Using a patella reduced technique while balancing a TKA results in restored physiological strain in the collateral ligaments: an ex vivo kinematic analysis.

Introduction: Poor soft tissue balance in total knee arthroplasty (TKA) often results in patient dissatisfaction and reduced joint longevity. Patella-in-place balancing (PIPB) is a novel technique which aims to restore native collateral ligament behavior without collateral ligament release, while restoring post-operative patellar position. This study aimed to assess the effectiveness of this novel technique through a detailed ex vivo biomechanical analysis by comparing post-TKA tibiofemoral kinematics and collateral ligament behavior to the native condition.

A cell-based combination product for the repair of large bone defects.

Regenerative cell-based implants using periosteum-derived stem cells were developed for the treatment of large 3 cm fresh and 4.5 centimeter biological compromised bone gaps in a tibial sheep model and compared with an acellular ceramic-collagen void filler. It was hypothesized that the latter is insufficient to heal large skeletal defects due to reduced endogenous biological potency.

Vibration-based fixation assessment of tibial knee implants: A combined in vitro and in silico feasibility study.

The preoperative diagnosis of loosening of cemented tibial knee implants is challenging. This feasibility study explored the basic potential of a vibration-based method as an alternative diagnostic technique to assess the fixation state of a cemented tibia implant and establish the method's sensitivity limits. A combined in vitro and in silico approach was pursued.

Warning About the Use of Critical-Size Defects for the Translational Study of Bone Repair: Analysis of a Sheep Tibial Model.

The repair of large long bone defects requires complex surgical procedures as the bone loss cannot simply be replaced by autologous grafts due to an insufficient bone stock of the human body. Tissue engineering strategies and the use of Advanced Therapy Medicinal Products (ATMPs) for these reconstructions remain a considerable challenge, in particular since robust outcomes in well-defined large animal models are lacking. To be suitable as a model for treatment of human sized bone defects, we developed a large animal model in both skeletally immature and mature sheep and made close observations on the spontaneous healing of defects.

Evaluation of predicted knee function for component malrotation in total knee arthroplasty.

Soft-tissue balancing for total knee arthroplasty (TKA) remains subjective and highly dependent on surgical expertise. Pre-operative planning may support the clinician in taking decisions by integrating subject-specific computer models that predict functional outcome. However, validation of these models is essential before they can be applied in clinical practice.

Inflammatory Neuropathy of the Lumbosacral Plexus following Periacetabular Osteotomy.

Introduction. During periacetabular osteotomy (PAO), the sciatic, femoral, and obturator nerves are at risk. Most frequently nerve lesions can be attributed to a mechanical cause; however, in the absence of a clear mechanical cause surgeons are faced with a diagnostic problem and in many cases no diagnosis will be established.

Restoration of constitutional alignment in TKA leads to more physiological strains in the collateral ligaments.

Purpose: Currently, controversy exists whether restoration of neutral mechanical alignment should be attempted in all patients undergoing TKA. Our hypothesis was that restoration of constitutional rather than neutral mechanical alignment may in theory lead to a more physiological strain pattern in the collateral ligaments; therefore, it could potentially be beneficial to patients. Thus, the aim of this study was to measure collateral ligament strains during three motor tasks in the native knee and compare them with the strains noted after TKA in different post-operative alignment conditions.

Patient-specific instruments: industry's innovation with a surgeon's interest.

Purpose: The aim of this study was (1) to survey the orthopaedic companies about the volume of patient-specific instruments (PSI) used in Europe and worldwide; (2) to survey a group of knee arthroplasty surgeons on their acceptance of PSI and finally; (3) to survey a medico-legal expert on PSI-related issues.

Methods: Seven orthopaedic implant manufacturers were contacted to obtain their sales figures (in volume) of PSI in Europe and worldwide for the 2011 and 2012 period. During the Open Meeting of the Belgian Knee Society, a survey by a direct voting system was submitted to a selection of knee surgeons.

New possible pathways in improving outcome and patient satisfaction after TKA.

Patient dissatisfaction after TKA has not been improved dramatically since the introduction of new alignment (navigation, custom guides) and balancing techniques. Orthopaedic surgeons consider the ligaments as essentially passive stabilizing structures. However, during the activities of daily living, the joints are stabilized primarily by our muscle actions that both move and stabilize the joints.

Collateral ligament strains during knee joint laxity evaluation before and after TKA.

Background: Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty.

The Pentaconcept in skeletal tissue engineering. A combined approach for the repair of bone defects.

Tissue engineering has become a hot topic in modern medicine. Its application in a surgical setting, such as for the treatment of skeletal defects, still has to tackle some problems that might look simple at first sight, but need a well-structured handling combining surgery and science, with in a central position the patient, who is both cell donor and receptor of the tissue engineered end product. To achieve this goal in a clinical setting, a five steps pathway is described and designated as the Pentaconcept, integrating all ingredients for successful reconstructive procedures.

Resurfacing hip arthroplasty. A 3 to 5-year matched pair study of two different implant designs.

We compared the 3 to 5 year clinical and radiological results of two different hybrid metal-on-metal resurfacing hip arthroplasty designs in 28 patients who had undergone bilateral hip resurfacing with ReCap implants on one side and BHR implants on the other side. Both hips were compared in each patient, to specifically evaluate the bone response to the cemented femoral component. Post operative function was measured with the Harris Hip Score and University of California at Los Angeles (UCLA) Activity Score, and was excellent in these patients.

Quantitative Computerized Assessment of the Degree of Acetabular Bone Deficiency: Total radial Acetabular Bone Loss (TrABL).

A novel quantitative, computerized, and, therefore, highly objective method is presented to assess the degree of total radical acetabular bone loss. The method, which is abbreviated to "TrABL", makes use of advanced 3D CT-based image processing and effective 3D anatomical reconstruction methodology. The output data consist of a ratio and a graph, which can both be used for direct comparison between specimens.

Debonding of the acetabular porous coating in hip resurfacing arthroplasty. A case report.

This report presents the case of a patient in whom hip resurfacing arthroplasty failed because of loosening of the acetabular shell secondary to debonding of the surface coating. During normal function, there will inevitably be cyclic shear stress between the coating and the surrounding bone. This might result in fatigue failure of the bond.

Arthroscopic psoas release for iliopsoas impingement after total hip replacement.

Psoas impingement is a rare cause of persisting pain after hip arthroplasty. Diagnosis is based on clinical examination and exclusion of other complications after arthroplasty by radiographs, ultrasound, CT and blood analysis. The diagnosis is strongly supported by temporary pain relief after infiltration.

Reconstruction of the medial patellofemoral ligament for patellar instability using an autologous gracilis tendon graft.

Patellofemoral dislocations are common. In cases with recurrence or residual instability, surgical intervention is usually considered. Numerous treatment protocols have been used in the past to treat patellofemoral instability secondary to patella dislocation.

Comparative gravimetric wear analysis in mobile versus fixed-bearing posterior stabilized total knee prostheses.

Polyethylene (PE) wear is the limiting factor for the longevity of a conventional total knee arthroplasty (TKA). Excessive wear leads to loosening and eventual implant failure. The aim of our in vitro study was to investigate wear of a PE tibial insert on a rotating platform as compared to the same insert fixed to the tibial baseplate and articulating with a similar femoral component.

Influence of the cementing technique on the cement mantle in hip resurfacing: an in vitro computed tomography scan-based analysis.

Background: The cement mantle within a hip resurfacing head is important for implant survival. Too much cement leads to thermal bone necrosis, whereas not enough cement might cause mechanical failure and particle-induced osteolysis. We evaluated the impact of different cementing techniques on the quality of the cement mantle in hip resurfacing.

Variations in serum electrolyte concentrations and renal function after therapeutic hip arthroscopy: a pilot study.

Purpose: The purpose of this study was to analyze changes in serum electrolyte concentration and renal function after hip arthroscopy.

Methods: We studied 10 consecutive patients (4 men and 6 women; median age, 30.5 years [range, 20 to 50 years]) undergoing hip arthroscopy.