Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m2 (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97).Aims
Methods
Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis. We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).Aims
Methods
There is a paucity of long-term data on modular fluted tapered (MFT) stems for two-stage reimplantation following periprosthetic joint infection (PJI). The purpose of this study was to evaluate implant survivorship, radiographic results, and clinical outcomes in a large cohort of reimplantation THAs using MFT stems. We identified 236 reimplantation THAs from a single tertiary care academic institution from 2000 to 2020. Two designs of MFT stems were used as part of an established two-stage exchange protocol for the treatment of PJI. Mean age at reimplantation was 65 years, mean BMI was 32 kg/m2, and 46% were female. Median stem diameter was 19 mm, and median stem length was 195 mm. Mean follow-up was 7 years. A competing risk model accounting for death was utilized. The 15-year cumulative incidence of any revision was 24%. There were 48 revisions, with the most common reasons being dislocation (n=25) and PJI (n=16). The 15-year cumulative incidence of any reoperation was 28%. Only 13 revisions involved the fluted tapered portion of the component (FTC), for a 15-year cumulative incidence of any FTC revision of 8%. Only 2 FTCs were revised for aseptic loosening, resulting in a 15-year cumulative incidence of FTC revision for aseptic loosening of 1%. Stem subsidence >5 mm occurred in 2% of unrevised cases, and all stems were radiographically stable at most recent follow-up. Mean HHS was 77 at most recent follow-up. This series demonstrated that MFT stems were durable and reliable even in the setting of two-stage reimplantation for infection. While the incidence of aseptic loosening was very low, the incidence of any revision was 24% at 15 years, primarily caused by dislocation and recurrent PJI. Level of Evidence: IV
Cup-cage constructs are one of several methods commonly used to treat severe acetabular bone loss during contemporary revision total hip arthroplasty. The purpose of this study was to provide a long-term results of the technique with emphasis on implant survivorship, radiographic results, and clinical outcomes for both full and half cup-cage reconstructions. We identified 57 patients treated with a cup-cage reconstruction for major acetabular bone loss between 2002–2012. All patients had Paprosky Type 2B through 3B bone loss, with 60% having an associated pelvic discontinuity. Thirty-one patients received a full cup-cage construct, and 26 a half cup-cage. Mean age at reconstruction was 66 years, 75% were female, and the mean BMI was 27 kg/m2. Mean follow-up was 10 years. The 10-year cumulative incidences of any revision were 14% and 12% for the full and half cup-cage construct groups, respectively. Of the 9 revisions, 3 were for dislocation, 2 for aseptic loosening and construct failure (both were pelvic discontinuities), 1 for adverse local tissue reaction, and 1 for infection with persistent pelvic discontinuity. The 10-year cumulative incidences of revision for aseptic loosening were 4.5% and 5% for the full and half cup-cage constructs, respectively. Of the unrevised cases, incomplete and non-progressive zone 3 radiolucent lines were observed in 10% of patients in each group. Three patients experienced partial motor and sensory sciatic nerve palsies (2 in the full and 1 in the half cup-cage group). Both the full and half cup-cage cohorts demonstrated significantly improved Harris hip scores. Full and half cup-cage reconstructions for major acetabular defects were successful at 10 years in regards to acetabular fixation without appreciable differences between the two techniques. However, zone 3 radiolucent lines were not uncommon in association with discontinuities, and dislocation continues to be a problem.
The last two decades have seen remarkable technological advances in total hip arthroplasty (THA) implant design. Porous ingrowth surfaces and highly crosslinked polyethylene (HXLPE) have been expected to dramatically improve implant survivorship. The purpose of the present study was to evaluate survival of contemporary cementless acetabular components following primary THA. 16,421 primary THAs performed for osteoarthritis between 2000 and 2019 were identified from our institutional total joint registry. Patients received one of 12 contemporary cementless acetabular designs with HXLPE liners. Components were grouped based on ingrowth surface into 4 categories: porous titanium (n=10,952, mean follow-up 5 years), porous tantalum (n=1223, mean follow-up 5 years), metal mesh (n=2680, mean follow-up 6.5 years), and hydroxyapatite (HA) coated (n=1566, mean follow-up 2.4 years). Kaplan-Meier analyses were performed to assess the survivorship free of acetabular revision. A historical series of 182 Harris-Galante-1 (HG-1) acetabular components was used as reference. The 15-year survivorship free of acetabular revision was >97% for all 4 contemporary cohorts. Compared to historical control, porous titanium (HR 0.06, 95% CI 0.02–0.17, p<0.001), porous tantalum (HR 0.09, 95%CI 0.03–0.29, p<0.001), metal mesh (HR 0.11, 95%CI 0.04–0.31, p<0.001), and HA-coated (HR 0.14, 95%CI 0.04–0.48, p=0.002) ingrowth surfaces had significantly lower risk of any acetabular revision. There were 16 cases (0.1%) of acetabular aseptic loosening that occurred in 8 (0.07%) porous titanium, 5 (0.2%) metal mesh, and 3 (0.2%) HA-coated acetabular components. 7 of the 8 porous titanium aseptic loosening cases occurred in one known problematic design. There were no cases of aseptic loosening in the porous tantalum group. Modern acetabular ingrowth surfaces and HXLPE liners have improved on historical results at the mid-term. Contemporary designs have extraordinarily high revision-free survivorship, and aseptic loosening is now a rare complication. At mid-term follow-up, survivorship of contemporary uncemented acetabular components is excellent and aseptic loosening occurs in a very small minority of patients.
Septic arthritis of the hip often leads to irreversible osteoarthritis (OA) and the requirement for total hip arthroplasty (THA). The aim of this study was to report the mid-term risk of any infection, periprosthetic joint infection (PJI), aseptic revision, and reoperation in patients with a past history of septic arthritis who underwent THA, compared with a control group of patients who underwent THA for OA. We retrospectively identified 256 THAs in 244 patients following septic arthritis of the native hip, which were undertaken between 1969 and 2016 at a single institution. Each case was matched 1:1, based on age, sex, BMI, and year of surgery, to a primary THA performed for OA. The mean age and BMI were 58 years (35 to 84) and 31 kg/m2 (18 to 48), respectively, and 100 (39%) were female. The mean follow-up was 11 years (2 to 39).Aims
Methods
The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFFs). Our study aimed to assess treatment methodologies, implant survivorship, and IPFF clinical outcomes. A total of 76 patients treated for an IPFF from February 1985 to April 2018 were reviewed. Prior to fracture, at the hip/knee sites respectively, 46 femora had primary/primary, 21 had revision/primary, three had primary/revision, and six had revision/revision components. Mean age and BMI were 74 years (33 to 99) and 30 kg/m2 (21 to 46), respectively. Mean follow-up after fracture treatment was seven years (2 to 24).Aims
Methods
Patients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study was to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, non-tantalum, porous acetabular components in the setting of prior pelvic radiation. We retrospectively reviewed 33 patients (38 hips) with prior therapeutic pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (Depuy-Synthes) in 76%, followed by Trident (Stryker) in 8%, Tritanium (Stryker) in 8%, Trilogy (Zimmer-Biomet) in 5%, and G7 (Zimmer-Biomet) in 3%. Eighty-seven percent of cups were fixed with screws, of which the mean number used was 3. The mean age at primary THA was 74 years, 76% were male, and the mean BMI was 30 kg/m2. Mean follow-up was 5 years.Introduction
Methods
The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFF). Our study aimed to assess treatment methodologies, implant survivorship, and clinical outcomes of patients with IPFF. 77 patients treated for an IPFF from 1985–2017 at a single large referral center were reviewed. Prior to the fracture, at the hip/knee sites respectively 46 femurs had primary/primary, 21 had revision/primary, 3 had primary/revision and 7 had revision/revision components. Mean age and BMI were 74 years and 30 kg/m2, respectively. Mean follow-up after fracture treatment was 7 years.Introduction
Methods
Instability remains a common complication following total hip arthroplasty (THA) and continues to account for the highest percentage of revisions in numerous registries. Many risk factors have been described, yet a patient-specific risk assessment tool remains elusive. The purpose of this study was to apply a machine learning algorithm to develop a patient-specific risk score capable of dynamic adjustment based on operative decisions. 22,086 THA performed between 1998–2018 were evaluated. 632 THA sustained a postoperative dislocation (2.9%). Patients were robustly characterized based on non-modifiable factors: demographics, THA indication, spinal disease, spine surgery, neurologic disease, connective tissue disease; and modifiable operative decisions: surgical approach, femoral head size, acetabular liner (standard/elevated/constrained/dual-mobility). Models were built with a binary outcome (event/no event) at 1-year and 5-year postoperatively. Inverse Probability Censoring Weighting accounted for censoring bias. An ensemble algorithm was created that included Generalized Linear Model, Generalized Additive Model, Lasso Penalized Regression, Kernel-Based Support Vector Machines, Random Forest and Optimized Gradient Boosting Machine. Convex combination of weights minimized the negative binomial log-likelihood loss function. Ten-fold cross-validation accounted for the rarity of dislocation events.Introduction
Methods
Dual mobility (DM) bearings are an attractive treatment option to obtain hip stability during challenging primary and revision total hip arthroplasty (THA) cases. The purpose of this study was to analyze data submitted to the American Joint Replacement Registry (AJRR) to characterize utilization trends of DM bearings in the USA. All primary and revision THA procedures reported to AJRR from 2012 to 2018 were analyzed. Patients of all ages were included and subdivided into DM and traditional bearing surface cohorts. Patient demographics, geographical region, hospital size, and teaching affiliation were assessed. Associations were determined by chi-squared analysis and logistic regression was performed to assess outcome variables.Aims
Methods
Trochanteric fractures account for up to 20% of all periprosthetic fractures occurring during or after total hip arthroplasties (THAs). They are frequently managed conservatively except in cases with significant displacement. There is a paucity of literature describing the indications and results of operative or non-operative management of these fractures. 173 trochanteric fractures occurred in 171 patients, after all primary THAs performed from 1989–2017. Mean age at fracture was 64-years, with 65% being female. Mean follow-up was 7.6-years. Patient's radiographs and Harris Hip Scores (HHS) were recorded. There were 85 (49%) intraoperative and 88 postoperative fractures. Mean time from THA to fracture was 66 months for the postoperative group. 79 (46%) cases were fixed (68 intraoperative, 11 postoperative). Fixation was considered at the discretion of the surgeon. Within the 88 postoperative fractures, 30 were associated with polyethylene wear and osteolysis. 77 were initially treated conservatively and 11 were immediately fixed (8 revisions due to osteolysis, and 3 fracture fixations due to disability associated to displacement >1cm). 19 of the 30 postoperative fractures associated with polyethylene wear and osteolysis, eventually underwent revision.Background
Methods
Pelvic discontinuity is a challenging complication. One treatment option that has garnered enthusiasm is acetabular distraction. This method obtains stability via distraction of the discontinuity and placement of an oversized socket (± augments) and elastic recoil of the pelvis. The aims of this study were to report implant survivorship, radiographic results, clinical outcomes, and complications of acetabular distraction for pelvic discontinuity in the largest series to date. We retrospectively identified all revision THAs with a Paprosky 3B defect and pelvic discontinuity between 2005 and 2017. Of the 162 patients, 32 were treated with distraction. The mean distraction achieved was 5mm (range, 3–8mm). In addition to distraction with a hemispherical cup, augments were utilized in 3 and cages in 19. The mean age at revision was 68 years with 75% female. Mean follow-up was 3 years.Introduction
Methods
Dual mobility bearings are an attractive treatment option to obtain hip stability during challenging primary and revision total hip arthroplasty (THA) cases. Despite growing enthusiasm in the United States, long-term results of modern dual mobility implants are lacking. The purpose of this study is to analyze data submitted to the American Joint Replacement Registry (AJRR) to characterize utilization trends of dual mobility bearings in the United States. All primary and revision THA procedures reported to AJRR from 2012–2018 were analyzed. Patients of all ages were included and subdivided into dual mobility and traditional bearing surface cohorts. Independent variables included patient demographics, geographic region, hospital size, and teaching affiliation. Associations were determined by chi-square analysis and a logistic regression was performed to assess the association between dual mobility and independent variables.Background
Methods
Cementation of a new liner into an existing well-fixed acetabular component is common during revision total hip arthroplasties (THAs) for many indications, but most commonly for lack of a modern compatible crosslinked polyethylene liner. However, little is known about the long-term durability of this strategy. The purpose of this study was to evaluate the long-term implant survivorship, risk of complications, clinical outcomes, and radiographic results of cementing a new highly cross-linked polyethylene (HXLPE) liner into a well-fixed acetabular component. We retrospectively identified 326 revision THAs where a non-constrained HXLPE liner was cemented into a well-fixed acetabular component. Mean age at revision THA was 63 years, with 50% being female. The most common indications for revision THA were wear and osteolysis (49%), aseptic femoral loosening (35%), and instability (8%). Mean follow-up was 10 years.Introduction
Methods
Many surgeons are reluctant to use a constrained liner at the time of acetabular component revision given concerns this might result in early acetabular component loosening. We hypothesized that with appropriate initial implant stabilization of highly porous acetabular components with supplemental screw fixation, constrained liners could be safely used at the time of acetabular revision. We retrospectively identified 148 revision total hip arthroplasties (THAs) where a constrained liner of one design was cemented into a newly placed highly porous acetabular component fixed with supplemental screws (mean 5 screws). Mean age at revision THA was 69 years, with 68% being female. The most common indications for revision were two-stage re-implantation (33%), recurrent dislocation (30%), and aseptic loosening (22% acetabular; 9% acetabular/femoral component). Mean follow-up was 8 years.Introduction
Methods
The aims of this study were to characterize antibiotic choices for perioperative total knee arthroplasty (TKA) and total hip arthroplasty (THA) prophylaxis, assess antibiotic allergy testing efficacy, and determine rates of prosthetic joint infection (PJI) based on perioperative antibiotic regimen. We evaluated all patients undergoing primary TKA or THA at a single academic institution between January 2004 and May 2017, yielding 29 695 arthroplasties (22 705 patients), with 3411 arthroplasties in 2576 patients (11.5%) having undergone preoperative allergy testing. A series of institutional databases were combined to identify allergy consultation outcomes, perioperative antibiotic regimen, and infection-free survivorship until final follow-up.Aims
Patients and Methods
Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA. We identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m2 (19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated.Aims
Patients and Methods
Historically, the most common indications for re-revision of a total hip arthroplasty (THA) have been aseptic loosening, instability, infection, and peri-prosthetic fracture. As revision implants and techniques have evolved and improved, understanding why contemporary revision THAs fail is important to direct further improvement and innovation. As such, the goals of this study were to determine the implant survivorship of contemporary revision THAs, as well as the most common indications for re-revision. We retrospectively reviewed 2568 aseptic revision THAs completed at our academic institution between 2005 and 2015 through our total joint registry. There were 34% isolated acetabular revisions, 18% isolated femoral revisions, 28% both component revisions, and 20% modular component exchanges. The mean age at index revision THA was 66 years, and 46% were males. The most common indications for the index revision THA were aseptic loosening (21% acetabular, 15% femoral, 5% both components), polyethylene wear and osteolysis (18%), instability (13%), fracture (11%), and other (17%). Mean follow-up was 6 years.Introduction
Methods
The American Joint Replacement Registry (AJRR) was created to capture total hip (THA) and total knee arthroplasty (TKA) procedural data in order to conduct implant-specific survivorship analyses, produce risk-adjusted patient outcome data, and provide hospitals and surgeons with quality benchmarks. The purpose of this study is to compare early reports from the AJRR to other national registries to identify similarities and differences in surgeon practice and potential topics for future analysis. Hip arthroplasty data were extracted from the annual reports from the AJRR and other national registries including: the Australian registry; the New Zealand registry; the United Kingdom, Wales, and Isle of Man registry; the Norwegian registry; and the Swedish registry from 2014 to 2016. Data regarding femoral and acetabular fixation, bearing surface type, femoral head size, the use of dual mobility articulation bearings, hip resurfacing utilization, and THA revision burden were evaluated. Revision burden is defined as the ratio of implant revisions to the total number of arthroplasties performed in a given time period. Registry characteristics and patient demographic data were recorded across all registries. The results were compared between the various registries and reported using descriptive statistics.Introduction
Methods
Manual chart review is labor-intensive and requires specialized knowledge possessed by highly-trained medical professionals. The cost and infrastructure challenges required to implement this is prohibitive for most hospitals. Natural language processing (NLP) tools are distinctive in their ability to extract critical information from raw text in the electronic health records (EHR). As a simple proof-of-concept, for the potential application of this technology, we examined its ability to discriminate between a binary classification (periprosthetic fracture [PPFFx] vs. no PPFFx) followed by a more complex classification of the same problem (Vancouver). PPFFx were identified among all THAs performed at a single academic institution between 1977 and 2015. A training cohort (n = 90 PPFFx) selected randomly by an electronic program was utilized to develop a prototype NLP algorithm and an additional randomly-selected 86 PPFFx were used to further validate the algorithm. Keywords to identify, and subsequently classify, Vancouver type PPFFx about THA were defined. The algorithm was applied to consult and operative notes to evaluate language used by surgeons as a means to predict the correct pathology in the absence of a listed, precise diagnosis (e.g. Vancouver B2). Validation statistics were calculated using manual chart review as the gold standard.Introduction
Methods
The purpose of this study was to determine the lifetime risk
of revision surgery for patients undergoing Charnley cemented total
hip arthroplasty (THA), with 40-year follow up, using death as a
competing risk. We retrospectively reviewed 2000 cemented Charnley THAs, with
51 living hips available at 40 years. Aims
Materials and Methods
The goals of this study were to define the risk factors, nature,
chronology, and treatment strategies adopted for periprosthetic
femoral fractures in 32 644 primary total hip arthroplasties (THAs). There were 564 intra-operative fractures (1.7%); 529 during uncemented
stem placement (3.0%) and 35 during cemented stem placement (0.23%).
Intra-operative fractures were more common in females and patients
over 65 years (p <
0.001). The majority occurred during placement
of the femoral component (60%), and involved the calcar (69%). There
were 557 post-operative fractures (20-year probability: 3.5%; 95%
confidence interval (CI) 3.2 to 3.9); 335 fractures after placement
of an uncemented stem (20-year probability: 7.7%; 95% CI 6.2 to
9.1) and 222 after placement of a cemented stem (20-year probability:
2.1%; 95% CI 1.8 to 2.5). The probability of a post-operative fracture
within 30 days after an uncemented stem was ten times higher than
a cemented stem. The most common post-operative fracture type was
a Vancouver AG (32%; n = 135), with 67% occurring after
a fall. In all, 36% (n = 152) were treated with revision arthroplasty. Aim and Methods
Results
The goals of this study were to define the risk factors, characteristics,
and chronology of fractures in 5417 revision total hip arthroplasties
(THAs). From our hospital’s prospectively collected database we identified
all patients who had undergone a revision THA between 1969 and 2011
which involved the femoral stem. The patients’ medical records and
radiographs were examined and the relevant data extracted. Post-operative
periprosthetic fractures were classified using the Vancouver system.
A total of 5417 revision THAs were identified.Aims
Patients and Methods
Revision total hip arthroplasty (THA) is challenging
when there is severe loss of bone in the proximal femur. The purpose
of this study was to evaluate the clinical and radiographic outcomes
of revision THA in patients with severe proximal femoral bone loss
treated with a fluted, tapered, modular femoral component. Between
January 1998 and December 2004, 92 revision THAs were performed
in 92 patients using a single fluted, tapered, modular femoral stem
design. Pre-operative diagnoses included aseptic loosening, infection
and peri-prosthetic fracture. Bone loss was categorised pre-operatively
as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic
fracture. The mean clinical follow-up was 6.4 years (2 to 12). A
total of 47 patients had peri-operative complications, 27 of whom
required further surgery. However, most of these further operations
involved retention of a well-fixed femoral stem, and 88/92 femoral
components (97%) remained Revision THA in patients with extensive proximal femoral bone
loss using the Link MP fluted, tapered, modular stem led to a high
rate of osseointegration of the stem at mid-term follow-up. Cite this article:
Total hip replacement (THR) after acetabular
fracture presents unique challenges to the orthopaedic surgeon.
The majority of patients can be treated with a standard THR, resulting
in a very reasonable outcome. Technical challenges however include
infection, residual pelvic deformity, acetabular bone loss with
ununited fractures, osteonecrosis of bone fragments, retained metalwork,
heterotopic ossification, dealing with the sciatic nerve, and the
difficulties of obtaining long-term acetabular component fixation.
Indications for an acute THR include young patients with both femoral
head and acetabular involvement with severe comminution that cannot
be reconstructed, and the elderly, with severe bony comminution.
The outcomes of THR for established post-traumatic arthritis include
excellent pain relief and functional improvements. The use of modern
implants and alternative bearing surfaces should improve outcomes
further. Cite this article:
This conversation represents an attempt by several
arthroplasty surgeons to critique several abstracts presented over
the last year as well as to use them as a jumping off point for trying
to figure out where they fit in into our current understanding of
multiple issues in modern hip and knee arthroplasty.
