Effect of angular correction during posterior instrumentation of spinal fractures on postoperative outcomes and quality of life

Abstract

BACKGROUND:

OBJECTIVE:

We aimed to determine whether the magnitude of sagittal angular correction during posterior instrumentation of the spine had an effect on postoperative quality of life, pain and function outcomes as measured using the EQ5D-3L and the Core Outcome Measures Index (COMI) instruments. We also aimed to quantify the correlation between EQ5D-3L and COMI scores.

METHODS:

We analyzed the pre- and postoperative radiographs of 52 patients who underwent percutaneous pedicle screw placement for thoracolumbar fractures, as well as their self-reported EQ5D-3L and COMI quality of life, pain and functional outcome scores. Regression models were constructed to estimate the effect that the magnitude of Cobb angle correction had on postoperative outcomes. We also estimated the correlation between EQ5D-3L and COMI scores.

RESULTS:

The median EQ5D-3L TTO score was 0.9 (range, $-$ 0.1 to 1). The median COMI score was 3.1 (range, 0 to 10). There was no significant effect of the magnitude of correction on EQ5d-3L TTO scores ( $p=$ 0.3379; $R=$ 0.36) or on COMI scores ( $p=$ 0.3379; $R=$ 0.15). Age and bone mineral density were not found to be significant predictors of outcome ( $p=$ 0.05). There was a strong correlation between the EQ5D-3L TTO and COMI scores ( $r=$ $-$ 0.62).

CONCLUSION:

The magnitude of Cobb angle correction during pedicle screw instrumentation of thoracolumbar fractures did not influence quality of life, pain or function outcomes. There was good correlation between EQ5D-3L TTO scores and COMI scores.

Keywords

Thoracolumbar fracture closed reduction comi-score EuroQol EQ-5D quality of life

1. Introduction

Thoracic and lumbar spine fractures are common injuries with a incidence in the total population of 64 per 100,000 inhabitants [1, 2]. Thoracolumbar fractures can occur as a result of both high-energy trauma in younger patients and low-energy trauma in geriatric patients and in patients with osteoporosis [3].

Posterior instrumentation using pedicle screws and rods is the most commonly used technique for the treatment of thoracolumbar fractures of the spine. The procedure aims to restore the neurologic and biomechanical functions of the spine and allows for early mobilization and rapid functional reintegration into society [4, 5]. While pedicle screw instrumentation can be performed as an open procedure, a percutaneous approach reduces tissue disruption, blood loss and surgical time [6, 7]. Furthermore, the percutaneous approach has been shown to achieve significant pain outcomes and angular correction compared to the open technique [8, 9, 10].

Sagittal deformity correction has long been a goal of stabilizing spinal procedures. While numerous studies have described planning and estimation of deformity correction in the setting of scoliosis surgery [11, 12, 13, 14, 15], it is not yet clear whether the magnitude of correction has an effect on postoperative outcomes after pedicle screw placement for thoracolumbar fractures. In addition, it is currently being discussed whether there is a positive correlation of surgical approach with survival in the geriatric trauma patient population with early surgical intervention for thoracolumbar spine injuries [16].

In the current study, we aimed to determine whether the magnitude of sagittal angular correction during posterior instrumentation of the spine had an effect on postoperative quality of life, pain and function outcomes as measured using the EQ5D-3L and the Core Outcome Measures Index (COMI) instruments. We also aimed to quantify the correlation between EQ5D-3L and COMI scores.

2. Materials and methods

After obtaining approval from our institutional review board (Nr. 8-030), we identified patients who were operatively treated for spinal fractures at our level 1 trauma center between January 2015, and December 2017. The minimally invasive percutaneous dorsal instrumentation technique was used in all included patients. The Medtronic CD HORIZON LONGITUDE II screw-rod system was used in more than three quarters of the patients. In the remainder, the VIPER 2 system from DepuySynthes was used. We excluded patients under the age of 18 years, as well as patients with pathological fractures and those with infection-associated fractures.

Figure 1.

To determine the bisegmental Cobb angle between the base plate of the caudal vertebral body and the cover plate of the cranial vertebral body in relation to the injured vertebral body pre (left) to post (right) operatively in a CT-scan.

We reviewed patient charts to collect demographic and clinical data on all patients. We also searched for all available pre- and postoperative radiographs of the spine and measured the bisegmental Cobb angle (Fig. 1) [17, 18] whenever possible. In addition, to quantify quality of life and pain and functional outcomes, we surveyed patients using the standardized EQ5D-3L and COMI instruments [19, 20, 21]. We sent the questionnaires to a total of 137 patients three times and received a postal response from 52 patients. The EQ5D-3L assesses five dimensions, including mobility, self-care, usual activities, pain/discomfort and anxiety/depression, with each dimension having three levels: no problems, some problems, and extreme problems. This score is one of the most widely used and has provided evidence in the upper extremity and other areas [22]. The COMI is a brief instrument aimed at quickly assessing pain, function, symptom-specific well-being, quality of life and disability in patients with spinal deformity. It has been validated in several languages and is the preferred instrument for back patients in the Eurospine international spine registry, “Spine Tango” [20].

The main outcome measures were the EQ5d-3L time trade-off (TTO) score and the COMI score. Additional variables that were evaluated included: pre- and postoperative bisegmental Cobb angle, age, sex, bone mineral density, AO fracture type, Frankel neurological status, length of stay, surgical time and blood loss.

Bone densitometry was performed exclusively using the DXA measurement technique, which remains the gold standard for bone densitometry measurement assessment.

2.1 Statistical analysis

R was used for all analyses [23]. Descriptive statistics were calculated in the form of mean and standard deviation (SD), median and range, or percent and number of observations (n), wherever appropriate. We used generalized linear regression models to estimate quality of life and functional outcomes measured using the EQ5D-3L and COMI instruments as a function of the magnitude of bisegmental Cobb angle correction and adjusting for age and bone mineral density. We also used Pearson correlation to quantify the relationship between EQ5D-3L scores and COMI scores. Alpha was set to 0.05 for all analyses.

3. Results

A total of 52 patients responded to our inquiry and returned filled-out outcome questionnaires. There were 23 women (43%) and 31 men (57%), with a median age of 68 years (range, 16 to 88 years). Of those patients, 36 had radiographic images available for analysis. Additional characteristics of the cohort are described in Table 1.

Table 1
Demographic and clinical characteristics of the patients

	Overall
$n$	52
Age (years) (median [range])	70.0 [20.0, 88.0]
Sex $=$ Male/Female (%)	30/22 (57.7/42.3)
Bone mineral density (BMD) (Hounsfield units) (median [range])	153.5 [56.0, 388.5]
AO fracture type (%)
A	44 (84.6)
B	7 (13.5)
NA	1 (1.9)
Frankel neurological status (%)
E	44 (84.6)
D	4 (7.7)
B	1 (1.9)
NA	3 (5.8)
Length of stay (days) (median [range])	14.0 [2.0, 57.0]
OR time (median [range])	85.0 [26.0, 271.0]
Blood loss (ml) (median [range])	100.0 [0.0, 3000.0]
Segmental Cobb angle preop (median [range])	9.6 [1.1, 27.5]
Segmental Cobb angle postop (median [range])	6.3 [0.5, 25.5]
Deformity correction (median [range]))	3.7 [0.1, 17.8]
COMI Score (median [range])	3.0 [0.0, 10.0]
EQ5D-3L TTO (median [range])	0.9 [ $-$ 0.1, 1.0]

The median EQ5D-3L TTO score was 0.9 (range, $-$ 0.1 to 1). The median COMI score was 3.1 (range, 0 to 10).

We observed no significant effect of the magnitude of correction on quality of life as quantified by the EQ5d-3L TTO score ( $p=$ 0.3379; $R=$ 0.36) or on functional outcomes assessed using the COMI score ( $p=$ 0.3379; $R=$ 0.15) (Table 2). Age and bone mineral density were not found to be significant predictors of outcome ( $p=$ 0.05).

Table 2

Estimation of EQ5D-3L TTO scores and COMI scores as a function of the magnitude of sagittal correction, age and bone mineral density

	Dependent variable
	EQ5D-3L TTO	COMI score
	(1)	(2)
Correction	$-$ 0.010	0.156
	(0.012)	(0.154)
Age (years)	$-$ 0.015	0.057
	(0.008)	(0.108)
BMD (HU)	$-$ 0.003	0.006
	(0.002)	(0.031)
Age * BMD	0.0001	$-$ 0.0003
	(0.00004)	(0.0005)
Constant	1.708 ${}^{\ast\ast}$	0.435
	(0.600)	(7.935)
$R^{2}$	0.319	0.148

Note: ${}^{\ast}p<$ 0.05; ${}^{\ast\ast}p<$ 0.01; ${}^{\ast\ast\ast}p<$ 0.001.

Finally, we found a negative correlation of $r=$ $-$ 0.62 between the EQ5D-3L TTO scores and the COMI scores.

4. Discussion

In the current study, we have examined the effect of the magnitude of sagittal angular correction on postoperative outcomes after posterior spinal instrumentation for vertebral fractures. We found no evidence that the magnitude of correction influenced quality of life as measured by the EQ5D-3L TTO instrument or pain and function as measured using the COMI instrument. We also found no significant relationship between age or bone mineral density and either EQ5d-3L TTO or COMI scores.

We also studied the relationship between EQ5D-3L TTO scores and COMI scores and found a moderate-to-strong correlation between them. While the scores reflected some association between them, a perfect correlation was not to be expected, as the COMI score aims to provide additional information about the patient, such as pain and functional status.

There are some limitations to this research. First, the retrospective nature of the study carries intrinsic drawbacks inherent to the study design. Second, there was a relatively low number of responders to our survey inquiry. However, given the known difficulty of following up with trauma patients and the current paucity of published data concerning COMI score outcomes after spinal fracture instrumentation, the results of the study provide important information on outcomes after operative treatment of spinal fractures and provides a basis for future clinical care and research. The sample size is also comparatively higher than that of the few similar studies reporting on outcomes after spinal fractures [24]. Third, the limited sample size meant that we were not able to adjust for all possible confounders in our model, so as not to risk overfitting. Studies with a larger cohort should aim to further elucidate our findings.

One important finding of this study was that bone mineral density was not a significant predictor of outcome. While one would expect patients with osteoporosis to have worse quality of life, pain and functional outcomes, that was not the case in this study. Although it is hard to precisely explain this phenomenon, it is possible that modern fracture fixation implants and the choice of using cement augmentation could provide enough stability to the construct, therefore reducing the potential deleterious effect of poor bone quality. Another possibility is that, at our institution, patients with known osteoporosis at the time of surgery are initiated in a regimen of osteoporosis treatment including vitamin D supplementation and possibly bisphosphonates or other medications. The positive effect of osteoporosis treatment on outcomes has been previously described and should remain a mainstay of treatment, particularly in women and geriatric patients [25, 26].

5. Conclusion

This study found that the magnitude of bisegmental Cobb angle correction after spinal fracture instrumentation did not have an effect on postoperative quality of life and functional outcomes.

Funding

The authors have no financial or proprietary interests in any material discussed in this article.

Availability of data and materials

Not applicable.

Footnotes

Conflict of interest

None of the authors have any conflicts of interest related to this work.

References

Mustard

Burns

. Epidemiology of incident spinal fracture in a complete population. Spine (Phila Pa 1976). 1996.

Reinhold

Knop

Beisse

Audigé

Kandziora

Pizanis

, et al. Operative behandlung traumatischer frakturen der brust- und lendenwirbelsäule: Teil I: epidemiologie. Unfallchirurg. 2009; 112(1): 33-45.

Gonschorek

Lorenz

Bühren

. Wirbelsäulenverletzungen: Fraktur bei Osteoporose. Trauma und Berufskrankheit. 2015; 17(1): 157-63.

Spivak

Vaccaro

Cotler

. Thoracolumbar Spine Trauma: II. Principles of Management. J Am Acad Orthop Surg. 1995; 3(6): 353-60.

Kirkpatrick

. Thoracolumbar fracture management: anterior approach. J Am Acad Orthop Surg. 2003; 11(5): 355-63.

Alander

Cui

. Percutaneous Pedicle Screw Stabilization: Surgical Technique, Fracture Reduction, and Review of Current Spine Trauma Applications. J Am Acad Orthop Surg. 2018; 26(7): 231-40.

Wild

Glees

Plieschnegger

Wenda

. Five-year follow-up examination after purely minimally invasive posterior stabilization of thoracolumbar fractures: A comparison of minimally invasive percutaneously and conventionally open treated patients. Arch Orthop Trauma Surg. 2007; 127(5): 335-43.

Erichsen

Heyde

Josten

Gonschorek

Panzer

Rüden Von

, et al. Percutaneous versus open posterior stabilization in AOSpine type A3 thoracolumbar fractures. 2020; 6: 1-10.

Vanek

Bradac

Konopkova

De Lacy

Lacman

Benes

. Treatment of thoracolumbar trauma by short-segment percutaneous transpedicular screw instrumentation: Prospective comparative study with a minimum 2-year follow-up: Clinical article. J Neurosurg Spine. 2014; 20(2): 150-6.

10.

Wang

Zhou

Liu

Xiang

. Comparison of open versus percutaneous pedicle screw fixation using the sextant system in the treatment of traumatic thoracolumbar fractures. Clin Spine Surg. 2017; 30(3): E239-46.

11.

Kiriyama

Yamazaki

Nagura

Matsumoto

Chiba

Toyama

. Prediction of deformity correction by pedicle screw instrumentation in thoracolumbar scoliosis surgery (Computer simulation study). JSME Int Journal, Ser C Mech Syst Mach Elem Manuf. 2006; 48(4): 577-85.

12.

Pesenti

Lafage

Henry

Kim

Bolzinger

Elysée

, et al. Deformity correction in thoracic adolescent idiopathic scoliosis. Bone Jt J. 2020; 102(3): 376-82.

13.

Yong

Zhen

Zezhang

Bangping

Feng

Tao

, et al. Comparison of Sagittal Spinopelvic Alignment in Chinese Adolescents With and Without Idiopathic Thoracic Scoliosis. Spine (Phila Pa 1976). 2012; 37(12): E714-20.

14.

Ghandhari

Ameri

Safari

Kheirabadi

Asl

Zarghampour

, et al. The effect of Cobb angle correction on spinal length gain in patients with adolescent idiopathic scoliosis. J Pediatr Orthop Part B. 2019; 28(1): 22-6.

15.

Ogura

Okada

Fujii

Yagi

Fujita

Suzuki

, et al. Midterm surgical outcomes of a short fusion strategy for adolescent idiopathic scoliosis with Lenke 5C curve. Spine J. 2020; 20(3): 361-8.

16.

Wiedl

Förch

Fenwick

Mayr

. Importance of surgical treatment of thoracolumbar vertebral fractures for the survival probability of orthogeriatric patients. Unfallchirurg. 2021; 124(4): 303-10.

17.

Keynan

Fisher

Vaccaro

Fehlings

Oner

Dietz

, et al. Radiographic measurement parameters in thoracolumbar fractures: A systematic review and consensus statement of the spine trauma study group. Spine (Phila Pa 1976). 2006; 31(5): 156-65.

18.

Jiang

Lan

Dai

. Reliability of the measurement of thoracolumbar burst fracture kyphosis with Cobb angle, Gardner angle, and sagittal index. Arch Orthop Trauma Surg. 2012; 132(2): 221-5.

19.

Mannion

Porchet

Kleinstück

Lattig

Jeszenszky

Bartanusz

, et al. The quality of spine surgery from the patient’s perspective. Part 1: The Core Outcome Measures Index in clinical practice. Eur Spine J. 2009; 18(Suppl 3): 367-73.

20.

Mannion

Vila-Casademunt

Domingo-Sàbat

Wunderlin

Pellisé

Bago

, et al. The Core Outcome Measures Index (COMI) is a responsive instrument for assessing the outcome of treatment for adult spinal deformity. Eur Spine J. 2016; 25(8): 2638-48.

21.

EuroQol Research Foundation. EQ-5D-3L User Guide. 2018.

22.

Grobet

Marks

Tecklenburg

Audigé

. Application and measurement properties of EQ-5D to measure quality of life in patients with upper extremity orthopaedic disorders: a systematic literature review. Arch Orthop Trauma Surg [Internet]. 2018; 138(7): 953-61. Available from: doi: 10.1007/s00402-018-2933-x.

23.

R Core Team. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/. Vienna, Austria, 2016.

24.

Loibl

Korsun

Reiss

Gueorguiev

Nerlich

Neumann

, et al. Spinal fracture reduction with a minimal-invasive transpedicular Schanz Screw system: Clinical and radiological one-year follow-up. Injury. 2015; 46: S75-82.

25.

Neuerburg

Mittlmeier

Schmidmaier

Kammerlander

Böcker

Mutschler

, et al. Investigation and management of osteoporosis in aged trauma patients: A treatment algorithm adapted to the German guidelines for osteoporosis. J Orthop Surg Res. 2017; 12(1): 1-12.

26.

Schray