Significance of paraspinal muscle quality in risk between single and multiple osteoporotic vertebral fractures.

PURPOSE: To compare paraspinal muscle quality between patients with single and multiple osteoporotic vertebral fractures (OVFs) and evaluate the role of the paraspinal muscles in OVFs. METHODS: A total of 262 consecutive patients with OVFs were retrospectively analyzed in two groups: those with single OVF (n = 173) and those with multiple OVFs (n = 89). The cross-sectional area (CSA) and fatty degeneration of the paraspinal muscles were calculated from axial T2-weighted magnetic resonance imaging at the level of the L4 upper endplate by manual tracing in ImageJ software. Pearson's correlation analysis was performed to analyze correlations of paraspinal muscle quality to multiple OVFs. RESULTS: FD in all the paraspinal muscles was significantly higher in the multiple OVF group than the single OVF group (all p < 0.005). The functional CSA (fCSA) of the paraspinal muscles was significantly lower in the multiple OVF group than the single OVF group (all Ps < 0.001), except for the erector spine (p = 0.304). The Pearson's correlation analysis showed significant positive inter-correlations for the fCSAs of all the paraspinal muscles and the occurrence of multiple OVFs. CONCLUSIONS: The pure muscle volumes of the multifidus, psoas major, and quadratus lumborum were lower in patients with multiple OVFs than in those with a single OVF. Furthermore, the inter-correlation among all the paraspinal muscles indicate that the muscle-bone crosstalk profoundly existed in vertebral fracture cascade. Therefore, special attention to paraspinal muscle quality is needed to prevent progression to multiple OVFs.

The occurrence of vascular displacement into intervertebral disc space following the compensated sagittal imbalance of the spine: a case report and review of literature.

BACKGROUND: It is known that sagittal compensating mechanisms are created for counteracting sagittal imbalance problems; however, they can sometimes be associated with incidents which affect the plan of management. PURPOSE: The purpose of this study was to report a case of the occurrence of common iliac vessel displacement into the intervertebral disc space following one of the spinal compensatory mechanisms. MATERIAL AND METHODS: The authors demonstrated this case by showing the patient history, physical examination, imaging studies, and treatment strategy as well as by reviewing some related literature. RESULTS: An 81-year-old woman presented with a long history of low back pain with claudication. An upright plain radiograph and flexion-extension study demonstrated a progressive local thoracolumbar kyphosis and losing of lumbar lordosis with significant widening of the intervertebral disc space of L4-L5. An MRI scan and 3D volume rendering spiral computed tomography (3D-CT) revealed an abnormal content which was depicted as common iliac vessels inside the disc space of L4-L5. Consequently, a rare case of the occurrence of common iliac vessel displacement into the intervertebral disc space following one of the spinal compensatory mechanisms was reported. CONCLUSION: The occurrence of vascular displacement into the intervertebral disc space related to lumbar hyperextension, as a compensating mechanism, is a rare incident but can occur. Consequently, when this mechanism presents with abnormal widening of the intervertebral disc space, especially at the low lumbar level, it should raise surgeon's concern about the probability of vascular injury when performing a disc procedure. Thorough investigation with imaging studies and selecting the optimum surgical treatment are warranted.

Overcorrection of lumbar lordosis for adult spinal deformity with sagittal imbalance: comparison of radiographic outcomes between overcorrection and undercorrection.

PURPOSE: To determine the correlation of the difference between postoperative lumbar lordosis (LL) and ideal LL with the sagittal vertical axis (SVA) at the final follow-up in patients with adult spinal deformity (ASD). METHODS: Fifty-one patients with degenerative lumbar kyphosis (DLK) (mean age 66.5 years) who underwent surgical correction with a minimum 2-year follow-up were evaluated. Based on the difference between postoperative LL and ideal LL using the Korean version of Legaye's formula, we divided the 51 patients into two groups: overcorrection (degree of postoperative LL > ideal LL) and undercorrection (degree of postoperative LL < ideal LL). RESULTS: Our clinical series of patients comprised 24 in the overcorrection and 27 in the undercorrection group. No significant differences were found in preoperative pelvic incidence (PI 52.6° vs. 57.3°), sacral slope (SS 23.3° vs. 18.3°), LL (-6.9° vs. -2.3°), thoracic kyphosis (TK 4.7° vs. 4.9°) and SVA (140 vs. 139 mm) except pelvic tilt (PT 29.4° vs. 39.0°), between the two groups. All the patients in the overcorrection group and 16 in the undercorrection group achieved postoperative optimal sagittal balance based on SVA ≤ 50 mm. In addition, significant differences in PT (10.5° vs. 26.7°), SS (42.1° vs. 30.6°), LL (-64.3° vs. -37.1°), TK (22.6° vs. 15.8°), and SVA (-1 vs. 41 mm) between the two groups were observed postoperatively. Furthermore, four patients (16.7 %) in the overcorrection group and eight (50 %) in the undercorrection group had sagittal decompensation at the final follow-up. Our results showed that the difference between postoperative LL and ideal LL had a significant correlation with postoperative and final follow-up SVA in our clinical series. CONCLUSION: Overcorrection of LL is an effective treatment modality to maintain optimal sagittal alignment in patients with DLK; this suggests that it should be considered in preoperative planning for patients with ASD with sagittal imbalance.

Bone marrow aspirate concentrate and platelet-rich plasma enhanced bone healing in distraction osteogenesis of the tibia.

BACKGROUND: During lower limb lengthening, poor bone regeneration is a devastating complication. Several local or systemic applications have been used to promote osteogenesis, and biologic stimulations are gaining attention, but their utility has not been proven in this setting. QUESTIONS/PURPOSES: In patients undergoing bilateral tibial lengthening, we compared those receiving an osteotomy site injection of autologous bone marrow aspirate concentrate (BMAC) plus platelet-rich plasma (PRP) with those not receiving such an injection in terms of external fixator index (time in external fixation divided by amount of lengthening), full weightbearing index (time until a patient was permitted to do full weightbearing divided by amount of lengthening), four cortical healing indexes (time until each cortical union divided by amount of lengthening), and callus shape and type. METHODS: Twenty-two patients (44 tibias) undergoing bilateral tibial lengthening enrolled in this randomized trial. Two patients were excluded, one due to insufficient radiographic evaluation and one who was lost to followup, leaving 20 patients (40 segments) for inclusion. Ten patients (20 segments) received BMAC combined with PRP injection (treatment group) and 10 patients (20 segments) received no injection (control group). All patients underwent stature lengthening for familial short stature with the lengthening over nail technique. Autologous BMAC combined with PRP was injected at the tibial osteotomy site at the end of the index surgery. Mean distraction rates were similar between groups (0.75 mm/day in the treatment group versus 0.72 mm/day in the control group; p = 0.24). Full weightbearing was permitted when we observed radiographic evidence of healing at two cortices; this assessment was made by the surgeon who was blinded to the treatment each patient received. Minimum followup was 24 months (mean, 28 months; range, 24-34 months). RESULTS: There was no difference in mean external fixator index between groups. However, mean cortical healing indexes (anterior/posterior/medial/lateral) were 1.14/0.81/0.96/0.88 months/cm in the treatment group and 1.47/1.26/1.42/1.22 months/cm in the control group (all p < 0.001), showing faster healing in the treatment group at each cortex. Full weightbearing was permitted earlier in the treatment group than in the control group (index: 0.99 months/cm and 1.38 months/cm, respectively, p < 0.001). Callus shape and type were not different between groups. CONCLUSIONS: Autologous BMAC combined with PRP injection at the osteotomy site helped improve bone healing in distraction osteogenesis of the tibia, although the effect size was small. LEVEL OF EVIDENCE: Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Surgical Outcomes of Extensive Dome-Like Laminoplasty Using En Bloc Resection of C2 Inner Lamina for Patients With Severe Cord Compression Behind C2 Body.

STUDY DESIGN: A retrospective, single-center study. OBJECTIVE: The aim of this study is to evaluate the efficacy and safety of a newly developed extensive dome-like laminoplasty using en bloc resection of the C2 inner lamina in patients with severe cord compression behind the C2 body. SUMMARY OF BACKGROUND DATA: A surgery for severe cord compression behind C2 body is challenging for spinal surgeons. To date, there has been no established solution for severe cord compression behind the C2 body. MATERIALS AND METHODS: Patients with severe cord compression behind the C2 body who underwent posterior surgery consecutively were enrolled. Extensive dome-like laminoplasty that was newly developed was performed to remove en bloc removal of the C2 inner lamina were performed. Preoperative and postoperative canal diameters behind the C2 and mean removed area of the C2 inner lamina were measured using MRI and CT scan. Clinical and radiographic parameters were assessed preoperative and postoperative periods. In addition, perioperative complications were analyzed. RESULTS: A total of 36 patients underwent extensive dome-like laminoplasty and their diagnoses were ossification of the posterior longitudinal ligament (OPLL, 66.7%) and congenital stenosis with spondylosis (33.3%). The mean canal diameter behind the C2 increased from 9.85 (2.28) mm preoperatively to 19.91 (3.93) mm at the last follow-up ( P <0.001). Clinically, neck and arm visual analog scale, Japanese Orthopaedic Association score, and neck disability index significantly improved at postoperative 1 month ( P <0.05), and the scores were maintained until the last follow-up. No meaningful radiographic changes occurred after the surgeries. During the procedures, there were no particular complications, but one patient showed deteriorated myelopathic symptoms and underwent additional C1-C2 decompressive surgery. CONCLUSIONS: After extensive dome-like laminoplasty, surgical outcomes are satisfactory, and complications are rare. This technique may be a viable option for patients with severe cord compression behind the C2 body. LEVEL OF EVIDENCE: Level IV.

Effects of Minimally Invasive Lateral Lumbar Interbody Fusion with Accessory Rod Technique on Rod Fracture in Adult Spinal Deformity Surgery: Analysis of 239 Patients.

STUDY DESIGN: A retrospective study. OBJECTIVES: To analyze factors associated with rod fracture (RF) in adult spinal deformity (ASD), and to assess whether the accessory rod (AR) technique can reduce RF occurrence in deformity correction in the setting of minimally invasive lateral lumbar interbody fusion (LLIF). SUMMARY OF BACKGROUND DATA: Instrumentation failure is the most common reason for revision surgery in ASD. Several RF reduction methods have been introduced. However, there are insufficient studies on postoperative RF after deformity correction using minimally invasive LLIF. METHODS: This study included 239 patients (average age 71.4 y and a minimum 2-year follow up) with ASD who underwent long-segment fusion from T10 to sacrum with sacropelvic fixation. Patients were classified into the non-RF group and the RF group. After logistic regression analysis of the risk factors for RF, subgroup analyses were performed; pedicle subtraction osteotomy (PSO) with 2-rod (P2 group) versus PSO with 2-rod and AR (P4 group), and LLIF with 2-rod (L2 group) versus LLIF with 2-rod and AR (L4 group). RESULTS: RF occurred in 50 patients (21%) at an average of 25 months. RF occurred more frequently in patients who underwent PSO than in those who underwent LLIF (P=0.002), and the use of the AR technique was significantly higher in the non-RF group (P<0.05).Following logistic regression analysis, preoperative PI-LL mismatch, PSO, and the AR technique were associated with RF. In subgroup analyses, RF incidence was 65% (24/37 cases) of P2 group, 8% (4/51 cases) of P4 group, and 21% (22/105 cases) of L2 group. In the L4 group, there was no RF. CONCLUSION: Minimally invasive multilevel LLIF with the AR technique is capable of as much LL correction as conventional PSO and appears to be an effective method for reducing RF.

The positive impact of smoking cessation on fracture risk in a nationwide cohort study.

Many studies sought to demonstrate the association between smoking and fracture risk. However, the correlation between smoking and fractures remains controversial. This study aimed to examine the impact of smoking and smoking cessation on the occurrence of fractures using prospective nationwide cohort data. We enrolled those who underwent a National Health Insurance Service (NHIS) health checkup in 2009-2010 who had a previous health checkup 4-year prior (2005-2006). The study population of 4,028,559 subjects was classified into three groups (non-smoker, smoking cessation, current smoker). The study population was also analyzed according to fracture type (all fractures, vertebral fracture, hip fracture). Lastly, the smoking cessation group and current smoker group were divided into four subgroups based on a lifetime smoking amount cut-off of 20 pack-years (PY). Multivariate-adjusted hazard ratios (HRs) of fracture were examined through a Cox proportional hazards model. After multivariable adjustment, non-smokers showed the lowest risk of fracture (HR = 0.818, CI 0.807-0.828, p < 0.0001) and smoking cessation significantly lowered the risk of fracture (HR 0.938, 95% CI 0.917-0.959, p < 0.0001) compared to current smokers. Regardless of 20PY, all smoking cessation subgroups showed significantly less risk of fractures than current smokers with ≥ 20PYs. Smoking increases the risk of fracture, and smoking cessation lowers the risk of fracture.

Ideal length of accessory rod for the prevention of rod fracture after pedicle subtraction osteotomy in adult spinal deformity: short or long?

OBJECTIVE: Pedicle subtraction osteotomy (PSO) is an effective surgical procedure for adult spinal deformity (ASD). However, the complexity of the procedure and its associated complications including rod fracture (RF) remain challenging issues. Among several RF reduction methods, the accessory rod (AR) is an important surgical technique. To date, knowledge about the ideal length and configuration of the AR is limited. This study aimed to assess the influence of the connection levels and configuration of the AR on RF occurrence in patients with ASD who underwent long level constructs and PSO. METHODS: The authors retrospectively selected 57 consecutive patients (mean age 70.6 years) who underwent deformity correction including PSO and the AR technique with a minimum 2-year follow-up. The patients were classified into a non-RF group (n = 49) and an RF group (n = 8). Along with analysis of patient and radiological factors in the 2 groups, comparative studies were performed including configuration of the AR (D shaped vs linear shaped) and the connection levels of AR (long AR [the lower end below S1-2] vs short AR [above L5-S1]). RESULTS: The overall rate of RF incidence was 14% (8/57 cases) at an average of 42.5 months (2 patients with unilateral RF and 6 with bilateral RF). RF occurred most commonly at the L4-5 level, below the lower end of the AR: 6 below the lower end of the AR and 2 at the PSO site. There were no significant differences in patient and radiological factors between the groups. Comparisons between the 2 groups indicated that more RFs occurred when the configuration of the AR was a linear shape (p = 0.016) and when the distal end of the AR was above L5-S1 (p = 0.025). CONCLUSIONS: In this study the authors found that the D-shaped configuration of the AR and lower end of the AR below S1-2 (i.e., long AR) could be preventive methods for reducing RF after deformity correction performed using PSO and the AR technique for ASD. Here, the authors have provided the first comprehensive outline for the AR technique. These findings could establish effective guidelines for spine surgeons.

A comparative study between thoracoscopic surgery and posterior surgery using all-pedicle-screw constructs in the treatment of adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: To present the results of thoracoscopic surgery in the treatment of adolescent idiopathic scoliosis (AIS) and to compare the results of thoracoscopic surgery with those of posterior surgery. SUMMARY OF BACKGROUND DATA: Although racoscopic scoliosis correction has attracted attention since the early 2000s, its use has declined gradually, whereas posterior surgery using pedicle screws has become popular. Few studies have compared thoracoscopic surgery with posterior pedicle screw fixation for single thoracic AIS correction. METHODS: Sixty-five patients with Lenke type-1 AIS were included and followed up for a minimum of 24 months. Forty-two patients underwent thoracoscopic surgery (thoracoscopic group) and 23 patients underwent posterior surgery (posterior group). Radiographic outcomes, including the correction rate and loss of correction, perioperative morbidities, and complications, were compared. RESULTS: Both groups were similar in terms of the preoperative baseline data. Although the correction rate of major thoracic curve was similar, the posterior group had a tendency to have a greater correction rate (72% vs. 66%). A loss of correction was significantly greater in the thoracoscopic group. The thoracoscopic group had a longer operation time and less intraoperative blood loss, with a lower transfusion rate than the posterior group. There was no difference at the last follow-up in terms of pain score and satisfaction. Five implant failures (12%) occurred in the thoracoscopic group and none in the posterior group. There were 3 patients with significant pulmonary complications necessitating active treatments in the thoracoscopic group. CONCLUSIONS: Despite its advantages, thoracoscopic surgery is losing its place in the surgical correction of AIS because of the frequent perioperative pulmonary complications and fixation problems compared with posterior pedicle screw fixation. Nevertheless, it can be utilized in selected cases particularly in cases of patient's strong demand for minimally invasive surgery.

Difference between Anterior and Posterior Cord Compression and Its Clinical Implication in Patients with Degenerative Cervical Myelopathy.

In degenerative cervical myelopathy (DCM), the low anteroposterior compression ratio of the spinal cord is known to be associated with a neurologic deficit. However, there is little detailed analysis of spinal cord compression. Axial magnetic resonance images of 183 DCM patients at normal C2-C3 and maximal cord compression segments were analyzed. The anterior (A), posterior (P), and anteroposterior length and width (W) of the spinal cord were measured. Correlation analyses between radiographic parameters and each section of Japanese Orthopedic Association (JOA) scores and comparisons of the patients divided by A (below or above 0, 1, or 2 mm) were performed. Between C2-C3 and maximal compression segments, the mean differences of A and P were 2.0 (1.2) and 0.2 (0.8) mm. The mean anteroposterior compression ratios were 0.58 (0.13) at C2-C3 and 0.32 (0.17) at maximal compression. The A and A/W ratio were significantly correlated with four sections and the total JOA scores (p < 0.05), but the P and P/W ratio did not demonstrate any correlations. Patients with A < 1 mm had significantly lower JOA scores than those with A ≥ 1 mm. In patients with DCM, spinal cord compression occurs mainly in the anterior part and the anterior cord length of <1 mm is particularly associated with neurologic deficits.

Impact of lamina-open side on unilateral open door laminoplasty in patients with degenerative cervical myelopathy.

Surgeons should select one side for cervical unilateral open door laminoplasty (UODL). However, few reports suggest proper guidelines for deciding which side to open. The aim of this study is to evaluate the impact of opening side in UODL on dominant cord compressive or symptomatic side. 193 degenerative cervical myeloradiculopathy patients with followed-up more than 2 years were enrolled. In all cases, UODL was performed uniformly on the right side. Patients were sub-grouped based on preoperative dominant 3 characteristics: cord compression, myelopathy symptom and radiculopathy symptom (right, symmetric, left). Pre- and postoperative radiographic and clinical parameters and incidence of postoperative C5 palsy were analyzed and compared among the groups. According to dominant compressive side, there were no significant differences in postoperative radiographic and clinical parameters among three groups. According to dominant myelopathy or radiculopathy symptom side, there were no significant differences of all radiographic and clinical parameters postoperatively, except slightly lower neck VAS in groups of preoperative right dominant myelopathy or radiculopathy symptom side at postoperative 1 month. C5 palsies occurred in twelve patients (6.2%), but the incidences were not different among the groups. Therefore, when performing UODL, the choice of lamina opening side can be left to surgeon's preference.

Does the Amount of Correction of Sagittal Deformity Really Promote Proximal Junctional Kyphosis? Multivariate Analyses According to Uppermost Instrumented Vertebra Levels.

BACKGROUND: The present study assumed that the effects of deformity correction amounts on proximal junctional kyphosis (PJK) development after long deformity surgery would vary according to uppermost instrumented vertebrae (UIV) levels. Our study was to reveal the association between the amount of correction and PJK according to UIV levels. METHODS: Adult spinal deformity patients aged >50 years who underwent thoracolumbar fusion (≥4 levels) were included. PJK was defined by proximal junctional angles ≥15°. Presumed demographic and radiographic risk factors for PJK were evaluated including parameters regarding the correction amount such as postoperative change in lumbar lordosis and postoperative offset grouping, the value associated with age-adjusted pelvic incidence-lumbar lordosis mismatch. The patients were divided according to UIV levels of T10 or above (group A) and T11 or below (group B). Multivariate analyses were performed separately for both groups. RESULTS: The present study included 241 patients (74 for group A and 167 for group B). PJK developed in approximately half of all patients within an average of 5 years of follow-up. For group A, only body mass index (P = 0.002) was associated with PJK. No radiographic parameters were correlated. For group B, postoperative change in lumbar lordosis (P = 0.009) and offset value (P = 0.030) were significant risk factors for PJK development. CONCLUSIONS: The correction amount of sagittal deformity increased the risk of PJK only in patients with UIV at or below T11. However, it was not associated with PJK development in patients with UIV at or above T10.

Cervical Radiculopathy: Focus on Factors for Better Surgical Outcomes and Operative Techniques.

For patients with cervical radiculopathy, most studies have recommended conservative treatment as the first-line treatment; however, when conventional treatment fails, surgery is considered. A better understanding of the prognosis of cervical radiculopathy is essential to provide accurate information to the patients. If the patients complain of persistent and recurrent arm pain/numbness not respond to conservative treatment, or exhibit neurologic deficits, surgery is performed using anterior or posterior approaches. Anterior cervical discectomy and fusion (ACDF) has historically been widely used and has proven to be safe and effective. To improve surgical outcomes of ACDF surgery, many studies have been conducted on types of spacers, size/height/position of cages, anterior plating, patients' factors, surgical techniques, and so forth. Cervical disc replacement (CDR) is designed to reduce the incidence of adjacent segment disease during long-term follow-up by maintaining cervical spine motion postoperatively. Many studies on excellent indications for the CDR, proper type/size/shape/height of the implants, and surgical techniques were performed. Posterior cervical foraminotomy is a safe and effective surgical option to avoid complications associated with anterior approach and fusion surgery. Most recent literature demonstrated that all three surgical techniques for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice the operative techniques for patients with cervical radiculopathy.

Clostridium difficile infection after orthopedic surgery: Incidence, associated factors, and impact on outcome.

BACKGROUND: To identify the incidence, associated factors, and impact of hospital-acquired Clostridium difficile infection (CDI) among patients who have undergone orthopedic surgery. METHODS: We retrospectively reviewed the charts of all adults patients who underwent orthopedic surgery from January 2016 through December 2017 at a tertiary hospital. RESULTS: Of 7,363 patients who underwent orthopedic surgical procedures, 52 (0.7%) developed hospital-acquired CDI. The independent factors associated with CDI were age ≥65 years (adjusted odds ratio [aOR], 3.4; P < .001), preoperative hospital stay ≥3 days (aOR, 3.7; P < .001), operating time ≥3 hours (aOR, 2.5; P < .005), and antibiotic use for infection treatment (aOR, 4.3; P < .001). After adjusting for the timing of CDI using a multistate model, the mean excess LOS attributable to CDI was 2.8 days (95% confidence interval [CI], 0.4-5.3). The impact of CDI on excess LOS was more evident among patients aged ≥65 years (4.4 days; 95% CI, 1.8-7.0) and those with any comorbidity (5.6 days; 95% CI, 3.0-8.1). CONCLUSIONS: The overall incidence of CDI after orthopedic surgery was 0.7%. The occurrence of CDI after orthopedic surgery contributes to increased LOS. The greatest impact of CDI on LOS occurs among elderly patients and patients with comorbidities.

Prospective randomized clinical trial of single- versus double-row suture anchor repair in 2- to 4-cm rotator cuff tears: clinical and magnetic resonance imaging results.

PURPOSE: The purpose of this study was to compare the clinical outcomes and the retear rates of arthroscopic single-row (SR) and double-row (DR) suture anchor repair in 2- to 4-cm rotator cuff tears. METHODS: From 2005 to 2007, 71 patients with a 2- to 4-cm rotator cuff tear (proven by arthroscopy) were prospectively randomized to SR and DR repair groups. Of these patients, 62 (31 in each group) were available for evaluation at final follow-up. Demographic data, clinical scores, mean surgical times, and patient satisfaction were compared. Retear rates and clinical scores were also analyzed for 47 patients who underwent follow-up magnetic resonance imaging. RESULTS: Comparisons of demographic data, tear size on preoperative magnetic resonance imaging, global fatty degeneration index, and concomitant procedures showed no differences between the SR and DR groups. Preoperative clinical scores were significantly improved postoperatively in both groups. No intergroup differences in pain visual analog scale, American Shoulder and Elbow Surgeons, Constant, or University of California, Los Angeles scores were found at final follow-up. Only mean surgical time was significantly different between the 2 groups. In the SR group, there were 4 full-thickness retears and 11 partial-thickness retears, whereas in the DR group, there were 6 full-thickness retears and 1 partial-thickness retear. However, despite numerical differences, these differences were not statistically different. Statistically, there were no significant differences both in full-thickness retear (P = .999) and retear including partial-thickness tear between the 2 groups (P = .124). CONCLUSIONS: This study indicates that the clinical results and retear rates of DR repair with 1 additional medial suture anchor were not significantly different from those of SR repairs with 2 lateral suture anchors in patients with medium to large rotator cuff tear. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Changes of upper thoracic curve and shoulder balance in thoracic adolescent idiopathic scoliosis treated by anterior selective thoracic fusion using VATS.

STUDY DESIGN: A retrospective radiographic analysis. OBJECTIVES: To evaluate changes of upper thoracic curve and shoulder balance in thoracic adolescent idiopathic scoliosis patients treated by anterior selective thoracic fusion using video-assisted thoracoscopic surgery and to identify adequacy of earlier criteria of double thoracic (DT) curve for anterior correction. SUMMARY OF BACKGROUND DATA: Although anterior and posterior scoliosis correction show many differences in correction mechanisms, fusion levels, loss of correction etc., the criteria of DT curve was applied without differences. There are no reports about these differences. MATERIALS AND METHODS: Forty patients were followed for a minimum of 3 years (range, 3-8 y). The magnitude and flexibility of upper thoracic, lower thoracic, and the superior portion of the lower thoracic curve were measured using full length standing and side-bending radiographs before surgery, at 1 week postoperatively, and at last follow-up. The correction rate and loss of correction of these curves were calculated and preoperative and postoperative radiographic shoulder heights (RSHs) were measured. RSH was defined as balanced (shoulder height difference <10 mm), mildly imbalanced (10-20 mm), or moderately imbalanced (>20 mm). T1 tilt and coronal balance were also evaluated. Patients were divided into groups based on these factors and postoperative RSH was compared. RESULTS: Flexibility of the upper thoracic curve was 46% and magnitude of the upper thoracic curve was corrected spontaneously from 28.6±7.8 degrees to 17.9±7.0 degrees with a 37.4% correction rate that did not change during follow-up. On average, preoperative left shoulder was 6.3±10.5 mm lower than right shoulder and this changed to 10.4±11.8 mm and 6.0±8.2 mm higher than right shoulder at 1 week postoperatively and at last follow-up, respectively. The group with an upper thoracic curve of ≥30 degrees or a superior portion of the lower thoracic curve of ≥30 degrees preoperatively had a higher left shoulder postoperatively (P=0.016, 0.040). Of the 12 patients with a symmetric or higher left shoulder (≥0 mm) preoperatively, 9 patients had a balanced shoulder (-10-10 mm) and 3 patients showed mild shoulder imbalance (<20 mm) at last follow-up. CONCLUSIONS: Among patients who have DT curve, patients with mild left shoulder elevation (<20 mm) can be treated by anterior correction unless the magnitude of upper thoracic curve or superior portion of lower thoracic curve are ≥30 degrees. For anterior correction, criteria of DT curve might be applied less strictly.

Diagnostic usefulness of 10-step tandem gait test for the patient with degenerative cervical myelopathy.

Tandem gait is considered one of the most useful screening tools for gait impairment. The aim of this study is to evaluate diagnostic usefulness of 10-step tandem gait test for the patients with degenerative cervical myelopathy (DCM). Sixty-two DCM patients were compared to 55 persons without gait abnormalities as control. We counted the number of consecutive steps and graded into five according the number of steps and stability. Five grades of tandem gait were investigated for association with clinical parameters including qualitative Japanese orthopedic association (JOA) sub-score for lower extremities and Nurick scale and quantitative balance and gait assessments. The number of tandem steps were reduced and the grades of tandem gait were differently distributed in the DCM patients compared to controls (steps, 7.1 ± 3.6 versus 9.9 ± 0.4, p < 0.001; grades of 0/1/2/3/4/5, 1/13/14/15/19 versus 0/0/2/15/38, p < 0.001 in patients with DCM and control respectively). Patients with DCM showed more unstable balance and abnormal gait features including slower velocity, shorter strides, wider bases with increased stance phase of a gait cycle compared to the control group. The grades of tandem gait were correlated with JOA sub-score (r = 0.553, p < 0.001) and the Nurick scale (r = - 0.652, p < 0.001) as well as both balance and gait parameters. In DCM patients, tandem gait was impaired and correlated with severity of gait abnormality. The authors believe that 10-step tandem gait test is an objective and useful screening test for evaluating gait disturbance in patients with DCM.

Extent and characteristic of relationships in canal dimension and canal body ratio between cervical and lumbar spine.

A known prevalence of concurrent cervical and lumbar spinal stenosis was shown to be 5-25%, but there is a lack of evidence regarding direct relationships in canal dimension and canal-body ratio between cervical and lumbar spine. Total 247 patients (mean age: 61 years, male: 135) with cervical and lumbar computed tomography scans were retrospectively reviewed. Midsagittal vertebral body and canal diameters in reconstructed images were measured at all cervical and lumbar vertebrae, and canal-body ratios were calculated. The canal diameter and ratio were also compared according to the gender and age, and correlation analysis was performed for each value. There were significant correlations between cervical (C3-C7) and lumbar (L1-L5) canal dimension (p < 0.001). C5 canal diameter was most significantly correlated with L4 canal diameter (r = 0.435, p < 0.001). Cervical canal-body ratios (C3-C7) were also correlated with those of lumbar spine (L1-L5) (p < 0.001). The canal-body ratio of C3 was most highly correlated with L3 (r = 0.477, p < 0.001). Meanwhile, mean canal-body ratios of C3 and L3 were significantly smaller in male patients than female (p = 0.038 and p < 0.001) and patient's age was inversely correlated with C5 canal diameter (r = - 0.223, p < 0.001) and C3 canal-body ratio (r = - 0.224, p < 0.001). Spinal canal dimension and canal-body ratio have moderate degrees of correlations between cervical and lumbar spine and the elderly male patients show the tendency of small canal diameter and canal-body ratio. This relationship of cervical and lumbar spine can be an important evidence to explain to the patients.

Strategies for prevention of rod fracture in adult spinal deformity: cobalt chrome rod, accessory rod technique, and lateral lumbar interbody fusion.

OBJECTIVE: Restoring the proper sagittal alignment in adult spinal deformity (ASD) can improve radiological and clinical outcomes, but pseudarthrosis including rod fracture (RF) is a common problematic complication. The purpose of this study was to analyze the methods for reducing the incidence of RF in deformity correction of ASD. METHODS: The authors retrospectively selected 178 consecutive patients (mean age 70.8 years) with lumbar degenerative kyphosis (LDK) who underwent deformity correction with a minimum 2-year follow-up. Patients were classified into the non-RF group (n = 131) and the RF group (n = 47). For predicting the crucial factors of RF, patient factors, radiographic parameters, and surgical factors were analyzed. RESULTS: The overall incidence of RF was 26% (47/178 cases), occurring in 42% (42/100 cases) of pedicle subtraction osteotomy (PSO), 7% (5/67 cases) of lateral lumbar interbody fusion (LLIF) with posterior column osteotomy, 18% (23/129 cases) of cobalt chrome rods, 49% (24/49 cases) of titanium alloy rods, 6% (2/36 cases) placed with the accessory rod technique, and 32% (45/142 cases) placed with the 2-rod technique. There were no significant differences in the incidence of RF regarding patient factors between two groups. While both groups showed severe sagittal imbalance before operation, lumbar lordosis (LL) was more kyphotic and pelvic incidence (PI) minus LL (PI-LL) mismatch was greater in the RF group (p < 0.05). Postoperatively, while LL and PI-LL did not show significant differences between the two groups, LL and sagittal vertical axis correction were greater in the RF group (p < 0.05). Nonetheless, at the last follow-up, the two groups did not show significant differences in radiographic parameters except thoracolumbar junctional angles. As for surgical factors, use of the cobalt chrome rod and the accessory rod technique was significantly greater in the non-RF group (p < 0.05). As for the correction method, PSO was associated with more RFs than the other correction methods, including LLIF (p < 0.05). By logistic regression analysis, PSO, preoperative PI-LL mismatch, and the accessory rod technique were crucial factors for RF. CONCLUSIONS: Greater preoperative sagittal spinopelvic malalignment including preoperative PI-LL mismatch was the crucial risk factor for RF in LDK patients 65 years or older. For restoring and maintaining sagittal alignment, use of the cobalt chrome rod, accessory rod technique, or LLIF was shown to be effective for reducing RF in ASD surgery.

Cervical Radiculopathy Focus on Characteristics and Differential Diagnosis.

Cervical radiculopathy is characterized by neurological dysfunction caused by compression and inflammation of the spinal nerves or nerve roots of the cervical spine. It mainly presents with neck and arm pain, sensory loss, motor dysfunction, and reflex changes according to the dermatomal distribution. The most common causes of cervical radiculopathy are cervical disc herniation and cervical spondylosis. It is important to find the exact symptomatic segment and distinguish between conditions that may mimic certain cervical radicular compression syndromes through meticulous physical examinations and precise reading of radiographs. Non-surgical treatments are recommended as an initial management. Surgery is applicable to patients with intractable or persistent pain despite sufficient conservative management or with severe or progressive neurological deficits. Cervical radiculopathy is treated surgically by anterior and/or posterior approaches. The appropriate choice of surgical treatment should be individualized, considering the patient's main pathophysiology, specific clinical symptoms and radiographic findings thoroughly.