Preliminary Clinical and Radiological Outcomes of the "No-Punch" Decompression Techniques for Unilateral Biportal Endoscopic Spine Surgery.

OBJECTIVE: To avoid the most offending surgical instrument for dural tears, we develop a "no-punch" decompression technique for unilateral biportal endoscopic (UBE) spine surgery. METHODS: This retrospective study enrolled 68 consecutive patients with degenerative lumbar spinal stenosis segments. The treatment results were evaluated using the visual analogue scale (VAS) for low back and leg pain, the Japanese Orthopaedic Association (JOA) scores, and the Oswestry Disability Index (ODI). Radiological outcomes were evaluated using the preoperative and postoperative magnetic resonance imaging. RESULTS: This study included 36 male and 32 female patients who received 109 segments of decompression, with an average age of 68.7 (37-90 years). The average operation time was 52.2 minutes. The average hospital stay was 3.1 days. There were no dural tears but 3 minor surgical complications, all treated conservatively. The VAS for low back and leg pain improved from 4.6 and 7.0 to 0.8 and 1.2. The JOA score improved from 16.2 to 26.8, with an improvement rate of 82.0%. The ODI improved from 50.1 to 18.7. All these improvements were statistically significant. The cross-sectional dural area improved from 61.1 to 151.3 mm2, with an average increase of 90.2 mm2 and 205.3%. 87.1% of the ipsilateral facet joints and 84.7% of the contralateral facet joints were preserved. In 61% of the decompressed segments, the ipsilateral facet joints were preserved better than the contralateral facet joints. CONCLUSION: The UBE "no-punch" decompression technique effectively avoids the dural tears. It provides effective neural decompression, excellent facet joint preservation, and good treatment outcomes.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Using Double Cages: Surgical Techniques and Treatment Outcomes.

OBJECTIVE: To describe the surgical techniques and the treatment outcomes of biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) using double cages. METHODS: This study included 89 patients with 114 fusion segments between July 2019 and May 2021. One pure polyetheretherketone (PEEK) cage and 1 composite titanium-PEEK cage were used for interbody fusion. Clinical outcomes measures included visual analogue scale (VAS) scores for lower back pain and leg pain, Oswestry Disability Index (ODI), and Japanese Orthopedic Association (JOA) scores. Computed tomography (CT) of the lumbar spine 1 year postoperatively was used to evaluate the Bridwell interbody fusion grades. RESULTS: There were significant improvement in VAS for lower back pain from 5.2 ± 3.1 to 1.7 ± 2.1, VAS for leg pain from 6.3 ± 2.5 to 1.7 ± 2.0, ODI from 46.7 ± 17.0 to 12.7 ± 16.1, and JOA score from 15.6 ± 6.3 to 26.4 ± 3.2. The p-values were all < 0.001. The average hospital stay was 5.7 ± 1.1 days. The CT studies available for 60 fusion segments showed successful fusion (Bridwell grade I or grade II) in 56 segments (93.3%). Significant cage subsidence of more than 2 mm was only noted in 3 segments (5.0%). Complications included 1 dural tear, 2 pedicle screws malposition, and 2 epidural hematomas, in which 2 patients required reoperations. CONCLUSION: BETLIF with double cages provided good neural decompression and a sound environment for interbody fusion with a big cage footprint, a large amount of bone graft, endplate preservation, and segmental stability.

Unusual capitate fracture with dorsal shearing pattern and concomitant carpometacarpal dislocation with a 6-year follow-up: A case report.

BACKGROUND: Isolated capitate fractures are rare carpal fractures. Following high-energy injuries, capitate fractures are usually associated with other carpal fractures or ligament injuries. The management of capitate fractures depends on the fracture pattern. Here, we report an unusual capitate fracture with a dorsal shearing pattern and concomitant carpometacarpal dislocation, with a 6-year follow-up. To the best of our knowledge, this fracture pattern and surgical management have not been previously reported. CASE SUMMARY: A 28-year-old man presented with left-hand volar tenderness and decreased grip strength that persisted for one month after a traffic accident. Radiography showed a distal capitate fracture with carpometacarpal joint incongruence. Computed tomography (CT) revealed a distal capitate fracture with carpometacarpal joint dislocation. The distal fragment was rotated by 90° in the sagittal plane, and an oblique shearing fracture pattern was noted. Open reduction and internal fixation (ORIF) with a locking plate were performed using the dorsal approach. The imaging studies performed 3 mo and 6 years following surgery revealed a healed fracture, and the Disabilities of the Arm, Shoulder, and Hand and visual analog scale scores were significantly improved. CONCLUSION: CT can detect capitate fractures with dorsal shearing pattern and concomitant carpometacarpal dislocation. ORIF using a locking plate are possible.

Indications for and Outcomes of Three Unilateral Biportal Endoscopic Approaches for the Decompression of Degenerative Lumbar Spinal Stenosis: A Systematic Review.

OBJECTIVE: In this systematic review, we summarized the indications for and outcomes of three main unilateral biportal endoscopic (UBE) approaches for the decompression of degenerative lumbar spinal stenosis (DLSS). METHODS: A comprehensive search of the literature was performed using Ovid Embase, PubMed, Web of Science, and Ovid's Cochrane Library. The following information was collected: surgical data; patients' scores on the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Macnab criteria; and surgical complications. RESULTS: In total, 23 articles comprising 7 retrospective comparative studies, 2 prospective comparative studies, 12 retrospectives case series, and 2 randomized controlled trials were selected for quantitative analysis. The interlaminar approach for central and bilateral lateral recess stenoses, contralateral approach for isolated lateral recess stenosis, and paraspinal approach for foraminal stenosis were used in 16, 2, and 4 studies, respectively. In one study, both interlaminar and contralateral approaches were used. L4-5 was the most common level decompressed using the interlaminar and contralateral approaches, whereas L5-S1 was the most common level decompressed using the paraspinal approach. All three approaches provided favorable clinical outcomes at the final follow-up, with considerable improvements in patients' VAS scores for leg pain (63.6-73.5%) and ODI scores (67.2-71%). The overall complication rate was <6%. CONCLUSIONS: The three approaches of UBE surgery are effective and safe for the decompression of various types of DLSS. In the future, long-term prospective studies and randomized control trials are warranted to explore this new technique further and to compare it with conventional surgical techniques.

Successful real-world application of an osteoarthritis classification deep-learning model using 9210 knees-An orthopedic surgeon's view.

This study aimed to evaluate the performance of a deep-learning model to evaluate knee osteoarthritis using Kellgren-Lawrence grading in real-life knee radiographs. A deep convolutional neural network model was trained using 8964 knee radiographs from the osteoarthritis initiative (OAI), including 962 testing set images. Another 246 knee radiographs from the Far Eastern Memorial Hospital were used for external validation. The OAI testing set and external validation images were evaluated by experienced specialists, two orthopedic surgeons, and a musculoskeletal radiologist. The accuracy, interobserver agreement, F1 score, precision, recall, specificity, and ability to identify surgical candidates were used to compare the performances of the model and specialists. Attention maps illustrated the interpretability of the model classification. The model had a 78% accuracy and consistent interobserver agreement for the OAI (model-surgeon 1 К = 0.80, model-surgeon 2 К = 0.84, model-radiologist К = 0.86) and external validation (model-surgeon 1 К = 0.81, model-surgeon 2 К = 0.82, model-radiologist К = 0.83) images. A lower interobserver agreement was found in the images misclassified by the model (model-surgeon 1 К = 0.57, model-surgeon 2 К = 0.47, model-radiologist К = 0.65). The model performed better than specialists in identifying surgical candidates (Kellgren-Lawrence Stages 3 and 4) with an F1 score of 0.923. Our model not only had comparable results with specialists with respect to the ability to identify surgical candidates but also performed consistently with open database and real-life radiographs. We believe the controversy of the misclassified knee osteoarthritis images was based on a significantly lower interobserver agreement.

Triage admission protocol with a centralized quarantine unit for patients after acute care surgery during the COVID-19 pandemic: A tertiary center experience in Taiwan.

BACKGROUND: During the COVID-19 surge in Taiwan, the Far East Memorial Hospital established a system including a centralized quarantine unit and triage admission protocol to facilitate acute care surgical inpatient services, prevent nosocomial COVID-19 infection and maintain the efficiency and quality of health care service during the pandemics. MATERIALS AND METHODS: This retrospective cohort study included patients undergoing acute care surgery. The triage admission protocol was based on rapid antigen tests, Liat® PCR and RT-PCT tests. Type of surgical procedure, patient characteristics, and efficacy indices of the centralized quarantine unit and emergency department (ED) were collected and analyzed before (Phase I: May 11 to July 2, 2021) and after (Phase II: July 3 to July 31, 2021) the system started. RESULTS: A total of 287 patients (105 in Phase I and 182 in Phase II) were enrolled. Nosocomial COVID-19 infection occur in 27 patients in phase I but zero in phase II. More patients received traumatological, orthopedic, and neurologic surgeries in phase II than in phase I. The patients' surgical risk classification, median total hospital stay, intensive care unit (ICU) stay, intraoperative blood loss, operation time, and the number of patients requiring postoperative ICU care were similar in both groups. The duration of ED stay and waiting time for acute care surgery were longer in Phase II (397 vs. 532 minutes, p < 0.0001). The duration of ED stay was positively correlated with the number of surgical patients visiting the ED (median = 66 patients, Spearman's ρ = 0.207) and the occupancy ratio in the centralized quarantine unit on that day (median = 90.63%, Spearman's ρ = 0.191). CONCLUSIONS: The triage admission protocol provided resilient quarantine needs and sustainable acute care surgical services during the COVID-19 pandemic. The efficiency was related to the number of medical staff dedicated to the centralized quarantine unit and number of surgical patients visited in ED.

Salmonella spondylodiscitis and epidural abscess successfully treated with unilateral biportal endoscopic discectomy and debridement: a rare case report.

Spinal epidural abscess (SEA) is a rare but severe infection with potentially devastating consequences. Epidural abscesses caused by Salmonella serogroup C2 are even rarer and tend to be more invasive with multidrug resistance. Early diagnosis, effective use of antibiotics and surgical intervention are the mainstay strategies for managing SEA, especially for more virulent and multidrug-resistant Salmonella infections. This case report presents a rare case of an elderly and fragile woman with Salmonella spondylodiscitis and an extensive epidural abscess, which were successfully treated with intravenous antibiotics and unilateral biportal endoscopic (UBE) debridement and drainage through four small surgical incisions. After surgery, her fever subsided, she regained consciousness and her low back pain dramatically improved. Follow-up magnetic resonance imaging showed complete resolution of the epidural abscess. At 6 months after surgery, the patient regained muscle strength, ambulated with a walker and had no recurrence of the infection. The UBE technique can effectively eradicate infection while minimizing surgery-related risks and complications. A multidisciplinary team is required to achieve a good outcome.

Thematic analysis of articles on artificial intelligence with spine trauma, vertebral metastasis, and osteoporosis using chord diagrams: A systematic review and meta-analysis.

BACKGROUND: Spine trauma, vertebral metastases, and osteoporosis (SVO) can result in serious health problems. If the diagnosis of SVO is delayed, the prognosis may be deteriorated. The use of artificial intelligence (AI) is an essential method for minimizing the diagnostic errors associated with SVO. research achievements (RAs) of SVO on AI are required as a result of the greatest number of studies on AI solutions reported. The study aimed to: classify article themes using visualizations, illustrate the characteristics of SVO on AI recently, compare RAs of SVO on AI between entities (e.g., countries, institutes, departments, and authors), and determine whether the mean citations of keywords can be used to predict article citations. METHODS: A total of 31 articles from SVO on AI (denoted by T31SVOAI) have been found in Web of Science since 2018. The dominant entities were analyzed using the CJAL score and the Y-index. Five visualizations were applied to report: the themes of T31SVOAI and their RAs in comparison for article entities and verification of the hypothesis that the mean citations of keywords can predict article citations, including: network diagrams, chord diagrams, dot plots, a Kano diagram, and radar plots. RESULTS: There were five themes classified (osteoporosis, personalized medicine, fracture, deformity, and cervical spine) by a chord diagram. The dominant entities with the highest CJAL scores were the United States (22.05), the University of Pennsylvania (5.72), Radiology (6.12), and Nithin Kolanu (Australia) (9.88). The majority of articles were published in Bone, J. Bone Miner. Res., and Arch. Osteoporos., with an equal count (=3). There was a significant correlation between the number of article citations and the number of weighted keywords (F = 392.05; P < .0001). CONCLUSION: A breakthrough was achieved by displaying the characteristics of T31SVOAI using the CJAL score, the Y-index, and the chord diagram. Weighted keywords can be used to predict article citations. The five visualizations employed in this study may be used in future bibliographical studies.

Calcaneal lengthening using ipsilateral fibula autograft in the treatment of symptomatic pes valgus in adolescents.

BACKGROUND: Evans calcaneal lengthening osteotomy is used to treat symptomatic flexible flatfoot when conservative treatment fails. Grafts such as autologous iliac bone grafts, allografts, and xenografts are implanted at the osteotomy site to lengthen the lateral column of the hindfoot. This study aimed to present the outcomes of an autologous mid-fibula bone graft used for calcaneal lengthening in symptomatic pes valgus in adolescents. METHODS: We retrospectively examined 23 ft of 13 adolescents who underwent surgery between July 2014 and January 2018. The radiological and clinical outcomes (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale scores) were assessed during a mean follow-up of 49.7 (range, 30.9-73.4) months. The mean distance of the lengthening site was measured to evaluate graft sinking or collapse. The Goldberg scoring system was used to determine the degree of union at the donor and recipient sites. RESULTS: The calcaneal pitch and the anteroposterior and lateral talo-first metatarsal (Meary) angles showed significant correction, from 14.4 to 19.6 (p < 0.001), and from 14.5 to 4.6 (p < 0.001) and 13.5 to 8.5 (p < 0.001), respectively. The mean distance of the lengthening site showed no significant change (p = 0.203), suggesting no graft sinking or postoperative collapse. The lateral distal tibial angle showed no significant difference (p = 0.398), suggesting no postoperative ankle valgus changes. Healing of the recipient and donor sites occurred in 23 and 21 ft, respectively. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scores improved significantly, from 68.0 to 98.5 (p < 0.001). CONCLUSIONS: Evans calcaneal lengthening using an ipsilateral mid-fibula bone autograft resulted in significant improvement in clinical and radiological outcomes without ankle valgus deformity. Hence, it could be a treatment option for lateral column calcaneal lengthening in adolescents.

A Review of Unilateral Biportal Endoscopic Decompression for Degenerative Lumbar Canal Stenosis.

BACKGROUND: The unilateral biportal endoscopic (UBE) technique provides minimally invasive decompression for degenerative lumbar canal stenosis (DLCS). With appropriate control of the hydrostatic pressure of normal saline irrigation, the surgery can be performed in a clear and magnified surgical field through 2 small surgical wounds. METHODS: A review of published literature in PubMed was performed to identify studies of UBE decompression for DLCS. The outcome measures include operation time, length of hospital stay, estimated blood loss, visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI), and the Macnab criteria. RESULTS: A total of 76 relevant studies were retrieved through the PubMed search. After screening, 15 studies comprising 6 case series, 6 comparative studies, and 3 randomized controlled trials were included in this review. Significant improvements in pain and neurological symptoms were obtained in all studies. In the 6 case series studies, the outcome measures were extracted from each study and summarized. The follow-up periods ranged from 8.6 to 29 months. The operation time was 72.0 min. The VAS score for leg pain was reduced from 7.8 to 1.7, and the VAS score for back pain was reduced from 5.8 to 1.7. The ODI was reduced from 63.0 to 20.7, and 87.3% of patients reported good to excellent outcomes according to the Macnab criteria. The complication rates ranged from 5.5% to 13.8%, with dural tear having the highest incidence rate. In the comparative studies and randomized controlled trials examining the UBE, microscopic, microendoscopic, and uniportal endoscopic techniques, the UBE technique showed treatment results that were comparable with the others. Compared with the microscopic technique, the UBE technique resulted in significantly less tissue trauma and quicker recovery with less wound pain, lower serum creatine kinase and C-reactive protein levels, and lower ODI in the very early postoperative period. The UBE technique also provided adequate decompression with less facet joint destruction than all the other decompression techniques. CONCLUSIONS: The UBE technique is safe and effective for decompression of DLCS. Along with its efficacy in decompression, this technique is capable of preserving segmental stability. However, a long-term comparative study is required to verify this hypothesis.

Unilateral biportal endoscopic decompression for degenerative lumbar canal stenosis.

BACKGROUND: Unilateral biportal endoscopic (UBE) decompression is a minimally invasive (MI) approach to treat degenerative lumbar canal stenosis (DLCS). Decompression can be performed in a clear and magnified surgical field with proper control of normal saline inflow and outflow. METHODS: Clinical and radiographic data of 81 consecutive patients of DLCS treated between July 2018 and Feb 2019 using UBE techniques were reviewed. They were 38 males and 43 females with an average age of 70.2. Sixty-nine had pure canal stenosis and 12 patients had associated spondylolisthesis. Bilateral decompression via unilateral laminotomy was performed from the side on patients with more severe neurological symptoms. This is a retrospective study from chart review and image analysis. Therefore, we don't have formal ethical information for this study, and it is not mandatory in our hospital. RESULTS: At the final follow-up, the mean VAS for low back pain was improved from 4.3±3.0 to 1.2±1.0 and the VAS for leg symptoms was improved from 7.3±2.2 to 0.9±0.7. The mean JOA score and ODI was significantly improved from 13.3±7.9 to 25.3±5.0 and from 54.6±16.9 to 14.6±12.6, respectively. Modified Macnab criteria were excellent in 47 patients (58.0%), good in 29 (35.8%), fair in 5 (6.2%). The average hospital stay was 3.6±2.4 days. MRI before and after the operation showed the cross-sectional dural area (CSDA) was significantly increased from 71.4±36.5 to 177.3±59.2 mm2, corresponding to a 201.9%±188.0% increase. The percentage of facet joint preservation was 84.2% on the approach side and 92.9% on the contralateral side. Complications included 4 dural tears, 1 transient motor weakness, 1 inadequate decompression, and 1 epidural hematoma. CONCLUSIONS: With UBE techniques, decompression for DLCS can be performed safely and effectively. The soft tissue and facet joint destruction are minimized; therefore, it is possible to avoid spinal fusion as well as to preserve the segmental stability.

Pneumocephalus with Conscious Disturbance After Full Endoscopic Lumbar Diskectomy.

BACKGROUND: Pneumocephalus is a rare complication after an elective lumbar spine surgery. Full endoscopic lumbar diskectomy (FELD) is an evolving minimally invasive surgical procedure gaining its popularity in the past decade. Although seizure was recognized as a possible complication, organic injury to the central nervous system such as pneumocephalus has not yet been reported after FELD. CASE DESCRIPTION: A 63-year-old man with L3-4 intervertebral disk herniation received FELD via the transforaminal approach under general anesthesia. A small dural tear about 2 mm was encountered. After the operation, the patient was unable to recover from anesthesia and failed to be extubated due to tachypnea and generalized tonic-clonic seizures. Emergent brain computed tomography (CT) revealed pneumocephalus in the subdural and subarachnoid space. Pure oxygen was given, and hyperbaric oxygen therapy (HBO2) was arranged immediately. Fortunately, he started to regain his consciousness 8 hours after the operation and had full recovery of consciousness on the next day. Follow-up brain CT showed nearly complete resolution of the pneumocephalus. He had no neurologic deficits at final follow-up. CONCLUSIONS: This case report highlights the risk of pneumocephalus with conscious disturbance when a dural tear occurs during FELD under general anesthesia. FELD is safer when performed under local anesthesia because the patient is awake to report his discomfort and thus possible to prevent serious neurologic sequels. An emergent brain CT is critical to obtain a prompt diagnosis and HBO2 is probably helpful for resolving the mass effect caused by the pneumocephalus.

Suboptimal outcomes after closed reduction and internal fixation of displaced femoral neck fractures in middle-aged patients: is internal fixation adequate in this age group?

BACKGROUND: There have been many studies regarding nongeriatric femoral neck fractures (FNFs), which included patients of a wide age range (between 20 and 60 years old). We aimed to determine whether internal fixation provided acceptable outcomes for middle-aged patients with displaced FNFs, and identify predictors of successful internal fixation. METHODS: A total of 117 patients, aged 50-60 years and who underwent closed reduction and unilateral internal fixation using cannulated screws, were included. The outcomes were classified as either "complications" (varus malunion, femoral neck shortening, non-union/early collapse, avascular necrosis, or arthroplasty during the follow-up) or "optimal outcomes" (no complications). Patients with displaced FNFs (Garden stages III-IV, n = 69) were categorized according to whether they experienced acceptable or unacceptable reduction. We evaluated whether patients' clinical characteristics could predict optimal outcomes. RESULTS: Patients with displaced FNFs generally experienced complications (84.1%). Twenty-two percent of patients experienced optimal outcomes when acceptable reduction was achieved. Patients with unacceptable reductions experienced complications. Optimal outcomes were positively associated with Pauwels' type II fracture (OR: 8.67, p = 0.025) and negatively associated with excessive alcohol consumption (p = 0.045). CONCLUSIONS: Compared with the younger age group, complication rates are higher in middle-aged patients with displaced FNFs treated using cannulated screws. If internal fixation is to be used for a displaced FNF, patient selection is essential. Care must be taken to avoid selecting patients with excessive alcohol consumption, while successful internal fixation may be more likely for patients with Pauwels' type II fracture.

Evaluation of New Biphasic Calcium Phosphate Bone Substitute: Rabbit Femur Defect Model and Preliminary Clinical Results.

Autogenous bone grafting, used to repair bone defects, is limited and the donor site can experience complications. Compared to autogenous bone graft, artificial bones have different porosity, which might make them suitable alternatives to bone grafts. Here, two porous biphasic calcium phosphate bone substitutes, namely Bicera™ and Triosite™, are used in an animal study and clinical practice to find a suitable porosity for implantation. Bicera™ and Triosite™ consist of 60 wt% hydroxyapatite and 40 wt% ß-tricalcium phosphate, with the porosity of Bicera™ (82%) being higher than that of Triosite™ (70%). In the animal study, the implantation procedure was carried out on twenty-four female New Zealand rabbits. 12 weeks after implantation, the new bones were well infiltrated into the Bicera™ and Triosite™ bone grafts. In the clinical study, patients with comminuted fracture, fracture nonunion, or arthrodesis were included in the study of bone substitution with Bicera™. 27 patients underwent fracture fixation treatment. Bone healing of 22.22% (6/27) of patients happened within 3 months after the surgery, and that of 66.67% (18/27) of patients happened within 6 months. These results reveal that Bicera™ has good incorporation with host bone, and that new bone is able to grow within the porous structure, giving it high potential in the treatment of bone defects.

The adaptive changes in muscle coordination following lumbar spinal fusion.

Limited back motion and damage of paraspinal muscles after spinal fusion surgery may lead to abnormal compensatory movements of the body. Whether neuromuscular control changes after surgery remains unclear. The purpose of the study was to identify the muscle activation patterns employed before and after lumbar spinal fusion. Nineteen patients having low back pain and undergoing minimally invasive lumbar spinal fusion were evaluated at 1 day before and 1 month after fusion surgery. Nineteen matched healthy participants were recruited as controls. Patients' pain severity and daily activity functioning were recorded. All participants were instructed to perform forward reaching, and the muscle activities were monitored using surface electromyography (EMG) with sensors placed on both sides of their trunk and lower limbs. The muscle activation patterns were identified using the principal component analysis (PCA). All patients had significant improvements in pain intensity and daily activity functioning after surgery, but exhibited an adaptive muscle activation pattern during forward reaching movement compared with the controls. Significant loading coefficients in the dominant movement pattern (reflected in the first principal component) were observed in back muscles for controls whereas in leg muscles for patients, both pre- and postoperatively. Despite substantial improvements in pain intensity and daily activity functioning after surgery, the patients exhibited decreased paraspinal muscle activities and adaptive muscle coordination patterns during forward reaching. They appeared to rely mainly on their leg muscles to compensate for their insufficient paraspinal muscle function. Early intervention focusing on training paraspinal muscles should be considered after spinal fusion surgery.

Trunk Control Ability after Minimally Invasive Lumbar Fusion Surgery during the Early Postoperative Phase.

[Purpose] Lumbar fusion has been used for spinal disorders when conservative treatment fails. The minimally invasive approach causes minimal damage to the back muscles and shortens the postoperative recovery time. However, evidence regarding functional recovery in patients after minimally invasive lumbar spinal fusion is limited. The purpose of this study was to investigate how trunk control ability is affected after minimally invasive lumbar fusion surgery during the early postoperative phase. [Subjects and Methods] Sixteen patients and 16 age- and sex-matched healthy participants were recruited. Participants were asked to perform a maximum forward reaching task and were evaluated 1 day before and again 1 month after the lumbar fusion surgery. Center of pressure (COP) displacement, back muscle strength, and scores for the Visual Analog Scale, and Chinese version of the modified Oswestry Disability Index (ODI) were recorded. [Results] The healthy control group exhibited more favorable outcomes than the patient group both before and after surgery in back strength, reaching distance, reaching velocity, and COP displacement. The patient group improved significantly after surgery in all clinical outcome measurements. However, reaching distance decreased, and the reaching velocity as well as COP displacement did not differ before and after surgery. [Conclusion] The LBP patients with lumbar fusion surgery showed improvement in pain intensity 1 month after surgery but no improvement in trunk control during forward reaching. The results provide evidence that the back muscle strength was not fully recovered in patients 1 month after surgery and limited their ability to move their trunk forward.

Clinical significance of postdecompression facet joint effusion after minimally invasive decompression for degenerative lumbar spinal stenosis.

STUDY DESIGN: A retrospective case series study. OBJECTIVE: To investigate the clinical significance of postdecompression facet effusion (PDFE) after microendoscopic decompressive laminotomy (MEDL). SUMMARY OF BACKGROUND DATA: The facet joint effusion noted on magnetic resonance imaging was considered as an indicator of degeneration of the facet joints and segmental instability. PDFE occurring after MEDL might imply postdecompression segmental instability. Its clinical significance has not yet been clarified. MATERIALS AND METHODS: From 2005 to 2010, 165 patients with degenerative lumbar spinal stenosis (average age: 64.5, average follow-up: 25.8 mo) who received MEDL were reviewed. We investigated the incidence of PDFE with preoperative and repetitive magnetic resonance imaging at 6 months postoperatively. The clinical data and treatment courses were reviewed. The treatment outcomes were evaluated with Oswestry Disability Index and Japanese Orthopedic Association scores. RESULTS: The incidence of PDFE was 17.0% (n=28), which was significantly higher in patients receiving multilevel decompression and patients with scoliosis or spondylolisthesis. The intensity of low back pain was similar between patients with and without PDFE, but "mechanical" low back pain was only noted in patients with PDFE. Of the 28 patients with PDFE, only 9 symptomatic patients required invasive treatment (5 facet joint steroid injection, 3 revision MEDL, and 1 spinal fusion). Although the postoperative Oswestry Disability Index and Japanese Orthopedic Association scores were significantly worse these 9 patients, the final outcomes were good. Progression of spondylolisthesis was noted in 2 patients without PDFE but no patients with PDFE during the follow-up period. CONCLUSIONS: The relatively high incidence of PDFE after MEDL suggests that injury to the integrity of facet joint is inevitable during decompression of the stenosis, even using minimally invasive techniques. However, the overall stability is well preserved with very rare progression of spondylolisthesis. Most patients with PDFE are asymptomatic. The prognosis of PDFE is very good. Spinal fusion is rarely indicated.

Image changes of paraspinal muscles and clinical correlations in patients with unilateral lumbar spinal stenosis.

STUDY DESIGN: This is a retrospective study. PURPOSE: To compare the morphometric parameters of the psoas major and lumbar multifidus muscles in lumbar spinal stenosis (LSS) patients exhibiting different functional performance. LSS refers to symptoms related to size reduction of the lumbar spinal canal; however, the degree of stenosis is poorly related to symptom severity and functional impairments. Morphometric changes in the paraspinal muscles have been correlated with chronic lower back pain in previous studies. However, correlations between the functional performance of LSS patients and the morphometric changes in paraspinal muscles have seldom been reported. METHODS: Sixty-six LSS patients without mechanical back pain or segmental instability were enrolled in the study. A review of their medical records and MRI images was performed. Morphometric parameters, including the fatty infiltration (FI) of the lumbar multifidus muscle as well as the relative cross-sectional area (RCSA) of the psoas major and lumbar multifidus muscles, were measured. Subjects were divided into high and low functional performance groups according to their Japanese Orthopedic Association (JOA) scores. RESULTS: The male LSS patients exhibited a larger psoas RCSA than the female patients, whereas the older patients exhibited a smaller psoas RCSA and higher multifidus FI than the younger patients. LSS patients in the high functional performance group exhibited a significantly larger psoas RCSA and lower multifidus FI. CONCLUSION: The psoas RCSA and multifidus FI can be used as predictive factors for functional performance in LSS patients.

Intraoperative myelography in minimally invasive decompression for degenerative lumbar spinal stenosis.

STUDY DESIGN: A retrospective comparative series study. OBJECTIVE: To develop an intraoperative myelography protocol and determine its value on the treatment results in microendoscopic decompressive laminotomy (MEDL) for degenerative lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: The MEDL is a minimally invasive but technically demanding technique for decompressing spinal stenosis. An intraoperatively assessing method for adequate decompression is lacking, but may be helpful and has positive value on the treatment results. METHODS: Forty consecutive degenerative lumbar spinal stenosis patients receiving MEDL were included in this study. The earlier 20 patients received MEDL without myelography (the traditional group); the later 20 patients received MEDL with the myelography protocol (the myelography group). An additional intraoperative myelography was performed in the myelography group to help localizing the stenosis before decompression and verifying adequate decompression after decompression. Any residual filling defects identified in the postdecompression myelogram were considered signs of inadequate decompression and additional decompression was performed until they resolved. RESULTS: Inadequate decompression was identified in 4 of 20 patients in the myelography group, but none in the traditional group. Both groups had significant improvement after surgery. However, the myelography group had significantly better results with lower 6-month Oswestry Disability Index (ODI) (6 vs. 10, P=0.049), more ODI improvement (44 vs. 28, P=0.009), higher Japanese Orthopedic Association (JOA) scores (27.5 vs. 24, P=0.043), a higher JOA improvement rate (92.8% vs. 73.2%, P=0.013), and greater decompression effect (56.8% vs. 41.4% cross-sectional dural area, P=0.024). The myelography group also had a higher proportion of patients to have "significant ODI improvement," "JOA success," and "JOA good-to-excellent results." There were no myelography-related complications. CONCLUSIONS: The intraoperative myelography protocol provides a simple method to precisely localize the stenosis and verifies the adequacy of decompression; hence, improves the treatment result of MEDL.

Clinical outcomes of microendoscopic decompressive laminotomy for degenerative lumbar spinal stenosis.

The goal of surgical treatment for degenerative lumbar spinal stenosis (LSS) is to effectively relieve the neural structures by various decompressive techniques. Microendoscopic decompressive laminotomy (MEDL) is an attractive option because of its minimally invasive nature. The aim of prospective study was to investigate the effectiveness of MEDL by evaluating the clinical outcomes with patient-oriented scoring systems. Sixty consecutive patients receiving MEDL between December 2005 and April 2007 were enrolled. The indications of surgery were moderate to severe stenosis, persistent neurological symptoms, and failure of conservative treatment. The patients with mechanical back pain, more than grade I spondylolisthesis, or radiographic signs of instability were not included. A total of 53 patients (36 women and 17 men, mean age 62.0) were included. Forty-five patients (84.9%) were satisfied with the treatment result after a follow-up period of 15.7 months (12-24). The clinical outcomes were evaluated with the Oswestry disability index (ODI) and the Japanese Orthopedic Association (JOA) score. Of the 50 patients providing sufficient data for analysis, the ODI improved from 64.3 +/- 20.0 to 16.7 +/- 20.0. The JOA score improved from 9.4 +/- 6.1 to 24.2 +/- 6.0. The improvement rate was 73.9 +/- 30.7% and 40 patients (80%) had good or excellent results. There were 11 surgical complications: dural tear in 5, wrong level operation in 2, and transient neuralgia in 4 patients. No wound-related complication was noted. Although the prevalence of pre-operative comorbidities was very high (69.8%), there was no serious medical complication. There was no post-operative instability at the operated segment as evaluated with dynamic radiographs at final follow-up. We concluded that MEDL is a safe and very effective minimally invasive technique for degenerative LSS. With an appropriate patient selection, the risk of post-operative instability is minimal.