Robert Jan Peter van der Wal

Leiden University Medical Centre | LUMC · Department of Orthopedic Surgery

Background Multidisciplinary team (MDT) management of prosthetic joint infections (PJI) and other bone and joint infections (BJI) is increasingly put into practice. However, studies evaluating the performance of MDTs in this field are scarce. We aimed to assess our MDT for complex BJI by determining the implementation rate of team decisions, analyz...

Purpose Determine incidence, location and features of insufficiency fractures (IF) in sacral chordoma patients treated with high-dose radiotherapy (HDR) with(out) resection, relative to radiation therapy type and irradiation plans. Materials and methods Clinical data, including details of all surgical procedures and radiotherapies of patients hist...

Background and purpose: Despite evolving management strategies for atypical cartilaginous tumors (ACT)-shifting from radical resection to intralesional curettage and "wait-and-scan" approaches-there remains no universal consensus on optimal treatment. We primarily aimed to evaluate disease-specific and progression-free survival following intralesi...

Fluoroquinolones (FQs) are considered the most effective antimicrobial treatment for Gram-negative prosthetic joint infection (GN-PJI). Alternatives are needed due to increasing FQ resistance and side effects. We aimed to compare different targeted antimicrobial strategies for GN-PJI managed by debridement, antibiotics, and implant retention (DAIR)...

Aim: Aim of this explorative pilot study was to evaluate the capability of an electronic nose (aeoNose, the eNose Company) to classify healthy individuals and patients with chondrosarcoma, based on their volatile organic compound profiles in exhaled breath. Materials & methods: Fifty-seven patients (25 healthy controls, 24 chondrosarcoma and 8 diff...

Introduction: Limited data inform about the optimal dosing and duration of suppressive antimicrobial therapy (SAT) for orthopedic implant infection (OII). We aimed to compare the effectiveness of low-dosage with standard-dosage SAT and evaluate the safety of stopping SAT. Methods: All patients with OII treated with SAT from 2011 to 2022 were retros...

Background Chordomas are rare cancers from the axial skeleton which present a challenging clinical management with limited treatment options due to their anatomical location. In recent years, a few clinical trials demonstrated that chordomas can respond to immunotherapy. However, an in-depth portrayal of chordoma immunity and its association with c...

Aim Multidisciplinary team (MDT) management of complex bone and joint infections (BJI) is increasingly implemented but studies evaluating this approach are scarce. We assessed the effectiveness of our MDT by analyzing the adherence to its treatment decisions. Method A cohort study was conducted comprising patients with complex BJI of which the man...

Chordomas are cancers from the axial skeleton presenting immunological hallmarks of unknown significance. In recent years, some clinical trials demonstrated that chordomas can respond to immunotherapy. We present a comprehensive characterisation of immunological features of 76 chordomas through application of a multimodal approach comprising transc...

Aim: The aim of this pilot study was to assess whether an electronic nose can detect patients with soft tissue sarcoma (STS) based on volatile organic compound profiles in exhaled breath. Patients & methods: In this cross-sectional pilot study, patients with primary STS and healthy controls, matched on sex and age, were included for breath analysis...

Background: Differentiation between uncomplicated and complicated postoperative wound drainage after arthroplasty is crucial to prevent unnecessary reoperation. Prospective data about the duration and amount of postoperative wound drainage in patients with and without prosthetic joint infection (PJI) are currently absent. Methods: A multicentre coh...

Background Local tissue and serum metal ions have been shown to be elevated in some metal-on-metal and metal-on-polyethylene joint replacements. Local elevations have been linked to adverse local tissue reactions in some patients, and systemic elevation has been less commonly implicated cardiac and neurologic issues. Using a prospective study desig...

Background Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of s...

Background Langerhans cell histiocytosis (LCH) is a rare haematological neoplasm characterized by the accumulation of CD1a⁺, CD207/Langerin⁺ histiocytes within inflammatory lesions. LCH can involve any organ, but osteolytic bone lesions are most often encountered. Unifocal bone lesions may regress spontaneously after a thick needle biopsy has been...

Objective To explore the co-expression network of the osteoarthritis (OA) risk gene WWP2 in articular cartilage and study cartilage characteristics when mimicking the effect of OA risk allele rs1052429-A on WWP2 expression in a human 3D in vitro model of cartilage. Methods Co-expression behavior of WWP2 with genes expressed in lesioned OA articula...

Objective Due to the complexity and heterogeneity of osteoarthritis (OA) pathophysiology, studying the interaction between intrinsic molecular changes in chondrocytes after hyper-physiological mechanical stress (MS) and aberrant signalling of OA risk genes remains a challenge. In this study we set out to set up an in vitro 3D neo cartilage pellet m...

Background Failing of intrinsic chondrocyte repair after mechanical stress is known as one of the most important initiators of osteoarthritis. Nonetheless, insight into these early mechano-pathophysiological processes in age-related human articular cartilage is still lacking. Such insights are needed to advance clinical development. To highlight im...

Prosthetic joint infection (PJI) is a severe complication of arthroplasty. Due to biofilm and persister formation current treatment strategies often fail. Therefore, innovative anti-biofilm and anti-persister agents are urgently needed. Antimicrobial peptides with their broad antibacterial activities may be such candidates. An in vitro model simula...

Purpose: Evaluation of survival of meniscal allograft transplantation (MAT) and postoperative patient-reported outcome (PRO), and their association with prior interventions of the knee. Methods: A prospective consecutive study of 109 consecutive patients who had an arthroscopic meniscal allograft transplantation (MAT) between 1999 and 2017 by a...

A 44-year-old man presented with symptoms of intermittent ischemia of the right foot. Computed tomography scanning of the right foot revealed a talar beak that had a close anatomic relation with the dorsalis pedis artery. Duplex ultrasound performed during a symptomatic episode confirmed ischemia induced by severe vasospasm of the dorsalis pedis ar...

Radiomics can differentiate an enchondroma (a “don't touch” lesion) from an atypical cartilaginous tumor (which justifies watchful waiting) and a high‐grade chondrosarcoma (which necessitates resection with negative margins), and it will aid in individualized medicine for cartilaginous lesions of the appendicular skeleton.

Prosthetic joint infection A prosthetic joint infection (PJI) is a serious complication that can lead to lengthy hospitalization, significant limitations in mobility, and a reduced quality of life. For acute PJI, the aim is to cure the infection whilst retaining the prosthesis; this can be achieved by means of thorough surgical debridement, cleanin...

Two-stage revision anterior cruciate ligament (ACL) reconstruction is an effective way to revise suboptimal tunnel-placement allowing for proper graft fixation. However, prolonged increased laxity of the knee may increase the risk of meniscal or chondral injury. It was hypothesized that no additional meniscal or chondral lesions occur in between th...

Pathologic fractures of the distal femur caused by bone metastases are not as common as those in the proximal femur but provide great difficulty to adequately treat. This systematic review shows that insufficient literature exists to draw clinically relevant conclusions for essential questions, such as “what factors indicate an endoprosthetic recon...

Background: The potential chondroprotective effect of meniscal allograft transplantation (MAT) is unclear. Subchondral bone mineral density (BMD) and subchondral bone remodeling play important roles in osteoarthritis development. Evaluation of subchondral BMD after MAT might give more insight into the potential chondroprotective effect. The purpos...

Purpose The aim of this study was to translate and culturally adapt the Toronto Extremity Salvage Score (TESS) to Dutch and to validate the translated version. Methods The TESS lower and upper extremity versions (LE and UE) were translated to Dutch according to international guidelines. The translated version was validated in 98 patients with surg...

The Dutch translation of the TESS for lower and upper extremities.

The objective of the study was the determination of the intra- and interobserver agreement of three magnetic resonance imaging (MRI) criteria for reparability: a peripheral rim smaller than 4 mm, a tear longer than 10 mm, and homogenous aspect of meniscal tissue. In two rounds with an interval of at least 6 weeks, three orthopedic surgeons and thre...

The aim of this study was to translate the Western Ontario Meniscal Evaluation Tool (WOMET) into Dutch, to evaluate the content validity, construct validity, reliability, and responsiveness, and to determine the minimal important change (MIC) of the Dutch version. The WOMET was translated into Dutch according to a standardized forward-backward tran...

Arthroscopic meniscal repair is the gold standard for longitudinal peripheral meniscal tears. The time interval between trauma and meniscal repair remains controversial. The aim of this study was to evaluate failure rates and clinical outcome of arthroscopic meniscal repair in relation to chronicity of injury. A total of 238 meniscal repairs were p...

: Infusion of fat into the small intestine induces satiety. Reducing fat droplet size accelerates fat digestion, but the effect on satiety after ileal fat infusion is not known. The aim of the study was to compare the effects of fat emulsions differing in droplet size (fine, coarse) infused in either duodenum or ileum on satiety, gastric emptying a...

Meniscal allograft transplantation is an accepted treatment for the symptomatic postmeniscectomized knee in younger patients; however, long-term data are scarce on clinical outcome. Cryopreserved meniscal allograft transplantations can, in the long term, be a good alternative for the symptomatic postmeniscectomized knee in younger patients. Case se...

Intestinal intubation studies have demonstrated that lipids induce satiety, but the contribution of lipid processing by the stomach on satiety remains poorly understood. In this explorative, randomized, placebo-controlled, crossover study we tested whether delayed lipid absorption, increased cholecystokinin (CCK), decelerated gastric emptying (GE),...