Balloon kyphoplasty for the treatment of pathological vertebral compressive fractures

Abstract

Background: Previous clinical studies have shown the safety and effectiveness of balloon kyphoplasty in the treatment of pathological vertebral compression fractures (VCFs). However, they have not dealt with the impact of relatively common comorbid conditions in this age group, such as spinal stenosis, and they have not explicitly addressed the use of imaging as a prognostic indicator for the restoration of vertebral body height. Neither have these studies dealt with management and technical problems related to surgery, nor the effectiveness of bone biopsy during the same surgical procedure. This is a prospective study comparing preoperative and postoperative vertebral body heights, kyphotic deformities, pain intensity (using visual analogue scale) and quality of life (Oswestry disability questionnaire) in patients with osteoporotic vertebral compression fractures (OVCFs) and osteolytic vertebral tumors treated with balloon kyphoplasty.

Methods: Thirty-two consecutive patients, 27 OVCFs (49 vertebral bodies [VBs]) and 5 patients suffering from VB tumor (12 VBs) were treated by balloon kyphoplasty. The mean age was 68.2 years. All patients were assessed within the first week of surgery, and then followed up after one, three and six months; all patients (27 OVCFs and 5 tumor patients) were followed up for 12 months, 17 patients (14 OVCFs and 3 tumors) were followed up for 18 months and 9 patients (8 OVCFs and 1 tumor) were followed up for 24 months (mean follow up 18 months). The correction of kyphosis and vertebral heights were measured by comparing preoperative and postoperative radiographic measurements.

Results: Thirty-one patients (96.9%) exhibited significant and immediate pain improvement: 90% responded within 24 h and 6.3% responded within 5 days. Daily activities improved by 53% on the Oswestry scale. In the OVCF group, kyphosis correction was achieved in 24/27 patients (89.6%) with a mean correction of 7.6 degrees . Anterior wall height was restored in 43/49 VBs (88%) (mean increment of 4.3 mm), and mid vertebral body height was restored in 45/49 VBs (92%) (mean increment of 4.8 mm). Edema (high intensity signal) on short tau inversion recovery (STIR) was evidenced in all OVCF patients who experienced symptoms for less than nine months and was associated with correction of deformity. Cement leakage was the only technical problem encountered; it occurred in 5/49 VBs (10.2%) of the osteoporotic group and 1/12 VBs (8.3%) of the tumor group but had no clinical consequences. The incidence of leakage to the anterior epidural space was 2%. Spinal stenosis was present in three patients (11.1%) who responded successfully to subsequent laminectomy. Retrieval of tissue samples for biopsy was successful in 10/15 cases (67%). New fractures occurred in the adjacent level in 2/27 OVCF patients (7.4%).

Conclusions: Associated spinal stenosis with OVCF should not be overlooked; STIR MRI is a good predictor of deformity correction with balloon kyphoplasty. The prevalence of a new OVCF in the adjacent level is low.

Fig. 1a,b

Vertebral bodies distribution treated by balloon kyphoplasty. a OVCF group; b tumor group

Fig. 2a–c

A 62-year-old woman who suffered from severe back pain demonstrating a high intensity signal on L1 and L4 VBs. a Both regions were tender to point pressure over the spinal processes. b Radionuclide uptake was marked on the L1 vertebra and questionably present on the L4 vertebra. c STIR MRI showed a high signal intensity suggestive of edema due to micro-fractures. Both levels were successfully treated by means of balloon kyphoplasty

Fig. 3a–c

66-year-old female patient with a nine month history of back pain after lifting a grocery bag while shopping . a STIR MRI revealed a high intensity signal in the T12 collapsed vertebra, which was the only vertebra tender to point pressure over the spinal process. This finding is highly suggestive of a non-healed fracture (pseudarthrosis). Note that L1, L2, L3 and L5 vertebrae have also sustained OVCFs that have healed—spinal alignment is compromised. Note on plain X-rays improvement of vertebral height after kyphoplasty nine months after the onset of symptoms. b Preoperative X-ray. c Postoperative X-ray

Fig. 4a–d

Superior wedge OVCF with a kyphotic deformity of 24.2°. a Expanding bone tamp. b–d Restoration of vertebral height and significant correction of kyphosis (9.9°) by balloon expansion

Fig. 5

Mean restoration of vertebral body height after balloon kyphoplasty. The reduction of the mid wall was 0.48 mm greater than the anterior wall ( p =0.001)

Fig. 6a–b

Lateral radiograph demonstrating correction of kyphotic deformity. a Preoperative X-ray; b post balloon kyphoplasty restoration of vertebral body height

Fig. 7

Kyphosis correction after balloon kyphoplasty by a mean of 7.9° ( p =0.001)

Fig. 8a–e

A 91-year-old man with incapacitating back pain that confined him to bed for four months. He was admitted to the hospital with the tentative diagnosis of metastatic tumor. a A lateral radiograph demonstrated a collapsed L1 vertebra. b STIR MRI was suggestive of an OVCF at L1 and L4 vertebrae. Tenderness to point pressure was present over both L1 and L4 spinal processes. The patient underwent a successful balloon kyphoplasty as seen on c lateral X-ray images; d axial view images; e lateral reformatted CT scan images

Fig. 9

Mean improvement of back pain as rated on VAS before balloon kyphoplasty (8.5 cm), and one week (2.5 cm) and one month (1.5 cm) after balloon kyphoplasty ( p =0.001)

Fig. 10

VCF disability showed marked improvement of functions after balloon kyphoplasty as rated on the Oswestry disability questionnaire at one month after surgery

Fig. 11 a

Lateral wall burst fracture from the expanding balloon. b Egg shell cementoplasty as proposed by Lieberman. A shell of cement can be seen around the expanding balloon