Side Effects of Stem Cell Transplant Mimicking Symptoms of Known Amyloidosis.

Introduction: AL amyloidosis can involve the gastrointestinal (GI) tract in a sporadic manner, affecting certain anatomical areas while sparing others. Case Presentation: Our patient with AL amyloidosis and confirmed colonic involvement was found to have new odynophagia, GI bleeding, and imaging findings that might suggest AL amyloidosis. However, negative pathology results from esophageal biopsies suggested the patient's new ulcerations were more likely a side effect of her autologous stem cell transplant (SCT) and chemotherapy meant to target amyloidosis, as opposed to an effect of amyloid infiltration itself. Conclusion: GI involvement of amyloidosis requires a high degree of clinical suspicion and should be considered in patients with systemic diseases affecting the kidney, heart, and GI tract; however, when satisfactory biopsies obtained from endoscopy results are negative, other causes should be considered.

Metastatic Squamous Cell Carcinoma of the Lung Disclosed From Constipation Workup.

A palpable rectal mass associated with gastrointestinal (GI) symptoms immediately raises concern for colorectal cancer, but rarely can represent distant metastatic disease. The incidence of symptomatic colorectal metastasis from a primary lung cancer without any pulmonary symptom is extremely rare. We report a rare case of constipation as the presenting symptom in a patient ultimately found to have metastatic squamous cell carcinoma of the lung. A rectal mass was readily palpable on examination, illustrating the importance of digital rectal examination. In addition, GI clinicians should maintain a high index of suspicion when evaluating patients at risk of non-GI malignancies.

Midgut Volvulus in a Pregnant Patient Presenting With Abdominal Pain.

Abdominal pain is a common symptom during pregnancy, but bowel obstruction as the cause is a rare phenomenon. Moreover, intestinal volvulus is an even more unusual cause of obstruction during pregnancy and normally involves the sigmoid colon. We report a unique case of midgut volvulus in a pregnant patient entering her third trimester who presented to the hospital with abdominal pain. Our case demonstrates the safety of computed topography in pregnancy while restricting radiation dose and highlights the need to have a high index of suspicion for bowel obstruction when approaching a pregnant patient with abdominal pain.

Intramural Esophageal Hematoma With Associated Hemothorax.

Intramural esophageal hematoma (IEH) is a rare manifestation of esophageal wall injury with nonspecific symptoms. It may be caused by trauma or occur spontaneously. IEH is often discovered on computed tomography or esophagogastroduodenoscopy and is typically managed conservatively with supportive care to allow healing. It is frequently an isolated finding in the esophagus and seldom involves any other organ. We report a rare case of a patient discovered to have an obstructing IEH with associated hemothorax after an unrelated surgical admission.

Cutibacterium acnes Infection in Orthopedics: Microbiology, Clinical Findings, Diagnostic Strategies, and Management.

Cutibacterium (formerly called Propionibacterium) acnes is a human skin flora often implicated in orthopedic infections. The unique characteristics of this microorganism make the diagnosis of infection difficult. The diagnosis often is made based on clinical evidence, radiographic signs, and laboratory and/or surgical findings combined. Treatment often involves both pharmacologic and surgical methods. In addition, formation of biofilms and increased resistance to drugs exhibited by the microorganism can require combined antimicrobial therapy. Prophylactic measures are particularly important, but no single method has been shown to fully eliminate the risk of C acnes infections. Previous reports have focused on C acnes infections involving surgical implants or after certain orthopedic procedures, particularly in the shoulder and spine. This article reviews current clinical, diagnostic, and treatment principles for C acnes in orthopedics in general. [Orthopedics. 2020; 43(1):52-61.].

External Beam Irradiation Preferentially Inhibits the Endochondral Pathway of Fracture Healing: A Rat Model.

BACKGROUND: External beam irradiation is an accepted treatment for skeletal malignancies. Radiation acts on both cancerous and normal cells and, depending on the balance of these effects, may promote or impair bone healing after pathologic fracture. Previous studies suggest an adverse effect of radiation on endochondral ossification, but the existence of differential effects of radiation on the two distinct bone healing pathways is unknown. QUESTIONS/PURPOSES: The purpose of this study was to investigate the differential effects of external beam irradiation on endochondral compared with intramembranous ossification with intramedullary nail and plate fixation of fractures inducing the two respective osseous healing pathways through assessment of (1) bone biology by histomorphometric analysis of cartilage area and micro-CT volumetric assessment of the calcified callus; and (2) mechanical properties of the healing fracture by four-point bending failure analysis of bending stiffness and strength. METHODS: Thirty-six male Sprague-Dawley rats underwent bilateral iatrogenic femur fracture: one side was repaired with an intramedullary nail and the other with compression plating. Three days postoperatively, half (n = 18) received 8-Gray external beam irradiation to each fracture. Rodents were euthanized at 1, 2, and 4 weeks postoperatively (n = 3/group) for quantitative histomorphometry of cartilage area and micro-CT assessment of callus volume. The remaining rodents were euthanized at 3 months (n = 9/group) and subjected to four-point bending tests to assess stiffness and maximum strength. RESULTS: Nailed femurs that were irradiated exhibited a reduction in cartilage area at both 2 weeks (1.08 ± 1.13 mm versus 37.32 ± 19.88 mm; 95% confidence interval [CI] of the difference, 4.32-68.16 mm; p = 0.034) and 4 weeks (4.60 ± 3.97 mm versus 39.10 ± 16.28 mm; 95% CI of the difference, 7.64-61.36 mm; p = 0.023) compared with nonirradiated fractures. There was also a decrease in the volume ratio of calcified callus at 4 weeks (0.35 ± 0.08 versus 0.51 ± 0.05; 95% CI of the difference, 0.01-0.31; p = 0.042) compared with nonirradiated fractures. By contrast, there was no difference in cartilage area or calcified callus between irradiated and nonirradiated plated femurs. The stiffness (128.84 ± 76.60 N/mm versus 26.99 ± 26.07 N/mm; 95% CI of the difference, 44.67-159.03 N/mm; p = 0.012) and maximum strength (41.44 ± 22.06 N versus 23.75 ± 11.00 N; 95% CI of the difference, 0.27-35.11 N; p = 0.047) of irradiated plated femurs was greater than the irradiated nailed femurs. However, for nonirradiated femurs, the maximum strength of nailed fractures (36.05 ± 17.34 N versus 15.63 ± 5.19 N; 95% CI of the difference, 3.96-36.88 N; p = 0.022) was greater than plated fractures, and there was no difference in stiffness between the nailed and plated fractures. CONCLUSIONS: In this model, external beam irradiation was found to preferentially inhibit endochondral over intramembranous ossification with the greatest impairment in healing of radiated fractures repaired with intramedullary nails compared with those fixed with plates. Future work with larger sample sizes might focus on further elucidating the observed differences in mechanical properties. CLINICAL RELEVANCE: This work suggests that there may be a rationale for compression plating rather than intramedullary nailing of long bone fractures in select circumstances where bony union is desirable, adjunctive radiation treatment is required, and bone stock is sufficient for plate and screw fixation.

Process Improvement Project Using Tranexamic Acid Is Cost-Effective in Reducing Blood Loss and Transfusions After Total Hip and Total Knee Arthroplasty.

BACKGROUND: Tranexamic acid (TXA) has been associated with decreased blood loss and transfusion after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to examine both transfusion utilization and the economic impact of a Process Improvement Project implementing TXA for THA and TKA. METHODS: After standardization of TXA administration in THA and TKA patients, retrospective data were compared from 12 consecutive months before (group A, n = 336 procedures) and after (group B, n = 436 procedures) project initiation. RESULTS: TXA administration increased with project implementation (group A = 3.57%, group B = 86.01%) and was associated with reductions in perioperative hemoglobin decrement (20.2%), patients transfused (45%), and number of units transfused per patient (61.9%). Cost savings were notable per patient ($128) and annually program wide ($55,884) with the primary THA subgroup contributing the most to the savings. No increase in adverse effects was observed. CONCLUSION: Standardized administration of TXA is an effective and economically favorable blood-reduction strategy for patients undergoing elective THA or TKA. Although reduction in transfusions with TXA may be greater after TKA, the economic and clinical impact of transfusion reduction is more substantial in THA patients.

In situ observation of fracture behavior of canine cortical bone under bending.

Cortical bone provides many important body functions and maintains the rigidness and elasticity of bone. A common failure mode for bone structure is fracture under a bending force. In the current study, the fracture behavior of canine cortical bone under three-point bending was observed in situ using an atomic force microscope (AFM), a scanning electron microscope (SEM), and an optical microscope to examine the fracture process in detail. Nanoindentation was carried out to determine the elastic modulus and hardness of different building blocks of the canine cortical bone. The results have shown that the special structure of Haversian systems has significant effects on directing crack propagation. Although Haversian systems contain previously believed weak points, and micro-cracks initiate within Haversian systems, our findings have demonstrated that macro-cracks typically form around the boundaries of Haversian systems, i.e. the cement lines. Micro-cracks that developed inside Haversian systems have the functions of absorbing and dissipating energy and slow down on expanding when interstitial tissue cannot hold any more pressure, then plastic deformation and fracture occur.

Safety, Efficacy, and Cost-effectiveness of Tranexamic Acid in Orthopedic Surgery.

Perioperative bleeding and postsurgical hemorrhage are common in invasive surgical procedures, including orthopedic surgery. Tranexamic acid (TXA) is a pharmacologic agent that acts through an antifibrinolytic mechanism to stabilize formed clots and reduce active bleeding. It has been used successfully in orthopedics to reduce perioperative blood loss, particularly in total hip and knee arthroplasty and spine surgery. Numerous research studies have reported favorable safety and efficacy in orthopedic cases, although there is no universal standard on its administration and its use has not yet become the standard of practice. Reported administration methods often depend on the surgeon's preference, with both topical and intravenous routes showing efficacy. The type and anatomic site of the surgery seem to influence the decision making but also result in conflicting opinions. Reported complication rates with TXA use are low. The incidence of both arterial and venous thromboembolic events, particularly deep venous thrombosis and pulmonary embolism, has not been found to be significantly different with TXA use for healthy patients. The route of administration and dosage do not appear to affect complication rates either. However, data on patients with higher-risk conditions are deficient. In addition, TXA has shown potential to reduce blood loss, transfusion rates and volumes, perioperative hemoglobin change, and hospital-related costs at various degrees among the published studies. Conservation of blood products, reduced laboratory costs, and shorter hospital stays are likely the major factors driving the cost savings associated with TXA use. This article reviews current data supporting the safety, efficacy, and cost-effectiveness of TXA in orthopedic surgery.