Navigation-Assisted Posterior Open Reduction and Internal Fixation in a C-CLAMP Fashion for an Isolated C1 Fracture.

C1 fractures with an intact transverse ligament are usually treated conservatively. Patients who present with a progressive diastasis of bone fragments and a progressive articular subluxation mainly attributed to progressive lengthening of the transverse ligament (TAL) fibers can be treated with a C1 "C-clamp" fusion. A 75-year-old male who sustained a motor vehicle accident was neurologically intact.

One-year follow-up for type II odontoid process fractures in octogenarians: Is there a place for surgical management?

Background: Type II odontoid fractures are becoming one of the most common injuries among elderly patients and are associated with increased morbidity rates. Here, we compared the safety/efficacy of conservative versus surgical treatment for type II C2 fractures and, in particular, evaluated the complications, hospital lengths of stay, and mortality rates for patients over 80 years of age.

Methods: We retrospectively reviewed the records of 63 nonsurgically versus 18 surgically treated C2 fractures in patients over 80 years of age (2003-2018).

[Vertebroplasty: the new CHUV consensus].

Should we continue to treat patients suffering from an acute osteoporotic vertebral fracture with vertebroplasty ? What is the potential benefit ? What are its indications ? What are its risks ? Which way to perform it ? How to manage the osteoporosis evaluation and therapy ? In 2009 we published the « CHUV consensus » on the management of vertebral osteoporotic fractures by vertebroplasty. We here propose an update including recent knowledge on the management of vertebral fractures by bone insufficiency by percutaneous cementoplasty.

Spinal angiolipomas in pregnancy: Natural history and surgical treatment.

Spinal angiolipomas (SALs) are rare extradural tumors frequently located at the level of the thoracic spine and they are associated with spinal cord compromise that might result in severe myelopathy. While the first macroscopic description dates 1890, histologically these tumors where not described as angiolipomas until 1986 by Haddad et al. Occurrence in pregnancy is even more infrequent.

Augmented marker tracking for peri-acetabular osteotomy surgery.

We developed and validated a small, easy to use and cost-effective augmented marker-based hybrid navigation system for peri-acetabular osteotomy (PAO) surgery. The hybrid system consists of a tracking unit directly placed on the patient's pelvis, an augmented marker with an integrated inertial measurement unit ('MU) attached to the patient's acetabular fragment and the host computer. The tracking unit sends a live video stream of the marker to the host computer where the marker's pose is estimated.

Lavage prior to vertebral augmentation reduces the risk for cement leakage.

Purpose: This study aimed at assessing the cement leakage rate and the filling pattern in patients treated with vertebroplasty, kyphoplasty and stentoplasty with and without a newly developed lavage technique.

Study Design: Retrospective clinical case-control study.

Methods: A newly developed bipedicular lavage technique prior to cement application was applied in 64 patients (45.

Prospective Use of a Standardized Nonoperative Early Weightbearing Protocol for Achilles Tendon Rupture: 17 Years of Experience.

Background: Acute traumatic rupture of the Achilles tendon can be treated operatively or nonoperatively. Throughout the literature, there is no consensus regarding the optimal treatment protocol.

Purpose: To report on 17 years of experience with treating this injury with a standardized nonoperative treatment protocol.

Evaluation of Constant Thickness Cartilage Models vs. Patient Specific Cartilage Models for an Optimized Computer-Assisted Planning of Periacetabular Osteotomy.

Modern computerized planning tools for periacetabular osteotomy (PAO) use either morphology-based or biomechanics-based methods. The latter relies on estimation of peak contact pressures and contact areas using either patient specific or constant thickness cartilage models. We performed a finite element analysis investigating the optimal reorientation of the acetabulum in PAO surgery based on simulated joint contact pressures and contact areas using patient specific cartilage model.

Periacetabular osteotomy through the pararectus approach: technical feasibility and control of fragment mobility by a validated surgical navigation system in a cadaver experiment.

Purpose: The pararectus approach has been validated for managing acetabular fractures. We hypothesised it might be an alternative approach for performing periacetabular osteotomy (PAO).

Methods: Using four cadaver specimens, we randomly performed PAO through either the pararectus or a modified Smith-Petersen (SP) approach.

Computer assisted planning and navigation of periacetabular osteotomy with range of motion optimization.

Femoroacetabular impingement (FAI) before or after Periacetabular Osteotomy (PAO) is surprisingly frequent and surgeons need to be aware of the risk preoperatively and be able to avoid it intraoperatively. In this paper we present a novel computer assisted planning and navigation system for PAO with impingement analysis and range of motion (ROM) optimization. Our system starts with a fully automatic detection of the acetabular rim, which allows for quantifying the acetabular morphology with parameters such as acetabular version, inclination and femoral head coverage ratio for a computer assisted diagnosis and planning.

LCPD: reduced range of motion resulting from extra- and intraarticular impingement.

Background: Legg-Calvé-Perthes disease (LCPD) often results in a deformity that can be considered as a complex form of femoroacetabular impingement (FAI). Improved preoperative characterization of the FAI problem based on a noninvasive three-dimensional computer analysis may help to plan the appropriate operative treatment.

Questions/purposes: We asked whether the location of impingement zones, the presence of additional extraarticular impingement, and the resulting ROM differ between hips with LCPD and normal hips or hips with FAI.

Computer-assisted femoral head-neck osteochondroplasty using a surgical milling device an in vitro accuracy study.

Surgical navigation might increase the safety of osteochondroplasty procedures in patients with femoroacetabular impingement. Feasibility and accuracy of navigation of a surgical reaming device were assessed. Three-dimensional models of 18 identical sawbone femora and 5 cadaver hips were created.

Automated detection of the osseous acetabular rim using three-dimensional models of the pelvis.

An automated algorithm for detection of the acetabular rim was developed. Accuracy of the algorithm was validated in a sawbone study and compared against manually conducted digitization attempts, which were established as the ground truth. The latter proved to be reliable and reproducible, demonstrated by almost perfect intra- and interobserver reliability.

The Equidistant Method - a novel hip joint simulation algorithm for detection of femoroacetabular impingement.

Introduction: A novel computerized algorithm for hip joint motion simulation and collision detection, called the Equidistant Method, has been developed. This was compared to three pre-existing methods having different properties regarding definition of the hip joint center and behavior after collision detection. It was proposed that the Equidistant Method would be most accurate in detecting the location and extent of femoroacetabular impingement.

Second-generation uncemented stems: excellent 5-13-year results.

Introduction: The purpose of this study was to prospectively evaluate the 5-13-year results of a cementless total hip arthroplasty with a special focus on the survivorship,occurrence of osteolysis, incidence of intraoperative femoral fractures, thigh pain, and cortical hypertrophy of the femoral stem. The femoral component used in this study was titanium fluted, slotted, symmetrical component that was prepared with intraoperative machining. The proximal third of the stem had hydroxyl-apatite coating and horizontal steps.

Factors affecting bony impingement in hip arthroplasty.

Computer modeling of 10 patients' computed tomographic scans was used to study the variables affecting hip arthroplasty range of motion before bony impingement (ROMBI) including acetabular offset and height, femoral offset, height and anteversion, and osteophyte removal. The ROMBI was compared with the ROM before component impingement and the native hip ROM. The ROMBI decreased with decreased total offset and limb shortening.

Clinical presentation of a traumatic cervical spine disc rupture in alpine sports: a case report.

Isolated non-skeletal injuries of the cervical spine are rare and frequently missed. Different evaluation algorithms for C-spine injuries, such as the Canadian C-spine Rule have been proposed, however with strong emphasis on excluding osseous lesions. Discoligamentary injuries may be masked by unique clinical situations presenting to the emergency physician.

Pathomorphologic alterations predict presence or absence of hip osteoarthrosis.

Abnormal morphology of the hip has been associated with primary osteoarthrosis. We evaluated the morphology of 464 consecutive hips contralateral to hips treated by THA. We excluded all hips with known diagnoses leading to secondary osteoarthritis and all hips with advanced arthrosis to eliminate the effect of arthritic remodeling on the morphologic measurements.

Computed tomography-based surgical navigation for hip arthroplasty.

Component malpositioning and postoperative leg length discrepancy are the most common technical problems associated with total hip arthroplasty (THA). Surgical navigation offers the potential to reduce the incidence of these problems. We reviewed 317 patients (344 hips) that underwent THA using computed tomography-based surgical navigation, including 112 THAs using a simplified method of measuring leg length.

Passive kinematics and laxity of prosthetic knees and intact knees as measured by a novel computer-assisted system.

A system was developed for recording and analyzing passive kinematics and laxity of intact and operated knees using contemporary infrared surgical navigation hardware with custom-written data analysis software. Initial results are presented, suggesting that intra- and interobserver laxity assessment and kinematic behavior with the knee intact vs arthrotomy performed are repeatable. Normal and diseased knees have distinct kinematic and laxity behaviors, but, because of the laxity of the quadriceps in this study, additional data are needed before generalizations can be made.

Evaluation of a new leg length measurement algorithm in hip arthroplasty.

Leg length inequality after hip arthroplasty is a major source of patient dissatisfaction and dysfunction. Despite numerous reported methods to intraoperatively determine leg length change, it remains a challenge. We developed a reliable and reproducible method to measure leg length change using surgical navigation.