[Trends in navigation-handheld systems].

Navigation-assisted surgical procedures in orthopedics and trauma surgery have become increasingly widespread over the last 20 years. In addition to applications in spinal surgery, they are primarily available for knee and hip endoprosthetics. On the one hand, computer-assisted procedures have been increasingly expanded with robotic assistance systems in recent years, and on the other hand, so-called handheld navigation systems have been developed, which enable specialized use directly in the operating field at lower acquisition costs.

Cementing technique in femoral resurfacing.

Introduction: The cementing technique is one of the various speculated factors that might contribute to the failures of resurfacing arthroplasty of the hip. The influence of bony preparation by jet lavage or lavage only in combination with different cementing techniques and cements of different viscosity in a study on fresh human femoral heads has not been evaluated so far.

Materials And Methods: Sixty fresh human femoral heads were prepared for resurfacing following manufacturers' instructions and divided into 12 groups.

Leg axis correction with ConforMIS iForma (interpositional device) in unicompartmental arthritis of the knee.

Degeneration of the meniscus and the articular cartilage in unicompartmental osteoarthritis of the knee results in progressive deformity of the leg axis. It is the aim of this study to evaluate if a leg axis correction can be achieved by implanting a customised metallic interpositional device for the knee (ConforMIS iForma). Before and after implanting a ConforMIS iForma knee implant, a radiological analysis of the leg axis deviation in the frontal plane was performed prospectively in 27 patients by evaluating anteroposterior single-leg stance radiographs.

Fluoroscopically based drilling of the femoral head in a model of adiposis.

Objective: Exact drilling into the ischemic areas of necrotic lesions of the femoral head remains a challenging procedure, particularly in obese patients. This study was conducted to evaluate the precision of fluoroscopically based drilling and the associated radiation exposure in an in-vitro model of adiposis.

Materials And Methods: In an in-vitro model of necrotic lesions in adiposis, 20 sawbones were drilled under the guidance of an intraoperative navigation system (VectorVision, BrainLAB, Munich, Germany) and 20 more were drilled conventionally under fluoroscopic control only.

The effect of femoral component rotation on patellar tracking in total knee arthroplasty.

Rotational adjustment of the femoral component in total knee arthroplasty influences patellar tracking. Sixty patients underwent TKA; the femoral component was placed parallel to the epicondylar axis in 30 patients and the femoral component was placed in 3 degrees external rotation to the posterior condylar axis in 30 patients. The epicondylar axis was identified using an image-guided navigation system.

Computer-assisted total knee arthroplasty versus the conventional technique: how precise is navigation in clinical routine?

Restoration of the mechanical leg axis and component positioning are crucial factors affecting long-term results in total knee arthroplasty (TKA). In a prospective study, 1,000 patients were operated on either using a CT-free navigation system or the conventional jig-based technique. Leg alignment and component orientation were determined on postoperative X-rays.

The effectiveness of sequential medial soft tissue release on coronal alignment in total knee arthroplasty: using a computer navigation model.

Soft tissue management is a major step in total knee arthroplasty. We aimed to analyze the relationship between sequential medial soft tissue release and the resulting change in the anteroposterior limb axis and the tibiofemoral gaps. Measurements were obtained using a CT-free navigation system (Ci navigation system, DePuy I-Orthopaedics, Munich, Germany).

Gap configuration and anteroposterior leg axis after sequential medial ligament release in rotating-platform total knee arthroplasty.

Background: Soft tissue management is a major issue in total knee replacement. There have been very few papers dealing with its effect on leg axis and tibiofemoral gap.

Methods: In a cadaver specimen study, we analyzed this effect by performing a sequential medial soft tissue release after a mobile-bearing total knee arthroplasty.

Position of the acetabular cup -- accuracy of radiographic calculation compared to CT-based measurement.

Objective: A variety of mathematical and trigonometric methods has been described for determining the position of the acetabular cups from conventional radiographs. However, these formulae are subject to unduly large inaccuracies. The aim of the study was to compare the reliability and the accuracy of radiological and CT-based determination of acetabular cup position.

Computer-assisted cannulated screw fixation for slipped capital femoral epiphysis.

In slipped capital femoral epiphysis (SCFE), cannulated screw fixation is a standard procedure. The aim of this study was to investigate the feasibility of a fluoroscopy-supported navigation system for screw fixation in SCFE. Using a fluoroscopy-enhanced navigation system, a cannulated screw fixation was performed in seven hips of four patients.

Midvastus approach in total knee arthroplasty: a randomized, double-blinded study on early rehabilitation.

The medial parapatellar approach has become the standard technique in total knee arthroplasty (TKA). However, recent studies have reported superior results regarding functional recovery when using the midvastus approach. It was the aim of this study to evaluate the early functional outcome of both surgical techniques.

Navigation in total-knee arthroplasty: CT-based implantation compared with the conventional technique.

Background Exact axial limb alignment in total-knee arthroplasty (TKA) is important for a successful outcome. We evaluated the efficiency of computer-assisted implantation in TKA and compared it with the classical surgeon-controlled technique. Patients and methods We implanted 100 TKA using either the computer-assisted technique (50) or the conventional approach (50).

Revision total knee arthroplasty: a comparison of postoperative leg alignment after computer-assisted implantation versus the conventional technique.

Accurate reconstruction of leg alignment is one important factor for long-term survival in total knee arthroplasty (TKA). Recent developments in computer-assisted surgery focused on systems improving TKA. The aim of the study is to compare the results of computer-assisted revision TKA with the conventional technique.

Efficacy of extracorporal shock-wave treatment for calcific tendinitis of the shoulder: experimental and clinical results.

The effects of various extracorporal shock wave energy levels and impulse rates were investigated using an in vitro model. In addition, we performed a controlled, randomized study to examine the clinical outcome after treatment for calcific tendinitis of the shoulder. Two groups of 40 patients each received 2000 impulses twice with an energy flux density of 0.

Navigation-assisted, minimally invasive implant removal following a triple pelvic osteotomy.

Introduction: Triple pelvic osteotomy is known as a surgical option in young patients suffering from severe hip dysplasia. In most patients, implant removal is performed after bony consolidation. Due to the pelvic anatomy, the conventional technique is often associated with soft-tissue damage and high X-ray exposure.

Implementation of a CT-based navigation system in two-stage reimplantation for infected total knee arthroplasty.

Femorotibial alignment is an important factor affecting patient outcome after total knee arthroplasty (TKA). It was the aim of this study to report our first results using a CT-based navigation system in two-stage revision surgery for infected TKA. Two patients with chronic deep infection after primary TKA underwent two-stage revision arthroplasty with temporary articulating cement spacers followed by prosthesis re-implantation using a CT-based navigation system.