Five-year follow-up of total disc replacement compared to fusion: a randomized controlled trial

Purpose

To evaluate long-term clinical results of lumbar total disc replacement (TDR) compared with posterior lumbar fusion.

Methods

This prospective randomized controlled trial comprised 152 patients; 80 were randomized to TDR and 72 to fusion. All patients had chronic low back pain (CLBP) and had not responded to nonsurgical treatment. Primary outcome measure was global assessment of back pain (GA), secondary outcome measures were back and leg pain, Oswestry Disability Index (ODI), EQ5D, and SF-36. All measures were collected from SweSpine (Swedish national register for spinal surgery) at 1, 2, and 5 years. Follow-up rate at 5 years was 99.3 %.

Results

Both groups showed clinical improvement at 5-year follow-up. For GA, 38 % (30/80) in the TDR group were totally pain free vs. 15 % (11/71) in the fusion group (p < 0.003). Back pain and improvement of back pain were better in the TDR group: VAS back pain at 5 years 23 ± 29 vs. 31 ± 27, p = 0.009, and VAS improvement of back pain at 5 years 40 ± 32 vs. 28 ± 32, p = 0.022. ODI and improvement in ODI were also better in the TDR group: ODI at 5 years 17 ± 19 vs. 23 + 17, p = 0.02 and ODI improvement at 5 years 25 ± 18 vs. 18 ± 19 (p = 0.02). There was no difference in complications and reoperations between the two groups.

Conclusions

Global assessment of low back pain differed between the two surgical groups at all follow-up occasions. Significant differences between groups concerning back pain, pain improvement, and ODI were present at 1 year and disappeared at 2 years, but reappeared at the 5-year follow-up.     

Influence of lumbar intervertebral disc degeneration on the outcome of total lumbar disc replacement: a prospective clinical, histological, X-ray and MRI investigation

Introduction

The role of fusion of lumbar motion segments for the treatment of axial low back pain (LBP) from lumbar degenerative disc disease (DDD) without any true deformities or instabilities remains controversially debated. In an attempt to avoid previously published and fusion-related negative side effects, motion preserving technologies such as total lumbar disc replacement (TDR) have been introduced. The adequate extent of preoperative DDD for TDR remains unknown, the number of previously published studies is scarce and the limited data available reveal contradictory results. The goal of this current analysis was to perform a prospective histological, X-ray and MRI investigation of the index-segment’s degree of DDD and to correlate these data with each patient’s pre- and postoperative clinical outcome parameters from an ongoing prospective clinical trial with ProDisc II (Synthes, Paoli, USA).

Materials and methods

Nucleus pulposus (NP) and annulus fibrosus (AF) changes were evaluated according to a previously validated quantitative histological degeneration score (HDS). X-ray evaluation included assessment of the mean, anterior and posterior disc space height (DSH). MRI investigation of DDD was performed on a 5-scale grading system. The prospective clinical outcome assessment included Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores as well as the patient’s subjective satisfaction rates.

Results

Data from 51 patients with an average follow-up of 50.5 months (range 6.1–91.9 months) were included in the study. Postoperative VAS and ODI scores improved significantly in comparison to preoperative levels (p < 0.002). A significant correlation and interdependence was established between various parameters of DDD preoperatively (p < 0.05). Degenerative changes of NP tissue samples were significantly more pronounced in comparison to those of AF material (p < 0.001) with no significant correlation between each other (p > 0.05). Preoperatively, the extent of DDD was not significantly correlated with the patient’s symptomatology (p > 0.05). No negative influence was associated with increasing stages of DDD on the postoperative clinical outcome parameters following TDR (p > 0.05). Increasing stages of DDD in terms of lower DSH scores were not associated with inferior clinical results as outlined by postoperative VAS or ODI scores or the patient’s subjective outcome evaluation at the last FU examination (p > 0.05). Conversely, some potential positive effects on the postoperative outcome were observed in patients with advanced stages of preoperative DDD. Patients with more severe preoperative HDS scores of NP samples demonstrated significantly lower VAS scores during the early postoperative course (p = 0.02).

Conclusion

Increasing stages of DDD did not negatively impact on the outcome following TDR in a highly selected patient population. In particular, no preoperative DDD threshold value was identified from which an inferior postoperative outcome could have been deduced. Conversely, some positive effects on the postoperative outcome were detected in patients with advanced stages of DDD. Combined advantageous effects of progressive morphological structural rigidity of the index segment and restabilizing effects from larger distraction in degenerated segments may compensate for increasing axial rotational instability, one of TDR’s perceived disadvantages. Our data reveal a “therapeutic window” for TDR in a cohort of patients with various stages of DDD as long as preoperative facet joint complaints or degenerative facet arthropathies can be excluded and stringent preoperative decision making criteria are adhered to. Previously published absolute DSH values as contraindication against TDR should be reconsidered.     

Outcomes of posterior facet versus pedicle screw fixation of circumferential fusion: a cohort study

Purpose

To compare single-level circumferential spinal fusion using pedicle (n = 27) versus low-profile minimally invasive facet screw (n = 35) posterior instrumentation.

Method

A prospective two-arm cohort study with 5-year outcomes as follow-up was conducted. Assessment included back and leg pain, pain drawing, Oswestry disability index (ODI), pain medication usage, self-assessment of procedure success, and >1-year postoperative lumbar magnetic resonance imaging.

Results

Significantly less operative time, estimated blood loss and costs were incurred for the facet group. Clinical improvement was significant for both groups (p < 0.01 for all outcomes scales). Outcomes were significantly better for back pain and ODI for the facet relative to the pedicle group at follow-up periods >1 year (p < 0.05). Postoperative magnetic resonance imaging found that 20 % had progressive adjacent disc degeneration, and posterior muscle changes tended to be greater for the pedicle screw group.

Conclusion

One-level circumferential spinal fusion using facet screws proved superior to pedicle screw instrumentation.     

Association of facet tropism and progressive facet arthrosis after lumbar total disc replacement using ProDisc-L®

Purpose

The purpose of this retrospective study was to examine the association of facet tropism and progressive facet arthrosis (PFA) after lumbar total disc replacement (TDR) surgery using ProDisc-L^®.

Methods

A total of 51 segments of 42 patients who had undergone lumbar TDR using ProDisc-L^® between October 2003 and July 2007 and completed minimum 36-month follow-up period were retrospectively reviewed. The changes of facet arthrosis were categorized as non-PFA and PFA group. Comparison between non-PFA and PFA group was made according to age, sex, mean follow-up duration, grade of preoperative facet arthrosis, coronal and sagittal prosthetic position and degree of facet tropism. Multiple logistic regression analysis was also performed to analyze the effect of facet tropism on the progression of facet arthrosis.

Results

The mean age at the surgery was 44.43 ± 11.09 years and there were 16 males and 26 females. The mean follow-up period was 53.18 ± 15.79 months. Non-PFA group was composed of 19 levels and PFA group was composed of 32 levels. Age at surgery, sex proportion, mean follow-up period, level of implant, grade of preoperative facet arthrosis and coronal and sagittal prosthetic position were not significantly different between two groups (p = 0.264, 0.433, 0.527, 0.232, 0.926, 0.849 and 0.369, respectively). However, PFA group showed significantly higher degree of facet tropism (7.37 ± 6.46°) than that of non-PFA group (3.51 ± 3.53°) and p value was 0.008. After adjustment for age, sex and coronal and sagittal prosthetic position, multiple logistic regression analysis revealed that facet tropism of more than 5° was the only significant independent predictor of progression of facet arthrosis (odds ratio 5.39, 95 % confidence interval 1.251–19.343, p = 0.023).

Conclusions

The data demonstrate that significant higher degree of facet tropism was seen in PFA group compared with non-PFA group and facet tropism of more than 5° had a significant association with PFA after TDR using ProDisc-L^®.     

Comparison of alcohol ablation with repeated thermal radiofrequency ablation in medial branch neurotomy for the treatment of recurrent thoracolumbar facet joint pain

Purpose

Chemical denervation is not recommended as part of the routine care of chronic non-cancer pain. Physicians face a dilemma when it comes to repeated interventions in cases of recurrent thoracolumbar facet joint pain after successful thermal radiofrequency ablation (RFA) in medial branch neurotomy. This study was performed to compare the effects of alcohol ablation (AA) with thermal RFA in patients with recurrent thoracolumbar facet joint pain after thermal RFA treatment.

Methods

Forty patients with recurrent thoracolumbar facet joint pain after successful thermal RFA defined as a numeric rating scale (NRS) score of ≥7 or a revised Oswestry disability index (ODI) of ≥22 % were randomly allocated to two groups receiving either the same repeated RFA (n = 20) or AA (n = 20). The recurrence rate was assessed with NRS and ODI during the next 24 months, and adverse events in each group were recorded.

Results

During the 24-month follow-up after RFA and AA, one and 17 patients, respectively, were without recurring thoracolumbar facet joint pain. The median effective periods in the RFA and AA groups were 10.7 (range 5.4–24) and 24 (range 16.8–24) months, respectively (p < 0.000). No significant complications were observed with the exception of injection site pain, which occurred in both groups.

Conclusion

In our patient cohort, alcohol ablation in medial branch neurotomy provided a longer period of pain relief and better quality of life than repeated radiofrequency medial branch neurotomy in the treatment of recurrent thoracolumbar facet joint pain syndrome after successful thermal RFA without significant complications during the 24-month follow-up.     

Parameters influencing the outcome after total disc replacement at the lumbosacral junction. Part 1: misalignment of the vertebrae adjacent to a total disc replacement affects the facet joint and facet capsule forces in a probabilistic finite element analysis

Purpose

After total disc replacement with a ball-and-socket joint, reduced range of motion and progression of facet joint degeneration at the index level have been described. The aim of the study was to test the hypothesis that misalignment of the vertebrae adjacent to the implant reduces range of motion and increases facet joint or capsule tensile forces.

Methods

A probabilistic finite element analysis was performed using a lumbosacral spine model with an artificial disc at level L5/S1. Misalignment of the L5 vertebra, the gap size of the facet joints, the transection of the posterior longitudinal ligament, and the spinal shape were varied. The model was loaded with pure moments.

Results

Misalignment of the L5 vertebra reduced the range of motion up to 2°. A 2-mm displacement of the L5 vertebra in the anterior direction already led to facet joint forces of approximately 240 N. Extension, lateral bending, and axial rotation caused maximum facet joint forces between 280 and 380 N, while flexion caused maximum forces of approximately 200 N. A 2-mm displacement in the posterior direction led to capsule forces of approximately 80 N. Additional moments increased the maximum facet capsule forces to values between 120 and 230 N.

Conclusions

Misalignment of the vertebrae adjacent to an artificial disc strongly increases facet joint or capsule forces. It might, therefore, be an important reason for unsatisfactory clinical results. In an associated clinical study (Part 2), these findings are validated.     

Lumbar total disc replacement: correlation of clinical outcome and radiological parameters

Background

The objective of this study was to correlate various radiological parameters with clinical outcome in patients who had undergone lumbar total disc replacement (TDR). Lumbar TDR is one possible treatment option in patients with low back pain (LBP), offering an alternative to lumbar fusion. Favourable clinical outcome hinges on a number of radiological parameters, such as mobility, sintering, and—most importantly—accurate positioning of the implant.

Methods

A total of 46 patients received a prosthetic disc because of degenerative lumbar disc disorders. Follow-up evaluation included analysis of radiographs and subjective rating of the clinical status by the patient using the North American Spine Society (NASS) patient questionnaire, visual analogue scale (VAS) for pain and state of health, and the EuroQol EQ-5D. Radiological follow-up took place after 2 years. Coronal and sagittal positions of the prosthesis, intervertebral disc height, facet joint pressure, mobility, sintering, and calcification were evaluated. Optimal positioning of the prosthesis was defined as a central coronal position and a most dorsal position in the sagittal plane. Based on the radiologically determined placement of the prosthesis, the patient population was divided into three groups, i.e., prosthesis ideally placed (<2 mm), discretely shifted (2–3 mm), or suboptimally placed (>3 mm).

Results

Overall, 81 % of patients stated that they would undergo the operation again. Health status was stable at a VAS score of 7.04 points 2 years after TDR, compared to 3.97 points before TDR. Mean working capacity had increased from 53 % preoperatively to 88 % 2 years after TDR. Overall, 39 % of the prostheses were rated as ideally positioned, while 13 % were discretely shifted and 48 % were suboptimally placed with respect to one of the radiological criteria. In 80.4 % of patients, follow-up assessment after ≥2 years indicated good mobility at the operated segment, while calcification was noted in 4 % and sintering was detected in 15 % of the implants.

Conclusions

Our data indicate poor correlation between clinical outcome and position of the prosthesis. Although 48 % of the implants were suboptimally placed in either the coronal or sagittal plane, most of the patients reached a very good clinical outcome. However, suboptimally placed devices appeared to cause significantly more neurological symptoms in long-term follow-up.     

Artificial total disc replacement versus fusion for lumbar degenerative disc disease: a meta-analysis of randomized controlled trials

Objective

The purpose of this study is to compare the effectiveness and safety of artificial total disc replacement (TDR) with fusion for the treatment of lumbar degenerative disc disease (DDD).

Summary of background data

Spinal fusion is the conventional surgical treatment for lumbar DDD. Recently, TDR has been developed to avoid the negative effects of the fusion by preserving function of the motion segment. Controversy still surrounds regarding whether TDR is better.

Methods

We systematically searched six electronic databases (Medline, Embase, Clinical, Ovid, BIOSIS and Cochrane registry of controlled clinical trials) to identify randomized controlled trials (RCTs) published up to March 2013 in which TDR was compared with the fusion for the treatment of lumbar DDD. Effective data were extracted after the assessment of methodological quality of the trials. Then, we performed the meta-analysis.

Results

Seven relevant RCTs with a total of 1,584 patients were included. TDR was more effective in ODI (MD ?5.09; 95 % CI [?7.33, ?2.84]; P < 0.00001), VAS score (MD ?5.31; 95 % CI [?8.35, ?2.28]; P = 0.0006), shorter duration of hospitalization (MD ?0.82; 95 % CI [?1.38, ?0.26]; P = 0.004) and a greater proportion of willing to choose the same operation again (OR 2.32; 95 % CI [1.69, 3.20]; P < 0.00001). There were no significant differences between the two treatment methods regarding operating time (MD ?44.16; 95 % CI [?94.84, 6.52]; P = 0.09), blood loss (MD ?29.14; 95 % CI [?173.22, 114.94]; P = 0.69), complications (OR 0.72; 95 % CI [0.45, 1.14]; P = 0.16), reoperation rate (OR 0.83; 95 % CI [0.39, 1.77]; P = 0.63) and the proportion of patients who returned to full-time/part-time work (OR 1.10; 95 % CI [0.86, 1.41]; P = 0.47).

Conclusion

TDR showed significant safety and efficacy comparable to lumbar fusion at 2 year follow-up. TDR demonstrated superiorities in improved physical function, reduced pain and shortened duration of hospitalization. The benefits of operating time, blood loss, motion preservation and the long-term complications are still unable to be proved.     

Can cantilever transforaminal lumbar interbody fusion (C-TLIF) maintain segmental lordosis for degenerative spondylolisthesis on a long-term basis?

Purpose

To determine if cantilever transforaminal lumbar interbody fusion (C-TLIF) using the crescent-shaped titanium interbody spacer (IBS) favors acquisition of segmental and lumbar lordosis even for degenerative spondylolisthesis (DS) on a long-term basis.

Methods

We analyzed 23 consecutive patients who underwent C-TLIF with pedicle screw instrumentations fixed with compression for a single-level DS. Measurements on the lateral radiographs taken preoperatively, 2 weeks postoperatively and at final follow-up included disc angle (DA), segmental angle (SA), lumbar lordosis (LL), disc height (%DH) and slip rate (%slip).

Results

There was a good functional recovery with 100 % fusion rate at the mean follow-up of 62 months. Segmental lordosis (DA and SA) and  %DH initially increased, but subsequently decreased with the subsidence of the interbody spacer, resulting in a significant increase (p = 0.046) only in SA from 13.2° ± 5.5° preoperatively to 14.7° ± 6.4° at the final follow-up. Changes of LL and  %slip were more consistent without correction loss finally showing an increase of LL by 3.6° (p = 0.005) and a slip reduction by 6.7 % (p < 0.001).

Conclusions

Despite the inherent limitation of placing the IBS against the anterior endplate of the upper vertebra in the presence of DS, the C-TLIF helped significantly restore segmental as well as lumbar lordosis on a long-term basis, which would be of benefit in preventing hypolordosis-induced back pain and the adjacent level disc disease.     

Cervical arthroplasty with Discover prosthesis: clinical outcomes and analysis of factors that may influence postoperative range of motion

Purpose

The aim of this current study was to analyze the clinical outcomes after Discover cervical disc replacement and its effects on maintaining cervical lordosis and range of motion (ROM). The possible factors influencing postoperative ROM were analyzed.

Method

27 men and 28 women with a mean age of 46.4 ± 8.7 years were prospectively followed up for 2 years. Clinical outcomes were assessed using Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), visual analog scale (VAS) and Odom’s criteria. Radiographic information including segment and overall alignment, functional spinal unit (FSU) and overall ROM, and disc heights were prospectively collected during the follow-up. The correlations between the postoperative FSU ROM at last follow-up and influencing factors were analyzed.

Results

Mean NDI, JOA and VAS scores showed statistical improvements at last follow-up. Anterior migration of the prosthesis was detected in six cases. Heterotopic ossification was observed in ten patients. Mean FSU angle, endplate angle of the treated level and mean overall cervical alignment were all improved significantly at last follow-up (P < 0.001). However, mean FSU ROM of the treated segment significantly decreased postoperatively (P = 0.008), while mean overall ROM showed no significant differences. A significant correlation was found between preoperative FSU ROM and postoperative FSU ROM by the Pearson correlation coefficient (r = 0.325, P = 0.034). Multiple linear regression analysis confirmed that preoperative FSU ROM contributed independently to a model with a coefficient of determination of 0.37 (P = 0.034).

Conclusions

In the 2 years follow-up, the Discover cervical disc arthroplasty has provided satisfactory clinical outcomes. It was able to substantially restore segment and overall cervical alignment while partially maintaining segment and overall cervical ROM. Additionally, we found that postoperative FSU ROM positively correlated with preoperative FSU ROM.     

Clinical and radiological results of total disc replacement in the cervical spine with preoperative reducible kyphosis

Purpose

To investigate the clinical and radiological results of total disc replacement (TDR) in the cervical spine with preoperative reducible kyphosis, and discuss when TDR is indicated for the patients with preoperative kyphosis.

Methods

Fifty-two patients who underwent single-level cervical TDR from June 2008 to May 2010 were included in this study. TDR was indicated for patients with preoperative lordosis or reducible kyphosis, and the patients were divided into a lordotic group (preoperative global angle of ≥0°) and kyphotic group (preoperative global angle of <0°). Clinical results were evaluated using the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score and Neck Disablity Index (NDI). For radiological evaluation, the global and functional spinal unit (FSU) angles and the global and FSU range of motion were measured preoperatively and postoperatively.

Results

The mean NDI in the kyphotic group was significantly higher than that in the lordotic group preoperatively and at six months postoperatively, but the groups showed no significant differences in JOA score, VAS score and NDI at the two year follow-up. The mean global and FSU angles in the kyphotic group were significantly lower than those in the lordotic group preoperatively and at six months postoperatively, but they gradually improved postoperatively. The differences lost significance at the two year follow-up.

Conclusions

Postoperative cervical kyphosis had adverse effects on the NDI after TDR. Artificial discs, symptom relief, and neck functional exercises may contribute to correction of preoperative reducible kyphosis at different stages after cervical TDR. Preoperative reducible kyphosis should not be an independent contraindication for cervical TDR.     

Comparative effectiveness of PEEK rods versus titanium alloy rods in lumbar fusion: A preliminary report

Background

Posterior lumbar instruments made of titanium and its alloys could change the physiological distribution of load at the instrumented and adjacent segments, which is a main cause of implant failure, non-fusion and adjacent segment degeneration. Posterior lumbar rods made of polyetheretherketone (PEEK) which is a semirigid alternative to titanium and its alloys have been introduced in lumbar fusion. This prospective study compared the radiological and clinical outcomes of patients undergoing lumbar fusion with PEEK rods versus titanium alloy rods.

Methods

Using transpedicular fixation and lumbar fusion, 21 patients were treated with titanium alloy rods (TI group), and 20 patients with PEEK rods (PEEK group). Radiological and clinical outcomes were evaluated, including the status of the implanted instruments, fusion rate, lumbar lordosis angle (LA), disc space height (DH), visual analog score (VAS) for lower back pain (VAS-BP) and leg pain (VAS-LP), Japanese Orthopedic Association scoring system (JOA score) and complications.

Results

Clinical VAS-BP, VAS-LP and JOA scores were significantly improved at 3 months, 6 months, and 1 year postoperatively as compared with preoperative scores in both groups (p?<?0.05), with similar levels of improvement observed at the same time points postoperatively between the two groups. The overall fusion rate was 100 % at the 1-year follow-up for both groups. No significant differences in lumbar lordosis angle were found preoperatively, 1 week and 1 year postoperatively in both groups (p?>?0.05). The postoperative increase of disc space height and loss of disc space height during the follow-up showed a similar extent of change between both groups (p?>?0.05).

Conclusions

PEEK rods offer a similar radiological and clinical efficacy as titanium alloy rods. PEEK rods, as a semirigid implant with unique characteristics, may be an effective alternative treatment for patients with degenerative lumbar disease in lumbar fusion.     

Clinical outcomes of minimally invasive versus open approach for one-level transforaminal lumbar interbody fusion at the 3- to 4-year follow-up

Purpose

Supporters of minimally invasive approaches for transforaminal lumbar interbody fusion (TLIF) have reported short-term advantages associated with a reduced soft tissue trauma. Nevertheless, mid- and long-term outcomes and specifically those involving physical activities have not been adequately studied. The aim of this study was to compare the clinical outcomes of mini-open versus classic open surgery for one-level TLIF, with an individualized evaluation of the variables used for the clinical assessment.

Methods

A prospective cohort study was conducted of 41 individuals with degenerative disc disease who underwent a one-level TLIF from January 2007 to June 2008. Patients were randomized into two groups depending on the type of surgery performed: classic open (CL-TLIF) group and mini-open approach (MO-TLIF) group. The visual analog scale (VAS), North American Spine Society (NASS) Low Back Pain Outcome instrument, Oswestry Disability Index (ODI) and the Short Form 36 Health Survey (SF-36) were used for clinical assessment in a minimum 3-year follow-up (36–54 months).

Results

Patients of the MO-TLIF group presented lower rates of lumbar (p = 0.194) and sciatic pain (p = 0.427) and performed better in daily life activities, especially in those requiring mild efforts: lifting slight weights (p = 0.081), standing (p = 0.097), carrying groceries (p = 0.033), walking (p = 0.069) and dressing (p = 0.074). Nevertheless, the global scores of the clinical questionnaires showed no statistical differences between the CL-TLIF and the MO-TLIF groups.

Conclusions

Despite an improved functional status of MO-TLIF patients in the short term, the clinical outcomes of mini-open TLIF at the 3- to 4-year follow-up showed no clinically relevant differences to those obtained with open TLIF.     

Effect of pulsed radiofrequency in treatment of facet-joint origin back pain in patients with degenerative spondylolisthesis

Background

Degenerative spondylolisthesis is a well-recognized source of low back pain mainly induced by facet joint pain. Pulsed radiofrequency (PRF) allows heat dissipation, thus producing a temporary injury that affects only type C fibers responsible for pain conduction.

Objectives

We attempted to test whether PRF is a better choice for facet pain due to spondylolisthesis compared to routine steroid injection.

Methods

Patients were randomly assigned to one of two groups: group one received pulsed RF, and group 2 received injection by steroids (triamcinolone) and bupivacaine.

Outcomes assessment

Multiple outcome measures were utilized which included the numeric rating scale (NRS), the Oswestry Disability Index (ODI), satisfaction status, and analgesic intake with assessment at 3, 6, and 12 months post-treatment. Significant pain relief was defined as 50 % or more, whereas significant improvement in disability score was defined as reduction of 40 % or more.

Results

Eighty patients were enrolled in the study and were divided into the two groups of study. PRF significantly reduced NRS at 6-month follow-up compared to steroid + bupivacaine. 75.6 ± 14.3 % at pre-treatment and 19.3 ± 9.5 % at 6 months (p = 0.001) in PRF group. The mean ODI is depicted in two groups of study (Fig. 1). Interestingly, ODI% was significantly lower in PRF group at 12 weeks and 6 months compare to steroid + bupivacaine group (p = 0.022 and 0.03, respectively), but it was not significantly different at 6 weeks (p = 0.31). Proportion of patients who did not require analgesics were significantly higher in PRF group compared to other group (p = 0.001) in Log-rank (Mantel–Cox) test.

Conclusion

Our results demonstrated that the application of PRF might be more effective than steroid and bupivacaine injection in decreasing back pain due to degenerative facet pain and improvement in function of patients.     

Optimizing success with lumbar disc arthroplasty

Purpose

This study aimed at determining the variables that may prove useful in predicting clinical outcomes following lumbar disc arthroplasty.

Methods

Pre- and post-operative imaging assessments were obtained for 99 single-level lumbar disc arthroplasty patients from a prospective IDE study. The assessments and patient demographics were tested to identify variables that were significantly associated with clinical outcomes.

Results

Clinical outcome data were available for 85 % of patients at the 5-year follow-up. Numerous assessments made from the pre-operative imaging were found to have statistically significant associations with clinical outcomes at 2 and 5 years. The most notable factors were related to the amount of degeneration at the index level, with patients achieving better outcome scores at 5 years if they have higher grades of degeneration preoperatively.

Conclusions

Several variables may prove effective at optimizing clinical outcomes including a preoperative disc height <8 mm, Modic type 2 changes adjacent to the target disc, a low amount of lordosis present at the treatment level, low levels of fatty replacement of the paraspinal musculature, a prominent amount of facet joint or disc degeneration, and the presence of flat or convex vertebral endplates. There were also post-operative findings associated with better patient outcomes including a larger percent of the endplate covered with the implant, larger implant heights, greater increases in disc space heights, and a larger increase in index level lumbar lordosis. These variables could be explored in other clinical studies to facilitate meta-analyses that could identify effective strategies to optimize clinical outcomes with lumbar disc arthroplasty.     

Posterolateral versus circumferential instrumented fusion for monosegmental lumbar degenerative disc disease using an expandable cage

Background

Theoretically, 360° instrumented fusion has been considered to offer better radiological correction than PLF. Despite numerous publications, this correlation is still weak with several controversies in the relative literature.

Purpose

This prospective randomized study was designed to compare the radiological segmental results, complications and outcome of 360° instrumented fusion with the use of a single diagonal expandable PLIF device versus posterolateral pedicle screw fixation in monosegmental lumbar DDD and to show that the use of an novel expandable cage is associated with low PLIF-related complication rate compared to conventional cages reported previously.

Study design

Prospective randomized controlled clinical and radiological study.

Patient sample

Adults who suffered from monosegmental DDD were eligible for enrolment in this trial. We randomly assigned 150 patients to receive either 360° instrumented fusion (group A) with expandable cage or PLF (group B).

Outcome measures

Differences between the two groups regarding clinical parameters and radiographic sagittal measurements after 36?months of follow-up.

Methods

The record included global [T12-S1 lordosis, sagittal global spinal balance (SB) (C7-mid-femoral axis)] and segmental [segmental disc wedging (SDW), anterior (ADHr) and posterior (PDHr) disc height ratio] radiological measurements at the instrumented segment. Additionally, clinical outcome was evaluated with VAS, SF-36 (Physical function and Bodily Pain) and ODI questionnaires. Fusion was evaluated with the use of Christiansen method.

Results

In 73 and 72 participants of group A and B, respectively, who completed follow-up to 36?months, there were no differences with respect to the rate of improvement in SF-36, ODI and VAS scores. However, in the spines of group A, there was a significant increase in anterior disc height ratio (P?=?0.0057), posterior disc height (P?=?0.016) and segmental disc wedging (P?=?0.00021) without subsequent loss of correction. Fusion rate was radiologically shown in 94.5% and 87% spines of group A and B, respectively (P?>?0.2). Four and 9 spines in group A and B, respectively, showed non-union at the final observation.

Conclusions

Our findings suggest that 360° fusion offers better sagittal radiological restoration associated with circumferential fusion. However, this difference seemed not to have any medium-term clinical impact. The use of expandable cage was associated with low PLIF-related complications compared to conventional cages.     

Clinical assessment of a CMC/PEO gel to inhibit postoperative epidural adhesion formation after lumbar discectomy: a randomized, control study

Purpose

To evaluate effectiveness of carboxymethylcellulose/polyethylene oxide (CMC/PEO) gel in improving clinical outcomes after the first-time lumbar discectomy.

Method

Ninety-three patients with herniated lumbar disc at L4–L5 or L5–S1 were enrolled and randomized into two groups: CMC/PEO gel treatment group and control group. All the patients underwent laminotomy and discectomy by posterior approach. The preoperative and postoperative Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) scores for lower-back pain and leg pain were analyzed and compared between two groups at 30- and 60-day time points.

Results

No patient presented with any clinically measurable adverse event during surgery. There were no significant differences between the treated group and the control group on the preoperative ODI and VAS scores. In general, the ODI and VAS scores decreased in both groups at all the time points. At the 30-day time point, the VAS scores for back pain and leg pain and the ODI scores in treatment group were lower by 9.9 % (P = 0.0302), 27.0 % (P = 0.0002) and 16.3 % (P = 0.0007) than those in control group. And at the 60-day time point, the ODI and VAS scores further decreased in both groups. The VAS scores for leg pain in treatment group were lower by 4.5 % than that in the control group (P = 0.0149). However, no significant difference was detected between two groups on the ODI and VAS scores for back pain.

Conclusions

The results demonstrated that CMC/PEO gel is effective in reducing posterior dural adhesions in the spine with no apparent safety issues. It can improve patients’ postoperative clinical outcome.     

Extreme lateral interbody fusion for unilateral symptomatic vertical foraminal stenosis

Purpose

Asymmetric loss of disc height in adult deformity patients may lead to unilateral vertical foraminal stenosis and radiculopathy. The current study aimed to investigate whether restoration of foraminal height on the symptomatic side using extreme lateral interbody fusion (XLIF) would alleviate unilateral radiculopathy.

Methods

In a retrospective study, patients with single-level unilateral vertical foraminal stenosis and corresponding radicular pain undergoing XLIF were included. Functional data (visual analog scale (VAS) for buttock, leg and back, as well as Oswestry Disability Index (ODI)) and radiographic measurements (bilateral foraminal height, disc height, segmental coronal Cobb angle and regional lumbar lordosis) were collected preoperatively, postoperatively and at the last follow-up.

Results

Twenty-three patients were included, among whom 61 % had degenerative scoliosis. History of previous surgery at the level of index was present in 43 % of patients. Additional instrumentation was performed in 91 %. The foraminal height on the stenotic side was significantly increased postoperatively (p < 0.001), and remained significantly increased at the last follow-up of 11 ± 3.7 months (p < 0.001). Additionally, VAS buttock and leg on the stenotic side, VAS back and ODI were significantly improved postoperatively and at the last follow-up (p ≤ 0.001 for all parameters). The foraminal height on the stenotic side showed correlation with the VAS leg on the stenotic side, both postoperatively and the last follow-up (r = ?0.590; p = 0.013, and r = ?0.537; p = 0.022, respectively).

Conclusions

Single-level XLIF is an effective procedure for treatment of symptomatic unilateral foraminal stenosis leading to radiculopathy. In deformity patients with radicular pain caused by nerve compression at a single level, when not associated with other symptoms attributable to general scoliosis, treatment with single-level XLIF can result in short- and mid-term satisfactory outcome.

     

The results of a consecutive series of dynamic posterior stabilizations using the PercuDyn device

Purpose

To evaluate the results of a consecutive series of patients affected by lumbar discogenic pain associated with facet pain and canal stenosis surgically treated with the PercuDyn device.

Methods

From 2009, 129 consecutive patients (96 M, 33 F, mean age 62) were treated with posterior dynamic stabilization screws (PercuDyn). Inclusion criteria were minimum follow-up of 24 months; pain localized at the lumbar spine column alone or in association to lower limb radicular pain; magnetic resonance evidence of disc degeneration associated with facet degeneration and canal stenosis. Patients were clinically studied using VAS scale and Oswestry Disability Index (ODI); CT assessment of the neuroforamina and spinal canal areas was done at 1 month of follow-up.

Results

At 24 months of follow-up, 96 patients fulfilled the inclusion criteria. 96 intervertebral spaces were treated (85 levels L5–S1, 11 levels L4–L5). The VAS scale showed a statistically significant difference at 1 month, 6 months and 2 years with respect to the pre-operative value (p < 0.001). The ODI score registered a significant difference with the same fashion (p < 0.001 both at 1- and 6-month, and 2-year follow-up with respect to the pre-operatory). At 1-month follow-up, neuroforamina and spinal canal areas were considerably wider (p < 0.05). 70 (72.5 %) patients were satisfied of the procedure.

Conclusions

In this wide cohort study, the PercuDyn ensured good clinical and radiological results, with more than 70 % of patients satisfied of the procedure. Very few complications were noted, with an immediate return to daily activities. At longer follow-ups, 10 % of patients received revision surgery.