Angular proximal femoral deformities increase the technical complexity of primary total hip arthroplasties (THAs). The goals were to determine the long-term implant survivorship, risk factors, complications, and clinical outcomes of contemporary primary THAs in this difficult cohort.

Our institutional total joint registry was used to identify 119 primary THAs performed in 109 patients with an angular proximal femoral deformity between 1997 and 2017. The deformity was related to previous femoral osteotomy in 85%, and developmental or metabolic disorders in 15%. 53% had a predominantly varus angular deformity. The mean age was 44 years, mean BMI was 29 kg/m², and 59% were female. An uncemented metaphyseal fixation stem was used in 30%, an uncemented diaphyseal fixation stem in 28%, an uncemented modular body stem with metaphyseal fixation sleeve in 24%, and a cemented stem in 18%. Simultaneous corrective femoral osteotomy was performed in 18%. Kaplan-Meier survivorships and Harris hip scores were reported. Mean follow-up was 8 years.

The 10-year survivorships free of femoral loosening, aseptic femoral revision, any revision, and any reoperation were 95%, 93%, 90% and 88%, respectively. Revisions occurred in 13 hips for: aseptic femoral component loosening (3), stem fracture (2), dislocation (2), aseptic acetabular loosening (2), polyethylene liner exchange (2), and infection (2). Preoperative varus angular deformities were associated with a higher risk of any revision (HR 10, p=0.03), and simultaneous osteotomies with a higher risk of any reoperation (HR 3.6, p=0.02). Mean Harris hip scores improved from 52 preoperatively to 82 at 10 years (p<0.001).

In the largest series to date of primary THAs in patients with angular proximal femoral deformities, we found a good 10-year survivorship free from any revision. Varus angular deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher reoperation rate.

Keywords: Proximal femoral deformity; dysplasia; femoral osteotomy; survivorship; revision

Level of evidence: Level III, comparative retrospective cohort

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

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.

Introduction

Mechanical or corrosive failure of total knee arthroplasties (TKAs) is difficult to diagnose with current laboratory and radiographic analyses. As such, the goal of this study was to determine the mean blood concentration of cobalt, chromium, and titanium in a series of revision TKAs with mechanical implant failure and evaluate whether they facilitated identification of the underlying TKA failure mechanism.

Introduction

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.

Introduction

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.

Introduction

Adverse local tissue reactions (ALTR) can result in devastating soft tissue and osseous destruction, while potentially increasing the risk of concomitant periprosthetic joint infection (PJI). The aims of this study were to evaluate cobalt (Co) and chromium (Cr) levels generated in simulators from metal-on-polyethylene (MoP) and ceramic-on-polyethylene (CoP) constructs, and determine their impact on native tissues and PJI risk through evaluation of human adipose-derived mesenchymal stem cells (AMSCs) and Staphylococcus epidermidis isolates.

Introduction

In the setting of periprosthetic joint infection, the complete removal of implants and cement can be challenging with well-fixed, cemented implants about the knee. This can get especially complex in the setting of long cemented femoral stems. Osteotomies are well described in the proximal femur and tibia for removal of implants and cement. There is little information available on distal femoral osteotomies to facilitate knee implant and retained cement removal.

Introduction

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.

Introduction

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.

Introduction

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.

Introduction

Modular dual-mobility constructs reduce the risk of dislocation after total hip arthroplasty (THA). However, questions about metal ions from the cobalt-chrome (CoCr) liner persist, and are particularly germane to patients being revised for adverse local tissue reactions (ALTR) to metal. We determined the mid-term serum Co and Cr levels after modular dual-mobilities used in revision and complex primary THAs, and specifically included patients revised for ALTR.

Introduction

Bilateral total knee arthroplasty (TKA) can be performed under a single-anesthetic (SA) or staged under a two-anesthetic (TA) technique. Recently, our institution began piloting a two-surgeon team SA method for bilateral TKA. The purpose of this study was to compare the inpatient costs and clinical outcomes in the first 90 days after surgery between the team SA, single-surgeon SA, and single-surgeon TA approaches for bilateral TKA.

Introduction

The influence of surgical approach for total hip arthroplasty (THA) on scar healing and scar perception is unknown. The purpose of this study was to evaluate patients’ perception of their scar following direct anterior (DA) or posterior approach (PA) for THA utilizing validated scar assessment scales.