Jingfeng Li

Analysis of radiographic parameters relevant to the lowest instrumented vertebrae and postoperative coronal balance in Lenke 5C patients.

Study Design. A retrospective radiographic study. Objective. To investigate which preoperative radiographic parameters best correlate with the angulation and translation of the lowest instrumented vertebra (LIV) and global coronal balance after posterior spinal pedicle screw fixation for thoracolumbar/lumbar (TL/L) adolescent idiopathic scoliosis. Summary of Background Data. Lenke 5C patients with a single, structural TL/L curve can be treated by either an anterior or posterior approach. One of the operative goals when treating Lenke 5C patients is to level and center the LIV, thereby achieving a better global coronal balance. To our knowledge, no study has investigated which specific radiographic parameters correlate with these surgical outcomes after posterior pedicle screw fixation. Methods. Twenty-seven patients with TL/L adolescent idiopathic scoliosis were identified in this study, and they underwent posterior fixation and fusion by pedicle screws with a minimum 2-year follow-up. Preoperative and postoperative radiographs were reviewed measuring various radiographic parameters as well as specific measurements related to the LIV. Correlation of these parameters to LIV translation and global and regional coronal balance (C7-central sacral vertical line [CSVL], LIV-CSVL distance) were then evaluated. Results. Four patients demonstrated global coronal imbalance postoperatively by radiographic and clinical evaluation. Regression analysis identified three radiographic parameters that correlated significantly with the postoperative global coronal balance (C7-CSVL): preoperative C7-CSVL (r = 0.44, P = 0.023), preoperative LIV tilt (r = 0.60, P = 0.001), and postoperative LIV tilt (r = 0.65, P = 0.0002). The radiographic parameters that correlated with postoperative LIV-CSVL were: preoperative LIV-CSVL (r = 0.57, P = 0.017), preoperative LIV tilt (r = 0.40, P = 0.04), and postoperative LIV tilt (r = 0.46, P = 0.015). The radiographic parameters correlating to LIV translation were preoperative LIV-CSVL (r = 0.88, P < 0.001) and preoperative C7-CSVL (r = 0.44, P = 0.02). Conclusion. LIV tilt is a very important radiographic parameter that strongly correlates to postoperative global and regional coronal balance. In patients with Lenke 5C curves undergoing posterior spinal fixation using pedicle screw constructs, preoperative LIV tilt equal to or exceeding 25° and failure of postoperative LIV tilt to reduce below 8° correlate with a high risk of developing postoperative global coronal imbalance.

A multicenter study to evaluate the safety and efficacy of a stand-alone anterior carbon I/F Cage for anterior lumbar interbody fusion: two-year results from a Food and Drug Administration investigational device exemption clinical trial.

Study Design. Two-year prospective multicenter clinical trial. Objective. To determine the safety and efficacy of the anterior I/F Cage in the primary treatment of single-level degenerative disc disease. Summary of Background Data. A carbon fiber-reinforced polymer cage was designed to replace the traditional allograft/autograft structural graft used in an anterior lumbar interbody fusion (ALIF). Although the outcomes of various types of ALIF cages have previously been reported, the safety and efficacy of the I/F cage are unknown. Methods. Between June 2000 and June 2004, 112 patients were prospectively enrolled at 12 study sites for the current study. Efficacy was evaluated clinically and radiographically. “Patient success” was declared only when the following 4 criteria were present at final follow-up: (1) “clinical success”: improvement of 15 points on Oswestry Disability Index, (2) absence of a new neurologic abnormality, (3) successful radiographic fusion, and (4) no subsequent secondary surgical intervention at 24-month follow-up. Safety was inferred by way of an objective summary of complications and adverse events, as reported at regular intervals throughout the course of the study. Results. A total of 112 patients (mean age: 41.7 years) underwent a single-level ALIF procedure (L5–S1: 95 patients, L4–L5: 17 patients). The mean surgical time was 126 minutes, the mean estimated blood loss was 134 mL, and the mean duration of hospitalization was 3.3 days. There were 80 patients available for 24-month follow-up. Overall patient success was 25% (20/80). Clinical success was present in 46.3% (37/80), fusion success was 57.5% (46/80), and 87.5% of patients (70/80) avoided a subsequent secondary surgical intervention. Disc space height had significantly increased after surgery, and this increase was maintained at 2 years follow-up period. Complications and adverse events included the following: 8 infections (7.1%) (7 superficial, 1 deep), 2 vascular injuries (1.8%) (left common iliac vein), and 12 secondary surgical interventions (15%). Conclusion. This safety and efficacy study suggests that the anterior I/F Cage is a safe surgical option in the treatment of single-level lumbar degenerative disc disease. As a stand-alone construct, the I/F Cage yields suboptimal radiographic and clinical outcomes. Additional benefit may be gained from adjunctive posterior stabilization.

Development of a simplified Chinese version of the hip disability and osteoarthritis outcome score (HOOS): cross-cultural adaptation and psychometric evaluation

Osteoarthritis (OA) has a profound impact on health-related quality of life 1 . Increasing importance has been attached to utilization of disease-specific, self-reported outcome measures 2 , such as the Hip Disability and Osteoarthritis Outcome Score (HOOS) instrument 3 . China is the most populous country in the world with 1.3 billion people. Hence, we translated and adapted the HOOS into a Simplified Chinese version (SC-HOOS) and validated it in a cohort of native Chinese-speaking patients with hip OA, relative to the Short Form Health Survey (SF-36), a visual analog scale (VAS), and the Harris hip score (HHS) test. Psychometric testing for internal consistency, testeretest reliability, construct validity, and responsiveness was conducted. The SC-HOOS showed satisfactory internal consistency, testeretest reliability, construct validity, and responsiveness when evaluated in Chinese-speaking patients with hip OA.

Radiographic Parameters in Adult Degenerative Scoliosis and Different Parameters Between Sagittal Balanced and Imbalanced ADS Patients.

Abstract A retrospective study. To summarize and describe the radiographic parameters of adult degenerative scoliosis (ADS) and explore the radiological parameters which are significantly different in sagittal balanced and imbalanced ADS patients. ADS is the most common type of adult spinal deformity. However, no comprehensive description of radiographic parameters in ADS patients has been made, and few studies have been performed to explore which radiological parameters are significantly different between sagittal balanced and imbalanced ADS patients. Medical records of ADS patients in our outpatient clinic from January 2012 to January 2014 were reviewed. Demographic data including age and sex, and radiographic data including the coronal Cobb angle, location of apical vertebra/disc, convexity of the curve, degree of apical vertebra rotation, curve segments, thoracic kyphosis (TK), lumbar lordosis (LL), thoracolumbar kyphosis (TL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), and PI minus LL (PI − LL) were reviewed to make comprehensive description of radiographic parameters of ADS. Furthermore, patients were divided into 2 groups according to whether the patients’ sagittal plane was balanced: Group A (imbalanced, SVA > 5 cm) and Group B (balanced, SVA ⩽ 5 cm). Demographic and radiological parameters were compared between these 2 groups. A total of 99 patients were included in this study (Group A = 33 and Group B = 66; female = 83 and male = 16; sex ratio = 5:1). The median of age were 67 years (range: 41–92 years). The median of coronal Cobb angle and length of curve was 23 (range: 10–75°) and 5 segments (range: 3–7), respectively. The most common location of apical vertebra was at L2 to L3 (81%) and the median of degree of apical vertebra rotation was 2° (range: 1–3). Our study also showed significant correlations between coronal Cobb angle and curve segments (r = 0.23, P < 0.005) and degree of apical vertebra rotation (r = 0.53, P < 0.005). With regard to the sagittal balance, there were significant differences in age, LL, PT, coronal Cobb angle, degree of apical vertebra rotation, and PI − LL between imbalanced group and balanced group (all P < 0.05); however, no significant difference was observed in gender, TK, TL, SS, and PI. Our study provided the general radiographic parameters of ADS. Weak or moderate but significant correlations between coronal Cobb angle and curve segments and degree of apical vertebra rotation were observed. Furthermore, age, coronal Cobb angle, LL, PT, and PI − LL were significantly different between sagittal balanced and imbalanced ADS patients.

A valid cross-culturally adapted simplified Chinese version of the Quebec Back Pain Disability Scale

OBJECTIVE To evaluate the reliability and validity of the simplified Chinese version of the Quebec Back Pain Disability Scale (SC-QDS). STUDY DESIGN AND SETTING The QDS was translated and cross-culturally adapted into SC following international guidelines. The SC-QDS was completed by 114 patients with low back pain (LBP) and 65 healthy controls, along with the SC Oswestry Disability Index (SC-ODI) and visual analogue scale (VAS). Psychometric evaluation included homogeneity and reproducibility by internal consistency and test-retest reliability and construct validity by calculating the Pearsons correlation coefficients among QDS, SC-ODI, and VAS. Discriminative validity was determined by students t-test. RESULTS SC-QDS scores were well distributed, with no floor or ceiling effects. Internal consistency was excellent (Cronbach α 0.976). The items and overall SC-QDS were correlated (r=0.640-0.898 and P<0.0001). Intraclass correlation coefficient of test-retest reliability was excellent (0.987, 95% confidence interval: 0.978-0.992). Construct validity was confirmed by high correlation of SC-QDS and SC-ODI (r=0.901 and P<0.0001) and VAS (r=0.770 and P<0.0001) scores, as was discriminative validity by significantly different SC-QDS scores for patients with LBP and controls (46.3 ± 19.9 vs. 14.6 ± 8.5 and P<0.0001). CONCLUSIONS The SC-QDS has good internal consistency, test-retest reliability, and construct and discriminative validity. The SC-QDS is appropriate for clinical and research uses with Chinese-speaking patients with LBP in mainland China.

Validation of the simplified chinese version of the functional rating index for patients with low back pain.

Study Design. Cross-cultural translation and psychometric testing of the Functional Rating Index (FRI). Objective. To evaluate the reliability and validity of the adapted simplified Chinese FRI (SC-FRI) for patients with low back pain (LBP). Summary of Background Data. The FRI is a reliable and valid instrument to assess the perception of function and pain for patients with LBP. However, there is no culturally adapted, reliable, and validated FRI for use in mainland China. Methods. The translation and cross-cultural adaptation were performed following international guidelines. The SC-FRI was administered to 115 patients with LBP along with the simplified Chinese version of the Oswestry Disability Index, 36-Item Short Form Health Survey, and the visual analogue scale. Psychometric testing included internal consistency, test-test reliability, concurrent criterion validity, and construct validity. Results. A high completion rate of 96% and no floor or ceiling effects were noted for the SC-FRI. The internal consistency was good (i.e., Cronbach &agr; = 0.897 for the overall SC-FRI; range, 0.851–0.890, if an item was deleted). Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.948 (95% confidence interval, 0.917–0.968). Concurrent criterion validity assessment demonstrated that the SC-FRI significantly correlated with the visual analogue scale (r = 0.852, P < 0.0001) and the simplified Chinese version of the Oswestry Disability Index (r = 0.958, P < 0.0001). Construct validity was confirmed by the significant Pearson correlation between the SC-FRI and Physical Functioning (r = −0.802, P < 0.0001), Bodily Pain (r = −0.698, P < 0.0001), Social Functioning (r = −0.573, P < 0.0001), Role-Physical (r = −0.503, P < 0.0001), and General Health (r = −0.502, P < 0.0001) domains of the 36-Item Short Form Health Survey. Conclusion. The SC-FRI showed excellent reliability and validity in the evaluation of pain and the functional health status of Chinese-speaking patients with LBP. It is simple and easy to use and can be recommended in clinical and research practice in mainland China.

Key-Vertebral Screws Strategy for Main Thoracic Curve Correction in Patients With Adolescent Idiopathic Scoliosis.

Study Design:The following study was a prospective radiographic and retrospective clinical data assessment of adolescent idiopathic scoliosis (AIS) patients who had undergone a key-vertebral screws strategy (KVSS) at a single institution, with a minimum of 2 years’ follow-up. Objectives:The aim of the study was to introduce the KVSS for the operative treatment of AIS of the main thoracic curve, and to address the role of the fulcrum-bending radiograph (FBR) in predicting the outcome of surgical management by this method. Summary of Background Data:The application of multilevel pedicle screws for the main thoracic curve in AIS patients is popular in an effort to provide spinal stability, enhance fusion outcome, and provide optimal curve correction. However, with the application of pedicle screw also comes a potential risk for soft tissue and neural injury and increased health care costs. It remains unknown whether limited screw placement can provide proper curve correction without compromising patient outcome. Methods:A total of 17 consecutive patients with AIS extending to the main thoracic spine, who had undergone posterior fusion and fixation by the KVSS, a procedure in which screws are placed at important strategic points in the spine (ie, bilaterally at the upper and lower end segments of the fusion block, apical vertebra on the convex side, adjacent cephalad, and caudal screw placement on the concave side), at a single institution, with a minimum of 2 year’ follow-up, were included. The assessment of preoperative standing posteroanterior and sagittal, FBR, and postoperative standing posteroanterior and sagittal plain radiographs were assessed in all patients. The flexibility of the curve as well as the fulcrum-bending correction index (FBCI) were calculated for all patients. Postoperatively, radiographs were assessed at the immediate (ie, 1 wk) and last follow-up. Clinical assessment entailed evaluation of patient demographics and the presence of any intraoperative or postoperative complications. Results:The mean age at the time of surgery was 15.6 years. The mean follow-up was 39.8 months. The average FBR flexibility was 62.2%. The mean immediate curve correction was 71.2%, which did not differ in comparison with the last follow-up assessment (P>0.05). The mean immediate and last follow-up FBCIs were 119.3% and 112.5%, respectively (P=0.079). A significant negative correlation was found between immediate FBCI to that of the FBR curve flexibility (r=−0.706; P=0.002), which remained similar on the last follow-up (r=−0.681; P=0.003). Sagittal alignment did not significantly change from the immediate to last follow-up (P=0.163) Fusion was achieved in all patients. No instrumentation-related complications were noted. Conclusions:Key-vertebral screws strategy is a safe and cost-effective method for the surgical treatment of the main thoracic curve in AIS patients. Moreover, in the context of this strategy, the FBR may have some predictive utility in the correction of the main thoracic curve in AIS patients.

An innovative fulcrum-bending radiographical technique to assess curve flexibility in patients with adolescent idiopathic scoliosis.

Study Design. A prospective clinical and radiographical study. Objective. To introduce a redesigned fulcrum-bending radiographical (FBR) method, and to validate the effectiveness of this method in assessing patients with (AIS). Summary of Background Data. Several radiographical methods exist to evaluate curve flexibility in patients with AIS. The technique of FBR has been demonstrated to better predict coronal plane correction of main thoracic curves. However, the amount of weight applied may affect the results of flexibility evaluation and have not been well studied to date. Methods. Seventeen patients with AIS with 19 curves were involved in this study. The assessment of radiographs included preoperative standing posterior-anterior, supine side-bending, traditional FBR, new FBR (CH-FBR), and postoperative standing posterior-anterior radiographs. CH-FBR was performed at variable device heights while measuring the applied weight at the apex. Results. Preoperatively, the mean Cobb angle was 47.5°± 8.8° on the posterior-anterior radiographs, 14.3°± 7.0° on supine side-bending radiographs, 13.3°± 5.7° on traditional FBR, 11.3°± 4.5° at the lowest height using CH-FBR (lowest weight), and 7.8°± 4.1° at the optimized height using CH-FBR (maximal weight). Postoperatively, the mean Cobb angle was 9.1°± 5.2°. There was a significant difference found between supine side-bending radiograph and postoperative Cobb angle (P = 0.001), traditional FBR, and postoperative Cobb angle (P = 0.002). There was no significant difference found between optimized height CH-FBR and postoperative Cobb angle (P = 0.16). Correlation analysis indicated that the maximum height of CH-FBR positively correlated with maximum weight applied (r = 0.68, r2= 0.46, P = 0.001). Conclusion. CH-FBR is a more reliable and effective method than traditional FBR and supine side-bending radiographs to measure curve flexibility in patients with AIS. Moreover, the flexibility suggested by the CH-FBRs more closely approximated the postoperative results from posterior pedicle screw instrumentation. Level of Evidence: 3

Acquired Hemophilia A in a Patient With Lumbar Disc Herniation: A Case Report and Review of the Literature

Objective. To summarize the clinical manifestations and treatment of acquired hemophilia A in a patient with lumbar disc herniation. Summary of Background Data. Acquired hemophilia A is a rare but potentially life-threatening hemorrhagic disorder. It is caused by the development of autoantibodies directed against coagulation factor VIII (F VIII) in adults or elderly patients, who do not have a personal or family history of bleeding episodes. The mortality is high if the diagnosis was missed or delays, especially after a surgery. Methods. A case was investigated retrospectively and the relevant literature was reviewed. Results. A 59-year-old man with a 1-year history of lower back and leg pain was admitted to the hospital. He has no family medical history of hemophilia A and the routine laboratory examination did not find abnormality on blood coagulation function. He underwent decompression by laminectomy and discectomy. Seven hours after operation, it was found that the incision was oozing profusely and hemoglobin was reduced gradually, though platelet count was within the normal range. He was diagnosed with acquired factor VIII (FVIII) deficiency based on a prolonged activated partial-thromboplastin time (61.0 seconds), reduced FVIII activity (4.2%), and FVIII inhibitor (8 BU). After treatment with hemodynamic stabilization and immunosuppression therapies (including transfusion of packed red blood cells, fresh frozen plasma, and cryoprecipitate) and administration of human antihemophilic globulin, corticosteroid, and cyclophosphamide, bleeding was stopped gradually. The clinical and biologic condition of the patient improved, though neurological deficit was left. Conclusion. Surgical operation may be a factor contributing to acquired hemophilia A, which, to our knowledge, has not been reported in the literature. Diagnosis of acquired hemophilia requires clinical acumen and any patient who presents with bleeding and a prolonged activated partial-thromboplastin time should be considered. Initial hemodynamic stabilization followed by treatment with immunosuppressive therapy is straightforward and highly successful.

Key Vertebral Pedicle Screw Strategy for the Correction of Flexible Lenke Type 1 Adolescent Idiopathic Scoliosis: A Preliminary Study of a 5-year Minimum Radiographic Follow-up

Study Design. A retrospective clinical and radiographic study. Objective. The aim of this study was to evaluate outcomes of the key vertebral pedicle screw strategy (KVPSS) for the correction of flexible Lenke type 1 adolescent idiopathic scoliosis (AIS) with a minimum follow-up of 5 years. Summary of Background Data. The KVPSS has been described as an alternative screw placement strategy for surgically treating the main thoracic curve in AIS patients. However, there have been no long-term, three-dimensional correction studies of selective thoracic fusion using the KVPSS in Lenke type 1AIS. Method. Twenty consecutive patients with Lenke type 1 main thoracic AIS underwent one-stage posterior correction and fusion using the KVPSS. Preoperative and postoperative radiographic and clinical parameters were analyzed. Results. The mean preoperative major thoracic curve was 47.4° ± 5.8°, and mean corrections of 67.0%, 63.4%, and 61.5% were observed at the immediate, 2-year postoperative, and final follow-ups, respectively. Thoracickyphosis decreased significantly from the preoperative period to the immediate postoperative period (P = 0.042) but did not change significantly from the 2-year postoperative follow-up to the final follow-up (P = 0.067). Apical vertebral rotation achieved 34.7% correction and exhibited correction loss of 8.2% at the final follow-up. The average intraoperative blood loss was 802.3 mL, and the mean operative time was 138.6 minutes. SRS-22 scores for self-image and satisfaction improved significantly from the preoperative period to the final follow-up. No neurologic or implant-associated complications were observed in this study. Conclusion. The KVPSS is an effective method for correcting Lenke type 1 AIS and achieves satisfactory correction of the deformity. Relative to other approaches, the KVPSS can not only achieve a satisfactory and cost-effective clinical outcome but also reduce both operative time and intraoperative blood loss. Level of Evidence: 4