Kyphoplasty: A Systemic New Technology Research of Vertebral Fractures

Research Article | DOI: https://doi.org/doi.org/10.31579/jsdr.2

Kyphoplasty: A Systemic New Technology Research of Vertebral Fractures

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Citation:

Copyright: © francisco 2018 et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Received: 30 November -0001 | Accepted: 31 August 2018 | Published: 03 September 2018

Keywords: Kyphoplasty, vertebral compression fractures, vertebroplasty, pathological fractures, osteoporosis, vertebral augmentation

Abstract

Kyphoplasty introduced a method of creating bilateral bone voids and in many cases elevation (reduction) of depressed end plates with variable degrees of height restoration. This was achieved by using bilateral balloon bone tamps capable of pressures significantly higher than conventional angioplasty balloons. This allows creation of bilateral bone voids, resulting in the ability to apply a much thicker cement mixture. This is felt to be the reason for fewer cement-related complications compared with vertebroplasty including extravasation and embolization. Although the procedural cost presently is higher for kyphoplasty, this is expected to decrease as patents expire and industry competition increases. Kyphoplasty indications include all those of vertebroplasty plus additional ones either contraindicated or not recommended for treatment with vertebroplasty. Kyphoplasty achieves the same degree of pain relief as vertebroplasty but may offer additional benefits of fewer complications, more indications, better biopsy specimens, and potential for height restoration of compression fractures of the spine. Further studies regarding potential benefits are warranted to assess any added value of kyphoplasty compared with vertebroplasty.

Introduction

The incidence of vertebral compression fractures (VCFs) increases markedly with age and is one of the most common sequelae of osteoporosis, comprising almost half of all osteoporotic fractures in the US annually (1-3). Patients with VCFs often experience severe back pain that may limit mobility and subsequently increase mortality in an already vulnerable elderly population (1). Thus, multiple treatment modalities have been indicated including pain medication, medical osteoporosis treatment, physical therapy, bracing, and surgery. The surgical indications for vertebral augmentation procedures, such as kyphoplasty and vertebroplasty, have varied in the literature, but are most commonly reserved for fractures with significant local deformity and patients with pain refractory to conservative management (4,5).

Vertebroplasty procedures involve the percutaneous injection of bone cement into a fractured vertebra, with the intent of stabilizing the vertebral body thereby improving pain control. Unfortunately, vertebroplasty is unable to restore vertebral height and has been associated with retropulsion of cement into the canal in up to 67% of cases (6-9). Kyphoplasty, a subset of the vertebroplasty procedure, involves the inflation of a small balloon in the vertebral cavity and restoration of sagittal parameters in addition to stabilizing the fractured vertebra (10). Multiple retrospective and prospective trials demonstrating the efficacy of vertebroplasty or kyphoplasty compared to placebo and standard medical therapy have been published (11-13). However, the evidence in those trials was limited by a lack of true blinding with sham-surgery.

Osteoporosis and low bone mass affect >50 million people in the United States: Every other person older than 50 years of age has low bone mass or osteoporosis.1 The major sources of morbidity and community health care costs from osteoporosis are related to fractures. By 50 years of age, the remaining lifetime fracture risk is 1 in 2 for women and 1 in 5 for men.2 By 2025, >3 million osteoporotic fractures and $25 billion in related health care costs will occur in the United States.3 Of these, vertebral compression fractures (VCFs) will account for one-quarter of osteoporotic fractures.3

Some osteoporotic VCFs result in minimal or mild pain. Symptoms typically subside during 6–8 weeks as healing occurs. For such patients, medical management with analgesics or limiting activities/bed rest, back braces, and physical therapy or a combination of these are the mainstay of treatment. Patients with more severe pain seek medical attention or require hospitalization. Annually, >60,000 office visits and >70,000 admissions occur from osteoporotic VCFs in the United States.4,5 For these patients, medical management often involves bed rest. As few as 2 days of bed rest lead to bone mass loss6; by 1 week, the rate of bone loss is 50 times the normal age-related rate.7 After 10 days of bed rest, 15% of aerobic capacity and lower extremity strength is lost,8 equivalent to 10 years of age-related loss.8 Adding narcotic anesthesia and the associated adverse effects of sedation, nausea, and constipation further increases physical deconditioning and fall risk and prolongs recovery. After hospitalization, >50% require ongoing care4; chronic pain occurs in 40%.9 Thus, while medical management is widely used, there are significant negative effects.

Methods

Recent Prospective Randomized Controlled Data

During these early trials, there remained ongoing doubt regarding the influence of the placebo effect. The sham procedure trials were designed to minimize the placebo effect, but patients with acute, subacute, and chronic fractures causing both moderate and severe pain were enrolled. Moreover, there is now increased recognition of placebo, nocebo, and the concept of active control treatments (such as periosteal local anesthetic injection in the early RCTs) that contribute to success or failure of pain relief.32 In addition, clinicians performing vertebral augmentation recognized that older patients with severe pain from recent fracture, particularly those admitted to the hospital, may form a subgroup for which vertebroplasty may be of greater benefit. These patients have been included in the recent RCTs.

Patient selection and characteristics

Descriptive statistics were performed to compare variables. A two-sample student t-test was employed to analyze the difference in continuous variables and Chi-squared or Fisher’s exact test was employed for categorical variables. Findings were considered statistically significant when P<0.05. Analysis was conducted using IBM SPSS Statistics Version 24. The NIS database is de-identified and was therefore deemed exempt by our institutional review board. 

Results

An estimated 81,690 patients underwent vertebroplasty and 169,413 patients underwent kyphoplasty in the United States from 2006 to 2014. The annual total number of procedures for vertebroplasty and kyphoplasty fluctuated until 2009. Subsequently, the number of kyphoplasty cases continued to fluctuate, while vertebroplasty cases progressively declined for the next 5 years. The number of vertebroplasty procedures decreased 53% from 13,128 in 2008.

Discussion

The decreased functional status and severe back pain refractory to conservative management associated with some VCFs has led to the development surgical approaches such as vertebroplasty and kyphoplasty. Despite the differing approaches, the goals behind both treatment modalities are similar: alleviation of pain and prevention of further deformity (10,20). The purpose of the current study was to determine the trends in utilization and cost of these vertebral augmentation procedures over the recent decade.

The data from this study is consistent with previously published studies. Following the publication in 2009 of the two RCTs questioning the efficacy of vertebroplasty, a decline in both vertebroplasty and kyphoplasty procedures was observed. Sayari and colleagues demonstrated a 94.5% decrease in vertebral augmentation procedures performed in the Medicare dataset alone (20). Soon after the RCTs in 2009, results of the VERTOS II trial were published in 2010, demonstrating vertebroplasty as more effective than conservative therapy treatment of refractory pain following vertebral osteoporotic fractures (21). Despite these positive results, utilization of vertebroplasty procedures continued to decrease. Our analysis showed a 53% decrease in the use of vertebroplasty from its peak in 2008.

The decline in utilization of vertebral augmentation procedures was sustained until 2014 for vertebroplasty but interestingly changed direction from 2011 to 2014 for kyphoplasty (Figure 1). The emerging increase in kyphoplasty procedures may be the result of a majority of procedures performed by radiologists since 2012 (22). Though the efficacy of vertebroplasty was questioned in the 2009 studies in the New England Journal of Medicine, a study published in The Lancet in 2009 demonstrated the efficacy of kyphoplasty in alleviating pain in cancer patients with VCFs (23). As a result of these reports in the literature, physicians have gravitated towards kyphoplasty as the surgical treatment of choice for VCFs in recent years. Interestingly, a recent meta-analysis of trials between 2005 and 2014 failed to report significant difference between kyphoplasty and vertebroplasty (24).

Conclusions

Vertebral augmentation procedures continue to be vital surgical procedures for alleviating refractory pain in patients with VCFs. In this analysis of the NIS database, both kyphoplasty and vertebroplasty utilization have declined after the publication of highly regarded trials in 2009 failing to demonstrate efficacy of vertebroplasty procedures for pain relief in VCFs. Since 2011, kyphoplasty procedures have experienced an emerging increase in utilization. Our findings corroborate the trend of kyphoplasty and vertebroplasty in the current literature, which may be a direct consequence of the results of the 2009 trials and increasing radiologist involvement in these procedures. Further prospective randomized trials are necessary to more rigorously evaluate the long-term outcomes and cost-effectiveness of kyphoplasty versus vertebroplasty from a national healthcare perspective.

References

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