Sex-specific sagittal and frontal plane gait mechanics in persons post-hip arthroscopy for femoroacetabular impingement syndrome

Postoperative gait mechanics in persons with femoroacetabular impingement syndrome (FAIS) remain understudied as a treatment outcome despite observed, yet inconclusive, preoperative gait abnormalities. Females with FAIS demonstrate worse preoperative patient-reported hip function and altered hip mechanics when compared with males; it is unknown whether these sex differences persist postarthroscopy. The purpose of this study was to compare sex-specific gait kinematics between persons at least 1 year postarthroscopy for FAIS and healthy comparisons. General linear models with estimating equations were used to evaluate the effect of (a) limb and sex within each group, and (b) limb and group within each sex for peak sagittal and frontal plane trunk, pelvis, and hip kinematics during stance phase of gait. Analyses were covaried by gait speed. Seventeen females and eight males an average 2.5 years postarthroscopy (1.1-7.2 year) for FAIS were compared with healthy females (n = 7) and males (n = 5). Females in the FAIS group presented with an average of 4.6° more anterior pelvic tilt, and 4.8° less hip extension compared with healthy females (P ≤ .03) and 8.6° less trunk flexion, 4.8° more anterior pelvic tilt, 3.1° more pelvic drop, and 7.5° more hip flexion than males with FAIS (P ≤ .03). Males in the FAIS group presented with 2.9° less pelvic drop, and 3.2° less hip adduction than healthy males. Preoperative gait mechanics were not collected and thus changes in mechanics could not be evaluated. This study is significant to clinicians who treat patients postarthroscopy to consider sex-specific gait impairments.     

Patients with cam-type femoroacetabular impingement demonstrate increased change in bone-to-bone distance during walking: A dual fluoroscopy study

Cam-type femoroacetabular impingement (FAI) syndrome is a painful, structural hip disorder. Herein, we investigated hip joint mechanics through in vivo, dynamic measurement of the bone-to-bone distance between the femoral head and acetabulum in patients with cam FAI syndrome and morphologically screened controls. We hypothesized that individuals with cam FAI syndrome would have larger changes in bone-to-bone distance compared to the control group, which we would interpret as altered joint mechanics as signified by greater movement of the femoral head as it articulates within the acetabulum. Seven patients with cam FAI syndrome and 11 asymptomatic individuals with typical morphology underwent dual fluoroscopy imaging during level and inclined walking (upward slope). The change in bone-to-bone distance between femoral and acetabular bone surfaces was evaluated for five anatomical regions of the acetabulum at each timepoint of gait. Linear regression analysis of the bone-to-bone distance considered two within-subject factors (activity and region) and one between-subjects factor (group). Across activities, the change in minimum bone-to-bone distance was 1.38–2.54 mm for the cam FAI group and 1.16–1.84 mm for controls. In all regions except the anterior–superior region, the change in bone-to-bone distance was larger in the cam group than the control group (p ≤ 0.024). An effect of activity was detected only in the posterior–superior region where larger changes were noted during level walking than incline walking. Statement of clinical significance: Patients with cam FAI syndrome exhibit altered hip joint mechanics during the low-demand activity of walking; these alterations could affect load transmission, and contribute to pain, tissue damage, and osteoarthritis.     

Functional testing provides unique insights into the pathomechanics of femoroacetabular impingement and an objective basis for evaluating treatment outcome

Femoroacetabular impingement (FAI) has been recognized as a significant clinical problem. While hip reshaping surgery for treating FAI has had positive clinical outcomes, there remains a need for objective functional outcomes of FAI treatment. We tested the hypothesis that during walking and stair climbing significant changes in hip kinematics would occur following hip reshaping surgery that indicate restoration of normal function post‐operatively. Hip and pelvic kinematics were collected for 17 FAI patients pre‐ and 1 year post‐operatively and compared to 17 healthy matched controls. Prior to surgery, FAI patients had significantly reduced hip internal rotation and hip sagittal plane range of motion during walking (p = 0.01, p < 0.001, respectively) and stair climbing (p = 0.01, p < 0.001, respectively) as compared with controls. Post‐operatively, these motions were restored to normal during walking (p = 0.70, p = 0.46, respectively), but remained significantly reduced in the FAI patients during stair climbing (p = 0.03, p < 0.001, respectively). These results have important implications for understanding the functional pathomechanics of FAI and providing an objective basis for evaluating treatment outcome. The stair climbing results indicate that problems still exist in the hip joint for activities requiring higher ranges of hip motion and suggest a basis for exploring future improvements for the treatment of FAI. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1461–1468, 2013     

Bone Microarchitecture and Strength in Long-Standing Type 1 Diabetes

Type 1 diabetes (T1DM) is associated with an increased fracture risk, specifically at nonvertebral sites. The influence of glycemic control and microvascular disease on skeletal health in long-standing T1DM remains largely unknown. We aimed to assess areal (aBMD) and volumetric bone mineral density (vBMD), bone microarchitecture, bone turnover, and estimated bone strength in patients with long-standing T1DM, defined as disease duration ≥25 years. We recruited 59 patients with T1DM (disease duration 37.7 ± 9.0 years; age 59.9 ± 9.9 years.; body mass index [BMI] 25.5 ± 3.7 kg/m²; 5-year median glycated hemoglobin [HbA1c] 7.1% [IQR 6.82–7.40]) and 77 nondiabetic controls. Dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT) at the ultradistal radius and tibia, and biochemical markers of bone turnover were assessed. Group comparisons were performed after adjustment for age, gender, and BMI. Patients with T1DM had lower aBMD at the hip (p < 0.001), distal radius (p = 0.01), lumbar spine (p = 0.04), and femoral neck (p = 0.05) as compared to controls. Cross-linked C-telopeptide (CTX), a marker of bone resorption, was significantly lower in T1DM (p = 0.005). At the distal radius there were no significant differences in vBMD and bone microarchitecture between both groups. In contrast, patients with T1DM had lower cortical thickness (estimate [95% confidence interval]: −0.14 [−0.24, −0.05], p < 0.01) and lower cortical vBMD (−28.66 [−54.38, −2.93], p = 0.03) at the ultradistal tibia. Bone strength and bone stiffness at the tibia, determined by homogenized finite element modeling, were significantly reduced in T1DM compared to controls. Both the altered cortical microarchitecture and decreased bone strength and stiffness were dependent on the presence of diabetic peripheral neuropathy. In addition to a reduced aBMD and decreased bone resorption, long-standing, well-controlled T1DM is associated with a cortical bone deficit at the ultradistal tibia with reduced bone strength and stiffness. Diabetic neuropathy was found to be a determinant of cortical bone structure and bone strength at the tibia, potentially contributing to the increased nonvertebral fracture risk. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

Acetabular and spino‐pelvic morphologies are different in subjects with symptomatic cam femoro‐acetabular impingement

Acetabular and spino‐pelvic (SP) morphological parameters are important determinants of hip joint dynamics. This prospective study aimed to determine whether acetabular and SP morphological differences exist between hips with and without cam morphology and between symptomatic and asymptomatic hips with cam morphology. A cohort of 67 patients/hips was studied. Hips were either asymptomatic with no cam (Controls, n = 18), symptomatic with cam (n = 26) or asymptomatic with cam (n = 23). CT‐based quantitative assessments of femoral, acetabular, pelvic, and spino‐pelvic parameters were performed. Measurements were compared between controls and those with a cam deformity, as well as between the three groups. Morphological parameters that were independent predictors of a symptomatic cam were determined using a regression analysis. Hips with cam deformity had slightly smaller subtended angles superior‐anteriorly (87° vs. 84°, p = 0.04) and greater pelvic incidence (53° vs. 48°, p = 0.003) compared to controls. Symptomatic cams had greater acetabular version (p < 0.01), greater subtended angles superiorly and superior‐posteriorly (p = 0.01), higher pelvic incidence (p = 0.02), greater alpha angles and lower femoral neck‐shaft angles compared to asymptomatic cams (p < 0.01) and controls (p < 0.01). The four predictors of symptomatic cam included antero‐superior alpha angle, femoral neck‐shaft angle, acetabular depth, and pelvic incidence. In conclusion, this study illustrates that symptomatic hips had a greater amount of supero‐posterior coverage; which would be the contact area between a radial cam and the acetabulum, when the hip is flexed to 90°. Furthermore, individuals with symptomatic cam morphology had greater PI. Acetabular‐ and SP parameters should be part of the radiological assessment of femoro‐acetabular impingement. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1840–1848, 2018.

     

A lifestyle intervention randomized controlled trial in obese women with infertility improved body composition among those who experienced childhood adversity

Previous research indicates that tailoring lifestyle interventions to participant characteristics optimizes intervention effectiveness. Our objective was to assess whether the effects of a preconception lifestyle intervention in obese infertile women depended on women's exposure to adversity in childhood. A follow-up of a preconception lifestyle intervention randomized controlled trial (the LIFEstyle study) was conducted in the Netherlands among 577 infertile women (age 18–39 years) with a body mass index (BMI) ≥29 kg/m² at time of randomization; N = 110 (19%) consented to the follow-up assessment, 6 years later. A 6-month preconception lifestyle intervention aimed weight loss through improving diet and increasing physical activity. The control group received care as usual. Outcome measures included weight, BMI, waist and hip circumference, body fat percentage, blood pressure and metabolic syndrome. The potential moderator, childhood adversity, was assessed with the Life Events Checklist-5 questionnaire. Among the 110 women in our follow-up study, n = 65 (59%) reported no childhood adverse events, n = 28 (25.5%) reported 1 type of childhood adverse events and n = 17 (15.5%) reported ≥2 types of childhood adverse events. Regression models showed significant interactions between childhood adversity and effects of lifestyle intervention at the 6-year follow-up. Among women who experienced childhood adversity, the intervention significantly reduced weight (−10.0 [95% CI −18.5 to −1.5] kg, p = 0.02), BMI (−3.2 [−6.1 to −0.2] kg/m², p = 0.04) and body fat percentage (−4.5 [95% CI −7.2 to −1.9] p < 0.01). Among women without childhood adversity, the intervention did not affect these outcomes (2.7 [−3.9 to 9.4] kg, p = 0.42), (0.9 [−1.4 to 3.3] kg/m², p = 0.42) and (1.7 [95% CI −0.3 to 3.7] p = 0.10), respectively. Having a history of childhood adversity modified the effect of a preconception lifestyle intervention on women's body composition. If replicated, it may be important to consider childhood adversity as a determinant of lifestyle intervention effectiveness.     

Three-dimensional shoulder kinematics: Upright four-dimensional computed tomography in comparison with an optical three-dimensional motion capture system

Although shoulder kinematics have been analyzed by various methods, dynamic shoulder motion is difficult to track. This study aimed to validate the shoulder kinematic analysis using upright four-dimensional computed tomography (4DCT) and to compare the results with optical three-dimensional motion capture. During active elevation, bilateral shoulders of 10 healthy volunteers were tracked using 4DCT and motion capture. The scapulothoracic and glenohumeral rotations and the scapulohumeral rhythm (SHR) at each position were calculated, and the differences between 4DCT and motion capture were compared. During 10−140° of humerothoracic elevation, the scapulothoracic joint showed upward rotation, internal rotation, and posterior tilting, and the glenohumeral joint showed elevation, external rotation, and anterior plane of elevation in both analyses. In scapulothoracic rotations, the mean differences between the two analyses were −2.6° in upward rotation, 13.9° in internal rotation, and 6.4° in posterior tilting, and became significant with humerothoracic elevation ≥110° in upward rotation, ≥50° in internal rotation, and ≥100° in posterior tilting. In glenohumeral rotations, the mean differences were 3.7° in elevation, 9.1° in internal rotation, and −8.8° in anterior plane of elevation, and became significant with humerothoracic elevation ≥110° in elevation, ≥90° in internal rotation, and ≥100° in anterior plane of elevation. The mean overall SHRs were 1.8 in 4DCT and 2.4 in motion capture, and the differences became significant with humerothoracic elevation ≥100°. The 4DCT analysis of in vivo shoulder kinematics using upright computed tomography scanner is feasible, but the values were different from those by skin-based analysis at the elevated arm positions.     

Sagittal plane walking patterns are related to MRI changes over 18‐months in people with and without mild‐moderate hip osteoarthritis

The purpose was to evaluate the association of sagittal plane gait mechanics with MRI changes in the hip joint over 18‐months. Subjects with and without radiographic hip OA (n = 57) underwent MRI at baseline and 18 months for grading of cartilage lesions, bone marrow lesions (BML), cysts, and labral tears. 3D gait analyses at baseline were used for sagittal plane hip kinematics and kinetics during the stance phase. Subjects were classified as progressors or non‐progressors based on increase in any MRI OA parameter. Multivariate ANOVA were used for differences in sagittal gait parameters between progressors and non‐progressors at baseline while adjusting for age. Logistic regression was used to estimate the probability of being classified as a progressor or non‐progressor with increasing hip flexion while adjusting for age, BMI, sex, and presence of radiographic hip OA. Of the 57, 35 were classified as non‐progressors and 22 were classified as progressors. At baseline, the progressors walked with 4.5° greater hip flexion during early stance (p = 0.021) and 3.5° lesser hip extension in late stance that was nearly significant (p = 0.059). Walking with greater hip flexion at baseline was associated with a greater risk of increase in MRI defined structural changes in the hip joint (Odds Ratio = 1.1, p = 0.038). Greater hip flexion during walking was associated with a risk of structural progression of hip OA. The results may guide future interventions to alter the walking patterns and slow structural hip OA progression.© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1472–1477, 2018.

     

Therapeutic Efficacy and Safety of Percutaneous Curved Vertebroplasty in Osteoporotic Vertebral Compression Fractures: A Systematic Review and Meta‐Analysis

This systematic review and meta-analysis is aimed to provide higher quality evidence regarding the efficacy and safety between PCVP and PVP/KP in OVCFs. We searched the Cochrane Library, PubMed, Web of Science, and Embase databases for all randomized controlled trials (RCTs) and observational studies (cohort or case–control studies) that compare PCVP to PVP/KP for OVCFs. The Cochrane Collaboration's Risk of Bias Tool and Newcastle–Ottawa Scale (NOS) were used to evaluate the quality of the RCTs and non-RCTs, respectively. Meta-analysis was performed using RevMan 5.4 software. A total of seven articles consisting of 562 patients with 593 diseased vertebral bodies were included. Statistically significant differences were found in the postoperative visual analog scale (VAS) at 1 day (MD = −0.11; 95% CI: [−0.21 to −0.01], p = 0.03), but not at 3 months (MD = −0.21; 95% CI: [−0.41–0.00], p = 0.05) or 6 months (MD = 0.03; 95% CI: [−0.13–0.20], p = 0.70). There was no statistically significant difference in postoperative Oswestry disability index (ODI) at 1 day (MD = −0.28; 95% CI: [−0.62–0.05], p = 0.10), 3 months (MD = −1.52; 95% CI: [−3.11–0.07], p = 0.06), or 6 months (MD = 0.18; 95% CI: [−0.13–0.48], p = 0.25). Additionally, there were no statistically significant differences in Cobb angle (MD = 0.30; 95% CI: [−1.69–2.30], p = 0.77) or anterior vertebral body height (SMD = −0.01; 95% CI: [−0.26–0.23], p = 0.92) after surgery. Statistically significant differences were found in surgical time (MD = −8.60; 95% CI: [−13.75 to −3.45], p = 0.001), cement infusion volume (MD = −0.82; 95% CI: [−1.50 to −0.14], P = 0.02), and dose of fluoroscopy (SMD = −1.22; 95% CI: [−1.84 to −0.60], p = 0.0001) between curved and noncurved techniques, especially compared to bilateral PVP. Moreover, cement leakage showed statistically significant difference (OR = 0.40; 95% CI: [0.27–0.60], p < 0.0001). Compared with PVP/KP, PCVP is superior for pain relief at short-term follow-up. Additionally, PCVP has the advantages of significantly lower surgical time, radiation exposure, bone cement infusion volume, and cement leakage incidence compared to bilateral PVP, while no statistically significant difference is found when compared with unilateral PVP or PKP. In terms of quality of life and radiologic outcomes, the effects of PCVP and PVP/KP are not significantly different. Overall, this meta-analysis reveals that PCVP was an effective and safe therapy for patients with OVCFs.     

The Complex Relationship Between In Vivo ACL Elongation and Knee Kinematics During Walking and Running

In vivo anterior cruciate ligament (ACL) bundle (anteromedial bundle [AMB] and posterolateral bundle [PLB]) relative elongation during walking and running remain unknown. In this study, we aimed to investigate in vivo ACL relative elongation over the full gait cycle during walking and running. Ten healthy volunteers walked and ran at a self‐selected pace on an instrumented treadmill while biplane radiographs of the knee were acquired at 100 Hz (walking) and 150 Hz (running). Tibiofemoral kinematics were determined using a validated model‐based tracking process. The boundaries of ACL insertions were identified using high‐resolution magnetic resonance imaging (MRI). The AMB and PLB centroid‐to‐centroid distances were calculated from the tracked bone motions, and these bundle lengths were normalized to their respective lengths on MRI to calculate relative elongation. Maximum AMB relative elongation during running (6.7 ± 2.1%) was significantly greater than walking (5.0 ± 1.7%, p = 0.043), whereas the maximum PLB relative elongation during running (1.1 ± 2.1%) was significantly smaller than walking (3.4 ± 2.3%, p = 0.014). During running, the maximum AMB relative elongation was significantly greater than the maximum PLB relative elongation (p < 0.001). ACL relative elongations were correlated with tibiofemoral six degree‐of‐freedom kinematics. The AMB and PLB demonstrate similar elongation patterns but different amounts of relative elongation during walking and running. The complex relationship observed between ACL relative elongation and knee kinematics indicates that ACL relative elongation is impacted by tibiofemoral kinematic parameters in addition to flexion/extension. These findings suggest that ACL strain is region‐specific during walking and running. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1920–1928, 2019     

Femoral derotation osteotomy with multi-level soft tissue procedures in children with cerebral palsy: Does it improve gait quality?

Purpose

Poor motor control and delayed thumb function and a delay in walking are the main factors which retard the natural decrease of the femoral anteversion (FA) with age. In addition, cerebral palsy (CP) patients usually have muscular imbalance around the hip as well as muscle contractures, both of which are main factors accounting for the increased FA which is commonly present in CP patients. The purpose of this retrospective study was to analyze the mid-term results of femoral derotational osteotomy (FDO) on the clinical findings, temporospatial and kinematic parameters of gait in children with CP.

Methods

We performed a retrospective review of all patients diagnosed with CP and increased FA who were treated with FDO with multi-level soft tissue surgeries at a single institution between 1992 and 2011. FA assessment was done in the prone position, and internal (IR) and external rotation (ER) of the hip was measured in the absence of pelvis rotation. Surgical procedures were performed on the basis of both clinical findings and video analysis. Clinical findings, Edinburgh Visual Gait Scores (EVGS) and results from three-dimensional gait analysis were analyzed preoperatively and last follow-up.

Results

A total of 93 patients with 175 affected extremities were included in this review. Mean age was 6.2 ± 3.1 (standard deviation) at initial surgery. The average length of the follow-up period was 6.3 ± 3.7 years. At the last follow-up, the postoperative hip IR had significantly decreased (73.9° vs. 46.2°; p < 0.0001), the hip ER had significantly improved (23.8° vs. 37°; p < 0.0001) and the popliteal angle had significantly decreased (64.2° vs. 55.8°; p < 0.0001). The total EVGS showed significant improvement after FDO (35.2 ± 6.4 vs. 22.5 ± 6.1; p < 0.001). Computed gait analysis showed significant improvement in the foot progression angle (FPA; 8.1° vs. ?16.9°; p = 0.005) and hip rotation (?13.9° vs. 5.7°; p = 0.01) at the last follow-up. Stance time was improved (60.2 vs. 65.1 %; p = 0.02) and swing time was decreased (39.9 vs. 35.2 %; p = 0.03). Double support time and cadence were both decreased (p = 0.032 and p = 0.01).

Conclusions

Our data suggest that the FDO is an appropriate treatment strategy for the correction of FA and associated in-toeing gait in children with CP. Improvements in clinical and kinematic parameters were observed in both groups after FDO with multi-level soft tissue release. The most prominent effects of FDO were on transverse plane hip rotation and FPA.

     

Hip joint kinematics and segment coordination variability according to pain and structural disease severity in hip osteoarthritis

This study aimed to evaluate hip joint kinematic variability and segment coordination variability during walking according to pain and radiographic disease severity in people with hip osteoarthritis. Fifty-five participants with hip osteoarthritis had pain severity assessed during walking using an item on the Western Ontario and McMasters Universities Osteoarthritis Index (no pain = 10; mild pain = 28; moderate pain = 17). Radiographic disease severity was graded by Kellgren and Lawrence scale (KL2 = 29; KL3 = 21; KL4 = 5). Hip kinematics variability was estimated as the curve coefficient of variation. Vector coding was used to calculate coordination variability for select joint couplings. One-way analysis of variances with planned adjusted post hoc comparisons were used to compare hip kinematics variability and coordination variability of select segment couplings (pelvis sagittal vs thigh sagittal; pelvis frontal vs thigh frontal; pelvis transverse vs thigh transverse; thigh sagittal vs shank sagittal; thigh frontal vs shank sagittal; thigh transverse vs shank sagittal) according to pain and radiographic disease severity. No main effect of pain severity was observed for sagittal or transverse plane hip kinematic variability (P ≥ .266), and although there was a main effect for frontal plane hip kinematic variability (P = .035), there were no significant differences when comparing between levels of pain severity (P > .006). There was no main effect of radiographic disease severity on hip kinematic variability in the sagittal (P = .539) or frontal (P = .307) plane. No significant differences in coordination of variability of segment couplings were observed (all P ≥ .229). Movement variability as assessed in this study did not differ according to pain severity during walking or radiographic disease severity.     

In vivo kinematic evaluation of total hip arthroplasty during stair climbing

Stair climbing is a physically demanding task and a painful limitation for patients suffering from severe hip osteoarthritis. Although total hip arthroplasty (THA) is the definitive treatment for end‐stage osteoarthritis, it is not well understood whether THA restores hip kinematics during strenuous activities. The purpose of this study was to compare the 3D kinematics of THA and native hip during physically demanding tasks and correlate potential differences with THA components orientations/positions in patients with unilateral THA. In vivo hip kinematics were determined during step‐up and leg stance activities using a validated combination of 3D CT‐based computer modeling and dual fluoroscopic imaging system (DFIS). The THA side demonstrated an average 3.4° (±6.5°, range: ?5.9° to 15.2°) greater internal rotation than the contralateral native hip, during the step‐up activity but not during leg stance. The difference in internal rotation was highly correlated to the difference in femoral anteversion and anterior translation of hip joint center between implanted and native hip (R² = 0.71, p < 0.01). The results suggest the importance of accurate THA component placement in restoring normal hip kinematics during functional activities. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1087–1093, 2015.

     

Editorial Commentary: The Measurement of the Alpha Angle in Femoroacetabular Impingement Syndrome With a 45° Dunn-View Radiograph Predicts the Cartilage Damage on the Acetabular Side of the Hip Joint—Is It as Simple as That?

In recent years, femoroacetabular impingement syndrome (FAIS) has developed itself into a well-known pathology throughout the orthopaedic community worldwide. The more we learned, the more sophisticated it became: In the beginning, we measured the femoral head-neck offset; then, the alpha angle was found to be a useful measurement in detecting FAIS. We learned to perform these measurements with, for example, the 45° Dunn view. The alpha angle, but not the femoral head-neck offset, measured as described, predicts not only the acetabular cartilage damage resulting from FAIS but also the correlation between the degree of the alpha angle and the severity of the cartilage damage within the acetabular labrum articular disruption and Outerbridge classifications. The femoral head-neck offset cannot provide us with this information, but it is the first sign we all look at before taking any measurements on radiographs or magnetic resonance imaging scans if a cam morphology could be present. It is paramount to understand the underlying problems of the individual hip and distinguish instability (dysplasia) from FAIS and also to evaluate femoral torsional abnormalities to perform the appropriate treatment using magnetic resonance imaging and computed tomography scans if necessary. The alpha angle quantifies the severity of the pathology and predicts the possible cartilage damage in FAIS patients, but in our opinion, we cannot neglect the femoral head-neck offset, because it is often the first radiologic sign of FAIS that most of us realize on a radiograph. Therefore, both signs have their place in detecting and treating FAIS.     

Report of the Primary Outcomes for Gait Mechanics in Men of the ACL-SPORTS Trial: Secondary Prevention With and Without Perturbation Training Does Not Restore Gait Symmetry in Men 1 or 2 Years After ACL Reconstruction

Background

Movement asymmetries during walking are common after anterior cruciate ligament (ACL) injury and reconstruction and may influence the early development of posttraumatic osteoarthritis. Preoperative neuromuscular training (like perturbation training, which is neuromuscular training requiring selective muscle activation in response to surface perturbations) improves gait asymmetries and functional outcomes among people who are ACL-deficient, but the effect of postoperative perturbation training on gait mechanics after ACL reconstruction is unknown.

Questions/purposes

Among men undergoing ACL reconstruction, we sought to compare strength, agility, and secondary prevention (SAP) treatment with SAP plus perturbation training (SAP+PERT) with respect to (1) gait mechanics; and (2) elimination of gait asymmetries 1 and 2 years after ACL reconstruction.

Methods

Forty men were randomized into a SAP group or a SAP+PERT group after ACL reconstruction and before returning to preinjury activities. Participants were required to achieve ≥ 80% quadriceps muscle strength symmetry, minimal knee effusion, full ROM, no reports of pain, and completion of a running progression (all between 3 and 9 months postoperatively) before enrollment. Of 94 potentially eligible athletic male patients evaluated < 9 months after ACL reconstruction, 54 were excluded for prespecified reasons. Participants underwent motion analysis during overground walking at 1 and 2 years postoperatively. Variables of interest included (1) sagittal and frontal plane hip and knee angles and moments at peak knee flexion angle; (2) sagittal plane hip and knee angles and moments at peak knee extension angle; (3) sagittal plane hip and knee excursion during weight acceptance; and (4) sagittal plane hip and knee excursion during midstance. We also calculated the proportion of athletes in each group who walked with clinically meaningful interlimb asymmetry in sagittal plane hip and knee variables and compared these proportions using odds ratios. There was no differential loss to followup between groups.

Results

There were no differences between the SAP or SAP+PERT groups for the biomechanical gait variables. The involved limb’s knee excursion during midstance for the SAP (mean ± SD: 1 year: 15° ± 5°; 2 years: 16° ± 5°) and SAP+PERT (1 year: 16° ± 5°; 2 years: 15° ± 4°) athletes was not different between groups at 1 year (mean difference: −1°; 95% confidence interval [CI], −5° to 2°; p = 0.49) or 2 years (mean difference: 1°; 95% CI, −2° to 4°; p = 0.54). There were no differences between SAP and SAP+PERT athletes regarding the elimination of gait asymmetries, and gait asymmetries persisted to a large degree in both groups 1 and 2 years postoperatively. At 1 year, 11 of 18 SAP and 11 of 20 SAP+PERT athletes walked with truncated knee excursions during weight acceptance (odds ratio: 0.8, p = 0.70) and midstance (SAP 12 of 18, SAP+PERT 12 of 20; odds ratio: 0.8, p = 0.67), whereas at 2 years postoperatively, truncated knee excursions during weight acceptance (SAP seven of 17, SAP+PERT eight of 19; odds ratio: 1.0, p = 0.96) and midstance (SAP five of 17, SAP+PERT 11 of 19; odds ratio: 3.3, p = 0.09) remained prevalent.

Conclusions

We found that a comprehensive, progressive return-to-sport training program with or without perturbation was not effective at restoring interlimb symmetry among men 1 or 2 years after ACL reconstruction. Although gait asymmetries improved from 1 to 2 years postoperatively, meaningful asymmetries persisted in both groups. To restore gait symmetry after ACL reconstruction, additional interventions likely are necessary.

Level of Evidence

Level II, therapeutic study.

     

Osteoarthritis develops in the operated joint of an ovine model following ACL reconstruction with immediate anatomic reattachment of the native ACL

We tested the hypothesis that immediate reattachment of the native anterior cruciate ligament (ACL) can prevent kinematic changes and the development of osteoarthritis (OA). Five sheep underwent anatomic unilateral ACL reconstruction (ACL‐R). Animals from a previous study served as sham (n = 7) or non‐operated (n = 17) controls. At 4 points of walking gait, 6 degrees of freedom stifle joint kinematics of ACL‐R animals were compared with sham controls at 4 and 20 weeks post‐surgery. Gross cartilage, bone, and meniscal changes were graded at euthanasia; paired and differential scores were compared. Inter‐animal differences were noted in all groups. Of 48 points of gait comparison between ACL‐R and sham operated groups, 42 points showed no difference (p > 0.05). Of the six significant differences (p < 0.05), internal rotation in ACL‐R animals accounted for three. At 20 weeks, differential scores showed that sham operated joints were morphologically indistinguishable from non‐operated controls (p ≥ 0.129) while ACL‐R joints had significantly higher combined cartilage and osteophyte scores than those controls (p ≤ 0.003). This method of ACL reconstruction in sheep did not restore normal walking gait kinematics completely and allowed some OA to develop in operated joints. OA may result from relatively subtle mechanical abnormalities, apparently more so in some individuals than others. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:35–43, 2012     

Positive emotion in posttraumatic stress disorder: A global or context-specific problem?

Problems with positive emotion are an important component of posttraumatic stress disorder (PTSD), with competing perspectives as to why. The global model suggests that people with PTSD experience a relatively permanent shift in their capacity for positive emotion regardless of context, whereas the context-specific model posits access to the full repertoire of positive emotion that only becomes reduced during exposure to trauma reminders. We tested the global versus context-specific models using ecological momentary assessment (EMA). Trauma-exposed adult community members (N = 80) with (n = 39) and without diagnosed PTSD completed 3 days of EMA (n = 2,158 observations). Participants with PTSD reported lower average momentary levels of positive emotion, B = −0.947, 95% CI [−1.35, −0.54], p < .001, and positive situations, B = −0.607, 95% CI [−1.16, −0.05], p = .032, and more thinking about trauma reminders, B = 0.360, 95% CI [0.21, 0.51], p < .001. There was no between-group difference in positive emotion reactivity (degree of positive emotion derived from positive situations), B = 0.03, 95% CI [−0.09, 0.14], p = .635. Increased thinking about trauma reminders predicted lower momentary levels of positive emotion, B = −0.55, 95% CI [−0.83, −0.26], p < .001, but not reactivity, B = 0.02, 95% CI [−0.35, 0.40], p = .906, irrespective of PTSD status. Findings supported the global model and were inconsistent with the context-specific model. This study helps clarify positive emotional functioning in trauma-exposed adults and highlights future directions to better understand problems with positive emotion in PTSD.     

Lower limb kinematic alterations during drop vertical jumps in female athletes who have undergone anterior cruciate ligament reconstruction

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL‐R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non‐injured age, sex, and activity matched control group. Fourteen ACL‐R and 14 non‐injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time‐averaged angular displacements were quantified and utilized for between‐group analysis. The ACL‐R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL‐R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time‐averaged, following landing. The ACL‐R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre‐dispose ACL‐R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:72–78, 2012     

In vivo six‐degree‐of‐freedom knee‐joint kinematics in overground and treadmill walking following total knee arthroplasty

No data are available to describe six‐degree‐of‐freedom (6‐DOF) knee‐joint kinematics for one complete cycle of overground walking following total knee arthroplasty (TKA). The aims of this study were firstly, to measure 6‐DOF knee‐joint kinematics and condylar motion for overground walking following TKA; and secondly, to determine whether such data differed between overground and treadmill gait when participants walked at the same speed during both tasks. A unique mobile biplane X‐ray imaging system enabled accurate measurement of 6‐DOF TKA knee kinematics during overground walking by simultaneously tracking and imaging the joint. The largest rotations occurred for flexion‐extension and internal‐external rotation whereas the largest translations were associated with joint distraction and anterior‐posterior drawer. Strong associations were found between flexion‐extension and adduction‐abduction (R ² = 0.92), joint distraction (R ² = 1.00), and anterior‐posterior translation (R ² = 0.77), providing evidence of kinematic coupling in the TKA knee. Although the measured kinematic profiles for overground walking were grossly similar to those for treadmill walking, several statistically significant differences were observed between the two conditions with respect to temporo‐spatial parameters, 6‐DOF knee‐joint kinematics, and condylar contact locations and sliding. Thus, caution is advised when making recommendations regarding knee implant performance based on treadmill‐measured knee‐joint kinematic data. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1634–1643, 2017.

     

Using real‐time MRI to quantify altered joint kinematics in subjects with patellofemoral pain and to evaluate the effects of a patellar brace or sleeve on joint motion

Abnormal patellofemoral joint motion is a possible cause of patellofemoral pain, and patellar braces are thought to alleviate pain by restoring normal joint kinematics. We evaluated whether females with patellofemoral pain exhibit abnormal patellofemoral joint kinematics during dynamic, weight‐bearing knee extension and assessed the effects of knee braces on patellofemoral motion. Real‐time magnetic resonance (MR) images of the patellofemoral joints of 36 female volunteers (13 pain‐free controls, 23 patellofemoral pain) were acquired during weight‐bearing knee extension. Pain subjects were also imaged while wearing a patellar‐stabilizing brace and a patellar sleeve. We measured axial‐plane kinematics from the images. Females with patellofemoral pain exhibited increased lateral translation of the patella for knee flexion angles between 0°and 50° (p = 0.03), and increased lateral tilt for knee flexion angles between 0° and 20° (p = 0.04). The brace and sleeve reduced the lateral translation of the patella; however, the brace reduced lateral displacement more than the sleeve (p = 0.006). The brace reduced patellar tilt near full extension (p = 0.001), while the sleeve had no effect on patellar tilt. Our results indicate that some subjects with patellofemoral pain exhibit abnormal weight‐bearing joint kinematics and that braces may be effective in reducing patellar maltracking in these subjects. Published by Wiley Periodicals, Inc. J Orthop Res 27: 571–577, 2009