Telerehabilitation intervention after total knee arthroplasty in Iran: a feasibility and acceptability randomised controlled trial

Abstract

Objectives

To assess the feasibility and acceptability of a culturally adapted telerehabilitation programme for Iranian patients following total knee arthroplasty (TKA) and to explore preliminary clinical outcomes to inform the design of a future definitive randomised controlled trial (RCT).

Design

Parallel-group, open-label, single-centre randomised controlled feasibility trial.

Setting

A private multi-specialty hospital in Tehran, Iran.

Participants

Thirty adults aged 50–90 years undergoing primary TKA were randomised (1:1) using a block randomisation method to the intervention (n=15) or usual care (n=15); 27 participants completed the final assessment. Eligible participants were Persian-speaking adults with smartphone access. Patients with cognitive impairment, inflammatory or neurological disorders, sensory impairment, concurrent rehabilitation or postoperative complications precluding participation were excluded.

Interventions

Participants received either a 4-week culturally adapted telerehabilitation programme comprising 12 supervised virtual physiotherapy sessions delivered via a locally developed digital platform in addition to usual care or usual care alone. Participants were followed for 4 weeks, with the final assessment conducted at the end of the intervention period.

Outcome measures

Primary outcomes were feasibility (screening, recruitment and assessment completion rates) and acceptability (participant satisfaction, adherence, attendance, attrition and willingness to recommend the programme). Secondary exploratory outcomes included the Knee Injury and Osteoarthritis Outcome Score subscales, patient global assessment, walking aid use, exercise adherence, adverse events and receipt of outpatient physiotherapy.

Results

Fifty-nine patients were approached, and 30 were randomised (mean age 67.3 years; 76.7% women), with 27 completing the study. Prespecified feasibility targets were achieved, with screening, recruitment and retention rates of 86.4% (95% CI 75.0% to 94.0%), 69.8% (95% CI 53.9% to 82.8%) and 90.0% (95% CI 73.5% to 97.9%), respectively. The attrition rate was 10.0% (95% CI 2.1% to 26.5%). In the intervention group, acceptability was favourable, with mean satisfaction and adherence scores of 76.3 (SD 17.3) and 82.7 (SD 15.1), respectively; 83.3% of scheduled sessions were attended, and 84.6% of participants indicated that they would recommend the programme. Exploratory clinical outcomes were summarised descriptively to provide preliminary estimates for planning a future definitive trial. No intervention-related adverse events were reported.

Conclusions

This pilot RCT demonstrated that a culturally adapted telerehabilitation programme following TKA was feasible, acceptable and safe in the Iranian setting. The exploratory clinical findings provide preliminary data to inform the design of a fully powered multicentre RCT to evaluate the clinical effectiveness, cost-effectiveness and long-term outcomes of this intervention.

Trial registration number

Thai Clinical Trials Registry, TCTR20231020004, registered on 8 October 2023.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• The intervention was delivered via a locally developed digital platform tailored to the cultural and linguistic context of Iranian patients, potentially enhancing relevance, accessibility and patient engagement.

• Stratified block randomisation, together with blinded outcome assessment and statistical analysis, minimised the risk of selection and detection bias.

• As a single-centre pilot feasibility trial with a small sample size, the findings have limited generalisability, and the exploratory clinical outcomes were not powered to detect definitive between-group differences.

Introduction

Knee osteoarthritis (KOA) is a chronic, degenerative joint disease characterised by progressive cartilage loss, pain, stiffness and impaired mobility, representing a major global public health and socioeconomic challenge. The worldwide burden of KOA has increased steadily in recent decades, largely due to population ageing and rising obesity rates.^{1 2} In 2021, the prevalence of KOA was estimated at 374.7 million individuals, with more than 30 million new cases and 12 million disability-adjusted life years attributed to the condition.³ Projections suggest that, by 2045, the number of affected individuals could exceed 650 million.¹ Women are disproportionately affected, particularly in older age groups, partly due to hormonal and biomechanical factors.^{2 3} In Iran, as in many low-income and middle-income countries (LMICs), the increasing prevalence of KOA presents growing challenges for health systems already under resource constraints.⁴

For individuals with advanced KOA unresponsive to conservative measures, total knee arthroplasty (TKA) is the gold-standard surgical intervention.^{5 6} TKA reliably relieves pain, improves mobility and enhances health-related quality of life (QoL), with survival rates exceeding 90% at 15 years postimplantation.⁶ Despite these outcomes, approximately 10% of patients report persistent dissatisfaction, often due to residual pain, stiffness or functional limitations, which may reinforce one another.^{5 7} Successful recovery following TKA depends on structured, progressive postoperative rehabilitation, which targets joint range of motion (ROM), quadriceps strength, gait mechanics, balance and endurance.⁸ Within 1 month of surgery, quadriceps function can decrease by 20%–25%, walking speed by 18%, and stair-climbing speed by more than 50%, with deficits sometimes persisting for a year or more.⁹

Rehabilitation is essential to mitigate these deficits and promote functional recovery. Conventional physiotherapy, typically delivered in-person, has demonstrated substantial benefits in improving strength, ROM and QoL after TKA.¹⁰ However, access to rehabilitation services is often constrained by geographic, economic and logistical barriers, particularly in low-resource settings or among older adults with limited mobility.¹¹ These challenges have prompted growing interest in telerehabilitation, a modality that leverages digital technologies to deliver remote physiotherapy interventions.¹²

Telerehabilitation has become increasingly adopted worldwide, especially in the wake of the COVID-19 pandemic, which accelerated the adoption of remote healthcare solutions.¹³ Systematic reviews and meta-analyses have shown that telerehabilitation can yield outcomes comparable to traditional care in terms of pain reduction, functional improvement and patient satisfaction.^14–17 Moreover, it offers advantages such as reduced travel burden, enhanced convenience and cost-effectiveness.^{18 19} In countries such as Canada, Australia and Italy, telerehabilitation has been successfully integrated into post-TKA care pathways.^20–22

Despite these advancements, the implementation of telerehabilitation in Iran remains limited. Cultural factors, digital literacy and infrastructural limitations pose unique challenges to its adoption.^{23 24} While Iran has seen increased interest in telemedicine, there is a notable absence of randomised controlled trials (RCTs) evaluating telerehabilitation for patients undergoing TKA within its healthcare system.²⁵ This gap is particularly concerning given Iran’s ageing population and rising KOA prevalence, which are expected to increase demand for joint replacement surgery and subsequent rehabilitation.²⁶ Furthermore, the development of locally developed telerehabilitation platforms tailored to Iranian patients has been limited. Issues such as data privacy, patient engagement and technical reliability must be addressed to ensure successful implementation.^{27 28} Previous qualitative studies have highlighted barriers, including lack of personal interaction, reduced motivation and concerns about clinical oversight in remote settings.²⁹ These factors underscore the need for culturally responsive, evidence-based interventions that align with the preferences and capabilities of Iranian patients and healthcare providers.

To address this gap, our study investigated the feasibility and acceptability of a structured telerehabilitation programme for patients undergoing TKA in Iran. Delivered via a locally developed digital platform, the intervention includes supervised virtual physiotherapy sessions over a 4-week period. By assessing recruitment, retention, adherence, patient satisfaction and exploratory functional outcomes, this pilot RCT aimed to determine whether a definitive trial is feasible and to generate preliminary data to inform the design of future trials.

Methods

Study design and setting

This parallel-group, open-label, randomised pilot feasibility trial was conducted at Atieh Hospital in Tehran, Iran, between May and August 2024. Each participant was followed for 4 weeks after enrolment, with the final assessment conducted at the end of the 4-week intervention/follow-up period. The study protocol has been published previously in BMJ Open.³⁰ The study adhered to the Consolidated Standards of Reporting Trials (CONSORT) guidelines.³¹

Participants

Adults aged 50–90 years undergoing primary TKA for KOA were screened postoperatively at the hospital by the intervention physiotherapist.

Inclusion criteria

Required that participants had no history of prior knee replacement, could read and write Persian, and either had personal smartphone access or access to a companion to assist with mobile applications. All participants were required to provide written informed consent and express a willingness to participate in all sessions and assessments.

Exclusion criteria

Included diagnosed cognitive impairment, rheumatoid arthritis or other systemic inflammatory or neurological diseases, uncorrectable vision or hearing loss, concurrent participation in external rehabilitation programmes and postoperative complications that rendered further participation unsafe.

Randomisation and blinding

Participants were randomised 1:1 to the intervention or control group using a computer-generated random sequence. Block randomisation with a block size of four patients was used to ensure balanced allocation, stratified by sex and surgical status (unilateral vs simultaneous bilateral TKA).³² An independent researcher who was not involved in enrolment generated the allocation sequence. Allocation was concealed using sequentially numbered, opaque, sealed envelopes, which were opened only after eligibility had been confirmed and informed consent had been obtained. Due to the nature of the intervention, neither participants nor therapists were blinded to group allocation; however, participants were advised not to disclose their group assignment to others after allocation. Outcome assessors and the statistician remained blinded throughout data collection and analysis.

Intervention

The intervention was described in detail in the protocol article.³⁰ Briefly, it included the following components:

Telerehabilitation (intervention group)

Participants received a 4-week structured telerehabilitation programme following hospital discharge, delivered through a locally developed platform (web/app). The programme comprised 12 live virtual physiotherapy sessions (three sessions per week), each lasting approximately 30–45 min, delivered by a trained intervention physiotherapist. The intervention content was based on a validated postoperative rehabilitation protocol^{30 33} and progressed according to participants’ recovery from breathing and oedema-control exercises to passive and active ROM exercises, strengthening, gait training, proprioception and, where feasible, aquatic exercises (table 1).

Table 1. Key components of the telerehabilitation programme.

Week	Key activities and exercises	Goals
1	Patient education (oedema control, positioning) Wound inspection PROM: heel slides, knee flexion/extension Isometric exercises (quadriceps, hamstrings, gluteals) AROM: ankle dorsiflexion/plantarflexion—gait training with a walker/crutches Transition to A/AROM and SLR exercises	Pain control, oedema reduction, initiation of safe mobility
2	Progression of week 1 exercises Transfer training (car, various seat heights) Aggressive PROM/AROM for knee flexion Functional strengthening: step-ups/downs, squats	Improved ROM, safe ambulation, transfer independence
3	Continued progression Full weight-bearing gait training Home safety assessment Soft-tissue and myofascial release (with caution)	Functional mobility, home safety, strength building
4	Optional aquatic therapy Progressive resistance exercises (leg press, bridging) Cardiovascular conditioning (cycling, walking, swimming) Hip and core strengthening BAPS	Return to ADLs, balance and endurance, full ROM

A/AROM, active assisted range of motion; ADLs, activities of daily living; AROM, active range of motion; BAPS, balance and proprioception exercises; PROM, passive range of motion; ROM, range of motion; SLR, straight leg raise.

The intervention was delivered in Persian and adapted to the cultural and clinical context of Iranian patients undergoing TKA. Educational materials were developed with input from six faculty members in physiotherapy and orthopaedic surgery and addressed common postoperative concerns and health beliefs. Communication was tailored to older adults, and family members were involved, when appropriate, to support and supervise home exercises. Guidance also addressed culturally relevant daily and functional activities familiar to participants. The intervention was further adapted to the local healthcare and technological context by using participants’ smartphones and a locally developed telehealth platform.

In addition to live sessions, participants received digital educational materials, including handouts and videos on postoperative care, exercises, pain management and prevention of complications. Participants were encouraged to perform the prescribed exercises daily and maintain an exercise log. Reminders for scheduled sessions and home exercises were sent via SMS (Short Message Service) or through the application to support adherence.

Usual care (both groups)

Usual care for both groups included postoperative vital‐sign monitoring, wound care, pain control, ambulation and postoperative exercise training in the hospital, and provision of an educational pamphlet on exercises and precautions (online supplemental file 1). The pamphlet was developed based on Rehabilitation for the Postsurgical Orthopaedic Patient (3rd ed.) ³³and validated by faculty experts. All participants underwent TKA using a subvastus approach with kinematic alignment and were routinely discharged on postoperative day 1, provided that they met the standard discharge criteria. Discharge criteria required independent transfers, walking (with an assistive device), manageable pain and stable medical status.

After hospital discharge, participants continued postoperative follow-up according to the treating surgical team’s usual care pathway. In the study setting, outpatient physiotherapy was not routinely prescribed during the first 2 weeks after TKA. During subsequent postoperative follow-up, the treating surgeons determined whether outpatient physiotherapy was required based on the patient’s clinical status and postoperative progression. Receipt of outpatient physiotherapy during the 4-week study period was recorded as an exploratory outcome. One participant who received outpatient physiotherapy and consequently did not complete the final study assessment was not included in the clinical outcome analysis, as additional physiotherapy could potentially influence the clinical outcomes.

Data collection

Outcomes were assessed at baseline and at the 4-week follow-up, corresponding to the end of the intervention period.

Primary outcomes

Feasibility

Feasibility was assessed using predefined progression criteria based on recruitment and data completion. These criteria included at least 80% of interested individuals agreeing to eligibility screening, at least 60% of eligible individuals enrolling in the trial, a baseline questionnaire completion rate exceeding 80% and a final questionnaire completion rate exceeding 70%.

Acceptability

Acceptability was assessed at the end of the intervention using a self-administered online questionnaire. Participant satisfaction was evaluated using three items adapted from a validated patient satisfaction scale for patients undergoing TKA.^{30 34} Each item was rated on a 4-point Likert scale: ‘very satisfied’ (100 points), ‘somewhat satisfied’ (75 points), ‘somewhat dissatisfied’ (50 points) and ‘very dissatisfied’ (25 points). For each participant, the satisfaction score was calculated as the arithmetic mean of the 3 item scores, resulting in a possible score range of 25–100, with higher scores indicating greater satisfaction.

Adherence was assessed using five study-specific items rated on a 5-point Likert scale: ‘always adhere’ (100 points), ‘mostly adhere’ (75 points), ‘sometimes adhere’ (50 points), ‘rarely adhere’ (25 points) and ‘never adhere’ (0 points) (online supplemental file 2). These items were developed specifically for this study and underwent content validation by a panel of experts in orthopaedic surgery and physiotherapy. For each participant, the adherence score was calculated as the arithmetic mean of the 5 item scores, resulting in a possible score range of 0–100, with higher scores indicating greater adherence.

Attendance was calculated as the proportion of completed sessions relative to the total number of prescribed sessions and expressed as a percentage. In addition, they were asked whether they would be willing to participate in the programme again or recommend it to others (yes/no).

Acceptability was considered achieved if the predefined progression criteria were met: (1) an attrition rate of <20%; (2) attendance at >80% of scheduled sessions; (3) mean satisfaction and adherence scores of at least 75 points and (4) at least 75% of participants indicating that they would participate in the programme again or recommend the programme to others.

Qualitative interviews

To further explore the practical acceptability of the telerehabilitation programme, all participants in the intervention group who completed the 4-week protocol ($n=13$) were invited to participate in a brief semistructured exit interview via telephone. These interviews were conducted by the outcome assessor (MH), who was independent of the intervention delivery to ensure objectivity. A brief, open-ended interview guide was used to gather patient feedback across five domains: overall programme experience, perceived clinical utility, technical or operational friction, participation barriers and recommendations for system refinement (online supplemental file 3). Participant responses were documented through detailed, contemporaneous note-taking during the phone calls.

Interview data were analysed descriptively using conventional content analysis. The written notes were reviewed to identify explicit manifest content regarding patient experiences. Responses were coded directly from the text, grouped based on common operational issues (eg, platform usability, internet connectivity and scheduling constraints), and summarised in a structured matrix mapping-specific user barriers to patient-derived suggestions for improvement. To ensure analytical accuracy, two researchers independently reviewed the interview documentation and reached a consensus on the final descriptive groupings.³⁵

Secondary outcomes (exploratory clinical outcomes)

Secondary outcomes were assessed using the Persian version of the Knee Injury and Osteoarthritis Outcome Score (KOOS), with a focus on its subscales rather than overall score due to the limited validity of the overall score.^{36 37} We used Activities of Daily Living (ADL), Symptoms, Pain, Knee-related QoL subscales of the questionnaire and excluded the sport and recreation subscale because most items could not be assessed within the first 4 weeks after surgery.^{30 37} The KOOS was administered at baseline and again at 4 weeks, at the end of the intervention period. In addition, a single-item patient global assessment (PGA) of functional ability during ADL was used to evaluate perceived recovery.³⁸ The type and number of walking aids used were recorded at both baseline and follow-up. Participants also self-reported the average number of daily exercise sessions performed throughout the study period. Adverse events, hospitalisations and reoperations were monitored through participant self-reports, clinician follow-up and structured electronic questionnaires administered at the final assessment. Receipt of outpatient physiotherapy during the study period was also recorded as an exploratory outcome and compared descriptively between the two groups.

Baseline demographic and clinical data were collected during hospitalisation or at the first follow-up visit. Follow-up data were collected electronically using a Persian-language online survey platform, and supplemented by telephone calls where necessary. Survey links were sent via SMS, and responses were submitted through encrypted online forms. A team member independent of data entry verified the data for accuracy, and a blinded statistician performed data cleaning and analysis.

Sample size

Consistent with the pilot feasibility design, no formal power calculation was performed. Instead, the sample size was pragmatically determined to estimate key feasibility parameters. A target sample of 30 participants (15 per arm) was selected to allow calculation of CIs and variance estimates for a future definitive trial, in line with recommendations for feasibility study design.^{39 40} For transparency, we additionally report the precision associated with the chosen sample size. With a total sample size of 30 participants, a feasibility proportion of approximately 80% would be estimated with an approximate 95% CI spanning about 28 percentage points (approximately ±14% using the normal approximation). This estimate is provided to illustrate the precision afforded by the selected sample size and was not used prospectively to determine the sample size.

Statistical analysis

The primary objective of this study was to evaluate the feasibility and acceptability of the intervention. Feasibility and acceptability outcomes were summarised as frequencies and percentages with 95% CIs. Continuous exploratory clinical outcomes were summarised as means with SDs or medians with IQRs, depending on the distribution of the data. Week 4 clinical outcomes were summarised among participants who completed the final assessment. One participant who did not complete the final assessment was not included in the corresponding week 4 outcome summaries because outcome measurements were unavailable. All randomised participants were retained in their originally assigned groups for reporting of trial flow, feasibility and attrition outcomes.

Given the pilot design of this trial, the analysis was primarily descriptive and focused on parameter estimation rather than formal hypothesis testing. Secondary clinical outcomes were reported descriptively only, consistent with the pilot feasibility design of the study.³¹ All statistical analyses were conducted using SPSS software (V.16).

Patient and public involvement

Patients and/or the public were not involved in the design, conduct, reporting, or dissemination plans of this research.

Results

Baseline characteristics

The study enrolled 30 participants with a mean age of 67.3 years (SD 7.12), and the majority were female (76.7%) and residents of Tehran (63.3%). Educational levels varied, with half of the participants holding a diploma, one-third having completed primary education, and the remainder having higher education. Clinically, 43.3% had undergone TKA on the left knee, 40% on the right knee and 16.7% had bilateral procedures. Baseline KOOS subscale scores indicated moderate limitations in ADLs, pain and symptoms, with notably low scores in knee-related QoL. The mean PGA score was 4.4 (SD 2.2). At the initial assessment, nearly all participants (93.3%) used a walker, with only two reporting no use of an assistive device. The baseline demographic and clinical characteristics of the participants in the intervention and usual care groups are summarised in table 2.

Table 2. Baseline demographic and clinical characteristics of participants.

Characteristic	Participants
	Intervention (n=15)	Usual care (n=15)
Age, mean (SD)	66.1 (4.9)	68.5 (8.8)
Gender, number (%)
Male	3 (20)	4 (26.7)
Female	12 (80)	11 (73.3)
Residence, number (%)	10 (66.7)	9 (60)
Tehran other cities	5 (33.3)	6 (40)
Education, number (%)
Primary education	3 (20)	7 (46.7)
Diploma	9 (60)	6 (40)
Higher education	3 (20)	2 (13.3)
Surgical side, number (%)
Right	6 (40)	6 (40)
Left	6 (40)	7 (46.7)
Bilateral	3 (20)	2 (13.3)
KOOS subscales, mean (SD)
ADLs	53.2 (23.4)	51.9 (19.6)
Symptoms	63.4 (13.9)	59.4 (9.1)
Pain	55.8 (20.9)	53.9 (18.2)
Knee-related QoL	20.3 (15.3)	34.4 (25.4)
PGA, mean (SD)	3.92 (2.5)	4.73 (1.9)
Walking assistive device, number (%)
Walker	14 (93.3)	14 (93.3)
No assistive device	1 (6.7)	1 (6.7)

ADL, activities of daily living; KOOS, Knee Injury and Osteoarthritis Outcome Score; PGA, patient global assessment; QoL, quality of life.

Primary outcomes

Feasibility

Of the 59 patients approached for screening, 51 consented and were assessed for eligibility, yielding a screening agreement rate of 86.44% (95% CI 75.0% to 93.9%). Among them, 43 met the inclusion criteria, while eight were excluded. Additionally, 13 patients declined participation, resulting in a recruitment rate of 69.8% (95% CI 53.9% to 82.8%). Ultimately, 30 eligible patients were randomised to the intervention or usual care group (n=15 per group) using block randomisation. All participants completed the baseline assessment (100% completion rate). During the 4-week follow-up, one participant in the intervention group did not complete the final assessment because she received outpatient physiotherapy, and one additional participant in the intervention group did not complete the final assessment for another reason. In the control group, one participant was lost to follow-up because the final assessment was incomplete. Consequently, 13 participants from the intervention group and 14 from the control group completed the final assessment and were included in the primary outcome analysis. This resulted in an overall trial retention rate of 90.0% (95% CI 73.5% to 97.9%) (figure 1).

Figure 1. Flow diagram. PT, physical therapy.

Acceptability

The intervention met all prespecified acceptability criteria defined in the study protocol. The overall attrition rate was 10.0% (95% CI 2.1% to 26.5%), comprising 6.7% (95% CI 0.3% to 31.9%) in the control group and 13.3% (95% CI 2.4% to 37.9%) in the intervention group (figure 1). Participants in the intervention group attended 83.3% of the scheduled telerehabilitation sessions, with a mean attendance of 10.0 (SD 1.5) sessions out of the 12 planned sessions. The intervention physiotherapist also reported acceptable participant engagement throughout the programme. Mean satisfaction and adherence scores exceeded the prespecified acceptability threshold of 75% and were comparable between groups (table 3). Furthermore, 84.6% (11 out of 13) of participants in the intervention group indicated that they would participate in the programme again or recommend it to others (95% CI 51.3% to 97.7%), exceeding the prespecified acceptability criterion of 75%.

Table 3. Outcome scores at week 4 (intervention vs usual care).

Outcome	Intervention (n=13)	Control (n=14)
Satisfaction score, mean (SD)	76.28 (17.29)	77.38 (13.64)
Adherence score, mean (SD)	82.69 (15.01)	77.38 (13.80)
KOOS subscales, mean (SD)
ADL	70.36 (13.09)	66.33 (15.61)
Symptoms	67.03 (10.63)	65.31 (14.79)
Pain	64.77 (12.92)	59.82 (11.22)
QoL	35.58 (19.33)	27.23 (9.04)
PGA, mean (SD)	5.62 (2.46)	6.07 (1.38)
Walking assistive device, number (%)
Non	10 (76.9)	10 (71.4)
Cane	1 (7.7)	1 (7.1)
Walker	2 (15.4)	3 (21.4)
Exercise adherence/day, number (%)
None	1 (7.7)	1 (7.1)
One time	1 (7.7)	2 (14.3)
2–3 times	7 (53.8)	6 (42.9)
4–5 times	3 (23.1)	3 (21.4)
>5 times	1 (7.7)	2 (14.3)
Adverse events, number (%)	0 (0)	1 (7.1)

ADLs, activities of daily living; KOOS, Knee Injury and Osteoarthritis Outcome Score; PGA, patient global assessment; QoL, quality of life.

Qualitative interviews

Of the 13 intervention group participants who completed the trial, all were successfully reached and invited to participate in the qualitative exit interview. Eleven participants provided detailed feedback regarding their experiences with the telerehabilitation platform. Conventional content analysis of the interview data revealed three primary descriptive categories: (1) platform usability, (2) connection quality, and (3) appointment scheduling. While the remote delivery model and features such as virtual clinical checks were highly praised, notable barriers were identified regarding low digital literacy among older participants, who required substantial technical onboarding and active caregiver assistance to operate the interface. Additionally, regional internet instability occasionally compromised audio-visual quality during live physiotherapy sessions. A summary of individual participant feedback, linking operational barriers with participant-derived suggestions for platform and logistical improvements, is presented in table 4. The matrix includes feedback from all participants who contributed detailed comments, ensuring transparent reporting.

Table 4. Summary of patient-reported operational barriers and suggestions for platform improvement.

Descriptive category	Identified operational barrier (manifest content)	Patient-derived recommendations
Platform usability	Difficulty using the platform independently; required caregiver assistance. (#3; female) Difficulty contacting therapist or support; the platform was difficult to use independently. (#7; female) The therapist’s profile was difficult to access on the platform. (#10; female)	In-person visits preferred for accurate ROM1 assessment. (#3; female) Improve accessibility and provide support for patients with limited digital literacy. (#7; female) Simplify navigation. (#10; female) Provide clear user onboarding guidance. (#12; female)
Connection quality	Poor image and audio quality affected communication. (#2; female) Connection issues and poor image quality disrupted sessions. (#12; female)	Improve the technical infrastructure to enhance audio and video quality. (#2; female) Improve overall platform stability. (#12; female)
Appointment scheduling	Coordination and technical checks felt rushed. (#1; female) Morning-only appointments were restrictive. (#11; male)	Increase the time between platform setup and the therapist’s visit for smoother communication. (#1; female) Expand appointment time options, especially in the evenings. (#10; female) Offer evening time slots to accommodate patient and caregiver schedules. (#11; male)

#, participant number; ROM, range of motion.

Secondary outcomes

Exploratory clinical outcomes at week 4 are presented descriptively in table 3. Mean KOOS ADL scores at week 4 were 70.36 (SD 13.09) in the intervention group and 66.33 (SD 15.61) in the usual-care group. The corresponding mean scores were 67.03 (SD 10.63) and 65.31 (SD 14.79) for symptoms, 64.77 (SD 12.92) and 59.82 (SD 11.22) for pain, and 35.58 (SD 19.33) and 27.23 (SD 9.04) for knee-related QoL, respectively. Mean PGA scores were 5.62 (SD 2.46) in the intervention group and 6.07 (SD 1.38) in the usual-care group. Walking-aid use and self-reported exercise frequency are also reported descriptively in table 3. No inferential comparisons were performed; these estimates are intended to provide preliminary information for planning a future definitive trial. No adverse events related to the study intervention were reported. One participant in the usual-care group was hospitalised because of respiratory complications during the follow-up period. The participant did not receive any telerehabilitation sessions; therefore, the event was considered unrelated to the telerehabilitation intervention (table 3). One participant in the intervention group received outpatient physiotherapy during the 4-week study period (1/15, 6.7%), whereas none of the participants in the usual-care group received outpatient physiotherapy (0/15, 0%).

Discussion

To the best of our knowledge, this trial represents the first pilot RCT evaluating the feasibility and acceptability of a culturally adapted telerehabilitation programme for patients undergoing TKA in Iran. Rather than evaluating intervention effectiveness, this study was designed to determine whether a definitive RCT is feasible and to provide preliminary estimates of clinical outcomes. The findings provide culturally contextualised evidence regarding the implementation of telerehabilitation in an LMIC setting.^41–44 By integrating feasibility, acceptability and exploratory clinical outcomes, this discussion explores the multifaceted implications of telerehabilitation and its potential for scale-up, and how these findings may inform the design of a future definitive trial.

Principal findings

The feasibility of telerehabilitation after TKA in this study is supported by favourable screening, recruitment and retention metrics, which are broadly consistent with findings from previous studies reporting high patient engagement and successful implementation of telerehabilitation following TKA.^{41 45} No intervention-related safety concerns were identified during the study, although larger studies are needed to confirm the safety of telerehabilitation in this population.

Although feasibility was assessed using predefined progression criteria, including screening and recruitment rates, recruitment duration was not formally evaluated. Given the defined recruitment pathway and high surgical volume at our study site, recruitment duration was considered less informative in this context. However, future multicentre trials should report recruitment duration alongside other progression criteria to provide a more comprehensive assessment of feasibility.

Acceptability was similarly supported by high session attendance, good adherence, satisfaction, willingness to recommend the intervention and low attrition. These outcomes may have been facilitated by culturally adapted content, active caregiver involvement and structured onboarding processes. Nonetheless, implementation challenges emerged, particularly connectivity limitations and platform usability issues, which were the most pronounced among older adults with low digital literacy. Such barriers are consistent with those reported in other LMICs, where insufficient technological infrastructure and limited digital health competencies continue to hinder the feasibility of equitable access to telerehabilitation services.^{24 43 44 46}

Regarding the exploratory clinical outcomes, the observed week 4 estimates varied across the KOOS subscales, PGA and functional measures (table 3). The mean KOOS QoL score was 35.58 (SD 19.33) in the intervention group and 27.23 (SD 9.04) in the usual-care group at week 4, while the other KOOS subscales and PGA showed different patterns of observed group-specific estimates. Because this pilot trial was not designed or powered to evaluate intervention effectiveness, these observations should not be interpreted as evidence of between-group treatment effects. Rather, they provide preliminary information on outcome distributions and variability that may inform outcome selection and the broader planning of a future fully powered RCT. However, given the uncertainty and potential instability of estimates obtained from small pilot studies, these data should not be used in isolation to determine the sample size or power of a definitive trial.⁴⁷

Implications of the study

This study yielded several key insights that can inform the design and implementation of future larger-scale telerehabilitation interventions.

Digital infrastructure and technological literacy

The success of synchronous telerehabilitation appears closely tied to internet connectivity, which depends on regional infrastructure and device capabilities. In our study, while most participants reported acceptable communication, some experienced slow or unstable video connections, echoing findings from studies on infrastructure disparities in Iran.²³ The intervention physiotherapist also noted variability in connection quality across cities or different areas of Tehran, highlighting the need for coordinated support between the healthcare and telecommunications sectors.²³ Additionally, digital literacy significantly influenced platform usability. Most participants were aged 60 years or older, and many required assistance from younger family members to operate smartphones. Despite structured onboarding and technical support, some patients reported difficulties navigating the system. Future research should consider digital literacy as a potential mediating factor and consider tailored training modules to improve accessibility and reduce confusion among older users.

Financial sustainability and cost considerations

The financial model through which telerehabilitation is delivered plays a critical role in patient engagement and long-term sustainability. In this study, services were provided at no cost to participants; however, it remains uncertain whether similar adherence and satisfaction levels would be achieved under a paid model. Previous research indicates that telerehabilitation programmes in LMICs can achieve satisfaction rates exceeding 90%, while substantially reducing travel and service-related expenses.⁴⁴ For broader implementation, a well-defined financial framework is essential to ensure both affordability for patients and equitable compensation for providers. Future research should incorporate cost-effectiveness analyses and evaluate the economic feasibility of these models to inform sustainable, large-scale implementation within the Iranian healthcare system.

Surgical factors and telerehabilitation responsiveness

Surgical technique and surgeon expertise are critical determinants of rehabilitation outcomes following TKA. Procedures performed by experienced surgeons may be associated with shorter tourniquet times and less soft tissue disruption, both of which are associated with faster recovery and improved functional outcomes.⁴⁸ In this study, surgical variability was minimised by including only patients who underwent minimally invasive TKA with kinematic alignment, performed by a consistent surgical team. However, the effectiveness of telerehabilitation may be influenced by postoperative surgical factors in ways that are more difficult to detect remotely than during in-person care, due to limitations in physical assessment and intervention. Remote settings restrict therapists’ ability to detect subtle postoperative complications or deliver hands-on techniques, which are often essential in the early phases of recovery.^{49 50} While referral pathways to in-person care, as implemented in this study, can partially mitigate these limitations, future research should consider surgical factors such as technique, intraoperative parameters and surgeon experience as potential moderators to better understand how they may influence responsiveness to telerehabilitation.

Clinical justification

Delivering rehabilitation remotely necessitates careful clinical justification and appropriate patient selection. Procedures such as joint mobilisation, stretching, manual muscle testing and palpation require tactile feedback, which cannot be replicated virtually. Recent research cautions that overextending telerehabilitation capabilities may compromise treatment efficacy and reinforce inequities.⁵¹ In this study, the physiotherapist relied on subjective feedback and the patient’s recovery stage to tailor interventions; however, limitations in objective assessment, such as determining joint end feel, measuring ROM, assessing muscle strength and testing balance, were acknowledged. Future research should compare the accuracy of remote versus in-person evaluations and explore alternative strategies for physical assessment in virtual settings.⁵¹

Strengths and limitations

This was the first pilot randomised feasibility trial in Iran to evaluate a culturally adapted telerehabilitation approach for patients following TKA. Key strengths of the study include its randomised design, blinded outcome assessment and the use of a mixed-methods framework to evaluate both feasibility and acceptability. The cultural adaptation of the intervention and the integration of caregiver support were additional strengths that enhanced participant engagement.

Nevertheless, the study had several limitations. As a single-centre feasibility pilot, its generalisability is limited, and it was not designed or powered to determine definitive clinical effectiveness. In addition, the 4-week follow-up period may have been insufficient to capture meaningful changes in the secondary outcomes. Future research should include a fully powered multicentre trial with longer follow-up to evaluate clinical effectiveness, implementation outcomes and scalability across more diverse patient populations and healthcare settings.

An additional limitation is that this pilot study focused primarily on patient-level feasibility and acceptability. Other implementation outcomes, including physiotherapist training, intervention fidelity and the acceptability of the programme among healthcare professionals, were not formally evaluated. Furthermore, although participants provided feedback on their experiences after completing the intervention, they were not involved in developing the research question, selecting outcome measures or designing the study procedures. Future trials should incorporate patient and public involvement from the outset, including the codevelopment of intervention materials and active involvement throughout the design, refinement, implementation and dissemination of the research.

Conclusion

To the best of our knowledge, this is the first pilot RCT in Iran designed to evaluate the feasibility and acceptability of telerehabilitation following TKA. The findings demonstrate that the intervention is feasible to implement, acceptable to participants and safe within the Iranian context. The exploratory clinical outcome data provide preliminary information to support the design of a future fully powered RCT, which will be needed to determine the clinical effectiveness and cost-effectiveness of telerehabilitation following TKA.

Data availability statement

Data are available upon reasonable request.