[Evolution and principles of intramedullary locked nailing]

[Proximal femoral fracture with bony ankylosis of the hip joint : Case report of difficult surgical treatment]

A 78-year-old female patient sustained a left-sided proximal femoral fracture due to a fall. Since childhood the patient had suffered from ankylosis of unknown origin in the ipsilateral hip joint. The recommended intramedullary osteosynthesis could restore the original status quo before the fracture. It needs less time in the operating room (OR) and includes a lower risk for intraoperative complications than a hip joint endoprosthesis. Arthroplasty can lead to a significant improvement in mobility of the hip joint but requires more time in the OR for the surgical procedure and anesthesia time and includes a higher risk for intraoperative and postoperative complications. The antetorsion angle of 76° in this patient deviated extremely from the standard and made the intramedullary osteosynthesis for this type of fracture a challenge. Using improvised techniques led to a load-stable fracture treatment that ultimately led to a satisfactory result.

Minimally Invasive Internal Fixation of Femoral Shaft Fractures-A Biomechanical Study with a Disruptive Technique

(1) Background: In polytrauma patients, femur fractures are usually stabilised by external fixation for damage control, later being treated with definitive plate or nail osteosynthesis. Screw/rod systems established in spinal surgery might be inserted for internal fixation, providing sufficient fracture stability that subsequent intervention is unnecessary. This was to be investigated biomechanically. (2) Methods: The unilaterally applied spinal internal fixator (IF) was subjected to load and deformation analysis on artificial femurs with 32-A3 fracture according to AO classification. Distance of screws to fracture and rod to cortical bone were analysed as parameters influenced surgically as stiffness and deformation of the treated fracture. In addition, the stability of another construct with a second screw/rod system was determined. The axial load in stance phase during walking was simulated. The results were compared against an established fixed-angle plate osteosynthesis (IP). (3) Results: There were no implant failures in the form of fractures, avulsions or deformations. All unilateral IF combinations were inferior to IP in terms of stability and stiffness. The bilateral construct with two screw/rod systems achieved biomechanical properties comparable to IP. 4) Conclusion: Biomechanically, a biplanar screw/rod system is suitable for definitive fracture stabilisation of the femur, despite a damage control approach.

Strategies to Improve Bone Healing: Innovative Surgical Implants Meet Nano-/Micro-Topography of Bone Scaffolds

Successful fracture healing is dependent on an optimal mechanical and biological environment at the fracture site. Disturbances in fracture healing (non-union) or even critical size bone defects, where void volume is larger than the self-healing capacity of bone tissue, are great challenges for orthopedic surgeons. To address these challenges, new surgical implant concepts have been recently developed to optimize mechanical conditions. First, this review article discusses the mechanical environment on bone and fracture healing. In this context, a new implant concept, variable fixation technology, is introduced. This implant has the unique ability to change its mechanical properties from “rigid” to “dynamic” over the time of fracture healing. This leads to increased callus formation, a more homogeneous callus distribution and thus improved fracture healing. Second, recent advances in the nano- and micro-topography of bone scaffolds for guiding osteoinduction will be reviewed, particularly emphasizing the mimicry of natural bone. We summarize that an optimal scaffold should comprise micropores of 50–150 µm diameter allowing vascularization and migration of stem cells as well as nanotopographical osteoinductive cues, preferably pores of 30 nm diameter. Next to osteoinduction, such nano- and micro-topographical cues may also reduce inflammation and possess an antibacterial activity to further promote bone regeneration.

The role of mechanical stimulation in the enhancement of bone healing

The biomechanical environment plays a dominant role in the process of fracture repair. Mechanical signals control biological activities at the fracture site, regulate the formation and proliferation of different cell types, and are responsible for the formation of connective tissues and the consolidation of the fractured bone. The mechanobiology at the fracture site can be easily manipulated by the design and configuration of the fracture fixation construct and by the loading of the extremity (weight-bearing prescription). Depending on the choice of fracture fixation, the healing response can be directed towards direct healing or towards indirect healing through callus formation. This manuscript summarizes the evidence from experimental studies and clinical observations on the effect of mechanical manipulation on the healing response. Parameters like fracture gap size, interfragmentary movement, interfragmentary strain, and axial and shear deformation will be explored with respect to their respective effects on fracture repair. Also, the role of externally applied movement on the potential enhancement on the fracture repair process will be explored. Factors like fracture gap size, type and amplitude of the mechanical deformation as well as the loading history and its timing will be discussed.

Trends in Orthopedic Surgery in Chile: Analysis Between 2004 and 2020

Purpose To describe the trends of orthopedic surgery in Chile since 2004 in terms of the number and gender of surgeons, the incidence of procedures per 100,000 inhabitants (IR), and access by health insurance and type of health center. Methods A cross-sectional study was designed. Three databases were analyzed: the free access database of the Chilean Department of Statistics and Health Information (DEIS), which had information on all procedures performed in health institutions in Chile from 2004 to 2020. Then, the orthopedic surgeon registry was requested from the National Superintendence of Health (NSH). Finally, the database of the Chilean Society of Orthopaedic Surgeons (SCHOT) was analyzed. Spearman's correlation was used to determine significant trends during the analyzed period. Results The NSH reported 1770 orthopedic surgeons in 2020; 56% were affiliated with SCHOT. An upward trend in the proportion of female orthopedic surgeons was found, from 4.8% in 2004 to 7.6% in 2020. Since 2004, the IR of orthopaedic surgeries has been increasing significantly in both health insurances; the growth in public insurance follows a linear model (R2 = 0.970) of parameters β0 = - 55982.6 (p <0.000) and β1 = 28.02 (p <0.000) while in private insurance, the growth is also linear (R2 = 0.890) but with a greater slope: β0 = - 104136 (p <0.000) and β1 = 52.15 (p <0.000). A significant downward trend was found in the proportion of surgeries performed in the public health network (rho = -0.797, p = 0.0002). Conclusions There is a significant increase in the number of orthopedic surgeons and the number of procedures per 100,000 inhabitants. Nevertheless, there is evident inequity in access to orthopedic surgery in Chile and low gender diversity.

Intraoperative torsion control using the cortical step sign and diameter difference in tibial mid-shaft fractures

AIM

Intramedullar nailing of tibial mid-shaft fractures is a common surgical treatment. Fracture reduction, however, remains challenging and maltorsion is a common discrepancy which aggravates functional impairment of gait and stability. The use of radiographic tools such as the cortical step sign (CSS) and the diameter difference sign (DDS) could improve fracture reduction. Therefore, the validity of the CSS and DDS was analyzed to facilitate detection of maltorsion in tibial mid-shaft fractures.

METHODS

Tibial mid-shaft fractures were induced in human cadaveric tibiae according to the AO classification type A3. Torsional discrepancies from 0° to 30° in-/external direction were enforced after intramedullary nailing. Fluoroscopic-guided fracture reduction was assessed in two planes via analysis of the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD), anterior cortical thickness (ACT), posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and distal fracture fragment.

RESULTS

The TD, LCT and ACT have shown a highly significant correlation to predict tibial maltorsion. While a model combining ACT, LCT, PCT and TD lateral was most suitable model to identify tibial maltorsion, a torsional discrepancy of 15°was most reliably detected with use of the TD and ACT.

CONCLUSION

The present study has shown, that maltorsion can be reliably assessed by the CSS and DDS during fluoroscopy. Thus, torsional discrepancies in tibial mid-shaft fractures can be most reliably assessed in the lateral plane by analysis of the LCT and TD.

Does auxiliary cerclage wiring provide intrinsic stability in cephalomedullary nailing of trochanteric and subtrochanteric fractures?

Purpose

The aim of this study was to assess functional and radiological results following cephalomedullary nailing with and without use of auxiliary cable cerclages in a large series of trochanteric and subtrochanteric femoral fractures.

Methods

In a retrospective study of prospectively collected data between January 2014 and March 2019, a total of 260 consecutive patients (155 women and 105 men) with the diagnosis of AO/OTA A1 to A3 fractures were included. The mean age of patients was 76.4 ± 15.6 years. According to the AO/OTA classification, 72 A1 fractures, 124 A2 fractures, and 64 A3 fractures were found. In 72 patients with auxiliary cerclage wiring three A1 fractures, 27 A2 fractures and 42 A3 fractures were assessed. In the patient group with auxiliary cerclages, fracture healing according to the Radiographic Union Score for Hip (RUSH) within one year after surgery was assessed in 68 out of 72 patients (healing rate 94%). The mean RUSH in the group with cerclages was 28.7 ± 2.2 points and was 28.5 ± 2.2 points in the group without cerclages (p = 0.72). In 91 patients available for a complete follow-up, mean functional outcome according to the Lower Extremity Functional Scale (LEFS) was 65.3 ± 17.2 points in the group with cerclages versus 58.4 ± 21 points in the group without cerclages (p = 0.04).

Conclusion

The additional use of cerclages provides intrinsic stability and enables axial alignment and medial cortical support during anatomical fracture reduction and cephalomedullary nail insertion. In the current study, this technique resulted in significantly better functional long-term outcomes than without cerclages. Therefore, it can be recommended as a useful supportive tool especially in comminuted trochanteric and subtrochanteric fractures. Trial registration number DRKS00020550, 01/30/2020, retrospectively registered.

Computer tomographic analysis of anatomic characteristics of the ulna - essential parameters for preshaped implants

Purpose

Anatomically preshaped implants are needed for exact restoration of the anatomy after fractures of the proximal ulna and ulnar shaft, which enables a good functional outcome. Aim of this computed tomographic analysis was to identify specific characteristics of the ulna. The data serve for the development of a new intramedullary implant for stabilisation of proximal and diaphyseal ulna fractures.

Methods

With a standardized research method 100 CT scans of the ulna were evaluated regarding anatomic parameters like width of the medullary canal, proximal ulna dorsal angulation and varus angulation. Also, correlations of these parameters were analyzed statistically.

Results

The mean proximal ulna dorsal angulation (PUDA) was 6.4° (SD 2.8°), while the mean varus angulation of the proximal ulna was 12.4° (SD 3.3°). The length of the ulna bone was 253.6 mm (SD 19.9 mm) on average. The average minimum diameter of the medullary canal was 4.2 mm (SD 1.1 mm) located at 141.3 mm (SD 19.7 mm) from the olecranon tip. There is a positive correlation between age and minimum diameter in our patient cohort (p< 0.001).

Conclusion

Our study described the anatomy of the proximal ulna and the ulna shaft with a reproducible research method in a representative patient cohort. The knowledge of the evaluated anatomic parameters can lead to an improvement of any implant design for the fixation of proximal and diaphyseal ulna fractures.

Evolution of imaging in surgical fracture management

Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety.

Nailing of diaphyseal ulna fractures in adults-biomechanical evaluation of a novel implant in comparison with locked plating

Background

Adult forearm fractures require surgical treatment in most cases. Open reduction and internal fixation with plate osteosynthesis is the therapy of choice. Intramedullary fixation offers several advantages compared to plate fixation but is not routinely used. The aim of our study was to compare a newly designed ulna nail with angular stable plating in a biomechanical testing setup of an ulna shaft fracture with a diaphyseal defect.

Methods

Ten pairs of sawbones with a defect osteotomy of the ulna shaft (OTA 2U2C3) were fixed with an interlocked nail or locked plate osteosynthesis. The constructs were tested under four-point bending, torsional loading and axial loading in a servo-pneumatic testing machine to compare the stiffness of both stabilization methods.

Results

The nail constructs show lower yet sufficient bending stiffness (62.25 ± 6.64 N/mm) compared to the plate constructs (71.2 ± 5.98 N/mm, p = 0.005). The torsional loading test shows superior stiffness of the plate constructs (0.24 ± 0.03 Nm/deg vs. 0.1 ± 0.01 Nm/deg; p < 0.001), while the axial loading shows superior stiffness of the nail constructs (1028.9 ± 402.1 N/mm vs. 343.9 ± 112.6 N/mm; p < 0.001).

Conclusions

Intramedullary nailing of ulna shaft fractures obtains sufficient but lower stability in bending and torsional loading when compared to rigid angular stable plating and could be an alternative technique to plate fixation. The lower stability and the closed stabilization technique allow for a rapid periosteal healing, which is not present in stiffer constructs.

[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.