In an interdisciplinary project involving electronic engineers and clinicians, a telemetric system was developed to measure the bending load in a titanium internal femoral fixator. As this was a new device, the main question posed was: what clinically relevant information could be drawn from its application? As a first clinical investigation, 27 patients (24 men, three women) with a mean age of 38.4 years (19 to 66) with femoral nonunions were treated using the system. The mean duration of the nonunion was 15.4 months (5 to 69). The elasticity of the plate-callus system was measured telemetrically until union. Conventional radiographs and a CT scan at 12 weeks were performed routinely, and healing was staged according to the CT scans. All nonunions healed at a mean of 21.5 weeks (13 to 37). Well before any radiological signs of healing could be detected, a substantial decrease in elasticity was recorded. The relative elasticity decreased to 50% at a mean of 7.8 weeks (3.5 to 13) and to 10% at a mean of 19.3 weeks (4.5 to 37). At 12 weeks the mean relative elasticity was 28.1% (0% to 56%). The relative elasticity was significantly different between the different healing stages as determined by the CT scans. Incorporating load measuring electronics into implants is a promising option for the assessment of bone healing. Future application might lead to a reduction in the need for exposure to ionising radiation to monitor fracture healing.

ObjectivesThe monitoring of fracture healing is a complex process. Typically, successive radiographs are performed and an emerging calcification of the fracture area is evaluated. The aim of this study was to investigate whether different bone healing patterns can be distinguished using a telemetric instrumented femoral internal plate fixator.Materials and MethodsAn electronic telemetric system was developed to assess bone healing mechanically. The system consists of a telemetry module which is applied to an internal locking plate fixator, an external reader device, a sensor for measuring externally applied load and a laptop computer with processing software. By correlation between externally applied load and load measured in the implant, the elasticity of the osteosynthesis is calculated. The elasticity decreases with ongoing consolidation of a fracture or nonunion and is an appropriate parameter for the course of bone healing. At our centre, clinical application has been performed in 56 patients suffering nonunion or fracture of the femur.ResultsA total of 39 cases of clinical application were reviewed for this study. In total, four different types of healing curves were observed: fast healing; slow healing; plateau followed by healing; and non-healing.ConclusionThe electronically instrumented internal fixator proved to be valuable for the assessment of bone healing in difficult healing situations. Cost-effective manufacturing is possible because the used electronic components are derived from large-scale production. The incorporation of microelectronics into orthopaedic implants will be an important innovation in future clinical care.Cite this article: B. Kienast, B. Kowald, K. Seide, M. Aljudaibi, M. Faschingbauer, C. Juergens, J. Gille. An electronically instrumented internal fixator for the assessment of bone healing. Bone Joint Res 2016;5:191–197. DOI: 10.1302/2046-3758.55.2000611.

We conclude that mentioned factors are associated with weaning outcome and useful for clinical recommendations and patient counselling. These data further support the complexity of ventilator weaning in the SCI population due to associated complications, therefore we recommend conducting weaning of patients with SCI on intensive or intermediate care units (ICU/IMCU) in specialised centres.

Study design Longitudinal study. Objectives To describe the severity of spinal cord injury/disease (SCI/D), type and management of neurogenic lower urinary tract dysfunction, tumor characteristics, and bladder cancer latency period in SCI/D patients. Setting Spinal cord injury centers in Germany, Austria, and Switzerland. Methods Data of SCI/D patients diagnosed with bladder cancer were collected between Jan 2012–Dec 2019 in the course of annual surveys in the neuro-urological departments of all 28 centers. Demographic and paralysis-specific data, data on the type and management of neurogenic lower urinary tract dysfunction, and histopathological tumor characteristics were collected. Results Regarding histopathological tumor characteristics, no significant differences were found in 135 individuals with SCI/D when stratified for bladder management without chronic catheterization, SCI/D severity, and ASIA classification. The mean latency period between the onset of SCI/D and the diagnosis of bladder cancer was significantly longer in patients with catheter-free emptying methods compared to patients with intermittent catheterization, and in patients with LMNL (Lower Motor Neuron Lesion) compared to patients with UMNL (Upper Motor Neuron Lesion). Conclusions Urinary bladder carcinomas are late events in the long-term course of SCI/D. Follow-up and approaches to screening must therefore be intensified with increasing duration of long-term SCI.

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