Combinations of two imaging parameters to improve bone mineral density (BMD) assessment in patients with lumbar degenerative diseases.

PURPOSE: To explore whether combining the Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores can improve the BMD assessment in patients with lumbar degenerative diseases. METHODS: The HU values were measured by CT image, and VBQ scores were calculated by lumbar MRI image. The correlations of the opportunistic imaging parameters to the lowest T-scores were analyzed. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the accuracy in detecting osteoporosis. Finally, the specificity and sensitivity of different combined methods of the HU values and VBQ scores in the diagnosis of osteoporosis were compared. RESULTS: Patients with osteoporosis had the lowest HU values and the highest VBQ scores. The correlation coefficients between the VBQ scores and the T-scores were smaller than HU values (L1 HU value: 0.702; average HU value:0.700; L1 VBQ score: -0.413; VBQ score: -0.386). The areas under the curve (AUCs) of the HU values were greater than those of the VBQ scores, and the AUCs of the L1 VBQ score were similar to the VBQ score (L1 HU value: 0.850; average HU value:0.857; L1 VBQ score: 0.704; VBQ score: 0.673). When combining the two imaging parameters in series, the specificity of the detection of osteoporosis was improved (L1 HU value and L1 VBQ score: 87.3%; Average HU value and VBQ score: 85.9%). When combining the two imaging parameters in parallel, the sensitivity of the detection of osteoporosis was improved (L1 HU value or L1 VBQ score: 88.1%; Average HU value or VBQ score: 91.5%). CONCLUSIONS: Combinations of the HU values and VBQ scores could improve the diagnostic performance of osteoporosis. In addition, considering the same diagnostic performance but easier measurement, parameters at the single-segment level were recommended to assist in the diagnosis of osteoporosis.

Vertebral Bone Quality Score as a Predictor of Pedicle Screw Loosening Following Surgery for Degenerative Lumbar Disease.

STUDY DESIGN: Retrospective study. OBJECTIVE: To investigate whether magnetic resonance imaging-based vertebral bone quality (VBQ) score can predict pedicle screw loosening in patients who underwent pedicle screw fixation, and to compare, which measurement, the VBQ score or the Hounsfield unit (HU) value, is more predictive of pedicle screw loosening. SUMMARY OF BACKGROUND DATA: In clinical work, we found that patients with screw loosening had higher VBQ scores. In addition, some studies have found a correlation between VBQ scores and osteoporosis. PATIENTS AND METHODS: Patients who were treated with lumbar pedicle screw fixation were reviewed. The VBQ score was measured using magnetic resonance imaging scans. The HU value for L1 to L4 lumbar bone mineral density was measured with computed tomography scans. Logistic regression analysis was used to identify factors associated with pedicle screw loosening. Receiver-operating characteristic curve analysis was used to evaluate the value of VBQ scores in predicting pedicle screw loosening. RESULTS: A total of 156 patients were included in the final analysis. The pedicle screw loosening rate was 35% (55 of 156 patients). The postoperative low-back pain visual analog scale score was higher in the loosening group (3.0 ± 2.0 vs . 2.4 ± 1.8; P < 0.05). The VBQ score was higher in the loosening group than in the nonloosening group (3.28 ± 0.58 vs . 2.82 ± 0.50; P < 0.01). In multivariable analysis, nonsingle segment fixation [odds ratio (OR): 3.992; 95% CI: 1.643-9.701; P = 0.002], lowest instrumented vertebrae at S1 (OR: 3.378; 95% CI: 1.387-8.226; P = 0.007), HU value (OR: 0.988; 95% CI: 0.976-1.000; P = 0.047), and VBQ score (OR: 3.908; 95% CI: 1.624-9.405; P = 0.002) were factors associated with screw loosening. The areas under the curve for using the VBQ score and HU value to predict pedicle screw loosening were 0.720 and 0.702, respectively. The optimal VBQ score threshold was 3.05 for predicting pedicle screw loosening (sensitivity: 0.655; specificity: 0.713). CONCLUSIONS: The VBQ score was an influential factor associated with lumbar pedicle screw loosening, and a higher VBQ score was significantly correlated with a higher risk of screw loosening. The VBQ score was a better predictor of pedicle screw loosening than the HU value in patients who underwent pedicle screw fixation for degenerative lumbar disease.

The morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation.

OBJECTIVE: The objective of this study was to explore the morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation. METHODS: This study retrospectively analyzed young patients aged 18-40 years who were hospitalized for lumbar disc herniation in our hospital from June 2017 to June 2020. Data on sex, age, body mass index (BMI), subcutaneous fat tissue thickness (SFTT) at the L1-L2 level, duration of symptoms, degree of lumbar disc herniation, visual analog scale (VAS) for the lower back, Mo-fi-disc score, relative cross-sectional area (RCAS) of the paravertebral muscles (psoas major [PM], multifidus [MF], and erector spinae [ES]), and degree of fat infiltration (DFF) of the paravertebral muscles were collected. The VAS was used to evaluate the intensity of low back pain. Patients with VAS-back >4 points were defined as the low back pain group, and patients with ≤4 points were defined as the control group. The demographic characteristics, as well as the bilateral and ipsilateral paravertebral muscles, of the two groups were compared and analyzed. RESULT: A total of 129 patients were included in this study (52 patients in the LBP group and 77 patients in the control group). There were no significant differences in sex, BMI, or Pfirrmann grade of lumbar disc herniation between the two groups (P > 0.05). The age of the LBP group (33.58 ± 2.98 years) was greater than that of the control group (24.13 ± 2.15 years) (P = 0.002), and the SFTT at the L1-L2 level (13.5 ± 7.14 mm) was higher than that of the control group (7.75 ± 6.31 mm) (P < 0.05). Moreover, the duration of symptoms (9.15 ± 0.31 months) was longer than that of the control group (3.72 ± 0.48 months) (P < 0.05), and the Mo-fi-disc score (8.41 ± 3.16) was higher than that of the control group (5.53 ± 2.85) (P < 0.05). At L3/4 and L5/S1, there was no significant difference in the RCSA and DFF of the bilateral and ipsilateral paraspinal muscles between the LBP group and the control group. At L4/5, there was no significant difference in the RCSA and DFF of the paraspinal muscles on either side in the LBP group (P > 0.05). In the control group, the RCSA of the MF muscle on the diseased side was smaller than that on the normal side (P < 0.05), and the DFF of the MF muscle on the diseased side was larger than that on the normal side (P < 0.05). In addition, there was no significant difference in the ES and PM muscles on both sides (P > 0.05). At L4/5, the RCSA of the MF muscle on the normal side was significantly smaller in the LBP group than in the control group (P < 0.05), and the DFF of the MF muscle on the normal side was significantly larger in the LBP group than in the control group (P < 0.05). There was no significant difference in the ES and PM muscles on the same side between the two groups (P > 0.05). CONCLUSION: In young patients with unilateral neurological symptoms of lumbar disc herniation, symmetrical atrophy of the bilateral MF muscle is more prone to causing low back pain. Older age, higher SFTT at the L1-L2 levels, longer symptom duration, higher Mo-fi-di score, and greater muscle atrophy on the normal side of the MF increased the incidence of low back pain in young patients with unilateral lumbar disc herniation.

Risk factors for poor neurological outcomes after unilateral open-door laminoplasty: an analysis of the characteristics of ectopic bone.

BACKGROUND: The factors affecting neurological outcomes with unilateral open-door laminoplasty have been controversial. The purpose of this study was to evaluate the impact of the characteristics of ectopic bone on poor neurological outcomes after unilateral open-door laminoplasty. METHODS: We retrospectively analyzed the clinical data of 112 patients who underwent unilateral open-door laminoplasty from September 2017 to September 2020. According to the Japanese Orthopedic Association score recovery rate after surgery (Japanese Orthopedic Association recovery rate ≥ 50% and < 50%, respectively), all patients were divided into "poor" and "good" groups. The characteristics of ectopic bone and the position relationship between the open side and ectopic bone (for lateral ossification) in the two groups were compared and analyzed. Univariate and multivariate analyses were used to determine the risk factors for poor neurological outcome. RESULTS: We identified patients with a mean age of 58.39 years and a mean follow-up of 25.43 months. Sixty (53.6%) patients experienced recovery of poor neurological function. On univariable analysis, significant predictors of poor neurological recovery were occupation rate of spinal canal > 60% (p = 0.000), ossification extending to C2 (p = 0.006), lateral ossification (p = 0.032) and opening side on the ipsilateral side of the ectopic bone (p = 0.011). Multivariate logistic regression analysis revealed that the occupation rate of spinal canal > 60% (P = 0.003), ossification extending to C2 (P = 0.041) and opening the door on the ipsilateral side for lateral ossification (P = 0.013) were independent risk factors for poor prognosis of neurological function. CONCLUSIONS: An occupation ratio > 60% is the most important risk factor. Another one is ossification of the posterior longitudinal ligament extending to C2. Meanwhile, opening the door on the ipsilateral side is indeed a risk factor for lateral ossification. Better neurological function may be obtained by choosing the opposite side of the heterotopic bone as the open side. Therefore, the design of the surgical plan should comprehensively consider these factors.

Impact of sarcopenia and sagittal parameters on the residual back pain after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fracture.

OBJECTIVE: The objective of this study was to explore the impact of sarcopenia and sagittal parameters on the residual back pain (RBP) after percutaneous vertebroplasty (PVP) for treatment of osteoporotic vertebral compression fracture (OVCF). METHODS: This retrospective study included elderly patients (age range 60-90 years) with OVCF treated with PVP from January 2015 and December 2020 in our hospital. The skeletal muscle mass index (SMI) was calculated by dividing the T12 pedicle level muscle cross-sectional area by the square of body height from chest CT to diagnose sarcopenia. The radiological parameters for measuring the sagittal alignment were included: C7-sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI). RESULT: According to whether the VAS score > 4, patients were divided into RBP group (56 patients) and Control group (100 patients). There was no difference in age, gender, body mass index, BMD, surgical segment, bone cement usage between the groups (P > 0.05). The SMI in RBP group (27.3 ± 5.1) was significantly lower compared to that in Control group (36.8 ± 3.2) (P < 0.05). Sarcopenia was present in 19 patients (20.3%) in RBP group, which was significantly more than that in Control group (P < 0.05). C7-SVA and TPA was significantly larger in the RBP group than in the Control group (P < 0.05). PI and LL was significantly smaller in the RBP group compared to the Control group (P < 0.05). However, no significant differences between the two groups with respect to TK, SS and PT (P > 0.05). CONCLUSION: Poor sagittal parameters and sarcopenia in OVCF patients after PVP were more prone to residual back pain. Larger C7-SVA, TPA and PI-LL mismatch could increase the incidence of RBP in elderly patients with single-segment osteoporotic compression fractures.

Porous tantalum implant for treatment of early-stage osteonecrosis of the femoral head: a minimum 5-year follow-up study.

BACKGROUND: To evaluate the survival rate of porous tantalum rod implantation in the treatment of osteonecrosis of the femoral head (ONFH), evaluate its clinical effect and imaging results. METHODS: From January 2008 to December 2013, porous tantalum rod implantation for ONFH was performed in two institutions. Statistical analysis of operation data, including operation time, blood loss and blood transfusion were recorded. RESULTS: 52 hips received complete follow-up, the average follow-up time was 85.7 months (60-132 months). 24 hips turned to THA at the end of follow-up (46.2%), the average time was 44.3 ± 32.8 months, and the average Harris hip score before THA was 57.1 ± 7.6. Cox proportional-hazards model revealed that Association Research Circulation Osseous (ARCO) stage (P = 0.017), bone marrow edema (P = 0.006) and age > 40 years (P = 0.043) were independent risk factors for conversion to THA. CONCLUSION: ARCO stage, age and bone marrow edema were risk factors for the failure of porous tantalum rod implantation to convert to THA.

The Assessment of Dynamic Spinal Cord Impingement by Kinematic Magnetic Resonance Imaging in Patients with Traumatic Central Cord Syndrome.

BACKGROUND: There are few reports describing the imaging features of traumatic central cord syndrome (TCCS) in kinematic magnetic resonance imaging (kMRI) scans. The current study aimed to assess and characterize dynamic spinal cord impingement (DSCI) using kMRI and evaluate the risk factors for poor outcomes in patients with TCCS after surgery. METHODS: This retrospective study included 63 patients with TCCS who underwent surgery in the authors' hospital. The American Spinal Injury Association impairment scale grade and Japanese Orthopedic Association (JOA) score were collected preoperatively and at the final follow-up to assess neurological function. Patients were divided into two groups based on the JOA score (> or <50%), and clinical and radiographic evaluations were compared. The metrics examined included age at the time of surgery, gender, type of trauma, the interval from injury to surgery, surgical approach, pathological signs, range of motion, DSCI and the length of intramedullary hyperintensity signal (LIHS). RESULTS: There were statistical differences in the LIHS, DSCI and preoperative JOA score between good (JOA >50%; n = 50) and poor (JOA <50%, n =13) recovery patient groups (P<0.05). Logistic regression, with poor outcomes as the dependent variable, suggested independent risk associations with preoperative JOA score (P<0.05), DSCI (P<0.05) and LIHS (P<0.05). CONCLUSION: kMRI can be effective for decision-making in the treatment of TCCS. The lower preoperative JOA score, longer high signal cord and higher dynamic spinal cord impingement were risk factors for poor outcomes in patients with TCCS after surgery.

Comparison of cylindrical and tapered stem designs for femoral revision hip arthroplasty.

BACKGROUND: Both cylindrical and tapered stems are commonly used in revision total hip arthroplasty. However, whether the geometry of prosthesis stem has an effect on patient prognosis is unclear. We assume that the tapered stem results in better clinical outcome than the cylindrical stem. METHODS: A multicenter review of 120 femoral revisions with Paprosky I, II, and III defects using cobalt chrome cylindrical stem (54 hips) or titanium tapered stem (66 hips) was performed with an average follow-up of 6 years. Demographic data were comparable between groups. RESULTS: No significant group differences were found in surgery time, bleeding volume, postoperative Harris Hip Score, level of overall satisfaction, and 8-year cumulative survival. However, intraoperative fractures occurred significantly less in the tapered group (4.5%) than in the cylindrical group (14.8%), and stem subsidence was significantly less in the tapered group (2.17 mm) than in the cylindrical group (4.17 mm). A higher ratio of bone repair and lower bone loss were observed in the tapered group compared with the cylindrical group. The postoperative thigh pain rate was higher in the cylindrical group (12.9%) than in the tapered group (4.5%). CONCLUSION: Both cylindrical stem and tapered stem can achieve satisfactory mid-term clinical results in revision total hip arthroplasty. The tapered stem has better bone restoration of proximal femur, lower incidence of intraoperative fractures, and lower postoperative thigh pain rate compared with the cylindrical stem.