Comparison Between the Onlay and Inlay Techniques for Patellar Resurfacing in Posterior Cruciate Ligament-Substituting Total Knee Arthroplasty

Comparison Between the Onlay and Inlay Techniques for Patellar Resurfacing in Posterior Cruciate Ligament-Substituting Total Knee Arthroplasty: A Prospective, Randomized Controlled Trial

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03650426

Enrollment

235

Registered

2018-08-28

Start date

2018-02-20

Completion date

2020-02-20

Last updated

2021-04-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Inlay Patellar Resurfacing Technique, Onlay Patellar Resurfacing Technique, Patellar Resurfacing

Brief summary

The purpose of this study is to compare clinical outcome in posterior cruciate ligament-substituting total knee arthroplasty with onlay patellar resurfacing technique and inlay patellar resurfacing technique

Interventions

PROCEDURETotal knee with onlay patellar resurfacing technique

The patellar resurfacing technique that the patellar implant is embedded on the patellar bone.The patellar implant is placed on top of a flat tibial osteotomy or cut-surfaced bone

PROCEDURETotal knee with inlay patellar resurfacing technique

The patellar resurfacing technique that the patellar implant is embedded in the patellar bone.The patellar implant is surrounded by a rim of cortical bone and supported by hardened, sclerotic bone

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

TRIPLE (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Healthy volunteers

Inclusion criteria

* Primary osteoarthritis of knee who were scheduled for a primary total knee arthroplasty

Exclusion criteria

* Valgus deformity * History of inflammatory arthroplathy * Previous fracture or open surgery on the same knee * History of patellar instability

Design outcomes

Primary

Measure	Time frame	Description
Change of post-operative anterior knee pain	Change from baseline Visual Analog Scale for anterior knee pain at 3 months, 6 months, and 12 months after surgery	Visual Analog Scale for anterior knee pain (minimum 0, maximum 10) Do higher values represent a worse outcome
range of motion of knee	Change from baseline Knee Society and Knee Society function score at 3 months, 6 months, and 12 months after surgery	Knee Society and Knee Society function score (minimum 0, maximum 200)
Knee Society and Knee Society function score	Change from baseline Knee Society and Knee Society function score at 3 months, 6 months, and 12 months after surgery	Knee Society and Knee Society function score (minimum 0, maximum 200)
New patellar score	Change from baseline new patellar score at 3 months, 6 months, and 12 months after surgery	New patellar score (minimum 0, maximum 30)
Oxford knee score	Change from baseline Oxford knee score 3 months, 6 months, and 12 months after surgery	Oxford knee score (minimum 0, maximum 48)
Prevalence of anterior knee pain ,AKP	Change from baseline Prevalence of anterior knee pain ,AKP 3 months, 6 months, and 12 months after surgery	Prevalence of anterior knee pain ,AKP (minimum 0, maximum 10)
Prevalence of patellar crepitus complication	Change from baseline patellar crepitus complication 3 months, 6 months, and 12 months after surgery	Prevalence of patellar crepitus complication (present, absent)

Countries

Thailand

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026