The Use of the Esclera Scleral Contact Lens in the Treatment of Moderate to Severe Dry Eye Disease

PURPOSE

To evaluate the efficacy of the Esclera scleral contact lens (SCL) treatment and its impact on clinical testing for moderate to severe dry eye disease (DED).

DESIGN

Prospective interventional case series.

METHODS

A total of 41 eyes from 25 patients with moderate to severe DED were evaluated for the Esclera SCL treatment. Best-corrected visual acuity (BCVA), tear osmolarity, the Schirmer I test, tear film breakup time (TBUT), corneal and conjunctival staining, meibomian grading, and Ocular Surface Disease Index and SF-36v2 questionnaires were assessed before and after the SCL treatment. These values were compared to assess the real benefit of using SCL as a treatment for DED.

RESULTS

Forty-one eyes from 25 patients were fitted with SCL for management of DED. The underlying diseases were Stevens-Johnson syndrome (22 eyes), Sjogren syndrome (11 eyes), graft-vs-host disease (2 eyes), dry eye after keratomileusis in situ (2 eyes), and undifferentiated ocular surface disease (4 eyes). BCVA improved from 0.703 ± 0.55 logMAR with habitual correction to 0.406 ± 0.43 logMAR with SCL (P < .001). There was a significant decrease in tear osmolarity values (338.1 ± 27.1 to 314.25 ± 38.8 mOsm/L, P < .001) and van Bijsterveld scores (3.63 ± 2.33 to 2.63 ± 2.46 grade, P = .015) between the baseline and 12 months after SCL wear. There were also significant improvements in dry eye symptoms and quality of life as assessed by the OSDI and SF-36v2 questionnaires (both with P < .001).

CONCLUSIONS

The Esclera SCL treatment had a positive impact on tear osmolarity and van Bijsterveld score, as well as an improvement in the patients' BCVA, dry eye symptoms, and quality of life.

Three-Dimensional Measurement and Cluster Analysis for Determining the Size Ranges of Chinese Temporomandibular Joint Replacement Prosthesis

The aim of this study was to investigate the osseous characteristics of Chinese temporomandibular joint (TMJ) and detect the size clusters for total joint prostheses design.Computer tomography (CT) data from 448 Chinese adults (226 male and 222 female, aged from 20 to 83 years, mean age 39.3 years) with 896 normal TMJs were chosen from the Department of Radiology in the Shanghai 9th People's Hospital. Proplan CMF 1.4 software was used to reconstruct the skulls. Three-dimensional (3D) measurements of the TMJ fossa and condyle-ramus units with 13 parameters were performed. Size clusters for prostheses design were determined by hierarchical cluster analyses, nonhierarchical (K-means) cluster analysis, and discriminant analysis.The glenoid fossa was grouped into 3 clusters, and the condyle-ramus units were grouped into 4 clusters. Discriminant analyses were capable of correctly classifying 97.24% of the glenoid fossa and 94.98% of the condyle-ramus units. The means and standard deviations for the parameter values in each cluster were determined.Fossa depth and angles between the condyle and ramus were important parameters for Chinese TMJ prostheses design. 3D measurements and cluster analysis of the osseous morphology of the TMJ provided an anatomical reference and identified the dimensions of the minimum numbers of prosthesis sizes required for Chinese TMJ replacement.

Progressive lengthening of short congenital forearm stump in children for prosthetic fitting

PURPOSE

The sufficient length of congenital forearm stump is essential for prosthetic fitting. In our study we reviewed the results of a series of forearm stump lengthening, observed complications and their outcomes. We evaluated possibilities of combined technique to reduce or avoid problems and complications in forearm stump lengthening.

METHODS

We retrospectively reviewed 18 children who have undergone forearm stump lengthening. In all patients the forearm lengthening was performed by means of Ilizarov frame. Additional flexible intramedullary nailing (FIN) was applied in two cases.

RESULTS

The mean lengthening gain was 4.6 cm. The planned lengthening gain was obtained in all cases. The mean healing index (HI) was 34.1 days/cm. The most reduced HI was observed in two cases of combined technique (Ilizarov frame with FIN): 25.4 and 27.0 days/cm. Considering complications and outcomes the results were classified according to Lascombes: grade I--5 cases, IIa--10 cases, IIb--2 cases, IIIa--1 case. In the long term follow-up all patients used their prostheses fixed at the forearm stump with natural function of elbow joint.

CONCLUSION

Forearm progressive lengthening in children with congenital transverse deficiency of the forearm is justified in order to facilitate prosthetic procedures and to preserve natural function of elbow joint. Sufficient lengthening can be achieved within one operation with a low rate of major complications. In our experience a repeated lengthening of forearm stump is not mandatory.

Die CAD/CAM­-gefertigte Totalprothese mit dem «Digital Denture Professional System»

The article describes the medical and dental procedures for four treatment sessions with the Digital Denture Professional (DDP) system. First, conventional preliminary dental impressions of the full arch are taken to achieve accurate jaw positioning records. The study models and patient data are digitalised using a laboratory scanner. The dental lab technician then constructs and mills custom impression trays and a mount as an intraoral instrument. A closed-mouth impression is then taken to record vertical dimensions and central relation position. After this is digitalised in the laboratory, DDP add-on software is used to virtually design the full dental implants and mill monolithic test implants. These can be tested for aesthetics, function and phonetics in the third session. The testing phase can also be skipped on request. In the last session, the final dental implants are fitted for the patient. The patient’s individual data are precisely recorded and digitally processed, which ensures the results are always as planned. The patient benefits from the spared time and costs. The range of care will be expanded in future to include reconstructions using implants. The digitalisation of the technique would be ideal for the planning and provision of digital implant prosthetics.

COMBINED EFFECT OF THERMAL LOAD AND MECHANICAL LOAD IN TRANSTIBIAL PROSTHESIS. AN EMPIRICAL STUDY

Probably the most important factor in evaluating a patient's prosthesis is quality of life. Transtibial amputations, are among the most frequently performed major limb amputations. Many individuals with transtibial amputations successfully achieve rehabilitation at or near their preamputation levels. Discomfort in prosthetic sockets continues to be a critical challenge faced by both prosthetists and amputees.

MATERIAL AND METHODS

This paper proposes a fusion Graphic User Interface that combines two types of information (pressure and temperature). Data from pressure sensors and thermistors (an electrical resistor whose resistance is greatly reduced by heating, used for measurement and control) placed on the stump in transtibial prosthetics are collected in real time using a National Instruments Data Acquisition device.

RESULTS

All the data stored in files are available for offline processing. The user has the possibility to analyse the signal by zooming or positioning the marker and window on different parts of signal. A complex analysis that involves the pressure and temperature for a location (where both sensors are placed) is available in time domain.

CONCLUSIONS

Blunt-prosthesis interface is characterized by few parameters among the most important are pressure and friction. The action of these parameters during static and dynamic stage is very important because their actions can produce lesions of skin at the level of interface. Despite the advancements in surgical techniques and prostheses, much still needs to be done. We made certain that the sensors were in the same location by pressing on specific cells on the residual limb during various stages of the experimentation. The highest pressures recorded were during the stance phase of walking. The curve that shows the temperature evolution or pressure in one point could differ in different points from patient to patient.

Impact of Prosthesis-Patient Mismatch after Mitral Valve Replacement

BACKGROUND

The study aim was to determine the impact of prosthesis-patient mismatch (PPM) on early and late clinical outcomes, left atrial and ventricular remodeling, late tricuspid valve regurgitation and pulmonary hypertension (PH) in patients after mitral valve replacement (MVR).

METHODS

A total of 46 patients (mean age 66 ± 9.3 years) with mitral valve diseases and undergoing isolated MVR was enrolled in the study. The mitral valve effective orifice area (EOA) was determined using the continuity equation and indexed for the patient's body surface area (EOAi). PPM was defined as EOAi ≤1.2 cm2/m2. PH was defined as a systolic pulmonary artery pressure (sPAP) >40 mmHg. Both, clinical and echocardiographic follow up were performed.

RESULTS

PPM was identified in 25% of patients, but no significant differences were observed in baseline and operative characteristics when comparing patients with and without PPM. The NYHA class was improved in most cases after surgery. Indeed, significant decreases in mean transvalvular gradient (from 8.6 ± 2.8 mmHg to 5 ± 1.3 mmHg, p = 0.001), left atrial dimension (LAD) (from 31.9 ±9.8 mm to 29.5 ± 7 mm, p = 0.011), left ventricular end-systolic diameter (from 42.6 ± 18.1 mm to 35.5 ± 6.6 mm, p = 0.044) and left ventricular end-diastolic diameter (from 55.8 ± 19.2 mm to 48.7 ± 6.1 mm, p = 0.024) were observed over time when comparing preoperative and postoperative echocardiographic data. In addition, at follow up (mean 6.9 ± 1.8 years) there were significant decreases in LAD (from 31.9 ± 9.8 mm to 28 ± 11.1 mm, p = 0.001), left ventricular enddiastolic volume (from 106.9 ± 32.9 ml to 92.3 ± 21.9 ml, p = 0.024), tricuspid regurgitation (TR) (from 87% to 27%, p = 0.002) and PH (from 78.3% to 58.7%, p = 0.043) in all patients. No significant differences were observed in hemodynamic, clinical outcome and atrial natriuretic peptide levels of patients with and without PPM.

CONCLUSIONS

Mitral PPM does not appear to have any negative effect on ventricular and atrial remodeling, TR and PH during the early and late postoperative periods.

MRI is more accurate than CT for patient-specific total knee arthroplasty

Previous reports have stated that MRI is less accurate than CT for patient specific guide creation in total knee arthroplasty (TKA). Twenty-three TKAs were performed with CT-based guides and 27 with MRI-based guides. A mechanical axis through the central third of the knee was achieved in 88.9% of MRI-guided TKA versus 69.6% of CT-guided TKA (p=0.07). There were nine component outliers in the CT group (39.1%) and two in the MRI group (7.4%, p=0.00768). The relative risk of having an outlier using a CT-based guide was 5.28 times that of an MRI-based guide. Superior overall alignment and fewer outliers were achieved with the use of MRI compared with CT. MRI is the best imaging modality for surgeons wishing to utilize patient specific guides for TKA.

Effect of orthokeratology in patients with myopic regression after refractive surgery

PURPOSE

To evaluate the clinical effect of orthokeratology (ortho-K) lenses and to introduce the fitting steps of ortho-K lens for myopic regression after keratorefractive surgery.

METHODS

Twenty-one eyes from 12 patients with myopic regression after keratorefractive surgery were fitted with ortho-K lenses and followed up for 12.11±3.68 months. The mean K value of the peripheral cornea was used to speculate preoperative central corneal K value, estimated K. After dispensing the lenses according to estimated K, biomicroscopic examination including fluorescein staining and over-refraction were performed to determine the final K and final lens power.

RESULTS

LogMAR uncorrected visual acuity was 0.48±0.39 before and 0.00±0.00 after wearing ortho-K lenses (p<0.001). Pre-fitted refractive error was -1.87±1.05 diopters (D) in myopia, 0.54±0.42 D in astigmatism, and spherical equivalent of -2.14±1.01 D. At the final visit myopia level and spherical equivalent significantly decreased to -0.73±0.84 D (p<0.001) and -1.01±0.87 D (p<0.001), respectively. Estimated K was 8.07±0.36 mm, and final K used for ortho-K prescription was 8.19±0.30 mm. Final K significantly correlated with K value of pre-fitted peripheral cornea (r=0.737, p<0.001) and estimated K (r=0.721, p<0.001), respectively. There was no correlation between pre-fitted degree of myopia and the Final lens power (r=0.429, p=0.053).

CONCLUSIONS

Ortho-K lenses may be an effective solution for patients with myopic regression following keratorefractive surgery. Estimated K value can be used as reference value in ortho-K prescription.

Effects of Training on the Use of a Manual Microphone Shutoff on a BiCROS Device

BACKGROUND

Bilateral contralateral routing of signals (BiCROS) hearing aids function to restore audibility of sounds originating from the side of the unaidable ear. However, when speech is presented to the side of the aidable ear and noise to the side of the unaidable ear, a BiCROS arrangement may reduce intelligibility of the speech signal. This negative effect may be circumvented if an on/off switch is available on the contralateral routing of signals (CROS) transmitter.

PURPOSE

This study evaluated if the proper use of the on/off switch on a CROS transmitter could enhance speech recognition in noise and sound localization abilities. The participants' subjective reactions to the use of the BiCROS, including the use of the on/off switch in real-life were also evaluated.

RESEARCH DESIGN

A between-subjects, repeated-measures design was used to assess differences in speech recognition (in quiet and in noise) and localization abilities under four hearing aid conditions (unaided, unilaterally aided, fixed BiCROS setting, and adjusted BiCROS setting) with speech and noise stimuli presented from different azimuths. Participants were trained on the use of the on/off switch on the BiCROS transmitter before testing in the adjusted BiCROS settings. Subjective ratings were obtained with the Speech, Spatial, and Sound Quality (SSQ) questionnaire and a custom questionnaire.

STUDY SAMPLE

Nine adult BiCROS candidates participated in this study.

DATA COLLECTION AND ANALYSIS

Participants wore the Widex Dream-m-CB hearing aid on the aidable ear for 1 week. They then wore the BiCROS for the remainder of the study. Speech recognition and localization testing were completed in four hearing aid conditions (unaided, unilateral aided, fixed BiCROS, and adjusted BiCROS). Speech recognition was evaluated during the first three visits, whereas localization was evaluated over the course of the study. Participants completed the SSQ questionnaire before each visit. The CROS questionnaire was completed at the final visit. A repeated measures analysis of variance with Bonferroni post hoc analysis was used to evaluate the significance of the results on speech recognition, localization, and the SSQ.

RESULTS

The results revealed that the adjusted BiCROS condition improved speech recognition scores by 20 rau (rationalized arcsine unit) when speech was presented to the aidable ear and localization by 37% when sounds are presented from the side of the unaidable ear over the fixed BiCROS condition. Statistically significant benefit on the SSQ was also noted with the adjusted BiCROS condition compared to the unilateral fitting.

CONCLUSIONS

These findings supported the value of an on/off switch on a CROS transmitter because it allows convenient selective transmission of sounds. It also highlighted the importance of instructions and practice in using the BiCROS hearing aid successfully.

Hemodynamic comparison between Trifecta and Freestyle valves implanted in small aortic roots. One-year echocardiographic results from a prospective randomized study

BACKGROUND AND AIM OF THE STUDY

Aortic valve replacement in patients with a small aortic root may be associated to high residual gradients. In such patients, both stentless valves and aortic annulus enlargement can reduce these residual gradients. Several studies have reported that Trifecta valves yield very good hemodynamic results. The aim of the present study was to compare the hemodynamic performance of Trifecta vs. Freestyle valves at one year in patients with an aortic annulus ≤ 2.3 cm.

METHODS

Between September 2011 and September 2013, 40 patients with a native aortic annulus diameter ≤ 2.3 cm and average age of 81 ± 4 years, were randomized to receive either a St-Jude Trifecta stented prosthesis (20 patients) or a Medtronic Freestyle stentless prosthesis (20 patients).

RESULTS

No differences between Trifecta and Freestyle were found at one year in mean gradient s: 6.1 ± 3 mmHg and 6.6 ± 3 mmHg (p = 0.796); effective ori fice area: 1.82 ± 0.3 mmHg and 1.76 ± 0.4 mmHg (p = 0.676) or regression of left ventricular mass: - 25% ± 14 vs. -19% ± 16 (p = 0.204), respectively. Only moderate patient -pro sthesis mismatch was found, which affected 3 patient s in each group.

CONCLUSION

At one year both stentless and stented prostheses yielded comparable hemodynamic results. These data suggest that Trifecta implantation is a valid means of avoiding patient -prosthesis mismatch in aortic valve replacement in elderly patients with a small native aortic annulus.

Regression of left ventricular mass after implantation of the sutureless 3f Enable aortic bioprosthesis

Left ventricular hypertrophy in aortic stenosis is considered a compensatory response for the maintenance of systolic function but a risk factor for cardiac morbidity and death. We investigated the degree of left ventricular mass regression after implantation of the sutureless Medtronic 3f Enable Aortic Bioprosthesis. We studied 19 patients who, from May 2010 through July 2011, underwent isolated aortic valve replacement with the 3f Enable bioprosthetic valve, with clinical and echocardiographic follow-up at 6 months. The mean age was 77.1 ± 5.1 years (range, 68-86 yr); 14 patients were women (73.7%); and the mean logistic EuroSCORE was 15.4% ± 11.8%. Echocardiography was performed preoperatively, at discharge, and at 6 months' follow-up. The left ventricular mass was calculated by means of the Devereux formula and indexed to body surface area. The left ventricular mass index decreased from 146.1 ± 47.6 g/m(2) at baseline to 118.1 ± 39.8 g/m(2) at follow-up (P=0.003). The left ventricular ejection fraction did not change significantly. The mean transaortic gradient decreased from 57.3 ± 14.2 mmHg at baseline to 12.3 ± 4.6 mmHg at discharge and 12.2 ± 5.3 mmHg at follow-up (P <0.001), and these decreases were accompanied by substantial clinical improvement. No moderate or severe paravalvular leakage was present at discharge or at follow-up. In isolated aortic stenosis, aortic valve replacement with the 3f Enable bioprosthesis results in significant regression of left ventricular mass at 6 months' follow-up. However, this regression needs to be verified by long-term echocardiographic follow-up.

[The use of navigation system in the process of hip replacement]

Endoprosthesis replacement is the leading surgical procedures among the whole range of procedures performed on hip joint. The optimal position of the acetabular component of prosthesis is an important factor determining the success of the operation. In the Center of Traumatology and Orthopedics of the Burdenko Main Military Clinical Hospital of the Russian Ministry of Defense was developed a hip replacement navigation system. In the given prospective and randomized clinical study acetabular component prosthesis was fixed with the help of "image-free" navigation system (the control group, n=56) and with the help of navigation system developed by the authors (experimental group, n=50). An evaluation of the cup position after the operation was carried out by means of computed tomography of the pelvis. An average value of anteversion in the experimental group was 14 +/- 3 degrees in the control group--13 +/- 4 degrees. The average value of the inclination of the experimental group was 44?5, in the control was 45 +/- 4 degrees. Developed navigation system allows us orienting acetabular component of prosthesis properly, reducing time of surgical procedure and obtaining good and excellent functional results after the surgery.

Adhesive strength of the luting technique for passively fitting screw-retained implant-supported prostheses: an in vitro evaluation

PURPOSE

This in vitro study evaluated the adhesive strength of a technique to lute implant cylinders to metal frameworks in implant-supported prostheses and ensure a good passive fit.

MATERIALS AND METHODS

Different height samples were tested: In group 1, implant cylinders were 5 mm long; in group 2, they were 10 mm long. A universal testing machine (Instron) was used to perform pullout tests.

RESULTS

The luting technique provided enough adhesive strength for clinical use with greater adhesive strength in group 2 (mean pull-out strength: 2.85 kN in group 1 versus 3.79 kN in group 2).

CONCLUSIONS

The luting technique provides enough adhesive strength for clinical use. Moreover, specimens with a larger surface for adhesion demonstrated higher adhesive strength compared with shorter specimens.

Value of computed tomography-based three-dimensional surgical preoperative planning software in total hip arthroplasty with developmental dysplasia of the hip

INTRODUCTION

Preoperative planning with computed tomography (CT)-based three-dimensional templating has been expanded to achieve more precise placement of hip components. However, few reports have addressed the utility of three-dimensional surgical planning software for secondary osteoarthritis cases. This study therefore investigated the value of CT-based three-dimensional templating software for preoperative planning in primary total hip arthroplasty (THA), with an emphasis on developmental dysplasia of the hip.

MATERIALS AND METHODS

We performed a retrospective review of 65 hips in 57 patients who underwent cementless primary THA. The preoperative diagnosis was secondary osteoarthritis in all cases due to developmental dysplasia of the hip. All preoperative planning and postoperative evaluations were completed using CT-based three-dimensional templating software. We analyzed the accuracy of stem size prediction and cup size prediction, the reproducibility of preoperative and postoperative stem anteversion, and the absolute error in preoperative and postoperative stem anteversion using CT-based three-dimensional templating software.

RESULTS

The sizes of 65 % of the femoral stems (42/65) were estimated exactly, and 98 % (63/65) were accurately estimated to within one stem size. The final acetabular cup sizes corresponded exactly to the preoperatively planned size in 92 % of all cases (62/65). 100 % of the cup size estimates were accurate to within one cup size. There was strong reproducibility of preoperative and postoperative stem anteversion (r = 0.88, P < 0.05). The absolute error in stem anteversion was 4.0° ± 3.6°.

CONCLUSIONS

Using CT-based three-dimensional templating software made it possible to achieve reproducible stem anteversion and choose accurate stem and cup sizes in patients with developmental dysplasia of the hip.

Prosthodontics rehabilitation in velopharyngeal insufficiency

When surgical correction is less than successful or when children are poor candidates for surgery due to a large gap, a neuromuscular cause of velopharyngeal insufficiency (VPI), a strong gag reflex, or unfavorable anatomy, prosthetic intervention can result in the elimination of VPI. Surgery is ideal and best suited for long-term results; however, if needed, prosthetic correction can resolve VPI and is presented here. Indications for obturators, various designs, and clinical pearls when managing a child with an obturator are discussed. Correction of VPI must always be considered a multidisciplinary approach involving multiple modalities of treatment and specialties.

Patient-specific implants for lateral unicompartmental knee arthroplasty

PURPOSE

The lateral compartment of the knee is biomechanically and anatomically different from the medial compartment. Most commercially available unicompartmental implants are not designed specifically for the lateral compartment. Patient-specific custom-made unicompartmental knee arthroplasty (UKA) are designed to provide optimal fit on both femoral and tibial surfaces. This study aimed to determine if the use of patient-specific lateral unicompartmental implants provide better bone coverage than standard, off-the-shelf commercially available unicompartmental implants in lateral unicompartmental knee arthroplasties. As a secondary question, we wished to determine if patient-specific unicompartmental implants provide good clinical outcomes in surgical treatment of lateral unicompartmental osteoarthritis.

METHODS

We prospectively evaluated 33 patients who underwent lateral unicompartmental arthroplasty using patient-specific implants and instrumentation with a minimum of 24 months of follow-up. We analysed bone coverage observed in plain radiographs in 33 patient-specific lateral unicompartmental arthroplasties and compared to 20 lateral unicompartmental arthroplasties performed with commercially-available, standard off-the-shelf unicondylar implants.

RESULTS

The mean tibial implant lateral coverage mismatch in the patient-specific implant group was 1.0 mm (S.D. 1.2, range 0-5.7 mm ) versus 3.3 mm (S.D. 2.43, range 0.4-7.8 mm) in the conventional implant group (p < 0.01). In the patient specific cohort, pre-operative limb alignment was 3.3 (valgus) and post-operative limb alignment was -0.9 (varus). The Knee Society score improved from 48 (S.D. 16.2) to 95 (S.D. 7.6). Survivorship in the patient-specific implant group was 97% at an average follow up of 37 months, versus 85% at a follow-up period of 32 months for the standard implant group.

CONCLUSIONS

Patient-specific lateral unicompartmental knee replacements demonstrated better tibial coverage and provide excellent short-term clinical and radiological results as compared to a standard lateral UKA.

The 2014 Frank Stinchfield Award: The 'landing zone' for wear and stability in total hip arthroplasty is smaller than we thought: a computational analysis

BACKGROUND

Positioning of total hip bearings involves tradeoffs, because cup orientations most favorable in terms of stability are not necessarily ideal in terms of reduction of contact stress and wear potential. Previous studies and models have not addressed these potentially competing considerations for optimal total hip arthroplasty (THA) function.

QUESTIONS/PURPOSES

We therefore asked if component positioning in total hips could be addressed in terms of balancing bearing surface wear and stability. Specifically, we sought to identify acetabular component inclination and anteversion orientation, which simultaneously resulted in minimal wear while maximizing construct stability, for several permutations of femoral head diameter and femoral stem anteversion.

METHODS

A validated metal-on-metal THA finite element (FE) model was used in this investigation. Five dislocation-prone motions as well as gait were considered as were permutations of femoral anteversion (0°-30°), femoral head diameter (32-48 mm), cup inclination (25°-75°), and cup anteversion (0°-50°), resulting in 4320 distinct FE simulations. A novel metric was developed to identify a range of favorable cup orientations (so-called "landing zone") by considering both surface wear and component stability.

RESULTS

When considering both wear and stability with equal weight, ideal cup position was more restrictive than the historically defined safe zone and was substantially more sensitive to cup anteversion than to inclination. Ideal acetabular positioning varied with both femoral head diameter and femoral version. In general, ideal cup inclination decreased with increased head diameter (approximately 0.5° per millimeter increase in head diameter). Additionally, ideal inclination increased with increased values of femoral anteversion (approximately 0.3° per degree increase in stem anteversion). Conversely, ideal cup anteversion increased with increased femoral head diameter (0.3° per millimeter increase) and decreased with increased femoral stem anteversion (approximately 0.3° per degree increase). Regressions demonstrated strong correlations between optimal cup inclination versus head diameter (Pearson's r=-0.88), between optimal cup inclination versus femoral anteversion (r=0.96), between optimal cup anteversion versus head diameter (r=0.99), and between optimal cup anteversion and femoral anteversion (r=-0.98). For a 36-mm cup with a 20° anteverted stem, the ideal cup orientation was 46°±12° inclination and 15°±4° anteversion.

CONCLUSIONS

The range of cup orientations that maximized stability and minimized wear (so-called "landing zone") was substantially smaller than historical guidelines and specifically did not increase with increased head size, challenging the presumption that larger heads are more forgiving. In particular, when the cup is oriented to improve not only stability, but also wear in the model, there was little or no added stability achieved by the use of larger femoral heads. Additionally, ideal cup positioning was more sensitive to cup anteversion than to inclination.

CLINICAL RELEVANCE

Positioning THA bearings involves tradeoffs regarding stability and long-term bearing wear. Cup positions most favorable to minimization of wear such as low inclination and elevated anteversion were detrimental in terms of construct stability. Orientations were identified that best balanced the competing considerations of wear and stability.

A two-dimensional gauge and protocol for fitting oral appliances used in treating sleep breathing disorders

The authors tested whether a novel dental gauge that adjusts the mandibular position in both anterior-posterior (A-P) and vertical directions would improve the airway opening. A pilot study of nine patients with sleep breathing disorder used a snoring sound to guide mandibular vertical and protrusion positions with an adjustable mandibular positioning gauge (AMPG). Volumetric airway changes were confirmed by 2-dimensional (2-D) and 3-dimensional (3-D) measurements taken from cone-beam computed tomography (CBCT) scans. Patients experienced a significant average improvement in airway volumetric increase of 50%. The authors concluded that the AMPG device along with employing a snore sound technique as feedback can be used to ensure an improved awake state airway patency and may prove to be a means to optimize fit for oral appliances in treating obstructive sleep apnea.

Methods and preliminary outcomes of pediatric auditory brainstem implantation

OBJECTIVE

The objective was to provide information about methods used and preliminary outcomes for pediatric ABI (auditory brainstem implant).

STUDY DESIGN

An analysis of outcome was performed in children who received an ABI.

METHODS

Twelve children received a MED-EL ABI system. Progress in audition and language was monitored through parental reports, questionnaires, profiles, and closed-set tests.

RESULTS

The median number of active electrodes was 9 of 12. Seven of 12 users consistently respond to sound, and 5 of 12 do not. Highest performers can recognize words in small sets and have begun to use some words.

CONCLUSION

Auditory brainstem implants appear to be beneficial for some pediatric patients who cannot benefit from traditional cochlear implant surgery. Benefits in the short-term can be recognition of environmental sounds, recognition of some words and very commonly used phrases, and the beginning use of words. Although some of our ABI users demonstrate no response to sound, they do want to wear their sound processors all waking hours. The cause of lack of response may be related to the second intervention, which might have led to displacement of the electrode array, or presence of additional handicaps or syndromes. However, the results are less than optimal. The relatively short postoperative follow-up duration is a considered weakness of this study.

Correlation of intraoperative anthropometric measurement of resected Thai distal femurs between unisex and gender-specific implants

OBJECTIVE

To measure the intraoperative anthropometric dimensions of Thai distal femurs in order to correlate that data with unisex and gender-specific TKR implants, and to analyze the suitability of gender-specific prostheses for Thai female knees.

MATERIAL AND METHOD

Two hundred Thai patients (170 females and 30 males) who underwent unilateral TKR were recruited. Three parameters of resected distal femurs were measured intraoperatively including anteroposterior dimensions of medial (APM) and lateral (APL) condyles, and mediolateral (ML) width of total condyles which were compared with the dimensional data of two femoral implant components, Nexgen LPS-Flex and Gender Solution Nexgen LPS-Flex. Scatter diagrams were used to assess compatibility; the final type and size of implanted prostheses were recorded.

RESULTS

Thai females had significantly smaller knees than Thai males. The femoral components of both types of prostheses were found to have a tendency toward ML under-coverage in both female and male femurs. These mismatches were more noticeable when small-sized, gender-specific prostheses were used. The overall rate of use of gender-specific components in this study was 15%.

CONCLUSION

The unisex and gender-specific prostheses evaluated in this study do not appear suitable for Thai knees. Particular modifications of implants are required for Thai knees.

Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device compared to keratoplasty for the treatment of corneal ectasia

PURPOSE

To compare the ocular characteristics and visual outcomes of eyes with corneal ectasia that were fitted with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device to those that underwent keratoplasty.

DESIGN

Retrospective, comparative case series.

METHODS

We reviewed the charts of consecutive patients with corneal ectasia that were evaluated for PROSE or underwent keratoplasty at our institution. Clinical data, topographic indices, and corneal thickness were reviewed, and eyes were stratified according to the Amsler-Krumeich classification for severity of ectasia. Only the more severe eye of each patient was included in the study. We compared visual acuity before and after PROSE fitting or keratoplasty. For PROSE evaluations, achievement of satisfactory fit and continued wear at 1 year of follow-up were recorded.

RESULTS

From 2010 to 2012, 36 patients underwent PROSE evaluation for corneal ectasia while 37 patients underwent keratoplasty for the same indication. All eyes were successfully fitted with the PROSE device. Eyes in the keratoplasty group had more severe ectasia than eyes in the PROSE group (P = .038). Visual acuity was achieved more rapidly in the PROSE cohort compared to keratoplasty, and mean visual acuity was significantly better for all eyes (P < .0001) and when including only eyes with stage 4 ectasia (P < .001). More eyes with stage 4 ectasia achieved 20/25 visual acuity after PROSE than after keratoplasty (P = .003). At 1 year follow-up in the PROSE cohort, Snellen acuity was 20/28 (P = .108 vs keratoplasty), improving to 20/25 with over-refraction (P = .006 vs keratoplasty).

CONCLUSIONS

Eyes with advanced corneal ectasia can be successfully fitted with the PROSE device, and the visual acuity outcome for stage 4 ectasia was better and more rapid compared to keratoplasty. The acuity remained excellent with 1 year of follow-up. PROSE evaluation should be considered in patients with advanced corneal ectasia before proceeding to keratoplasty, especially if the ectasia is deemed stable.

Accuracy of acetabular cup placement in navigated THA with modified registration technique in semilateral decubitus position

BACKGROUND

The accuracy of cup placement in navigated total hip arthroplasty (THA) depends on the bony landmark registration intraoperatively. We created a semilateral decubitus position that combined the advantage of supine position for registration and lateral decubitus position for better femoral canal visualization.

OBJECTIVE

To evaluate the accuracy of cup placement within the "safe zone" and of imageless navigation measurement by comparing the intraoperative values of acetabular cup abduction and anteversion to postoperative CT values.

MATERIAL AND METHOD

All cases were performed in semilateral decubitus position with OrthoPilot THA plus 3.2 (cup only) software (Aesculap AG). Postoperatively, a multislice computed tomographic (CT) scan was obtained at two months or later for abduction and anteversion angle measurement. The abduction and anteversion angle measured on postoperative CTwere compared to the intraoperative measurement with apaired t-test anda correlation test at a 0.05 level ofsignificance.

RESULTS

Sixty-five cases were included in the present study. The median CT abduction value was 41 degrees, range 35 degrees to 48 degrees and the median navigated abduction value was 39.8 degrees, range 37.5 degrees to 45.5 degrees. The median paired difference was 1.60, range -3.4 degrees to 7.9, this difference was significant (p<0.001). The median CTanteversion value was 150, range 8 degrees to 28 degrees and the median navigated anteversion value was 12 degrees, range 5.9 degrees to 16.5 degrees. The mean paired difference was 3.2 degrees, range -2.6 degrees to 14.9 degrees, this difference was significant (p<0.0001).

CONCLUSION

Navigated THA with modified registration technique in semilateral decubitus position offered a more precise cup position as in supine and lateral decubitus position. It combined the advantage of supine position for registration and lateral decubitus position for better femoral canal visualization. Our modified registration technique by compressing the soft tissue above pubic symphysis (PS) to the abdomen and registering at the antero-superior-pubic-symphysis (ASPS) help us to increase the accuracy of anteversion angle.

Task-specific fall prevention training is effective for warfighters with transtibial amputations

BACKGROUND

Key factors limiting patients with lower extremity amputations to achieve maximal functional capabilities are falls and fear of falling. A task-specific fall prevention training program has successfully reduced prospectively recorded trip-related falls that occur in the community by the elderly. However, this program has not been tested in amputees.

QUESTIONS/PURPOSES

In a cohort of unilateral transtibial amputees, we aimed to assess effectiveness of a falls prevention training program by (1) quantifying improvements in trunk control; (2) measuring responses to a standardized perturbation; and (3) demonstrating retention at 3 and 6 months after training. Second, we collected patient-reported outcomes for balance confidence and falls control.

METHODS

Fourteen male military service members (26 ± 3 years) with unilateral transtibial amputations and who had been walking without an assistive device for a median of 10 months (range, 2-106 months) were recruited to participate in this prospective cohort study. The training program used a microprocessor-controlled treadmill designed to deliver task-specific postural perturbations that simulated a trip. The training consisted of six 30-minute sessions delivered over a 2-week period, during which task difficulty, including perturbation magnitude, increased as the patient's ability progressed. Training effectiveness was assessed using a perturbation test in an immersive virtual environment. The key outcome variables were peak trunk flexion and velocity, because trunk kinematics at the recovery step have been shown to be a determinant of fall likelihood. The patient-reported outcomes were also collected using questionnaires. The effectiveness of the rehabilitation program was also assessed by collecting data before perturbation training and comparing the key outcome parameters with those measured immediately after perturbation training (0 months) as well as both 3 and 6 months posttraining.

RESULTS

Mean trunk flexion angle and velocity significantly improved after participating in the training program. The prosthetic limb trunk flexion angle improved from pretraining (42°; 95% confidence interval [CI], 38°-47°) to after training (31°; 95% CI, 25°-37°; p < 0.001). Likewise, the trunk flexion velocity improved from pretraining (187°/sec; 95% CI, 166°-209°) to after training (143°/sec; 95% CI, 119°-167°; p < 0.004). The results display a significant side-to-side difference for peak trunk flexion angle (p = 0.01) with perturbations of the prosthetic limb resulting in higher peak angles. Prosthetic limb trips also exhibited significantly greater peak trunk flexion velocity compared with trips of the prosthetic limb (p = 0.005). These changes were maintained up to 6 months after the training. The peak trunk flexion angle of the subjects when the prosthetic limb was perturbed had a mean of 31° (95% CI, 25°-37°) at 0 month, 32° (95% CI, 28°-37°) at 3 months, and 30° (95% CI, 25°-34°) at 6 months. Likewise, the peak trunk flexion velocity for the prosthetic limb was a mean of 143°/sec (95% CI, 118°-167°) at 0 months, 143°/sec (95% CI, 126°-159°) at 3 months, and 132° (95% CI, 115°-149°) at 6 months. The peak trunk flexion angle when the nonprosthetic limb was perturbed had a mean of 22° (95% CI, 18°-24°) at 0 months, a mean of 26° (95% CI, 20°-32°) at 3 months, and a mean of 23° (95% CI, 19°-28°) at 6 months. The peak trunk flexion velocity for the nonprosthetic limb had a mean of 85°/sec (95% CI, 71°-98°) at 0 months, a mean of 96° (95% CI, 68°-124°) at 3 months, and 87°/sec (95% CI, 68°-105°) at 6 months. There were no significant changes in the peak trunk flexion angle (p = 0.16) or peak trunk flexion velocity (p = 0.35) over time after the training ended. The skill retention was present when either the prosthetic or nonprosthetic limb was perturbed. There were side-to-side differences in the trunk flexion angle (p = 0.038) and trunk flexion velocity (p = 0.004). Perturbations of the prosthetic side resulted in larger trunk flexion and higher trunk flexion velocities. Subjects prospectively reported decreased stumbles, semicontrolled falls, and uncontrolled falls.

CONCLUSIONS

These results indicate that task-specific fall prevention training is an effective rehabilitation method to reduce falls in persons with lower extremity transtibial amputations.

Evaluation of prominence of straight plates and precontoured clavicle plates using automated plate-to-bone alignment

Hardware prominence after plate fixation for clavicle fracture is a common complication. The aim of the study was to perform a 3D analysis of the prominence of different types of superior clavicle plates. An automated fitting of 3 straight and 10 precontoured plates was performed on 52 3D-CT-scan reconstructed cadaver clavicles. The mean and maximum bone-plate distance and maximum prominence was significant higher with the straight plates compared to the precontoured plates. The mean and maximum boneplate distance was significant higher with the precontoured DePuy-Synthes plates compared to the precontoured Acumed plates but when evaluating the maximum prominence there was no significant difference between the most commonly used 8-holes plates. To conclude, precontoured plates of the clavicula diminish significantly hardware prominence. There exists a difference in hardware prominence between different brands of precontoured plates but this difference is limited and in most cases not significant.