Desmoplastic fibroma in a child: a 9-year follow-up case report.

BACKGROUND: Desmoplastic fibroma is an extremely rare primary bone tumor. Its characteristic features include bone destruction accompanied by the formation of soft tissue masses. This condition predominantly affects individuals under the age of 30. Since its histology is similar to desmoid-type fibromatosis, an accurate diagnosis before operation is difficult. Desmoplastic fibroma is resistant to chemotherapy, and the efficacy of radiotherapy is uncertain. Surgical excision is preferred for treatment, but it entails high recurrence. Further, skeletal reconstruction post-surgery is challenging, especially in pediatric cases. CASE PRESENTATION: Nine years ago, a 14-year-old male patient presented with a 4-year history of progressive pain in his left wrist. Initially diagnosed as fibrous dysplasia by needle biopsy, the patient underwent tumor resection followed by free vascularized fibular proximal epiphyseal transfer for wrist reconstruction. However, a histological examination confirmed a diagnosis of desmoplastic fibroma. The patient achieved bone union and experienced a recurrence in the ipsilateral ulna 5 years later, accompanied by a wrist deformity. He underwent a second tumor resection and wrist arthrodesis in a single stage. The most recent annual follow-up was in September 2023; the patient had no recurrence and was satisfied with the surgery. CONCLUSIONS: Desmoplastic fibroma is difficult to diagnose and treat, and reconstruction surgery after tumor resection is challenging. Close follow-up by experienced surgeons may be beneficial for prognosis.

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.

Enfermedad de Caffey: reporte de un caso clínico / Caffey's disease: report of a clinical case / Doença de Caffey: relato de um caso clínico

Introducción: La enfermedad de Caffey es una patología ósea inflamatoria, rara, autolimitada, casi exclusiva de lactantes. Objetivos: Jerarquizar el abordaje diagnóstico de una patología poco frecuente. Caso clínico: 4 meses 22 días, varón, consulta por irritabilidad y edema de miembro inferior izquierdo de 4 días de evolución. Sin traumatismos ni fiebre. Examen físico: edema indurado en tercio medio e inferior de pierna izquierda, no rubor ni calor local. Dolor a la palpación de cara anterior y lateral de tibia y peroné. Limitación funcional, no resaltos óseos. Radiografía: engrosamiento del periostio en tibia y peroné a nivel diafisario. Hemograma: Glóbulos blancos 15.380 KU/L, Hemoglobina 10,8 g/dL, Plaquetas 816.400 10/ul, proteína C reactiva 13,90 mg/dl. Con planteo de probable infección osteoarticular se inicia clindamicina ( gentamicina e ingresa a cuidados moderados. Dada la persistencia de edema e irritabilidad, al quinto día se solicita resonancia magnética: hallazgos sugerentes de un probable proceso inflamatorio- infeccioso de partes blandas con compromiso óseo. Completa 14 días de clindamicina y 7 días de gentamicina intravenosa, hemocultivo negativo. Persiste con edema, irritabilidad y dolor. A los 21 días, se revalora la presentación clínica-imagenológica, se plantea enfermedad de Caffey. Se inicia anti-inflamatorio con buena evolución. Conclusiones: La enfermedad de Caffey es una colagenopatía rara, que afecta lactantes. El diagnóstico es clínico - radiológico (irritabilidad, tumefacción de partes blandas y alteraciones radiológicas). El pronóstico a largo plazo suele ser favorable. Es importante considerar el diagnóstico en lactantes que se presentan con esta sintomatología para evitar retrasos diagnósticos e instauración de tratamientos innecesarios.

Introduction: Caffey's disease is a rare disease that is reported almost exclusively in infants. Objective: Describe the case of a rare pathology, prioritizing the diagnostic approach. Clinical case: 4 month -old, healthy male. Consultation due to irritability and edema of the left lower limb for 4 days. No trauma or fever. Physical examination: indurated edema in the left leg, no redness or local heat. Pain on palpation of the anterior and lateral aspect of the tibia and fibula. Functional limitation, no bony protusions. Leg x-ray: thickening of the periosteum in the tibia and fibula at the diaphyseal level. Hemogram: White Blood Cells 15,380 KU/L Hemoglobin: 10.8 g/dL. Platelets: 816,400 10/ul, C-reactive protein: 13.90 mg/dl. He was admitted with a suggestion of probable osteoarticular infection. Clindamycin ( gentamicin is started. Given the persistence of edema and irritability despite treatment, on the fifth day an MRI was requested: findings suggestive of a probable inflammatory-infectious process of soft tissues with bone involvement. Completed 14 days of clindamycin and 7 days of intravenous gentamicin, blood culture negative. It persists with edema, irritability and pain. After 21 days, the clinical-imaging presentation was reassessed and Caffey's disease was considered. Anti-inflammatory begins with good evolution. Conclusions: Caffey's disease is a rare collagenopathy, that affects infants. The diagnosis is clinical - radiological (irritability, soft tissue swelling and radiological alterations). The long-term prognosis is usually favorable. It is important to consider the diagnosis in infants who present with these symptoms to avoid diagnostic delays and initiation of unnecessary treatments.

Introdução: A doença de Caffey é uma patologia óssea inflamatória rara, autolimitada, quase exclusiva de lactentes. Objetivos: Priorizar a abordagem diagnóstica de uma patologia rara. Caso clínico: 4 meses 22 dias, sexo masculino, consulta por irritabilidade e edema do membro inferior esquerdo de 4 dias de evolução. Sem trauma ou febre. Exame físico: edema endurecido em terço médio e inferior da perna esquerda, sem vermelhidão ou calor local. Dor à palpação das faces anterior e lateral da tíbia e fíbula. Limitação funcional, sem saliências ósseas. Radiografia: espessamento do periósteo na tíbia e fíbula ao nível diafisário. Hemograma: Glóbulos brancos 15.380 KU/L, Hemoglobina 10,8 g/dL, Plaquetas 816.400 10/ul, Proteína C reativa 13,90 mg/dl. Com sugestão de provável infecção osteoarticular, foi iniciada clindamicina + gentamicina e internado em cuidados moderados. Dada a persistência do edema e da irritabilidade, no quinto dia foi solicitada ressonância magnética: achados sugestivos de provável processo inflamatório-infeccioso de partes moles com envolvimento ósseo. Completou 14 dias de clindamicina e 7 dias de gentamicina intravenosa, hemocultura negativa. Persiste com edema, irritabilidade e dor. Após 21 dias, o quadro clínico-imagem foi reavaliado e considerada doença de Caffey. O antiinflamatório começa com uma boa evolução. Conclusões: A doença de Caffey é uma colagenopatia rara que afeta lactentes. O diagnóstico é clínico-radiológico (irritabilidade, edema de partes moles e alterações radiológicas). O prognóstico a longo prazo é geralmente favorável. É importante considerar o diagnóstico em lactentes que apresentam esses sintomas para evitar atrasos no diagnóstico e início de tratamentos desnecessários.

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.

Intercalary allograft reconstruction following femoral tumour resection: mid- and long-term results and benefits of adding a vascularised fibula autograft.

PURPOSE: Bone healing in femoral reconstructions using intercalary allografts can be compromised in a tumour context. There is also a high revision rate for non-union, infection, and fractures in this context. The advantages and disadvantages of an associated vascularised fibula graft (VFG) are still a matter of debate. METHODS: In a multicentre study, we retrospectively analysed 46 allograft reconstructions, operated on between 1984 and 2017, of which 18 were associated with a VFG (VFG+) and 28 without (VFG-), with a minimum follow-up of 2 years. We determined the cumulative probability of bone union as well as the mid- and long-term revision risks for both categories by Kaplan-Meier survival analysis and a multivariate Cox model. We also compared the MSTS scores. RESULTS: Significant differences in favour of VFG+ reconstruction were observed in the survival analyses for the probability of bone union (log-rank, p = 0.017) and in mid- and long-term revisions (log-rank, p = 0.032). No significant difference was observed for the MSTS, with a mean MSTS of 27.6 in our overall cohort (p = 0.060). The multivariate Cox model confirmed that VFG+ was the main positive factor for bone union, and it identified irradiated allografts as a major risk factor for the occurrence of mid- and long-term revisions. CONCLUSION: Bone union was achieved earlier in both survival and Cox model analyses for the VFG+ group. It also reduced the mid- and long-term revision risk, except when an irradiated allograft was used. In case of a tumour, we thus recommend using VFG+ from a fresh-frozen allograft, as it appears to be a more reliable long-term option.

Masticatory performance in patients undergoing free fibula flap for mandible reconstruction.

BACKGROUND: To explore the masticatory performance in patients undergoing an osteo(cutaneous) free fibula (OFF) flap for mandible reconstruction by a prospective design. METHODS: A total of 56 patients who had undergone OFF flap reconstructions for mandibular reconstruction secondary to malignant (squamous cell carcinoma) or benign (ameloblastoma) tumor resection were prospectively enrolled. They were asked to complete the masticatory performance test by the weigh method and the chew domain of the University of Washington quality of life questionnaire (version 4) preoperatively and at 3, 6, and 12 months postoperatively. The pair nonparametric test was used to analyze the dynamic change of masticatory performance and subjective chew function. RESULTS: Fifty-one patients were included for analysis finally. The mean masticatory performance for patients with malignant tumors were 53.4% ± 10.3%, 36.4% ± 10.3%, 42.6% ± 9.6%, 52.8% ± 10.9%, and 53.1% ± 11.8% preoperatively, at 2 weeks, 3 months, 6 months, and 12 months postoperatively, respectively. Compared with the preoperative level, the masticatory performance had a significant reduction immediately after surgery (p < 0.001), followed by a return to the baseline level within three months. A similar trend was noted for those with benign tumors. The mean score of chew domain for patients with malignant tumors were 100 ± 0, 54.3 ± 32.9, 81.4 ± 24.5, and 92.9 ± 17.8 preoperatively, at 3 months, 6 months, and 12 months postoperatively, respectively. Compared with the preoperative level, the subjective chew function was greatly affected within the first three months (p < 0.001), and it gradually recovered to the baseline level in the following nine months. A similar trend was noted in patients with benign tumors. CONCLUSIONS: The masticatory performance and subjective chew function was significantly affected after OFF flap reconstructions in the short term, but both recovered to the preoperative levels within 9-12 months.

Associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and changes in tibiofemoral joint structures in patients with knee osteoarthritis.

BACKGROUND: To describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA). METHODS: The participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ), and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs), and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes. RESULTS: In the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (ß: - 0.07), Sυ (ß: - 0.07), and S (ß: - 0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs. CONCLUSIONS: This longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01176344 Anzctr.org.au Identifier: ACTRN12610000495022 Date of registration: 7 May 2010.

Reconstruction of the distal radius using a double-barrel vascularized fibula flap: A case series.

Treatment of distal radius tumor sometimes requires sacrificing the epiphysis. We propose adding to currently available reconstruction options a technique using a double-barrel vascularized fibula flap fixed distally to the first carpal row, conserving midcarpal mobility. We monitored 4 cases of Campanacci III giant-cell tumor and 2 cases of osteosarcoma. After en-bloc tumor resection, a double-barrel vascularized fibula flap was lodged distally in the scaphoid and lunate and proximally in the radius. Follow-up was clinical and radiological, using DASH, PRWE and MSTS functional scores. At a median 3 years' follow-up, there were no cases of recurrence or non-union. Median ranges of motion were 23° flexion, 28° extension, 90° pronation and 62° supination. Median grip strength proportional to the contralateral side was 67%. Median DASH and PRWE functional scores were respectively 13.7 and 17 points. Median MSTS was 83%. Although this technique is challenging, with difficulties in double-barrel flap placement and in pedicle plication, the double-barrel vascularized fibula flap provided a stable and mobile wrist.

Wrist Reconstruction Using Free Vascularized Fibular Head Graft Following Intralesional Excision for Campanacci Grade 3 Giant Cell Tumors Involving the Articular Surface of the Distal Radius.

Reconstruction with a free vascularized fibular head graft after en bloc excision of a Campanacci grade 3 giant cell tumor of bone in the distal radius can effectively control local recurrence. However, it leads to the loss of wrist movement, subsequent radiocarpal subluxation, and an osteoarthritic change. Another treatment option for grade 3 lesions is intralesional excision and cementation, which preserves wrist movement but does not restore the articular surface. We report a case of wrist reconstruction using a free vascularized fibular head graft after the intralesional excision of a Campanacci grade 3 giant cell tumor of bone with invasion of the articular surface of the distal radius. In patients with this type of a lesion, wrist reconstruction using a free vascularized fibular head graft after intralesional excision can help prevent local tumor recurrence, restore the articular surface, and maintain movements of the wrist joint.

Survival analysis of segmental mandibulectomy with immediate vascularized fibula flap reconstruction in stage IV oral squamous cell carcinoma patients.

PURPOSE: This study aims to assess the survival rate of oral squamous cell carcinoma (OSCC) patients following immediate mandibular reconstruction with vascularized fibula flap (VFF) and to identify risk factors influencing the overall survival rate and postoperative outcomes. PATIENTS AND METHODS: Patients suitable for the inclusion criterion diagnosed and treated between January 1996 till June 2019 for OSCC were retrospectively reviewed (n = 74). Potential risk factors and postoperative outcomes were recorded and analyzed. RESULTS: The overall cumulative survival rate of patients was 0.52 at the end of 5th year. Overall, advanced pN stage (p = 0.0422), poor tumor differentiation (p < 0.0001), positive/close surgical margins (p = 0.0209), vascular invasion (p = 0.0395), perineural invasion (p = 0.0022) and tumor recurrence (p = 0.0232) were significantly related to a decreased cumulative survival. Tumor recurrence was significantly correlated with involvement of positive/close surgical margins, moderate (p = 0.0488), poor-differentiated tumors (p = 0.202), extracapsular spread (p = 0.0465), computer-assisted surgery (p = 0.0014) and early complications (p = 0.0224). Pain was significantly associated with the extracapsular spread (p = 0.0353) and early complications (p = 0.0127). CONCLUSION: The five-year survival rate of advanced OSCC patients after segmental mandibulectomy with fibula free-flap reconstruction was 52.4%. Clinical/pathological risk factors such as the pN stage, tumor differentiation, surgical margins, vascular invasion, perineural invasion, tumor recurrence significantly influenced the overall cumulative survival rate.

Visualization and quantification of the degenerative pattern of the distal tibia and fibula in unilateral varus ankle osteoarthritis.

The present study aimed to quantify and visualize the degenerative patterns of the distal tibia and fibula due to ankle osteoarthritis (OA). We analyzed differences in tibial and fibular surface deviation between sides of patients with unilateral varus ankle OA (medial talar tilt > 4°) by registering each surface model to the mirror image of corresponding bone. Computed tomography images of both feet of 33 patients (OA: 22, control: 11) were examined. Statistically significant surface depression of approximately 2.5 mm on the anterior articular surface of the medial malleolus, and surface elevation of approximately 1 mm on the anterodistal edge of the tibiofibular joint and the lateral malleolus were observed in OA patients. These bone degenerations were found to be correlated with those on the other side of the ankle joint, the medial margin of the talar trochlea and the lateral articular surface of the talus, respectively. In contrast, the amount of bone depression on the plafond was smaller than previously anticipated. Such quantitative information about stereotypical patterns of bone degeneration in ankle OA would contribute to better understanding of the development of ankle OA and possible therapeutic interventions.

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.

Multiple Osteochondromas Comorbid With Enlarged Parietal Foramina, Elongated Styloid Processes, and Tibiofibular Synostosis.

OBJECTIVES: This study investigates a unique case of multiple osteochondromas (MO) comorbid with enlarged parietal foramina and correlates the findings with the existing literature. The aim of this study is to provide a deeper understanding of anatomic variation for physicians. METHODS: A 66-year-old White male donor was examined during a routine cadaveric dissection performed by medical students in an anatomy laboratory. Detailed exploration of the skeleton and organs was performed, and photographs were taken. Tissue samples were obtained from multiple outgrowths, and histopathologic examination was done. RESULTS: Bilateral bony growths were noted rising from the long bones of the upper and lower extremities (femur, tibia, fibula, and radius). An accessory muscle was found to be associated with the left radial bony growth. Histopathologic examination was positive for osteochondroma. Inspection of the skull revealed enlarged parietal foramina. Other findings included tibiofibular synostosis, abnormally shaped vertebral bodies and ribs, and elongated styloid processes of the skull. CONCLUSIONS: In combination with the histopathologic examination, the case report and literature review elucidate a more precise clinical picture for those affected with MO or similar disorders. This report also emphasizes the necessity of further investigation of the pathogenesis of MO and Potocki-Shaffer syndrome.

Identification of EWSR1-NFATC2 fusion in simple bone cysts.

AIMS: Simple bone cysts are benign intramedullary tumours primarily involving the long bones in skeletally immature individuals. Several mechanisms have been proposed for their pathogenesis. Although the diagnosis is typically straightforward, the interpretation can be problematic, because of superimposed fracture causing them to resemble aneurysmal bone cysts and other tumours. EWSR1-NFATC2 or FUS-NFATC2 fusions, which are characteristic of a subset of aggressive round cell sarcomas, have been recently detected in simple bone cysts. The aim of this study was to examine the clinicopathological and molecular features in a series of simple bone cysts. METHODS AND RESULTS: Using RNA-based next-generation sequencing and/or fluorescence in-situ hybridisation, we investigated the presence of EWSR1 or FUS rearrangements in nine simple bone cysts. The patients were five females and four males, aged 3-23 years (median, 14 years); the tumours ranged from 19 mm to 160 mm (median, 46 mm) in size, and involved the femur (n = 3), humerus (n = 2), fibula (n = 2), tibia (n = 1), and iliac wing (n =1). We identified three cases with EWSR1-NFATC2 fusion (showing identical breakpoints to those in EWSR1-NFATC2 sarcomas) and one additional case with FUS rearrangement. Unlike in EWSR1-NFATC2 sarcomas, immunohistochemical expression of NKX3.1 and NKX2.2 was absent in two simple bone cysts tested. CONCLUSIONS: More than 40% of simple bone cysts harbour genetic alterations confirming that they are neoplastic, investigation of EWSR1 and/or FUS rearrangement may help to distinguish simple bone cysts from mimics, and NFATC2 rearrangement is not pathognomonic of malignancy.

Percutaneous bridge plating of extra-articular distal fibular fracture for the management of distal tibia type III open fracture.

PURPOSE: The aim of this study is to conduct clinical and radiographic evaluations of the use of percutaneous bridge plating for distal fibular fractures combined with distal tibia type III open fractures. METHODS: Thirty-four patients with acute distal third fibular shaft fractures (4F2A(c) and 4F2B(c) according to the AO/OTA classification) combined with distal tibia type III open fractures were enrolled. Concurrent fibular fractures were fixed with the percutaneous bridge plating simultaneously, while distal tibia open fractures were temporally stabilized with a spanning external fixator. Clinical and radiographic outcomes were evaluated using the Lower Extremity Functional Scale (LEFS), the proportional length difference of the fibula, the talocrural angle, the union rate of the fibula and tibia, the operation time, and complications at the final follow-up. RESULTS: All fibular fractures healed with an average bone healing time of 20.7 ± 6.3 weeks (range, 16-35). The mean proportional length difference was 0.492 ± 0.732% compared with that in the uninjured fibula. The functional assessment result according to the LEFS was 74.0 ± 3.70 points (range, 57-80). No cases of fibula fracture infection developed throughout the follow-up period in any of the patients. Iatrogenic postoperative superficial peroneal nerve injury was not found in any of the patients. CONCLUSION: With the perspective of minimizing soft tissue problems due to high-energy trauma, the application of percutaneous bridge plating for the treatment of distal fibular fractures can be an alternative to conventional treatment methods.

Peroneal Nerve Function Before and Following Surgical Excision of a Proximal Fibular Osteochondroma.

BACKGROUND: Osteochondromas occur most commonly in the distal femur, proximal tibia, and humerus. There are no large studies reviewing the outcome of treatment for patients with an osteochondroma involving the proximal fibula. The purpose of this study is to specifically understand the manifestations of a proximal fibular osteochondroma (PFO) on the preoperative peroneal nerve function, and how surgical management of the osteochondroma affects function immediately postoperatively and at long-term follow-up. METHODS: This is an institutional review board-approved retrospective review of a consecutive series of patients with a PFO treated operatively at a single institution. The medical record was carefully reviewed to identify demographic data, clinical data especially the status of the peroneal function at various time points. RESULTS: There were 25 patients with 31 affected extremities who underwent surgical excision of the PFO at an average age of 12.4 years (range, 3.0 to 17.9 y). There were 16 males and 9 females. The underlying diagnosis was isolated PFO in 2 (8%) patients and multiple hereditary exostosis in 23 (92%) patients. Preoperatively, 9 (29%) had a foot drop and 22 (71%) did not. Those with a preoperative foot drop underwent surgery at a younger age (9.1 vs. 13.8 y) (P<0.004) and postoperatively 5 (55.5%) had complete resolution, 3 (33.3%) had improvement, and 1 (11.1%) persisted requiring an ankle foot orthosis. Of the 22 who were normal preoperatively, 5 (22.7%) developed an immediate postoperative foot drop, 3 (60%) completely resolved, 1 (20%) improved, and 1 (20%) persisted and was found to have a transected nerve at exploration. In total, 23 of the 25 (92%) patients who had a PFO excision, had a normal or near-normal peroneal nerve function including those who had poor function preoperatively. CONCLUSIONS: Patients with a PFO have a preoperative peroneal nerve dysfunction 30% of the time and 23% of those who were normal preoperatively have postoperative dysfunction. Fortunately, nearly all patients have a complete recovery following excision of the osteochondroma. LEVEL OF EVIDENCE: Level IV.

Predictive value of the morphology of proximal tibiofibular joint for total knee replacement in patients with knee osteoarthritis.

The association between proximal tibiofibular joint (PTFJ) and knee osteoarthritis (OA) has been understudied. The objective of this study was to determine whether the morphology of PTFJ has predictive value for the risk of total knee replacement (TKR). Case knees from Osteoarthritis Initiative participants with TKR at 24-60 months follow up (cases) were 1:1 matched with control knees (no TKR throughout 60 months) by baseline age, sex, and Kellgren-Lawrence grade. PTFJ morphological parameters, including coronal inclination angle (angle α), sagittal inclination angle (angle ß), fibular contacting area (S), load-bearing area (Sτ), lateral stress-bolstering area (Sφ), and posterior stress-bolstering area (Sυ) were assessed using coronal and sagittal magnetic resonance imaging (MRI), respectively. Associations of the morphological measures at baseline and the time point before TKR (T0 ) and their changes with TKR risks were examined using conditional logistic regression analyses. Two hundred and twenty-three knees of 193 participants received TKR between 12 and 60 months and therefore were matched with 223 control knees. Of these, 173 paired knees had MRI readings available both at baseline and T0 time point. While baseline angle α was positively associated with TKR risk, other measures at baseline and all measures at T0 were not significantly associated with TKR risk. Changes in S, Sτ, and Sυ were significantly and negatively associated with the risk of TKR (ΔS, odds ratio [OR] = 0.38, 95% confidence interval [CI]: 0.19-0.76; ΔSτ, OR = 0.37, 95% CI: 0.16-0.87; ΔSυ, OR = 0.22, 95% CI: 0.08-0.62, respectively). This data shows that morphological changes of PTFJ predict the risk of TKR, suggesting PTFJ may play a role in knee OA.

Can Syndesmosis Screws Displace the Distal Fibula?

Background. There has been historical debate as to whether the distal tibiofibular syndesmosis can be overtightened during operative fixation. We used finite-element analysis to determine if overtightening of syndesmotic screws can cause widening of the lateral gutter clear space in the ankle joint. Methods. A 3D finite-element model was constructed and analyzed using geometries from a computed tomography scan of a cadaveric lower leg. Starting 2 cm from the plafond, screw fixation was simulated at 5-mm increments to a distance of 5 cm from the plafond. The fibula was compressed 2 mm toward the tibia at each interval, and the change in distance between the lateral talus and distal fibula was measured. Results. Medial deflection of the fibula resulted in widening of the lateral clear space, which was proportional to the amount of deflection. The effect increased as screws were placed closer to the plafond, with 1.5 mm of widening at 2 cm (0.76 mm/mm) versus 0.7 mm at 5 cm (0.34 mm/mm). Conclusion. Our finite-element model demonstrated that overtightening of the distal tibiofibular syndesmosis with medial fibular displacement can cause widening of the lateral clear space. Clinical relevance. The results suggest that screws placed farther from the plafond widen the lateral clear space to a lesser degree, which may be advantageous during surgical fixation to prevent clear space widening and increased tibiotalar contact forces.Levels of Evidence: Level I.

A comprehensive diagnostic approach combining phylogenetic disease bracketing and CT imaging reveals osteomyelitis in a Tyrannosaurus rex.

Traditional palaeontological techniques of disease characterisation are limited to the analysis of osseous fossils, requiring several lines of evidence to support diagnoses. This study presents a novel stepwise concept for comprehensive diagnosis of pathologies in fossils by computed tomography imaging for morphological assessment combined with likelihood estimation based on systematic phylogenetic disease bracketing. This approach was applied to characterise pathologies of the left fibula and fused caudal vertebrae of the non-avian dinosaur Tyrannosaurus rex. Initial morphological assessment narrowed the differential diagnosis to neoplasia or infection. Subsequent data review from phylogenetically closely related species at the clade level revealed neoplasia rates as low as 3.1% and 1.8%, while infectious-disease rates were 32.0% and 53.9% in extant dinosaurs (birds) and non-avian reptiles, respectively. Furthermore, the survey of literature revealed that within the phylogenetic disease bracket the oldest case of bone infection (osteomyelitis) was identified in the mandible of a 275-million-year-old captorhinid eureptile Labidosaurus. These findings demonstrate low probability of a neoplastic aetiology of the examined pathologies in the Tyrannosaurus rex and in turn, suggest that they correspond to multiple foci of osteomyelitis.

A Cadaveric Study of the Distal Biceps Femoris Muscle in relation to the Normal and Variant Course of the Common Peroneal Nerve: A Possible Cause of Common Peroneal Entrapment Neuropathy.

The most frequent mononeuropathy in the lower extremity has been reported as the common peroneal nerve entrapment neuropathy (CPNe) around the head and neck of the fibula, although the mechanism of the neuropathy in this area cannot be fully explained. Therefore, the aim of this cadaveric study was to evaluate the relationship between morphologic variations of the distal biceps femoris muscle (BFM) and the course of the common peroneal nerve (CPN) and to investigate the incidence and morphological characteristics of anatomical variations in the BFM associated with CPNe. The popliteal region and the thigh were dissected in 115 formalin-fixed lower limbs. We evaluated consensus for (1) normal anatomy of the distal BFM, (2) anatomic variations of this muscle, and (3) the relationship of the muscle to the CPN. Measurements of the distal extents of the short and long heads of the BFM from insertion (fibular head) were performed. Two anatomic patterns were seen. First, in 93 knees (80.8%), the CPN ran obliquely along the lateral side of the BFM and then superficial to the lateral head of the gastrocnemius muscle. Second, in 22 cases (19.2%), the CPN coursed within a tunnel between the biceps femoris and lateral head of the gastrocnemius muscle (LGCM). There was a positive correlation between the distal extents of the short heads of the biceps femoris muscle (SHBFM) and the presence of the tunnel. The "popliteal intermuscular tunnel" in which the CPN travels can be produced between the more distal extension variant of the SHBFM and the LGCM. This anatomical variation of BFM may have a clinical significance as an entrapment area of the CPN in the patients in which the mechanism of CPNe around the fibula head and neck is not understood.