INTRODUCTION. 3D preoperative planning software for anatomic total shoulder arthroplasty (ATSA) provides surgeons with increased ability to visualize complex joint relationships and deformities. Interestingly, the advent of such software has seemed to create less of a consensus on the optimal way to plan an ATSA rather than more. In this study, a survey of shoulder specialists from the American Shoulder and Elbow Society (ASES) was conducted to examine thought patterns in current ATSA implant selection and placement. METHODS. 172 ASES members completed an 18-question survey on their thought process for how they select and place an ATSA
Background:. Glenoid component loosening remains as an unsolved clinical problem in total shoulder arthroplasty. Current clinical assessment relies on subjective quantification using a two-dimensional plane X-ray image with arbitrarily defined criteria. There is a need to develop a readily usable clinical tool to accurately and reliably quantify the glenoid component motion over time after surgery. A high-resolution clinical CT has the potential to quantify the glenoid motion, but is challenged by metal artifact from the prosthetic humeral components. The objective of this study is to demonstrate the feasibility of using a clinical CT reconstruction to quantify the
INTRODUCTION. 3D preoperative planning software for anatomic and reverse total shoulder arthroplasty (ATSA and RTSA) provides additional insight for surgeons regarding implant selection and placement. Interestingly, the advent of such software has brought previously unconsidered questions to light on the optimal way to plan a case. In this study, a survey of shoulder specialists from the American Shoulder and Elbow Society (ASES) was conducted to examine thought patterns in current
INTRODUCTION. The advent of CT based 3D preoperative planning software for reverse total shoulder arthroplasty (RTSA) provides surgeons with more data than ever before to prepare for a case. Interestingly, as the usage of such software has increased, further questions have appeared over the optimal way to plan and place a
Background and Motivation. Accurate placement of glenoid components in reverse and total shoulder arthroplasty has been shown to reduce the risk of implant failure (1, 2, 6). Surgical techniques and literature describe methods to determine favorable positions for implant placement (3, 4, 5) but achieving that position surgically remains a challenge. Placement of glenoid components is faced with the challenge of variable glenoid morphology on which conventional instrumentation does not always provide a reliable reference (6, 7, 8). Limited surgical exposure is another challenge since many anatomic landmarks are not visible to the surgeon to use as spacial reference. Anatomic landmarks and angles can be more reliabily selected on CT scans with 3-dimentional reconstruction (9,10) yet few methods allow for the reproducible translation of these plans to surgery. Navigation has produced better accuracy and lower variability than conventional instrumentation (11), yet its regular usage remains limited, especially in the shoulder. Methods. A patient specific planning and guiding system has been developed for
Common post-operative problems in shoulder arthroplasty such as glenoid loosening and joint instability can be reduced by improvements in glenoid design shape, material choice and fixation method [1]. Innovation in shoulder replacement is usually carried out by introducing incremental changes to functioning implants [2], possibly overlooking other successful design combinations. We propose an automated framework for parametric analysis of implant design in order to efficiently assess different possible glenoid configurations. Parametric variations of reference geometries of a
INTRODUCTION. Variability in placement of total shoulder arthroplasty (TSA)
Reverse shoulder arthroplasty has a high complication rate related to
Patients receiving reverse total shoulder arthroplasty (RTSA) often have osseous erosions because of glenohumeral arthritis, leading to increased surgical complexity.
Introduction. The degree of glenoid bone loss associated with primary glenohumeral osteoarthritis can influence the type of
Introduction. Reverse Total Shoulder Arthroplasty (rTSA) is an efficient treatment, to relieve from pain and to increase function. However, scapular notching remains a serious issue and post-operative range of motion (ROM) presents many variations. No study compared implant positioning, different implant combinations, different implant sizes on different types of patient representative to undergo for rTSA, on glenohumeral ROM in every degree of freedom. Material and Methods. From a CT-scan database classified by a senior surgeon, CT-exams were analysed by a custom software Glenosys® (Imascap®, Brest, France). Different
Glenoid failure remains the most common mode of total shoulder arthroplasty failures. Porous tantalum metal (Trabecular Metal™, Zimmer) have grown in popularity in hip and knee arthroplasty. First-generation porous tantalum metal-backed glenoid components demonstrated metal debris, resulted in failure, and were revised to second-generation
In an effort to address the relatively high rate of glenoid component lucent lines, loosening and failure, tantalum/trabecular metal
CT-based three-dimensional (3D) pre-operative imaging along with 2D orthogonal sections defined by the plane of the scapula (axial, sagittal and coronal planes) has been demonstrated by many research groups to be a very accurate way to define the bone pathology and alignment/subluxation of the humeral head in relationship to the center line of the scapula or the center of the glenoid fossa. When 3D CT imaging is combined with 3D implant templating the surgeon is best able to define the optimal implant and its location for the desired correction of the bone abnormalities. The use and value of 3D imaging is best when the there is more severe bone pathology and deformity. Transferring the computer-based information of implant location to the surgical site can involve multiple methods. The three methods discussed in the literature to date including use of standard instrumentation in a manner specified by the pre-operative planning, use of single-use patient specific instrumentation and use of reusable patient specific instrumentation. Several cadaver and sawbone studies have demonstrated significant improvement in placement of the
INTRODUCTION. Preoperative planning software for reverse total shoulder arthroplasty (RTSA) allows surgeons to virtually perform a reconstruction based off 3D models generated from CT scans of the glenohumeral joint. While anatomical studies have defined the range of normal values for glenoid version and inclination, there is no clear consensus on glenoid component selection and position for RTSA. The purpose of this study was to examine the distribution of chosen
Background. A challenge to obtaining proper glenoid placement in total shoulder arthroplasty is eccentric posterior bone loss and associated glenoid retroversion. This bone loss can lead to poor stability and perforation of the glenoid during arthroplasty. The purpose of this study was to evaluate the three dimensional morphology of the glenoid with associated bone loss for a spectrum of osteoarthritis patients using 3-D computed tomography imaging and simulation software. Methods. This study included 29 patients with advanced glenohumeral osteoarthritis treated with shoulder arthroplasty. Three-dimensional (3D) reconstruction of preoperative CT images was performed using image analysis software. Glenoid bone loss was measured at ten, vertically equidistant axial planes along the glenoid surface at four distinct anterior-posterior points on each plane for a total of 40 measurements per glenoid. The glenoid images were also fitted with a modeled pegged
Radiolucent lines in total shoulder arthroplasty around the glenoid component are not uncommon in post-operative x-rays and the incidence varies. A certain percentage progress and as the lines enlarge can lead to component loosening. One study reported a 9% incidence at 2 years and 27% incidence at 5 years. A recent long term study (15 to 20 years) reported a 73% incidence. Radiolucent lines can be caused by anatomy (posterior glenoid wear) or pathology (inflammatory arthritis) as well as technical factors such as
Background. Total shoulder arthroplasty is technically demanding in regards to implantation of the glenoid component, especially in the setting of increased glenoid deformity and posterior glenoid wear. Augmented
Introduction. Varying degrees of posterior glenoid bone loss occurs in patients with end stage osteoarthritis and can result in increased glenoid retroversion. The excessive retroversion can affect implant stability, eccentric glenoid loading, and fixation stresses. Ultimately, the goal is to correct retroversion to restore normal biomechanics of the glenohumeral joint. The objective of this study was to identify the optimal augmented glenoid design based on finite element analysis (FEA) modeling which will provide key insights into implant loosening mechanisms and stability. Materials and Methods. Two different augmented glenoid designs, posterior wedge and posterior step- were created as a computer model by a computer aided design software (CAD). These implant CAD models were created per precise manufacturers dimensions and sizes of the augmented implant designs. These implants were virtually implanted to correct 20° glenoid retroversion and the different mechanical parameters were calculated including: the glenohumeral subluxation force, relative micromotion at the bone-cement interface the
Introduction. Posterior glenoid wear is common with glenohumeral osteoarthritis. To correct posterior wear, surgeons may eccentrically ream the anterior glenoid to restore version. However, eccentric reaming undermines prosthesis support by removing unworn anterior glenoid bone, compromises cement fixation by increasing the likelihood of peg perforation, and medializes the joint line which has implications on joint stability. To conserve bone and preserve the joint line when correcting glenoid version, manufacturers have developed posterior augment glenoids for aTSA and rTSA applications. This clinical study quantifies outcomes achieved using posteriorly augmented aTSA/rTSA