Overdistraction of the Fracture Eases Reduction in Delayed Femoral Nailing: Results of Intraoperative Force Measurements

One‐Stage Closed Intramedullary Nailing for Delayed Femoral Fracture in Multiple Injured Patients

Objective

To tackle the challengeable dilemma of delayed femoral fracture, a technique of fixator‐assisted closed reduction and intramedullary nailing at one stage was introduced herein and its clinical results were investigated.

Methods

A retrospective study was conducted on delayed femoral shaft fracture between February 2008 and January 2017. The multiple injured patients aged from 18 to 60 years with delayed femoral fracture was included. All patients were treated by one‐stage internal fixation technique and followed up for more than 1 year. Outcome measures including the operation time, intraoperative blood loss and limb alignment, healing time of fracture, visual analog scale (VAS), and range of knee motion were recorded and evaluated.

Results

A total of 13 patients (16 sides) with a mean injury severity score (ISS) of 32.77 ± 9.98 (range, 19 to 52) participated in the investigation. The median length of time‐after‐fracture was 38 days (range, 21 to 110 days). The average shortening distance of the fracture ends was 35.48 ± 19.24 mm (range, 10.00 to 79.00 mm). The average surgery time was 192.19 ± 29.38 min for unilateral femoral fracture, with blood loss of 587.50 ± 232.02 ml. The postoperative discrepancy of lower limb was 3.87 ± 2.52 mm. No patient had vascular and neurologic complications due to the lengthening. All fractures healed successfully with a mean time of 2.98 ± 0.57 months. The mean VAS and maximal knee flexion were 1.63 ± 1.09 and 131.25° ± 5.32° at final follow‐up, respectively.

Conclusions

Our findings indicated that fixator‐assisted closed reduction and intramedullary nailing at one stage is an effective treatment for delayed femoral fracture with satisfactory functional recovery.

[Femoral shaft fractures]

Femoral shaft fractures after completion of growth predominantly affect young people with healthy bones. The causes are mostly high-velocity traffic accidents, crushing or running over mechanisms and falls from a great height. Gunshot wounds are relatively rare in Germany but have a certain importance internationally and in military medicine. Accompanying injuries in local or other regions are frequent. The predominant fracture types are transverse, wedge, segment and comminuted fractures. Spiral fractures are a sign of indirect force and are therefore frequently found in older patients with osteoporosis. Atypical fractures under or following bisphosphonate treatment are a new entity, which are typically subtrochanteric and begin on the lateral side of the bone. The characteristics of pathological fractures, femoral shaft fractures in childhood and adolescence as well as periprosthetic fractures are not dealt with in this article.

Biomechanical and histological analyses of the fracture healing process after direct or prolonged reduction

Background

Reduction of femoral shaft fractures remains a challenging problem in orthopaedic surgery. Robot-assisted reduction might ease reduction and fracture treatment. However, the influence of different reduction pathways on patients’ physiology is not fully known yet. Therefore, the aim of this study was to examine the biomechanics and histology of fracture healing after direct and prolonged robot-assisted reduction in an in vivo rat model.

Methods

144 male CD^® rats were randomly assigned to 12 groups. Each animal received an external fixator and an osteotomy on the left femoral shaft. On the fourth postoperative day, the 1× reduction groups received a single reduction maneuver, whereas the 10× reduction groups received the same reduction pathway with ten repetitions. The control groups did not undergo any reduction maneuvers. Animals were killed after 1, 2, 3 and 4 weeks, respectively, and the composition of the fracture gap was analyzed by µCT and non-decalcified histology. Biomechanical properties were investigated by a three-point bending test, and the bone turnover markers PINP, bCTx, OPG, sRANKL, TRACP-5b, BALP, and OT/BGP were measured.

Results

One week after the reduction maneuver, µCT analysis showed a higher cortical bone volume in the 1× reduction group compared to the 10× reduction group. Biomechanically, the control group showed higher maximum force values measured by three-point bending test compared to both reduction groups. Furthermore, less collagen I formation was examined in the 10× reduction group compared to the control group after 1 week of fracture healing. PINP concentration was decreased in 10× reduction group after 1 week compared to control group. The same trend was seen after 3 weeks.

Conclusion

A single reduction maneuver has a beneficial effect in the early phase of the fracture healing process compared to repeated reduction maneuvers. In the later phase of fracture healing, no differences were found between the groups.

Minimally invasive treatment of displaced femoral shaft fractures with a teleoperated robot-assisted surgical system

BACKGROUND

Minimally invasive surgical operation of intramedullary (IM) nailing is a standard technique for treating diaphyseal fractures. However, in addition to its advantages, there are some drawbacks such as the frequent occurrence of malalignment, physical fatigue and high radiation exposure to medical staff. The use of robotic and navigation techniques is promising treatments for femoral fractures.

MATERIALS AND METHODS

This paper presents a novel robot-assisted manipulator for femoral shaft fracture reduction with indirect contact with the femur. An alternative clinical testing model was proposed for orthopedic surgeons to practice femoral fracture reduction. This model imitates the human musculoskeletal system in shape and functional performance. The rubber tube simulate muscles providing contraction forces, and the silicone simulates passive elasticity of muscles. Two-group experiments were performed for studying feasibility of the teleoperated manipulator.

RESULTS

The average operative time was about 7min. In the first group experiments, the femur axial, antero-posterior (AP) and lateral views mean errors were 2.2mm, 0.7mm and 1.1mm, respectively, and their maximums were 3.0mm, 0.9mm and 1.5mm; the mean errors of rotation were 0.8° around x-axis, 1.6° around y-axis, 2.0° around z-axis, and their maximums were 1.1°, 2.2°, 2.9°, respectively. For the second group experiments, the femur axial, AP and lateral views mean errors were 1.8mm, 0.4mm and 0.8mm, respectively, and their maximums were 2.2mm, 0.7mm and 1.1mm; the mean errors of rotation were 1.2° around x-axis, 1.6° around y-axis, 1.9° around z-axis, and their maximums were 2.4°, 1.8°, 2.7°, respectively. Reduction for AP view displacement is easier than lateral (p<0.05) because of the tube-shaped anatomy and the muscle contraction forces. Errors around x-axis are smaller than those around y-, and z- axes (p<0.05), i.e., electro-mechanical actuator is easier to control than pneumatic.

CONCLUSION

An experimental model for simulating human femoral characteristics was proposed. Experiments conducted on the artificial lower limb model demonstrated high reduction accuracy, safety, sufficient working space, and low radiation exposure of the proposed robot-assisted system. Thus, the minimally invasive teleoperated manipulator would have greater development prospect.

Comparison of algorithms for automated femur fracture reduction

PURPOSE

We designed an experiment to determine the comparative effectiveness of computer algorithms for performing automated long bone fracture reduction.

METHODS

Automated reduction of 10 3D fracture models was performed using two computer algorithms, random sample matching (RANSAM) and Z-buffering (Z-Buffer), and one of five options of post-processing: none; iterative closest point algorithm (ICP); ICP-X1; ICP-X2; and ICP-X3. We measured the final alignment between the two fragments for each algorithm and post-processing option.

RESULTS

The RANSAM algorithm combined with postprocessing algorithm ICP-X1 or ICP-X3 resulted in the most accurate fracture reduction in the translational plane. No discernible difference was observed in the rotational plane. Automated reduction had more accurate translational displacement than telemanipulated manual reductions.

CONCLUSION

This study supports the use of the RANSAM algorithm for automated fracture reduction procedures. The use of ICP algorithms provides further optimization of the initial reduction.

Epidemiological and economic aspects of polytrauma management in Austria

INTRODUCTION

In Austria, treatment of multiple trauma patients has developed into an established nationwide trauma center specialty with its own unique identity. Although it represents a substantial financial investment, it ensures supply at international standards. The question of whether multiple trauma patients should be treated only in specialized trauma centers or in several hospitals remains controversial on both national and international grounds. The aim of this study was to assess Austrian trauma departments for international comparison.

MATERIAL AND METHODS

We performed a survey of all 54 Austrian trauma departments by collecting data through questionnaires. The number of staff, potential of infrastructure, and treatment strategies were obtained.

RESULTS

93.3% of the trauma departments responded to the questionnaires. In level I trauma centers the amount of trauma beds reached 11% of the total bed capacity, 13% in level II, and 18% in level III units. Level I centers showed an average of 35% of intensive care beds for trauma patients. 53% and 51% were the proportions for level II and III centers. Level I hospitals displayed an average of 28.3 trauma surgeons, while level II and III units had less doctors at their disposal in the trauma departments. On average, 94% of the patients arrived by emergency medical support at the hospital. 94% of the trauma departments used chest tubes, 70% performed craniotomies and neurovascular reconstruction. 33% of the centers were equipped to perform replantations.

DISCUSSION

The data demonstrate the broad spectrum of polytrauma treatment in Austrian trauma centers. The discussed need for centralization of polytrauma care cannot be justified based on these data. Limiting from a medical perspective, however, is the lacking comparability of quality of care due to the currently missing objective quality criteria.

[Comparison of early total care (ETC) and damage control orthopedics (DCO) in the treatment of multiple trauma with femoral shaft fractures: benefit and costs]

INTRODUCTION

Femoral fractures are common injuries in multiple trauma patients. The treatment concept of damage control orthopedics (DCO) is in competition with the concept of early total care (ETC).

PATIENTS AND METHODS

In a retrospective study (2003-2007) 73 multiple trauma patients with femoral shaft fractures were included. The cohort was subdivided according to the Injury Severity Score (ISS) (16-24, 25-39 and more than 40) and treatment strategy (ETC versus DCO). Patients were analyzed for outcome and cost aspects.

RESULTS

In the patient group with an ISS 16-24 ventilation time and intensive care treatment were longer after DCO treatment, overall costs and deficient cost cover were higher in the DCO group. In the patient group with an ISS 25-39 cost aspects showed a higher cover deficient in the DCO group.

CONCLUSION

From an economic point of view the cost deficits for the ETC group were lower than in the DCO group. The treatment strategy should be selected by the pattern of injuries. The costs should be addressed by the Institute for the Hospital Remuneration System (INEK).

Alternative fixation method for open femoral fractures from a damage control orthopaedics perspective

A decision for immediate versus delayed fixation in a polytrauma patient mainly in cases of open femoral fracture depends upon time elapsed since injury, duration of stay in intensive care, soft tissue status, probable intra-operative difficulties and presence of systemic complication. We studied the outcome of the Taylor Spatial Frame (TSF) as a solution in the role of primary and definitive fixator for patients in whom definitive osteosynthesis with intramedullary nailing (IMN) can be associated with higher rate of complications. In view of damage control orthopaedics (DCO), we found that TSF is an effective technique compared to internal nails and earlier external fixator devices, attributable to its advantages such as continuity of frame till union, preventing any second-hit phenomenon, early mobilisation and restoration of primary defect due to bone loss by differential distraction osteogenesis without additional surgery. According to the Paley and Maar's evaluation criteria, 11 patients had an excellent result with clinical and radiological union; the functional result was excellent in three patients, good in five, fair in two and poor in one.

Robot-assisted Long Bone Fracture Reduction

The preferred treatment of femoral (thigh bone) shaft fractures nowadays is the minimally invasive technique of intramedullary nailing. However, in addition to its advantages, this technique also has a number of disadvantages, such as the frequent occurrence of malaligned fracture reductions and high X-ray exposure, especially to the operating team. The aim of our research is to overcome these shortcomings by utilizing modern techniques such as three-dimensional (3D) imaging, navigation, and robotics. In this paper we present the current state of our interdisciplinary research project. We first introduce a telemanipulated fracture reduction procedure, which is based on 3D imaging data. This set-up is improved one step further towards an automated fracture reduction procedure. Finally, two drilling tasks, namely the opening of the medullar cavity and the distal locking of the intramedullary nail, are presented, which are supported by automated X-ray-based image analysis and robot-assisted drill guidance. We show that high reduction accuracies can be achieved with our robotic system. Furthermore, the robot-assisted drill guidance achieves superior results with respect to increased precision and decreased X-ray exposure compared with the conventional procedure. We conclude that this surgical procedure benefits conspicuously from the support of robotic assistance systems and that further research and development in this field is worthwhile.