Outcome measurement for vertebral augmentation

Introduction

The prevalence of spine fractures in the United States was estimated to be 11% in people 70 to 79 years old and 18% in those over 80 years of age. With the increasing morbidity and diminished quality of life resulting from these fractures, percutaneous vertebral body augmentation procedures have become a favorable treatment option by many providers and interventionists. Vertebral augmentation is a minimally invasive procedure that involves the injection of polymethylmethacrylate (PMMA) into the vertebral body to internally stabilize it, leading to pain relief. As with any procedure, in order to improve the intervention or continue to recommend it, a measurement of outcomes should be a cornerstone.

Measuring outcomes aids in improving the efficacy and efficiency of a procedure. It allows utilization of the data as evidence for clinical decisions and selecting the best-fitted intervention for a patient. Furthermore, it promotes the adoption of best practices and creates an opportunity for further research. It is vital to recognize that defining pre- and post–Visual Analog Scale (VAS) pain scores may not be sufficient for outcome measurement and that other metrics, such as disability and quality of life changes, also need to be included. After all, the primary aim should be to improve the patient’s quality of life and well-being. Before considering vertebral augmentation, the careful selection of a patient, as discussed in Chapter 2 , is a critical step for the success and better outcomes of the procedure.

Outcome measurement components and tools

A careful history, pain score, and characterization of pain are prudent to obtain during the first patient encounter. In addition, a history of prior treatments, surgeries, their efficacy, personal medical history, and medications are a valuable addition to the decision-making process. There are multiple tools available to clinicians that can aid in assessing the patient’s pain, quality of life, physical limitations, and psychological impact of the disease. Some of the most commonly used instruments are summarized next, grouped by pain, disability, and quality of life.

1.

Visual Analog Scale (VAS)
- A.
  
  Publicly available scale.
- B.
  
  Measures pain intensity and is suitable for a broad range of ages.
- C.
  
  Scores are self-reported with a mark on a 10-cm line representing a continuum of “no pain” at the zero mark and “the worst pain” at the 10-cm mark.
- D.
  
  The scale can be downloaded from many sources online or made manually.
2.

Brief Pain Inventory (BPI)
- A.
  
  It is a proprietary questionnaire that assesses the severity of both malignant and nonmalignant pain and their impact on daily functions.
- B.
  
  This instrument measures seven domains: general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life. The scale ranges from 0 to 10.
- C.
  
  The form can be ordered from https://www..mdanderson.org/symptomresearch/index.cfm .
3.

McGill Pain Questionnaire
- A.
  
  A questionnaire that was developed by Dr. Melzack at McGill University in Montreal, Canada that helps describe the pain a patient is experiencing and translate it to a numerical score.
- B.
  
  The minimum score is 0 and the maximum score is 78. The higher the score, the more severe the pain.
- C.
  
  A publicly available version can be downloaded from the following link: https://www.sralab.org/sites/default/files/2017-07/McGill%20Pain%20Questionnaire%20%281%29.pdf .
4.

Roland-Morris Disability Questionnaire (RMDQ)
- A.
  
  Publicly available
- B.
  
  It measures disability consisting of a total of 24 items that can be marked or not. Every item that is not marked is counted as zero. The higher scores represent a higher level of disability.
- C.
  
  A change of 2 to 3 points from the baseline is considered significant.
- D.
  
  The form can be downloaded for free from http://www.rmdq.org/Download.htm .
5.

Oswestry Disability Index (ODI)
- A.
  
  It is used to assess pain-related disability with low back pain (most commonly in patients with severe symptoms).
- B.
  
  Two versions of the ODI questionnaire are available. The original version 1.0 has been adopted by the American Academy of Orthopaedic Surgeons (AAOS) whereas Version 2.0 has been more widely used in the United Kingdom.
- C.
  
  Each question has a possible 5 points with a total score of 50, which is interpreted as completely disabled.
- D.
  
  Version 1.0 can be downloaded from https://aaos.org/globalassets/quality-and-practice-resources/patient-reported-outcome-measures/spine/oswestry-2.pdf .
6.

Short Form 36 Health Survey Questionnaire (SF-36)
- A.
  
  The most widely used tool that measures the health status and the quality of life.
- B.
  
  The scale provides a measure of the physical and mental components of health. It reflects eight domains of health: physical function, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, general mental health, social functioning, energy/fatigue or vitality, and general health perceptions.
- C.
  
  A licensed revised version can be found from Optum Incorporated ( https://cdn-aem.optum.com/content/dam/optum/resources/Manual%20Excerpts/SF-36v2_Manual_Chapter_1.pdf ) and a publicly available version of the SF-36 with scoring instructions can be downloaded from the following link: https://www.rand.org/health-care/surveys_tools/mos/36-item-short-form/scoring.html .
7.

Karnofsky Performance Status (KPS) Scale
- A.
  
  This is a frequently used scale for quantifying the functional status of cancer patients.
- B.
  
  The scale goes from 0 (dead) to 100 (normal without evidence of disease).
- C.
  
  A publicly available version can be downloaded from http://www.npcrc.org/files/news/karnofsky_performance_scale.pdf .
8.

EuroQoL-5 (EQ5D)
- A.
  
  It is a fee-based tool to assess a patient’s quality of life.
- B.
  
  The 5L version assesses five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has three levels: no problems, moderate problems, severe problems. A summary index with a maximum score of 1 indicates the best health state.
- C.
  
  The fee-based version can be downloaded from https://euroqol.org/support/how-to-obtain-eq-5d/ .
9.

Quality of Life for Osteoporosis (QUALEFFO-41)
- A.
  
  Publicly available questionnaire to assess the quality of life in patients with osteoporosis.
- B.
  
  The survey consists of seven domains: pain, activities of daily living, jobs around the house, mobility, leisure and social activities, general health perception, and mental function.
- C.
  
  A scoring algorithm can be found from https://www.osteoporosis.foundation/sites/iofbonehealth/files/2020-01/Qualeffo-Scoring-Algorithm.pdf .
- D.
  
  The free version can be downloaded from https://www.osteoporosis.foundation/health-professionals/research-tools/quality-life-questionnaires .
10.

Tokuhashi Score
- A.
  
  Used for preoperative evaluation of a patient’s prognosis with a metastatic spinal tumor. A revised score from 2017 has been shown to have an improved prognostic ability. ^,
- B.
  
  The tool consists of five domains: general condition (based on Karnofsky Performance Status Scale), number of metastases in the vertebral body, metastases to the major internal organs, the primary site of the cancer, and state of paralysis. A score of 0 to 5 represents < 6 months’ mean survival period, 6 to 8 more than 6 months, and 9 to 12 more than 12 months.
- C.
  
  Some studies recommend vertebroplasty for a score of 4 or less.
- D.
  
  A publicly available version can be found from the following link: https://link.springer.com/article/10.1007/s00432-017-2519-y/tables/4 .

In order for the outcomes to be relevant, a vertebral augmentation intervention must be deemed successful. A technical and procedural success can be defined as appropriate vertebral height change ; absence of inadequately filled fractures ; cement reaching the posterior fourth of the vertebral body ; absence of an epidural, foraminal, or venous leakage ; an absence of any immediate postprocedural complications, such as infection, cord compression, or hemodynamic instability, including cardiac perforation, allergic reactions, and pulmonary embolism.

Patients who have undergone successful invasive treatment interventions are followed up closely to monitor their response to therapy. The timing of follow-up is not clearly defined, but several studies implemented 1 to 2 weeks for short-term and 12 to 24 months for long-term follow up. The follow-up includes assessing the ability to resume and maintain activities of daily living such as self-care, housework, family and leisure activities, improvement in anxiety and depression scores, and adverse events. ^, In addition, measurement of postprocedure VAS score and, equally important, physical and quality of life improvement, may be necessary to determine whether the intervention was efficacious when compared with preintervention baseline scores. It would also be helpful to collect information through imaging on the subsequent or adjacent vertebral fracture or re-fractures at the treated level. ^, ^, In summary, during the initial patient encounter, obtaining a thorough history that includes prior interventions and their efficacy, updated imaging for characterization of the vertebral deformities, and answers to the pain, quality-of-life and disability questionnaires is key to starting a patient on a path to freedom from the debilitating effects of osteoporotic vertebral fractures. Moreover, it is important to recognize that there is no single instrument that can be utilized to evaluate results following an osteoporotic vertebral fracture intervention. A combination of surveys building an overall health assessment picture is the recommended approach.