Load Limits After Orthopaedic Surgery: Biofeedback vs. Conventional Method (AppPWB)

Application of Load Limits After Orthopaedic Surgery With Biofeedback-based Instructions Compared to a Conventional Method

The aim of this single-centre prospective randomized-controlled clinical trial is to assess whether patients adhere to prescribed weight bearing limits after surgical orthopaedic or traumatological interventions more accurately after instruction using a biofeedback method than using the standard method.

Study Overview

• Status: Completed
• Conditions: Surgery
• Intervention / Treatment: Other: Standard one-off instruction using a scale; Device: Plantar pressure insoles

Detailed Description

Partial weight bearing, commonly prescribed post-surgery in orthopaedics and traumatology, aims to stimulate healing while preventing overloading. Partial weight bearing refers to that the patient is only allowed to put 10 to 50% of their body weight on the affected limb.

The most commonly used method for instructing partial weight bearing with the patient is using a personal scale. This means that the patient can only exercise in a static position and the perceived load must be transferred to dynamic activities of daily living without further feedback. Previous reports indicate that patients often struggle to adhere to prescribed partial weight-bearing limits, frequently exceeding the specified load by 100% or more. However, when additional feedback was incorporated into training, approximately 90% of subjects successfully adhered to the partial load.

Portable or wearable measuring systems, such as pressure-sensitive insoles, offer feedback during dynamic tasks, facilitating a smoother transition to daily activities. Unlike the standard one-time instruction using a scale, these systems provide repeated feedback at each step, promoting a higher frequency of exercises. This aids patients in developing a better sense of the correct load.

This single-centre prospective randomized-controlled clinical trial aims to investigate the effectiveness of pressure insoles connected to a smartphone via Bluetooth and operated using an app in improving partial weight bearing adherence. The insoles provide direct feedback through acoustic and visual signals if the affected leg is overloaded, possibly leading to a lower proportion of steps over the load limit compared to those without feedback. Participants are randomized into either the intervention group (dynamic condition - plantar pressure insoles) or the control group (static condition - standard one-off instruction using a scale).

The primary objective is to determine whether the proportion of steps exceeding the weight bearing limit is lower in the intervention group compared to the control group 2 weeks after surgery. Secondary objectives include assessing subjective ratings of the permitted load, perceived pain, and mobility. Additionally, the trial hypothesizes that patients using the insoles can estimate applied load more accurately. The intervention group will also provide feedback on the usability of the app and insoles.

The results of this trial will contribute to enhancing postoperative treatment of patients undergoing orthopaedic surgery, thereby improving treatment outcomes and optimizing therapy regimens.

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Basel-Stadt
    • Basel, Basel-Stadt, Switzerland, 4052
      • Department of Orthopaedics and Traumatology, University Hospital Basel, Bethesda Spital Basel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients with prescribed partial weight bearing (joint-independent) for at least 2 weeks
• Unilateral injury of the lower extremity
• Having their own smartphone
• Age 18 years and older

Exclusion Criteria:

• Patients with prescribed full weight bearing
• Patients with prescribed complete unloading
• Patients with prescribed self-selected loading "according to pain"
• Bilateral injuries of lower extremities
• Upper extremity injuries precluding the use of crutches
• Use of walking aids prior to injury
• Neurological conditions affecting gait
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc.,
• Previous enrolment in a clinical trial
• Body mass > 135 kg
• Age under 18 years

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Control group; The control group receives instructions on partial weight bearing using the standard method.	Other: Standard one-off instruction using a scale; The permitted weight is demonstrated to the patient once using a scale in the static position. The patient repeatedly places the foot with the permitted weight on a scale in order to develop a feeling for the load. After this exercise in the static position, the patient applies the perceived load to dynamic activities of daily living without receiving any feedback. The instruction is given by a trained physiotherapist. Simultaneously with the instruction, the effective weight applied on the leg will be measured using instrumented insoles without any feedback.
Experimental: Intervention group; The intervention group receives instructions on partial weight bearing using a plantar pressure sole inserted into the shoe that measures the force/weight applied to the foot and indicates the applied weight to the patient both visually and acoustically via a smartphone app.	Device: Plantar pressure insoles; The insoles are used in both static and dynamic conditions such as walking straight along the hallway or walking stairs if applicable. Initial instruction is given by a trained physiotherapist and will be continuously applied at home using the smartphone app for 5 out of 7 days per week during the first 2 weeks after surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of steps (%) over of the prescribed weight bearing limit on the injured leg while walking, assessed with the instrumented insoles.	After 2 weeks of continuous use of the feedback-providing insoles by the intervention group, the adherence to load limits is evaluated at the follow-up visit. This assessment aims to determine if the intervention group adheres better to the prescribed weight-bearing limits compared to the control group, which did not receive feedback during this period. Both groups have the proportion of steps (%) exceeding the prescribed weight-bearing limit on the injured leg while walking assessed using instrumented insoles.	At 2 weeks post-surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of perceived pain	To assess the pain level, the numeric analog scale is used. Patients are asked to rate their pain on a scale from 0 to 10, where 0 indicates no pain while 10 indicates the worst possible pain.	Baseline and at 2 weeks post-surgery
Assessment of physical activity	To assess the physical activity, the UCLA Activity Scale(UCLA) is used The UCLA Activity Scale consists of questions related to different activities, and patients rate their ability to perform each activity on a scale from 1 to 10, with higher scores indicating greater activity levels.	Baseline and at 2 weeks post-surgery
Assessment of mobility	To assess the mobility, the Life Space Questionnaire and Parker Mobility Score are used. The former asks respondents to report on their frequency of movement and the distance traveled within various zones, such as within their home, neighborhood, and beyond. The latter evaluates an individual's ability to perform three basic mobility tasks. A score is given to each activity on a 4 point scale (0 - not at all, 1 - assistance of one person, 2 - with an aid, 3 - no difficulty and no aid) and then combined to provide a final score between 0 and 9, where 9 is independent with no aid in all three activities, and 0 is not able to carry out any of the activities.	Baseline and at 2 weeks post-surgery
Assessment of the quality of life	The health-related quality of life is assessed using the EuroQol-5 Dimensions (EQ-5D). It is a standardized questionnaire used to assess an individual's health status across five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has three levels of severity (no problems, some problems, extreme problems), allowing for the classification of 243 unique health states.	Baseline and at 2 weeks post-surgery
Assessment of perceived load applied	Patients are asked to estimate the applied load.	At 2 weeks post-surgery
Assessment of the usability of the planar pressure insoles (intervention group only)	The intervention group is asked to provide feedback on the usability of the app and insoles using a questionnaire.	At 2 weeks post-surgery

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Investigators: Principal Investigator: Marlene Mauch, Dr., Department of Orthopaedics and Traumatology, University Hospital Basel

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2024
• Primary Completion (Actual): November 30, 2024
• Study Completion (Actual): November 30, 2024

Study Registration Dates

• First Submitted: May 17, 2024
• First Submitted That Met QC Criteria: May 17, 2024
• First Posted (Actual): May 23, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 7, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Orthopaedic surgery; Partial weight bearing; Portable measurement systems; Plantar pressure insoles; Biofeedback function
• Other Study ID Numbers: 2024-00106; mu24Mauch

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No