The OGmend® implant system is for the use with screws as part of a fracture fixation plate system in long bones in rescue scenarios where the screw has lost purchase due to screw loosening, back out, or breakage and the stability of the plate construct is at risk. The OGmend® Implant System is for use in skeletally mature patients.

Device Description

The OGmend® Implant System is a sterile, single-use device intended to provide supplemental fixation to restore stability if the screw/bone interface of a plate and screw system becomes mechanically compromised. When inserted into a prepared bone pilot hole, the OGmend® Implant System is designed to use the principles of interference fit to serve as a rescue technology to secure a bone screw and stabilize the fracture construct. The OGmend® Implant System is manufactured from woven polyethylene terephthalate (PET), with an inner diameter of 6.5mm and an outer diameter of 7.5mm, and can be used with screws ranging in diameter from 3.5mm to 6.5mm. The OGmend® Implant System is 100mm in length and is cut intraoperatively to the appropriate length.

When a screw loses stability due to loosening, backout, or breakage, the OGmend® Implant System is intended to restore stability. The device is placed into a prepared hole after removal of the failed screw, and a new screw is inserted though the inner diameter of the OGmend® Implant System, in order to generate mechanical interferences and improve the stability of the screw and bone-plate construct.

AI/ML Overview

Here's an analysis of the acceptance criteria and the studies proving the device meets them, based on the provided text.

Acceptance Criteria and Device Performance for OGmend® Implant System

1. Table of Acceptance Criteria and Reported Device Performance

Test	Purpose	Acceptance Criteria	Reported Device Performance
Bench Studies:
Screw Axial Pullout	To assess if the subject device provides improved stability compared to an alternate treatment for a failed screw.	The axial pullout force of the screw in combination with the sleeve must be equivalent to or greater than the pullout force for a rescue screw alone.	Test results show that the force required to pull out a 3.5 mm screw with the OGmend® Implant System in place exceeded the force required to pull out a 4.0 mm screw without the OGmend® Implant System. The acceptance criteria were met.
Sleeve Dynamic Axial Loading, Pullout and Removal/Extraction Torque	To assess if dynamic loading would damage the implant and/or cause a reduction in pullout strength.	After (b)(4) cycles, there should be no decrease in pullout values or damage to the device.	The test results showed no decrease in axial pullout force or removal torque in either the control group or in the OGmend® Implant System treatment group. This demonstrated that cyclic loading did not negatively affect the mechanical strength of the device or the stability of the interference fit.
Sleeve Insertion Force	To evaluate the force required to insert the sleeve compared to the force required to insert the sleeve manually during a surgical procedure.	No more than (b) N should be required to insert the OGmend® Implant System. This was based on an assessment of load needed to damage the device with a margin of safety.	For both a 3.5 mm and a 6.5 mm pilot hole, it required less than (b) N to insert the device ((b)(4) N in the 3.5 mm hole, and (b)(4) N in the 6.5 mm hole). This compares to an average force of (b).1 N needed to rupture the distal end of the sleeve. This demonstrated that the device can be successfully inserted into bone using the provided surgical technique and instruments without damage to the device.
Screw Removal/Extraction Torque	To assess the ability of the screw to be inserted and extracted when used with the OGmend® Implant System compared to a traditional, fully threaded bone screw, demonstrating that the interference generated by the implant did not increase the insertion/removal torque sufficiently to cause breakage or prevent proper implantation.	The torque required to insert and remove the screw with the OGmend® Implant System in place must be less than the torsional strength of the screw.	The OGmend® Implant System did increase the torque needed to insert and remove the screw (e.g., 0.025 Nm to 0.133 Nm for 3.5mm insertion). While there was an increase, the torque was still significantly less than the yield torque of the screws being tested, indicating no risk of screw failure during insertion and removal.
Durability of Sleeve during Screw Implantation	To assess if the OGmend® Implant System can be inserted into the bone without damage of the device, using the provided instruments, in preparation for the placement of a screw.	Screw pullout force following repeated insertions must not be reduced compared to prior axial pullout testing.	Testing showed no reduction in pullout strength of a screw compared to baseline. This indicates the device can withstand the handling of surgery without damage that could affect its mechanical performance.
Wear Particle Generation	To assess if the sleeve can withstand screw insertion and cyclic loading without damage, and to characterize any potential wear particles.	The device should not sustain damage such that it fails to perform its intended function, and wear particles generated should be fully characterized.	Assessment of images found no significant damage occurred to the structural integrity of the device. A total particulate measure of 0.12 ± 0.24 mg of PET was recorded in dynamically loaded samples, compared to 0.21 ± 0.23 mg in the control group. Total particle count was also characterized.
Animal Studies (Spine Model - Pivotal Study):
Axial Pullout Force	To assess the fixation strength of the implant compared to controls.	Data from the pivotal spine study was used in the final safety and efficacy determination. (Implicit: Show improved or equivalent fixation to positive control and better than negative control).	At 0 months, Control + SRT (OGmend®) pullout force was 662.56 N (similar to control 1524.50 N, but the control here is a proper placement, not a rescue scenario). At 3 months, Control + SRT was 3043.43 N vs. 1147.63 N for control. At 6 months, Control + SRT was 2862.94 N vs. 723.74 N for control. (It's unclear if "control" here refers to the positive or negative control mentioned in the sample size. However, the graph clearly shows OGmend® improving pullout force over an unassisted "Control" at 3 and 6 months.) Data supported safety and efficacy.
Insertion Torque	To validate bench models so as to ensure the sleeve does not excessively increase the torque needed in implant screws.	(Implicit: Insertion torque with OGmend® should be acceptable and not lead to screw failure)	Positive control: 1.15 N-m; Negative control: 0.06 N-m; Negative control with SRT: 0.96 N-m. This shows the OGmend® system provides torque similar to a properly placed screw and significantly higher than a failed screw, without exceeding limits.
Extraction Torque	To assess the stability of the implant over time compared to controls.	(Implicit: Maintain stability over time).	At 0 months, +SRT (-7.85 N-m) was comparable to +Control (-7.24 N-m) and significantly better than -Control (-0.31 N-m). At 6 months, +SRT (-11.90 N-m) was comparable to +Control (-11.05 N-m) and significantly better than -Control (-1.29 N-m). Data supported stability over time.
Pullout Stiffness	To assess the mechanical stability of the implant compared to controls.	(Implicit: Maintain mechanical stability over time).	At 0 months, Control + SRT (436.91 N/mm) was comparable to control (432.47 N/mm). At 6 months, Control + SRT (501.00 N/mm) was comparable to control (567.36 N/mm). Data supported mechanical stability.
Kinematics of the fusion site	To demonstrate that the device provided sufficient stability to allow for clinically relevant healing of the fusion site, as an analog for fusion of a fracture.	(Implicit: Show appropriate range of motion and bending stiffness for healing).	Lateral Bending Range of Motion showed decreases from 11.35° (0 months) to 0.19° (6 months) for Control + SRT. Lateral Bending Stiffness showed increases from 0.84 N-m/Deg (0 months) to 71.40 N-m/Deg (6 months) for Control + SRT. This demonstrated sufficient stability for healing.
Histological, Histopathological, and Histromorphometric assessment	To determine if the implant or wear particles generated by the implant resulted in a negative biologic reaction detrimental to long-term health.	(Implicit: No significant adverse biologic reaction).	While there was an ongoing foreign body reaction at the final time point (24 weeks) in the animal spine model study, it was determined that the degree of reaction would not lead to unacceptable risk to patients. Adequate data to assess safety.
Radiographic review of the fusion site	To confirm that fusion occurred.	(Implicit: Demonstrate fusion comparable to controls).	Bridging Averages for Group 1 (Positive Control), Group 2 (Negative Control), and Group 3 (Treatment) were all around 1 (indicating 76-100% bridging). New Bone Formation scores were all around 3 (best score is 4). No significant difference observed between groups, supporting fusion.
Biocompatibility	To demonstrate compatibility with biological systems.	All listed ISO 10993 endpoints must be met.	Cytotoxicity, Sensitization, Irritation/Intracutaneous Reactivity, Acute Systemic Toxicity, Material-Mediated Pyrogenicity, Subacute/Subchronic Toxicity, Genotoxicity, Implantation, Chronic Toxicity, and Carcinogenicity all met acceptance criteria. Additional in vivo studies data were leveraged. Endpoint Met for all.

2. Sample Size Used for the Test Set and the Data Provenance

Bench Studies: The sample sizes vary per test. For Axial Pullout, there were multiple samples (e.g., 20 pcf Sawbone). For Dynamic Axial Loading, Insertion Force, Screw Removal/Extraction Torque, and Durability, specific numbers are redacted (b)(4), but implied to be sufficient for statistical analysis. For Wear Particle Generation, samples were dynamically loaded (number redacted) and control samples were also analyzed.
Animal Studies:
- Screw Model: 10 Animals
- Osteotomy Model (1): 4 Animals
- Osteotomy Model (2): 18 Animals + 6 Cadaveric
- Spine Model (Pivotal Study): 54 Animals (divided into 3 groups of 18 animals each for Positive Control, Negative Control, and Treatment). Assessment was done on six animals at 0, 12, and 24 weeks for specific parameters.
Data Provenance: The data is from non-clinical bench studies and animal studies (sheep metatarsals and sheep lumbar spine), which are inherently prospective. The country of origin is not explicitly stated, but typically these studies are conducted by or for the sponsor.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts

Bench Studies: Ground truth for these studies is established by engineering/biomedical standards (e.g., ASTM F543) and physical measurements. No human "experts" in the sense of clinical reviewers are typically involved in establishing ground truth for these types of mechanical tests. The "ground truth" is the objective measurement (e.g., pullout force in Newtons).
Animal Studies:
- For quantitative measures like pullout force, torque, and stiffness, the "ground truth" is the objective measurement from the testing equipment.
- For histological, histopathological, and histomorphometric assessment, and radiographic review, these would typically be performed by veterinary pathologists and radiologists, respectively. The text does not specify the number of experts or their qualifications (e.g., "board-certified veterinary pathologist with 10 years experience"), but implies that these assessments were conducted by qualified personnel suitable for an animal study.
- The "final safety and efficacy determination" and "assessment of six animals" would involve interpretation by study investigators and likely veterinary specialists.

4. Adjudication Method for the Test Set

Bench Studies: Adjudication is not applicable in the typical sense (e.g., 2+1, 3+1). Results are quantitative measurements against predefined acceptance criteria.
Animal Studies:
- For quantitative mechanical tests, direct measurements are taken.
- For qualitative assessments (histology, radiography), a formal adjudication method (like 2+1) is not explicitly mentioned. Usually, an experienced pathologist/radiologist makes the assessment, and sometimes a second reviewer is used for quality control or confirmatory reading, but this is not detailed here. The statement "no significant difference observed between groups" for radiographic scores implies a statistical comparison of scores, rather than a reader adjudication process.

5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

No MRMC comparative effectiveness study was mentioned or performed. This device is a physical implant, not an AI-powered diagnostic tool that assists human readers. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not relevant to this device's evaluation.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done

Not applicable. This is a physical medical device, not an algorithm, so "standalone algorithm performance" is not relevant.

7. The Type of Ground Truth Used

Bench Studies: Performance standards from mechanical testing (e.g., ASTM standards) specifying quantifiable metrics (force, torque, cycles) and visual inspection for damage.
Animal Studies (Pivotal Spine Model):
- Objective measurement data: Axial pullout force, insertion torque, extraction torque, pullout stiffness, kinematics (range of motion, bending stiffness).
- Biological/Pathological assessment: Histological, histopathological, and histomorphometric assessment of tissue, and radiographic review of fusion site. These would represent expert consensus/pathology as interpreted by specialist veterinarians/pathologists/radiologists.
- Outcomes Data: The overall result of "sufficient stability for healing" is an outcome from the animal study.

8. The Sample Size for the Training Set

Not applicable. This is a physical medical device, not an algorithm that requires a training set. The development of the device itself would involve iterative design and testing, but not in the "training set" sense of machine learning.

9. How the Ground Truth for the Training Set was Established

Not applicable. As above, no training set for an algorithm was utilized.

Summary

{0}------------------------------------------------

DE NOVO CLASSIFICATION REQUEST FOR OGMEND® IMPLANT SYSTEM

REGULATORY INFORMATION

FDA identifies this generic type of device as:

Screw sleeve bone fixation device: A screw sleeve bone fixation device is intended to be implanted in conjunction with a non-resorbable, metallic bone screw where the screw has lost purchase due to loosening, backout, or breakage. The device fits between the screw threads and surrounding bone, and provides increased surface area to create an interference fit to restore stability of the implant construct.

NEW REGULATION NUMBER: 21 CFR 888.3043

CLASSIFICATION: Class II

PRODUCT CODE: QAC

BACKGROUND

DEVICE NAME: OGmend® Implant System

SUBMISSION NUMBER: DEN180065

DATE DE NOVO RECEIVED: December 13, 2018

SPONSOR INFORMATION:

Woven Orthopedic Technologies, LLC 63 E. Center Street Manchester, Connecticut 06040

INDICATIONS FOR USE

The OGmend® Implant System is indicated as follows:

LIMITATIONS

The sale, distribution, and use of the OGmend® Implant System is restricted to prescription use in accordance with 21 CFR 801.109.

{1}------------------------------------------------

The safety and effectiveness of the OGmend® Implant System has not been established for use with non-metallic, resorbable, or self-tapping screws.

The OGmend® Implant System should not be used with stand-alone screws, joint arthroplasty systems, and spinal fixation procedures.

The OGmend® Implant System should not be used in a situation where other rescue techniques (i.e., rescue screw, repositioning of bone plating system or stand-alone screw) will provide a better patient outcome.

The OGmend® Implant System has not been tested in patients with osteoporosis, osteopenia, diabetes, nor in patients who smoke or who have any other metabolic bone diseases.

PLEASE REFER TO THE LABELING FOR A COMPLETE LIST OF WARNINGS, PRECAUTIONS AND CONTRAINDICATIONS.

DEVICE DESCRIPTION

Image /page/1/Picture/7 description: The image shows two metal objects, one above the other, against a dark background. The top object is a cylindrical pin with a textured surface, while the bottom object is a screw with a pointed tip and threading along its length. The pin appears to have a smooth section at one end, possibly for insertion or attachment.

Figure 1: View of OGmend® Implant System on sample screw

{2}------------------------------------------------

System, in order to generate mechanical interferences and improve the stability of the screw and bone-plate construct.

Image /page/2/Figure/1 description: The image shows three diagrams illustrating the process of inserting a screw into a bone. The first diagram, labeled "A. Plate and Pilot Hole," shows a plate placed on top of the bone with a pilot hole drilled through the plate and into the bone. The second diagram, labeled "B. Insert OGmend," shows an OGmend device inserted into the pilot hole. The third diagram, labeled "C. Insert Screw," shows a screw inserted into the OGmend device.

Figure 2: Illustration of placement of OGmend® Implant System in hole during the repair of a failed screw on a bone plate system.

SUMMARY OF NONCLINICAL/BENCH STUDIES

BIOCOMPATIBILITY/MATERIALS

The OGmend® Implant System is manufactured from the following materials:

Table 1: Device Materials

Description	Material	Direct PatientContact	Contact Duration
OGmend®Implant System	Polyethylene Terephthalate	Yes	(b)(4)
InserterInstrument	(b)(4)	Yes	(b)(4)

Biocompatibility Testing is described in the table below.

Table 2: Biocompatibility Testing

ISO 10993 Endpoint	Test Performed	Endpoint Met
Cytotoxicity	Yes	Yes
Sensitization	Yes	Yes
Irritation / IntracutaneousReactivity	Yes	Yes
Acute Systemic Toxicity	Yes	Yes
Material-MediatedPyrogenicity	Yes	Yes

{3}------------------------------------------------

Subacute / SubchronicToxicity	Yes	Yes
Genotoxicity	Yes	Yes
Implantation	Yes	Yes
Chronic Toxicity	Yes	Yes
Carcinogenicity	Yes	Yes

Additional in vivo studies data were leveraged to address biocompatibility of the OGmend® Implant System (See Animal Testing section below). In conjunction with the CDRH Guidance Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process", the in vivo testing and ISO 10993 testing provided, was used to demonstrate the biocompatibility of the device.

SHELF LIFE/STERILITY

The subject device is a single use device and is provided sterile to the end user. The sterilization method is gamma radiation at a dose of 25 kGy. Sterilization was validated using the VDmax method as per ISO 11137, and achieved a Sterility Assurance Level (SAL) of 10-6. The subject device and instruments are packaged together in sealed double-blister Tyvek pouches.

Sterilized samples accelerated-aged to ""months, and real-time aged to """months were used to determine the shelf life of the device. Distribution testing and package integrity testing (bubble/leak test, ASTM F2096), and seal strength testing (ASTM F88/F88M) were used to validate the sterile shelf life of device. Non-clinical performance testing of the implant (See Table 3) was used to assess the performance shelf life of the device. The testing confirmed a (b)(4) shelf life.

The following standards were utilized in the validation of the sterilization and shelf-life:

ANSI/AAMI/ISO 11137-1:2006: Sterilization of health care products -. Radiation - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices
ANSI/AAMI/ISO 11137-2:2012: Sterilization of Health Care Products -Radiation ● - Establishing the Sterilization Dose - Method VDmax25
ISO 11737-1 2006/(R)2011 Sterilization of medical devices Microbiological ● methods - Part 1: determination of a population of microorganisms on products
ANSI/AAMI/ISO 11737-2:2009 Sterilization of medical devices -● Microbiological methods - Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process
ASTM F88/ F88M-15: Standard Test Method for Seal Strength of Flexible ● Barrier Materials
. ASTM F1886/ F1886M-09 (2013): Standard Test Method for Determining Integrity of Seals for Flexible Packaging by Visual Inspection

{4}------------------------------------------------

ANSI/AAMI/ISO11607-1:2006: Packaging for terminally sterilized medical . devices - Part 1: Requirements for materials, sterile barrier systems, and packaging systems
. ANSI/AAMI/ISO11607-2:2006: Packaging for terminally sterilized medical devices - Part 2: Validation requirements for forming, sealing, and assembly processes
. ASTM F1980, Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical Devices
ASTM F 1140:2007, Standard Test Methods for Internal Pressurization Failure ● Resistance of Unrestrained Packages.
ASTM F2096-2004. Standard Test Method for Detecting Gross Leaks in Medical ● Packaging by Internal Pressurization (Bubble Test)
ASTM D-4332/1991, Standard practice for conditioning containers, packages, or ● packaging components for testing
ISTA 2A-2011, Partial Simulation Performance Tests ●

MAGNETIC RESONANCE (MR) COMPATIBILITY

The subject device was not evaluated for safety in a (b)(4) Environment. The device is manufactured from a non-ferromagnetic, non-metallic, and radiofrequency transparent material, PET; however, as it is intended to be used with metallic bone plate and screw systems, the following precaution is included in the labeling:

. There may be concerns regarding the MR safety of the metallic hardware (i.e., plates and screws) used in conjunction with the OGmend® Implant System.

PERFORMANCE TESTING - BENCH

Test	Purpose	Method	Acceptance Criteria	Results
Screw AxialPullout	This test is intendedto assess if thesubject deviceprovides improvedstability comparedto an alternatetreatment for afailed screw.	To simulate a rescue scenario, a3.5 mm pilot hole was made in 20pcf Sawbone. The device wasthen implanted in combinationwith a 3.5 mm screw. The screwwas then pulled axially untilfailure as per ASTM F543. 4.0mm screws were inserted into 3.5mm pilot holes to simulateplacing a larger screw in a failedscrew hole as a control.	The axial pulloutforce of the screw incombination with thesleeve must beequivalent to orgreater than thepullout force for arescue screw alone.	Test results showthat the forcerequired to pullout a 3.5 mmscrew with theOGmend®Implant Systemin place exceededthe force requiredto pull out a 4.0mm screwwithout theOGmend®Implant System.The acceptancecriteria were met.
Test	Purpose	Method	Acceptance Criteria	Results
		(b) (4)
		Figure 3: Test setup for AxialPullout
Sleeve DynamicAxial Loading,Pullout andRemoval/ExtractionTorque	This test is intendedto assess if dynamicloading woulddamage the implantand/or cause areduction in pulloutstrength.	A control group (without theOGmend® Implant System) andtreatment group (with theOGmend® Implant System) weredefined. (b) (4)Axial loading is considered toconstitute the worst-case clinicalloading scenario as compressionplates are designed to generateaxial loading on the screw, andthe resultant force on the screwwould be reduced by transfer ofsome load to the plate.Each screw was sinusoidallyloaded between $(b)$ N and $(b)$ % ofthe pullout force determined from	After (b) (4) cycles,there should be nodecrease in pulloutvalues or damage tothe device.	The test resultsshowed nodecrease in axialpullout force orremoval torque ineither the controlgroup or in theOGmend®Implant Systemtreatment group.This testingdemonstratedthat cyclicloading did notnegatively affectthe mechanicalstrength of thedevice or thestability of theinterference fit.
Test	Purpose	Method	Acceptance Criteria	Results
		static testing for a total of (b) (4)cycles at a rate of Hz. Forreference, the pullout force wasre-evaluated during this testing todetermine the correct (b)% value.The (b)% pullout force value forthe subject device was (b) N andwas (b) N for the control.At the completion of(b) (4)cycles, removal torque andpullout testing were conductedper ASTM F543.
Sleeve InsertionForce	This test is intendedto evaluate the forcerequired to insert thesleeve compared tothe force required toinsert the sleevemanually during asurgical procedure.	The axial force needed to pushthe sleeve into a pilot hole usingan inserter tool in (b) pcf bonefoam was measured. Testing wasperformed with both a 3.5 mmand 6.5 mm pilot hole to representthe smallest and largest potentialholes compatible with the device.To assess the load needed tocause damage to the sleeve, aprobe was pressed through thesleeve against the distal tip at aconstant rate until failure of thesleeve occurred.(b) (4)Figure 4: Test setup for sleevemechanical strength test	No more than(b) Nshould be required toinsert the OGmend®Implant System. Thiswas based on anassessment of loadneeded to damage thedevice with a marginof safety.	For both a 3.5mm and a 6.5mm pilot hole, itrequired less than(b) N to insert thedevice (b) (4)N in the 3.5 mmhole, and(b) (4)N in the 6.5 mmhole). Thiscompares to anaverage force of(b) .1 N neededto rupture thedistal end of thesleeve.Thisdemonstratedthat the devicecan besuccessfullyinserted intobone using theprovided surgicaltechnique andinstrumentswithout damageto the device.
Screw Removal/ExtractionTorque	This test is intendedto assess the abilityof the screw to beinserted andextracted when usedwith the OGmend®Implant Systemcompared to atraditional, fullythreaded bone screw	The investigational cohort,consisting of the OGmend®Implant System and screw, wastested with two screw diameters(3.5mm and 6.5mm) in 20 pcfsawbone. Pilot holes were madein the sawbone, and the sleeveand screw were implantedfollowing the surgical technique.During insertion, torque was	The torque requiredto insert and removethe screw with theOGmend® ImplantSystem in place mustbe less than thetorsional strength ofthe screw	The OGmend®Implant Systemdid increase thetorque needed toinsert andremove thescrew. Thetorque to insertthe screwincreased from0.025 Nm to
Test	Purpose	Method	Acceptance Criteria	Results
	OGmend® ImplantSystem. The intentof the test is todemonstrate that theinterferencegenerated by theimplant did notincrease theinsertion/removaltorque sufficientlybreakage of thescrew duringimplantation orremoval, or notallow for properimplantation of thescrew.	insertion, the screw was thenremoved while measuring torque,as per ASTM F543-17.The torsional strength of thescrew was assessed by torqueingthe screw until failure as perASTM F543.(b) (4)Image: Figure 5: Test setup for insertion torque testing.		0.133 Nm (3.5mm) and from0.123 Nm to0.651 Nm (6.5mm screw).Similarly, thetorque to extractthe screwincreased from0.025 Nm to0.180 Nm (3.5mm) and from0.137 to 0.803Nm (6.5 mmscrews)While there wasan increase in thetorque requiredto implant andremove thescrew, the torquewas stillsignificantly lessthan the yieldtorque of thescrews beingtested, indicatingthere is no risk ofscrew failureduring insertionand removal.
Durability ofSleeve duringScrewImplantation	This test is intendedto assess if theOGmend® ImplantSystem can beinserted into thebone withoutdamage of thedevice, using theprovidedinstruments, inpreparation for theplacement of ascrew.	(b) (4)	Screw pullout forcefollowing repeatedinsertions must not bereduced compared toprior axial pullouttesting.	Testing showedno reduction inpullout strengthof a screwcompared tobaseline. Thisindicates thedevice canwithstand thehandling ofsurgery withoutdamage thatcould affect itsmechanicalperformance.
Wear ParticleGeneration	This test is intendedto assess if thesleeve can withstandscrew insertion andcyclic loading	(b) (4)	The device shouldnot sustain damagesuch that it fails toperform its intendedfunction, and wear	Assessment ofimages found nosignificantdamage occurredto the structural
Test	Purpose	Method	Acceptance Criteria	Results
	without damage.There is potentialfor the screw threadsto generate wearparticles duringinsertion, or duringtoggling duringcyclic loading.	layer was used. The device wasimplanted following the surgicaltechnique, and a 325 N load wasapplied at R = 10 at 5 Hz for 1million cycles. Following testing,the test block and specimens wereassessed for particulategeneration, and high-resolutionphotographs of the sleeve weretaken to assess if damageoccurred to the device.	particles generatedshould be fullycharacterized.	integrity of thedevice.A totalparticulatemeasure of 0.12$\pm$ 0.24 (range0.005 to 0.661)mg of PET wasrecorded in thedynamicallyloaded samples,compared to 0.21$\pm$ 0.23 (range0.026 to 0.654)in the controlgroup. Totalparticle countwas differentbetween groups,with an averageof 3.26E4 $\pm$2.70E4 particlesin the togglegroup and1.26E6 $\pm$ 1.64E6in the controlgroup.

Table 3: Summarv of Bench Testing

{5}------------------------------------------------

{6}------------------------------------------------

{7}------------------------------------------------

{8}------------------------------------------------

PERFORMANCE TESTING - ANIMAL AND/OR CADAVER

The sponsor conducted and provided a total of four (4) animal studies to support safety and effectiveness of the subject device. Three of these studies were conducted in sheep metatarsals, and the fourth study was conducted in the sheep lumbar spine to evaluate vertebral pedicle screw fixation for spinal fusion. While the sponsor is not proposing any spinal indications or sleeve compatibility with pedicle screws in this submission, they included this animal study for further evaluation of bony response to PET in a load-bearing scenario.

The high-level protocol information for each of these animal studies is shown in the table below:

Table 4: Overview of Animal Studies

	Screw Model	Osteotomy Model	Osteotomy Model	Spine Model
Animal Model	Ovine Metatarsal	Ovine Metatarsalwith Osteotomy	Ovine Metatarsalwith Osteotomy	Ovine LumbarSpine Fusion
Sample Size	10 Animals	4 Animals	18 Animals + 6Cadaveric	54 Animals
Construct	Screw only (6Cortical and 2Cancellous screwsper animal)	9-Hole Plate (7Cortical and 2Cancellous screwsper plate)	9-Hole Plate (7Cortical and 2Cancellous screwsper plate)	L2-L3 Fusion (4pedicle screws and2 rods)

{9}------------------------------------------------

	Screw Model	Osteotomy Model	Osteotomy Model	Spine Model
Cohorts	Control: BoneScrew (n=5)Treatment: Screwswith OGmend®Implant System(n=5)	Control: Plate andScrew Alone (n=2)Treatment: Plateand Screw withOGmend® ImplantSystem (n=2)	Control: CadavericSheep (n=6)Treatment: Plateand Screw withOGmend® ImplantSystem(n=18)	Positive Control (n= 18)Negative Control(n=18)Treatment(Negative Controlwith OGmend®Implant System, n=18)

For the Spine model, the positive control consisted of a standard screw, in which a 4.5 mm screw was placed in a 3.5 mm pilot hole. The negative screw represented a "failed" screw, in which a 4.5 mm screw was placed in a 4.5 mm pilot hole. The treatment group were also prepared with a 4.5 mm pilot hole and 4.5 mm screw, however the OGmend® Implant System was used in conjunction with the screw. Data from the pivotal spine study was used in the final safety and efficacy determination. The sponsor provided assessment of six animals at 0, 12, and 24 weeks. The final determination of the safety and effectiveness of the device was based upon data generated by the Spine Model study. Data provided in the Spine Model Study used to determine the safety and efficacy of the device included:

Axial Pullout force of screws at each time point to assess the fixation strength of the . implant compared to controls.
Image /page/9/Figure/3 description: The image is a bar graph titled "Screw Pull Out Force" that shows the pullout force in Newtons on the y-axis and the treatment type on the x-axis. There are three sets of bars, representing 0 months, 3 months, and 6 months. Each set has two bars, one for "Control" and one for "Control + SRT", with corresponding values of 1524.50 and 662.56 for 0 months, 1147.63 and 3043.43 for 3 months, and 723.74 and 2862.94 for 6 months. The pullout force increases with the addition of SRT.

Figure 6: Screw pullout force test results. For this test, the OGmend® Implant System is labeled as "-Control + SRT". The +Control and -Control groups represent the positive and negative controls described above.

{10}------------------------------------------------

Insertion Torque at the time of implantation, to validate bench models so as to ensure the ● sleeve does not excessively increase the torque needed in implant screws.
Image /page/10/Figure/1 description: This bar graph shows the in vivo insertion torque for different treatments. The x-axis represents the treatment type, and the y-axis represents the torque in Newton-meters. The positive control has a torque of 1.15 N-m, the negative control has a torque of 0.06 N-m, and the negative control with SRT treatment has a torque of 0.96 N-m.

Figure 7: Insertion Torque results, measured at baseline

Extraction Torque at each time point, to assess the stability of the implant over time ● compared to controls.
Image /page/10/Figure/4 description: The image is a bar graph titled "Screw Break Out Torque". The x-axis is labeled "Treatment Type" and has three categories: 0 Months, 3 Months, and 6 Months. The y-axis is labeled "Break Out Torque (N-m)" and ranges from -16 to 0. For each treatment type, there are three bars representing different control conditions: +Control, -Control, and +SRT. At 0 months, the +Control bar is at -7.24, the -Control bar is at -0.31, and the +SRT bar is at -7.85. At 6 months, the +Control bar is at -11.05, the -Control bar is at -1.29, and the +SRT bar is at -11.90.

Figure 8: Extraction Torque results, measured at each time point

{11}------------------------------------------------

Pullout Stiffness was measured at each time point, to assess the mechanical stability of . the implant compared to controls.
Image /page/11/Figure/1 description: The image is a bar graph titled "Screw Pullout Stiffness" that compares the screw pullout stiffness (N/mm) of different treatment types over 0, 3, and 6 months. The x-axis represents the treatment type, which includes control and control + SRT, while the y-axis represents the screw pullout stiffness in N/mm, ranging from 0 to 800. At 0 months, the control group has a stiffness of 432.47, while the control + SRT group has a stiffness of 436.91. At 6 months, the control group has a stiffness of 567.36, while the control + SRT group has a stiffness of 501.00.

Figure 9: Pullout Stiffness data at each timepoint

Kinematics of the fusion site to demonstrate that the device provided sufficient stability ● to allow for clinically relevant healing of the fusion site, as an analog for fusion of a fracture. Assessment included range of motion and bending stiffness in Flexion/Extension, Lateral bending, and Axial Rotation.
Image /page/11/Figure/4 description: The image contains two bar charts comparing the lateral bending range of motion and stiffness with and without rods over 0, 3, and 6 months. The left chart shows the range of motion in degrees, with values of 11.35, 9.39, and 10.62 at 0 months, decreasing to 1.22, 2.65, and 1.01 at 3 months, and further decreasing to 0.21, 0.20, and 0.19 at 6 months. The right chart shows stiffness in N-m/Deg, with values of 0.86, 1.25, and 0.84 at 0 months, increasing to 13.55, 15.15, and 12.84 at 3 months, and further increasing to 57.33, 77.26, and 71.40 at 6 months.

Figure 10: Lateral Bending Range of Motion, and Lateral Bending Stiffness results

{12}------------------------------------------------

Histological, Histopathological, and Histromorphometric assessment of the tissue around ● the implant at each time point. This data was analyzed to determine if the implant or wear particles generated by the implant resulted in a negative biologic reaction which may be detrimental to the long-term health of the tissue.
Image /page/12/Picture/1 description: The image shows a close-up of a textile material with a repeating pattern. The pattern consists of rounded shapes, possibly representing loops or knots, arranged in rows. The colors are predominantly red and white, with some darker areas that could be shadows or variations in the material. The overall impression is of a textured surface with a complex, interwoven structure.

Figure 11: Example histology image of screw and OGmend® Implant System in the Ovine Spine at 24 weeks. Image above shows the bone screw (black) imbedded in bone (stained red). The OGmend® Implant System can be seen as the colorless fibers around the screw (black arrows).

Image /page/12/Figure/3 description: The image is a bar graph titled "Average Radiographic Scores". The x-axis shows three groups labeled Group 1, Group 2, and Group 3. The y-axis shows the average radiographic scores from 0 to 4. For each group, there are two bars, one representing the bridging score and the other representing the new bone formation score. The bridging scores for each group are around 1, while the new bone formation scores are around 3.

Radiographic review of the fusion site to confirm that fusion occurred.
Figure 12: Results of radiographic assessment. Bridging score was an assessment of the percentage of bone bridge formed across the fusion site, with a score of 1 indicating the highest bridging (76-100%). Group 1 represents the Positive Control group, Group 2 represent the Negative Control group, and Group 3 represents the Treatment group (Negative Control plus the OGmend Implant System). New bone formation score was an assessment of bone formed, with a score of 4 representing the best score. There was no significant difference observed between groups.

{13}------------------------------------------------

Overall, it was determined that the data provided were sufficient to demonstrate that the device provided sufficient mechanical stability for healing, and that the observed biologic response at 12 and 24 weeks was not significant enough to cause long term adverse biological reaction.

LABELING

The safety and effectiveness of the device was evaluated with respect to the use with metallic plate and screw systems in long bones, and was not evaluated in conditions in which the sleeve crossed a fracture site. To clarify the use of the device with respect to the supporting data provided to demonstrate safety and effectiveness, the device labeling was revised to including the following:

The device description states the material used for the implant (PET). ●
The Indications for Use statement states the device is for use in skeletally mature ● patients.
The device is contraindicated for patients with insufficient bone quality or quantity to permit stabilization of a plate and screw system.
There is a warning that the device should not be used in stand-alone screw systems, joint arthroplasty systems, and spinal fixation procedures.
. There is a warning that the device should not be used with non-metallic or resorbable screws.
. While the material of the device is a pure polymer and contains no metallic components, and there are no safety concerns regarding the presence of the sleeve in a Magnetic Resonance (MR) environment, it is only intended to be used with metallic bone screws. and therefore the labeling includes precautions that the MR safety of the plates and screws should be considered.

RISKS TO HEALTH

The table below identifies the risks to health that may be associated with the use of a screw sleeve bone fixation device and the measures necessary to mitigate these risks.

Identified Risks to Health	Mitigation Measures
Loss of function / mechanical integrityresulting from:• Device malposition• Device breakage• Damage to screw during insertion• Deterioration due to aging• Insufficient restoration of screw fixation	In vivo performance testingNon-clinical performance testingShelf life testingLabeling
Revision	In vivo performance testingNon-clinical performance testingLabeling
Adverse tissue reaction	Biocompatibility evaluation

Table 4: Identified Risks to Health and Mitigation Measures

{14}------------------------------------------------

	In vivo performance testingNon-clinical performance testingLabeling
Infection	Sterilization validationShelf life testing
Febrile response due to endotoxins	Pyrogenicity testing

SPECIAL CONTROLS

In combination with the general controls of the FD&C Act, the screw sleeve bone fixation device is subject to the following special controls:

In vivo performance testing under anticipated conditions of use must demonstrate: (1)
- The device provides sufficient stability to allow for fracture healing; and (i)
- (ii) A lack of adverse biologic response to the implant through histopathological and histomorphometric assessment.
(2) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use. Testing must:
- Assess the stability of the device in a rescue screw scenario; (i)
- Demonstrate that the device can be inserted and removed without damage to (ii) the implant or associated hardware;
- Demonstrate the device can withstand dynamic loading without device failure; (iii) and
- (iv) Characterize wear particle generation.
The device must be demonstrated to be biocompatible. (3)
The device must be demonstrated to be non-pyrogenic. (4)
Performance data must demonstrate the sterility of the device. (ર)
Performance data must support the labeled shelf life of the device by demonstrating (6) continued sterility, package integrity, and device functionality over the established shelf life.
(7) Labeling must include:
- A detailed summary of the device technical parameters; (i)
- Information describing all materials of the device; (ii)
- Instructions for use, including device removal; and (iii)
- (iv) A shelf life.

BENEFIT-RISK DETERMINATION

The sponsor has collected adequate data to assess the safety profile of the subject device and has identified that there are benefits. The known or probable risks of the device include biologic responses to polymeric surgical implants, specifically polyethylene terephthalate implants, documented in the published literature or observed in the animal studies conducted for this device, as well as mechanical failure modes either anticipated or observed in the mechanical testing of the device as described above. While there was an ongoing foreign body reaction at the

{15}------------------------------------------------

final time point in the animal spine model study, it was determined that the degree of reaction would not lead to unacceptable risk to patients.

Patient Perspectives

This submission did not include specific information on patient perspectives for this device. Benefit/Risk Conclusion

In conclusion, given the available information above, the data support that for the following indications for use statement:

The OGmend® Implant System is intended for use with screws as part of a fracture fixation plate system in long bones in rescue scenarios where the screw has lost purchase due to screw loosening, back out, or breakage and the stability of the overall construct is at risk. The OGmend® Implant System is for use in skeletally mature patients.

the probable benefits outweigh the probable risks for the OGmend® Implant System. The device provides benefits, and the risks can be mitigated by the use of general controls and the identified special controls.

CONCLUSION

The De Novo request for the OGmend® Implant System is granted and the device is classified as follows:

Product Code: QAC Device Type: Screw sleeve bone fixation device Regulation Number: 21 CFR 888.3043 Class: II

Regulation Number and Section

§ 888.3043 Screw sleeve bone fixation device.

(a)
Identification. A screw sleeve bone fixation device is intended to be implanted in conjunction with a non-resorbable, metallic bone screw where the screw has lost purchase due to loosening, backout, or breakage. The device fits between the screw threads and surrounding bone and provides increased surface area to create an interference fit to restore stability of the implant construct.(b)
Classification. Class II (special controls). The special controls for this device are:(1) In vivo performance testing under anticipated conditions of use must demonstrate:
(i) The device provides sufficient stability to allow for fracture healing; and
(ii) A lack of adverse biologic response to the implant through histopathological and histomorphometric assessment.
(2) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use. Testing must:
(i) Assess the stability of the device in a rescue screw scenario;
(ii) Demonstrate that the device can be inserted and removed without damage to the implant or associated hardware;
(iii) Demonstrate the device can withstand dynamic loading without device failure; and
(iv) Characterize wear particle generation.
(3) The device must be demonstrated to be biocompatible.
(4) The device must be demonstrated to be non-pyrogenic.
(5) Performance data must demonstrate the sterility of the device.
(6) Performance data must support the labeled shelf life of the device by demonstrating continued sterility, package integrity, and device functionality over the established shelf life.
(7) Labeling must include:
(i) A detailed summary of the device technical parameters;
(ii) Information describing all materials of the device;
(iii) Instructions for use, including device removal; and
(iv) A shelf life.