Observational study of a new modular femoral revision system

Petersen M, Stürup J, Winther NS. Implant Survival of an Uncemented Modular Femoral Implant in Patients With Severe Femoral Bone Loss and 2-Stage Hip Revision

Background and Purpose: Revision total hip arthroplasty (rTHA) is a challenging procedure especially in the presence of severe bone loss where implant fixation is compromised. The aim of this study was to evaluate implant survival, clinical outcome, and midterm results in a group of complex patients after femoral revision using an uncemented modular implant design. Patients and Methods: We performed a retrospective study including 100 patients (101 hips) treated with revision THA using an uncemented modular implant design. We identified 51 hips as Paprosky types I-II and 50 hips as Paprosky III-IV bone defects. We reviewed operative reports and radiographs. Patients underwent a clinical examination to assess the Harris Hip Score (HHS) and completed patient-reported outcome measures (PROM), including the Oxford Hip Score (OHS) and the EQ-5D Visual Analog Scale (VAS). Minimum follow-up was 2 years (average, 5.8 years; range, 2.0-9.4 years). Results: Among the cases, 46 hips were revised for infection in a 2-stage procedure and 44 hips for aseptic loosening. 11 hips had periprosthetic fractures of Vancouver type B2 or B3. A total of 5 hips required revision with removal of the femoral implant and 11 patients experienced complications resulting in fracture (n = 1), dislocation (n = 10), and soft tissue revision (n = 1). The 5-year implant survival estimated by Kaplan-Meier survival analysis was 95% (95%-CI: 91%-99%). All hips had radiographic evidence of osseointegration and no one with subsidence greater than 5 mm. Additionally, 80% showed radiographic evidence of restoration of proximal femoral bone. Mean HHS was 78. Conclusion: In complex cases of revision THA, using a modular revision femoral system yielded promising results. The 5-year implant survival estimated by Kaplan-Meier survival analysis was 95% (95%-CI: 91%-99%), with all hips demonstrating radiographic evidence of osseointegration and no one with subsidence greater than 5 mm. Notably 80% showed radiographic evidence of restoration of proximal femoral bone.

Clinical outcomes and survival rates of a uncemented modular revision stem system in hip arthroplasty: a 10-year single-institution study on a frail population

INTRODUCTION

The increasing prevalence of primary hip arthroplasty has led to a parallel rise in revision cases. Femoral revision often entails compromised bone integrity, requiring consideration of various solutions for optimal reconstructive options. Despite technological advancements, there is limited evidence on the clinical outcomes of the latest modular revision stems. This study aimed to evaluate the clinical outcomes and survival rates of next generation uncemented modular revision stem in patients undergoing hip revision surgery.

MATERIALS AND METHODS

This retrospective single-center study assessed the survival and failure causes of a specific uncemented modular stem in 48 patients undergoing hip revision surgery between 2012 and 2022. Data included preoperative parameters, surgical details, and postoperative outcomes measured through clinical and radiographic assessments. Forty-eight patients (25 males, 23 females; mean age 72 years) were included, with a mean Charlson Comorbidity Index of 5. Preoperative diagnoses varied, with periprosthetic joint infection (PJI) being the most common (45.8%), followed by periprosthetic fractures (27.1%). Partial revisions occurred in 60.4%, total revisions in 39.6%. According to Paprosky classification of femoral bone loss, type II and III were the most represented, respectively 35.4% and 50%.

RESULTS

At a mean follow-up of 4.6 years, stem survival was 92.5%. Complications (20%) included dislocation, PJI, fracture, and loosening; the overall reoperation rate was 12.5%. The SF-12 physical score was 43.6, while the mental score was 51.1. The HOOS score was 71.8, and the HHS score was 71.4. Radiographic analysis identified nonprogressive osteolysis in 15.1% of patients.

CONCLUSIONS

This study on this uncemented modular revision stem demonstrated favorable outcomes in an elder fragile population with moderate to severe femoral bone loss. The implant's modularity provides versatility in addressing various defects, without any implant breakage observed during the study period. Literature comparison highlighted similar outcomes despite sample size differences. The promising results warrant continued investigation into the long-term survivorship of this modular stem system.

Trochanteric Bolt Failure in a Modular Femoral Revision System

With the incidence of primary total hip arthroplasty continuing to rise in the United States, the innovation behind improving current total hip arthroplasty systems inevitably grows with it-each new design potentially ushering in new flaws. We report a case of screw failure with the Arcos Modular Femoral Revision System-Trochanteric Bolt and Claw Technique in a 74-year-old male patient. The patient presented to the investigator's clinic for their 20-month follow-up evaluation of their complex right hip revision. Radiographs revealed failure of the screw attaching the claw plate to the stem resulting in dislodgement and relocation of the screw within the intra-articular cavity. The patient elected for nonsurgical management and will continue to be monitored. Consent by the patient involved in this case report was obtained.

The Early- to Mid-term Outcome of Novel Cementless Modular Femoral Stem in East Asian Patients

Background

Early firm fixation of the femoral implant is crucial in total hip arthroplasty (THA) with unstable metaphysis or a large degree of femoral bone loss. This study aimed to evaluate the outcomes of THA using a novel cementless modular, fluted, tapered stem in such cases.

Methods

From 2015 to 2020, 105 hips (101 patients) had surgery performed by two surgeons at two tertiary hospitals using a cementless modular, fluted, tapered stem for periprosthetic fractures, massive bone loss, prosthetic joint infection sequelae, or tumorous condition. Clinical outcomes, radiographic results, and survivorship of the implant were evaluated.

Results

The average follow-up period was 2.8 years (range, 1-6.2 years). The Koval grade was 2.7 ± 1.7 preoperatively and maintained at 1.2 ± 0.8 at the latest follow-up. The plain radiograph showed bone ingrowth fixation in 89 hips (84.8%). The average stem subsidence at postoperative 1 year was 1.6 ± 3.2 mm (range, 0-11.0 mm). Five reoperations (4.8%) were needed, including 1 for acute periprosthetic fracture, 1 for recurrent dislocation, and 3 for chronic periprosthetic joint infection. Kaplan-Meier survivorship with reoperation for any reason as the endpoint was 94.1%.

Conclusions

The early- to mid-term results of THA with the novel cementless modular, fluted, tapered THA stem system were satisfactory clinically and radiologically. The shortcomings inherent to its modularity were not identified. This modular femoral system may provide adequate fixation and be a practical option in the setting of complicated THA.

Comparison of two tapered fluted modular titanium (TFMT) stems used in revision hip arthroplasty from a single center

Background

TFMT stems are modular porous coated stems widely used in revision hip arthroplasty. Although TFMT stems are popular due to its proven advantage in the setting of severe bone deficiency, subsidence is a concern in these stem designs. We used two TFMT stems between 2013 and 2019, ARCOS(Zimmer Biomet) and Reclaim(Depuy Synthes). We reviewed our results and compared these stems.

Aim

The primary aim was a) look for early to mid-term stem survival b) radiological outcome measuring subsidence, secondary aim was to measure proximal femoral bone stock changes.

Materials and methods

Data was collected retrospectively. There were 51 patients in Arcos and 57 patients in Reclaim cohort. Both cohorts were comparable with respect to gender, side, BMI, paprosky defect, indications for surgery, ETO and stem length. The mean age group was 78.03 in Arcos and 73.75 in Reclaim.

Results

At a mean follow up of 5 years both cohorts showed excellent stem survival, 96.4% in Reclaim cohort as compared to 100% in Arcos. Subsidence was observed in both but none required a revision due to subsidence. There was a significant difference (p = 0.017) between the cohorts with mean of 2.3 mm(0-12 mm) in Arcos as compared to 4.5 mm(0-25 mm) in Reclaim. Both cohorts showed excellent restoration of proximal femoral bone stock.

Conclusion

Our data shows promising results using TFMT stems at 5 year follow up with more than 95% stem survival, minimal subsidence and good restoration of proximal femoral bone stock. The difference in subsidence between these stems may be attributed to stem geometry and difference in taper.

Distal fixation modular stem hemiarthroplasty versus proximal femoral nailing for unstable intertrochanteric fractures: a retrospective cohort study

The treatment of unstable intertrochanteric fractures (UITF) is a controversial issue in the current literature. The aim of this study was to compare the curative effects of distal fixation modular stem (DFMS) hemiarthroplasty with proximal femoral nailing (PFN) on UITFs in the elderly. From February 2017 to November 2019, 98 elderly (≥65 years) patients with UITF were included in this single-center retrospective cohort study. Mean follow-up duration was 24.1±11.9 months. Patients were divided into the DFMS group (52 patients) and the PFN group (46 patients). In the DFMS group, trochanteric fixation was performed using a trochanteric cable plate system. Primary outcome measures included Harris hip score (HHS), mobility score, implant related complications and mortality. Secondary outcome measures included hospitalization duration, surgical time and transfusion rate. Mean age of the patients was 78.7±7.2 years (65-96 years). DFMS group had longer surgical time, higher transfusion rates and longer hospital stays (p<0.05). Mean HHS was 80.7±10.5 and 81.9±12.2 in the DFMS group and PFN group, respectively. There was no statistically significant difference between the two groups in terms of HHS, mobility score and mortality. Implant failure rates were significantly higher in the PFN group (p=0.015). Implant failure, one year mortality and overall mortality rates were 0%, 15.4% and 17.3% in DFMS group and 10.9%, 15.2% and 19.5% in PFN group, respectively. Both surgical methods can be effectively used in the treatment of UITFs with similar satisfactory functional results and similar mortality rates. In addition, the DFMS group exhibited significantly lower implant failure rates and PFN group provided significantly lower surgical time duration, transfusion rate and hospital stay duration.

Impending Trunnion Failure: An Uncommon Radiographic Presentation of Total Hip Arthroplasty Failure

Trunnionosis is emerging as an early mode of failure in conventional metal-on-polyethylene total hip arthroplasty. It is defined as wear or corrosion at the trunnion, the taper at the femoral head-neck interface. Trunnion wear can result in a variety of negative sequelae and, in severe cases, necessitate revision arthroplasty. We describe a 64-year-old man with a metal-on-polyethylene total hip arthroplasty who presented with a sensation of clunking in the hip. Initial imaging and laboratory studies were inconclusive, and the decision was made to monitor. Two years later, trunnion wear was detected on radiographs, presenting as an abnormal alignment of the femoral neck relative to the femoral head. Several case reports and series describe catastrophic total hip arthroplasty failure due to trunnionosis. However, few describe the radiographic signs of wear at the trunnion before gross failure. This early presentation is important to recognize to minimize patient morbidity and aid surgical planning.