Fracture Cleft Research Articles

CT-Guided Percutaneous Vertebroplasty for Vertebral Non-union Following Posterior Fixation: A Preliminary Retrospective Study

Traumatic thoracolumbar vertebral fractures are frequently treated with posterior fixation (PF) and vertebral augmentation. Sometimes, it is deemed too risky to offer vertebral augmentation under fluoroscopic guidance alone. Adjuvant CT/fluoroscopy-guided percutaneous vertebroplasty (PVP) could be offered in certain scenarios. The aim was to evaluate feasibility, safety and effectiveness of PVP in patients presenting with vertebral non-union (VNU) following PF performed without concomitant vertebral augmentation. All patients treated in our institution with PVP between July 2015 and July 2020 were retrospectively reviewed. Patients treated with CT/fluoroscopy-guided PVP under local anesthesia for symptomatic VNU following PF were selected. Three criteria were established to assess cement distribution, considering vertebral filling of: (1) fracture cleft, (2) anterior two-thirds of the vertebral body, (3) from superior to inferior endplates. Numeric pain rating scale (NPRS) assessing grade of discomfort (0 = no pain; 10 = worst pain) and complications were evaluated before and 1month after PVP. Ten patients were identified (mean age 53 ± 12y). Mean time between PF and PVP was 9.6 [2-35] months. Two patients required further cement injection with a second PVP. Eight patients had satisfactory vertebral filling according to the three criteria. Mean NPRS reduction was 2.7(-42%, p < 0.05). No significant complications occurred. Combined CT/fluoroscopy guidance seems a useful tool to perform PVP in VNU following PF, even in presence of orthopedic metalwork. Interventional radiologists may help in these scenarios, performing an adjuvant PVP under local anesthesia. In this small series, the procedure seems safe and effective and could be taken in consideration as alternative to revision surgery.

Minding the Gap in Vertebroplasty: Vertebral Body Fracture Clefts and Cement Nonunion

Vertebroplasty and kyphoplasty are leading treatments for patients with vertebral body compression fractures. Although cement augmentation has been shown to help relieve pain and instability from fractures containing a cleft, there is some controversy in the literature regarding the procedure's efficacy in these cases. Additionally, some of the literature blurs the distinction between clefts and cement patterns (including cement nonunion and cement fill pattern). Both clefts and cement patterns have been mentioned in the literature as risks for poorer outcomes following cement augmentation, which can result in complications such as cement migration. This study aims to identify the prevalence of fracture clefts and cement nonunion, the relationship between them as well as to cement fill pattern, and their association with demographics and other variables related to technique and outcomes. Retrospective cohort study. Interventional radiology department at a single site university hospital. This retrospective cohort study assessed 295 vertebroplasties/kyphoplasties performed at the University of Colorado Hospital from 2008 to 2018. Vertebral fracture cleft and cement nonunion were the main variables of interest. Presence and characterization of a fracture cleft was determined on pre-procedural imaging, defined as an air or fluid filled cavity within the fractured vertebral body on magnetic resonance or computed tomography. Cement nonunion was evaluated on post-procedural imaging, defined as air or fluid surrounding the cement bolus on magnetic resonance or computed tomography or imaging evidence of cement migration. Cement fill pattern was assessed on procedural and/or post-procedural imaging. Pain improvement scores were based on a visual analog score immediately prior to the procedure and during clinical visits in the short-term follow-up period. Additional patient demographics, medical history, and procedure details were obtained from electronic medical chart review. Pre-procedural vertebral fracture clefts were demonstrated in 29.8% of our cases. Increasing age, secondary osteoporosis, and thoracolumbar junction location were associated with increased odds of clefts. There was no significant difference in pain improvement outcomes in patients following cement augmentation between clefted and non-clefted compression fractures. Clefts, especially large clefts, and cleft-only fill pattern were associated with increased odds of cement nonunion. Procedure techniques (vertebroplasty, curette, and balloon kyphoplasty) demonstrated similar proportion of cement nonunion and distribution of cement fill pattern. Cement nonunion was observed in only 6.8% of cases. Due to this low proportion, statistical inference tends to have low power. Multiple levels were treated in nearly half of the study's patients undergoing a single vertebroplasty/kyphoplasty session; in these cases, each level was treated as independent rather than spatially correlated within the same study patient. Vertebral body fracture clefts are not uncommon and are related to (but distinct from) cement nonunion and cement fill patterns. Our study shows that, although patients with clefts will benefit from cement augmentation just as much as patients without a cleft, the performing provider should take note of cement fill and take extra steps to ensure optimal cement fill. These providers should also identify cement nonunion and associated complications (such as cement migration) on follow-up imaging.

Abstract No. 470 - Posterior fragment encasement vertebroplasty in cord-level burst fractures

No. 469 Salvage vertebroplasty after failed kyphoplasty R. Florek, C. Simonson; Radiology, Lourdes Regional Medical Center, Lafayette, LA; Radiology, West Jefferson Medical Center, Marrero, LA Purpose: Review the technique and theraputic benefit of vertebroplasty after unsuccesssful kyphoplasty for pain control in vertebral compression fractures. Materials and Methods: Three cases were reviewed in which kyphoplasty was unsuccessful in relieving back pain due to osteoporotic vertebral compression fractures. Two cases were at one level and one case had two levels, all were lumbar. After CT review, verteboplasty was elected to be done to increase the distribution of bone cement (polymethylmethacrylate PMMA) around the kyphoplasty balloon cavity spheres. Using realtime biplane fluoroscopy, the vertebroplasty bone cement was seen to track beyond the previous kyphoplasty cement balls and tracted into the vertebral fracture clefts. Less than 1.5 cc of PMMA bone cement was used at each level. Follow-up CT scans showed bone cement in the anterior vertebral fracture clefts. Results: All three patients experienced significant pain relief after vertebroplasty and no further procedures were needed. No new fractures were detected. No complications were encountered. Conclusion: 1. Kyphoplasty bone cement fills the cavity made by the inflation of a balloon in the vertebral body, but may not always enter the fracture cleft. 2. Re-do procedure with vertebroplasty injection of bone cement may be able to alleviate pain by entering the anterior fracture cleft and stabilizing the fracture site.

Pathomorphism of spiral tibial fractures in computed tomography imaging

Spiral fractures of the tibia are virtually homogeneous with regard to their pathomorphism. The differences that are seen concern the level of fracture of the fibula, and, to a lesser extent, the level of fracture of the tibia, the length of fracture cleft, and limb shortening following the trauma. While conventional radiographs provide sufficient information about the pathomorphism of fractures, computed tomography can be useful in demonstrating the spatial arrangement of bone fragments and topography of soft tissues surrounding the fracture site. Multiple cross-sectional computed tomography views of spiral fractures of the tibia show the details of the alignment of bone chips at the fracture site, axis of the tibial fracture cleft, and topography of soft tissues that are not visible on standard radiographs. A model of a spiral tibial fracture reveals periosteal stretching with increasing spiral and longitudinal displacement. The cleft in tibial fractures has a spiral shape and its line is invariable. Every spiral fracture of both crural bones results in extensive damage to the periosteum and may damage bellies of the long flexor muscle of toes, flexor hallucis longus as well as the posterior tibial muscle. Computed tomography images of spiral fractures of the tibia show details of damage that are otherwise invisible on standard radiographs. Moreover, CT images provide useful information about the spatial location of the bone chips as well as possible threats to soft tissues that surround the fracture site. Every spiral fracture of the tibia is associated with disruption of the periosteum. 1. Computed tomography images of spiral fractures of the tibia show details of damage otherwise invisible on standard radiographs, 2. The sharp end of the distal tibial chip can damage the tibialis posterior muscle, long flexor muscles of the toes and the flexor hallucis longus, 3. Every spiral fracture of the tibia is associated with disruption of the periosteum.

Morphologic Change in Vertebral Body After Percutaneous Vertebroplasty: Follow-Up With MDCT

The purpose of this prospective study was to evaluate maintenance of spinal canal size and restoration of vertebral height and wedge angle after percutaneous vertebroplasty. This study included 27 patients (19 women, eight men) with osteoporotic compression fractures (52 vertebrae). MDCT with multiplanar reformation was performed within 1 day before and 1 hour after the procedure and 1 year after the procedure on a routine or as-needed basis. The degree of retropulsion, smallest size of the spinal canal, and vertebral height and wedge angle were measured. Statistical analyses were performed with the paired Student's t and Mann-Whitney U tests. There were no statistically significant differences in degree of retropulsion or size of the spinal canal before and after treatment and at the follow-up evaluation (p > 0.05). Even in the 36 vertebrae with spinal canal compromise before the procedure, there was no significant change in spinal stenosis (p > 0.05). Vertebral height and wedge angle were restored immediately after treatment (1.2 mm and 2.8 degrees , p < 0.05). These restorations were more prominent in vertebrae with fracture clefts than in those without clefts (p < 0.05). Restoration of vertebral height and wedge angle were diminished, but the preprocedure results were maintained in follow-up (0.4 mm and 1.1 degrees , p > 0.05). Vertebroplasty can maintain vertebral height and wedge angle and spinal canal size at least 1 year after treatment.

Importance of Intravertebral Fracture Clefts in Vertebroplasty Outcome

The importance of filling intravertebral fracture clefts with polymethylmethacrylate during percutaneous vertebroplasty to maximize stabilization of fracture fragments has been emphasized in the literature. The purpose of this study was to determine whether patients with a single compression fracture with an intravertebral cleft have better outcome after percutaneous vertebroplasty than do patients with a compression fracture but no cleft. A retrospective study was conducted to review 354 consecutive percutaneous vertebroplasty procedures on 694 compression fractures. Patients were excluded from consideration if they were treated for metastatic compression fracture or if they were treated at more than a single vertebral body level. Sixty-five patients met the inclusion criteria. Preprocedure radiographs and MR images were reviewed with specific attention to the presence or absence of intravertebral gas or fluid. Images obtained at the procedure also were reviewed for the presence or absence of an intravertebral cleft. Imaging findings were correlated with subjective pain scores immediately, 2 weeks, 1 month, 3 months, 6 months, 1 year, and 2 years after the procedure. Thirty-one (48%) of the 65 patients had evidence of a fracture cleft. Twenty-seven patients had opacification of an intravertebral fracture cleft at percutaneous vertebroplasty, and four patients had an intravertebral cleft on preprocedure imaging but did not have cleft opacification. Thirty-four (52%) of the patients had no evidence of a fracture cleft and had only a trabecular pattern of opacification. Although there was a trend toward a greater failure rate in patients with a filled cleft, there was no statistically significant difference in subjective pain scores between the groups. Pain relief with vertebroplasty is similar in patients with and those without intravertebral fracture clefts. Because of the small number of unfilled fracture clefts in our population, the true incidence of post-percutaneous vertebroplasty pain in patients with an un-filled cleft remains uncertain.

Intraosseous Venography with Carbon Dioxide Contrast Agent in Percutaneous Vertebroplasty

Our objectives were to ascertain whether CO2 can be used as a contrast agent in venography during percutaneous vertebroplasty and to evaluate whether it might be capable of replacing nonionic iodinated contrast agents. Intraosseous venography with CO2 contrast agent was slightly inferior to iodine venography in terms of its ability to visualize the vertebral bodies and perivertebral veins, but it remains a useful technique because no interference with optimal visualization of bone cement occurs during the cement injection when CO2 remains within the fracture cleft.

A non-union model of the rabbit tibial diaphysis

A consistently reproducible non-union model has been created in the adult rabbit tibial diaphysis. After making an osteotomy, the marrow was removed, the periosteum was excised and a silastic sheath was wrapped around the shaft. The fracture cleft was invaded by a non osteogenic fibrous tissue following the removal of the sheath after an interval of 4 weeks.

Injury to Articular Cartilage Joint Surfaces

Thirty-two pathologic specimens from patients who previously had sustained intraarticular fractures, usually of either the radial head or the patella, and subsequently had excision of the affected bone, were analyzed with respect to the healing mechanisms of articular fractures in humans. The cases were divided into five groups based on the duration of the time interval between fracture and joint-surface resection. The fracture clefts were sometimes perpendicular to the joint surface but often were more complex, and microscopically showed far more comminution than was appreciated from the gross examination. In all cases the articular chondrocytes demonstrated minimal reactive or reparative response to the injuries, even those cells that were situated directly adjacent to a fracture cleft. All significant repair was derived from the fracture-exposed bone marrow. At early stages, this consisted of granulation tissue. Later specimens showed fibrous tissue bridging the cartilage fracture gaps. Chondrous metaplasia within the surface layers of this fibrous callus could be observed occasionally, particularly in specimens with older fractures. However, it was often absent. In the cancellous bone, the healing of the fractures was by osseous, not chondroosseous, callus. In comminuted fractures areas of osteonecrosis were demonstrated in a number of cases.

Reparative Cartilaginous Callus in Subarticular Osteonecrosis of Bone

A histopathologic study of a series of 346 resected femoral heads with gross osteonecrosis secondary to trauma, steroid therapy, idiopathic or other disease processes demonstrated the production of significant cartilaginous callus tissue at fracture clefts in 19 specimens (5.5%). Although subarticular fracture clefts were commonly present in such specimens, the formation of cartilaginous callus occurred only when one of the two opposing surfaces at the fracture cleft consisted of viable bone. Usually this was osseous tissue that originally had composed a portion of the infarct but had undergone revascularization. In another group of five cases from the same series, fragmentation of all tissue superior to the layer of cartilaginous callus had occurred by the time of surgery. The previously formed cartilaginous callus layer then became the actual weightbearing surface. Pathologically, callus must be differentiated from the cartilaginous tuft phenomenon of exposed intra-articular bone.