Selection of patients and clinical and imaging evaluation criteria:
This retrospective study was approved by the Medical Ethics Committee of Shandong Provincial Hospital and was conducted in accordance with the guidelines of the Declaration of Helsinki.Written informed consent was obtained from each patient.From February 2016 to May 2018, 30 cases of Kümmell’s disease with thoracolumbar kyphosis who underwent surgical treatment in our department were recruited into this study. Then,all patients were divided into two groups according to whether there were neurological deficits.And the imaging parameters and clinical evaluation indexes of patients before operation,after operation and at the last follow-up were collected and analysed.
Group A included 14 cases of kyphosis with neurological deficits,including 12 females and 2 males, with an average age of 66.8 ± 7.5 years.The mean T value of bone mineral density (BMD) was - 3.3 ± 1.4.As for the neurological function, according to the American Spinal Injury Association (ASIA) impairment scale,2 cases were classified as B,5 cases as C and 7 cases as D.
Group B included 16 cases of simple kyphosis, including 13 females and 3 males, with an average age of 64.3 ± 7.7 years;the mean T value of BMD was -3.6 ± 0.4.
Inclusion criteria
Group A:
1, Meet the diagnostic criteria for Kümmell’s disease, T value of BMD < - 2.5.
2, After conservative treatment for more than 3 months,refractory low back pain still exists.
3, Kyphosis appeared gradually,and it continued to progress.Neurological deficits appeared gradually and aggravated slowly with the progression of kyphosis.
4, Single segment kyphosis with neurological deficits was graded as B-D,according to ASIA impairment scale.
Group B:In line with the 1-2 criteria above,thoracolumbar kyphosis is associated with sagittal global/local parameter abnormalities or sagittal imbalance without neurological deficits.
Exclusion criteria
1. Kümmell’s disease without kyphosis.
2. Severe cardiovascular and cerebrovascular diseases;Diabetes mellitus and other contraindications.
3. Multiple segmental osteoporotic fractures.
4. Kümmell’s disease with old spinal fractures of other segment(s).
5. Patients with lumbar disc herniation,ankylosing spondylitis, spinal tuberculosis, lumbar spondylolisthesis and spinal tumors.
6. Patients who had undergone spinal surgery or vertebroplasty before.
Imaging evaluation parameters
SVA,Cobb angle,TK,TLK,LL,PI,PT,SS
Clinical evaluation indexes
ODI,NRS,ASIA grades and complications,such as infection, deep vein thrombosis(DVT) of lower limbs,cerebrospinal fluid (CSF) leakage,subsidence of internal implants,broken screws and rods,pseudoarthrosis and etc,were recorded. Since it was inconvenient to perform ODI and NRS assessment immediately after surgery,only preoperative assessment and final assessment were performed. Moreover, the recovery of neurological function was relatively slow, so the neurological function of preoperative and final assessment were performed.
Surgical procedure
Group A:Under general anesthesia and electrophysiological monitoring,the patient was prone on the operating bed.A posterior median incision was performed centering on the injured vertebra.Firstly,pedicle screws were placed in the two upper and two lower vertebrae with the injured vertebra as the center and each screw was strengthened with bone cement.If the injured vertebra was a thoracic vertebra,the proximal ends of bilateral ribs were removed for about 5cm then the spinous process and the lower 2/3 of the lamina of the upper vertebrae of the injured vertebra were excised.Next the spinous process and lamina of the injured vertebra were excised to expose the spinal canal,protecting the dura and nerve roots.And then the injured vertebra and its upper and lower intervertebral discs were excised.After that,a C-shaped cage made of polyetheretherketone of appropriate size was selected,and autologous bone grains were inserted and placed between the upper and lower end plates of adjacent vertebral bodies.Afterwards the two pre-bent connecting rods were installed,and the cantilever beam technology was used for orthopedic and pressurized locking.During the process of VCR, a temporary rod was used to maintain the spinal stability.Finally,after the drainage tube was placed in the incision,and the incision was closed with layer by layer sutures (Figure1).
Group B:After taking the same procedures of general anesthesia,electrophysiological monitoring as in group A,patients in group B were also exposed with a posterior midline incision.After that,pedicle screws were placed in the two upper and two lower vertebrae on the both sides of the intervertebral space which closed to the collapsed endplate of the injured vertebrae,and the screws were cemented too.Next,the bilateral inferior articular processes of the upper vertebra of the injured vertebra and the bilateral superior articular processes of the injured vertebra were resected.The lower 2/3 lamina of the upper vertebra and the upper 1/3 lamina of the injured vertebra were resected,and the ligamentum flavum was also resected.To protect the nerve roots of both sides,discectomy was performed from the lateral of the dura,and the intervertebral space was released thoroughly.Soon after the upper and lower endplates of the intervertebral space were removed,autologous bone granulation grafting in the intervertebral space was performed,and finally the kyphosis was corrected.After the drainage tube was placed in the incision,the incision was closed with layer by layer sutures too(Figure 2).
Postoperative attention should be paid to the prevention of infection and complications such as deep venous thrombosis of lower extremities.
The drainage tube was removed 3-5 days after the operation,and the patient got out of bed as soon as possible under the protection of braces.Support protection of the brace spanned 3 months.Patients in both groups were treated for osteoporosis according to the current consensus.
Statistical methods
Statistical software SPSS21.0 was used for statistical analysis of the above statistical data.The comparison of general data and postoperative and final imaging parameters between the two groups was performed by independent sample T test.One-way ANOVA was used to compare preoperative and postoperative imaging parameters and the last imaging parameters.Paired T test was used to compare ODI and NRS results in groups.Setting P<0.05 was statistically significant.