Gamma Angle Research Articles

An automated method for the generation of bloodstain pattern metrics from images of blood spatter patterns

An improved automated bloodstain pattern analysis method has been developed and validated, which utilises computer vision techniques to identify bloodstains on a plain background within a digital image. The method generates metrics relating to the individual stains as well as the overall pattern, including bloodstain pattern specific metrics such as the gamma angle, circularity, solidity, area of convergence, stain density and pattern linearity. This method provides an objective approach to the analysis of bloodstains and bloodstain patterns and can generate a wealth of quantitative data that is currently not obtainable using manual techniques or other image-based programs currently utilised in the discipline. This method will be useful to analysts and researchers investigating the application of quantitative methods to bloodstain pattern analysis.

Evaluation of Foot Structure in Preschool Children Based on Body Mass.

BACKGROUND The human foot has a complex structure and the ligamentous and muscular apparatus undergoes transformation and adaptation during its ontogenetic development. Excessive body mass may be one of the factors disrupting proper foot formation. This study aimed to assess the foot structure in preschool children in relation to body mass. MATERIAL AND METHODS A total of 105 children aged 6.27±0.60 years were examined. Height, weight, and segmental body composition were determined using the Tanita MC-780 body composition analyzer. The foot structure was assessed using the Kasperczyk method, supplemented with digital analysis using the Podoscan 2D camera. The Weisflog index and gamma angle for feet were calculated. Children were divided into 2 groups: children in Group I did not have foot deformities and those in Group II had foot deformities. RESULTS No correlation was observed between body mass and the occurrence of anomalies in foot structure. A correlation was noted between the Weisflog index for the right foot and height in both groups. The Weisflog index for both feet was correlated with BMI, with higher values obtained for the left foot in both groups. In Group II, a correlation was observed between the gamma angle value for the left foot and the predicted muscle mass for the right lower limb, as well as between the same foot and the predicted muscle mass for the left lower limb. CONCLUSIONS No correlation was observed between high BMI and the occurrence of anomalies in foot structure. A relationship was identified between muscle mass and foot structure.

Assessment of Lower Third Molar Eruption Status in Different Facial Growth Patterns in Adults

Introduction Various skeletal and dental factors help in predicting the mandibular third molar eruption, but the reliability of these factors may vary within subjects with different growth patterns. Thus, the present study aims to analyze these parameters for the lower third molar eruption in subjects with different facial growth patterns. Material and Methods The study was conducted on 120 pre-treatment lateral cephalograms and orthopantomograms of the subjects who were equally divided (based on the SN-GoGn angle) into three groups: normodivergent, hypodivergent, and hyperdivergent. The groups were further subdivided into impacted and erupted subgroups based on mandibular third molar eruption status. Nine radiographic parameters were compared between the impacted and erupted subgroups, using the independent Student’s t-test, to check their association with mandibular third molar eruption in different growth patterns. Results Beta angle was significantly different in the erupted and impacted subgroups in all three groups (with p <.05). The retromolar space and alpha angle was significant in hypodivergent group (p <.01) and the gamma angle was significant in the hyperdivergent group (p <.01). Conclusion Among all the parameters that were analyzed for the third molar eruption, only the beta angle was significantly related to the third molar eruption in subjects with all three different growth patterns.

An Optimal Solution Study on a Non-Invasive Stereotactic Radiosurgery Instrument Optimizer for Stereotactic Radiosurgery of Single Brain Metastasis

<h3>Purpose/Objective(s)</h3> This study looks at a fast inverse planning (FIP) optimizer that enables more efficient and less planner dependent stereotactic radiosurgery (SRS) treatment planning. FIP generates a plan using multiple user-inputted variables that affect plan quality metrics, such as target coverage (TC), maximum dose to the target and organs-at-risk, low dose (LD), and beam-on time (BOT). The objective of this study is to systematically characterize each of these variables and determine which combination leads to the best SRS plan quality metrics. <h3>Materials/Methods</h3> Thirty patients with a single brain metastasis who were previously treated with SRS were evaluated. Each lesion was planned using FIP by varying the LD and BOT variables in 0.1 increments from 0.0 to 1.0 (i.e., plan #1 [0.0, 0.0], plan #2 [0.0, 0.1], ..., plan #120 [1.0, 0.9] and plan #121 [1.0, 1.0]). All plans were generated with the same prescription dose (24 Gy/1 fraction), TC (100%), maximum allowed dose (43.2 Gy), and Gamma angle (90°). The following metrics were recorded for each plan to evaluate plan quality: Paddick conformity index (PCI), gradient index (GI), and BOT. Heat maps for each of the above metrics as a function of LD and BOT penalties were analyzed. An objective score matrix was calculated for each plan using a linear weighted combination of scaled and normalized GI, PCI, and BOT. An optimal solution space containing the 5 lowest values of the score matrix per patient was extracted. A frequency histogram was subsequently created in the LD-BOT coordinate space. <h3>Results</h3> The target volumes in the study ranged from 1.0 cc to 2.5 cc. For every patient, 121 plans were generated across the range of LD and BOT penalties, resulting in 3630 plans included in this analysis. The range of PCI, GI, and BOT across all plans were 0.71 to 0.95, 2.5 to 2.9, and 17.2 to 221 minutes, respectively. The variation of the LD/BOT penalties had a much larger impact resulting in a higher deviation about the mean for BOT (169%), followed by PCI (28%). Heat map analysis revealed that the plans that maximized PCI and minimized GI values occupied the upper triangular matrix of the LD/BOT penalty space, while plans that minimized BOT occupied the lower triangular space. The optimal solutions frequently occupied the diagonal space in between these zones. Specifically, the histogram analysis showed that 4 highest frequencies occurred at the user-inputted settings (LD, BOT) of (0.6, 0.5), (0.8, 0.6), (0.7, 0.5), and (0.7, 0.6), in order of plan quality. <h3>Conclusion</h3> In this study, the user-inputted variables (LD and BOT) were systematically varied to determine the optimal solutions to simultaneously maximize PCI while minimizing GI and BOT. The results of this study may permit SRS planners to generate single brain metastasis plans more efficiently using the study-defined optimal settings of LD and BOT.

Conservative treatment of acute traumatic posterior shoulder dislocations (Type A) is a viable option especially in patients with centred joint, low gamma angle, and middle or old age

PurposePurpose of this study was to evaluate the mid- to long-term outcome after conservatively treated first-time posterior shoulder dislocations and to determine structural defects associated with failure.MethodsIn this multi-centric retrospective study, 29 shoulders in 28 patients with first-time acute posterior shoulder dislocation (Type A1 or A2 according to the ABC classification) and available cross-sectional imaging were included. Outcome scores as well as radiological and magnetic resonance imaging were obtained at a mean follow-up of 8.3 ± 2.7 years (minimum: 5 years). The association of structural defects with redislocation, need for secondary surgery, and inferior clinical outcomes were analysed.ResultsRedislocation occurred in six (21%) shoulders and nine shoulders (31%) underwent secondary surgery due to persistent symptoms. The posttraumatic posterior glenohumeral subluxation was higher in the redislocation group compared to the no redislocation group; however, statistical significance was not reached (61.9 ± 12.5% vs. 50.6 ± 6.4%). Furthermore, a higher adapted gamma angle was observed in the failed conservative treatment group versus the conservative treatment group, similarly without statistically significant difference (97.8° ± 7.2°, vs. 93.3° ± 9.7°). The adapted gamma angle was higher than 90° in all patients of failed conservative therapy and the redislocation group. An older age at the time of dislocation showed a significant correlation with better clinical outcomes (SSV: r = 0.543, p = 0.02; ROWE: r = 0.418, p = 0.035 and WOSI: r = 0.478, p = 0.045). Posterior glenohumeral subluxation after trauma correlated with a worse WOSI (r = − 0.59, p = 0.02) and follow-up posterior glenohumeral decentring (r = 0.68, p = 0.007). The gamma angle (r = 0.396, p = 0.039) and depth of the reverse Hill–Sachs lesion (r = 0.437, p = 0.023) correlated significantly with the grade of osteoarthritis at follow-up.ConclusionConservative treatment is a viable option in patients with an acute traumatic posterior shoulder dislocation with good outcome after mid- and long-term follow-up especially in patients with centred joint, low gamma angle, and middle or old age.Level of evidenceIV.

Risk factors of de novo hyperextension developed after posterior cruciate ligament substituting total knee arthroplasty: a matched case-control study.

To investigate factors contributing to the de novo hyperextension after posterior cruciate ligament substituting (PS) total knee arthroplasty (TKA). Through a retrospective case-control study, de novo hyperextension patients were compared with patients without hyperextension after primary PS TKA. Eighty-five hyperextension patients were compared with 85 patients in a control group matched by age, sex, surgeon and implant. The clinical and radiographic parameters, including the mechanical axis (MA), joint line convergence angle (JLCA), posterior tibial slope angle (PTSA), posterior condylar offset (PCO), and the gamma angle, were evaluated preoperatively and immediate postoperatively. Comparisons between the two groups and logistic regression analysis were performed to investigate factors contributing to de novo hyperextension. Among the clinical factors, preoperative flexion contracture was less (5° ± 6° vs. 11° ± 6°, p < 0.001) and the range of motion was greater (125° ± 12° vs. 118° ± 5°, p = 0.041) in the de novo hyperextension group than in the control group. Among the radiographic parameters, preoperative and postoperative JLCA were greater (8.1° ± 4.4° vs. 6.1° ± 3.5°, p < 0.001, 1.0° ± 1.3° vs. 0.2° ± 0.8°, p = 0.002, respectively), postoperative PTSA was greater (3.7° ± 2.0° vs. 3.3° ± 1.6°, p < 0.001) and preoperative and postoperative PCO were less in the hyperextension group than in the control group (26.3mm ± 3.3mm vs. 29.1mm ± 3.2mm, p < 0.001, 26.4mm ± 3.2mm vs. 29.1mm ± 3.0mm, p < 0.001, respectively), whereas, change in PCO was greater in the hyperextension group (1.1mm ± 7.7mm vs. - 0.1mm ± 3.3mm, p < 0.001). In multivariate analysis, the degree of medial soft tissue release [odds ratio (OR) 2.83, p = 0.003], flexion contracture [OR 0.86, p = 0.028], postoperative JLCA [OR 2.45, p = 0.004], preoperative PCO and a change in PCO [OR 0.74, p = 0.002, OR 1.89, p = 0.001, respectively] were the factors associated with de novo hyperextension. An increased degree of medial soft tissue release, small preoperative flexion contracture, increased postoperative JLCA, decreased preoperative PCO and increased change in PCO were risk factors of de novo hyperextension. III.

Elongation of the disc-fovea distance and retinal vessel straightening in high myopia in a 10-year follow-up of the Beijing eye study

To assess changes in the disc-fovea distance (DFD) in highly myopic eyes in a 10-year population-based follow-up study. The case control study included all highly myopic eyes (myopic refractive error ≥ − 6.0 diopters or axial length ≥ 26.0 mm) and a randomized group of non-highly myopic eyes examined in the population-based Beijing Eye Study 2001 and 2011. Using fundus photographs and optical coherence tomographic images, we assessed changes in DFD, parapapillary gamma zone, angle kappa (angle between the temporal arterial arcades), and course of papillo-macular retinal vessels. The study included 89 highly myopic eyes and 86 non-highly myopic eyes. DFD elongation, gamma zone widening, angle kappa decrease and straightening of papillo-macular retinal vessels were detected more often (all P < 0.001) in the highly myopic group than in the non-highly myopic group (63/89 versus 9/86;75/89 versus 18/86;61/89 versus 9/86; and 58/89 versus 7/86,respectively). Gamma zone enlargement, angle kappa reduction and papillo-macular retinal vessel straightening were significantly (all P < 0.001) associated with DFD elongation. The length of macular Bruch’s membrane on the disc-fovea line and the vertical distance between the temporal arterial arcade did not change during follow-up. DFD elongation (10-year incidence 70.8% in highly myopic eyes) was associated with gamma zone enlargement, while macular Bruch’s membrane length remained unchanged. It supports the notion of a temporal shift of an otherwise stable posterior Bruch’s membrane in axially elongated eyes. Straightening of the papillo-macular vessels with increasing gamma zone width suggests a coincident stretching of the papillo-macular retinal nerve fibers and inner limiting membrane.

Evaluation of Late Postural Complications in Breast Cancer Patients Undergoing Breast-Conserving Therapy in Relation to the Type of Axillary Intervention-Cross-Sectional Study.

Purpose: The aim of the study was to evaluate posture in patients undergoing breast-conserving therapy (BCT) in relation to the type of surgical intervention to the axilla. Methods: The study was conducted on patients who had undergone breast-conserving surgical treatment for breast cancer 5–6 years earlier. In 54 patients, BCT+ALND (axillary lymph node dissection) was performed, while 63 patients were subjected to BCT+SLND (sentinel lymph node dissection). The control group consisted of 54 females. The study was conducted using digital postural assessment. Results: No statistically significant differences were observed with respect to the parameters between the BCT+SLNB and BCT+ALND groups (p > 0.05). However, the differences were highly significant between the CG (control group) and the studied groups (BCT+ALND, BCT+SLNB) for the following parameters: BETA angle of thoracolumbar spine inclination (p = 0.002), GAMMA angle of thoracic spine inclination (p = 0.0044), TKA (thoracic kyphosis angle) (p < 0.0001) and shoulder level inclination (p = 0.0004). The BCT+ALND patients were characterized by higher dependency of raised shoulder (p = 0.0028) and inferior angle of the scapula (p = 0.00018) on the operated side compared to BCT+SLNB patients. Conclusions: Postural imbalance occurs independent of the type of axillary intervention. Disturbances within the upper torso (abnormal position of shoulders and inferior angles of scapulae) are more pronounced in patients after ALND.

Assessment of early prediction of mandibular third molar impaction by panoramic indices: A radiological study

Introduction: Mandibular third molar is one of the most frequently impacted tooth. The assessment and early prediction of the mandibular third molar impaction is of considerable clinical significance as it helps in early intervention so as to opt for its prophylactic removal. This reduces the risk of developing various pathologies like cysts, tumors, root resorption of adjacent teeth, pericoronitis etc, and also reduces risk of complications associated with extraction of fully developed tooth. The objective of this study is to compare different linear and angular measurements between the impacted and erupted mandibular third molar groups on digital panoramic radiograph and to assess the predictive validity of these panoramic measurements in mandibular third molar impaction.&#x0D; Materials and Method: 90 mandibular third molars were assessed using the linear and angular measurements made on digital panoramic radiograph. Mesiodistal width of mandibular third molar (MDW), lower eruption space- ramus (LES-R), lower eruption space- Rickett’s Xi (LES-Xi), alpha angle (α-angle), gamma angle (γ-angle) and gonial angle (Go-angle) were the measurements made. Space/width ratio 1 (R1) and space/width ratio 2 (R2) were also calculated. These parameters were compared between the impacted and erupted groups using Independent sample t-test and predictive validity with sensitivity and specificity of these parameters was assessed using ROC curve analysis.&#x0D; Result: LES-R, LES-Xi, R1, R2 and α-angle showed significant statistical difference between the impacted and erupted groups. R1 followed by R2, LES-R showed good predictive validity and LES-Xi showed fair predictive validity in mandibular third impaction.&#x0D; Conclusion: Decrease in lower eruption space, space/width ratio and increase in the mandibular third molar angulation favor impaction of the mandibular third molar. Among different panoramic linear and angular measurements, R1, R2 and LES-R can prove to be a relatively good predictor for mandibular third molar impaction.

Comparative assessment of flatfoot in preschool children.

The increase or reduction of the medial longitudinal arch (MLA) can affect essential functions in the foot biomechanics with long-term health consequences. The aim of the present study was to determine the height of the MLA in children from 3 to 6 years of age through five methods of footprint analysis for the diagnosis of flat foot. A cross-sectional observational study was conducted with 367 children aged 3 to 6 years in a municipality of the State of Mexico. We conducted a complete postural evaluation, plantoscopy by Viladot classification, and footprint analysis calculating the height of the ALM using the Clarke angle (CA), the Staheli index (SI), the Chippaux-Smirak index (CSM), and the gamma angle (gA). The prevalence of flat feet using the podoscope was 57.7%. Through the angles and indexes, the prevalence was 86.9% for SI, 83.3% for CSI, 95.9% for CA, and 22.3% for gA. The gA was less sensitive for flat foot detection compared to CSI, SI and CA. Based on the present results, we propose that footprint analysis should be used for flat foot diagnosis besides the classic evaluation by podoscope. We recommend that flat foot diagnosis and surveillance should be included on in the consultation of the healthy child, as a trend for podalic architecture can be detected from early ages.

Scoopy Blade for Low Current River Waterwheel Supporting the Energy Needs in the Rural Areas of Indonesia

A series of experiment has been carried out to measure the effectiveness of the new rotor blades of waterwheel in order to absorb as much as possible the energy of flow water. The scoopy blade is predicted convert more effectively and efficiently the water energy into useful mechanical energy compared to flat blade. This blade is intended to used for undershot waterwheels operated in low current rivers in Indonesia. The scoop blades are tested at a flow range from 0.8 m / sec - 2.5 m / sec in the range of gamma angle 100, 150 and 200. All results are compared to the flat blade where gamma angle is zero. The test results show the scoopy blade with gamma angle 100 is effectively harnessed the water energy compared to others. The blades with gamma angle 100 produce bigger power and bigger efficiency than blades of other gamma angles.

Clinical radiotherapy application of N-vinylpyrrolidone-containing 3D polymer gel dosimeters with remote external MR-reading

PurposeAdvanced 3D dosimetry is required for verifications of complex dose distributions in modern radiotherapy. Two 3D polymer gel dosimeters, coupled with magnetic resonance (MR) imaging (3 T MRI) readout and data processing with polyGeVero® software, were tested for the verification of calculated 3D dose distributions by a treatment planning system (TPS) and ArcCHECK®–3DVH®, related to eradication of a lung tumour. MethodsN-vinylpyrrolidone-containing 3D polymer gel dosimeters were used: VIC (containing ascorbic acid and copper sulfate pentahydrate) and VIC-T (containing tetrakis(hydroxymethyl)phosphonium chloride). Three remote centers were involved in the dosimeters preparation and irradiation (Poland), and MRI (Austria). Cross beam calibration of the dosimeters and verification of a 3D dose distribution calculated with an Eclipse External Beam TPS and ArcCHECK®–3DVH® were performed. The 3D-to-3D comparisons of the VIC and VIC-T with TPS and ArcCHECK®–3DVH® along with ArcCHECK®–3DVH® versus TPS dose matrixes were performed with the aid of the polyGeVero® by analyzing dose profiles, isodoses lines, gamma index, gamma angle, dose difference, and related histograms. ResultsThe measured MR-relaxation rate (R2 = 1/T2) for the dosimeters relates to the dose, as follows: R2 = 0.0928 ± 0.0008 [Gy−1 s−1] × D [Gy] + 2.985 ± 0.012 [s−1] (VIC) and 0.1839 ± 0.0044 [Gy−1 s−1] × D [Gy] + 2.519 ± 0.053 [s−1] (VIC-T). The 3D-to-3D comparisons revealed a good agreement between the measured and calculated 3D dose distributions. ConclusionsVIC and VIC-T with 3T MRI readout and polyGeVero® showed potential for verifications of calculated irradiation plans. The results obtained suggest the implementation of the irradiation plan for eradication of the lung tumour.

The relationship between sagittal spinal curvatures and isokinetic trunk muscle endurance after aquatic exercise training in survivors of breast cancer

Assessment of the impact of aquatic exercises on the relationship between sagittal spinal curvatures and isokinetic trunk muscle endurance against standard land exercises in women after breast cancer treatment. 40 women post breast cancer divided into two groups: a study group (n = 20) participated in the aquatic exercises and a control group (n = 20) performed the land exercises. Data collection occurred both before and after the 8 week intervention. Measurements were taken from the SG and CG performing antagonistic movements (flexions/extensions) to assess the endurance (120 °/s) in isokinetic conditions and a photogrammetric examination to define sagittal spinal curvatures. A significant improvement (p < 0.05) in total work and average power was found among women after the aquatic exercises irrespective of the muscle group under examination. There were no significant changes in any examined parameters after the land exercises. In the study group, there was a significant association of gamma angle decrease and an increase of all examined functional parameters of total work and average power of both the extensor muscles (r = -0,49 to -0.51) and the trunk flexors (r = -0.48 to -0.51). In the control group, a similar tendency of functional-postural changes was observed only for the extensor muscles of the trunk (r = -0.54 to -0.58). General exercises performed in water, as opposed to those performed on land, are more effective in terms of the functional-postural retations in women after breast cancer.

Gamma angle, a measurement tool of the femoral head angular translation in adults hips with cam or mix form of impingement femoroacetabulare

Femoral head translation leads to the cam deformity development. It is formed on the femoral head-neck junction. Cam deformity produces femoroacetabular impingement. There are no particular techniques for femoral head translation assessment. The offset index is the most regularly applied. It quantifi es the relation between the femoral head and neck junction. We introduce the original method to test the femoral head translation.

The role of bone in glenohumeral stability.

Shoulder stability depends on several factors, either anatomical or functional. Anatomical factors can be further subclassified under soft tissue (shoulder capsule, glenoid rim, glenohumeral ligaments etc) and bony structures (glenoid cavity and humeral head).Normal glenohumeral stability is maintained through factors mostly pertaining to the scapular side: glenoid version, depth and inclination, along with scapular dynamic positioning, can potentially cause decreased stability depending on the direction of said variables in the different planes. No significant factors in normal humeral anatomy seem to play a tangible role in affecting glenohumeral stability.When the glenohumeral joint suffers an episode of acute dislocation, either anterior (more frequent) or posterior, bony lesions often develop on both sides: a compression fracture of the humeral head (or Hill–Sachs lesion) and a bone loss of the glenoid rim. Interaction of such lesions can determine ‘re-engagement’ and recurrence.The concept of ‘glenoid track’ can help quantify an increased risk of recurrence: when the Hill–Sachs lesion engages the anterior glenoid rim, it is defined as ‘off-track’; if it does not, it is an ‘on-track’ lesion. The position of the Hill–Sachs lesion and the percentage of glenoid bone loss are critical factors in determining the likelihood of recurrent instability and in managing treatment.In terms of posterior glenohumeral instability, the ‘gamma angle concept’ can help ascertain which lesions are prone to recurrence based on the sum of specific angles and millimetres of posterior glenoid bone loss, in a similar fashion to what happens in anterior shoulder instability.Cite this article: EFORT Open Rev 2018;3:632-640. DOI: 10.1302/2058-5241.3.180028

Does Patient-specific Instrumentation Yield Better Component Position than Standard Instrumentation in Total Ankle Arthroplasty?

Category: Ankle Arthritis Introduction/Purpose: The unique anatomy and biomechanics of the ankle joint have made total ankle arthroplasty (TAA) challenging over the past few decades. Final implant position and successful soft tissue balancing are key components to the longevity of total ankle implants. Preoperative computer navigation, templating, and patient-specific instrumentation (PSI) have shown promising results in total ankle replacement with accurate and reproducible radiographic outcomes. Recent data has also suggested that even experienced surgeons benefit from the improved time efficiency of PSI. The purpose of this study is to determine if radiographic outcomes differ between patients undergoing TAA with PSI and those who undergo TAA with standard instrumentation (SI). Methods: The first 67 consecutive patients who underwent primary Infinity total ankle arthroplasty (TAA) at 2 North American sites between 2013 and 2015 were reviewed in a prospective observational study. All TAA’s were performed by one of four fellowship-trained foot and ankle surgeons. Demographic, radiographic, and functional outcome data was collected preoperatively, at 6-12 months postoperatively, and annually thereafter. The radiographic variables measured were the medial distal tibial angle (MDTA), talar tilt angle (TTA), lateral talar station (LTS), sagittal distal tibial articular angle (sDTAA), and the gamma angle. Acceptable intervals for each parameter were selected and TAAs were then categorized as being “correctly aligned” or “not correctly aligned” for all the parameters described. The rate of “correctly aligned” TAA’s was compared between cases with PSI and those with SI. Fisher’s exact test was used to analyze difference by groups. A significance of 5% was used. Results: Of a total of 67 TAAs included, 51 were in the PSI group and 16 in the SI group. No significant statistically differences were found between PSI and NPSI regarding MDTA (p=0.174), LTS (p=0.922), sDTAA (p=0.986), gamma angle (p=0.252) and TTA (p=0.145). We did not find a significant statistical difference in the rate of “correctly aligned TAR” when we compared both groups (p=0.35). Conclusion: This study suggests that both PSI and SI provide accurate and reproducible TAA radiographic alignment when performed by experienced surgeons. In view of previously published data demonstrating high levels of reproducibility for PSI in TAA, these data also suggest that PSI may offer a means for less experienced surgeons to achieve radiographic results similar to those achieved by experienced surgeons. It also suggests that experienced surgeons may not need to use PSI to achieve satisfactory implant alignment, though improved time efficiency with PSI, as demonstrated in other studies, may still be of benefit for experienced surgeons.

Intraoperative Radiographic Assessment of Ankle Prosthesis Alignment

Category: Ankle Arthritis Introduction/Purpose: In the last 2 decades, total ankle replacement (TAR) has gained greater acceptance as a treatment option for patients with end-stage ankle osteoarthritis. However, TAR still has a higher failure rate than either hip or knee replacements. One of the most common reasons for TAR failure is malalignment of the prosthesis component which accounts for 15% of all failures. The purpose of this study was to assess ankle prosthesis alignment using intraoperative fluoroscopy images and to compare the results with postoperative weightbearing radiographs. Methods: Sixty-eight primary TARs were performed using the Zimmer trabecular metal implant (37 men and 31 women, mean age of 67.7±8.2 years) from October 2012 to August 2017. Alpha and beta angles were used to assess the alignment of the tibial component in the coronal and sagittal plane, respectively. Gamma angle was used to assess the alignment of the talar component in the sagittal plane. All measurements were performed by two observers (ICC 0.787-0.984). One observer evaluated all images twice at a 6-week interval to determine the intraobserver reliability (ICC 0.858-0.986). Results: There were significant differences between intraoperative and postoperative assessment for all three angles. For the alpha angle, the mean absolute difference was 1.8º±1.5º with a range between 0º and 6º (p = 0.001). For the beta angle, the mean absolute difference was 2.1º±1.5º with a range between 0º and 7º (p = 0.034). For gamma angle, the mean absolute difference was 2.0º±1.5º with a range between 0º and 6º (p = 0.002). The Pearson coefficient for the alpha, beta, and gamma angle was 0.664 (p &lt; 0.001), 0.852 (p &lt; 0.001), and 0.928 (p &lt; 0.001), respectively. Conclusion: In the present study, radiographic assessment of the prosthesis’ component alignment demonstrated significant differences up to 7 degrees. This can be partially explained by the lack of a standardized radiographic technique to obtain fluoroscopic images, difficult identification of anatomic landmarks for intraoperative measurements, and distortion of x-rays using fluoroscopy.

Radiographic Analysis of Total Ankle Replacements

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacements (TAR) are an increasingly common treatment for end-stage ankle arthritis but evidence on optimal alignment is not as well-established as in the hip and knee arthroplasty literature. Many believe that restoration of coronal and sagittal alignment is critical, while others suggest malalignment within a certain range has no impact on failure (Braito et al. 2015). There is controversy on the ideal TAR component positioning to minimize failure and requiring revision surgery. In this study we examine 9 radiographic measures of TARs, 6 of which have previously been described for TARs, 1 commonly used on preoperative ankles, and 2 novel measures on a database of 146 TARs to identify predictors of TAR re-operation. Methods: A retrospective review was performed on the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis, selecting for all total ankle replacements done at a single institution by one of three fellowship-trained foot and ankle surgeons between September 2004 and June 2015. Those with complete series of anteroposterior and lateral standing ankle radiographs both preoperative and postoperative, and minimum of 1 year of follow-up were included. Measurements were performed on the postoperative radiographs and included: coronal and sagittal distal tibial component angles, talar center migration, talar tilt angle, lateral talar station, tibial axis-talus ratio, talar component gamma angle, anterior and posterior tibial component overhang and underhang. Standard descriptive statistical methods were used to analyze the data. Results: Of a total of 296 TARs, 146 were included and 14 TARs failed (9.6%), defined as requiring re-operation, 8 of which were metal-component revisions (5%). The TARs were stratified into those with measurements within previously published normal values and those that fall outside that range. Time to failure ranged from 1.4 to 9.6 years. Our preliminary data analysis showed that TARs with coronal distal tibial component angles between 87-93 degrees demonstrated an odds ratio of 0.11 for re-operation compared with those beyond that range, p=0.003. TARs with talar tilt angles of 0 degrees demonstrated an odds ratio of 0.24 for re-operation compared with those whose talar tilt was not zero, p=0.02. Conclusion: Post-operative coronal alignment of TARs, namely distal tibial component angle and talar tilt, appear to be associated with TAR-reoperation. Specifically, if the measurements are within previously described normal limits, the odds ratio for re-operation is low and statistically significant. Further data analysis is underway and may demonstrate more parameters of significance in predicting TAR failure.

Assessment of Foot Shape in Children and Adolescents with Intellectual Disability: A Pilot Study.

BackgroundAvailable publications provide little evidence pertaining to assessment of foot shape in children with intellectual disability. The aim of this study was to assess the parameters of foot shape in children and adolescents with intellectual disability and to evaluate the relationship between the degree of disability and these parameters.Material/MethodsThe study involved 90 individuals aged 7–15 years, including 45 subjects with mild and moderate levels of intellectual disability (study group) and 45 peers with normal intellectual development (control group). Each participant was subjected to photogrammetric assessment of foot shape based on the projection moire effect.ResultsAnalysis of the relationship between the disability level and the assessed parameters showed that the length of the right (p=0.006) and left (p=0.004) foot, as well as Wejsflog’s rate for the right (p<0.001) and left (p<0.001) foot, were significantly higher among children with mild disability, whereas GAMMA angle of the right (p=0.028) and left (p=0.006) foot was significantly higher among children with moderate disability.ConclusionsThe findings show a significant relationship between the degree of disability and the assessed foot parameters. Significant differences between the subjects with intellectual disability and the control group were identified in the basic parameters defining foot structure.

Analyze of relation between passive stiffness of pelvic girdle muscles and foot architecture in preschool children

Abstract Background: The aim of the study is assessment of relation between passive stiffness of chosen pelvic girdle muscles and formation of heel angle (gamma) and medial longitudinal arch (MLA; determined by the Clarke's angle (AC) ). Material/Methods: 124 preschool children underwent observation. The examined group included 46 five years old children and 78 six years old children (girls (n=53); boys (n=71). Passive stiffness of chosen muscles that have insertions within pelvis were assessed in participants and gamma and Clarke's angles were evaluated with use of plantography. Results: Analysis of ANOVA variance showed significant diversification (p&lt;0.01) of iliopsoas muscles stiffness between groups designated in regard to gamma angle (between body sides). Statistically substantial differences of passive stiffness of hamstrings and adductors (P&lt;0.01, respectively) was also obtained in these groups. In case of analyze of passive stiffness of pelvic girdle muscles in the groups appointed in regard to Clarke's angle the only essential effect (P&lt;0.01) was noted within iliopsoas between body sides, but without important interactions.