Predicting Tibia-Fibula Geometry and Density From Anatomical Landmarks Via Statistical Appearance Model: Influence of Errors on Finite Element-Calculated Bone Strain

State-of-the-art participant-specific finite element models require advanced medical imaging to quantify bone geometry and density distribution; access to and cost of imaging is prohibitive to the use of this approach. Statistical appearance models may enable estimation of participants' geometry and density in the absence of medical imaging. The purpose of this study was to: (1) quantify errors associated with predicting tibia-fibula geometry and density distribution from skin-mounted landmarks using a statistical appearance model and (2) quantify how those errors propagate to finite element-calculated bone strain. Participant-informed models of the tibia and fibula were generated for thirty participants from height and sex and from twelve skin-mounted landmarks using a statistical appearance model. Participant-specific running loads, calculated using gait data and a musculoskeletal model, were applied to participant-informed and CT-based models to predict bone strain using the finite element method. Participant-informed meshes illustrated median geometry and density distribution errors of 4.39-5.17 mm and 0.116-0.142 g/cm3, respectively, resulting in large errors in strain distribution (median RMSE = 476-492 με), peak strain (limits of agreement =±27-34%), and strained volume (limits of agreement =±104-202%). These findings indicate that neither skin-mounted landmark nor height and sex-based predictions could adequately approximate CT-derived participant-specific geometry, density distribution, or finite element-predicted bone strain and therefore should not be used for analyses comparing between groups or individuals.

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.

Pachydysostosis of the fibula in a case of familial adenomatous polyposis

BACKGROUND

Familial Adenomatous Polyposis (FAP) is a colorectal cancer (CRC) predisposition syndrome caused by germline APC mutations and characterised by an increased risk of CRC and colonic polyps and, in certain forms, of specific prominent extraintestinal manifestations, namely osteomas, soft tissue tumours and dental anomalies. Pachydysostosis of the fibula is a rare clinical entity defined by unilateral bowing of the distal portion of the fibula and elongation of the entire bone, without affectation of the tibia.

CLINICAL REPORT

We report a 17-year-old male, who presented with a non-progressive bowing of the right leg detected at 18 months of age caused by a fibula malformation (later characterized as pachydysostosis) and a large exophytic osteoma of the left radius, noticed at the age of 15 years, without gastrointestinal symptoms. There was no relevant family history. Detailed characterisation revealed multiple osteomas, skin lesions and dental abnormalities, raising the hypothesis of FAP. This diagnosis was confirmed by genetic testing [c.4406_4409dup p.(Ala1471Serfs*17) de novo mutation in the APC gene] and endoscopic investigation (multiple adenomas throughout the colon, ileum and stomach).

DISCUSSION

This case report draws attention to the phenotypic spectrum of skeletal manifestations of FAP: this patient has a congenital fibula malformation, not previously associated with this syndrome, but which is likely to have been its first manifestation in this patient. This clinical case also illustrates the challenges in the early diagnosis of FAP, especially without family history, and highlights the importance of a multidisciplinary approach and the adequate study of rare skeletal abnormalities.

An imageology-based feasibility study of plating posterolateral tibial plateau fractures via an anterolateral trans-fibular-head approach

BACKGROUND

There are many difficulties in the reduction and fixation of the tibial plateau fractures involving posterolateral quadrant using general plates via traditional approaches. By imaging the area above the fibulae capitulum, this study was performed to investigate the feasibility of the trans-fibular-head approach and to design an ideal anatomical plate.

METHODS

MRI and CT scans of the knee joint were collected from 205 healthy volunteers (103 males, 102 females). Gender and height were used to divide the volunteers into groups separately: (1) A1 group and A2 group according to gender, (2) B1 group and B2 group according to height. Based on the images, several parameters were defined and measured to describe the space above the head of the fibula. In addition, differences in these parameters between genders and height were compared.

RESULTS

The narrowest distance in the bony region was (10.96 ± 1.39) mm, (5.41 ± 0.97 mm) in the bone-ligament region. The narrowest distance of bony region in the A1 group was more than that in the A2 group (11.21 ± 1.62 mm, 10.85 ± 1.47 mm, p = 0.029). The narrowest distance of the bony region was (10.21 ± 1.42) mm and (11.65 ± 1.39) mm in the B1 group and B2 group, respectively (p = 0.002). The narrowest distance of the bone-ligament region was (5.39 ± 0.78) mm and (5.22 ± 1.21) mm in the A1 group and A2 group, respectively. No statistically significant differences were observed between the A1 group and the A2 group in terms of the narrowest distance of the bone-ligament region. In the B1 group, the narrowest distance of the bone-ligament region (5.18 ± 0.71 mm) was not significantly less than that (5.31 ± 0.91 mm) in the B2 group.

CONCLUSION

The space above the fibular capitellum was ample enough to place the plate for treating tibial plateau fractures involving posterolateral quadrant. The divisions of the lateral tibial plateau by 3-dimensional CT and the parameters of each region were crucial for providing guidance for designing the anatomical plate for the trans-fibular-head approach.

Ultrasound Assessment of Ankle Syndesmotic Injuries in a Pediatric Population

OBJECTIVE

To determine sensitivity and specificity for anterior-inferior tibiofibular ligament (AiTFL) integrity and tibiofibular clear-space (TFCS) cut-off points for dynamic evaluation using ultrasound (US) in a pediatric population.

DESIGN

Prospective cohort study.

SETTING

Tertiary care university-affiliated pediatric hospital patients between the ages of 12 and 18 sustaining acute ankle trauma with syndesmotic injury.

INTERVENTIONS

Participants were assigned to the syndesmotic injury protocol that included a standardized MRI and US.

MAIN OUTCOME MEASURES

Anterior-inferior tibiofibular ligament integrity for static assessment and TFCS measurements for dynamic assessment on US. For dynamic assessment, the distance between the distal tibia and fibula was first measured in neutral position and then in external rotation for each ankle. The US results on AiTFL integrity were compared with MRI, considered as our gold standard. Optimal cut-off points of TFCS values were determined with receiver operating characteristics curve analysis.

RESULTS

Twenty-six participants were included. Mean age was 14.8 years (SD = 1.3 years). Sensitivity and specificity for AiTFL integrity were 79% and 100%, respectively (4 false negatives on partial tears). For dynamic assessment, the cut-off points for the differences in tibiofibular distance between the 2 ankles in 1) neutral position (TFCS N I-U ) and 2) external rotation (TFCS ER I-U ) were 0.2 mm (sensitivity = 83% and specificity = 80%) and 0.1 mm (sensitivity = 83% and specificity = 80%), respectively.

CONCLUSIONS

Static US could be used in a triage context as a diagnostic tool for AiTFL integrity in a pediatric population as it shows good sensitivity and excellent specificity.

Image Rotation Alters Apparent Fibula Length: An Evaluation of Talocrural Angle, Shenton Line, and Dime Sign

BACKGROUND

Fibula shortening can compromise ankle stability and force transmission, thereby impacting clinical outcomes. Because radiographs depict 3-dimensional anatomy in 2 dimensions, accurate radiographic assessment of fibula length is a commonly encountered clinical challenge. The talocrural angle (TCA), Shenton line, and dime sign are useful parameters of fibula length. Yet, the impact of 3-dimensional limb positioning on these radiographic parameters is not established.

METHODS

Bone models were constructed from CT scans of 30 lower limbs. Fibula length was computationally manipulated, and digitally reconstructed radiographs were generated reflecting 1-degree increments of sagittal and axial plane rotation of each limb for each fibula length condition. The TCA was computationally measured on each image. The presence of an aligned mortise view, intact Shenton line, and intact dime sign was assessed by 2 observers.

RESULTS

The mean TCA, which was 78.0 (95% CI ± 1.6) degrees for a true mortise projection with anatomic fibula length, changed by approximately 1 degree per millimeter of fibula length change. On average, 14.7 degrees of caudal rotation obscured 2 mm of fibular shortening by virtue of producing the same TCA as a true mortise view with anatomic fibula length, designated a false positive view. Axial rotation had a comparatively small effect. Observers 1 and 2 were, respectively, 91% and 88% less likely to accurately judge the image alignment of the false positive images compared to true mortise images. Moreover, intraobserver agreement was poor to moderate (mean 0.47, range 0.13-0.59) and interobserver agreement was uniformly poor (mean 0.08, range 0.01-0.20).

CONCLUSION

In our study using digitally reconstructed radiographs from CT scans of 30 limbs, we found that sagittal plane rotation impacts the radiographic appearance of fibula length as measured by the TCA. Limb axial rotation had a comparatively small effect. Further study of human perception of Shenton line and dime sign is needed before the effect of rotation on these parameters can be fully understood.

LEVEL OF EVIDENCE

Level IV, case series.

Does Fibular Displacement Predict Tibial Malrotation in Simulated Tibia-Fibula Fractures

INTRODUCTION

Tibial malrotation can occur with medullary nailing of diaphyseal tibial fractures. Fibular alignment has been proposed as a surrogate for axial plane reduction intraoperatively. The purpose of this study was to determine whether fibular alignment is a reliable marker of accurate tibial rotation.

METHODS

Deidentified CT scans of 50 patients with normal tibial anatomy were selected. Using ImageJ software, we simulated osteotomies at three sites (proximal third, mid-diaphysis, and distal third). We overlaid adjacent CT slices and rotated them around the central axis of the tibia in 5° increments of external rotation (ER) and internal rotation (IR). At each increment, measurements of fibular overlap (%) were obtained from anteroposterior (AP) and lateral views. To simulate fixation of the fibula, we repeated rotation around the axis of the fibula with and without a simulated medullary implant in the tibia.

RESULTS

A total of 50 patients were included. The mean age was 62 years, average BMI was 25.8, and 28 of 50 patients (56%) were male. Earliest loss of fibular contact occurred at 24° ER and 22° IR at the proximal site. Contact was lost at 26° ER and 28° IR on the AP view and 42° ER and 29° IR on the lateral view. The mean fibular contact at each 5° increment was similar for ER and IR. Fibular contact was reduced to 50% at 10 to 15° of rotation in ER and IR at all sites. Tibial canal contact was lost at 24° in both ER and IR around the fibula. With a virtual medullary implant, the mean maximal rotation was 6°.

DISCUSSION

Surgeons should be aware that 20° or more of malrotation is likely present when fibular contact is lost during medullary nailing of the tibia. Greater than 50% loss of contact should raise suspicion for malrotation. A fixed fibula and medullary tibial implant theoretically preclude significant tibial malrotation.

Predictive value of clinical features and CT radiomics in the efficacy of hip preservation surgery with fibula allograft

BACKGROUND

Despite being an effective treatment for osteonecrosis of the femoral head (ONFH), hip preservation surgery with fibula allograft (HPS&FA) still experiences numerous failures. Developing a prediction model based on clinical and radiomics predictors holds promise for addressing this issue.

METHODS

This study included 112 ONFH patients who underwent HPS&FA and were randomly divided into training and validation cohorts. Clinical data were collected, and clinically significant predictors were identified using univariate and multivariate analyses to develop a clinical prediction model (CPM). Simultaneously, the least absolute shrinkage and selection operator method was employed to select optimal radiomics features from preoperative hip computed tomography images, forming a radiomics prediction model (RPM). Furthermore, to enhance prediction accuracy, a clinical-radiomics prediction model (CRPM) was constructed by integrating all predictors. The predictive performance of the models was evaluated using receiver operating characteristic curve (ROC), area under the curve (AUC), DeLong test, calibration curve, and decision curve analysis.

RESULTS

Age, Japanese Investigation Committee classification, postoperative use of glucocorticoids or alcohol, and non-weightbearing time were identified as clinical predictors. The AUC of the ROC curve for the CPM was 0.847 in the training cohort and 0.762 in the validation cohort. After incorporating radiomics features, the CRPM showed improved AUC values of 0.875 in the training cohort and 0.918 in the validation cohort. Decision curves demonstrated that the CRPM yielded greater medical benefit across most risk thresholds.

CONCLUSION

The CRPM serves as an efficient prediction model for assessing HPS&FA efficacy and holds potential as a personalized perioperative intervention tool to enhance HPS&FA success rates.

Morphology of the proximal tibiofibular joint and ligaments using three-dimensional computed tomography: A cadaveric study

BACKGROUND

The aim of our study was to clarify the morphology of the proximal tibiofibular joint (PTFJ), insertion sites of the proximal tibiofibular ligaments (PTFLs), and related osseous landmarks on three-dimensional (3D) computed tomography (CT) images.

METHODS

Cadaveric knees were evaluated by dissection and 3D CT imaging. The anterior PTFL (A-PTFL) and posterior PTFL (P-PTFL) were isolated, and their tibial and fibular insertion sites were identified. The morphology and location of insertion sites and their positional relationships with osseous structures were analyzed on 3D CT images.

RESULTS

The A-PTFL comprised up to four bundles, and the P-PTFL comprised two bundles. The mean length of the A-PTFL and P-PTFL was 11.3 mm and 10.3 mm, respectively. On the tibial side of the PTFJ, bony prominences were present at the A-PTFL and P-PTFL insertion sites and were clearly identified as osseous landmarks in all knees. On the fibular side, the A-PTFL and P-PTFL insertion sites were at the edge of the triangular pyramid of the fibular head. The mean PTFJ area was 198.8 mm2, and the mean inclination angle between PTFJ and tibial plane was 38.4°. There was an inverse correlation between the PTFJ surface area and the inclination angle.

CONCLUSION

The present study clearly identified PTFL insertion sites on the tibia and fibula and showed the relationships between these insertions and osseous landmarks. These data improve our understanding of the anatomy of PTFL insertions, which may assist surgeons in performing anatomical reconstruction.

The anteroposterior distance between the posterior edge of the medial tibial condyle and the posterior edge of the fibular head in the lateral view can be a reference in determining the axis perpendicular to the tibial anteroposterior axis

BACKGROUND

Obtaining an accurate tibial lateral view is important during high tibial osteotomy. This study investigated whether the posterior edge of the medial/lateral tibial condyle (PEMTC/PELTC) and the posterior edge of the fibular head (PEFH) in a lateral view could be a reference for determining the accurate tibial lateral view.

METHODS

A total of 75 lower limbs in 38 subjects were evaluated in this study. In order to target healthy knees, subjects undergoing primary total hip arthroplasty were selected. The MF/LF, comprising the anteroposterior distance between PEMTC/PELTC and PEFH, was measured on the lateral view of the tibial bone model based on the tibial anteroposterior (AP) axis (true lateral view: TLV). In addition, measurements were calculated in the model with a 10° external/internal rotation. Using these measurements, linear regression analysis was performed to predict the tibial rotation with MF/LF.

RESULTS

The mean MF/LF was 0.9/4.6 mm (P < 0.001). MF and LF increased with incremental tibial rotation. Regression formulas were derived from these results as follows: Tibial rotation = (1) -1.01 + 1.06 × MF (R2 = 0.87, P < 0.001), (2) -8.70 + 1.86 × LF (R2 = 0.51, P < 0.001). The mean tibial rotation angle when MF was 0 mm was -0.9°.

CONCLUSIONS

Based on formula (1) and actual measurements, the mean tibial rotation angle when MF is 0 mm is an internal rotation of about 1°. Therefore, a lateral view, in which PEMTC and PEFH are seen colinearly, can be the approximate TLV. The MF can be a suitable intraoperative reference in determining TLV.

Radiological landmark of syndesmotic ligament complex by magnetic resonance imaging correlate with fibula free flap harvesting procedure

Preservation of syndesmotic ligaments is crucial for preventing adverse sequelae at the donor site following free fibula osteocutaneous flap harvesting. This study sought to determine the relationship between distal tibiofibular ligaments and the fibular segment to identify radiological landmarks that facilitate safe and precise flap. The distances between the distal tibiofibular ligaments (anterior inferior tibiofibular ligament [AITFL], posterior inferior tibiofibular ligament [PITFL]) and the fibular segment, as well as the lower border of the interosseous membrane, were measured on magnetic resonance imaging (MRI) scans of 296 patients without any perceivable ankle abnormalities. The mean distances (± SD) between the distal end of the fibula and the AITFL, PITFL, and lower interosseous membrane border were 3.0 ± 0.4 cm, 2.6 ± 0.4 cm, and 3.9 ± 0.6 cm, respectively. The distance between the talar dome and the PITFL exhibited a range of 0.0-0.5 cm. Our findings support preserving a distal fibular remnant of at least 4 cm to avoid injury to the syndesmotic ligament throughout fibula osteocutaneous flap harvesting. The talar dome could serve as a useful radiological landmark for identifying the upper border of PITFL during preoperative evaluation, and thus facilitating precise and safe flap procurement.

Automatic segmentation of inconstant fractured fragments for tibia/fibula from CT images using deep learning

Orthopaedic surgeons need to correctly identify bone fragments using 2D/3D CT images before trauma surgery. Advances in deep learning technology provide good insights into trauma surgery over manual diagnosis. This study demonstrates the application of the DeepLab v3+ -based deep learning model for the automatic segmentation of fragments of the fractured tibia and fibula from CT images and the results of the evaluation of the performance of the automatic segmentation. The deep learning model, which was trained using over 11 million images, showed good performance with a global accuracy of 98.92%, a weighted intersection over the union of 0.9841, and a mean boundary F1 score of 0.8921. Moreover, deep learning performed 5-8 times faster than the experts' recognition performed manually, which is comparatively inefficient, with almost the same significance. This study will play an important role in preoperative surgical planning for trauma surgery with convenience and speed.

Comparison of different fibula procedures in tibiotalocalcaneal arthrodesis with a retrograde intramedullary nail: a mid-term retrospective study

BACKGROUND

Tibiotalocalcaneal (TTC) arthrodesis with a retrograde intramedullary nail for severe tibiotalar and talocalcaneal arthritis has a high fusion rate; however, no studies have focused on how to handle the fibula intraoperatively to achieve better results. This study aimed to compare the efficacies of various fibular procedures.

METHODS

We retrospectively reviewed the cases of severe tibiotalar and talocalcaneal arthritis in adults treated with TTC arthrodesis using a retrograde intramedullary nail between January 2012 and July 2017. The patients were divided into three groups according to different fibular procedures: Fibular osteotomy (FO), fibular strut (FS), and fibular preservation (FP). Functional outcomes and pain were assessed using the American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score and visual analog scales (VAS), respectively. The operation time, fusion time, radiographic evaluation, and complications were also recorded.

RESULTS

Fifty-eight patients with an average age of 53.2 (range, 32-69) years were enrolled in the final analysis. The numbers of patients enrolled in the three groups were 21, 19, and 18 in the FO, FS, and FP groups, respectively. The mean postoperative follow-up time was 66.0 (range, 60-78) months. All groups showed a high fusion rate (90.5% for FO, 94.7% for FS, and 94.4% for FP) and significant improvement in AOFAS ankle and hindfoot scores and VAS scores at the latest follow-up. There were no significant differences in these parameters among the three groups. The mean operation time of FS (131.3 ± 17.1 min) was longer than that of FO (119.3 ± 11.7 min) and FS (112.2 ± 12.6 min), but the fusion time was shorter (15.1 ± 2.8 weeks for FS, 17.2 ± 1.9 weeks for FO, and 16.8 ± 1.9 weeks for FP). Statistically significant differences were observed in these parameters.

CONCLUSIONS

TTC arthrodesis using a retrograde intramedullary nail is an effective procedure with a high rate of fusion to treat severe tibiotalar and talocalcaneal arthritis in adults; however, FSs can shorten fusion time when compared with FO and FP.

LEVEL OF CLINICAL EVIDENCE

Level 3.

Treatment of Recalcitrant Isolated Congenital Fibular Pseudarthrosis: Fibular Segment Transfer and Tibiofibular Synostosis with Unilateral External Fixator

Isolated congenital pseudarthrosis of the fibula is a rare entity with a limited number of cases reported in the literature. Treatment is challenging because of recalcitrant nonunion and because no consensus about the best treatment plan exists. We report a case of isolated congenital fibular pseudarthrosis with valgus deformity of the ankle. The patient had a history of two failed operations. We used a novel surgical plan that combined tibiofibular synostosis with fibular segment transfer through a unilateral external fixator. The patient showed good early results with fibular union. We advocate the combination of tibiofibular synostosis and fibular segment transfer to restore the integrity and stability of the ankle in recalcitrant isolated congenital fibular pseudarthrosis cases with a history of failed surgery.

Reconstruction of complicated spinal tuberculosis with long-segment fibula transplantation: a case report

BACKGROUND

Treating complex cases of spinal tuberculosis (STB) that involve multiple vertebral bodies and cause destruction of the spinal structure, kyphotic deformity, and acute nerve injury can be challenging. This report describes the course of treatment and 5-year follow-up of a complex case of multisegmental STB.

CASE PRESENTATION

This report describes a case of tuberculosis affecting the vertebrae extending from thoracic 12 to lumbar 5 in a 60-year-old woman who suffered sudden paralysis in both lower extremities. The patient underwent emergency posterior paraspinal abscess clearance, laminectomy with spinal decompression. Partial correction of the kyphotic deformity via long-segment fixation from the T9 vertebral body to the ilium in a one-stage posterior procedure. The patient's neurological status was diagnosed as grade E on the American Spinal Injury Association (ASIA) scale after the one-stage operation. Following standardized 4-combination anti-tuberculosis drug therapy for three months in postoperative patients, the patient underwent two-stage transabdominal anterior abscess removal, partial debridement of the lesion and bilateral fibula graft support. One year after the two-stage operation, the patient's visual analog scale (VAS) score of back pain was 1 point, and the patient's erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels returned to normal. Five years after the second-stage operation, the Oswestry disability index (ODI) of patient quality of life was 14 points. There was a 4-degree change in the Cobb angle over five years. During the five-year follow-up period, the grafted fibula did not experience any subsidence.

CONCLUSION

For patients with spinal tuberculosis and acute paralysis, it is essential to relieve spinal cord compression as soon as possible to recover spinal cord function. For lesions that cannot be debrided entirely, although limited debridement combined with anti-tuberculosis drug therapy has the risk of sinus formation and tuberculosis recurrence, it is much safer than the risk of thorough debridement surgery. In this case, an unconventional long-segment fibula graft, pelvis-vertebral support, was an effective reconstruction method.

Impact of the adjacent bone on pseudarthrosis in mandibular reconstruction with fibula free flaps

BACKGROUND

Mechanical and morphological factors have both been described to influence the rate of pseudarthrosis in mandibular reconstruction. By minimizing mechanical confounders, the present study aims to evaluate the impact of bone origin at the intersegmental gap on osseous union.

METHODS

Patients were screened retrospectively for undergoing multi-segment fibula free flap reconstruction of the mandible including the anterior part of the mandible and osteosynthesis using patient-specific 3D-printed titanium reconstruction plates. Percentage changes in bone volume and width at the bone interface between the fibula/fibula and fibula/mandible at the anterior intersegmental gaps within the same patient were determined using cone-beam computed tomography (CBCT). Additionally, representative samples of the intersegmental zones were assessed histologically and using micro-computed tomography (µCT).

RESULTS

The bone interface (p = 0.223) did not significantly impact the change in bone volume at the intersegmental gap. Radiotherapy (p < 0.001), time between CBCT scans (p = 0.006) and wound healing disorders (p = 0.005) were independent risk factors for osseous non-union. Preliminary analysis of the microstructure of the intersegmental bone did not indicate morphological differences between fibula-fibula and fibula-mandible intersegmental bones.

CONCLUSIONS

The bone interface at the intersegmental gap in mandibular reconstruction did not influence long-term bone healing significantly. Mechanical and clinical properties seem to be more relevant for surgical success.

Fibular Fixation in Same-Level Distal Third Tibiofibular Fractures: Is Fibular Fracture Regarded as a Secondary Importance?

Background

Although most studies focused on the alignment or union of the tibia in same-level distal third tibiofibular fractures, the outcome of a concomitant fibular fracture is generally regarded as being of secondary importance in the literature. This study aimed to assess the outcomes of fibular fractures in same-level distal third tibiofibular fractures.

Methods

In this retrospective study, we enrolled 111 patients with same-level distal third tibiofibular fractures treated at our institute between January 2016 and August 2020. Tibial fractures were stabilized with intramedullary nailing, and the cases were divided into two groups based on whether they additionally underwent fibular fixation (group 1, 57 cases) or not (group 2, 54 cases). Clinical and radiographic outcomes were used for the evaluation of tibial and fibular alignments, union of the tibia and fibula, number of interlocking screws in the distal tibial fragment, range of motion of the ankle joint, and complications.

Results

No statistically significant differences in the tibial union rate or mean tibial alignment were observed between the two groups on either the immediate postoperative or final radiographs. The fibular union rate in group 1 was significantly higher than that in group 2 (fibular nonunion, 0 vs. 15; p < 0.001). Statistically significant differences in fibular displacement were observed on immediate postoperative radiographs between patients with fibular union and those without it. At the final follow-up, the mean range of ankle motion and lower extremity functional scale scores did not differ between the two groups.

Conclusions

Regardless of whether fibular fixation was performed, the overall tibial alignment with intramedullary nailing was well restored and the union rate of the tibia was comparable in the two groups. Fibular nonunion is not uncommon in unfixed fibula fractures. Displacement of the fibula as seen on immediate postoperative radiographs was related to fibular nonunion.

Pediatric Peroneal Nerve Palsy Secondary to Fibular Osteochondroma

Peripheral nerve injuries due to mass effect from bony lesions can occur when the nerve exists in an anatomically constrained location, such as the common peroneal nerve at the fibular head which passes into the tight fascia of the lateral leg compartment. We report a case of a pediatric patient who developed a common peroneal nerve palsy secondary to an osteochondroma of the fibular head and describe the clinical evaluation, radiographic findings, and surgical approach. Rapid diagnosis and nerve decompression after the onset of symptoms restored full motor function at the 8-month postoperative mark.

The lowest point of fibula (LPF) could be used as a reliable bony landmark for arthroscopic anchor placement of lateral ankle ligaments ----compared with open Broström procedure

BACKGROUND

Arthroscopic technique procedures was wide accepted for the treatment of chronic ankle instability (CAI). But little acknowledge was involved to the bony landmarks and anatomic features of different bundles of lateral ligaments under arthroscopic view.

METHODS

Sixty patients with acute or chronic lateral ankle ligaments injury (LAI) were collected prospectively, and divided randomly into two groups. In arthroscopic group, the bone tunnels were made on the LPF arthroscopically. And in open group, the bone tunnels were made on the Fibular obscure tubercle (FOT) in open procedure. The inferior bundle of ATFL and Arcuate fibre was also identified reference to the LPF and labeled by a PDS II suture penetration. Following that, The distances of the bone tunnels to the different bony markers were measured and compare between two groups. The penetrating locations of PDS II on the inferior bundle of ATFL and Arcuate fibre were also confirmed intraoperatively. And the safe angle of anchor implantation on the axial view was measured on postoperative CT scan.

RESULTS

The distances of bone tunnel to the fibular tip, the fibular insertion of anterior-inferior tibiofibular ligament (AITFL), and the FOT in arthroscopic and open locating groups were 4.9 ± 2.2 and 6.3 ± 2.2 mm, 13.5 ± 2.7 and 12.4 ± 1.1 mm, 5.8 ± 2.2 and 5.6 ± 1.0 mm, respectively. The distances of bone tunnels to the FOT and fibular tip on 3d-CT view was 4.4 ± 1.5 and 4.6 ± 0.9 mm, 14.4 ± 3.2 and 13.2 ± 1.8 mm in arthroscopic and open group, and there were no significant differences between two groups. The safe angle of arthroscopic anchor placement on the axial plan was ranged from 24.9 ± 6.3o to 58.1 ± 8.0o. The PDS II sutures penetrating on the inferior bundles of ATFL and the arciform fibres were also comfirmed successfully by open visualizaion.The average distance of penetration point to the horizontal line cross the fibular tip was 2.3 ± 2.7 mm (ranged from - 3.1 to 6.0 mm), and to the vertical line cross the FOT was 2.7 ± 2.7 mm (ranged from - 2.5 to 7.5 mm).

CONCLUSION

Take the lowest point of fibula under arthroscopy (LPF) as a bony reference, we could identify the iATFL under arthroscopic visualization. By this way, we could place the suture anchors properly to the fibular footprint and suture the iATFL fibres successfully.

The safe zone of distal fibula was determined based on the classification of lateral malleolus fossa

BACKGROUND

Lateral malleolus fractures are very common, and the distal fibular geometry is complex. This study aimed to classify the lateral malleolus fossa (MF) into different types by characterizing the lateral MF imaging morphology and exploring the relationship between the lateral MF and internal fixation position after distal fibula fractures.

METHODS

Anteroposterior CT reconstruction was performed on 248 subjects. After reconstruction, the deepest point of the lateral MF was located, and then, the cross-sectional shape of the lateral MF was observed and classified.

RESULTS

According to the morphology of the CT cross section, the lateral MF was divided into three types: type C (43.1%), type V (32.2%), and type Flat (24.7%). Type V (3.98 ± 0.82) was significantly longer than type C(2.83 ± 0.54) and type Flat (1.84 ± 0.42) in cd. Similarly, in ∠α, Type Flat(136.31 ± 9.63) was the largest, followed by type C (116.51 ± 8.79), and type V (89.31 ± 9.07) was the smallest. Other measurements were not found any significant differences between the above.

CONCLUSION

According to the morphology of the CT cross section, the lateral MF was divided into three types: type C, type V and type Flat. Type V is most likely to be invaded when fixing the distal fibula. Screws less than 9 mm should be selected when fixing, and screws no more than 10 mm should be selected when there are type C and type Flat of MF.

Proximal fibular axis is a reliable landmark for tibial coronal alignment in patients with or without knee osteoarthritis: A radiological comparative study

BACKGROUND

Proper coronal alignment of the limb is of vital importance in the progression of knee osteoarthritis even in the long-term survivorship of component after total knee arthroplasty (TKA). Nevertheless, to the best of our knowledge, the relationship between coronal fibular axis and tibial mechanical axis had not reached a consensus in the literatures available. The current study aimed to explore the anatomic relationship between tibia and fibula alignment.

METHODS

A total of 100 patients with knee osteoarthritis scheduled for total knee arthroplasty were enrolled in this study (Group A), and radiographic measurement was compared to a control group of 100 healthy volunteers without knee osteoarthritis (Group B). Full-length standing hip-to-ankle radiographs were used to assess limb alignment. The angle between coronal proximal fibular anatomic axis and tibia mechanical axis (PFTA) was used to represent the anatomic relationship between tibia and fibula alignment. A negative value indicates fibula varus relative to tibia mechanical axis, while a positive value indicates fibula valgus.

RESULTS

The mean PFTAs were -0.9° ± 0.9° and -1.0° ± 0.8° in Groups A and B. There was no significant difference between the two groups. No significant difference was detected in PFTA distribution in the group A and B. When the mean value of PFTA is used as baseline data, the percentage of subjects in which the PFTA deviation was within 0.5°, 1°, and 1.5° was 51%, 84%, and 94% in Group A and 53%, 87%, and 96% in Group B. There was also no significant difference in distribution deviation between the two groups. No patient-specific factors were correlated with the PFTA.

CONCLUSIONS

The proximal fibular anatomic axis is a reliable landmark for tibial mechanical axis in the coronal plane in patients with or without knee osteoarthritis.

Automated Classification of Free-Text Radiology Reports: Using Different Feature Extraction Methods to Identify Fractures of the Distal Fibula

PURPOSE

Radiology reports mostly contain free-text, which makes it challenging to obtain structured data. Natural language processing (NLP) techniques transform free-text reports into machine-readable document vectors that are important for creating reliable, scalable methods for data analysis. The aim of this study is to classify unstructured radiograph reports according to fractures of the distal fibula and to find the best text mining method.

MATERIALS & METHODS

We established a novel German language report dataset: a designated search engine was used to identify radiographs of the ankle and the reports were manually labeled according to fractures of the distal fibula. This data was used to establish a machine learning pipeline, which implemented the text representation methods bag-of-words (BOW), term frequency-inverse document frequency (TF-IDF), principal component analysis (PCA), non-negative matrix factorization (NMF), latent Dirichlet allocation (LDA), and document embedding (doc2vec). The extracted document vectors were used to train neural networks (NN), support vector machines (SVM), and logistic regression (LR) to recognize distal fibula fractures. The results were compared via cross-tabulations of the accuracy (acc) and area under the curve (AUC).

RESULTS

In total, 3268 radiograph reports were included, of which 1076 described a fracture of the distal fibula. Comparison of the text representation methods showed that BOW achieved the best results (AUC = 0.98; acc = 0.97), followed by TF-IDF (AUC = 0.97; acc = 0.96), NMF (AUC = 0.93; acc = 0.92), PCA (AUC = 0.92; acc = 0.9), LDA (AUC = 0.91; acc = 0.89) and doc2vec (AUC = 0.9; acc = 0.88). When comparing the different classifiers, NN (AUC = 0,91) proved to be superior to SVM (AUC = 0,87) and LR (AUC = 0,85).

CONCLUSION

An automated classification of unstructured reports of radiographs of the ankle can reliably detect findings of fractures of the distal fibula. A particularly suitable feature extraction method is the BOW model.

KEY POINTS

· The aim was to classify unstructured radiograph reports according to distal fibula fractures.. · Our automated classification system can reliably detect fractures of the distal fibula.. · A particularly suitable feature extraction method is the BOW model..

CITATION FORMAT

· Dewald CL, Balandis A, Becker LS et al. Automated Classification of Free-Text Radiology Reports: Using Different Feature Extraction Methods to Identify Fractures of the Distal Fibula. Fortschr Röntgenstr 2023; 195: 713 - 719.

Repair of Distal Fibula Fractures with Minimally Invasive Intramedullary Nailing in the Elderly

Ankle fractures have been well documented and are common, especially in the elderly, behind hip and distal radius fractures. Open reduction and internal fixation (ORIF) is the standard of treatment for displaced and unstable ankle fractures. Traditionally, ankle fractures in the elderly population have been treated with nonoperative methods; however, nonoperative methods have been associated with increased mortality. Thus, there has been a shift toward operative management for the elderly and less healthy patients. However, these patients often present with more comorbidities that make them not ideal candidates for ORIF of the fracture. Minimally invasive intramedullary nailing of the fibula has gained popularity in recent years for the treatment of displaced ankle fractures. A 72-year-old man presented to the clinic with left ankle pain with a duration of 2 weeks. Radiography revealed a displaced fracture of the left fibula at the level of the ankle joint. This case report documents the surgical treatment of a displaced distal fibula fracture using minimally invasive intramedullary nailing of the fibula. At 4 months' follow-up, the patient was walking with minimal assistance and weightbearing as tolerated. Left untreated, displaced ankle fractures can be very debilitating, with increased mortality and morbidity, especially in the elderly population. Thus, early diagnosis and surgical treatment of displaced ankle fractures are imperative. The purpose of this report was to raise awareness of minimally invasive fibular nailing as an alternative to ORIF in the treatment of displaced ankle fractures in the elderly.

Fibula-Only Fixation for a Very Distal Tibia-Fibula Fracture: A Case Report

A 70-year-old patient with multiple medical problems presented to us with displaced closed very distal tibia and fibula fractures and a prior total knee replacement on the affected extremity. We treated the patient with an isolated fibula open reduction and internal fixation. At a 1-year follow-up, both the tibial and fibular fractures had healed, and the patient had an excellent outcome. "Fibula-only" fixation of very distal tibia-fibula fractures appears to be a viable option to manage these difficult fractures. The novelty of the case report lies in that this technique has not been described previously in the literature.

Donor site changes in early months following nonvascularized fibular harvest in children: a prospective radiological analysis

The exact timing of non regeneration and ankle valgus in post fibular harvest donor limbs remain elusive. The study examined the serial radiographs post harvest to better understand the transitions occurring in the ankle and leg region. We specifically focused on the noncontinuity of fibular regenerate, lateral distal tibial angle (LDTA), fibular length (fibular/tibial ratio, F/T ratio) and fibular station in the donor leg. Completeness of longitudinal fibular regeneration was documented at 6 months and accordingly two groups, with (R+) and without complete longitudinal regeneration (R-), were available for comparisons. There were 25 fibular harvests in 19 patients. The longitudinal regenerate was complete in 14 limbs (56%) (R+ group) at 6 months. The average LDTA at 6 months did not differ significantly from preoperative values. The F/T ratio decreased immediately postoperative and the trend remained sustained till 6 months. Malhotra grade corresponded inversely to F/T ratio. There was insignificant intra or intergroup affection of LDTA in R+ and R- groups over initial 6 months. The F/T ratio in R+ group recorded a downward trend till 3 months but remained static thereafter. Malhotra grades comparisons between R+ and R- revealed significant differences only at 6 months. Fibular length (F/T ratio) was found to be the critical indicator of regeneration. For the nonregenerates, ratios deteriorated significantly by 3 months. Malhotra station corresponded to changes in fibular length, although it was less quantitative. The secondary changes in lower tibia may not manifest till 6 months.

Ultrasound-Guided Needle Aspiration of Subperiosteal Abscess in a Child with Acute Osteomyelitis of the Fibula: A Case Report

CASE

An 8-year-old boy with left lateral ankle pain was diagnosed with acute osteomyelitis after methicillin-susceptible Staphylococcus aureus was identified in a subperiosteal abscess in the distal fibula that had been aspirated using an ultrasound-guided needle. Symptoms improved after 2 weeks of intravenous and 4 weeks of oral antimicrobial therapy; no additional treatment was required. No growth retardation or sequelae were observed at the 6-year follow-up.

CONCLUSIONS

In acute osteomyelitis, the identification of subperiosteal abscess is key for early diagnosis. Ultrasound evaluation of the distal fibula should also be considered in the diagnosis of lateral ankle pain in children.

Recurrence in infantile tibia vara (Blount disease) after high tibia and fibula osteotomy

Infantile Tibia Vara (ITV or Blount disease) often recurs after surgical correction of the deformity. Vastly different recurrence rates have been reported in the literature. The main objective of this study was to identify any risk factors for the recurrence of ITV following high tibia and fibula valgus osteotomy. This was a retrospective cohort comparative study of 44 patients with ITV (16 with bilateral involvement) who underwent a total of 60 high tibia and fibula osteotomies. Demographics, family history, BMI, walking age and age at surgery were recorded. Pre-, post- and follow-up weight-bearing anatomic femorotibial angles, were measured from X-rays. The limbs were divided into Langenskiöld stages based on preoperative X-rays. The study found an overall recurrence rate of 63.3% for children who had a high tibia and fibula osteotomy for ITV. Surgery after the age of 4 years, advanced Langenskiöld stages (stages 3-5) and overcorrection of less than 15 degrees of valgus were identified as risk factors for recurrence. This study recommends performing a high tibia and fibula valgus osteotomy before the age of 4 years in ITV to avoid recurrence. Overcorrection of the high tibia and fibula osteotomy to 15 degrees of valgus should be considered in older patients with high Langenskiöld stages at time of presentation.

Lower limb deformities and limb length discrepancies in hereditary multiple exostoses

There is a high rate of lower limb deformity and limb length discrepancy in patients with hereditary multiple exostoses (HME). The aim of this study was to evaluate the type and frequency of lower limbs axial deviation and limb length discrepancy and the type of exostoses being risk factors for theses deformities. We retrospectively reviewed standing full-length radiograph of 32 HME patients (64 limbs) followed in our institution between October 2009 and December 2020. Patient demographics were recorded. Radiographic analysis of the coronal limb alignment was performed, limb length discrepancy was measured and topography of the exostoses was recorded. We propose a classification of lower legs in 2 groups and 4 types according to the presence and the location of exostoses. In group I, there is an intertibio- fibular exostose with fibular origin at the level of the tibiofibular joints. In type IA, at the level of the distal tibiofibular joint with ascension of the distal fibula; in type IB at the level of the proximal tibiofibular joint with a bracketing effect on the proximal tibia and a lateral slope of the proximal tibial growth plate; the type IC is combining features of both IA and IB. In group II, there is no intertibio-fibular exostose coming from the fibula and no growth abnormality is obvious. A clinically notable lower limb discrepancy (LLD) of ≥2 cm was found in 19% of our patients. Approximately 33% of patients had a knee valgus deformity and 44% had an ankle valgus deformity. The knee valgus deformity was due to fibular growth anomalies and not to distal femur anomalies. The majority of lower legs had fibular growth anomalies (72%) which was a significant risk factor for knee valgus deformity and leg length discrepancy. On the contrary, we found no correlation between number, location and volume of distal femoral exostoses and genu valgum nor leg length discrepancy. Presence of intertibio-fibular exostoses is a risk factor for knee valgus deformity and leg length discrepancy. The presence of these exostoses should lead to a close follow-up of the patient.

Assessing the Necessity for the "Joint Above and Below" Radiography Approach for Lower-extremity Long Bone Fractures in Children

OBJECTIVES

A common strategy for evaluation of extremity fractures is the "joint above and below" (JAB) radiograph approach, which includes dedicated imaging of the joint proximal and distal to a fracture independent of clinical suspicion for an injury involving the joint. The incidence of concomitant ipsilateral lower-extremity fractures or dislocations associated with lower-extremity long bone fractures in children has not been commonly reported and represents an evidential gap for determining a radiograph approach. Our purpose was to determine the frequency of and risk factors for concomitant ipsilateral lower-extremity fractures or dislocations.

METHODS

A retrospective study of children aged 1 to 17 years treated at an academic medical center emergency department from 2015 to 2018 with any fracture involving the tibia, fibula, or femur. Children with pathologic fractures, transferred from another facility, and/or designated as a level I trauma were excluded. The primary outcome was the prevalence of a concomitant bony injury (fracture or dislocation) at a distinct site in the same extremity. Differences between the concomitant bony injury group and single injury group were characterized using Fisher exact tests. Regression analysis was used to determine predictors of concomitant bony injuries, including age, sex, and mechanism of injury (with injuries requiring level II or III trauma activation classified as high risk).

RESULTS

During the study period, 241 patients with lower-extremity long bone fractures were included. Complete JAB radiographs, defined as dedicated orthogonal radiographs of the joint proximal to and distal to the fracture site, were taken in 85 (35.3%) of 241 patients. Concomitant bony injuries were found in 9 (3.73%) of 241 patients (95% confidence interval, 1.7-7.0%). No additional concomitant bony injuries were identified at follow-up. When comparing patients with and without concomitant bony injuries, there was no significant difference in age (P = 0.34) and sex (P = 0.73). However, patients with a high-risk injury were more likely to have a concomitant bony injury (P < 0.01; odds ratio, 21.9; 95% confidence interval, 3.6-131.5).

CONCLUSIONS

Concomitant ipsilateral lower-extremity fractures or dislocations are uncommon in children sustaining tibia, fibula, and/or femur fractures. Although the JAB approach to radiographs may be useful in identifying additional injuries in children with lower-extremity injuries resulting from a "high-risk" mechanisms, its overall yield is low. To provide safe, cost-effective care, providers should continue to value clinical suspicion, history, and physical examination findings to guide selection of radiographs in those with lower-extremity long bone fractures as significant fractures can typically be identified with limited imaging in patients with low-risk injury mechanisms.

Development of tibia & fibula bone deficits in children with neurofibromatosis type I - A longitudinal case-control comparison

Neurofibromatosis type 1 (NF1) is associated with lower bone mass and increased risk of fracture. Children with NF1 display faltering growth from mid-childhood. However, to date tibia bone development in children with NF1 across childhood and the role of body size have not been explored. Therefore, we recruited 24 children with NF1 (12 girls, mean age 8.2 ± 1.1y) and 104 children without NF1 (52 girls, mean age 11 ± 1.7y). Tibia and fibula bone characteristics were assessed at 4% and 38% distal-proximal tibia length in all children at baseline using peripheral quantitative computed tomography (pQCT). Longitudinal scans were obtained in 21 children with NF1 (12 girls) over 3.4 ± 0.3y and 71 children without NF1 (34 girls) over 1.1 ± 0.1y, such that at follow-up mean age of both groups (NF1 10.9 ± 1.3y, controls 11.4 ± 1.4y) were similar. Effects of group (NF1/control) on bone outcomes as well as group-by-age interactions, indicating differences in rate of change in bone outcome bone outcomes were assessed via linear mixed effects models with adjustment for sex, age, pubertal status and in additional models with adjustment for height and weight Z-scores. Group (NF1/control)-by-age interactions indicated a slower rate of tibia and fibula bone mass accrual in children with NF1 at all measured sites. These associations were attenuated by 25-50% by adjustment for height and weight Z-scores. At the 4% site, deficits in bone mass at older ages were related to slower trabecular BMD accrual. At the 38% site, group-by-age interactions suggested that bone mass deficits resulted from poorer accrual of cortical CSA and to a lesser extent cortical BMD. Lower limb bone mass deficits evident in children with NF1 appear to be progressive and emerge in mid-childhood. In part, they are related to development of a similar pattern of deficits in longitudinal growth and body weight in NF1. Interventions promoting muscle development or physical activity may be partially effective in attenuating bone mass accrual deficits in this population.

[Traumatic isolated dislocation of the proximal tibiofibular joint is a rare injury]

Dislocation of the proximal tibiofibular joint should be promptly reduced when recognised in the emergency room. If closed reduction technique is unsuccessful, open reduction with the possibility of fixation should be performed. Currently, no consensus exists regarding the optimal post-reduction regime. We present a case report of a 30-year-old male who suffered a dislocation of the proximal tibiofibular joint during soccer. Closed reduction was successful, and the patient did not suffer from any sequalae later on.

Comparable Subjective and Objective Clinical Outcomes After Fibular or Combined Tibial-Fibular-based Reconstruction of the Posterolateral Corner of the Knee: A Systematic Review and Meta-analysis

INTRODUCTION

To compare subjective and objective outcomes of fibular and combined tibial-fibular (TF)-based posterolateral corner (PLC) reconstruction.

METHODS

A systematic review of literature reporting outcomes of posterolateral corner reconstruction was conducted including outcome studies of surgically treated PLC injuries with a minimum 1-year follow-up, postoperative subjective and objective outcomes including the patient-reported outcome scorings of Lysholm score, International Knee Documentation Committee evaluation (subjective and objective), dial test, and varus stress radiographs.

RESULTS

The 32 studies included comprised 40 cohorts: 12 cohorts (n = 350 knees) used a fibular-based technique, and 28 cohorts (n = 593 knees) used a combined TF-based technique. No statistically significant differences were found in patient-reported outcomes or objective clinical measurements comparing the two techniques using the Lysholm score (P = 0.204, τ2 = 3.46), International Knee Documentation Committee evaluation (subjective P = 0.21 τ2 = 15.57; objective P = 0.398), dial test (P = 0.69), or varus stress radiographs (P = 0.98, τ2 = 0.08).

CONCLUSIONS

This study found no statistically significant differences in subjective or objective clinical outcome measurements after fibular-based versus combined TF-based PLC reconstruction. Further prospective evaluation comparing long-term clinical outcomes, complications, and surgical time may help to elucidate a preferred reconstructive technique.

Classification of vascularized fibular flap hypertrophy based on X-ray evaluation

OBJECTIVE

The aim of this study was to analyze and classify hypertrophy seen in vascularized fibula flaps used for reconstruction of tubular bone defects.

METHODS

Thirty-three patients who underwent a vascularized fibula flap for the reconstruction of massive bone defects of the upper or lower extremity long bones were retrospectively reviewed and included in this study. There were 24 lower extremities (21 tibial and 3 femoral) and 9 upper extremities (4 humeral, 2 radial and 3 ulnar) reconstructions in this series. The mean age was 32.7 (range= 10- 59) years. The mean length of bony defect following initial debridement was 10.3 (range= 4-25) cm. The fibula was inserted as a single strut in 29 patients, and as a double barrel construct in 4 patients. The degree of fibular hypertrophy was calculated based on anteroposterior (AP) and lateral X-ray measurements of fibular flaps at an average postoperative period of 52 months. The difference in thickness between the initial and final x- ray measurements were expressed as percentage of hypertrophy. The variances seen in this period were defined and classified.

RESULTS

When bony consolidation of the 33 cases were examined in detail, 4 different modes of flap hypertrophy were defined: type 0- absence of hypertrophy, type 1- limited hypertrophy, type 2- marked hypertrophy triggered by stress fracture, and type 3- massive hypertrophy enhanced by peripheral bone production.

CONCLUSION

Fibular hypertrophy follows different modes based on vascularity of the flap, amount of stress imparted on the flap, site of reconstruction, and whether the periosteal sleeve is retained at the reconstruction site. Determination of these factors at the initial period may help the surgeons to predict the final hypertrophy that will be seen at the end of flap maturation Level of Evidence: Level IV, Therapeutic Study.

Towards novel osteoarthritis biomarkers: Multi-criteria evaluation of 46,996 segmented knee MRI data from the Osteoarthritis Initiative

Convolutional neural networks (CNNs) are the state-of-the-art for automated assessment of knee osteoarthritis (KOA) from medical image data. However, these methods lack interpretability, mainly focus on image texture, and cannot completely grasp the analyzed anatomies' shapes. In this study we assess the informative value of quantitative features derived from segmentations in order to assess their potential as an alternative or extension to CNN-based approaches regarding multiple aspects of KOA. Six anatomical structures around the knee (femoral and tibial bones, femoral and tibial cartilages, and both menisci) are segmented in 46,996 MRI scans. Based on these segmentations, quantitative features are computed, i.e., measurements such as cartilage volume, meniscal extrusion and tibial coverage, as well as geometric features based on a statistical shape encoding of the anatomies. The feature quality is assessed by investigating their association to the Kellgren-Lawrence grade (KLG), joint space narrowing (JSN), incident KOA, and total knee replacement (TKR). Using gold standard labels from the Osteoarthritis Initiative database the balanced accuracy (BA), the area under the Receiver Operating Characteristic curve (AUC), and weighted kappa statistics are evaluated. Features based on shape encodings of femur, tibia, and menisci plus the performed measurements showed most potential as KOA biomarkers. Differentiation between non-arthritic and severely arthritic knees yielded BAs of up to 99%, 84% were achieved for diagnosis of early KOA. Weighted kappa values of 0.73, 0.72, and 0.78 were achieved for classification of the grade of medial JSN, lateral JSN, and KLG, respectively. The AUC was 0.61 and 0.76 for prediction of incident KOA and TKR within one year, respectively. Quantitative features from automated segmentations provide novel biomarkers for KLG and JSN classification and show potential for incident KOA and TKR prediction. The validity of these features should be further evaluated, especially as extensions of CNN-based approaches. To foster such developments we make all segmentations publicly available together with this publication.

Bone microarchitecture of the distal fibula assessed by HR-pQCT

The distal fibula represents one of the most common fracture sites, and its epidemiology is characterized by a high incidence in both adolescence and the elderly. While fracture occurrence is influenced by trauma mechanism, a possible underlying skeletal microarchitectural deterioration in certain patient groups remains elusive. The purpose of this study was to determine the influence of age, sex, and overall skeletal status on fibular microarchitecture. We analyzed the microarchitecture of the distal fibula in 300 people by high-resolution peripheral quantitative computed tomography (HR-pQCT). Three areal bone mineral density (aBMD) groups (normal, osteopenia, osteoporosis; n = 100 per group) based on the concurrent assessment of aBMD by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and total hip were established. Next to group comparisons, linear and non-linear regression analyses were carried out to assess the association between age, sex, BMI, tibial and fibular microarchitecture. While women had lower values for both trabecular bone volume fraction (BV/TV^d, p < 0.001) and cortical thickness (Ct.Th^d, p < 0.001) than men, osteoporosis by DXA negatively affected these parameters in both sexes. Remarkably, cortical but not trabecular microarchitecture declined with age, with a stronger decrease in females compared to males (Ct.Th^d female -10.0 μm/year (95% CI: -12.2 to -7.7 μm/year), male -4.0 μm/year (95% CI: -6.3 to -1.7 μm/year)). Moderate positive associations between distal tibial and fibular microarchitecture were noted (e.g., BV/TV^d R² = 0.54, Ct.Th^d R² = 0.58). In summary, we here demonstrate the severe negative effects of age, female sex and osteoporosis on distal fibula bone mineralization and microarchitecture. The presented findings are likely to explain the higher susceptibility to distal fibula fractures in elderly women (independent of trauma mechanism). These alterations in fibular bone quality must be taken into account in the context of fracture prevention and treatment (e.g., osteosynthesis planning).

Assessment of the Viability and Union Feature of Diaphysis Reconstruction Using Pasteurized Tumor Bone and Intramedullary Free Fibular After Tumor Resection

BACKGROUND

Reconstruction using pasteurized tumor bone (PTM) and intramedullary-placed vascularized free fibular (VFG) has the combined advantages of mechanical strength and biological activity. The aims of this study were to investigate scintigraphic viability and radiographic union patterns of composite grafts after surgery, union rates, functional outcomes, and complication rates.

METHODS

Seventeen patients underwent intercalary composite reconstruction using PTM and VFG (12 male, 2 female, mean age: 10.9 y). Retrospective evaluation of radiography and bone scintigraphy was performed. The most common diagnosis was osteosarcoma (12/14, 85.7%). All radiography and bone scintigraphy was reviewed for bone healing and tracer uptake semiquantitatively using the ratio of the reconstructed portion to the contralateral side. Complications and oncological and functional outcomes were recorded.

RESULTS

At a mean follow-up of 33.1 months, primary union was achieved in all 28 host-graft junctions in all 14 patients. The respective mean times to proximal and distal junction bone union were 6.9 and 6.5 months. Metaphyseal junctions healed faster than diaphysis junctions (5.2 vs. 8.0 mo, P=0.02). Free fibular was integrated with surrounding bone after a mean of 10.1 months. The mean tracer uptake ratio was 1.1 after a mean of 4.8 months postoperatively. Half patients (50%) had higher uptake on bone scan than contralateral side. There was no significant correlation between uptake value and bone healing time. Five complications occurred in 4 patients (28.6%), and 1 patient (7.1%) contracted an infection. No fractures or breakages were observed. The mean Musculoskeletal Tumor Society 93 score was 87.6%.

CONCLUSIONS

Reconstruction using PTM combined with VFG is associated with good short-term biological activity as indicated by bone scintigraphy, a high union rate, and an acceptable complication rate. The technique is a useful reconstruction option for large segmental bone defects after tumor resection in lower extremities.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

The physical examination is unreliable in determining the location of the distal fibular physis

OBJECTIVES

Salter-Harris type 1 (SH1) fractures of the distal fibula are acute orthopedic injuries with tenderness over the physis without radiographic evidence of fracture. Our primary objective was to establish the accuracy of the physical examination performed by pediatric emergency medicine (PEM) physicians in determining the location of the distal fibular physis compared to a criterion standard of ultrasound.

METHODS

This was a prospective, observational study at an urban academic pediatric emergency department of a convenience sample of children aged 4 to 10 years old between March 2019 and March 2020. A PEM physician or fellow examined the patient's distal fibula and marked the location of the physis with a marker. A study investigator scanned the distal fibula to establish the location of the physis on ultrasound and measured the distance between the clinician's estimated position and the actual sonographic position. We a priori defined a clinically accurate position as a distance of ≤5 mm. We compared the accuracy rate of physical examination to ultrasound landmarking using proportions with 95% confidence intervals (CI).

RESULTS

We enrolled 71 patients, of whom 52 (73%) were male. The mean age was 6.7 years and the mean weight was 25.5 kg. Participating PEM physicians included 18 attending physicians and 2 fellows. The distal fibular physis was correctly identified in 24 patients, yielding an accuracy rate of 34% (95% CI 23%-46%). The mean distance between the physician's estimated position and the sonographic position was 7.4 mm (95% CI 6.4-8.4 mm).

CONCLUSIONS

PEM physicians were unable to accurately identify the distal fibular physis on physical examination.

Combining Lower Extremity Radiographic Markers Begets More Accurate Predictions of Remaining Skeletal Growth

BACKGROUND

Radiographic markers of skeletal maturity are vital to the prediction and interpretation of skeletal growth patterns. Accurate predictions of skeletal maturity factor into the management of common musculoskeletal disorders. Bone age is conventionally measured using hand and wrist radiographs. The primary study objective was to optimize skeletal maturity estimates based on the morphology of markers at the hip, knee, and foot rather than conventional upper extremity radiographs.

METHODS

This was a retrospective analysis of children from the Bolton-Brush collection with anteroposterior radiographs of the hip and anteroposterior and lateral radiographs of the knee and foot, and heights recorded at the time of each radiograph. The percent growth achieved (%GA) was calculated as a function of final patient height. Poor quality radiographs were excluded, leaving 50 patients-32 females and 18 males-and 1068 radiographs for analysis. Skeletal maturity was evaluated using the Oxford bone, O'Connor knee, and calcaneal apophyseal scores. Interrater and intrarater reliability analyses were performed for hip and knee scores. Multiple linear regressions were conducted on these scores and chronologic age as predictors of %GA. Mean differences were calculated between actual and estimated %GAs. All analyses were performed in Prism 8.0.

RESULTS

Each lower extremity skeletal maturity score served as statistically significant, independent predictors of %GA, the accuracy and strength of which increased with the addition of chronologic age. The integration of all 3 systems and chronologic age yielded the most predictive, accurate model predictive of %GA, which can be used to determine percent growth remaining. However, this fully integrated system was not statistically superior to the combination of knee and foot scores and knee score and chronologic age, which yield similarly accurate %GA predictions. The hip and knee systems demonstrated good to excellent interrater and intrarater reliability.

CONCLUSIONS

Integration of bone age scores across different regions of the lower extremity has the potential to facilitate orthopaedic decision-making using radiographs already obtained in the treatment of pediatric musculoskeletal conditions.

LEVEL OF EVIDENCE

Level IV.

Ipsilateral vascularised fibula with external locking plate for treatment of massive tibial bone defects

INTRODUCTION

Management of massive tibial bone defects remains challenging for orthopaedic doctors. This study aimed to ascertain the viability and reliability of utilising an ipsilateral vascularised fibula with an external locking plate for the difficult situation.

MATERIALS AND METHODS

Between January 2012 and December 2017, eight patients (7 men) with a mean age of 32.3 (19-54) years who presented with massive tibial bone defects were treated using the described technique. The mean length of the bone defect was 12.4 (8-20) cm. The patients were assessed for clinical and radiographic results, hypertrophy of the fibular graft with DeBoer and Wood's method, and SF-36 functional score.

RESULTS

The mean follow-up period was 40.3 (26-60) months. The average time for union was 5.6 (3-8) months. At the final follow-up, all patients had fully united grafts and walked without restriction. The mean graft hypertrophy index was 98.2 %. The SF-36 score was > 75 % in five patients, and 50-75 % in three. Three patients had a leg length discrepancy of > 1.5 cm. Two patients with equinus foot were treated using tibiotalocalcaneal fusion. Three patients had pin-tract infections. Four screws were broken in two cases.

CONCLUSION

Ipsilateral vascularised fibular transfer combined with an external locking plate as a definitive external fixator provides a simple and comfortable treatment, and appropriate mechanical loading and vascularisation of the graft site to achieve hypertrophy of the fibular graft. Hence, our technique can serve as a valuable alternative for the treatment of massive tibial bone defects.

Simultaneous Total Knee Arthroplasty and Proximal Tibiofibular Joint Arthrodesis: A Case Report

CASE

A 57-year-old man presented with tricompartmental left knee osteoarthritis, as well as proximal tibiofibular joint arthritis and a ganglion cyst. He underwent simultaneous total knee arthroplasty and proximal tibiofibular joint arthrodesis, with an excellent outcome.

CONCLUSION

Proximal tibiofibular joint arthritis is uncommon and may be associated with tibiofemoral arthritis, proximal tibiofibular joint instability, and ankylosing spondylitis. We present a case of simultaneous total knee arthroplasty and proximal tibiofibular arthrodesis. This is an effective option for treating patients with dual pathology. The proximal tibiofibular joint should be considered as an uncommon cause of lateral knee pain.

Three-dimensional morphological analysis of neocondyle bone growth after fibula free flap reconstruction

The aim of this retrospective study was to verify the three-dimensional morphological change in neocondyle bone growth after fibula free flap (FFF) reconstruction. The independent variables were age, sex, and diagnosis. Outcome variables included the direction and volume of neocondyle bone growth, and the time to a stable neocondyle following bone growth. The outcome variables were measured on postoperative computed tomography scans using iPlan 3.0. Of the 35 patients included, 25 showed neocondyle bone growth. The direction of neocondyle bone growth included the direction of lateral pterygoid traction (DLPT) and the direction towards the glenoid fossa (DGF). The bone growth of the neocondyle showed three patterns: only DLPT (eight patients), only DGF (two patients), and a combination of DLPT and DGF (15 patients). The average volume of bone growth in the 25 patients was 0.479 ± 0.380 cm³. The average volume of neocondyle bone growth was significantly greater in patients aged <18 years (0.746 ± 0.346 cm³) than in patients aged >18 years (0.219 ± 0.191 cm³) (P < 0.001). The time to a stable neocondyle following bone growth was 5.6 months postoperatively. In conclusion, neocondyle bone growth after FFF reconstruction occurred in two different directions, DLPT and DGF. Osteogenesis of the lateral pterygoid muscle affects neocondyle growth with DLPT. Neocondyle bone growth is more marked in paediatric patients than in adults.

An accurate method for locating the joint line during revision total knee arthroplasty: A radiologic study in the Chinese population

BACKGROUND

The systems for precisely locating the joint line during primary and revision total knee arthroplasty are still controversial, and they should be better evaluated in the Chinese population.

METHODS

A total of 451 standard anteroposterior knee radiographs from 451 healthy Chinese people (283 males and 168 females, the average age of 33.26 years, range 20-50 years) were included to measure the femoral width (FW) and the distances from the adductor tubercle (AT), the medial epicondyle (ME), the lateral epicondyle (LE), and the fibular head (FH) to the joint line (JL). Correlation between FW and distances from landmarks to the joint line was evaluated using Pearson correlation coefficient, and the ratios of ATJL, MEJL, LEJL, FHJL to FW were calculated.

RESULTS

The average distances from the AT, the ME, the LE, the FH to the JL were 49.4 ± 5.0 mm, 28.3 ± 3.1 mm, 26.9 ± 2.9 mm, 20.0 ± 4.0 mm, respectively. An excellent linear correlation was found between FW and the distance from AT to the joint line (R = 0.836, R² = 0.698); it was more reliable than the LE (R = 0.686, R² = 0.471) and the ME (R = 0.672, R² = 0.452). The average ratios of ATJL/FW, MEJL/FW, LEJL/FW were 0.553, 0.317, and 0.302, respectively. There were significant differences between our results and the studies based on the Western people.

CONCLUSION

The AT can be used as a reliable landmark to locate the JL precisely by the formula (ATJL = 0.548 × FW in males; ATJL = 0.562 × FW in females) in the Chinese population. The LE and ME can be the second choices. Moreover, it may be better to use ratios from the research based on the same race.

Role of Ultrasound in Early Diagnosis of Stress Fracture: A Case Report of Bilateral Distal Fibular Stress Fracture in a Female Recreational Badminton Player

A 34-year-old female recreational badminton player presented with left ankle pain 1 week after a recreational badminton game. She reported experiencing a similar pattern of pain in her right ankle 4 months before that had persisted for 3 months. On plain radiography, callus formation was evident on the right distal fibula, and a subtle lesion was observed on the left side. Ultrasound was performed with the clinical suspicion of bilateral, nonsimultaneous, distal fibular stress fracture. Focal hyperechoic thickening of the periosteum with irregularity and hypoechoic periosteal edema over the left distal fibula were identified. These findings were consistent with stress fracture, and an early phase of distal fibular stress fracture was diagnosed. This case report highlights that ultrasound can be an alternative modality to magnetic resonance imaging or bone scan scintigraphy for the early diagnosis of stress fracture.