|Year : 2019 | Volume
| Issue : 1 | Page : 44-48
Assessment of spinal arthrodesis in dorsolumbar spine trauma using hydroxyapatite, tricalcium phosphate, and 60% hydroxyapatite + 40% tricalcium phosphate: A comparative study
Sumanta Pal1, Kiran Kumar Mukhopadhyay2, Anant Kumar Garg2, Sanjay Kumar2, Pradip Mukherjee3
1 Department of Orthopaedic Surgery, Burdwan Medical College Hospital, Burdwan, West Bengal, India
2 Department of Orthopaedic Surgery, Nil Ratan Sircar Medical College and Hospital, Kolkata, West Bengal, India
3 Department of Endocrinology, IPGMER, Kolkata, West Bengal, India
|Date of Web Publication||19-Aug-2019|
Dr. Kiran Kumar Mukhopadhyay
Department of Orthopaedic Surgery, Nil Ratan Sircar Medical College and Hospital, 138 A.J.C. Bose Road, Kolkata - 700 014, West Bengal
Source of Support: None, Conflict of Interest: None
Study Design: Open level experimental design. Purpose: Ceramics are effective, safe, and good alternatives of iliac crest autograft for spinal fusion. There were not enough study available to compare among ceramics for fusion in spinal surgery. Our aim was comparative assessment of posterolateral spinal arthrodesis radiologically and clinically in dorsolumbar spine trauma using hydroxyapatite (HA), tricalcium phosphate (TCP), and 60% HA + 40% TCP. Overview of Literature: Surgical management of thoracolumbar spine injury has encouraged early rehabilitation and avoided adverse effects of prolonged recumbency. Instrumentation enhanced spinal fusion which was the main technique of spinal stabilization. Although iliac crest autograft is the gold standard for spinal fusion,the procedure is not devoid of major and minor complications. A variety of ceramics are available as good alternatives for spinal arthrodesis. There are not any studies in the literature comparing spinal fusion rate among commonly used ceramics. Materials and Methods: Patients having Thoraco Lumbar Injury Classification and Severity score ≥4 underwent pedicle screw fixation and decompression (if required). We applied chips of HA, TCP, or 60% HA + 40% TCP for fusion. At 12-month follow-up, computed tomography scan of involved spine was done to assess posterolateral fusion by Lenke classification. Clinical follow-up was done evaluating pain status (visual analog scale). Mean follow-up duration was 27.8 months. Radiological and clinical parameters were compared among three groups. Results: A total of 45 patients (16 received HA, 15 received TCP, and 14 received [60%HA + 40%TCP]) were analyzed. About 28.88% of total patients had Lenke Grade A fusion and 51.11% had Grade B, but no statistically significant difference (P = 0.09) among three groups. Although reduction of pain score occurred individually in all three groups,no significant difference (P = 0.3)was noted among three groups. Conclusions: There was no statistically significant difference in fusion rate and change in pain perception with applied ceramics (HA/TCP/[60%HA + 40%TCP]).
Keywords: Ceramics, dorsolumbar spine injury, hydroxyapatite, posterolateral fusion, tricalcium phosphate
|How to cite this article:|
Pal S, Mukhopadhyay KK, Garg AK, Kumar S, Mukherjee P. Assessment of spinal arthrodesis in dorsolumbar spine trauma using hydroxyapatite, tricalcium phosphate, and 60% hydroxyapatite + 40% tricalcium phosphate: A comparative study. J Orthop Traumatol Rehabil 2019;11:44-8
|How to cite this URL:|
Pal S, Mukhopadhyay KK, Garg AK, Kumar S, Mukherjee P. Assessment of spinal arthrodesis in dorsolumbar spine trauma using hydroxyapatite, tricalcium phosphate, and 60% hydroxyapatite + 40% tricalcium phosphate: A comparative study. J Orthop Traumatol Rehabil [serial online] 2019 [cited 2019 Sep 15];11:44-8. Available from: http://www.jotr.in/text.asp?2019/11/1/44/264714
| Introduction|| |
The goals of the management of dorsolumbar fracture are to make a stable, painless, and balanced spinal column with fusion of minimum number of vertebrae. The gold standard for spinal fusion is iliac crest autograft but is associated with donor site morbidity such as persistent pain, hypoesthesia, abdominal hernia, and complications such as local infection, neurovascular injury, and ilium fracture. The use of bone substitutes is currently emerging to overcome the problems of inadequate source of autograft and the associated complications. Ceramics are used often nowadays for spinal fusion; but, in the literature, not much studies are available to compare among themselves. The aim of the present study was comparative assessment of posterolateral spinal fusion in unstable dorsolumbar spine trauma radiologically and clinically using ceramic-based bone substitutes – hydroxyapatite (HA), tricalcium phosphate (TCP), and 60% HA + 40% TCP.
| Materials and Methods|| |
This prospective experimental open level study was approved by our institutional ethical committee. From June 2014 to October 2016, patients who met the inclusion criteria were enrolled and included in any one of the three groups by computerized random number generation. We included patients of 15–65 years of age and Thoraco Lumbar Injury Classification and Severity (TLICS) score ≥4. The criteria for exclusion were patients with preexisting neurological disorder, tumor, and infections of spine.
Patients who sustained thoracolumbar spine trauma were admitted either through OPD or emergency of orthopedics department. After resuscitation, neurological evaluation was done by American Spinal Injury Association (ASIA) grade. Radiological evaluations (X-ray, computed tomography [CT] scan, and magnetic resonance imaging [MRI] of spine) were done to determine the exact location and severity of injury. Operative stabilization was planned [Figure 1]. Through posterior midline incision after pedicle screw fixation, decompression was done if neurodeficit was detected preoperatively. Thereafter, posterolateral fusion was done using chips (10 cc for fusion of 3 vertebrae and 15 cc for 4–5 vertebrae) of any one of the three bone substitutes – HA, TCP, or combination (60% HA + 40% TCP). The patients were explained during the preoperative phase about the alternatives and the comparable safety profiles for all the options. The process of random allocation was explained, and only those who provided written consent were included in the study. The three modalities were allocated using random number table. The only difference in patient management was the bone graft substitute used, and rest of the operative and postoperative management were standardized by following the usual protocol for such cases. Wound was closed after applying drain. All the operations were done by two experienced surgeon. Drain was removed after 72 h, dressing was done, and patients were asked to ambulate with support-wearing thoracolumbosacral orthoses till 10–12 weeks. They were followed up clinically and radiologically (X-ray) at 3-month interval for 1 year. Helical CT scan of involved spinal segment was advised at 1-year follow-up and evaluated for posterolateral fusion by Lenke, classification [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d, [Figure 2]e, [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3]d, [Figure 3]e and [Figure 4]a, [Figure 4]b, [Figure 4]c, [Figure 4]d, [Figure 4]e. Grade A and B indicate fusion and Grade C and D indicate no fusion. Radiological assessments were done by 2 radiologists independently. Thereafter clinically followed up at 6-month intervals. Clinical parameter observed during follow-ups was pain status by visual analog scale (VAS). The primary focus was to analyze the CT scan-guided Lenke classification for fusion assessment during the follow-up. These parameters were compared among three groups using SPSS 21 software (IBM 2015, Armonk, NewYork, USA).
|Figure 2: A 17-year-old male had history of fall from height and admitted with American Spinal Injury Association Grade D, (a) magnetic resonance imaging findings of the patient showing fracture L1 and L2 with retropulsed bony fragments, (b) computed tomography scan picture of burst fracture L1 and L2, (c) intraoperative picture of application of tricalcium phosphate chips for posterolateral fusion after pedicle screw fixation, (d) early postoperative X-ray showing good alignment of vertebral column, (e) computed tomography scan finding at 12-month postoperative showed solid posterolateral fusion of Lenke Grade A|
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|Figure 3: A 45-year-old male admitted with incomplete burst fracture L1 with American Spinal Injury Association Grade C, (a) X-ray picture of the patient showing fractured body of L1, (b) T1 magnetic resonance imaging of the patient showing fractured L1 vertebrae with signal changes over the cord, (c) computed tomography scan delineation of the fractured L1 vertebrae, (d) direct decompression at L1 level following pedicle screw fixation, (e) helical computed tomography scan at 12-month follow-up showed solid posterolateral fusion of Lenke Grade A (hydroxyapatite chips were used for fusion)|
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|Figure 4: A 35-year-old male patient sustained compression fracture D 12 following fall from height, (a) X-ray picture of the patient showing compression fracture D12, (b) T1 magnetic resonance imaging showing the fractured vertebrae and the cord, (c) computed tomography scan picture of the fractured D12 vertebrae, (d) after pedicle screw fixation, chips of 60% hydroxyapatite + 40% tricalcium phosphate applied for posterolateral fusion, (e) helical computed tomography scan at 12-month postoperation showed Lenke Grade B posterolateral fusion|
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| Results|| |
A total of 45 patients with unstable dorsolumbar spine injury were included in the present study. Mean age of patients was 33.43 years, and mean injury to operation interval was 15.5 days. We used HA in 16 patients, TCP in 15 patients, and 60% HA + 40% TCP in 14 patients for posterolateral fusion. Patients were followed up with a mean follow-up duration of 27.8 months. Fusion was assessed at 12-month postoperatively by helical CT scan and graded by method of Lenke et al., [Table 1]. Overall, 28.88% patients had Grade A fusion and 51.11% had Grade B. Hence, radiologically, posterolateral fusion was noted in 80% (28.88% +51.11%) of cases and no fusion was detected in rest 20% of cases; but, there was no statistically significant difference of fusion with applied bone substitutes of three types (P = 0.09) [Table 2]. Pain perception (by VAS) was compared between preoperative state and last follow-up (>18 months). Although significant pain reduction occurred in all the three groups, the improvement of pain status by VAS was not statistically related (P = 0.3) with applied bone substitutes [Table 3].
|Table 2: Comparative assessment of posterolateral fusion (By Lenke classification) at 12 months follow up using HA, TCP & (60%HA+40%TCP).|
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| Discussion|| |
Injury to dorsolumbar spine is not associated with high mortality but causes severe morbidity and financial burden to the family. TLICS Score is new classification system for thoracolumbar fractures; this was devised by the Spine Trauma Study Group. It has been validated, and it not only showed good reliability but also recommended a guideline for whether surgical management is needed. Operative intervention was planned to provide immediate stability to the spine, to correct deformities, and to improve neurology by relieving any residual impingement on the spinal cord. Thus, surgical techniques have the potential to improve clinical outcomes, encourage early rehabilitation, and avoid adverse effects of nonoperative treatment. In our study, injury to operation interval was between 6 and 54 days with a mean interval of 15.5 days. Bellabarba et al. demonstrated improved results with early treatment (<72 h) of thoracic and lumbar spine injury. As it is a tertiary center, most of the patients were referred from other hospitals, and admission in our hospital from injury was late. For thoracolumbar injuries, posterior operative approaches were commonly used for restoring alignment, relieving compression over neural elements, and making a solid arthrodesis of the vertebral column. The posterior direct decompression was used as one of the treatments for lower thoracic and lumbar fractures combined with neurodeficit. Spinal fusion was the main technique of stabilization of spine. Chou et al. in their study concluded that posterior fusion need not be a routine procedure for surgically treated thoracolumbar burst fractures. However, the majority of authors were in favor of arthrodesis in unstable fractures of dorsolumbar spine, and they used autogenous iliac crest bone most of the times. A study conducted by Arrington et al. showed that iliac crest bone graft harvesting was associated with minor complications (such as hematoma formation, localized infection, and seroma formation) in 10% of cases and major complications (such as abdominal hernia, neurovascular injury, and iliac wing fractures) in 5.8% of cases. Ceramics bone substitutes are the best alternatives of iliac crest bone graft for safeness, effectiveness, and cost. Polycrystalline ceramics are made from calcium phosphate biomaterials fused by high temperature sintering. A variety of ceramics have been evaluated, most of which are composed of either HA (Ca10(PO4)6(OH)2) or TCP. HA is crystalline form of TCP. We compared posterolateral fusion rate among HA, TCP, and 60% HA + 40% TCP. Instrumentation maintained spinal stability and facilitated process of fusion. In our study, radiological fusion was assessed by thin slice helical CT scan at 12-month follow-up. Dynamic lateral flexion and extension radiographic views are useful for detecting the progression of an arthrodesis. Those films have significant intra- and inter-observer variation. Although CT images overestimate the extent of fusion, it accurately identify the presence of a fusion in 83% of cases. Analysis of posterolateral fusion was done by Lenke classification,, where Grade A and Grade B indicate solid fusion with stability and Grade D and Grade C indicate pseudoarthrosis. In our study, 28.88% had Grade-A fusion and 51.11% had Grade-B fusion, whereas 20% of patients had pseudoarthrosis. Boden and Rothman in their studies showed that the incidence of pseudoarthrosis ranges from 5% to 34% in large adult series., Ceramic blocks have been evaluated in anterior cervical fusion of a goat model and showed 50% to 70% fusion rate. In our study, there was no statistically significant difference of fusion among those three bone substitutes. Dai and Jiang compared beta TCP versus autograft in patients having single-level instrumented posterolateral fusion and found similar clinical outcomes and fusion rates and suggested that beta-TCP as bone graft substitute may eliminate the need for harvesting bone graft from the ilium. Study done by Sanjay Bansal and Vijendra Chauhan to evaluate HA and TCP mixed with bone marrow aspirate as a bone graft substitute for posterolateral spinal fusion showed that HA and beta-TCP mixed with bone marrow aspirate seemed to be a promising alternative to conventional autologous iliac crest bone graft. After intensive search, we did not find any study comparing fusion rates among ceramics.
It was found that 80% of patients had mild pain and rest 20% had moderate pain during last follow-up (>18 months). Moderate pain was noted in those patients who had pseudoarthrosis. Significant pain improvement occurred in most of the patients of all three groups, but no statistical difference of pain improvement were detected (P = 0.3) among the three groups. The drawbacks of our study were delay in surgery and short follow-up period.
In our study, we found 3 (6.66%) patients having pressure sore over sacrum, one of them required flap coverage. Wound infection occurred in 5 (11.11%) patients. Infection was controlled after debridement and antibiotics in four of them and one patient required flap coverage. A study shows that the complication rates in operation using pedicle screw fixation range from 18% to 46%.
| Conclusion|| |
From our study, we came to the conclusion that among the used ceramics (HA/TCP/ [60% HA + 40% TCP]), there is no statistically significant difference in fusion rate and improvement of pain (VAS score) status.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3]