Search Results (23)

Background/Objective: Endoprosthetic proximal femoral replacement is a reconstructive procedure for preserving ambulatory function following tumor resection. Different prosthetic systems for endoprosthetic proximal femoral replacement may result in different stem placement techniques, especially regarding the anteversion angle of the stem. The aim of this study was to evaluate femoral rotation and stem anteversion following endoprosthetic proximal femoral replacement using two different prosthetic systems, and to investigate their influence on postoperative quality of life. Methods: We retrospectively reviewed 30 patients who underwent endoprosthetic proximal femoral replacement at our institution between 2008 and 2022. The evaluated parameters included patient demographics, anatomical and functional stem anteversion, femoral rotation, femoral resection length, implant type, and Musculoskeletal Tumor Society score. Results: The cohort comprised 16 males and 14 females with a mean age of 65.2 ± 13.5 years. Twenty patients received the Global Modular Replacement System implants and 10 received the Kyocera Modular Limb Salvage System implants. The mean anatomical stem anteversion was 17.0 ± 17.7°, and the mean femoral rotation was 14.4 ± 22.6°. The Global Modular Replacement System implants demonstrated less variability in anatomical stem anteversion (11.7 ± 15.2°) compared to the Kyocera Modular Limb Salvage System (27.6 ± 18.4°, p = 0.02). A significant negative correlation was found between anatomical stem anteversion and femoral rotation (r = −0.78, p < 0.01), and a positive correlation between femoral rotation and functional stem anteversion (r = 0.62, p < 0.01). Musculoskeletal Tumor Society scores were available in 14 patients and correlated significantly with functional stem anteversion (r = −0.62, p = 0.02) and femoral resection length (r = −0.61, p = 0.02), but not with anatomical stem anteversion or femoral rotation alone. Conclusions: This study demonstrated that stem placement angles differ between prosthetic systems. These differences are attributable to variations in surgical implantation techniques and prosthesis design philosophies. In particular, the Global Modular Replacement System incorporates built-in anteversion, and when using such prostheses, referencing the linea aspera enables more stable restoration of the anatomical stem anteversion. Excessive reduction in anatomical stem anteversion is not recommended to avoid excessive external femoral rotation. Full article

Background: The perfusion of viscera, kidney, and spinal cord represents one of the main concerns during open repair (OR) of Thoraco-Abdominal Aortic Aneurisms (TAAAs). Passive shunting (PS) has been historically used for intraoperative distal aortic perfusion but has been progressively replaced almost entirely by partial left-sided heart or total cardiopulmonary bypass with extra-corporeal circulation (ECC). Despite several advantages of these methods, PS still has potential in mitigating some drawbacks of long extracorporeal circuits connected with centrifugal or roller pumps, such as the need for cardiac and great vessels cannulation, priming and large intravascular fluid volume shifts, high heparin dose, immunosuppressive effects, and systemic inflammatory response syndrome. Methods: This study prospectively analyzed data of a cohort of patients who underwent TAAA OR using a PS in a single institution. Outcomes of interest were mortality, rate of mesenteric, renal and spinal cord ischemia, cardiac complications, and intraoperative hemodynamic stability achieved in this setting. Our institutional bundle and a comprehensive literature review about the different configurations and applicability of PS for TAAA OR is also reported. The search was performed based on three databases (PubMed, EMBASE, and Cochrane Library) by two independent reviewers (LS and AA) from inception to 31 December 2023, and the reported clinical results (visceral, renal, and spinal cord complications and mortality) using PS during TAAAs OR were analyzed. Results: Between March 2021 and December 2023, 51 TAAA repairs were performed and eleven patients (n = 8, 73% male; mean age 67 years, range 63–79) were operated using a PS for a total of one (9%) type I, one (9%) type II, two (18%) type III, five (45%) type IV, and two (18%) type V TAAA. In our early experience, PS was indicated for limited staff resources during the COVID-19 pandemic to treat five non-deferable cases. The sixth and seventh patients were selected for PS as they already had a functioning axillo-bifemoral bypass that was used for this purpose. For the most recent cases, PS was chosen as the primary perfusion method according to a score based on clinical and anatomical factors with ECC as a bailout strategy. Selective renal perfusion with cold (4 °C) Custodiol solution was the method of choice for renal protection in all cases while antegrade perfusion of the coeliac trunk and the superior mesenteric artery was assured by PS through a loop graft (8–10mm) proximally anastomosed to the axillary artery (10 patients, 90.9%) or the descending thoracic aorta (one patient, 9%) and distally anastomosed to the infrarenal aorta (3), common iliac (3), or femoral vessels (5). In-hospital mortality was 9% as one patient died on the 10th postoperative day from mesenteric ischemia following hemodynamic instability; permanent spinal cord ischemia rate was 0% and the rate of AKI stage 3 was 9% (one patient). Bailout shifting to ECC was never required. No cardiac complications, nor a significant increase in serum CK-MB were reported in any patient. No prolonged severe intraoperative hypotension episodes (Mean Arterial Pressure < 50 mmHg) were assessed using the Software Acumen Analytics (Edwards LifeSciences, Irvine CA, USA). No peri-operative coagulopathy nor major bleeding was reported. Conclusions: Our experience showed satisfactory outcomes with the use of PS in specifically selected cases. Current data indicate that PS may represent an alternative to ECC techniques during TAAAs OR in high volume centers where assisted extracorporeal circulation could eventually be applied as a bailout strategy. However, due to the small sample size of this and previously published series, more data are needed to clearly define the potential role of such approach during TAAA OR. Full article

Background/Objectives: Avascular necrosis of the femoral head is a debilitating condition that, if left untreated, leads to progressive arthritis necessitating total hip replacement (THR). In the younger adult population, there is a drive towards joint-preserving procedures, particularly where alternative techniques such as core decompression or vascularised bone grafting are anticipated to fail. Proximal femoral osteotomy is a technique that aims to remove the necrotic segment from the weight bearing area. The presented review aims to examine the efficacy of this technique in the management of avascular necrosis of the femoral head, reporting both rates of conversion to total hip replacement and patient reported outcomes. Methods: This systematic review was conducted according to PRISMA guidelines. A search was conducted of PubMed, Ovid Medline, EMBASE, and the Cochrane Library using pre-defined search terms. Data were extracted, and descriptive data presented. Quality of each study was assessed using the NIH quality assessment tool for case series studies. Results: Fifty-three studies with data for 2686 osteotomies are presented. Progression of radiological arthrosis was present in 40% of cases, with 20.3% of patients having undergone conversion to THR at a mean of 75.4 months (range 20–132 months). Patient-reported outcome measures were recorded in 1416 patients, of which the Harris Hip Score was the most commonly utilised. This score improved from a mean of 58.3 to 84.4 at a mean follow-up of 102 months. Conclusions: Osteotomy represented a valid head-preserving technique in the armamentarium against avascular necrosis of the femoral head, with conversion to THR required in 20.3% of patients at 7 years. In those patients who did not require THR, PROMS were similar to the arthroplasty population. Full article

Background: Total hip replacement replaces the femoral head, which cannot heal, with an artificial femoral shaft to ensure the patient’s normal life. However, due to the stress-masking effect of the proximal femur loaded with the artificial femur stem, the implant bears a large part of the load, resulting in insufficient stress stimulation of the proximal femur and bone waste remodeling. In turn, it is easy to lose bone, resulting in loosening. As a new treatment method, electrical stimulation has been widely used for bone loss, nonunion, and other diseases, and it has achieved good therapeutic effects. Methods: Therefore, in this work, electrical stimulation was introduced for postoperative density assessment, and a new disuse remodeling model was established to simulate density loss after remodeling and the resistance effect of electrical stimulation. The effects of various parameters on density loss in the model are discussed. Results: The simulation results revealed significant stress masking and density loss in the neck of the femur after hip replacement, and electrical stimulation placed in the neck of the femur may resist this density loss to a certain extent. The rate of bone mineral density reduction decreased after the addition of electrical stimulation, indicating that electrical stimulation can have a certain resistance to the density reduction caused by stress shielding, and this result is helpful for the rehabilitation of hip arthroplasty. Full article

Background: Surgical accuracy in total knee replacement (TKR) may vary with the surgeon, the patient preoperative deformity, and the guiding system to perform the procedure. Navigation systems attempt to increase the intraoperative information the surgeon requires to make the appropriate decisions, sometimes associating cumbersome procedures and unclear effectiveness to place the implant more precisely than conventional instruments. Methods: We conducted a retrospective case-control study with prospective data collection of radiographic measurements (alignment, joint line and patellar height) in a sample of 100 consecutive patients receiving TKR Optetrak Logic PS, either with standard surgical technique with Trulion Instrumentation (n = 59) or with the Guided Personalized Surgery (GPS) system (n = 41). Results: The GPS group improved the alignment of the mechanical Lateral Distal Femoral Angle (mLDFA) in 1.6° compared to the control (p = 0.003), but not evident in the mechanical Medial Proximal Tibial Angle (mMPTA) (p = 0.132). The GPS system achieved a normal patellar height in 98% of cases, according to the Blackburne–Peel Index (BP), compared to 71% in the control group (p = 0.002). This was obtained in the femoral side, as measured in the Epicondylar Ratio (ER) (p = 0.004). A lower dispersion of postoperative measurements was observed in the GPS group in comparison with the control, being statistically significant in mMPTA (p = 0.000), CD-Index (p = 0.011), IS-Index (p = 0.002), mIS-Index (p = 0.008), BP-Index (p = 0.011), and ER (p = 0.004). Conclusions: Better post-surgical restoration of joint line and patellar height is observed in surgeries performed with the GPS system, as well as a tendency to more accurate mechanical alignment and lower inter-patient variability, suggesting higher reproducibility. Full article

Background: Fibrous dysplasia (FD) is a rare condition in which normal spongy and cortical bone is replaced by non-neoplastic fibrous tissue, leading to weakened bone matrix and increased risk of pathological fractures and deformities. Treating these deformities poses a significant challenge for surgeons. While various cases of surgical stabilization and limb lengthening using intramedullary nails have been reported, there is limited evidence on the use of Motorized Intramedullary Limb-Lengthening Nails (MILLNs) in FD patients. This case report presents the clinical history of a patient with FD who underwent multiple surgical interventions to address severe lower limb length discrepancy (LLD) and angular deformity caused by multiple fractures. Case presentation: A sixteen-year-old Caucasian girl with polyostotic FD developed a severe post-traumatic LLD of 10 cm on the right side, associated with coxa vara, valgus knee, and patellar instability. The deformity of the proximal femur was addressed with a valgus and derotational femoral osteotomy. However, this procedure exacerbated the knee’s valgus deformity and only partially corrected the LLD, leading to the decision to proceed with femoral lengthening. A retrograde magnetic intramedullary nail (PRECICE, NuVasive) was utilized for this purpose. Approximately three months postoperatively, radiographs revealed the loosening of the proximal anchoring screw, while the nail had reached maximum distraction. We then proposed reactivating the previously implanted nail. Nine months after the final surgery, standing long-leg radiographs showed a residual shortening of 1 cm, with excellent healing at the fracture sites and the nail and screws remaining securely in place. The patient was monitored regularly, with the latest follow-up occurring four years and five months after the conclusion of the last lengthening procedure. Conclusions: This case report describes the reactivation of a MILLN in a patient with polyostotic fibrous dysplasia. While nail reactivation has been previously described in the literature, to our knowledge, it has not been reported for treating complications arising from FD. In cases of mechanical complications, this approach can equalize leg length discrepancies and correct deformities, avoiding additional invasive surgeries and reducing healthcare costs. As this is an off-label treatment, preoperative consent from both the patient and the parents is required. Full article

This study aims to evaluate the mechanical behavior, by ways of the FEM, of three femoral stems made of a Ti-6Al-4V titanium alloy with transverse holes in the proximal zone and a stem made of a β-type titanium alloy with a stiffness varying from 65 GPa in the proximal zone to 110 GPa in the distal zone and the CFRP composite material. The purpose of the study was to evaluate the effect of stress shielding on an intact femoral bone. A three-dimensional model of the intact femur was created, and the three prostheses were inserted with perfect stem bone fit. Applying constraint conditions such as fixation in all directions of the distal part of the femur and the application of a static load simulating standing still during a gait cycle allowed the stresses of both the implants and the bone to be compared. Evaluating the stress shielding for the three proposed materials was possible by identifying the seven Gruen zones. We can see from the results obtained that the metal alloys produced observable stress shielding in all the Gruen zones. There was a difference for the β-type alloy which, as a result of its stiffness variation from the proximal to the distal zone, did not show any level of stress shielding in Gruen zones 1 and 2. The CFRP composite, in contrast, showed no stress shielding in all of the Gruen zones and is an excellent material for the fabrication of total hip replacements. Further in vitro and in vivo validation studies are needed to make the modeling more accurate and understand the biological effects of the use of the three materials. Full article

Reconstruction of the abductor mechanism remains a primary challenge with contemporary proximal femoral replacement (PFR) surgery. Previously, techniques such as trochanteric preservation or direct repair to the implant have been described; however, these strategies are limited in their ability to tension the repair and reattach other muscles of the hip girdle. The aim of this study was to evaluate the outcomes of patients undergoing oncologic PFR using a novel technique of mesh augmentation for soft tissue repair. Methods: We reviewed 18 (mean age 64 years; 8 female: 10 male) consecutive patients undergoing PFR with Marlex mesh augmentation between 2018 and 2023 at a single institution. The most common indication was metastatic disease (n = 13). The mean follow-up in the 14 surviving patients was 27 months (range 12–34). Results: All patients were ambulatory at final follow-up. There were no post-operative dislocations, infections, or wound issues. At the final follow-up, the mean total MSTS score was 77%. Conclusion: Mesh augmentation of PFRs allowed for adequate soft tissue tensioning and muscular attachment to the body of the implant. In our series, this technique was durable, with no dislocations and no mesh-related complications. In summary, mesh augmentation of PFRs may be considered during reconstruction for oncologic indications. Full article

Total hip replacement is one of the most successful orthopedic operations in modern times. Osteolysis of the femur bone results in implant loosening and failure due to improper loading. To reduce induced stress, enhance load transfer, and minimize stress, the use of Ti-6Al-4V alloy in bone implants was investigated. The objective of this study was to perform a three-dimensional finite element analysis (FEA) of the femoral stem to optimize its shape and analyze the developed deformations and stresses under operational loads. In addition, the challenges associated with the manufacturing optimization of the femoral stem using large strain-based finite element modeling were addressed. The numerical findings showed that the optimized femoral stem using Ti-6Al-4V alloy under the normal daily activities of a person presented a strains distribution that promote uniform load transfer from the proximal to the distal area, and provided a mass reduction of 26%. The stress distribution was found to range from 700 to 0.2 MPa in the critical neck area of the implant. The developed computational tool allows for improved customized designs that lower the risk of prosthesis loss due to stress shielding. Full article

Intramedullary nailing insertion from the proximal-to-distal femur is frequently performed for impending and complete pathological femur fractures due to osteolytic metastases. After nailing through cancer-laden bone, residual chemotherapy- and/or radiation-resistant tumor may progress. Progression of osteolysis risks future nail failure or pathological fractures. This study assesses the incidence of cancer progression following intramedullary nailing in a femur-only cohort and describes a percutaneous rod-retaining salvage technique. A single-institution, retrospective study was conducted to identify adult patients who underwent intramedullary nailing for femoral osteolytic lesions for complete or impending nail failure from 2016 to 2023. Progression was defined as enlargement of the pre-existing lesion and/or appearance of new lesions on radiographs. Surgical outcomes were assessed with a combined pain and functional score. A total of 113 patients (median age 66.8 years (IQR = 16.4); median follow-up 6.0 months (IQR = 14.5)) underwent intramedullary nailing. Sixteen patients (14.2%) exhibited post-nailing cancer progression. Pre- and postoperative radiation and chemotherapy did not decrease the odds of cancer progression. Three patients underwent initial open surgical salvage consisting of proximal femur replacement arthroplasty, and six patients did not receive salvage due to poor surgical candidacy or patient choice. Seven patients (median follow-up 10.7 months (IQR = 12.9)) received percutaneous salvage. In this group, pain and functional scores improved by 4.0 points (p = 0.0078) at two-week postoperative follow-up and 2.0 points (p = 0.0312) at the most recent follow-up (mean follow-up 13.0 ± 9.4 months). All three nonambulatory patients became ambulatory, and six patients were able to ambulate independently without walking aids. No major complications were reported 30 days postoperatively. Progression of femoral osteolytic metastases may occur following intramedullary nailing. Continued monitoring of the entire femur is needed to maintain improved functional status and to prevent catastrophic progression of pre-existing lesions or appearance of new lesions. In patients with more proximal metastases only, the customary practice of bringing a long nail from the proximal femur to distal metaphysis should be reconsidered. Furthermore, there is concern of mechanical transport of cancer cells during guide wire insertion, reaming, and rod insertion through cancer laden bone to cancer free distal bone. Full article

The Gamma Nail represents one of the most popular and efficient implants for treating proximal femoral fractures. Our paper reports a case of a failed Gamma Nail which was used for the surgical treatment of a 69-year-old woman with a right femoral trochanteric fracture due to a car accident. After the surgical intervention, 6 months later, the patient presented to the hospital reporting pain and limited mobility of the right hip. An X-ray was performed at the level of the pelvis, which highlighted the fracture nonunion and the implant failure. The implant removal and its replacement with a dynamic condylar screw system (DCS) was decided. Because Gamma Nail failures are rare occurrences, the implant was subjected to analyses and experimental determinations to find out the cause. For the implant analyses, a stereomicroscope, an optical microscope, and scanning electron microscopy were used. After the tests were conducted, preparation and processing irregularities as causes of the implant failure were eliminated. Also, the experimental analyses showed that the Gamma Nail did comply with chemical composition and microstructure regulations. Thus, it was concluded that the implant failed due to the mechanical overloading caused by surgical technique errors. Full article

Hip replacement surgery is increasingly being performed on older patients, raising the risk of periprosthetic proximal femur fractures (PPFFs). While the impact of surgery timing on mortality in proximal femoral fractures is established, its effect on PPFFs remains unclear. This study aims to examine the correlation between surgery timing and mortality in PPFF patients. In a historical cohort study, we analyzed data from 79 PPFF patients treated from 2012 to 2022. Patients were categorized by surgery timing (≤48 h, 32 patients vs. >48 h, 47 patients). Outcomes and mortality rates were compared. No significant difference in mortality was observed between patients undergoing early (<48 h) and delayed (>48 h) surgery at 30 days and 1 year. Factors such as age (p = 0.154), gender (p = 0.058), ASA score (p = 0.893), Vancouver classification (p = 0.577), and surgery type (implant revision p = 0.691, OR = 0.667) did not affect 30-day mortality. However, 1-year mortality was influenced by gender (male p = 0.045) and age (p = 0.004), but not by other variables (Vancouver classification p = 0.443, implant revision p = 0.196). These findings indicate no association between surgery timing and mortality in PPFF patients, suggesting that other factors may influence outcomes. Further research is needed to optimize PPFF management. Full article

In current-generation designs of total primary hip joint replacement, the prostheses are fabricated from alloys. The modulus of elasticity of the alloy is substantially higher than that of the surrounding bone. This discrepancy plays a role in a phenomenon known as stress shielding, in which the bone bears a reduced proportion of the applied load. Stress shielding has been implicated in aseptic loosening of the implant which, in turn, results in reduction in the in vivo life of the implant. Rigid implants shield surrounding bone from mechanical loading, and the reduction in skeletal stress necessary to maintain bone mass and density results in accelerated bone loss, the forerunner to implant loosening. Femoral stems of various geometries and surface modifications, materials and material distributions, and porous structures have been investigated to achieve mechanical properties of stems closer to those of bone to mitigate stress shielding. For improved load transfer from implant to femur, the proposed study investigated a strategic debulking effort to impart controlled flexibility while retaining sufficient strength and endurance properties. Using an iterative design process, debulked configurations based on an internal skeletal truss framework were evaluated using finite element analysis. The implant models analyzed were solid; hollow, with a proximal hollowed stem; FB-2A, with thin, curved trusses extending from the central spine; and FB-3B and FB-3C, with thick, flat trusses extending from the central spine in a balanced-truss and a hemi-truss configuration, respectively. As outlined in the International Organization for Standardization (ISO) 7206 standards, implants were offset in natural femur for evaluation of load distribution or potted in testing cylinders for fatigue testing. The commonality across all debulked designs was the minimization of proximal stress shielding compared to conventional solid implants. Stem topography can influence performance, and the truss implants with or without the calcar collar were evaluated. Load sharing was equally effective irrespective of the collar; however, the collar was critical to reducing the stresses in the implant. Whether bonded directly to bone or cemented in the femur, the truss stem was effective at limiting stress shielding. However, a localized increase in maximum principal stress at the proximal lateral junction could adversely affect cement integrity. The controlled accommodation of deformation of the implant wall contributes to the load sharing capability of the truss implant, and for a superior biomechanical performance, the collared stem should be implanted in interference fit. Considering the results of all implant designs, the truss implant model FB-3C was the best model. Full article

Background: Femoral nailing is a largely widespread procedure in the elderly population, and the number of these surgeries is rising. Hip arthroplasty is a salvage procedure performed to improve function of the hip after femoral nail failure. The aim of the study is to evaluate functional outcomes, complications and survivorship in hip arthroplasty after femoral nail failure. Methods: A systematic review of three databases (Pubmed, Embase and Cochrane) was performed using the PRISMA 2020 guidelines. After selection, four studies met the inclusion criteria, and 483 treated hips have been analyzed (476 total hip arthroplasties, 7 partial hip arthroplasties). Results: The median value of Harris Hip Score (HHS) after salvage treatment was 86.1. The main indications for salvage treatment were osteoarthrosis, avascular necrosis of the femoral head and instability of the hip. Complications are more frequent than in primary total hip arthroplasty, in particular aseptic loosening and dislocation. Good outcomes have also been achieved using revision-type stems and proximal femoral replacements (PFR). Conclusions: Conversion total hip arthroplasty is confirmed as the optimal treatment for femoral nail failure in the elderly population. Cemented or hybrid total hip arthroplasties have better outcomes than uncemented total hip arthroplasties, and the use of different types of implants widens the possible approaches to surgery in restoring the biomechanics of the hip and increases the satisfaction of patients. Full article

Little is known about dynamic changes of femoral anatomy after total hip arthroplasty (THA), in particular about sagittal femoral bowing (SFB). A 3D CT study was designed to evaluate the chronological changes of SFB after cementless femoral stem implantation for primary THA. Ten patients who underwent unilateral primary THA with a cementless femoral stem, with 2 consecutive CT scans (extending from the fourth lumbar vertebra to the tibial plateaus), performed before THA and at least 3 years after THA, were enrolled. The 3D models of femurs were created using image segmentation software. Using the two CT scans, SFB values of the proximal and middle thirds were calculated on the replaced and untreated sides by two different observers. Eight anatomical stems and two conical stems were involved. The post-operative CT was performed at an average follow-up of 6.5 years after THA (range: 3–12.5). The measurements performed by the two observers did not differ in the proximal and middle regions. A significant difference between the pre-operative and post-operative SFB compared to the untreated side was found in the proximal femur segment (p = 0.004). Use of a cementless stem in THA induced chronological changes in SFB of the proximal femur, after a minimum timespan of 3 years. Full article