Structured postoperative physiotherapy in patients with cervical radiculopathy: 6-month outcomes of a randomized clinical trial

OBJECTIVE Structured physiotherapy has been suggested as treatment before as well as after surgery to improve clinical outcomes in patients with cervical radiculopathy (CR), but randomized clinical trials to inform evidence-based clinical guidelines for the treatment of patients with CR after surgery are lacking. The aim of this study was to compare the results of structured postoperative physiotherapy combining neck-specific exercises with a behavioral approach to a standard postoperative approach in patients who had undergone surgery for cervical disc disease with CR at 6 months after surgery. METHODS Patients with cervical disc disease and persistent CR who were scheduled for surgery were randomized preoperatively to structured postoperative physiotherapy (n = 101) or a standard postoperative approach (n = 100). The latter included pragmatic physiotherapy in accordance with the usual Swedish postoperative care. Outcome measures included patient-reported neck disability as measured with the Neck Disability Index (NDI), intensity and frequency of neck and arm pain, global outcome of treatment, and expectation fulfillment, as well as enablement. RESULTS Patients who received structured postoperative physiotherapy reported greater expectation fulfillment (p = 0.01), and those who attended at least 50% of the treatment sessions reported less neck pain frequency (p = 0.05), greater expectation fulfillment (p = 0.001), and greater enablement (p = 0.04) compared with patients who received the standard postoperative approach. No other difference between treatment groups was found (p > 0.15). The NDI and neck and arm pain intensity were improved in both groups at 6 months after surgery (p < 0.001). Additional use of postoperative physiotherapy was reported by 61% of the patients who received the standard postoperative approach. CONCLUSIONS The results from this first randomized clinical trial of postoperative physiotherapy showed only minor additional benefit of structured postoperative physiotherapy compared with standard postoperative approach 6 months postoperatively in patients who underwent surgery for cervical disc disease with CR. Patients who received structured postoperative physiotherapy reported higher expectation fulfillment, and many patients in the standard postoperative approach group perceived a need for additional treatments after surgery, suggesting that patients with CR are in need of further postoperative support. The results confirm that neck-specific exercises are tolerated postoperatively by patients with CR, but more studies of postoperative physiotherapy are needed to inform clinical guidelines for this patient group. Clinical trial registration no.: NCT01547611 (clinicaltrials.gov).

Comparative analysis of 3 surgical strategies for adult spinal deformity with mild to moderate sagittal imbalance

OBJECTIVE Surgical treatment of adult spinal deformity (ASD) is an effective endeavor that can be accomplished using a variety of surgical strategies. Here, the authors assess and compare radiographic data, complications, and health-related quality-of-life (HRQoL) outcome scores among patients with ASD who underwent a posterior spinal fixation (PSF)-only approach, a posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), or a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF). METHODS The medical records of consecutive adults who underwent thoracolumbar fusion for ASD between 2003 and 2013 at a single institution were reviewed. Included were patients who underwent instrumentation from the pelvis to L-1 or above, had a sagittal vertical axis (SVA) of < 10 cm, and underwent a minimum of 2 years' follow-up. Those who underwent a 3-column osteotomy were excluded. Three groups of patients were compared on the basis of the procedure performed, LLIF+PSF, ALIF+PSF, and PSF only. Perioperative spinal deformity parameters, complications, and HRQoL outcome scores (Oswestry Disability Index [ODI], Scoliosis Research Society 22-question Questionnaire [SRS-22], 36-Item Short Form Health Survey [SF-36], visual analog scale [VAS] for back/leg pain) from each group were assessed and compared with each other using ANOVA. The minimal clinically important differences used were -1.2 (VAS back pain), -1.6 (VAS leg pain), -15 (ODI), 0.587/0.375/0.8/0.42 (SRS-22 pain/function/self-image/mental health), and 5.2 (SF-36, physical component summary). RESULTS A total of 221 patients (58 LLIF, 91 ALIF, 72 PSF only) met the inclusion criteria. Average deformities consisted of a SVA of < 10 cm, a pelvic incidence-lumbar lordosis (LL) mismatch of > 10°, a pelvic tilt of > 20°, a lumbar Cobb angle of > 20°, and a thoracic Cobb angle of > 15°. Preoperative SVA, LL, pelvic incidence-LL mismatch, and lumbar and thoracic Cobb angles were similar among the groups. Patients in the PSF-only group had more comorbidities, those in the ALIF+PSF group were, on average, younger and had a lower body mass index than those in the LLIF+PSF group, and patients in the LLIF+PSF group had a significantly higher mean number of interbody fusion levels than those in the ALIF+PSF and PSF-only groups. At final follow-up, all radiographic parameters and the mean numbers of complications were similar among the groups. Patients in the LLIF+PSF group had proximal junctional kyphosis that required revision surgery significantly less often and fewer proximal junctional fractures and vertebral slips. All preoperative HRQoL scores were similar among the groups. After surgery, the LLIF+PSF group had a significantly lower ODI score, higher SRS-22 self-image/total scores, and greater achievement of the minimal clinically important difference for the SRS-22 pain score. CONCLUSIONS Satisfactory radiographic outcomes can be achieved similarly and adequately with these 3 surgical approaches for patients with ASD with mild to moderate sagittal deformity. Compared with patients treated with an ALIF+PSF or PSF-only surgical strategy, patients who underwent LLIF+PSF had lower rates of proximal junctional kyphosis and mechanical failure at the upper instrumented vertebra and less back pain, less disability, and better SRS-22 scores.

Is fusion necessary for thoracolumbar burst fracture treated with spinal fixation? A systematic review and meta-analysis

OBJECTIVE Thoracolumbar fractures account for 90% of spinal fractures, with the burst subtype corresponding to 20% of this total. Controversy regarding the best treatment for this condition remains. The traditional surgical approach, when indicated, involves spinal fixation and arthrodesis. Newer studies have brought the need for fusion associated with internal fixation into question. Not performing arthrodesis could reduce surgical time and intraoperative bleeding without affecting clinical and radiological outcomes. With this study, the authors aimed to assess the effect of fusion, adjuvant to internal fixation, on surgically treated thoracolumbar burst fractures. METHODS A search of the Medline and Cochrane Central Register of Controlled Trials databases was performed to identify randomized trials that compared the use and nonuse of arthrodesis in association with internal fixation for the treatment of thoracolumbar burst fractures. The search encompassed all data in these databases up to February 28, 2016. RESULTS Five randomized/quasi-randomized trials, which involved a total of 220 patients and an average follow-up time of 69.1 months, were included in this review. No significant difference between groups in the final scores of the visual analog pain scale or Low Back Outcome Scale was detected. Surgical time and blood loss were significantly lower in the group of patients who did not undergo fusion (p < 0.05). Among the evaluated radiological outcomes, greater mobility in the affected segment was found in the group of those who did not undergo fusion. No significant difference between groups in the degree of kyphosis correction, loss of kyphosis correction, or final angle of kyphosis was observed. CONCLUSIONS The data reviewed in this study suggest that the use of arthrodesis did not improve clinical outcomes, but it was associated with increased surgical time and higher intraoperative bleeding and did not promote significant improvement in radiological parameters.

Sagittal craniosynostosis: a utility outcomes study

OBJECTIVE Sagittal craniosynostosis results in a characteristic scaphocephalic head shape that is typically corrected surgically during a child's 1st year of life. The authors' objective was to determine the potential impact of being born with sagittal craniosynostosis by using validated health state utility assessment measures. METHODS An online utility assessment was designed to generate health utility scores for scaphocephaly, monocular blindness, and binocular blindness using standardized utility assessment tools, namely the visual analog scale (VAS) and the standard gamble (SG) and time trade-off (TTO) tests. Utility scores were compared between health states using the Wilcoxon and Kruskal-Wallis tests. Univariate regression was performed using age, sex, income, and education as independent predictors of utility scores. RESULTS Over a 2-month enrollment period, 122 participants completed the online survey. One hundred eighteen participants were eligible for analysis. Participants rated scaphocephaly due to sagittal craniosynostosis with significantly higher (p < 0.001) median utility scores (VAS 0.85, IQR 0.76-0.95; SG 0.92, IQR 0.84-0.98; TTO 0.91, IQR 0.84-0.95) than both monocular blindness (VAS 0.60, IQR 0.50-0.70; SG 0.84, IQR 0.68-0.94; TTO 0.84, IQR 0.67-0.91) and binocular blindness (VAS 0.25, IQR 0.20-0.40; SG 0.51, IQR 0.18-0.79; TTO 0.55, IQR 0.36-0.76). No differences were noted in utility scores based on participant age, sex, income, or education. CONCLUSIONS Using objective health state utility scores, authors of the current study demonstrated that the preoperatively perceived burden of scaphocephaly in a child's 1st year of life is less than that of monocular blindness. These relatively high utility scores for scaphocephaly suggest that the burden of disease as perceived by the general population is low and should inform surgeons' discussions when offering morbid corrective surgery, particularly when driven by aesthetic concerns.

Microendoscopic laminotomy versus conventional laminoplasty for cervical spondylotic myelopathy: 5-year follow-up study

OBJECTIVE The goal of this study was to characterize the long-term clinical and radiological results of articular segmental decompression surgery using endoscopy (cervical microendoscopic laminotomy [CMEL]) for cervical spondylotic myelopathy (CSM) and to compare outcomes to conventional expansive laminoplasty (ELAP). METHODS Consecutive patients with CSM who required surgical treatment were enrolled. All enrolled patients (n = 78) underwent CMEL or ELAP. All patients were followed postoperatively for more than 5 years. The preoperative and 5-year follow-up evaluations included neurological assessment (Japanese Orthopaedic Association [JOA] score), JOA recovery rates, axial neck pain (using a visual analog scale), the SF-36, and cervical sagittal alignment (C2-7 subaxial cervical angle). RESULTS Sixty-one patients were included for analysis, 31 in the CMEL group and 30 in the ELAP group. The mean preoperative JOA score was 10.1 points in the CMEL group and 10.9 points in the ELAP group (p > 0.05). The JOA recovery rates were similar, 57.6% in the CMEL group and 55.4% in the ELAP group (p > 0.05). The axial neck pain in the CMEL group was significantly lower than that in the ELAP group (p < 0.01). At the 5-year follow-up, cervical alignment was more favorable in the CMEL group, with an average 2.6° gain in lordosis (versus 1.2° loss of lordosis in the ELAP group [p < 0.05]) and lower incidence of postoperative kyphosis. CONCLUSIONS CMEL is a novel, less invasive technique that allows for multilevel posterior cervical decompression for the treatment of CSM. This 5-year follow-up data demonstrates that after undergoing CMEL, patients have similar neurological outcomes to conventional laminoplasty, with significantly less postoperative axial pain and improved subaxial cervical lordosis when compared with their traditional ELAP counterparts.

Modified dorsal root entry zone lesioning for intractable pain relief in patients with root avulsion injury

OBJECTIVE Dorsal root entry zone (DREZ) lesioning has been the most effective surgical treatment for the relief of intractable pain due to root avulsion injury, but residual pain and a decrease in pain relief in the follow-up period have been reported in 23%-70% of patients. Based on pain topography in the most recent studies on neuropathic pain, the authors modified the conventional DREZ lesioning procedure to improve clinical outcomes. The presumed rationale for this procedure is to eliminate the spontaneous discharges of neurons in the superficial spinal dorsal horn as well as wide dynamic range neurons in the deep spinal dorsal horn. METHODS Ten patients with avulsion-related pain underwent surgery between 2011 and 2015. The surgical procedure was described and postoperative pain relief was assessed as follows: excellent (residual pain never exceeded 3 on the visual analog scale [VAS] without medication), good (residual pain never exceeded 5 on the VAS with medication), and poor (residual pain was greater than 5 with medication). Specific perioperative complications were assessed. RESULTS The aim of this surgical procedure was to destroy the deeper layers of the posterior horn of spinal gray matter, which was in contrast to the procedures of Nashold and Sindou, which were to destroy the superficial layers. All patients achieved excellent (n = 7, pain relief without medication) or good (n = 3, pain relief with medication) pain relief postoperatively, and the recurrence of pain was not reported in any patients (median 29 months after surgery, range 12-64 months). Nine patients (90%) achieved complete pain relief (a score of 0 or 1 on the VAS) with or without medication. No surgical site complications such as infection or CSF leakage were noted. No motor deficit was observed in any patient. A sensory deficit was observed in 2 patients and disappeared within 1 month in 1 patient. New pain at the adjacent level of DREZ lesioning was observed in 3 patients and disappeared within 1 month in 2 patients. In the other patient, new pain persisted and required analgesics. CONCLUSIONS These preliminary results demonstrated that total and persistent global pain relief was achieved with the modified DREZ lesioning procedure in 90% of patients without major neurological deficits. The clinical improvements achieved by this modified surgical procedure support the hypothesis that not only the superficial layers, but also deeper layers of the spinal dorsal horn are associated with intractable pain due to root avulsion injury.

Postoperative quality-of-life assessment in patients with spine metastases treated with long-segment pedicle-screw fixation

OBJECTIVE In recent decades, progress in the medical management of cancer has been significant, resulting in considerable extension of survival for patients with metastatic disease. This has, in turn, led to increased attention to the optimal surgical management of bone lesions, including metastases to the spine. In addition, there has been a shift in focus toward improving quality of life and reducing hospital stay for these patients, and many minimally invasive techniques have been introduced with the aim of reducing the morbidity associated with more traditional open approaches. The goal of this study was to assess the efficacy of long-segment percutaneous pedicle screw stabilization for the treatment of instability associated with thoracolumbar spine metastases in neurologically intact patients. METHODS This study was a retrospective review of data from a prospective database. The authors analyzed cases in which long-segment percutaneous pedicle screw fixation was performed for the palliative treatment of thoracolumbar spinal instability due to spinal metastases in neurologically intact patients. All of the patients included in the study underwent surgery between January 2014 and May 2015 at the authors' institution. Postoperative radiation therapy was planned within 10 days following the stabilization in all cases. Clinical and radiological follow-up assessments were planned for 3 days, 3 weeks, 6 weeks, 3 months, 6 months, and 1 year after surgery. Outcome was assessed by means of standard postoperative evaluation and oncological and spinal quality of life measures (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Version 3.0 [EORTC QLQ-C30] and Oswestry Disability Index [ODI], respectively). Moreover, 5 patients were given an activity monitoring device for recording the distance walked daily; preoperative and postoperative daily distances were compared. RESULTS Data from 17 cases were analyzed. There were no complications, and patients showed improvement in pain level and quality of life from the early postoperative period on. The mean ODI score was 62.7 (range 40-84) preoperatively, 35.4 (range 24-59) on postoperative Day 3, and 46.1 (range 30-76) at 3 weeks, 37.6 (range 25-59) at 6 weeks, 34.0 (range 24-59) at 3 months, 39.1 (range 22-64) at 6 months, and 30.0 (range 20-55) at 1 year after screw placement. The mean ODI was significantly improved in the first 45 days (p < 0.001). Improvement was also evident in scores for functional and symptomatic scales of the EORTC QLQ-C30. All patients underwent postoperative radiation therapy within 10 days (mean 7.5). All patients (n = 5) with an activity monitoring device showed improvement in daily walking distance. CONCLUSIONS Less-invasive palliative treatment for advanced spinal metastases is promising as part of a multidisciplinary approach to the care of patients with metastatic disease. The results of this study indicate that percutaneous surgery may allow for rapid improvement in quality of life and walking ability for patients with thoracolumbar instability due to spine metastases. Long-segment percutaneous screw fixation followed by early radiation therapy appears to be a safe and effective treatment option for providing solid and durable stability and improved quality of life for these patients.

Bone loss of vertebral bodies at the operative segment after cervical arthroplasty: a potential complication?

OBJECTIVE Bony overgrowth and spontaneous fusion are complications of cervical arthroplasty. In contrast, bone loss or bone remodeling of vertebral bodies at the operation segment after cervical arthroplasty has also been observed. The purpose of this study is to investigate a potential complication-bone loss of the anterior portion of the vertebral bodies at the surgically treated segment after cervical total disc replacement (TDR)-and discuss the clinical significance. METHODS All enrolled patients underwent follow-up for more than 24 months after cervical arthroplasty using the Baguera C disc. Clinical evaluations included recording demographic data and measuring the visual analog scale and Neck Disability Index scores. Radiographic evaluations included measurements of the functional spinal unit's range of motion and changes such as bone loss and bone remodeling. The grading of the bone loss of the operative segment was classified as follows: Grade 1, disappearance of the anterior osteophyte or small minor bone loss; Grade 2, bone loss of the anterior portion of the vertebral bodies at the operation segment without exposure of the artificial disc; or Grade 3, significant bone loss with exposure of the anterior portion of the artificial disc. RESULTS Forty-eight patients were enrolled in this study. Among them, bone loss developed in 29 patients (Grade 1 in 15 patients, Grade 2 in 6 patients, and Grade 3 in 8 patients). Grade 3 bone loss was significantly associated with postoperative neck pain (p < 0.05). Bone loss was related to the motion preservation effect of the operative segment after cervical arthroplasty in contrast to heterotopic ossification. CONCLUSIONS Bone loss may be a potential complication of cervical TDR and affect early postoperative neck pain. However, it did not affect mid- to long-term clinical outcomes or prosthetic failure at the last follow-up. Also, this phenomenon may result in the motion preservation effect in the operative segment after cervical TDR.

Multilevel cervical arthroplasty: current evidence. A systematic review

OBJECTIVE Cervical disc arthroplasty (CDA) has been demonstrated to be an effective treatment modality for single-level cervical radiculopathy or myelopathy. Its advantages over an anterior cervical discectomy and fusion (ACDF) include motion preservation and decreased reoperations at the index and adjacent segments up to 7 years postoperatively. Considering the fact that many patients have multilevel cervical disc degeneration (CDD), the authors performed a systematic review of the clinical studies evaluating patients who underwent multilevel CDA (2 or more levels). METHODS A systematic review in the MEDLINE database was performed. Clinical studies including patients who had multilevel CDA were selected and included. Case reports and literature reviews were excluded. Articles were then grouped according to their main study objective: 1) studies comparing multilevel CDA versus ACDF; 2) studies comparing single-level CDA versus multilevel CDA; and 3) multilevel CDA after a previous cervical spine surgery. RESULTS Fourteen articles met all inclusion criteria. The general conclusions were that multilevel CDA was at least as safe and effective as ACDF, with preservation of cervical motion when compared with ACDF and potentially with fewer reoperations expected in most of the studies. Multilevel CDAs are clinically effective as single-level surgeries, with good clinical and radiological outcomes. Some studies reported a higher incidence of heterotopic ossification in multilevel CDA when compared with single-level procedures, but without clinical relevance during the follow-up period. A CDA may be indicated even after a previous cervical surgery in selected cases. CONCLUSIONS The current literature supports the use of multilevel CDA. Caution is necessary regarding the more restrictive indications for CDA when compared with ACDF. Further prospective, controlled, multicenter, and randomized studies not sponsored by the device manufactures are desirable to prove the superiority of CDA surgery over ACDF as the treatment of choice for CDD in selected cases.

Adjacent-level arthroplasty following cervical fusion

OBJECTIVE Adjacent-level disc degeneration following cervical fusion has been well reported. This condition poses a major treatment dilemma when it becomes symptomatic. The potential application of cervical arthroplasty to preserve motion in the affected segment is not well documented, with few studies in the literature. The authors present their initial experience of analyzing clinical and radiological results in such patients who were treated with arthroplasty for new or persistent arm and/or neck symptoms related to neural compression due to adjacent-segment disease after anterior cervical discectomy and fusion (ACDF). METHODS During a 5-year period, 11 patients who had undergone ACDF anterior cervical discectomy and fusion (ACDF) and subsequently developed recurrent neck or arm pain related to adjacent-level cervical disc disease were treated with cervical arthroplasty at the authors' institution. A total of 15 devices were implanted (range of treated levels per patient: 1-3). Clinical evaluation was performed both before and after surgery, using a visual analog scale (VAS) for pain and the Neck Disability Index (NDI). Radiological outcomes were analyzed using pre- and postoperative flexion/extension lateral radiographs measuring Cobb angle (overall C2-7 sagittal alignment), functional spinal unit (FSU) angle, and range of motion (ROM). RESULTS There were no major perioperative complications or device-related failures. Statistically significant results, obtained in all cases, were reflected by an improvement in VAS scores for neck/arm pain and NDI scores for neck pain. Radiologically, statistically significant increases in the overall lordosis (as measured by Cobb angle) and ROM at the treated disc level were observed. Three patients were lost to follow-up within the first year after arthroplasty. In the remaining 8 cases, the duration of follow-up ranged from 1 to 3 years. None of these 8 patients required surgery for the same vertebral level during the follow-up period. CONCLUSIONS Artificial cervical disc replacement in patients who have previously undergone cervical fusion surgery appears to be safe, with encouraging early clinical results based on this small case series, but more data from larger numbers of patients with long-term follow-up are needed. Arthroplasty may provide an additional tool for the management of post-fusion adjacent-level cervical disc disease in carefully selected patients.

Randomized, double-blinded, placebo-controlled trial comparing two multimodal opioid-minimizing pain management regimens following transsphenoidal surgery

OBJECTIVE Pain control is an important clinical consideration and quality-of-care metric. No studies have examined postoperative pain control following transsphenoidal surgery for pituitary lesions. The study goals were to 1) report postoperative pain scores following transsphenoidal surgery, 2) determine if multimodal opioid-minimizing pain regimens yielded satisfactory postoperative pain control, and 3) determine if intravenous (IV) ibuprofen improved postoperative pain scores and reduced opioid use compared with placebo. METHODS This study was a single-center, randomized, double-blinded, placebo-controlled intervention trial involving adult patients with planned transsphenoidal surgery for pituitary tumors randomized into 2 groups. Group 1 patients were treated with scheduled IV ibuprofen, scheduled oral acetaminophen, and rescue opioids. Group 2 patients were treated with IV placebo, scheduled oral acetaminophen, and rescue opioids. The primary end point was patient pain scores (visual analog scale [VAS], rated 0-10) for 48 hours after surgery. The secondary end point was opioid use as estimated by oral morphine equivalents (OMEs). RESULTS Of 136 patients screened, 62 were enrolled (28 in Group 1, 34 in Group 2). The study was terminated early because the primary and secondary end points were reached. Baseline characteristics between groups were well matched except for age (Group 1, 59.3 ± 14.4 years; Group 2, 49.8 ± 16.2 years; p = 0.02). Mean VAS pain scores were significantly different, with a 43% reduction in Group 1 (1.7 ± 2.2) compared with Group 2 (3.0 ± 2.8; p < 0.0001). Opioid use was significantly different, with a 58% reduction in Group 1 (26.3 ± 28.7 mg OME) compared with Group 2 (62.5 ± 63.8 mg OME; p < 0.0001). CONCLUSIONS Multimodal opioid-minimizing pain-management protocols resulted in acceptable pain control following transsphenoidal surgery. IV ibuprofen resulted in significantly improved pain scores and significantly decreased opioid use compared with placebo. Postoperative multimodal pain management, including a nonsteroidal antiinflammatory medication, should be considered after surgery to improve patient comfort and to limit opioid use. Clinical trial registration no.: NCT02351700 (clinicaltrials.gov) ■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized, controlled trial; evidence: Class III.

The role of the mini-open thoracoscopic-assisted approach in the management of metastatic spine disease at the thoracolumbar junction

Objective

Treatment advances have resulted in improved survival for many cancer types, and this, in turn, has led to an increased incidence of metastatic disease, specifically to the vertebral column. Surgical decompression and stabilization prior to radiation therapy have been shown to improve functional outcomes, but anterior access to the thoracolumbar junction may involve open thoracotomy, which can cause significant morbidity. The authors describe the treatment of 12 patients in whom a mini-open thoracoscopic-assisted approach (mini-open TAA) to the thoracolumbar junction was used to treat metastatic disease, with an analysis of outcomes.

Methods

The authors reviewed a retrospective cohort of patients treated for thoracolumbar junction metastatic disease with mini-open TAA between 2004 and 2016. Data collection included operative time, estimated blood loss, length of stay, follow-up duration, and pre- and postoperative visual analog scale scores and Frankel grades.

Results

Twelve patients underwent a mini-open TAA procedure for metastatic disease at the thoracolumbar junction. The mean age of patients was 59 years (range 53-77 years), mean estimated blood loss was 613 ml, and the mean duration of the mini-open TAA procedure was 234 minutes (3.8 hours). The median length of stay in the hospital was 7.5 days (range 5-21 days). All 12 patients had significant improvement in their postoperative pain scores in comparison with their preoperative pain scores (p < 0.001). No patients suffered from worsening neurological function after surgery, and of 7 patients who presented with neurological dysfunction, 6 (86%) had an improvement in their Frankel grade after surgery. No patients experienced delayed hardware failure requiring reoperation over a mean follow-up of 10 months (range 1-45 months).

Conclusions

The mini-open TAA to the thoracolumbar junction for metastatic disease is a durable procedure that has a reduced morbidity rate compared with traditional open thoracotomy for ventral decompression and fusion. It compares well with traditional and novel posterior approaches to the thoracolumbar junction. The authors found a significant improvement in preoperative pain and neurological symptoms that supports greater use of the mini-open TAA for the treatment of complex metastatic disease at the thoracolumbar junction.

A comparison of minimally invasive posterior cervical decompression and open anterior cervical decompression and instrumented fusion in the surgical management of degenerative cervical myelopathy

OBJECTIVE Minimally invasive posterior cervical decompression (miPCD) has been described in several case series with promising preliminary results. The object of the current study was to compare the clinical outcomes between patients undergoing miPCD with anterior cervical discectomy and instrumented fusion (ACDFi). METHODS A retrospective study of 74 patients undergoing surgery (45 using miPCD and 29 using ACDFi) for myelopathy was performed. Outcomes were categorized into short-term, intermediate, and long-term follow-up, corresponding to averages of 1.7, 7.7, and 30.9 months, respectively. Mean scores for the Neck Disability Index (NDI), neck visual analog scale (VAS) score, SF-12 Physical Component Summary (PCS), and SF-12 Mental Component Summary (MCS) were compared for each follow-up period. The percentage of patients meeting substantial clinical benefit (SCB) was also compared for each outcome measure. RESULTS Baseline patient characteristics were well-matched, with the exception that patients undergoing miPCD were older (mean age 57.6 ± 10.0 years [miPCD] vs 51.1 ± 9.2 years [ACDFi]; p = 0.006) and underwent surgery at more levels (mean 2.8 ± 0.9 levels [miPCD] vs 1.5 ± 0.7 levels [ACDFi]; p < 0.0001) while the ACDFi patients reported higher preoperative neck VAS scores (mean 3.8 ± 3.0 [miPCD] vs 5.4 ± 2.6 [ACDFi]; p = 0.047). The mean PCS, NDI, neck VAS, and MCS scores were not significantly different with the exception of the MCS score at the short-term follow-up period (mean 46.8 ± 10.6 [miPCD] vs 41.3 ± 10.7 [ACDFi]; p = 0.033). The percentage of patients reporting SCB based on thresholds derived for PCS, NDI, neck VAS, and MCS scores were not significantly different, with the exception of the PCS score at the intermediate follow-up period (52% [miPCD] vs 80% [ACDFi]; p = 0.011). CONCLUSIONS The current report suggests that the optimal surgical strategy in patients requiring dorsal surgery may be enhanced by the adoption of a minimally invasive surgical approach that appears to result in similar clinical outcomes when compared with a well-accepted strategy of ventral decompression and instrumented fusion. The current results suggest that future comparative effectiveness studies are warranted as the miPCD technique avoids instrumented fusion.

Outcomes and effectiveness of posterior occipitocervical fusion for suboccipital spinal metastases

OBJECTIVE The incidence of suboccipital spinal metastases is rare but has increased given cancer patients' longer life expectancies. Operative treatment in this region is often challenging because of limited fixation points due to tumor lysis, as well as adjacent neural and vascular anatomy. Few studies have reported on this population of cancer patients. The purpose of this study was to evaluate clinical outcomes and complications of patients with suboccipital spinal metastases who had undergone posterior occipitocervical fixation. METHODS A single-institution database was reviewed to identify patients with suboccipital metastases who had undergone posterior-only instrumented fusion between 1999 and 2014. Clinical presentation, perioperative complications, and postoperative results were analyzed. Pain was assessed using the visual analog scale. Survival analysis was performed using a Kaplan-Meier curve. The revised Tokuhashi and the Tomita scoring systems were used for prognosis prediction. RESULTS Fifteen patients were identified, 10 men and 5 women with mean age of 64.8 ± 11.8 years (range 48-80 years). Severe neck pain without neurological deficit was the most common presentation. Primary tumors included lung, breast, bladder, myeloma, melanoma, and renal cell cancers. All tumors occurred in the axis vertebra. Preoperative Tokuhashi and Tomita scores ranged from 5 to 13 and 3 to 7, respectively. All patients had undergone occipitocervical fusion of a mean of 4.6 levels (range 2-7 levels). Median survival was 10.3 months. In all cases, neck pain markedly improved and patients were able to resume activities of daily living. The average postoperative pain score was significantly improved as compared with the average preoperative score (1.90 ± 2.56 and 5.50 ± 2.99, respectively, p = 0.01). Three patients experienced postoperative medical complications including urinary tract infection, deep vein thrombosis, myocardial infarction, and cardiac arrhythmia. In the follow-up period, no wound infections or reoperations occurred and no patients experienced spinal cord deficits from tumor recurrence. CONCLUSIONS Posterior-only occipitocervical stabilization was highly effective at relieving patients' neck pain. No instrumentation failures were noted, and no neurological complications or tumor progression causing spinal cord deficits was noted in the follow-up period.

Algorithm for bionic hand reconstruction in patients with global brachial plexopathies

OBJECTIVE Global brachial plexus lesions with multiple root avulsions are among the most severe nerve injuries, leading to lifelong disability. Fortunately, in most cases primary and secondary reconstructions provide a stable shoulder and restore sufficient arm function. Restoration of biological hand function, however, remains a reconstructive goal that is difficult to reach. The recently introduced concept of bionic reconstruction overcomes biological limitations of classic reconstructive surgery to restore hand function by combining selective nerve and muscle transfers with elective amputation of the functionless hand and its replacement with a prosthetic device. The authors present their treatment algorithm for bionic hand reconstruction and report on the management and long-term functional outcomes of patients with global brachial plexopathies who have undergone this innovative treatment. METHODS Thirty-four patients with posttraumatic global brachial plexopathies leading to loss of hand function consulted the Center for Advanced Restoration of Extremity Function between 2011 and 2015. Of these patients, 16 (47%) qualified for bionic reconstruction due to lack of treatment alternatives. The treatment algorithm included progressive steps with the intent of improving the biotechnological interface to allow optimal prosthetic hand replacement. In 5 patients, final functional outcome measurements were obtained with the Action Arm Research Test (ARAT), the Southampton Hand Assessment Procedure (SHAP), and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. RESULTS In all 5 patients who completed functional assessments, partial hand function was restored with bionic reconstruction. ARAT scores improved from 3.4 ± 4.3 to 25.4 ± 12.7 (p = 0.043; mean ± SD) and SHAP scores improved from 10.0 ± 1.6 to 55 ± 19.7 (p = 0.042). DASH scores decreased from 57.9 ± 20.6 to 32 ± 28.6 (p = 0.042), indicating decreased disability. CONCLUSIONS The authors present an algorithm for bionic reconstruction leading to useful hand function in patients who lack biological treatment alternatives for a stiff, functionless, and insensate hand resulting from global brachial plexopathies.

Congenital hypoplasia of the lumbar pedicle with spondylolisthesis: report of 2 cases

Congenital hypoplasia of the spinal pedicle is a rare condition. Previously reported cases were treated conservatively or with posterior instrumented fusion. However, the absence or hypoplasia of the lumbar pedicle may increase the difficulty of pedicle screw fixation and fusion. Herein, the authors describe 2 cases of rare adult congenital hypoplasia of the right lumbar pedicles associated with spondylolisthesis. The patients underwent anterior lumbar interbody fusion with a stand-alone cage as well as percutaneous pedicle screw fixation. This method was used to avoid the difficulties associated with pedicle screw fixation and to attain solid fusion. Both patients achieved satisfactory outcomes after a minimum of 2 years of follow-up. This method may be an alternative for patients with congenital hypoplasia of the lumbar spinal pedicle.

Radiofrequency ablation of spinal osteoid osteoma: a prospective study

OBJECTIVE Surgery has been considered the standard treatment for spinal osteoid osteomas that are refractory to analgesic agents. Radiofrequency ablation (RFA) is a less invasive technique with established efficiency for the treatment of peripheral osteoid osteomas. The main objectives of this study are to evaluate the safety of RFA based on the results of a previous experimental study in rats conducted in the authors' laboratory and to identify its short- and long-term efficiency in the treatment of spinal osteoid osteomas. METHODS Between March 2009 and July 2016, 8 consecutive patients with spinal osteoid osteomas were enrolled in the study and underwent 9 CT-guided RFA procedures. All patients presented with spinal pain (median preoperative visual analog scale [VAS] score 7.55, range 6-8.8) predominantly during the night, and they all had normal neurological examination results before the procedure. Pain (according to the VAS score) and neurological status were reassessed immediately before discharge, with further follow-up at 1, 6, and 12 months after the procedure. At the final follow-up, VAS score, neurological examination, patient satisfaction, and a radiological control (CT scan) were documented (median 48 months, range 12-84 months). VAS scores before and after the procedure were compared during the 3 days before surgery (D0), on the day of the surgery, Day 1 (D1), and at the final follow-up. RESULTS No neurological deficit was documented following the procedure or at the final follow-up. A statistically significant reduction in the VAS score was observed on Day 1 (mean 2.56 ± 0.68, p = 0.005) compared with D0. At the final follow-up, all patients reported a VAS score of 0 and a satisfaction rate of 100%. Only 1 patient had recurrent symptoms (pain, VAS score 8.1) 6 months after the initial RFA. A second procedure was performed, and the patient was subsequently symptom free at the final follow-up. CT scanning performed in all patients (12-84 months post-RFA) showed residual sclerosis in 4 patients and complete resolution of the radiological lesion in the remaining 4 patients. CONCLUSIONS CT-guided RFA appears to be a safe and effective method for the management of spinal osteoid osteoma and can be safely performed for lesions close to the dura or exiting nerve root based on the motor response threshold testing performed during the procedure. It should be considered the treatment of choice for spinal osteoid osteomas refractory to conservative treatment, thus avoiding more aggressive spinal approaches with subsequent potential morbidity.

Early experience with endoscopic foraminotomy in patients with moderate degenerative deformity

OBJECTIVE Asymmetrical degeneration of the disc is one of the most common causes of primary degenerative scoliosis in adults. Coronal deformity is usually less symptomatic than a sagittal deformity because there is less expenditure of energy and hence less effort to maintain upright posture. However, nerve root compression at the fractional curve or at the concave side of the main curve can give rise to debilitating radiculopathy. METHODS This study was a retrospective analysis of 16 patients with coronal deformity of between 10° and 20°. All patients underwent endoscopic foraminal decompression surgery. The pre- and postoperative Cobb angle, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index scores were measured. RESULTS The average age of the patients was 70.0 ± 15.5 years (mean ± SD, range 61-86 years), with a mean followup of 7.5 ± 5.3 months (range 2-14 months). The average coronal deformity was 16.8° ± 4.7° (range 10°-41°). In 8 patients the symptomatic foraminal stenosis was at the level of the fractional curve, and in the remaining patients it was at the concave side of the main curve. One of the patients included in the current cohort had to undergo a repeat operation within 1 week for another disc herniation at the adjacent level. One patient had CSF leakage, which was repaired intraoperatively, and no further complications were noted. On average, preoperative VAS and SF-36 scores showed a tendency for improvement, whereas a dramatic reduction of VAS, by 65% (p = 0.003), was observed in radicular leg pain. CONCLUSIONS Patients with mild to moderate spinal deformity are often compensated and have tolerable levels of back pain. However, unilateral radicular pain resulting from foraminal stenosis can be debilitating. In select cases, an endoscopic discectomy or foraminotomy enables the surgeon to decompress the symptomatic foramen with preservation of essential biomechanical structures, delaying the need for a major deformity correction surgery.

Clinical outcomes after percutaneous transforaminal endoscopic discectomy for lumbar disc herniation: a prospective case series

OBJECTIVE Throughout the last decades, full-endoscopic techniques to treat lumbar disc herniation (LDH) have gained popularity in clinical practice. To date, however, no Class I evidence on the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) has been published, and studies describing its safety and short- and long-term efficacy are scarce. In this study the authors aimed to evaluate the clinical outcomes and safety in patients undergoing PTED for LDH. METHODS Patients who underwent PTED for LDH between January 2009 and December 2012 were prospectively followed. The primary outcomes were the visual analog scale (VAS) score for leg pain and the score on the Quebec Back Pain Disability Scale (QBPDS). Secondary outcomes were the perceived experience with the local anesthesia used and satisfaction with the results after 1 year using Likert-type scales. The pretreatment means were compared with the means obtained 6 and 52 weeks after surgery using paired t-tests. RESULTS A total of 166 patients underwent surgery for a total of 167 LDHs. The mean duration of surgery (± SD) was 51.0 ± 9.0 minutes. The 1-year follow-up rate was 95.2%. The mean reported scores on the VAS and QBPDS were 82.5 ± 17.3 mm and 60.0 ± 18.4 at baseline, respectively. Six weeks after surgery, the scores on the VAS and QBPDS were significantly reduced to 28.8 ± 24.5 mm and 26.7 ± 20.6, respectively (p < 0.001). After 52 weeks of follow-up, the scores were further reduced compared with baseline scores (p < 0.001) to 19.6 ± 23.5 mm on the VAS and 20.2 ± 18.1 on the QBPDS. A total of 4 complications were observed, namely 1 dural tear, 1 deficit of ankle dorsiflexion, and 2 cases of transient paresis in the foot due to the use of local anesthetics. CONCLUSIONS PTED appears to be a safe and effective intervention for LDH and has similar clinical outcomes compared to conventional open microdiscectomy. High-quality randomized controlled trials are required to study the efficacy and cost-effectiveness of PTED.

Early experience with endoscopic revision of lumbar spinal fusions

Approximately half a million spinal fusion procedures are performed annually in the US. It is estimated that up to one-third of arthrodesis constructs require revision surgeries. In this study the authors present endoscopic treatment strategies targeting 3 types of complications following arthrodesis surgery: 1) adjacent-level foraminal stenosis; 2) foraminal stenosis at an arthrodesis segment; and 3) stenosis caused by a displaced interbody cage. A retrospective chart review of 11 patients with a mean age of 68 ± 15 years was performed (continuous variables are shown as the mean ± SEM). All patients had a history of lumbar arthrodesis surgery and suffered from unilateral radiculopathy. Endoscopic revision surgeries were done as outpatient procedures, and there were no intraoperative or perioperative complications. The cohort included 3 patients with foraminal stenosis at the level of previous arthrodesis. They presented with unilateral radicular leg pain (visual analog scale [VAS] score: 7.3 ± 2.1) and were severely disabled, as evidenced by an Oswestry Disability Index (ODI) of 46 ± 4.9. Transforaminal endoscopic foraminotomies were performed, and at a mean follow-up time of 9.0 ± 2.5 months VAS was reduced by an average of 6.3. The cohort also includes 7 patients suffering unilateral radiculopathy due to adjacent-level foraminal stenosis. Preoperative VAS for leg pain of the symptomatic side was 6.0 ± 1.6, VAS for back pain was 5.2 ± 1.7, and ODI was 40 ± 6.33. Endoscopic decompression led to reduction of the ipsilateral leg VAS score by an average of 5, resulting in leg pain of 1 ± 0.5 at an average of 8 months of follow-up. The severity of back pain remained stable (VAS 4.2 ± 1.4). Two of these patients required revision surgery for recurrent symptoms. Finally, this study includes 1 patient who presented with weakness and pain due to retropulsion of an L5/S1 interbody spacer. The patient underwent an endoscopic interlaminar approach with partial resection of the interbody cage, which resulted in complete resolution of her radicular symptoms. Endoscopic surgery may be a useful adjunct for management of certain arthrodesis-related complications. Endoscopic foraminal decompression of previously fused segments and resection of displaced interbody cages appears to have excellent outcomes, whereas decompression of adjacent segments remains challenging and requires further investigation.

Technical considerations in transforaminal endoscopic spine surgery at the thoracolumbar junction: report of 3 cases

OBJECTIVE In this study the authors describe the technical considerations and feasibility of transforaminal discectomy and foraminoplasty for the treatment of lumbar radiculopathy in patients who have herniated discs at the thoracolumbar junction. METHODS After institutional review board approval, charts from 3 consecutive patients with lumbar radiculopathy and T12-L1 herniated discs who underwent endoscopic procedures between 2006 and 2014 were reviewed. RESULTS Consecutive cases (n = 1316) were reviewed to determine the incidence and success of surgery performed at the T12-L1 level. Only 3 patients (0.23%) treated with endoscopic surgery for their herniated discs had T12-L1 herniated discs; the rest were lumbar or lumbosacral herniations. For patients with T12-L1 disc herniations, the average preoperative visual analog scale score was 8.3 (indicated in the questionnaire as describing severe and constant pain). The average 1-year postoperative visual analog scale score was 1.7 (indicated in the questionnaire as mild and intermittent pain). CONCLUSIONS Transforaminal endoscopic discectomy and foraminotomy can be used as a safe yet minimally invasive technique for the treatment of lumbar radiculopathy in the setting of a thoracolumbar disc herniation.

Utility of multilevel lateral interbody fusion of the thoracolumbar coronal curve apex in adult deformity surgery in combination with open posterior instrumentation and L5-S1 interbody fusion: a case-matched evaluation of 32 patients

OBJECTIVE The aim of this study was to evaluate the utility of supplementing long thoracolumbar posterior instrumented fusion (posterior spinal fusion, PSF) with lateral interbody fusion (LIF) of the lumbar/thoracolumbar coronal curve apex in adult spinal deformity (ASD). METHODS Two multicenter databases were evaluated. Adults who had undergone multilevel LIF of the coronal curve apex in addition to PSF with L5-S1 interbody fusion (LS+Apex group) were matched by number of posterior levels fused with patients who had undergone PSF with L5-S1 interbody fusion without LIF (LS-Only group). All patients had at least 2 years of follow-up. Percutaneous PSF and 3-column osteotomy (3CO) were excluded. Demographics, perioperative details, radiographic spinal deformity measurements, and HRQoL data were analyzed. RESULTS Thirty-two patients were matched (LS+Apex: 16; LS: 16) (6 men, 26 women; mean age 63 ± 10 years). Overall, the average values for measures of deformity were as follows: Cobb angle > 40°, sagittal vertical axis (SVA) > 6 cm, pelvic tilt (PT) > 25°, and mismatch between pelvic incidence (PI) and lumbar lordosis (LL) > 15°. There were no significant intergroup differences in preoperative radiographic parameters, although patients in the LS+Apex group had greater Cobb angles and less LL. Patients in the LS+Apex group had significantly more anterior levels fused (4.6 vs 1), longer operative times (859 vs 379 minutes), and longer length of stay (12 vs 7.5 days) (all p < 0.01). For patients in the LS+Apex group, Cobb angle, pelvic tilt (PT), lumbar lordosis (LL), PI-LL (lumbopelvic mismatch), Oswestry Disability Index (ODI) scores, and visual analog scale (VAS) scores for back and leg pain improved significantly (p < 0.05). For patients in the LS-Only group, there were significant improvements in Cobb angle, ODI score, and VAS scores for back and leg pain. The LS+Apex group had better correction of Cobb angles (56% vs 33%, p = 0.02), SVA (43% vs 5%, p = 0.46), LL (62% vs 13%, p = 0.35), and PI-LL (68% vs 33%, p = 0.32). Despite more LS+Apex patients having major complications (56% vs 13%; p = 0.02) and postoperative leg weakness (31% vs 6%, p = 0.07), there were no intergroup differences in 2-year outcomes. CONCLUSIONS Long open posterior instrumented fusion with or without multilevel LIF is used to treat a variety of coronal and sagittal adult thoracolumbar deformities. The addition of multilevel LIF to open PSF with L5-S1 interbody support in this small cohort was often used in more severe coronal and/or lumbopelvic sagittal deformities and offered better correction of major Cobb angles, lumbopelvic parameters, and SVA than posterior-only operations. As these advantages came at the expense of more major complications, more leg weakness, greater blood loss, and longer operative times and hospital stays without an improvement in 2-year outcomes, future investigations should aim to more clearly define deformities that warrant the addition of multilevel LIF to open PSF and L5-S1 interbody fusion.

How does back muscle strength change after posterior lumbar interbody fusion?

OBJECTIVE There is a lack of evidence of how back muscle strength changes after lumbar fusion surgery and how exercise influences these changes. The aim of this study was to evaluate changes in back muscle strength after posterior lumbar interbody fusion (PLIF) and to measure the effects of a postoperative exercise program on muscle strength and physical and mental health outcomes. METHODS This prospective study enrolled 59 women (mean age 58 years) who underwent PLIF at 1 or 2 spinal levels. To assess the effects of a supervised lumbar stabilization exercise (LSE), the authors allocated the patients to an LSE (n = 26) or a control (n = 33) group. The patients in the LSE group performed the LSEs between 3 and 6 months postoperatively. Back extensor strength, visual analog scale (VAS) scores in back pain, and physical component summary (PCS) and mental component summary (MCS) scores on the 36-Item Short Form Health Survey were determined for the both groups. RESULTS Mean strength of the back muscles tended to slightly decrease by 7.5% from preoperatively to 3 months after PLIF (p = 0.145), but it significantly increased thereafter and was sustained until the last follow-up (38.1%, p < 0.001). The mean back muscle strength was similar in the LSE and control groups preoperatively, but it increased significantly more in the LSE group (64.2%) than in the control group (21.7%) at the last follow-up 12 months after PLIF (p = 0.012). At the last follow-up, decreases in back pain VAS scores were more significant among LSE group patients, who had a pain reduction on average of 58.2%, than among control group patients (reduction of 26.1%) (p = 0.013). The patients in the LSE group also had greater improvement in both PCS (39.9% improvement) and MCS (20.7% improvement) scores than the patients in the control group (improvement of 18.0% and 1.1%, p = 0.042 and p = 0.035, respectively). CONCLUSIONS After PLIF, strength in back muscles decreased until 3 months postoperatively but significantly increased after that period. The patients who regularly underwent postoperative LSE had significantly improved back strength, less pain, and less functional disability at 12 months postoperatively.

Facet joint changes after application of lumbar nonfusion dynamic stabilization

OBJECTIVE The long-term effects on adjacent-segment pathology after nonfusion dynamic stabilization is unclear, and, in particular, changes at the adjacent facet joints have not been reported in a clinical study. This study aims to compare changes in the adjacent facet joints after lumbar spinal surgery. METHODS Patients who underwent monosegmental surgery at L4-5 with nonfusion dynamic stabilization using the Dynesys system (Dynesys group) or transforaminal lumbar interbody fusion with pedicle screw fixation (fusion group) were retrospectively compared. Facet joint degeneration was evaluated at each segment using the CT grading system. RESULTS The Dynesys group included 15 patients, while the fusion group included 22 patients. The preoperative facet joint degeneration CT grades were not different between the 2 groups. Compared with the preoperative CT grades, 1 side of the facet joints at L3-4 and L4-5 had significantly more degeneration in the Dynesys group. In the fusion group, significant facet joint degeneration developed on both sides at L2-3, L3-4, and L5-S1. The subjective back and leg pain scores were not different between the 2 groups during follow-up, but functional outcome based on the Oswestry Disability Index improved less in the fusion group than in the Dynesys group. CONCLUSIONS Nonfusion dynamic stabilization using the Dynesys system had a greater preventative effect on facet joint degeneration in comparison with that obtained using fusion surgery. The Dynesys system, however, resulted in facet joint degeneration at the instrumented segments and above. An improved physiological nonfusion dynamic stabilization system for lumbar spinal surgery should be developed.

Dynamic stabilization for L4-5 spondylolisthesis: comparison with minimally invasive transforaminal lumbar interbody fusion with more than 2 years of follow-up

OBJECTIVE In the past decade, dynamic stabilization has been an emerging option of surgical treatment for lumbar spondylosis. However, the application of this dynamic construct for mild spondylolisthesis and its clinical outcomes remain uncertain. This study aimed to compare the outcomes of Dynesys dynamic stabilization (DDS) with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for the management of single-level spondylolisthesis at L4-5. METHODS This study retrospectively reviewed 91 consecutive patients with Meyerding Grade I spondylolisthesis at L4-5 who were managed with surgery. Patients were divided into 2 groups: DDS and MI-TLIF. The DDS group was composed of patients who underwent standard laminectomy and the DDS system. The MI-TLIF group was composed of patients who underwent MI-TLIF. Clinical outcomes were evaluated by visual analog scale for back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores at each time point of evaluation. Evaluations included radiographs and CT scans for every patient for 2 years after surgery. RESULTS A total of 86 patients with L4-5 spondylolisthesis completed the follow-up of more than 2 years and were included in the analysis (follow-up rate of 94.5%). There were 64 patients in the DDS group and 22 patients in the MI-TLIF group, and the overall mean follow-up was 32.7 months. Between the 2 groups, there were no differences in demographic data (e.g., age, sex, and body mass index) or preoperative clinical evaluations (e.g., visual analog scale back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores). The mean estimated blood loss of the MI-TLIF group was lower, whereas the operation time was longer compared with the DDS group (both p < 0.001). For both groups, clinical outcomes were significantly improved at 6, 12, 18, and 24 months after surgery compared with preoperative clinical status. Moreover, there were no differences between the 2 groups in clinical outcomes at each evaluation time point. Radiological evaluations were also similar and the complication rates were equally low in both groups. CONCLUSIONS At 32.7 months postoperation, the clinical and radiological outcomes of DDS were similar to those of MI-TLIF for Grade I degenerative spondylolisthesis at L4-5. DDS might be an alternative to standard arthrodesis in mild lumbar spondylolisthesis. However, unlike fusion, dynamic implants have issues of wearing and loosening in the long term. Thus, the comparable results between the 2 groups in this study require longer follow-up to corroborate.