Risk Factors for Periprosthetic Femoral Fractures After Cementless Total Hip Arthroplasty

Side-to-side differences in hip bone mineral density in patients with unilateral hip osteoarthritis

BACKGROUND

Accurately evaluating bone mineral density (BMD) in patients with unilateral hip osteoarthritis (OA) is crucial for diagnosing osteoporosis and selecting implants for hip arthroplasty. Our goal was to measure the BMD differences between sides, examine contributing factors, and identify the optimal side for BMD assessment in these patients.

METHODS

We analyzed 108 women with unilateral hip OA. Bilateral hip BMD was assessed automatically through quantitative CT (QCT) utilizing a validated, deep-learning-based approach. We evaluated BMD variations between the OA and healthy hips across total, neck, and distal regions. To determine their contributions, we analyzed factors, including patient demographics, Crowe classification, Bombelli classification, knee OA status, hip functional score, and gluteal muscle volume and density. Furthermore, we examined how side-to-side BMD differences influenced osteoporosis diagnosis using T-scores based on QCT.

RESULTS

The average BMD on the OA side was 6.9 % lower in the total region, 14.5 % higher in the neck region, and 9.4 % lower in the distal region than on the healthy side. Contributing factors to the reduced BMD in the OA hip included younger age, Bombelli classification (atrophic type), and significant gluteal muscle atrophy. Diagnoses from the OA side revealed lower sensitivity (61 %) than those from the healthy side (88 %).

CONCLUSIONS

Analysis on one side alone yields a more precise osteoporosis diagnosis from the healthy side. Nonetheless, bilateral BMD assessment remains crucial, particularly in younger individuals and those with atrophic OA types. Although based on QCT, our findings support bilateral analysis by dual-energy X-ray absorptiometry for these patients.

Patients with periprosthetic femoral fractures are older adults who are commonly diagnosed with osteoporosis

This study focused on individuals aged ≥ 50 years with periprosthetic femoral fractures (PFF). When compared to those with native hip fractures, patients with PFF were older, had a higher BMI, and demonstrated a greater number of comorbidities. Given the high frequency of osteoporosis risk factors and the BMD results, PFF should be classified as osteoporotic fractures.

INTRODUCTION

To compare patients presenting with periprosthetic femoral fractures (PFF) to patients with native hip fractures with a special focus on bone mineral density (BMD) measurements, in order to reinforce the hypothesis that PFF are osteoporotic fractures.

METHODS

A retrospective, single-centre, observational study of all patients aged ≥ 50 years with low-energy PFF identified at the Lille University Hospital from January 1, 2016, to December 31, 2022, was conducted. The PFF group was compared to a group of patients with native hip fractures hospitalized during the same period. To compare the T-score data, we used a linear mixed model that considered a predefined adjustment for age, sex, and BMI. Adjusted means ± standard error of the mean (SEM) are derived from the mixed model.

RESULTS

Among 71 patients with PFF (78.9% female, median (IQR) age 81 (72-88) years), osteoarthritis (57.8%) was the primary indication for hip surgery. Compared with the native hip fracture group (n = 117), patients in the PFF group were significantly older (p = 0.002), had a significantly greater BMI (p = 0.043), and had a higher history of multiple falls (54.3% vs. 26.1%, p < 0.001). A greater frequency of previous low-energy fractures (69.0% vs. 44.0%, p < 0.001) and an increased prescription of anti-osteoporosis medications (26.8% vs. 11.1%, p = 0.006) in patients with PFF were found. Adjusted T-scores differed between the two groups at the lumbar spine (mean adjusted ± SEM, - 0.5 ± 0.2 (PFF group) vs. - 1.2 ± 0.2 (comparator group), p = 0.008) but not at the femoral neck or at the total hip.

CONCLUSION

Low-energy PFF should be considered as an osteoporotic fracture and treated accordingly.

Combined direct anterior approach and navigation-assisted percutaneous anterograde posterior column fixation for acetabular periprosthetic fractures

OBJECTIVE

Management of acetabular periprosthetic fractures using a combined direct anterior approach (DAA) with or without proximal intrapelvic Levine extension and navigation-assisted percutaneous anterograde posterior column screw fixation.

INDICATIONS

Acute and subacute non-displaced or minimally displaced periprosthetic posterior column fracture, pathological fracture, or osteolysis of the posterior column.

CONTRAINDICATIONS

Highly displaced posterior column, and/or comminuted fractures, narrow osseous corridor, large abdominal pannus, and inguinal skin infection.

SURGICAL TECHNIQUE

A classic DAA approach with or without proximal extension is performed, as for acetabular revisions. The hip is then dislocated, and both the femoral head and insert are extracted. The stability of the acetabular component is assessed. If it is found to be loose, the acetabular component is removed, and the fracture line is evaluated. Following this step, if criteria for anterograde percutaneous screw fixation are met, a minimally invasive stab incision over the iliac crest is performed. After calibration of the navigation system and 3D computed tomography (CT) data acquisition, the fascia is sharply opened, and blunt dissection of the iliac muscle is performed using a Cobb elevator under hip flexion to protect the femoral nerve and iliac muscle. After defining the trajectory in three planes using the navigation system, pre-drilling is performed with a 2.8-mm K-wire. Subsequently, a 7.5-mm fully threaded screw is inserted, and intraoperative CT is repeated to verify the correct screw position. The procedure is then completed by replacing the acetabular component via the DAA if it was loose. Additional screw fixation through the acetabular implant is advised.

RESULTS

Based on our preliminary experience, this technique offers a safe alternative with favorable outcomes compared to combined anterior and posterior approaches. It diminishes soft tissue trauma and procedural complexity while retaining the advantages of the anterior approach. The utilization of navigation allows for precise screw positioning and enhances surgical accuracy. Consequently, this surgical technique enables the increasing number of DAA surgeons to address rare complications using their preferred approach.

Does Stem Design Affect the Incidence of Periprosthetic Femoral Fractures in Arthroplasty for Femoral Neck Fractures? A Secondary Analysis of the HEALTH Trial

BACKGROUND

The aim of this study was to evaluate how stem design influences the risk of periprosthetic femoral fractures (PFFs) after hemiarthroplasty (HA) and total hip arthroplasty for femoral neck fractures.

METHODS

We performed a secondary analysis of the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty trial, a multicenter, prospective, randomized control trial that assessed total hip arthroplasty versus hemiarthroplasty for low-energy femoral neck fractures. Between 1,374 patients (414 men, 960 women) that were assessed, 72 sustained PFFs (5.2%). Intraoperative PFFs were recorded in 42 patients, early postoperative PFFs in 15 and late PFFs in 15 patients. The incidence of PFFs was compared between cemented and cementless stems. Within the cemented group (n = 896), we analyzed the effect of taper-slip (n = 482) versus composite-beam (n = 414) designs, while within the cementless group (n = 478), we assessed the impact of single-wedged (n = 206) versus metaphyseal-filling stems (n = 272). The role of collars (n = 87) was also examined within the press-fit stems. Clinical outcomes were recorded with the Western Ontario and McMaster Universities Arthritis Index RESULTS: Cemented stems had a significantly lower incidence of PFFs than their cementless counterparts (2.6 versus 10.3%, P < 0.001). There was no difference in fracture rates between taper-slip and composite-beam stems (2.3 versus 2.9%, P > 0.05). Most of the composite-beam PFFs occurred intraoperatively (75%), while most of the taper-slip PFFs occurred late (55%). There was no difference between the. press-fit stems, while the presence of a collar did not show protective results (P > 0.05). Patients who underwent HA with taper-slip stems demonstrated inferior Western Ontario and McMaster Universities Arthritis Index scores and higher incidence of reoperation for pain than those treated with composite-beam stems (2.6 versus 0.4%, P = 0.048).

CONCLUSIONS

Cementless stems have a high PFF rate, regardless of the stem type or presence of collar. Taper-slip stems are responsible for late fractures, raising concerns about their performance in the long term. Patients treated with HA may present a higher risk of reoperation for pain when taper-slip stems are used.