Despite the fast development in modern techniques and instrumentation, the management of severe kyphoscoliosis remains challenging. It even becomes more crucial if the curve angle is >100° with significant kyphosis and/or a history of intraspinal pathology is present [1]. Kyphoscoliosis can involve the thoracic region, lumbar region, or both, and it may occur alone or as a manifestation of any neuromuscular disease. Severe and rigid deformities are much more complicated to address even with surgery.

Patients with severe spine deformities typically undergo surgery using anterior, posterior, and combined anterior–posterior approaches. However, complication risks are higher if the deformity becomes rigid and severe. These difficult curves require prolonged surgeries with complex osteotomies and are usually accompanied by tissue releases that may cause several problems. Literature indicates that complication rates range from 18% to 74% in spinal deformity surgeries, particularly when the preoperative curve angle is >60°. Pulmonary complications are most common, followed by implant-related issues, infections, neurological complications, and pseudoarthrosis [2–5]. These patients require extensive medical care and prolonged hospital stays [6]. Given the potentially life-threatening nature of complications, interventions before corrective surgeries are essential to minimize risks.

Methods such as preoperative halo-femoral, halo-tibial, and halo-gravity traction offer significant corrective forces; however, hitches such as extended periods of bed rest and hospital stay, difficulty in performing daily living activities, and discomfort have been reported. Literature suggests that improving and modifying the traction devices, particularly halo-pelvic devices, can effectively manage kyphoscoliotic deformities before corrective surgery. Accordingly, our team developed a modified halo-pelvic distraction device using a standard Ilizarov ring fixator set. This innovation has shown promising results in reducing perioperative and postoperative complications. Unlike traditional and other versions of halo-pelvic devices, patients responded well to our modified version [7]. Thus, this study aimed to analyze comprehensively the outcome of 34 patients with severe kyphoscoliotic deformity managed using our modified halo-pelvic Ilizarov distraction device.

Patients with kyphoscoliosis who presented with a coronal Cobb angle of >90° and had no radiological evidence of osseous fusion along ≥3 vertebrae between January 2021 and September 2021 were recruited after obtaining ethical approval and informed consent. Patients with a history of blood dyscrasias, any psychiatric illness, or cerebral palsy were not included. The project was approved by the Ethical Review Committee of Ghurki Trust Teaching Hospital Lahore Pakistan (IRB approval no., 2020/11/R-20).

The complete demographic and clinical profiles were obtained along with standing radiographs. Patients were evaluated for upper and lower limb neurology, cranial nerves, bladder and bowel reflexes, and pulmonary function tests including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Anteroposterior and lateral standing radiographs of the whole spine were obtained to assess the magnitude of the coronal and sagittal deformities by measuring the coronal and sagittal Cobb angles, apical vertebral translation (AVT), and coronal and sagittal balance. In addition, right and left bending and traction views were taken to assess curve flexibility.

Whole spine computed tomography and magnetic resonance were also obtained to rule out any vertebral column and spinal cord anomaly, respectively. The patients were evaluated using the Scoliosis Research Society-30 Questionnaire (SRS-30) before the application of the assembly and 3 months after surgery [8].

After the application of the assembly, pin tract infections developed in 20 patients, which were treated successfully with oral antibiotic therapy. Half-pin (in one patient, supra-acetabular; and in two, iliac) loosening was reported in three patients after 3 weeks; thus, the half-pins were removed, and distraction was continued with the remaining half-pins. Two patients experienced decreased lower limb muscle strength after 2–3 weeks of distraction. The traction was stopped, and patients were allowed to recover. Another patient was observed to have decreased sensation over the T11–T12 dermatome, which was also managed in the same way. Those two patients who presented with impaired lower limb neurology remained as such.

In this study, our modified halo-pelvic Ilizarov distraction assembly achieved significant curve reduction before the definitive correction surgery (Fig. 4). The results showed average correction of the coronal and sagittal Cobb angles of >50% and 40%, respectively, which were quite considerable in magnitude when compared with the average Cobb angle in the traction X-ray images that signify the excellent efficacy of the device. In addition, a significant increase in the average height of nearly 8 cm was noted. Spinal curve reduction significantly increased the amount of space in the chest, which effectively improved pulmonary functions and provided better tolerance and prognosis for aggressive surgery.

The concept of halo-pelvic assembly dates back to 1959 when it was initially applied to immobilize unstable cervical segments and later in the 1970s for spinal deformities [9]. The gradual traction force exerted through the halo-pelvic device creates continual fatigue of the paraspinal muscles while displacing the adjacent soft tissues such as tendons and ligaments. Tissue cells adapt to this new structural state, which facilitates correction [10]. This traction mechanism is preferred over halo-femoral and halo-gravity tractions, particularly in severe and rigid curves where a slightly longer traction period is required. Halo-femoral traction requires an extended period of bed rest, and patients have increasing risks of pressure sores, chest infections, and deep venous thrombosis [11], whereas halo-gravity traction provides limited traction [12]. Nonetheless, the traditional halo-pelvic traction device led to major complications, such as paraplegia, cranial nerve palsies, pain, radiological degenerative changes, avascular necrosis of dens, and various others, contributing to its gradual decline in use. The circular pelvic ring in the traditional device caused discomfort for patients when lying on their backs; furthermore, the anchoring pins passing through the pelvis were associated with a higher incidence of infections [13,14].

Recently, clinical studies have reported reasonable results with fewer complications using their modified assemblies; however, limitations persist, including patients’ distress and negative sagittal balance [9,15,16]. Our tailored assembly addressed all those concerns and yielded satisfactory results. A slow and continuous distraction was infused with the components of the Ilizarov distraction assembly, and severe and rigid deformities were effectively corrected, surpassing the outcomes of halo-gravity traction [17]. The versatility of the Ilizarov apparatus allowed us to customize the assembly for the needs of each patient. Linear distraction and angular correction were comfortably adjusted based on individual’s requirement, achieving stable fixation while minimizing neurological complications. Surgical correction did not require extensive soft tissue releases or osteotomies, such as Ponte osteotomy or vertebral procedures, which are significantly associated with morbidity, increased operative time, and blood loss [18,19].

The lateral arches in our assembly enhanced the comfort level of the patients and allowed them to perform routine tasks easily and sleep in the supine position. The selection of the supracetabular area for half-pin insertion proved to be a strong anchorage point and provided sturdy support unlike previous assembly in which pins are inserted between the inner and outer tables of the ileum [15]. Because patients with scoliosis are frequently osteoporotic with weak bones, using only the ilium in these cases may be a poor anchorage point for screws.

In our technique, we used four rods, two anterolateral and two posterolateral, instead of just anterolateral rods used in the previously reported halo-pelvic assembly [15], which provided balanced distraction force. The distraction duration depended on the severity of the curve and response of the patient. In most patients, the desired correction was achieved in 3–4 weeks. However, in some patients with compromised neurology, the distraction rate was adjusted and reverted a few millimeters to reverse the neurology. No complications related to cranial nerves, brachial plexus, broken pins, subluxation of atlantoaxial joint, and so forth were reported as with previous modified assemblies [9,15,20]. The most frequent complication was mild pin tract infection, which was handled effectively with antibiotics, compared with previously reported severe infections [21]. Close monitoring of the patients during the distraction period helped us identify and handle the complications immediately.

In developing countries where patients with scoliosis usually present with severe and rigid curves along with cardiorespiratory complications, surgical correction is a major challenge [22]; thus, appropriate and well-managed halo-pelvic traction combined with correction surgery is highly efficacious in these cases, as in our modified halo-pelvic Ilizarov traction, which is reliable and has relatively minor complications. Compared with previously documented halo-pelvic assemblies and alternative techniques, patient mobility remained uncompromised, and notable enhancements in curvature severity were observed, avoiding the need for complex osteotomies during corrective surgery. However, the study’s strength could have been further enhanced with comprehensive data comparing different traction methods specifically from our institution.

Our modified halo-pelvic Ilizarov distraction assembly is a potent, effective, and safe tool for the preoperative correction of rigid and severe kyphoscoliosis before definitive surgery. It reduces the rigidity and severity of the curve to an extent that surgical procedure becomes convenient and conducive with minimal risks of complications.