Radiographic Evaluation of Bone Remodeling Around Osseointegration Implants Among Transfemoral Amputees

Abstract

Objectives: To examine periprosthetic bone remodeling among the recipients of 2 types of lower-limb osseointegrated systems, the Integral Leg Prosthesis (ILP) and the Osseointegration Prosthetic Limb (OPL) type A, over a >24-month period. Design: Retrospective cohort study. Setting: Private hospital, with a specialized osseointegration unit. Patients: Twenty-eight patients with transfemoral lower-limb amputations were fitted with osseointegrated systems. Of these patients, 15 received the ILP and 13 the OPL osseointegrated implant. Intervention: Radiographic measurements were taken at baseline (0.4 ± 0.5 years) and at follow-up (3.0 ± 0.8 years) after the osseointegration procedure. Main Outcome Measurements: Radiographic bone density, longitudinal bone coverage, and bone width outcomes were measured in inverse “Gruen zones.” Bone remodeling was evaluated by comparing changes between baseline and follow-up measurements. Results: Radiographic bone density decreased in all zones among both ILP and OPL groups. Cortical bone thickness increased among the OPL group in zones 3 (P < 0.05) and 5 (P < 0.05). Distal bone coverage of the ILP implant decreased by 2.3% (P < 0.01) and 4.1% (P < 0.05) of the total implant length on the medial and lateral sides, respectively. Conclusions: Decreased bone density with increased periprosthetic cortical thickness suggests a change in the bone architecture for the OPL group. The findings of this study raise concerns for the long-term success of the ILP implant. Radiographic analysis of x-rays seems to be a useful tool for clinicians to evaluate bone remodeling around osseointegrated prosthesis. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Use of computer tomography imaging for analyzing bone remodeling around a percutaneous osseointegrated implant

“…The POP titanium alloy (Ti6Al4V) femoral stem was 100 mm long (Figure 1) with a tapered, proximal region with splines to reduce stress-shielding and a distal osteotomy collar to cap the end of the bone. 20,25 A circumferential titanium porous coating (P-Squared, P 2TM ) was present on the distal 30 mm of the stem and on the collar. Implantation of the POP device was performed in two surgical stages.…”

“…This would provide clinicians with an enhanced data set to better evaluate the integrity of the bone-implant interface and take preventative measures to avoid possible implant failure. 25,26 The goal of this study was to develop a proficient, reproducible method using three-dimensional models constructed from clinical computed tomography (CT) scans to perform an objective in vivo analysis of bone morphological changes around the POP device in transfemoral amputees. CT imaging is now used as the gold standard for analyzing morphology measurements in three-dimensional (3D) reconstructions of bone 27,28 and has the potential to provide a more complete and accurate analysis of bone remodeling that is occurring around OI devices over time.…”

“…To make informed decisions on prescribed postoperative loading and patient activity, physicians need an effective way to measure bone remodeling parameters around the device. This would provide clinicians with an enhanced data set to better evaluate the integrity of the bone‐implant interface and take preventative measures to avoid possible implant failure 25,26 …”

Extramedullary Osseointegration—A Novel Design of Percutaneous Osseointegration Prosthesis for Amputees

“…A major breakthrough was the introduction of press-fit Endo-Exo- Prosthesis (EEPs) by Hans Grundei et al who applied porous cobalt chromium metal stem as the intramedullary implant ( Mittelmeier et al, 1997 ). Dr. Al Muderis and co-workers later developed the Osseointegrated Prosthetic Limb (OPL) system, in which the implant material was changed from cobalt-chromium to titanium ( Thomson et al, 2019 ). The press-fit systems shortened the time for surgery and rehabilitation, becoming favorable choices for patients and surgeons in recent years ( Hoellwarth et al, 2020 ).…”

A Comparative Analysis on Adaptation Behavior and Failure Risk of Femurs of Different Qualities Under the Effect of Direct Transfemoral Fixations

“…Furthermore, reduction of periprosthetic bone mineral density (BMD) may lead to complications such as aseptic loosening, infection, and fractures (Electricwala et al 2016;Marks 2009). Hence, several empirical studies have been conducted to monitor the periprosthetic bone remodeling around osseointegrated trans-femoral prostheses (Nebergall et al 2012;Thomson et al 2019).…”