Retrograde tibial nailing of far distal tibia fractures: a biomechanical evaluation of double- versus triple-distal interlocking

Objectives Retrograde tibial nailing using the Distal Tibia Nail (DTN) is a novel surgical option in the treatment of distal tibial fracture. Its unique retrograde insertion increases the range of surgical options in far distal fractures of the tibia beyond the use of plating. The aim of this study was to assess the feasibility of the DTN for far distal tibia fractures where only double rather than triple-distal locking is possible due to fracture localisation and morphology. Methods Six Sawbones® were instrumented with a DTN and an AO/OTA 43-A3 fracture simulated. Samples were tested in two configurations: first with distal triple locking, second with double locking by removing one distal screw. Samples were subjected to compressive (350 N, 600 N) and torsional (± 8 Nm) loads. Stiffness construct and interfragmentary movement were quantified and compared between double and triple-locking configurations. Results The removal of one distal screw resulted in a 60–70% preservation of compressive stiffness, and 90% preservation of torsional stiffness for double locking compared to triple locking. Interfragmentary movement remained minimal for both compressive and torsional loading. Conclusions The DTN with a distal double locking can, therefore, be considered for far distal tibia fractures where nailing would be preferred over plating.

Study to Determine the Outcomes of Closed Tibial Shaft Fractures Treated with Reamed Inter Locking Nails

Aim: The aim of the study is to evaluate the results of treatment of a closed reamed interlocking in the treatment of closed fractures of the tibial shaft. Study design: A Descriptive observational study Venue and Duration: This study was conducted in the Orthopedic department of Ayub Teaching Hospital, Abbottabad for six months duration i.e from September 2020 to February 2021. Patients and methods: The study included 43 patients over 19 years of age. The patients were taken to the emergency and Orthopedic department for surgery of Ayub Teaching Hospital, Abbottabad for six months duration i.e from September 2020 to February 2021. Written approvals were granted from all selectees. Detailed history was asked and each patient was assessed clinically and radiographically. The reamed intramedullary nailing performed according to the protocol. Patients were followed for 1 year and assessed for infection, union, knee and ankle range of motion, and implant problems. 3 patients were excluded from follow-up, and the study was held in 40 patients. Results: All fractures were having complete union without the need for bone grafting. Simple fractures have union at mean of 14 weeks, comminuted and segmented fractures have union for longer than five weeks, and a mean duration of 18.5 weeks. Superficial infection at the screw site occurred in two patients, and the drainage was done, antibiotics were given and distal screw were removed, respectively. While all patients had a full range of knee motion, 37 patients had a full range of ankle movement. The other three patients had a 15-to-20-degree dorsiflexion loss at the ankle joint. No nail fracture, proximal screw end fracture in one patients and distal screw fracture in two patients were observed. Conclusion: We came to the conclusion that closed intramedullary nailing in the case of a closed shaft fracture of the tibia is a safe and satisfactory technique with a high rate of union and a relatively low complication rate and early return to activity. Keywords: Fracture, Internal, Fixation, Interlocking nail.

Biomechanical Evaluation of Extramedullary Versus Intramedullary Reduction in Unstable Femoral Trochanteric Fractures

Introduction: The failure rate of operations involving the cephalomedullary nail technique for unstable femoral trochanteric fractures is 3-12%. Changing the reduction strategy may improve the stability. This study aimed to confirm whether reducing the proximal fragment with the medial calcar contact, as opposed to utilizing an intramedullary reduction, would improve the stability of such fractures. Materials and Methods: The unstable femoral trochanteric fracture model was created with fixation by cephalomedullary nails in 22 imitation bones. The 2 reduction patterns were as follows: one was with the proximal head-neck fragment external to the distal bone in the frontal plane and anterior in the sagittal plane as “Extramedullary,” while the other was the opposite reduction position, that is, bone in the frontal plane and sagittal plane as “Intramedullary.” We evaluated the tip-apex distance, compression stiffness, change in femoral neck-shaft angle, amount of blade telescoping, and diameter of the distal screw hole after the compression test. Statistical analysis was conducted using the Mann-Whitney U test. Results: No significant differences were seen in compression stiffness ( p = 0.804) and femoral neck-shaft angle change ( p = 0.644). Although the “Extramedullary” tip-apex distance was larger than the “Intramedullary” distance ( p = 0.001), it indicated clinically acceptable lengths. The amount of blade telescoping and the distal screw hole diameter were significantly larger in “Intramedullary” than in “Extramedullary” ( p < 0.001, p = 0.019, respectively). Our results showed that “Intramedullary” had significantly larger blade telescoping and distal screw hole diameters than “Extramedullary,” and contrary to our hypothesis, no significant differences were seen in compression stiffness and femoral neck-shaft angle change. Conclusions: As opposed to the “Intramedullary” reduction pattern, the biomechanical properties of the “Extramedullary” reduction pattern improved stability during testing and decreased sliding.

DISTAL UNLOCKED PROXIMAL FEMORAL NAIL - A PROSPECTIVE STUDY AND REVIEW ABOUT ITS FUNCTIONAL OUTCOME AND COMPLICATIONS IN INTERTROCHANTERIC FRACTURES.

Background: Proximal femur nailing has become the treatment of choice in intertrochanteric femur fractures. There are different views regarding the use of distal locking in these fractures. It is said that the distal locking does not only provide rotational and axial stability but also improves the fracture healing ; However, reports of implant failure , implant breakage , stress fracture at nail tip or at distal screw insertion site , thigh pain ,cortical hypertrophy and difficulty in distal screw insertion are among the possible complications that can be encountered. In our study we investigated the outcome of omitting the distal screw in intertrochatric fractures. Materials and Methods: 19 patients with intertrochanteric femur fractures were treated with proximal femoral nail without distal locking. Distal locking was omitted when a tight fit of PFN was felt in the medullary canal by the operating surgeon. The results were evaluated with Modified Harris Hip Score. Results: 19 patients were followed up clinically and radiologically for 2 years. Conclusions: Distally unlocked proximal femoral Nail is an effective treatment modality with minimal complications in treatment of only STABLE intertrochantric fractures. Keywords: PFN, without distal lock, intertrochanteric fractures

True Antiglide Fixation of Weber B Ankle Fractures has Lower Rates of Removal of Hardware

Category: Trauma; Ankle Introduction/Purpose: Plating of unstable OTA/AO 44-B1 lateral malleolus fractures has been associated with pain, peroneal irritation, and subsequent hardware removal. There has been speculation that this is due to the prominent plate and distal screw placement. Previous studies have looked at posterior vs lateral plate position but have had fairly low numbers in each group. The purpose of this study was to retrospectively compare the rates of hardware removal in unstable OTA/AO-type 44-B1 lateral malleolus fractures fixed with a posterior, true anti-glide plate with no screws in the distal segment versus those that were fixed with a similarly placed posterior, neutralization construct that included screws in the distal fragment thus evaluating the role of the distal screw in rates of hardware removal. Methods: Skeletally mature patients that were treated for an isolated OTA/AO 44-B1 fracture over a ten-year period (2007- 2017) were reviewed. Fractures treated with a single posterior plate were included and those fixed with a direct lateral plate were excluded. We evaluated post-op radiographs to determine application of a true anti-glide plate or a neutralization plate with screws in the distal fragment. Radiographic follow-up was used to determine bony union, malunion and need for hardware removal. Hardware removal was determined as entire plate removal; isolated syndesmotic screw removal was not included. Patients were excluded if they had less than six months of follow up. Relative risk was determined for the rate of hardware removal based on fixation technique. Results: There were 548 OTA/AO 44-B1 fractures treated over the course of ten years (2007-2017). After screening, 88 patients were included in the study. The majority of excluded patients lacked adequate follow-up. Average age of the cohort was 46 years old (range 17-84), with 47 females and 41 males included. Average length of follow up was forty months (range 6.1- 140.3). There were 28 patients in the true anti-glide plate group and sixty in the neutralization plate group. Five (18%) in the anti- glide plate group and 19 (32%) in the neutralization plate underwent a second procedure of hardware removal. Relative risk of hardware removal was 0.56 (95% CI 0.23-1.36, p=0.2). There was a 100% union rate with 0% malunion in both groups. Conclusion: Anti-glide plating has a near 50% relative risk reduction in the rate of hardware removal when compared to posterior based neutralization plating. Fractures fixed with or without distal screws had equivalent excellent results related to bony union and alignment. A true anti-glide plating construct should be considered as a safe and effective way of managing OTA/AO 44-B1 lateral malleolus fractures with a lower relative risk of a second operation for hardware removal.

MON-348 Surgical Management of Bilateral Hip Fracture in a Patient with Fibrodysplasia Ossificans Progressiva Treated with Palovarotene

Background: Fibrodysplasia Ossificans Progressiva (FOP) is a rare genetic disorder marked by painful, recurrent flare-ups and progressive heterotopic ossification (HO) in soft tissues. The bone formation can be idiopathic or provoked by trauma, illness, or inflammation. There are limited treatment options, with glucocorticoids and non-steroidal anti-inflammatory agents being used for palliative treatment. Palovarotene (PVO), an investigational retinoic acid receptor gamma agonist, offers a potential avenue to prevent HO development. Clinical Case: The patient was a 29 year-old male, diagnosed with FOP at age 9, who enrolled in a study evaluating chronic PVO (5mg/day) for the treatment of FOP. Major joints affected at enrollment were his spine, jaw, shoulders, right hip and ankles. One year after starting PVO, he had a fall that resulted in a left intertrochanteric fracture. He underwent intramedullary nailing of the femur shaft with screw placement at the distal femur. After surgery, he received flare-dosing PVO at 20 mg/day for 4 weeks, then 10 mg/day for 8 weeks. Post-surgical imaging 12 weeks after the surgery showed new bridging HO at the site of intramedullary rod insertion and around the distal screw. Nine months after the fracture the patient had a second fall resulting in a right intertrochanteric fracture. He underwent intramedullary nailing of the right hip, in a modified procedure which did not require distal screw placement. PVO was increased similarly to the above flare protocol, but, at the time of fracture occurrence rather than post-surgery. He had no skin or healing complications with either treatment regimen. After each fracture the patient had prolonged recurrent flare-ups at the injury sites, significantly increasing his number of flare-ups per year. After the fractures there was new Brooker class D HO at the left hip, originating at the insertion of the intramedullary rod, and new class B HO at the right greater trochanter, again near the insertion site of the intramedullary rod compared to his pre-surgery baseline. In contrast, there was no new HO at the right distal intramedullary rod whereas HO occurred around the screw placement site at the left distal rod. Conclusion: This case suggests that PVO in the dosing regimen received by this patient can be tolerated in an individual with FOP following major surgery. HO still occurred in this patient, particularly along the rod insertion track, suggesting that the PVO regimen may need to be optimized for surgical cases or that poly-trauma events may not be adequately blocked by the dosing regimen received by this patient. However, PVO did not negatively impact fracture healing or osteointegration, and no major skin healing effects were identified. Further investigation is needed to assess whether PVO can lead to a dose-dependent reduction in HO in the setting of trauma and surgery.

Utility of an image fusion system for 3D preoperative planning and fluoroscopy in the osteosynthesis of distal radius fractures

Background Recently, computerized virtual surgery planning has been increasingly applied in various orthopedic procedures. In this study, we developed an image fusion system for 3D preoperative planning and fluoroscopy for the osteosynthesis. To assess the utility of image fusion system, we evaluated the reproducibility of preoperative planning in the osteosynthesis of distal radius fractures with using the image fusion system, and compared with the reproducibility of the patients without using the image fusion system. Methods Forty-two wrists of 42 distal radius fracture patients who underwent osteosynthesis using volar locking plates were evaluated. The patients were divided into two groups. Image fusion group utilized three-dimensional (3D) preoperative planning and image fusion system. Control group utilized only 3D preoperative planning. In both groups, 3D preoperative planning was performed in order to determine reduction, placement, and choice of implants. In the image fusion group, the outline of planned image was displayed on a monitor overlapping with fluoroscopy images during surgery. Reductions were evaluated by volar tilt and radial inclination of 3D images. Plate positions were evaluated with distance to joint surface, plate center axis position, and inclination relative to the radius axis. Screw choices were recorded for the plan and actual choices for each screw hole. Differences in the parameters between pre- and postoperative images were evaluated. Differences in reduction shape, plate positions, and screw choices were compared between groups. Results The differences in the distance from plate to joint surface were significantly smaller in the image fusion group compared to the control group (P < 0.01). The differences in the distal screw choices were significantly smaller in the image fusion group compared to the control group (P < 0.01). Conclusions The image fusion system was useful to reproduce the planned plate position and distal screw choices in the osteosynthesis of distal radius fractures. Trial registration ClinicalTrials.gov, NCT03764501

Finite Element Modeling of Electromagnetic-Coils Targeting System for Locating Distal Screw-Hole in Intramedullary Interlocking-Nail Surgery

In this paper, we report a finite element modeling of an electromagnetic-coils targeting system to locate a distal screw-hole in intramedullary interlocking-nail surgery. The system consists of an internal coil, external coil, and control/measurement electronics. The internal coil is embedded in a distal screw-hole of the nail inserted into the bone. A current is applied to the internal coil to produce a directional magnetic flux penetrating the nail/bone. Thus, the external coil scans different regions of the nail/bone will receive different amount of magnetic flux, and thereby produces different voltage outputs due to the electromagnetic induction. By analyzing the voltage outputs, the distal screw-hole is targeted. However, to precisely apply this system to many different nails for people in different regions, modification and optimization of the system are needed. For rapid modification and optimization, we implement finite element method to model the targeting system. Because the modeling results are qualitatively consistent to experimental results, the modeling is successfully validated to be able to qualitatively predict experimental trends and thereby can be used for rapid system modification and optimization.