Supplemental cerclage wiring in angle stable plate fixation of distal tibial spiral fractures enables immediate post-operative full weight-bearing: a biomechanical analysis

Impact of fracture morphology on the biomechanical stability of osteosynthetic fixation

Biomechanical testing is essential for evaluating osteosyntheses, particularly in assessing stability, stiffness, and fragment motion. However, traditional flat-fracture models created via osteotomy fail to replicate the complex morphology of real-world fractures, potentially reducing the applicability of results. This study introduces patient-specific distal femur fracture models to investigate the impact of fracture morphology on the biomechanical performance of osteosyntheses. Realistic fracture models were generated using 3D printing and molding, based on CT-derived geometry, alongside traditional osteotomy models. Four groups were tested: osteotomized and realistic fracture models, with and without gaps. All constructs were treated with distal femur locking plates and subjected to axial and torsional loading. Dynamic testing simulated physiological conditions and tracked interfragmentary motions with a 3D optical motion system. Realistic fracture models exhibited higher torsional stiffness and reduced interfragmentary motion compared to osteotomized models, particularly in closed fracture gaps. Axial stiffness increased significantly upon fracture gap closure in all gap groups, transitioning from exclusively plate-bearing to construct-bearing configurations. The irregular geometry of realistic fractures provided enhanced interlocking, improving stability under both axial and torsional loads. Patient-specific fracture models better replicate the mechanical behaviour of clinical distal femur fractures, demonstrating advantages over osteotomized fracture models. The inclusion of realistic fracture geometries in biomechanical testing improves the transfer of biomechanical results into a clinical setting and offers valuable insights for optimizing designs and improving clinical outcomes.

Relaxation Behavior of Cerclage Cables and Its Effect on Bone Clamping Force

Cerclage is an orthopedic surgical fixation technique using a cable wrapped, tensioned, and secured around a bone's circumference. It is important to minimize the loss in cable tension that often occurs due to stress relaxation. The purpose of this work was to study the effect of tensioning protocols on the long-term loss of tension due to stress relaxation. The native mechanical properties and relaxation behavior of the cables were determined using traditional mechanical testing machines and methods. Four step-wise cable tensioning protocols were then trialed to compare the cable tension losses. A testing apparatus was developed to simultaneously measure cable tension and the resulting clamping force on a real bone. A five-parameter linear viscoelastic model was used to fit relaxation data to estimate the long-term relaxation of the cables beyond the time of the experiment. The four cables were found to have similar mechanical and viscoelastic behaviors. A two-step cable-tightening protocol was found to significantly reduce cable tension loss when compared to a one-step protocol for all cables. The benefit of the two-step protocol was reinforced by the relaxation results of the cable wrapped and tightened around a pig femoral bone. These results indicate that one retightening step should be conducted during the surgical placement of a cerclage cable to reduce the loss of cable tension resulting from relaxation.

Minimally invasive cerclage at the tibia using a modified Goetze technique: An anatomical study

INTRODUCTION

The use of minimally invasive cerclages at the tibia is not very common. First, clinical results of a new operative technique published recently showed no increased complication rate. The aim of this anatomical study was to determine, if it is possible to introduce a minimally invasive cerclage at different levels of the tibia without encasing relevant nerves, vessels or tendons into the cerclage using this technique.

HYPOTHESIS

The minimally invasive introduction of a cerclage at the tibia is possible without encasing relevant anatomical structures.

MATERIAL AND METHODS

Using the minimally invasive operative technique in 10 human cadaveric lower legs, cerclages were inserted at 4 different levels of each tibia. They were defined from proximal to distal as level 1-4. The legs were severed at the levels of the cerclages and examined for any relevant encased anatomical structures. Afterwards, the shortest distance between each relevant anatomical structure and the cerclage was measured.

RESULTS

There was no encasing of any relevant anatomical structures in any specimen at any level. In the proximal half of the lower leg, the closest anatomical structures to the inserted cerclage were arteria et vena tibialis posterior (at level 1: 5.2 resp. 4.3mm, at level 2: 4.0 resp. 5.5mm). In the distal half of the lower leg arteria et vena tibialis anterior (level 3: 1.8 and 2.0mm, level 4: 1.6 and 1.5mm), nervus fibularis profundus (level 3: 2.2mm, level 4: 1.2mm) and the tendon of musculus tibialis posterior (level 3: 0.8mm, level 4: 1.1mm) were in closest proximity of the cerclage.

DISCUSSION

The results of this anatomical study suggest that the minimally invasive insertion of cerclages at the tibia without encasing relevant anatomical structures is possible but requires a correct operative technique. The structures at highest risk are arteria et vena tibialis posterior in the proximal half of the tibia and arteria et vena tibialis anterior, nervus fibularis profundus and the tendon of musculus tibialis posterior in the distal half.

LEVEL OF EVIDENCE

Not applicable; experimental anatomical study.

Plain X-ray is insufficient for correct diagnosis of tibial shaft spiral fractures: a prospective trial

PURPOSE

Tibial shaft spiral fractures and fractures of the distal third of the tibia (AO:42A/B/C and 43A) frequently occur with non-displaced posterior malleolus fractures (PM). This study investigated the hypothesis that plain X-ray is not sufficient for a reliable diagnosis of associated non-displaced PM fractures in tibial shaft spiral fractures.

METHODS

50 X-rays showing 42A/B/C and 43A fractures were evaluated by two groups of physicians, each group was comprised of a resident and a fellowship-trained traumatologist or radiologist. Each group was tasked to make a diagnosis and/or suggest if further imaging was needed. One group was primed with the incidence of PM fractures and asked to explicitly assess the PM.

RESULTS

Overall, 9.13/25 (SD ± 5.77) PM fractures were diagnosed on X-ray. If the posterior malleolus fracture was named or a CT was requested, the fracture was considered "detected". With this in mind, 14.8 ± 5.95 posterior malleolus fractures were detected. Significantly more fractures were diagnosed/detected (14 vs. 4.25/25; p < 0.001/14.8 vs. 10.5/25; p < 0.001) in the group with awareness. However, there were significantly more false positives in the awareness group (2.5 vs. 0.5; p = 0.024). Senior physicians recognized slightly more fractures than residents (residents: 13.0 ± 7.79; senior physicians: 16.5 ± 3.70; p = 0.040). No significant differences were demonstrated between radiologists and trauma surgeons. The inner-rater reliability was high with 91.2% agreement. Inter-rater reliability showed fair agreement (Fleiss-Kappa 0.274, p < 0.001) across all examiners and moderate agreement (Fleiss-Kappa 0.561, p < 0.001) in group 2.

CONCLUSION

Only 17% of PM fractures were identified on plain X-ray and awareness of PM only improved diagnosis by 39%. While experiencing improved accuracy, CT imaging should be included in a comprehensive examination of tibial shaft spiral fractures.

LEVEL OF EVIDENCE

II. Diagnostic prospective cohort study.

TRAIL REGISTRATION NUMBER

DRKS00030075.

Cerclage Wiring Improves Biomechanical Stability in Distal Tibia Spiral Fractures Treated by Intramedullary Nailing

BACKGROUND

Partial weight-bearing after operatively treated fractures has been the standard of care over the past decades. Recent studies report on better rehabilitation and faster return to daily life in case of immediate weight-bearing as tolerated. To allow early weight-bearing, osteosynthesis needs to provide sufficient mechanical stability. The purpose of this study was to investigate the stabilizing benefits of additive cerclage wiring in combination with intramedullary nailing of distal tibia fractures.

METHODS

In 14 synthetic tibiae, a reproducible distal spiral fracture was treated by intramedullary nailing. In half of the samples, the fracture was further stabilized by additional cerclage wiring. Under clinically relevant partial and full weight-bearing loads the samples were biomechanically tested and axial construct stiffness as well as interfragmentary movements were assessed. Subsequently, a 5 mm fracture gap was created to simulate insufficient reduction, and tests were repeated.

RESULTS

Intramedullary nails offer already high axial stability. Thus, axial construct stiffness cannot be significantly enhanced by an additive cerclage (2858 ± 958 N/mm NailOnly vs. 3727 ± 793 N/mm Nail + Cable; p = 0.089). Under full weight-bearing loads, additive cerclage wiring in well-reduced fractures significantly reduced shear (p = 0.002) and torsional movements (p = 0.013) and showed similar low movements as under partial weight-bearing (shear 0.3 mm, p = 0.073; torsion 1.1°, p = 0.085). In contrast, additional cerclage had no stabilizing effect in large fracture gaps.

CONCLUSIONS

In well-reduced spiral fractures of the distal tibia, the construct stability of intramedullary nailing can be further increased by additional cerclage wiring. From a biomechanical point of view, augmentation of the primary implant reduced shear movement sufficiently to allow immediate weight-bearing as tolerated. Especially, elderly patients would benefit from early post-operative mobilization, which allows for accelerated rehabilitation and a faster return to daily activities.

New ways of treatment of fractures of the humeral shaft: does the combination of intramedullary nail osteosynthesis and cerclage improve the healing process?

Introduction

The humeral shaft fracture is a rare fracture of the long bones with various treatment options. Dreaded complications such as lesions of the radial nerve or non-unions make the decision for what kind of therapy option more difficult. Biomechanically the upper arm is mostly exposed to rotational forces, which affect intramedullary nail osteosynthesis. Additive cerclage may compensate for these in spiral fractures. The aim of this study is to investigate what effect a combination of intramedullary nail osteosynthesis and limited invasive cerclage has on the rate of healing. In addition, this study addresses the question if complications arise as a result of cerclage.

Methods

In this retrospective study, 109 patients were evaluated, who, during a period of 6 years, underwent operative treatment of a humerus shaft fracture with a combination of intramedullary nail osteosynthesis and additive cerclage. The primary end point was to establish the rate of healing. A secondary end point was to evaluate complications such as infections and damage to the nerve. This was followed by an examination of patient files and X-ray images and a statistical analysis with SPSS.

Results and conclusion

The healing process shows a non-union rate of 2.6%, and complications such as secondary radial nerve lesions of 4.6%. The antegrade intramedullary nail osteosynthesis with limited invasive, additive cerclage reduces the risk of non-union and does not lead to an increased risk of iatrogenic damage to the radial nerve. Wound healing was not impaired and there were no infections through the cerclage in our patient cohort.

A minimally invasive cerclage of the tibia in a modified Goetze technique: operative technique and first clinical results

Introduction

In spiral fractures of the tibia, the stability of an osteosynthesis may be significantly increased by additive cerclages and, according to biomechanical studies, be brought into a state that allows immediate full weight bearing. As early as 1933, Goetze described a minimally invasive technique for classic steel cerclages. This technique was modified, so that it can be used for modern cable cerclages in a soft part saving way.

Method

After closed reduction, an 8 Fr redon drain is first inserted in a minimally invasive manner, strictly along the bone and placed around the tibia via 1 cm incisions on the anterolateral and dorsomedial tibial edges using a curette and a tissue protection sleeve.

Via this drain, a 1.7 mm cable cerclage can be inserted. The fracture is then anatomically reduced while simultaneously tightening the cerclage. Subsequently, a nail or a minimally invasive plate osteosynthesis is executed using the standard technique.

Using the hospital documentation system, data of patients that were treated with additional cerclages for tibial fractures between 01/01/2014 and 06/30/2020 were subjected to a retrospective analysis for postoperative complications (wound-healing problems, infections and neurovascular injury). Inclusion criteria were: operatively treated tibial fractures, at least one minimally invasive additive cerclage, and age of 18 years or older. Exclusion criteria were: periprosthetic or pathological fractures and the primary need of reconstructive plastic surgery. SPSS was used for statistical analysis.

Results

96 tibial shaft spiral fractures were treated with a total of 113 additive cerclages. The foregoing resulted in 10 (10.4%) postoperative wound infections, 7 of which did not involve the cerclage. One lesion of the profundal peroneal nerve was detected, which largely declined after cerclage removal. In 3 cases, local irritation from the cerclage occurred and required removal of material.

Conclusion

In the described technique, cerclages may be inserted additively at the tibia in a minimally invasive manner and with a few complications, thus significantly increasing the stability of an osteosynthesis. How this ultimately affects fracture healing is the subject of an ongoing study.

Biomechanical comparison of different cerclage types in addition to an angle stable plate osteosynthesis of distal tibial fractures

BACKGROUND

Different stand-alone cerclage configurations and their optimal twisting techniques have been investigated over the years. This study tests for the stabilizing effect of different supplemental cerclage materials in combination with locked plating of distal tibia fractures.

METHODS

Locking plate fixation of a distal tibial spiral fracture was tested as stand-alone and with supplemental cerclage materials (one cable, two cables, wire, fiber tape). Construct stiffness and fracture gap movements were investigated under quasi-static and dynamic loads and compared to the stand-alone locking plate.

RESULTS

With each of the tested cerclages, stiffness was significantly higher than for a solitary plate osteosynthesis. Most reduction in fracture gap movement was achieved by cable cerclages, followed by double-looped wire and double-looped fiber tape cerclages. Under dynamic loading an additional cable cerclage reduces excessive gap movement.

CONCLUSION

Compared to solitary plate osteosynthesis all supplemental cerclage materials were generally superior with reduced fracture gap movements whereas cable cerclages showing the greatest stabilizing effect.

[Compromising due to additive cerclages : Can surgical treatment of humeral shaft fractures cause damage to the radial nerve?]

BACKGROUND

In many cases the treatment of humeral shaft fractures is challenging and despite the large diversity of available approaches, no standard treatment exists. In addition to conservative treatment, intramedullary nails and plate osteosynthesis are competing methods for healing humeral shaft fractures. Furthermore, cerclage is considered to be an additive treatment for spiral fractures; however, this also increases the risk of radial nerve neuropathy and is said to compromise the perfusion of bone fragments. The goal of this study was to investigate secondary radial nerve neuropathy using additive and limited invasive cerclages for nail osteosynthesis of humeral shaft fractures.

METHODS

In the present study a total of 102 patients with humeral shaft fractures were clinically and neurologically re-examined after having been treated with nail osteosynthesis and additive cerclage via a limited invasive access over the past 5 years. In total 193 cerclages with limited invasive access were inserted during this time period.

RESULTS AND CONCLUSION

Of the patients four (3.9%) showed a secondary radial neuropathy during operative stabilization. Neurophysiological and neurosonographic examinations revealed that this had not been caused by compromising, embedding or severance of the radial nerve due to the cerclage. Two out of these nerve lesions recovered spontaneously within 3 and 6 months, respectively. The other two cases could not be documented over a period of 12 months due to death of the patient. With 3.9% of iatrogenic radial nerve lesions the rate of nerve lesions falls into the lower range of that which has previously been described in the literature for nerve lesions due to operative treatment of humeral shaft fractures (3-12%). We thus conclude that there is no increased risk for iatrogenic injury of the radial nerve using additive and limited invasive cerclage.