Trial Outcomes & Findings for Patellar Resurfacing Versus Patellar Retention in Total Knee Arthroplasty - A Randomized Clinical Trial (NCT NCT01500252)

Results Overview

This index assesses pain as reported by the patient. The WOMAC Pain scale has a minimum value of 0 (worst pain) to a maximum value of 100 (no pain). The change score was calculated by subtracting the preoperative score from the five year score.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

38 participants

Primary outcome timeframe

Preoperative to 5 years postoperative

Results posted on

2021-07-27

Participant Flow

Participant milestones

Participant milestones
Measure	Patellar Resurfacing Subjects received patellar resurfacing.	Patellar Retention Subjects retained their native patella.
Overall Study STARTED	21	17
Overall Study One Years	20	16
Overall Study Five Years	17	13
Overall Study Ten Years	12	11
Overall Study COMPLETED	12	11
Overall Study NOT COMPLETED	9	6

Reasons for withdrawal

Reasons for withdrawal
Measure	Patellar Resurfacing Subjects received patellar resurfacing.	Patellar Retention Subjects retained their native patella.
Overall Study Death	4	2
Overall Study Lost to Follow-up	5	4

Baseline Characteristics

Patellar Resurfacing Versus Patellar Retention in Total Knee Arthroplasty - A Randomized Clinical Trial

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Patellar Resurfacing n=21 Participants Subjects received patellar resurfacing.	Patellar Retention n=17 Participants Subjects retained their native patella.	Total n=38 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	9 Participants n=5 Participants	13 Participants n=7 Participants	22 Participants n=5 Participants
Age, Categorical >=65 years	12 Participants n=5 Participants	4 Participants n=7 Participants	16 Participants n=5 Participants
Age, Continuous	64.9 years STANDARD_DEVIATION 4.0 • n=5 Participants	62.0 years STANDARD_DEVIATION 5.6 • n=7 Participants	63.6 years STANDARD_DEVIATION 4.9 • n=5 Participants
Sex: Female, Male Female	16 Participants n=5 Participants	10 Participants n=7 Participants	26 Participants n=5 Participants
Sex: Female, Male Male	5 Participants n=5 Participants	7 Participants n=7 Participants	12 Participants n=5 Participants
Region of Enrollment Canada	21 participants n=5 Participants	17 participants n=7 Participants	38 participants n=5 Participants

PRIMARY outcome

Timeframe: Preoperative to 5 years postoperative

Population: One subject in the patellar retention group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This index assesses pain as reported by the patient. The WOMAC Pain scale has a minimum value of 0 (worst pain) to a maximum value of 100 (no pain). The change score was calculated by subtracting the preoperative score from the five year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=17 Participants Subjects received patellar resurfacing.	Patellar Retention n=12 Participants Subjects retained their native patella.
Change in Western Ontario MacMaster (WOMAC) Osteoarthritis Index Pain Score From Preoperative to 5 Years Postoperative	34.7 units on a scale Standard Deviation 20.9	39.2 units on a scale Standard Deviation 19.6

PRIMARY outcome

Timeframe: Preoperative to 5 years postoperative

Population: One subject in the patellar retention group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This measures the change in patients' reported function from preoperative to 5 years postoperative. The WOMAC Function scale has a minimum value of 0 (worst function) to a maximum value of 100 (no functional limitations). The change score was calculated by subtracting the preoperative score from the five year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=17 Participants Subjects received patellar resurfacing.	Patellar Retention n=12 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Function Score From Preoperative to 5 Years Postoperative	21.8 units on a scale Standard Deviation 17.9	27.5 units on a scale Standard Deviation 15.6

PRIMARY outcome

Timeframe: Preoperative to 5 years postoperative

Population: One subject in the patellar retention group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This is the change in the patients' perceived pain between preoperative and 5 years postoperative. The WOMAC stiffness scale has a minimum value of 0 (maximal stiffness) to a maximum value of 100 (no stiffness). The change score was calculated by subtracting the preoperative score from the five year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=17 Participants Subjects received patellar resurfacing.	Patellar Retention n=12 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Stiffness Score From Preoperative to 5 Years Postoperative	38.2 units on a scale Standard Deviation 32.0	29.2 units on a scale Standard Deviation 26.3

SECONDARY outcome

Timeframe: Preoperative to 1 year postoperative

Population: Two subjects, one in the patellar retention group and one in the patellar resurfacing group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This index assesses pain as reported by the patient. The WOMAC Pain scale has a minimum value of 0 (worst pain) to a maximum value of 100 (no pain). The change score was calculated by subtracting the preoperative score from the one year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=19 Participants Subjects received patellar resurfacing.	Patellar Retention n=15 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Pain Score From Preoperative to 1 Year Postoperative	32.9 units on a scale Standard Deviation 18.2	34.3 units on a scale Standard Deviation 21.5

SECONDARY outcome

Timeframe: Preoperative to 1 year postoperative

Population: Two subjects, one in the patellar retention group and one in the patellar resurfacing group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This index assesses function as reported by the patient. The WOMAC function scale has a minimum value of 0 (worst function) to a maximum value of 100 (no functional limitations). The change score was calculated by subtracting the preoperative score from the one year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=19 Participants Subjects received patellar resurfacing.	Patellar Retention n=15 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Function Score From Preoperative to 1-year Postoperative	24.1 units on a scale Standard Deviation 16.6	19.5 units on a scale Standard Deviation 16.9

SECONDARY outcome

Timeframe: Preoperative to 1 year postoperative

This index assesses stiffness as reported by the patient. The WOMAC stiffness scale has a minimum value of 0 (worst stiffness) to a maximum value of 100 (no stiffness). The change score was calculated by subtracting the preoperative score from the one year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=19 Participants Subjects received patellar resurfacing.	Patellar Retention n=15 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Stiffness Score From Preoperative to 1 Year Postoperative	24.4 units on a scale Standard Deviation 24.5	8.3 units on a scale Standard Deviation 32.3

SECONDARY outcome

Timeframe: 5 years postoperative to 10 years postoperative

Population: Two subjects, one in the patellar retention group and one in the patellar resurfacing group missed too many responses on the WOMAC questionnaire and was not included in the analysis.

This index assesses pain as reported by the patient. The WOMAC Pain scale has a minimum value of 0 (worst pain) to a maximum value of 100 (no pain). The change score was calculated by subtracting the five year score from the 10 year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=12 Participants Subjects received patellar resurfacing.	Patellar Retention n=11 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Pain Score From 5 Years Postoperative to 10 Years Postoperative	12.7 units on a scale Standard Deviation 20.0	10.0 units on a scale Standard Deviation 12.0

SECONDARY outcome

Timeframe: 5 years postoperative to 10 years postoperative

This index assesses function as reported by the patient. The WOMAC function scale has a minimum value of 0 (worst pain) to a maximum value of 100 (no pain). The change score was calculated by subtracting the five year score from the 10 year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=12 Participants Subjects received patellar resurfacing.	Patellar Retention n=11 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Function Score From 5 Years Postoperative to 10 Years Postoperative	14.2 units on a scale Standard Deviation 17.7	14.4 units on a scale Standard Deviation 13.6

SECONDARY outcome

Timeframe: 5 years postoperative to 10 years postoperative

This index assesses stiffness as reported by the patient. The WOMAC stiffness scale has a minimum value of 0 (worst stiffness) to a maximum value of 100 (no stiffness). The change score was calculated by subtracting the five-year score from the 10 year score.

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=12 Participants Subjects received patellar resurfacing.	Patellar Retention n=11 Participants Subjects retained their native patella.
Change in WOMAC Osteoarthritis Index Stiffness Score From 5 Years Postoperative to 10 Years Postoperative	3.4 units on a scale Standard Deviation 33.6	15.0 units on a scale Standard Deviation 19.4

SECONDARY outcome

Timeframe: 10 years

Population: All participants were analyzed.

This measure examined the number of reoperation in the two groups of subjects

Outcome measures

Outcome measures
Measure	Patellar Resurfacing n=21 Participants Subjects received patellar resurfacing.	Patellar Retention n=17 Participants Subjects retained their native patella.
Number of Revision Surgeries	3 participants	1 participants

Adverse Events

Patellar Resurfacing

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Patellar Retention

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Lauren Beaupre

UAlberta

Phone: 780-407-3945

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place