Radiostereometry

PURPOSE: The pivot-shift test is used to clinically assess knee instability in patients with anterior cruciate ligament (ACL) lesions; however, it has low interobserver reliability. Dynamic radiostereometry (dRSA) is a highly precise and noninvasive method for the objective evaluation of joint kinematics. The purpose of this study was to quantify precise knee kinematics during a pivot-shift test using dRSA imaging. METHOD: Eight human donor legs, including hemipelvises, were evaluated...

BACKGROUND AND PURPOSE: Cementless arthroplasty fixation relies on early bone ingrowth and may be poor in patients with low proximal tibial bone density or abnormal bone turnover. We aimed first to describe the baseline bone properties in patients undergoing medial unicompartmental knee replacement (UKR), and second to investigate its association with cemented and cementless tibial component migration until 2 years. METHODS: A subset investigation of 2 patient groups from a 3-armed randomized controlled trial was conducted...

BACKGROUND AND PURPOSE: Radiostereometry (RSA) is the current gold standard for evaluating early implant migration. CT-based migration analysis is a promising method, with fewer handling requirements compared with RSA and no need for implanted bone-markers. We aimed to evaluate agreement between a new artificial intelligence (AI)-based CT-RSA and model-based RSA (MBRSA) in measuring migration of cup and stem in total hip arthroplasty (THA). PATIENTS AND METHODS: 30 patients with THA for primary osteoarthritis (OA) were included...

When we checked our data in our article "Similar outcome with a new anteverted or a straight standard stem: a randomized study of 72 total hip arthroplasties evaluated with clinical variables, radiostereometry, and DXA up to 2 years" by Karin Rilby, Maziar Mohaddes, Emma Nauclér, and Johan Kärrholm, Acta Orthop 2021; 92, Published online October 21, 2021 we noticed that the numbers in Table 7 (Supplementary data) were incorrect. We have not been able to fully reconstruct the reason for this error...

PURPOSE: The most used cup designs for trapeziometacarpal (TMC) arthroplasty are of hemispherical and conical geometrical shape. Using a validated pig bone model, we compared the bone fixation using radiostereometry (RSA). METHODS: Twenty saddle-shaped pig forefoot bones were prepared with insertion of bone markers and reaming. Hemispherical Type T cups (Beznoska, Kladno, Czech Republic) (N = 10) and conical Moovis cups (Stryker, Pusignan, France) (N = 10) of 9-mm diameter were inserted press-fit...

BACKGROUND: An increasing number of radiostereometry (RSA) research studies have long-term follow-up implant migration outcomes, which show ascending curves of implant migration with occasionally decreasing migration. After scrutinizing images and RSA scenes related to the alternating curves, we suppose that intra-exposure patient motion may contribute to that. The main purposes of this in vitro study were 1) to identify whether the patient motion in different directions could result in the inaccurate assessment of implant migration, and 2) to figure out which direction(s) accounted for the alternating curves...

AIMS: Conflicting clinical results are reported for the ATTUNE Total Knee Arthroplasty (TKA). This randomized controlled trial (RCT) evaluated five-year follow-up results comparing cemented ATTUNE and PFC-Sigma cruciate retaining TKAs, analyzing component migration as measured by radiostereometric analysis (RSA), clinical outcomes, patient-reported outcome measures (PROMs), and radiological outcomes. METHODS: A total of 74 primary TKAs were included in this single-blind RCT...

INTRODUCTION: Cut-out is the most frequently reported mechanical failure of internal fixation of pertrochanteric fractures. The purpose of this study was to examine if hydroxyapatite-coated screw thread on a sliding hip screw (SHS) could reduce screw migration within the femoral head in patients with stable pertrochanteric fractures. MATERIALS AND METHODS: In a double-blinded randomized controlled study, 37 patients at mean age 78 (range 56-96), with pertrochanteric fracture (Evans I, II, IV) received surgery with a SHS with a hydroxyapatite-coated or a non-coated lag screw thread...

BACKGROUND: The role of meniscal lesions and repair in combination with anterior cruciate ligament (ACL) injury and reconstruction has not been extensively investigated in vivo and under weightbearing conditions. PURPOSE: The purposes of this study were to (1) compare the in vivo knee kinematics between patients with ACL tear and those with combined ACL and medial meniscal tears and (2) investigate kinematic differences between isolated ACL reconstruction and ACL reconstruction plus medial meniscal repair (MR)...

BACKGROUND AND PURPOSE: 3-dimensional midfoot motion is hard to evaluate in clinical practice. We present a new computed tomography (CT)-based radiostereometric analysis (CT-RSA) technique to examine in vivo midfoot kinematics during single-leg stance and compare it with marker-based radiostereometry (RSA). PATIENTS AND METHODS: 8 patients were examined with bilateral non- and full-weight-bearing CT images of the midfoot. 1st tarsometatarsal motion was analyzed using a surface-registration technique (CT-RSA)...

AIMS: The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems. METHODS: In this case-control study, 25 patients (22 female) at mean age of 78 years (70 to 89) received cemented Exeter short stem (case group). Cases were selected based on Dorr type A femora and matched first by Dorr type A and then age to a control cohort of 21 patients (11 female) at mean age of 74 years (70 to 89) who received with cemented Exeter standard stems (control group)...

BACKGROUND AND PURPOSE: Dual mobility (DM) articulation total hip arthroplasty (THA) is used increasingly to reduce dislocation risk. We investigated cup fixation, polyethylene (PE) wear, serum chromium and cobalt ions, and their correlation to physical activity in patients with DM cups at 6-year follow-up. PATIENTS AND METHODS: In a patient-blinded RCT, 60 patients with hip osteoarthritis at a median age of 74 years (70-82) were randomly allocated to cemented (n = 30) or cementless hydroxyapatite-coated (n = 30) fixation of Avantage DM THA with a highly-crosslinked vitamin-E PE liner...

BACKGROUND: Recently, temporary bridge plate fixation has gained popularity in the treatment of unstable Lisfranc injuries. The technique aims to reduce the risk of posttraumatic osteoarthritis, and after plate removal, the goal is to regain joint mobility. Here we explore marker-based radiostereometric analysis (RSA) to measure motion in the 1st tarsometatarsal (TMT) joint and asses the radiological outcome in patients treated with this surgical technique. METHOD: Ten patients with an unstable Lisfranc injury were included...

Background  Measurement of in vivo distal radioulnar joint (DRUJ) pathomechanics during simple activities can represent the disability experienced by patients and may be useful in diagnostics of DRUJ instability. A first step is to describe the physiological normal limits for DRUJ kinematics in a reproducible and precise test setup, which was the aim of this study. Methods  DRUJ kinematics were evaluated in 33 participants with dynamic radiostereometry (RSA) while performing a standardized press test examination...

PURPOSE: New total knee arthroplasty implant designs attempt to normalize kinematics patterns that may improve functional performance and patient satisfaction. It was hypothesized that a more medial congruent (MC) anatomic bearing design (1) influences the tibiofemoral kinematics and (2) enhances articular congruency compared to a standard symmetrical cruciate retaining (CR) bearing design. METHODS: In this double-blinded randomized study, 66 patients with knee osteoarthritis were randomly included in two groups: MC (n = 31) and CR (n = 33)...

BACKGROUND AND PURPOSE: Foveal triangular fibrocartilage complex (TFCC) lesion may cause distal radioulnar joint (DRUJ) instability. Dynamic radiostereometry (dRSA) has been validated for objective measurement of DRUJ kinematics. We evaluated DRUJ kinematics by dRSA before surgery and 12 months following open foveal reinsertion of the TFCC in comparison with contralateral non-injured DRUJs. PATIENTS AND METHODS: In a prospective cohort study, 21 patients (11 men) of mean age 34 years (22-50) with arthroscopically confirmed foveal TFCC lesion were evaluated preoperatively, and at 6 and 12 months after open foveal TFCC reinsertion with QDASH, PRWE, pain on NRS, and bilateral dRSA imaging during a patient active press test motion cycle, including a force-loaded downstroke and a release phase...

AIMS: BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems. METHODS: A total of 53 patients were randomized to be treated using Bi-Metric cementless femoral stems with either only a porous titanium plasma-sprayed coating (P group) or a porous titanium plasma-sprayed coating with an additional BoneMaster coating (PBM group)...

Radiostereometic analysis (RSA) is an accurate method for rigid body pose (position and orientation) in three-dimensional space. Traditionally, RSA is based on insertion of periprosthetic tantalum markers and manual implant contour selection which limit clinically application. We propose an automated image registration technique utilizing digitally reconstructed radiographs (DRR) of computed tomography (CT) volumetric bone models (autorsa-bone) as a substitute for tantalum markers. Furthermore, an automated synthetic volumetric representation of total knee arthroplasty implant models (autorsa-volume) to improve previous silhouette-projection methods (autorsa-surface)...

BACKGROUND AND PURPOSE: Dual-mobility hip arthroplasty utilizes a freely rotating polyethylene acetabular liner to protect against dislocation. As liner motion has not been confirmed in vivo, we undertook this using dynamic radiostereometry (RSA). PATIENTS AND METHODS: 6 patients with Anatomical Dual Mobility acetabular components were included. Markers were implanted in the liners using a drill guide. Static RSA recordings and patient-reported outcome measures were obtained postoperatively and at 1-year follow-up...

INTRODUCTION: The Exeter short stem (ESS) is 25 mm shorter than the standard length v40 Exeter stem (Stryker) and intended for a narrow femoral diaphysis. The purpose of the study was to evaluate the migration pattern of the cemented ESS. MATERIAL AND METHOD: In a prospective single-center cohort study, 23 patients (21 female) mean age 78 (range 70-89) with hip osteoarthritis and Dorr Type A femurs were included. Preoperative DXA was used to group patients into normal (> - 1) and low (< - 1) T-score...