Comparison of Postoperative Functional Outcomes Between Subvastus and Medial Parapatellar Approach in Total Knee Arthroplasty

July 29, 2026 updated by: Peking University Third Hospital

Comparison of Postoperative Functional Outcomes Between Subvastus and Medial Parapatellar Approach in Total Knee Arthroplasty: a Prospective Random Controlled Trial

This study aims to compare the effects of the medial parapatellar approach (MP) and the subvastus approach (SV) on postoperative clinical function in total knee arthroplasty (TKA). A total of 84 patients, who visit the Joint Surgery Department of Peking University Third Hospital and are diagnosed with end-stage knee osteoarthritis and require unilateral, primary total knee arthroplasty, will be recruited. The patients will be randomly assigned to two groups, with 42 patients in each group. TKA will be performed using the MP and SV approaches respectively. Postoperative data such as quadriceps muscle strength, the time of first unassisted straight leg raise (SLR), joint range of motion (ROM), KSS score, WOMAC score, SF-12 score, VAS score, and shear wave elastography (SWE) of the medial thigh muscle will be collected. The patients will be followed up for 2 years postoperatively to compare the short-term and long-term clinical functional outcomes of the two surgical approaches.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
84

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Haidian
      • Beijing, Haidian, China
        • Orthopaedic Department of Peking University Third Hospital
        • Contact:
          • Orthopaedic Department of Peking University Third Hospital
          • Phone Number: +8613161866294
          • Email: 2411210441@pku.edu.cn

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients aged 50 to 80 who are diagnosed with end-stage knee osteoarthritis that require unilateral primary total knee arthroplasty;
  • Patients who are determined by clinical and laboratory tests to have no absolute surgical contraindications;
  • Patients with good compliance, willing and able to undergo follow-up observations as required and sign the informed consent form;

Exclusion Criteria:

  • Patients with a history of surgery on the affected knee joint in the past;
  • Patients with neuromuscular diseases;
  • Patients scheduled for knee joint replacement revision surgery;
  • Patients with active knee joint infection or systemic infection;
  • Patients who receive primary joint replacement due to non-knee osteoarthritis, such as rheumatoid arthritis, tuberculous arthritis, traumatic arthritis, etc;
  • Patients with valgus or varus deformity of the knee joint greater than 15°;
  • Patients with knee flexion deformity greater than 15°;
  • Patients whose heart and lung functions are determined by clinical and laboratory tests to be unable to tolerate surgery;
  • Patients with mental disorders who are unable to cooperate with treatment;
  • Patients who is lactating or pregnant;
  • Patients who are unwilling to participate in this study and did not sign the informed consent form;
  • Patients with poor compliance and inability to cooperate in completing the follow-up observers at critical times;
  • For any reason, the researchers believe that the subject is unlikely to complete this study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: subvastus approach
Patients receive total knee arthroplasty with subvastus approach.
Procedure: subvastus
Patients receive total knee arthroplasty with subvastus approach to expose the knee joint.
Active Comparator: medial parapatellar approach
Patients receive total knee arthroplasty with medial parapatellar approach, which is classic, mature and with exact curative effect.
Procedure: medial parapatellar
Patients receive total knee arthroplasty with medial parapatellar approach to expose the knee joint

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
The higher the score, the more severe the symptoms and the worse the postoperative functional recovery.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Knee Society Score(KSS)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
The lower the score, the more severe the symptoms and the worse the postoperative functional recovery.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Short Form 12 Health Survey Questionnaire(SF-12)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
The higher score equals to the better postoperative satisfaction.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
First Unassisted Straight Leg Raise(SLR)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Record the time of the first postoperative unassisted straight leg raise of every patient.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Range of Motion of Knee Joint(ROM)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Visual Analogue Scale(VAS)
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
The higher the score, the stronger the patient's subjective pain perception.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Myodynamia of Quadriceps Femoris
Time Frame: From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Surgeons will measure the patients' muscle strength of Quadriceps Femoris using manual muscle testing, based on Lovett Scale for Muscle Strength Assessment.
From enrollment to the end of follow-up at 2 years after receiving total knee arthroplasty
Shear Wave Elastography of Quadriceps Femoris
Time Frame: 3 months after receiving total knee arthroplasty
SWE displays the strength and hardness with precise values.
3 months after receiving total knee arthroplasty

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Peking University Third Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 15, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 15, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 6, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PUTH00238

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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