2. Vertebral Fracture: Associated Conditions Diagnosis of osteoporosis Glucocorticoid therapy (≥ 7.5 mg prednisolone) Postmenopausal women > age 55 Loss of 2 or more inches in height Prominent thoracic kyphosis Low BMD Ismail AA et al. Osteoporos Int . 1999;9:206–213.
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4. Radiologic Assessment 8 weeks post fracture First week post fracture Courtesy of B. Boszczyk & R. Bierschnieder, BG Unfallklinik, Dept. of Neurosurgery, Murnau, Germany MRI: T2 Image
16. Case Study 19 o 3 o 15mm 28mm Patient: 91 YO Female Diagnosis: Primary osteoporosis Fracture Reduced: L-1, 4 months old Courtesy of Alexander Hadjipavlou, M.D., Crete, Greece
17. Case Study Patient: 78 YO Female Diagnosis: Primary osteoporosis Fracture Reduced: L-1 & L-2 6 weeks old Courtesy of Frank Phillips, MD, Chicago, IL (L3 Treated 6 Wks Prior) L1-L2 Height Restoration
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19. Example: Percent Lost Height Restored % Lost Height Restored = (24 – 20) / (30 - 20) or 4/10 = 40% 20 mm 24 mm Avg. 30 mm
20. Percent Lost Height Restored Kyphon U.S. Study. Data on file at Kyphon Inc. Theodorou et al (2002) J Clin Imaging 26:1-5 Lieberman et al (2001) Spine 26: 2, 1631-1638 NR = Not Reported Study Vertebral Body Site Mean Fracture Age (mos.) % Lost vertebral Body Height Restored All Fractures Reducible Fractures % N % N U.S. Study Midline 4.3 30.2 65 58 47 Lieberman (2001) Midline 5.9 35 70 47 49 Theodorou (2002) Midline 3.2 66 24 NR NR Theodorou (2002) Anterior 3.2 52 24 NR NR
21. Case Study: Correction of Angular Deformity Kyphosis = 25 º Kyphosis = 10 º Kyphosis = 16 º Immediate post- fracture Post-kyphoplasty Post-fracture + 4 days Lieberman et al. (2001) Spine 26: 2, 1631-1638
A lateral spine X-ray examination is a method that can be used to screen for the presence of vertebral compression fractures. STIR sequence MRI can be useful to determine index and/or plain radiograph culprit.
Some fractures may collapse acutely while others collapse progressively over time.
The location of VCFs correspond to the most mechanically compromised regions of the spine are most commonly located at the midthoracic region (T7–T8) and the thoracolumbar junction (T12–L1). In the midthoracic region , thoracic kyphosis is most pronounced and loading (stress) during flexion is increased. At the thoracolumbar junction , the relatively rigid thoracic spine connects to the more freely mobile lumbar segments.
Wedge fractures are the most common type of vertebral fracture.
Left untreated, one VCF may lead to subsequent fracture, resulting in kyphosis. Kyphosis compresses the chest and abdominal cavity with the following potential consequences: Chronic, debilitating pain Decreased lung function (FVC, FEV1) Impaired physical function Early satiety and risk of malnutrition due to a compressed abdomen Sleep disorders Significantly decreased Activities of Daily Living (ADL) Increased dependence on family members and friends Clinical anxiety and/or depression A 23% increase in mortality rate in women over the age of 65 with prevalent fracture. Ignoring vertebral fracture causes a vicious downward spiral of physical, social, and psychological consequences, resulting in increased mortality for those afflicted.
Left untreated, vertebral compression fractures have demonstrated physical, functional, and psychological consequences that dramatically impact quality of life.
Reduction of pulmonary function is significantly correlated with severity of spinal deformation due to osteoporotic VCF .
The number of prevalent fractures is a predictor of subsequent fracture risk. After first VCF, risk of subsequent VCF is increased 5-fold after first VCF, 12-fold after 2 or more VCFs, and 75-fold after 2 or more VCFs and low bone mass (below the 33 rd percentile)
It is well known that the use of oral glucocorticoids or corticosteroids can increase the risk of fracture.
The Study of Osteoporotic Fractures (SOF) is an ongoing US multi-center observational study of osteoporosis that was initiated in 1989. It is sponsored by the US National Institute of Aging, National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health. The study has enrolled nearly 10,000 women aged 65 years or older at four clinical centers. Over 100 publications have been based on SOF since 1989.
Balloon kyphoplasty is a minimally invasive option which addresses both the deformity and pain by stabilizing the fracture and helping to correct the vertebral body deformity.
Kyphoplasty can be performed under local anesthesia, often supplemented with conscious sedation, or under a general anesthesia. In both cases, the choice of anesthesia is based on the patient’s general medical condition, as well as, the treating physician’s and patient’s preferences. Most kyphoplasty procedures are performed under general anesthesia. The Kyphon U.S. single-arm prospective study supports a low rate of anesthesia-related complications in kyphoplasty. In 155 prospectively enrolled patients who received kyphoplasty, there was only 1 complication that could be related to anesthesia, an intra-operative episode of PSVT (although the patient had a history of PVST). On average, both procedures require 1 hour or less of anesthesia per level treated, limiting the risk of anesthesia exposure. (Komp 2004, Ortiz 2002, Theodorou 2002).
A vertebral body should be 30 mm at the midline but measures 20 mm at the midline due to the fracture. After kyphoplasty, the midline measurement is 24 mm. (Post KP height – Pre KP height) / (pre-fx height – pre KP height) = % of lost height restored.
In the prospective multicenter U.S. study, among measurable fractures (n=65), average midline height restored for all fractures was 30.2%, while among the fractures that were reducible, average midline height restored was 58%. There was no evidence of loss of improvement at two year follow-up. Mean fracture age before balloon kyphoplasty was 4.3 months.(12) Lieberman et al. (2001) reported that among 70 fractures prospectively treated, 70% were reducible*. Average lost midline height restoration for all fractures was 35%, while among the group of fractures that were reducible, average lost midline height restoration was 47%. Mean fracture age before balloon kyphoplasty was 5.9 months.(15) Theodorou et al. (2002) reported that, among 24 fractures treated, average lost anterior height restored was 52%, average lost midline height restored was 66% and average lost posterior height restored was 53%. Mean fracture age before balloon kyphoplasty was 3.2 months.(26)+
This case study demonstrates an improvement in angular deformity post kyphoplasty. Also noted radiographically is fracture progression over time before treatment with balloon kyphoplasty.
Following Balloon Kyphoplasty, patients report significant pain reduction at short-term follow-up, sometimes within hours of the procedure. In a retrospective analysis, patients discontinued use of narcotics for fracture-related pain, changing to over-the-counter analgesics post operatively.
In the prospective multicenter U.S. study, there was an average of 60% reduction in pain (pre-operative VAS score = 7.5, 7 days post-op VAS = 3, p<0.01) at one week follow-up. Results persisted for two years (n=100). Ledlie et al. (2002) reported similar results, with a continuation in improvement at one year. Coumans et al. (2003) prospectively followed 78 consecutive patients for 12 to 18 months and reported substantial improvement (p<0.001) in bodily pain as measured by SF-36. These results were not different at three month follow-up.
In a retrospective analysis following 79 patients treated (Ledlie et al., 2002), 80% of all patients were fully ambulatory at one week follow-up. 27 of the patients followed one year maintained full ambulatory status. 90% of patients (10 out of 12) who were wheelchair-bound pre-operatively were ambulatory at one week follow-up.
Komp et al reported on the only published concurrently controlled, prospective study regarding long-term outcomes after balloon kyphoplasty for osteoporosis-related VCFs. Twenty-one patients underwent balloon kyphoplasty and 19 underwent conservative treatment. Patient populations were similar in age, gender, fracture history, and other risk factors. After six months, 7 out of 19 evaluable balloon kyphoplasty patients had new fractures (37%), whereas 11 out of 17 conservatively-treated patients (67%) had new fractures.
As with any surgical procedure, there are risks associated with balloon kyphoplasty. In the prospective, multicenter, single arm U.S. study involving 214 fractures with 155 patients enrolled, there were no serious procedure-related adverse events. One patient, with a know history, experienced an intraoperative episode of an arrhythmia, PSVT, that could be related to anesthesia.
The overall procedure-related complication rate for balloon kyphoplasty-treated patients was 0.89% versus 5.44% for vertebroplasty (p=0.0009). The overall procedure-related complication rate for balloon kyphoplasty in the treatment of VCFs due to osteoporosis (n=805) is statistically significantly lower than the same rate for vertebroplasty in the treatment of VCFs due to osteoporosis (n=1148) (0.99% for kyphoplasty vs. 4.44% for vertebroplasty, p=0.0320). The overall procedure-related complication rate for balloon kyphoplasty in the treatment of VCFs due to cancer (n=92) is statistically significantly lower than the same rate for vertebroplasty in the treatment of VCFs due to cancer (n=303) (0.00% for kyphoplasty vs. 9.24% for vertebroplasty, p=0.0018).
The Bone Cement Procedure-Related Complication Rate for kyphoplasty was 0.22% versus 3.07% for vertebroplasty (p=0.0008). Procedure-related complications that were clearly or potentially related to bone cement were tabulated. Asymptomatic cement extravasations were not included as complications. Although the non-bone cement procedure-related complication rate for total balloon kyphoplasty-treated patients (osteoporosis and cancer combined) (n=897) was less than that for total vertebroplasty-treated patients (n=2408), the difference is not statistically significant (0.22% for kyphoplasty vs. 3.07% for vertebroplasty, p=0.1054). These results are further supported by Kyphon’s U.S. multicenter prospective single arm study involving 214 fractures treated with balloon kyphoplasty in 155 patients —there were no bone cement or other device-related adverse events (data are currently on file at Kyphon and are in preparation for publication.).
The combination of compaction of cancellous bone, cavity creation, and controlled cement delivery suggest the difference in adverse events caused by cement extravasation. Compaction of Cancellous Bone: The KyphX® Inflatable Bone Tamp is designed to correct vertebral body deformity by elevating the vertebral endplates toward their pre-fracture position. In an attempt to achieve an “en masse” fracture reduction, the procedure is performed bilaterally, using two balloons. Balloon inflation compacts the cancellous bone is, disrupts internal venous pathways and fills fracture lines, reducing leak pathways. Cavity Creation and Controlled Delivery: Once the fracture has been reduced, both balloons are deflated and removed, leaving behind an intervertebral cavity. This cavity allows for the delivery of doughy bone cement (KyphX® HV-R™) under low pressure and fine manual control. The creation of a specific space with a known volume also defines the location and amount of bone cement required, thus avoiding the need to use a pressurized device for cement delivery.
In the Kyphon U.S. study, patients were asked how satisfied they were with the outcomes of their kyphoplasty procedure on a scale of 1-20, where 1 was completely dissatisfied and 20 was completely satisfied. The mean score at one week post-operative was 17.9, and the mean score did not significantly differ at any point post-operative out to two years (N=100 patients).
Balloon kyphoplasty is an excellent option associated with a low complication rate for patients suffering from painful vertebral compression fractures due to primary and secondary osteoporosis. By achieving fracture stabilization and correction of spinal deformity, patients experience significant reduction in pain and improvement in mobility, thus reducing the number of days in bed and increasing overall quality of life.