Update on the reliability of gait analysis interpretation in cerebral palsy: Inter-institution agreement.

BACKGROUND: Studies have shown good reliability for gait analysis interpretation among surgeons from the same institution. However, reliability among surgeons from different institutions remains to be determined. RESEARCH QUESTION: Is gait analysis interpretation by surgeons from different institutions as reliable as it is for surgeons from the same institution? METHODS: Gait analysis data for 67 patients with cerebral palsy (CP) were reviewed prospectively by two orthopedic surgeons from different institutions in the same state, each with > 10 years' experience interpreting gait analysis data. The surgeons identified gait problems and made treatment recommendations for each patient using a rating form. Percent agreement between raters was calculated for each problem and treatment, and compared to expected agreement based on chance using Cohen's kappa. RESULTS: For problem identification, the greatest agreement was seen for equinus (85% agreement), calcaneus (88%), in-toeing (89%), and out-toeing (90%). Agreement for the remaining problems ranged between 66-78%. Percent agreement was significantly higher than expected due to chance for all issues (p ≤ 0.01) with modest kappa values ranging from 0.12 to 0.51. Agreement between surgeons for treatment recommendations was highest for triceps surae lengthening (89% agreement), tibial derotation osteotomy (90%), and foot osteotomy (87%). Agreement for the remaining treatments ranged between 72-78%. Percent agreement for all treatments was significantly higher than the expected values (p ≤ 0.002) with modest kappa values ranging from 0.22 to 0.52. SIGNIFICANCE: Previous research established that computerized gait analysis data interpretation is reliable for surgeons within a single institution. The current study demonstrates that gait analysis interpretation can also be reliable among surgeons from different institutions. Future research should examine reliability among physicians from more institutions to confirm these results.

Dedicated Early Morning Orthopaedic Trauma Operating Room Is Associated With Shorter Time to Surgery and Decreased Length of Hospital Stay for Children Undergoing Surgical Treatment of Supracondylar Humerus Fractures: A Retrospective Cohort Study.

INTRODUCTION: The purpose of this study was to investigate whether the use of a dedicated early morning orthopaedic trauma operating room (OR) resulted in shorter wait times, decreased surgical times, decreased length of stay (LOS), and decreased complications in children treated with urgent surgical intervention for supracondylar humerus fractures. METHODS: This retrospective comparative cohort study at a level I pediatric trauma center included patients younger than 12 years with supracondylar humerus fractures urgently treated with closed or open reduction and percutaneous pinning. Index surgical cases from April 28, 2013, to February 26, 2020, were included. Patients with prior humerus fracture, concomitant injuries, open fracture, pulseless supracondylar fracture, or missing data were excluded. Patients were analyzed based on the type of OR: dedicated early morning orthopaedic trauma OR or typical daytime orthopaedic OR. The primary outcome was time from presentation to surgery. Secondary outcomes included surgical time, complications, and LOS. RESULTS: A total of 401 patients with a mean age of 5 ± 2 (range: 1 to 11) years and a mean follow-up of 2.0 ± 2.1 (range: 0.5 to 25.0) months were included, of whom 137 patients (34%) underwent surgery in the early morning dedicated orthopaedic trauma OR. The dedicated early morning orthopaedic OR group had significantly less time from presentation to surgery (7.5 versus 9.4 hours; P = 0.0002) and shorter LOS (21.0 versus 24.0 hours; P = 0.004) compared with children treated in the typical daytime orthopaedic OR. Surgical time (31.1 versus 32.6 minutes; P = 0.40) and complication rates (5.8% versus 4.9%; P = 0.65) were similar between the groups. No revision surgery was required in either group. DISCUSSION: Surgical wait times were diminished with use of the dedicated early morning OR, as was LOS. Surgical times and complication rates were similar between groups. Institutions may consider adopting a dedicated early morning orthopaedic trauma OR to improve surgical wait times and decrease LOS. LEVEL OF EVIDENCE: III.

The Efficacy of Platinum Chemotherapy in a Japanese Malignant Melanoma Patient With a BRCA2 Mutation Identified by Gene Panel Testing.

A BRCA2 mutation increases the chance of developing cancer and has been linked to several diseases, including hereditary breast, ovarian, pancreatic, and prostate cancers. We present a case of advanced malignant melanoma treated with platinum-containing chemotherapy and demonstrate a momentarily favorable clinical outcome as determined by a Next Generation Sequencer (NGS) gene panel testing. A 54-year-old female with BRAF wild-type of anal primary melanoma received adjuvant immunotherapy with nivolumab following surgical resection. Novel distant lung metastasis was identified four months after the adjuvant therapy. Multi-gene panel testing figured out another potential treatment strategy using a sample from a distant metastatic tumor and identified a BRCA2 mutation in the tumor. Based on the sensitivity to platinum agents in BRCA2 mutation-positive tumors, DAC-Tam therapy (Dacarbazine, Nimustine, Cisplatin, and Tamoxifen) was administrated and showed tumor size reduction. After five rounds of DAC-Tam treatment, the metastatic lesion decreased from 17 mm to 5 mm. The parent was treated with platinum and Dacarbazine alone because of deteriorated renal function and grade 3 myelosuppression. In addition, the tumor showed resistance to the platinum plus Dacarbazine chemotherapy. Her chemotherapy-induced renal failure and bone marrow suppression did not improve well. Additionally, she felt significant weakness due to poor dietary intake and did not want to receive additional chemotherapy. To relieve her symptoms, she and her family desired the best supporting care and moved her to another hospital. The patient died 12 months after submitting the gene panel.

Predictors of Changes in Pelvic Rotation after Surgery with or without Femoral Derotational Osteotomy in Ambulatory Children with Cerebral Palsy.

Asymmetry of pelvic rotation affects function. However, predicting the post-operative changes in pelvic rotation is difficult as the root causes are complex and likely multifactorial. This retrospective study explored potential predictors of the changes in pelvic rotation after surgery with or without femoral derotational osteotomy (FDRO) in ambulatory children with cerebral palsy (CP). The change in the mean pelvic rotation angle during the gait cycle, pre- to post-operatively, was examined based on the type of surgery (with or without FDRO) and CP distribution (unilateral or bilateral involvement). In unilaterally involved patients, pelvic rotation changed towards normal with FDRO (p = 0.04), whereas patients who did not undergo FDRO showed a significant worsening of pelvic asymmetry (p = 0.02). In bilaterally involved patients, the changes in pelvic rotation did not differ based on FDRO (p = 0.84). Pelvic rotation corrected more with a greater pre-operative asymmetry (ß = -0.21, SE = 0.10, p = 0.03). Sex, age at surgery, GMFCS level, and follow-up time did not impact the change in pelvic rotation. For children with hemiplegia, internal hip rotation might cause compensatory deviation in pelvic rotation, which could be improved with surgical correction of the hip. The predicted changes in pelvic rotation should be considered when planning surgery for children with CP.

[A Case of Angioimmunoblastic T-cell Lymphoma (AITL)].

A 84-year-old female noticed erythema over her whole body for several months and was referred to our department for evaluation of her skin eruption. A physical examination revealed millet-sized erythematous papules and macules all over her body, a high body temperature, and a decreased level of consciousness. A laboratory examination showed an elevated white blood cell count (8200/µl), atypical lymphocytes (3%) and sIL-2R (4030U / ml). Computed Tomography showed systemic lymphadenopathy. A lymph node biopsy taken from the left inguinal lymph node revealed destruction of the lymph nodes, enlargement of the high endothelial venules, and atypical lymphocyte infiltration. Based on the clinical findings and laboratory examination, we diagnosed angioimmunoblastic Tcell lymphoma (AITL). AITL is a relatively rare peripheral T-cell lymphoma with severe systemic symptoms such as fever and lymph node swelling. While approximately half of all cases experience skin symptoms, which are one of the initial symptoms, it is difficult to determine the diagnosis due to the various clinical features or many non-specific rashes. We should keep in mind a differential diagnosis of lymphoma in cases of the presence of persistent eruption, systemic symptoms, and the existence of atypical lymphocytes in peripheral blood.

STING expression is an independent prognostic factor in patients with mycosis fungoides.

Mycosis fungoides is recognized as an indolent cutaneous malignant T-cell lymphoma. In contrast, there are few therapeutic options for advanced forms of mycosis fungoides. Since immunotherapy is desirable as an alternative therapeutic option, identifying candidate molecules is an important goal for clinicians. Although tumor-derived negative immunomodulatory molecules, such as PD-1/PD-L1, have been identified in various malignancies, the useful positive immunological drivers of mycosis fungoides are largely unknown. We found that the stimulator of interferon (IFN) genes (STING) was highly upregulated in early-stage mycosis fungoides. Immunohistochemical examination revealed different STING staining patterns in patients with mycosis fungoides. Although there were no significant differences in clinical factors' characteristics, STING expression was associated with the survival of patients with mycosis fungoides. The survival rate was significantly poor in patients with low STING-expressing mycosis fungoides. Univariate and multivariate analyses revealed that low STING expression was associated with an increased hazard ratio. Our results indicate that STING expression independently influences the prognosis of mycosis fungoides.

Predicting the location of the hip joint centres, impact of age group and sex.

Clinical gait analysis incorporating three-dimensional motion analysis plays a key role in planning surgical treatments in people with gait disability. The position of the Hip Joint Centre (HJC) within the pelvis is thus critical to ensure accurate data interpretation. The position of the HJC is determined from regression equations based on anthropometric measurements derived from relatively small datasets. Current equations do not take sex or age into account, even though pelvis shape is known to differ between sex, and gait analysis is performed in populations with wide range of age. Three dimensional images of 157 deceased individuals (37 children, 120 skeletally matured) were collected with computed tomography. The location of the HJC within the pelvis was determined and regression equations to locate the HJC were developed using various anthropometrics predictors. We determined if accuracy improved when age and sex were introduced as variables. Statistical analysis did not support differentiating the equations according to sex. We found that age only modestly improved accuracy. We propose a range of new regression equations, derived from the largest dataset collected for this purpose to date.

Quantification of pelvic soft tissue artifact in multiple static positions.

Soft tissue artifact (STA) has been identified as the most critical source of error in clinical gait analysis. Multiple calibration is a technique to reduce the impact of STA on kinematic data, which involves several static calibrations through the range of motion of the joint of interest. This study investigated how skin markers at the pelvis were displaced in relation to anatomical body landmarks in multiple static calibration positions. The magnitude and direction of the pelvic marker displacement was assessed in nine different body positions including 90° and 45° hip flexion, maximum hip extension, and pelvic tilt in 20 healthy young adults. ASIS markers were found to be more susceptible to relative displacement than PSIS markers, with displacement particularly evident in positions where the hip was flexed (up to 17 mm). A strong correlation was found between the hip flexion angle and marker displacement (r(2) = 0.70). While the estimated impact of pelvic STA on gait kinematics was relatively small, the findings suggest that activities with large hip flexion would cause larger STA with a greater impact on pelvic kinematics. The skin surface located over the ASIS differed by a mean of 17 mm between standing and supine positions, which could affect the inter-ASIS distance and the location of hip joint center (HJC) by up to 20mm and 10mm, respectively.

Outcomes of lower extremity orthopedic surgery in ambulatory children with cerebral palsy with and without gait analysis: results of a randomized controlled trial.

This study examined the impact of gait analysis on surgical outcomes in ambulatory children with cerebral palsy (CP) through a randomized controlled trial. 156 children with CP (94 male; age 10.2 ± 3.7 years) underwent gait analysis and were randomized to two groups: Gait Report group (N = 83), where the referring surgeon received the patient's gait analysis report, and Control group (N = 73), where the surgeon did not receive the gait report. Outcomes were assessed pre- and 1.3 ± 0.5 years post-operatively. An intent-to-treat analysis compared outcomes between the two groups. Outcome measures included the Gillette Functional Activity Questionnaire (FAQ), Gait Deviation Index (GDI), oxygen cost, gross motor function measure, Child Health Questionnaire (CHQ), Pediatric Outcomes Data Collection Instrument (PODCI), and Pediatric Evaluation and Disability Inventory. The outcomes that differed significantly between groups were change in health from the CHQ, which was rated as much better for 56% (46/82) of children in the Gait Report group compared with 38% (28/73) in the Control group (p = 0.04), and upper extremity physical function from the PODCI. Gait outcomes (FAQ and GDI) improved more when over half of the recommendations for a patient were followed or the recommended extent of surgery (none, single, or multi-level) was done (p ≤ 0.04). On average, however, only 42% of the recommendations were followed in the Gait Report group, compared with 35% in the Control group (p = 0.23). This is much less than the >85% reported in previous studies and may account for the lack of differences between groups for some of the outcome measures.

Influence of gait analysis on decision-making for lower extremity orthopaedic surgery: Baseline data from a randomized controlled trial.

Previous studies examining the influence of gait analysis on surgical decision-making have been limited by the lack of a control group. The aim of this study was to use data from a randomized controlled trial to determine the effects of gait analysis on surgical decision-making in children with cerebral palsy (CP). 178 ambulatory children with CP (110 male; age 10.3±3.8 years) being considered for lower extremity orthopaedic surgery underwent gait analysis and were randomized into one of two groups: gait report group (N=90), where the orthopaedic surgeon received the gait analysis report, and control group (N=88), where the surgeon did not receive the gait report. Data regarding specific surgeries were recorded by the treating surgeon before gait analysis, by the gait laboratory surgeon after gait analysis, and after surgery. Agreement between the treatment done and the gait analysis recommendations was compared between groups using the 2-sided Fisher's Exact test. When a procedure was planned initially and also recommended by gait analysis, it was performed more often in the gait report group (91% vs. 70%, p<0.001). When the gait laboratory recommended against a planned procedure, the plan was changed more frequently in the gait report group (48% vs. 27%, p=0.009). When the gait laboratory recommended adding a procedure, it was added more frequently in the gait report group (12% vs. 7%, p=0.037). These results provide a stronger level of evidence demonstrating that gait analysis changes treatment decision-making and also reinforces decision-making when it agrees with the surgeon's original plan.

Infero-eyebrow blepharoplasty for the upper eyelids of elderly patients.

AIMS: To describe a procedure for removing excess wrinkles from the upper lids of elderly patients. METHODS: Excess wrinkles were resected with a razor blade and scissors or CO(2) laser along the lower eyebrow margin. Ninety-five patients (average age 74 ± 8.1 years) (157 eyes) underwent this procedure and were followed for at least 6 months postoperatively. RESULTS: The average size of the excised skin was 40 ± 9.7 × 12 ± 3.9 mm. Complications included under-resection, which required another resection in six eyes (4%) and a subcutaneous haemorrhage in two eyes (1%). All patients expressed satisfaction with the final cosmetic results. The incision faded almost completely by 6 months postoperatively without camouflage. CONCLUSION: The design and technique were extremely uncomplicated. The main drawbacks were the long incision line under the eyebrow, a slightly slimmer eyebrow and postoperative brow drop. However, all incision lines faded almost completely by 6 months postoperatively, and brow drop was not problematic in bilateral surgeries. This procedure does not replace the current popular procedure for lid crease formation. However, general ophthalmologists can perform the current simple procedure to remove excess wrinkles from the upper lids of elderly patients.

Effect of high-frequency, low-magnitude vibration on bone and muscle in children with cerebral palsy.

BACKGROUND: Children with cerebral palsy (CP) have decreased strength, low bone mass, and an increased propensity to fracture. High-frequency, low-magnitude vibration might provide a noninvasive, nonpharmacologic, home-based treatment for these musculoskeletal deficits. The purpose of this study was to examine the effects of this intervention on bone and muscle in children with CP. METHODS: Thirty-one children with CP ages 6 to 12 years (mean 9.4, SD 1.4) stood on a vibrating platform (30 Hz, 0.3 g peak acceleration) at home for 10 min/d for 6 months and on the floor without the platform for another 6 months. The order of vibration and standing was randomized, and outcomes were measured at 0, 6, and 12 months. The outcome measures included computed tomography measurements of vertebral cancellous bone density (CBD) and cross-sectional area, CBD of the proximal tibia, geometric properties of the tibial diaphysis, and dynamometer measurements of plantarflexor strength. They were assessed using mixed model linear regression and Pearson correlation. RESULTS: The main difference between vibration and standing was that there was a greater increase in the cortical bone properties (cortical bone area and moments of inertia) during the vibration period (all P's ≤ 0.03). There was no difference in cancellous bone or muscle between vibration and standing (all P's > 0.10) and no correlation between compliance and outcome (all r's < 0.27; all P's > 0.15). The results did not depend on the order of treatment (P > 0.43) and were similar for children in gross motor function classification system (GMFCS) 1 to 2 and GMFCS 3 to 4. CONCLUSIONS: The primary benefit of the vibration intervention in children with CP was to the cortical bone in the appendicular skeleton. Increased cortical bone area and the structural (strength) properties could translate into a decreased risk of long bone fractures in some patients. More research is needed to corroborate these findings, to elucidate the mechanisms of the intervention, and to determine the most effective age and duration of the treatment. LEVEL OF EVIDENCE: Level II, prospective randomized cross-over study.

Achilles tendon length and medial gastrocnemius architecture in children with cerebral palsy and equinus gait.

BACKGROUND: The aim of this study was to examine both the tendon and muscle components of the medial gastrocnemius muscle-tendon unit in children with cerebral palsy (CP) and equinus gait, with or without contracture. We also examined a small number of children who had undergone prior surgical lengthening of the triceps surae to address equinus contracture. METHODS: Ultrasound was used to measure Achilles tendon length and muscle-tendon architectural parameters in children of ages 5 to 12 years. Muscle and tendon parameters were compared among 4 groups: Control group (N=40 limbs from 21 typically developing children), Static Equinus group (N=23 limbs from 15 children with CP and equinus contracture), Dynamic Equinus group (N=12 limbs from 7 children with CP and equinus gait without contracture), and Prior Surgery group (N=10 limbs from 6 children with CP who had prior gastrocnemius recession or tendo-achilles lengthening). The groups were compared using analysis of variance and Scheffe post hoc tests. RESULTS: The CP groups had longer Achilles tendons and shorter muscle bellies than the Control group (P<0.001). Normalized tendon length was also longer in the Prior Surgery group compared with the Static Equinus group (P<0.001). The Prior Surgery group had larger pennation angles than the CP groups (P< or =0.009) and tended to have shorter muscle fascicle lengths (P< or =0.005 compared with Control and Static Equinus, P=0.08 compared with Dynamic Equinus). Similar results were observed for pennation angles and normalized muscle fascicle lengths throughout the range of motion. CONCLUSIONS: Children with spastic CP and equinus gait have longer-than-normal Achilles tendons and shorter-than-normal muscle bellies. These characteristics are observed even in children with dynamic equinus, before contracture has developed. Surgery further lengthens the tendon, restoring dorsiflexion but not normal muscle-tendon architecture. These architectural features likely affect function, possibly contributing to functional deficits such as plantarflexor weakness after surgery. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Effects of preoperative gait analysis on costs and amount of surgery.

BACKGROUND: The purpose of this study was to determine the effects of clinical gait analysis (GA) on the costs of care in ambulatory children with cerebral palsy (CP) and the amount of surgery these children undergo. METHODS: A retrospective review identified all ambulatory patients with CP who had undergone lower extremity orthopaedic surgery at our hospital from 1991 to 2005 with at least a 6-month follow-up. The patients were grouped into those who had undergone GA before their index surgery (GA group, N=313) and those who had not (NGA group, N=149). The groups were compared in terms of the number of procedures during index surgery and subsequent surgeries and the direct costs associated with these surgeries. Costs were calculated in US dollars by using a standardized protocol including fees for the surgeon, anesthesia, operating room, hospital stay, physical therapy, and GA. RESULTS: Patients in the GA group were significantly older and less functionally involved, had their first surgery in later years, and had a shorter follow-up than patients in the NGA group (P<0.001). Adjusting for these differences, patients in the GA group had more procedures (GA: 5.8, NGA: 4.2; P<0.001) and higher cost (GA: $43,006, NGA: $35,215; P<0.001) during index surgery, but less subsequent surgery. A higher proportion of patients went on to additional surgery in the NGA group (NGA: 32%, GA: 11%; P<0.001), with more additional surgeries per person-year (NGA: 0.3/person-year, GA: 0.1/person-year; P<0.001) resulting in higher additional costs (NGA: $3009/person-year, GA: $916/person-year; P<0.001). The total number of procedures (GA: 2.6/person-year, NGA: 2.3/person-year; P=0.22) and cost (GA: $20,448/person-year, NGA: $19,535/person-year; P=0.58) did not differ significantly between the 2 groups. CONCLUSIONS: Clinical GA is associated with a lower incidence of additional surgery, resulting in lesser disruption to patients' lives. This finding has not been shown before and may assist patients, physicians, policy makers, and insurance companies in assessing the role of GA in the care of ambulatory children with CP. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Concurrent and discriminant validity of Spanish language instruments for measuring functional health status.

BACKGROUND: Questionnaires translated into languages other than English are often not validated to the same extent as the English versions. This study examined the concurrent and discriminant validity of selected domains related to physical function from Spanish language versions of the Child Health Questionnaire (CHQ), Pediatric Outcomes Data Collection Instrument (PODCI), and Pediatric Evaluation and Disability Inventory (PEDI). METHODS: Concurrent validity was examined in 93 children with cerebral palsy by correlating questionnaire domain scores with Gross Motor Function Measure and Gillette Functional Assessment Questionnaire walking scale scores. Discriminant validity with respect to Gross Motor Function Classification System (GMFCS) level was examined using analysis of variance and nonparametric discriminant analysis. RESULTS: Concurrent validity was demonstrated for 3 domains from the PEDI (Mobility functional skills, tau = 0.62; Mobility caregiver assistance, tau = 0.46-0.55; and Self-care functional skills, tau = 0.30-0.36), 3 domains from the PODCI (Sports and physical function, tau = 0.48-0.51; Transfer and basic mobility, tau = 0.48-0.51; and Upper extremity physical function, tau = 0.28), and 1 domain from the CHQ (Physical function, tau = 0.31-0.36). Discriminant validity was demonstrated for the same domains based on significant decreases in domain scores with increasing GMFCS level. Discriminant validity was highest for the PODCI, which correctly classified 98% (91/93) of subjects into the correct GMFCS level when all 3 domains were considered. CONCLUSIONS: For the first time, concurrent validity and discriminant validity have been demonstrated for the physical function domains of Spanish language versions of the PODCI, PEDI, and CHQ questionnaires. PODCI and PEDI had the highest concurrent validity, and PODCI had the best discriminant ability. CLINICAL RELEVANCE: It is important to examine the validity of instruments when they have been translated from English into other languages. This importance will only increase as the population of non-English-speaking patients expands.

Use of a patella marker to improve tracking of dynamic hip rotation range of motion.

Hip rotation during gait has traditionally been measured using thigh wand markers. Hip rotation data calculated using thigh wands shows large variability between different laboratories and underestimates the rotation movement. This study investigated effectiveness of a patella marker in tracking hip rotation range of motion in comparison with traditional thigh wands. In controlled trials of isolated hip internal-external rotation, the patella marker detected 98+/-8% of the actual range of motion, compared with 53+/-10% for a distal thigh wand and 43+/-13% for a proximal thigh wand. The patella marker produced the smoothest hip rotation curves and the smallest hip rotation range in walking, and results from the patella marker did not depend on walking speed. These results suggest that the patella marker is less vulnerable to wobbling, inertial effects, and soft tissue movement than traditional thigh wands. The use of patella markers with knee alignment devices may therefore allow for more accurate measurement of hip rotations during clinical gait analysis than is currently possible using traditional thigh wands.

Elastic motion of RecA filaments and its role in recombination.

RecA filaments form two types of structures having different helical pitches according to the nucleotide condition. We have investigated the effect of nucleotide cofactor exchange upon the RecA-ssDNA filaments by observing a fluorescently-labelled single molecule in water solution. The result indicated that the RecA-ssDNA filamentous complex is an elastic helical molecule whose length is controlled by binding and release of nucleotide cofactors. We propose that this elastic motion couples to the DNA rotation within the filament by synchronizing the helical phases, and promotes exchange of homologous strands of two DNAs.

Gillette Gait Index as a gait analysis summary measure: comparison with qualitative visual assessments of overall gait.

BACKGROUND: The Gillette Gait Index (GGI) is a summary measure incorporating 16 clinically important kinematic and temporal parameters. The purpose of this study was to compare GGI scores from computerized gait analysis versus qualitative visual assessments of overall gait to assess the validity of the GGI as a summary score for gait analysis. METHODS: The GGI was calculated for 25 children with cerebral palsy who underwent computerized gait analysis before and 1 year after lower extremity surgery to correct gait problems. Twelve observers reviewed video recordings from the gait analysis to assess the severity of each patient's gait impairment preoperatively and postoperatively and the amount of preoperative to postoperative change. Variability of the video ratings was assessed, and GGI scores were compared with the mean video ratings. RESULTS: The individual ratings showed some variability, with moderate intrarater agreement (weighted kappa = 0.49-0.56) and slight to fair interrater agreement (kappa = 0.11-0.25). However, the mean scores from all raters were much more consistent, as demonstrated by a highly significant relationship in preoperative to postoperative change viewing the videos separately versus together (r2 = 0.62; P = 0.0001). GGI scores were correlated with these mean scores preoperatively (r2 = 0.34; P = 0.003), postoperatively (r2 = 0.30; P= 0.005), and in preoperative to postoperative change (r2 = 0.30, P = 0.006 for absolute change; r2 = 0.22, P = 0.02 for percentage change). CONCLUSIONS: These results support the validity of GGI as a gait analysis summary score and suggest that GGI may be a useful outcome measure in patients undergoing gait analysis. CLINICAL RELEVANCE: Clinicians and researchers should consider using the GGI as a quantitative outcome measure for assessing overall gait.

Liquid crystal formation of RecA-DNA filamentous complexes.

Spontaneous optical birefringence of RecA-bound linear and closed circular single-stranded DNA filaments, as well as RecA self-assembled polymer, was observed in aqueous buffer solutions, which demonstrates the formation of lyotropic liquid crystalline phases.

Elastic behavior of RecA-DNA helical filaments.

Escherichia coli RecA protein forms a right-handed helical filament with DNA molecules and has an ATP-dependent activity that exchanges homologous strands between single-stranded DNA (ssDNA) and duplex DNA. We show that the RecA-ssDNA filamentous complex is an elastic helical molecule whose length is controlled by the binding and release of nucleotide cofactors. RecA-ssDNA filaments were fluorescently labelled and attached to a glass surface inside a flow chamber. When the chamber solution was replaced by a buffer solution without nucleotide cofactors, the RecA-ssDNA filament rapidly contracted approximately 0.68-fold with partial filament dissociation. The contracted filament elongated up to 1.25-fold when a buffer solution containing ATPgammaS was injected, and elongated up to 1.17-fold when a buffer solution containing ATP or dATP was injected. This contraction-elongation behavior was able to be repeated by the successive injection of dATP and non-nucleotide buffers. We propose that this elastic motion couples to the elastic motion and/or the twisting rotation of DNA strands within the filament by adjusting their helical phases.