Robotic TKA allows for quantifiable precision performing bone resections for implant realignment within acceptable final component and limb alignments. One of the early steps in this robotic technique is after initial exposure and removal of medial and lateral osteophytes, a “pose-capture” is performed with varus and valgus stress applied to the knee in near full extension and 90° of flexion to assess gaps. Component alignment adjustments can be made on the preoperative plan to balance the gaps. At this point in the procedure any posterior osteophytes will still be present, which could after removal change the flexion and extension gaps by 1–3mm. This must be taken into consideration, or changes in component alignment could result in over-correction of gaps can occur. The purpose of this study was to identify what effect the posterior osteophyte's size and location and their removal had on gap measurements between pose-capture and after bone cuts are made and gaps assessed during implant trialing.Introduction
Objective
Background.
The study describes the topography, morphology and growth of osteophytes in forty femoral heads removed from patients presenting with advanced osteoarthritis of the hip. In addition to standard histological techniques, radiography of serial bone slices and in vivo bone labelling with tetracycline and . 32. P were used. The pattern of major osteophyte formation appeared to be influenced by the direction, degree and rate of displacement of the femoral head in relation to the acetabulum; four principal patterns of growth were noted.
INTRODUCTION. In total hip arthroplasty, preoperative planning is almost indispensable. Moreover, 3-dimensional preoperative planning became popular recently. Anteversion management is one of the most important factors in preoperative planning to prevent dislocation and to obtain better function. In arthritic hip patients osteophytes are often seen on both femoral head and acetabulum. Especially on femoral head, osteophytes are often seen at posterior side and its surface creates smooth round contour that assumes new joint surface. (Fig. 1). We can imagine new femoral head center tracing that new joint surface. OBJECTIVES. In the present study, the posterior osteophytes are compared in osteoarthritic patients and other patients. MATERIALS & METHODS. Anteversion and new anteversion which was reduced by osteophyte formation were assessed in 28 hip CAT scans, (22 arthritic hips, 6 avascular necrotic hips). RESULTS. Only in arthritic patients, osteophytes on posterior side were observed. The anteversion was 33.7+/− 13.0 degree in arthritic patients, which was reduce to 29.7+/−13.1 degree. The mean difference was 4.0+/−4.7 degree reduction. In AVN patients the mean anteversion was 21.4 +/− 9.40 in AVN patients. No reduction was observed in AVN patients. DISCUSSION.
Purpose. The effects of Acetabular Rim
Sagittal plane imbalance (SPI), or asymmetry between extension and flexion gaps, is an important issue in total knee arthroplasty (TKA). The purpose of this study was to compare SPI between kinematic alignment (KA), mechanical alignment (MA), and functional alignment (FA) strategies. In 137 robotic-assisted TKAs, extension and flexion stressed gap laxities and bone resections were measured. The primary outcome was the proportion and magnitude of medial and lateral SPI (gap differential > 2.0 mm) for KA, MA, and FA. Secondary outcomes were the proportion of knees with severe (> 4.0 mm) SPI, and resection thicknesses for each technique, with KA as reference.Aims
Methods
While osteophytes are a hallmark feature of knee osteoarthritis (OA), there is limited information regarding their location. In particular, it is unknown whether osteophytes develop in patient-specific locations or if there are consistent osteophyte locations among OA knees. This lack of data mainly stems from the fact that osteophytes have been mostly assessed with scores quantifying their size or severity but not their location. Given the important role that bone could play in OA development and the option it offers for OA treatment, there is a need to better understand the osteophyte locations. This study aimed to develop a method to compare osteophyte locations among knees and determine the overlapping ratio. CT arthrogram of 11 medial-compartment OA tibias (Kellgren-Lawrence grade ≥ 3) were segmented to locate the osteophytes and a bone matching technique was used to report the osteophyte locations of the 11 knees on a single reference tibia. This newly proposed method was highly reproducible (intra-operator ICC = 0.89). When used to compare the 11 tibias, it showed that more than 60% of the overall subosteophytal area, defined as the reference bone area covered by at least one osteophyte from one knee, was common to less than two tibias. Moreover, less than 20% of the overall subosteophytal area was common to five or more tibias. The results of this study suggest that osteophyte locations are specific to each knee. Future work should determine the relationships with mechanical loading, as this could explain the high inter-patient variability.
We present to you a match-controlled study assessing co-existing arthroscopic findings during hip arthroscopy in patients with an intraoperative diagnosis of a central acetabular osteophyte (CAO). We feel that this manuscript is both pertinent and timely. Recent literature has described the entity of central acetabular impingement, in which an osteophyte of the cotyloid fossa impinges against the superomedial femoral head and fovea. The technique for central acetabular decompression has also been described to treat this entity. The primary purpose of this study was to report the prevalence of femoral head articular damage in a matched cohort of patients with and without central acetabular osteophyte (CAO) that was identified during hip arthroscopy. A secondary purpose was to identify the rates of co-existing intraarticular pathology in both patient groups. Intraoperative data was collected prospectively on all patients undergoing hip arthroscopy at our institution between February 2008 to March 2015,. The inclusion criteria for this study were the presence of a CAO identified during hip arthroscopy for a labral tear and/or femoroacetabular impingement (FAI). Exclusion criteria were revision surgeries, Tönnis grade 1 and higher, and previous hip conditions such as Legg-Calves-Perthes disease, avascular necrosis, and prior surgical intervention. The matched cohort control group was selected based on gender, age within 5 years, body mass index (BMI), and workers' compensation claim, on a 1:3 ratio to patients who underwent hip arthroscopy for a labral tear and/or FAI and did not have a CAO. The CAO group consisted of 126 patients, which were matched to 378 patients in the control group. The grades of femoral and acetabular chondral damage were significantly different between the two groups (p<0.01). This study showed that patients with CAO had a significantly higher prevalence of femoral and acetabular chondral damage, size of articular defects on both surfaces and the prevalence of LT tears compared to matched controls.
Newer prosthetic total knee arthroplasty (TKA) designs as well as unicondylar TKAs spare the anterior cruciate ligament (ACL). Although success of these procedures requires near normal ACL function, little has been written about the arthritic ACL. This study was designed to evaluate the relationship between cross sections of the intercondylar notch and the macroscopic condition of ACL degeneration. Thirty osteoarthritic patients who underwent TKA as a result of severe osteoarthritis were randomly selected. Occupation rate of the osteophytes to the notch width were measured at the anterior 1/3, middle 1/3, and posterior 1/3 notche images obtained from preoperative tunnel view. Macroscopic conditions of the ACL and PCL were classified into four types of Normal, Frayed, Partial rupture, and Absent. The macroscopic ACL conditions were Normal: 9 cases, Frayed: 9 cases, Partial rupture: 9 cases, and Absent: 3 cases. The macroscopic PCL conditions were Normal: 24 cases, Frayed: 3 cases, Partial rupture: 3 cases, and Absent: 0 case. Occupation rate of the osteophytes to the notch correlated to the preoperative femorotibial angle (p<
0.05). In terms of ACL, the occupation rate of the osteophytes to the notch were 22.9%, 28.8%, 46.0%, and 81.8% in Normal, Frayed, partial ruptured, and Absent, respectively. The patients with more than 40% occupation rate showed either partial rupture or absent of the ACL during the surgery. We conclude that occupation rate of the osteophytes to the notch is a good predictor of evaluating the ACL degeneration in osteoarthritic knee.
The influence of Posterior Cruciate Ligament (PCL) removal and re-establishment of the posterior condylar recess on flexion and extension gaps width during posterior-stabilized Total Knee Arthroplasty (TKA) is still controversial. It has been reported that PCL resection lead to a selective increase of the flexion space of 3–4 mm, creating a potential for instability in flexion. Our hypothesis was that these surgical steps will equally increase both gaps. Measurements of the flexion and extension gaps heights were obtained during different surgical phases in 50 consecutive primary posterior-stabilised TKAs using a tensor device and a calibrated torque wrench. There was a slight symmetrical increase in both gaps after PCL release. In extension the width of the gap increased on average 1.3 mm and 1.0 mm in the medial and lateral compartment respectively. The same pattern was observed in flexion, averaging 1.3 mm medially and 1.3 mm laterally. Another increase of the two gaps was observed after the posterior condylar osteophytes were removed and the posterior recess was re-established. The gaps in extension increased, with respect to the baseline value, on average 1.8 mm medially and 1.8 mm laterally, while in flexion the increase averaged 2.0 mm and 2.2 respectively on the medial and lateral side. Again there were no statistical differences between flexion and extension gaps. No independent differences between the flexion and extension gaps were found in any considered surgical phase. PCL removal and re-establishment of posterior condylar recess does not seem to require any additional consideration in gap balancing during posterior-stabilized TKA.
Objectives.
It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion. A retrospective chart review was conducted to identify patients undergoing primary total hip arthroplasty (THA). Plain AP pelvic radiographs were reviewed to document the morphological characteristic of osteoarthritic hips. Lateral spine-pelvis-hip sitting and standing plain radiographs were used to measure sacral slope (SS) and pelvic femoral angle (PFA) in each position. Lumbar disc spaces were measured to determine the presence of DDD. The difference between sitting and standing SS and PFA were calculated to quantify spinopelvic motion (ΔSS) and hip motion (ΔPFA), respectively. Univariate analysis and Pearson correlation were used to identify morphological hip characteristics associated with changes in spinopelvic motion.Aims
Methods
The objective of our study is to evaluate the accuracy of an X-ray based image segmentation system for patient specific instrument (PSI) design or any other surgical application that requires 3D modeling of the knee. The process requires two bilateral short film X-ray images of knee and a standing long film image of the leg including the hip and ankle. The short film images are acquired with an X-ray positioner device that is embedded with fiducial markers to correct for setup variation in source and cassette position. An automated image segmentation algorithm, based on a statistical model that couples knee bone shape and radiographic appearance, calculates 3D surface models of the knee from the bi-lateral short films (Imorphics, Manchester UK) (Figure 1). Surface silhouettes are used to inspect and refine the automatically generated segmentation; the femur and tibia mechanical axes are then calculated using automatically generated surface model landmarks combined with user-defined markups of the hip and ankle center from the standing long film (Figure 2). The accuracy of the 2D/3D segmentation system was evaluated using simulated X-ray imagery generated from one-hundred osteoarthritic, lower limb CT image samples using the Insight Toolkit (Kitware, Inc.). Random, normally distributed variations in source and cassette positions were included in the dataset. Surface accuracy was measured using root-mean-square (RMS) point-to-surface (P2S) distance calculations with respect to paired benchmark CT segmentations. Landmark accuracy was calculated by measuring angular differences between the 2D/3D generated femur and tibia mechanical tibia with respect to paired CT-generated landmark data. The paired RMS sample mean and standard deviation of femur P2S errors on the distal quarter of the femur after auto-segmentation was 1.08±0.20mm. The RMS sample mean and standard deviation of tibia P2S errors on the proximal quarter of the tibia after auto-segmentation was 1.16±0.25mm. The paired sample mean and standard deviation of the femur and tibia mechanical axis accuracy with respect to benchmark CT data landmarks were 0.02±0.42[deg] and −0.33±0.56[deg], respectively. Per surface-vertex sample RMS P2S errors are illustrated in Figure 3. Visual inspection of RMS results found the automatically segmented femur to be very accurate in the shaft, distal condyles, and posterior condyles, which are important for PSI guide fit and accurate planning. Similarly, the automatically segmented tibia was very accurate in the shaft and plateaus, which are also important for PSI guide fit.
Stiffness after a TKA might be said to be present when reasonable functions of daily living cannot be performed or can only be performed with difficulty or pain. This will certainly be true if flexion is less than 75 degrees and/or there is a 15-degree lack of full extension. The purpose of this presentation is to discuss the causes of a stiff TKA, consider the aspects of surgical technique that are associated with the occurrence of stiffness, present post-surgical management that impacts on the development of stiffness and summarise the results of the surgical treatment of a stiff TKA. Pre-operative stiffness is strongly correlated with post-operative limitation of motion. Therefore, pre-surgical measures to optimise motion should be carried out. These include appropriate physical therapy, adequate pain management and a discussion with the patient of the issues likely to affect post-operative range of motion. It is particularly important to discuss with the patient appropriate expectations with regard to the likely range of motion that will be achieved following TKA surgery. There are a number of steps that can be taken during the performance of a TKA that have an impact on range of motion.
We report the technique and results of a new method of debridement arthroplasty for advanced primary osteoarthritis of the elbow. Triceps and the periosteum of the olecranon are reflected towards the ulnar side and the joint is opened by dividing the radial collateral ligament.
Tissue engineering is a rapidly expanding field of research. Bone and cartilage engineering are being undertaken in an attempt to treat osteoarthritis and repair bone defects. In spite of extensive research little successful clinical application of this work has been seen. There are however many advances in the field that one day may have therapeutic interest. One particular area of interest is the potential for using osteophyte tissue in repairing osteoarthritic defects.