Effect of J-Shaped Incision After Total Knee Arthroplasty (J-TKA)

NCT07514598 | Completed

• 1 other identifier: J-TKA-2026
• Study Type: interventional
• Target: 62
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective randomized controlled trial evaluates whether a modified J-shaped skin incision can reduce peri-incisional numbness after primary total knee arthroplasty (TKA) compared with the conventional midline skin incision. Peri-incisional numbness is a common postoperative complaint after TKA and is thought to be mainly related to injury of the infrapatellar branch of the saphenous nerve. Although often considered a minor issue, it may adversely affect postoperative comfort, pain perception, and patient satisfaction. A total of 62 patients undergoing primary TKA for Kellgren-Lawrence grade 4 varus knee osteoarthritis were randomized to either a conventional midline incision or a modified J-shaped incision. In the J-shaped technique, the distal part of the incision is curved laterally at the level of the tibial tuberosity in an effort to decrease injury to the infrapatellar branch of the saphenous nerve. The primary outcome is the extent of peri-incisional sensory loss, assessed using Semmes-Weinstein 10-g monofilament testing with a grid-mapping method before surgery and at 2 and 6 months after surgery. Secondary outcomes include pain scores, functional knee scores, range of motion, blood loss, tourniquet time, and wound-related complications.

Conditions

Osteoarthritis, Knee

Keywords

Total Knee Arthroplasty; Knee Osteoarthritis; J-shaped Incision; Saphenous Nerve; Numbness

Outcome Measures

Primary Outcomes (1)

• Area of peri-incisional sensory loss

  The extent of peri-incisional sensory loss will be assessed using Semmes-Weinstein 10-g monofilament testing combined with a standardized grid-mapping method to quantify the area of numbness around the surgical incision.

  2 months and 6 months postoperatively

Secondary Outcomes (10)

• Postoperative pain

  2 months and 6 months postoperatively

• Range of motion

  2 months and 6 months postoperatively

• Intraoperative Blood Loss

  Intraoperative period

• Tourniquet Time

  Intraoperative period

• Incision Length

  Intraoperative period

Study Arms (2)

Midline Incision

ACTIVE COMPARATOR

Participants undergo primary total knee arthroplasty using a conventional midline skin incision.

Procedure: Conventional Midline Incision

J-shaped Incision

EXPERIMENTAL

Participants undergo primary total knee arthroplasty using a modified J-shaped skin incision, in which the distal portion of the incision is curved laterally at the level of the tibial tuberosity.

Procedure: J-shaped Incision

Interventions

Conventional Midline Incision PROCEDURE

A conventional midline skin incision is used during primary total knee arthroplasty.

Also known as: Standard midline incision

Midline Incision

J-shaped Incision PROCEDURE

A modified J-shaped skin incision is used during primary total knee arthroplasty, in which the distal portion of the incision is curved laterally at the level of the tibial tuberosity.

Also known as: Modified J-shaped incision

J-shaped Incision

Eligibility Criteria

• Age: 56 Years - 81 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults undergoing primary total knee arthroplasty
• Diagnosis of Kellgren-Lawrence grade 4 varus knee osteoarthritis
• Planned treatment with primary total knee arthroplasty
• Ability to provide written informed consent
• Ability to comply with postoperative follow-up evaluations

You may not qualify if:

• Valgus knee deformity
• Revision total knee arthroplasty
• Previous surgery on the affected knee
• History of periarticular fracture around the knee
• Pre-existing sensory deficit or neurologic disorder affecting the operative lower extremity
• History of lumbar disc herniation
• Known neuromuscular disease
• Peripheral vascular disease
• Inability to comply with follow-up and postoperative evaluations
• Refusal or inability to provide informed consent

Sponsors & Collaborators

• Fatih Sultan Mehmet Training and Research Hospital: lead

Study Sites (1)

Fatih Sultan Mehmet Training and Research Hospital

Ataşehir, Istanbul, 34752, Turkey (Türkiye)

Location

Related Publications (2)

• James NF, Kumar AR, Wilke BK, Shi GG. Incidence of Encountering the Infrapatellar Nerve Branch of the Saphenous Nerve During a Midline Approach for Total Knee Arthroplasty. J Am Acad Orthop Surg Glob Res Rev. 2019 Dec 12;3(12):e19.00160. doi: 10.5435/JAAOSGlobal-D-19-00160. eCollection 2019 Dec.

  PMID: 32072122 BACKGROUND

• MacDonald B, Kurdin A, Somerville L, Ross D, MacDonald S, Lanting B. The Effect of Sensory Deficit After Total Knee Arthroplasty on Patient Satisfaction and Kneeling Ability. Arthroplast Today. 2021 Jan 11;7:264-267.e2. doi: 10.1016/j.artd.2020.11.020. eCollection 2021 Feb.

  PMID: 33786352 BACKGROUND

MeSH Terms

Conditions

Osteoarthritis, Knee; Hypesthesia

Condition Hierarchy (Ancestors)

Osteoarthritis; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Somatosensory Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Masking was not feasible due to the visible nature of the surgical incision during postoperative assessments. Therefore, surgeons, participants, and outcome assessors were not blinded to group allocation.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Doctor, Orthopedic Surgery Resident

Model Details: This is a prospective, randomized, parallel-group study comparing a conventional midline incision with a modified J-shaped incision in patients undergoing primary total knee arthroplasty.

Study Record Dates

• First Submitted: March 27, 2026
• First Posted: April 7, 2026
• Study Start: September 17, 2025
• Primary Completion: April 17, 2026
• Study Completion: May 17, 2026
• Last Updated: May 29, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)