Changes in serum creatine phosphokinase MM isoenzyme after lumbar spine surgery

Comparison of Clinical and Radiographic Outcomes Between Percutaneous Endoscopic Transforaminal Diskectomy and Unilateral Biportal Endoscopic Diskectomy for the Treatment of L4/5-Level MSU Size-3 Lumbar Disk Herniation: A 2-Year Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

Percutaneous endoscopic transforaminal diskectomy (PETD) and unilateral biportal endoscopic diskectomy (UBED) have demonstrated favorable clinical outcomes in managing lumbar disk herniation (LDH). The surgical treatment of Michigan State University (MSU) Size-3 LDH remains technically challenging. The aim of this study was to compare the clinical and radiographic outcomes of PETD and UBED, specifically in the treatment of L4/5-level MSU Size-3 LDH.

METHODS

The study included 138 patients who underwent either PETD (75 cases) or UBED (63 cases). During a follow-up period of at least 2 years, clinical outcomes were evaluated using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), modified MacNab criteria, complication and recurrence rates, serum creatine phosphokinase (CPK) levels, and other surgical data. Radiographic parameters, including intraoperative bone loss, paraspinal muscle-disk ratio, and intervertebral height index, were also monitored.

RESULTS

Both VAS scores for low back and leg pain, as well as ODI scores, showed significant decreases in both groups postoperatively. At baseline, 3 months postoperation, and at the final follow-up, VAS and ODI scores showed no statistically significant differences between the 2 groups. Compared with the UBED group, the PETD group showed lower VAS scores for incision pain on the first day and third day after surgery ( P < .001). Although no significant differences were observed in modified MacNab criteria, complication rates, or LDH recurrence, PETD demonstrated advantages in operative time, incision length, intraoperative blood loss, postoperative length of stay, total hospitalization costs, serum CPK levels, and intraoperative bone loss volume ( P < .001). No statistically significant differences were observed in the intervertebral height index or paraspinal muscle-disk ratio.

CONCLUSION

Both PETD and UBED can achieve favorable clinical outcomes in the treatment of L4/5-level MSU Size-3 LDH. Compared with UBED, PETD performed under local anesthesia offers superior short-term postoperative incision pain relief, improved perioperative quality of life, and reduced surgical invasiveness.

The feasibility and efficacy of pedicle fixation by the Wiltse approach in the thoracic spine

Study design

Retrospective Cohort Study.

Objectives

To explore the feasibility and assess the efficacy of pedicle fixation with the Wiltse approach in the thoracic spine.

Summary of background data

The current application of Wiltse approach is mainly practiced in the lumbar and thoracolumbar spines. Its application in the thoracic spine, however, has received little attention, especially in cases that requires only pedicel screw fixation without spinal decompression.

Methods

The study analyzed the clinical records of consecutive patients with thoracic diseases who underwent pedicle fixation with either Wiltse or the conventional transmuscular approach (Wiltse group: 60 cases; Transmuscular group: 48 cases). Perioperative parameters, Visual Analogue Scale (VAS) scores, accuracy of pedicle screw placement, dead space between the muscles, Magnetic Resonance Imaging (MRI) appearance, electrophysiological changes in the multifidus muscle were compared between the two groups.

Results

Compared with the transmuscular group, the Wiltse group was significantly better in blood loss and postoperative VAS scores. No difference was observed in incision length, operation time, and hospital stay. The dead space between the muscle cross-sectional region in the transmuscular group was 315 ± 53 mm2, and no dead space was found in the Wiltse group. On MRI images, the multifidus cross-sectional area (CSA) in the Wiltse group between the preoperative period and the last follow-up reduced by only 10.1%, while transmuscular group showed 46.1% CSA reduction. Electrophysiologically, the median frequency slope of the transmuscular group grew by 47.8% with average amplitude reduced by 16.4% between the preoperative period and 12-month postoperative.

Conclusion

The Wiltse approach for pedicle fixation in the thoracic spine is a feasible and effective treatment, with fewer traumas and reliable clinical results. In particular, the Wiltse approach reduces postoperative dead space between the muscles and causes less atrophy in the multifidus muscle.

Preoperative Multifidus Muscle Quality is Associated With Patient Reported Outcomes After Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) commonly involves a transpsoas approach. Despite the association between LLIF, postoperative iliopsoas weakness, and iatrogenic neuropraxia, no study has yet examined the effect of psoas or multifidus muscle quality on patient-reported outcomes (PROs).

METHODS

This study retrospectively reviewed patients who underwent LLIF with 1-year minimum follow-up. Psoas and multifidus muscle qualities were graded on preoperative magnetic resonance imaging using two validated classification systems for muscle atrophy. Average muscle quality was calculated as the mean score from all levels (L1-2 through L5-S1). Univariate and multivariate statistics were utilized to investigate the relationship between psoas/multifidus muscle quality and preoperative, 6-weeks postoperative, and final postoperative PROs.

RESULTS

74 patients (110 levels) with a mean follow-up of 18.71 ± 8.02 months were included for analysis. Greater multifidus atrophy was associated with less improvement on ODI, SF12, and VR12 (P < .05) on univariate analysis. On multivariate analysis, worse multifidus atrophy predicted less improvement on SF12 and VR12 (P < .05).

CONCLUSION

Despite the direct manipulation of the psoas muscle inherent to LLIF, preoperative psoas muscle quality did not affect postoperative outcomes. Rather, the extent of preoperative multifidus fatty infiltration and atrophy was more likely to predict postoperative pain and disability. These findings suggest that multifidus atrophy may be more pertinent than psoas atrophy in its association with patient-reported outcome measures after LLIF.

Comparison of a novel hand-held retractor-assisted transforaminal lumbar interbody fusion by the wiltse approach and posterior TLIF: a one-year prospective controlled study

BACKGROUND

This study aims to compare the clinical outcomes and safety of a novel hand-held retractor system-assisted Wiltse TLIF with that P-TLIF and assess whether this hand-held retractor system assisted Wiltse TLIF can yield less paraspinal muscle injury.

METHODS

56 patients (P-TLIF: 26, Wiltse TLIF: 30) were included in this one year prospective controlled study. The operation time, intraoperative blood loss, postoperative drainage, mobilization time, and discharge time were recorded. The clinical outcomes were evaluated by ODI, VAS, JOA, and SF-36 scores (7 days, 3, 6, and 12 months after surgery). Paraspinal muscle injury was assessed by postoperative MRI (6 months after surgery). CK and C-reaction protein were measured pre and postoperatively, and CT or X-ray (one year postoperatively) was used to assess bony union/non-union.

RESULTS

The Wiltse (study) group was associated with significantly less estimated blood loss (79.67 ± 28.59 ml vs 192.31 ± 59.48 ml, P = 0.000*), postoperative drainage (43.33 ± 27.89 ml vs 285.57 ± 123.05 ml, P = 0.000*), and shorter mobilization (4.1 ± 1.2 d vs. 3.0 ± 0.9 d, P < 0.05) and discharge times (7.7 ± 1.9 d vs. 6.1 ± 1.2 d, P = 0.002*) than the P-TLIF (control) group. Serum CK activity at 24 h postoperatively in the study group was significantly lower than in the control group (384.10 ± 141.99 U/L vs 532.76 ± 225.76 U/L, P = 0.018*). At 7 days after surgery, VAS (2.3 ± 0.6 vs 3.2 ± 0.7, P = 0.000*)and ODI scores (43.9 ± 11.9 vs 55.2 ± 12.9, P = 0.001*) were lower, while the JOA scores (18.4 ± 3.4 vs 16.3 ± 4.2, P = 0.041*) was higher in the control group than in the study group. Results observed at 3 months of follow-up were consistent with those at 7 days. After six months postoperatively, paraspinal muscle degeneration in the control group was more significant than in the study group (P = 0.008*).

CONCLUSION

Our study showed that this novel hand-held retractor system assisted Wiltse approach TLIF can significantly reduce paraspinal muscle injury, postoperative drainage, and intraoperative blood loss, mobilization and discharge time, as well as yield better short-term outcomes compared to P-TLIF.

TRIAL REGISTRATION

25/09/2023 NCT06052579.

Unilateral Biportal Endoscopic Posterior Cervical Foraminotomy: An Outcome Comparison With the Full-endoscopic Posterior Cervical Foraminotomy

STUDY DESIGN

Retrospective control study.

OBJECTIVE

To compare the curative effects of unilateral biportal endoscopic posterior cervical foraminotomy (UBE-PCF) with full-endoscopic posterior cervical foraminotomy (FPCF).

SUMMARY OF BACKGROUND DATA

There are few studies directly comparing outcomes between UBE-PCF and FPCF. The objective of this study was to compare outcomes between UBE-PCF and FPCF.

METHODS

A retrospective control study was conducted for 69 patients of cervical radiculopathy from July 2019 to December 2021. Clinical outcomes scores, including neck disability index, visual analog scale (VAS)-arm, and VAS-neck were evaluated. Serum creatine kinase levels and the size of the operating hole were measured.

RESULTS

Postoperative neck disability index, VAS-neck, and VAS-arm scores showed statistically significant improvement over preoperative scores ( P <0.01). The operating time was significantly shorter in the UBE-PCF group ( P <0.001). No significant differences were found in serum creatine kinase levels between the 2 groups ( P >0.05). The mean area of the operating hole was 1.47+0.05 cm 2 in the FPCF group and 1.79+0.11 cm 2 in the UBE-PCF group. The difference was statistically significant ( P <0.001).

CONCLUSIONS

Both UBE-PCF and FPCF are safe and effective procedures for cervical radiculopathy. Predictable and sufficient decompression could be achieved by UBE-PCF in a shorter operation time.

LEVEL OF EVIDENCE

Treatment Benefits Level III.

MIS-TLIF or CLIF for single segmental lumbar degenerative disease

We aimed to compare the effect of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and Crenel lateral interbody fusion (CLIF) on single segmental lumbar degenerative disease. Patients with single segmental lumbar degenerative disease undergoing MIS-TLIF (n = 28) and CLIF (n = 28) were enrolled from April to October 2017. Preoperative medical history, anthropometric data, and clinical data were recorded. Visual analogue scores and Oswestry disability index (ODI) were assessed. Radiography was performed before and after surgery. X-ray films were evaluated according to the Bridwell method, visual analogue scores and ODI scores were evaluated. There were no significant differences in the gender, age, clinical diagnosis, involved segment or preoperative ODI score between 2 groups (P > .05). During 12-month follow-up, MIS-TLIF group had less intraoperative blood loss, drainage, postoperative bedridden time, and hospital stay (P < .05), but more operation time and radiation exposure time compared with CLIF group (P < .05). CLIF group reported less pain than MIS-TLIF group (P > .05). Both groups had similar lumbar fusion rate (P > .05). Overall, CLIF has less complications, less trauma and faster recovery for the treatment of single segmental lumbar degenerate disease when compared with MIS-TLIF. Evaluation of more patients and long-term follow-up are still needed to further validate our findings.

[Short-term effectiveness of unilateral biportal endoscopic transforaminal lumbar interbody fusion for Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis]

Objective

To investigate the short-term effectiveness of unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) in the treatment of Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis.

Methods

The clinical data of 26 patients with Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis treated with UBE-TLIF between January 2021 and August 2021 were retrospectively analyzed. Among them, there were 10 males and 16 females with a mean age of 61.5 years (range, 35-76 years). The lesion segment included L 3, 4 in 2 cases, L 4, 5 in 18 cases, and L 5, S 1 in 6 cases. There were 17 cases of degenerative spondylolisthesis and 9 cases of isthmic spondylolisthesis; according to the Meyerding classification of spondylolisthesis, 19 cases were grade Ⅰ and 7 cases were grade Ⅱ. Twenty-one cases were complicated with lumbar disc herniation and spinal stenosis and 5 cases with lumbar spinal stenosis. The operation time, hospitalization stay, complications, hemoglobin (Hb) and serum creatine kinase (CK) levels before operation and at 1 day after operation were recorded; lumbar lordosis angle changes and postoperative spondylolisthesis reduction were evaluated by lumbar anteroposterior and lateral X-ray films before operation and at last follow-up; visual analogue scale (VAS) score was used to evaluate the low back pain and leg pain before operation, at 2 days, 1 week, 2 weeks after operation, and at last follow-up; Oswestry disability index (ODI) was used to evaluate the functional recovery of the patients before operation and at last follow-up.

Results

The operation was successfully completed in all 26 patients, with an average operation time of 181.9 minutes (range, 130-224 minutes) and an average hospitalization stay of 6.3 days (range, 3-9 days). Hb levels were significantly lower and serum CK levels were significantly higher at 1 day after operation when compared with those before operation ( t=7.594, P<0.001; t=-15.647, P<0.001). No serious complication occurred during and after operation. CT examination at 3 days after operation showed that the percutaneous screw was not in good position in 1 case, and nerve paralysis (pain, numbness) occurred in 2 cases after operation, which were improved within 2 weeks after operation. All the 26 patients were followed up 6-11 months, with an average of 8.7 months. Complete reduction (the slippage reduction rate was 100%) was achieved in 24 patients (92.3%), and partial reduction (the slippage reduction rate was 87.5%) in 2 patients (7.7%). During the follow-up, there was no complication such as incision infection, fusion Cage subsidence or displacement, and internal fixator loosening. The VAS scores of low back pain and leg pain significantly improved at each time point after operation when compared with those before operation ( P<0.05); there was no significant difference in the VAS scores of low back pain and leg pain between at 2 days and 1 week after operation, the VAS scores of low back pain between at 1 week and 2 weeks after operation, and the VAS scores of leg pain between at 2 weeks after operation and last follow-up ( P>0.05); but there was significant difference between the other time points after operation ( P<0.05). ODI and lumbar lordosis angle significantly improved at last follow-up ( P<0.05).

Conclusion

UBE-TLIF provides favorable short-term effectiveness and obvious advantages of minimally invasive in the treatment of Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis. However, the safety and long-term effectiveness need to be further studied.

A Comparative Study of a New Retractor‐Assisted WILTSE TLIF, MIS‐TLIF, and Traditional PLIF for Treatment of Single‐Level Lumbar Degenerative Diseases

Objectives

To compare the clinical efficacy of a new retractor‐assisted Wiltse transforaminal lumbar interbody fusion (TLIF), minimally invasive TLIF (MIS‐TLIF), and traditional posterior lumbar interbody fusion (PLIF) in treating single‐level lumbar degenerative diseases.

Methods

A retrospective study was conducted by analyzing the clinical and imaging data of consecutive patients with single‐level lumbar degenerative diseases who underwent the new retractor‐assisted Wiltse TLIF, MIS‐TLIF, or traditional PLIF. This study enrolled 87 concurrent patients between June 2016 and December 2019 (Wiltse TLIF 29 cases; MIS‐TLIF 28 cases; PLIF 30 cases). The three groups were compared for perioperative indicators (including intraoperative blood loss, postoperative drainage volume, operation time, intraoperative fluoroscopy time, bedridden time), creatine kinase (CK), visual analog score (VAS), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) score, intervertebral fusion rate, muscle atrophy, and fatty infiltration (including ratio of multifidus atrophy and ratio of lean‐to‐total cross‐sectional area [CSA]).

Results

Intraoperative blood loss (F = 62.628, p < 0.001), postoperative drainage volume (F = 72.048, p < 0.001), and bedridden time (χ² = 62.289, p < 0.001) were significantly lower in the MIS‐TLIF and Wiltse groups than in the PLIF group. The operative and intraoperative radiation times of the MIS‐TLIF group were significantly longer than those of the Wiltse and PLIF groups. The CK concentration in the Wiltse and MIS‐TLIF groups were significantly lower than those in the PLIF group 1 day (F = 9.331, p < 0.001) and 3 days after surgery (F = 15.967, p < 0.001). The PLIF group's back pain VAS score was higher than those of the Wiltse and MIS‐TLIF groups. The PLIF group had a higher ODI 6 months (F = 3.282, p = 0.042) and 12 months (F = 5.316, p = 0.007) after surgery and a lower JOA score than the Wiltse and MIS‐TLIF groups 6 months (F = 3.234, p = 0.044) and 12 months (F = 3.874, p = 0.025) after surgery. The ratio of multifidus atrophy in the PLIF group (41.70 ± 8.84%) was significantly higher than those of the Wiltse group (24.13 ± 6.82%) and the MIS‐TLIF group (22.35 ± 5.03%). The ratio of lean‐to‐total CSA in the PLIF group was lower than those of the Wiltse and MIS‐TLIF groups after surgery (F = 8.852, p < 0.001). MIS‐TLIF group showed longer operation time (169.11 ± 29.38 min) and intraoperative fluoroscopy time (87.61 ± 3.13 s) than the Wiltse group.

Conclusion

Wiltse TLIF assisted by the new retractor is a more convenient and minimally invasive surgical method than the traditional PLIF and MIS‐TLIF methods, which are linked to a long learning curve and long operation and fluoroscopy time.

Enhanced Recovery after an Innovative Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion for the Treatment of Lumbar Spinal Stenosis: A Prospective Observational Study

Background

The objective of this study was to investigate the enhanced recovery clinical effects of an innovative percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of patients with LSS and degenerative instability.

Methods

From January 2019 to March 2020, 51 patients with single-segment LSS and degenerative instability were prospectively included in our study (ChiCTR1900020679). The Oswestry Disability Index (ODI), the visual analogue scale (VAS) on lumbar and leg pain (VAS-LBP and VAS-LP), serum creatine kinase (CK), the peak intensity of sulphur hexafluoride microbubble contrast agent (PI), and the maximal cross-sectional area of multifidus muscle (Max-CSA) around the surgical incision were assessed preoperatively, postoperatively, and at regular follow-up.

Results

All patients were followed up. The mean postoperative bedridden time was 20.45 ± 2.66 hours. The ODI, VAS-LBP, and VAS-LP were improved significantly after operation compared to these data before operation in all the patients (P < 0.05). The CK at 1 day after operation was higher compared to the data before the operation (P < 0.05), and there was no significant difference on CK at 1 week after operation (P > 0.05). The PI at 1 week after operation was higher compared to this item before operation (P < 0.05), and there was no significant difference on PI at 1 month or 3 months after operation (P > 0.05). The Max-CSA at 1 week after operation was higher compared to this item before the operation (P < 0.05), and there was no significant difference in Max-CSA at 1 month or 3 months after operation compared with before the operation (P > 0.05).

Conclusions

Our results and systematic review presented the innovative PE-TLIF technique could obtain satisfactory and effective outcomes for the treatment of patients with LSS and degenerative instability. Our PE-TLIF technique also had the ability to decrease the MF injury and obtain an enhanced recovery.

The role of serum creatine kinase levels in anterior cervical spinal surgery: Change trends and risk factors

This study aimed to describe change trends in serum creatine kinase (CK) values for patients undergoing anterior cervical spinal surgery and identify risk factors that affect the CK values perioperatively, intending to decrease the degree of the iatrogenic invasiveness of the procedure.We retrospectively analyzed 122 patients undergoing anterior cervical spinal surgery from January 2019 to May 2020. For all patients, CK level was measured 1 day before the operation. Daily CK levels were evaluated on postoperative days 1 to 7. These data were analyzed in terms of age, gender, the use of microendoscopy during surgery, the number of cervical operative segments, and operative methods to determine whether these risk factors influenced postoperative CK increases.A total of 122 patients were enrolled. The preoperative average CK level was 72.7 U/L, and the average CK levels were 130.6, 122.4, 99.1, 82.8, 73.7, 63.9, and 55.4 U/L from the postoperative day (POD) 1 to POD7, respectively. CK level changes on POD1 increased with the number of operated cervical segments. However, changes were not related to age, gender, microendoscopy, or the operative method.Increased serum CK level was associated with the number of cervical operative segments, rather than age, gender, the use of microendoscopy, or the operative methods. These findings suggest that the number of cervical operative segments determined the degree of iatrogenic injury for anterior cervical spinal surgery.

Peri-Surgical Inflammatory Profile Associated with Mini-Invasive or Standard Open Lumbar Interbody Fusion Approaches

BACKGROUND

Different surgical approaches are available for lumbar interbody fusion (LIF) to treat disc degeneration. However, a quantification of their invasiveness is lacking, and the definition of minimally invasive surgery (MIS) has not been biochemically detailed. We aimed at characterizing the inflammatory, hematological, and clinical peri-surgical responses to different LIF techniques.

METHODS

68 healthy subjects affected by single-level discopathy (L3 to S1) were addressed to MIS, anterior (ALIF, n = 21) or lateral (LLIF, n = 23), and conventional approaches, transforaminal (TLIF, n = 24), based on the preoperative clinical assessment. Venous blood samples were taken 24 h before the surgery and 24 and 72 h after surgery to assess a wide panel of inflammatory and hematological markers.

RESULTS

martial (serum iron and transferrin) and pro-angiogenic profiles (MMP-2, TWEAK) were improved in ALIF and LLIF compared to TLIF, while the acute phase response (C-reactive protein, sCD163) was enhanced in LLIF.

CONCLUSIONS

MIS procedures (ALIF and LLIF) associated with a reduced incidence of post-operative anemic status, faster recovery, and enhanced pro-angiogenic stimuli compared with TLIF. LLIF associated with an earlier activation of innate immune mechanisms than ALIF and TLIF. The trend of the inflammation markers confirms that the theoretically defined mini-invasive procedures behave as such.

Clinical Research and Technique Note of TLIF by Wiltse Approach for the Treatment of Degenerative Lumbar

Objective

To assess the clinical efficacy and share the technique notes of Wiltse Approach TLIF for the treating single segment degenerative lumbar spinal disease.

Method

In this retrospective controlled study, 780 patients with single segment degenerative lumbar disease who were operated in our hospital from January 2016 to December 2020 were analyzed retrospectively. The patients were randomly assigned to Wiltse approach group (group A, 410 cases) and conventional open approach group (group B, 370 cases). Patient's assessment of pain and disability were evaluated by the visual analogue scale (VAS) and the Oswestry disability index (ODI) before and after surgery. The incision length, operative time, exposure time, intraoperative blood loss, hidden blood loss, time to ambulation, total length of hospitalization, serum creatine kinase, X‐rays, CT and MRI were also evaluated.

Results

There were no differences in sex, age, pre‐operative ODI score, VAS score between the two groups (P > 0.05). The Wiltse approach group had a shorter incision length with 7.69 ± 0.44 cm compared to the conventional group with 11.13 ± 0.36 cm (P < 0.01). The average operative time was 119.20 ± 14.64 min with exposure time of 16.20 ± 3.42 min in the Wiltse approach group and 145.65 ± 16.98 min with 29.20 ± 3.42 min in the conventional group (P < 0.05, P < 0.01). Comparing the intraoperative blood loss, hidden blood loss, serum creatine kinase, time to ambulation, total length of hospitalization, the Wiltse approach group was less than the conventional open approach group (P < 0.05). The VAS score of the two groups decreased significantly with time, and the VAS score of the Wiltse group was significantly lower than that of the conventional open approach group (P < 0.05). At last investigation after operation, ODI scores of the two groups were significantly decreased compared with that before operation. Wiltse approach group was significantly lower than that of the conventional open approach group (P < 0.05). The multifidus of the two groups of patients had a certain degree of atrophy. But the Wiltse approach group multifidus muscle atrophy rate is significantly lower than the conventional open approach group.

Conclusion

The Wiltse approach TLIF significantly reduces the damage to the paravertebral muscles and the postoperative incidence of chronic low back pain.

Comparison of Preliminary clinical outcomes between percutaneous endoscopic and minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative diseases in a tertiary hospital: Is percutaneous endoscopic procedure superior to MIS-TLIF? A prospective cohort study

BACKGROUND

Percutaneous endoscopic transforaminal lumbar interbody fusion (PETLIF) has been used in the treatment of lumbar degenerative diseases, as a novel minimally invasive technique.

OBJECTIVES

To compare the surgical trauma and the medium-short term postoperative outcomes of PETLIF and traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

From April to August of 2018, 75 patients with lumbar degenerative diseases received PETLIF (Group PE, 35 cases) or MIS-TLIF (Group MIS, 40 cases) were enrolled in the prospective cohort study. We recorded the serum creatine kinase (CK) and C-reactive protein (CRP), blood loss, visual analog scale (VAS), Oswestry Disability Index (ODI), modified Macnab criteria score, complications, and fusion rates of the 2 groups.

RESULTS

There were significant reductions in CRP (P = 0.002) on postoperative day (POD) 3, and CK (P = 0.011) on POD 1 for Group PE than Group MIS. The mean true total blood loss (P < 0.001), intraoperative blood loss (P < 0.001), postoperative drains (P < 0.001), and hidden blood (P = 0.020) in the Group PE were significantly less compared with Group MIS. The VAS score for low-back pain, leg pain and ODI score improved significantly in both groups after surgery (P < 0.05). The VAS of low-back pain on POD 1 was significant less (P < 0.001) for Group PE. There was no statistical difference (P = 0.561) in CT fusion rates between Group PE (85%) and Group MIS (92%). No serious complication was observed in any patients.

CONCLUSION

The study indicated that PETLIF had advantages of less surgical trauma, less postoperative low-back pain, less hidden blood loss, and faster recovery, compared with MIS-TLIF. There was no significant difference in medium-short term surgical outcomes between the 2 techniques. However, the indications of PETLIF is relatively limited, and the learning curve of PETLIF is deep, surgeons need to select indications strictly. Further study with big sample size and long-term follow-up is needed.

Devices for minimally-invasive microdiscectomy: current status and future prospects

Introduction: The current gold standard technique for lumbar disc herniation (LDH) is open lumbar microdiscectomy. The use of a tubular retractor system in the microdiscectomy technique can minimize tissue trauma by muscle-splitting sequential dilation during the surgical approach. This review aimed to describe the devices and surgical procedure of this minimally invasive microdiscectomy (MI-MD) and to discuss the pros and cons of the use of tubular retractors.Areas covered: Published medical literatures were extensively reviewed to summarize the practical devices and techniques related to the MI-MD for LDH. The placement of the tubular retractor by gradual muscle-splitting dilation technique may reduce muscle damage and postoperative wound pain. The use of flexible arm may easily change the tube direction and create a wide surgical field.Expert opinion: With reference to published literature, the MI-MD provides comparable clinical outcomes with less tissue trauma and early recovery. Development of devices for MI-MD is still ongoing. Extensive studies, including high-quality randomized trials, are required to establish a more practical and relevant MI-MD technique.

Defining the Normal Trends of Serum Creatine Kinase Levels Following Spinal Surgery

Study Design

Prospective, prognostic study, level II evidence.

Purpose

To define the normal change in the creatine kinase (CK) levels in patients undergoing prone or supine lumbar or cervical spine surgery and to determine if positioning influences the postoperative changes in the CK levels.

Overview of Literature

Spine surgery is one of the most commonly performed and fastest growing areas of surgery in the United States. Thus, the various possible complications need to be understood, and risk factors for these complications need to be mitigated. One of the rare complications, reported in the literature as small case series and case reports, is rhabdomyolysis, diagnosed by high CK levels. Thus far, very few studies have examined the rise in CK levels following spine surgery, and to our knowledge, none has assessed the potential association of surgical positioning and the rise in CK levels.

Methods

We retrospectively analyzed 94 patients. We obtained their preoperative CK levels, and re-assessed their CK levels at postoperative day (POD) 1, 2, and 3, as well as at their 2-week follow-up. The data were analyzed with respect to the spine level and positioning to determine if positioning had any effect on the postoperative rise in the CK level.

Results

Total 94 consecutive patients were enrolled in this study. The average preoperative CK level was 179.64, and the average CK level was 847.04 on POD 1. Prone positioning showed a greater rise in the CK levels following surgery than the supine positioning. In a similar manner, lumbar procedures led to a larger rise in the CK levels than cervical surgery. Prone/lumbar surgery showed the largest increase among all groups. Finally, revision surgery and instrumentation both increased the postoperative CK levels.

Conclusions

This study demonstrated that positioning can affect the postoperative CK level rise, with patients undergoing prone/lumbar surgery showing the greatest rise in the postoperative CK levels. This rise, however, may be related to paraspinal muscle damage, rather than the positioning itself.

Complication Rate in Minimally Invasive Revision Lumbar Discectomy: A Case Series and Technical Note

Revision lumbar discectomy, given the disruption of anatomic planes, can be a more technically complicated operation. Historically, it may have higher complication rates than first-time microdiscectomy. Recently, minimally invasive tubular discectomy (MITD) has been reported as an equivalent treatment to traditional approaches and may have better utility for revision surgery. A retrospective review of MITDs performed by the senior surgeon (F.A.S.) on 42 patients with single-level, recurrent disk herniation was analyzed. Surgical technique, preoperative and postoperative visual analogue score, modified Macnab criteria, and complication rate were compared with similar patient series in the literature. One case is reviewed and the technique is described in detail. There were no significant differences across age (49.5±14.1), sex, or obesity status. Visual analogue scores improved significantly from 7.24±1.75 to 2.45±2.12 (P<0.001). Successful clinical outcome (excellent or good Macnab score) was reported in 83.3% of patients. There were no postoperative complications, including dural tears or wound infections: fewer than any reported series of this size to date. MITD can be safely performed for revision discectomies with low morbidity. A paramedian approach helps to decrease the exposure to preexisting scar tissue and may offer a significant advantage over the traditional midline approach to treat recurrent disk herniation.

Comparison of Surgical Invasiveness Between Microdiscectomy and 3 Different Endoscopic Discectomy Techniques for Lumbar Disc Herniation

OBJECTIVE

Muscle injury is inevitable during surgical exposure of the spine. This study compared paraspinal muscle injury after 4 surgical techniques: microdiscectomy (MD), percutaneous endoscopic lumbar discectomy (PELD), percutaneous endoscopic interlaminar discectomy (PEID), unilateral biportal endoscopic discectomy (UBED).

METHODS

Eighty patients who underwent MD, PELD, PEID, and UBED were prospectively observed. Creatine phosphokinase (CPK) and C-reactive protein levels were measured on admission and postoperative days 1, 3, 5, and 7. CPK ratio was calculated as CPK on postoperative day 1/CPK on admission. Cross-sectional area of the high-intensity lesion in the paraspinal muscle was measured on magnetic resonance imaging after surgery. Operative time and hospital stay duration were also examined. Clinical outcome was evaluated using the visual analog scale for back and leg pain.

RESULTS

MD group had the highest CPK levels on postoperative days 1 and 3 and CPK ratio (P < 0.01, P = 0.02, P = 0.04). Serial C-reactive protein levels were highest in MD group (P < 0.01). PELD and PEID groups had lower C-reactive protein level on postoperative day 1 than UBED group. MD group had largest cross-sectional area (P < 0.01). Cross-sectional area was larger in UBED group than in PELD and PEID groups (P < 0.01). Operative time and hospital stay duration were shortest in PELD group (P < 0.01, P < 0.01). MD group had significantly higher visual analog scale scores for back pain on postoperative days 1 and 3 than the other groups (P < 0.01, P = 0.02).

CONCLUSIONS

PELD is the least invasive spinal surgical technique.

Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorso lateral thoracolumbar hemilaminectomy in dogs

Objectives: To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI).

Methods: Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12–24 hours postoperatively.

Results: Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi re-tractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow.

Clinical significance: Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.

Assessment of Paraspinal Muscle Cross-sectional Area After Lumbar Decompression: Minimally Invasive Versus Open Approaches

STUDY DESIGN

A retrospective, blinded analysis of imaging studies.

SUMMARY OF BACKGROUND DATA

To evaluate changes in paraspinal muscle cross-sectional area (CSA) after surgical treatment for lumbar stenosis and to compare these changes between minimally invasive and standard open approaches. The open approach to lumbar stenosis is effective, but it involves retraction and resection of muscle from the spinous process, which can result in ischemia and denervation of paraspinal musculature and may lead to muscle atrophy and pain.

OBJECTIVE

It is hypothesized that the microendoscopic decompression of stenosis (MEDS) technique will better preserve the paraspinal muscles compared with the open procedure.

MATERIALS AND METHODS

A total of 18 patients underwent a 1-level posterior decompression for lumbar stenosis, (9 open, 9 MEDS). Lumbar magnetic resonance imaging was obtained before surgery and after surgery (open approach average 16.3 mo; MEDS average 16.6 mo). CSA of paraspinal muscles were averaged over the distance of the surgical site.

RESULTS

The mean age of patients treated with the open and MEDS approaches were 55.2 and 66.4 years, respectively (P=0.07). Paraspinal muscle CSA decreased by an average of 5.4% (SD=10.6%; range, -24.5% to +7.7%) in patients treated with the open approach and increased by an average of 9.9% (SD=14.4%; range, -9.8% to +33.1%) in patients treated with MEDS (P=0.02). For the open approach, changes in CSA did not differ significantly between the left and right sides for erector spinae (P=0.35) or multifidus muscles (P=0.90). After the MEDS approach there were no significant differences between the dilated and contralateral sides with regard to change in CSA for erector spinae (P=0.85) or multifidus muscles (P=0.95).

CONCLUSIONS

Compared with the open approach for lumbar stenosis, MEDS had significantly less negative impact on the paraspinal muscle CSA. Previous reports have documented negative effects of paraspinal muscle injury, including weakness, disability, and pain. Collectively, these data suggest that the MEDS approach for lumbar decompression is less destructive to the paraspinous muscles than the open approach and may facilitate better clinical outcomes.

Minimally invasive surgery for resection of ossification of the ligamentum flavum in the thoracic spine

Introduction

Thoracic ossification of the ligamentum flavum (TOLF) is a common cause of progressive thoracic myelopathy. Surgical decompression is commonly used to treat TOLF.

Aim

To evaluate the clinical outcomes of microsurgical decompression of TOLF via a paraspinal approach, using a percutaneous tubular retractor system.

Material and methods

First, three-dimensional (3D) image reconstruction and printed models were made from thin computed tomography scans for each patient. Then, 3D computer-assisted virtual surgery was performed using the 3D reconstruction to calculate the precise location and sizes of the bone window and the angle of insertion of the percutaneous tubular retractor system. In total, 13 patients underwent the surgery through the percutaneous micro channel unilateral vertebral approach under electrophysiological monitoring. Five days after the surgery, increased creatine phosphokinase levels returned to preoperative levels. The Japanese Orthopedic Association (JOA) score was improved and computed tomography reconstruction and magnetic resonance imaging of the thoracic spine showed that decompression was achieved without injuries to the spinal cord or nerve root. The stability of the spine was not affected, nor were any deformities of the spine detected. Finally, nerve functional recovery was achieved with minimal injury to the paraspinal muscle, articulum, spinous process and ligament.

Results

The mean operative time was 98.23 ±19.10 min, and mean blood loss was 19.77 ±5.97 ml. At a mean follow-up of 13.3 months (median: 12 months), the mean JOA score was 7.54 ±1.13 at the final follow-up, yielding a mean RR of 49.10 ±15.71%. Using The recovery rate, 7 (53.85%) patients had good outcomes, 5 (38.46%) patients had a fair outcome, and 1 (7.69%) patient had poor outcomes, indicating significant improvement by the final follow-up examination (p < 0.05).

Conclusions

The 3D printed patient model-based microsurgical resection of TOLF via the paraspinal approach can achieve decompression of the spinal canal with minimal complications, faster recovery and improved stability of the vertebral body.

Comparison of pedicle fixation by the Wiltse approach and the conventional posterior open approach for thoracolumbar fractures, using MRI, histological and electrophysiological analyses of the multifidus muscle

PURPOSE

To use imaging, histology and electrophysiological assessment to compare the Wiltse approach to pedicle fixation with the conventional posterior open approach for thoracolumbar fractures.

METHODS

We analyzed clinical and histopathological information of consecutive patients with thoracolumbar fractures who underwent short-segment pedicle fixation using either the Wiltse approach or the posterior open approach. Seventy-five patients were enrolled between June 2010 and August 2014 (Wiltse group 35 cases; posterior open group 40 cases). The two groups were compared for MRI appearance, histological and electrophysiological changes in multifidus muscle.

RESULTS

On MRI, multifidus cross-sectional area (CSA) in the Wiltse group decreased by only 7.6% between pre-op and the last follow-up, compared to 35.4% in the posterior open group, and less fatty infiltration was found in the Wiltse group. Histologically, post-op (removal of internal fixation) tissue from the posterior open group showed disordered myofibrils, with diameter and CSA decreased by 11.6 and 24.3%, respectively; also, the myofibril gap became larger with fat deposition and scar formation. The Wiltse group had no such significant changes. Electrophysiologically, in the posterior open group, median frequency slope (MFs) significantly increased by 67.6% with average amplitude (AA) significantly decreased by 17.5% between pre-op and 12 months post-op. No significant changes were found in the Wiltse group. At 12 months post-op, AA was significantly lower and MFs was higher in the posterior open group than the Wiltse group.

CONCLUSION

The Wiltse approach showed a lower incidence of multifidus atrophy and denervation, and less fatty infiltration. It is an effective and minimally invasive approach for thoracolumbar fractures.

Mini-invasive Transforaminal Lumbar Interbody Fusion through Wiltse Approach to Treating Lumbar Spondylolytic Spondylolisthesis

OBJECTIVE

To assess the clinical efficacy of mini-invasive transforaminal lumbar interbody fusion (TLIF) through the Wiltse approach for treating lumbar spondylolytic spondylolisthesis.

METHODS

In this retrospective controlled study, 69 cases with lumbar spondylolytic spondylolisthesis treated in Qilu hospital from April to November 2014 were randomly assigned to Wiltse approach (31 cases, 16 male, 15 female; mean age 45.1 years) and traditional approach groups (38 cases, 21 male, 17 female; 47.2 years. In the Wiltse approach group, the affected level was L4, 5 in 19 cases and L5 S1 in 12, 9 of whom had low back pain (LBP) only and 21 both LBP and leg pain. There were 17 cases of I degree and 14 of II degree spondylolisthesis. Pre-operative Japanese Orthopedic Association (JOA) score was 13.1 ± 2.6; visual analog scale (VAS) for LBP 7.4 ± 1.2; VAS for leg pain 6.1 ± 2.0 and Oswestry disability index (ODI) score 42.2% ± 1.2%. In the traditional approach group, the affected level was L4, 5 in 22 cases and L5 S1 in 16, 11 of whom had LBP only and 27 both LBP and leg pain. There were 21 cases of I degree and 17 of II degree spondylolisthesis. Pre-operative JOA score was 12.8 ± 1.2; VAS for LBP 6.9 ± 1.1; VAS for leg pain 7.1 ± 2.0 and ODI score 41.2% ± 2.0%. The JOA score, VAS for LBP and leg pain, ODI dynamic X-rays, CT and/or MR were evaluated 3 and 6 months and 1 year postoperatively.

RESULTS

There were no differences in sex, age, affected levels, spondylolisthesis degree, pre-operative JOA score, VAS for LBP or leg pain and ODI score between the two groups (P > 0.05). The incision length, blood loss and time to achieving exposure were better in the Wiltse approach than the traditional approach group (P < 0.05). The VAS for LBP and muscle atrophy MRI scores were significantly lower in the Wiltse approach than the traditional approach group on Days 1 and 14 and at 1 year follow-up (P < 0.05). The VAS for leg pain, JOA recovery rate and JOA and ODI scores tended to be lower in the Wiltse approach than the traditional approach group at 1 year follow-up examinations (no differences statistically significant, P > 0.05). The interbody fusion rate was not significantly different between the groups (P > 0.05). There were no complications of internal fixation in either group.

CONCLUSION

TLIF via both approaches has satisfactory clinical efficacy. TLIF through the Wiltse approach significantly reduces the damage of multifidus and postoperative incidence of chronic LBP.

Serum creatine phosphokinase levels as an indicator of muscle injury following lumbar disc surgery: Comparison of fully endoscopic discectomy and microdiscectomy

OBJECTIVE

The aim of this study is to make a comparison between fully endoscopic lumbar discectomy (FELD) and conventional microdiscectomy (MD) by using pre- and postoperative serum creatine phosphokinase (CPK) levels in correlation with postoperative low-back pain.

METHODS

Fortyfive consecutive patients who underwent surgery for lumbar disc herniation were allocated into three groups with 15 patients on each: (1) FELD with interlaminar approach (IL), (2) FELD with transforaminal approach (TF), (3) Conventional MD. Serum CPK levels pre- and 1, 6, 12 and 24h postoperatively, patients' body mass index (BMI), operation duration and hospital stays were recorded. The low-back pain pre- and postoperatively was assessed with the use of the 100mm visual analog scale (VAS) and the "Oswestry Disability Index" (ODI).

RESULTS

There were 16 female (35.5%) and 29 male (64.5%) patients with a mean age of 44.1 years. CPK levels at 6th, 12th and 24th hours postoperatively were found significantly lower in TF and IL groups compared to MD group (p<0.004). Mean operation duration was significantly shorter in MD group (p: 0.014). There was a significant decrease in both the VAS and ODI scores after the surgery in all patient groups (p<0.001). Postoperative VAS scores were found significantly higher in MD group (p: 0.04).

CONCLUSION

Minimal invasive nature of FELD procedures compared to the MD was substantiated by serum CPK levels in this study. To draw definitive conclusions regarding pain relief, larger patient samples should be evaluated, although postoperative VAS scores were found in favor of FELD.

Comparison of multifidus muscle atrophy after posterior lumbar interbody fusion with conventional and cortical bone trajectory

OBJECTIVE

To determine if minimally invasive posterior interbody fusion with cortical bone trajectory (CBT) is associated with reduced paraspinal muscle damage compared to conventional open posterior lumbar interbody fusion (PLIF).

METHODS

Sixteen consecutive patients who underwent CBT were grouped into matched pairs with 16 patients who underwent conventional PLIF between May 2013 and January 2014, in terms of age, sex, body mass index, and spinal levels. Perioperative data and clinical data, including the Japanese Orthopedics Association (JOA) score, visual analogue scale (VAS) score, Oswestry Disability Index (ODI),before and after surgery were evaluated. Magnetic resonance imaging was performed preoperatively and 6 months postoperatively. The fat infiltration ratio was calculated.

RESULTS

Thirty-two patients with an 18-month follow-up period were evaluated. Clinical improvement, indicated by the VAS score for back and leg pain, ODI, and JOA score, was significant in both groups. However, there were no significant differences in operative time, blood loss, hospital stay duration, and recovery rate between the groups. The fat infiltration ratio was lower in the CBT group (p<0.05) than in the conventional PLIF group.

CONCLUSIONS

CBT is comparable with conventional PLIF with respect to short-term clinical outcomes but induced less multifidus muscle damage.

Comparison of Spinous Process-Splitting Laminectomy versus Conventional Laminectomy for Lumbar Spinal Stenosis

STUDY DESIGN

Seventy-five patients who had been treated for lumbar spinal stenosis (LSS) were reviewed retrospectively.

PURPOSE

Invasion into the paravertebral muscle can cause major problems after laminectomy for LSS. To address these problems, we performed spinous process-splitting laminectomy. We present a comparative study of decompression of LSS using 2 approaches.

OVERVIEW OF LITERATURE

There are no other study has investigated the lumbar spinal instability after spinous process-splitting laminectomy.

METHODS

This study included 75 patients who underwent laminectomy for the treatment of LSS and who were observed through follow-ups for more than 2 years. Fifty-five patients underwent spinous process-splitting laminectomy (splitting group) and 20 patients underwent conventional laminectomy (conventional group). We evaluated the clinical and radiographic results of each surgical procedure.

RESULTS

Japanese Orthopaedic Association score improved significantly in both groups two years postoperatively. The following values were all significantly lower, as shown with p-values, in the splitting group compared to the conventional group: average operating time (p=0.002), postoperative C-reactive protein level (p=0.006), the mean postoperative number of days until returning to normal body temperature (p=0.047), and the mean change in angulation 2 years postoperatively (p=0.007). The adjacent segment degeneration occurred in 6 patients (10.9%) in the splitting group and 11 patients (55.0%) in the conventional group.

CONCLUSIONS

In this study, the spinous process-splitting laminectomy was shown to be less invasive and more stable for patients with LSS, compared to the conventional laminectomy.

Intraoperative systemic infusion of lidocaine reduces postoperative pain after lumbar surgery: a double-blinded, randomized, placebo-controlled clinical trial

BACKGROUND CONTEXT

Analgesic effect of lidocaine infusion on postoperative pain.

PURPOSE

The aim of this study was to evaluate the analgesic effect of lidocaine infusion on postoperative pain after lumbar microdiscectomy.

STUDY DESIGN

This study used a prospective, randomized, double-blinded, and placebo-controlled clinical trial.

PATIENT SAMPLE

Fifty-one patients participated in this randomized, double-blinded study.

OUTCOME MEASURES

The primary outcome was the visual analog scale (VAS) (0-100 mm) pain score at 4 hours after surgery. The secondary outcomes were the VAS pain score at 2, 8, 12, 24, and 48 hours after surgery, the frequency with which patients pushed the button (FPB) of the patient-controlled analgesia system, and the fentanyl consumption at 2, 4, 8, 12, 24, and 48 hours after surgery. Other outcomes were satisfaction scores regarding pain control and the overall recovery process, incidence of postoperative nausea and vomiting (PONV), and length of hospital stay (HS).

METHODS

Preoperatively and throughout the surgery, Group L received intravenous lidocaine infusion (a 1.5-mg/kg bolus followed by a 2-mg/kg/h infusion until the end of the surgical procedure) and Group C received normal saline infusion as a placebo.

RESULTS

The VAS scores and fentanyl consumption were significantly lower in Group L compared with Group C except at 48 h after surgery (p<.05). Total fentanyl consumption, total FPB, length of HS, and satisfaction scores were also significantly lower in Group L compared with Group C (p<.05).

CONCLUSIONS

Intraoperative systemic infusion of lidocaine decreases pain perception during microdiscectomy, thus reducing the consumption of opioid and the severity of postoperative pain. This effect contributes to reduce the length of HS.

Is Minimally Invasive Spine Surgery Also Minimally Pro-Inflammatory? Muscular Markers, Inflammatory Parameters and Cytokines to Quantify the Operative Invasiveness Assessment in Spine Fusion

Over the last decades, minimally invasive surgery (MIS) techniques entered in the surgical routine due to their major advantage in reducing the unnecessary exposure of tissue and, thus, the trauma. Even in the context of orthopedics and spine surgery these practices have been widely developed and applied. Besides the clinical outcome of the patients, few studies have quantitatively assessed the traumatic and inflammatory effects of a specific surgical technique. Indeed, currently, a universally accepted biological outcome measure, such as a panel of biochemical markers, to define the success of MIS approach is still lacking. We reviewed the literature to collect the published data regarding the quantitative analysis of trauma induced by either conventional or minimally invasive surgery with the aim of highlighting evidence useful to guide future studies. Previous publications show some evidence in support of the hypothesis that MIS approaches are less traumatic, and possibly less pro-inflammatory, than conventional ones. Creatin kinase (as a marker of muscular damage) and C-reactive protein (as a marker of systemic inflammation) seem to reproducibly follow different trends in minimally invasive surgery compared to conventional procedures. Moreover, cytokines, such as interleukin (IL)-6 and IL-10 are also promising markers in this context.

Resultados postoperatorios inmediatos y a largo plazo de un abordaje mini-invasivo para la corrección de escoliosis idiopática del adolescente

OBJETIVO: Analizar los resultados de una nueva técnica quirúrgica mínimamente invasiva (MIS, por el inglés "minimally invasive surgery") por vía posterior aislada para la corrección quirúrgica de la escoliosis idiopática del adolescente (EIA). MÉTODOS: Se comparan dos grupos de pacientes con EIA tipo 1A de Lenke, similares en cuanto a edad, género, ángulo de Cobb, ápex de la curva, rotación vertebral, cifosis torácica, niveles de fusión, tipo de instrumentación y seguimiento. El Grupo 1 fue tratado con la técnica mínimamente invasiva que describiremos y el Grupo 2, de forma convencional. Se analizaron el tiempo quirúrgico, la pérdida sanguínea intraoperatoria, los requerimientos analgésicos en el postoperatorio inmediato, la estancia hospitalaria, la tasa de mal posición de los tornillos, la pérdida de corrección, la tasa de pseudoartrosis y la movilización de implantes. RESULTADOS: En el Grupo 1 (MIS) la cirugía disminuyó significativamente el sangrado y presentó menor número de casos de tornillos mal posicionados en la concavidad que el grupo tratado de forma convencional; sin embargo la cirugía tuvo mayor duración. Ambos grupos tuvieron requerimientos analgésicos similares y la estancia hospitalaria no presentó diferencias. A largo plazo en ninguno de los dos grupos se encontraron casos de no-unión, pérdidas de corrección, ni movilización de los implantes. CONCLUSIONES: La técnica MIS demostró prolongación del tiempo quirúrgico y menores pérdidas hemáticas, sin disminuir los requerimientos analgésicos ni la estancia hospitalaria. La corrección inicial de la escoliosis por la convexidad disminuyó la incidencia de tornillos mal posicionados en la concavidad, no dio lugar a pérdidas de corrección, movilización de implantes y no-unión.

Percutaneous short-segment pedicle screw placement without fusion in the treatment of thoracolumbar burst fractures: is it effective?: comparative study with open short-segment pedicle screw fixation with posterolateral fusion

BACKGROUND

Since introduction of the pedicle screw-rod system, short-segment pedicle screw fixation has been widely adopted for thoracolumbar burst fractures (TLBF). Recently, the percutaneous pedicle screw fixation (PPSF) systems have been introduced in spinal surgery; and it has become a popularly used method for the treatment of degenerative spinal disease. However, there are few clinical reports concerning the efficacy of PPSF without fusion in treatment of TLBF. The purpose of this study was to determine the efficacy and safety of short-segment PPSF without fusion in comparison to open short-segment pedicle screw fixation with bony fusion in treatment of TLBF.

METHODS

This study included 59 patients, who underwent either percutaneous (n = 32) or open (n = 27) short-segment pedicle screw fixation for stabilization of TLBF between December 2003 and October 2009. Radiographs were obtained before surgery, immediately after surgery, and at the final follow-up for assessment of the restoration of the spinal column. For radiologic parameters, Cobb angle, vertebral wedge angle, and vertebral body compression ratio were assessed on a lateral thoracolumbar radiograph. For patient's pain and functional assessment, the visual analogue scale (VAS), the Frankel grading system, and Low Back Outcome Score (LBOS) were measured. Operation time, and the amount of intraoperative bleeding loss were also evaluated.

FINDINGS

In both groups, regional kyphosis (Cobb angle) showed significant improvement immediately after surgery, which was maintained until the last follow up, compared with preoperative regional kyphosis. Postoperative correction loss showed no significant difference between the two groups at the final follow-up. In the percutaneous surgery group, there were significant declines of intraoperative blood loss, and operation time compared with the open surgery group. Clinical results showed that the percutaneous surgery group had a lower VAS score and a better LBOS at three months and six months after surgery; however, the outcomes were similar in the last follow-up.

CONCLUSIONS

Both open and percutaneous short-segment pedicle fixation were safe and effective for treatment of TLBF. Although both groups showed favorable clinical and radiologic outcomes at the final follow-up, PPSF without bone graft provided earlier pain relief and functional improvement, compared with open TPSF with posterolateral bony fusion. Despite several shortcomings in this study, the result suggests that ongoing use of PPSF is recommended for the treatment of TLBF.

Modified Marmot operation versus spinous process transverse cutting laminectomy for lumbar spinal stenosis

STUDY DESIGN

Retrospective comparative cohort study.

OBJECTIVE

To compare clinical outcomes for lumbar spinal stenosis (≥3 levels) treated with posterior decompression without exposing the paravertebral muscles (PVM) with outcomes from surgery with PVM exposure.

SUMMARY OF BACKGROUND DATA

Exposure of the PVM can cause muscle injury and denervation, which may induce failed back syndrome. However, it is unknown whether lumbar spinal stenosis is more likely to lead to clinical improvement after PVM preservation than the procedure involving exposure of the PVM.

METHODS

Fifty-three patients with lumbar spinal stenosis were divided on the basis of the timing of the surgery into 2 groups: modified split-spinous process laminotomy (Marmot operation) (MM) group (26 patients) and spinous process transverse cutting laminectomy through a unilateral approach (control) group (27 patients). The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, visual analogue scale score of low back pain, and patients' satisfaction were assessed preoperatively and 1 year postoperatively. Operation time, blood loss, and creatine phosphokinase and C-reactive protein levels were measured 7 days postoperatively. Magnetic resonance imaging changes in the PVM were evaluated at the follow-up.

RESULTS

The preoperative visual analogue scale and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores did not differ between groups. The operation time did not differ between groups, but blood loss was less in the MM group than in the control group (129 vs. 205 mL) (P < 0.05). C-reactive protein (1.1 vs. 2.8 mg/dL) and creatine phosphokinase (68 vs. 253 IU/L) levels were lower in the MM group (P < 0.05). The visual analogue scale score for low back pain and patient satisfaction did not differ between groups. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores for pain-related disorders, gait disturbance, and social life disturbance improved significantly in the MM group compared with the control group (P < 0.05). Nine patients in the control group showed positive changes in the PVM.

CONCLUSION

The MM operation was less invasive and produced superior clinical outcomes compared with laminectomy involving exposure of the PVM.

Back muscle changes after pedicle based dynamic stabilization

OBJECTIVE

Many studies have investigated paraspinal muscle changes after posterior lumbar surgery, including lumbar fusion. However, no study has been performed to investigate back muscle changes after pedicle based dynamic stabilization in patients with degenerative lumbar spinal diseases. In this study, the authors compared back muscle cross sectional area (MCSA) changes after non-fusion pedicle based dynamic stabilization.

METHODS

Thirty-two consecutive patients who underwent non-fusion pedicle based dynamic stabilization (PDS) at the L4-L5 level between February 2005 and January 2008 were included in this retrospective study. In addition, 11 patients who underwent traditional lumbar fusion (LF) during the same period were enrolled for comparative purposes. Preoperative and postoperative MCSAs of the paraspinal (multifidus+longissimus), psoas, and multifidus muscles were measured using computed tomographic axial sections taken at the L4 lower vertebral body level, which best visualize the paraspinal and psoas muscles. Measurements were made preoperatively and at more than 6 months after surgery.

RESULTS

Overall, back muscles showed decreases in MCSAs in the PDS and LF groups, and the multifidus was most affected in both groups, but more so in the LF group. The PDS group showed better back muscle preservation than the LF group for all measured muscles. The multifidus MCSA was significantly more preserved when the PDS-paraspinal-Wiltse approach was used.

CONCLUSION

Pedicle based dynamic stabilization shows better preservation of paraspinal muscles than posterior lumbar fusion. Furthermore, the minimally invasive paraspinal Wiltse approach was found to preserve multifidus muscles better than the conventional posterior midline approach in PDS group.

Iatrogenic injury to the erector spinae during posterior lumbar spine surgery: underlying anatomical considerations, preventable root causes, and surgical tips and tricks

The approach-related morbidity resulting from iatrogenic erector spinae injury in posterior lumbar surgery has become an increasing concern for spine surgeons. Many studies have explained the injury mechanisms and reported new surgical approaches to prevent this iatrogenic injury from their own point of views, but there is still no systemic information for a thorough understanding of this iatrogenic erector spinae injury that may give spine surgeons practical advices in their individual operations. We consequently reviewed the literature on the anatomy of erector spinae, causes of injury, and relative minimally invasive approaches. We found that the local anatomic structures make the erector spinae vulnerable to injury during posterior lumbar surgery, especially the medial multifidus which is innervated only by the medial branch of the dorsal ramus, with no intersegmental nerve supply as in the other paraspinal muscles, and the injury factors mainly include dissection, retraction, denervation, and immobility. Studies suggest that the goal of prevention is to preserve the physiological structure of erector spinae and to avoid or limit the injury causes: approaches through spatium intermusculare and approaches with endoscope and tubular retractor system can prevent the erector spinae from injury by less dissection and retraction; non-fusion techniques may prevent the erector spinae from disuse atrophy by preserving the segmental motion and the adjacent erector spinae activity.

Extent of intraoperative muscle dissection does not affect long-term outcomes after minimally invasive surgery versus open-transforaminal lumbar interbody fusion surgery: A prospective longitudinal cohort study

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus open TLIF, addressing lumbar degenerative disc disease (DDD) or grade I spondylolisthesis (DS), are associated with shorter hospital stays, decreased blood loss, quicker return to work, and equivalent short- and long-term outcomes. However, no prospective study has assessed whether the extent of intraoperative muscle trauma utilizing creatinine phosphokinase levels (CPK) differently impacts long-term outcomes.

METHODS

Twenty-one patients underwent MIS-TLIF (n = 14) versus open-TLIF (n = 7) for DDD or DS. Serum CPK levels were measured at baseline, and postoperatively (days 1, 7, and 1.5, 3 and 6 months). The correlation between the extent of intraoperative muscle trauma and two-year improvement in functional disability was evaluated (multivariate regression analysis). Additionally, baseline and two-year changes in Visual Analog Scale (VAS)-leg pain (LP), VAS-back pain (BP), Oswestry Disability Index (ODI), Short-Form-36 (SF-36) Physical Component Score (PCS) and SF-36 Mental Component Score (MCS), and postoperative satisfaction with surgical care were assessed.

RESULTS

Although the mean change from baseline in the serum creatine phosphokinase level on POD 1 was greater for MIS-TLIF (628.07) versus open-TLF (291.42), this did not correlate with lesser two-year improvement in functional disability. Both cohorts also showed similar two-year improvement in VAS-LP, ODI, and SF-36 PCS/MCS.

CONCLUSION

Increased intraoperative muscle trauma unexpectedly observed in higher postoperative CPK levels for MIS-TLIF versus open-TLIF did not correlate with any differences in two-year improvement in pain and functional disability.

The interspinous spacer: a clinicoanatomical investigation using plastination

Purpose. The relatively new and less-invasive therapeutic alternative "interspinous process decompression device (IPD)" is expected to result in improved symptoms of neurogenic intermittent claudication (NIC) caused by lumbar spinal stenosis. The aim of the study was to analyze IPD position particularly regarding damage originating from surgical implantation. Methods. Anatomic assessments were performed on a fresh human cadaver. For the anatomic examination, the lumbar spine was plastinated after implantation of the IPDs. After radiographic control, serial 4 mm thick sections of the block plastinate were cut in the sagittal (L1-L3) and horizontal (L3-L5) planes. The macroanatomical positioning of the implants was then analyzed. The insertion procedure caused only little injury to osteoligamentous or muscular structures. The supraspinous ligament was completely intact, and the interspinous ligaments were not torn as was initially presupposed. No osseous changes at the spinal processes were apparent. Contact of the IPD with the spinous processes was visible, so that sufficient biomechanical limitation of the spinal extension seems likely. Conclusions. Minimally invasive IPD implantation with accurate positioning in the anterior portion of the interspinous place is possible without severe surgical trauma.

Single incision percutaneous pedicle screw fixation for transforaminal lumbar interbody fusion

OBJECTIVE

Percutaneous pedicle screw fixation (PPSF) offers some of the advantages of minimally invasive surgery. However, an additional skin incision is necessary in order to gain these advantages. The author recently performed a modified PPSF through a single skin incision and it yielded good results. Here, we report the single incision percutaneous pedicle screw fixation (SIPPSF).

METHODS

The medical records of 51 patients who underwent single segment transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation (PSF) between December 2009 and December 2011 were reviewed. The patients were divided into 3 groups according to the PSF technique used; conventional group (Group C), SIPPSF (Group S) and PPSF through multiple skin incisions (Group M). Operation time, estimated blood loss (EBL) and pain intensity before and after the operation using a numeric rating scale (NRS) were evaluated.

RESULTS

The number of patients in Group S, Group C and Group M was 25, 17 and 9, respectively. The NRS demonstrated a reduction in pain intensity in all the patients, and there were no differences in NRS scoring between the three groups. Group S showed a reduction in the EBL compared to Group C (p=0.001) and a reduction in the operation time compared to Group M(p=0.003).

CONCLUSION

The author supposes that the type of skin incision does not correlate significantly with the clinical results of TLIF with PPSF. However, it can be considered that SIPPSF offers the advantage of avoiding an additional paramedian skin incision.

Differences in damage to CGRP immunoreactive sensory nerves after two lumbar surgical approaches: investigation using humans and rats

STUDY DESIGN

Immunohistochemical study.

OBJECTIVE

To evaluate invasive surgical approaches by analyzing the number of sensory nerve fibers at 2 back muscle sites in rats and humans and the number of injured nerve fibers innervating these 2 sites after muscle injury in rats. SUMMARY OF BACKGROUND DATA.: Several minimally invasive approaches have recently become popular in the treatment of lumbar spine disorders. Minimally invasive surgery (MIS) is not invasive to back muscle and is thought to reduce low back pain. Muscle damage has been generally evaluated by magnetic resonance imaging (MRI); however, damage to sensory nerve fibers in and around back muscle that is directly related to pain has apparently not been explored.

METHODS

Human muscle at L4-L5 was obtained from the paraspinous process (during a midline approach) and from paraspinal back muscle (during a Wiltse paraspinal approach) (n = 10 each). The muscle was sectioned and immunostained for calcitonin gene-related peptide (CGRP). To detect dorsal root ganglion (DRG) neurons innervating back muscle in rats, Fluoro-Gold (FG) was applied to the same 2 sites on the lower back muscle at L4-L5 (only application, n = 12; application of FG + muscle injury, n = 12). DRGs were harvested and immunostained for CGRP and activating transcription factor-3 (ATF-3: marker for nerve injury). The numbers of FG-labeled CGRP-immunoreactive or FG-labeled ATF-3-immunoreactive DRG neurons innervating the 2 sites were counted and compared.

RESULTS

CGRP-immunoreactive sensory nerve fibers were found at the 2 sites. The average number of CGRP-immunoreactive sensory nerve fibers in muscle obtained in a midline approach was significantly higher than that in muscle obtained in a Wiltse paraspinal approach (P < 0.01). The numbers of FG-labeled CGRP- and ATF-3-immunoreactive DRG neurons innervating paraspinous process muscle were significantly greater than those innervating paraspinal back muscle in rats (P < 0.01).

CONCLUSION

There are more CGRP-immunoreactive sensory nerve fibers and DRG neurons innervating muscle in the midline approach area than in the Wiltse paraspinal approach area in humans and rats. There are more ATF-3-immunoreactive DRG neurons innervating muscle in the midline approach area than in the Wiltse paraspinal approach area after muscle injury in rats. This result may show the differences in sensory nerve injury during the 2 surgical approaches.

Reduced postoperative wound pain after lumbar spinous process-splitting laminectomy for lumbar canal stenosis: a randomized controlled study

OBJECT

to reduce intraoperative damage to the posterior supporting structures of the lumbar spine during decompressive surgery for lumbar canal stenosis (LCS), lumbar spinous process-splitting laminectomy (LSPSL or split laminectomy) was developed. This prospective, randomized, controlled study was conducted to clarify whether the split laminectomy decreases acute postoperative wound pain compared with conventional laminectomy.

METHODS

forty-one patients with LCS were enrolled in this study. The patients were randomly assigned to either the LSPSL group (22 patients) or the conventional laminectomy group (19 patients). Questionnaires regarding wound pain (intensity, depth, and duration) and activities of daily living (ADL) were administered at postoperative days (PODs) 3 and 7. Additionally, the authors evaluated the pre- and postoperative serum levels of C-reactive protein and creatine phosphokinase, the amount of pain analgesics used during a 3-day postoperative period, and the muscle atrophy rate measured on 1-month postsurgical MR images.

RESULTS

data obtained in patients in the LSPSL group and in 16 patients in the conventional laminectomy group were analyzed. The mean visual analog scale for wound pain on POD 7 was significantly lower in the LSPSL group (16 ± 17 mm vs 34 ± 31 mm, respectively; p = 0.04). The mean depth-of-pain scores on POD 7 were significantly lower in the LSPSL group than in the conventional group (0.9 ± 0.6 vs 1.7 ± 0.8, respectively; p = 0.013). On POD 3, the mean serum creatine phosphokinase level was significantly lower in the LSPSL group (126 ± 93 U/L) than in the other group (207 ± 150 U/L) (p = 0.02); on POD 7, the mean serum C-reactive protein level was significantly lower in the LSPSL group (1.1 ± 0.6 mg/dl) than in the conventional laminectomy group (1.9 ± 1.5 mg/dl) (p = 0.04). The number of pain analgesics taken during the 3-day postoperative period was lower in the LSPSL group than in the conventional laminectomy group (1.7 ± 1.3 tablets vs 2.3 ± 2.4 tablets, respectively; p = 0.22). The mean muscle atrophy rate was also significantly lower in the LSPSL group (24% ± 15% vs 43% ± 22%; p = 0.004).

CONCLUSIONS

lumbar spinous process-splitting laminectomy for the treatment of LCS reduced acute postoperative wound pain and prevented postoperative muscle atrophy compared with conventional laminectomy, possibly because of minimized damage to the paraspinal muscles.

Minimally Invasive Muscle Sparing Transmuscular Microdiscectomy : Technique and Comparison with Conventional Subperiosteal Microdiscectomy during the Early Postoperative Period

OBJECTIVE

The authors introduce a minimally invasive muscle sparing transmuscular microdiscectomy (MSTM) to treat herniated lumbar disc disease. Its results are compared with conventional subperiosteal microdiscectomy (CSM) to validate the effectiveness.

METHODS

Muscle sparing transmuscular microdiscectomy, which involves muscle dissection approach using the natural fat cleavage plane between the multifidus to expose the interlaminar space, was performed in 23 patients to treat a single level unilateral lumbar radiculopathy. The creatine phosphokinase (CPK)-MM serum levels were measured on admission and at 1, 3, and 5 days postoperatively. Postoperative pain was evaluated using a 10-point visual analogue scale (VAS) and recorded on admission and at 1, 3, and 5 days postoperatively. The results were compared to those from the conventional subperiosteal microdiscectomy (43 patients).

RESULTS

The CPK-MM levels were significantly lower in the serum of the MSTM group compared to the CSM group on postoperative days three and five (p = 0.03 and p = 0.02, respectively). The clinical scales for back pain using VAS were significantly lower in the MSTM group than in the CSM group on postoperative days three (p = 0.04). The mean VAS scores for leg pain in both groups showed no significant differences during the early postoperative period.

CONCLUSION

Muscle sparing transmuscular microdiscectomy is a minimally invasive surgical option to treat lumbar radiculopathy due to herniated disc. The approach affected minimal injury to posterior lumbar supporting structures with alleviated postoperative back pain.

Does minimally invasive lumbar disc surgery result in less muscle injury than conventional surgery? A randomized controlled trial

The concept of minimally invasive lumbar disc surgery comprises reduced muscle injury. The aim of this study was to evaluate creatine phosphokinase (CPK) in serum and the cross-sectional area (CSA) of the multifidus muscle on magnetic resonance imaging as indicators of muscle injury. We present the results of a double-blind randomized trial on patients with lumbar disc herniation, in which tubular discectomy and conventional microdiscectomy were compared. In 216 patients, CPK was measured before surgery and at day 1 after surgery. In 140 patients, the CSA of the multifidus muscle was measured at the affected disc level before surgery and at 1 year after surgery. The ratios (i.e. post surgery/pre surgery) of CPK and CSA were used as outcome measures. The multifidus atrophy was classified into three grades ranging from 0 (normal) to 3 (severe atrophy), and the difference between post and pre surgery was used as an outcome. Patients’ low-back pain scores on the visual analogue scale (VAS) were documented before surgery and at various moments during follow-up. Tubular discectomy compared with conventional microdiscectomy resulted in a nonsignificant difference in CPK ratio, although the CSA ratio was significantly lower in tubular discectomy. At 1 year, there was no difference in atrophy grade between both groups nor in the percentage of patients showing an increased atrophy grade (14% tubular vs. 18% conventional). The postoperative low-back pain scores on the VAS improved in both groups, although the 1-year between-group mean difference of improvement was 3.5 mm (95% CI; 1.4–5.7 mm) in favour of conventional microdiscectomy. In conclusion, tubular discectomy compared with conventional microdiscectomy did not result in reduced muscle injury. Postoperative evaluation of CPK and the multifidus muscle showed similar results in both groups, although patients who underwent tubular discectomy reported more low-back pain during the first year after surgery.

[Minimally invasive spine arthrodesis in degenerative spinal disorders]

BACKGROUND AND PURPOSE

As in many other surgical fields, new minimally invasive techniques have been developed over the past 20 years, with reducing the muscular trauma associated with the traditional surgical approach and reducing related morbidity as the main goals. Initially limited to the laparoscopic or video-assisted approaches of the anterior spine, these techniques have been extended to the posterior transmuscular access of the lumbar spine. This article reviews the value of these approaches in the treatment of degenerative lumbar spine disorders.

METHODS

We describe the main techniques used in minimally invasive lumbar spine surgery, including posterior pedicle screwing as well as anterior (ALIF), posterior (PLIF), transforaminal (TLIF), extreme lateral (XLIf), and presacral (AxiaLIF) interbody fusion. The results of recently published series are reported.

RESULTS

Percutaneous pedicle screwing is reported to be an effective technique of lumbar spine arthrodesis associated with a low rate of screw misplacement. Minimally invasive PLIF, TLIF, and ALIF have been associated with shorter mean operative time, less postoperative pain, reduction of the estimated blood loss, a shorter hospital stay, and quicker functional recovery. Despite these encouraging early clinical results, no prospective, randomized published scientific study has proved that minimally invasive techniques are better than standard techniques. Larger clinical series with a longer follow-up could fill this gap.

Multifidus muscle changes and clinical effects of one-level posterior lumbar interbody fusion: minimally invasive procedure versus conventional open approach

We set out to determine whether a minimally invasive approach for one-level instrumented posterior lumbar interbody fusion reduced undesirable changes in the multifidus muscle, compared to a conventional open approach. We also investigated associations between muscle injury during surgery (creatinine kinase levels), clinical outcome and changes in the multifidus at follow-up. We studied 59 patients treated by one team of surgeons at a single institution (minimally invasive approach in 28 and conventional open approach in 31, voluntarily chosen by patients). More than 1 year postoperatively, all the patients were followed up with the visual analogue scale (VAS) and Oswestry disability index (ODI), and 16 patients from each group were evaluated using MRI. This enabled the cross-sectional area (CSA) of lean multifidus muscle, and the T2 signal intensity ratio of multifidus to psoas muscle, to be compared at the operative and adjacent levels. The minimally invasive group had less postoperative back pain (P < 0.001) and lower postoperative ODI scores (P = 0.001). Multifidus atrophy was less in the minimally invasive group (P < 0.001), with mean reductions in CSA of 12.2% at the operative and 8.5% at the adjacent levels, compared to 36.8% and 29.3% in the conventional open group. The increase in the multifidus:psoas T2 signal intensity ratio was similarly less marked in the minimally invasive group where values increased by 10.6% at the operative and 8.3% at the adjacent levels, compared to 34.4 and 22.7% in the conventional open group (P < 0.001). These changes in multifidus CSA and T2 signal intensity ratio were significantly correlated with postoperative creatinine kinase levels, VAS scores and ODI scores (P < 0.01). The minimally invasive approach caused less change in multifidus, less postoperative back pain and functional disability than conventional open approach. Muscle damage during surgery was significantly correlated with long-term multifidus muscle atrophy and fatty infiltration. Furthermore these degenerative changes of multifidus were also significantly correlated with long-term clinical outcome.

A new endoscopic spine system: the first results with "Easy GO"

PURPOSE

Endoscopy meets increasing interest by spine surgeons. However, endoscopic results are diverging and many spinal endoscopic systems are difficult to apply and handle.

METHODS

A system for endoscopic spinal surgery was developed where the main goals were: (1) easy intraoperative handling with standard microsurgical techniques, and (2) avoidance of a prolonged learning curve. The system consists of various dilators, two different work sheaths, two different 30 degrees endoscopes, and an endoscope holder.

RESULTS

Between August 2006 and April 2008, 80 spinal surgeries were performed in degenerative lumbar spine cases (mean age 52 years, range 22-85 years). Intraoperatively, the system was easy to handle. Standard microsurgical techniques were used. Mean surgical time scored 75 min (range 28-168 min). There was no intraoperative complication, no new postoperative deficit and no infection. In four cases, the endoscope was abandoned and the procedure microsurgically continued (5%). At the last follow-up (mean FU 10 months, range 2 weeks up to 21 months), 89% of the patient were pain free (71/80). Four patients suffered from recurrent disc prolapses (5%). Another five patients (6%) were not satisfied without evidence of re-prolaps. Of those who answered the questionnaire of patient satisfaction, 83% (45/54) considered their postoperative status as excellent, 13% as good (7/54), 4% were not satisfied (2/54).

CONCLUSIONS

The Easy GO system was easy and safe to handle with the standard bimanual microsurgical technique and good postoperative results. Further studies are needed to show a significant advantage of the technique in comparison to the microsurgical standard procedure.

Mini-open versus conventional open posterior lumbar interbody fusion for the treatment of lumbar degenerative spondylolisthesis: comparison of paraspinal muscle damage and slip reduction

STUDY DESIGN

A comparative analysis of paraspinal muscle damage and radiographic parameters after mini-open and conventional open posterior lumbar interbody fusion (PLIF).

OBJECTIVE

To determine whether mini-open PLIF decreases paraspinal muscle damage and yields the same radiographic results as those in conventional open PLIF.

SUMMARY OF BACKGROUND DATA

Compared with conventional open PLIF, mini-open PLIF using a paramedian approach reduces intraoperative hemorrhage and decreases postoperative back pain. However, whether the latter produces less paraspinal muscle damage than the former remains unclear. No comparative study has investigated slip reduction and segmental lordosis at the fusion level in the 2 techniques.

METHODS

We studied 20 patients (10 in each group) who had undergone single-level conventional (midline approach) or mini-open (bilateral Wiltse approach) PLIF with pedicle screws and interbody cages at the L4-L5 level for lumbar degenerative spondylolisthesis. The rate of improvement in the Japanese Orthopedic Association score; radiographic parameters, including %slip; segmental lordotic angle at the L4-L5 level; and fusion rate were examined. Postoperative multifidus (MF) atrophy and degeneration were evaluated using magnetic resonance imaging. RESULTS.: No significant differences were detected between the 2 groups with respect to the rate of improvement in the Japanese Orthopedic Association score, segmental lordotic angle, and fusion rate. Both groups showed significant reduction in %slip after surgery. The degree of MF atrophy and the increase in T2-signal intensity in the MF muscle after mini-open PLIF were significantly lesser than those following open PLIF.

CONCLUSION

Mini-open PLIF is safe and effective. Mini-open PLIF was less invasive than open PLIF with regard to the MF muscle.