Standard Prosthesis Research Articles

COMPARATIVE EVALUATION OF THE ORAL CAVITY HYGIENE DEPENDING ON THE PARTIAL REMOVABLE DENTURE

The aim of the work is to investigate the state of oral hygiene and survey the condition of patients prosthetic with an improved orthopedic construction and standard partial removable laminar prostheses. Material and methods. A total of 150 patients were examined, of which 150 patients with dentition defects aged from 18 to 68 years. To determine the diagnosis, Kennedy's classification of dentition defects, periodontal diseases, proposed by MF, was used. Danilevsky. For comparative evaluation, we used the data obtained in 50 people in the control group of the same age without dentition defects. The study included a comprehensive comparative analysis of the nature of changes in the dental system at different stages of the development of the pathological process. To determine the state of oral hygiene, Fedorov-Volodkina and Green-Vermillion indices were used. Assessment of the state of solid tissues was performed using the index of the CPU. Results. In patients with prosthetics with improved temporary removable prosthesis for the prevention of infectious and inflammatory processes, the improvement of hygienic indices in all periods after prosthetics was determined. Conclusion. According to the data on the intensity of caries, we found a statistically significant increase in this indicator in accordance with the type of construction used, namely, in the control group, the intensity of caries was set at 4.15±0.052, 4.06±0.050, and 5.33±0.057. We observed a statistically significant increase in the Green-Vermillion index between all groups, namely, from 0.95±0.0241.06±0.038, 1.17±0.055, respectively, in individuals with a prosthesis duration of 1 month, 3 months and 6 months of the Fedorov index – Volodkina in persons of group 1 (prosthetic 6 months back) was at the level of 1.65±0.034 and 1.78±0.052, which corresponds to a good index value, whereas in the control group the corresponding indicator was at the level of 1.74±0.048, which corresponded to a satisfactory index value.

Study of the Quality of Life in Patients With Standard External Breast Prosthesis Compared to Patients With Custom-made Breast Prosthesis.

Study of the Quality of Life in Patients With Standard External Breast Prosthesis Compared to Patients With Custom-made Breast Prosthesis.

Extended total tmj prostheses for simultaneous tmj replacement and restoration of major mandibular defects

Background: The temporomandibular joint (TMJ) replacement may be required in complex cases with additional mandibular or temporal bone defects. In cases in which the length and complexity of these bone defects made autogenous grafts unsuitable, the customized extended TMJ prostheses can be a viable treatment option, restoring the facial anatomical contour and function. The computer-aided-design/computer-aided-manufacturing (CAD/CAM) technology made it possible pushing the boundaries of the customized standard TMJ prostheses to include extended versions, in which the mandibular and fossa components can both replace the TMJ and restore mandibular or temporal bones continuity. Considering the bone defects diversity, there is a need of different lengths to the prosthesis's extensions.

Stapes Prosthesis Length: One Size Fits All?

Background: The insertion of the stapes piston into the vestibule provides the physical basis for a successful stapedotomy. In routine clinical practice, two different ways to handle prosthesis length are performed: (1) an individualized measurement of the stapes prosthesis length or (2) a standard prosthesis length for all cases. Objective: The objective of this study was to compare both ways of handling prosthesis length and the effect of these methods on insertional prosthesis depth. Material and Method: We retrospectively evaluated 39 patients after performing a stapedotomy for radiologically estimated vestibular stapes prosthesis insertion depth. The individual measured length data were hypothetically changed to a standard length of 4.75, 5, 5.25, and 5.5 mm, and the insertion depths were compared. Results: The individually measured prosthesis lengths led to an insertion depth between 0.2 and 1.6 mm (mean 0.74 mm). The ratio of insertion depth/vestibular depth was between 8 and 59.1% (mean 26.6%). The different assumed standard lengths led to different rates of the vestibulum positions and possible bony contacts at the vestibulum floor. Conclusion: The individual measurement led to a zero rate of the vestibulum positions of stapes prosthesis pistons with a low insertion depth/vestibular depth ratio.

A new method to evaluate the influence of the glenosphere positioning on stability and range of motion of a reverse shoulder prosthesis

PurposeShoulder instability and reduced range of motion are two common complications of a total reverse shoulder arthroplasty. In this work, a new approach is proposed to estimate how the glenoid component positioning can influence the stability and the range of motion of a reverse shoulder prosthesis. Materials and methodsA standard reverse shoulder prosthesis has been analysed. To perform virtual simulation of the shoulder-prosthesis assembly, all the components of the prosthesis have been acquired via a 3D laser scanner and the solid models of the shoulder bones have been reconstructed through CT images. Loads on the shoulder joint have been estimated using anatomical models database. A new virtual/numerical procedure has been implemented using a 3D parametric modelling software to find the optimal position of the glenosphere. ResultsSeveral analyses have been performed using different configurations obtained by changing the glenoid component tilt and the lateral position of the glenosphere, modified through the insertion of a cylindrical spacer. For the analysed case study, it was found that the interposition of a spacer (between the baseplate and the glenoid) and 15° inferior tilt of the glenosphere allow improving the range of motion and the stability of the shoulder. ConclusionsSome common complications of the reverse shoulder arthroplasty could be effectively reduced by a suitable positioning of the prosthesis components. In this work, using a new method based on virtual simulations, the influence of the glenosphere positioning has been investigated. An optimal configuration for the analysed case study has been found. The proposed approach could be used to find, with no in vivo experiments, the optimal position of a reverse shoulder prosthesis depending on the different dimensions and shape of the bones of each patient.

Preliminary clinical study of Chinese standard alloplastic temporomandibular joint prosthesis

PurposeTo evaluate the preliminary clinical outcomes on the Chinese standard temporomandibular joint (TMJ) prostheses. Patients and methodsPatients who underwent Zimmer Biomet and Chinese standard prostheses by one surgeon between January 1st 2016 and June 30th 2017 were included in the study. Maximum incisal opening (MIO), pain, diet, and joint function were measured; CT scans were taken before and after the operation and during at least a 12-months follow-up for evaluation. ResultsThirty-five patients including 12 with Chinese standard prostheses and 23 with Biomet stock prostheses participated in the study. After an average of 14.3 months follow-up, both types of prostheses could significantly improve MIO, diet, and joint function, and relieve pain (p < 0.05). There were no significant differences in diet, pain level and joint function either before or after the operation between the two types of prostheses, whereas after the operation, the MIO with Chinese standard prostheses was significantly larger than with the Biomet stock prostheses (p < 0.05). However, there was no significant difference before operation (p > 0.05). A computed tomography (CT) scan showed that no prostheses dislocated or broke, no screws loosened, and ectopic bone formation appeared around the alloplastic condyle. ConclusionChinese standard TMJ prostheses are effective and stable in clinical application. They can significantly improve mouth opening, diet, and joint function and relieve pain.

ИССЛЕДОВАНИЕ КАЧЕСТВА ЖИЗНИ СТОМАТОЛОГИЧЕСКИХ БОЛЬНЫХ, ИСПОЛЬЗУЮЩИХ ИММЕДИАТ-ПРОТЕЗЫ В ПЕРИОД ПОСЛЕ ЭКСТРАКЦИИ ЗУБА ДО ПРОВЕДЕНИЯ ИМПЛАНТАЦИИ

Objective: To investigate the quality of life (QL) of dental patients using original and classic immediate prostheses in the post-extraction tooth period before implantation. Methods: Within the frame of this study, we analyzed 86 questionnaires of patients separated into two groups: the main (n=67) and the control (n=19) group. The level of QL was assessed using the standard OHIP-14 questionnaire (Oral Health Impacts Profile) consisting of 14 questions. Patient questionnaires were conducted 4 times: to the next day after tooth extraction and overlaying of the immediate prosthesis, 2 weeks after the extraction, which corresponds to the ending of acute inflammatory phase, as well as after 3 and 6 months. In the main group, as an immediate prosthesis was used a prosthesis with an intermediate part, the basis of which is made of a hollow base with a bioinert mesh stretched between the walls of the basis of the intermediate part, and in the comparison group patients used immediate prosthesis, made by standard technology. Results: A study of the questionnaires in terms of observation from the time of tooth removal to 6 months showed that in the main and control groups on the first day after the overlaying immediate prosthesis levels of QL were 18.45±2.642 and 19.79±2.485, respectively. On the 14th day of these parameters corresponded to the values of 16.52±2.331 and 17.32±2.709. In the III and IV stages of the study (i.e. 3 and 6 months) determine the equalization of the average QL is defined by the advantage of the values in the III stage of the main group. Conclusion: The use of the original immediate prosthesis in temporary prosthetics of the post-extraction defect of the front incisor of the upper jaw gives the prevailing dynamics and more positive results relative to the standard immediate prosthesis. Keywords: Quality of life, implantation, immediate prostheses, rehabilitation, post-extraction period, orthopedic dentistry.

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics.

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off-the-shelf prosthesis in posterior cruciate-retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off-the-shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep-knee-bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior-posterior translation and internal-external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep-knee-bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep-knee-bend loading conditions.

Blood cytokine pattern and clinical outcome in knee arthroplasty patients: comparative analysis 5 years after standard versus “hypoallergenic” surface coated prosthesis implantation

Background and purpose — Metal sensitivity might provoke complications after arthroplasty. Correspondingly, coated “hypoallergenic” implants are of interest but long-term follow-up data are missing. Thus, we assessed immunological and clinical parameters in such patients.Patients and methods — 5 years’ follow-up data were obtained from 3 centers, which used either a standard total knee replacement (TKR) or the identical implant with multilayer surface zirconium nitride based coating. Of the 196 patients (mean age 68 years (44–84), 110 females) 97 had arthroplasty with a coated surface, and 99 were treated by a standard TKR of the same type. Investigations were Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS), radiographic analysis, and cytokine measurement in peripheral blood. Pro- and anti-inflammatory cytokines were evaluated by cytometric beads assay and RT-PCR.Results — Survival rate (Kaplan–Meier) was 98% for coated and 97% for uncoated implants after 5 years. Mechanical axis and KSS pain score (42 vs. 41 (0–50)) were comparable. Most serum cytokine levels were comparable, but mean interleukin-8 and interleukin-10 levels were higher in the group with an uncoated implant. IL-8: 37 (SD 7.5) pg/mL vs. 1.1 (SD 4.3) (p < 0.001); IL-10: 3.6 (SD 2.5) vs. 0.3 (SD 1.8) pg/mL (p < 0.001).Interpretation — There was similar clinical outcome 5 years after standard and surface-coated TKR. In peripheral blood there was an increased pro-inflammatory status, i.e., significant elevation of IL-8 and the anti-inflammatory IL-10, after standard uncoated prosthesis. Any long-term effects of these cytokine changes are unknown.

Comparison of bone adaptation after modification in biomet standard alloplastic temporomandibular joint prostheses

PurposeThe aim of the study was to compare bone adaptation after design modification in Biomet stock prostheses. Materials and methodsComputed tomography (CT) data of the patients treated with a Biomet TMJ replacement from 2010 to 2016 were recruited. Fossa prosthesis with a bulge and 4 types of condyle-ramus angle prostheses were virtually designed and implanted by computer-assisted simulation. The amount of bone trimming including fossa, mandibular ramus and bone graft were measured by ProPlan CMF 1.4 software. The differences between the original and modified prostheses were compared by SPSS 17.0 software for statistical analysis. ResultsThere were 54 patients’ CT data included in the study. The amount of fossa bone trimming was 150.20 mm3 in the modified prosthesis and 281.82 mm3 in the original one. The amount of ramus bone trimming was 103.86 mm3 in the modified prosthesis and 229.45 mm3 in the original one. The amount of fossa bone grafting was 95.88 mm3 in the modified prosthesis and 263.03 mm3 in the original one. There were significant differences between them (p = 0.000). ConclusionsThe modified Biomet prostheses design requires less bone trimming and grafting for implantation.

A novel gel liner system with embedded electrodes for use with upper limb myoelectric prostheses.

We present the development and evaluation of a gel liner system for upper limb prosthesis users that enables acquisition of electromyographic (myoelectric) control signals through embedded electrodes and flexible, conductive fabric leads. This liner system is constructed using a manufacturing approach rather than by modifying a commercially available liner. To evaluate the efficacy, eight male individuals with transhumeral amputations used this system, with standard myoelectric prostheses, for home trials lasting an average of 7.3 weeks. Before and after the home trials, electrical resistance of the cumulative 218 embedded electrodes and leads within 10 gel liner systems was measured and found to increase slightly (from an average of 13.4 to 27.5 Ω) after usage. While this increase was statistically significant (p = 0.001), all but one of the final resistance values remained low enough to enable consistent myoelectric control. User impressions were evaluated through a questionnaire comparing the liner prototypes to their own myoelectric prosthesis socket interface. Subjects preferred the liner prototype (p = 0.008) over their own system in the clinical areas of comfort, suspension, function, and, especially, ease of use. These results suggest that this gel liner system is a clinically viable option and that it may offer advantages over current clinical technology for users of upper limb myoelectric prostheses.

Dual-energy CT and ceramic or titanium prostheses material reduce CT artifacts and provide superior image quality of total knee arthroplasty

PurposeTo evaluate the influence of different scan parameters for single-energy CT and dual-energy CT, as well as the impact of different material used in a TKA prosthesis on image quality and the extent of metal artifacts.MethodsEight pairs of TKA prostheses from different vendors were examined in a phantom set-up. Each pair consisted of a conventional CoCr prosthesis and the corresponding anti-allergic prosthesis (full titanium, ceramic, or ceramic-coated) from the same vendor. Nine different (seven dual-energy CT and two single-energy CT) scan protocols with different characteristics were used to determine the most suitable CT protocol for TKA imaging. Quantitative image analysis included assessment of blooming artifacts (metal implants appear thicker on CT than they are, given as virtual growth in mm in this paper) and streak artifacts (thick dark lines around metal). Qualitative image analysis was used to investigate the bone–prosthesis interface.ResultsThe full titanium prosthesis and full ceramic knee showed significantly fewer blooming artifacts compared to the standard CoCr prosthesis (mean virtual growth 0.6–2.2 mm compared to 2.9–4.6 mm, p < 0.001). Dual-energy CT protocols showed less blooming (range 3.3–3.8 mm) compared to single-energy protocols (4.6–5.5 mm). The full titanium and full ceramic prostheses showed significantly fewer streak artifacts (mean standard deviation 77–86 Hounsfield unit (HU)) compared to the standard CoCr prosthesis (277–334 HU, p < 0.001). All dual-energy CT protocols had fewer metal streak artifacts (215–296 HU compared to single-energy CT protocols (392–497 HU)). Full titanium and ceramic prostheses were ranked superior with regard to the image quality at the bone/prosthesis interface compared to a standard CoCr prosthesis, and all dual-energy CT protocols were ranked better than single-energy protocols.ConclusionsDual-energy CT and ceramic or titanium prostheses reduce CT artifacts and provide superior image quality of total knee arthroplasty at the bone/prosthesis interface. These findings support the use of dual-energy CT as a solid imaging base for clinical decision-making and the use of full-titanium or ceramic prostheses to allow for better CT visualization of the bone–prosthesis interface.

One-Stage Treatment of Giant Condylar Osteoma: Alloplastic Total Temporomandibular Joint Replacement Aided by Digital Templates

To introduce the surgical techniques and evaluate the effect of alloplastic total temporomandibular joint (TMJ) replacement aided by digital templates in giant condylar osteoma. Three patients with giant condylar osteoma were enrolled in this study. The maximal mouth opening was 1.9 cm on average. All the patients were underwent the computed tomography scan (slice thickness 1 mm) and the data were imported to Proplan 1.3 software for 3-dimensional bony segmentation and reconstruction. Osteotomy line and digital template according the 3-dimensional measurement were designed. All the joints were replaced with Biomet standard prosthesis under general anesthesia. All the operations were successfully performed. The follow-up period was from 6 to 18 months (average, 12 months). Pain relief of the joint and mouth-opening improvement were significant in 3 patients. No infection or loosening the prostheses was occurred. The occlusal relationship kept stable in all patients. Total TMJ replacement with standard prosthesis is a good strategy for TMJ reconstruction after giant condylar osteoma excision. The joint pain and the mouth-opening limitation resulted from giant condylar osteoma were markedly improved. Long-term effect remains to be evaluated based on a long-term follow-up.

A prospective multicentric analysis of patient data and functional tests of standard knee prosthesis compared to individualized knee prosthesis implantation (NexGen CR vs. ConforMIS iTotal CR)

Aims and Objectives: Knee prosthesis have traditionally been developed using average knee morphologies. However, patient-specific knee implants are now available, which are designed on the basis of an individual patient anatomy with preoperative CT scan. The Aim of this study was a comprehensive comparison of patient reports and blinded functional tests between patients who received a conventional implant (OTS, Zimmer NexGen CR Flex) and patients with a patient-specific implant (CIM, ConforMIS iTotal). Materials and Methods: 121 patients with either a ConforMIS iTotal CR prosthesis (ConforMIS, Bedford USA, 60 patients) or a NexGen CR Flex prosthesis (Zimmer, Winterthur Switzerland, 61 patients) were prospectively recorded. Both patient group reveal no significant differences in BMI or age. However, patients in ConforMIS group were examined on an average of two months earlier than control group. The follow-up examinations were blinded and the collected data consist of the Knee Society Score (KSS) as well as functional tests consisting of an 8 m “walk” (WALK), a “Timed-Up-and-Go” (TUG) and the “Timed Up and Down Stairs” Test (TUDS). The “aggregated locomotor function (ALF) score” was then calculated based on the addition of the average times of the three function tests (ALF = WALK + TUG + TUDS). A 2-sample t-test was used to compare the functional tests between the CIM and OTS prosthesis groups. Results: The analysis of functional tests showed no significant difference between patients of both cohorts. Patients which received a ConforMIS prosthesis moved as quickly as patients with a conventional prosthesis (p> 0.05 each). In addition, the ALF values showed no significant difference between the two groups (21.2 s vs. 21.7 s, p = 0.67). Furthermore, also the KSS scores did not differ in the two cohorts. Conclusion: The results of this blinded follow-up study demonstrates, that patients with individualized knee prosthesis had no benefit in functional activities of daily life (WALK, TUG and TUDS) in comparison to patients with conventional knee endoprosthesia. Additionally, this study revealed no evidence of improved patient satisfaction, pain relief or fulfillment of expectations as measured by the KSS.

Total Ossicular Replacement Prosthesis: A New Fat Interposition Technique.

Objective:To compare audiometric results between the standard total ossicular replacement prosthesis (TORP-S) and a new fat interposition total ossicular replacement prosthesis (TORP-F) in pediatric and adult patients and to assess the complication and the undesirable outcome.Study design:This is a retrospective study.Methods:This study included 104 patients who had undergone titanium implants with TORP-F and 54 patients who had undergone the procedure with TORP-S between 2008 and 2013 in our tertiary care centers. The new technique consists of interposing a fat graft between the 4 legs of the universal titanium prosthesis (Medtronic Xomed Inc, Jacksonville, FL, USA) to provide a more stable TORP in the ovale window niche. Normally, this prosthesis is designed to fit on the stapes’ head as a partial ossicular replacement prosthesis.Results:The postoperative air-bone gap less than 25 dB for the combined cohort was 69.2% and 41.7% for the TORP-F and the TORP-S groups, respectively. The mean follow-up was 17 months postoperatively. By stratifying data, the pediatric cohort shows 56.5% in the TORP-F group (n = 52) compared with 40% in the TORP-S group (n = 29). However, the adult cohort shows 79.3% in the TORP-F group (n = 52) compared with 43.75% in the TORP-S group (n = 25). These improvements in hearing were statistically significant. There were no statistically significant differences in the speech discrimination scores. The only undesirable outcome that was statistically different between the 2 groups was the prosthesis displacement: 7% in the TORP-F group compared with 19% in the TORP-S group (P = .03).Conclusions:The interposition of a fat graft between the legs of the titanium implants (TORP-F) provides superior hearing results compared with a standard procedure (TORP-S) in pediatric and adult populations because of its better stability in the oval window niche.

TWO-STAGE REVISION HIP REPLACEMENT PATIENS WITH SEVERE ACETABULUM DEFECT (CASE REPORT)

Favorable short-term results of arthroplasty are observed in 80–90% of cases, however, over the longer follow up period the percentage of positive outcomes is gradually reduced. Need for revision of the prosthesis or it’s components increases in proportion to time elapsed from the surgery. In addition, such revision is accompanied with a need to substitute the bone defect of the acetabulum. As a solution the authors propose to replace pelvic defects in two stages. During the first stage the defect was filled with bone allograft with platelet-rich fibrin (allografting with the use of PRF technology). After the allograft remodeling during the second stage the revision surgery is performed by implanting standard prostheses. The authors present a clinical case of a female patient with aseptic loosening of acetabular component of prosthesis in the right hip joint, with failed hip function of stage 2, right limb shortening of 2 cm. Treatment results confirm the efficiency and rationality of the proposed bone grafting option. The authors conclude bone allograft in combination with the PRF technology proves to be an alternative to the implantation of massive metal implants in the acetabulum while it reduces the risk of implant-associated infection, of metallosis in surrounding tissues and expands further revision options.

Functional midterm follow-up comparison of stemless total shoulder prostheses versus conventional stemmed anatomic shoulder prostheses using a 3D-motion-analysis

BackgroundThe aim of this study is to compare the functional midterm outcome of stemless shoulder prostheses with standard anatomical stemmed shoulder prostheses and to show that the STEMLESS results are comparable to the STEMMED with respect to active maximum range of shoulder motion (ROM) and Constant score (CS).MethodsSeventeen patients underwent total shoulder arthroplasty (TSA) in 25 shoulder joints. Stemless TSA was performed in 12 shoulder joints (group STEMLESS), third-generation stemmed TSA in 13 shoulder joints (group STEMMED). Functional results were documented using the CS. 3D-motion-analysis using the Heidelberg upper extremity model (HUX) was conducted to measure active maximum (ROM).ResultsThe group STEMLESS achieved a CS of 67.9 (SD 12.0) points and the group STEMMED of 70.2 (SD 5.8 points) without significant difference between the groups (p = 0.925). The maximum ROM of the group STEMLESS, ascertained by 3-D-motion-analysis, was in forward flexion 125.5° (SD 17.2°), in extension 49.4° (SD 13.8°), in abduction 126.2° (SD 28.5°) and in external rotation 40.3° (SD 13.9°). The maximum ROM of the group STEMMED, also ascertained by 3-D-motion analysis, was in forward flexion 135.0° (SD 16.8°), in extension 47.2° (SD 11.5°), in abduction 136.3° (SD 24.2°) and in external rotation 40.1° (SD 12.2°). The maximum ROM of the STEMLESS group was lower in forward flexion and abduction, higher in extension and almost identical in external rotation. But there was no significant difference (forward flexion p = 0.174, extension p = 0.470, abduction p = 0.345, external rotation p = 0.978).ConclusionBoth types of shoulder prostheses achieve a similar and good active ROM and similar results in CS.Trial registrationDRKS00013166, retrospectively registered, 11.10.2017

Prosthetic Considerations in Neophallic Reconstruction

Phalloplasty may be performed in patients with acquired or congenital penile insufficiency or transgender individuals who desire phallic construction. Demand for neophallus creation and prosthesis placement has increased in recent years with growing coverage for gender affirming surgery among transgender patients. This report describes consideration of prosthetic implantation in neophallic reconstruction. Prosthesis implantation in a neophallus requires special consideration regarding avoidance of critical structures, proximal prosthesis anchoring, and distal cushioning in patients without native corpora cavernosa. Neophallus prostheses are associated with increased risk of infection, extrusion, erosion, and device migration relative to standard prostheses, with a high revision rate. Implanters should have a thorough understanding of neophallic reconstructive technique prior to proceeding with device placement. Current literature on this subject consists predominantly of retrospective reviews and case reports with variable outcome measures. The creation of validated assessment tools will provide more meaningful data to inform provider counseling and patient expectations.

Mid-term outcomes of 77 modular radial head prostheses.

Radial head arthroplasty (RHA) may be used in the treatment of non-reconstructable radial head fractures. The aim of this study was to evaluate the mid-term clinical and radiographic results of RHA. Between 2002 and 2014, 77 RHAs were implanted in 54 men and 23 women with either acute injuries (54) or with traumatic sequelae (23) of a fracture of the radial head. Four designs of RHA were used, including the Guepar (Small Bone Innovations (SBi)/Stryker; 36), Evolutive (Aston Medical; 24), rHead RECON (SBi/Stryker; ten) or rHead STANDARD (SBi/Stryker; 7) prostheses. The mean follow-up was 74.0 months (standard deviation (sd) 38.6; 24 to 141). The indication for further surgery, range of movement, mean Mayo Elbow Performance (MEP) score, quick Disabilities of the Arm, Shoulder and Hand (quickDASH) score, osteolysis and positioning of the implant were also assessed according to the design, and acute or delayed use. The mean MEP and quickDASH scores were 90.2 (sd 14; 45 to 100), and 14.0 points (sd 12; 1.2 to 52.5), respectively. There were no significant differences between RHA performed in acute or delayed fashion. There were 30 re-operations (19 with, and 11 without removal of the implant) during the first three post-operative years. Painful loosening was the primary indication for removal in 14 patients. Short-stemmed prostheses (16 mm to 22 mm in length) were also associated with an increased risk of painful loosening (odds ratio 3.54 (1.02 to 12.2), p = 0.045). Radiocapitellar instability was the primary indication for re-operation with retention of the implant (5). The overall survival of the RHA, free from re-operation, was 60.8% (sd 5.7%) at ten years. Bipolar and press-fit RHA gives unsatisfactory mid-term outcomes in the treatment of acute fractures of the radial head or their sequelae. The outcome may vary according to the design of the implant. The rate of re-operation during the first three years is predictive of the long-term survival in tight-fitting RHAs. Cite this article: Bone Joint J 2017;99-B1197-1203.

Availability of Additional Mediolateral Implant Option During Total Knee Arthroplasty Improves Femoral Component Fit Across Ethnicities: Results of a Multicenter Study.

Background:Anatomical variation may represent a challenge in achieving a close fit between a prosthesis and a patient’s osseous geometry in total knee arthroplasty (TKA). The purposes of this study were to determine whether the shape of the distal part of the femur differs among ethnicities, whether these differences affect the fit of the femoral component of a standard prosthesis, and whether the additional availability of a femoral component with a reduced mediolateral dimension for the same anteroposterior dimension improves femoral component fit across ethnicities.Methods:Femoral dimensions were measured intraoperatively during 967 TKAs performed using the same type of prosthesis in patients of 5 different ethnicities. Aspect ratios were calculated to determine whether the shapes of the femora differed among ethnicities. The component fit (“perfect,” overhang, or underhang) when only standard prostheses were available was compared with the fit when both standard and narrow prostheses were available in all ethnic groups. This enabled us to determine whether the femoral component fit was improved by the additional availability of the narrow version.Results:Wide variations in shape were found among ethnicities as were variations among individuals of the same ethnicity. Differences in shape among ethnicities influenced the rate of overhang. However, overhang was more frequent at the trochlear than at the condylar level across all ethnicities. The availability of both the standard and the narrow femoral components improved the rate of a perfect fit in women in 3 of the 5 ethnic groups and reduced the overhang rate in women in all 5 of the ethnic groups. In contrast, only modest improvements in femoral component fit, which were not statistically significant, were seen in men.Conclusions:The shape of the distal part of the femur varies not only among ethnicities but also within ethnic groups, leading to a high prevalence of overhang when only standard prostheses are available. The additional availability of a femoral component with a reduced mediolateral dimension for the same anteroposterior size can reduce overhang and improve component fit across ethnicities.