Performance of high-translucent zirconia CAD/CAM fixed dental prostheses using a digital workflow: A clinical study up to 6 years

Background/purpose

Zirconia has recently become a popular material for fixed restorations. The purpose of this study was to use a digital workflow to fabricate monolithic zirconia fixed dental prostheses (FDPs) and assess the connection between variable connector sizes compared to their clinical performance.

Materials and methods

Clinicians evaluated monolithic zirconia FDPs in 58 patients. After definitive impressions were made, stone casts were obtained. The stone casts were scanned to a standard triangle language (STL) file. A digital wax up was fabricated, and corresponding provisional restorations were milled. Final FDPs were fabricated from a high-translucent zirconia material. During digital fabrication, the connector area of each FDP was recorded while meticulous attention was paid to ensure that the connector cross-sectional area was ≥9 mm² for the 3-unit restorations (pontic to retainer) and ≥12 mm² for the 4-unit restorations (pontic to pontic). Biological an technical outcomes of the FDPs were performed at 1 week, 6 months and then annually for 6 consecutive years.

Results

A total of 23 men and 35 women received a total of 63 full-contour zirconia FDPs in the posterior regions and were observed for a time period ranging between 50 and 70 months. No decementation occurred and no caries were detected during the observation period, however signs of gingivitis were detected in 4 patients. The dimension of the connector areas was 12 mm² in the two broken 4-unit FDPs.

Conclusion

The results of this study suggest that the use of digital scanning and milling to fabricate monolithic zirconia FDPs of posterior regions may be an acceptable alternative restorative approach to traditional metal-ceramic restorations.

Removable partial prosthesis combined with swallowing training is an efficient clinical solution for oral cancer post-operation patients with palatal defect and dysphagia: a prospective study

OBJECTIVE

Dysphagia is one of the major complications of oral cancer patients, and is disturbing thousands of patients worldwide. Our study aim to evaluate the clinical efficacy of prosthesis combined with swallowing training on palatal defect and dysphagia in post-operative oral cancer patients.

MATERIALS AND METHODS

Sixteen oral cancer patients with palatal defect and dysphagia post-operation were treated with removable prosthesis and individualized swallowing function training. Swallowing function of patients before and after treatment was analyzed and compared by videofluoroscopic swallowing examination. The severity of depression and life quality were evaluated by Depression Scale (SDS) and Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N) scores, respectively.

RESULTS

Oral transit time (OTT) significantly shortened after treatment (P < 0.01), and Penetration-Aspiration Scale (PAS) scores was significantly higher after treatment (P < 0.001). Different consistency bolus showed different risk of aspiration. Thickened liquids were related to lower PAS scores (P < 0.001). SDS standard score was significantly lower after treatment (P < 0.05). The total score of FACT-H&N after treatment was significantly higher (P < 0.05). No patients came back for regressed swallowing function during the follow-up period (17.06 ± 2.376 months).

CONCLUSION

Removable prosthesis and swallowing training can significantly improve swallowing function, reduce depression degree, and improve quality of life (QOL).

CLINICAL RELEVANCE

Removable prosthesis combined with swallowing training is a cheap and effective method to improve QOL in patients with palate defect and dysphagia after oral cancer.

Metallic implant-associated lymphoma: ALK-negative anaplastic large cell lymphoma associated with total knee replacement arthroplasty

Metallic implant-associated lymphomas are extremely rare. Only seven cases have been reported in association with knee joint arthroplasty, and all tumors were large B-cell lymphomas. This report is the first case of anaplastic large cell lymphoma occurring after total knee replacement arthroplasty. An 80‑year‑old female patient was admitted because of right knee pain for 2 years. She had undergone total knee replacement arthroplasty 10 years prior. Computed tomography showed an irregular osteolytic lesion in the right lateral femoral condyle, adjacent to the metallic prosthesis. Histologic findings reveal sheets of anaplastic tumor cells that were positive for CD2, CD4, CD5, CD43, and CD30 but negative for CD3, CD20, CD15, and anaplastic lymphoma kinase. Epstein-Barr encoding region in situ hybridization was negative. Analysis of T-cell receptor γ gene rearrangement studies using BIOMED-2-based multiplex polymerase chain reaction confirmed monoclonal T cell proliferation. The woman was finally diagnosed with ALK-negative anaplastic large cell lymphoma.

Letter to the Editor Regarding: Evolving Business Models in Orthotics by Schneider, N

The purpose of this letter is to continue the dialogue regarding the paper "Evolving business models in Orthotics" in the Canadian Prosthetics & Orthotics Journal Volume 4, Issue2, No.3, 2021. In it we present the perspective of the current Alberta Association of Orthotists and Prosthetists (AAOP) and provide additional context and information on historical events. Finally, we provide additional clarity on how costing is approached in the Province of Alberta (Canada) and the purported inequity in compensation between the two disciplines.

Technology Management as a Core Component of a Client-centric Prosthetic Orthotic Practice Model

Technological innovation has transformed how we communicate, work, and conduct business. Over the next decade how we experience health care both as health care professionals and as client-patients will also change significantly. This presents both an opportunity and a challenge to medical clinical professionals that are device-focused, including prosthetists orthotists, as they consider how best to adapt. Current prosthetic orthotic education and practice is heavily clinically weighted, with less emphasis being given to engineering and business skills. Yet all three are essential core elements of a successful, sustainable prosthetics orthotics practice. Furthermore, it is the latter two that will heavily influence the future face of prosthetics & orthotics. It is not certain how current prosthetic orthotic practitioners can best adapt in response. One solution, proposed in this editorial, could be by rebalancing their professional persona to equally weight the three essential core elements. The result, a Clinical Prosthetic Orthotic Technology Management Professional, would engage in a professional practice that is functionally grounded, uses a client-centric model and incorporate eight professional attributes: professional, advocate, scholar, leader, communicator, collaborator, assistive technology expert and business justification specialist.

AMPREDICT PROsthetics-Predicting Prosthesis Mobility to Aid in Prosthetic Prescription and Rehabilitation Planning

OBJECTIVE

To develop and validate a patient-specific multivariable prediction model that uses variables readily available in the electronic medical record to predict 12-month mobility at the time of initial post-amputation prosthetic prescription. The prediction model is designed for patients who have undergone their initial transtibial (TT) or transfemoral (TF) amputation because of complications of diabetes and/or peripheral artery disease.

DESIGN

Multi-methodology cohort study that identified patients retrospectively through a large Veteran's Affairs (VA) dataset then prospectively collected their patient-reported mobility.

SETTING

The VA Corporate Data Warehouse, the National Prosthetics Patient Database, participant mailings, and phone calls.

PARTICIPANTS

Three-hundred fifty-seven veterans who underwent an incident dysvascular TT or TF amputation and received a qualifying lower limb prosthesis between March 1, 2018, and November 30, 2020 (N=357).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The Amputee Single Item Mobility Measure (AMPSIMM) was divided into a 4-category outcome to predict wheelchair mobility (0-2), and household (3), basic community (4), or advanced community ambulation (5-6).

RESULTS

Multinomial logistic lasso regression, a machine learning methodology designed to select variables that most contribute to prediction while controlling for overfitting, led to a final model including 23 predictors of the 4-category AMPSIMM outcome that effectively discriminates household ambulation from basic community ambulation and from advanced community ambulation-levels of key clinical importance when estimating future prosthetic demands. The overall model performance was modest as it did not discriminate wheelchair from household mobility as effectively.

CONCLUSIONS

The AMPREDICT PROsthetics model can assist providers in estimating individual patients' future mobility at the time of prosthetic prescription, thereby aiding in the formulation of appropriate mobility goals, as well as facilitating the prescription of a prosthetic device that is most appropriate for anticipated functional goals.

Three-dimensional printed customized uncemented unipolar prosthesis combined with ligament reconstruction for tumorous defect of the distal femur in children

BACKGROUND

Hemiarthroplasty following tumor resection of the distal femur in children provides a chance to preserve the proximal tibial physis for limb elongation. Based on three-dimensional (3D) printing technology, the uncemented unipolar prosthesis with joint stability reinforced structures (JSRSs) was custom-designed for our cases. This study aimed to describe the design and assess the short-term outcomes of this refined prosthetic hemiarthroplasty.

METHODS

Seven patients (four females and three males) received 3D-printed customized uncemented unipolar prosthesis for hemiarthroplasty after removal of the distal femur, from September 2019 to October 2020 at our Orthopedics department. The limb function, growth of the preserved proximal tibial physis, joint stability, and limb length discrepancy (LLD) were assessed. Complications were recorded.

RESULTS

Six patients survived with no evidence of metastasis or local recurrence at the last follow-up, and one patient died of lung metastasis at 19 months postoperatively. Follow-up ranged from 19 to 32 months, with an average of 26 months. Elongation of the tibia was observed in all cases. At the last follow-up, four patients exhibited equal growth length compared with the healthy contralateral tibia. LLD ranged from 0.8 to 1.6 cm with a mean of 1.3 cm. The average knee range of motion was 95.3° of flexion and 4.5° of extension. All patients achieved satisfactory postoperative limb function with a mean MSTS score of 25.8. The results of the drawer, Lachman, and pivot shift tests were negative in all patients. During follow-up, painless joint space narrowing was observed in two patients. The screw for ligament fixation loosened in one of the seven patients at 17 months postoperatively. No subluxation of the joint, angular deformity, or breakage of the implant was detected in the remaining patients.

CONCLUSIONS

3D-printed customized uncemented unipolar prosthesis with JSRS would be a good choice for reconstructing tumorous defect in the distal femur in children.

Stress distributions of the short stem and the tapered wedge stem at different alignments: a finite element analysis study

BACKGROUND

The mechanical effects of stem length reduction and stem alignment on the surrounding femur remain unknown. This study directly compared the stress distribution on the surrounding femur of existing tapered wedge stems and short stems and examined the properties of stress distribution at different stem alignments in three dimensions.

METHODS

Finite element analysis was conducted for standing and walking. The cementless stem was appropriately sized to ensure adequate contact with the medial cortical bone line that contours the medullary cavity. The stem neck axis was aligned with the femoral neck axis in the mid-position and placed in 2° of the varus and valgus, 3° of flexion and extension, and 10° and 40° of anteversion.

RESULTS

Regardless of stem length, the trend of stress distribution was similar. The short stem generated less stress around the stem than the tapered wedge stem. In the coronal plane, the effect of varus and valgus deflection was small. In the sagittal plane, the stress generated around the stem was higher in the extended position than in the flexed position. In the horizontal plane, the stress generated around the stem was higher when the stem anteversion was smaller.

CONCLUSIONS

Depending on the design, short stems can reduce the stress on the surrounding bone, compared to a longer tapered wedge with similar stress distribution. Additionally, a short stem can reduce the effect of the varus position. Stems should be placed to achieve stable initial fixation while noting that stresses increase with extension and reduced anteversion.

Comparative Evaluation of Hearing in Cartilage Umbrella, Boomerang and Torp in Chronic Otitis Media Cases with Absent Stapes Suprastructure: Our Experience

Ossicular discontinuity is one of the most common causes of conductive hearing loss. Ossicular chain reconstruction improves conductive hearing loss. With no additional cost, cartilage ossiculoplasty is easy to perform, and also the cartilage is well tolerated being an autograft. In this study we compared the audiological outcome in ossiculoplasty done by cartilage umbrella, cartilage boomerang and alloplastic TORP. 75 patients of age group 10-50 years clinically diagnosed with chronic otitis media with conductive hearing loss and an air bone gap (ABG) of at least 20 dB posted for surgery were included. Ossiculoplasty was done in three groups with autologous cartilage boomerang, cartilage umbrella and alloplastic TORP. In mucosal disease hearing gain was better in umbrella technique (17.66 ± 1.1) dB than Boomerang (16.9 ± 0.8) dB and TORP (10.68 ± 0.9) dB. ABG closure was higher in Boomerang and TORP. Hearing improvement in patients with squamosal disease managed by canal wall up surgery was 25.01 ± 1.1 dB, 27.73 ± 3.1 dB and 20.12 ± 1.8 dB in Boomerang, Umbrella and TORP group respectively showing that umbrella method gave maximum improvement. ABG closure was better in TORP group. In canal wall down surgery patient's maximum improvement was seen in Boomerang (29.51 ± 0.9) dB followed by Umbrella (26.67 ± 1.2) dB and TORP (25.27 ± 0.8) dB group. ABG closure was higher in Boomerang group. Cartilage ossiculoplasty is a reliable and effective method of ossicular chain reconstruction for both mucosal and squamosal disease. Cartilage ossiculoplasty has the added advantage of reduced chances of prosthesis extrusion as compared to TORP.

Results of Hip Arthroplasty Using a COREN Stem at a Minimum of Ten Years

Purpose

We report on the 10-year clinical hip function and radiologic outcomes of patients who underwent hip arthroplasty using a COREN stem.

Materials and Methods

A consecutive series of 224 primary cementless hip arthroplasty implantations were performed using a COREN stem between 2009 and 2011; among these, evaluation of 128 hips was performed during a minimum follow-up period of 10 years. The mean age of patients was 65.4 years (range, 40-82 years) and the mean duration of follow-up was 10.8 years (range, 10-12 years). Evaluation of clinical hip function and radiologic implant outcomes was performed according to clinical score, thigh pain, and radiologic analysis.

Results

Dramatic improvement of the mean Harris hip score (HHS) from 59.4 preoperatively to 93.5 was observed at the final follow-up (P≤0.01). Stable fixation was demonstrated for all implants with no change in position except for one case of Vancouver type B2 periprosthetic femur fracture. A radiolucent line (RLL) was observed in 16 hips (12.5%). Thigh pain was observed in only two hips (1.6%) at the final follow-up. There were no cases of osteolysis around the stem. The survival rate for the COREN stem was 97.7%.

Conclusion

Good long-term survival with excellent clinical and radiological outcomes can be achieved using the COREN femoral stem regardless of Dorr type.

Using magnetic panels to enlarge a transtibial prosthetic socket

A novel method is described to connect a prosthetic liner to the panels of an adjustable socket to facilitate limb fluid volume stabilization in prosthesis users. Magnets are placed in the socket panels, and iron powder is embedded in the user's prosthetic liner. When the magnet is in close proximity to the liner, a firm connection is formed. The system's capability to execute panel pull on transtibial prosthesis users was tested. The backs of the panels were supported by a bracket mounted to the external surface of the socket that allowed the radial position of the panels to be adjusted. Bench testing demonstrated an optimized strength-to-weight ratio using 1.27-cm thick annular-shaped magnets supported by 0.32-cm thick backplates. Testing on four people with transtibial amputation showed that the maximum socket increase achieved using magnetic panel pull ranged from 5.3% to 13.8% of the initial (panels flush) socket volume. The results indicate that magnetic panel pull induces a meaningful increase in socket volume during sitting. The clinical relevance is a novel strategy that may help stabilize prosthesis users' limb fluid volume over the day.

Single subject analysis of individual responses to prosthetic modifications based on passive dynamic walking model

BACKGROUND

Group statistical analysis may mask individual differences in response to interaction with rehabilitative devices such as prostheses. This study sets out to evaluate the effect of asymmetric prosthesis using a single subject methodology on individuals with unilateral transfemoral amputation.

METHODS

Acceleration data of 17 participants with unilateral transfemoral amputation were collected using a triaxial accelerometer attached at the L3 level of the spine during level ground walking under four prosthesis conditions: 1) no added mass; 2) the knee joint relocated downwards by 18% of the total shank length, shank mass decreased by 68%, thigh mass increased by 7%; 3) the knee joint relocated downwards by 37% of the total shank length, shank mass decreased by 68%, thigh mass increased by 7%, and 4) thigh mass increased 17%, shank mass decreased by 38%. Step length, step time, step length variability, step time variability and Floquet multiplier were statistically assessed.

FINDINGS

The single subject analysis highlighted that under prosthetic modifications, intact limb step length was increased and prosthetic step length was deceased in most participants (n > 9). No significant changes were observed in Floquet multiplier (n > 14), step length (n > 6) and step time variability (n > 9) across all conditions.

INTERPRETATION

Single subject analysis showed that in response to the immediate effect of asymmetric prosthesis, increase in the intact limb step length and decrease in the prosthetic limb step length emerged as a dominant strategy for most participants. Regarding Floquet multiplier, step length, and step time variability, our prosthetic modifications did not produce the anticipated effects.

Finite element analysis of coronoid prostheses with different fixation methods in the treatment of comminuted coronoid process fracture

BACKGROUND

Comminuted fractures of the coronoid process significantly compromise the stability and function of the elbow joint. Reconstruction of the coronoid process with a prosthesis has been suggested as an alternative to restore the architecture. The purpose of this study was to investigate the strength and stability of various methods for the fixation of a coronoid prosthesis by finite element analysis.

MATERIALS AND METHODS

A coronoid prosthesis was designed based on the morphological information from computed tomography images acquired from 64 subjects in whom the top 40% of the coronoid process height was replaced. Four methods for the fixation of the prosthesis were suggested: (1) a double 2.0-mm fixation bolt, anterior to posterior; (2) a double 2.5-mm fixation bolt, anterior to posterior; (3) a single 4.0-mm fixation bolt, posterior to anterior; (4) a single 4.5-mm fixation bolt, posterior to anterior. The integrated prosthesis-bone constructs were analyzed via the finite element analysis of 10 simulated proximal ulna models with loading applied along the axis of the humerus and with three different elbow flexion angles (30°, 90°, and 130°). The maximum principal stress and the total deformation were quantified and compared.

RESULTS

A coronoid prosthesis was developed. The maximum principal stress of the fixation bolts occurred around the neck of the fixation bolt. For a comparison of the strengths of the four fixation methods, the maximum principal stress was the lowest for fixation using a single 4.5-mm fixation bolt. The value of the maximum principal stress significantly decreased with increased elbow flexion angle for all fixation methods. The maximum deformation of the fixation bolts occurred at the head of the fixation bolt. For a comparison of the maximum deformations in the four fixation methods, the maximum deformation was the lowest for fixation using a single 4.5-mm fixation bolt. The value of the maximum deformation significantly decreased with increased elbow flexion angle for all fixation methods.

CONCLUSIONS

The present study suggested that fixation of a coronoid prosthesis with a single 4.5-mm fixation bolt from posterior to anterior is an excellent option in terms of the strength and stability. Level of Evidence Experimental study.

Clinical Performance of Complete-Arch Implant- Supported Rehabilitations Using Monolithic Lithium Disilicate Restorations Bonded to CAD/CAM Titanium and Zirconia Frameworks up to 5 Years

This clinical study evaluated the survival of monolithic lithium disilicate (ML) (IPS Emax, Ivoclar Vivadent) restorations bonded to complete-arch CAD/CAM made titanium or zirconia frameworks. Between August 2007 and December 2009, 15 patients (7 female, 8 male; mean age: 56.8 years old) received 30 implant-supported screw-retained rehabilitations with ML restorations cemented to CAD/CAM made titanium (T) (n=6) or zirconia (Z) frameworks (n=24) adhesively (Multilink Automix, RelyX Unicem) and followed up until December 2015. The evaluation protocol involved technical failures (chipping, debonding or fracture of crown/framework, screw loosening), Californian Dental Association (CDA) quality criteria (Romeo: Excellent; Sierra: Acceptable; Tango: Retrievable; Victor: Not acceptable) and biological failures (mucositis, peri-implantitis). Mean observation time was 60.3 months. No implants were lost, and all the prostheses were in situ. Four mechanical failures occurred in the form of minor chipping (n=3 in ML-Z, n=1 in ML-T) and major fracture in ML crown (n=1 in ML-Z). Romeo scores (N=370) decreased until final observation (N=347) and 23 Sierra scores were given to the restorations. Mucositis was observed in 3 patients and peri-implantitis in one patient. Complete-arch implant-borne FDPs made of monolithic lithium disilicate bonded to titanium or zirconia frameworks could be a promising alternative.

Revision tibiotalar arthrodesis with posterior iliac autograft after failed arthroplasty: A matched comparative study with primary ankle arthrodeses

INTRODUCTION

Tibiotalar arthrodeses performed after failed ankle arthroplasties are known to be complex procedures with often disappointing functional outcomes. This study reports the results of a revision technique using a posterior iliac crest autograft.

HYPOTHESES

We hypothesized that: (1) revision tibiotalar arthrodeses (RTTAs) had functional outcomes which were similar to those of a reference cohort of primary tibiotalar arthrodeses (TTAs) and that (2) the union rate was satisfactory.

MATERIALS AND METHODS

This retrospective study compared 16 RTTAs performed for failed arthroplasties that caused pain and a functional disability (4 aseptic loosening, 4 massive progressive periprosthetic cysts, 5 malpositioning of implants, and 3 cases of unexplained mechanical pain) with a series of 16 primary TTAs performed for painful ankle osteoarthritis. The groups were matched at a 1:1 ratio for age, sex, side and body mass index. The preoperative workup included a physical exam, the American Orthopaedic Foot and Ankle Society (AOFAS) score, weight bearing radiographs, CT and SPECT scans. Outcomes were assessed both clinically (AOFAS score) and radiographically (X-rays and scans). The mean duration of the procedure (DP), average length of stay (LOS), fusion and complication rates, and time to union were also compared.

RESULTS

At the mean follow-up of 30 months (range, 12-88) for the RTTA group and 59 months (range, 23-94) for the TTA group (p=.001), the AOFAS score increased from 27 to 70.8 points (p<.001) and from 29.8 to 76.2 points (p<.001), respectively; values were similar at the last follow-up (p=.442). Both groups had similar fusion (94%) and complication rates (12%). The DP was 196.9±33.6min (range, 179-213) vs. 130±28.4min (range, 118-141) (p<.001) and the LOS was 3.8 days (range, 2-6) vs. 3.9 days (range, 2-6) (p<.445) for both groups (RTTA vs. TTA).

CONCLUSION

This RTTA technique using a posterior iliac crest allograft for filling bone defects was validated by the quality of the functional outcomes obtained.

LEVEL OF EVIDENCE

IV; Comparative retrospective study.

Our problems and observations in 3D facial implant planning

BACKGROUND

Three-dimensional renderings of two-dimensional computed tomography data have allowed for more precise analysis in the craniofacial field. Design, engineering, architecture, and other industries have paved the way for the manipulation and printing of three-dimensional objects. The usual planning is only carried out based on the bony structures, often without taking into consideration the presence of soft tissues and soft structures. During our practice, we have found ourselves facing the challenge posed by these structures; the aim of this article is to discuss our experience in designing implants presenting our tips and tricks for a better planning leading to an easy and reliable positioning.

CASE PRESENTATION

We have retrieved all patients in 5 years among those who underwent computer-aided design/computer-aided manufacturing implant placement in the last 5 years in order to review the eventual problems and the solutions found. A total number of 25 patients were retrieved and, among them, 10 patients were selected, in which planning inaccuracy caused difficulties during implant placement and which then led to induced changes during the planning of similar cases or in which the problems were noted before or during the planning which led to changes in the plan to address those problems. Six of the selected cases were polyetheretherketone facial implants for the correction of residual deformities in malformed or deformed patients. One case was a delayed orbital reconstruction with a titanium implant. Two cases were titanium functional and anatomical reconstruction of the mandible in patients with failed post-oncological reconstructions. There was 1 case with a mandibular ramus complex and hard-to-treat fracture.

CONCLUSIONS

The planning of the implant mostly relies on hard tissue three-dimensional reconstruction, but it should not be limited at what is immediately evident. A surgeon's clinical experience should always guide the process, with knowledge of the patient's anatomy and evaluation of the quality and of the soft tissue response being taken into consideration. The implant should always be tailored not only based on the bone defect and evaluations but also using the patient's previewed and actual anatomy, evaluating eventual interferences and pitfalls.

The impact of added mass placement on metabolic and temporal-spatial characteristics of transfemoral prosthetic gait

BACKGROUND

Despite prosthetic technology advancements, individuals with transfemoral amputation have compromised temporal-spatial gait parameters and high metabolic requirements for ambulation. It is unclear how adding mass at different locations on a transfemoral prosthesis might affect these outcomes. Research question Does walking with mass added at different locations on a transfemoral prosthesis affect temporal-spatial gait parameters and metabolic requirements compared to walking with no additional mass?

METHODS

Fourteen participants with unilateral transfemoral amputations took part. A 1.8 kg mass was added to their prostheses in three locations: Knee, just proximal to the prosthetic knee; Shank, mid-shank on the prosthesis; or Ankle, just proximal to the prosthetic foot. Temporal-spatial gait parameters were collected as participants walked over a GAITRite® walkway and metabolic data were collected during treadmill walking for each of these conditions and with no mass added, the None condition. Separate linear mixed effects models were created and post-hoc tests to compare with the control condition of None were performed with a significance level of 0.05.

RESULTS

Overground self-selected walking speed for Ankle was significantly slower than for None (p < 0.05) (None: 1.16 ± 0.24; Knee: 1.15 ± 0.19; Shank: 1.14 ± 0.24; Ankle 0.99 ± 0.20 m/s). Compared to None, Ankle showed significantly increased oxygen consumption during treadmill walking (p < 0.05) (None: 13.82 ± 2.98; Knee: 13.83 ± 2.82; Shank: 14.30 ± 2.89; Ankle 14.56 ± 2.99 ml O₂/kg/min). Other metabolic outcomes (power, cost of transport, oxygen cost) showed similar trends. Knee and Shank did not have significant negative effects on any metabolic or temporal-spatial parameters, as compared to None (p > 0.05). Significance Results suggest that additional mass located mid-shank or further proximal on a transfemoral prosthesis may not have negative temporal-spatial or metabolic consequences. Clinicians, researchers, and designers may be able to utilize heavier components, as long as the center of mass is not further distal than mid-shank, without adversely affecting gait parameters or metabolic requirements.

[Update on prosthesis for partial hand and finger amputations]

Partial hand and finger amputations are relatively rare but devastating due to the consequences they provoque. In addition, they are more likely than lower limb amputations in car accidents, work accidents and by certain weapons of war. Men are going to have a much higher risk of traumatic amputation than women, with a rate 6.6 times higher. Fitting can be a complex process and a challenge for professionals. For this reason, it is important to know all the options available on the market that can meet the needs of patients, from cosmetic to myoelectric prostheses. Fitting requires the coordinated activity of a multiassistant clinical work team, the center of the team being the person who has suffered the amputation, who must have all the information possible to be able to actively participate in decision-making.

Biomechanical comparative analysis of temporomandibular joint, glenoid fossa and head of the condyle of conventional models prothesis with new PEEK design

This article reviews the design of the temporomandibular joint (TMJ) prostheses used for TMJ joint replacement from 2000 to 2020. The TMJ is a complex joint, with distinct anatomical and functional characteristics making it challenging to maintain. Many authors from the early 20th century reported techniques for TMJ reconstruction, with the goal of restoring its shape and ideal function. Many prototypes have been developed in pursuit of an ideal prosthesis that adheres to the principles of biomechanics and biocompatibility, with good long-term performance and lower cost. The TMJ prosthesis is divided in two parts: the glenoid fossa and the mandibular ramus component. These two parts are fixed with metal screws in the glenoid fossa and fixed in the zygomatic arch with 4 or 5 screws. The mandibular part is fixed to the mandible ramus with 8 or 9 titanium screws. In our review, since 2000 to 2020, little has changed to improve the design and allow for natural mandible movement. From 2000 to 2006, 48 TMJ surgeries were performed using UHMWPE with this design. All patients had good results, preserving opening mouth and lateral movements. All the designs are similar in principle. The glenoid fossa, which resembles a box, limiting the rotation and translation movement. It is known that lateral movements are lost in function as the lateral pterygoid muscle is detached.

[Finite element analysis of the effect of knee movable unicompartmental prosthesis insertion shape and mounting position on stress distribution in the knee joint after replacement]

In unicompartmental replacement surgery, there are a wide variety of commercially available unicompartmental prostheses, and the consistency of the contact surface between the common liner and the femoral prosthesis could impact the stress distribution in the knee after replacement in different ways. Medial tibial plateau fracture and liner dislocation are two common forms of failure after unicompartmental replacement. One of the reasons is the mismatch in the mounting position of the unicompartmental prosthesis in the knee joint, which may lead to failure. Therefore, this paper focuses on the influence of the shape of the contact surface between the liner and the femoral prosthesis and the mounting position of the unicompartmental prosthesis on the stress distribution in the knee joint after replacement. Firstly, a finite element model of the normal human knee joint was established, and the validity of the model was verified by both stress and displacement. Secondly, two different shapes of padded knee prosthesis models (type A and type B) were developed to simulate and analyze the stress distribution in the knee joint under single-leg stance with five internal or external rotation mounting positions of the two pads. The results showed that under a 1 kN axial load, the peak contact pressure of the liner, the peak ACL equivalent force, and the peak contact pressure of the lateral meniscus were smaller for type A than for type B. The liner displacement, peak contact pressure of the liner, peak tibial equivalent force, and peak ACL equivalent force were the smallest for type A at 3° of internal rotation in all five internal or external rotation mounting positions. For unicompartmental replacement, it is recommended that the choice of type A or type B liner for prosthetic internal rotation up to 6° should be combined with other factors of the patient for comprehensive analysis. In conclusion, the results of this paper may reduce the risk of liner dislocation and medial tibial plateau fracture after unicompartmental replacement, providing a biomechanical reference for unicompartmental prosthesis design.

Oncologic and functional outcomes of different reconstruction modalities after resection of chondrosarcoma of the scapula: a medium- to long-term follow-up study

Objectives

To evaluate the oncologic and functional results of scapular reconstruction after partial or total scapulectomy for chondrosarcoma.

Materials and methods

Twenty-one patients with chondrosarcoma who underwent partial or total scapulectomy between January 2005 and July 2019 were reviewed retrospectively.

Results

At a mean follow-up of 62.6 months (range, 13–123 months), four patients developed local recurrence, and three developed distant metastases, one of which developed both recurrence and metastasis. The overall survival rate of patients at 5 years was 84.6%, the disease-free survival rate was 69.3%, and the complication rate was 19% (4/21). The 1993 American Musculoskeletal Tumor Society (MSTS93) scores of patients in the partial scapulectomy group, total scapulectomy + humeral suspension group and prosthetic reconstruction group were 26.50 ± 1.38, 19.00 ± 2.58, and 21.38 ± 2.62, respectively. There was a statistically significant difference between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group ( P = 0.006 and 0.0336, respectively). The range of motion of the shoulder joint for forward flexion was 80.83° ± 11.14°, 51.25° ± 21.36°, and 52.50° ± 11.02°, respectively. The p-values for the comparison between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group were 0.0493 and 0.0174, respectively. And the range of motion of abduction was 75.00° ± 10.49°, 32.50° ± 11.90°, 41.88° ± 11.63°, respectively. Patients in the partial scapulectomy group had significantly better postoperative shoulder abduction function than the total scapulectomy + humeral suspension or prosthetic reconstruction group (P = 0.0035 and 0.0304, respectively). There was no significant difference in MSTS93 scores and flexion and abduction function of the shoulder joint in the upper extremity after total scapulectomy with humeral suspension or prosthetic reconstruction (P > 0.05).

Conclusions

Surgical treatment of chondrosarcoma of the scapula can achieve a satisfactory prognosis and shoulder function. Total scapulectomy followed by prosthetic reconstruction or humeral suspension are both feasible treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05661-7.

Surgical treatment of chondrosarcoma of the scapula can achieve good oncologic and functional outcomes.

Prosthetic reconstruction of the scapula after scapulectomy does not provide better functional results than humeral suspension, and both are feasible treatment modalities.

Evaluation of User's Satisfaction With Orthotic and Prosthetic Devices and Services in Orthotics and Prosthetics Center of Iran University of Medical Sciences

BACKGROUND

The number of patients receiving orthotics and prosthetic services is increasing globally. A way to investigate patients' insight about services provided to them is to evaluate their satisfaction with the received services. Furthermore, incorporating patients' preferences into practice is an inseparable part of evidence-based practice. Applying such information in practice can contribute to the enhancement of the quality of services, the effectiveness of therapeutic interventions, and finally, the economic growth of service centers.

OBJECTIVES

To evaluate patients' satisfaction with the orthotic and prosthetic devices and services provided by the orthotics and prosthetics clinic of Iran University of Medical Sciences.

METHODOLOGY

In this study, 173 people referring to the orthotics and prosthetics clinic of Iran University of Medical Sciences were recruited, and their satisfaction level was examined using the Orthotics and Prosthetics Users' Survey questionnaire (OPUS) through a phone interview.

FINDINGS

Concerning the devices, the mean value of total satisfaction score was 74:00±19.80 and the highest score belonged to no wear or rupture of the clothes with their devices (mean value = 4.76±0.84). In terms of services, the mean value of total satisfaction score was 72.12 ± 15.90 with the highest score belonging to the politeness of the clinic staff (mean value = 4.92±0.57). When the time point from receiving service was taken into account, the patients who received the service for less than a year showed higher satisfaction level with the service (p=0.024). Although satisfaction with the device was slightly higher among the participants who used the devices for more than a year, no significant difference was observed between the two groups in terms of device satisfaction.

CONCLUSIONS

The overall satisfaction level from the devices and services was relatively high. However, the satisfaction level with the costs and coordination of the staff with the physicians showed a decline.

Editorial Opinion: Value Within the Prosthetic and Orthotic Provision Process

This Editorial presents an overview of the uptake of clinical outcome measures in the prosthetics and orthotics sector and considers how the use of objective measures contribute to demonstrating value provided. A decade ago, payors began to demand objective data to document costs vs. benefits from prosthetic and orthotic providers. The speed with which the sector responded to help develop measures and to begin to integrate them into practice is remarkable. This suggests an encouraging resilience and ability to adapt on the part of the sector as other trends such as Values-Based Health Care emerge to challenge the sector.

Clinical mobility metrics estimate and characterize physical activity following lower-limb amputation

Background

Regular physical activity following a lower-limb amputation is essential for maintaining health and a high quality of life. Most adults with a lower-limb amputation, however, participate in insufficient daily physical activity, and thus, are predisposed to poor health outcomes. Estimating physical activity after lower-limb amputation via common mobility metrics may aid in clinical decisions regarding treatment prioritization and prosthesis prescription. The objectives of this study were (a) to examine associations between daily physical activity and patient-reported and performance-based mobility metrics among adults with lower-limb amputation, and (b) to determine whether patient-reported and performance-based mobility metrics can distinguish between physical activity status [i.e., sedentary (< 5000 steps/day) or non-sedentary (≥ 5000 steps/day)] of adults with lower-limb amputation.

Methods

A cross-sectional study involving 35 adults with a unilateral transtibial (N = 23; 63.0 ± 10.4 years) or transfemoral amputation (N = 12; 58.8 ± 9.5 years) was conducted. Participants completed patient-reported (Prosthesis Evaluation Questionnaire-Mobility Subscale) and performance-based mobility metrics (L-Test, 10-m Walk Test, 6-min Walk Test). Physical activity, i.e., average steps/day, was measured with an accelerometer.

Results

Patient-reported and performance-based mobility metrics were associated with daily physical activity (p < 0.050). Prosthesis Evaluation Questionnaire-Mobility Subscale scores, L-Test time, 10-m Walk Test speed and 6-min Walk Test distance independently explained 11.3%, 31.8%, 37.6% and 30.7% of the total variance in physical activity. Receiver operating characteristic curves revealed patient-reported and performance-based mobility metrics significantly distinguish between physical activity status, i.e., sedentary (< 5000 steps/day) versus non-sedentary (≥ 5000 steps/day). Preliminary cut-points for mobility metrics to classify physical activity status were determined.

Conclusions

Following a lower-limb amputation, patient-reported and performance-based mobility metrics may estimate daily physical activity, thereby aiding clinical decisions regarding treatment prioritization as well as prosthesis selection.

Efficacy and safety of a 3D-printed arthrodesis prosthesis for reconstruction after resection of the proximal humerus: preliminary outcomes with a minimum 2-year follow-up

Background

The purpose of this study was to investigate the feasibility of using a three-dimensional (3D)-printed arthrodesis prosthesis for reconstruction of the proximal humeral defect after tumor resection.

Methods

A novel proximal humeral prosthesis was designed to restore bone continuity and shoulder arthrodesis and was fabricated via 3D printing technology. Ten patients with primary malignancies in the proximal humerus underwent intra-articular resection and replacement with this prosthesis from 2017 to 2019. Baseline and operative data, oncological and prosthetic survival, and functional status were summarized.

Results

This cohort consisted of 9 males and 1 female with a mean age of 32.1 ± 16.1 years. Diagnoses included 5 cases of osteosarcoma, 3 cases of chondrosarcoma and 1 each case of undifferentiated pleomorphic sarcoma and malignant myoepithelioma. The mean operative duration, intraoperative hemorrhage and postoperative length of hospitalization were 151.5 ± 61.0 min, 410.0 ± 353.4 ml and 5.3 ± 1.9 d, respectively. The mean follow-up duration was 29.3 ± 6.4 months, with a minimum of 24 months for the surviving patients. Two patients experienced local recurrence, and four patients developed distant metastases. Detachment of the taper occurred in two patients. One was managed conservatively, and the other received amputation due to concurrent tumor recurrence. The mean MSTS-93 and ASES scores and ranges of forwards flexion and abduction were 24.9 ± 3.1, 79.4 ± 8.3, 71.3 ± 19.4°, and 61.3 ± 16.4°, respectively. The functional outcomes were independent of the preservation of the axillary nerve. Histological study of the glenoid component showed evidence of bone ingrowth at the bone-prosthesis porous interface.

Conclusion

Application of the 3D-printed arthrodesis prosthesis might be a safe and efficacious method for functional reconstruction in patients who underwent resection of the proximal humerus, especially for those without preservation of the axillary nerve.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05581-6.