Introduction: Transient posterolateral subluxation of the lateral femoral condyle has been postulated as a non-contact mechanism of ACL rupture. The consistent location of MRI bone bruises on the anterior half of the lateral femoral condyle and the posterior rim of the
The aim was to report operative complications, radiographic and patient-reported outcomes following
Knee laxity following anterior cruciate ligament (ACL) injury is a complex phenomenon influenced by various biomechanical and anatomical factors. The contribution of soft tissue injuries – such as ligaments, menisci, and capsule – has been previously defined, but less is known about the effects of bony morphology. (Tanaka et al, KSSTA 2012) The pivot shift test is frequently employed in the clinical setting to assess the combined rotational and translational laxity of the ACL deficient knee. In order to standardise the maneuver and allow for reproducible interpretation, the quantitative pivot shift test was developed. (Hoshino et al, KSSTA 2013) The aim of this study is to employ the quantitative pivot shift test to determine the effects of bone morphology as determined by magnetic resonance imaging (MRI) on rotatory laxity of the ACL deficient knee. Fifty-three ACL injured patients scheduled for surgical reconstruction (36 males and 17 females; 26±10 years) were prospectively enrolled in the study. Preoperative magnetic resonance imaging (MRI) scans were reviewed by two blinded observers and the following parameters were measured: medial and lateral tibial slope, tibial plateau width, femoral condyle width, bicondylar width, and notch width. (Musahl et al. KSSTA 2012). Preoperatively and under anaesthesia, a quantitative pivot shift test was performed on each patient by a single experienced examiner. An image analysis technique was used to quantify the lateral compartment translation during the maneuver. Subjects were classified as “high laxity” or “low laxity” based upon the median value of lateral compartment translation. (Hoshino et al. KSSTA 2012) Independent t-tests and univariate logistic regression were used to investigate the relationship between the pivot shift grade and various features of bone morphology. Statistical significance was set at p<0.05. A high inter-rater reliability was observed in all MRI measurements of bone morphology (ICC=0.72–0.88). The median lateral compartment translation during quantitative pivot shift testing was 2.8mm. Twenty-nine subjects were classified as “low laxity” (2.8mm). The
Purpose of the study: We compared in vitro the efficacy of screw-plate fixation versus double screw fixation on a model of type 2 Schatzker fracture of the
This study reports the 5-year clinical and radiological outcomes of a simple arthroscopic-assisted technique for Schatzker type II and III tibial plateau fractures, without bone grafting. Forty six patients (46% males, 54% females, average age 48 years, SD 13.6 years), with tibial plateau fractures Schatzker type II (41%) and III (59%), underwent an arthroscopic-assisted technique conceived to use a compacted cancellous bone graft, taken from the medial metaphyseal side of the tibia, and a percutaneous fixation. The patients were prospectively followed-up at one, three and five years from surgery. Independent assessments were carried out using Knee Society Score, HSS score and Rasmussen’s clinical and radiological scores. At 5-year follow-up patients underwent a weight-bearing radiograph of both limbs. At last follow-up evaluation Knee Score (average 93.2, SD 7.7) was excellent in 37 patients (80%), good in six (13%), fair in three (7%). Function Score (average 94.8, SD 8.51) was excellent in 38 patients (83%), good in five (11%), fair in three (6%). HSS score (average 93.4, SD 8.23) was excellent in 41 patients (89%), good in five (11%). The average Rasmussen clinical score was 28.2 (SD 1.4). The radiological Rasmussen score was excellent in five patients (11%), good in 39 (85%) and fair in two (4%). In the weight-bearing radiographs a valgus deviation was present in four patients (8.7%). Arthroscopic-assisted technique for
We compared internal fixation augmented with a trabecular metal implant to internal fixation augmented with morcellized bone grafting for depressed
Aims. Osteoarthritis (OA) is a common degenerative joint disease. The osteocyte transcriptome is highly relevant to osteocyte biology. This study aimed to explore the osteocyte transcriptome in subchondral bone affected by OA. Methods. Gene expression profiles of OA subchondral bone were used to identify disease-relevant genes and signalling pathways. RNA-sequencing data of a bone loading model were used to identify the loading-responsive gene set. Weighted gene co-expression network analysis (WGCNA) was employed to develop the osteocyte mechanics-responsive gene signature. Results. A group of 77 persistent genes that are highly relevant to extracellular matrix (ECM) biology and bone remodelling signalling were identified in OA subchondral lesions. A loading responsive gene set, including 446 principal genes, was highly enriched in OA medial tibial plateaus compared to
Aims. Commonly performed unicompartmental knee arthroplasty (UKA) is not designed for the lateral compartment. Additionally, the anatomical medial and
Introduction: To our knowledge there are no published data comparing the actual anteroposterior (AP) and mediolateral (ML) dimensions of the medial and
Several studies have highlighted the relationship between anterior cruciate (ACL) injury and knee geometry particularly tibial slope (TS). However, clinical data are inconsistent, whether the lateral or medial or slopes have a different influence on ACL injury. Our goal was to assess whether the medial, lateral slopes are associated with ACL injury and whether meniscus geometry is associated with ACL injury. In addition, we sought to determine if lateral meniscal height could serve as a simple surrogate measurement for ACL injury risk. A case-controlled study compared 68 patients with an ACL injury and 68 matched nested controls. Radiological analysis of MRI measured the anterior-posterior distance of the medial and
Introduction and Aims: A number of x-ray appearances have been identified as indicative of discoid menisci. None are reliable or statistically significant. The purpose of this paper is to identify a reliable radiographic sign, diagnostic of the discoid lateral meniscus. Method: The anteroposterior view radiographs of 14 knees in 13 patients with arthroscopically proven discoid meniscus were studied. Ages ranged from 11 to 26, with a mean age of 18.4 ± 4.84 years, right to left ratio 9/5, male to female ratio 8/5. Fifteen normal knees in 14 people were used as a control group, age from 11 to 30, mean age 16.20 ± 6.41, right to left ratio 8/7, male to female ratio 6/8. The parameters measured were: Lateral Joint Space (LJS); Height of the Lateral Tibial Spine (LTS); change of the Medial Tibial Spine (MTS); Height of Fibular Head (HFH); changes of the Edge of the
Computer Assisted Total Knee Arthroplasty (CAS TKR) has been shown to provide excellent and reproducible limb mechanical alignment. CAS TKR has also been demonstrated to reduce limb alignment variance and outliers. Previous studies have shown improved mechanical alignment both radiographically and clinically. Specifically, CAS TKR has been shown to result in alignment deviations less than 3 degrees from neutral mechanical femoral and tibial axes. Furthermore, CAS TKR also permits any significant pre-operative tibial deformity to be quantified prior to performing tibial osteotomies. In this study, we describe the use of computer navigation to quantify the amount of bone loss on the medial or
Biplane video X-ray (BVX) – with models segmented from magnetic resonance imaging (MRI) – is used to directly track bones during dynamic activities. Investigating tibiofemoral kinematics helps to understand effects of disease, injury, and possible interventions. Develop a protocol and compare in-vivo kinematics during loaded dynamic activities using BVX and MRI. BVX (60 FPS) was captured whilst three healthy volunteers performed three repeats of lunge, stair ascent and gait. MRI scans were performed (Magnetom 3T Prisma, Siemens). 3D bone models of the tibia and femur were segmented (Simpleware Scan IP, Synopsis). Bone poses were obtained by manually matching bone models to X-rays (DSX Suite, C-Motion Inc.). Mean range of motion (ROM) of the contact points on the medial and
Aims. Mobile-bearing unicompartmental knee arthroplasty (UKA) with a flat tibial plateau has not performed well in the lateral compartment, leading to a high rate of dislocation. For this reason, the Domed Lateral UKA with a biconcave bearing was developed. However, medial and
Abstract. INTRODUCTION. A paucity of literature exists regarding efficacy of lateral unloader bracing in treatment for pathologies effecting the lateral compartment of the knee. We evaluate patient outcomes following customised lateral unloader bracing (cLUB) in treatment of lateral compartment osteoarthritis (LCOA),
Tibial plateau fracture reduction involves restoration of alignment and articular congruity. Restorations of sagittal alignment (tibial slope) of medial and lateral condyles of the tibial plateau are independent of each other in the fracture setting. Limited independent assessment of medial and
Introduction. Posterolateral tibial plateau fractures account for 7 % of all proximal tibial fractures. Their fixation often requires posterolateral buttress plating. Approaches for the posterolateral corner are not extensile beyond the perforation of the anterior tibial artery through the interosseous membrane. This study aims to provide accurate data about the inferior limit of dissection by providing measurements of the anterior tibial artery from the lateral joint line as it pierces the interosseous membrane. Materials and Methods. Forty unpaired adult lower limbs cadavers were used. The posterolateral approach to the proximal tibia was performed as described by Frosch et al. Perpendicular measurements were made from the posterior limit of the articular surface of the
Introduction. Failure of total knee replacements due to the generation of polyethylene wear debris remains a crucial issue in orthopedics. Unlike the hip, it is difficult to accurately determine knee implant wear rates from retrieved components. Several studies have relied on thickness measurements to estimate penetration, but the complicated geometry of contemporary tibial liners poses a challenge to accurately assess wear. In this study we address the question whether linear penetration can serve as a surrogate measure for volumetric material loss. Methods. Eighty-one retrieved UHMWPE NexGen cruciate-retaining tibial liners (Zimmer, Warsaw, IN) with an average time in situ of 5.27±2.89 years were included in the study. Metrology data for the surfaces of the tibial liners were obtained with a coordinate measuring machine (OGP, Rochester, NY). Using a laser scanner with two micrometer depth accuracy, at least 400,000 measurement points were taken by investigator #1. Areal thickness changes were mapped for the lateral and medial sides with the help of an autonomous mathematical reconstruction algorithm and volume loss was calculated based on wear scar area and local thickness change. Investigator #2, blinded from these results, measured the minimum thickness of the medial and
Open reduction and internal fixation of tibial plateau fractures is traditionally performed through an anterior, anterolateral or an anteromedial approach and more recently a posteromedial approach. These approaches allow satisfactory access to the majority of fracture patterns with the exception of posterolateral tibial plateau fractures. To improve access to posterolateral tibial plateau fractures, we developed a posterolateral transfibular neck approach that exposes the tibial plateau between the posterior margin of the iliotibial band and the PCL. The approach can be combined with a posteromedial and/or an anteromedial approach to the tibial plateau. Since April 2007, we have used this approach to treat nine posterolateral tibial plateau fractures. All cases were followed up prospectively. Fracture reduction was assessed on radiographs, CT scans and arthroscopicaly. Maintenance of fracture reduction was assessed with radiostereometric analysis. Clinical outcomes were measured using Lysholm and KOOS scores. Anatomic or near anatomic reduction was achieved in all cases. All fractures healed uneventfully and no loss of osteotomy or tibial plateau fracture reduction was identified on postoperative plain X-rays. In the cases monitored with radiostereometric analysis, the fracture fragments displaced less than 2 mm during the course of healing. All osteotomies healed either at the same rate or quicker than the tibial plateau fractures. There were no signs and no symptoms of lateral or posterolateral instability of the knee during or after the healing of the osteotomy. There were no complications related to the surgical approach, including the fibular head osteotomy. All wounds healed uneventfully and there were no symptoms related to the CPN. The patient reported outcomes recorded for this group at six months, using the Lysholm score (mean 71, median 77, range 42–95), compared favourably to the entire cohort of 33 patients treated operatively at our institution for a tibial plateau fracture and followed up prospectively during the same time period (mean 64, median 74, range 20–100). The posterolateral transfibular approach for
