Malunion of the Tibia: A Systematic Review

Effect of matrix material property on the composite tibia fracture plate: a biomechanical study

For the purpose of fixing tibia fractures, composite bone plates are suggested. Metal plates cause stress shielding, lessen the compression force at the fracture site, and have an impact on the healing process because they are significantly more rigid than bone. To prevent excessive shear strain and consequent instability at the fracture site, it is imperative to reduce stiffness in the axial direction without lowering stiffness in the transverse direction. Only a carefully crafted fiber reinforced composite with anisotropic properties will suffice to accomplish this. The purpose of the current study is to examine the impact of axial and shear movements at the fracture site on the fixing of metal and composite bone plates. After modeling the tibia with a 1 mm fracture gap, titanium plates, carbon/epoxy, carbon/PEEK, and carbon/UHMWPE composite bone plates were used to fix it. There are 6 holes on each of the 103 mm long plates. To determine the stresses and axial movement in the fracture site, anatomical 3D Finite Element (FE) models of the tibia with composite bone plates are built. The simulations that were run for various composite plate layouts and types give suggestions for selecting the best composite bone plate. Although the matrix material causes some variations in behaviors, most of the plates perform as well as or even better than metal plates. Thus, the appropriate composite combinations are recommended for a given fracture structure.

Importance of injury severity in the choice of treatment and its impact on prognosis in gunshot fractures

PURPOSE

The management of femur and tibia fractures resulting from gunshot injuries is a challenge for orthopedic surgeons. One-stage and two-stage treatments are applied according to the anatomical location and severity of the injury. In this study, the importance of injury severity and anatomical location was evaluated in the choice of treatment method and its impact on prognosis in cases of lower extremity gunshot fractures.

METHODS

A total of 124 patients who met the study criteria were evaluated. They were grouped separately according to the anatomical location of the injury (femur, n = 73; tibia, n = 51) and the surgical method (one-stage, n = 77; two-stage, n = 47). The demographic characteristics of the patients, fracture classification, presence of neurological or vascular damage at the time of diagnosis, anatomical location of the injury, surgical procedure, and follow-up time were recorded. The time of union and the presence of malunion were evaluated radiologically. Finally, patients were assessed clinically with the New Injury Severity Score (NISS) and leg length discrepancy (LLD) calculated through measurements made on lower extremity orthoroentgenograms.

RESULTS

The rate of vascular injury and the number of Gustilo-Anderson type IIIB and IIIC cases were significantly higher in the two-stage treatment group (p = 0.001 and p = 0.000, respectively). The infection rate was also higher in the two-stage group; therefore, time to union was significantly longer (p = 0.004 and p = 0.05, respectively). LLD was higher among patients who received two-stage treatment (p = 0.015). According to the NISS scale used in clinical assessment, better scores were obtained for the one-stage group (p = 0.002). In comparisons made according to anatomical location, no significant difference was found between femur and tibia injuries.

CONCLUSION

Regardless of anatomical location and treatment method, injuries of higher severity such as Gustilo-Anderson type IIIB and IIIC are correlated with higher rates of complications such as vascular injury, postoperative infection, delayed union, and LLD. Furthermore, in cases of severe injuries, a two-stage approach is commonly favored.

Conversion of failed revision total knee arthroplasty in arthrodesis with modular nail maintaining the uncemented femoral stem in patient with extensor mechanism insufficiency: a case report

BACKGROUND

The transition from revision total knee arthroplasty (RTKA) to arthrodesis involves the replacement of cemented femoral and tibial stems with a modular nail designed for arthrodesis. This conversion process is associated with challenges such as bone loss, blood loss, and prolonged surgical durations. Effectively addressing these complexities through a less invasive surgical approach could be pivotal in enhancing patient outcomes and minimizing associated complications.

CASE PRESENTATION

A 75-year-old white Caucasian female patient with a revision total knee arthroplasty (RTKA) performed with a modular uncemented rotating-hinge system, reporting an history of recurrent patellar dislocation, was referred to our institution after a fall resulting in periprosthetic tibial plateau fracture. The fracture was treated with open reduction and internal fixation, but afterwards the patient had been unable to walk again. Tibial stem was mobilized, and extensor mechanism was insufficient due to chronic incomplete quadriceps tendon rupture. The femoral stem was stable, so we decided to convert the rotating-hinge in a arthrodesis with an uncemented modular knee fusion nail maintaining the previous femoral stem.

CONCLUSIONS

The result was a successful arthrodesis with minimal bone and blood loss, reduced operative time, and optimal functional outcome at the one-year follow-up. This case highlights the advantage of using a modular knee revision platform system that gives the opportunity to convert a RTKA in arthrodesis.

Analyzing the Accuracy of Digital Sizing on Long-Leg Alignment X-rays by Using a 1-Inch Ball Bearing: A Cheap and Effective Method

Background and objective Sizing on digital films is important for implants and planning deformity correction. CT is the most accurate digital measurement method. We use a 1-inch ball bearing (cost: $1) to size our long-leg standing films (LLSFs) when planning deformity correction. In this study, we aimed to assess the accuracy of digital measurements calibrated by this method. Methods We conducted An IRB-approved study involving 25 patients having both an LLSF with a 1-inch ball bearing taped to the inner mid-thigh and a CT scanogram. The longest distance in the axial cut of the bilateral ankle, knee, and femoral heads of the CT images were compared to the same anatomic locations on LLSFs calibrated with the ball bearing using the online digital planning software DetroitBonesetter (DBS) and measurements from our Picture Archiving Communication Software (PACS). Five observers performed each measurement. Results The average measurement differences between the gold standard CT scan and LLSFs calibrated with DBS were as follows: 0.110 ± 0.432 mm (femoral head); 2.173 ± 0.0619 mm (knee); and 3.671 ± 0.30 mm (ankle). In PACS, they were as follows: 5.470 ± 0.381 mm (femoral head); 6.248 ± 0.712 mm (knee); and 1.806 ± 0.548 mm (ankle). The intraclass correlation coefficient for 600 measurements by five observers was 0.972. Conclusions The $1 ball-bearing sizing on DBS using LLSFs provides accuracy to <1 mm for the femoral head, 2 mm at the knee, and 3.7 mm at the ankle. It was significantly better than the PACS system for both the femoral head and knee (<0.001), while PACS was better at the ankle (<0.001).

Stability of One-Step Spray-on Splint for Lower Extremity Fractures During Splinting, MEDEVAC, and Impact

INTRODUCTION

Military transport can induce whole-body vibrations, and combat almost always involves high impact between lower extremities and the ground. Therefore, robust splinting technology is necessary for lower extremity fractures in these settings. Our team compared a novel one-step spray-on foam splint (FastCast) to the current military standard structured aluminum malleable (SAM) splint.

MATERIALS AND METHODS

Ten cadaveric specimens were subjected to complete tibia/fibula osteotomy. Specimens were fitted with custom accelerometer and gyroscope sensors superior and inferior to the fracture line. Each specimen underwent fracture and splinting from a standard of care SAM splint and an experimental FastCast spray foam splint in a randomized order. Each specimen was manually transported to an ambulance and then released from a 1 meter height to simulate impact. The custom sensors recorded accelerations and rotations throughout each event. Repeated-measures Friedman tests were used to assess differences between splint method within each event and between sensors within each splint method.

RESULTS

During splinting, overall summation of change and difference of change between sensors for accelerations and rotations were greater for SAM splints than FastCast across all axes (P ≤ 0.03). During transport, the range of acceleration along the linear superior/inferior axis was greater for SAM splint than FastCast (P = 0.02), as was the range of rotation along the transverse plane (P < 0.01). On impact, the summation of change observed was greater for SAM splint than FastCast with respect to acceleration and rotation on the posterior/anterior and superior/inferior axes (P ≤ 0.03), and the cumulative difference between superior and inferior sensors was greater for SAM than FastCast with respect to anterior-axis rotation (P < 0.05).

CONCLUSION

FastCast maintains stabilization of fractured lower extremities during transport and impacts to a significantly greater extent than SAM splints. Therefore, FastCast can potentially reduce the risk of fracture complications following physical stressors associated with combat and extraction.

Association of Fracture Location and Pattern With Nonunion or Malunion in Tibia Fractures Managed With Intramedullary Nailing: A Retrospective Study

Background and objective Extra-articular fractures of the tibia are common orthopedic injuries that are frequently treated with rigid intramedullary nailing. Fracture location and pattern may increase the risk of nonunion or malunion in fractures managed with intramedullary nails. This study aimed to assess the relationship between fracture pattern and location with malunion and nonunion. The primary objective was to evaluate the influence of fracture location and pattern on adverse clinical outcomes such as nonunion, delayed union, and malunion in tibial shaft fractures that are treated operatively with rigid intramedullary nails. Methodology This was a retrospective cross-sectional study conducted on patients operated in a tertiary care center in the Kingdom of Bahrain. The study included patients who sustained tibia shaft fractures and were subsequently operated with intramedullary of the tibia. The primary endpoint was the rate of adverse outcomes associated with fracture patterns. Fracture characteristics were to determine which fracture patterns healed well with intramedullary nailing and which fractures ended up with malunion or nonunion and would likely benefit from additional measures to augment the nail fixation and help encourage union. Results One hundred and eighty-nine patients were included in the study. The level of associated fibula fracture was significantly associated with an increased risk of nonunion and malunion (P = 0.0034, P = 0.001). The presence of a concomitant distal fibula fracture in association with tibia fractures increased the odds of nonunion (odds ratio [OR] = 4.871, P = 0.033, confidence interval [CI] = 1.133-20.948). Conclusions The level and pattern of some tibia and fibula fractures were associated with nonunion, malunion, and delayed union. Further studies with more robust follow-up are needed to examine these findings in greater detail.

[Three-dimensional analysis of posttraumatic tibial shaft malunion and correction based on the healthy, contralateral leg]

OBJECTIVE

Three-dimensional (3D) analysis and implementation with patient-specific cutting and repositioning blocks enables correction of complex tibial malunions. Correction can be planned using the contralateral side or a statistical model. Patient-specific 3D-printed cutting guide blocks enable a precise osteotomy and reduction guide blocks help to achieve anatomical reduction. Depending on the type and extent of correction, fibula osteotomy may need to be considered to achieve the desired reduction.

CONTRAINDICATIONS

a) Poor soft tissue (flap surgery, adherent skin in field of operation); b) infection; c) peripheral artery disease (stage III and IV classified according to Fontaine, critical transcutaneous oxygen partial pressure, TcPO2); d) general contraindication to surgery.

SURGICAL TECHNIQUE

Before surgery, a 3D model of both lower legs is created based on computed tomography (CT) scans. Analysis of the deformity based on the contralateral side in a 3D computer model (CASPA) and planning of the osteotomy. If the contralateral side also has a deformity, a statistical model can be used. Printing of patient-specific guides made of nylon (PA2200) for the osteotomy and reduction. Surgery is performed in supine position, antibiotic prophylaxis, thigh tourniquet, which is used as needed. Ventrolateral approach to the tibia. Attachment of the patient-specific osteotomy guide, performance of the osteotomy. Reduction using the guide. Fibula osteotomy through a lateral approach is performed if the reduction of the tibia is hindered by the fibula. This can be performed freehand or with patient-specific guides. Wound closure.

POSTOPERATIVE MANAGEMENT

Compartment monitoring. Passive mobilization of the ankle in the cast as soon as the wound healing has progressed. Partial weightbearing in a lower leg cast for at least 6-12 weeks, depending on the routinely performed radiographic assessment 6 weeks postoperatively. Thromboprophylaxis with low molecular weight heparin until cast removal.

RESULTS

Patient-specific correction of malunions are generally good. This could be confirmed for distal tibial corrections. For tibial shaft deformities, the final results are still pending. Preliminary results, however, show good feasibility with a pseudarthrosis rate of 10% without postoperative infection.

Mathematically Directed Single-Cut Osteotomy

A mathematically directed osteotomy (MDO) is a surgical planning technique for correcting long bone deformities. Using a mathematically derived osteotomy plane, the single-cut correction simultaneously addresses angular deformity, axial malrotation, and minor shortening. This review describes an MDO’s indications for use, defines its input and output variables, includes the required graphs for osteotomy planning, and provides intraoperative tips and tricks for successful execution. Finally, the authors present a digital MDO calculator to simplify the complex computations and allow for more precise planning.

Does a Customized 3D Printing Plate Based on Virtual Reduction Facilitate the Restoration of Original Anatomy in Fractures?

The purpose of this study was to evaluate the restoration of original anatomy after fixation of sawbone fractures using case-specific 3D printing plates based on virtual reduction (VR). Three-dimensional models of 28 tibia sawbones with cortical marking holes were obtained. The sawbones were fractured at various locations of the shaft and 3D models were obtained. The fractured models were reduced virtually and customized non-locking metal plates that fit the reduced model were produced via 3D printing. The fractured sawbones were actually fixed to the customized plate with nonlocking screws and 3D models were generated. With the proximal fragments of the 3D models overlapped, the changes in length, 3D angulation, and rotation of the distal fragment were evaluated. Compared to the intact model (IN), the virtual reduction model (VR) and the actual fixation model (AF) showed no significant differences in length. Compared to the IN, the VR and the AF had mean 3D angulations of 0.39° and 0.64°, respectively. Compared to the IN model, the VR and the AF showed mean rotations of 0.89° and 1.51°, respectively. A customized plate based on VR facilitates the restoration of near-original anatomy in fractures of tibial sawbone shaft.