Teriparatide anabolic therapy as potential treatment of type II dens non-union fractures

Efficacy and Safety of Teriparatide in Improving Fracture Healing and Callus Formation: A Systematic Review

Fracture nonunion remains a great challenge for orthopedic surgeons. Some bone fractures don't heal promptly, resulting in delayed unions and nonunions, and there is a need for an additional surgical procedure. Previous research has shown that teriparatide, a type of synthetic parathyroid hormone, can promote the formation of callus and lead to healing in individuals with delayed or non-healing bone fractures. Limited systematic reviews exist that examine the use of teriparatide in cases of delayed healing or non-healing bone fractures, which have their limitations. In this review, we overcome those limitations by including prospective studies, retrospective studies, case reports, and case series together. A systematic search of the literature was conducted in both PubMed and Google Scholar up to September of the year 2022. The studies included in our research included adult patients (over the age of 16) diagnosed with delayed union or nonunion of any bone in the body (flat bone, long bone, short bone, or irregular bone). The studies were limited to those written in English. The outcomes that were tracked and recorded include the healing of the fracture and any negative side effects or adverse events. The initial search yielded 504 abstracts and titles. After reviewing these, 32 articles were selected for further analysis, which included 19 case reports, five case series, two retrospective studies, and six prospective studies. Studies included daily (20 micrograms) or weekly (56.5 micrograms) subcutaneous administration of teriparatide. The duration of follow-up for these studies varied from three to 24 months. Based on the available research, it appears that administering teriparatide subcutaneously is a safe treatment option for delayed healing and non-healing bone fractures, with very few to no reported negative side effects. Using teriparatide for induction of callus formation and treating delayed and nonunions is highly safe and effective.

Posterior fusion for fragility type 2 odontoid fractures

OBJECTIVE

The purpose of this study was to evaluate the outcomes of elderly patients with type 2 odontoid fractures treated with an instrumented posterior fusion.

METHODS

Ninety-three consecutive patients older than 65 years of age in whom a type 2 odontoid fracture had been treated with a variety of C1-2 posterior screw fixation techniques were retrospectively reviewed.

RESULTS

The average age was 78 years (range 65-95 years). Thirty-seven patients had an additional fracture, 30 of which involved C1. Three patients had cervical spinal cord dysfunction due to their injury. All patients had comorbidities. The average total hospitalization was 9.6 days (range 2-37 days). There were 3 deaths and 19 major complications, the most common of which was pneumonia. No patient suffered a vertebral artery injury. Imaging studies were obtained in 64 patients at least 12 months postsurgery (mean 19 months). Fusion was assessed by dynamic radiographs in all cases and with a CT scan in 80% of the cases. Four of the 64 patients did not achieve fusion (6.25% overall). All patients in whom fusion failed had undergone C1 lateral mass fixation and C2 pars (1/29, 3.4%) or laminar (3/9, 33.3%) fixation.

CONCLUSIONS

Instrumented posterior cervical fusions may be performed in elderly patients with acceptable morbidity and mortality. The fusion rate is excellent except when bilateral C2 translaminar screws are used for axis fixation.

Scope and Limits of Teriparatide Use in Delayed and Nonunions: A Case Series

Nonunion is known to occur in up to 10% of all bone fractures. Until recently, the treatment options considered in cases of delayed union and nonunion focused on revision surgery and improvement of local healing. Lately, teriparatide has been introduced as an osteoanabolic factor that induces fracture healing in cases with delayed or nonunions. We report on a series of five cases of delayed and nonunions treated with teriparatide: delayed unions of an atypical femoral fracture, of a multifragmentary clavicle fracture, and of a periprosthetic humeral fracture; nonunion of a tibial and fibular fracture; and infected nonunion of a tibial and fibular fracture. Based on this series, the indications and limits of application of teriparatide in cases of impaired fracture healing are discussed. Due to the “off-label” character of this application, informed consent, and cost coverage from the healthcare insurance must be obtained prior to treatment. In our experience and according to the limited existing literature, teriparatide is a safe feasible treatment in cases of delayed and nonunions with a reasonable need of resources. While adequate biomechanical stability remains the cornerstone of fracture healing, as well as healing of nonunions, teriparatide could help avoid repetitive surgeries, especially in atrophic delayed and nonunions, as well as in patients with impaired fracture healing undergoing bisphosphonate therapy. There is an urgent need for widely accepted definitions, standardized protocols, as well as further clinical trials in the field of impaired fracture healing.

Teriparatide for treating delayed union and nonunion: A systematic review

INTRODUCTION

Fracture nonunion remains a great challenge for orthopaedic surgeons. Approximately 5-10% of bone fractures do not heal promptly, and require another surgical procedure. Previously, several small studies have found that teriparatide, a parathyroid hormone (PTH) analogue, has been found to induce union in those with delayed union and nonunion. However, to date, no systematic reviews regarding the use of teriparatide for delayed union and nonunion are available. The present review aims to investigate the safety and efficacy of teriparatide in delayed union and nonunion.

METHODS

Systematic literature search was performed in PubMed, ScienceDirect, and Google Scholar until September 26, 2019. We included studies involving adult patients (age >16 years) diagnosed with delayed union or nonunion fracture regardless of location (long bone, short bone, flat bone or irregular bone). The language was restricted to English and Indonesian. Outcomes that were recorded were fracture union and adverse events.

RESULTS

Initial search found 5416 abstract and titles. Of these, 20 articles consisting of 64 subjects were retrieved. Of these, 15 case reports, 4 case series, and one prospective study were included. All of the studies administered subcutaneous injection of teriparatide 20 μg/day with mean duration of 7.3 ± 1.5 weeks to 9.7 months. Sixty-one (95.3%) of 64 subjects developed complete union. The follow-up ranged from 3 to 24 months. No side effects occurred during the follow-up period.

CONCLUSIONS

Limited evidence demonstrates that daily subcutaneous injection of teriparatide 20 μg is a potential new safe treatment for delayed union and nonunion with no side effects. We highly suggest the use of such drug, as it is highly effective and safe. However, further clinical studies are required to investigate its safety and efficacy.

Therapy of aseptic nonunions with parathyroid hormone

The absence of osseous consolidation of a fracture for 9 or more months with no potential to heal is defined as nonunion. Both for the patient and from a socioeconomic point of view, nonunions represent a major problem. Hypertrophic, vital nonunions are distinguished from atrophic avital ones. Risk factors for a delayed fracture healing are insufficient immobilisation, poor adaptation of the fracture surfaces or residual instability, interposition of soft tissue within the fracture gap, as well as circulation disturbances and infections. The incidence of nonunions after fractures of the long bones lies between 2.6 and 16% depending on the surgical technique used. In human and animal studies, a positive effect of parathyroid hormone (PTH) on fracture healing has been shown. PTH has a direct stimulatory effect on osteoblasts and osteoclasts. In addition, it appears to influence the effect of osseous growth factors. In this prospective study, 32 patients with nonunions were treated with teriparatide to investigate the effects of PTH on fracture healing. Definitive healing of the nonunions following PTH treatment could be observed in 95% of the cases.

Predisposing Factors of Fracture Nonunion After Posterior C1 Lateral Mass Screws Combined with C2 Pedicle/Laminar Screw Fixation for Type II Odontoid Fracture

INTRODUCTION

The aim of this study was to explore the predisposing factors for fracture nonunion after a lateral screw was combined with C2 pedicle/laminar screw for a type II odontoid fracture and hopefully provide references in decision making and surgical planning for spinal surgeons.

METHODS

This is a retrospective study. By retrieving the medical records from January 2010 to July 2015 in our hospital, 117 type II odontoid fracture patients were reviewed. According to the occurrence of fracture union at the final follow-up, patients were divided into 2 groups: union and nonunion. To investigate the predisposing factors for fracture nonunion, 3 categorized factors were analyzed statistically: patient characteristics-age, sex, body mass index, preoperative Japanese Orthopaedic Association (JOA) scores, duration, comorbidity, and complicated injuries; surgical variables-surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2; radiographic parameters-preoperative and immediate postoperative data of C_0-2 curvature, C_2-7 curvature, C_2-7 sagittal vertical axis, C7 slope, fracture classification, congenital hypoplastic vertebral artery, and the separation and displacement of the odontoid fracture. Other variables including JOA and visual analog scale scores for neck pain, neck stiffness, and patient satisfaction at final follow-up were recorded and compared between the 2 groups.

RESULTS

Postoperative fracture nonunion was detected in 76 of 117 patients (65%) at final follow-up. There was no statistically significant difference between the 2 groups in patient characteristics of sex, body mass index, JOA score, comorbidity, and complicated injuries. The mean age at operation was younger in the union group than in the nonunion group, and the mean duration was shorter in the union group than in the nonunion group. There was no difference in surgical variables of surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2. There was no difference in radiographic parameters of fracture classification, congenital hypoplastic vertebral artery, preoperative and immediate postoperative C_0-2 curvature, C_2-7 curvature, C_2-7 SVA, and C7 slope. No difference was found in preoperative and immediate postoperative displacement of the odontoid fracture or immediate postoperative separation of the odontoid fracture, while the preoperative separation of the odontoid fracture was shorter in the union group than in the nonunion group. The logistic regression analysis revealed that advanced age (>45 years), long duration (>2 months), and preoperative separation of the odontoid fracture (>4 mm) were independently associated with the postoperative fracture nonunion. There were no differences between the 2 groups in JOA, neck pain, neck stiffness, and patient satisfaction at final follow-up.

CONCLUSIONS

Advanced age, long duration, and preoperative separation of odontoid fracture >4 mm are predisposing factors for fracture nonunion after posterior C1 lateral screw combined with C2 pedicle/laminar screw fixation for type II odontoid fracture. Our findings did not demonstrate any evidence of lower functional outcome and patients satisfaction for those patients who had odontoid nonunion.