ORIGINAL ARTICLE


https://doi.org/10.5005/jp-journals-10079-1080
Journal of Orthopedics and Joint Surgery
Volume 4 | Issue 1 | Year 2022

Delayed Neurological Deficit in Osteoporotic Vertebral Compression Fracture: An Analysis of Surgical Outcome

Thirumalai Murugan1, Arivasan Rathinam2, Sathiya Prakash3

1-3Department of Orthopaedics, Madurai Medical College, Madurai, Tamil Nadu, India

Corresponding Author: Sathiya Prakash, Department of Orthopaedics, Madurai Medical College, Madurai, Tamil Nadu, India, Phone: +91 9944043230, e-mail: sathiyathegr8@gmail.com

ABSTRACT

Introduction: The International Osteoporosis Foundation has estimated that worldwide, approximately 30-50% of people aged over 50 years are at risk for the development of fragility fractures secondary to osteoporosis. Vertebral compression fractures occur in 20% of people older than 70 years and in 16% of postmenopausal women. The majority of fractures heal with conservative treatment after 8-10 weeks. Surgery is indicated for patients who present with neurological deficits, deformities, and incapacitating pain with conservative treatment failure. Two percent of patients with osteoporotic vertebral fractures (OVFs) develop cord compression. This study aimed to identify the clinical presentation and predictors of clinical outcomes among patients operated for delayed neurological deficits after OVFs.

Materials and methods: eight cases—five women, three men, dorsolumbar junction—seven cases, dorsal spine one case. Neurological status - ASIA B - 1 - ASIA C - 5 - ASIA D - 2. All cases underwent posterior short segment fixation (pedicle screws one level above and below the fracture vertebra) and percutaneous vertebroplasty and indirect decompression.

Results and analysis: Postoperatively neurology improved up to ASIA grade E - 7, grade D - 1. All patients were followed up with neurological assessment every 2 weeks up to 3 months and every month up to 6 months. One patient could not walk, and seven patients walked with assistance. Two patients had sphincter disturbance. The mean preoperative Baba’s score was 6 and postoperative score was 11 after follow-up. The mean values of lateral anterior vertebral body height (LAH) were 41.0% preoperatively and 60.7% postoperatively, and lateral posterior vertebral body height (LPH) were 37.4% preoperatively and 58.8% after 6 months postoperatively. The average retropulsion was 36.5%.

Conclusion: Although OVFs are common and generally considered benign, severe and delayed neurological deficits can occur following spinal cord compression. In experienced hands and with appropriate patient selection, posterior short segment fixation (PSF) and vertebroplasty is a safe and efficacious procedure for the treatment of osteoporotic compression fractures with neurological deficit.

How to cite this article: Murugan T, Rathinam A, Prakash S. Delayed Neurological Deficit in Osteoporotic Vertebral Compression Fracture: An Analysis of Surgical Outcome. J Orth Joint Surg 2022;4(1):14–18.

Source of support: Nil

Conflict of interest: None

Keywords: Delayed neurological deficit, Nonunion, Osteoporosis, Osteoporotic vertebral fractures, Vertebroplasty

INTRODUCTION

The International Osteoporosis Foundation has estimated that worldwide, approximately 30–50% of people older than 50 years are at risk for the development of fragility fractures secondary to osteoporosis.1 Vertebral compression fractures occur in 20% of people older than 70 years and in 16% of postmenopausal women.2

The majority of fractures heal with conservative treatment after 8–10 weeks. Surgery is indicated for patients who present with neurological deficits, deformities, and incapacitating pain with conservative treatment failure. Three percent of the patients with OVFs develop cord compression3–5 for whom the treatment is very challenging.

This study aimed to identify the clinical presentation and predictors of clinical outcomes among patients operated for delayed neurological deficits after OVFs.

MATERIALS AND METHODS

Patients older than 60 years with OVFs, presenting with severe back pain and delayed neurological deficit were followed in our institution from 2015 to 2019.

Inclusion Criteria

  • Age more than 60 years.

  • Osteoporotic compression fractures with severe back pain not responding to conservative treatment and with neurological deficit.

Exclusion Criteria

  • Acute osteoporotic fracture with back pain,

  • Pt having normal neurological status,

  • Suspected malignancy and infection in spine,

  • Any h/o bleeding diathesis.

The following number of cases were taken for study:

  • Eight cases - five females, three males.

  • Dorsolumbar junction - seven cases, dorsal spine one case.

  • Neurological status

  • – ASIA B - 1

  • – ASIA C - 5

  • – ASIA D - 2

Surgical Technique

All the cases underwent posterior short segment fixation (PSF) with pedicle screws one level above and one level below the fractured vertebrae. After inserting the pedicle screws and rods, indirect decompression done by gentle distraction and then vertebroplasty done by injection of PMMA cement into the vertebral body through Jamshidi needle placed in the vertebral body (Figs 1 and 2).

Figs 1A and B: Intraoperative posterior short-segment fixation and vertebroplasty

Figs 2A to E: (A and B) Preoperative; (C and D) postoperative- 66 years woman presenting 2 months postinjury with back pain and neurological deficit ASIA grade C. She underwent PSF, indirect decompression, and vertebroplasty and recovered to ASIA grade E; (E) Postoperative clinical picture after surgery

RESULTS AND ANALYSIS

All patients were followed up with neurological assessment and radiological assessment with x-rays every 2 weeks upto 2 months and every month upto 1 year.

The following scores were used to assess the patient postoperatively.

All patients had significant improvement in the VAS pain score.

Postoperatively all patients had neurological improvement and it improved up to ASIA grade E in seven patients, and to ASIA grade D in one patient.

The mean preoperative Baba’s score was 4 and improved to 11 at 6 months postoperative. The mean values of lateral anterior vertebral body height (LAH) were 41.0% preoperatively and it improved to 60.7% postoperatively, and lateral posterior vertebral body height (LPH) were 37.4% preoperatively and it improved to 58.8% after 6 months postoperatively. The average retropulsion was 36.5% preoperatively which reduced to 10.2% postoperatively at 6 months (Table 1).

Table 1: Baba pain-neurological scoring system of osteoporotic vertebral fracture (total score = 14)
Categories Score (point)
Spinal pain (3)
Incapacitating and uncontrollable 0
Controllable with medication 1
Painful but no medication needed 2
Negligible or absent 3
Motor function of lower extremities (4)
Impossible to walk 0
Cane or aid on flat ground 1
Aid only on stairs 2
Walk unaided but slow 3
Normal 4
Sensory function (2)
Trunk
Apparent 0
Minimal 1
Normal 2
Lower extremity (2)
Apparent 0
Minimal 1
Normal 2
Bladder function (3)
Urinary retention or incontinence 0
Severe dysuria (sense of retention) 1
Slight dysuria 2
Normal 3

Postoperative improvement rate was calculated as postoperative score minus preoperative score, divided by 14 minus preoperative score, multiplied by 100 and shown in percent. Excellent was defined as improvement ≥80%; good 50-79%; fair 25-49%; and poor ≤24%.6

DISCUSSION

The majority of OVFs fractures heal with conservative treatment after 8-10 weeks. Very few patients presenting with persistent back pain not responding to conservative treatment may be treated with percutaneous vertebroplasty or kyphoplasty, which is very minimally invasive procedure and give dramatic pain relief.

The natural history of VCF is that 30% develop further collapse, 13% go for nonunion, and 3% develop neurological deficit as per Taenichi et al.6

VCF may present as neurological deficits (in 3% of patients) due to spinal cord compression in which vertebroplasty alone may not be useful and treating these fractures is a big challenge. A gradual or delayed onset of neurological deficits from 1 to 8 weeks and 1 week to 3 months after OVFs is common.

Surgery is indicated for patients who present with neurological deficits, deformities, and incapacitating pain with conservative treatment failure.

Spinal Instability

The concept of spinal instability has been recently introduced in the osteoporotic VCFs, as these fractures were traditionally considered stable and treated with conservative treatment. However, there are certain risk factors when present make these fractures unstable leading onto a progressive collapse, kyphotic deformity and neurological deficit (Fig. 3).

Figs 3A to C: Risk factors of progression

The following were considered as the risk factors for neurological deficit:7

  • Middle column burst fractures were suggested to have a higher risk of neurological deficits because of retropulsed fragments. In a Japanese series, approximately 91% of OVFs causing paraplegia were burst fractures.8,9

  • Angular instability of >15° and retropulsion of >42% were predictive factors for neurological deficits.10,11

  • Cobb’s angle of >30° was regarded as a precipitating factor in one study3,12 vacun sign.13

The goal of treatment in these fractures are:

  • Neurological decompression.

  • Kyphotic deformity correction.

  • Stable arthrodesed spine.

The surgical procedures available for treating these fractures with neurological deficit are:

  • Direct anterior decompression and reconstruction.14

  • Posterior column shortening osteotomy and stabilization, and decompression.15

  • Posterior short segment fixation, decompression, and vertebroplasty16 (Fig. 4).

Figs 4A to D: (A and B) Showing preoperative; (C and D) postoperative pictures of 65 years old male presenting with Asia grade B - 2 months post-injury

Direct Anterior Surgery

The advantage of anterior surgery is that decompression is much better and direct. The main disadvantage is the complications associated with Anterior Surgery (Thoracotomy and Laparotomy needed) is as high as 70%.17

Surgery in elderly individuals is associated with high complication rate as Nguyen et al. reported a complication rate of 70%, due to comorbid conditions, and severe osteoporosis, implant purchase very poor.18

Indirect Posterior Surgery

All orthopaedic surgeons are familiar and morbidity is less. Pedicle screws are biomechanically stronger than screws used in vertebral body by anterior approach. At the same time vertebroplasty when done is a less invasive procedure for creating anterior column stability, which is very essential to prevent future collapse and maintain stability of the spine.19

Direct vs Indirect Decompression

Most authors feel that the neurological deficit following VCFs is mainly due to instability rather than mechanical compression and hence they had suggested to stabilise the spine and do an indirect decompression by gentle distraction and anterior column support by vertebroplasty.20

Ho et al. in Injury 2018 February 49,2 in a prospective study of 31 patient had concluded that surgery in the form of indirect reduction, kyphoplasty and post short segment fixation gives best results.

Masofumi et al. in Euro Spine Journal 201316 has concluded the direct decompression is not always necessary, and majority of the patients can be treated with a less invasive procedure like post short segment fixation,21 indirect decompression and vertebroplasty.

Alpantaki et al. in spine journal 2017 concluded that neurologic deficit associated with fractures responds to indirect postural reduction, kyphoplasty and posterior percutaneous short segment instrumentation.22

Yeung and Ho in 2018 published that delayed neurological deficits can occur from 1 week to 5 months after OVFs.23 Predictive factors for neurological deficits include burst type, vacuum sign, angular instability and retropulsion.

LIMITATIONS

Our study is limited by its retrospective nature, relatively small group of patients, lack of a control group and continuous BMD monitoring.

CONCLUSION

Although OVFs are common and generally considered benign, severe and delayed neurological deficits can occur following spinal cord compression.

In experienced hands and with appropriate patient selection, Posterior short segment fixation, indirect decompression and vertebroplasty is a safe and efficacious procedure for the treatment of osteoporotic compression fractures with neurological deficit.

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