Bed exercises following total hip replacement: a randomised controlled trial

Transcription

1 Physiotherapy 94 (2008) Bed exercises following total hip replacement: a randomised controlled trial Toby O. Smith a,, Charles J.V. Mann b, Allan Clark c, Simon T. Donell d a Orthopaedic Physiotherapy Research Unit, Physiotherapy Department, Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, UK b Department of Trauma and Orthopaedics, Norfolk and Norwich University Hospital, Norwich, UK c School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, UK d Faculty of Health, University of East Anglia, Norwich, UK Abstract Objectives To determine whether the addition of bed exercises after primary total hip replacement (THR) improves functional outcomes and quality of life, in adult patients, during the first six postoperative weeks. Design Single-blind randomised controlled trial. Setting Inpatient and outpatient orthopaedic departments at a National Health Service hospital. Participants Sixty primary elective THR patients. Intervention Patients were assigned at random to receive either a standard gait re-education programme and bed exercises, or the standard gait re-education programme without bed exercises after THR. The bed exercises consisted of active ankle dorsiflexion/plantarflexion, active knee flexion, and static quadriceps and gluteal exercises. Main outcome measures Iowa Level of Assistance Scale (ILOA), the Short Form-12 Health Survey (SF-12), duration of hospital admission and postoperative complications were assessed at baseline, and 3 days and 6 weeks postoperatively. Results There was no statistically significant difference in ILOA scores between the two groups on the third postoperative day [gait reeducation and bed exercise group median 40.5, interquartile range (IQR) 17.5 to 44.5; gait re-education alone group median 38, IQR 22.0 to 44.5; P = 0.70]. Although there was a small difference between the median ILOA scores at Week 6 between the two groups (3.5, IQR 0 to 6.4 and 5.0, IQR 3.5 to 12.5; P = 0.05), this difference was not statistically or clinically significant. There was no difference between the groups in duration of hospital admission, SF-12 scores or postoperative complications at Week 6. Conclusion This study suggests that during the first six postoperative weeks, the addition of bed exercises to a standard gait re-education programme following THR does not significantly improve patient function or quality of life Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved. Keywords: Hip; Replacement; Exercise; Clinical Trial; Rehabilitation Introduction Standard postoperative rehabilitation for total hip replacement (THR) patients has traditionally consisted of a gait re-education programme and bed exercises [1]. This combined programme has been shown to improve mobility and function [2]. A review of the literature suggested that little Corresponding author. Tel.: ; fax: address: toby.smith@nnuh.nhs.uk (T.O. Smith). work has been undertaken to evaluate the individual contributions of each regime on outcome. Only one study has evaluated the efficacy of bed exercises after THR [3]. In this randomised controlled trial, the authors concluded that bed exercises did not appear to be of any additional benefit; however, this was only assessed during the first eight postoperative days. Furthermore, no assessment was made of patients quality of life. The aim of this study was to assess the effects of bed exercises on function and quality of life over the first six postoperative weeks /$ see front matter 2008 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved. doi: /j.physio

2 T.O. Smith et al. / Physiotherapy 94 (2008) Patients and methods All subjects were recruited at their pre-operative assessment clinic by the trial physiotherapist, and provided signed informed consent before entering into the trial. The study took place over 6 months between November 2006 and April This study was a single-blind randomised controlled trial, with the follow-up data obtained by a trial physiotherapist masked to treatment. The inclusion criteria were all patients undergoing a unilateral primary THR, aged at least 18 years of either gender, who had an ability to understand written and spoken English. The exclusion criteria were an inability to undertake assessment and treatment procedures, an inability to mobilise independently with or without walking aids, patients required to be non-weight bearing after surgery, complex primary THRs requiring bone grafting and/or acetabulum screw fixation, and an unwillingness to participate. The following baseline data were collected on admission to assess the homogeneity of the two treatment groups: age; gender; duration of hip symptoms; presence of other ipsilateral lower limb joint disability (i.e. knee, ankle or foot disability), contralateral lower limb joint disability (i.e. hip, knee, ankle or foot disability) or multi-joint problems (upper limb or spinal disability); Oxford Hip Score [4,5]; the Iowa Level of Assistance Scale (ILOA) [6]; and the Short Form- 12 Health Survey (SF-12) [7]. The enrolled patients stayed under the clinical care of their admitting consultant team, and underwent their standard operation and treatment. Details of the operative approach and whether or not the hip replacement was cemented were noted. After the patient returned from theatre, the ward physiotherapist reviewed the postoperative notes to ensure that the subjects still fulfilled the selection criteria. Once determined, each subject was allocated at random to one of two groups. The unit of randomisation was the individual patients. The ward physiotherapist randomised patients consecutively using a random number table. Allocation took place on the ward before the initial physiotherapy session on the first postoperative day. The trial physiotherapist, who recruited and assessed all the patients, was blinded to randomisation and subject allocation. Once randomised, all patients remained within the groups to which they were assigned. Patients allocated to Group A followed a standard gait reeducation protocol, involving sitting on the edge of the bed, and attempting to stand and walk using the appropriate walking aid, from the first postoperative day. This was performed at least once daily for the duration of their hospital admission, progressing walking distance and walking aid dependency from one frame, to two elbow crutches to two sticks. Step and stair practice was performed. Progression was determined by the ward physiotherapist, dependent on patient performance. Patients were also encouraged to mobilise throughout the day, either independently or with nursing assistance. Assistance in standing and mobilising was provided by the ward physiotherapist, with assistance from another physiotherapist or physiotherapy assistant, determined by the patient s condition. In addition, Group A patients received a programme of bed exercises. These included active hip flexion, active ankle dorsi- and plantarflexion, static quadriceps and static gluteal exercises performed bilaterally whilst supine. The objectives of these exercises were to increase hip, knee and ankle strength and movement. Patients were advised to perform each exercise 10 times, five times daily. These were taught by the ward physiotherapist and then supervised once daily for the duration of hospital admission. Each patient was advised to continue their exercises for as long as they wished once discharged. Patients were given an exercise sheet with the programme detailed. Patients in Group B received the standard gait re-education protocol, but not the programme of bed exercises. The ward physiotherapists, who were not part of the trial team, were instructed on these two protocols to promote standardisation between subjects. The primary outcome measures chosen were the ILOA and SF-12. The ILOA is a five-item functional outcome measure that assesses patients ability to transfer from supine lying to sitting on the edge of the bed, sitting to standing, walking 4.57 metres, climbing up and down three stairs, and walking speed over 13.4 metres [6]. Each task is scored according to the level of assistance and use of assistive devices, such as a walking frame, required to complete the task. The ILOA scale is scored out of 56, where a higher score represents greater disability. Both the ILOA and SF-12 have been shown to be valid and reliable measures for THR patients [6,8,9]. Secondary outcome measures included determining if patients received postoperative physiotherapy, duration of hospital admission, and whether patients experienced complications such as hip subluxation or dislocation, deep vein thrombosis, wound dehiscence, joint loosening and infection, whilst surgical approach and prosthesis fixation were determined after reviewing the postoperative theatre notes. These were selected as it was thought that they were important complications related to exercise and mobility. Patients were also asked how long they continued their exercise programme following discharge, to evaluate whether this was associated with outcome. ILOA scores were measured pre-operatively, and 3 days and 6 weeks postoperatively, whilst SF-12 results were assessed pre-operatively and 6 weeks postoperatively. Secondary outcomes were recorded 6 weeks postoperatively by reviewing the medical notes and questioning patients. Preoperative and Day 3 assessments were performed on the ward, whilst the assessment at Week 6 was undertaken in the outpatient orthopaedic department at the patient s routine postoperative review. Since the day of discharge varied from 3 to 21 postoperative days, the postoperative assessment was standardised to Day 3 to ensure that all patients would be evaluated before they returned home. A power calculation was performed based on a standard deviation of the ILOA after primary THR of 6.9 [6]. A differ-

3 288 T.O. Smith et al. / Physiotherapy 94 (2008) ence of 7.0 was deemed to be clinically significant [6], and a power of 90% with a 5% level of significance. This indicated a total sample of 44 patients; 22 in each group. Since nonparametric tests were planned, the sample size was adjusted by 20%, making 53 subjects. To compensate for potential patient dropout, 60 patients, 30 in each group, were recruited. The primary analysis was a comparison between the two treatment arms in terms of ILOA and SF-12 scores at Week 6 using a Mann Whitney test. A change from baseline analysis was also undertaken using a Mann Whitney test. ILOA scores at Day 3 and Week 6 were compared using a Mann Whitney test. Fisher s exact test was used to assess for differences between the groups in postoperative complications or the need for follow-up physiotherapy. In Group A, a Spearman s rank correlation coefficient was used to assess whether there was a correlation between ILOA scores or SF-12 scores and the duration for which patients exercised following discharge. Subgroup analyses were also undertaken to test if there was any difference in the effectiveness between cemented and uncemented prostheses, and also between the surgical approaches (anterolateral and posterolateral). The subgroup analysis was undertaken by testing for an interactive effect between treatment arms and subgroup using a non-parametric ranked analysis of covariance. Analyses were performed using Statistical Package for the Social Sciences Version 12.0 (SPSS Inc, Chicago, IL, USA). Results Patient flow is illustrated in Fig. 1. All 60 patients completed the study. Thirty-one subjects declined to participate after being approached and provided with a patient information leaflet. Reasons for not wishing to participate were Fig. 1. Study patient flow.

4 T.O. Smith et al. / Physiotherapy 94 (2008) Table 1 Baseline characteristics Gait re-education and bed exercises (n = 30) Gait re-education alone (n = 30) Gender (female/male) 21/9 19/11 Mean (SD) age (years) 66.2 ± ± 10.5 Mean (SD) symptom duration (months) 34.7 ± ± 22.8 Frequency of other joint disability of operated leg (yes/no) Frequency of joint disability of the non-operated leg (yes/no) Frequency of multi-joint disability (yes/no) Median (IQR) Oxford Hip Score 42.0 (35.3 to 51.0) 41.5 (36.5 to 48.8) Median (IQR) ILOA score 4.0 (2.8 to 7.0) 4.5 (2.8 to 8.3) Median (IQR) SF-12 score 29.5 (28.0 to 31.0) 31.5 (28.8 to 33.0) Surgical approach (posterior/antrolateral) 22/8 24/6 Fixation (cemented/uncemented) 23/7 28/2 SD, standard deviation; IQR, interquartile range; ILOA, Iowa Level of Assistance Scale; SF-12, Short-Form-12 Health Survey. unknown. Once consented, no patients were excluded based on the exclusion criteria. All enrolled subjects remained in their allocated groups throughout this period. There were no substantial differences in pre-operative characteristics at baseline between the groups (Table 1). Fig. 2 shows that ILOA scores varied both during the study period and between the two groups. In addition, using Tables 1 and 2, it appears that ILOA scores increased in both groups on Day 3 compared with the pre-operative figures. Group B had lower ILOA scores than Group A (Group A median 40.5, Group B median 38), but this difference was not statistically significant (P = 0.70). There was no statistically significant difference between the treatment groups in SF-12 scores when assessed at Week 6(P = 0.26). However, Group A had lower ILOA scores at this assessment (median 3.5) than Group B (median 5). Although this was of borderline statistical significance (P = ), it was not clinically significant with a difference of 1.5; a clinically significant difference was determined as 7 out of 56. After adjustment for the baseline ILOA score, the difference was still not statistically significant (P = 0.06 using a rank analysis of covariance). The difference in ILOA scores between Day 3 and Week 6 was smaller in Group B (median 27.5) compared with Group A (median 34), but this difference was not statistically significant (P = 0.14). When Group A was assessed further, there appeared to be no statistically significant correlation between duration of exercise and SF- 12 scores (P = 0.56) or ILOA (P = 0.54) scores at Week 6. There was no difference in the numbers of patients requiring follow-up physiotherapy, or postoperative complications between the groups. In this sample, two subjects reported postoperative complications. One patient in Group A had a deep vein thrombosis, and one patient in Group B dislocated their hip whilst climbing off an exercise bike at home. As Table 2 shows, although the length of hospital admission was longer in Group B (median 6.5) compared with Group A (median 7), this difference was not statistically significant (P = 0.52). There was no evidence of a difference in efficacy between cemented and uncemented prostheses in terms of ILOA Fig. 2. Differences in median Iowa Level of Assistance Scale (ILOA) score and interquartile ranges between the two treatment groups on assessment.

5 290 T.O. Smith et al. / Physiotherapy 94 (2008) Table 2 Post-Treatment results Gait re-education and bed exercises (n = 30) Gait re-education alone (n = 30) P-value ILOA score at Day (17.5 to 44.5) 38.0 (22.0 to 44.5) 0.70 ILOA score at Week (0 to 6.4) 5.0 (3.5 to 12.5) 0.05 Difference between ILOA scores at Day 3 and Week (15.0 to 41.0) 27.5 (11.5 to 36.5) 0.14 SF-12 score at Week (28.0 to 31.5) 31.0 (29.0 to 32.0) 0.26 Duration of hospital admission (days) 7.0 (5.0 to 8.0) 6.5 (5.0 to 9.5) 0.52 Cases of joint loosening (n) a Cases of deep vein thrombosis (n) a Cases of wound dehiscence (n) a Cases of joint infection (n) a Cases of joint dislocation (n) a Cases requiring follow-up physiotherapy (n) a Values are either median (interquartile range) or the number of subjects in the category. ILOA, Iowa Level of Assistance Scale; SF-12, Short-Form-12 Health Survey. a Fisher s exact test, otherwise Mann Whitney test applied. scores at Day 3 (P = 0.20) or Week 6 (P = 0.33), or SF-12 scores (P = 0.90). However, the difference between ILOA scores at Day 3 and Week 6 was significant (P = 0.044). For subgroup analysis of surgical approach, there were no significant differences in ILOA scores at Day 3 (P = 0.89) or Week 6 (P = 0.66). Also, the difference between ILOA scores at Day 3 and Week 6 (P = 0.92), and SF-12 results (P = 0.98) was not significant. Discussion This study shows that there was no apparent benefit in the inclusion of bed exercises in a postoperative rehabilitation programme following THR. This is in agreement with earlier findings by Jesudson and Stiller [3]. However, these authors did not assess outcomes after the eighth postoperative day. When assessed over the longer term, the present findings suggest that there was a small median difference (1.5 points) between the groups. Since a clinically meaningful difference in ILOA score of 7.0 was recommended by Shield et al. [6], this result can be regarded as being below that of clinical importance. Furthermore, the addition of bed exercises did not appear to influence patients perceptions of their quality of life, as assessed using SF-12. Similarly, the addition of bed exercises did not influence complication rates or significantly alter duration of hospital stay in this sample. For subgroup analysis, the findings should be viewed with caution due to the small number of patients with uncemented prostheses. Study bias may have impacted upon these findings. Patients social circumstance may have influenced the results, as patients who live alone may need to be more active than a subject who has support at home. For this reason, Jesudson and Stiller [3] justified why they only assessed outcomes whilst patients remained in hospital. This was not controlled in the present study since the authors wished to be pragmatic and assess longer-term outcomes to enhance the generalisability of findings. Similarly, in a wish to increase generalisability, patients with ipsilateral and/or contralateral disease were included. This may have been viewed as a possible confounding factor, but nonetheless a factor which presents in clinical practice. Besides social circumstances, bias may have occurred with the postoperative physiotherapy regimes as these were under the control of the ward staff and not the triallists, although attempts were made to standardise treatments. Although the ILOA score was a useful tool for assessing mobility and function, as it was possible to make comparisons with Jesudson and Stiller s study [3], its design means that it is unable to evaluate differences in the quality of gait pattern. This was an important factor since, while some patients were able to mobilise with no aids at Week 6, some of these patients still presented with a combination of a positive Trendlenburg test, poor capacity to weight bear and an inability to walk further than 15 metres. Further studies to assess whether there is a difference in quality of walking and differences in gait pattern would be worthwhile. Similarly, a number of patients stated that they felt the exercises actually gave them more empowerment over their condition and recovery. Although it may be suggested that the SF-12 results may have been able to capture this, the findings suggest that this may not have been the case. Both patient function and quality of life may have been influenced by hip strength and range of movement. Likewise, subsections of the ILOA, particularly walking velocity, may be more closely related to a patient s hip strength than their dependency on a walking aid. Since hip strength and range of movement were not assessed, this could not be determined. In accordance, it is recommended that future studies on this topic should incorporate these physiological outcomes to gain a greater appreciation of the subjects physical capabilities. A further limitation of this study was that the randomisation method was not concealed using sealed envelopes, since a random number table was used. Concealed allocation may have reduced the potential for selection bias [10]. However, in an attempt to limit this, subject allocation was performed by the ward physiotherapist, whilst the trial physiotherapist, who recruited and assessed all patients, was independent to subject allocation.

6 T.O. Smith et al. / Physiotherapy 94 (2008) Patients who were non-weight bearing on clinical grounds were excluded from the trial since their ILOA score may have been far higher than a full weight-bearing subject due to greater dependence on walking aids. Whilst they may not have gained the same therapeutic strength or range of movement benefits from a gait re-education programme, they are potentially able to gain significant improvement from gait re-education. The findings of this study suggest that the time spent on bed exercises may not necessarily improve function or quality of life during the early postoperative period following primary THR. Whether physiotherapists time may be spent more usefully on further gait re-education sessions or on teaching alternative postoperative exercises has yet to be investigated. Given this study s limited follow-up period, it would not be appropriate to state whether bed exercises should be withdrawn from postoperative rehabilitation programmes at present. Only once a longer-term follow-up study has been conducted, assessing this patient group with additional outcome measures, could such a statement be made with greater confidence. In conclusion, this study shows that during the first 6 weeks following THR, the addition of bed exercises to a gait reeducation programme does not have a significant effect on function or quality of life. Acknowledgements The authors wish to thank Mr D. Calder, Mr N. Chirodian, Mr P. Hopgood, Mr J. Nolan, Mr N. Walton and Mr J. Wimhurst for allowing their patients to participate in this study. This study was carried out as part of a MSc in Health Sciences degree at the University of East Anglia, UK. Ethical approval: Norfolk Research Ethics Committee, Ref. No. 06/Q0101/152. Conflict of interest: None declared. References [1] Fagerson TL. Post-operative physical therapy. In: Fagerson TL, editor. The hip handbook. Oxford: Butterworth Heinemann; p [2] Gilbey HJ, Ackland TR, Ang AW, Morton AR, Trouchet T, Tapper J. Exercise improves early functional recovery after total hip arthroplasty. Clin Orthop 2003;408: [3] Jesudson C, Stiller K. Are bed exercises necessary following hip arthroplasty? Aust J Physiother 2002;48: [4] Dawson J, Fitzpatrick R, Carr A, Murray D. Questionnaire on the perceptions of patients about total hip replacement. J Bone Joint Surg [Br] 1996;78-B: [5] Fitzpatrick R, Morris R, Hajat S, Reeves B, Murray DW, Hannen D, et al. The value of short and simple measures to assess outcomes for patients of total hip replacement surgery. Qual Health Care 2000;9: [6] Shield RK, Enloe LJ, Evans RE, Smith KB, Steckel SD. Reliability, validity and responsiveness of functional tests in patients with total joint replacement. Phys Ther 1995;75: [7] Ware JE, Kosinski M, Keller SD. A 12-item short-form health survey: construction of scales and preliminary tests of reliability and validity. Med Care 1996;34: [8] Ostendorf M, van Stel HF, Buskens E, Schrijver AJ, Marting LN, Verbout AJ, et al. Patient-reported outcome in total hip replacement. A comparison of five instruments of health status. J Bone Joint Surg [Br] 2004;86-B: [9] Gandek B, Ware JE, Aaronson NK, Apolone G, Bjorner JB, Brazier JE, et al. Cross-validation of item selection and scoring for the SF-12 Health Survey in nine countries: results from the IQOLA Project. International Quality of Life Assessment. J Clin Epidemiol 1998;51: [10] Jadad A. Randomised controlled trials. London: BMJ Publishing Group; Available online at