Superior mesenteric artery syndrome: A diagnosis to be kept in mind (Case report and literature review)

IntroductionSuperior mesenteric artery (SMA) syndrome or what is called Wiklie’s syndrome is one of the rare causes of small bowel obstruction. Its exact incidence is not known. It is due to decrease in Aortomesenteric angle.Case presentationA thirty-Four-year old male patient presented to our accident and emergency (department) with 3 days history of epigastric pain, which was not radiating anywhere. It had no aggravating or relieving factors. Patient complained of repeated attack of vomiting as well. Contrast enhanced Computed tomography (CT) showed duodenal obstruction caused by superior mesenteric artery compression on 3rd part of duodenum.DiscussionSuperior mesenteric artery syndrome (SMA) is one of the rare causes of small bowel obstruction. Incidence of superior mesenteric artery syndrome reported in literature is ranging from 0.1 to 0.3%. The most common cause is significant weight loss which leads to loss of retroperitoneal fat. Treatment usually is conservative but surgical intervention should be considered if that failed.ConclusionSuperior mesenteric artery syndrome is a rare cause of intestinal obstruction but should be kept in mind. Persistent vomiting after history of weight loss should raise the suspicion of this diagnosis. Upper GI endoscopy may be necessary to exclude mechanical causes of duodenal obstruction. Contrast enhanced CT scan is useful in the diagnosis of superior mesenteric artery syndrome and can provide diagnostic information.     

Cytomegalovirus (CMV) infection and risk of mortality in allogeneic hematopoietic stem cell transplantation (Allo‐HSCT): A systematic review,meta‐analysis,and meta‐regression analysis

Controversy surrounds the potential association between cytomegalovirus (CMV) infection and increased risk of mortality after allogeneic hematopoietic stem cell transplantation (Allo‐HSCT). A systematic literature search was conducted using the PubMed, EMBASE, and Web of Science databases, assessing the association between CMV infection, as documented by the pp65 antigenemia assay or by polymerase chain reaction (PCR) using blood specimens, and overall mortality (OM) and nonrelapse mortality (NRM) in the allo‐HSCT setting. Pooled effects were estimated using the generic inverse variance random effects model. Heterogeneity was evaluated by Cochrane's Q test and I² statistics. The source of heterogeneity was investigated by meta‐regression and subgroup analyses. Twenty‐six of 1367 studies fulfilled eligibility criteria. CMV infection identified by PCR monitoring was significantly associated with an increased risk of OM and NRM (hazard ratio 1.47, 95% confidence interval [1.20‐1.81], P ≤ .001; hazard ratio 1.68, 95% confidence interval [1.14‐2.49], P = .05, respectively). In this setting, the use of preemptive antiviral therapy (PET) resulted in a twofold increased risk of OM and NRM. The estimated effect sizes were associated with allo‐HSCT modalities. Although our analyses point to an association between CMV infection and an increased risk of OM and NRM in allo‐HSCT recipients, the high heterogeneity across studies prevented drawing of robust conclusions on this matter.     

Healing of fracture nonunions treated with low-intensity pulsed ultrasound (LIPUS): A systematic review and meta-analysis

IntroductionBone fractures fail to heal and form nonunions in roughly 5% of cases, with little expectation of spontaneous healing thereafter. We present a systematic review and meta-analysis of published papers that describe nonunions treated with low-intensity pulsed ultrasound (LIPUS).MethodsArticles in PubMed, Ovid MEDLINE, CINAHL, AMED, EMBASE, Cochrane Library, and Scopus databases were searched, using an approach recommended by the Methodological Index for Non-Randomized Studies (MINORS), with a Level of Evidence rating by two reviewers independently. Studies are included here if they reported fractures older than 3 months, presented new data with a sample N ≥ 12, and reported fracture outcome (Heal/Fail).ResultsThirteen eligible papers reporting LIPUS treatment of 1441 nonunions were evaluated. The pooled estimate of effect size for heal rate was 82% (95% CI: 77–87%), for any anatomical site and fracture age of at least 3 months, with statistical heterogeneity detected across all primary studies (Q = 41.2 (df = 12), p < 0.001, Tau² = 0.006, I² = 71). With a stricter definition of nonunion as fracture age of at least 8 months duration, the pooled estimate of effect size was 84% (95% CI: 77%–91.6%; heterogeneity present: Q = 21 (df = 8), p < 0.001, Tau² = 0.007, I² = 62). Hypertrophic nonunions benefitted more than biologically inactive atrophic nonunions. An interval without surgery of <6 months prior to LIPUS was associated with a more favorable result. Stratification of nonunions by anatomical site revealed no statistically significant differences between upper and lower extremity long bone nonunions.ConclusionsLIPUS treatment can be an alternative to surgery for established nonunions. Given that no spontaneous healing of established nonunions is expected, and that it is challenging to test the efficacy of LIPUS for nonunion by randomized clinical trial, findings are compelling. LIPUS may be most useful in patients for whom surgery is high risk, including elderly patients at risk of delirium, or patients with dementia, extreme hypertension, extensive soft-tissue trauma, mechanical ventilation, metabolic acidosis, multiple organ failure, or coma. With an overall average success rate for LIPUS >80% this is comparable to the success of surgical treatment of non-infected nonunions.     

Association of antiviral prophylaxis and rituximab use with posttransplant lymphoproliferative disorders (PTLDs): A nationwide cohort study

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation (SOT). Most PTLD cases are associated with Epstein–Barr virus (EBV) infection. The role of antiviral prophylaxis or rituximab therapy for prevention of PTLD in SOT recipients is controversial. In a nationwide cohort, we assessed the incidence, presentation, and outcome of histologically proven PTLD. We included 4765 patients with a follow-up duration of 23 807 person-years (py). Fifty-seven PTLD cases were identified; 39 (68%) were EBV positive (EBV+ PTLD). Incidence rates for EBV+ PTLD at 1, 2, and 3 years posttransplant were 3.51, 2.24, and 1.75/1000 py and 0.44, 0.25, and 0.29/1000 py for EBV− PTLD. We did not find an effect of antiviral prophylaxis on early and late EBV+ PTLD occurrence (early EBV+ PTLD: SHR 0.535 [95% CI 0.199–1.436], p = .264; late EBV+ PTLD: SHR 2.213, [95% CI 0.751–6.521], p = .150). However, none of the patients (0/191) who received a rituximab-containing induction treatment experienced PTLD, but 57 of 4574 patients without rituximab induction developed PTLD. In an adjusted restricted mean survival time model, PTLD-free survival was significantly longer (0.104 years [95% CI 0.077–0.131]) in patients receiving rituximab as induction treatment. This study provides novel data on the association of rituximab induction and reduced risk for PTLD.     

Comprehensive meta-analysis of antibiotic-impregnated bone cement versus plain bone cement in primary total knee arthroplasty for preventing periprosthetic joint infection

PurposeAntibiotic-loaded bone cement (ALBC) was usually used to prevent periprosthetic joint infection (PJI) in primary total knee arthroplasty (PTKA), but whether to use ALBC or plain bone cement in PTKA remains unclear. We aimed to compare the occurrence rate of PJI using two different cements, and to investigate the efficacy of different antibiotic types and doses administered in preventing surgical site infection (SSI) with ALBC.MethodsThe availability of ALBC for preventing PJI was evaluated by using a systematic review and meta-analysis referring to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Existing articles until December 2021 involving PTKA patients with both ALBC and plain bone cement cohorts were scanned by searching “total knee arthroplasty”, “antibiotic-loaded cement”, “antibiotic prophylaxis”, “antibiotic-impregnated cement” and “antibiotic-laden cement” in the database of PubMed/MEDLINE, Embase, Web of Science and the Cochrane Library. Subgroup analysis included the effectiveness of different antibiotic types and doses in preventing SSI with ALBC. The modified Jadad scale was employed to score the qualities of included articles.ResultsEleven quantitative studies were enrolled, including 34,159 knees undergoing PTKA. The meta-analysis results demonstrated that the use of prophylactic ALBC could significantly reduce the prevalence of deep incisional SSI after PTKA, whereas there was no significant reduction in the rate of superficial incisional SSI. Moreover, gentamicin-loaded cement was effective in preventing deep incisional SSI, and the use of high-dose ALBC significantly reduced the rate of deep incisional SSI after PTKA. Besides, no significant adverse reactions and complications were stated during the use of ALBC in PTKA.ConclusionThe preventive application of ALBC during PTKA could reduce the rates of deep PJI. Furthermore, bone cement containing gentamicin and high-dose ALBC could even better prevent deep infection after PTKA. However, the existing related articles are mostly single-center and retrospective studies, and further high-quality ones are needed for confirmation.     

Dual antibiotic loaded bone cement in patients at high infection risks in arthroplasty: Rationale of use for prophylaxis and scientific evidence

In view of the demographic changes and projected increase of arthroplasty procedures worldwide, the number of prosthetic joint infection cases will naturally grow. Therefore, in order to counteract this trend more rigid rules and a stricter implementation of effective preventive strategies is of highest importance. In the absence of a "miracle weapon" priorities should lie in evidence-based measures including preoperative optimization of patients at higher infection risks, the fulfilment of strict hygiene rules in the operating theatre and an effective antibiotic prophylaxis regimen. Instead of a "one size fits all" philosophy, it has been proposed to adjust the antibiotic prophylaxis protocol to major infection risks taking into account important patient-and procedure-related risk factors. A stronger focus on the local application mode via use of high dose dual antibioticloaded bone cement in such risk situations may have its advantages and is easy to apply in the theatre. The more potent antimicrobial growth inhibition in vitro and the strong reduction of the prosthetic joint infection rate in risk for infection patients with aid of dual antibiotic-loaded bone cement in clinical studies align with this hypothesis.     

Polymethylmethacrylate bone cements and additives: A review of the literature

Polymethylmethacrylate (PMMA) bone cement technology has progressed from industrial Plexiglass administration in the 1950s to the recent advent of nanoparticle additives. Additives have been trialed to address problems with modern bone cements such as the loosening of prosthesis, high post-operative infection rates, and inflammatory reduction in interface integrity. This review aims to assess current additives used in PMMA bone cements and offer an insight regarding future directions for this biomaterial. Low index (< 15%) vitamin E and low index (< 5 g) antibiotic impregnated additives significantly address infection and inflammatory problems, with only modest reductions in mechanical strength. Chitosan (15% w/w PMMA) and silver (1% w/w PMMA) nanoparticles have strong antibacterial activity with no significant reduction in mechanical strength. Future work on PMMA bone cements should focus on trialing combinations of these additives as this may enhance favourable properties.     

磷酸钙与聚甲基丙烯酸甲酯制备复合型骨水泥的生物安全性研究

目的探讨磷酸钙(CPC)和聚甲基丙烯酸甲酯(PMMA)按不同比例混合而制备复合型骨水泥(CPC/PMMA)的方法及评价其生物安全性。方法制备CPC/PMMA复合型骨水泥试件并分组,共分为CPC(100%)组、CPC/PMMA(75%、67%、50%、33%、16.7%、9.1%、6.25%、4.8%)组、PMMA(100%)组;通过急性毒性实验、全身亚急性毒性实验、热源实验、致敏实验、溶血实验检测CPC/PMMA复合型骨水泥的生物安全性。结果 CPC(100%)组、CPC/PMMA(75%)组、CPC/PMMA(67%)组、CPC/PMMA(50%)组OD值两两比较差异无统计学意义(P0.05),细胞毒分级为1级,无细胞毒性。CPC/PMMA(50%)组与对照组、CPC(100%)组、PMMA(100%)组小鼠的血常规检、生化检查、脏器湿重、体重变化差异无统计学意义(P0.05)。实验组的组织病理学检查、热源实验、致敏实验、溶血实验未出现异常。结论复合型骨水泥CPC/PMMA制备过程简便可靠,具有良好的生物安全性、血液与组织相容性,无毒性及致敏性。     

Morphological changes in bone following intramedullary implantation of methyl methacrylate: A morphometrical study of calcium deficiency

Adult male Sprague-Dawley rats had a methyl methacrylate implant in their right femur. After 16 weeks a group of rats was given a calcium-deficient diet. The rats were followed for another 31 weeks. Due to calcium deficiency a loss of femoral bone mass occurred which was relatively greater in the non-operated femur, as compensatory periosteal bone apposition and remaining necrotic bone areas contributed to the bone mass in the operated femur. The calcium deficiency did not affect the interface between bone and implant, where a thin sleeve of new bone was formed. While the non-operated femur lost its bone through endosteal resorption, the loss of bone in the operated femur was due to intracortical resorption.     

Effect of Age on Calcification of Poly(hydroxyethyl methacrylate) in Animals

The effect of age on the calcification of biomaterials was studied by the subcutaneous implantation of poly(hydroxyethyl methacrylate) hydrogel in rats. The hydrogel sheets were implanted in rats 6, 12, 24, and 52 weeks (1 year) of age. The retrieved implants were compared and the percentage weight increase by mineralization was determined quantitatively. Significant differences in the rate and amount of calcification were observed between the growing (6 weeks old) and the adult (greater than or equal to 12 weeks of age) rats. The onset of calcification in the adult rats was significantly delayed. The immature rats had deposits three to four times as heavy as the mature rats.     

Intraoperative evaluation of polymorphonuclear leukocyte during second-stage revision surgery promote overdiagnosis of persistent periprosthetic joint infection

Objective

The aim of this study was to evaluate whether intraoperative histopathological examination could predict the risk of relapse of infection in periprosthetic joint infections (PJI).

Strong effect of PTH (1-34) on regenerating bone: A time sequence study in rats

This study compares the effects of parathyroid hormone (PTH) treatment on new bone formation and normal baseline remodelling in rats. To study new bone formation we used a titanium bone chamber, and to study normal remodelling we used the femur and vertebrae from the same animals. One titanium bone chamber was inserted in the proximal tibia of each of 37 rats. The rats were randomly assigned to daily injections of human PTH (1-34) 60 &#119 g/kg) or vehicle control and killed after 2, 4 or 6 weeks. The total distance of bone growth into the chamber was slightly increased by PTH. Body weight was not affected, and there was only a minor increase in trabecular density of the vertebral and femoral cancellous bone after 6 weeks. The only dramatic effect of PTH was seen in the chambers. In the controls, a marrow cavity formed in the chamber so that the cancellous density decreased from 44% to 24%, and 11% over 2, 4 and 6 weeks. In the PTH-treated animals, a dense network of bone trabeculae was found in the entire bone chamber at all times. The cancellous density increased from 48% to 60%, and 73% at 2, 4 and 6 weeks, respectively. The results suggest that PTH treatment can reduce the development of a resorption cavity. Thus, PTH in this model had a net antiresorptive effect, probably solely because it stimulated osteoblastic activity. Even though osteoclastic activity was present throughout the PTH specimens, it was not sufficient to resorb all newly formed bone. Since PTH seemed to have a greater effect on new bone formation in the chamber than on normal bone remodeling, it might become useful for improving the incorporation of orthopedic implants and stimulating fracture repair.     

Long-lasting bioresorbable poly(lactic acid) (PLA<Subscript>94</Subscript>) mesh: a new approach for soft tissue reinforcement based on an experimental pilot study

The purpose of this study was to evaluate host response and soft-tissue regeneration after poly(lactic acid) (PLA) mesh implantation in a rat model, in comparison with light-weight polypropylene (PPL) and poly(glycolic acid) (PGA) meshes. Full-thickeness abdominal wall defects were created in 45 Wistar rats and reconstructed with 15 PLA₉₄, 15 PPL and 15 PGA meshes. Animals were killed on days 7, 30 and 90 to evaluate the presence of adhesions and changes in tensile strength of the implants. Histolopathology and immunohistochemistry were performed to evaluate the collagen deposition and the inflammatory response. Statistics were done using unpaired Student’s t-test, Mann–Whitney rank sum test, Student–Newman–Keuls test and Bonferroni (Dunn) t-test. The inflammatory response induced by the PLA mesh implantation was significantly milder than after PPL mesh. In PLA, vascularity and collagen organization was significantly higher than in PPL and PGA at 30 and 90 days, and collagen composition score was significantly higher than in PPL at 7 and 30 days. In PLA, shrinkage was significantly lower than in PPL and PGA at 7 and 30 days. Elongation at break and tensile strength were comparable between PLA and PPL over the 90-day period. The PLA mesh induces a milder inflammatory response, more orderly collagen deposition than PPL, and preserved comparable tensile strength after 90 days.     

Percutaneous extra-spinal cementoplasty in patients with cancer: A systematic review of procedural details and clinical outcomes

PurposeTo perform a systematic review of technical details and clinical outcomes of percutaneous extra-spinal cementoplasty in patients with malignant lesions.Materials and methodsPUBMED, MEDLINE, MEDLINE in-process, EMBASE and the Cochrane databases were searched between January 1990 and February 2019 using the keywords «percutaneous cementoplasty», «percutaneous osteoplasty» and «extra-spinal cementoplasty». Inclusion criteria were: retrospective/prospective cohort with more than 4 patients, published in English language, reporting the use of percutaneous injection of cement inside an extra-spinal bone malignant tumour using a dedicated bone trocar, as a stand-alone procedure or in combination with another percutaneous intervention, in order to provide pain palliation and/or bone consolidation.ResultsThirty articles involving 652 patients with a total of 761 lesions were reviewed. Mean size of lesion was 45 mm (range of mean size among publications: 29–73 mm); 489 lesions were located in the pelvis, 262 in the long bones of the limbs and 10 in other locations. Cementoplasty was reported as a stand-alone procedure for 60.1% of lesions, and combined with thermal ablation for 26.2% of lesions, implant devices for 12.3% of lesions, and balloon kyphoplasty for 1.4% of lesions. The mean volume of injected cement was 8.8 mL (range of mean volume among publications: 2.7–32.2 mL). The preoperative visual analogic scores ranged between 3.2 and 9.5. Postoperative scores at last available follow-up ranged from 0.4 to 5.6. Thirteen papers reported a reduction of the visual analogic scores of 5 points or more. Nerve injury was the most frequent symptomatic leakage (0.6%).ConclusionPercutaneous extra-spinal cementopasty is predominantly performed as a stand-alone procedure and for lesions in the bony pelvis. It appears to be an effective tool to manage pain associated with malignant bone tumours. There is however a lack of standardization of the technique among the different publications.     

Vanishing bone disease (Gorham-Stout syndrome): A review of a rare entity

Vanishing bone disease (Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by destruction of osseous matrix and proliferation of vascular structures, resulting in destruction and absorption of bone. Despite the extensive investigation of the pathogenetic mechanisms of the disease, its etiology hasn’t been clarified and several theories exist. The syndrome can affect one or multiple bones of the patient, including the skull, the upper and lower extremities, the spine and pelvis. The clinical presentation of a patient suffering from vanishing bone disease includes, pain, functional impairment and swelling of the affected region, although asymptomatic cases have been reported, as well as cases in which the diagnosis was made after a pathologic fracture. In this short review we summarize the theories regarding the etiology as well as the clinical presentation, the diagnostic approach and treatment options of this rare disease.     

Local injection of thrombin‐related peptide (TP508) in PPF/PLGA microparticles–enhanced bone formation during distraction osteogenesis

We have previously demonstrated that injections of the thrombin‐related peptide, TP508, into the lengthening gap have significantly enhanced bone consolidation in a rabbit model of distraction osteogenesis. This study was to further test the effect of a single TP508 injection in slow release preparation on bone formation during distraction osteogenesis. Rabbits had left tibiae lengthened unilateral lengthener at rate of 1.4 mm/day for 6 days. TP508 was injected into as the following: Group 1, TP508 in saline; Group 2, in PPF/PLGA [poly(propylene fumarate)/poly(D,L ‐lactic‐co‐glycolic acid)] microparticles; and Group 3, dextran gel only. All the animals were killed 2 weeks after lengthening. On radiographies, more bone was formed in the two TP508‐treated groups at first and secnd week postlengthening than that of the control Group 3. Microcomputed tomography (microCT) at 2 weeks indicated that the most advanced bone formation and remodeling was seen in Group 2. The mean volumetric BMD of the regenerates was significantly higher in the TP508 treated groups compared to the control group (p < 0.05). Histological evaluations supported the radiographic and the microCT results. In conclusion, we have demonstrated that a single injection of small amount of TP508 (300 µg) at the end of lengthening phases has significantly enhanced bone consolidation process in a rabbit model of distraction osteogenesis. The delivery of TP508 in PPF/PLGA microparticles appears to lead to a better quality bone formation over the saline delivery, further examinations are needed to confirm if PPF/PLGA microparticles may be desirable drug delivery form in augmenting bone formation. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:539–546, 2008     

A brief review for orthopedic surgeons: Fatigue damage (microdamage) in bone (its determinants and clinical implications)

Bone modeling can slowly strengthen bones to keep their strains below bone's microdamage (MDx) threshold. When that condition is satisfied the slow basic multicellular unit (BMU)-based remodeling can usually repair the little MDx that occurs anyway, and some always does. While this arrangement minimizes fatigue fractures of whole bones or trabeculae, they can still happen if: (A) drugs, disease, or dead bone impair MDx repair; (B) if bone loads increase faster than the sluggish modeling can strengthen bone to meet the new loads, and/or faster than remodeling can repair the increased MDx; (C) if a cyst, tumor, or surgery removes enough bone to let strains in the remaining bone reach or exceed the MDx threshold; (D) if abnormal properties of bone as a material cause too much MDx to repair; (E) if altered modeling and remodeling thresholds cause an osteopenia that lets normal activities cause bone strains in or above the MDx threshold range; (F) or if strains in the bone supporting a load-bearing implant reach or exceed bone's MDx threshold. Received for publication on Dec. 15, 1997; accepted on April 7, 1998     

Core decompression and bone marrow aspirate concentrate injection for Avascular Necrosis (AVN) of the femoral head: A scoping review

BackgroundVarious joint preserving treatments are available for use in Avascular Necrosis of the femoral head. Most of these are effective in the pre-collapse stage of the disease. This review aimed to evaluate the effectiveness of core decompression and Bone Marrow Aspirate Concentrate in various stages of AVN, in modifying the progression of the disease and the need for hip replacement.Material and methodsThe Preferred Reporting Items for Systematic reviews and Meta-Analysis Extension for Scoping Reviews reporting guidelines were followed. The literature search was conducted from inception till 2^nd May 2021, on the PUBMED, SCOPUS, and Google Scholar search engines, using “bone marrow aspirate concentrate osteonecrosis femur” and “bmac osteonecrosis femur” as the keywords. In all these studies, Core Decompression with Bone marrow Aspirate concentrate was performed. The evaluation was done based on the progression of osteonecrosis, improvement in functional outcomes and the conversion to total hip arthroplasty.ResultsWe have analyzed 612 hips from11 studies, based on our inclusion and exclusion criteria. The mean age of the patients was 38.27 years. There was a predominance of males. The grade of AVN ranged from grade 1 to 4. The average follow-up period of the cases ranged from 2 to 12 years (average: 4.38 years). The functional scores were improved in the majority of cases. Radiographic progression occurred in 23.5% of hips, and the Total Hip Arthroplasty was performed in 14.9% of hips.ConclusionsCore decompression with Bone Marrow Aspirate Concentrate in pre-collapse stages of the disease is beneficial in improving the functions scores and for reducing the radiological progression of the disease and need for total hip arthroplasty, in the majority of cases.