Publications by authors named "Arjan Loenen"

Study Design: Systematic review.

Objective: Examine the clinical evidence for the use of osteobiologics in hybrid surgery (combined anterior cervical discectomy and fusion (ACDF) and total disc replacement (TDR)) in patients with multilevel cervical degenerative disc disease (DDD).

Methods: PubMed and Embase were searched between January 2000 and August 2020.

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Introduction: Malalignment of the Total Ankle Replacement (TAR) has often been postulated as the main reason for the high incidence of TAR failure. As the ankle joint has a small contact area, stresses are typically high, and malalignment may lead to non-homogeneous stress distributions, including stress peaks that may initiate failure. This study aims to elucidate the effect of TAR malalignment on the contact stresses on the bone-implant interface, thereby gaining more understanding of the potential role of malalignment in TAR failure.

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Article Synopsis
  • 3D printed trussed titanium interbody cages can stimulate bone growth by creating specific strains on their surface, but the variation in these strains due to individual patient factors is not yet understood.
  • The study investigated how patient-specific factors affect strain patterns by using finite element models of the lumbar spine for four spinal fusion surgery patients with the same cage size.
  • Results showed that around 30% of the cage surface experienced relevant strains for bone health, and while strain values varied with different loading conditions, differences between patients were less significant. This research could lead to better interbody cage designs tailored to individual patient needs.
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Introduction: Although computed tomography (CT) can identify the presence of eventual bony bridges following lumbar interbody fusion (LIF) surgery, it does not provide information on the ongoing formation process of new bony structures. F sodium fluoride (F-NaF) positron emission tomography (PET) could be used as complementary modality to add information on the bone metabolism at the fusion site. However, it remains unknown how bone metabolism in the operated segment changes early after surgery in uncompromised situations.

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Background Context: Lumbar interbody fusion is an effective treatment for unstable spinal segments. However, the time needed to establish a solid bony interbody fusion between the two vertebrae may be longer than twelve months after surgery. During this time window, the instrumented spinal segment is assumed to be at increased risk for instability related complications such as cage migration or subsidence.

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Study Design: Preclinical ovine model.

Objective: To assess the efficacy and safety of the P-15 L bone graft substitute and compare its performance to autologous iliac crest bone graft (ICBG) for lumbar interbody fusion indications.

Methods: Thirty skeletally mature sheep underwent lumbar interbody fusion surgery.

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Background Context: Manual contouring of spinal rods is often required intraoperatively for proper alignment of the rods within the pedicle screw heads. Residual misalignments are frequently reduced by using dedicated reduction devices. The forces exerted by these devices, however, are uncontrolled and may lead to excessive reaction forces.

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Pressure ulcers are a type of local soft tissue injury due to sustained mechanical loading and remain a common issue in patient care. People with spinal cord injury (SCI) are especially at risk of pressure ulcers due to impaired mobility and sensory perception. The development of load improving support structures relies on realistic tissue load evaluation e.

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