The aetiology of the non-ossifying fibroma of the distal femur and its relationship to the surrounding soft tissues

The Role of Surveillance in Predicting Fracture in Pediatric Patients With Incidentally Discovered Nonossifying Fibromas and Fibrous Cortical Defects: Is It Worth It?

BACKGROUND

Nonossifying fibroma (NOF) and fibrous cortical defect (FCDs), the most common benign pediatric bone lesions, are usually incidental x-ray findings. Surveillance of characteristic lesions has been recommended to monitor for enlargement and assess fracture risk. However, no accepted fracture risk prediction guidelines exist, so indications for prophylactic surgery are unclear. The study's purposes were to (1) characterize the timing of NOF/FCD-associated fractures, (2) quantify the resources devoted to surveillance, and (3) evaluate the potential for surveillance to prevent pathologic fracture.

METHODS

A single institution retrospective review was conducted to identify pediatric patients (below 18 y old) with clinical-radiographic documentation of an NOF or FCD diagnosis from 2012 to 2020. Patients who presented with fracture were tallied but excluded from the surveillance analysis. Patients without at least one follow-up visit were also excluded. Lesional radiographic features were characterized on initial imaging. The number of visits and imaging studies devoted to surveillance were tabulated. The number of fractures and prophylactic surgeries were recorded to quantify the potential of surveillance to prevent pathologic fractures.

RESULTS

The study population presenting without fracture consisted of 301 patients with 364 lesions with a mean follow-up of 20 months. By contrast, over the same period, 38 patients presented with NOF/FCD associated pathologic fractures. Surveillance included 1037 additional imaging tests over 1311 follow-up visits, or on average, 3.4 imaging studies and 4.4 visits per patient. During surveillance, only 2 (0.55%) lesions fractured. Another 10/364 (2.8%) patients underwent curettage and grafting, suggesting that-at best-the potential for preventing pathologic fracture by surveillance, assuming all 10 patients who underwent surgery would have subsequently fractured along with the 2 documented fractures, is 3.3% of lesions (12/364).

CONCLUSIONS

The small number of fractures and surgeries during the follow-up period probably does not justify additional resources for surveillance beyond the initial visit, except in symptomatic patients with large lesions. However, subsequent visits may play a role in educating patients and their families regarding the natural history of these lesions.

LEVEL OF EVIDENCE

Prognostic Level II-retrospective study.

Tumor-Like Distal Femoral Cortical Irregularities of the Knee in Adolescent Competitive Alpine Skiers: Longitudinal Assessment Over 48 Months

BACKGROUND

Tumor-like distal femoral cortical irregularities (DFCIs) are a frequent incidental finding on knee magnetic resonance imaging (MRI) and are common in young competitive athletes.

PURPOSE

To assess and compare the morphology and prevalence of DFCIs in competitive alpine skiers over 48 months during adolescence.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Adolescent competitive alpine skiers were prospectively recruited in 2018 and received bilateral 3-T MRI of the knee at baseline and after 48 months. All MRIs were evaluated for the presence and location of DFCIs, which were marked at 1 of 3 anatomic positions: (1) the femoral attachment of the medial head of the gastrocnemius muscle, (2) the lateral head of the gastrocnemius muscle, or (3) the attachment of the adductor magnus aponeurosis. The size of the DFCI was measured by 2 radiologists independently. The measurements were compared using the Wilcoxon signed-rank test, the interclass correlation coefficient (ICC), and Cohen Kappa.

RESULTS

A total of 63 athletes (mean age at follow-up, 19.6 ± 1.2 years; n = 25 female) were included in the study. At baseline, DFCIs were detected in 84 out of 126 knees (67%). At the 48-month follow-up, DFCIs were found in 88 out of 126 knees (70%), with multiple DFCIs in 3 knees and no significant difference between male and female patients (n = 24 male, n = 19 female; P = .71). No significant increase was detected for the number (P = .21) and size of the DFCIs between the baseline and the 48-month follow-up (mean size: baseline, 3.7 ± 0.8 mm; 48-month follow-up: 3.6 ± 0.9 mm; P = .66). The interrater agreement for the mean size measurements of DFCIs was good to excellent (ICC 0.88).

CONCLUSION

DFCIs remain a frequent finding on knee MRI in competitive alpine skiers after skeletal maturation and do not disappear during adolescence. The DFCI size was constant in athletes aged between 15 and 19 years. Moreover, DFCIs should not be mistaken for a pathologic finding.

Pseudolesions involving bone and soft tissue regarding orthopedic oncology

Pseudolesions in bone and muscle are encountered mostly incidentally in routine imaging studies, especially due to the recent advancements on many different imaging modalities. These lesions can be categorized into the following categories: normal variants; congenital; iatrogenic; degenerative; and postoperative. In this review, we discuss the many different radiological characteristics of musculoskeletal pseudolesions that appear on imaging, which can prevent non-essential additional studies.

A nonossifying fibroma of the femoral neck treated with curettage and dynamic hip screw with free fibular bone graft: a case report

Introduction and importance

Nonossifying fibroma (NOF) is a benign fibrogenic lesion that is related to dysfunctional ossification and one of the most common benign bone tumors in childhood with incidence rate of 30-40% of skeletally immature children.

Presentation of case

A 25-year-old female with left hip pain for the past 2 months, which was treated conservatively, presented with severe pain in the hip. X-ray showed a pathologic fracture in the neck of the femur with underlying lesion. MRI showed an osteolytic lesion in neck of the femur. Curettage of the lesion was done with free fibular bone graft and stabilized by Dynamic Hip Screw and specimen sent to pathology. The pathology report consisted with NOF. No-weight bearing for 8 weeks with physical rehabilitation were ordered and six months later the patient had a full range of motion and healed fracture.

Clinical discussion\Conclusion

This study revealed that the surgical treatment with bone graft for pathologic femoral neck fracture and underlying NOF allowed a quick return to mobility and can be fixed sufficiently to achieve excellent postoperative recovery.

Curettage and external fixation for displaced pathological fracture through non-ossifying fibroma in the radius: A case report

Non-ossifying fibromas are extremely rare in the upper extremity, such as those in the radius and humerus. The treatment of completely displaced fractures following non-ossifying fibromas in the radius has not been reported. We present the case of a pathological fracture caused by a non-ossifying fibroma in the radius treated using external fixation. The patient was a 10-year-old girl who presented to our hospital with right forearm pain after an accidental fall. She had no remarkable medical history. Radiographs and computed tomography showed a pathological fracture through osteolytic lesions with sclerotic rims in the diaphysis of the radius, suggesting a pathological fracture through a non-ossifying fibroma in the radius. We performed tumor curettage and external fixation due to marked fracture displacement. Histological findings were compatible with those of non-ossifying fibroma. Six months post-surgery, there were no limitations in the range of motion of supination and pronation of the forearm, and radiographs confirmed a bone union. Although non-ossifying fibromas in the radius are rare, cases with large lesions can cause pathological fractures after minor trauma. This case suggests that curettage and external fixation are beneficial, especially if early surgery is required due to unacceptable displacement and when there is no time for a biopsy to rule out malignancy.

Metaphyseal and Diaphyseal Contours: Variants and Pitfalls

We discuss several variants of the metaphyseal and diaphyseal bone surfaces that may be misleading in clinical practice. They include metaphyseal stripes, spiculated metaphyseal cortex, cortical desmoid, laminated lateral supracondylar ridge, cortical vascular canals, variations in shape or lucency of normal tuberosities, cortical thickening of normal ridges, and well-organized undulated hyperostosis at the proximal phalanges.

Cortical Desmoid of the Distal Femur-Incidentaloma or Insertional Tendinopathy?

BACKGROUND

The cortical desmoid (DFCI) of the posteromedial femoral condyle is considered an asymptomatic incidental finding in adolescents without clinical relevance. The aim of this study was to evaluate the clinical relevance of DFCI from both a tumor orthopedic and sports medicine point of view.

METHODS

n = 23 patients (13.74 ± 2.74 years; nineteen female, four male) with DFCI of the posteromedial femoral condyle were included. A localized posteromedial knee pain on exertion was differentiated from non-specific knee pain. Symptom duration, additional pathologies, number of MRIs, sports activity and training intensity, downtime, therapeutic modalities, and relief/remission of symptoms were documented. The Tegner activity scale (TAS) and Lysholm score (LS) were collected. The influence of specific posteromedial pain, MRI presence of paratendinous cysts, sports level as well as physiotherapy on downtime and LS/TAS was statistically analyzed.

RESULTS

100% reported knee symptoms at initial presentation. A localized posteromedial pain was documented in 52%. In 16/23 (70%) additional functional pathologies were diagnosed. Patients were physically highly active with high training intensities (6.52 ± 5.87 h/week) and performance level (65% competitive vs. 35% recreational). Patients underwent 1.91 ± 0.97 MRIs (max four). Symptom duration was 10.48 ± 11.02 weeks. A follow-up examination was performed after 12.62 ± 10.41 months (n = two lost to follow-up). 17/21 had physiotherapy, on average 17.06 ± 13.33 units. Overall downtime was 13.39 ± 12.50 weeks, the return-to-sports (RTS) rate 81%. 100%/38% reported a relief/remission of complaints. LS was 93.29 ± 7.95, median TAS before onset of knee complaints/at follow-up 7 (6-7)/7 (5-7). Specific posteromedial pain, presence of paratendinous cysts, sports level and physiotherapy had no significant influence on downtime and outcome parameters (n.s.).

CONCLUSIONS

DFCI as a pathognomonic finding is recurrently encountered in the MRIs of children and adolescents. This knowledge is essential to spare patients from overtreatment. Contrary to the literature, the present results implicate a clinical relevance of DFCI particularly in those who are physically highly active with localized pain on exertion. Structured physiotherapy as basic treatment is recommended.

Edema-like marrow signal intensity (ELMSI) associated with nonossifying fibroma (NOF) on MRI: an uncommon finding in a common bone lesion

OBJECTIVE

To investigate the association between nonossifying fibroma (NOF) and perilesional edema-like marrow signal intensity (ELMSI) on MRI and discuss the clinical and diagnostic implications of this finding.

MATERIALS AND METHODS

A retrospective search for "nonossifying fibroma" and "NOF" on knee MRI reports of patients up to 20 years of age over a 5-year period was performed. A total of 77 patients (34 males, 43 females, ages 11-20) were identified, and each MRI was reviewed to evaluate for ELMSI associated with the NOF. Statistical analysis was performed to determine if there was a correlation with the presence of perilesional ELMSI and age, gender, lesion size, or signal characteristics.

RESULTS

Twelve patients out of 77 (16%) had ELMSI associated with a NOF. Excluding patients who had additional findings of pathologic fracture (n = 2), a known potential complication of NOFs, and edema related to an adjacent osteoid osteoma (n = 1), a total of 9 patients (12%) had otherwise unexplained perilesional ELMSI. There was no statistically significant difference between patients with vs. without perilesional ELMSI with respect to age (p = 0.08), gender (p = 0.28), lesion size (p = 0.52), or appearance on fluid-sensitive sequences (p = 0.81).

CONCLUSION

ELMSI can be seen about NOFs encountered around the knee joint on MRI, which may represent active healing and/or involutional change of this "do not touch" lesion in cases where no other explanation is identified.

CLINICAL FEATURES OF CONNECTIVE TISSUE DYSPLASIA, OSGOOD-SCHLATTER DISEASE AND MULTIPLE CORTICAL DISORDERS IN A CHILD

OBJECTIVE

The aim: To analyze scientific data on the problems of disorders of bone morphogenesis in children, in particular, non-ossifying fibroma. To analyze modern methods of diagnosis and treatment of this disease in the context of the latest scientific achievements.

PATIENTS AND METHODS

Materials and methods: The latest data of scientists from the world's leading clinics describing various forms of fibrous skeletal lesions in children of differ¬ent ages were analyzed. We examined a boy with fibrous lesions of the cortical layer of the knee joint bones and a girl with a large fibrous focus of the distal femoral metaphysis, which resulted in a closed pathological bone fracture. Surgical treatment, osteosynthesis, marginal resection of the tumor, bone grafting and histological examination were conducted.

CONCLUSION

Conclusions: Despite numerous studies of this disease, the etiopathogenesis of this disease has not been studied. There are no early symptoms of fibrous bone lesions in children. Diagnosis is possible only when a pathological fracture of the affected bone occurs due to extensive growth of fibrous tissue and a significant decrease in the mechanical strength of the bone. Most cases of recognition of such a disease occur accidentally when performing X-ray examinations for other reasons - bruises, sprains, arthralgias, osteochondropathy, infectious diseases, etc. It is known that boys are more mobile and require more frequent X-ray examinations for limb injuries than girls, so the likelihood of accidental detection of such changes increases significantly. Thus, long-term observations of children with fibrous bone lesions have shown that after 40 years, patients rarely developed malignant tumors - osteogenic sarcoma, fibrosarcoma, malignant fibroma of tubular bones, pelvic bones. There are no early symptoms of fibrous bone lesions in children. Recognition of such a disease occurs by chance when X-ray examinations are performed for other reasons.

Non-ossifying fibromas and fibrous cortical defects around the knee - an epidemiologic survey in a Japanese pediatric population

Background

The aim of the present study was to evaluate the prevalence of non-ossifying fibroma (NOF) and fibrous cortical defect (FCD) in a Japanese pediatric population and the association between the lesion size and pain.

Methods

This retrospective study, conducted across 10 Japanese institutions, included patients aged 5–15 years who had undergone standard antero-posterior and lateral view radiography of the knee. Using these radiographs, we diagnosed the lesion as a NOF or FCD. Patient demographics, including age, sex, the size and location of the NOF, and chief complaint were recorded. The lesion size was determined using radiographs. Student’s t-test was used to compare the associations between the lesion size and spontaneous pain.

Results

A total of 6222 subjects (3567 boys and 2455 girls) were included in this study. The number of NOF and FCD cases was 143 and 437, respectively, and the prevalence of NOF and FCD was 2.3% and 7.0%, respectively. The average size of NOF and FCD was 22.1 mm (range: 4–102 mm) and 13.2 mm (range: 5–21 mm), respectively. Three patients (2.1%) had pathological fractures due to NOF. Of the 140 NOFs and 437 FCDs, we obtained complaints from the medical records of 126 and 393 patients, respectively. The number of patients with spontaneous pain or other problems with NOF was 68 (54%) and 58 (46%), respectively, that of patients with FCD was 195 (50%) and 198 (50%) patients, respectively. The lesion size was not associated with spontaneous pain in either lesion (p = 0.67 and p = 0.27, respectively).

Conclusion

The prevalence of NOF and FCD around the knee was lower than that reported in previous studies. The prevalence of NOF increased and that of FCD decreased with advancing age. In both lesions, the lesion size may not be associated with pain.

Non-ossifying Fibroma Pathological Fracture in a Patient With Lactose Intolerance

Non-ossifying fibroma (NOF) is a frequently occurring benign tumor of children and adolescents. In the long bones, it appears as an eccentric, expanded lesion in the metaphyseal diaphyseal area. Most cases are asymptomatic and resolve at a later age while others might become symptomatic and have a high risk of fracture. We present a case of a 15-year-old boy who is known to have lactose intolerance, suffered a pathological fracture following trauma, and was diagnosed with non-ossifying fibroma of the proximal tibia. The etiology of these lesions is not well-known. However, there might be a relation between tendons and NOF. This reported case of NOF is in the proximal tibia, which is a common site of the lesion beside the distal femur. Our reported case was treated by open curettage and grafting, which is the recommended classical treatment. On follow-up, full union was achieved without complications.

Nonossifying Fibroma of the Distal Tibia: Predictors of Fracture and Management Algorithm

BACKGROUND

Nonossifying fibroma (NOF) is a common benign lesion in children and adolescents. This study investigated the risk of pathologic fracture in NOF lesions of the distal tibial based on anatomic location, clinical symptomatology, and imaging features, in order to propose an algorithm for the management of such lesions.

METHODS

In an IRB-approved retrospective case-control study, all patients diagnosed with NOF between 2010 and 2017 were extracted from our database. Patients below 18 years of age at the time of diagnosis and with lesions involving the distal tibia were included. Demographic data, the reason for visit, and the mechanism of injury were recorded. Radiographs were reviewed to record the size (absolute and relative to bone width) and location of each lesion. Computed tomography and magnetic resonance imaging examinations were also reviewed when available. Two authors graded all lesions using the Ritschl classification and determined the presence of 2 novel signs: the syndesmosis sign and the Pac-Man sign.

RESULTS

A total of 84 patients were included in the final analysis, of which 25 were in the fracture group and 59 in the nonfracture group. None of the patients in the fracture group was previously diagnosed with NOF, but nine (36%) patients had symptoms for >6 months preceding the fracture. Ankle sprain was the most common reason for visit in the nonfracture group. The lateral location of the lesion in the distal tibia (P=0.001), size (P<0.001 for both absolute and relative values), Ritschl stage (P=0.003), syndesmosis sign (P=0.005), and the Pac-Man sign (P=0.002) were significant predictors of fracture. All measurements had almost-perfect to perfect inter-rater agreements.

CONCLUSIONS

The most significant imaging risk factors for fracture are a larger size, Ritschl stage B, and the presence of cortical thinning on anteroposterior or lateral radiographs. We introduced 2 signs for these distal tibial NOFs, a scoring system, and a management algorithm that is based on radiographs alone but incorporates advanced imaging findings in equivocal cases.

LEVEL OF EVIDENCE

Therapeutic Level III-case-control study.

Possible Novel Treatment Modality for Non Ossifying Fibroma Neck of Femur

Nonossifying fibromas (NOFs) are benign bone tumors occurring in the second decade of life. Most of the NOFs are diagnosed incidentally on the basis of its presentation on plain radiographs where they typically appear as small, cortical osteolytic lesions with sclerotic margin. They are mostly asymptomatic but can result in pathologic fractures if the lesion involves more than 50% of bone diameter. They are mostly treated with curettage and bone grafting. But in challenging situations where the classical surgery has failed or there is impending fracture of the neck of femur, bone structural support is needed. We are discussing two cases diagnosed as NOFs of intracapsular femoral neck. Both cases underwent curettage of tumor followed by free vascularized fibular graft. Results in both the cases were very gratifying, with complete resolution of symptoms during 1 year of follow-up.

[Tumor-like bony lesions of the skeleton]

Tumor-like bony lesions are, by definition bony lesions, which can be clinically, radiologically and histologically mistaken for real bone tumors. This article presents the aneurysmal bone cyst (ABC), solitary bone cyst (SBC), fibrous dysplasia, osteofibrous dysplasia Campanacci and non-ossifying fibroma (NOF). Many tumor-like bony lesions are often incidental findings. The combination of X‑ray imaging specifically supplemented by magnetic resonance imaging (MRI) or computed tomography (CT) enables a diagnostic classification in the majority of cases.

68Ga DOTA-TOC Uptake in Non-ossifying Fibroma: a Case Report

Non-ossifying fibroma (NOF) is a common benign bone tumor with a high probability of occurrence in children and adolescents. It is commonly seen in the metaphysis of long bones, eccentrically located, and can coexist with other malignant tumors such as neuroendocrine tumors (NET). To date, plain radiographs play a major role in the diagnosis of these benign bone tumors. Herein, we report the case of a 13-year-old male patient who was diagnosed with pulmonary NET and underwent right lung lobectomy for a hilar mass which later revealed a well-differentiated NET. The follow-up ⁶⁸Ga DOTA-TOC PET/CT showed a focal somatostatin receptor expression in the left distal femur, with corresponding CT component findings of a well-defined osteolytic bone lesion located within the medial aspect of the left distal femoral metaphysis, strongly indicative of NOF. To the best of our knowledge, this is the first reported case of such an occurrence.

[Tumor-like bony lesions of the skeleton]

Tumor-like bony lesions are, by definition bony lesions, which can be clinically, radiologically and histologically mistaken for real bone tumors. This article presents the aneurysmal bone cyst (ABC), solitary bone cyst (SBC), fibrous dysplasia, osteofibrous dysplasia Campanacci and non-ossifying fibroma (NOF). Many tumor-like bony lesions are often incidental findings. The combination of X‑ray imaging specifically supplemented by magnetic resonance imaging (MRI) or computed tomography (CT) enables a diagnostic classification in the majority of cases.

Distal Femoral Cortical Irregularity at Knee MRI: Increased Prevalence in Youth Competitive Alpine Skiers

Background Tumor-like cortical irregularities at the posterior distal femur are common incidental findings in adolescents, but the origin of these irregularities is debated. Purpose To compare the prevalence of distal femoral cortical irregularities (DFCIs) at different tendon attachment sites in youth competitive alpine skiers with that in young adults. Materials and Methods In this secondary analysis of a prospective trial, unenhanced 3-T knee MRI scans obtained in youth competitive alpine skiers were compared with images in control participants of the same age from 2014 to 2019 (Cantonal Ethics Committee Zurich registry number: KEK-ZH-2017-01395) for presence of DFCIs at the femoral attachment of the medial head of the gastrocnemius muscle (MHG) and/or lateral head of the gastrocnemius muscle (LHG) and adductor magnus tendon by two radiologists. DFCI size and tendon attachment position were measured. Tendon attachment position and associated MRI findings (meniscus, cartilage, bone marrow edema, joint effusion, ligaments, tendons) were examined for an association with DFCI. Pearson χ², Student t test, logistic regression, and κ statistics were applied. Results Unilateral knee MRI scans obtained in 105 skiers (mean age, 14.8 years ± 0.6 [standard deviation]; 66 boys) and in 105 control participants (mean age, 14.6 years ± 0.5; 59 boys) were evaluated. DFCIs were found in 61 of 105 skiers (58%; 95% confidence interval [CI]: 48.5%, 67.2%) compared with 28 of 105 control participants (27%; 95% CI: 18.9%, 35.7%) (P < .001). Two skiers had more than one DFCI. Distribution of DFCIs for skiers and control participants was 60 of 63 (95.2%) and 26 of 28 (92.8%) at the MHG, three of 63 (4.8%) and one of 28 (3.6%) at the LHG, and zero of 63 (0%) and one of 28 (3.6%) at the adductor magnus attachment site, respectively. Interreader agreement was almost perfect (κ = 0.87; 95% CI: 0.80, 0.93). The mean size of MHG-related DFCIs in skiers (3.7 mm) was not different compared to the size of those in control participants (3.4 mm) (P = .32), nor was a difference found for the MHG tendon attachment position in knees with DFCI (63.9 mm vs 63.0 mm, P = .83) or without DFCI (63.6 mm vs 62.8 mm, P = .86). Regarding associated MRI findings, increased signal intensity of the MHG tendon showed a significant association with MHG-related DFCI in both groups (P = .01 for both). Conclusion A distal femoral cortical irregularity at the attachment sites of tendons was a frequent incidental finding on knee MRI scans, with an increased prevalence in youth competitive alpine skiers. © RSNA, 2020 Online supplemental material is available for this article.

Remarkably high prevalence of overuse-related knee complaints and MRI abnormalities in youth competitive alpine skiers: a descriptive investigation in 108 athletes aged 13-15 years

Background/aim

Competitive alpine skiing is known to be associated with a high risk of traumatic knee injuries. However, little is known about the exact prevalence of knee overuse injuries and their associations with structural changes, particularly in youth skiers. Accordingly, the aim of the present study was to describe the overuse-related knee complaints and MRI abnormalities in a cohort of youth skiers around the growth spurt.

Methods

108 youth competitive alpine skiers aged 13–15 years were examined using an MRI of both knees, an interview on existing knee complaints and a physical examination. As a common baseline for these assessments, skiers were prospectively monitored by the use of the Oslo Sports Trauma Research Centre questionnaire on health problems over a period of 12 months preceding the major investigations.

Results

88.0% of the youth skiers showed at least one MRI abnormality in the knees. The most frequent findings were distal femoral cortical irregularities (63%), focal periphyseal oedema (FOPE) zones (25.0%) and cartilage lesions (18.5%). 47.2% of all skiers suffered from at least one overuse-related knee complaint during the 12 months preceding the MRI examination, mostly at the distal and proximal patellar tendon. However, despite a certain association with corresponding MRI abnormalities, the sensitivity of an MRI-based detection of such complaints was strongly limited.

Conclusion

Youth competitive alpine skiers suffer from a remarkably large number of knee overuse injuries. Accordingly, an effective prevention strategy should include a systematic screening of clinical complaints, ideally already starting around the growth spurt.

Nonossifying Fibromas: A Computed Tomography-based Criteria to Predict Fracture Risk

BACKGROUND

Nonossifying fibroma (NOF) is the most common benign osseous lesion in children; however, our understanding of which lesions progress to a fracture remains unclear. In this study, we seek to formulate a classification system for NOFs to assess for fracture risk and determine what this classification system tells us regarding fracture risk of the distal tibia and distal femur NOFs.

METHODS

Charts were retrospectively reviewed for patients with NOFs. A 4-point criteria was created and used to calculate fracture risk for distal tibia and distal femur NOFs. The analysis included incidence, specificity, and sensitivity.

RESULTS

One point was given for each of the following findings on computed tomography (CT) scan: (1) >50% width on coronal view; (2) >50% width on sagittal view; (3) any cortical breach; (4) lack of a neocortex. In total, 34 patients with NOFs of the distal tibia had CT scans, of which 14 fractured. Zero with a 0- or 1-point score fractured, 2 with a 2-point score fractured (20%), 4 with a 3-point score fractured (44%), and 8 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 100%, 85.7%, and 57.1%, respectively, and specificities were 71.4%, 71.4%, 80%, and 100%, respectively. A total of 41 patients with NOFs of the distal femur had CT scans, of which 5 fractured. Zero with a 0-point score fractured, 1 with a 1-point score fractured (4%), 0 with a 2-point score fractured, 1 with a 3-point score fractured (20%), and 3 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 80%, 80%, and 60%, respectively; and specificities were 60%, 87.8%, 90%, and 100%, respectively.

CONCLUSIONS

Our 4-point CT criteria is easy to apply and identifies patients at high risk of fracture, helping surgeons make decisions regarding treatment.

LEVEL OF EVIDENCE

Level IV-prognostic study.