Treatment of Thoracolumbar Type A3 Fractures Using a Percutaneous Intravertebral Expandable Titanium Implant: Long-term Follow-up Results of a Pilot Single Center Study

Abstract

BACKGROUND: There are controversies about the optimal management of AO subtype A3 burst fractures. The most common surgical treatment consists of posterior fixation with pedicle screw and rod augmentation. Nevertheless, a loss of correction in height restoration and kyphotic reduction has been observed. OBJECTIVES: The aim of this study was to assess long-term outcomes of a minimally invasive technique using a percutaneous intravertebral expandable titanium implant (PIETI). STUDY DESIGN: This prospective, single center, pilot study was carried out on a consecutive case series of 44 patients with acute (< 2 weeks) traumatic thoracolumbar fractures AO type A3. The average follow-up was 5.6 years. SETTING: A single center in Castilla y Leon, Spain METHODS: Clinical outcomes (pain intensity on visual analog scale [VAS], Oswestry Disability Index [ODI], analgesic consumption) and radiographic outcomes (anterior/mid/posterior vertebral body height, vertebral area, local kyphosis angle, traumatic regional angulation) were analyzed before surgery, at one month after surgery, and at the end of the follow-up period. RESULTS: At one-month postsurgery, significant improvements in VAS score and ODI score were observed. PIETI achieved significant vertebral body height restoration with median height increases of 2.9 mm/4.3 mm/2.3 mm for anterior/middle/posterior parts, respectively. Significant correction of the local kyphotic angle and improvement of the traumatic regional angulation were accomplished. All these improvements were maintained throughout the follow-up period. The only complication reported was a case of cement leakage. LIMITATIONS: In our opinion, the main limitation of the study is the small number of patients. However, the sample is superior to that shown in other papers. CONCLUSIONS: This study showed that using a PIETI in the treatment of fractures type A3 is a safe and effective method that allows marked clinical improvement, as well as anatomical vertebral body restoration. Unlike with other treatments, results were maintained over time, allowing a better long-term clinical and functional improvement. The rate of cement leakage was lower than other reports. KEY WORDS: Traumatic thoracolumbar fractures, burst fractures, AO type A3 fractures, kyphoplasty, percutaneous intravertebral expandable titanium implant

The role of kyphoplasty and expandable intravertebral implants in the acute treatment of traumatic thoracolumbar vertebral compression fractures: a systematic review

“…Furthermore, armed kyphoplasty may be associated with lower rates of pain and adjacent vertebral fractures, probably due to its superior capacity for vertebral reduction and maintenance of this reduction in the long term, which is also associated with a higher quality of life due to improved posture, reduction of tension moments, and relaxation of the paravertebral muscles, minimizing its fatigue. These theoretical conclusions, in comparison with kyphoplasty, have already been demonstrated in some biomechanical studies on human cadavers and in clinical studies regarding fractures of osteoporotic and neoplastic origin, and are therefore likely, but still to be defined, to be similar also regarding fractures of the traumatic nature ( 28 , 29 , 30 , 40 , 42 , 43 , 44 , 45 , 46 , 47 , 54 , 59 , 61 , 62 , 65 , 75 , 103 , 105 , 107 ). Furthermore, we consider that currently there are two main types of expandable intravertebral implants with different indications for vertebral fractures: reducing and space-occupying implants, which replace the majority of the interior of the vertebral body, such as VBS® stents; and reducing implants, which elevate vertebral endplates and preserve intact bone trabeculae, such as Spinejack®.…”

“…The main studies referring to treatment with kyphoplasty or armed kyphoplasty in acute traumatic thoracolumbar burst-type vertebral fractures are summarized in Supplementary Tables 1 and 2 ( 3 , 5 , 12 , 37 , 46 , 52 , 70 , 71 , 72 , 73 , 74 , 75 ). Several other studies, some of them randomized clinical trials, include in their sample vertebral compression fractures types A1, A2 and A3 of the AOSpine classification ( 45 , 65 , 70 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ).…”

“…Nevertheless, if the cement is applied in a progressive and controlled manner to the anterior third of the vertebral body and its injection is stopped when it reaches the posterior quarter of the vertebral body, the risk of canal extravasation is greatly decreased ( 90 ). Supplementary Table 1 bring together the ten studies currently available on kyphoplasty applied exclusively to traumatic burst fractures, and their analysis allows us to verify that the majority of authors applied the combination of kyphoplasty with pedicle instrumentation of the adjacent vertebrae ( 3 , 5 , 12 , 37 , 46 , 70 , 71 , 72 , 73 , 74 , 75 ). Most studies are retrospective.…”

“…Regarding the imaging aspect, this restoration of the anterior column carried out by a posterior percutaneous transpedicular approach is effective and maintained throughout the studies follow-up periods, which makes it an important alternative to corporectomy, particularly in patients of advanced age and comorbidities. As for expandable intravertebral implants, exclusively in acute traumatic burst fractures, only two main studies were identified (Supplementary Table 2): a retrospective by Hartmann et al ( 52 ), regarding VBS® stents, and a prospective one by Noriega DC ( 75 ) et al , regarding Spinejack® devices. Both also address incomplete burst fractures.…”

“…Several studies demonstrate the treatment of acute vertebral fractures with kyphoplasty alone (with or without expandable intravertebral implants). However, the important role of pedicle fixation of adjacent vertebrae has come to be understood, particularly in burst fractures, not only as an additional method for indirect reduction of the fracture, but even in cases where direct reduction by isolated kyphoplasty is sufficient and adjacent pedicle instrumentation works as an additional stabilization method ( 5 , 46 , 52 , 61 , 63 , 64 , 65 , 72 , 75 , 77 , 79 , 81 , 86 , 87 , 90 , 100 , 101 , 102 , 103 , 104 , 105 ). Complementing kyphoplasty with short adjacent pedicle fixation allows the fractured vertebral body to be more efficiently protected from compression and rotational forces, minimizing the loads it suffers during the bone healing process.…”