Towards the Digital Hospital: From Implant Design to In-Clinic Bio Fabrication

Background: The intermetatarsal joint between the fourth and fifth metatarsals (4-5 IM) is important in defining fifth metatarsal fractures. The purpose of the current study was to quantify this joint in order to determine the mean cartilage area, the percentage of the articulation that is cartilage, and to give the clinician data to help understand the joint anatomy as it relates to fifth metatarsal fracture classification. Methods: Twenty cadaver 4-5 IM joints were dissected. Digital images were taken and the articular cartilage was quantified by calibrated digital imaging software. Results: For the lateral fourth proximal intermetatarsal articulation, the mean area of articulation was 188 ± 49 mm2, with 49% of the area composed of articular cartilage. The shape of the articular cartilage had 3 variations: triangular, oval, and square. A triangular variant was the most common (80%, 16 of 20 specimens). For the medial fifth proximal intermetatarsal articulation, the mean area of articulation was 143 ± 30 mm2, with 48% of the joint surface being composed of articular cartilage. The shape of the articular surface was oval or triangular. An oval variant was the most common (75%, 15 of 20 specimens). Conclusion: This study supports the notion that the 4-5 IM joint is not completely articular and has both fibrous and cartilaginous components. Clinical Relevance: The clinical significance of this study is that it quantifies the articular surface area and shape. This information may be useful in understanding fifth metatarsal fracture extension into the articular surface and to inform implant design and also help guide surgeons intraoperatively in order to minimize articular damage.

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Relationship between the form and function of implant design in total knee replacement

Journal of Biomechanics ◽

10.1016/j.jbiomech.2021.110296 ◽

2021 ◽

pp. 110296

Author(s):

Malte Asseln ◽

Sonja A.G.A. Grothues ◽

Klaus Radermacher

Keyword(s):

Total Knee Replacement ◽

Knee Replacement ◽

Implant Design ◽

Form And Function ◽

Total Knee ◽

And Function

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Innovative implant design for continuous implant stability: A mechanical and histological experimental study in the iliac crest of goats

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2021.104651 ◽

2021 ◽

pp. 104651

Author(s):

Jan Willem M Hoekstra ◽

Bart AJA. van Oirschot ◽

John A. Jansen ◽

Jeroen JJP. van den Beucken

Keyword(s):

Experimental Study ◽

Iliac Crest ◽

Implant Design ◽

Implant Stability

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Comparative In Vitro Evaluation of the Primary Stability in D3 Synthetic Bone of Two Different Shapes and Pitches of the Implant Threads

Applied Sciences ◽

10.3390/app11125612 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5612

Author(s):

Stefano Fanali ◽

Margherita Tumedei ◽

Pamela Pignatelli ◽

Alessandra Lucchese ◽

Francesco Inchingolo ◽

...

Keyword(s):

Surgical Techniques ◽

Primary Stability ◽

Implant Design ◽

Insertion Torque ◽

Synthetic Bone ◽

One Stage ◽

Prosthetic Joint ◽

Joint Connection ◽

The One

Background: Implant primary stability can be affected by several factors related to implant macrogeometry, local anatomy, and surgical techniques. The aim of this research was to study primary stability on polyurethane foam sheets of wide-threaded implant design compared to narrow-threaded implants. Materials and methods: Two different implant designs were positioned on D3 density polyurethane blocks in a standardized environment: the wide-threaded implant and the narrow-threaded implant, for a total of 160 specimens. Moreover, for each group, two different sizes were considered: 3.8mm × 12mm and 4.8mm × 12 mm. The insertion torque (IT) values, the removal strength (RT), and the Periotest analyses were evaluated. Results: A significantly higher IT and RT was reported for wide-threaded implants and two-stage implants (p < 0.01), compared to the narrow-threaded implants. The diameters seemed to provide a significant effect on the primary stability for both implants’ geometry (p < 0.01). A higher mean of the one-stage implant was evident in the Periotest measurements (p < 0.01). Conclusions: Both of the implants showed sufficient stability in polyurethane artificial simulation, while the wide-threaded implant design showed a higher primary stability on alveolar cancellous synthetic bone in vitro. Additionally, the prosthetic joint connection seemed to have a determinant effect on Periotest analysis, and the one-stage implants seemed to provide a high stability of the fixture when positioned in the osteotomy, which could be important for the immediate loading protocol.

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Modular tapered conical revision stem in hip revision surgery: mid- term results

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03886-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Loris Perticarini ◽

Stefano Marco Paolo Rossi ◽

Alberto Fioruzzi ◽

Eugenio Jannelli ◽

Mario Mosconi ◽

...

Keyword(s):

Preoperative Assessment ◽

Bone Defects ◽

Implant Design ◽

Harris Hip Score ◽

Radiographic Evaluation ◽

Stem Design ◽

Additional Surgery ◽

Prime Concern ◽

Distal Fixation

Abstract Background The aim of this paper is to evaluate the clinical and radiological outcomes of a fluted tapered modular distal-fixation stem at medium to long-term follow-up. The hypothesis of this investigation was to verify if the use of this implant design may have provided potential advantages in femoral revisions and post-traumatic instances where the restoration of the anatomy was the prime concern. Methods We retrospectively reviewed 62 cases of femoral revision surgeries, performed in Paprosky type IIIA and IIIB bone defects between January 2001 and December 2011 with a mean follow-up of 8.5 ± 1.5 years (range 5.1–15.9 years) where a modular fluted stem was used. The clinical assessment was performed with the Harris Hip Score (HHS), and the radiographic evaluation was carried in order to assess the stability of the femoral component. Intra-operative and postoperative complications were recorded, and the rates of complications and revisions for any cause were determined. Results Mean HHS improved 35.4 points from the preoperative assessment. Radiographic evaluation showed a stable stem anchorage in 90.3% of the cases at the last follow-up. Five (8%) implants required additional surgery. Neither breakage of the stem nor loosening of the taper junction were recorded. Kaplan-Meier survivorship was 89.4% (CI: 88.8–90%) for any complication and 92.3% (CI: 91.8–92.7%) according to revision for any causes at 81 months follow-up. Conclusions Our findings suggest that this stem design is a reliable option in cases of complex femoral bone defects, as well as in cases with high functional deficiencies, with promising survivorship.

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Surgical Advances in Osteosarcoma

Cancers ◽

10.3390/cancers13030388 ◽

2021 ◽

Vol 13 (3) ◽

pp. 388

Author(s):

Marcus J. Brookes ◽

Corey D. Chan ◽

Bence Baljer ◽

Sachin Wimalagunaratna ◽

Timothy P. Crowley ◽

...

Keyword(s):

Fluorescent Dyes ◽

Imaging Techniques ◽

Intraoperative Imaging ◽

Survival Rates ◽

Computer Navigation ◽

Bone Cancer ◽

Technical Difficulty ◽

Implant Design ◽

Patient Specific ◽

Patient Specific Instruments

Osteosarcoma (OS) is the most common primary bone cancer in children and, unfortunately, is associated with poor survival rates. OS most commonly arises around the knee joint, and was traditionally treated with amputation until surgeons began to favour limb-preserving surgery in the 1990s. Whilst improving functional outcomes, this was not without problems, such as implant failure and limb length discrepancies. OS can also arise in areas such as the pelvis, spine, head, and neck, which creates additional technical difficulty given the anatomical complexity of the areas. We reviewed the literature and summarised the recent advances in OS surgery. Improvements have been made in many areas; developments in pre-operative imaging technology have allowed improved planning, whilst the ongoing development of intraoperative imaging techniques, such as fluorescent dyes, offer the possibility of improved surgical margins. Technological developments, such as computer navigation, patient specific instruments, and improved implant design similarly provide the opportunity to improve patient outcomes. Going forward, there are a number of promising avenues currently being pursued, such as targeted fluorescent dyes, robotics, and augmented reality, which bring the prospect of improving these outcomes further.

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The Effect of Coronal Implant Design and Drilling Protocol on Bone-to-Implant Contact: A 3-Month Study in the Minipig Calvarium

Materials ◽

10.3390/ma14102645 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2645

Author(s):

Omer Cohen ◽

Dieter D. Bosshardt ◽

Evegeny Weinberg ◽

Gil Slutzkey ◽

Ofer Moses

Keyword(s):

Implant Design ◽

Drill Diameter ◽

Bone To Implant Contact ◽

Type 3

Stress concentrated at an implant’s neck may affect bone-to-implant contact (BIC). The objective of this study was to evaluate four different implant neck designs using two different drilling protocols on the BIC. Methods: Ninety-six implants were inserted in 12 minipigs calvarium. Implants neck designs evaluated were: type 1–6 coronal flutes (CFs), 8 shallow microthreads (SMs); type 2–6 CFs,4 deep microthreads (DMs); type 3–4 DMs; type 4–2 CFs, 8 SMs. Two groups of forty-eight implants were inserted with a final drill diameter of 2.8 mm (DP1) or 3.2 mm (DP2). Animals were sacrificed after 1 and 3 months, total-BIC (t-BIC) and coronal-BIC (c-BIC) were evaluated by nondecalcified histomorphometry analysis. Results: At 1 month, t-BIC ranged from 85–91% without significant differences between implant types or drilling protocol. Flutes on the coronal aspect impaired the BIC at 3 m. c-BIC of implant types with 6 CFs was similar and significantly lower than that of implant types 3 and 4. c-BIC of implant type 4 with SMs was highest of all implant types after both healing periods. Conclusions: BIC was not affected by the drilling protocol. CFs significantly impaired the -BIC. Multiple SMs were associated with greater c-BIC.

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