The ISKD System is an intramedullary limb lengthening system that provides gradual, controlled osteogenic distraction of the tibia and femur. The ISKD System consists of the telescoping internal limb lengthening device, titanium locking screws, instrumentation and an external handheld Monitor. As the patient performs rotational oscillations of the affected limb during normal ambulation, the ISKD distracts as the distal section of the implant gradually telescopes out of the proximal section. The the implant is controlled by a one-way clutch mechanism and a threaded and. A small magnet sealed within the ISKD implant rotates simultaneously as the implant distracts. The hand-held external Monitor is similar to an electronic compass and communicates with the magnet by detecting and tracking changes in the magnet poles. The external Monitor enables both trationing and physicians to monitor the daily limb lengthening progress. Titanium locking screws (2 proximal and 2 distal) secure the device in place in the intramedullary canal.

AI/ML Overview

The provided text describes the Orthodyne ISKD System, an intramedullary limb lengthening system. However, it does not detail specific acceptance criteria with quantitative targets for device performance or a formal study designed to "prove the device meets acceptance criteria" in the way one might typically expect for a software or AI-driven medical device. Instead, the document presents a summary of biomechanical, animal, and clinical testing to demonstrate the device's safety, effectiveness, and substantial equivalence to predicate devices.

Let's break down what is available in the text according to your requested categories:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly state "acceptance criteria" with numerical thresholds for performance. Instead, it describes performance in relation to predicate devices and the intended use.

Acceptance Criteria Category	Reported Device Performance
Biomechanical Strength & Stiffness	- 4-point bend testing: More rigid than predicate nails.
	- Torsional testing: Stiffer than predicate nails.
	- Nail fatigue testing: All nails completed 1 million cycles.
	- Locking screw 3-point bend testing: Significantly greater in yield strength, ultimate strength, and fatigue life than commercially available bone screws. Stiffness was slightly higher, but not statistically significant.
Functional Testing	- All samples passed functional testing of clutches, magnet, and interface with locking screws.
Animal Model Performance (Limb Lengthening)	- Successfully lengthened a sheep's femur (27mm) at a consistent rate (1.3mm/day).
	- Usual physiologic formation of regenerate bone tissue continued normally, comparable to undisturbed bone.
	- No signs of infection or unusual pain.
	- Full circumferential osteogenic callus formation verified.
Clinical Efficacy (Pilot Study - "Compassionate Use")	- 8 out of 9 patients achieved needed limb length, despite complicated histories.
Clinical Efficacy (Feasibility Study)	- 8 out of 10 patients achieved the length needed.
	- Mean length attained: 45.0mm.
	- Mean distraction rate: 0.78mm/day.
	- 6 patients achieved complete healing; 4 achieved partial healing (with subsequent healing for 2 of these).
Clinical Safety/Adverse Events (Feasibility Study)	- 8 adverse events in 4 patients.
	- 2 device-related events (loose/broken screw) that did not affect outcome.
	- 6 events unrelated to the device.
Substantial Equivalence	- Demonstrated substantial equivalence in design, material, and intended use to Grosse and Kempf Locking Nail System and Orthofix Dynamic Axial Fixation System.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

The document describes clinical studies rather than a "test set" in the context of an algorithm or AI.

Pilot Study (Clinical): 9 patients. "Compassionate use" indicates these were likely very severe or difficult cases, possibly without strict prospective protocol adherence given their "last stage option" nature. Data provenance is not specified (e.g., country), but implied to be from a clinical setting.
Feasibility Study (Clinical): 10 patients (11 lengthening procedures). This study appears to be prospective due to enrollment and follow-up. Data provenance is not specified (e.g., country).
Animal Testing: 1 female sheep. This was a prospective animal study.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)

This information is not applicable to the provided document. The clinical studies describe patient outcomes and physician assessments rather than a "ground truth" established by an expert panel for a test set (as would be relevant for an AI algorithm). The animal study involved radiographic evaluation and surgical removal of bone, implying veterinary and possibly pathology expertise, but no specific number or qualifications are given.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

Not applicable. The studies described are clinical trials and animal studies, not an adjudication process for an AI algorithm's test set. Clinical outcomes were assessed by treating physicians and followed up clinically and radiographically.

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 done as the device is a mechanical implant, not an AI or imaging diagnostic tool.

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

Not applicable. The ISKD is a mechanical device with an external monitor for tracking, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

For the studies presented:

Biomechanical Testing: Physical measurements and comparisons against established engineering standards and predicate devices (e.g., yield strength, stiffness, fatigue cycles).
Animal Testing: Direct observation, radiographic evaluation of bone formation and distraction, and post-mortem pathological evaluation of the bone and implant site. The "ground truth" for lengthening was determined by counting threads on successive radiographs.
Clinical Testing: Patient outcomes, including achieved limb length (measured clinically and radiographically), healing status (radiographic evaluation), adverse events, and physician assessment.

8. The sample size for the training set

Not applicable. The device is not an AI algorithm, so there is no "training set."

9. How the ground truth for the training set was established

Not applicable.

Summary

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MAY - 2 2001

K0/0322

SUMMARY OF SAFETY AND EFFECTIVENESS ORTHODYNE ISKD SYSTEM

GENERAL INFORMATION 1.

Classification Names:

Common Name:

Device Trade Name:

Intramedullary fixation rod & Smooth or threaded metallic bone fixation fastener

Internal Limb Lengthener

"ISKD": (Intramedullary Skeletal Kinetic Distractor)

21 CFR Parts 888.3020 and 888.3040

Classification Code(s):

Submitter's Name & Address:

Orthodyne Inc. 1118 So. Orange Avenue, Suite 204 Orlando, FL 32804 (407)316-8098

pending Establishment Registration No: Contact Person:

Carl Knobloch

Summary Preparation Date:

January 17, 2001

II. PREDICATE DEVICE

System is substantially equivalent to two The Orthodyne ISKD commercially available devices. The Orthodyne ISKD System is substantially equivalent in design and function to the Grosse and Kempf Locking Nail System manufactured by Howmedica Corp. of Rutherford, New Jersey. The Gross Kempf (i.e., GK Nail) device was originally cleared by FDA under K813371 on March 1, 1982, and most recently under The Orthodyne ISKD System is K983358 on November 18, 1998. substantially equivalent in intended use to the Orthofix Dynamic Axial Fixation System cleared by FDA under 510(k) K955848 on March 20, 1996

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Device Description III.

IV. INDICATIONS FOR USE

The ISKD System intended for limb lengthening of the femur and tibia.

BIOMECHANICAL TESTING V.

In order to demonstrate that the ISKD Internal Limb Lengthener has the mechanical properties necessary to perform its intended use, and that the ISKD Internal Limb Lengthener performs as well as or better than the predicate device, Orthodyne has conducted mechanical and functional testing of the ISKD System.

Static 4-point bend testing, torsional testing, nail fatigue testing, 3-point bend testing of the locking screw and functional testing was performed on the ISKD System. In general, the ISKD internal limb lengthener was more rigid in 4-point bending than the predicate nails. Also, the ISKD internal limb lengthener was stiffer in torsion than the predicate nails. In all nail fatigue testing, all nails ultimately completed the necessary one million cycles. In the 3-point bend testing of the locking screws, the statistical analysis showed the ISKD screws significantly greater in yield strength, ultimate strength and fatigue life than a commercially available bone screw. The stiffness was slightly higher but was not statistically significant. All samples passed the functional testing of the clutches, magnet and interface with the locking screws.

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VI. Animal Testing

ANMAL TESTING
A 10mm ISKD Internal Limb Lengthener was implanted in the left femur of A Tonin ISKD internal Limb Longthonor was grin of the ISKD was 15cm.
a 20-month old female sheep. The start length of the ISKD was 15cm. After the desired distraction, the device was designed to lock both linearly And torsionally to function, the assume intramedullary (IM) nail until bone regenerate formation was complete.

The sheep was allowed to immediately bear full weight on the implant without the use of any external device constraining movement. without "the "use" of " any "Oxtornal " "Unes a week for the first 3 weeks. Radiographs of the threaded rod within the ISKD is easily identifiable on By design, the threads Tour was is 1mm per rotation of the rod. (Note: the external monitoring device was not available at the time of this study). the external monitoring downer of threads seen between the clutches on each consecutive radiograph. ISKD distraction was determined within 0.5 mm
consecutive radiograph. ISKD distraction was determined what wasn't be consecutive radiograph: Torte alone of threads seen between the clutches on each consecutive radiograph.

During the first 10 days following surgery, the animal walked with a slight Dunny the first 10 days following our the limb with the implant. By the limp, gradually increasing the freatment was given to any limb, second week, no notioouble proferential was not and the animal walked normariy. Altis time, the ISKD distracted at a manipulated of consistent 1.3mm each day. After 27mm of distraction, on Day felatively consistent 1.5mm Saon uxyl stopped lengthening. (The cause 24, this protoxpe implant promatinely of the ISKD stopped lengthening, the was addressed in a readolight) ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... to any limb.

The usual physiologic formation of regenerate bone tissue continued normally. Callus formation was visible on radiograph at 19 days. An normally. Oallus Tormation was evident at 35 days. At no time did the sheep show signs of infection or unusual pain. On Day 40 the sheep was show 'Signs' of Throotion' of 'arrantallawed to roam a 70-acre field with other transported to a shoop family steogenic callus formation was verified at 78 Sheep. I ull circumic evaluation of both the undisturbed bone and the days. Radiographic evaluation of both a remodeling of the femoral lengthened - bone - on was surgically removed from the diaphysis. On day 100 the 10.0 inn first femur shows complete cortical bone Sheep. A radiograph of the hartstripped from the femur and the bone was formation. The penostedinal axis with a band saw. The regenerate bone blisected down its fongitualifial allus. In summary, the results of is comparable to that of the and the ISKD lengthening device performed as inis animal Study materially lengthened the femur in an ovine model without untoward effects.

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BIOCOMPATIBILITY VII.

The ISKD Internal Limb Lengthening device and locking screws are made from titanium alloy, Ti6A14V ELI conforming to ASTM F136.

CLINICAL TESTING VIII.

Orthodyne has clinical experience with 19 patients implanted with an ISKD Internal Limb Lengthener. Upon IRB approval, nine patients participated in a pilot study followed a 10 patient feasibility study.

The nine patients participating in the pilot study were considered "compassionate use" as these patients presented with complicated histories, numerous risk factors including unresolved poly-trauma, severe soft tissue defect, severe contractures, poor bone quality, previous and recurring infections, multiple illnesses, etc. These patients required limb lengthening of the femur or the tibia ranging from 31-105mm. And in most cases, the ISKD was a last stage option as these patient's deformities were so extreme and/or previous lengthening procedures had failed.

Despite their complicated histories, eight of the nine patients were able to achieve the limb length they needed. One patient received 75mm out of the 105mm of length needed, but was not able to lengthen further due to the severe soft tissue contractures resulting from the pre-existing soft tissue deficit.) Certain design improvements were made to the ISKD system based upon this clinical experience.

Ten patients are enrolled to date into the feasibility study. The feasibility study patients presented with fewer complications and risk factors than those in the pilot study. Of the 10 patients, seven were males and three were females; age at surgery ranged from 18-63 with a mean age of 40.8 years. The cause of limb discrepancy was trauma for nime patients and post-polio infection for one patient. Eleven lengthening procedures were performed with these 10 patients (one patient required 2 procedures to reach his goal length). The discrepancy range was 30-120mm, with a mean discrepancy of 57.6mm. The goal length range was 30-80mm with a mean of 48.1mm. The distraction period range (implant to end of distraction) was 22-169 days, with a mean of 83 days. The length attained was 23-80mm, with a mean range of 45.0mm. The distraction rate range was 0.40-1.79mm/day, with a mean range of 0.78mm/day. Of these 10, eight patients achieved the length needed.

Two of the patients were noncompliant - one exceeded the recommended level of daily physical activity and one failed to meet the recommended level of daily physical activity. Six patients achieved complete healing (4/4 with intact cortices); and four patients achieved partial healing (3/4 intact cortices) as of the last completed radiographic follow-up.

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Of the four patients who achieve partial healing, two patients were lost to follow-up, and one patient had a second ISKD implanted and healed afterwards. The fourth patient is still being followed and has since been noted as healed by the physician. Of those who completely healed, the consolidation period range was 219-505 days.

Four patients experienced a total of eight adverse events. Two events (a loose screw and a broken screw) were device related. These events occurred after distraction was complete and did not affect outcome. Six events were determined to be unrelated to the device (two related to the lengthening procedure, one due to a pre-existing condition, one due to surgical error, one as a complication of surgery and one non-compliance).

Though the feasibility study patients presented with fewer complications and risk factors, it was determined that patients presenting with severe soft tissue defects and/or contractures should be excluded as this complicates limb lengthening process and can prevent proper functioning of the ISKD.

IX. STERILIZATION

ISKD Intramedullary Lengthening device
Method	Gamma Radiation
Radiation Dose	25 Mrad
Sterility Assurance Level	10-6
Sterility Validation Method	ANSI/AAMI ST32-1991; Method I
Packaging	PETG tray with double Tyvek lid
Pyrogenicity	Not labeled pyrogen free

	ISKD Instrument Set
Method	Steam Sterilization
Cycle	Pre-Vacuum
Temperature	132° - 135° C [270° - 275°F]
Exposure Time	Minimum of 10 minutes
Sterility Assurance Level (SAL)	10-6
Sterility Validation Method	ANSI/AAMI ST46-1993-Prevacuum Steam Sterilization ofMedical Devices

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X.

SUBSTANTIAL EQUIVALENCE
ISKD is claimed to be substantially equivalent in design and function to

FEATURES	ISKD	GROSSE & KEMPFINTRAMEDULLARYLOCKING NAIL	ORTHOFIX DYNAMICAXIAL FIXATION SYSTEM
INTENDED USE	"Limb lengthening ofthe tibia and femur"	"Temporary stabilizationof various types offractures, osteotomies,malunions and nonunionsof the femur and tibia.Other types ofprocedures includereconstrunction, bonelengthening/shortening,prophylactic nailing ofimpending fractures andfusions.	Intended for use in thetreatment of boneconditions including leglengthening, osteotomies,arthrodesis, fracturefixation and other boneconditions amendable totreatment by use of theexternal fixation modality.
MATERIAL	Ti6A14V ELI	316 LVM Stainless Steel	316 LVM stainless steelbone pins
DESIGN FEATURES	Intramedullary nail	Intramedullary nail	Unilateral external fixator
	Telescoping sections	NA	Telescoping sections
	One way clutch design	NA	Both compression anddistraction
METHOD OFFIXATION	4.0 mm diametersmooth shaft Lockingscrews(proximal and distal)	Tibial: 4.6mm threadedLocking Screws (proximaland distal)Femoral:6.28mm threadedLocking ScrewsProximal and distal)	Bone pins
NUMBER OFFIXATION POINTS	2 proximal/2 distal	Tibial - 2 proximal/2 distalFemoral - 1 proximal/2distal	2-3 proximal/ 2-3 distal
DESIGN OF ENDS	Blunt	Blunt	NA
LONGITUDINALCURVATURE	Tibial Device - 15°±1°bend; femoral - none	Tibial- 17.5°; femoral -none	None
CROSSSECTIONAL SHAPE	Circular	Tibial: SlottedCloverleafFemoral: Partiallyslotted Cloverleaf	NA

・ .

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XI. Conclusion

Based upon the results of animal, biomechanical and clinical testing the ISKD System has the mechanical properties to perform its intended use of limb lengthening of the tibia and femur and is considered to be substantially equivalent to the predicate devices in design, material and intended use.

Orthodyne Inc. Premarket Notification: ISKD Internal Limb Lengthening System Submitted: January 22, 2001

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Image /page/7/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three tail feathers, representing the department's commitment to health, human services, and well-being. The eagle is encircled by the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" in a circular arrangement.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

MAY - 2 2001

Mr. Carl Knobloch Vice President and General Manager Orthodyne Inc. 1118 South Orange Avenue, Suite 204 Orlando, Florida 32806

Re: K010322

Trade Name: ISKD Intramedullary Skeletal Kinetic Distractor Regulation Number: 888.3020 Regulatory Class: II Product Code: HSB Dated: January 22, 2001 Received: February 2, 2000

Dear Mr. Knobloch:

We have reviewed your Section 510(k) notification of intent to market the device referenced wo have have determined the device is substantially equivalent (for the indications for use above and 10 have assnowned in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in encerhen actor of the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations (1 remancer ripproval), in may of the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

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Page 2 - Mr. Carl Knobloch

If you desire specific advice for your device on our labeling regulation (21 CFF Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, (201) 594-4637. Radhiance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small mormation on your responsionates and in the mumber (800) 638-2041 or at (301) 443-6597, or at its Internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Miriam C. Provost

for Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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INDICATION FOR USE STATEMENT

Page _ of _

510(k) Number (if known):

Kolosar

Device Name:

"ISKD" Intramedullary Skeletal Kinetic Distractor

Indications for Use:

The ISKD is indicated for limb lengthening of the tibia and femur.

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use:
(Per 21 CFR 801.109)
96)

Over-The-Counter_No

(Optional Format 1-2-

Muriam C. Provost

(Division Sign-Off) Division of (veneral, Restorative and Neurol gical Devices

510(k) Number K010322

Orthodyne Inc. Premarket Notification: ISKD Internal Limb Lengthening System Submitted: January 22, 2001

Regulation Number and Section

§ 888.3020 Intramedullary fixation rod.

(a)
Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures.(b)
Classification. Class II.