Using a Smart Implantable Device to Compare Early Recovery in Two Different Knee Arthroplasty Approaches

NCT07348835 | Not Yet Recruiting

• 1 other identifier: NSH1432
• Study Type: interventional
• Target: 110
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-institution, prospective, randomized study comparing the medial parapatellar and subvastus approaches in primary total knee arthroplasty using continuous, implant-based gait monitoring. Patients receiving a Zimmer Persona IQ smart implant will be followed preoperatively and through the first 30 days post-operatively, with extended follow-up to 6 months. Preoperative activity is captured using iPhone Health step-count data, while post-operative recovery is assessed using continuous tibial implant data, including step count, range of motion, cadence, walking speed, stride length, and distance. These objective metrics are correlated with PROMs. The primary outcome is daily step count. Secondary outcomes include early functional milestones, pain, and patient-reported functional scores. This study is designed to characterize early recovery trajectories and determine whether meaningful differences exist between surgical approaches.

Conditions

Total Knee Anthroplasty

Keywords

Total Knee Arthroplasty; Medial Parapatellar Approach; Subvastus Approach

Outcome Measures

Primary Outcomes (2)

• Step Count (steps/day)

  Continuously recorded from PIQ device after it is implanted during surgery

  Through study completion, minimum 6 months

• Step Count (steps/day)

  Recorded from patients iPhone Health App for 2 weeks preoperatively

  Baseline

Secondary Outcomes (21)

• Stride Length (m)

  Through study completion, minimum 6 months

• Distance Travelled (km)

  Through study completion, minimum 6 months

• Functional Range of Motion (degrees)

  Through study completion, minimum 6 months

• Tibial Range of Motion (degrees)

  Through study completion, minimum 6 months

• Cadence (steps/minute)

  Through study completion, minimum 6 months

Study Arms (2)

Medial Parapatellar Approach

ACTIVE COMPARATOR

Primary total knee arthroplasty performed using the medial parapatellar surgical approach

Procedure: Total Knee Arthroplasty Medial Parapatellar Approach

Subvastus Approach

ACTIVE COMPARATOR

Primary total knee arthroplasty performed using the subvastus surgical approach

Procedure: Total Knee Arthroplasty Subvastus Approach

Interventions

Total Knee Arthroplasty Medial Parapatellar Approach PROCEDURE

Incision splitting quad

Medial Parapatellar Approach

Total Knee Arthroplasty Subvastus Approach PROCEDURE

quad-sparing approach

Subvastus Approach

Eligibility Criteria

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

You may qualify if:

• All patients older than 18 years of age who plan to undergo medial congruent polyethylene bearing primary TKA with a PIQ
• Eligible for both approaches
• Have an iPhone and willing to "wear" it for two weeks preoperatively to get an estimated average stepcount
• Provide informed consent
• Willing to complete follow ups

You may not qualify if:

• Patients with TKA revisions
• Patients with insufficient pre-operative range of motion in the operative knee (flexion contracture of \> 20 degrees or \< 90° of knee flexion)
• Patients with Contralateral TKA within study time frame
• Patients with TKA other than medial congruent polyethylene bearing
• Patients with bilateral surgery
• Patients without a valid and active email address
• Patients not willing or able to participate in study and follow-ups
• Patients who use assisted devices to ambulate
• Rheumatoid arthritis

Sponsors & Collaborators

• Total Joint Specialists: lead

Study Sites (1)

Total Joint Surgery Center Atlanta

Sandy Springs, Georgia, 30328, United States

Location

Related Publications (8)

• Matsueda M, Gustilo RB. Subvastus and medial parapatellar approaches in total knee arthroplasty. Clin Orthop Relat Res. 2000 Feb;(371):161-8. doi: 10.1097/00003086-200002000-00020.

  PMID: 10693563 BACKGROUND

• Kazarian GS, Siow MY, Chen AF, Deirmengian CA. Comparison of Quadriceps-Sparing and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials. J Arthroplasty. 2018 Jan;33(1):277-283. doi: 10.1016/j.arth.2017.08.025. Epub 2017 Aug 30.

  PMID: 28947369 BACKGROUND

• Cila E, Guzel V, Ozalay M, Tan J, Simsek SA, Kanatli U, Ozturk A. Subvastus versus medial parapatellar approach in total knee arthroplasty. Arch Orthop Trauma Surg. 2002 Mar;122(2):65-8. doi: 10.1007/s004020100319.

  PMID: 11880904 BACKGROUND

• Tomek IM, Kantor SR, Cori LA, Scoville JM, Grove MR, Morgan TS, Swarup I, Moschetti WE, Spratt KF. Early Patient Outcomes After Primary Total Knee Arthroplasty with Quadriceps-Sparing Subvastus and Medial Parapatellar Techniques: A Randomized, Double-Blind Clinical Trial. J Bone Joint Surg Am. 2014 Jun 4;96(11):907-915. doi: 10.2106/JBJS.L.01578. Epub 2014 Jun 4.

  PMID: 24897738 BACKGROUND

• Sukeik M, Sohail MZ, Hossain FS, AlShryda S, Powell J. Comparing the Sub-Vastus and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Meta-Analysis of Short-Term Outcomes. Dr Sulaiman Al Habib Med J. 2021;3(2):66. doi:10.2991/dsahmj.k.210203.001

  BACKGROUND

• Khan MNH, Abbas K, Faraz A, Ilyas MW, Shafique H, Jamshed MH, Hashmi P. Total knee replacement: A comparison of the subvastus and medial parapatellar approaches. Ann Med Surg (Lond). 2021 Aug 8;68:102670. doi: 10.1016/j.amsu.2021.102670. eCollection 2021 Aug.

  PMID: 34408867 BACKGROUND

• van Hemert WL, Senden R, Grimm B, van der Linde MJ, Lataster A, Heyligers IC. Early functional outcome after subvastus or parapatellar approach in knee arthroplasty is comparable. Knee Surg Sports Traumatol Arthrosc. 2011 Jun;19(6):943-51. doi: 10.1007/s00167-010-1292-0. Epub 2010 Oct 17.

  PMID: 20953864 BACKGROUND

• Berstock JR, Murray JR, Whitehouse MR, Blom AW, Beswick AD. Medial subvastus versus the medial parapatellar approach for total knee replacement: A systematic review and meta-analysis of randomized controlled trials. EFORT Open Rev. 2018 Mar 26;3(3):78-84. doi: 10.1302/2058-5241.3.170030. eCollection 2018 Mar.

  PMID: 29657848 BACKGROUND

Related Links

• Persona IQ Device

Central Study Contacts

Thomas L Bradbury, M.D.

CONTACT

(404)-759-3912; tombradburymd@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Model Details: This is a prospective, randomized, parallel-group study. Eligible patients undergoing primary total knee arthroplasty are randomized in a 1:1 ratio to either the medial parapatellar or subvastus surgical approach and followed concurrently. Outcomes are assessed longitudinally.

Study Record Dates

• First Submitted: December 15, 2025
• First Posted: January 16, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027
• Last Updated: January 16, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)