OsteoSinter®
EVANS and COTTON wedges

In words of Leonardo DaVinci, the foot “is a masterpiece of engineering and a work of art”.

In words of Leonardo DaVinci, the foot “is a masterpiece of engineering and a work of art”, but, like any structure subjected to repeated mechanical loads, it can end up having problems.

The around 8,000 steps a day on average that it supports makes it prone over the years to suffer pathologies. It is estimated that more than 80% of the population will suffer health problems of varying severity in the feet at some point in their life.

Among the multiple pathologies that occur, flatfoot deformity (valgus flatfoot of the adult) is one of the most relevant and complex, and continuously changing and innovating.

Surgical treatment of valgus flatfoot rarely requires a single isolated procedure, but rather a selection of techniques. Among these techniques, Evans and Cotton osteotomies occupy an important place.

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OsteoSinter® EVANS and COTTON wedges: description and indications

OsteoSinter® EVANS and COTTON wedges are porous titanium implants used to correct adult-acquired flatfoot deformities, specifically for stage II posterior tibial tendon dysfunction.

The wedges are intended to be used as an implant specifically designed for Evans (for lateral foot column lengthening) or Cotton procedures (improve the inclination of the first radius and avoid overloading the external column).

The material of these wedges is OsteoSinter® porous CP Titanium, manufactured using Powder Metallurgy technology. A special design of the manufacturing process allows to obtain a product with interconnected porosity (62-66% in volume), favoring osteointegration of the surrounding bones.

OsteoSinter® EVANS and COTTON wedges are provided in 15 sizes to achieve proper anatomical correction in each particular case.

The OsteoSinter® EVANS and COTTON wedges are placed using a single-use instrument kit, which include a tweezer, an impactor and a set of sizers used to choose the right size for each patient.

kit-evans

Indications

OsteoSinter® EVANS and COTTON wedges are intended to be used for internal bone fixation of bone fractures, fusions, or osteotomies in the foot. Specific indications include:

  • Opening wedge osteotomies of the bones of the foot (including addition osteotomies for Hallux Valgus).

  • Opening wedge of medial cuneiform or Cotton osteotomies.

  • Lateral column lengthening (Evans lengthening osteotomy or calcaneal Z osteotomy).

  • Metatarsal/cuneiform arthrodesis.

OsteoSinter® EVANS and COTTON wedges are indicated to be used with ancillary fixations.

OsteoSinter® EVANS and COTTON wedges are not indicated for use in the spine.

Contraindications

  • Infection

  • Physiologically or psychologically inadequate patient.

  • Inadequate skin, bone or neurovascular conditions (conditions that tend to limit the patient´s ability or willingness to restrict activities or follow post-operative care instructions).

  • Growing patients with open epiphyses.

  • Foreign body sensitivity. Where material sensitivity is suspected, testing is to be completed prior to device implantation.

  • Patient smoking may result in delayed healing, non-healing and/or compromised stability in or around the placement site.

Single-use instruments kit

OsteoSinter® EVANS and COTTON wedges are delivered with a single-use and recyclable surgical instrument kit, made of polyamide grade 12 material.

This kit is used in conjunction with the typical instrumentation of a standard orthopedic surgery for both EVANS and COTTON osteotomies.

The single-use OsteoSinter® EVANS and COTTON instrument kits include a set of sizers (one for each size and type of wedge), a tweezer to hold and insert the wedge, and an impactor to seat the implant in its suitable position by tapping gently with a standard hammer (not supplied in the kit).

kit-cotton

OsteoSinter® kit
(a set of sizers, tweezer, and impactor)

Single-use OsteoSinter® EVANS and COTTON instruments

SIZES

OsteoSinter® EVANS wedges

9 sizes (3 dimensions with different surfaces and 3 thicknesses for each one)
Footprint
options
Name Width
(mm) [W]
Length
(mm) [L]
Height
(mm) [H]
Height
options
Reference

18x18 mm
OsteoSinter® EVANS wedge
18W x 18L x 8H
18 18 8 P00200
OsteoSinter® EVANS wedge
18W x 18L x 10H
18 18 10 P00201
OsteoSinter® EVANS wedge
18W x 18L x 12H
18 18 12 P00202

20x20 mm
OsteoSinter® EVANS wedge
20W x 20L x 8H
20 20 8 P00203
OsteoSinter® EVANS wedge
20W x 20L x 10H
20 20 10 P00204
OsteoSinter® EVANS wedge
20W x 20L x 12H
20 20 12 P00205

22x22 mm
OsteoSinter® EVANS wedge
22W x 22L x 8H
22 22 8 P00206
OsteoSinter® EVANS wedge
22W x 22L x 10H
22 22 10 P00207
OsteoSinter® EVANS wedge
22W x 22L x 12H
22 22 12 P00208

OsteoSinter® COTTON wedges

6 sizes (2 dimensions with different surfaces and 3 thicknesses for each one)
Footprint
options
Name Length
(mm) [L]
Height
(mm) [H]
Height
options
Reference

15 mm
OsteoSinter® COTTON wedge
15L x 4.5H
15 4.5 P00300
OsteoSinter® COTTON wedge
15L x 5.5H
15 5.5 P00301
OsteoSinter® COTTON wedge
15L x 6.5H
15 6.5 P00302

20 mm
OsteoSinter® COTTON wedge
20L x 4.5H
20 4.5 P00303
OsteoSinter® COTTON wedge
20L x 5.5H
20 5.5 P00304
OsteoSinter® COTTON wedge
20L x 6.5H
20 6.5 P00305

The OsteoSinter® material:
Trabecular bone mimicry

 

Ultraporous pure titanium

The OsteoSinter® material is biocompatible CP Titanium manufactured by means of Powder Metallurgy technology.

A special design of the manufacturing process allows to obtain a product with interconnected porosity (62-66% in volume)[3] , favoring osteointegration of the surrounding bones.

The result is a material that mimics the structure and characteristics of human bone, specially the apparent elastic modulus and the porosity shape.

Trabecular
bone[1]

OsteoSinter®
material[2]

[1] AME19-C015  [2] p00100_osteosinter porosity  [3] p00100_te_medical device

Mechanical properties

The OsteoSinter® material exhibits a mechanical behavior very similar to the human bone.

The porous structure of the material and the relief shape of the surfaces provide primary fixation to the bone.

Property Material
OsteoSinter®[1,2,3] Trabecular bone[4,5,6]
Apparent elastic modulus (GPa) 2.7 0.01-3
Compressive yield strength (MPa) 30 0.1-30
Friction coefficient 1.22 0.44-0.63
Compressive fatigue limit 5 M cycles at > 11.3 MPa without failure N.D.

[1] p00100_compressive properties OsteoSinter®
[2] proy180093.
[3] proy220128.
[4] ADVANCE® BIOFOAMTM Cancellous Titanium_Tibial implants_Technical Monograph.
[5] Morgan EF, Unnikrisnan GU, Hussein AI. Bone Mechanical Properties in Healthy and Diseased States. Annu Rev Biomed Eng. 2018 Jun 4;20:119-143. doi: 10.1146/annurev-bioeng-062117-121139. PMID: 29865872; PMCID: PMC6053074.
[6] Shirazi-Adl A1, Danmark M, Paiement G. Experimental determination of frictin characteristics at the trabecular bone/porous-coated metal interface in cementless implants. J Biomed Mater Res. 1993 Feb;27(2): 167-75.

BENEFITS IN HEALTHCARE COSTS

Material

Porous metallic material

  • OSTEOINTEGRATION
  • NO REABSORPTION
  • NO COLLAPSE
Fijacion

Primary fixation

corrección-precisa

Variety of sizes

  • DIRECT PLACEMENT
  • NO CARVING OR ON-SITE ADJUSTMENT
un solo uso

Single-use instruments

  • IMMEDIATE AVAILABILITY
  • PROVIDED STERILE
  • NO INVESTMENT IN INSTRUMENTS

REFERENCES

Haeomatogenous infection

Komnos, G., Banios, K., Kolonia, K., Poultsides, L. A., Petinaki, E., Sarrou, S., Zintzaras, E., Karachalios, T. (2020). Do trabecular metal and cancellous titanium implants reduce the risk of late haematogenous infection? An experimental study in rabbits.

https://pubmed.ncbi.nlm.nih.gov/32460572/

Single-use Orthopedic Instruments

Cook, Dan (2023). Interest in Single-Use Orthopedic Instruments Continues to Grow

bonezonepub.com/2023/02/06/interest-in…

Porous Titanium Wedges

Moore, S. H., Carstensen, S. E., Burrus, M. T., Cooper, T., Park, J. S., & Perumal, V. (2018). Porous Titanium Wedges in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity. Foot & Ankle Specialist, 11(4), 347–356.

https://pubmed.ncbi.nlm.nih.gov/29073794/

Porous Titanium Wedges

Gross, C. E., Huh, J., Gray, J., Demetracopoulos, C., & Nunley, J. A. (2015). Radiographic Outcomes Following Lateral Column Lengthening With a Porous Titanium Wedge. Foot & Ankle International, 36(8), 953–960.

https://pubmed.ncbi.nlm.nih.gov/25810461/

Corrective Osteotomies

Matthews, Michael et al. (2018). Long-Term Outcomes of Corrective Osteotomies Using Porous Titanium Wedges for Flexible Flatfoot Deformity Correction. The Journal of Foot and Ankle Surgery, Volume 57, Issue 5, 924 – 930.

https://pubmed.ncbi.nlm.nih.gov/29891128/

Porous Titanium Wedges

Andrew B. Bridgforth, M. Tyrrell Burrus, Joseph S. Park (2016). Varus Deformity of the Distal Tibia From Physeal Growth Arrest Treated Using a Titanium Metal Porous Wedge. Volume: 9 issue: 5, page(s): 452-456.

https://pubmed.ncbi.nlm.nih.gov/26644031/

titanium metal foam wedge implant

Tucker D (2010)..Lateral column lengthening in adult flatfoot surgery using a titanium metal foam wedge implant. Tech and Foot Ankle. (9), 205-210.

Wedge Osteotomy for Correction

Giovanni R. et al.(2019).Medial Cuneiform Opening Wedge Osteotomy for Correction of Flexible Flatfoot Deformity: Trabecular Titanium vs. Bone Allograft Wedges. BioMed Research International. Volume 2019, 7 pages.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6462320/

Porous Titanium Wedges

Carstensen S, Moore S, Park JD, Truitt M, Cooper M, Perumal.(2018)..Porous Titanium Wedges are an Alternative in Lateral Column Lengthening for Adult Acquired Flatfoot Deformity. AOFAS Annual Meeting. Foot & Ankle Orthopaedics, 3(3)

https://journals.sagepub.com/doi/abs/10.1177/2473011418S0018

Calcaneal Osteotomy

Gordon S, Clifton T.(2018)..Minimally Invasive Opening Wedge Calcaneal Osteotomy Usinga Titanium Structural Fusion device. EC Orthopaedics 9.9. 626-631.

https://www.semanticscholar.org/paper/Minimally-Invasive-Opening-Wedge-Calcaneal-Using-a-Slater-Clifton/8c4460f92b9ad071ed9fa54d263a029d6d32e858