Outcomes of two circular external fixation systems in the definitive treatment of acute tibial fracture related infections.

INTRODUCTION: Acute tibial fracture-related infection (FRI) is one of the most feared and challenging complications after a tibial fracture. The most appropriate treatment in this scenario is far from a resolved topic. Circular external fixators (CEFs) offer multiplanar control and minimize soft tissue injury using temporary implants far from the infected area. This study aimed to investigate the outcomes of two different types of CEFs (Ilizarov and hexapod) in the treatment of a series of acute tibial FRIs. MATERIAL AND METHODS: A retrospective study at two specialized limb reconstruction centres identified all patients with an acute tibial FRI (≤4 weeks after index procedure) definitively treated with a CEF from January 2015 to December 2020. PRIMARY OUTCOMES: fracture healing and infection eradication rate with a minimum FU of 12 months after frame removal. SECONDARY OUTCOMES: to investigate the differences between the two types of circular frames regarding final post-treatment deformity magnitude. RESULTS: We included 31 patients with acute tibial FRIs: 18 treated with hexapod-type and 13 with Ilizarov-type CEFs. Average age was 45.5±16.56 years. Fracture healing and infection eradication were achieved in all patients (31/31) after a mean follow-up of 24.7 months (range 12.1-55.3). Patients treated with an Ilizarov-type fixator presented shorter time to fracture union (5.5±2.2 months vs. 9.2±6.0 months; p-value 0.021) and shorter duration of external fixation (p-value 0.001). Regarding residual post-treatment deformity, the hexapod system presented significantly less residual coronal translation deformity (p-value 0.034) and better callus quality. Fixator-related complications were similar when comparing the two groups. No significant differences were seen in pain (p-value 0.25), RTW rate (35% vs. 45%; p-value 0.7) or functionality (p-value 0.4). CONCLUSIONS: Definitive circular external fixation is an excellent treatment for acute tibial FRI. Both Ilizarov and hexapod systems offer a very high rate of fracture healing and infection eradication. Although both presented very low radiological post-operative residual deformity, the hexapod system showed less residual coronal translation deformity and better callus quality.

Transarticular epithelioid hemangioma of the ankle-a case of a rare vascular neoplasm.

Epithelioid hemangioma of the bone is a rare kind of vascular neoplasm posing a diagnostic challenge because of its ability to mimic malignant tumors. We report a case of a fast-growing, talofibular joint-involving epithelioid hemangioma, which was suspectedly initiated by vascular damage due to trauma and arthroscopy. The ankle mass appeared as a lytic lesion on the CT images and as a T1 hypo-, T2 mildly hyperintense, lobulated structure on the MRI scans. The contrast enhancement pattern was typical to vascular neoplasms. Histologically the lesion consisted of well-formed vessels lined with epithelioid cells with a slightly atypical nuclear morphology, inflammation with a significant number of eosinophils, and low mitotic rate. Immunohistochemistry analysis showed the presence of vascular markers but no rearrangements characteristic of soft tissue sarcomas were registered by the next-generation sequencing. The surgical treatment was curative. The report presents current imaging methods and summarizes the imaging findings of transarticular spreading tumors. The paper also highlights that for the differential diagnosis of vascular tumors showing signs of aggressivity, the pathological analysis is inevitable. Correct diagnosis of the epithelioid hemangioma is essential, as the treatment of more malignant entities is substantially different. An added value of the report is that to the best of our knowledge, a transarticular spreading epithelioid hemangioma of the ankle has never been described before.

Author Correction: Precision and safety of Multilevel Cervical Transpedicular Screw Fixation with 3D Patient-Specific Guides; A Cadaveric Study.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Precision and safety of Multilevel Cervical Transpedicular Screw Fixation with 3D Patient-Specific Guides; A Cadaveric Study.

The aim is to design a patient-specific instrument (PSI) for multilevel cervical pedicle screw placement from C2 to C7, as well as verifying reliability and reproducibility. Computed tomography (CT) scans were obtained from 7 cadaveric cervical spines. Using Mimics software, semiautomatic segmentation was performed for each cervical spine, designing a 3D cervical spine bone model in order to plan transpedicular screw fixation. A PSI was designed according to the previously cited with two cannulated chimneys to guide the drill. The guides were 3D printed and surgeries performed at the laboratory. Postoperative scans were obtained to study screw placement. Sixty-eight transpedicular screws were available for study. 61.8% of all screws were within the pedicle or partially breached <4 mm. No differences were observed between cervical levels. None of these screws had neurovascular injury. Of the 27 screws with a grade 3 (screw outside the pedicle; 39.7%), only 2 had perforation of the transverse foramen and none of them would have caused a neural injury. In conclusion, multilevel PSI for cervical pedicle screw is a promising technology that despite showing improvements regarding free-hand technique requires further studies to improve the positioning of the PSI and their accuracy.

Vascularized Periosteal Flaps Accelerate Osteointegration and Revascularization of Allografts in Rats.

BACKGROUND: Surgical reconstruction of large bone defects with structural bone allografts can restore bone stock but is associated with complications such as nonunion, fracture, and infection. Vascularized reconstructive techniques may provide an alternative in the repair of critical bone defects; however, no studies specifically addressing the role of vascularized periosteal flaps in stimulating bone allograft revascularization and osseointegration have been reported. QUESTIONS/PURPOSES: (1) Does a vascularized periosteal flap increase the likelihood of union at the allograft-host junction in a critical-size defect femoral model in rats? (2) Does a vascularized periosteal flap promote revascularization of a critical-size defect structural bone allograft in a rat model? (3) What type of ossification occurs in connection with a vascularized periosteal flap? METHODS: Sixty-four rats were assigned to two equal groups. In both the control and experimental groups, a 5-cm critical size femoral defect was created in the left femur and then reconstructed with a cryopreserved structural bone allograft and intramedullary nail. In the experimental group, a vascularized periosteal flap from the medial femoral condyle, with a pedicle based on the descending genicular vessels, was associated with the allograft. The 32 rats of each group were divided into subgroups of 4-week (eight rats), 6-week (eight rats), and 10-week (16 rats) followup. At the end of their assigned followup periods, the animals were euthanized and their femurs were harvested for semiquantitative and quantitative analysis using micro-CT (all followup groups), quantitative biomechanical evaluation (eight rats from each 10-week followup group), qualitative confocal microscopic, backscattered electron microscopic, and histology analysis (4-week and 6-week groups and eight rats from each 10-week followup group). When making their analyses, all the examiners were blinded to the treatment groups from which the samples came. RESULTS: There was an improvement in allograft-host bone union in the 10-week experimental group (odds ratio [OR], 19.29 [3.63-184.50], p < 0.05). In contrast to control specimens, greater bone neoformation in the allograft segment was observed in the experimental group (OR [4-week] 63.3 [39.6-87.0], p < 0.05; OR [6-week] 43.4 [20.5-66.3], p < 0.05; OR [10-week] 62.9 [40.1-85.7], p < 0.05). In our biomechanical testing, control samples were not evaluable as a result of premature breakage during the embedding and assembly processes. Therefore, experimental samples were compared with untreated contralateral femurs. No difference in torsion resistance pattern was observed between both groups. Both backscattered electron microscopy and histology showed newly formed bone tissue and osteoclast lacunae, indicating a regulated process of bone regeneration of the initial allograft in evaluated samples from the experimental group. They also showed intramembranous ossification produced by the vascularized periosteal flap in evaluated samples from the experimental group, whereas samples from the control group showed an attempted endochondral ossification in the allograft-host bone junctions. CONCLUSIONS: A vascularized periosteal flap promotes and accelerates allograft-host bone union and revascularization of cryopreserved structural bone allografts through intramembranous ossification in a preclinical rat model. CLINICAL RELEVANCE: If large-animal models substantiate the findings made here, this approach might be used in allograft reconstructions for critical defects using fibular or tibial periosteal flaps as previously described.

Correction to: Triple elastofibromas located in the supra- and infrascapular regions-a case report.

The original version of this article unfortunately contained mistakes. The authornames of Matías de Albert, Manuel Perez, and Rosa Dominguez Oronoz as well as the affiliation of Dr. Perez are now corrected in this article.

Longitudinal deformation of drug-eluting stents: evaluation by multislice computed tomography.

BACKGROUND: Some modifications introduced in the design of the new generation of drug-eluting stent (DES) to improve their flexibility may entail a reduction in their longitudinal strength. This study sought to evaluate the longitudinal deformation of DESs by multislice computed tomography (MSCT). METHODS: This study included DESs that could have been potentially deformed by mechanical actions such as: (1) catheter impingement; (2) postdilation; (3) kissing balloon; and (4) intravascular imaging after implantation. Patients on atrial fibrillation or with overlapping stents were excluded. All patients underwent stent length evaluation by MSCT 9-12 months after implantation. RESULTS: Forty-five stents were included: 15 platinum chromium (PtCr-DES), 15 cobalt chromium (CoCr-DES), and 15 stainless-steel (SS-DES). The relative longitudinal deformation by stent type was 6.93 ± 5.82% for PtCr-DES, 6.19 ± 5.79% for CoCr- DES, and 4.03 ± 4.07% for SS-DES (P=.31). Among the mechanical actions studied, only catheter impingement was related to longitudinal stent deformation (P<.01). After adjustment, only catheter impingement (P<.01) and nominal stent length (P=.049) were independently related to longitudinal deformation. There were no stent fractures. CONCLUSIONS: Longitudinal deformation of DESs is common in all the studied platforms when subject to longitudinal forces. Guiding catheter impingement is the only mechanical action significantly associated with DES shortening.

Can magnetic resonance imaging of the hand and wrist differentiate between rheumatoid arthritis and psoriatic arthritis in the early stages of the disease?

OBJECTIVE: To investigate whether rheumatoid arthritis (RA) and psoriatic arthritis (PsA) can be differentiated in the early stages of the disease (duration of symptoms ≤1 year) on the basis of magnetic resonance imaging (MRI) features of the hand and wrist. MATERIAL AND METHODS: Twenty early RA and 17 early PsA patients with symptomatic involvement of the wrist and hand joints and inconclusive radiographic studies were examined prospectively with contrast-enhanced MRI. Images were evaluated in accordance with the Outcome Measures in Rheumatology Clinical Trials recommendations. RESULTS: Certain MRI features, such as the presence of enthesitis or extensive diaphyseal bone marrow edema, were observed exclusively in PsA (P = 0.0001). These distinctive findings were present in nearly 71% (12/17) of PsA patients. Diffuse and, in some cases, pronounced soft-tissue edema spreading to the subcutis was also seen more frequently in patients with PsA (P = 0.002). There were no significant differences in the frequency of synovitis, bone erosions, subchondral bone edema, or tenosynovitis between the 2 groups. However, in RA extensor tendons were involved more often than the flexor tendons, whereas in PsA the opposite was observed (P = 0.014). With respect to the discriminatory power of the different MRI findings examined, only the presence of enthesitis or diaphyseal bone edema and, to a lesser extent, the pattern of hand tendon involvement and the presence of soft-tissue edema accurately differentiated PsA from RA (all these features achieved accuracies greater than 0.70). CONCLUSIONS: We observed significant differences in the MRI findings of the hand and wrist that can help to distinguish between RA and PsA in the early stages of disease. This imaging method could help to assist in the differential diagnostic process in selected patients in whom diagnosis cannot be unequivocally established after conventional clinical, biochemical, and radiographic examinations.

MR imaging of early rheumatoid arthritis.

Early diagnosis and treatment have been recognized as essential for improving clinical outcomes in patients with early rheumatoid arthritis. However, diagnosis is somewhat difficult in the early stages of the disease because the diagnostic criteria were developed from data obtained in patients with established rheumatoid arthritis and therefore are not readily applicable. Magnetic resonance (MR) imaging is increasingly being used in the assessment of rheumatoid arthritis due to its capacity to help identify the key pathologic features of this disease entity at presentation. MR imaging has demonstrated greater sensitivity for the detection of synovitis and erosions than either clinical examination or conventional radiography and can help establish an early diagnosis of rheumatoid arthritis. It also allows the detection of bone marrow edema, which is thought to be a precursor for the development of erosions in early rheumatoid arthritis as well as a marker of active inflammation. In addition, MR imaging can help differentiate rheumatoid arthritis from some clinical subsets of peripheral spondyloarthropathies by allowing identification of inflammation at the insertions of ligaments and tendons (enthesitis).

Bone marrow edema in the cervical spine of symptomatic rheumatoid arthritis patients.

OBJECTIVE: To investigate the frequency and clinical significance of bone marrow edema (BME) in a series of patients with rheumatoid arthritis (RA) and symptomatic involvement of the cervical spine. METHODS: We studied 19 consecutive RA patients with cervical spine magnetic resonance imaging (MRI) according to a specifically designed protocol that included short inversion time inversion recovery sequences. All cases had neck pain unresponsive to conventional treatment, neurological symptoms, or signs suggestive of cervical myelopathy, or cervical pain with evidence of atlantoaxial subluxation on radiographs. RESULTS: The mean age of the 19 patients (15 women and 4 men) at time of the study was 59 +/- 12 years (range, 23-82) and the median disease duration was 14 +/- 7.4 years (range, 4-30). BME was observed in 74% (14/19) of the patients: at the atlantoaxial level alone in 16% of the patients; subaxially alone in 16%; and at both levels in 42% of the patients. At the atlantoaxial level, BME was usually observed involving the odontoid process, whereas subaxially BME was limited to the vertebral plates and the interapophyseal joints. Patients with BME had higher erythrocyte sedimentation rate (ESR) values at the time of MRI examination (P = 0.014) and more severe atlantoaxial joint MRI synovitis scores (P = 0.05) compared with the remaining patients; the frequency of odontoid erosions was also greater in this group, but the difference did not reach statistical significance. Altogether, these data suggest a more severe inflammatory response in these patients. In this group a significant correlation was found between BME scores at atlantoaxial level and (1) ESR values (r = 0.854; P = 0.001) and (2) atlantoaxial joint MRI synovitis scores (r = 0.691; P = 0.001). CONCLUSION: BME is frequently observed in patients with established RA and symptomatic cervical spine involvement. Both atlantoaxial and subaxial levels are equally affected. The presence of BME seems related to the intensity of the inflammatory response and to the severity of the atlantoaxial joint synovitis.