Osteoporosis: Molecular Pathology, Diagnostics, and Therapeutics

Osteoporosis is a major public health concern affecting millions of people worldwide and resulting in significant economic costs. The condition is characterized by changes in bone homeostasis, which lead to reduced bone mass, impaired bone quality, and an increased risk of fractures. The pathophysiology of osteoporosis is complex and multifactorial, involving imbalances in hormones, cytokines, and growth factors. Understanding the cellular and molecular mechanisms underlying osteoporosis is essential for appropriate diagnosis and management of the condition. This paper provides a comprehensive review of the normal cellular and molecular mechanisms of bone homeostasis, followed by an in-depth discussion of the proposed pathophysiology of osteoporosis through the osteoimmunological, gut microbiome, and cellular senescence models. Furthermore, the diagnostic tools used to assess osteoporosis, including bone mineral density measurements, biochemical markers of bone turnover, and diagnostic imaging modalities, are also discussed. Finally, both the current pharmacological and non-pharmacological treatment algorithms and management options for osteoporosis, including an exploration of the management of osteoporotic fragility fractures, are highlighted. This review reveals the need for further research to fully elucidate the molecular mechanisms underlying the condition and to develop more effective therapeutic strategies.

Does obesity and varying body mass index affect the clinical outcomes and safety of biportal endoscopic lumbar decompression? A comparative cohort study

BACKGROUND

Endoscopic spine surgery has recently grown in popularity due to the potential benefits of reduced pain and faster recovery time as compared to open surgery. Biportal spinal endoscopy has been successfully applied to lumbar disc herniations and lumbar spinal stenosis. Obesity is associated with increased risk of complications in spine surgery. Few prior studies have investigated the impact of obesity and associated medical comorbidities with biportal spinal endoscopy.

METHODS

This study was a prospectively collected, retrospectively analyzed comparative cohort design. Patients were divided into cohorts of normal body weight (Bone Mass Index (BMI)18.0-24.9), overweight (BMI 25.0-29.9) and obese (BMI > 30.0) as defined by the World Health Organization (WHO). Patients underwent biportal spinal endoscopy by a single surgeon at a single institution for treatment of lumbar disc herniations and lumbar spinal stenosis. Demographic data, surgical complications, and patient-reported outcomes were analyzed. Statistics were calculated amongst treatment groups using analysis of variance and chi square where appropriate. Statistical significance was determined as p < 0.05.

RESULTS

Eighty-four patients were followed. 26 (30.1%) were normal BMI, 35 (41.7%) were overweight and 23 (27.4%) were obese. Patients with increasing BMI had correspondingly greater American Society of Anesthesiologist (ASA) scores. There were no significant differences in VAS Back, VAS Leg, and ODI scores, or postoperative complications among the cohorts. There were no cases of surgical site infections in the cohort. All cohorts demonstrated significant improvement up to 1 year postoperatively.

CONCLUSIONS

This study demonstrates that obesity is not a risk factor for increased perioperative complications with biportal spinal endoscopy and has similar clinical outcomes and safety profile as compared to patients with normal BMI. Biportal spinal endoscopy is a promising alternative to traditional techniques to treat common lumbar pathology.

Trends in inpatient orthopedic surgery during the COVID-19 pandemic in Japan: a nationwide data study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has resulted in substantial morbidity and mortality globally. The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) covers 99.9% of health insurance claim receipts by general practitioners. The purpose of this study is to investigate the nationwide number of inpatient orthopedic surgeries in Japan during the effect of state of emergency (SoE) due to COVID-19.

METHOD

The NDB has been publicly available since 2014. We retrospectively reviewed the NDB from April 2019 to March 2022. We gathered the monthly number of all inpatient orthopedic surgeries. We also classified orthopedic surgeries into the following 11 categories by using K-codes, Japanese original surgery classification: fracture, arthroplasty, spine, arthroscopy, hardware removal, hand, infection/amputation, ligament/tendon, tumor, joint, and others. By using the average number from April to December 2019 as the reference period, we investigated the increase or decrease orthopedic surgeries during the pandemic period.

RESULTS

The NDB showed that the average number of total inpatient orthopedic surgeries during the reference period was 115,343 per month. In May 2020, monthly inpatient orthopedic surgeries decreased by 29.6% to 81,169 surgeries, accounting for 70.3% of the reference period. The second SoE in 2021 saw no change, while the third and fourth SoEs showed slight decreases compared to the reference period. Hardware removal and tumor surgeries in May 2020 decreased to 45.3% and 45.5%, respectively, while fracture surgeries had relatively small decreases.

CONCLUSION

According to NDB, approximately 1.3 million orthopedic inpatient surgeries were performed or claimed in a year in Japan. In May 2020, the first SoE period of the COVID-19 pandemic, the number of inpatient orthopedic surgeries in Japan decreased by 30%. Meanwhile, the decrease was relatively small during the SoE periods in 2021.

Biportal Endoscopic Approach for Lumbar Degenerative Disease in the Ambulatory Outpatient vs Inpatient Setting: A Comparative Study

BACKGROUND

Biportal spinal endoscopy is increasingly utilized for lumbar disc herniations and lumbar stenosis. The objective was to investigate the safety and effectiveness of the technique in the outpatient vs inpatient setting.

METHODS

This is a comparative study of consecutive patients who underwent biportal spinal endoscopy by a single surgeon at a single institution. Demographics, surgical complications, and patient-reported outcomes were prospectively collected and retrospectively analyzed. Statistics were calculated among treatment groups using unpaired t test and χ 2 analysis where appropriate. Statistical significance was determined as P < 0.05.

RESULTS

Eighty-four patients were included, 58 (69.0%) as outpatient, 26 (31.0%) as inpatient. Mean follow-up was 7.5 months. Statistically significant differences in age, American Society of Anesthesiologists classification, and Charleston Comorbidity Index scores were reported between cohorts, with younger and healthier patients undergoing outpatient surgery (P < 0.0001). Outpatients were more likely to have discectomies while inpatients were more likely to have decompressions for stenosis. No significant differences in postoperative complications were found between groups.Both cohorts demonstrated significant improvement in visual analog scale (VAS) back and leg pain scores and Oswestry Disability Index scores (P < 0.001). Outpatients had significantly lower postoperative VAS back pain (P = 0.001) and Oswestry Disability Index scores (P = 0.004) at 5-8 weeks compared with inpatients, but there was no significant difference for VAS leg pain scores at all time points between the cohorts.

CONCLUSIONS

Early results demonstrate that biportal spinal endoscopy can safely and effectively be performed in both inpatient and outpatient settings.

CLINICAL RELEVANCE

Outpatient biportal spinal endoscopy can be performed successfully in well selected patients, which may reduce the financial burden of spine surgery to the U.S. healthcare system.

LEVEL OF EVIDENCE: 3

Delayed Surgery Increases the Rate of Infection in Closed Diaphyseal Tibial and Femoral Fractures

BACKGROUND

Although delays in musculoskeletal care in low- and middle-income countries (LMICs) are well documented in the open fracture literature, the impact of surgical delays on closed fractures is not well understood. This study aimed to assess the impact of surgical delay on the risk of infection in closed long-bone fractures treated with intramedullary nailing in LMICs.

METHODS

Using the SIGN (Surgical Implant Generation Network) Surgical Database, patients ≥16 years of age who were treated with intramedullary nailing for closed diaphyseal femoral and tibial fractures from January 2018 to December 2021 were identified. Infection was diagnosed based on the assessment by the treating surgeon. A logistic regression model, adjusting for potential confounders, was used to analyze the association between delays to surgery (in weeks) and infection.

RESULTS

Of the 9,477 closed fractures that were included in this study, 58% were femoral fractures and 42% were tibial fractures. The mean age was 35 years, and 76.2% of the patients were men. The mean delay to surgery was 10.5 days, and the median delay to surgery was 6 days. The overall infection rate was 3.1%. The odds of developing an infection increased by 9.2% with each week of delayed surgical treatment (odds ratio,1.092; 95% confidence interval, 1.042 to 1.145). Increasing delays were also associated with longer surgery duration and higher rates of open reduction.

CONCLUSIONS

Surgical delays in LMICs were associated with an increased risk of infection in closed long-bone fractures. This study quantified the increased risk of infection due to delays in receiving care, highlighting the importance of timely surgery for closed fractures in LMICs.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Retrospective cohort study analyzing outcomes of the SIGN Fin Nail in adult femoral fractures using the retrograde approach

Purpose

There is high burden of long bone fractures in low- and middle-income countries (LMICs). Given a limited availability of fluoroscopy in LMICs, the Surgical Implant Generation Network (SIGN) developed two types of intramedullary nails: the SIGN standard nail and the SIGN Fin Nail. A limited number of studies have analyzed healing outcomes with the SIGN Fin Nail and the current study is the largest one to date. The purpose of this study is to compare outcomes between the SIGN standard nail and SIGN Fin Nails in adult femoral shaft fractures treated with a retrograde approach.

Method

A retrospective cohort study of adults with femoral shaft fractures was performed using the Sign Online Surgical Database (SOSD). The primary outcome was achieving full painless weight bearing and the secondary outcomes assessed were radiographic healing and infection. A propensity-score adjustment was performed for potential confounders and effect modification due to fracture location was tested using a Mantel-Haenszel test for heterogeneity.

Results

Of 19,928 adults with femoral shaft fractures, 2,912 (14.7%) had the required 6-month follow-up to be included. The overall propensity score weighted relative risk between the Fin and Standard Nail for achieving painless weight-bearing was 0.99, 95% CI [0.96-1.03] and for radiographical healing was 0.99, 95%CI [0.97-1.02]. The propensity score weighted relative risk for infection was 1.30, 95% [0.85-1.97]. Use of the Fin nail was also significantly associated with shorter surgery times (p < 0.005, effect size = 24 min). Sub-group analysis based on fracture location and injury cause demonstrated no change in relative risk.

Conclusion

The Fin nail showed no change in relative risk in terms of achieving full painless weightbearing or radiographic healing compared to the standard nail for retrograde nailing of femoral shaft fractures in adults. The heterogeneous nature of the cohort and large sample size allow for generalizability and add to a growing base of literature supporting use of the Fin Nail for retrograde femoral nailing. However, there are limitations as we could not correct for comminution at the fracture site or measure radiographic alignment or shortening.

Maurice A, Dogan TL, Ceesay B, Umukoro S, Okomo U, Nwakanma D, Roca A, Secka O, Forrest K, Garner OB. Using an Antibiogram Profile to Improve Infection Control and Rational Antimicrobial Therapy in an Urban Hospital in The Gambia, Strategies and Lessons for Low- and Middle-Income Countries

Antimicrobial resistance is a global health threat and efforts to mitigate it is warranted, thus the need for local antibiograms to improve stewardship. This study highlights the process that was used to develop an antibiogram to monitor resistance at a secondary-level health facility to aid empirical clinical decision making in a sub-Saharan African county. This retrospective cross-sectional descriptive study used 3 years of cumulative data from January 2016 to December 2018. Phenotypic data was manually imputed into WHONET and the cumulative antibiogram constructed using standardized methodologies according to CLSI M39-A4 guidelines. Pathogens were identified by standard manual microbiological methods and antimicrobial susceptibility testing was performed using Kirby-Bauer disc diffusion method according to CLSI M100 guidelines. A total of 14,776 non-duplicate samples were processed of which 1163 (7.9%) were positive for clinically significant pathogens. Among the 1163 pathogens, E. coli (n = 315) S. aureus (n = 232), and K. pneumoniae (n = 96) were the leading cause of disease. Overall, the susceptibility for E. coli and K. pneumoniae from all samples were: trimethoprim-sulfamethoxazole (17% and 28%), tetracycline (26% and 33%), gentamicin (72% and 46%), chloramphenicol (76 and 60%), and ciprofloxacin (69% and 59%), and amoxicillin/clavulanic (77% and 54%) respectively. Extended spectrum beta-lactamase (ESBL) resistance was present in 23% (71/315) vs. 35% (34/96) respectively. S. aureus susceptibility for methicillin was 99%. This antibiogram has shown that improvement in combination therapy is warranted in The Gambia.

The economic impact of infection and/or nonunion on long-bone shaft fractures: a systematic review

Background

Long-bone fractures are a major cause of morbidity worldwide. These injuries are often complicated by infection or nonunion, which significantly affect patient quality of life and economic costs. Although studies have quantified the impact of these fractures, there is not a comprehensive review summarizing their economic and lifestyle costs.

Study Objective

This review summarized the impact of long-bone fracture infection and nonunion on health-related quality of life, as measured by utility scores, and both direct and indirect economic costs.

Methods

A systematic review was conducted using the following databases: PubMed, EMBASE, Web of Science, and the Cochrane Library. The search included terms related to long-bone fractures, infection, nonunion, cost, and utility. The search yielded 1267 articles, and after deduplication, 1144 were screened, yielding 116 articles for full-text review. Screening was conducted using Covidence and extraction using REDCap.

Results

Twenty-two articles met inclusion criteria, with the majority being from the United States and Europe. Most articles were retrospective studies, predominantly regarding the tibia. Fifteen articles contained cost data and 8 contained utility data, with 1 article containing both. Ten cost articles and 1 utility article contained infection data. 8 cost and all utility articles contained nonunion data. Infection ranged from 1.5 to 8.0 times the cost of an uncomplicated fracture. Nonunion ranged from 2.6 to 4.3 times the cost of an uncomplicated fracture. Utility data were variable and ranged from 0.62 to 0.66 for infection and 0.48-0.85 for nonunion.

Conclusions

Infection and nonunion after long-bone fractures are associated with large decreases in health-related quality of life and incur substantial costs to both patients and health care systems. The data presented in this review quantify these impacts and may serve useful for future economic analyses. In addition, this study highlights the dearth of high-quality literature on this important topic.

Does the use of tranexamic acid intraoperatively reduce postoperative blood loss and complications following biportal endoscopic lumbosacral decompression?

Background

Biportal endoscopic spine surgery is an effective minimally invasive technique for treating common lumbar pathologies. We aim to evaluate the impact of intraoperative tranexamic acid (TXA) use on postoperative blood loss in biportal endoscopic decompression surgery.

Methods

Patients undergoing biportal endoscopic lumbar discectomies and decompressions either by same day surgery or overnight stay at a single institution beginning in October 2021 were prospectively enrolled. This study was non-randomized, non-blinded with the first cohort of consecutive patients receiving 1 g of intravenous TXA intra-operatively before closure and the second cohort of consecutive patients receiving no TXA. Exclusion criteria included any revision surgery, any surgery for the diagnosis of spinal instability, infection, tumor, or trauma, any contraindication for TXA.

Results

Eighty-four patients were included in the study, with 45 (54%) receiving TXA and 39 (46%) not receiving TXA. Median follow-up was 168 days [interquartile range (IQR), 85-368 days]. There were no differences in patient or surgical characteristics between cohorts. Estimated blood loss (EBL) was similar (P=0.20), while post-operative drain output was significantly lower in the TXA cohort (P=0.0028). Single level discectomies had significantly less drain output as compared to 2 level unilateral laminotomy, bilateral decompression (ULBD) cases (P<0.005). Post-operative complications were similar, with low rates of wound complication (1.2%) and transient postoperative weakness (2.4%, P>0.99 for both). Oswestry disability index (ODI), visual analog scale (VAS) back and VAS leg scores decreased significantly; the absolute decrease in scores did not differ between groups (P=0.71, 0.22, 0.86, respectively).

Conclusions

Systemic intraoperative TXA administration is associated with a significant decrease in post-operative blood loss in biportal spinal endoscopy, with no impact on the improvement in patient-reported outcomes (PROs) or rate of post-operative complications. Single level biportal discectomies had significantly less postoperative drainage with TXA and may not need drains postoperatively. Larger, randomized studies are necessary to evaluate the cost-effectiveness of TXA use in biportal spinal endoscopy.