Scientific articles

Take a comprehensive deep dive into specific clinical topics.

Our clinical experts disseminate their knowledge to orthopedic surgeons in periodic publications. They include a blend of clinical tips and literature digest to help surgeons keeping up with the current best clinical practice and the research landscape in specific reconstruction topics. Take a comprehensive deep dive into specific clinical topics.

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Volume 10, Number 2 | July 2024

Cementless knee replacement

A closer look at the current trends in total knee arthroplasty fixation

The use of cemented versus cementless fixation in total knee arthroplasty (TKA) has been the subject of ongoing debate for over a decade. Early use of cementless TKA was met with mixed results. However, technology has advanced and new generations of cementless TKA designs are now starting to show good short- to midterm outcomes. These modern designs, supported by radiosterometric analysis studies, hold promise in extending the lifespan of TKA implants.

In this series of articles, Gerard A Sheridan from the Department of Orthopaedic Surgery, University of Galway, Galway, Ireland, Bassam Masri from the Department of Orthopaedics, University of British Columbia, Vancouver, Canada, and David F Dalury from the University of Maryland St Joseph Medical Center, Baltimore, Maryland, USA will lead us in examining TKA registry data from the last 10 years, assessing mid-term outcomes of newer cementless designs, and taking a closer look at the results of studies using radiostereometric analysis of cementless TKAs.

Part 1 | Historic registry data for cementless total knee arthroplasty (TKA)
Part 2 | Mid-term outcomes of modern cementless total knee arthroplasty and patient selection in 2024
Part 3 | Radiostereometric analysis of newer cementless total knee arthroplasty designs

Volume 10, Number 1 | April 2024

Managing acetabular bone defects in revision total hip arthroplasty

Classification, implants, and surgical techniques

Total hip arthroplasty (THA) is one of the most successful and most commonly performed procedures in orthopedic surgery. However, every THA carries the risk of failure due to causes such as aseptic loosening, dislocation, and periprosthetic infection and fracture. When that occurs, a revision THA (rTHA) will likely be necessary. A recent projection of rTHA in the US Medicare population predicted an increase by 42% by 2040 and 101% by 2060. With each round of rTHA, more acetabular bone is lost, making subsequent surgery more and more challenging.

Surgical technologies and materials have been consistently evolving, facilitating the management of complex acetabular defects and enabling promising results. However, challenges still exist and an attempt to reach a consensus regarding management is of vital importance. In this current issue, Thomas Kostakos and George A Macheras, Henry Dunant Medical Center, Athens, Hellenic Republic (Greece), and Theofilos Karachalios, University General Hospital of Larissa at the University of Thessaly, Hellenic Republic (Greece) share with us their knowledge in managing rTHA, especially in case of severe acetabular bone defects. 

Part 1 | Acetabular bone defects: classification and diagnosis

Part 2 | Managing bone defects using large acetabular cups and highly porous augments

Part 3 | Management strategies for pelvic discontinuity

Volume 9, Number 3 | November 2023

Strategies for the unstable knee after total knee arthroplasty

Etiology, classification, evaluation, and treatment

Total knee arthroplasty (TKA) is a common and successful procedure associated with good outcomes. However, sometimes a patient is not fully satisfied, with pain being a common factor for patient dissatisfaction. One major cause of pain is instability after TKA. Instability is one of the leading causes of revision TKA, yet it is complex to diagnose and treat. In recent years the classification of instability has changed with the addition of midflexion instability, and the types of implants used in both primary and revision TKA have evolved. In this series of articles, Dario E Garin, Hospital Ángeles Tijuana, Tijuana, Mexico, Beatriz Montoya-Ortiz, Clinical Care Center for Joint Replacement at Clínica El Rosario in Medellín-Colombia, and Sam Oussedik, University College Hospital London, London, United Kingdom, will guide us in examining instability after total knee arthroplasty including the etiology, classification, and evaluation of instability as well as current treatment strategies.

Part 1 | Etiology and classification of the unstable total knee arthroplasty

Part 2 | Evaluation and treatment of extension and recurvatum instability

Part 3 | Evaluation and treatment of flexion, midflexion, and global instability

Volume 9, Number 2 | July 2023

Total hip arthroplasty in dysplastic hips

Current best practices

Total hip arthroplasty is, in general, a very successful surgery for treating primary end-stage osteoarthritis—with good clinical outcomes, long implant survivorship, and high patient satisfaction. In dysplastic hips, however, due to abnormal bone morphology of the acetabulum and femur and soft-tissue alterations, total hip arthroplasty can be unpredictable and challenging with a potentially high complication rate. In this series of articles, Youn Soo Park and Seung-Jae Lim from the Department of Orthopedic Surgery, Samsung Medical Center, Seoul, South Korea, and Seung Beom Han, Department of Orthopedics, Korea University Medical Center, Seoul, South Korea, will guide us in examining total hip arthroplasty in three types of dysplastic hips: developmental hip dysplasia, infection sequelae, and skeletal dysplasia—descriptions and definitions, current best practices, implant selection, and expected outcomes.

Part 1 | Dysplastic high-riding hips

Part 2 | Childhood infection sequelae

Part 3 | Patients with skeletal dysplasia

Volume 9, Number 1 | March 2023

Advances in reverse shoulder arthroplasty

Incorporating new techniques and preventive measures in shoulder arthroplasty

Reverse shoulder arthroplasty (RSA) is a viable treatment option for a variety of end-stage degenerative conditions of the shoulder. The clinical success of this technique is partially due to the biomechanical advantages provided by positioning the humerus below a spherical glenoid prothesis. Despite the good implant survival rates associated with this procedure, RSA is not exempt from complications. The complexity of the surgical technique, the impact of the implant design on shoulder biomechanics as well as the appearance of infections are some of the underlying causes of RSA failure. Innovative surgical techniques have recently emerged, such as the lateralization approach or the integration of mixed reality in the operating room. Together with a systematic approach to prevent infection, these strategies are helping the surgeons to improve the clinical success of this treatment, which is the cornerstone of patient satisfaction.

Part 1 | Adopting lateralization techniques

Part 2 | Mixed reality

Part 3 | Preventing infection

Volume 8, Number 3 | November 2022

Alignment strategies in total knee arthroplasty

Paving the way for more personalized approaches

In recent years, arthroplasty surgeons have acknowledged the large variability of knee phenotypes in the general population. The strategies to correct alignment in the osteoarthritic population cannot continue to be modeled around a 'one-size-fits-all' approach initially developed when the technique emerged. Surgeons should consider a variety of factors and measures in order to determine the optimal alignment technique that fits the patient's native alignment, and even develop personalized treatment and implants to do so. Advances in robotic-assisted surgery and personalized patient implants and cutting guides are revolutionizing the way surgeons perform surgery and clearly allows them to target the needs of their patients.

Part 1 | Evolution of alignment concepts

Part 2 | Robotic-assisted total knee arthroplasty

Part 3 | The use of custom implants

Volume 8, Number 2 | August 2022

The posttraumatic knee

Tackling the complex total knee arthroplasty

Traumatic joint injury and periarticular fractures can trigger instability or overall malalignment resulting in overload of cartilage and successive progressive osteoarthritis, which can cause significant challenges for a surgeon to treat. Patients with posttraumatic osteoarthritis of the knee are often young and active adults and therefore have higher expectations and demands on their joint replacement. However, these surgeries are more complex in nature and are at risk for worse postoperative outcomes than total knee arthroplasty for primary osteoarthritis. Surgeons therefore need a systematic approach to plan the surgery and carefully communicate realistic expectations to the patient. In addition, they have to select the appropriate implant, guide the patient through the often more challenging rehabilitation, and ultimately, prepare for possible revision surgeries down the road. This series provides the knowledge necessary to tackle these often challenging surgeries.

Part 1 | Preoperative planning

Part 2 | Corrective osteotomy

Part 3 | Techniques and implants

Volume 8, Number 1 | April 2022

Short stems in primary total hip arthroplasty

Not all short stems are created equal

Short-stem total hip arthroplasty (THA) promises easier future revision, better bone stock preservation, reduced stress shielding, and has become increasingly popular. Especially in patients younger than 55 years of age, where the probability of a future revision is a real risk, the advantage of a bone-preserving primary THA may mean that younger patients would not have to delay their primary THA for fear of future revisions. Although excellent short- to midterm results have been reported after short-stem THA, one should bear in mind that the outcomes may be applicable only to the specific short stems being studied.

Part 1 | Biomechanical advantages

Part 2 | Midterm outcomes

Part 3 | Conventional versus short stem

Volume 7, Number 3 | November 2021

Common modifiable risk factors in total joint arthroplasty

A 2021 information update

Total joint arthroplasty (TJA) is overall an effective treatment. After TJA, most patients regain good functionality and have improved quality of life. However, adverse events such as wound complications and periprosthetic joint infections can be costly, resulting in devastating consequences, and may even lead to death. To reduce postoperative complications and improve the outcome after TJA, some modifiable patient-related risk factors have been intensely discussed lately, such as diabetes, obesity, and smoking.

Part 1 | Diabetes

Part 2 | Obesity

Part 3 | Smoking

Volume 7, Number 2 | July 2021

Metaphyseal fixation in revision total knee arthroplasty

Looking at the evidence

The numbers of patients undergoing total knee arthroplasty (TKA) is steadily on the rise. As a logical consequence, there is also a rise in the frequency of revision TKAs. One of the most important challenges to be addressed in revision TKA is bone loss. The quantity and quality of the remaining bone stock practically dictates the options for implant anchorage. With the ultimate aim to preserve as much bone as possible, metaphyseal fixation often becomes the method of choice.

Part 1 | Indications for the use of metaphyseal fixation in revision total knee replacement

Part 2 | Surgical technique of metaphyseal sleeves and cones

Part 3 | Outcomes of revision total knee arthroplasty using metaphyseal sleeves and cones

Volume 7, Number 1 | March 2021

Extensor mechanism problems after total knee arthroplasty

Why they arise and how to deal with them

In spite of the good prosthesis survival rates and clinical outcomes after TKA nowadays, significant impairment can ensue from complications related to the extensor mechanism like patellofemoral instability, patellar fractures, and extensor tendon ruptures.

As failure mechanisms are manifold, so are the corresponding treatment modalities. Identifying the individual failure mode is essential to select the appropriate treatment mode for the individual patient, which is the basis for a satisfactory outcome.


Part 1 | Patellofemoral instability after total knee arthroplasty (TKA)

Part 2 | Patellar fractures after total knee arthroplasty (TKA)

Part 3 | Extensor tendon rupture after total knee arthroplasty (TKA)

Volume 6, Number 3 | December 2020

Periprosthetic fractures after hip replacement

Achieving the best outcome—pitfalls to avoid and practices to adhere to

Surgical treatment of periprosthetic femoral fractures (PPFF) is a challenging task. Understanding individual patients’ injury histories and needs, correct diagnosis, presurgical preparation, and optimal implant selection are all part of the equation leading to good outcomes. Best patient outcomes can be achieved through a patient-centered approach and a close look at the latest findings in this very dynamic research area.


Part 1 | Risk factors in treatment of periprosthetic fractures

Part 2 | Osteosynthesis in periprosthetic fractures: Indications, tips, and tricks

Part 3 | Revision hip arthroplasty in Vancouver B2/B3 fractures—best practice in a nutshell

Volume 6, Number 2 | September 2020

Unicompartmental knee arthroplasty (UKA)

Treating single compartment knee osteoarthritis—options and observations

Unicompartmental knee arthroplasties (UKAs), also known as partial knee arthroplasties, can achieve outcomes and survivorship comparable to those of total knee arthroplasties (TKAs) and high tibial osteotomies (HTOs). Indications and counterindications, procedure volume considerations, and thresholds for revision are constantly being reassessed, based on increased data on reported patient outcomes. Proper patient selection remains critical to achieve good results.


Part 1 | Unicompartmental knee arthroplasty versus total knee arthroplasty

Part 2 | Unicompartmental knee arthroplasty versus high tibial osteotomy

Part 3 | Unicompartmental knee arthroplasties: Tips and tricks

Volume 6, Number 1 | July 2020

Computer-assisted surgery (CAS)

The evolution of CAS and what the future might hold for us

Robotic surgery, computer-assisted navigation, and personalized instrumentation and implants are no longer science fiction: Many institutions already use some of these technologies for precision and planning support. Computers can calculate basic operations 10 million times faster than the human brain. Will they eventually replace orthopedic surgeons in the operating room?

Part 1 | Evolution and basic concepts

Part 2 | Current use in hips and knees

Part 3 | Looking to the future

Volume 5, Number 2 | November 2019

Periprosthetic joint infection (PJI)

The growing risk of PJI and how to manage it

Did you know that dragonflies have a nanoscale surface pattern on their wings that prevents microorganisms from attaching to them? Researchers are studying this phenomenon, together with other innovative avenues, to advance the options available in the prevention, diagnosis, and treatment of periprosthetic joint infection (PJI). Here we consider the nuances and difficulties that surgeons encounter when dealing with deep infection in their arthroplasty patients. Expert surgeons, Olivier Borens and Andrej Trampuz, provide valuable commentary and insights about the strategies available to address PJI.

Part 1 | Preventing PJI: how to lower infection rates

Part 2 | Diagnosing PJI: where to start, what to look for

Part 3 | Treating PJI: adopting an individualized approach

Volume 5, Number 1 | April 2019

Positioning of the acetabular component

Acetabular cup positioning—a patient-specific approach

Let us take a close look at the multi-factorial considerations in accurate acetabular cup placement during total hip arthroplasty (THA). This is a challenging aspect of the procedure as it requires knowledge and visualization of anatomy and component position in three dimensions, amongst other things. Understanding each patient’s unique kinematics and structure, screening for spinal and/or other comorbidities, and careful pre-operative planning all play an important part in providing a personalized procedure and positive outcome for patients.

Part 1 | Key elements

Part 2 | Preoperative planning

Part 3 | Intraoperative considerations

Volume 4, Number 1 | March 2018

Gap balancing versus measured resection in TKA

Evidence for/against the techniques, and comparison

Which is the better technique to deliver superior patient outcomes? Will the soft tissue tensioning method of gap balancing deliver accurate femoral component rotation in TKA? Or is measured resection the superior technique to achieve this? We look at the pros and cons of both approaches, weigh the evidence, and determine whether there is a best path through this debate.

What do two practicing surgeons think about the question of gap balancing versus measured resection? We spoke to Philipp von Roth from the Charité – Universitätsmedizin Berlin (DE), and Matthew Abdel from the Mayo Clinic in Rochester, Minnesota (US). They share their perspectives and make some educated guesses about the future.

Part 1 | Brief comparison of the techniques

Part 2 | Evidence for/against gap balancing

Part 3 | Evidence for/against measured resection

Volume 3, Number 1 | December 2017

Limb-length discrepancy in THA

Prevention, management, and dysplasia patients

A recognized and common complication of total hip arthroplasty (THA) is limb-length discrepancy (LLD). (Incidentally, this problem is the number one reason for litigation against orthopedic surgeons in the US). But there are actions surgeons can undertake to minimize leg-length issues, with prevention being at the top of the list.

Through patient evaluation/education, preoperative templating, and intraoperative assessments, strategies can be employed to lessen the risk of LLD. This three-part article series looks at the prevention and management of LLD after THA and gives special consideration to the challenges associated with the dysplastic hip.

Part 1 | Prevention of limb-length discrepancy during THA

Part 2 | Management of limb-length discrepancy after THA

Part 3 | Patients with hip dysplasia

Volume 2, Number 1 | December 2016

Taper corrosion

Risks, tools for diagnosis and surgical strategies

The last thirty years have seen many advances in the field of orthopedic medicine. The introduction of a modular taper joint for use in hip arthroplasty was embraced by surgeons for its intraoperative flexibility. However, it's been discovered that the modular taper is prone to corrosion and linked to problems such as pain, instability, pseudotumors, poor outcomes, increased revision rates, and higher rates of mortality.

Compounding the problem is the fact that researchers have not yet been able to reproduce the problem experimentally, which makes it a challenge to systematically understand the roles of contributing factors. This three-part article series on taper corrosion provides some background, looks at criteria to guide a diagnosis, as well as some points to consider when surgical intervention is under discussion.

Part 1 | Risk factors for taper corrosion in total hip arthroplasty

Part 2 | How to diagnose taper corrosion

Part 3 | Surgical options for addressing taper corrosion

Volume 1, Number 1 | December 2015

The Asian knee

Special surgical considerations

Increasing evidence of race-related anatomical differences is adding a level of complexity when performing total knee replacement (TKR) on Asian patients. Many of the current prosthetic options are developed using Caucasian anatomical data, which could be leading to a less-than-ideal fit and poor device performance.

In this three part article series we examine cultural demands and expectations for TKR, and some of the documented anatomical differences and surgical considerations that are unique to the Asian-Pacific region.

Part 1 | The Asian knee through a cultural lens

Part 2 | Anatomical variations in Asian knees: one size does not fit all

Part 3 | TKR in the Asian knee: a demanding procedure