSION: In this cadaveric model with satisfactory proximal bone stock, no difference existed between the reconstitution and scaffolding ETO repair techniques, and both provide sufficient immediate axial stability in a simulated revision total hip arthroplasty setting under physiologic loads.

Predictors of Reinfection in Prosthetic Joint Infections Following Two-Stage Reimplantation.

BACKGROUND: Two-stage reimplantation is an effective treatment for periprosthetic joint infection (PJI). Many factors are involved in the variable success of this procedure. The purpose of this study is to examine the relationship between patient risk factors, comorbidities, and the pathogen on reinfection rates following two-stage reimplantation. METHODS: We evaluated 158 patients treated for PJI from 2008-2019. Only patients who had completed a two-stage exchange were included. Patient demographics, comorbidities, laboratory values, time-to-reimplantation, pathogen, antibiotic sensitivities, host status, and reinfection rates were assessed. Multivariate analysis was performed to identify correlation between risk factors and reinfection. A P-value < .05 was considered statistically significant. RESULTS: 31 patients experienced a reinfection (19.6%). There was a statistically significant association between infection with Methicillin Sensitive Staphylococcus Aureus (MSSA) and reinfection (P = .046). Patients with a reinfection also had a significantly greater median serum C-reactive protein (CRP) level (12.65 g/dL) at the time of diagnosis compared to patients without a reinfection (5.0 g/dL) (P = .010). Median Erythrocyte Sedimentation Rate (ESR) (56 in no re-infection and 69 in re-infection) and time-to-reimplantation (101 days in no reinfection and 141 days in reinfection) demonstrated a trend toward an association with re-infection but were not statistically significant (P = .055 and P = .054 respectively). CONCLUSION: As the number of arthroplasties continue to rise, PJIs are increasing proportionately and represent a significant revision burden. Elevated C-reactive protein (CRP) levels and Methicillin Sensitive Staphylococcus aureus (MSSA) infection were strongly associated with failure of a two-stage reimplantation. While not statistically significant with our numbers, there were strong trends toward an association between elevated Erythrocyte Sedimentation Rate (ESR), longer time-to-reimplantation, and reinfection.

Salvage hip replacement after cut-out failure of cephalomedullary nail fixation for proximal femur fractures: a case series describing the technique and results.

BACKGROUND: Cut-out failure following proximal femoral fracture fixation is a compromising complication warranting surgical treatment. We describe 24 patients with cut-out failure after cephalomedullary nail fixation managed with salvage hip replacement. METHODS: Twenty-four consecutive patients who had sustained a proximal femoral fracture from December 2009 to December 2019, were managed with cephalomedullary nail fixation and experienced a cut-out failure were reviewed retrospectively. Data on demographics, comorbidities, injury characteristics, treatment, and post-operative course were analysed. RESULTS: Among 2802 proximal femoral fractures assessed, 28 fixations failed due to cut-out, with 24/28 patients subsequently undergoing salvage hip replacement. Intertrochanteric fractures (66.7%) managed with short nails predominated (79.2%). The median tip-to-apex distance (TAD) was 19 mm, but only two fractures had a good quality of reduction. Inverse correlations were identified between patient age and the time from fixation to cut-out (r = - 0.57; p = 0.02), and between the time of nailing to failure among patients with a greater TAD (r = - 0.43; p = 0.04). Most patients were managed via cemented hemiarthroplasty (66.7%). Surgical time was longer for total hip replacements (175.4 vs. 136.8 min; p < 0.01), but no bleeding or blood transfusion requirement differences were found. Two patients had orthopaedic complications, and three patients died within the first follow-up year. CONCLUSION: In our series, 1% of the proximal femoral fractures managed with a cephalomedullary nail failed due to cut-out. Salvage hip replacement appeared to be a relatively safe and reliable procedure for managing this challenging complication in patients who typically are elderly and physically frail.