The Application of Tannic Acid in Orthopedics

Tannic acid (TA) is a naturally occurring polyphenol compound commonly found in tea, wine, and fruits. Because of the excellent structural and functional properties afforded by TA, materials based on the structure of polyhydroxyphenols have great value, particularly for orthopedic transplantation. This compound, for example, can form a strong interaction with metals and can form a stable coating on their surfaces, thus, improving the physical and chemical properties of bone–implant surfaces and boosting implantation success rates. TA can also inhibit the activity of osteoclasts, thus, playing a potential role in the treatment of osteoporosis. Furthermore, if the body becomes polluted with heavy metals, TA can chelate the ions to protect bone morphology and structure. It also has a significant antibacterial effect and can reduce infections caused by surgical implantation and inhibit a variety of tumor cells, thereby promoting its potential application in spinal metastasis surgery. Furthermore, it can also slow the corrosion caused by magnesium alloys, thereby greatly improving the development of degradable orthopedic metal fixatives. Importantly, TA is cheap and easy to obtain, making it extremely valuable for use in orthopedics. This review focuses on the research status and practical applications of TA, and prospects for its future application for orthopedics (Figure 1).

Spinal metastasis of parotid acinic cell carcinoma followed by intradural extramedullary recurrence: illustrative case

BACKGROUND The diagnosis and management of acinic cell carcinoma (ACC) is often challenging given its similarity to benign tumors, high incidences of late recurrence and distant metastasis, and tendency to be resistant to systemic chemotherapy. A primary parotid ACC resulting in an intradural extramedullary mass has not been reported. OBSERVATIONS The authors describe such a case that presented as a progressive cervical myelopathy 29 years after initial diagnosis. The tumor, located at the C2–C3 level, infiltrated the dura and contained both extradural and intradural components. This occurred 18 months after the incomplete resection of an extradural metastasis at the same location. LESSONS Although intracranial and extradural metastases of various primary malignancies are well reported, secondary spinal intradural malignancies are rare. As a result, there are no established guidelines for the surgical management of intradural extramedullary metastases and prognosis may be difficult to establish. In this case, treatment options were limited because systemic therapy options had been exhausted and repeated radiation to the area was not recommended. We report on this case to highlight the clinical course of a rare local recurrence after spinal metastasis leading to an intradural extramedullary tumor and to show that surgical intervention can lead to improvement of neurological symptoms.

Surgical Efficacy and Prognosis of 54 Cases of Spinal Metastases from Breast Cancer

OBJECTIVE To analyze the efficacy and complications of spinal metastasis surgery for breast cancer; to understand the survival and the influencing factors; and to verify the predictive ability of the currently used spinal metastasis cancer survival prediction scoring system on the 1-year postoperative survival rate. METHODS A retrospective study was conducted on 54 patients with spinal metastases from breast cancer who underwent open surgery after multidisciplinary consultation in our hospital from January 2017 to October 2020. Patient demographic-related variables, breast cancer-related variables, spinal disorders-related variables, and treatment-related variables were collected. Survival curves were plotted using the Kaplan-Meier method, one-way tests were performed using the Log-rank method for factors that might affect prognosis, and candidate variables were included in the Cox model for multifactor analysis. The Tomita score, modified Tokuhashi score, modified Bauer score, modified Katagiri score were examined by plotting the subject operating characteristic curve (ROC) and calculating the area under curve (AUC) The AUC was used to test the predictive ability of the SORG (Skeletal Oncology Research Group) original version, SORG line graph version, and SORG web version for 1-year postoperative survival in patients with spinal metastases from breast cancer. RESULTS The average age was 51.3±8.6 years in 54 patients. Twenty-one patients underwent vertebral body debulking surgery, 32 patients underwent palliative canal decompression, and 1 patient underwent vertebral en bloc resection, with an operative time of 229.3 ± 87.6 minutes and intraoperative bleeding of 1018.1 ± 931.1 ml. Postoperatively, the patient experienced significant pain relief and gradual recovery from nerve injury. Major surgical complications included cerebrospinal fluid leakage, secondary spinal cord injury, spinal tumor progression, and broken of fixation. The mean survival time was 32.2 months, including a 6-month survival rate of 90.7%, a 1-year survival rate of 77.8%, and a 2-year survival rate of 60.3%. Univariate analysis showed that pre-operation with neurological deficits, hormone-insensitive type, with brain metastases were potential risk factors for poor prognosis. Multifactorial analysis showed that hormone-insensitive type and concomitant brain metastasis were independent risk factors associated with poor prognosis. The SORG web version had good ability to predict 1-year postoperative survival in patients with spinal metastases from breast cancer. Conclusion Spinal metastasis from breast cancer has good surgical efficacy, low postoperative recurrence rate, and relatively long survival time after surgery. Patients with hormone-insensitive type, with brain metastasis have poor prognosis, and SORG web version can predict patients' 1-year survival more accurately.

Quantified CIN Score From Cell-free DNA as a Novel Noninvasive Predictor of Survival in Patients With Spinal Metastasis

Purpose: Most currently available scores for survival prediction of patients with bone metastasis lack accuracy. In this study, we present a novel quantified CIN (Chromosome Instability) score modeled from cfDNA copy number variation (CNV) for survival prediction.Experimental Design: Plasma samples collected from 67 patients with bone metastases from 11 different cancer types between November 2015 and May 2016 were sent through low-coverage whole genome sequencing followed by CIN computation to make a correlation analysis between the CIN score and survival prognosis. The results were validated in an independent cohort of 213 patients.Results: During the median follow-up period of 598 (95% CI 364–832) days until December 25, 2018, 124 (44.3%) of the total 280 patients died. Analysis of the discovery dataset showed that CIN score = 12 was the optimal CIN cutoff. Validation dataset showed that CIN was elevated (score ≥12) in 87 (40.8%) patients, including 5 (5.75%) with head and neck cancer, 11 (12.6%) with liver and gallbladder cancer, 11 (12.6%) with cancer from unidentified sites, 21 (24.1%) with lung cancer, 7 (8.05%) with breast cancer, 4 (4.60%) with thyroid cancer, 6 (6.90%) with colorectal cancer, 4 (4.60%) with kidney cancer, 2 (2.30%) with prostate cancer, and 16 (18.4%) with other types of cancer. Further analysis showed that patients with elevated CIN were associated with worse survival (p < 0.001). For patients with low Tokuhashi score (≤8) who had predictive survival of less than 6 months, the CIN score was able to distinguish patients with a median overall survival (OS) of 443 days (95% CI 301–585) from those with a median OS of 258 days (95% CI 184–332).Conclusion: CNV examination in bone metastatic cancer from cfDNA is superior to the traditional predictive model in that it provides a noninvasive and objective method of monitoring the survival of patients with spine metastasis.

Cranial and Spinal Metastasis of a Nonfunctioning Pituitary Adenoma: Report of a Case

Pituitary carcinoma is a rare disease with surgical, radiotherapeutic, and chemotherapeutic treatment options. We present the case of a female patient diagnosed with a nonfunctioning pituitary adenoma who underwent several surgical procedures, radiations, and chemotherapeutic treatments with various substances. Sixteen years after the first diagnosis, a cranial and spinal metastatic spread of the tumor occurred. We opted for an individual therapy based on anecdotal evidence. Unfortunately, the recommended off-label treatment with a somatostatin analog substance was never given due to bureaucratic delays. This case report is about the challenging aspects of individual decision-making in rare neurosurgical diseases.

COMPLICATIONS OF SURGICAL TREATMENT OF SPINAL METASTASES

ABSTRACT Objectives: To evaluate the complications of surgical treatment in a group of patients with spinal metastasis with epidural compression, undergoing surgical treatment. Methods: This is a comparative retrospective study (level of evidence III), which evaluated 96 patients with spinal metastases undergoing surgical treatment. Intra- and postoperative complications were obtained from the patients’ medical records and correlated with the following clinical characteristics: tumor type, tumor location, neurological deficit, age, number of affected vertebrae, Tokuhashi scale, Tomita scale, Karnofsky performance scale, and type of approach. Results: Complications of surgical treatment were observed in 29 (30.20%) patients. Surgical wound infection was the most frequent complication, observed in 15% of patients. Conclusions: Surgical treatment of spinal metastases presents complications in about 30% of patients and their occurrence should be considered in the treatment planning, weighing the risks and benefits for achieving the treatment goals. Level III evidence; Retrospective Study.