UMIN-CTR Clinical Trial

Public title

A Prospective, Multi-Center, Post-Market Clinical Two Year Follow-Up Study that Hydroxyapatite coated stem shows Osseointegration New Evidence using DEXA and Tomosynthesis (HONE study)

Acronym

A Prospective, Multi-Center, Post-Market Clinical Two Year Follow-Up Study that Hydroxyapatite coated stem shows Osseointegration New Evidence using DEXA and Tomosynthesis (HONE study)

Scientific Title

A Prospective, Multi-Center, Post-Market Clinical Two Year Follow-Up Study that Hydroxyapatite coated stem shows Osseointegration New Evidence using DEXA and Tomosynthesis (HONE study)

Scientific Title:Acronym

A Prospective, Multi-Center, Post-Market Clinical Two Year Follow-Up Study that Hydroxyapatite coated stem shows Osseointegration New Evidence using DEXA and Tomosynthesis (HONE study)

Region

Japan

Condition

Hip joint disease that improves the hip joint function and patients

Classification by specialty

Surgery in general

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

To evaluate bone mineral density in Gruen zone 7 of the HA coated POLARSTEM two years post-operatively using the POLAR3 Hip System

Basic objectives2

Safety

Basic objectives -Others

Trial characteristics_1

Trial characteristics_2

Developmental phase

Primary outcomes

To evaluate bone mineral density in Gruen zone 7 of the HA coated POLARSTEM two years post-operatively using the POLAR3 Hip System

Key secondary outcomes

To assess perioperative clinical and safety outcomes after Total Hip Arthroplasty (THA) with POLAR3 Hip system:
1 X-ray evaluation (alignment, bone reaction)
2 Tomosynthesis evaluation (bone reaction)
3 Bone mineral density evaluation using Dual-energy X-ray absorptiometry (DEXA)
4 Harris Hip Score (HHS)
5 Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ)
6 Adverse event (AE)
7 Device Deficiency (DD)

Study type

Observational

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

Purpose of intervention

Type of intervention

Interventions/Control_1

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

20

years-old

<=

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

1 Has provided written informed consent for study participation
2 Patients of Japanese descent, of either gender, 20 years of age or older
3 A candidate for total hip arthroplasty (THA) due to NIDJD or any of its composite diagnoses such as osteoarthritis, avascular necrosis, traumatic arthritis, slipped capital epiphysis, fused hip, fracture of the pelvis, and diastrophic variant
4 Willing and able to comply with study visit schedule including all follow-up visits
5 Has no disease or conditions that in the opinion of the Investigator would compromise the study or would pose a risk due to study participation

Key exclusion criteria

1Acute or chronic infection, local or systemic
2Severe muscle, nerve, or vascular diseases that endanger the extremity
3Has previously received THA in the index joint
4Any of the following conditions in the contralateral joint:
Has received THA as a revision for a failed procedure
Has received THA that is not fully healed and well-functioning in the opinion of the Investigators
5Current diagnosis of immunosuppressive disorder
6History of cancer within 5 years of screening
7Known allergy to any component of the study device
8Conditions known to interfere with THA survival or outcomes including vascular insufficiency, muscular atrophy, uncontrolled diabetes, moderate to severe renal disease, neuromuscular disease
9Current diagnosis of fibromyalgia
10 Mass Index (BMI) over 40
11 Currently enrolled or has participated in a clinical research study (drug, device, or biologic) within 30 days of screening
12Has previously history of femur neck fracture
13Acetabular osteotomy in the index joint

Target sample size

152

Name of lead principal investigator

1st name	Wataru
Middle name
Last name	Taguchi

Organization

Smith & Nephew KK

Division name

Clinical Affairs

Zip code

105-0011

Address

14F, South Wing, World Trade Centre Building, 2-4-1 Hamamatsucho, Minato-ku, Tokyo

TEL

03-5403-8811

Email

Wataru.Taguchi@smith-nephew.com

Name of contact person

1st name	Wataru
Middle name
Last name	Taguchi

Organization

Smith & Nephew KK

Division name

Clinical Affairs

Zip code

105-5114

Address

14F, South Wing, World Trade Centre Building, 2-4-1 Hamamatsucho, Minato-ku, Tokyo

TEL

03-5403-8811

Homepage URL

Email

Wataru.Taguchi@smith-nephew.com

Institute

Jilei University Hospital

Institute

Department

Personal name

Organization

Smith & Nephew KK

Organization

Division

Category of Funding Organization

Profit organization

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Jikei University Hospital

Address

3-19-18 Nishishinbashi, Minatoku, Tokyo

Tel

03-3433-1111

Email

h.fujii@jikei.ac.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

Date of disclosure of the study information

2021

Year

01

Month

21

Day

URL releasing protocol

https://center6.umin.ac.jp/ cgi-open-bin/ctr/ ctr_view.cgi?recptno=R000049177

Publication of results

Unpublished

URL related to results and publications

https://center6.umin.ac.jp/ cgi-open-bin/ctr/ ctr_view.cgi?recptno=R000049177

Number of participants that the trial has enrolled

152

Results

The POLAR3 Total Hip System in patients undergoing primary THA, did not achieve the expected reduction in Gruen Zone 7 BMD at 2 years postoperatively. Radiographic assessments suggest that the observed BMD reduction was not clinically significant. Bone ingrowth into the stem was observed in the early postoperative period, as evidenced by tomosynthesis imaging. Furthermore, clinical outcomes - including improvements in HHS and JHEQ - were favorable, and no significant safety concerns were reported.

Results date posted

2025

Year

09

Month

30

Day

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

In the Full Analysis Set (FAS), 91 subjects (83.5%) were female and 18 (16.5%) were male, with a mean age of 68.4 years (standard deviation [SD] = 9.9) and a mean body mass index (BMI) of 24.3 (SD = 3.7). A total of 108 subjects (99.1%) were Asian, and 1 subject (0.9%) was White.

The primary diagnosis was subluxation-type osteoarthritis (OA) in 84 subjects (77.1%), primary OA in 19 subjects (17.4%), and idiopathic osteonecrosis in 5 subjects (4.6%).

Regarding the operated side, 35 subjects (32.1%) underwent surgery on the left hip only, 52 (47.7%) on the right hip only, and 22 (20.2%) on both hips.

The mean surgical time was 83.5 minutes (SD = 43.4). Of the 131 hip joints operated, 100 (76.3%) were approached via the anterior approach and 31 (23.7%) via the lateral approach.

Participant flow

A total of 152 hip joints from 128 subjects were enrolled in the study. Of these, 149 hip joints from 125 subjects were included in the analysis, excluding 3 hip joints from 3 subjects that were excluded due to issues related to the informed consent process. Seventeen (17) hip joints from 15 subjects who received non-investigational devices (POLARSTEM cementless stem with collar) were included in the Safety Analysis Set (SAF) but excluded from the FAS and the Per Protocol Set (PP). Additionally, one hip joint (from one subject) was excluded from FAS and PP due to the absence of postoperative device performance evaluation.

Enrolled subjects were followed up at the pre-operative visit, during hospitalization (from surgery to discharge), and post-operatively at the following time points: 6 weeks (optional), 3 months (optional), 6 months (optional), 1 year, and 2 years.

Adverse events

A total of 19 serious adverse events (SAEs) were reported during the study period among subjects included in the SAF. Of these, 4 events (ischiadic nerve palsy, fracture of left trochanter, right hip dislocation, and periprosthetic joint infection) were classified as anticipated procedure-related SAEs (ASADE). No device-related SAEs were reported. One death of unknown cause was reported.

No device deficiencies (DD) were observed.

Outcome measures

Primary Endpoint Results:
The primary endpoint was the percentage reduction in BMD at Gruen Zone 7 from discharge to 2 years postoperatively. Among 117 hips with complete BMD data, the mean reduction at 2 years was 18.4% (SD = 19.6%), showing a progressive decrease from 6 months onward.
The planned analysis tested whether the 2-year BMD reduction was less than the reference value of 14%, using multiple imputation (MI) for missing data. Five imputed datasets were generated, with the first used for primary analysis and the remaining four for sensitivity analysis. In the primary analysis (n = 121 hips), the mean reduction was 17.2% (SD = 20.7%), with a 95% confidence interval of 13.4% to 20.9%. The p-value was 0.953, exceeding the threshold of 0.025, and the null hypothesis was not rejected. Sensitivity analyses yielded consistent results, confirming that the reduction in Zone 7 BMD at 2 years was not significantly lower than the reference value.

Secondary Endpoint Results:
Radiographic Evaluation:
At 2 years postoperatively, the mean cup inclination angle was 38.8 degrees (SD = 4.4) and mean tilt was 0.2 degrees (SD = 1.4) in 81 hips. Cup position remained unchanged in 126 hips (100%), with cranial and medial migration observed in 3 hips each (2.4%). Stem fixation was achieved by bone ingrowth in 123 hips (97.6%). All hips showed grade 0 for Hodgkinson cup fixation and Brooker classification (heterotopic ossification). One hip showed stem radiolucency, and 10 hips showed stem atrophy.

DEXA Results:
Mean BMD decrease from discharge to 2 years postoperatively in all segments. Mean BMD in Gruen Zone 7 decreased from 1.106 (SD = 0.255, N = 122) at discharge to 0.903 (SD = 0.285, N = 123) at 2 years.

Tomosynthesis Spot Welds:
Spot welds were observed as early as 6 weeks postoperatively (N=35) in both frontal and lateral views, and their frequency increased progressively up to 2 years. At 6 months postoperatively (N=67), spot welds were present in over 40% of cases in frontal view Zones 3, 4, 5, and 6, and in lateral view Zones 3, 4, and 5. By the 2-year visit (N=58), spot welds were most frequently observed in frontal view Zone 3 (86.2%), followed by Zone 5 (84.5%), Zone 2 (74.1%), and Zone 4 (74.1%). In lateral views, Zone 4 was most common (72.4%), followed by Zone 5 (69.0%) and Zone 3 (65.5%).

Clinical Outcomes:
HHS total score improved from a mean of 45.7 (SD = 14.4) preoperatively to 92.7 (SD = 11.5) at 2 years. ANCOVA analysis showed a significant LSMean change of 47.05 (95% CI: 44.3549.75; p < 0.0001). JHEQ score improved from 21.3 (SD = 12.5) to 65.3 (SD = 19.7), with a significant LSMean change of 43.67 (95% CI: 40.33 - 47.01; p < 0.0001). All changes from baseline at other visits were also statistically significant.

Plan to share IPD

IPD sharing Plan description

Recruitment status

Completed

Date of protocol fixation

2019

Year

02

Month

12

Day

Date of IRB

2019

Year

12

Month

02

Day

Anticipated trial start date

2019

Year

12

Month

24

Day

Last follow-up date

2024

Year

09

Month

02

Day

Date of closure to data entry

Date trial data considered complete

2025

Year

03

Month

19

Day

Date analysis concluded

2025

Year

03

Month

19

Day

Other related information

Observation Study

Registered date

2021

Year

01

Month

21

Day

Last modified on

2025

Year

09

Month

30

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000049177