Posterior reduction with pedicle screws is often used for stabilization of unstable spondylolisthesis to directly reduce misalignment or protect against micromotion while fusion of the affected level occurs. Optimal treatment of spondylolisthesis combines consistent reduction with a reduced risk of construct failure. The authors compared the reduction achieved with a novel anterior integrated spacer with a built-in reduction mechanism (ISR) to the reduction achieved with pedicle screws alone, or in combination with an anterior lumbar interbody fusion (ALIF) spacer, in a cadaveric grade I spondylolisthesis model.
Grade I slip was modeled in 6 cadaveric L5–S1 segments by creation of a partial nucleotomy and facetectomy and application of dynamic cyclic loading. Following the creation of spondylolisthesis, reduction was performed under increasing axial loads, simulating muscle trunk forces between 50 and 157.5 lbs, in the following order: bilateral pedicle screws (BPS), BPS with an anterior spacer (BPS+S), and ISR. Percent reduction and reduction failure load—the axial load at which successful reduction (≥ 50% correction) was not achieved—were recorded along with the failure mechanism. Corrections were evaluated using lateral fluoroscopic images.
The average loads at which BPS and BPS+S failed were 92.5 ± 6.1 and 94.2 ± 13.9 lbs, respectively. The ISR construct failed at a statistically higher load of 140.0 ± 27.1 lbs. Reduction at the largest axial load (157.5 lbs) by the ISR device was tested in 67% (4 of 6) of the specimens, was successful in 33% (2 of 6), and achieved 68.3 ± 37.4% of the available reduction. For the BPS and BPS+S constructs, the largest axial load was 105.0 lbs, with average reductions of 21.3 ± 0.0% (1 of 6) and 32.4 ± 5.7% (3 of 6) respectively.
While both posterior and anterior reduction devices maintained reduction under gravimetric loading, the reduction capacity of the novel anterior ISR device was more effective at greater loads than traditional pedicle screw techniques. Full correction was achieved with pedicle screws, with or without ALIF, but under significantly lower axial loads. The anterior ISR may prove useful when higher reduction forces are required; however, additional clinical studies will be needed to evaluate the effectiveness of anterior devices with built-in reduction mechanisms.
ABBREVIATIONSALIF = anterior lumbar interbody fusion; AP = anterior-posterior; BPS = bilateral pedicle screw; BPS+S = BPS with an anterior spacer; ISR = integrated spacer with a built-in reduction mechanism; TLIF = transforaminal lumbar interbody fusion.
Correspondence Jonathan M. Mahoney: Globus Medical, Audubon, PA. email@example.com.
INCLUDE WHEN CITING Published online May 3, 2019; DOI: 10.3171/2019.2.SPINE18726.
Disclosures Surgeons P.W.H. and D.D. have no financial relationship with Globus Medical, Inc. (GMI). Investigator J.C.H. was a visiting research intern and compensated hourly by GMI. Cadaveric specimens and related materials were provided by GMI, at which J.M.M., J.A.H., M.M.H., N.F.K., and B.S.B. are, or were at one point, full-time employees. J.A.H. reports GMI direct stock ownership. The study was performed at GMI, using its 6-degrees-of-freedom motion simulator.
Note: The integrated spacer with a built-in reduction mechanism (ISR) device (MONUMENT, Globus Medical, Inc.), pedicle screws and rods (REVERE, Globus Medical, Inc.), and anterior lumbar interbody spacer (CONTINENTAL, Globus Medical, Inc.) examined in this study are FDA cleared for this indication.
BartolozziPSandriACassiniMRicciM: One-stage posterior decompression-stabilization and trans-sacral interbody fusion after partial reduction for severe L5-S1 spondylolisthesis. Spine (Phila Pa 1976)28:1135–11412003
BednarDA: Surgical management of lumbar degenerative spinal stenosis with spondylolisthesis via posterior reduction with minimal laminectomy. 15:105–109, 200210.1097/00024720-200204000-0000311927818)| false
BoulayC, TardieuC, HecquetJ, BenaimC, MouilleseauxB, MartyC, : Sagittal alignment of spine and pelvis regulated by pelvic incidence: standard values and prediction of lordosis. 15:415–422, 20061617999510.1007/s00586-005-0984-5)| false
FanGZhangHGuanXGuGWuXHuA: Patient-reported and radiographic outcomes of minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis with or without reduction: a comparative study. J Clin Neurosci33:111–1182016
FanG, ZhangH, GuanX, GuG, WuX, HuA, : Patient-reported and radiographic outcomes of minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis with or without reduction: a comparative study. 33:111–118, 201610.1016/j.jocn.2016.02.03727443498)| false
FogelGR, ReitmanCA, LiuW, EssesSI: Physical characteristics of polyaxial-headed pedicle screws and biomechanical comparison of load with their failure. 28:470–473, 20031261615910.1097/01.BRS.0000048652.45964.2E)| false
GongKWangZLuoZ: Reduction and transforaminal lumbar interbody fusion with posterior fixation versus transsacral cage fusion in situ with posterior fixation in the treatment of Grade 2 adult isthmic spondylolisthesis in the lumbosacral spine. J Neurosurg Spine13:394–4002010
GongK, WangZ, LuoZ: Reduction and transforaminal lumbar interbody fusion with posterior fixation versus transsacral cage fusion in situ with posterior fixation in the treatment of Grade 2 adult isthmic spondylolisthesis in the lumbosacral spine. 13:394–400, 201010.3171/2010.3.SPINE0956020809736)| false
HaKY, NaKH, ShinJH, KimKW: Comparison of posterolateral fusion with and without additional posterior lumbar interbody fusion for degenerative lumbar spondylolisthesis. 21:229–234, 20081852548110.1097/BSD.0b013e3180eaa202)| false
HsiehPCKoskiTRO’ShaughnessyBASugruePSalehiSOndraS: Anterior lumbar interbody fusion in comparison with transforaminal lumbar interbody fusion: implications for the restoration of foraminal height, local disc angle, lumbar lordosis, and sagittal balance. J Neurosurg Spine7:379–3862007
LabelleHRoussoulyPBerthonnaudEDimnetJO’BrienM: The importance of spino-pelvic balance in L5-s1 developmental spondylolisthesis: a review of pertinent radiologic measurements. Spine (Phila Pa 1976)30 (6 Suppl):S27–S342005
LabelleH, RoussoulyP, BerthonnaudE, DimnetJ, O’BrienM: The importance of spino-pelvic balance in L5-s1 developmental spondylolisthesis: a review of pertinent radiologic measurements. 30 (6 Suppl):S27–S34, 200510.1097/01.brs.0000155560.92580.90)| false
LeeCWYoonKJHaSS: Which approach is advantageous to preventing development of adjacent segment disease? Comparative analysis of 3 different lumbar interbody fusion techniques (ALIF, LLIF, and PLIF) in L4-5 spondylolisthesis. World Neurosurg105:612–6222017
LeeCW, YoonKJ, HaSS: Which approach is advantageous to preventing development of adjacent segment disease? Comparative analysis of 3 different lumbar interbody fusion techniques (ALIF, LLIF, and PLIF) in L4-5 spondylolisthesis. 105:612–622, 20172860292810.1016/j.wneu.2017.06.005)| false
MackiMBydonMWeingartRSciubbaDWolinskyJPGokaslanZL: Posterolateral fusion with interbody for lumbar spondylolisthesis is associated with less repeat surgery than posterolateral fusion alone. Clin Neurol Neurosurg138:117–1232015
MackiM, BydonM, WeingartR, SciubbaD, WolinskyJP, GokaslanZL, : Posterolateral fusion with interbody for lumbar spondylolisthesis is associated with less repeat surgery than posterolateral fusion alone. 138:117–123, 20152631836310.1016/j.clineuro.2015.08.014)| false
ManonJHussainMMHarrisJMoldavskyMLa MarcaFBucklenBS: Biomechanical investigation of a novel revision device in an osteoporotic model: pullout strength of pedicle screw anchor versus larger screw diameter. Clin Spine Surg30:265–2712017
ManonJ, HussainMM, HarrisJ, MoldavskyM, La MarcaF, BucklenBS: Biomechanical investigation of a novel revision device in an osteoporotic model: pullout strength of pedicle screw anchor versus larger screw diameter. 30:265–271, 201710.1097/BSD.0000000000000313)| false
MassieLWZakariaHMSchultzLRBasheerABuraimohMAChangV: Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis. Neurosurg Focus44(1):E82018
MassieLW, ZakariaHM, SchultzLR, BasheerA, BuraimohMA, ChangV: Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis. 44(1):E8, 201810.3171/2017.10.FOCUS1756229290133)| false
MatzPGMeagherRJLamerTTontzWLJrAnnaswamyTMCassidyRC: Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of degenerative lumbar spondylolisthesis. Spine J16:439–4482016
OkudaSOdaTYamasakiRHakuTMaenoTIwasakiM: Posterior lumbar interbody fusion with total facetectomy for low-dysplastic isthmic spondylolisthesis: effects of slip reduction on surgical outcomes: clinical article. J Neurosurg Spine21:171–1782014
PaikH, KangDG, LehmanRAJr, GaumeRE, AmbatiDV, DmitrievAE: The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?13:1617–1626, 201310.1016/j.spinee.2013.05.01323769931)| false
RoussoulyPGolloglySBerthonnaudELabelleHWeidenbaumM: Sagittal alignment of the spine and pelvis in the presence of L5-s1 isthmic lysis and low-grade spondylolisthesis. Spine (Phila Pa 1976)31:2484–24902006
RoussoulyP, GolloglyS, BerthonnaudE, LabelleH, WeidenbaumM: Sagittal alignment of the spine and pelvis in the presence of L5-s1 isthmic lysis and low-grade spondylolisthesis. 31:2484–2490, 200610.1097/01.brs.0000239155.37261.6917023859)| false
SatoK, KikuchiS, YonezawaT: In vivo intradiscal pressure measurement in healthy individuals and in patients with ongoing back problems. 24:2468–2474, 199910.1097/00007632-199912010-0000810626309)| false
ScheerJKAuffingerBWongRHLamSKLawtonCDNixonAT: Minimally invasive transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis in 282 patients: in situ arthrodesis versus reduction. World Neurosurg84:108–1132015
SpruitM, van JonbergenJP, de KleuverM: A concise follow-up of a previous report: posterior reduction and anterior lumbar interbody fusion in symptomatic low-grade adult isthmic spondylolisthesis. 14:828–832, 20051586466610.1007/s00586-005-0901-y)| false
WeinsteinJNSprattKFSpenglerDBrickCReidS: Spinal pedicle fixation: reliability and validity of roentgenogram-based assessment and surgical factors on successful screw placement. Spine (Phila Pa 1976)13:1012–10181988