Analysis of the curative effect and prognostic factors in patients with scapular fracture with surgical indications after conservative treatment: a case series and clinical outcomes.

Background: The choice of treatment for scapular fractures is a topic worth discussing. The type of scapular fracture is often complex, and more and more scholars prefer surgical treatment to obtain better shoulder joint function. In addition, because of the rich blood supply and muscles of the scapula, some scholars believe that simple suspension can also achieve satisfactory clinical effects. The aim of this study was to investigate the curative effect and prognostic factors of patients with scapular fracture with indications for surgery after receiving conservative treatment. Methods: Patients with scapular fracture who did not receive surgical treatment from July 2016 to May 2021 were recruited from the orthopedic trauma database of Nanjing Gulou Hospital, and the data from patients with indications for surgery were screened out for a retrospective analysis. The data were obtained from the database of orthopaedic trauma patients in Nanjing Drum Tower Hospital. The relevant data were recorded during telephone and video follow-up visits. Linear regression was used to analyze the factors associated with disabilities of the arm, shoulder and hand (DASH) score after receiving conservative treatment. Results: A total of 21 patients were included in the final statistical analysis. All patients were followed up for 31.0±20.3 (range, 6-63) months, aged 52.9±12.7 (range, 27-71) years. All fractures had clinical healing with a 100% recovery satisfaction rate. Outcome measures of efficacy [both DASH scores and visual analogue scale (VAS) scores], were correlated with whether the fracture involved the superior border of the scapular, were not associated with the following variables: age (P=0.18), Injury Severity Score (ISS) score (P=0.10), the glenopolar angle (GPA) value (P=0.76), superior shoulder suspensory complex (SSSC) injury (P=0.82), and glenoid fracture (P=0.84). The range of motion of the affected shoulder was significantly reduced compared to the healthy shoulder (P<0.01), but the range of forward flexion and elevation was not significantly different from that of the healthy shoulder (P>0.05). Patients with fractures not involving the superior border of the scapula had a much lower range of motion in the affected shoulder than in the healthy shoulder during abduction (P<0.05). Conclusions: The range of surgical indications for scapular fractures with scapular fractures involving the lower margin of the scapular can be appropriately narrowed. Some patients with scapular fracture who have surgical indications can regain satisfactory shoulder function after receiving conservative treatment.

[Analysis of risk factors of multiple fractures of limbs complicated with pleural effusion].

OBJECTIVE: To explore the risk factors of limb fracture complicated with pleural effusion, and to provide reference for the prevention of pleural effusion. METHODS: From January 2010 to December 2019, 137 patients with multiple limb fractures were treated surgically, including 102 males and 35 females, aged 16 to 92(48.34±15.85) years. Multiple limb fractures were defined as more than two limb fractures in the whole body, so the selected patients had complete clinical, impact and laboratory examination data before operation, including preoperative chest CT, gender, age, body mass index(BMI), hematocrit(HCT), American Society of Anesthesiologists(ASA), injury severity score (ISS), smoking history of operation, history of diabetes, history of hypertension, admission to operation time, fracture site, platelet count, albumin, C-reactive protein and D-dimer. Whether the patient was complicated with pleural effusion, calculate the amount of pleural effusion were recorded, and the relevant risk factors were statistically analyzed. RESULTS: All limb fractures received surgical treatment. The incision healed well after operation, and there were no complications such as wound infection, acute lung injury or acute respiratory distress syndrome. Multivariate regression analysis showed that ISS higher than 16(P=0.000), smoking history(P=0.001) and rib fracture(P=0.000) were the risk factors of multiple limb fractures complicated with pleural effusion. Multivariate linear regression analysis showed that smoking history, ISS and rib fracture were the risk factors for the increase of pleural effusion in multiple limb fractures. CONCLUSION: Multiple fractures of limbs combined with pleural effusion are related to ISS, smoking history and rib fracture;the amount of pleural effusion was related to smoking history, ISS and rib fracture. Patients with multiple fractures with ISS greater than 16, smoking history or rib fracture should be vigilant and intervene as soon as possible to reduce the risk of pleural effusion.

Diagnostic value of platelet indices in infected nonunion: a retrospective study.

BACKGROUND: The diagnostic value of platelet indices has been evaluated in various infectious diseases but not in infected nonunion. The purpose of this study was to assess the usefulness of platelet indices for diagnosis of infected nonunion after open reduction and internal fixation. METHODS: This retrospective study was performed in patients who underwent primary fracture nonunion revision surgeries from January 2016 to December 2021. A total of 297 patients were included in the study: 96 with infected nonunion (group A) and 201 with aseptic nonunion (group B). Receiver operator characteristic (ROC) curve analysis was performed to evaluate diagnostic value of each index. Area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated and compared. RESULTS: Demographic characteristics were comparable between the two groups. White blood cell (WBC) count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), plasma fibrinogen, plasma D-dimer, platelet count (PC), plateletcrit, and ratio of platelet count to mean platelet volume (PC/MPV) were significantly higher, and MPV and platelet distribution width (PDW) significantly lower, in group A than in group B (P < 0.05). ROC analysis showed PC/MPV and plasma fibrinogen to have better diagnostic value than the other coagulation indicators (AUC of 0.801 and 0.807, respectively). The combination of ESR, plasma fibrinogen, and PC/MPV had good sensitivity and specificity for diagnosis of infected nonunion. PC/MPV had better diagnostic value than ESR and plasma fibrinogen in the subgroup of patients with coagulation-related comorbidities. CONCLUSIONS: Plasma fibrinogen and PC/MPV ratio might be useful parameters for early diagnosis of infected nonunion.

Lentogenic NDV V protein inhibits IFN responses and represses cell apoptosis.

The V protein of Newcastle disease virus (NDV) has been shown to inhibit the secretion of interferon (IFN) during infection, which is responsible for the promotion of NDV pathogenicity. However, the ability of the V protein to suppress host innate immunity is not well understood. In this study, we explored the function of V protein and its relationship with virulence by generating V protein-inserted recombinant (r) NDVs. Using rNDVs as a model, we examined the efficiency of infection, IFN responses, and apoptosis of host cells during infection. We found that viral propagation occurred smoothly when V protein from lentogenic NDV is inserted instead of the V protein from the velogenic strain. The infection of lentogenic V protein-inserted rNDV induced less expression of IFNs and downstream antiviral proteins via efficient degradation of p-STAT1 and MDA5. Moreover, velogenic V protein triggered a higher apoptosis rate during infection thereby restricting the replication of NDV. Conversely, lentogenic V protein inhibits IFN responses efficiently and induces less apoptosis compared to the velogenic strain. Our findings provide a novel understanding of the role of V protein in NDV pathogenicity.

Single volar locking plating for the intra- and extra-articular distal radius fractures with dorsal metaphyseal comminution.

BACKGROUND: Volar locking plating remains a popular method for the surgical management of distal radius fractures. Dorsal metaphyseal comminution (DMC) is a common fracture pattern which weakens the stability during fracture fixation. In this study, we aimed to compare the radiographic and functional outcome of the intra- and extra-articular distal radius fractures with DMC following single volar locking plate fixation. MATERIALS AND METHODS: Patients suffered from a distal radius fracture with DMC were reviewed in the clinical database of the authors' institution between Jan 2016 and Jan 2020. The included patients were classified into the extra-articular (A3) group or the intra-articular (C2 and C3) group according to the AO/OTA system. The radiological parameters, wrist range of motion, and functional outcomes were evaluated following open reduction and volar locking plate fixation. RESULTS: A total of 130 patients were included in this study with a mean follow-up length of 17.2 months. Compared with the A3 fracture group, no significant fracture re-displacement or reduced wrist ROMs was observed in the C2 fractures after 12-month's follow-up. However, significantly decreased volar tilt (P = 0.003) as well as the extension/flexion ROMs were observed in the C3 fractures comparing to the A3 fractures. Most of the patients achieved an excellent (n = 75) or good (n = 51) Gartland and Werley wrist score. Four patients with C3 fractures resulted in a fair functional outcome due to a significant loss of volar tilt during follow-up. CONCLUSIONS: The single volar locking plate fixation provided sufficient stability for distal radius fractures with DMC, and resulted in similar radiological and functional outcomes in the intra-articular distal radius fractures with a simple articular component (C2 fractures) as those in the extra-articular fractures. Considering the intra-articular fractures with multifragmentary articular component (C3 fracture), despite of the subsequent loss of volar tilt, the majority of the patients achieved good to excellent wrist function following single volar locking plating. TRIAL REGISTRATION: This study has been registered on the ClinicalTrials.gov.

A modified intrafocal pinning technique with three-dimensional planning to facilitate volar plating in dorsally comminuted AO/OTA C2 and C3 distal radius fractures.

BACKGROUNDS: Theaim of this study was to assess the efficacy of a modified intrafocal pinningtechnique with three-dimensional (3D) planning to facilitate volar plating in dorsally comminuted intra-articular distal radius fractures. METHODS: Intotal 35 AO/OTA type C2 and C3 fractures were finally included.The 3D digital model of the fracture was reconstructed based on preoperative computedtomographic (CT) images, with the displacement of the comminuted dorsalfragment and the intra-articular fragment analyzed for preoperative planning. During operation, amodified intrafocal pinning technique was applied percutaneously from thedorsal aspect of the radius to reduce the collapsed intra-articular fragmentfollowing volar plating. Adequate reduction was confirmed in all of patientsconsidering radial height, radial inclination and volar tilt in postoperativeradiographs. RESULTS: No significant fracture re-displacement wasobserved in most of the cases during a mean follow-up period of 17.4 months, exceptfor two patients withthe C3 fracture. All of the patients achieved adequate clinicalROMs at 12 months postoperatively, with a mean DASH score of 12.0. Most of the patients achievedan excellent (n = 21) or good (n = 12) Gartland and Werley wrist score. CONCLUSIONS: Ourmodified intrafocal pinning technique with 3D planning contributes to a satisfactoryclinical and radiological outcome in dorsally comminuted intra-articular distalradius fractures fixed with a volar locking plate. TRIALREGISTRATION: Notapplicable because the design of the study is retrospective.

Plasma Fibrinogen as a Diagnostic Marker of Infection in Patients with Nonunions.

BACKGROUND: The timely and accurate diagnosis of infected nonunion is challenging, and there is a need for more efficient biomarkers. Previous studies have shown that fibrinogen plays an important role in mediating inflammation in bacterial infections and, therefore, could be a valuable biomarker for infected nonunion. The purpose of this study was to evaluate and compare the performance of plasma fibrinogen and other traditional blood markers for the diagnosis of infected nonunion. MATERIALS AND METHODS: We retrospectively studied 146 patients who underwent surgery for primary nonunion between January 2018 and January 2020. The patients were divided into those with infected nonunion (n = 55) and those with aseptic nonunion (n = 91). The preoperatively analyzed parameters were plasma fibrinogen, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and white blood cell (WBC) count. Receiver operating characteristic (ROC) curve analysis was used to assess the sensitivity and specificity of the biomarkers, and Youden's index was calculated to determine their optimal cut-off values. RESULTS: The plasma fibrinogen values were significantly higher (p < 0.001) in the patients with infected nonunion than in those with aseptic nonunion. ROC curve analysis showed that plasma fibrinogen had a high value of area under the curve (0.816), which indicated that it had good diagnostic ability. Further, at the optimal threshold value of 2.75 g/L, plasma fibrinogen had the highest sensitivity (78.2%; 95% CI = 64.6-87.8) and good specificity (82.4%; 95% CI, 72.7-89.3). CONCLUSION: In comparison to the traditional markers of infection, plasma fibrinogen showed good diagnostic ability for the detection of infected nonunion. It may have potential as a practical and cost-efficient biomarker for the diagnosis of infected nonunion.

What Is the Most Reliable Classification System to Assess Tibial Pilon Fractures?

The aim of this study was to assess inter- and intraobserver agreement of the traditional systems (Ruedi-Allgower, AO [Arbeitsgemeinschaft für Osteosynthesefragen], and Topliss) and the newly proposed Leonetti classification system of pilon fractures. We studied all patients at our center who underwent pilon fracture surgery over a 2-year period: 68 patients (70 legs) were included. Four observers independently classified each pilon fracture according to the Ruedi-Allgower, AO, Topliss, and Leonetti systems by evaluating radiographs and computed tomography images on 2 occasions. The inter- and intraobserver agreements were calculated using the Fleiss kappa test. Interobserver reliability was good for AO types (A, B, and C) and Ruedi-Allgower (κ = 0.71 and 0.61, respectively), whereas the interobserver reliability was moderate for AO groups (A1, A2, A3, B1, B2, B3, C1, C2, and C3), Topliss families, Topliss subfamilies, Leonetti types, and Leonetti subtypes. Intraobserver reproducibility was excellent for the Ruedi-Allgower classification, AO types, and Topliss families and good for AO groups, Topliss subfamilies, and Leonetti types and subtypes. Ruedi-Allgower and AO classification systems are the most reliable among those currently used for pilon fractures, but with lower agreement at the AO group level. The use of Topliss and Leonetti classification systems is not recommended because of less favorable results.

Pulsed electromagnetic field (PEMF): A potential adjuvant treatment for infected nonunion.

Infected nonunion is still a challenge for orthopaedic surgeons. The goal of treatment is to eliminate infection and achieve bone union. Surgery is the only effective method currently. However, it is invasive and the results are still unsatisfactory. Therefore, seeking a noninvasive and effective method to resolve infected nonunion is necessary. Pulsed electromagnetic field (PEMF) has been used for the treatment of nonunion for more than 40 years. PEMF could promote bone formation at tissue, cell and subcellular levels. Furthermore, our study showed that PEMF had bactericidal effect. The hypothesis we proposed herein is that PEMF may be an adjuvant treatment for infected nonunion by controlling infection and inducing bone formation.

Microwaves increase the effectiveness of systemic antibiotic treatment in acute bone infection: experimental study in a rat model.

BACKGROUND: Osteomyelitis is a challenge for orthopedic surgeons due to its protracted treatment process. Microwaves (MWs) can increase blood perfusion due to their thermal effect. Furthermore, MWs demonstrated significant bactericidal effects in vitro. In the present study, we assumed that the application of a 2450-MHz-frequency MW together with systemic antibiotic treatment would provide synergy for the treatment of acute osteomyelitis. METHODS: The medullary cavity of the right tibia was inoculated with 107 CFU of methicillin-sensitive Staphylococcus aureus (MSSA-ATCC 29213) in 40 rats, and the rats were randomly divided into four groups according to treatment: group I, saline (control); group II, saline + MW therapy; group III, systemic cefuroxime; and group IV, systemic cefuroxime + MW therapy. MWs were applied for 20 min per day to the infected limbs, and all rats were sacrificed on the 7th day. The severity of tibial osteomyelitis was assessed by quantitative culture analysis. RESULTS: Bacterial counts in groups III and IV were significantly reduced compared with those in the control (p = 0.001 and < 0.001, respectively). Furthermore, significant differences were detected between groups III and IV (p = 0.033). However, the difference between groups I and II was nonsignificant (p = 0.287). CONCLUSION: Our experimental model suggests that MW therapy provides a significant synergy for systemic antibiotic treatment. However, further clinical trials are required to safely use this treatment modality in patients.

Coating the plate with antibiotic cement to treat early infection after fracture fixation with retention of the implants: a technical note.

BACKGROUND: Local antibiotic therapy has gained increasing attraction in the prevention and treatment of fracture infection. However, no reports have used local antibiotic therapy in the management of early infection after fracture fixation with retention of implants. METHODS: The present surgical technique report the use of antibiotic impregnated bone cement in the management of early infection after fracture fixation. Initially, the fractures were fixed with plates. The average time from initial procedure to debridement was15 days (range 9 to 25 days). The infections were treated with irrigation, debridement, and retention of the implant. The lateral surface of the plates was coated with antibiotic cement and the bone defect was filled with antibiotic cement spacer after thorough debridement. RESULTS: Ten patients underwent this technique. The mean follow-up was 2.0 years (range 6 months to 4 years). The bone union rate was 100%, and the average time to bone healing was5.5 months.There was recurrence of infection in one patient before bone healing, but the implants were left in place until bone healed, and the infection was eradicated after implant removal. CONCLUSION: Coating the plate with antibiotic cement is a simple technique which may play a role in the management of early infection after fracture fixation.

Outcomes of cement beads and cement spacers in the treatment of bone defects associated with post-traumatic osteomyelitis.

BACKGROUND: Cement spacers (Masquelet technique) have traditionally been used for the treatment of segmental bone defects. However, no reports have used cement spacers for the treatment of small/partial segmental bone defects associated with osteomyelitis and compared the outcomes with cement beads. METHODS: We retrospectively analysed 40 patients with post-traumatic osteomyelitis of the tibia who underwent treatment, which was performed in two stages. In the first stage, thorough debridement was performed, and bone defects were filled with either antibiotic-impregnated cement beads (bead group, 18 patients) or spacers (spacer group, 22 patients). In the second stage, the cement beads or spacers were removed (for the spacer group, the induced membrane formed by the spacer was preserved) and the bone defects were filled with cancellous autografts. RESULTS: All patients in the bead group had small/partial segmental bone defects after debridement, while 3 patients in the spacer group had large/segmental bone defects. The mean volume of bone defects of the spacer group (40.4 cm3) was significantly larger than that of the bead group (32.4 cm3). The infection control rate (88.9%,16/18 vs 90.9%, 20/22), bone healing time (8.5 months vs 7.5 months) and complication rates (22.2%, 4/18 vs 27.2%, 6/22) were comparable between bead group and spacer group. CONCLUSION: The results of this study suggest that cement spacers may have an infection control rate comparable to cement beads in the treatment of bone defects associated with post-traumatic osteomyelitis. Furthermore, cement spacers could be used for the reconstruction of small/partial segmental bone defects as well as for large/segmental bone defects, whereas cement beads were not suitable for the reconstruction of large/segmental bone defects.

Comparison of the direct and indirect reduction techniques during the surgical management of posterior malleolar fractures.

BACKGROUND: The optimal method for the reduction and fixation of posterior malleolar fracture (PMF) remains inconclusive. Currently, both of the indirect and direct reduction techniques are widely used. We aimed to compare the reduction quality and clinical outcome of posterior malleolar fracture managed with the direct reduction technique through posterolateral approach or the indirect reduction technique using ligamentotaxis. METHODS: Patients with a PMF involving over 25% of the articular surface were recruited and assigned to the direct reduction (DR) group or the indirect reduction (IR) group. Following reduction and fixation of the fracture, the quality of fracture reduction was evaluated in post-operative CT images. Clinical and radiological follow-ups were performed at 6 weeks, 3 months, 6 months, 12 months, and then at 6 month-intervals postoperatively. Functional outcome (AOFAS score), ankle range of motion, and Visual Analog Scale (VAS) were evaluated at the last follow-up. Statistical differences were compared between the DR and IR groups considering the patient demographics, quality of fracture reduction, AOFAS score, and VAS. RESULTS: Totally 116 patients were included, wherein 64 cases were assigned to the DR group and 52 cases were assigned to the IR group. The quality of fracture reduction was significant higher in the DR group (P = 0.038). In the patients who completed a minimum of 12 months' follow-up, a median AOFAS score of 87 was recorded in the DR group, which was significantly higher than that recorded in the IR group (a median score of 80). The ankle range of motion was slightly better in the DR group, with the mean dorsiflexion restriction recorded to be 5.2° and 6.1° in the DR and IR group respectively (P = 0.331). Similar VAS score was observed in the two groups (P = 0.419). CONCLUSIONS: The direct reduction technique through a posterolateral approach provide better quality of fracture reduction and functional outcome in the management of PMF over 25% of articular surface, as compared with the indirect reduction technique using ligamentotaxis. TRIAL REGISTRATION: NCT02801474 (retrospectively registered, June 2016, ClinicalTrails.gov).

The LXR ligand GW3965 inhibits Newcastle disease virus infection by affecting cholesterol homeostasis.

Newcastle disease (ND) is a contagious disease that affects most species of birds. Its causative pathogen, Newcastle disease virus (NDV), also exhibits considerable oncolytic activity against mammalian cancers. A better understanding of the pathogenesis of NDV will help us design efficient vaccines and novel anticancer strategies. GW3965, a widely used synthetic ligand of liver X receptor (LXR), induces the expression of LXRs and its downstream genes, including ATP-binding cassette transporter A1 (ABCA1). ABCA1 regulates cellular cholesterol homeostasis. Here, we found that GW3965 inhibited NDV infection in DF-1 cells. It also inhibited NF-κB activation and reduced the upregulation of proinflammatory cytokines induced by the infection. Further studies showed that GW3965 exerted its inhibitory effects on virus entry and replication. NDV infection increased the mRNA levels of several lipogenic genes but decreased the ABCA1 mRNA level. Overexpression of ABCA1 inhibited NDV infection and reduced the cholesterol content in DF-1 cells, but when the cholesterol was replenished, NDV infection was restored. GW3965 treatment prevented cholesterol accumulation in the perinuclear area of the infected cells. In summary, our studies suggest that GW3965 inhibits NDV infection, probably by affecting cholesterol homeostasis.

Anatomical Study of the Clavicles in a Chinese Population.

BACKGROUND: A reemergence of interest in clavicle anatomy was prompted because of the advocacy for operative treatment of midshaft clavicle fractures. Several anatomical studies of the clavicle have been performed in western population. However, there was no anatomical study of clavicle in Chinese population. PATIENTS AND METHODS: 52 patients were included in the present study. Three-dimensional reconstructions of the clavicles were generated. The length of the clavicle, the widths and thicknesses of the clavicle, curvatures of the clavicle, the areas of the intramedullary canal, and sectional areas of the clavicle were measured. All the measurements were compared between genders and two sides. RESULTS: The mean length of the clavicles was 144.2 ± 12.0 mm. Clavicles in males were longer, wider, and thicker than in females; also males have different curvatures in both planes compared with females. The men's intramedullary canals and sectional areas of the clavicle were larger than those of women. No significant difference between the sides was found for all the measurements. CONCLUSION: This study provided an anatomical data of the clavicle in a Chinese population. These clavicle dimensions can be applied to the modifications of the contemporary clavicle plate or a new development for the Chinese population.

Antibiotic-impregnated cement spacer as definitive management for osteomyelitis.

BACKGROUND: Osteomyelitis is a challenge for orthopaedic surgeons. There is a lack of scientific evidence to guide treatment. The purpose of this study was to report the clinical outcome of unplanned retention of antibiotic-impregnated cement spacer (ACS) in the management of osteomyelitis. METHODS: Eight patients (7 with tibial infections and 1 with a calcaneal infection) with osteomyelitis received radical debridement and insertion of an ACS into the bone defect as the definitive management. The mean follow-up period was 2 years (6 months to 4 years). All of these patients had a cement spacer in place. RESULTS: No patient exhibited radiographic evidence of excessive bone loss. The patients reported no or occasional mild pain and exhibited complete weight-bearing abilities, with the exception of one patient who required a crutch because of a spinal cord injury. Signs of recurrence of the osteomyelitis were not noted in any of the patients, and no fractures occurred at last follow-up. CONCLUSION: Our study suggests that a proportion of patients with unplanned retention of ACS appear to function well without necessarily requiring further surgical intervention.

Lack of association between the CHL1 gene and adolescent idiopathic scoliosis susceptibility in Han Chinese: a case-control study.

BACKGROUND: A previous genome-wide association study (GWAS) suggested a strong association between the single nucleotide polymorphism (SNP) rs10510181 in the proximity of the gene encoding a cell adhesion molecule with homology to L1CAM (CHL1) and adolescent idiopathic scoliosis (AIS) in Caucasians. To clarify the role of CHL1 in the etiopathogenesis of AIS, we performed a case-control replication study in a Han Chinese population. METHODS: Five hundred female AIS patients between 10 and 18 years of age, as well as 500 age- and sex-matched controls were included. This study was conducted as a 2-stage case-control analysis: initial screening for the association between AIS and SNPs in and around the CHL1 gene (186 cases and 169 controls) followed by a confirmation test (314 cases and 331 controls). rs10510181 and 4 SNPs (rs2055314, rs331894, rs2272522, and rs2272524) in the CHL1 gene were selected for genotyping. RESULTS: Putative associations were shown between AIS and rs10510181, rs2055314, and rs2272522 in stage I. However, the associations were not confirmed in stage II. For rs10510181, the genotype frequencies were GG 28.8%, GA 46.2%, and AA 25.0% in AIS patients and GG 29.8%, GA 48.8%, and AA 21.4% in controls. No significant difference was found in genotype distribution between cases and controls (P = 0.39). Similarly, the genotype and allele distribution were comparable between case and control for rs2055314 and rs2272522. CONCLUSIONS: There was no statistical association between polymorphisms of the CHL1 gene and idiopathic scoliosis in a Chinese population.

Characteristics of the pelvic axial rotation in adolescent idiopathic scoliosis: a comparison between major thoracic curve and major thoracolumbar/lumbar curve.

BACKGROUND CONTEXT: As the biomechanical foundation of the spine, the pelvis was found to display rotation in the transverse plane in adolescent idiopathic scoliosis (AIS). However, the possible factors influencing the pelvic axial rotation (PAR) and its mechanism in patients with AIS remain unclear. PURPOSE: To characterize the PAR in AIS patients with right major thoracic (MT) or major left thoracolumbar/lumbar (TL/L) curve and to explore the associated influencing factors and probable mechanism of compensation by analyzing the association between PAR and other spinal radiographic parameters. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: All patients with the primary diagnosis of AIS from January 2008 to November 2009 were retrieved from our scoliosis database. OUTCOME MEASURES: Age, Cobb angle, and apex rotation of the main curve and the compensatory curve, curve flexibility, and PAR. METHODS: One-hundred thirty-two patients with right MT (14.7±1.8 years, 48±6.9°) and 83 patients with left major TL/L (14.7±1.5 years, 46±6.6°) were retrospectively reviewed. On standing full-spine posteroanterior radiographs, the PAR was quantified by the left/right hemi-pelvis width ratio (L/R ratio); then the subjects in both MT and major TL/L groups were divided into two subgroups: L/R ratio ≤1 (pelvis rotated to the right, R-PAR group); and L/R ratio >1 (pelvis rotated to the left, L-PAR group). Comparisons of all variables were performed between the L- and R-PAR subgroups; correlation and regression analysis were carried out to identify the influencing factors of PAR. RESULTS: The majority of the MT and major TL/L patients (75.8% vs. 60.2%) displayed right pelvic rotation, which was in the same direction as the thoracic curve. The incidence of R-PAR was greater in the MT patients than the major TL/L ones (p=.016). Lumbar flexibility in MT patients with R-PAR was greater than in MT patients with L-PAR (0.96±0.27 vs. 0.81±0.33, p=.038), which was contrary to the findings in the major TL/L patients (L-PAR>R-PAR, 0.79±0.15 vs. 0.70±0.22, p=.024). In the MT patients with R-PAR, the L/R ratio showed significant positive correlations with the lumbar Cobb angle (r=0.424) as well as with the apex rotation (r=0.488), which was further identified as an influencing factor (R=0.418) of the PAR. Significant positive correlations between L/R ratio and thoracic apex rotation (r=0.361) also were detected. CONCLUSION: The majority of AIS patients with right MT or left major TL/L curves were found to have PAR to the right, in the same direction as the thoracic curve. The lumbar flexibility and apex rotation significantly influenced the PAR direction and magnitude. Moreover, the pelvis might be involved in compensation for the MT deformity through its connection with the lumbar spine.