Progressive population aging and improved healthcare have led to a significant increase in patients with hip arthroplasty (HA). In this patient group, the proportion of those who require a new arthroplasty (prosthetic replacement or secondary revision of the hip), has also increased. For this subgroup of patients in whom surgical prosthetic replacement should be considered but is contraindicated, a new technique has been developed since 2010: percutaneous injection of periprosthetic cement under fluoroscopic or CT control ("femoroplasty; FMP") as an alternative and less invasive treatment compared to surgery to stabilize the HA without replacing it, with excellent results on patients' quality of life. In this brief communication, we describe our positive experience regarding FMP, which we have performed for the first time in Spain on four patients (age range between 74–83 years, 2 female and 2 male patients, 3 right HA and 1 left HA), without post-complications. We highlight both the relative simplicity of this technique, which can be incorporated into radiological intervention even in regional hospitals, and the significant clinical improvement observed in all patients. In conclusion, we hope that our experience can contribute to the increased adoption of this innovative technique within the scientific community.
El envejecimiento poblacional progresivo, junto a la mejor cobertura sanitaria, han generado un aumento progresivo del número de pacientes portadores de una primera artroplastia de cadera (ATC primaria), como de los que necesitan “recambiar” esta ATC (recambio o revisión protésica secundaria). Para este subgrupo de pacientes en los que el recambio protésico quirúrgico debería plantearse pero sin embargo está contraindicado, a partir de 2010 se ha desarrollado una nueva técnica, la inyección percutánea de cemento periprotésico mediante control fluoroscópico o TC (“femoroplastia; FMP”) como un tratamiento alternativo y menos invasivo respecto a la cirugía para estabilizar la ATC sin recambiarla, con excelentes resultados sobre la calidad de vida de los pacientes. En esta comunicación breve describimos nuestra positiva experiencia respecto a la FMP, que hemos realizado por primera vez en España a 4 pacientes (rango de edad entre 74–83 años, 2 pacientes de sexo femenino y 2 de sexo masculino, 3 ATC derechas y 1 izquierda), sin complicaciones post-intervencionismo, destacando tanto la relativa sencillez de esta técnica, (que puede incorporarse al intervencionismo radiológico incluso en hospitales de ámbito comarcal), como la notable mejoría clínica constatada en todos los pacientes. En conclusión, esperamos que nuestra experiencia pueda contribuir al aumento de la práctica de esta innovadora técnica en la comunidad científica.
Total hip arthroplasty (THA) is a common surgery to treat hip problems. Complications such as dislocation, loosening, fracture or infection may require surgical treatments such as revisions or prosthetic replacements. Twelve percent of all prosthetic THAs are replaced after 10 years1 and the rate is expected to increase due to the ageing population.2 In some patients (advanced age, comorbidities), the risk of further surgery outweighs the benefits of a prosthetic replacement.3 Since 2010, a small number of European studies4–7 have reported on the percutaneous injection of periprosthetic cement with fluoroscopic monitoring, known as femoroplasty (FMP), to stabilise THAs for a subgroup of patients who have aseptic loosening but are not candidates for surgery. This alternative and less invasive treatment to surgery has had excellent results on the quality of life of patients. Malan et al. evaluated the option of additionally injecting enzymes to remove periprosthetic fibrous tissue and while they observed greater cement penetration in these cases, they also reported an increase in periprosthetic cement leakage.4 To be a candidate for FMP, THA patients must have both symptoms (pain, functional limitation, etc.) and radiological signs of prosthetic loosening (extensive periprosthetic osteolytic areas, periosteal reaction). Additionally, there must be no suspicion of THA infection8,9 and they must not be candidates for prosthetic replacement, either because of comorbidities that pose a very high risk to the patient if further surgery was performed, or because the patient refuses to undergo further surgery.
Percutaneous cementationPatients who are candidates for FMP must have undergone a conventional radiology examination and a computed tomography (CT) scan to determine the ‘target’ area to be filled with cement at the level of the femoral stem (metaphyseal-diaphyseal or diaphyseal area) where we detect a greater degree of osteolysis. It is not necessary to administer heparin; on the contrary, the administration of anticoagulants should be stopped 24–72 h beforehand (depending on whether it is heparin or aspirin which requires a withdrawal time of 24 h, or acenocoumarol, dabigatran, warfarin which need longer periods). Allergies to contrast, tantalum, antibiotics or cement should also be ruled out. It is advisable to administer a prophylactic intravenous cephalosporin (ceftazidime 1 g) within 30 min. prior to the procedure. The technique is performed under general anaesthetic or nerve block, in strict sterile conditions in a vascular operating room, CT room or in the operating theatre with fluoroscopic monitoring of both the needle placement and cement distribution. The preferred access point for the intervention is lateral or anterolateral through the vastus lateralis muscle (at roughly 2 and 3 o'clock for a left hip), to avoid both the rectus femoris tendon (at 12 o'clock for a left hip) and the neurovascular pathway (posteromedial). Ultrasound-guided local anaesthesia (Bupivacaine) is administered by percutaneous puncture using a 22G needle measuring 9 or 15 cm in length, depending on the patient's phenotype. The needle is inserted until it reaches the femoral diaphyseal cortex adjacent to the ‘target’ area. Through the same percutaneous access, a vertebroplasty (VP) needle is introduced into the described area, perforating the femoral cortex until it makes contact with the prosthetic stem or the cement mantle in the case of a cemented prosthesis (Fig. 1). At this time it is advisable to perform a fine needle aspiration (FNA) puncture using the VP cannula so that periprosthetic samples can be sent for microbiological cultures (in aerobic + anaerobic + sterile S16 bottles) and cytology smears (if sufficient material is available) to obtain additional information on previously undetected infection or other complications such as granulomatous disease (particle disease) or an adverse reaction to metals. There is then the option of using ionic radiopaque contrast to check that the needle tip is positioned at the chosen ‘target’ area. Fluoroscopy with 2D rotation or CT scanning can ensure highly accurate positioning. The next step is to inject sterile poly(methyl methacrylate) (PMMA) cement through the VP cannula. The cement has a shorter solidification time here than in VP, as a more fluid distribution is sought in the stem area, and it is mixed with gentamicin (to reduce the risk of infection). In our case we did not inject fibrinolytic enzymes. Instead, the formation of the cement around the stem was monitored by imaging. The metaphyseal-diaphyseal femoral area is the primary focus for cementation as it provides the greatest stability. This is followed by the diaphyseal area (Fig. 2). No cement must reach the level of the prosthesis joint (this could lead to limited mobility or affect the friction torque), or any previous femoral bone defects (previous implant sites). Once the periprosthetic area is sufficiently filled (assessed by imaging; Fig. 3), the PMMA injection is stopped and the VP needle is carefully removed, blocking the PMMA residue with the mandrel to prevent it from migrating along the needle path to the soft tissues. In this final phase, sedation is discontinued if it is deemed no longer necessary for the patient. There is also the option of using a CT scan to monitor periprosthetic filling with cement and rule out local leakage. Pulmonary embolisms are a well-known complication of VP, but have not been reported for FMP. This is probably because femoral target areas are not as vascularised as vertebral bodies.
Femoroplasty technique. Sedation and local anaesthesia. Needles (10–13 G) guided by CT or fluoroscopy. Strict asepsis. Sometimes a hammer or drill is necessary to perforate the cortex, if it is not possible to do so by hand. Anterolateral access (to avoid the rectus femoris tendon). After mixing PMMA cement + tantalum (radiopaque) + antibiotic (gentamicin 2 g), there are approximately three minutes before it consolidates. Image-guided monitoring can rule out leakage and proximal progression.
Femoroplasty technique. Image-guided monitoring. Patient aged 81 years. The fluoroscopic image shows that the vertebroplasty needle is located in the prosthetic stem area, with the bevel facing the area of interest. Different projections confirm the linear progression of the cement in the stem area during the cement injection (arrows).
Femoroplasty technique. Image-guided monitoring. Patient aged 80 years. The 3D image after rotational acquisition (Axiom Artis; vascular) (A) shows that the vertebroplasty needle is located in the prosthetic stem area. Confirmation that the cement is located around the stem (arrow; B). Comparative axial CT images at baseline (C1 image) and after femoroplasty (C2 image), showing the annular arrangement of the cement around the stem (arrow).
After FMP, the patient is transferred to a recovery area, ward or, if necessary, to the post-anaesthesia recovery unit. If no complications are detected on clinical assessment (mobility, neurovascular status distal to the treated area, presence of pain), the patient is discharged. If any complication such as a haematoma is suspected, an ultrasound or CT scan may be performed. While the procedure can be performed on an outpatient basis, an overnight stay may be considered given the typically high associated level of comorbidity.
ConclusionFMP is an innovative interventional radiology technique that can be a viable and simple alternative for THA patients with mechanical loosening and pain who are not candidates for surgical prosthetic replacement. As we reported at the SERME 2022 Congress, the first hospital to carry out this procedure in Spain was the Hospital Clínic de Barcelona. Following approval by the Ethics Committee of our hospital, we have performed FMP on four patients (age range 74–83 years, two female and two male patients, three right and one left THA) between June 2021 and December 2022, with no associated complications and excellent post-intervention outcomes, in line with previous publications by Malan et al.4 and Prestat et al.,10 who carried out 17 THA and 1 THA respectively. In fact, one of our patients progressed from being a wheelchair user to being able to walk, and the improvements seen in all patients have remained, with no need for additional interventions according to the outpatient follow-ups carried out by the COT Hip Unit, which use the Merle d'Aubigne scale to evaluate three variables: pain, mobility and gait, giving a score between 0 and 6 for each of these (total range 0–18), with 0 being the most negative and 6 being excellent. All four patients showed significant improvements in their scores. Despite the limited experience and the need for more studies to determine the success rate and duration of the effect, it is important to share our experience with other centres through the RADIOLOGÍA journal so that this technique can become a palliative alternative for other cases of prosthetic loosening that do not require replacements. Furthermore, we believe that in the future this technique could be extended to other anatomical areas such as knees, shoulders or elbows, thus broadening the range of applications of cement injection in selected cases of mechanical loosening.10
Author contributionsAll the authors participated in drafting and reviewing the article, as well as completing the informed consent section and the peremptory prior approval by the Ethics Committee of our hospital. XTB, JCS and JBA performed the FMP technique, while JFV selected the candidate patients from the hip unit consultation and carried out the clinical follow-ups.
Conflicts of interestAll authors declare that they have no conflicts of interest in this publication.
