Bone union-promoting effect of romosozumab in a rat posterolateral lumbar fusion model

Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

Optimizing preoperative bone health assessment for adult spinal deformity: a prospective correlation analysis of intraoperative pedicle screw insertion torque and imaging modalities in Japan

STUDY DESIGN

Prospective cohort study.

PURPOSE

This study aimed to identify the optimal preoperative bone health assessment for adult spinal deformity (ASD) surgery through correlation analysis between intraoperative pedicle screw (PS) insertion torque and various bone quality measures, including bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DEXA), Hounsfield unit (HU) by computed tomography (CT), and vertebral bone quality (VBQ) score by magnetic resonance imaging.

OVERVIEW OF LITERATURE

Existing data on optimal assessment tools for ASD surgery are limited.

METHODS

The study included patients with ASD aged >60 years who underwent spinal corrective fusion surgery from the lower thoracic spine to the pelvis. The intraoperative PS insertion torque was measured using a torque meter. Pearson correlation coefficients were calculated between the PS insertion torque and the BMD, HU, and VBQ score. Preoperative bone quality was compared between the proximal junctional failure (PJF) and non-PJF groups.

RESULTS

Thirty-one patients with 177 PS at T10, T11, and T12 were analyzed. The PS insertion torque showed a moderate positive correlation with lumbar spine BMD (r=0.59-0.69, p<0.01), total hip BMD (0.58-0.62, p<0.01), and HU value (r=0.58-0.66, p<0.01). However, the VBQ score did not show significant correlation (r=-0.28 to -0.23, p >0.05). Notably, a strong correlation was found between the PS insertion torque and the HU value for screws of the same size (r=0.71 and 0.74, p<0.01). The HU value at T12 and the PS insertion torque at T10 were significantly lower in the PJF group than in the non-PJF group.

CONCLUSIONS

This study demonstrates a positive correlation between the PS insertion torque and HU value in the lower thoracic spine and a moderate correlation with BMD but not the VBQ score. Preoperative assessment using DEXA and CT is crucial for optimizing bone health management in ASD surgery.

Efficacy of Three Teriparatide Preparations and Romosozumab, Osteogenesis Promoters, in the Treatment of Fresh Vertebral Fractures: A Retrospective Observational Study

BACKGROUND

In Japan, daily, twice weekly, and weekly formulations of teriparatide (TPD) and monthly formulations of romosozumab (ROMO) are available as osteogenesis promoters for the treatment of osteoporosis with a high risk for fracture.

OBJECTIVE

To compare the effects of three TPD preparations and ROMO on fracture healing and low back pain after a fresh vertebral fracture.

METHODS

This was a retrospective observational study. Patients presenting with fresh osteoporotic vertebral fractures were treated subcutaneously with TPD daily (DTPD), twice weekly (2/WTPD), weekly (WTPD), or with ROMO monthly. Bone union, vertebral height changes, and low back pain in the injured vertebra were compared after 6 months of treatment.

RESULTS

Bone union and pain improvement were more frequent among those who received daily and twice weekly administration of TPD compared with those who received WTPD and ROMO administration. A comparison for multiplicity between the groups using the Steel-Dwass test showed significant differences between the DTPD and ROMO groups (p = 0.0029) and WTPD and ROMO groups (p = 0.0490), suggesting superior bone fusion in the DTPD and WTPD groups. Similarly, significant differences were noted between the DTPD and ROMO groups (p = 0.0001), WTPD and ROMO groups (p = 0.0341), and 2/WTPD and ROMO groups (p = 0.0009), indicating a higher degree of pain improvement in the DTPD, WTPD, and 2/WTPD groups compared with that in the ROMO group.

CONCLUSIONS

Daily, weekly, and twice-weekly administration of TPD may be superior to ROMO for promoting fresh vertebral fracture healing.

Combined effect of DBM, PRP, and bone marrow fluid on bone union in a rat posterolateral fusion model

Platelet-rich plasma (PRP) promotes bone union through osteoinduction. We investigated whether adding demineralized bone matrix (DBM), derived naturally from biomaterial and with various growth factors, for osteoconductivity and bone marrow fluid for osteogenesis results in different bone unions. Eight-week-old male Sprague-Dawley rats were divided into four groups of five based on transplantation material: sham control (C group); DBM alone (D group); DBM + PRP (DP group); and DBM + PRP + bone marrow fluid (DPB group). After posterolateral fusion at L3-5, postoperative weekly CT imaging determined average number of bone union in facet joints (4 joints × 5 animals = 20 joints) and bone formation. Pathological evaluation and bone strength were assessed using 3-point bending two weeks postoperatively. Facet joint bone union at four weeks postoperatively was 4/20 (20%, DP group) and 8/20 (40%, DPB group) joints. Six weeks postoperatively, it was 7/20 (35%, D group), 12/20 (60%, DP group), and 16/20 (80%, DPB group). Eight weeks postoperatively, it was 13/20 (65%, D group), 17/20 (85%, DP group), and 20/20 (100%, DPB group), suggesting that DPB > DP > D > C. Bone formation and bone strength showed a similar DPB > DP > D > C group trend. Adding PRP and bone marrow fluid to DBM promotes bone union and strength.

Post-Fracture Care Program: Pharmacological Treatment of Osteoporosis in Older Adults with Fragility Fractures

PURPOSE OF REVIEW

To present and discuss the recently published scientific evidence on the approach, mode of action, and timing of osteoporosis therapy initiation after fragility fractures.

RECENT FINDINGS

A comprehensive management approach is required to reduce mortality and morbidity associated with fragility fractures. This will help to reduce the risk of missing the diagnosis of osteoporosis as the underlying disorder while at the same time promoting the timely treatment of osteoporosis. The target is to minimize the incidence of post-traumatic disability and to reduce the imminent fracture risk. This article will present a Bone-Care algorithm for the diagnosis and management of fragility fractures in patients presenting for trauma surgery. This algorithm has been developed based on recently published national as well as international guidelines for implementation in standard clinical practice. International figures revealed that only a small proportion of those patients at high risk of sustaining a fragility fracture receive osteoporosis therapy. Based on the best currently available evidence, it is safe to start osteoporosis therapy in the acute post-fracture period (the optimal therapeutic window of romosozumab is the late endochondral phase/throughout bone remodeling). The right Bone-Care pathway ensures the delivery of a comprehensive management approach that meets the global call to action. All parameters including risk, benefit, compliance, and cost should be considered on an individual base for all kinds of therapy.

Medical optimization of osteoporosis for adult spinal deformity surgery: a state-of-the-art evidence-based review of current pharmacotherapy

PURPOSE

Osteoporosis is a common, but challenging phenomenon to overcome in adult spinal deformity (ASD) surgery. Several pharmacological agents are at the surgeon's disposal to optimize the osteoporotic patient prior to undergoing extensive reconstruction. Familiarity with these medications will allow the surgeon to make informed decisions on selecting the most appropriate adjuncts for each individual patient.

METHODS

A comprehensive literature review was conducted in PubMed from September 2021 to April 2022. Studies were selected that contained combinations of various terms including osteoporosis, specific medications, spine surgery, fusion, cage subsidence, screw loosening, pull-out, junctional kyphosis/failure.

RESULTS

Bisphosphonates, denosumab, selective estrogen receptor modulators, teriparatide, abaloparatide and romosozumab are all pharmacological agents currently available for adjunctive use. While these medications have been shown to have beneficial effects on improving bone mineral density in the osteoporotic patient, varying evidence is available on their specific effects in the context of extensive spine surgery. There is still a lack of human studies with use of the newer agents.

CONCLUSION

Bisphosphonates are first-line agents due to their low cost and robust evidence behind their utility. However, in the absence of contraindications, optimizing bone quality with anabolic medications should be strongly considered in preparation for spinal deformity surgeries due to their beneficial and favorable effects on fusion and hardware compared to the anti-resorptive medications.

Analgesic effects and arthritic changes following intra-articular injection of diclofenac etalhyaluronate in a rat knee osteoarthritis model

Background

Diclofenac etalhyaluronate (DF-HA) is a recently developed analgesic conjugate of diclofenac and hyaluronic acid that has analgesic and anti-inflammatory effects on acute arthritis. In this study, we investigated its analgesic effect on osteoarthritis, using a rat model of monoiodoacetate (MIA).

Methods

We injected MIA into the right knees of eight 6-weeks-old male Sprague–Dawley rats. Four weeks later, rats were randomly injected with DF-HA or vehicle into the right knee. Seven weeks after the MIA injection, fluorogold (FG) and sterile saline were injected into the right knees of all the rats. We assessed hyperalgesia with weekly von Frey tests for 8 weeks after MIA administration. We took the right knee computed tomography (CT) as radiographical evaluation every 2 weeks. All rats were sacrificed 8 weeks after administration of MIA for histological evaluation of the right knee and immunohistochemical evaluation of the DRG and spinal cord. We also evaluated the number of FG-labeled calcitonin gene-related peptide (CGRP)-immunoreactive(ir) neurons in the dorsal root ganglion (DRG) and ionized calcium-binding adapter molecule 1 (Iba1)-ir microglia in the spinal cord.

Results

Administration of DF-HA significantly improved pain sensitivity and reduced CGRP and Iba1 expression in the DRG and spinal cord, respectively. However, computed tomography and histological evaluation of the right knee showed similar levels of joint deformity, despite DF-HA administration.

Conclusion

DF-HA exerted analgesic effects on osteoarthritic pain, but did not affect joint deformity.