Postoperative Rehabilitation Interventions in Patients at Risk of Poorer Outcomes Following Total Knee Arthroplasty: A Systematic Review
Introduction Osteoarthritis (OA) is the most important cause of pain and disability in the general population (Domínguez‐Navarro et al. ; Papalia et al. ). Total knee arthroplasty (TKA) is often recommended for end‐stage knee OA when conservative treatments fail to control symptoms (Papalia et al. ; van Doormaal et al. ; Van Manen, Nace, and Mont ). Despite the surgical success of TKA, evidence shows suboptimal results in up to 30% of patients (Ewen et al. ; Snell et al. ; Larsen et al. ; Riddle et al. ). Various factors associated with poorer outcomes have been identified in previous studies (Te Molder et al. ), such as high body mass index (Hofstede et al. ; Santaguida et al. ), depression (Vissers et al. ), lower function (Batailler et al. ; Olsen et al. ), and pain (Alattas et al. ; Buirs et al. ; Hofstede et al. ; Santaguida et al. ; Vissers et al. ). Thus, modifying these factors may enhance postoperative outcomes. Postoperative rehabilitation is an important part of the provision of TKA to help patients regain and maintain functional recovery (Peter, Nelissen, and Vliet Vlieland ). Recent systematic reviews of rehabilitation interventions after TKA have focused on the general patient population, with unclear efficacy results (Konnyu et al. ; Papalia et al. ). Evidence suggests that postoperative rehabilitation is not necessary for all patients, as some can achieve full recovery through self‐directed rehabilitation (Artz et al. ; Piva et al. ). Instead, it has been proposed that rehabilitation interventions should target patients who are not recovering well or are at risk of poorer outcomes (Karimijashni et al. ) as these individuals have different rehabilitation needs (Bandholm, Wainwright, and Kehlet ; Larsen et al. ). This highlights the necessity of evidence specifically addressing the treatment of these patients (Childs et al. ). However, it remains unknown which rehabilitation interventions are effective in improving outcomes for patients who are at risk or not recovering well after arthroplasty. The objective of this systematic review was to summarise evidence on the efficacy of postoperative rehabilitation interventions on function, quality of life, and pain in patients not recovering well and/or at risk of poorer outcomes following TKA. 

Methods This systematic review followed the Cochrane Handbook (Cumpston et al. ) and the Preferred Reporting Items for Systematic Review and Meta‐analysis (PRISMA) guidelines (Shamseer et al. ). The protocol was registered in PROSPERO (CRD 42022355574) and published (Karimijashni et al. ). Methods are summarised in the following section. 2.1 Eligibility Criteria Using the Population, Intervention, Comparison, Outcomes, and Study design (PICOS) framework (Amir‐Behghadami and Janati ), we established the following criteria: Population : Adult patients with OA undergoing primary elective TKA who are at risk of poorer outcomes or not recovering well, identified by any pre‐operative and postoperative factors associated with or predictive of poorer outcomes. We categorised poorer outcomes based on the International Classification of Functioning, Disability, and Health (ICF) framework, as outlined in previous systematic reviews (Bletterman et al. ; Buirs et al. ; Elings et al. ; Hofstede et al. ; Olsen et al. ; Podmore et al. ; Pozzobon et al. ; Schatz et al. ; Sergooris et al. ; Sun and Li ) or as presented by authors. The details were provided elsewhere (Karimijashni et al. ). We included articles providing factor cut‐offs with justification. As there is no consensus on factor cut‐offs (Te Molder et al. ), we did not determine a pre‐determined cut‐off. Intervention : Postoperative rehabilitation interventions. Comparator : Patients receiving another rehabilitation treatment (distinct from the main intervention under investigation), usual care (standard or routine care), or no intervention. Outcome : Performance‐based test (PBT) and disease‐specific patient‐reported outcome measure (PROM) as primary outcomes, and generic Health‐Related Quality of Life (HRQoL) and pain as secondary outcomes. Study design : Randomised controlled trial (RCT) as the highest level of evidence to assess intervention effectiveness. 2.2 Data Sources and Search Strategy Medline, Embase, CINAHL, Web of Science, Pedro, and Otseeker databases were searched from inception to December 2023, using relevant keywords and Medical Subject Headings (MESH) terms (see Supporting Information : Appendix A for full search strategies). Four independent reviewers screened titles, abstracts, and full texts. Additional manual screening of reference lists was performed to identify potentially eligible studies. Disagreements were resolved through discussion or consultation with the senior author. 2.3 Data Collection and Risk of Bias Data were extracted by four independent reviewers using a pre‐developed form, which was piloted with two studies. Details of the extraction method are described in a previous publication (Karimijashni et al. ). The methodological quality of the included studies was appraised by two independent reviewers using the Cochrane Risk of Bias (ROB) Tool (Higgins et al. ). We assessed ROB for participants and personnel, with patient‐reported and provider‐assessed outcome measures evaluated separately for two blinding domains. All discrepancies were resolved through discussion. 2.4 Data Synthesis and Analysis Results of the included studies were synthesised according to primary and secondary outcomes. Studies were categorised by intervention type (exercise and non‐exercise therapy). We could not conduct meta‐analyses due to high heterogeneity in interventions and outcome measures. Instead, we summarised the results narratively. 

Eligibility Criteria Using the Population, Intervention, Comparison, Outcomes, and Study design (PICOS) framework (Amir‐Behghadami and Janati ), we established the following criteria: Population : Adult patients with OA undergoing primary elective TKA who are at risk of poorer outcomes or not recovering well, identified by any pre‐operative and postoperative factors associated with or predictive of poorer outcomes. We categorised poorer outcomes based on the International Classification of Functioning, Disability, and Health (ICF) framework, as outlined in previous systematic reviews (Bletterman et al. ; Buirs et al. ; Elings et al. ; Hofstede et al. ; Olsen et al. ; Podmore et al. ; Pozzobon et al. ; Schatz et al. ; Sergooris et al. ; Sun and Li ) or as presented by authors. The details were provided elsewhere (Karimijashni et al. ). We included articles providing factor cut‐offs with justification. As there is no consensus on factor cut‐offs (Te Molder et al. ), we did not determine a pre‐determined cut‐off. Intervention : Postoperative rehabilitation interventions. Comparator : Patients receiving another rehabilitation treatment (distinct from the main intervention under investigation), usual care (standard or routine care), or no intervention. Outcome : Performance‐based test (PBT) and disease‐specific patient‐reported outcome measure (PROM) as primary outcomes, and generic Health‐Related Quality of Life (HRQoL) and pain as secondary outcomes. Study design : Randomised controlled trial (RCT) as the highest level of evidence to assess intervention effectiveness. 

Data Sources and Search Strategy Medline, Embase, CINAHL, Web of Science, Pedro, and Otseeker databases were searched from inception to December 2023, using relevant keywords and Medical Subject Headings (MESH) terms (see Supporting Information : Appendix A for full search strategies). Four independent reviewers screened titles, abstracts, and full texts. Additional manual screening of reference lists was performed to identify potentially eligible studies. Disagreements were resolved through discussion or consultation with the senior author. 

Data Collection and Risk of Bias Data were extracted by four independent reviewers using a pre‐developed form, which was piloted with two studies. Details of the extraction method are described in a previous publication (Karimijashni et al. ). The methodological quality of the included studies was appraised by two independent reviewers using the Cochrane Risk of Bias (ROB) Tool (Higgins et al. ). We assessed ROB for participants and personnel, with patient‐reported and provider‐assessed outcome measures evaluated separately for two blinding domains. All discrepancies were resolved through discussion. 

Data Synthesis and Analysis Results of the included studies were synthesised according to primary and secondary outcomes. Studies were categorised by intervention type (exercise and non‐exercise therapy). We could not conduct meta‐analyses due to high heterogeneity in interventions and outcome measures. Instead, we summarised the results narratively. 

Results 3.1 Study Selection Searches of bibliographic databases yielded 25,308 potentially relevant citations. After removing 9619 duplicates, we screened 15,689 titles and abstracts, excluding 14,188 articles. 1165 were obtained for full‐text screening. Twenty‐two trials fulfilled the inclusion criteria. One trial was identified from the reference lists of the included articles. Supporting Information : Appendix B shows the screening process. 3.2 Study Characteristics Supporting Information : Appendix C provides an overview of the 23 included RCTs published between 2002 and 2022. The trials were conducted in China ( n = 3) (Cai et al. ; Li et al. ; Zhong et al. ), South Korea ( n = 3) (An, Son, and Lee ; Do and Yim ; Park, Kim, and Lee ), United Kingdom ( n = 3) (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ), United States ( n = 3) (Herbold et al. ; Papotto and Mills ; Piva et al. ), Turkey ( n = 2) (Gür and Başar ; Torpil and Kaya ), Denmark ( n = 1) (Christensen et al. ), France ( n = 1) (Moukarzel et al. ), Greece ( n = 1) (Thonga et al. ), India ( n = 1) (Bhatia, Karvannan, and Prem ), Italy ( n = 1) (Tornatore et al. ), Japan ( n = 1) (Tanaka et al. ), Netherland ( n = 1) (Lenssen et al. ), Spain ( n = 1) (Roig‐Casasús et al. ), and Taiwan ( n = 1) (Chang et al. ). All papers were published in English. 3.3 Study Population Across the 23 trials, 2282 patients underwent TKA (An, Son, and Lee ; Barker et al. ; Bhatia, Karvannan, and Prem ; Cai et al. ; Chang et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Li et al. ; Moukarzel et al. ; Papotto and Mills ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ; Tanaka et al. ; Thonga et al. ; Tornatore et al. ; Torpil and Kaya ; Zhong et al. ), with 72.2% being women. The participants' mean age ranged from 61 to 76 years, and their mean body mass index (BMI) was between 23.5 and 37.6 kg/m 2 . Ethnicity and socioeconomic characteristics were reported in two studies (Herbold et al. ; Piva et al. ) and two other studies (Cai et al. ; Thonga et al. ) respectively. Risk factors for poorer outcomes are described in Table . Fifteen studies used preoperative factors, while eight used postoperative factors to identify patients with poorer outcomes. 3.4 Description of Interventions Ten interventions were exercise therapies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ; Thonga et al. ), and 12 were non‐exercise therapies (Bhatia, Karvannan, and Prem ; Cai et al. ; Chang et al. ; Christensen et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Torpil and Kaya ; Zhong et al. ). All interventions began within 2 weeks after arthroplasty, except for four studies, which started at 6 (Papotto and Mills ), 8 (Hamilton et al. ), 12 (Frost, Lamb, and Robertson ) and 17 weeks (Piva et al. ) post‐surgery. The intervention duration ranged from 3 days to 12 weeks. Settings included outpatient (Hamilton et al. ; Li et al. ; Piva et al. ; Roig‐Casasús et al. ; Torpil and Kaya ), inpatient (An, Son, and Lee ; Christensen et al. ; Herbold et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ), home‐based (Chang et al. ; Gür and Başar ; Lenssen et al. ; Papotto and Mills ), community (50), or a combination of inpatient/outpatient (Bhatia, Karvannan, and Prem ; Cai et al. ; Moukarzel et al. ; Park, Kim, and Lee ), outpatient/home‐based (Frost, Lamb, and Robertson ) or inpatient/home‐based (Frost, Lamb, and Robertson ; Thonga et al. ). Details of interventions, control groups, timeframes, and assessments are in Table , Supporting Information : Appendix D, and Figures and . 3.5 Risk of Bias Within Studies Individual and overall ROB scores for the included studies are shown in Figures and . Random sequence generation, allocation concealment, and selective reporting were rated as low or unclear risk in all studies, except one with high risk in selective reporting (Gür and Başar ). Blinding of participants and providers was rated high risk in 13 (Barker et al. ; Cai et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Piva et al. ; Thonga et al. ; Tornatore et al. ) and nine studies (42,43,46–48,52,53,57,60) respectively. Blinding of participants was rated low in only one study (Gür and Başar ). Outcome assessment was not blinded in 13 studies for patient‐reported outcomes (Barker et al. ; Cai et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Piva et al. ; Thonga et al. ; Tornatore et al. ) and in four studies for provider assessments (Christensen et al. ; Gür and Başar ; Hamilton et al. ; Papotto and Mills ; Tornatore et al. ). Selection bias, inter‐rater reliability between outcome assessors, comparability of participant characteristics, and failure to report funding sources were rated high risk in four studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Li et al. ). Incomplete outcome data was rated high risk in three studies (Bhatia, Karvannan, and Prem ; Herbold et al. ; Li et al. ). Detailed information and justifications for ROB judgements are available upon request. 3.6 Efficacy of Rehabilitation Supporting Information : Appendix E summarises the findings of the included studies. Results were narratively synthesised based on intervention type (exercise and non‐exercise) and outcome measures. Only significant results are described, with a p ‐value < 0.05 indicating statistical significance. 3.6.1 Exercise Therapy Following TKA 3.6.1.1 PROMs Seven studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Li et al. ; Papotto and Mills ; Piva et al. ; Thonga et al. ) reported data on disease‐specific PROMs assessed between 2 and 52 weeks after TKA, with six reporting significant differences (An, Son, and Lee ; Do and Yim ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Thonga et al. ) and two reporting no differences (Barker et al. ; Piva et al. ). Patients with functional limitations who received outpatient therapist‐led ROM, strengthening, proprioception and gait exercises showed significant improvement at 14 weeks postoperatively ( p = 0.04), but no difference at 26 and 52 weeks ( p = 0.07) (Hamilton et al. ). Older patients receiving closed kinetic chain exercise ( p < 0.05) (Thonga et al. ), combined closed and open chain exercises ( p < 0.05) (An, Son, and Lee ) and Tai Chi ( p = 0.03) (Li et al. ) significantly improved at follow‐ups ranging from six to 52 weeks postoperatively. Patients with ROM deficits who received high‐intensity stretching exercises showed significantly greater improvement at 13 weeks after arthroplasty ( p = 0.048) (Papotto and Mills ). Patients with high pain who received hip strengthening exercises showed significant improvement at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention, while those receiving quadriceps strengthening exercises improved at 4 weeks post‐intervention (Do and Yim ). 3.6.1.2 PBTs Ten studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ) reported various PBTs at follow‐ups between 3 days and 52 weeks after TKA, with five finding significant differences (An, Son, and Lee ; Do and Yim ; Li et al. ; Park, Kim, and Lee ; Piva et al. ) and five finding no differences (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ; Roig‐Casasús et al. ; Thonga et al. ). Patients with high pain receiving hip or quadriceps strengthening exercises showed improvement at 4, 8, and 12 weeks post‐intervention ( p < 0.05) (Do and Yim ). Older patients receiving quadriceps strengthening with ankle weights (Park, Kim, and Lee ), Tai Chi ( p = 0.01) (Li et al. ), and combined closed and open chain exercises ( p = 0.001) (An, Son, and Lee ) significantly improved at follow‐ups ranging form two to 14 weeks after arthroplasty. Patients with functional limitations randomised to clinic‐based strengthening, cardiorespiratory and functional exercise showed improvement at 12 weeks after TKA (MD = 0.3, 95%CI = 0.3 0.1–0.4), with no difference at 26 weeks. In this study, patients receiving community‐based exercise also reported improvement at 12 weeks after TKA (MD = 0.2, 95%CI = 0.0–0.2), with no difference at 26 weeks (Piva et al. ). 3.6.1.3 HRQoL Four studies (Barker et al. ; Li et al. ; Piva et al. ; Thonga et al. ) reported various HRQoL measures assessed at follow‐up ranging from two to 52 weeks after TKA, with two reporting significant differences (Li et al. ; Piva et al. ) and two reporting no differences (Barker et al. ; Thonga et al. ). Patients with functional limitations randomised to clinic‐based exercises reported significantly better scores at 12 (MD = 1.3, 95%CI = 0.8–1.9) and 26 weeks (MD = 0.7, 95%CI = 0.2–1.3) post‐intervention. In this study, patients randomised to community‐based exercise also showed improvement at 12 and 26 weeks post‐intervention (Piva et al. ). Older patients receiving Tai Chi had significantly better scores than those participating in strengthening and ROM exercises at 14 weeks postoperatively ( p = 0.01) (Li et al. ). 3.6.1.4 Pain Six studies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ) reported pain data assessed between 2 and 52 weeks after TKA. Two studies found a significant difference (An, Son, and Lee ; Do and Yim ), while four found no differences (Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ). Patients with high pain performing hip strengthening exercises significantly improved at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention. In this study, patients undergoing quadriceps strengthening exercises also showed improvement at 8 weeks post‐intervention (Do and Yim ). Older patients receiving combined closed and open kinetic chain exercises significantly improved at 6 weeks after arthroplasty ( p < 0.05) (An, Son, and Lee ). 3.6.2 Non‐Exercise Therapy Following TKA 3.6.2.1 PROM Four studies (Chang et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ) reported data on disease‐specific PROMs, with one reporting a significant difference and three reporting no difference following arthroplasty. Older patients receiving an educational programme showed significant improvement at 12 and 16 weeks after arthroplasty ( p < 0.001) (Chang et al. ). 3.6.2.2 PBTs Five studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Moukarzel et al. ; Tanaka et al. ) reported data on PBTs, with two reporting a significant difference (Gür and Başar ; Tanaka et al. ) and three reporting no differences (Bhatia, Karvannan, and Prem ; Herbold et al. ; Moukarzel et al. ). Older patients using a limb assistive device with strengthening exercises had significantly better scores at 1 and 2 weeks after TKA ( p = 0.045), with no difference at 3 weeks ( p = 0.66) after arthroplasty (Tanaka et al. ). Patients with kinesiophobia and pain catastrophizing who received virtual reality (imagining walking while watching a video) significantly improved at 4 weeks postoperatively ( p = 0.01) (Gür and Başar ). 3.6.2.3 HRQoL Three studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Torpil and Kaya ) reported data on HRQoL, with one reporting a significant difference (Bhatia, Karvannan, and Prem ) and two reporting no differences (Gür and Başar ; Torpil and Kaya ). Patients with pain catastrophizing who received biopsychosocial rehabilitation had significantly improved scores 4 weeks after TKA ( p = 0.0001) (Bhatia, Karvannan, and Prem ). 3.6.2.4 Pain Eight studies (Cai et al. ; Christensen et al. ; Gür and Başar ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ) reported data on pain between one day and 12 weeks after TKA, with five reporting significant differences (Cai et al. ; Gür and Başar ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ) and three reporting no differences (Christensen et al. ; Lenssen et al. ; Zhong et al. ). Older patients receiving a combination of lymphatic drainage and kinesiotaping ( p = 0.005) (Tornatore et al. ), a limb assistive device with strengthening exercise ( p = 0.03) (Tanaka et al. ) and motor imagery training ( p < 0.001) (Moukarzel et al. ) reported reduced pain during the follow‐up between 4 days and 4 weeks postoperatively. Patients with kinesiophobia and pain catastrophizing who received virtual reality showed significant improvement at 4 weeks postoperatively ( p < 0.05) (Gür and Başar ). Patients with kinesiophobia receiving cognitive behavioural therapy reported pain improvements at four and 26 weeks after TKA ( p < 0.001) (Cai et al. ). 3.7 Adherence Rate Of the 29 included studies, five (Barker et al. ; Chang et al. ; Christensen et al. ; Hamilton et al. ; Lenssen et al. ) reported adherence rates to rehabilitation interventions after arthroplasty, which ranged from 41.2% to 97% in the experimental group and 95.2% to 100% in the control group (Table ). 

Study Selection Searches of bibliographic databases yielded 25,308 potentially relevant citations. After removing 9619 duplicates, we screened 15,689 titles and abstracts, excluding 14,188 articles. 1165 were obtained for full‐text screening. Twenty‐two trials fulfilled the inclusion criteria. One trial was identified from the reference lists of the included articles. Supporting Information : Appendix B shows the screening process. 

Study Characteristics Supporting Information : Appendix C provides an overview of the 23 included RCTs published between 2002 and 2022. The trials were conducted in China ( n = 3) (Cai et al. ; Li et al. ; Zhong et al. ), South Korea ( n = 3) (An, Son, and Lee ; Do and Yim ; Park, Kim, and Lee ), United Kingdom ( n = 3) (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ), United States ( n = 3) (Herbold et al. ; Papotto and Mills ; Piva et al. ), Turkey ( n = 2) (Gür and Başar ; Torpil and Kaya ), Denmark ( n = 1) (Christensen et al. ), France ( n = 1) (Moukarzel et al. ), Greece ( n = 1) (Thonga et al. ), India ( n = 1) (Bhatia, Karvannan, and Prem ), Italy ( n = 1) (Tornatore et al. ), Japan ( n = 1) (Tanaka et al. ), Netherland ( n = 1) (Lenssen et al. ), Spain ( n = 1) (Roig‐Casasús et al. ), and Taiwan ( n = 1) (Chang et al. ). All papers were published in English. 

Study Population Across the 23 trials, 2282 patients underwent TKA (An, Son, and Lee ; Barker et al. ; Bhatia, Karvannan, and Prem ; Cai et al. ; Chang et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Li et al. ; Moukarzel et al. ; Papotto and Mills ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ; Tanaka et al. ; Thonga et al. ; Tornatore et al. ; Torpil and Kaya ; Zhong et al. ), with 72.2% being women. The participants' mean age ranged from 61 to 76 years, and their mean body mass index (BMI) was between 23.5 and 37.6 kg/m 2 . Ethnicity and socioeconomic characteristics were reported in two studies (Herbold et al. ; Piva et al. ) and two other studies (Cai et al. ; Thonga et al. ) respectively. Risk factors for poorer outcomes are described in Table . Fifteen studies used preoperative factors, while eight used postoperative factors to identify patients with poorer outcomes. 

Description of Interventions Ten interventions were exercise therapies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ; Thonga et al. ), and 12 were non‐exercise therapies (Bhatia, Karvannan, and Prem ; Cai et al. ; Chang et al. ; Christensen et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Torpil and Kaya ; Zhong et al. ). All interventions began within 2 weeks after arthroplasty, except for four studies, which started at 6 (Papotto and Mills ), 8 (Hamilton et al. ), 12 (Frost, Lamb, and Robertson ) and 17 weeks (Piva et al. ) post‐surgery. The intervention duration ranged from 3 days to 12 weeks. Settings included outpatient (Hamilton et al. ; Li et al. ; Piva et al. ; Roig‐Casasús et al. ; Torpil and Kaya ), inpatient (An, Son, and Lee ; Christensen et al. ; Herbold et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ), home‐based (Chang et al. ; Gür and Başar ; Lenssen et al. ; Papotto and Mills ), community (50), or a combination of inpatient/outpatient (Bhatia, Karvannan, and Prem ; Cai et al. ; Moukarzel et al. ; Park, Kim, and Lee ), outpatient/home‐based (Frost, Lamb, and Robertson ) or inpatient/home‐based (Frost, Lamb, and Robertson ; Thonga et al. ). Details of interventions, control groups, timeframes, and assessments are in Table , Supporting Information : Appendix D, and Figures and . 

Risk of Bias Within Studies Individual and overall ROB scores for the included studies are shown in Figures and . Random sequence generation, allocation concealment, and selective reporting were rated as low or unclear risk in all studies, except one with high risk in selective reporting (Gür and Başar ). Blinding of participants and providers was rated high risk in 13 (Barker et al. ; Cai et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Piva et al. ; Thonga et al. ; Tornatore et al. ) and nine studies (42,43,46–48,52,53,57,60) respectively. Blinding of participants was rated low in only one study (Gür and Başar ). Outcome assessment was not blinded in 13 studies for patient‐reported outcomes (Barker et al. ; Cai et al. ; Christensen et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Hamilton et al. ; Herbold et al. ; Lenssen et al. ; Moukarzel et al. ; Piva et al. ; Thonga et al. ; Tornatore et al. ) and in four studies for provider assessments (Christensen et al. ; Gür and Başar ; Hamilton et al. ; Papotto and Mills ; Tornatore et al. ). Selection bias, inter‐rater reliability between outcome assessors, comparability of participant characteristics, and failure to report funding sources were rated high risk in four studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Li et al. ). Incomplete outcome data was rated high risk in three studies (Bhatia, Karvannan, and Prem ; Herbold et al. ; Li et al. ). Detailed information and justifications for ROB judgements are available upon request. 

Efficacy of Rehabilitation Supporting Information : Appendix E summarises the findings of the included studies. Results were narratively synthesised based on intervention type (exercise and non‐exercise) and outcome measures. Only significant results are described, with a p ‐value < 0.05 indicating statistical significance. 3.6.1 Exercise Therapy Following TKA 3.6.1.1 PROMs Seven studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Li et al. ; Papotto and Mills ; Piva et al. ; Thonga et al. ) reported data on disease‐specific PROMs assessed between 2 and 52 weeks after TKA, with six reporting significant differences (An, Son, and Lee ; Do and Yim ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Thonga et al. ) and two reporting no differences (Barker et al. ; Piva et al. ). Patients with functional limitations who received outpatient therapist‐led ROM, strengthening, proprioception and gait exercises showed significant improvement at 14 weeks postoperatively ( p = 0.04), but no difference at 26 and 52 weeks ( p = 0.07) (Hamilton et al. ). Older patients receiving closed kinetic chain exercise ( p < 0.05) (Thonga et al. ), combined closed and open chain exercises ( p < 0.05) (An, Son, and Lee ) and Tai Chi ( p = 0.03) (Li et al. ) significantly improved at follow‐ups ranging from six to 52 weeks postoperatively. Patients with ROM deficits who received high‐intensity stretching exercises showed significantly greater improvement at 13 weeks after arthroplasty ( p = 0.048) (Papotto and Mills ). Patients with high pain who received hip strengthening exercises showed significant improvement at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention, while those receiving quadriceps strengthening exercises improved at 4 weeks post‐intervention (Do and Yim ). 3.6.1.2 PBTs Ten studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ) reported various PBTs at follow‐ups between 3 days and 52 weeks after TKA, with five finding significant differences (An, Son, and Lee ; Do and Yim ; Li et al. ; Park, Kim, and Lee ; Piva et al. ) and five finding no differences (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ; Roig‐Casasús et al. ; Thonga et al. ). Patients with high pain receiving hip or quadriceps strengthening exercises showed improvement at 4, 8, and 12 weeks post‐intervention ( p < 0.05) (Do and Yim ). Older patients receiving quadriceps strengthening with ankle weights (Park, Kim, and Lee ), Tai Chi ( p = 0.01) (Li et al. ), and combined closed and open chain exercises ( p = 0.001) (An, Son, and Lee ) significantly improved at follow‐ups ranging form two to 14 weeks after arthroplasty. Patients with functional limitations randomised to clinic‐based strengthening, cardiorespiratory and functional exercise showed improvement at 12 weeks after TKA (MD = 0.3, 95%CI = 0.3 0.1–0.4), with no difference at 26 weeks. In this study, patients receiving community‐based exercise also reported improvement at 12 weeks after TKA (MD = 0.2, 95%CI = 0.0–0.2), with no difference at 26 weeks (Piva et al. ). 3.6.1.3 HRQoL Four studies (Barker et al. ; Li et al. ; Piva et al. ; Thonga et al. ) reported various HRQoL measures assessed at follow‐up ranging from two to 52 weeks after TKA, with two reporting significant differences (Li et al. ; Piva et al. ) and two reporting no differences (Barker et al. ; Thonga et al. ). Patients with functional limitations randomised to clinic‐based exercises reported significantly better scores at 12 (MD = 1.3, 95%CI = 0.8–1.9) and 26 weeks (MD = 0.7, 95%CI = 0.2–1.3) post‐intervention. In this study, patients randomised to community‐based exercise also showed improvement at 12 and 26 weeks post‐intervention (Piva et al. ). Older patients receiving Tai Chi had significantly better scores than those participating in strengthening and ROM exercises at 14 weeks postoperatively ( p = 0.01) (Li et al. ). 3.6.1.4 Pain Six studies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ) reported pain data assessed between 2 and 52 weeks after TKA. Two studies found a significant difference (An, Son, and Lee ; Do and Yim ), while four found no differences (Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ). Patients with high pain performing hip strengthening exercises significantly improved at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention. In this study, patients undergoing quadriceps strengthening exercises also showed improvement at 8 weeks post‐intervention (Do and Yim ). Older patients receiving combined closed and open kinetic chain exercises significantly improved at 6 weeks after arthroplasty ( p < 0.05) (An, Son, and Lee ). 3.6.2 Non‐Exercise Therapy Following TKA 3.6.2.1 PROM Four studies (Chang et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ) reported data on disease‐specific PROMs, with one reporting a significant difference and three reporting no difference following arthroplasty. Older patients receiving an educational programme showed significant improvement at 12 and 16 weeks after arthroplasty ( p < 0.001) (Chang et al. ). 3.6.2.2 PBTs Five studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Moukarzel et al. ; Tanaka et al. ) reported data on PBTs, with two reporting a significant difference (Gür and Başar ; Tanaka et al. ) and three reporting no differences (Bhatia, Karvannan, and Prem ; Herbold et al. ; Moukarzel et al. ). Older patients using a limb assistive device with strengthening exercises had significantly better scores at 1 and 2 weeks after TKA ( p = 0.045), with no difference at 3 weeks ( p = 0.66) after arthroplasty (Tanaka et al. ). Patients with kinesiophobia and pain catastrophizing who received virtual reality (imagining walking while watching a video) significantly improved at 4 weeks postoperatively ( p = 0.01) (Gür and Başar ). 3.6.2.3 HRQoL Three studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Torpil and Kaya ) reported data on HRQoL, with one reporting a significant difference (Bhatia, Karvannan, and Prem ) and two reporting no differences (Gür and Başar ; Torpil and Kaya ). Patients with pain catastrophizing who received biopsychosocial rehabilitation had significantly improved scores 4 weeks after TKA ( p = 0.0001) (Bhatia, Karvannan, and Prem ). 3.6.2.4 Pain Eight studies (Cai et al. ; Christensen et al. ; Gür and Başar ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ) reported data on pain between one day and 12 weeks after TKA, with five reporting significant differences (Cai et al. ; Gür and Başar ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ) and three reporting no differences (Christensen et al. ; Lenssen et al. ; Zhong et al. ). Older patients receiving a combination of lymphatic drainage and kinesiotaping ( p = 0.005) (Tornatore et al. ), a limb assistive device with strengthening exercise ( p = 0.03) (Tanaka et al. ) and motor imagery training ( p < 0.001) (Moukarzel et al. ) reported reduced pain during the follow‐up between 4 days and 4 weeks postoperatively. Patients with kinesiophobia and pain catastrophizing who received virtual reality showed significant improvement at 4 weeks postoperatively ( p < 0.05) (Gür and Başar ). Patients with kinesiophobia receiving cognitive behavioural therapy reported pain improvements at four and 26 weeks after TKA ( p < 0.001) (Cai et al. ). 

Exercise Therapy Following TKA 3.6.1.1 PROMs Seven studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Li et al. ; Papotto and Mills ; Piva et al. ; Thonga et al. ) reported data on disease‐specific PROMs assessed between 2 and 52 weeks after TKA, with six reporting significant differences (An, Son, and Lee ; Do and Yim ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Thonga et al. ) and two reporting no differences (Barker et al. ; Piva et al. ). Patients with functional limitations who received outpatient therapist‐led ROM, strengthening, proprioception and gait exercises showed significant improvement at 14 weeks postoperatively ( p = 0.04), but no difference at 26 and 52 weeks ( p = 0.07) (Hamilton et al. ). Older patients receiving closed kinetic chain exercise ( p < 0.05) (Thonga et al. ), combined closed and open chain exercises ( p < 0.05) (An, Son, and Lee ) and Tai Chi ( p = 0.03) (Li et al. ) significantly improved at follow‐ups ranging from six to 52 weeks postoperatively. Patients with ROM deficits who received high‐intensity stretching exercises showed significantly greater improvement at 13 weeks after arthroplasty ( p = 0.048) (Papotto and Mills ). Patients with high pain who received hip strengthening exercises showed significant improvement at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention, while those receiving quadriceps strengthening exercises improved at 4 weeks post‐intervention (Do and Yim ). 3.6.1.2 PBTs Ten studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ) reported various PBTs at follow‐ups between 3 days and 52 weeks after TKA, with five finding significant differences (An, Son, and Lee ; Do and Yim ; Li et al. ; Park, Kim, and Lee ; Piva et al. ) and five finding no differences (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ; Roig‐Casasús et al. ; Thonga et al. ). Patients with high pain receiving hip or quadriceps strengthening exercises showed improvement at 4, 8, and 12 weeks post‐intervention ( p < 0.05) (Do and Yim ). Older patients receiving quadriceps strengthening with ankle weights (Park, Kim, and Lee ), Tai Chi ( p = 0.01) (Li et al. ), and combined closed and open chain exercises ( p = 0.001) (An, Son, and Lee ) significantly improved at follow‐ups ranging form two to 14 weeks after arthroplasty. Patients with functional limitations randomised to clinic‐based strengthening, cardiorespiratory and functional exercise showed improvement at 12 weeks after TKA (MD = 0.3, 95%CI = 0.3 0.1–0.4), with no difference at 26 weeks. In this study, patients receiving community‐based exercise also reported improvement at 12 weeks after TKA (MD = 0.2, 95%CI = 0.0–0.2), with no difference at 26 weeks (Piva et al. ). 3.6.1.3 HRQoL Four studies (Barker et al. ; Li et al. ; Piva et al. ; Thonga et al. ) reported various HRQoL measures assessed at follow‐up ranging from two to 52 weeks after TKA, with two reporting significant differences (Li et al. ; Piva et al. ) and two reporting no differences (Barker et al. ; Thonga et al. ). Patients with functional limitations randomised to clinic‐based exercises reported significantly better scores at 12 (MD = 1.3, 95%CI = 0.8–1.9) and 26 weeks (MD = 0.7, 95%CI = 0.2–1.3) post‐intervention. In this study, patients randomised to community‐based exercise also showed improvement at 12 and 26 weeks post‐intervention (Piva et al. ). Older patients receiving Tai Chi had significantly better scores than those participating in strengthening and ROM exercises at 14 weeks postoperatively ( p = 0.01) (Li et al. ). 3.6.1.4 Pain Six studies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ) reported pain data assessed between 2 and 52 weeks after TKA. Two studies found a significant difference (An, Son, and Lee ; Do and Yim ), while four found no differences (Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ). Patients with high pain performing hip strengthening exercises significantly improved at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention. In this study, patients undergoing quadriceps strengthening exercises also showed improvement at 8 weeks post‐intervention (Do and Yim ). Older patients receiving combined closed and open kinetic chain exercises significantly improved at 6 weeks after arthroplasty ( p < 0.05) (An, Son, and Lee ). 

PROMs Seven studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Li et al. ; Papotto and Mills ; Piva et al. ; Thonga et al. ) reported data on disease‐specific PROMs assessed between 2 and 52 weeks after TKA, with six reporting significant differences (An, Son, and Lee ; Do and Yim ; Hamilton et al. ; Li et al. ; Papotto and Mills ; Thonga et al. ) and two reporting no differences (Barker et al. ; Piva et al. ). Patients with functional limitations who received outpatient therapist‐led ROM, strengthening, proprioception and gait exercises showed significant improvement at 14 weeks postoperatively ( p = 0.04), but no difference at 26 and 52 weeks ( p = 0.07) (Hamilton et al. ). Older patients receiving closed kinetic chain exercise ( p < 0.05) (Thonga et al. ), combined closed and open chain exercises ( p < 0.05) (An, Son, and Lee ) and Tai Chi ( p = 0.03) (Li et al. ) significantly improved at follow‐ups ranging from six to 52 weeks postoperatively. Patients with ROM deficits who received high‐intensity stretching exercises showed significantly greater improvement at 13 weeks after arthroplasty ( p = 0.048) (Papotto and Mills ). Patients with high pain who received hip strengthening exercises showed significant improvement at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention, while those receiving quadriceps strengthening exercises improved at 4 weeks post‐intervention (Do and Yim ). 

PBTs Ten studies (An, Son, and Lee ; Barker et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Park, Kim, and Lee ; Piva et al. ; Roig‐Casasús et al. ) reported various PBTs at follow‐ups between 3 days and 52 weeks after TKA, with five finding significant differences (An, Son, and Lee ; Do and Yim ; Li et al. ; Park, Kim, and Lee ; Piva et al. ) and five finding no differences (Barker et al. ; Frost, Lamb, and Robertson ; Hamilton et al. ; Roig‐Casasús et al. ; Thonga et al. ). Patients with high pain receiving hip or quadriceps strengthening exercises showed improvement at 4, 8, and 12 weeks post‐intervention ( p < 0.05) (Do and Yim ). Older patients receiving quadriceps strengthening with ankle weights (Park, Kim, and Lee ), Tai Chi ( p = 0.01) (Li et al. ), and combined closed and open chain exercises ( p = 0.001) (An, Son, and Lee ) significantly improved at follow‐ups ranging form two to 14 weeks after arthroplasty. Patients with functional limitations randomised to clinic‐based strengthening, cardiorespiratory and functional exercise showed improvement at 12 weeks after TKA (MD = 0.3, 95%CI = 0.3 0.1–0.4), with no difference at 26 weeks. In this study, patients receiving community‐based exercise also reported improvement at 12 weeks after TKA (MD = 0.2, 95%CI = 0.0–0.2), with no difference at 26 weeks (Piva et al. ). 

HRQoL Four studies (Barker et al. ; Li et al. ; Piva et al. ; Thonga et al. ) reported various HRQoL measures assessed at follow‐up ranging from two to 52 weeks after TKA, with two reporting significant differences (Li et al. ; Piva et al. ) and two reporting no differences (Barker et al. ; Thonga et al. ). Patients with functional limitations randomised to clinic‐based exercises reported significantly better scores at 12 (MD = 1.3, 95%CI = 0.8–1.9) and 26 weeks (MD = 0.7, 95%CI = 0.2–1.3) post‐intervention. In this study, patients randomised to community‐based exercise also showed improvement at 12 and 26 weeks post‐intervention (Piva et al. ). Older patients receiving Tai Chi had significantly better scores than those participating in strengthening and ROM exercises at 14 weeks postoperatively ( p = 0.01) (Li et al. ). 

Pain Six studies (An, Son, and Lee ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ) reported pain data assessed between 2 and 52 weeks after TKA. Two studies found a significant difference (An, Son, and Lee ; Do and Yim ), while four found no differences (Frost, Lamb, and Robertson ; Hamilton et al. ; Li et al. ; Thonga et al. ). Patients with high pain performing hip strengthening exercises significantly improved at 4 ( p = 0.003), 8 ( p = 0.001), and 12 weeks ( p = 0.001) post‐intervention. In this study, patients undergoing quadriceps strengthening exercises also showed improvement at 8 weeks post‐intervention (Do and Yim ). Older patients receiving combined closed and open kinetic chain exercises significantly improved at 6 weeks after arthroplasty ( p < 0.05) (An, Son, and Lee ). 

Non‐Exercise Therapy Following TKA 3.6.2.1 PROM Four studies (Chang et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ) reported data on disease‐specific PROMs, with one reporting a significant difference and three reporting no difference following arthroplasty. Older patients receiving an educational programme showed significant improvement at 12 and 16 weeks after arthroplasty ( p < 0.001) (Chang et al. ). 3.6.2.2 PBTs Five studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Moukarzel et al. ; Tanaka et al. ) reported data on PBTs, with two reporting a significant difference (Gür and Başar ; Tanaka et al. ) and three reporting no differences (Bhatia, Karvannan, and Prem ; Herbold et al. ; Moukarzel et al. ). Older patients using a limb assistive device with strengthening exercises had significantly better scores at 1 and 2 weeks after TKA ( p = 0.045), with no difference at 3 weeks ( p = 0.66) after arthroplasty (Tanaka et al. ). Patients with kinesiophobia and pain catastrophizing who received virtual reality (imagining walking while watching a video) significantly improved at 4 weeks postoperatively ( p = 0.01) (Gür and Başar ). 3.6.2.3 HRQoL Three studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Torpil and Kaya ) reported data on HRQoL, with one reporting a significant difference (Bhatia, Karvannan, and Prem ) and two reporting no differences (Gür and Başar ; Torpil and Kaya ). Patients with pain catastrophizing who received biopsychosocial rehabilitation had significantly improved scores 4 weeks after TKA ( p = 0.0001) (Bhatia, Karvannan, and Prem ). 3.6.2.4 Pain Eight studies (Cai et al. ; Christensen et al. ; Gür and Başar ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ) reported data on pain between one day and 12 weeks after TKA, with five reporting significant differences (Cai et al. ; Gür and Başar ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ) and three reporting no differences (Christensen et al. ; Lenssen et al. ; Zhong et al. ). Older patients receiving a combination of lymphatic drainage and kinesiotaping ( p = 0.005) (Tornatore et al. ), a limb assistive device with strengthening exercise ( p = 0.03) (Tanaka et al. ) and motor imagery training ( p < 0.001) (Moukarzel et al. ) reported reduced pain during the follow‐up between 4 days and 4 weeks postoperatively. Patients with kinesiophobia and pain catastrophizing who received virtual reality showed significant improvement at 4 weeks postoperatively ( p < 0.05) (Gür and Başar ). Patients with kinesiophobia receiving cognitive behavioural therapy reported pain improvements at four and 26 weeks after TKA ( p < 0.001) (Cai et al. ). 

PROM Four studies (Chang et al. ; Gür and Başar ; Herbold et al. ; Lenssen et al. ) reported data on disease‐specific PROMs, with one reporting a significant difference and three reporting no difference following arthroplasty. Older patients receiving an educational programme showed significant improvement at 12 and 16 weeks after arthroplasty ( p < 0.001) (Chang et al. ). 

PBTs Five studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Herbold et al. ; Moukarzel et al. ; Tanaka et al. ) reported data on PBTs, with two reporting a significant difference (Gür and Başar ; Tanaka et al. ) and three reporting no differences (Bhatia, Karvannan, and Prem ; Herbold et al. ; Moukarzel et al. ). Older patients using a limb assistive device with strengthening exercises had significantly better scores at 1 and 2 weeks after TKA ( p = 0.045), with no difference at 3 weeks ( p = 0.66) after arthroplasty (Tanaka et al. ). Patients with kinesiophobia and pain catastrophizing who received virtual reality (imagining walking while watching a video) significantly improved at 4 weeks postoperatively ( p = 0.01) (Gür and Başar ). 

HRQoL Three studies (Bhatia, Karvannan, and Prem ; Gür and Başar ; Torpil and Kaya ) reported data on HRQoL, with one reporting a significant difference (Bhatia, Karvannan, and Prem ) and two reporting no differences (Gür and Başar ; Torpil and Kaya ). Patients with pain catastrophizing who received biopsychosocial rehabilitation had significantly improved scores 4 weeks after TKA ( p = 0.0001) (Bhatia, Karvannan, and Prem ). 

Pain Eight studies (Cai et al. ; Christensen et al. ; Gür and Başar ; Lenssen et al. ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ; Zhong et al. ) reported data on pain between one day and 12 weeks after TKA, with five reporting significant differences (Cai et al. ; Gür and Başar ; Moukarzel et al. ; Tanaka et al. ; Tornatore et al. ) and three reporting no differences (Christensen et al. ; Lenssen et al. ; Zhong et al. ). Older patients receiving a combination of lymphatic drainage and kinesiotaping ( p = 0.005) (Tornatore et al. ), a limb assistive device with strengthening exercise ( p = 0.03) (Tanaka et al. ) and motor imagery training ( p < 0.001) (Moukarzel et al. ) reported reduced pain during the follow‐up between 4 days and 4 weeks postoperatively. Patients with kinesiophobia and pain catastrophizing who received virtual reality showed significant improvement at 4 weeks postoperatively ( p < 0.05) (Gür and Başar ). Patients with kinesiophobia receiving cognitive behavioural therapy reported pain improvements at four and 26 weeks after TKA ( p < 0.001) (Cai et al. ). 

Adherence Rate Of the 29 included studies, five (Barker et al. ; Chang et al. ; Christensen et al. ; Hamilton et al. ; Lenssen et al. ) reported adherence rates to rehabilitation interventions after arthroplasty, which ranged from 41.2% to 97% in the experimental group and 95.2% to 100% in the control group (Table ). 

Discussion This review systematically examined the literature on the efficacy of rehabilitation interventions for PBTs, disease‐specific PROMs, pain, and HRQoL to improve outcomes for patients at risk of or experiencing poorer recovery following TKA. Insufficient evidence supports cognitive behavioural therapy for reducing pain in patients with kinesiophobia. Some evidence shows that continuous passive motion may not benefit patients with ROM deficits. The impact of exercise therapy on PROMs and PBTs is conflicting; however, evidence suggests that longer durations of exercise therapy tend to be more effective than shorter ones for older patients and those with functional limitations. In addition, insufficient evidence indicates that exercise may not be beneficial for reducing pain after TKA. In terms of HRQoL, outpatient exercise therapy seems more effective than home‐based programs for older patients and those with functional limitations. The efficacy of other rehabilitation interventions remains inconclusive. The included studies examined various risk factors predictive of or associated with poorer outcomes after arthroplasty to identify patients with poorer outcomes. In addition, most studies focused on preoperative factors, while few studies assessed postoperative factors. However, it has been suggested that pre‐ and postoperative factors have greater predictive power for identifying patients at risk of poorer outcomes (Hartling et al. ) and that postoperative factors might better inform postoperative rehabilitation needs (Wylde et al. ). This highlights the need for future research to synthesise evidence on risk factors, particularly postoperative ones associated with suboptimal outcomes to enable more accurately targeted interventions (22). Furthermore, 14 studies (An, Son, and Lee ; Chang et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Gür and Başar ; Li et al. ; Moukarzel et al. ; Park, Kim, and Lee ; Piva et al. ; Tanaka et al. ; Thonga et al. ; Tornatore et al. ; Roig‐Casasús et al. ; Zhong et al. ) did not tailor rehabilitation interventions to the risk factors of interest. Although these studies focused on patients with poorer outcomes, they employed interventions that were not specifically designed for this group. Therefore, establishing strong connections between poorer outcome factors and interventions is essential for developing effective targeted rehabilitation strategies. Recent research indicates that interventions targeting specific problematic functional tasks may be more effective than traditional approaches (Trudelle‐Jackson ; Trudelle‐Jackson and Smith ). Future research assessing interventions focusing on managing risk factors to optimise postoperative outcomes is warranted. 4.1 Limitations Our review was not without limitations. We could not draw conclusions about the efficacy of some rehabilitation interventions due to heterogeneity in intervention type, timing, intensity, duration, and outcome measures, which limits the clear estimation of efficacy. Also, some studies did not report key details about interventions, such as the number, and duration of sessions and frequency of interventions in each session, limiting replicability or application in clinical practice. In addition, rationale for selecting intervention timing, intensity and duration was not provided in a majority of studies. Most studies began interventions within the first 2 weeks after surgery, and the duration of most of the interventions was less than 6 weeks. Because function can change for 6 months after arthroplasty (Wieczorek et al. ), many patients may complete rehabilitation before stabilisation, potentially resulting in lasting deficits. However, one of the studies showed a benefit of late‐stage rehabilitation on PBTs but not on PROMs (Piva et al. ). Since most functional recovery typically occurs within 6 months after surgery (Wieczorek et al. ), follow‐up assessments should continue for this duration to evaluate the patient's progress comprehensively. Only 8 of 23 included studies assessed outcomes 6 months or more after surgery (Barker et al. ; Cai et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Piva et al. ; Thonga et al. ). In two of these studies, positive short‐term results were not maintained later (Hamilton et al. ; Piva et al. ). As evidence on optimal rehabilitation delivery patterns is scarce, future research should focus on the timing and duration of interventions. Furthermore, many studies had small sample sizes that might have been underpowered to detect meaningful differences. Also, most lacked an appropriate control group, making it difficult to draw conclusions as the efficacy reported may not reflect the actual value in clinical practice (Levack et al. ). Finally, high or unclear risk of bias was prevalent, particularly regarding blinding of participants and personnel, which is inherently difficult in rehabilitation trials (Foley et al. ; Hartling et al. ). Researchers should find optimal ways to eliminate performance and detection biases, as the estimation of treatment efficacy may be impacted by biases resulting from a lack of blinding (Armijo‐Olivo et al. ) Moreover, although we conducted a comprehensive search to identify eligible studies, we limited our search to peer reviewed journals, so our findings may be subject to potential publication bias. 

Limitations Our review was not without limitations. We could not draw conclusions about the efficacy of some rehabilitation interventions due to heterogeneity in intervention type, timing, intensity, duration, and outcome measures, which limits the clear estimation of efficacy. Also, some studies did not report key details about interventions, such as the number, and duration of sessions and frequency of interventions in each session, limiting replicability or application in clinical practice. In addition, rationale for selecting intervention timing, intensity and duration was not provided in a majority of studies. Most studies began interventions within the first 2 weeks after surgery, and the duration of most of the interventions was less than 6 weeks. Because function can change for 6 months after arthroplasty (Wieczorek et al. ), many patients may complete rehabilitation before stabilisation, potentially resulting in lasting deficits. However, one of the studies showed a benefit of late‐stage rehabilitation on PBTs but not on PROMs (Piva et al. ). Since most functional recovery typically occurs within 6 months after surgery (Wieczorek et al. ), follow‐up assessments should continue for this duration to evaluate the patient's progress comprehensively. Only 8 of 23 included studies assessed outcomes 6 months or more after surgery (Barker et al. ; Cai et al. ; Do and Yim ; Frost, Lamb, and Robertson ; Hamilton et al. ; Piva et al. ; Thonga et al. ). In two of these studies, positive short‐term results were not maintained later (Hamilton et al. ; Piva et al. ). As evidence on optimal rehabilitation delivery patterns is scarce, future research should focus on the timing and duration of interventions. Furthermore, many studies had small sample sizes that might have been underpowered to detect meaningful differences. Also, most lacked an appropriate control group, making it difficult to draw conclusions as the efficacy reported may not reflect the actual value in clinical practice (Levack et al. ). Finally, high or unclear risk of bias was prevalent, particularly regarding blinding of participants and personnel, which is inherently difficult in rehabilitation trials (Foley et al. ; Hartling et al. ). Researchers should find optimal ways to eliminate performance and detection biases, as the estimation of treatment efficacy may be impacted by biases resulting from a lack of blinding (Armijo‐Olivo et al. ) Moreover, although we conducted a comprehensive search to identify eligible studies, we limited our search to peer reviewed journals, so our findings may be subject to potential publication bias. 

Conclusion Although some rehabilitation interventions have limited evidence supporting their efficacy, data is currently insufficient to assess the impact of most interventions on postoperative recovery for patients at risk of poorer outcomes following TKA. Robust evidence is necessary to inform future clinical practice and research on tailored interventions targeting poorer outcome factors and standardising outcome measures. 

Differences Between the Protocol and Review Our protocol includes inclusion criteria for the population with a cut‐off of 85% undergoing primary elective TKA due to OA. However, based on the results, we decided to include the article by Barker et al., which involves a population with 75% TKA, as it is the most relevant study for this review. 

M.K., S.Y., K.B., T.R. and S.P. contributed to conceptualisation. M.K., S.Y., K.B., H.L.‐D. and A.D. participated in data curation. M.K., T.R. and S.P. contributed to data analysis. M.K. drafted the manuscript. All authors reviewed and approved the final version of the manuscript. 

The authors have nothing to report. 

The authors declare no conflicts of interest. 

Supporting Information S1 

