The standard sagittal starting point and entry angle for tibia intramedullary nails results in malreduction of proximal tibial fractures.

INTRODUCTION: The aim of this study was to determine the sagittal starting point and entry angle necessary for anatomic reduction in proximal tibial fractures and to compare reductions obtained using a standard versus modified sagittal entry angle. METHODS: Extra-articular proximal tibial fracture sawbone models were divided into three groups. The first group was used to determine the sagittal starting point and entry angle necessary for an anatomic reduction by inserting nails into the distal fragment and then reducing the proximal fragment over the nail. The second and third groups had nails inserted through the standard coronal and sagittal starting point using the standard sagittal entry angle (parallel to the anterior cortex) versus a more posteriorly directed modified sagittal entry angle (directed at the center of the tibia at the level of the tibia tubercle prominence). Fracture gapping and translation in the sagittal plane were measured for each group. RESULTS: Anatomic reduction was only possible with a sagittal starting point that was too posterior for actual use. The standard sagittal entry angle resulted in greater posterior fracture translation and less anterior fracture gapping then the modified sagittal entry angle, 10.6 ± 1.1 versus 1.6 ± 2.8 mm (p < 0.01) and 1.3 ± 0.5 versus 5.3 ± 2.5 mm (p = 0.01), respectively. CONCLUSION: Anatomic reduction was not achieved with the standard sagittal starting point and entry angle. Considering these finding, surgeons should have a low threshold to utilize adjunct reduction methods for these injuries.

Neophyte Skill Judging Corneoscleral Lens Clearance.

PURPOSE: This study examines the accuracy of neophyte clinicians' assessments of central corneal clearance (CCC) of a corneoscleral lens using lens center thickness (CT) as a biometric scale. METHODS: A normal participant was fit with a corneoscleral lens on both eyes. Observers (n = 34) from the final semester of their fourth year in optometric clinical training were instructed to estimate the amount of CCC through the approximate geometrical center of the lens using a standardized script which included a photograph identifying various zones. Observer estimates were then compared against anterior segment-OCT (AS-OCT) values obtained during calibration. RESULTS: Mean observer estimates of central corneal clearances were OD 220.5 ± 121.microns (range 50 to 480 microns) and OS 398.0 ± 159.1 microns (range 140 to 800 microns). The mean AS-OCT values were OD 105.5 ± 11.microns (range 84 to 121 microns) and OS 340.8 ± 15.2 microns (range 315 to 362 microns). Mann-Whitney test was statistically significant for comparison of median values OD (177.0; p = 0.001) and OS (260.0; p = 0.012). CONCLUSIONS: Neophyte clinicians in the final semester of their fourth year of optometric clinical training tend to significantly overestimate the amount of CCC in a normal subject with declining accuracy as the amount of clearance diminishes.

Systematic review of some prosthetic risk factors for periimplantitis.

STATEMENT OF PROBLEM: The recent literature underlines a correlation between plaque and the development of periimplantitis but neglects the importance of the prosthetic factors. PURPOSE: The purpose of this systematic review was to appraise the available literature to evaluate the role played by cement excess and misfitting components on the development of periimplantitis. MATERIAL AND METHODS: An electronic search restricted to the English language was performed in PubMed, Embase, and the Cochrane Register up to September 1, 2014, based on a selected search algorithm. Only cohort studies and case-control studies were included without additional restrictions. The presence of periimplantitis and implant failure were considered primary and secondary outcome variables. RESULTS: The search produced 275 potentially relevant titles, of which only 2 were found eligible. They showed a correlation in cemented implant prostheses between cement excess and the presence of periimplant disease, especially in patients with a history of periodontal disease. After cement excess removal by means of debridement, disease symptoms disappeared around most of the implants. CONCLUSIONS: Scientific articles on prosthetic risk factors for periimplantitis are scarce. Although the studies found on cement remnants have a high risk for bias, cement excess seems to be associated with mucositis and possibly with periimplantitis, especially in patients with a history of periodontal disease.

[Hearing aid fitting: Effect of doubling the standard rate on compliance, quality of results, and excess payments]. / Hörgeräteversorgung: Folgen der Festbetragsverdoppelung auf Compliance, Ergebnisqualität und Zuzahlungen.

BACKGROUND: This study investigates the effect that doubling the standard rate for hearing aid fitting which is covered by statutory insurance has had on the size of excess payments and compliance, as well as on benefits for patients and their satisfaction. METHODS: In April 2014, 859 members of a statutory insurance scheme (hkk) who received hearing aids in the 6 months prior to the reform were questioned on the timing and financial details of their hearing aid fitting, as well as on treatment compliance and quality of the results using a standardized questionnaire. In October 2014, the same questionnaire was used to collect these data from a further 622 insurance holders who had received hearing aids in the 8 months following introduction of the new regulation. Most of the questions concerning hearing quality corresponded to those of the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. RESULTS: The project revealed a statistically significant decrease of 6 percent points in the proportion of hearing aid users who had to pay any excess whatsoever; from 80.6% to 74.1%. However, 40% of the insured persons continued to pay an excess of 1000 euros and more. The subjective hearing quality remained practically unimproved by the reform and was statistically, almost without exception, independent of whether hearing aid users wore expensive devices associated with a large excess, or devices available at the standard rate. Finally, the study confirmed a previously recognized usage pattern characterized by noncompliance. For example, approximately 40% of hearing aid users did not wear their device in the everyday environment. This observation was independent of the size of the excess and the timing of the most recent visit to the hearing aid acoustician. CONCLUSION: Despite doubling of the standard rate, three quarters of patients pay an excess--sometimes a substantial one. The subjective hearing quality was not improved by doubling the standard rate; the majority of patients continue to complain of considerable problems with hearing in difficult situations (environments with background or reverberant noise). Satisfaction with hearing quality is neither dependent on the doubling of the standard rate, nor on whether or not an excess was paid. Compliance may possibly be improved by structured follow-up, which should involve the prescribing otorhinolaryngologists, as well as phoniatrists, pedaudiologists, and hearing aid acousticians.

Proposed norms for the Glasgow hearing-aid benefit profile (Ghabp) questionnaire.

OBJECTIVE: To form a normative set of responses to the GHABP questionnaire from a large regional dataset. DESIGN: Participants were asked to rate their hearing disability, handicap, hearing-aid (HA) use, HA benefit, HA satisfaction, and residual (aided) disability on a five-point scale for four situations: quiet conversation, television (TV) listening, noisy conversation, and group conversation. A subset of participants also estimated the time spent in these situations. STUDY SAMPLE: A group of 1574 adults with normal to profound hearing thresholds participated. RESULTS: There was a significant relationship between increasing perceived disability and increasing hearing loss as given by the better-ear audiometric average (BEA). Responses for HA measures did not vary greatly with hearing loss: HA use was reported as high, whereas residual disability, HA benefit, and satisfaction were all reported on average as moderate. CONCLUSIONS: The results can be used as a normative dataset with which to evaluate individual responses in the clinic, where the GHABP provides a useful short-form questionnaire to engage the patient. The lack of systematic changes in hearing-aid related responses shows room for improvement in the benefit afforded by amplification.

Navigating the reaming of the acetabular cavity in total hip arthroplasty: does it improve implantation accuracy?

Computer navigation in total hip arthroplasty is used to improve accuracy of component implantation. Reaming of the acetabular cavity during total hip arthroplasty (THA) can be navigated although this is not done routinely. We hypothesised that navigating the reaming of the acetabular cavity will improve implantation accuracy. A single surgeon series of 100 navigated THAs were analysed retrospectively. In 49 the reaming of the acetabular cavity was done using navigation and in 51 this was done freehand. The verified cup position and the error from the planned position were recorded. The mean error from planned to verified inclination was 2.20 degrees (SD 1.59°) in the navigated group versus 2.33 degrees (SD 1.96°) in the freehand group. The mean anteversion error was 1.92 degrees (SD 1.51°) for the navigated group and 1.45 degrees (SD 1.38°) for the freehand group. This was not statistically significant. This rejects our hypothesis. Navigating the reaming of the acetabular cavity did not improve the accuracy of the implantation against the set inclination and anteversion target during computer navigated THA.

Patient-specific instruments in total knee arthroplasty.

PURPOSE: In recent years, patient-specific instruments (PSI) has been introduced with the aim of reducing the overall costs of the implants, minimising the size and number of instruments required, and also reducing surgery time. The purpose of this study was to perform a review of the current literature, as well as to report about our personal experience, to assess reliability of patient specific instrument system in total knee arthroplasty (TKA). METHODS: A literature review was conducted of PSI system reviewing articles related to coronal alignment, clinical knee and function scores, cost, patient satisfaction and complications. RESULTS: Studies have reported incidences of coronal alignment ≥3° from neutral in TKAs performed with patient-specific cutting guides ranging from 6% to 31%. CONCLUSIONS: PSI seem not to be able to result in the same degree of accuracy as the CAS system, while comparing well with standard manual technique with respect to component positioning and overall lower axis, in particular in the sagittal plane. In cases in which custom-made cutting jigs were used, we recommend performing an accurate control of the alignment before and after any cuts and in any further step of the procedure, in order to avoid possible outliers.

[Implementation of the new quality assurance agreement for the fitting of hearing aids in daily practice. Part 1: New regulations pertaining to hearing aid fitting]. / Umsetzung der neuen Qualitätssicherungsvereinbarung zur Hörgeräteversorgung im Praxisalltag. Teil 1: Neue Regeln der Hörgeräteverordnung.

Alongside evidence-based medicine, quality assurance has becoming increasingly important in daily medical practice during the last decade. The introduction of a specific quality assurance questionnaire in connection with hearing aid fitting represents the first large-scale assessment of certain elements of patient satisfaction within Germany's public healthcare system. Part 1 of this review describes the most important new regulations pertaining to hearing aid fitting in the context of statutory health insurance. Since the vast majority of diagnostic and therapeutic procedures constituting the treatment of hearing loss patients--particularly the subsequent rehabilitation of hearing aid wearers in cooperation with hearing aid acousticians--occur outside the clinic, this review concentrates on the rules relevant to this area. After studying this part of the overview, readers should be able to understand and apply the sections of the statutory health insurance reimbursement guidelines relating to ambulant hearing aid fitting; furthermore, they should be able to understand and apply the standard evaluation criteria (Einheitlicher Bewertungsmaßstab, EBM).

[Implementation of the new quality assurance agreement for the fitting of hearing aids in daily practice. Part 2: New diagnostic aspects of speech audiometry]. / Umsetzung der neuen Qualitätssicherungsvereinbarung zur Hörgeräteversorgung im Praxisalltag. Teil 2: Diagnostische Neuerungen in der Sprachaudiometrie.

Upon review of the statutory health insurance reimbursement guidelines, a specific quality assurance questionnaire concerned with the provision of hearing aids was introduced that assesses elements of patient satisfaction within Germany's public healthcare system. APHAB questionnaire-based patient evaluation of the benefit of hearing aids represents the third pillar of audiological diagnostics, alongside classical pure-tone and speech audiometry. Another new aspect of the national guidelines is inclusion of free-field measurements in noise with and without hearing aids. Part 2 of this review describes new diagnostic aspects of speech audiometry. In addition to adaptive speech audiometry, a proposed method for applying the gold standard of speech audiometry - the Freiburg monosyllabic speech test - in noise is described. Finally, the quality assurance questionnaire will be explained as an appendix to template 15 of the regulations governing hearing aids.

Real-life efficacy and reliability of training a hearing aid.

OBJECTIVES: Commercial trainable hearing aids (HA) (i.e., devices that for a period are adjusted by the user in different acoustic environments and that subsequently with changing environments automatically adapt to the user's preferred settings), are readily available; however, little information exists about the efficacy of training a HA. The purpose of this study was to investigate the efficacy and reliability of training a HA in everyday environments. DESIGN: The participants were 26 hearing-impaired volunteers with a median age of 79 years and an average pure-tone average of 53 dB HL. Test devices were commercial, multimemory, prototype devices that enabled training of the compression characteristics in four frequency bands and in six sound classes. Participants wore the National Acoustic Laboratories nonlinear fitting procedure version 2 prescription for 3 weeks and trained the devices from the prescribed response for 3 weeks, before comparing their trained response with the prescription for 2 weeks. The devices were reset to the prescription, and 19 participants repeated the training and comparison trials. During the comparison trial, participants made daily diary ratings of their satisfaction with the programs, and a structured interview was completed at the end of the comparison trial. RESULTS: The participants displayed different needs for changing the prescription, with more daily adjustments leading to training across more sound classes. Unreliable observations were obtained from 8 participants after each of the test and retest comparison trials. Of the 10 participants who made sufficient changes to the prescription during the first trial, 80% preferred their trained response. The 8 "low trainers" reported no preference, and also reported lower overall satisfaction with the device. Fewer adjustments were made during the repeat trial, resulting in less training. Significant correlations between trained variations were seen for 63% of 19 participants. Of the 10 participants who provided valid data after both comparison trials, those who trained the device consistently generally showed consistent preferences, and vice versa. CONCLUSIONS: For those who wanted a change to the prescription, training was mostly effective. Limited data on reliability showed reasonable consistency in training outcomes and preferences. Findings, in particular on reliability, should be verified in larger populations. A guideline on how to clinically manage training with clients is presented.

Subsidence of SB Charité total disc replacement and the role of undersizing.

PURPOSE: A possible complication after total disc replacement (TDR) is subsidence, presumably caused by asymmetric implantation, implant undersizing or reduced bone quality. This study aims to quantify the degree of subsidence of an SB Charité TDR, and investigate whether undersizing is related to subsidence. METHODS: A custom developed software package (Mathworks) reconstructed 3D bone-implant geometry. A threshold for subsidence was determined by comparing penetrated bone volume (PBV) and rotation angles. Inter- and intra-observer reproducibilities were calculated. Subsidence was correlated to undersizing. RESULTS: High inter- and intra-observer correlation coefficients were found for the method (R > 0.92). Subsidence was quantified as PBV 700 mm(3) combined with a rotation angle >7.5°. A reduced risk of subsidence was correlated to >60 and >62 % of the bony endplate covered by the TDR endplate for L4 and L5, respectively. CONCLUSIONS: A reproducible method to determine undersizing was developed. Thresholds were determined related to a reduced risk of subsidence.

Is the threshold for postoperative prosthesis-patient mismatch the same for all prostheses?

PURPOSE: The effective orifice area index (EOAI) is used to define the prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR). However, few studies have so far evaluated whether the cutoff value for PPM varies across prostheses. This study assessed the hemodynamics in patients given a mechanical valve and then re-evaluated the validity of the commonly accepted threshold. METHODS: The subjects included 329 patients that underwent AVR with a St. Jude Medical Regent valve. The transvalvular pressure gradient and EOAI were determined echocardiographically, and the commonly accepted threshold was analyzed in relation to survival. RESULTS: The mechanical valves very often yielded a postoperative transvalvular pressure gradient >10 mmHg, and thus, clinically significant residual pressure, regardless of the EOAI. The slope of the curve describing the relationship between the transvalvular pressure gradient and EOAI was gentler than that reported for bioprosthetic valves, for which the pressure gradient rises sharply at EOAI <0.85 cm(2)/m(2). The commonly defined PPM did not affect the long-term survival or regression of the left ventricular mass index. CONCLUSIONS: The relationship between the transvalvular pressure gradient and the EOAI in patients given a mechanical prosthesis differed from the reference standard. These data suggest the need to reconsider the appropriate cutoff value for PPM in relation to different prostheses.

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging.

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

[Current approach for the prosthesis patient mismatch]. / Hasta protez uyumsuzluguna güncel yaklasim.

All prosthetic valves are at least mildly stenotic and have relatively high transvalvular pressure gradients that can be observed despite normal prosthesis function. Such gradients may be due to a mismatch between prosthesis effective orifice area (EOA) and patient's body size. Valve prosthesis-patient mismatch (VP-PM) may occur due to mismatches of both parameters, the expected hemodynamic performance of the prosthesis and the cardiac output requirements of the patient, which are largely related to the body size at rest. In other words, a prosthesis may be adequate for patients with a small body surface area (BSA) but might become obstructive for patients with a large BSA. The only parameter that has proven to be consistently and realistically useful to predict and describe VP-PM is the effective orifice area index (EOAI). The projected EOAI was identified as the best parameter to predict the VP-PM occurrence after surgery. VP-PM has been known to be independently and significantly associated with clinical outcomes. Severe VP-PM has a significant impact on early and late mortality, whereas moderate VP-PM may have a significant effect on mortality only in vulnerable subsets of patients, and particularly in those with depressed LV systolic function. The surgeon's anticipation of VP-PM prior to surgery, and successfully implented preventive strategies can reduce the incidence of VP-PM. Preventive strategies to avoid VP-PM should be individualized according to the anticipated severity of VP-PM and of the patient's baseline risk profile.

Manufacturer-provided effective orifice area index charts and the prevention of prosthesis-patient mismatch.

Prosthesis-patient mismatch (PPM) occurs when an implanted prosthesis is too small relative to the patient's body surface area (BSA). However, mismatch can often be prevented by indexing the expected effective orifice area (EOA) of a prosthesis to the patient's BSA and then selecting the largest implantable prosthesis to avoid mismatch. Previously, prosthesis manufacturers have attempted to simplify this process by providing charts that include the expected EOA for their prosthesis, already indexed into an array of BSA values. One caveat with these charts is that the expected EOA data must truly be reliable, or the charts will misguide the implanting surgeon. Manufacturer-provided charts could be improved by standardizing the EOA data, with one potential source being the hemodynamic data submitted to the United States Food and Drug Administration. This review discusses PPM, manufacturer-provided EOA charts, and the regulation of EOA data.

Digital evaluation of the reproducibility of implant scanbody fit--an in vitro study.

Dental restorations are increasingly manufactured by CAD/CAM systems. Currently, there are two alternatives for digitizing dental implants: direct intra-oral data capturing or indirect from a master cast, both with transfer caps (scanbodies). The aim of this study was the evaluation of the fit of the scanbodies and their ability of reposition. At the site of the first molars and canines, implants were placed bilaterally in a polymer lower arch model (original model), and an impression was taken for fabricating a stone cast (stone model). Ten white-light scans were obtained from the original and the stone model with the scanbodies in place. The scanbodies were retrieved after each scan and re-attached to the same implant or lab analogue. The first scan of the series served as control in both groups. The subsequent nine scans and control were superimposed using inspection software to identify the discrepancies of the four scanbodies in both experimental groups. The systematic error of digitizing the models was 13 µm for the polymer and 5 µm for the stone model. The mean discrepancy of the scanbodies was 39 µm (±58 µm) on the original implants versus 11 µm (±17 µm) on the lab analogues. The difference in scanbody discrepancy between original implants and lab analogues was statistically significant (p < 0.05, Mann-Whitney U test). Scanbody discrepancy was higher on original implants than on lab analogues. Fit and reproducibility of the scanbodies on original implants should be improved to achieve higher accuracy of implant-supported CAD/CAM fabricated restorations.

Scaling digital radiographs for templating in total hip arthroplasty using conventional acetate templates independent of calibration markers.

We describe a scaling method for templating digital radiographs using conventional acetate templates independent of template magnification without the need for a calibration marker. The mean magnification factor for the radiology department was determined (119.8%; range, 117%-123.4%). This fixed magnification factor was used to scale the radiographs by the method described. Thirty-two femoral heads on postoperative total hip arthroplasty radiographs were then measured and compared with the actual size. The mean absolute accuracy was within 0.5% of actual head size (range, 0%-3%) with a mean absolute difference of 0.16 mm (range, 0-1 mm; SD, 0.26 mm). Intraclass correlation coefficient showed excellent reliability for both interobserver and intraobserver measurements with intraclass correlation coefficient scores of 0.993 (95% CI, 0.988-0.996) for interobserver measurements and intraobserver measurements ranging between 0.990 and 0.993 (95% CI, 0.980-0.997).

Intra- and inter-observer variation during femoral jig rotational alignment in knee arthroplasty.

INTRODUCTION/AIMS: Rotational alignment of the femoral prosthesis is important in total knee arthroplasty to improve performance and reduce complications. This study investigates the differences between two popular referencing methods and evaluates the variability of surgeons' techniques (inter-observer) and their reproducibility (intra-observer) of femoral alignment. METHODS: Eight surgeons each established the femoral rotational alignment on four duplicate sets of six cadaveric femoral bone casts, referencing from the epicondylar axis and from the posterior femoral condyles. These derived axes were compared against a reference Whiteside's line (anteroposterior axis). RESULTS/SUMMARY: There was no significant difference between referencing techniques and a tendency to align the femoral component in slight external rotation. Femoral rotational alignment was reproducible by each surgeon. Extensive and significant variation in alignment exists between surgeons, independent of other factors (p < 0.001).

[Templating and radiological outcome monitoring for elective total hip arthroplasty. Applied quality management principles for safe patient care]. / Operationsplanung und Ergebniskontrolle in der elektiven Hüftendoprothetik. Angewandtes Qualitätsmanagement als Grundlage einer sicheren Patientenversorgung.

Implementation of total hip arthroplasty is a successful and reliable treatment for end-stage osteoarthritis. The biomechanics and components as well as the fixation were selected with the aid of templating. Based on a cohort of 114 patients the quality of digital X-rays and the operative results were determined. There was a slight leg lengthening and a good offset reconstruction in these patients. For the patients with replacement of the second hip the leg lengthening was smaller. The cup inclination was at 43° and 44° within the desired range. The prediction of the exact component size used was 40% for the cup and 29% for the stem.Through variation in scaling of the digital X-ray a diminishing prediction accuracy was found in our study. The correction of biomechanics and position of components showed good quality in patient care. Templating and assessment of the postoperative result in total hip arthroplasty is a model for continuous quality management and can be recommended for safe patient care.