Fibula In Relation Research Articles

Pronounced cortical porosity and sex-specific patterns of increased bone and osteocyte lacunar mineralization characterize the human distal fibula with aging

The high occurrence of distal fibula fractures among older women suggests a potential link to impaired bone health. Here we used a multiscale imaging approach to investigate the microarchitecture, mineralization, and biomechanics of the human distal fibula in relation to age and sex. Micro-computed tomography was performed to analyze the local volumetric bone mineral density and various microarchitectural parameters of the trabecular and the cortical compartment. Bone mineral density distribution and osteocyte lacunar parameters were quantified using quantitative backscattered electron imaging in periosteal, endocortical, and trabecular regions. Additionally, cortical hardness and Young's modulus were assessed by nanoindentation. While cortical porosity strongly increased with age independent of sex, trabecular microarchitecture remained stable. Notably, nearly half of the specimens showed non-bony hypermineralized tissue located at the periosteum, similar to that previously detected in the femoral neck, with no consistent association with advanced age. Independent of this finding, cortical and trabecular mineralization, i.e., mean calcium content, as well as endocortical tissue hardness increased with age in males but not females. Importantly, we also observed mineralized osteocyte lacunae that increased with age specifically in females. In conclusion, our results indicate that skeletal aging of the distal fibula is signified not only by pronounced cortical porosity but also by an increase in mineralized osteocyte lacunae in females. These findings may provide an explanation for the increased occurrence of ankle fractures in older women.

Suture button versus syndesmotic screw in ankle fractures - evaluation with 3D imaging-based measurements

BackgroundInadequate reduction of syndesmotic injuries can result in disabling clinical outcomes. The aim of the study was to compare syndesmosis congruity after fixation by syndesmotic screws (SYS) or a suture button system (SBS) using three-dimensional (3D) computed imaging techniques.MethodsIn a retrospective single-center study, patients with unilateral stabilization of an ankle fracture with a syndesmotic injury and post-operative bilateral CT scans were analyzed using a recently established 3D method. The side-to-side differences were compared for tibio-fibular clear space (∆CS), translation angle (∆α), and vertical offset (∆z) among patients stabilized with syndesmotic screws or suture button system. Syndesmotic malreduction was defined for ∆CS > 2 mm and for |∆α| > 5°. ∆CS and ∆α were correlated with two-dimensional (2D) measurements.ResultsEighteen patients stabilized with a syndesmosis screw and 29 stabilized with a suture button system were analyzed. After stabilization, both groups revealed mild diastasis (SYS: mean ∆CS 0.3 mm, SD 1.1 mm vs SBS: mean ∆CS 0.2 mm, SD 1.2 mm, p = 0.710). In addition, both stabilization methods showed slight dorsalization of the fibula (SYS: mean ∆α 0.5°, SD 4.6° vs SBS: mean ∆α 2.1°, SD 3.7°, p = 0.192). Also, restoration of the fibula-to-tibia length ratio also did not differ between the two groups (SYS: mean Δz of 0.5 mm, SD 2.4 mm vs SBS: mean Δz of 0 mm, SD 1.2 mm; p = 0.477). Malreduction according to high ∆α was most common (26% of cases), with equal distribution between the groups (p = 0.234). ∆CS and ∆α showed good correlation with 2D measurements (ρ = 0.567; ρ = 0.671).ConclusionThis in vivo analysis of post-operative 3D models showed no differences in immediate post-operative alignment after syndesmotic screws or suture button system. Special attention should be paid to syndesmotic malreduction in the sagittal orientation of the fibula in relation to the tibia in radiological control of the syndesmotic congruity as well as intra-operatively.

Is the fibula positioned posteriorly in weight-bearing in individuals with chronic ankle instability? A case control study

ABSTRACT Background: Clinically, a discrepancy of fibular position in relation to the tibia has been proposed as a factor in the persistence of chronic ankle instability (CAI). Previous studies have produced conflicting findings, perhaps due to varying radiological methods and measurement of participants in non-weight-bearing positions. Objectives: To compare normalized-fibular position in weight-bearing in individuals with CAI with healthy controls. Design: A weight-bearing lateral X-ray was taken of the affected ankle of 33 adults with CAI and 33 matched controls. The distance between the anterior edges of the distal fibula and tibia was recorded, and then normalized as a proportion of maximal tibial width. Normalized-fibular position was compared between groups using independent t-tests. Intra-class correlation coefficients (ICC2,1) were calculated to determine reliability of measurements. A receiver-operating characteristic (ROC) curve was used to determine sensitivity, specificity, and a cutoff score to differentiate individuals with CAI from controls using normalized-fibular position. Results: Normalized fibular position was significantly different (CAI, 29.7 (6.6)%; healthy, 26.7 (4.8)%) between the groups. Measurement of intra-rater (0.99, 95%CI = 0.98 to 1.00) and inter-rater (0.98, 95%CI = 0.96 to 0.99) reliability were both excellent. The threshold normalized-fibular position was 27%, with a score more than 27% indicating a greater chance of being in the CAI group. Sensitivity was 69.7% and specificity was 54.5% for this threshold. Conclusion: A slightly posteriorly positioned fibula in relation to the tibia was observed in people with CAI. Specificity/sensitivity scores for normalized-fibular position indicate that it has little ability to predict CAI alone.

A new standard radiographic reference for proximal fibular height in children

Background and purpose — To date there is a lack of studies defining the anatomical position of the proximal fibula. This is especially relevant when planning surgical interventions affecting the knee joint such as permanent or temporary epiphysiodesis to correct leg length discrepancies or angular deformities in growing patients. The goal of this study is to establish a standardized measurement technique and radiological reference values for the position of the proximal fibula in children.Patients and methods — 500 measurements were performed in calibrated long standing anteroposterior radiographs of 256 skeletally immature patients (8–16 years; 233 female, 267 male legs). As a radiographic reference in the frontal plane, the distance between the center of the proximal tibial growth plate and a line tangential to the tip of the fibular head and horizontal to the imaging plane was measured (dPTFH).Results — The average value of dPTFH in the studied population (median age 12 years) was –2.7 mm (SD 3, CI –3.0 to –2.5) and normally distributed (p = 0.1). There were no clinically significant sex or age-dependent differences. The inter-rater reliability analysis showed excellent ICC values (ICC = 0.88; CI 0.77–0.93).Interpretation — This study provides a new radiographic reference value to assess the position of the proximal fibula in relation to the proximal tibia in children and adolescents. This reference can aid preoperative decision-making as to whether additional fibular epiphysiodesis is necessary when performing tibial epiphysiodesis to correct moderate leg-length discrepancies.

Nutrient Foramen of Fibula in Relation to Distal end, Potential Implications for Vascularised Done Graft Surgery

Background Free vascularised fibular bone grafting has gained popularity in various Orthopaedic and Oral & maxillofacial reconstructive surgeries. The objective of the present study was to identify the morphology and topography of nutrient foramina of fibula and to determine the foraminal index (FI) of the fibula using a more surgeon friendly bony landmark. Methods The study comprised examination of 100 fibulae specimens. Each bone was divided into 03 parts and topographical analysis was performed on each section. The nutrient foramina were identified macroscopically using size 24-gauge needle. Modified Hughes formula was used to calculate the foraminal index using distance of foramen (DF) from distal end which is easier to palpate in living human beings, total length of fibula (TL); and the formula was DF/TL x100. Results With respect to fibulae, 98% had single foramen and foramen was absent in 2%. The mean foraminal index (FI) was 56% for fibulae using modified Hughes’ formula. The majority of the fibulae showed nutrient foramen in the middle 3rd in relation to distal end of fibula. Conclusion The study provides information on the morphology of nutrient foramina in relation to easily palpable landmark on living human beings, which can provide guidance to surgeon while performing microvascular bone transfer procedures.

The effects of weight bearing on the distal tibiofibular syndesmosis: A study comparing weight bearing-CT with conventional CT

BackgroundSyndesmotic injures are common and weight bearing imaging studies are often advocated to assess disruption. Although studies have examined the anatomical relationship between the fibula and incisura, the effect of weight-bearing on the syndesmosis has not been well reported. We characterise the changes which occur at the syndesmosis during weight-bearing. MethodsIn this retrospective review we analysed the position of the fibula at the syndesmosis in a cohort of patients who underwent both non-weight-bearing and weight-bearing CT scans. The relative position of the fibula to the incisura was analysed to determine translation and rotation in the axial plane. Results26 patients were included. Comparison of measurements revealed statistically significant differences between groups which indicated that on weight-bearing the fibula translated laterally and posteriorly, and rotated externally with respect to the incisura. ConclusionsThis is the first study to measure the differences in position of the syndesmosis during weight-bearing in a population of patients that have undergone both weight bearing and non weight bearing CT. Our study confirms that weight-bearing results in lateral and posterior translation, and external rotation of the fibula in relation to the incisura and our findings should help in future studies looking at the effect of weight bearing on syndesmotic pathology.

Arthroscopic Evaluation of Syndesmotic Instability in a Cadaveric Model.

Ankle fractures are among the most common lower extremity injuries. Proper care requires evaluation for syndesmotic ligament disruption. Ankle arthroscopy has been proposed as an intraoperative tool that can evaluate stability. Our focus was to evaluate the amount of displacement produced in the coronal, sagittal, and transverse planes visualized through ankle arthroscopy in a cadaveric model. Seven below-knee specimens were mounted in a traction tower. Four groups were evaluated: no ligamentous disruption; anterior inferior tibiofibular ligament and interosseous ligament disruption; above plus anterior talofibular ligament and calcaneofibular ligament disruption; and posterior inferior tibiofibular ligament and transverse ligament disruption. Force was applied and measured using a digital scale. The amount of displacement of the fibula in relation to the center of the incisura was measured under arthroscopic evaluation using a calibrated probe. An intact syndesmosis and lateral ankle ligaments provided multiplanar stability. In group 2, syndesmosis diastasis was appreciated in the transverse-external rotation plane with as little as 6 lb of force. In group 3, a greater amount of displacement was appreciated with less force. Multiplane instability was visible in every specimen with as little as 2 lb of force. Group 4 specimens were completely disrupted and so grossly unstable that testing was impossible. Ankle arthroscopy has the potential to evaluate even partial disruption of the syndesmotic ligament complex. Instability in the sagittal and transverse planes was encountered early in the spectrum of disruption. Traditional evaluation methods have poor sensitivity for instability in these planes. Arthroscopic evaluation of subtle displacement in multiple planes may assist the surgeon in understanding the extent of the syndesmotic injury. Further studies are necessary to determine to what extent instability requires fixation as well as the role for arthroscopy in assessing anatomic reduction of the syndesmosis after fixation is performed.

Assessment of Bosworth-type fracture by external oblique radiographs

IntroductionBosworth described an unusual fracture dislocation of the ankle with fixed posterior fracture dislocation of the fibula. This ankle fracture variant is often not recognized in initial radiographs and requires a computed tomographic scan for verification. It is usually not reducible by the closed method, and repeated trials induce more damage. The purpose of this study was to verify the usefulness of simple external oblique radiographs for diagnosis of Bosworth-type fracture. MethodsWe reviewed the 327 patients who were diagnosed as unilateral malleolus ankle fracture in 2002 to 2012. Four cases of Bosworth-type fracture were identified. External oblique radiograph was taken initially, immediately after first closed reduction, and after open reduction (3 phases) was undertaken to check the position of fibula in relation with the talus. Fifty cases of bimalleolar fractures and unaffected ankle were compared. Longitudinal bisecting line along the proximal fibula was drawn, and the talus was divided in 2 parts. Anterior and posterior part of the talus was defined as part α and β. The ratio resulted from dividing α with (α + β) implies the fibula position relative to the talus. ResultsMean α/(α + β) ratio of each phase were 0.4994, 0.4891, 0.2875, 0.2698, and 0.2709. There was significant difference in initial and first reduction phase of Bosworth-type fracture than other groups (P = < .0001). There was no significant difference in open reduced Bosworth-type fracture with bimalleolar fractures and unaffected ankles (P = .528, .602). ConclusionsAn external oblique radiograph provides useful information that can differentiate Bosworth-type fracture from other reducible bimalleolar fractures.

Intermediate ray deficiency--a new type of lower limb hypoplasia.

ObjectiveDiagnosis of fibular hemimelia is based on the identification of absence or shortening of the fibula in relation to the tibia. Despite the existence of different classifications of this congenital deficiency, certain morphological forms defy proper classification. One such form is absence of foot rays with leg shortening in the presence of an entire fibula. In these cases, foot morphology suggests that central foot rays, not lateral ones, are affected by the deficiency; thus justifying the hypothesis concerning the existence of a separate type of hypoplasia, which may be named “intermediate ray deficiency” (IRD).Materials and methodsNine patients with IRD, with an average age of 9.4 years at diagnosis (2.9–15), were analyzed. Clinical and radiographic parameters of the leg and foot were recorded according to the Stanitski classification of fibular hemimelia. The position of the lateral and medial malleoli was assessed. Axial alignment was analyzed according to the Paley method.ResultsThe number of foot rays in eight cases was 4, while in one case, it was 3. Talocalcaneal synostosis was observed in seven cases. The shape of the ankle joint was spherical in six cases, horizontal in two cases and valgus in one case. The position of the lateral malleolus was slightly higher compared to normal. An average functional leg length discrepancy was 4.4 cm. The average percentage of fibular shortening was 9.5 %, tibial shortening 8.7 % and femoral shortening 3.3 %. In all of the cases, slight knee valgus was observed on the femoral level (average 3.3°) and tibial level (average 2.0°). As a result, criteria for IRD diagnosis were proposed.Conclusion“Intermediate ray deficiency” might be defined as a separate type of lower limb hypoplasia.

Motion of the fibula relative to the tibia and its alterations with syndesmosis screws: A cadaver study

The motion of the fibula in relation to the tibia is coupled on the motion of the talus in the ankle joint. Several authors investigated this motion with different methods. An injury of the elastic fixation of the fibula to the tibia and its treatment with the syndesmotic set screw has an impact on this motion. The motion of the fibula relative to the tibia was measured in eight embalmed human above the knee amputated cadaver specimens using a 3D-motion analysis system. The relative motion was measured from 50° of plantar flexion to 30° of dorsiflexion. Experiments were performed in the following conditions: without fixation and intact ligaments, after sectioning of the four syndesmotic ligaments and the interosseous membrane, and application of either a tricortical screw, or a quadricortical screw or two quadricortical screws. Concordant movements of the lateral malleolus were a medial translation during plantar flexion, external rotation around the sagittal axis during plantar and dorsiflexion. The motion of the proximal fibula was smaller and more variable than in the distal part. After sectioning of the syndesmosis the range of motion, compared to the intact state increased, particularly in translation along the transversal (118%), sagittal (160%) and the longitudinal (136%) axis and in axial rotation (145%). Syndesmotic screws reduced the range of motion in transversal (p<0.006) and sagittal translation (p<0.011) and axial rotation. The small relative motion of the tibia and fibula is increased by syndesmotic injuries. Syndesmosis screws significantly limit this increased relative motion below physiologic values, which makes it necessary to remove the screws before flexion in the ankle joint is performed.

Anterior positional fault of the fibula after sub-acute lateral ankle sprains

Recent evidence has suggested a positional fault of the fibula exists in chronically unstable ankles. However, there has been little research examining positional faults after a sub-acute lateral ankle sprain (LAS). Our purpose was to measure the position of the distal fibula in relation to the distal tibia in subjects with sub-acute LASs and to determine if there is a relationship between the amount of swelling and fibular position. Eleven subjects with a unilateral sub-acute LAS and 11 healthy controls participated. The Wilcoxon signed rank test revealed a significant ( p = 0.008 ) difference within the ankles of the injured group. The sprained ankles had a mean fibular position of 14.2+3.4 mm and were positioned significantly more anteriorly than the contralateral uninjured ankles (17.0+3.2 mm). The Mann–Whitney test revealed a significant difference ( p = 0.045 ) between the sprained ankle and the side-matched limbs of the controls (16.8+2.3) Pearson product moment correlations revealed a strong positive correlation between fibular position and swelling ( r=0.793, p = 0.004 ). Those ankles with more swelling had the most anteriorly positioned fibulae. The fibulae in sub-acutely sprained ankles appear to be positioned more anteriorly compared to the contralateral ankles. This positional fault may be maintained acutely by swelling.

Comparison of Digital and Conventional Radiostereometric Image Analysis in an Ankle Phantom Model

Radiostereometric analysis (RSA) allows accurate three-dimensional measurements of micromotion in skeletal structures. The current RSA techniques are based on the analysis of scanned plain films. This study was undertaken to compare digital filmless RSA technique to conventional scanning technique using a phantom model of the ankle mortise. In the first experiment, the relative displacement of the markers inserted to the fibula in relation to the markers inserted to the tibia was studied by means of double examinations and the precision of DICOM images were compared to scanned images of printed radiographs. In the second experiment, the film pair of double examination was re-imported or re-scanned and self-compared in order to show merely the error related to the image processing. The precision of RSA using scanned images of printed radiographs was compatible to DICOM images. However, the mean error of rigid body fitting (ME) values were significantly lower in use of DICOM images compared with scanned radiographs, indicating less deformation of rigid body segments in filmless analysis. Precision of the RSA method was improved under the completely filmless environment. Therefore, this technique can be recommended for clinical studies of radiostereometric analysis.

Variations in Mortise Anatomy

Background Variations in ankle mortise anatomy may be a predisposing factor to ankle instability. Hypothesis A posteriorly positioned fibula associated with ankle instability may not be a true pathologic entity but rather the result of measuring off an internally rotated talus. Study Design Cohort study (diagnosis); Level of evidence, 2. Methods The authors reviewed 60 ankle computed tomography scans performed on patients from their institution for reasons unrelated to ankle instability. They also reviewed ankle computed tomography scans on 21 patients surgically treated for clinical ankle instability. The position of the fibula in relation to the talar articular surface was calculated and expressed as the axial malleolar index, as described by Scranton et al. They also calculated the intermalleolar index, a new method that references the medial malleolus, not the talus. Results Using the method of Scranton et al, the axial malleolar index in the control and instability patients was similar to values previously described, and there was a significant difference between control and instability patients (P <. 01). However, using the intermalleolar index method referencing the medial malleolus, there was not a significant difference between control and instability patients (P =. 43). Conclusion The new method of referencing the medial malleolus assesses fibular position independent of talar rotation. The data, when referencing the medial malleolus, do not show significant variation in fibular position in patients with and without ankle instability.

The mobility of the proximal tibio-fibular joint. A Roentgen Stereophotogrammetric Analysis on six cadaver specimens.

In six cadaver specimens the mobility of the proximal fibula in relation to the tibia was investigated during plantar/dorsiflexion of the ankle, using Roentgen Stereophotogrammetric Analysis (RSA). The role of the ankle joint, and of the calcaneofibular and talofibular ligaments was also evaluated. The greatest movements were observed along the mediolateral and anterior-posterior axes, resulting in an anterolateral displacement of the fibula head during dorsiflexion and in a postero-medial displacement during plantarflexion. This study demonstrated a limited mobility of the proximal tibiofibular joint. Moreover, the ligament cutting and the presence of constraints in the ankle region did not show any effect on the fibular movement.

Biomechanical Study on the Load-Bearing Characteristics of the Fibula and the Effects of Fibular Resection

The objective of this research was to investigate the load-bearing function of the fibula in relation to donor leg morbidity in patients who have had fibular resections. Biomechanical loading experiments were performed on ten anatomic specimens. Force transducers were mounted in place of resected tibial and fibular segments to allow load transmission to be measured. Load transmission through the fibula varied with ankle position. With the ankle at neutral position, the load distribution to the fibula averaged 7.12% of the total force transmitted through the tibia and fibula. Maximum loads occurred at full dorsiflexion and eversion. Resection of the proximal fibula results in a significant reduction of load through the distal fibular remnant. The values varied between 0.62% and 0.81% of the total force transmitted. When a cortex screw was introduced to anchor the distal fibula remnant to the tibia, the load distribution to the distal fibula remnant was partially restored with values ranging from 1.71% to 5.14% of the total force transmitted depending on the different ankle positions. These observations suggest that more consideration of the loading characteristics of the fibula should be taken into account in planning resection operations.

In vivo fibular motions during various movements of the ankle

In eight healthy volunteers the angular and translatory motions of the fibula in relation to the tibia were investigated by roentgenstereophotogrammetry. Tantalum markers (0·8mm) were introduced into the tibia and fibula of the right leg. Examinations were performed with full body load in 10° increments of plantar-/dorsiflexion and pro-/supination of the foot, and during internal/external rotation of the leg. The reproducibility was found to be good. From 30° of plantar flexion to 30° of dorsiflexion there was an average widening of the ankle mortise of 1·04 mm and an average backward translation of the fibula in relation to the tibia of 1·03 mm. These displacements were statistically significant ( P < 0·5). Seventy-two per cent of the width increase occurred in the plantar flexion part of the arc. The upwards/downwards displacement of the fibula in no case exceeded 0·1 mm. The outward/inward rotation of the fibula was small. Movements resulting from input pro-/ supination of the foot and from internal/external rotation of the leg were small.

Mobility of the lateral malleolus. A roentgen stereophotogrammetric analysis.

In nine children and adolescents, the motion of the distal fibula in relation to the tibia was measured by roentgen stereophotogrammetry. Between the extremes of ankle flexion, the fibular epiphysis moved on average 1.4 mm.