Teriparatide - Indications beyond osteoporosis

Low bone mineral density: a primer for the spine surgeon

Within spinal surgery, low bone mineral density is associated with several postoperative complications, such as proximal junctional kyphosis, pseudoarthrosis, and screw loosening. Although modalities such as CT and MRI can be utilized to assess bone quality, DEXA scans, the "Gold Standard" for diagnosing osteoporosis, is not routinely included in preoperative workup. With an increasing prevalence of osteoporosis in an aging population, it is critical for spine surgeons to understand the importance of evaluating bone mineral density preoperatively to optimize postoperative outcomes. The purpose of this state-of-the-art review is to provide surgeons a summary of the evaluation, treatment, and implications of low bone mineral density in patients who are candidates for spine surgery.

Therapeutic advantage of teriparatide in very elderly patients with proximal femoral fractures: a functional and BMD analysis

BACKGROUND

Teriparatide, a recombinant parathyroid hormone, is pivotal in osteoporosis treatment, particularly in post-surgical recovery for hip fractures. This study investigates its efficacy in functional recovery post-hip fracture surgery in elderly patients, a demographic particularly susceptible to osteoporotic fractures.

METHODS

In this retrospective cohort study, 150 elderly patients with proximal femoral fractures undergoing open reduction and internal fixation were enrolled. They were categorized into two groups: receiving 20 µg of daily teriparatide injections for 18 months and receiving standard antiresorptive medications during a 24-month follow-up. Detailed records of patient demographics, Fracture Risk Assessment Tool scores, and comorbidities were kept. Key outcomes, including bone mineral density (BMD) and functional scores (Barthel Index and Visual Analog Scale for hip pain), were evaluated at 3 and 24 months post-surgery.

RESULTS

Out of the original cohort, 126 patients (20 men and 106 women with an average age of 85.5 ± 9.3 years) completed the study. The teriparatide group exhibited significant enhancements in both functional scores and BMD when compared to the control group. Notably, functional improvements were less pronounced in male patients compared to female patients. Additionally, the incidence of new fractures was markedly lower in the teriparatide group.

CONCLUSION

Administering teriparatide daily for 18 months post-surgery for proximal femoral fractures significantly benefits very elderly patients by improving functionality and bone density, with observed differences in recovery between genders. These results reinforce the efficacy of teriparatide as a potent option for treating osteoporosis-related fractures in the elderly and highlight the importance of considering gender-specific treatment and rehabilitation strategies.

Recombinant Human Parathyroid Hormone Biocomposite Promotes Bone-to-Tendon Interface Healing by Enhancing Tenogenesis, Chondrogenesis, and Osteogenesis in a Rabbit Model of Chronic Rotator Cuff Tears

PURPOSE

To investigate the effect of recombinant human parathyroid hormone (rhPTH) biocomposite on bone-to-tendon interface (BTI) healing for surgical repair of a chronic rotator cuff tear (RCT) model of rabbit, focusing on genetic, histologic, biomechanical and micro-computed tomography (CT) evaluations.

METHODS

Sixty-four rabbits were equally assigned to the 4 groups: saline injection (group A), nanofiber sheet alone (group B), rhPTH-soaked nanofiber sheet (nanofiber sheet was soaked with rhPTH, group C), and rhPTH biocomposite (rhPTH permeated the nanofiber sheet by coaxial electrospinning, group D). The release kinetics of rhPTH (groups C and D) was examined for 6 weeks in vitro. Nanofiber scaffolds were implanted on the surface of the repair site 6 weeks after the induction of chronic RCT. Genetic and histologic analyses were conducted 4 weeks after surgery. Furthermore, genetic, histologic, biomechanical, micro-CT, and serologic analyses were performed 12 weeks after surgery.

RESULTS

In vivo, group D showed the highest collagen type I alpha 1 (COL1A1), collagen type III alpha 1 (COL3A1), and bone morphogenetic protein 2 (BMP-2) messenger RNA (mRNA) expression levels (all P < .001) 4 weeks after surgery; however, there were no differences between groups at 12 weeks postsurgery. After 12 weeks postsurgery, group D showed better collagen fiber continuity and orientation, denser collagen fibers, more mature bone-to-tendon junction, and greater fibrocartilage layer formation compared with the other groups (all P < .05). Furthermore, group D showed the highest load-to-failure rate (28.9 ± 2.0 N/kg for group A, 30.1 ± 3.3 N/kg for group B, 39.7 ± 2.7 N/kg for group C, and 48.2 ± 4.5 N/kg for group D, P < .001) and micro-CT outcomes, including bone and tissue mineral density, and bone volume/total volume rate (all P < .001) at 12 weeks postsurgery.

CONCLUSIONS

In comparison to rhPTH-soaked nanofiber sheet and the other control groups, rhPTH biocomposite effectively accelerated BTI healing by enhancing the mRNA expression levels of COL1A1, COL3A1, and BMP-2 at an early stage and achieving tenogenesis, chondrogenesis, and osteogenesis at 12 weeks after surgical repair of a chronic RCT model of rabbit.

CLINICAL RELEVANCE

The present study might be a transitional study to demonstrate the efficacy of rhPTH biocomposites on BTI healing for surgical repair of chronic RCTs as an adaptable polymer biomaterial in humans.

From Cells to Environment: Exploring the Interplay between Factors Shaping Bone Health and Disease

The skeletal system is an extraordinary structure that serves multiple purposes within the body, including providing support, facilitating movement, and safeguarding vital organs. Moreover, it acts as a reservoir for essential minerals crucial for overall bodily function. The intricate interplay of bone cells plays a critical role in maintaining bone homeostasis, ensuring a delicate balance. However, various factors, both intrinsic and extrinsic, can disrupt this vital physiological process. These factors encompass genetics, aging, dietary and lifestyle choices, the gut microbiome, environmental toxins, and more. They can interfere with bone health through several mechanisms, such as hormonal imbalances, disruptions in bone turnover, direct toxicity to osteoblasts, increased osteoclast activity, immune system aging, impaired inflammatory responses, and disturbances in the gut-bone axis. As a consequence, these disturbances can give rise to a range of bone disorders. The regulation of bone's physiological functions involves an intricate network of continuous processes known as bone remodeling, which is influenced by various intrinsic and extrinsic factors within the organism. However, our understanding of the precise cellular and molecular mechanisms governing the complex interactions between environmental factors and the host elements that affect bone health is still in its nascent stages. In light of this, this comprehensive review aims to explore emerging evidence surrounding bone homeostasis, potential risk factors influencing it, and prospective therapeutic interventions for future management of bone-related disorders.

The Effect of Daily Teriparatide versus One-Time Annually Zoledronic Acid Administration After Transforaminal Lumbar Interbody Fusion in Osteoporotic Patients

Purpose

The research aimed to compare the therapeutic effect of teriparatide (TPTD) and zoledronic acid (ZOL) therapy on bone formation and spinal fusion in patients with osteoporosis (OP) who underwent transforaminal lumbar interbody fusion (TLIF).

Methods

On the basis of different anti-OP treatment options, the TPTD group was treated daily with TPTD (20 μg. ih. qd) for at least 6 months, while the ZOL group was treated with a single dose of ZOL (5 mg. ivgtt. st) postoperatively. The visual analogue scale (VAS), Oswestry Disability Index (ODI), bone mineral density (BMD), and concentration of bone turnover markers before, 6, and 12 months after surgery were evaluated. X-ray and three-dimensional computed tomography scans were performed at 6 and 12 months postoperatively to assess interbody fusion.

Results

The number of patients in the TPTD and ZOL groups was 29 and 38 patients, respectively. The VAS and ODI scores in both groups were significantly reduced at 6 and 12 months after TLIF. Compared with that of baseline, the lumbar spine BMD of TPTD patients increased significantly from 0.716±0.137 g/cm² to 0.745±0.124 g/cm² and 0.795±0.123 g/cm² at 6 and 12 months, respectively, and was significantly higher than that of the ZOL group at 12 months (0.720±0.128 g/cm²). The bone formation marker, P1NP, in the TPTD group increased significantly (145.48±66.64 ng/mL and 119.55±88.27 ng/mL) compared with baseline (44.67±25.15 ng/mL) and in the ZOL group (28.82±19.76 ng/mL and 29.94±20.67 ng/mL) at 6 and 12 months, respectively. The fusion rates in the TPTD and ZOL groups were 57% and 45% at 6 months, without statistical significance. However, TPTD had a more statistically significant positive influence on fusion rate than ZOL at 12 months (86% vs 70%).

Conclusion

TPTD was more efficient than ZOL in bone formation and spinal fusion in OP patients who underwent TLIF.

Combined Surgical and Medical Treatment for Vancouver B1 and C Periprosthetic Femoral Fractures: A Proposal of a Therapeutic Algorithm While Retaining the Original Stable Stem

INTRODUCTION

There is lack of consensus regarding best operative fixation strategy for periprosthetic femoral fractures (PFFs) around a stable stem. Evidence exists that some patterns of fracture around a stable stem are better treated with revision surgery than with standard fixation. Anyway, a more aggressive surgical procedure together with medical treatment could allow for stem retention, and reduced risk of nonunion/hardware failure, even in these cases.

SIGNIFICANCE

This paper is placed in a broader context of lack of studies on the matter, and its aim is to shed some light on the management of PFFs around a stable stem, when peculiar mechanical and biological aspects are present.

RESULTS

Based on our casuistry in the treatment of nonunions after PFF successfully treated with original stem retention, and on review of Literature about risk factors for fixation failure, an algorithm is proposed that can guide in choosing the ideal surgical technique even for first-time PFFs with a stable stem, without resorting to revision. Mechanical (major and minor) and biological (local and systemic) factors that may influence fracture healing, leading to nonunion and hardware failure, and subsequent need for re-operation, are considered. The proposed surgical technique consists of rigid fixation with absolute stability (using a plate and structural allograft) plus local biological support (structural allograft and autologous bone marrow concentrate over a platelet-rich plasma-based scaffold) at fracture site. Systemic anabolic treatment (Teriparatide) is also administered in the post-operative period.

CONCLUSION

Mechanical factors are not the only issues to be considered when choosing the surgical approach to PFFs over a stable stem. Systemic and local biological conditions should be taken into account, as well. A therapeutic algorithm is proposed, given the prosthetic stem to be stable, considering mechanical and biological criteria.

Rapid progression of aortic stenosis after initiation of teriparatide treatment: a case report

Introduction

Teriparatide, a recombinant formulation of endogenous PTH, is indicated for the treatment of osteoporosis in patients at high risk for fracture including postmenopausal women, men with primary or hypogonadal osteoporosis and patients with glucocorticoid-induced osteoporosis.

Case report

A 64-year-old Jewish osteoporotic woman initiated use of Teriparatide (FORTEOTM, 250 µg per 1 ml subcutaneously per day) in April 2018. Prior to therapy initiation, the patient has undergone eight echocardiograms with an aortic valve pressure gradient ranging between 29 and 39 mmHg, defined as mild aortic stenosis (AS), with no clear trend of progression. In two subsequent echo tests conducted 4 and 7 months after treatment initiation, there was a rapid progression of AS with gradient pressures of 55 and 58 mmHg, respectively.

Conclusion

Intermittent exposure to PTH analogues may be one of the causes of rapid progression of AS. Studies with sizeable populations are required to assess causal relationship between PTH analogues use and progression of AS.

Present and future scope of recombinant parathyroid hormone therapy in orthopaedics

Parathyroid Hormone (PTH) has a significant role in calcium metabolism. Its intermittent administration has an anabolic effect on bone mineralization. Teriparatide (PTH 1-34), a recombinant form of parathyroid hormone, is useful in the treatment of osteoporosis, fracture healing, non-union, stress fracture, augmentation of implant fixation with bone, and chondroprotection in osteoarthritis. The present review article will elaborate on the potential approved uses of recombinant PTH in orthopedics and its evolving role in the management of fracture osteosynthesis and other common challenging bone pathologies.

Treatment of an Acromial Stress Fracture After Reverse Total Shoulder Arthroplasty With Teriparatide: A Case Report

CASE

A 78-year-old woman who underwent reverse total shoulder arthroplasty (RTSA) for proximal humerus fracture developed a Type-3 acromial stress fracture, resulting in increased pain and decreased function 9 months post-op. She was managed nonoperatively with adjunctive teriparatide (FORTEO), and after a 4-month course, she had regained excellent motion and achieved union.

CONCLUSION

Teriparatide is a viable adjunct in treating patients nonoperatively with acromial stress fractures after RTSA.

Is Teriparatide Beneficial to Spinal Fusion Surgery in the Older Patient?: A Narrative Review

Since FDA approval in 2002, teriparatide has gained popularity as an anabolic therapy for the treatment of osteoporosis. Animal studies have suggested a role for teriparatide in spine surgery. Several recent studies have demonstrated adjunctive use of teriparatide in osteoporotic patients undergoing spine fusions improves fusion rates, decreases time to union, and decreases osteoporosis-related complications such as proximal junctional kyphosis. On the basis of the available literature, we outline an algorithm for the use of teriparatide in spine surgery.

Effect of teriparatide use on bone mineral density and spinal fusion: a narrative review of animal models

Purpose of the study: Teriparatide (Human recombinant Parathyroid Hormone 1-34) is an anabolic agent that is frequently used in patients with osteoporosis and has been extensively investigated with animal model and clinical studies in current literature. The purpose of the study was to evaluate the impact of teriparatide on bone mineral density and fusion. Materials and methods: The findings from preclinical studies that have investigated the role of teriparatide in animal models are summarized in presented review. Results: Overall, the studies show an improvement in bone mineral density and increased fusion rates for osteoporotic animals undergoing spine fusion with teriparatide use. Conclusion: Further studies should be conducted for unanswered questions, such as teriparatide use before surgery, the effect on cervical fusion and surgery related complications.

Efficacy of Teriparatide in Patients with Hypoparathyroidism: A Prospective, Open-label Study

CONTEXT

Conventional treatment of hypoparathyroidism with calcium, Vitamin D analogs, and thiazide diuretics is often suboptimal, and these patients have poor quality of life. Teriparatide (parathyroid hormone 1-34 [PTH (1-34)]), an amide of PTH, is widely available for the use in osteoporosis; however, its use in hypoparathyroidism is limited.

AIMS

The aim of this study is to evaluate the efficacy of PTH (1-34) in the treatment of patients with hypoparathyroidism.

SETTINGS AND DESIGN

This was a prospective, open-label interventional study in a tertiary care hospital of Indian Armed Forces.

SUBJECTS AND METHODS

All patients with hypoparathyroidism presented to the endocrinology outpatient department were included and were exhibited injection PTH (1-34) 20 μg twice daily that was gradually reduced to 10 μg twice daily along with calcium, active Vitamin D (alfacalcidol), and hydrochlorothiazide. Oral calcium and alfacalcidol doses were also reduced to maintain serum calcium within normal range. The quality of life (QOL) score was calculated using RAND 36 QOL questionnaire at baseline and termination of the study.

STATISTICAL ANALYSIS USED

Paired t-test was used to calculate pre- and post-treatment variables.

RESULTS

Eight patients (two males) were included in this study having mean age of 35.8 years. PTH (1-34) treatment led to the improvement in serum calcium (6.81-8.84 mg/dl), phosphorous (5.8-4.2 mg/dl), and 24 h urinary calcium excretion (416-203.6 mg). Parameters of QOL showed the improvement in overall QOL, physical performance, energy, and fatigue scores. No major adverse events were noted.

CONCLUSIONS

Treatment of hypoparathyroidism with PTH (1-34) leads to improvement in calcium profile, reduction in hypercalciuria, and improvement in QOL, whereas it is safe and well tolerated.

Retrospective radiological outcome analysis following teriparatide use in elderly patients undergoing multilevel instrumented lumbar fusion surgery

Elderly patients with chronic nonresolving symptoms due to degenerative spine pathologies are prone to have poor surgical outcomes and hardware-related complications, especially following multilevel instrumented lumbar fusion surgeries. With intention of analyzing if teriparatide can be an effective adjunct therapy to surgical management, radiological outcomes are studied. Sixty-two elderly patients were divided into 2 similar groups. Group 1 (n = 30; mean age = 69.83 years; fusion levels = 137; screws = 269) had taken teriparatide (20 mcg SC injection, once daily) for a duration of 7.4 ± 2.4 months following surgery and Group 2 (n = 32; mean age = 70.38 years; fusion levels = 144; screws = 283) did not take teriparatide. Radiological evaluation was done to determine the state of postero lateral fusion mass and to investigate the incidence of pedicle screw loosening at 1-year follow-up. Unilateral or bilateral bridging bone formation across the transverse process of adjacent vertebras showing continuous trabeculation suggestive of solid fusion was obtained in 66.7% patients in the teriparatide group and 50% patients in the control group (P = 0.20). 13.4% of the total no. of screws showed signs of loosening in the teriparatide group, compared to 24.4% in the control group (P = 0.001). Percentage of patients achieving solid fusion following teriparatide use was found to be more than that of the control group. This difference may have clinical importance but was not statistically significant. However, teriparatide use was more significantly influential in reducing the incidence of subsequent pedicle screw loosening.

Impact and risk factors of post-stroke bone fracture

Bone fracture occurs in stroke patients at different times during the recovery phase, prolonging recovery time and increasing medical costs. In this review, we discuss the potential risk factors for post-stroke bone fracture and preventive methods. Most post-stroke bone fractures occur in the lower extremities, indicating fragile bones are a risk factor. Motor changes, including posture, mobility, and balance post-stroke contribute to bone loss and thus increase risk of bone fracture. Bone mineral density is a useful indicator for bone resorption, useful to identify patients at risk of post-stroke bone fracture. Calcium supplementation was previously regarded as a useful treatment during physical rehabilitation. However, recent data suggests calcium supplementation has a negative impact on atherosclerotic conditions. Vitamin D intake may prevent osteoporosis and fractures in patients with stroke. Although drugs such as teriparatide show some benefits in preventing osteoporosis, additional clinical trials are needed to determine the most effective conditions for post-stroke applications.

The role of recombinant PTH in human fracture healing: a systematic review

OBJECTIVES

Human parathyroid hormone (PTH) is known to be efficacious in the treatment of osteoporosis and reduction of risk of vertebral and nonvertebral fractures; however, its role in the enhancement of human fracture healing is controversial. Our objective is to conduct a systematic literature review on the use of recombinant PTH in human fracture healing to (1) evaluate the evidence for recombinant PTH in human fracture healing and (2) assess whether there are notable differences between previous case reports and prospective trials.

DATA SOURCES

We performed a literature search in PubMed, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews for "teriparatide," "PTH (1-84)," "fracture," and "healing."

STUDY SELECTION

References of retrieved articles were screened for additional studies, and exclusion criteria were applied.

DATA EXTRACTION

Due to the limited publications on the subject, case reports and case series were included in our data analysis.

DATA SYNTHESIS

Due to the limited publications on the subject, our data are presented in simple tabular format.

CONCLUSIONS

Our literature review yielded 16 publications on the use of recombinant PTH in human fracture healing and 2 randomized controlled trial with 1 retrospective subgroup analysis. There continues to be anecdotal evidence for the use of recombinant PTH to enhance fracture healing. There are discrepancies in study design in the randomized controlled trials and the majority of case reports and, additional prospective studies are warranted.

Investigating hydrophobic ligand-receptor interactions in parathyroid hormone receptor using peptide probes

With an increasing number of new chemical entities entering clinical studies, and an increasing share of the market, peptides and peptidomimetics constitute one of the most promising classes of therapeutics. The success of synthetic peptides as therapeutics relies on the lead optimization step in which the lead candidates are modified to improve drug-like properties of peptides related to potency, pharmacokinetics, solubility, and stability, among others. Peptidomimetics based on the N-terminal stretch of the first 11 amino acids of the PTH have been investigated as potential lead compounds for the treatment of osteoporosis. On the basis of a peptide reported in the literature, referred to here as the Parent Peptide (H-Aib-Val-Aib-Glu-Ile-Gln-Leu-Nle-His-Gln-Har-NH2), we conducted systematic SAR analyses to investigate the effects of altering peptide hydrophobicity on PTH receptor functional potency as measured by the cAMP (cyclic adenosine monophosphate) accumulation and β-arrestin recruitment assays. Among hydrophobic residues, we found that the Val2 position shows the least flexibility in terms of the SAR studies, whereas the Leu7 position appeared to be most flexible. Through circular dichroism and nuclear magnetic resonance spectroscopy studies, we were able to establish that changes in hydrophobic residues significantly change the extent of peptide helicity and that the helical character correlates well with receptor agonist activity. Here, we report several novel PTH 1-11 peptidomimetics that show comparable or enhanced potency to stimulate Gs-signaling over β-arrestin recruitment as compared with such properties of PTH 1-34 and the Parent Peptide.

Adjunct teriparatide therapy with monitoring of bone turnover markers and bone scintigraphy for bisphosphonate-related osteonecrosis of the jaw

The management of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is still difficult in many cases that do not respond to conservative treatments. We report a case of BRONJ treated by adjunctive teriparatide therapy for 6 months with monitoring of bone turnover markers (at baseline, at 1, 3, and 6 months of treatment, and after 9 months off therapy) and bone scintigraphy (at baseline, 3 and 6 months, and after 9 months off therapy). The patient was a 78-year-old woman with osteoporosis and BRONJ. She had not responded to previous conventional treatment. Teriparatide was added for resolution of BRONJ. The pain disappeared after 1 month, and remarkable bone regeneration was obtained after 6 months, with significantly increasing bone formation and resorption markers. Bone scintigraphy showed regression of the uptake area. This case suggests the usefulness of monitoring bone turnover markers and using bone scintigraphy to increase the effectiveness of teriparatide therapy.