Bone Preservation Research Articles

Déjà vu: on the use of meat resources by sabretooth cats, hominins, and hyaenas in the Early Pleistocene site of Fuente Nueva 3 (Guadix-Baza Depression, SE Spain)

The late Early Pleistocene archaeological site of Fuente Nueva 3 (Orce, Guadix-Baza Depression, SE Spain), dated to ~1.4 Ma, provides evidence on the subsistence strategies of the first hominin population that dispersed in Western Europe. The site preserves Oldowan tool assemblages associated with abundant remains of large mammals. A small proportion of these remains show cut marks and percussion marks resulting from defleshing and bone fracturing, and a small proportion of bones also show tooth marks. Previous taphonomic studies of FN3 suggested that the hominins had secondary access to the prey leftovers abandoned by sabretooth cats and other primary predators. However, a recent analysis by Yravedra et al. (2021) of the frequency of anthropogenic marks and tooth marks has concluded that the hominins had primary access to the carcasses of a wide variety of ungulate prey, even though the frequency of evisceration marks is strikingly low. In this rebuttal, we analyse the patterns of bone preservation in FN3, which show that the exploitation of bone marrow by the hominins after hammerstone breakage was a usual activity at the site. Our study also reviews the evidence available on the lesser abilities of sabretooth cats for carcass processing compared to pantherine felids. This reinforces the hypothesis that primary predators provided the hominins the opportunity to scavenge sizeable chunks of meat and bone marrow of their prey carcasses before the arrival of hyaenas. Finally, we also provide new inferences on resource availability and competition intensity among the members of the carnivore guild in FN3, which reinforce our interpretation that a secondary access by the Oldowan hominins to the prey leftovers of sabretooth cats was an optimal foraging strategy in the Guadix-Baza Depression.

Is three-dimension-printed mesh scaffold an alternative to reconstruct cavity bone defects near joints?

Reconstruction of cavity bone defects after curettage of benign bone tumours around the joint remains challenging. We designed a novel 3D-printed mesh scaffold as a substitute for bone cement, aiming to support the articular surface, protect the subchondral bone, and reduce complication rates. We retrospectively analyzed seven patients who received curettage and reconstruction using a 3D-printed mesh scaffold between January 2020 and June 2021. Pain and function were evaluated using the 10-cm Visual Analogue Scale (VAS) score and the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score. Radiographs were used to evaluate articular surface supporting, subchondral bone protection, and complications. The median functional MSTS-93 and VAS scores were both improved after surgery, and the median 3D-printed mesh scaffold volume was smaller than the median defect volume. Articular surface supporting, subchondral bone preservation, and osteogenesis were observed post-operatively. No related complications were observed during the last follow-up. The 3D-printed mesh scaffold provided sufficient mechanical support for the articular surface and protected the subchondral bone. We recommended the 3D-printed mesh structure as an alternative to repair cavity bone defects around joints.

The Short Graft ACL Reconstruction

The Short Graft Anterior Cruciate Ligament (ACL) reconstruction is increasing in popularity. Surgeons are making use of autograft lengths of between 6-6.5 cm for ACL reconstruction. The grafts of choice are the hamstring and quadriceps tendon autograft. The grafts are prepared with cortical fixation on both the femur and tibia ends for cortical fixation. Short tunnels or sockets are reamed instead of full bone tunnels. This helps with bone preservation and the patients have less postoperative pain; but will require special instrumentation for retrograde drilling. The benefit of this technique is improved postoperative hamstring strength with the gracilis preserved, as only the semitendinosus tendon is harvested to obtain a quadrupled ACL graft. The outcomes of short graft ACL reconstruction are comparable to established transportal ACL reconstruction techniques. However, there is a learning curve and additional implant costs involved. The familiarity with the surgical technique, understanding of optimal graft fixation and biology are all paramount to success of this surgery.

ENDODONTIC SURGICAL TREATMENT: LATERAL WINDOW APPROACH AND USE PRF. CASE REPORT

Abstract Endodontic treatment needs a complete root canal disinfection and perfect sealing for a good conservative prognostic. Those treatments are performed also to build new crown when tooth is destroyed. This prosthetic construction is mandatory to insure the good mechanical prognosis, and to restore a complete function. But sometimes, those treatments fail. Due to the lack of disinfection for example, a new endodontic cleaning should be done. We need to retreat, and when the root access is not possible by an orthograde way (large intracanal post, perfect coronal restauration to preserve for example) a surgical approach is necessary. One key point of those treatments is also the retro preparation and retro filling of the apical part of the roots. Removing the inflammatory lesion is not sufficient, the origins of the abscess are all the intra canal bacteria, they could not be reached by the immune system of the host (immune cells are into the blood, and no more blood circulation could occur in an endodontically treated tooth. Same for all antibiotics). This case shows a new and original way to access the apical lesion, and how a blood concentration and Platelet Rich Fibrin membrane could be used to seal the bone window. The benefits of such technic are numerous, less pain, bone preservation, rapid healing, controlled bleeding of the area and improve the success rate.

OSSEODENSIFICATION CONCEPT IN IMPLANT DENTISTRY

Implant success is evaluated on the basis of the stability gained at the junction of the bone to the implant. The stability needed for the successful future outcomes are of two types, i.e., primary stability which is acquired while placing the implant and secondary stability acquired by osseointegration. At present a new idea of Osseodensication has been established for the preparing the osteotomy site for the insertion of the implant. It is a bone non-extraction technique for osteotomy site preparation. There is a low plastic deformation of bone caused by rolling plus sliding contact with osteotomes or densifying burs which have utes to densify bone as it drills into it and expand osteotomy site. This technique permits bone preservation along with its condensation by compaction autografting of bone through osteotomy site preparation resulting in enhanced peri-implant bone density, healing and mechanical stability as well as minimised micromotion of the implant. This clinical approach is valuable at the sites where there is anatomic paucity of the bone

A conundrum for the world of oral biology: Crestal bone loss

The aim of this article is to highlight the numerous causes of crestal bone loss (CBL) surrounding dental implants and the preventive measures to avoid the postoperative stigma associated with CBL. A pursuit was made using the Google scholar web and the PubMed database as a search engine. The keywords; “CBL,” “crestal bone aetiology,” “crestal bone preservation” were looked at in the title/abstract of distributions. A total of 98 studies were selected following the keywords, which included systematic reviews meta-analysis clinical observational studies from 2001 to 2021, of which 45 were included in the review. Cross references of selected articles were additionally looked into for conceivable incorporation in the study. For the long-term success of the implants, the crestal bone should be preserved. It should start from diagnosis, examination, and planning of the treatment and should extend to the micro and macro designs of the implant, patients’ compliance and the presence of soft or hard tissues.

Is sclerostin antibody an effective agent for alveolar bone regeneration in animal models? A scoping review

Objectives
 The use of Sclerostin Antibody(Scl-Ab) as a bone anabolic agent has shown significant benefit in bone disorders in preclinical animal models and human clinical trials. Currently available evidence on the use of Scl-Ab in alveolar bone regeneration is limited to animal studies and hence this scoping review encompasses the animal studies conducted to ascertain the effectiveness of Scl-Ab on alveolar bone regeneration. 
 Materials and methods
 The search strategy was aimed to locate published animal studies in which the treatment arm includes Sclerostin antibody administration for alveolar bone preservation or regeneration. The search terms used were (((Animal model) OR Rodent) AND Alveolar bone defect) AND Anti sclerostin antibody) OR Sclerostin antibody) AND Alveolar bone regeneration) OR Bone regeneration) AND Bone fill. 
 Results
 Of the 559 results from Medline/PubMed, Scopus, Web of Science, Google scholar and additional articles from the references, six were included in the review. Scl-Ab was found to be effective in improving the bone quality and quantity. It was also observed that Scl-Ab was useful in reduced bone density associated with diseases and conditiona affecting osteoblast activity. 
 Conclusion
 The review concluded that Scl-Ab promotes alveolar bone augmentation and improves bone quality without surgical interventions.

Thermodynamic stabilities of apatite phases in a wetland system: Implications for bone diagenesis

Evaluating the fate and stability of apatite minerals, the largest phosphorus (P) reservoir on Earth's surface, has direct consequences for understanding our vertebrate fossil record as well as biogeochemical cycling. Bone (bioapatite) deposited following the death of an animal represents a potential source of phosphorus in terrestrial and aquatic ecosystems for micro and macrofauna. Exposure of bone to ambient geochemical conditions also represents the first step of the fossilization process. However, the thermodynamic stability of bone in these ecosystems, which are frequently phosphorus-limited, is unknown. The goal of this study was to approach questions related to recrystallization, diagenesis, and fossilization from a thermodynamics perspective, focusing on the role of geochemistry on bioapatite (bone) preservation. By developing thermodynamic models, run using PHREEQC, the stabilities of a range of apatite and other phosphorus-bearing phases were considered under physiochemical conditions measured in a Louisiana wetland and an adjacent river. The models integrated variable temperatures (5–40 °C), concentrations of phosphorus ([PO43-] from 0.0006 to 0.0484 mmol/L), and pH (6.5–9.25) from representative waters collected over 3 years at the wetland. In all models, waters are undersaturated with respect to hydroxylapatite, except under the highest temperatures, [PO43-], and pH conditions. In contrast, fluorapatite approached stability under lower pH and temperatures, and carbonated fluorapatite exhibited a broad range of stable conditions. These results suggest that if bioapatite (bone) were deposited under these present-day conditions, solutions are predicted to be undersaturated with respect to many apatite phases, leading to mineral dissolution. However, if bioapatite undergoes substitutions forming a fluorinated and/or carbonated phase, stability may shift towards preservation. These results have implications for identifying potential biases and mechanisms driving bone preservation over geologic time in a wetland system. The modeling results demonstrate that preservation of bone is favored under subsurface (burial) rather than surface conditions, aligning with long-held views on the formation of our vertebrate fossil record.

4000-year-old hair from the Middle Nile highlights unusual ancient DNA degradation pattern and a potential source of early eastern Africa pastoralists

Petrous bones and teeth are the skeletal elements most often targeted by researchers for ancient DNA (aDNA) extraction, and the sources of the majority of previously published ancient African genomes. However, the high temperature environments that characterise much of Africa often lead to poor preservation of skeletal remains. Here, we successfully reconstruct and analyse genome-wide data from the naturally mummified hair of a 4000-year-old individual from Sudan in northeastern Africa, after failed attempts at DNA extraction from teeth, petrous, and cranium of this and other individuals from the Kadruka cemeteries. We find that hair DNA extracted with an established single-stranded library protocol is unusually enriched in ultra-short DNA molecules and exhibits substantial interior molecular damage. The aDNA was nonetheless amenable to genetic analyses, which revealed that the genome is genetically indistinguishable from that of early Neolithic eastern African pastoralists located 2500 kms away. Our findings are consistent with established models for the southward dispersal of Middle Nile Valley pastoral populations to the Rift Valley of eastern Africa, and provide a possible genetic source population for this dispersal. Our study highlights the value of mummified hair as an alternate source of aDNA from regions with poor bone preservation.

Oral rehabilitation through the application of a xenogenous bone graft prior to placement of a dental implant: a case report with 9 years of follow-up

Background: Implantology has been restoring dentition for decades with a quality never seen before. Currently, one of the largest challenges in oral rehabilitation using dental implants is bone reconstruction after tooth extraction. Bone reconstruction can be difficult because of residual bone defects caused by endodontic lesions, root fractures, periodontal involvement, or even the surgical stage. These factors can cause a reduction in the height and width of the alveolar bone, which leads to a lack of sufficient residual bone that can be used for implant placement. Lack of this residual bone can therefore impact upon locking, primary stability, and bone preservation. Guided bone regeneration is a highly useful technique for repairing critical defects. However, it is not a simple technique. It has a straightforward concept and technique, but its execution must be performed with great accuracy to ensure a satisfactory result. Successful cases using this precise technique provide valuable tips for performing guided bone regeneration in an outpatient setting, and with the addition of exams such as the histopathological examination of the bone involved, it is possible to confirm the health and further preservation of this regeneration.

Could Short Stems THA Be a Good Bone-Saving Option Even in Obese Patients?

Short femoral stems, with preservation of the femoral bone stock, are commonly used in recent years for hip replacement in younger and more active patients. Obesity is increasingly spreading even in the younger population. The aim of this case-series study is to evaluate short stems compared to traditional hip prostheses in the obese population. A total of 77 consecutive patients with a BMI greater than or equal to 30 Kg/m2 were enrolled in this prospective study and were divided into two groups: 49 patients have been implanted with short stems while 28 patients were implanted with traditional stems. All the patients were treated for primary osteoarthritis or avascular necrosis and all the stems were implanted by the same surgeon using a posterior approach. Clinical (Harris Hip Score—HHS, Western Ontario and McMaster Universities Osteoarthritis Index—WOMAC, visual analogue scale—VAS, 12-item Short Form Health Survey—SF-12) and radiographic outcomes were recorded. Radiological evaluations were carried out by three different blinded surgeons. A statistical analysis was performed (chi-square, t-test, Wilcoxon Rank Sum Test, 2-factor ANOVA). At a mean follow-up of 42.6 months both groups showed a marked improvement in pain and in the clinical scores between pre- and post-surgical procedures (p < 0.05) with no significant differences between the two groups at last follow-up (p > 0.05). The radiological evaluations, with high concordance correlation between the three blinded surgeons (ICC consistently >0.80), showed good positioning and osseointegration in all cases, with no significant differences in the restoration of the joint geometry and complications. No revisions were recorded during the follow-up period. In conclusion, short stems appear to be a good option for bone preservation even in obese patients, showing comparable results to traditional implants.

Evaluation of trephine osteotomy technique in direct sinus lifting with simultaneous implant placement

BackgroundRecently, in implant dentistry, trephine drills have been used instead of conventional drills to conserve the bone during osteotomy. Aim of the studyTo evaluate the effectiveness of trephine osteotomy for lateral sinus lifting technique associated with sinus floor augmentation using the autogenous bone resulting from implant drilling using specialized trephine drills. Materials and method12 Patients were included and have been subjected to lateral sinus lifting using trephine osteotomy with simultaneous implant placement with delay loading. A bone graft used in sinus floor augmentation has been prepared using autogenous bone resulting from implant site preparation in addition to β-tricalcium phosphate. ResultsAfter 6 months, the difference between the primary stability and implant stability was statistically significant p-value ≤ 0.05. After 6 months, the mean vertical bone height reached 11.71 ± 0.72 mm. The mean volume of the newly formed bone of the grafted area recorded after 6 months was 1126.7 ± 82.94 mm3. ConclusionTrephine osteotomy technique in both lateral approach of sinus lifting, and implant site preparation allows preservation of autogenous bone. Moreover, the trephine osteotomy technique in the lateral approach of sinus lifting eliminates the use of an absorbable membrane.

Optimizing glenoid bone preservation in reverse total shoulder arthroplasty using augmented baseplates

As techniques and implants for reverse total shoulder arthroplasty (rTSA) evolve, a greater emphasis is being placed on preserving glenoid bone stock and optimizing shoulder biomechanics. Augmented baseplates preserve glenoid bone and improve shoulder range of motion by lateralizing the center of rotation of the glenosphere, while also reducing postoperative complications after rTSA. The technique for bone preservation with use of augmented baseplates in the absence of bone loss and the outcomes of a series of cases are contained in this report. A retrospective chart review was conducted for 37 patients with Walch type A1/Sirveaux E0 glenoids who underwent primary rTSA using a bone preserving technique with an augmented baseplate between January 2018 and January 2019 at a single site by a single surgeon. The primary outcome measures were range of motion, strength, and patient-reported clinical outcomes (pain and function rated on a visual analog scale; single assessment numeric evaluation; American Shoulder and Elbow Surgeons score; and disabilities of the arm, shoulder, and hand score). Preoperative radiographs were analyzed for the presence of glenoid bone loss and postoperative radiographs were assessed for evidence of component loosening and scapular notching. A repeated measures design was used, and preoperative and postoperative comparisons were made using parametric t-tests. At an average follow-up of 23.3 ± 6.3 months, there was a significant improvement in active forward flexion and abduction and nonsignificant improvement in external rotation. There was no radiographic evidence of glenoid notching in any of the patients and optimal glenoid inclination was observed. Patient-reported outcome scores after an average of 25.2 ± 10.0 months indicated a significant improvement in pain, function, and scores for the American Shoulder and Elbow Surgeons and disabilities of the arm, shoulder, and hand assessments. There were no substantial postoperative radiographic findings, intra/postoperative complications, or revisions/reoperations. rTSA with augmented baseplates for glenoid bone preservation in patients with minimal or no bone loss is effective for preserving glenoid bone stock and significantly improves the range of motion and patient-reported outcomes after approximately 2 years.

Simultaneous Arthroscopic Anterior Cruciate Ligament Reconstruction Using Double Suspensory Technique and Medial Open-Wedge, High Tibial Osteotomy

Anterior cruciate ligament reconstruction (ACLR) is generally performed regardless of knee malalignments. However, there are some indications for either staged or simultaneous ACL reconstruction and realignment procedures, such as high tibial osteotomy (HTO). Simultaneous HTO-ACL reconstruction has the apparent benefit of a single surgical procedure with a faster recovery than a staged procedure, and it produces good clinical outcomes. Several techniques have been described for simultaneous ACLR and medial open wedge HTO. The tibial tunnel preparation and graft fixation are the most challenging part of the procedure. Recent studies on comparison of fixation of tibial tunnel graft using suspensory fixation versus bioabsorbable screws have shown superior results of more bone preservation and less graft rupture. We assumed suspensory fixation on the tibial side with bone preservation might be more reliable in patients who received ACLR and open wedge HTO at the same time. Therefore, we described our technique of simultaneous open-wedge HTO and ACLR using double suspensory graft fixation.

All-Inside Tibial Tunnel Drilling: How to Calculate a Safe Drilling Length to Avoid Anterior Cortex Violation

The all-inside technique for bone tunnel drilling during ligament reconstruction procedures (ACL, PCL etc.) is gaining popularity as a bone preserving, less invasive technique with the potential for more rapid recovery. To preserve the advantages of closed-socket tunnels, it is essential not to violate the cortex during retro-drilling. The risk of cortical breach is higher with the tibial tunnel compared to the femoral one due to the obliquity of the tunnel relative to the cortex. Our purpose is to introduce a trigonometric formula, which allows the surgeon to calculate the safe tibial tunnel drilling length during all-inside ligament reconstruction and explain its proof.

Tensionable Distal Biceps Tendon Repair With Intramedullary Knotless All-Suture Anchors and FiberLoop w/FiberTag Suture

Distal biceps tendon rupture is commonly repaired via bicortical drilling, extramedullary cortical button placement, and inlay tendon fixation. A retensionable technique with unicortical drilling, intramedullary knotless all-suture anchors placement, and onlay tendon fixation is presented, incorporating up-to-date advances in tendon-bone healing basic science, biceps tendon/radial tuberosity biomechanics, and knotless all-suture implant technology to facilitate radial tuberosity bone preservation, anatomic footprint restoration, improved suture-tendon connection security, and avoidance of drilling and implant-related injury to the posterior interosseous nerve.

LepR+ Niche Cell-Derived AREG Compromises Hematopoietic Stem Cell Maintenance Under Conditions of DNA Repair Deficiency and Aging

The maintenance of the rare hematopoietic stem cell (HSC) population in the bone marrow (BM) and preservation of their functional properties is supported by a highly specialized microenvironment inside the BM, the HSC niche. However, the crosstalk between extrinsic niche-derived and intrinsic HSC factors controlling hematopoiesis remain elusive. Using three niche-specific conditional knockout mouse models, here we demonstrate that epidermal growth factor (EGF)-like molecule, amphiregulin (AREG) from bone marrow (BM) leptin receptor (LepR+) stromal cells is an important factor that mediates the crosstalk between BM niche and HSCs in stem cell maintenance. Mice deficient for the DNA repair gene Brca2 specifically in LepR+ cells (LepR-Cre;Brca2fl/fl) exhibit increased frequencies of total and myeloid-biased HSCs. Furthermore, HSCs from LepR-Cre;Brca2fl/flmice show compromised repopulation, increased expansion of donor-derived myeloid-biased HSCs and myeloid output in the transplanted recipients. Brca2-deficient BM LepR+ cells exhibit persistent DNA damage-inducible overproduction of stromal AREG. Ex vivo treatment of WT HSCs or systemic treatment of C57BL/6 mice with recombinant AREG impairs repopulation, leading to HSC exhaustion. Conversely, inhibition of AREG by anti-AREG neutralizing antibody or deletion of the Areg gene in LepR-Cre;Brca2fl/flmice rescues the HSC defects caused by AREG. Mechanistically, AREG activates the PI3K/AKT/mTOR pathway, promotes HSC cycling and compromises HSC quiescence. Finally, we demonstrate that BM LepR+ niche cells from other DNA repair-deficient and aged mice also show persistent DNA damage-associated overexpression of AREG, which exerts similar negative effects on HSC maintenance. We have therefore identified an important niche factor negatively regulating HSCs function under conditions of DNA repair deficiency and aging, and underscored the therapeutic potential of AREG intervention in improving HSC function.

Stemless, short and standard humeral stems in total shoulder arthroplasty: is there a difference in intraoperative measures, pain, and outcomes in the short term?

BackgroundAs anatomic total shoulder arthroplasty (aTSA) has evolved, surgeons are utilizing stemless and short-stem humeral implants with increasing frequency. Bone preservation, decreased blood loss, decreased surgical time, decreased pain, and improved outcomes have been described as theoretical advantages for shorter stem and stemless implants. Comparisons of outcomes between different length humeral stems that control for manufacturer and model of humeral and glenoid implants are currently limited. The purpose of this study is to determine if differences exist in the short-term outcomes between stemless, short-stem (SS), and traditional-length (TL) humeral stems in aTSA. MethodsA multicenter international shoulder arthroplasty database utilizing a single implant system was retrospectively analyzed to compare intraoperative and short-term outcomes between stemless, SS, and TL humeral stem implants. Intraoperative measures including surgical time and estimated blood loss were recorded. Postoperative outcomes including improvements in multiple pain measures, Global Shoulder Function Score, Simple Shoulder Test, University of California at Los Angeles, American Shoulder and Elbow Surgeons, and Shoulder Pain and Disability Index scores were compared between the three cohorts at 0-3 months, 3-6 months, 6-12 months, and 1-2 years postoperatively. Statistical analysis was performed using a Student’s unpaired two-tailed t-test to quantify differences in means between cohorts with a P value < .05. Results203 stemless aTSAs were compared with 354 SS and 1159 TL aTSAs. Surgical time showed no difference between stemless (avg 89 min), SS (avg 94 min), and TL (avg 91 min) humeral component use (P > .05). Estimated blood loss was significantly higher in TL (avg 214 cc) when compared to SS (avg 165 cc, P < .001) and stemless (avg 180 cc, P < .001), with no significant difference between SS and stemless (P > .05). No differences were observed in improvement in postoperative pain between any cohort across all pain metrics recorded during the first 3 months postoperatively. Additionally, the stemless aTSA cohort did not show any significantly greater improvement in pain metrics at any time point postoperatively when compared to SS and TL cohorts. When evaluating improvements in global shoulder function, American Shoulder and Elbow Surgeons, Simple Shoulder Test, Constant, University of California at Los Angeles, and Shoulder Pain and Disability Index scores, the stemless cohort did not provide a significant advantage in outcome when compared to the SS and TL cohorts at 6-12 or 12-24 months. Discussion and ConclusionWhile stemless aTSA design provides distinct advantages in select patient populations, the proposed benefit of decreased pain and accelerated postoperative recovery following stemless aTSA are not substantiated by this study. The authors hope this study will aid surgeons in counseling prospective TSA patients in the risks and benefits of stem length selection in total shoulder replacement.

Body Composition, Sarcopenia and Physical Performance After Bariatric Surgery: Differences Between Sleeve Gastrectomy and Roux-En-Y Gastric Bypass.

Evaluate the differences between surgical techniques in the modifications of body composition and the interference in skeletal muscle health, risk of sarcopenia, and reduced physical performance. This is a cross-sectional prospective study. A total of 71 patients, who underwent sleeve gastrectomy (SG) or underwent Roux-en-Y gastric bypass (RYGB). Both groups underwent anthropometric, laboratory analysis, body composition assessment, presence of sarcopenia, and physical performance tests. The study found a higher percentage of weight loss and lower BMI in RYGB compared to SG. The other assessments of sarcopenia and physical performance showed similarity between the surgical models. Baumgartner index (7.9kg/m2 vs. 7.3kg/m2), FNIH (9.0 vs. 3.0), handgrip strength (27.3kg vs. 25.2kg), and SPPB (9.5 vs. 9.3). Leptin in the general SG group was higher than in RYGB (14.2ng/ml vs. 8.0ng/ml). RYGB and SG have a similar presence of sarcopenia and physical performance. However, SG allows greater preservation of bone and muscle mass and is associated with higher values of leptin, which may represent protection from long-term postoperative complications.

The bone-protective mechanisms of active components from TCM drugs in rheumatoid arthritis treatment.

Rheumatoid arthritis (RA) is an autoimmune disease whose hallmarks are synovial inflammation and irreversible bone destruction. Bone resorption resulting from osteoclasts involves the whole immune and bone systems. Breakdown of bone remodeling is attributed to overactive immune cells that produce large quantities of cytokines, upregulated differentiation of osteoclasts with enhanced resorptive activities, suppressed differentiation of osteoblasts, invading fibroblasts and microbiota dysbiosis. Despite the mitigation of inflammation, the existing treatment in Western medicine fails to prevent bone loss during disease progression. Traditional Chinese medicine (TCM) has been used for thousands of years in RA treatment, showing great efficacy in bone preservation. The complex components from the decoctions and prescriptions exhibit various pharmacological activities. This review summarizes the research progress that has been made in terms of the bone-protective effect of some representative compounds from TCM drugs and proposes the substantial mechanisms involved in bone metabolism to provide some clues for future studies. These active components systemically suppress bone destruction via inhibiting joint inflammation, osteoclast differentiation, and fibroblast proliferation. Neutrophil, gut microenvironment and microRNA has been proposed as future focus.