Heterotopic hip ossification resection: monocentric experiences of associated factors, outcomes, and complications.

PURPOSE: The exponential increase in total hip arthroplasty (THA) has led to acute and chronic surgery-related complications. Common chronic and local complications are represented by hip ossification (HO). The aim of our study was to assess the clinical and radiological correlates of patients undergoing surgical removal of heterotopic ossifications after THA and the possible association between HO and prosthetic joint infection. METHODS: Data of 26 patients who underwent surgical removal of periprosthetic calcifications after THA from 2000 to 2022 were analyzed and compared with characteristics of 156 subjects without HO. RESULTS: The preoperative radiographs of patients showed a high-grade Brooker, 3 or 4, later reduced to 1 or 2 in the postoperative radiographs. Ten (38.5%) patients underwent radiotherapy prophylaxis, administered as a single dose 24 h before surgery. In 19 (73%) patients, pharmacological prophylaxis with indomethacin was added in the 30 postoperative days. Only one patient who underwent radiotherapy had a recurrence, while new ossifications were found in three patients without prophylaxis (11.5%). Intraoperative cultures were performed for suspected periprosthetic infection in 8 study group patients. In logistic regression, the presence of HO was significantly and inversely associated with the ASA score (OR = 0.27, 95% CI = 0.09-0.82; P = 0.021) after adjusting. CONCLUSION: Surgical HO removal in symptomatic patients with high-grade disease produces good clinical and radiographic results. Radiotherapy was a good perioperative and preventive strategy for recurrence, also associated with NSAIDs and COX-2 inhibitors.

Validation of a novel smart drilling system to monitor bone impedance during transpedicular screw placement: a pilot study.

Transpedicular screw placement is a high-risk procedure routinely performed in spine surgery. To decrease the rate of complications, it is necessary to find innovative solutions to assist the surgeon during screw insertion so as to avoid the chance of mispositioning. In this study, we developed a new drilling system able to estimate the mechanical properties of drilled tissues. Several investigations show that cortical bone requires a high level of thrust force and torque during drilling compared to trabecular bone. To implement an algorithm for bony breakthrough detection, a new drilling system has been built together with a mechanical support to drill the pedicle along a pre-planned trajectory. The mechanical support is equipped with a smart rotative drill that embeds force and position sensors. Ten human vertebral segments have been used to test the surgical platform, for percutaneous bone drilling. 10 transpedicular holes from L1 to L5 have been performed bilaterally. The holes were further evaluated by computed tomographic scans to measure bone density in the cortical and in the trabecular layers. To compare bone density with the bony mechanical impedance two new parameters (DHU and DPAI) have been introduced. The results show that in 18 out of 20 cases the D values of bone density and mechanical impedance, related to the same bone transition, differ less than 10%. The proposed system is thus able to evaluate the variation of bone density of the cortical and the trabecular layer using impedance. Therefore, it is possible to use the described system to increase the accuracy of transpedicular screw placement.

Osseointegration for lower and upper-limb amputation a systematic review of clinical outcomes and complications.

The conventional use of prosthetic custom-design socket is affected by discomfort related to wellknown problems: sweating, sores or skin irritation, excessive weight and harness, impaired body image, that lead to a high rate of abandonment. Osseointegrated prosthetic implants for limb amputation are progressively evolving to overcome limitations of socket. The aim of this article is to present a systematic review of the use, safety in terms of rate of infection and complications, and reported outcomes of upper and lower limb osseointegrated prosthetic implants. A systematic search was carried out for studies that evaluated outcomes of osseointegration technique in case of upper and lower limb amputees according to the PRISMA guidelines with a PRISMA checklist and algorithm. MINORS score was used for methodologic assessment. 17 articles about the treatment of patients with upper or lower limb amputation treated with an osseointegrated prostesis were included. The overall rate of infections was 32%. All the clinical outcomes reported were related to lower limb. No clinical data for upper limb was found. The postoperative mean value of MCS and PCS SF-36 and Q-TFA was 55.1, 45.4 and 73.8 respectively, while six minute walk test (6MWT) and the timed up and go (TUG) test scored an average value of 388 meters and 11.5 seconds respectively. MINORS score ranged from 5 to 13, with a median of 11 [interquartile range (IQR), 9-11]. The osseointegration is associated to a high rate of postoperative complications but, significant improvement in clinical outcomes compared to preoperative time are shown. The data available from the literature are limited but suggest good clinical outcomes and significant survivorship of the implants. Further clinical studies are needed to establish which kind of implant is associated to higher clinical performance and lower rate of postoperative complications and infections.

Frailty of the elderly in orthopaedic surgery and body composition changes: the musculoskeletal crosstalk through irisin.

In recent years, scientific interest has been developed towards irisin, a novel molecule of the family of myokines, which is directly involved in body mass composition balance, chronic diseases susceptibility and physiologic resilience to stressful events, including surgery. In the context of musculoskeletal disease, the role of this molecule has been associated to the balance of lean and fatty mass, and the production of irisin is subordinated to a healthy lifestyle and exercise. The mechanism of action of irisin on tissues is complex, and several studies described the molecular pathways in animal model and human subjects. In particular, in adipose cells, the key-role of irisin is to stimulate the differentiation of white adipose tissue to brown adipose tissue, through the action on the uncoupling protein 1. Furthermore, in the bony tissue, irisin stimulates osteogenesis through expression of Sost and Opn genes. These features make irisin a suitable molecule to use as a biomarker of the overall musculoskeletal health of the elderly, before undergoing orthopaedic surgery. Further research on this topic should be carried out to highlight the possible clinical role and predictive value of irisin in a multidisciplinary approach to the elderly before musculoskeletal surgery.

Weil osteotomy for the treatment of grade III hallux rigidus: a case series.

Hallux rigidus (HR) is one of the most common pathologies of the forefoot. The conservative treatment is indicated for early stages, while surgical treatment is required for advanced osteoarthritis and rigidity. Surgical treatment of advanced stages of HR is still controversial and includes joint-destructive procedures such as arthrodesis and arthroplasty, Weil osteotomy for decompression of the joint space may be a safe and effective procedure for the treatment of grade III HR. Twenty-four patients that underwent Weil osteotomy for Grade III HR were retrospectively reviewed. American Orthopedic Foot and Ankle Score (AOFAS), ROM and a subjective 5-point satisfaction scale were evaluated preoperatively, at 1 year, and at a minimum follow-up of 2 years. Joint space width and metatarsal length were assessed through radiographic examination preoperatively, immediately postoperatively and at 2 years follow up. AOFAS score was 45.1±3.9 preoperatively, 84.9±6.4 at 1 year and 73.7±6.2 at two years of follow up. All patients were satisfied with the procedure at 2 years follow up. Mean ROM increased from 35.1° (range, 10°- 50°) preoperatively to 80.3° (range, 60°-90°) at 1 year. Mean dorsiflexion increased from 5° (range 0° to 10°) preoperatively to 15° (range 7° to 23°) at 1 year. Both total ROM and dorsiflexion values remained constant at 2 years. The joint space was 0.5±0.9 mm preoperatively, 2.0±1.9 mm at 1 year and 1.5±1.2 mm at 2 years. The average metatarsal shortening was 2±1.4 mm. Weil osteotomy alone can be beneficial for the treatment of patients affected by advanced HR. It can improve clinical and radiological outcomes at 2 years follow up in a series of patients affected by grade III HR. Therefore, the sliding oblique osteotomy represent a valid alternative to delay more aggressive procedures.

Adipose-derived stromal vascular fraction processed with different systems for the treatment of knee osteoarthritis: a pilot study on cell proliferation and clinical results.

In recent years, the interest in stromal vascular fraction (SVF) therapy for conservative treatment of osteoarthritis has grown significantly. This study aims to assess three different processing systems (micro-fragmentation, filtration, or slow centrifugation) in terms of cell proliferation in vitro and clinical results of intraarticular injections for the treatment of knee OA. From December 2017 to June 2018, 25 procedures were performed using three different systems. A considerable improvement of the clinical condition in almost all patients already one month after the treatment with a stable effect at 6 and 12 months was recorded. Patients treated with SVF, obtained by the micro-fragmentation system, had better outcomes one month after the treatment with a mean improvement of the symptomatology higher than that found in patients treated with the filtration or slow centrifugation system. The SVF product from the same system had a higher cell proliferation capacity in vitro.

The combined use of platelet rich plasma and hyaluronic acid: prospective results for the treatment of knee osteoarthritis.

Osteoarthritis represents an important social economic burden with a high incidence worldwide. Conservative management of knee OA consists in several therapeutic options: pharmacologic therapy such as analgesics, non-steroid and steroid anti-inflammatory drugs, physical therapy, and injective therapy with hyaluronic acid (HA) and platelet-rich plasma injections (PRP). The aim of our study is to evaluate the effect of combined autologous PRP and HHA (Hybrid Hyaluronic Acid) viscosupplementation on clinical outcomes of patients with knee OA, by assessing the subjects before and after injective treatment. The study was conducted on 60 patients with an age between 40 and 70 years old affected by unilateral symptomatic knee osteoarthritis (stage II and III of Kellgren-Lawrence scale) nonresponsive to pharmacologic and rehab treatment. We divided the patients in two groups, and we treated the group A with injection of HHA and group B with HHA+PRP. Each patient received 3 injections at an interval of 1 week for 3 consecutive weeks. The patients were evaluated by the Knee Injury and Osteroartrhitis Outcome Score (KOOS) and Visual Analog Scale (VAS) at 3, 6 and 12 months after treatment. Statistical comparison between groups showed a significantly better result for the group B concerning the KOOS value, at 3 months and at 6 months. This difference, although clinically relevant, lost the statistical significance at 12 months. The VAS trend differently showed a significant difference at 3 and 12 months, while at 6 months the superiority of group B did not achieve statistical significance. Few studies investigated the effects of HA+PRP combined treatment for knee OA. Numerous studies demonstrated the efficacy of HA injection therapy in knee OA for a clinical point of view, reducing the pain and improving the quality of life. PRP preparations also improved functional outcome scores compared to hyaluronic acid and placebo in patients affected by knee OA. Based on our results we can conclude that the combined PRP and HHA treatment is not only a safe and efficacious procedure which can provide functional benefit but is also significantly better than HHA injective therapy alone, as demonstrated by the comparison within our cohort.

Targeting VEGF-A in cartilage repair and regeneration: state of the art and perspectives.

Osteoarthritis (OA) is the most common joint disorders in western populations, and is characterized by a progressive degradation of articular cartilage (AC) leading to loss of joint function. Methods to cure, delay or prevent the onset of OA and/or improve AC repair strategies have high clinical and socioeconomic impact. Possible innovative strategies envisioned for early OA treatments or cartilage repair include the implantation/injection of mesenchymal progenitors (MPs)-based constructs or cell-free bioactive scaffolds/hydrogel coupled with the controlled recruitment and instruction of resident MPs or AC. However, these tissue engineering-based strategies still suffer from unreliable outcomes with poor fibro-cartilaginous repair and blood vessel invasion. In such conditions Vascular Endothelial Growth Factor (VEGF) family has been shown to play a key role in controlling AC catabolism on one hand and angiogenesis on the other as a crucial step for endochondral ossification of MPs, ultimately leading to progressive breakdown of the neo-formed matrix. This review aims to provide a summary of relevant relationships between impaired angiogenesis, OA and cartilage regeneration highlighting how VEGF might play a paramount role in the pathophysiology of cartilage aging or degeneration as well as in cartilage repair.

A new surgical positioning system for robotic assisted minimally invasive spine surgery and transpedicular approach to the disc.

Minimally Invasive Spine Surgery (MISS) procedures for the treatment of spinal pathologies have experienced exponential growth due to improved techniques and decreased trauma to the patient. Several MISS procedures that require the use of a trans-pedicular cannula as a guiding tool for pedicle screw placement, delivery of biomaterials to the vertebral body or injection of biologics to the disc space have been described. Although these are clear advantages of MISS, the limited dissection and exposure may reduce the accuracy and stability of operation and make spine surgeons rely heavily on intraoperative fluoroscopy, raising concerns over the level of radiation exposure. Robot-assisted minimal invasive surgery has aroused more attention for its high precision and stability, minimizing risks of damage to neurovascular structures and diminishing harmful exposure to ionizing radiation. The aim of this paper is to describe and characterize a new surgical positioning system for for robotic assisted MISS. The system is conceived to be integrated in a surgical platform capable of supporting the surgeon in a new procedure to treat degenerative intervertebral disc disease. For this purpose, it is necessary to orientate a cannula in order to guide the bone drill along a planned route, to access the intervertebral disc through the pedicle and endplate. In particular, we describe a mechanism that percutaneously guides a cannula towards the intervertebral disc based on the acquisition of few fluoroscopic images. The design of the positioning system, with its features and constrains imposed by the presence of instrumentation and medical staff in the operating room, as well as the software for trajectory planning during surgery, are here described.

Posterolateral bundle reconstruction of the anterior cruciate ligament to restore rotational stability of the knee.

Only 5-10% of partial tears of the anterior cruciate ligament (ACL) are symptomatic, especially in high demand individuals or in patients practicing sports requiring rotational motions.. A certain preoperative diagnosis of this condition is challenging and often needs the combination of clinical examination, magnetic resonance imaging (MRI) and knee-laxity tool measurements. However, the arthroscopic examination of the torn ACL bundle is the most important factor in decision-making. Evidence in various studies have shown that the preservation of the ACL remnant and its surgical augmentation can bring important advantages in terms of vascularity and proprioception, resulting in better outcomes. The purpose of our paper was to describe the surgical technique of arthroscopic posterolateral (PL) bundle reconstruction with the preservation of the anteromedial (AM) bundle for ACL partial tears. Moreover, we reported the current knowledge about rationale, diagnosis and treatment of partial tears of ACL.

Targeted muscle reinnervation for improved control of myoelectric upper limb prostheses.

Targeted muscle reinnervation (TMR) is a novel surgical technique developed to improve the control of myoelectric upper limb prostheses. Nerves transected by the amputation, which retain their original motor pathways even after being severed, are redirected to residual denervated muscles that serve as target for consequent reinnervation. Once the process is complete, reinnervated muscles will contract upon voluntary activation of transferred nerves while attempting to move missing regions of the amputated limb, generating EMG signals that can be recorded and used to control a prosthetic device. This allows creating new control sites that can overcome major drawbacks of conventional myoelectric prostheses by offering a more natural and intuitive control of prosthetic arms. TMR has been widely performed in individuals who underwent shoulder disarticulation amputation and transhumeral amputation since proximal amputations do not leave enough functional muscles exploitable to control independent degree of freedoms of multi-articulated prostheses. TMR application is currently under investigation in patients suffering further distal amputations, as well as for treating and preventing painful post-amputation neuromas. The purpose of this paper is to describe the physiologic basis and the surgical technique of TMR, reporting current knowledge on the clinical results.

The use of hyaluronic acid in the treatment of shoulder capsulitis: a systematic review.

Adhesive capsulitis (AC) is a common pathological condition of the shoulder characterized by painful restriction of range of motion (ROM) of the glenohumeral joint. Currently, no consensus has been reached regarding the best treatment. Hyaluronic acid (HA) injection is a safe procedure that can result in significant improvement in active and passive ROM, alleviating pain and improving shoulder function. We systematically reviewed current literature in order to evaluate the best evidence about the effectiveness of intra-articular HA injection for the treatment of primary AC. We searched Medline, CINAHL, Embase, Google Scholar and Cochrane Library. We selected studies comparing clinical outcomes of patients treated with HA in association or not with conventional therapy. Seven studies were evaluated: 2 uncontrolled randomized studies and 5 prospective randomized clinical trials with level of evidence I. Clinical outcome measures used included, among other, ROM, Visual Analogic Scale (VAS) pain scores, Constant score, Activity of daily living, Shoulder Pain and Disability Index (SPADI), American Shoulder and Elbow Surgeons (ASES) and Japanese Orthopedic Association Score (JOA score). Improvement was noted in terms of ROM, constant scores and pain in patients affected by AC treated with intra-articular HA injections. When compared with cortisone intra-articular injection, HA has equivalent clinical outcomes and ROM. The heterogeneity of treatments used in the studies reviewed, makes it difficult to draw a definite conclusion on the subject. HA injections do not seem to determine the final outcomes directly compared with conventional treatments. However, they could play an important role for early mobilization in the initial stages, during which, due to pain and inflammation, the patient keeps the shoulder immobilized for a long time, determining the direct cause of AC. Numerous variables, including use of lidocaine, different HA and AC stages, could influence the results and deserve to be accounted for in future investigations.

Hybrid hyaluronic acid versus high molecular weight hyaluronic acid for the treatment of osteoarthritis in obese patients.

Osteoarthritis (OA) of the knee is one of the most relevant and debilitating health problems. Obesity represents one of the major risk factor for early development of OA. In the obese population, knee replacement should be delayed and eventually avoided and prefer conservative treatments including intrarticular hyaluronic acid (HA) viscosupplementation. In the present clinical randomized trial, we present a comparison between two groups of 24 obese patients which were randomized to be treated with two intrarticular injections of hybrid (low and high molecular weight) hyaluronic acid (Group A) or two injections of high molecular weight hyaluronic acid (Group B). Patients were followed-up through to 6 months and assessed though IKDC and KOOS scores, pain was evaluated with VAS. All patients reported a significant improvement when compared to baseline value in all outcome measures. At 3-month follow-up, IKDC had significantly improved in patients of Group A, compared to Group B (53.1±1.9 vs 51.4±2.4, p=0.0079) and the same for KOOS (52.1±2.0 vs 50.1±2.9, p=0.010). Furthermore, the difference in KOOS was persistently significant at 6-month follow-up (54.7±2.3 vs 51.7±4.9, p=0.014). The VAS reduced significantly more in Group A at 3 months (3.7±0.5 vs 5.2±0.7, p less than 0.001). In an obese population, where basal inflammatory pattern increases symptoms of OA and conservative treatment is recommended, HA viscosupplementation improved function and pain of the knee. The treatment with hybrid HA showed better outcomes than high molecular weight HA in obese patients. The combination of the anti-inflammatory action of low molecular weight HA on chondrocytes and the biomechanical role of high molecular weight HA might explain the different results.

Comparing hybrid hyaluronic acid with PRP in end career athletes with degenerative cartilage lesions of the knee.

Cartilage lesions are very common causes of chronic knee pain in athletes. Current treatment options consist in conservative strategies, such as viscosupplementation and platelet-rich plasma injections. This randomized controlled trial aims to investigate the effect of intra-articular Hybrid Hyaluronic Acid injections compared to PRP for the treatment of cartilage lesions among athletes at the end of their career. Since March 2015, 48 professional soccer players were randomized into two groups: 24 patients received 3 injections of HHA and 23 patients received 3 intra-articular injections of PRP. All patients achieved a statistically significant clinical improvement from preoperative to postoperative time in both groups. Patients in the HHA group showed a significant superiority compared to PRP group at 3 and 6 months. Intergroup differences decrease gradually until loss of significance at 12 months follow-up. Athletes with chronic degenerative cartilage lesions of the knee responded positively both to HHA and PRP until last follow up.

The cytokinome in osteoarthritis, a new paradigm in diagnosis and prognosis of cartilage disease.

At present, diagnosis and progression monitoring of osteoarthritis (OA) is made through radiological and clinical assessment. Several studies investigated the role of synovial fluid analysis, to find out whether joint disease could be characterized by the pattern of cytokines, which acts during the pathogenic process or in specific stages of it. Online PubMed-Medline search was performed in order to retrieve evidence concerning synovial fluid analysis of cytokines involved in OA degenerative process. Concerning pro-inflammatory cytokines, it has been shown that interleukin (IL)-6, TNF-α and IL-17 are mainly over-expressed in the synovial fluid of OA joints, as well as anti-inflammatory cytokine IL-10. Variations of cytokines levels occur with radiological and clinical progression. It was also reported that metalloproteinases are involved. Synovial fluid analysis may be helpful in defining stage and type of OA, but more research is needed, especially focusing on the variation of sets of cytokines during OA stages and correlating these patterns with clinical features.

Bone marrow concentrated cells and stromal vascular fraction cells injections for osteoarthritis treatment: a systematic review.

The aim of this systematic review is to examine current clinical evidences supporting the intraarticular injection of bone marrow concentrate cells (BMC) and adipose-derived stromal vascular fraction cells (SVF) for the treatment of osteoarthritis (OA). The research was performed on PubMed (Medline), EMBASE and Cochrane Library considering the English literature. Only clinical trials have been included. The systematic research identified twelve clinical trials. Articles included in the study, were one of level II, four of level III, six of level IV and one level V. Among clinical trials, none were randomized, four were comparative, seven were case series, and one was a case report. Seven studies were focused on the use of SVF (1332 patients) and five on the use of BMC (963 patients), with preliminary interesting findings in the OA treatment. Despite the growing interest in this biological approach for OA, knowledge on this topic is still preliminary. Randomized controlled trials are needed to support the potential of BMC and SVF injections and to evaluate advantages and disadvantages with respect to the available treatments.

Autologous bone marrow concentrate combined with platelet-rich plasma enhance bone allograft potential to induce spinal fusion.

Bone marrow cells concentrate (BMCs) is a source of osteoprogenitor cells and platelet-rich plasma (PRP) is a source of growth factors. The objective of the study was to determine whether BMC and PRP could increase the potential of bone allograft to induce posterolateral-lumbar spinal fusion compared to the bone allograft alone. A prospective nonrandomized radiographic study has been conduced on 10 patients with posterolateral instrumented fusion for degenerative lumbar disease with 1-year follow-up using CT scan. A fresh frozen bone allograft alone and bone allograft with a mixture of autologous BMC and PRP blended with thrombin were apposed in the right and left posterolateral side, respectively. CT showed good right fusion masses (allograft alone) in 4 patients and poor in 6; good left masses (BMC and PRP plus allograft) in 9 patients and poor in 1. The differences detected between right-side and left-side masses show an advantage in adding BMC and PRP to the bone allograft to increase spinal fusion rate.

Mesenchymal stem cells for intervertebral disc regeneration.

Low back pain (LBP) is one of the most common disabling symptoms affecting the adult population throughout the industrialized world. The main cause underlying this condition is intervertebral disc degeneration (IDD), which is characterized by progressive decrease of the proteoglycan content within the nucleus pulposus (NP), leading to disc dehydration and loss of its morpho-functional and biomechanical properties. To date, LBP treatment is based upon conservative and invasive procedures which are not capable of restoring the degenerative alterations of the disc, as they only help relieve the symptoms and/or slow down disc degeneration and are, nonetheless, characterized by significant comorbidities, costs and secondary risks. The potential use of different mesenchymal stem/stromal cells (MSCs) for treating IDD has been promisingly tested in vitro and in vivo. The combination of different cell types, preconditioning culture conditions, engineered scaffolds and delivery systems have yielded proof of disc matrix reconstitution, increased cell viability and tissue regeneration in several experimental settings. This article reviews the current literature on stem cell-based therapy for IDD and the outcomes that diverse approaches have achieved.

Serum chitotriosidase in postmenopausal women with severe osteoporosis.

UNLABELLED: Human chitotriosidase (Chit) increases during the osteoclast differentiation and their activity. We demonstrated that serum Chit was significantly higher in osteoporotic subjects than in healthy control ones and revealed a negative correlation between Chit and bone mineral density (BMD). This is the first study showing a correlation between Chit and severe postmenopausal osteoporosis. INTRODUCTION: Mammalian chitinases exert important biological roles in the monocyte lineage and chronic inflammatory diseases. In particular, Chit seems to promote bone resorption in vitro. No in vivo studies have been performed to confirm this finding. We aim to evaluate Chit activity in postmenopausal women affected by severe osteoporosis. METHODS: In this cross-sectional study, 91 postmenopausal women affected by osteoporosis and 61 with either osteopenia or normal BMD were screened. All subjects were assessed by dual-energy X-ray absorptiometry (DXA) and X-ray vertebral morphometry. Osteoporotic subjects were considered eligible if they were affected by at least one vertebral osteoporotic fracture (group A = 57 subjects). Osteopenic or healthy subjects were free from osteoporotic fractures (group B = 51 subjects). Enzymatic Chit and serum ß-CrossLaps (CTX) were measured in the whole population. RESULTS: Group A showed higher serum levels of beta-CTX compared to group B (0.40 ± 0.26 ng/mL vs 0.29 ± 0.2 ng/mL, p = 0.022). Chit was significantly higher in group A than in group B (1042 ± 613 nmol/mL/h vs 472 ± 313 nmol/mL/h, p < 0.001, respectively) even after adjustment for age (p < 0.001). Spearman correlation test revealed a negative correlation between Chit and BMD at each site (lumbar spine: r = -0.38, p = 0.001, femoral neck: r = -0.35, p = 0.001, total femur: r = -0.39, p < 0.001). Furthermore, a positive correlation between Chit and PTH was observed (r = 0.26, p = 0.013). No significant correlation was found between Chit and beta-CTX (r = 0.12, p = 0.229). After a multivariate analysis, a positive correlation between severe osteoporosis and Chit (p < 0.001), beta-CTX (p = 0.013), and age (p < 0.001) was observed. CONCLUSION: This is the first clinical study showing a correlation between Chit and severe postmenopausal osteoporosis. Larger and prospective studies are needed to evaluate if Chit may be a promising clinical biomarker and/or therapeutic monitor in subjects with osteoporosis.