Update on hip and knee arthroplasty: current state of evidence

Can a Purposeful Walk Intervention with a Distance Goal Using an Activity Monitor Improve Individuals' Daily Activity and Function Post Total Hip Replacement Surgery. A Randomized Pilot Trial

Individuals have increasingly high expectations of return to activity following total hip replacement (THR) surgery. The current literature demonstrates marked improvements in pain following THR. However, there is limited evidence showing objective improvement in daily activity. This randomized pilot trial aimed to determine the effect of an intervention where outdoor walking distance is used as a goal to increase daily activity of older adults using a commercial activity monitor at 3 to 6 months post THR. Findings suggested that the participants in the intervention group had higher activity levels after THR, compared to those in the control group. The Cohen's effect sizes were larger for the changes in the gait, Hip Disability and Osteoarthritis Outcome Score, and Psychosocial Impact of Assistive Devices Scale data in the intervention group in contrast to the control group. However, further research with a larger sample size is required to provide tangible evidence on the significance of the effect of the purposeful walk compared to step count.

A feasibility study to evaluate a purposeful walk intervention with a distance goal using a commercially available activity monitor in elderly people post total hip replacement surgery

Introduction

Total hip replacement (THR) is performed in an increasing number of individuals around the world and while improvements in pain reduction and long-term enhancement of muscle strength are well documented, the improvement in daily activity does not follow the same trend. This study aimed to determine the feasibility of a 5-week intervention where a personalised outdoor walking distance is monitored using a commercial activity monitor (Fitbit Charge 4).

Method

Data was collected on gait and activities of daily living using patient reported outcome measures. Following the completion of the intervention period, participants took part in a semi-structured interview to voice their opinion on the use of the activity monitor, their experiences, and any challenges in order to assess the feasibility of the intervention. All quantitative data were presented descriptively, using appropriate summary statistics. Interviews were analysed using thematic analysis.

Results

Five participants who had undergone total hip replacement surgery within the postoperative period of 3 to 6 months were recruited from the local community.

Conclusion

The findings suggest that the intervention was feasible and that it encouraged all participants to increase their daily activity. Therefore, it can be concluded that a follow-up effectiveness trial is warranted.

Characteristics of young and lower functioning patients following total knee arthroplasty: a retrospective study

BACKGROUND

Rates of total knee arthroplasty (TKA) procedures in younger, more medically complex patients have dramatically increased over the last several decades. No study has examined categorization of lower and higher functioning subgroups within the TKA patient population. Our study aimed to determine preoperative characteristics of younger patients who are lower functioning following TKA.

METHODS

Patients were categorized into higher and lower functioning subgroups defined using a median split of 1) postoperative Timed Up and Go (TUG) test times and 2) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale scores. A split in age (65 years) was used to further classify patients into four categories: younger lower functioning, younger higher functioning, older lower functioning and older higher functioning. Measures from preoperative domains of health, psychological, physical performance and pain severity were examined for between-group differences.

RESULTS

Comparing mean values, the younger lower functioning subgroup using the TUG had significantly weaker knee extensor, slower gait speed, higher body mass index and greater pain compared to other subgroups. The younger lower functioning subgroup using the WOMAC physical function subscale demonstrated higher pain levels and Coping Strategies Questionnaire-Catastrophizing Subscale scores compared to the older lower functioning subgroup.

CONCLUSIONS

Poorer preoperative physical performance and pain severity appear to have the largest influence on early postoperative TKA recovery in younger lower functioning patients relative to both younger and older higher functioning patients.

Effects of Osteoarthritis Pain and Concurrent Insomnia and Depression on Health Care Use in a Primary Care Population of Older Adults

OBJECTIVE

To examine independent and combined effects of pain with concurrent insomnia and depression symptoms on the use of health care services in older adults with osteoarthritis (OA).

METHODS

Patients were Group Health Cooperative (GHC) patients with a primary diagnosis of OA (n = 2,976). We used survey data on pain (Graded Chronic Pain Scale), insomnia (Insomnia Severity Index), and depression (Patient Health Questionnaire-8), and health care use extracted from GHC electronic health records (office visits, length of stay, outpatient and inpatient costs, and hip or knee replacement) for 3 years after the survey. Negative binomial, logistic, and generalized linear models were used to assess predictors of health care use.

RESULTS

Approximately 34% and 29% of patients displayed at least subclinical insomnia and at least subclinical depression symptoms, respectively, in addition to moderate-to-severe pain. Pain had the greatest independent effects on increasing all types of health care use, followed by depression (moderate effects) on increased office visits, length of stay, outpatient and inpatient costs, and insomnia (mild effects) on decreased length of stay. No synergistic effects of the 3 symptoms on use of health care services were observed. The combined effects of pain plus insomnia and pain plus depression were significant for all types of health care use and increased greatly with increasing severity of insomnia and depression, except for hip/knee replacement.

CONCLUSION

Pain is the main driver for health care use in patients with OA. In addition to pain, insomnia plus depression jointly increased diverse types of health care use, and these combined effects increased greatly with increasing severity of insomnia and depression. These findings indicate the important role that concurrent symptomatic conditions may play in increasing use of health care services.

A review of wearable motion tracking systems used in rehabilitation following hip and knee replacement

Clinical teams are under increasing pressure to facilitate early hospital discharge for total hip replacement and total knee replacement patients following surgery. A wide variety of wearable devices are being marketed to assist with rehabilitation following surgery. A review of wearable devices was undertaken to assess the evidence supporting their efficacy in assisting rehabilitation following total hip replacement and total knee replacement. A search was conducted using the electronic databases including Medline, CINAHL, Cochrane, PsycARTICLES, and PubMed of studies from January 2000 to October 2017. Five studies met the eligibility criteria, and all used an accelerometer and a gyroscope for their technology. A review of the studies found very little evidence to support the efficacy of the technology, although they show that the use of the technology is feasible. Future work should establish which wearable technology is most valuable to patients, which ones improve patient outcomes, and the most economical model for deploying the technology.

High-Velocity Quadriceps Exercises Compared to Slow-Velocity Quadriceps Exercises Following Total Knee Arthroplasty: A Randomized Clinical Study

BACKGROUND AND PURPOSE

Despite improvement in pain and perceived function in older adults following total knee arthroplasty (TKA), objective outcome measures of muscular impairment and ambulatory function demonstrate significant deficits. Evidence suggests that quadriceps power may play a greater role in ambulatory function than measures of strength alone following TKA. The purpose of this study was to compare the effect of high-velocity (HV) quadriceps exercises with that of slow-velocity (SV) quadriceps exercises on functional outcomes and quadriceps power following TKA.

METHODS

This study was a randomized clinical study conducted in an outpatient physical therapy clinic. Twenty-one participants who were 4 to 6 weeks post unilateral TKA were randomly assigned to an HV or SV group. Participants performed an evidence-based standardized progressive resistance exercise program in addition to HV quadriceps exercises or SV quadriceps exercises. Participants attended 2 sessions per week for 8 weeks. Before and after the 8-week exercise intervention, participants completed a functional questionnaire, health survey, functional testing, and underwent quadriceps strength and power testing.

RESULTS

Both groups demonstrated improvements in ambulatory outcome measures, strength, speed, and power. The HV group demonstrated significantly greater improvements in distance walked and quadriceps strength than the SV group.

LIMITATIONS

These data should be considered preliminary because of a small sample size.

CONCLUSION

HV quadriceps exercises may be an effective rehabilitation strategy in conjunction with a standardized progressive resistance exercise program beginning 4 to 6 weeks after TKA.

Effects of preoperative walking ability and patient's surgical education on quality of life and functional outcomes after total knee arthroplasty

Objective

Prospectively analyze the effect of preoperative walking status and the patient's surgical education on functional outcomes and the three dimensions of quality of life (QoL) (pain, physical function, and mental health) after elective total knee arthroplasty (TKA).

Methods

A comparative analysis on the QoL and functional outcomes in patients who underwent total knee arthroplasty between January 2014 and June 2015. To compare effects of the patient's walking status and knowledge of the surgical procedure on QoL and functional outcomes following TKA by means of SF-36 questionnaire, CES D10, VAS, KSS, KSFS, WOMAC, as well as Friedmann and Wyman scores, 10MWT, and 30-second timed chair test, assessed before the operation and one, three, and six months after the operation.

Results

There were 168 knees in 154 patients: 46.75% men and 53.24% women. 52.38% of knees had grade-III OA and 40.47% of knees had grade-IV OA. Preoperatively, SF-36 PCS was 33.2 and MCS was 35.4. Mean KSS and KSFS in females was 37.3 (16.2) and 31.5 (13.8); in males it was 49.2 (18.4) and 42.5 (15.7), respectively. Mean WOMAC scores were 64.2 in females and 56.5 in males. Mean VAS and CES D10 scores were 8.8 and 8.2 in females, and 6.9 and 6.4 in males, respectively. Post operatively at the first, third, and sixth month, significant improvements in QoL and mean SF-36, CES D10, VAS, KSS, KSFS, WOMAC, and Friedmann and Wyman scores were observed, as well as in the 10MWT and 30 s timed chair test scores. Patients with better preoperative functional activity and satisfactory understanding of TKA presented a better functional performance and achieved a good quality life (p < 0.01).

Discussion

Surgeons educate TKA candidates regarding the surgical procedure, the nature of implants, and how the procedure would affect their lifestyle and what their expectations from TKA should be. These crucial considerations should boost their confidence, enhancing their involvement and cooperation in post-surgical rehabilitation, thereby improving their QoL, functional results, and post TKA experience.

Conclusion

TKA candidates with good preoperative walking ability and understanding of knee arthroplasty have better QoL in early and late post-surgery periods. Patient's lifestyle and understanding significantly enhances the postoperative functional ability.

No difference in terms of radiostereometric analysis between fixed- and mobile-bearing total knee arthroplasty: a randomized, single-blind, controlled trial

PURPOSE

A concern that arises with any new prosthesis is whether it will achieve satisfactory long-term implant stability. The gold standard of assessing the quality of fixation in a new or relatively new implant is to undertake a randomized controlled trial using radiostereometric analysis. It was hypothesized that both mobile-bearing total knee arthroplasty and fixed-bearing total knee arthroplasty have comparable migration patterns at 2-year follow-up. This study investigated two types of cemented total knee arthroplasty, the mobile- or fixed-bearing variant from the same family with use of radiostereometric analysis.

METHODS

This prospective, patient-blinded, randomized, controlled trial was designed to investigate early migration of the tibia component after two years of follow-up with use of radiostereometric analysis. A total of 50 patients were randomized to receive a mobile- or fixed-bearing TKA from the same family. Patients were evaluated during 2-year follow-up, including radiostereometric analysis, physical and clinical examination and patient reported outcome measures (PROMs).

RESULTS

At two-year follow-up, the mean (±SD) maximum total point motion (MTPM) in the fixed-bearing group was 0.82 (±1.16) versus 0.92 mm (±0.64) in the mobile-bearing group (p = n.s) with the largest migration seen during the first 6 weeks (0.45 ± 0.32 vs. 0.54 ± 0.30). The clinical outcome and PROMs significantly improved within each group, not between both groups.

CONCLUSIONS

Measuring early micromotion is useful for predicting clinical loosening that can lead to revision. The results of this study demonstrate that early migration of the mobile-bearing is similar to that of the fixed-bearing component at two years and was mainly seen in the first weeks after implantation.

LEVEL OF EVIDENCE

Randomized, single-blind, controlled trial, Level I.

[Rehabilitation after hip and knee endoprosthetic treatment in the elderly]

Due to current demographic developments with a continuous increase in average life expectancy and improved medical treatment, the number of elderly patients with joint replacement of the lower extremities also has increased in recent years. Most of these patients have not only one but several chronic diseases requiring treatment and medication. Drug-drug interaction and functional restrictions of the elderly additionally reduce the postoperative psychophysical capacity; therefore, special knowledge in rehabilitative treatment and pain management is necessary. Physiotherapy and exercise should include training of mobility, endurance, strength, coordination and training in activities of daily living. The individual constitution and pain during exercise must always be taken into consideration. Rehabilitative outcome is dependent on a functioning cooperation of an interdisciplinary rehabilitation team and requires an organized, holistic treatment approach in interconnected structures, which aims at rapid postoperative mobilization.

Diabetes is a Risk Factor for Restricted Range of Motion and Poor Clinical Outcome After Total Knee Arthroplasty

BACKGROUND

We investigated the effects of diabetes mellitus on knee range of motion, muscle strength, and functional outcome after total knee arthroplasty.

METHODS

A total of 20 patients with type 2 diabetes and 20 patients without diabetes matched for age, body mass index, knee range of motion, and muscle strength at baseline participated in this study. We examined knee range of motion and muscle strength and assessed functional activities using the new Knee Society Score questionnaire for each patient 1 month preoperatively and at 6 and 12 months postoperatively.

RESULTS

Patients with diabetes had significantly lower knee flexion and smaller improvements in the new Knee Society Score than patients without diabetes.

CONCLUSION

Our results suggest that clinicians should treat and monitor patients with diabetes closely to prevent restricted knee range of motion and poorer functional recovery after total knee arthroplasty.

Quality-Adjusted Life Years Gained by Hip and Knee Replacement Surgery and Its Aftercare

OBJECTIVES

To determine the lifetime quality-adjusted life years (QALYs) gained by total joint arthroplasty (TJA), and assess the QALYs attributed to specific postoperative rehabilitation interventions.

DESIGN

Secondary analysis of 2 multicenter, randomized controlled trials (RCTs) with 3-, 6-, 12-, and 24-month follow-up.

SETTING

Two university hospitals, 2 municipal hospitals, and 1 rural hospital.

PARTICIPANTS

Patients (N=827) who underwent total hip arthroplasty (THA) or total knee arthroplasty (TKA).

INTERVENTIONS

RCT A: 465 patients were randomly assigned to receive aquatic therapy (pool exercises aimed at training of proprioception, coordination, and strengthening) 6 versus 14 days after THA or TKA.

RCT B

362 patients were randomly assigned to either perform or not perform ergometer cycling beginning 2 weeks after THA or TKA.

MAIN OUTCOME MEASURE

QALYs, based on the Short Form-6 Dimensions utility, measured at baseline and 3, 6, 12, and 24 months' follow-up.

RESULTS

After hip arthroplasty, the lifetime QALYs increased by 2.35 years in the nonergometer group, and by 2.30 years in the early aquatic therapy group. However, after knee arthroplasty, the lifetime QALYs increased by 1.81 years in the nonergometer group, and by 1.60 years in the early aquatic therapy group. By ergometer cycling, .55 additional QALYs could be gained after hip and .10 additional QALYs after knee arthroplasty, while the additional QALYs attributed to the timing of aquatic therapy were .12 years after hip and .01 years after knee arthroplasty.

CONCLUSIONS

This analysis provides a sound estimate for the determination of the lifetime QALYs gained by THA and TKA. In addition, this analysis demonstrates that specific postoperative rehabilitation can result in an additional mean QALY gain of .55 years, which represents one fourth of the effect of surgery. Even if this is interpreted as a small effect at an individual level, it is important when extrapolated to all patients undergoing TJA. At a national level, these improvements appear to have a similar magnitude of QALY gain when compared with published data regarding medications to lower blood pressure in all persons with arterial hypertension.

Comparison of patients in three different rehabilitation settings after knee or hip arthroplasty: a natural observational, prospective study

Background

Patients after primary hip or knee replacement surgery can benefit from postoperative treatment in terms of improvement of independence in ambulation, transfers, range of motion and muscle strength. After discharge from hospital, patients are referred to different treatment destination and modalities: intensive inpatient rehabilitation (IR), cure (medically prescribed stay at a convalescence center), or ambulatory treatment (AT) at home. The purpose of this study was to 1) measure functional health (primary outcome) and function relevant factors in patients with hip or knee arthroplasty and to compare them in relation to three postoperative management strategies: AT, Cure and IR and 2) compare the post-operative changes in patient’s health status (between preoperative and the 6 month follow-up) for three rehabilitation settings.

Methods

Natural observational, prospective two-center study with follow-up. Sociodemographic data and functional mobility tests, Timed Up and Go (TUG) and Iowa Level of Assistance Scale (ILOAS) of 201 patients were analysed before arthroplasty and at the end of acute hospital stay (mean duration of stay: 9.7 days +/− 3.9). Changes in health state were measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before and 6 months after arthroplasty.

Results

Compared to patients referred for IR and Cure, patients referred for AT were significantly younger and less comorbid. Patients admitted to IR had the highest functional disability before arthroplasty. Before rehabilitation, mean TUG was 40.0 s in the IR group, 33.9 s in the Cure group, and 27.5 s in the AT group, and corresponding mean ILOAS was 16.0, 13.0 and 12.2 (50.0 = worst). At the 6 months follow-up, the corresponding effect sizes of the WOMAC global score were 1.32, 1.87, and 1.51 (>0 means improvement).

Conclusions

Age, comorbidity and functional disability are associated with referral for intensive inpatient rehabilitation after hip or knee arthroplasty and partly affect health changes after rehabilitation.

Total knee arthroplasty: Effect of obesity and other patients’ characteristics on operative duration and outcome

AIM: To examine the effects of patients’ characteristics mainly obesity on operative duration and other outcome measures of knee arthroplasty.

METHODS: This is a retrospective chart review of 204 patients who had knee arthroplasty within the past five years (2007-2011) at King Abdulaziz Medical City in Riyadh, Kingdom of Saudi Arabia. The data collection form was developed utilizing the literature review to gather all the needed variables. Data were gathered from admission notes, nursing notes, operative reports and discharge summaries.

RESULTS: A feasible sample of 204 patients were included in the study. Of those patients, 155 (76%) were females. The mean age was 70.1 years for males (SD ± 9.4) and 62.7 years (SD ± 8) for females. Regarding the type of total knee replacement (TKR), 163 (79.9%) patients had unilateral TKR and 41 (20.1%) had bilateral TKR. Nine patients (4.4%) had a normal body mass index (BMI) (18.5 to < 25). Overweight patients (BMI 25 to < 30) represented 18.1%. Obesity class I (BMI 30 to < 35) and obesity class II (BMI from 35 to < 40) were present in 23% and 29.9% of the patients, respectively. Morbid obesity (BMI greater than 40) was present in 24.5%. The mean duration of surgery was 126.3 min (SD ± 30.8) for unilateral TKR and 216.6 min (SD ± 55.4) for bilateral TKR.The mean length of stay in the hospital was 12 d (SD ± 4.9). The complications that patients had after the operation included 2 patients (1%) who developed deep venous thrombosis, 2 patients (1%) developed surgical wound infections and none had pulmonary embolism. Patients' characteristics (including age, gender, BMI and co-morbidities) did not have an effect on the operative duration of knee replacement nor the length of hospital stay.

CONCLUSION: Our study shows that obesity and other patients’ characteristics do not have effect on the operative duration nor the length of hospital stay following TKR.

One-to-one therapy is not superior to group or home-based therapy after total knee arthroplasty: a randomized, superiority trial

BACKGROUND

The aim of this study was to determine whether center-based, one-to-one physical therapy provides superior outcomes compared with group-based therapy or a simple monitored home-based program in terms of functional and physical recovery and health-related quality of life after total knee arthroplasty.

METHODS

Patients awaiting primary total knee arthroplasty at two Sydney metropolitan hospitals were enrolled into this prospective, randomized, superiority trial preoperatively. At two weeks postoperatively, participants were randomly allocated to one of three six-week treatment programs (twelve one-to-one therapy sessions, twelve group-based therapy sessions, or a monitored home program) with use of a computer-generated sequence. Self-reported outcomes (Oxford Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index pain and function subscales, and Medical Outcomes Study 12-Item Short-Form Survey) and performance-based functional outcomes were measured over twelve months postoperatively by a blinded assessor. The primary outcome was knee pain and function measured with use of the Oxford Knee Score at ten weeks postoperatively. Intention-to-treat analysis was conducted.

RESULTS

Two hundred and forty-nine patients (eighty-five who had one-to-one therapy, eighty-four who had group-based therapy, and eighty who were in the monitored home program) were randomized and 233 were available for their one-year follow-up assessment. Participants who received one-to-one therapy did not have a superior Oxford Knee Score at week ten compared with those who received the alternative interventions; the median score was 32 points for the one-to-one therapy group, 36 points for the group-based therapy group, and 34 points for the monitored home program group (p = 0.20). Furthermore, one-to-one therapy was not superior compared with group-based therapy or monitored home program in improving any of the secondary outcomes across the first postoperative year. No adverse events were associated with any of the treatment arms.

CONCLUSIONS

One-to-one therapy does not provide superior self-reported or performance-based outcomes compared with group-based therapy or a monitored home program, in the short term and the long term after total knee arthroplasty.

LEVEL OF EVIDENCE

Therapeutic level I. See Instructions for Authors for a complete description of levels of evidence.

A survey of patients' quality of life and health-care needs prior to undergoing total joint replacement surgery

The objective of this study was to identify patients' quality of life (QOL) and health-care needs before undergoing total joint replacement surgery. This study used a cross-sectional descriptive survey approach. Data were collected in 2007. The results for role limitations because of physical functioning were the lowest. Health-care needs for exercise guidance were the highest. Male participants experienced superior QOL for the physical components (t = 2.379, P < .05). Participants who were single (F = 3.804; F = 4.539) and employed full time (F = 4.961; F = 3.994) had superior QOL for both the physical and mental components (P < .05). The predictive factors for physical components of QOL included occupational status, the previous total joint replacement and other health problems. The predictive factor for the mental components of QOL was marital status. Because role performance is limited by physical functioning, the participants experienced a poor QOL for the physical components. The participants had substantial health-care needs before surgery, particularly for rehabilitation exercise guidance and pain management.

A phase III randomized three-arm trial of physical therapist delivered pain coping skills training for patients with total knee arthroplasty: the KASTPain protocol

BACKGROUND

Approximately 20% of patients report persistent and disabling pain following total knee arthroplasty (TKA) despite an apparently normally functioning prosthesis. One potential risk factor for unexplained persistent pain is high levels of pain catastrophizing. We designed a three-arm trial to determine if a pain coping skills training program, delivered prior to TKA, effectively reduces function-limiting pain following the procedure in patients with high levels of pain catastrophizing.

METHODS/DESIGN

The trial will be conducted at four University-based sites in the US. A sample of 402 patients with high levels of pain catastrophizing will be randomly assigned to either a pain coping skills training arm, an arthritis education control arm or usual care. Pain coping skills will be delivered by physical therapists trained and supervised by clinical psychologist experts. Arthritis education will be delivered by nurses trained in the delivery of arthritis-related content. The primary outcome will be change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain scale score 12 months following surgery. A variety of secondary clinical and economic outcomes also will be evaluated.

DISCUSSION

The trial will be conducted at four University-based sites in the US. A sample of 402 patients with high levels of pain catastrophizing will be randomly assigned to either a pain coping skills training arm, an arthritis education control arm or usual care. Pain coping skills will be delivered by physical therapists trained and supervised by clinical psychologist experts. Arthritis education will be delivered by nurses trained in the delivery of arthritis-related content. The primary outcome will be change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain scale score 12 months following surgery. A variety of secondary clinical and economic outcomes also will be evaluated.

Joint perception after hip or knee replacement surgery

INTRODUCTION

Knee and hip arthroplasties are recognized as being effective. However, subjects with a prosthetic joint rarely report returned sensation comparable to their native joint.

HYPOTHESIS

Joint perception by patients following hip joint replacement is better than following knee replacement and in both cases this perception is directly related to the clinical results measured with currently validated scores.

PATIENTS AND METHODS

Patient joint perception in prosthetic reconstruction was evaluated in 347 patients, 46 who underwent unicompartmental knee arthroplasty (UKA), 119 tricompartmental knee arthroplasty (TKA), 93 hip resurfacing (HR), and 89 total hip arthroplasty (THA). The subjects' joint perception, their satisfaction, and the WOMAC clinical score were recorded and compared.

RESULTS

Joint perception was significantly worse for knee arthroplasties (TKA and UKA) compared to hip arthroplasties (THA or HR) (P<0.001). The WOMAC score was also significantly less favorable for knee arthroplasties than for hip arthroplasties (P<0.0001). However, there was no significant difference for the clinical scores between TKA and UKA as well as between HR and THA. Joint perception was strongly correlated with the WOMAC score for all groups (R(2)=0.951).

DISCUSSION

No difference was found after more conservative surgeries such as HR or UKA compared to traditional arthroplasty procedures (THA or TKA). Demonstrating inferior results in comparison to the hip, knee arthroplasties deserve particular attention and can still be improved. The assessment of joint perception used in this study can be considered a valuable clinical tool that is strongly correlated to validated, but more complex to apply, clinical scores.

Fall incidence and risk factors in patients after total knee arthroplasty

PURPOSE

To prospectively investigate the relationship between physical function and falls among elderly patients who underwent total knee arthroplasty (TKA) and to determine the incidence of falls as well as their risk factors.

METHODS

A total of 108 patients (17 male, 91 female) over 60 years of age who underwent TKA were enrolled and who were living independently in community. 75 patients fulfilled our inclusion criteria and 74 (8 male, 66 female) of them agreed to participate. Baseline assessment (physical examination, physical performance tests, and self-administered questionnaire) were conducted between 6 and 12 months after the last arthroplasty and the follow-up assessment was performed 6 months after the baseline assessment. Monthly pre-stamped postcards were sent to assess the incidence of falls.

RESULTS

Of the 74 patients enrolled, 70 (94.6%) completed a 6-month prospective observation. 23 of 70 patients (32.9%) fell during the observational period. Postoperative range of knee flexion, ranges of knee flexion and extension and ankle plantar flexion were significantly lower in fallers than in non-fallers (P = 0.016, P = 0.037, P = 0.014, respectively). In the multivariate analysis, postoperative range of knee flexion (OR 0.277, 95%CI 0.088-0.869, P = 0.028) and ankle plantar flexion (OR 0.594, 95%CI 0.374-0.945, P = 0.028) were determined to be significant risk factors.

CONCLUSION

Elderly people who underwent TKA are considered more likely to fall compared with healthy elderly people. For patients with limited knee flexion and ankle plantar flexion, improvement of ROM by exercise therapy and patient education regarding the prevention of falls and fractures are considered necessary.

Comparison of postdischarge physiotherapy versus usual care following primary total knee arthroplasty for osteoarthritis: an exploratory pilot randomized clinical trial

Objective: To evaluate a pilot trial of a postdischarge physiotherapy intervention to improve patient function versus usual physiotherapy in patients undergoing total knee arthroplasty aiming to assess: recruitment rate, feasibility and acceptability of the intervention and control, suitability of outcomes, retention and adverse events and to inform sample size calculation for a definitive trial.

Design: Exploratory pilot randomized controlled trial using independent assessment.

Setting: Mixed urban and rural, UK.

Participants: Patients undergoing primary, elective unilateral knee arthroplasty for osteoarthritis.

Intervention: Two additional home physiotherapy visits of functional weight-bearing exercises, functional task-specific training versus treatment as usual.

Main outcome: Oxford Knee Score at 12 months. Secondary outcomes: completion rates, adverse events, Knee Injury and Osteoarthritis Outcome Score, leg extensor power, timed 10-m walk, timed sit-to-stand, resource use diaries. Assessments completed at baseline (pre-operatively), 3, 6 and 12 months.

Results: Of 181 eligible participants 107 (59.1%) were randomized over 13 months, one participant withdrew, no adverse events. Intervention group n = 56 (mean age 67.8), control group n = 51 (mean age 70.8). The difference in mean change of Oxford Knee Scores between groups (intervention – control) at 12 months was 0.2 (95% confidence interval (CI) –3.8, 4.2), P = 0.94. Patient diaries revealed non-trial additional physiotherapy requires improved measurement.

Conclusions: Successful recruitment and retention rates were achieved. The intervention appeared feasible and acceptable but may be suboptimal in intensity given recent research. A sample size of 1271 participants would be required for a fully powered randomized controlled trial using the main outcome. However new outcomes, potentially of greater validity and responsiveness, require consideration.

A public health perspective on physical activity after total hip or knee arthroplasty for osteoarthritis

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common treatments for osteoarthritis (OA) with good-to-excellent outcomes. As the US population ages, rates of OA and THA/TKA will continue to rise. People with OA and THA/TKA are less active than those without arthritis or arthrosplasty, respectively. With the numerous documented health benefits obtained from physical activity, it is imperative from a public health perspective that patients are sufficiently active to maintain health after surgery. Increasing moderate-intensity physical activity is a safe, efficacious, and cost-effective mechanism for improving health and reducing health care costs in this population. The return to leisure/sporting activities after THA/TKA is not as well studied as other aspects of functional recovery. In particular, no evidence-based guidelines for physical activity after THA/TKA are available. Most recommendations have been derived from cross-sectional surveys of orthopedic surgeons. Based on the literature, the general consensus for recommendations appears to be to: 1) return to low- to moderate-intensity activities and no-, low-, or intermediate-impact activities within 3 to 6 months postoperatively, 2) discourage high-impact activities, 3) avoid high-contact athletic activities, and 4) educate rather than dissuade patients from resuming leisure/sporting activities. Sports medicine physicians are in an ideal position to counsel patients in regard to leading active lifestyles. The physician can evaluate and treat any remaining functional limitations postoperatively, as well as prescribe the appropriate dose (ie, type, intensity, frequency, and duration) of physical activity. The 2008 Physical Activity Guidelines for Americans can help guide physicians in prescribing the appropriate dose of activity. Finally, physicians can refer patients to evidence-based, community-delivered group exercise and/or behavioral change interventions that are approved by the Centers for Disease Control and Prevention for people with arthritis.

Factors influencing health-related quality of life after TKA in patients who are obese

BACKGROUND

Although the health-related quality of life (HRQL) for patients who are obese seems to improve after TKA, the magnitude of improvement and the associated factors remain controversial. We previously found body mass index was not associated with changes in HRQL after TKA.

QUESTIONS/PURPOSES

The purposes of this secondary analysis were to determine which patient characteristics and surgical factors were associated with worse health status after TKA in patients who are severe or morbidly obese.

METHODS

We assessed 60 patients (53 females; mean age, 70 years) 12 months after surgery. The mean number of comorbidities was 2.5. Mean lower limb anthropometric index scores were: suprapatellar, 1.6; infrapatellar, 2; and suprapatellar/infrapatellar, 1.2. Intraoperative difficulty (IOD) was Grade 0, 40%; Grade 1, 48%; and Grade 2, 12%. Ten patients (17%) had complications. We measured HRQL using the disease-specific WOMAC questionnaire. Patient characteristics (sociodemographic variables, BMI, comorbidity, lower limb anthropometry) and surgical factors (IOD, complications, postoperative medical data) were collected. Associations between WOMAC dimension scores at 12 months and patient characteristics and surgical factors were analyzed using linear regression models.

RESULTS

Factors associated with worse WOMAC dimension scores in patients who were obese included the number of comorbidities, an infrapatellar index percentile less than 75, IOD Grade 2, and the number of complications after discharge.

CONCLUSIONS

For patients with knee osteoarthritis who were severe or morbidly obese, various lower limb anthropometric features, degree of IOD, and postoperative complications negatively influenced postoperative WOMAC scores.

LEVEL OF EVIDENCE

Level II Prognostic Study. See Guidelines for a complete description of levels of evidence.

Efficacy of total joint arthroplasty in patients with established rheumatoid arthritis: improved longitudinal effects on disease activity but not on health-related quality of life

Though excellent clinical results have been reported for total joint arthroplasty (TJA) in rheumatoid arthritis (RA) patients, the longitudinal effects of TJA on pain, physical function, and health-related quality of life in RA patients remain unknown. This study aimed to assess changes in disease activity and health-related quality of life after TJA in patients with established RA. We analyzed the effect of total knee arthroplasty (TKA) and total hip arthroplasty (THA) on RA disease activity in an observational cohort of RA patients. Of the registered RA patients, 333 TKA and 77 THA patients were followed for 5 years after surgery. RA disease activity and health-related quality of life were measured using the Disease Activity Score 28 (DAS28) and a Japanese version of the Stanford health assessment questionnaire (J-HAQ). The mean DAS28 in TKA patients decreased from 4.66 (preoperatively) to 4.02 (3 years postoperatively) and to 3.94 (5 years postoperatively); the mean DAS28 in THA patients decreased from 4.41 (preoperatively) to 3.99 (3 years postoperatively) and to 3.92 (5 years postoperatively). The mean J-HAQ for TKA remained essentially unchanged, ranging from 1.48 (preoperatively) to 1.45 (3 years postoperatively) and to 1.47 (5 years postoperatively); the mean J-HAQ for THA also remained unchanged, ranging from 1.74 (preoperatively) to 1.74 (3 years postoperatively) and to 1.73 (5 years postoperatively). Of the total J-HAQ score, the lower limb score improved while the upper limb score worsened. Although TKA and THA improve clinical outcomes in damaged knees and hips and have a positive secondary systemic effect on RA disease activity, they have not had a continuously good effect on the measures of health-related quality of life. We conclude that tight control of RA disease activity is indicated for those patients with TKA and/or THA.

Characterizing self-rated health during a period of changing health status

Self-rated health (SRH) is among the most frequently assessed health perceptions. The purpose of this study was to assess the tenability of the recently proposed distinctions of SRH, as a spontaneous assessment of overall health, or as an enduring self-concept. Individuals (n = 449) undergoing total joint replacement for hip or knee osteoarthritis in Toronto, Canada were followed over 6 months of recovery. Health questionnaires, completed pre-surgery, and at 3 and 6 months post-surgery, included measures of pain, physical function, sports/recreation, fatigue, anxiety, depression, social participation, passive/active recreation, and community access. Structural equation modeling was used for the analyses. SRH was found to be responsive to current and changing mental well-being throughout the six months of recovery. Current SRH strongly predicted future SRH. In this clinical sample undergoing significant changes in health status, SRH displayed both enduring and spontaneous features; evidence is provided that both operate simultaneously. SRH may prove to be a simple yet critical health measure for identifying individuals who would benefit most from targeted interventions for improving overall health.

Effect of total knee arthroplasty on disease activity in patients with established rheumatoid arthritis: 3-year follow-up results of combined medical therapy and surgical intervention

Though excellent clinical results have been reported for total knee arthroplasty (TKA) in rheumatoid arthritis (RA) patients, the medium-term effect of TKA on RA disease activity remains unknown. This analysis aimed to assess changes in disease activity after TKA in patients with established RA. We analyzed the systemic effects of TKA on RA disease activity 3 years after intervention. Routine clinical and laboratory assessments were recorded at baseline, less than less than 0.5 years after TKA, and 3 years after TKA. Of the registered RA patients, 130 TKA patients were followed for 3 years after surgery. RA disease activity was measured using the Disease Activity Score 28 (DAS28). Patients were divided into three groups by preoperative baseline DAS28: low (DAS28 ≤ 3.2, n = 8), moderate (DAS28 > 3.2 but ≤5.1, n = 68), and high (DAS28 > 5.1, n = 54) disease activity. The postoperative DAS28 (<0.5 years [DAS1] and 3 years [DAS3] after surgery) scores of each patient were compared to their baseline (DAS0) scores using the paired t-test. The mean DAS28 decreased from 4.85 (DAS0) to 4.14 (DAS1; P = 1.07E-12), and this decrease was sustained at 3 years (DAS3 = 3.97; P = 4.73E-15). Subanalysis results revealed a systemic effect of TKA on disease activity in patients with moderate or high disease activity (DAS0 = 4.33; DAS1 = 3.72 [P = 5.94E-06]; DAS3 = 3.81 [P = 7.89E-06]; and DAS0 = 5.79; DAS1 = 4.86 [P = 1.14E-08]; DAS3 = 4.37 [P = 1.03E-11], respectively). While no significant changes in medication were noted, the average dose of prednisolone tended to decrease over time. We conclude that TKA, which is known to result in good clinical outcomes for damaged knees, has a secondary systemic effect on RA disease activity. Combination therapy consisting of medical treatment and surgical intervention is thought to effectively improve the condition of RA patients who have destructive arthritis in the knee joint, with the effect lasting for at least 3 years.

Muscle deficits persist after unilateral knee replacement and have implications for rehabilitation

BACKGROUND

Knee joint arthritis causes pain, decreased range of motion, and mobility limitation. Knee replacement reduces pain effectively. However, people with knee replacement have decreases in muscle strength ("force-generating capacity") of the involved leg and difficulties with walking and other physical activities.

OBJECTIVE AND DESIGN

The aim of this cross-sectional study was to determine the extent of deficits in knee extensor and flexor muscle torque and power (ability to perform work over time) and in the extensor muscle cross-sectional area (CSA) after knee joint replacement. In addition, the association of lower-leg muscle deficits with mobility limitations was investigated.

METHODS

Participants were 29 women and 19 men who were 55 to 75 years old and had undergone unilateral knee replacement surgery an average of 10 months earlier. The maximal torque and power of the knee extensor and flexor muscles were measured with an isokinetic dynamometer. The knee extensor muscle CSA was measured with computed tomography. The symmetry deficit between the knee that underwent replacement surgery ("operated knee") and the knee that did not undergo replacement surgery ("nonoperated knee") was calculated. Maximal walking speed and stair-ascending and stair-descending times were assessed.

RESULTS

The mean deficits in knee extensor and flexor muscle torque and power were between 13% and 27%, and the mean deficit in the extensor muscle CSA was 14%. A larger deficit in knee extension power predicted slower stair-ascending and stair-descending times. This relationship remained unchanged when the power of the nonoperated side and the potential confounding factors were taken into account.

LIMITATIONS

The study sample consisted of people who were relatively healthy and mobile. Some participants had osteoarthritis in the nonoperated knee.

CONCLUSIONS

Deficits in muscle torque and power and in the extensor muscle CSA were present 10 months after knee replacement, potentially causing limitations in negotiating stairs. To prevent mobility limitations and disability, deficits in lower-limb power should be considered during rehabilitation after knee replacement.

Total knee replacement and health-related quality of life: factors influencing long-term outcomes

OBJECTIVE

To evaluate health-related quality of life (HRQOL) in patients with osteoarthritis undergoing total knee replacement (TKR); identify the influence of sociodemographic, clinical, intraoperative, and postoperative variables on HRQOL; and determine patient perceptions at 7 years.

METHODS

We conducted a prospective study with 7 years of followup. HRQOL measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] and Short Form 36 [SF-36]); sociodemographic, clinical, intraoperative, inpatient, and postoperative data; patient perceptions of TKR outcomes; and physical activity at 7 years were determined. Associations were analyzed using linear regression models.

RESULTS

Of 146 eligible patients, 112 (86 women, mean age 67.3 years) completed followup data. There were significant differences between pre- and postoperative WOMAC pain, stiffness, and function scores (P < 0.001). Variables retained in each of the models explained 14-32% (adjusted R(2)) of variability of the WOMAC dimensions. Obesity and postdischarge complications were associated with worse scores in all WOMAC dimensions (P < 0.05). Eighty-six percent of patients were satisfied with TKR, 80% would undergo the operation again, and 56% did regular physical activity and had better WOMAC scores (P < 0.05, except for stiffness [not significant]). Mean +/- SD SF-36 scores for men and women at 7 years were 55.1 +/- 27.1 and 39.5 +/- 22.9 for physical function, 71.2 +/- 36.5 and 51.5 +/- 42.7 for physical role, 66.2 +/- 26 and 55.6 +/- 28.9 for bodily pain, and 60.7 +/- 17.1 and 50.7 +/- 21.2 for general health, respectively.

CONCLUSION

WOMAC dimension scores, especially pain, significantly improved at 7 years and were negatively influenced by obesity and postdischarge complications. HRQOL measures may help identify an increased risk of negative outcomes after TKR.

Assessment of outcomes after hip arthroplasty

Because of the ever-increasing prevalence of joint replacement, it is important that patient outcomes after surgery are continuously reviewed and monitored, with the aim of optimising outcomes after surgery. Of central importance in assessing outcomes is choosing the most appropriate outcome measure. This article reviews five methods of assessing outcomes after hip arthroplasty, namely radiographic analysis, implant survivorship analysis, surgeon-based outcome measures, performance-related assessment and patient-reported outcome measures. The relative strengths and weaknesses of each method of assessment are discussed, with the aim of aiding the surgeon or researcher in choosing an outcome measure when designing a clinical trial.

Image-guided tissue engineering of anatomically shaped implants via MRI and micro-CT using injection molding

This study demonstrates for the first time the development of engineered tissues based on anatomic geometries derived from widely used medical imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Computer-aided design and tissue injection molding techniques have demonstrated the ability to generate living implants of complex geometry. Due to its complex geometry, the meniscus of the knee was used as an example of this technique's capabilities. MRI and microcomputed tomography (microCT) were used to design custom-printed molds that enabled the generation of anatomically shaped constructs that retained shape throughout 8 weeks of culture. Engineered constructs showed progressive tissue formation indicated by increases in extracellular matrix content and mechanical properties. The paradigm of interfacing tissue injection molding technology can be applied to other medical imaging techniques that render 3D models of anatomy, demonstrating the potential to apply the current technique to engineering of many tissues and organs.

Total knee arthroplasty: muscle impairments, functional limitations, and recommended rehabilitation approaches

The number of total knee arthroplasty (TKA) surgeries performed each year is predicted to steadily increase. Following TKA surgery, self-reported pain and function improve, though individuals are often plagued with quadriceps muscle impairments and functional limitations. Postoperative rehabilitation approaches either are not incorporated or incompletely address the muscular and functional deficits that persist following surgery. While the reason for quadriceps weakness is not well understood in this patient population, it has been suggested that a combination of muscle atrophy and neuromuscular activation deficits contribute to residual strength impairments. Failure to adequately address the chronic muscle impairments has the potential to limit the long-term functional gains that may be possible following TKA. Postoperative rehabilitation addressing quadriceps strength should mitigate these impairments and ultimately result in improved functional outcomes. The purpose of this paper is to describe these quadriceps muscle impairments and discuss how these impairments can contribute to the related functional limitations following TKA. We will also describe the current concepts in TKA rehabilitation and provide recommendations and clinical guidelines based on the current available evidence.

LEVEL OF EVIDENCE

Therapy, level 5.

Effectiveness of prolonged use of continuous passive motion (CPM), as an adjunct to physiotherapy, after total knee arthroplasty

Background

Adequate and intensive rehabilitation is an important requirement for successful total knee arthroplasty.

Although research suggests that Continuous Passive Motion (CPM) should be implemented in the first rehabilitation phase after surgery, there is substantial debate about the duration of each session and the total period of CPM application. A Cochrane review on this topic concluded that short-term use of CPM leads to greater short-term range of motion. It also suggested, however, that future research should concentrate on the treatment period during which CPM should be administered.

Methods

In a randomised controlled trial we investigated the effectiveness of prolonged CPM use in the home situation as an adjunct to standardised PT. Efficacy was assessed in terms of faster improvements in range of motion (RoM) and functional recovery, measured at the end of the active treatment period, 17 days after surgery.

Sixty patients with knee osteoarthritis undergoing TKA and experiencing early postoperative flexion impairment were randomised over two treatment groups. The experimental group received CPM + PT for 17 consecutive days after surgery, whereas the usual care group received the same treatment during the in-hospital phase (i.e. about four days), followed by PT alone (usual care) in the first two weeks after hospital discharge.

From 18 days to three months after surgery, both groups received standardised PT. The primary focus of rehabilitation was functional recovery (e.g. ambulation) and regaining RoM in the knee.

Results

Prolonged use of CPM slightly improved short-term RoM in patients with limited RoM at the time of discharge after total knee arthroplasty when added to a semi-standard PT programme. Assessment at 6 weeks and three months after surgery found no long-term effects of this intervention Neither did we detect functional benefits of the improved RoM at any of the outcome assessments.

Conclusion

Although results indicate that prolonged CPM use might have a small short-term effect on RoM, routine use of prolonged CPM in patients with limited RoM at hospital discharge should be reconsidered, since neither long-term effects nor transfer to better functional performance was detected.

Trial Registration

ISRCTN85759656

Risk factors for total knee arthroplasty in rheumatoid arthritis

We conducted a study to assess the predictive factors for total knee arthroplasty (TKA) in a cohort of rheumatoid arthritis (RA) patients recruited and followed prospectively for 5 years. A linked registry study using information from a large observational cohort of RA patients followed at the Institute of Rheumatology, Tokyo Women's Medical University (IORRA) was done. Baseline routine clinical and laboratory assessments were recorded. The data were analyzed using the multivariate piecewise-linear Cox (PL-Cox) regression model; the model initially included variables such as gender, age, duration of the disease, visual analog scale (VAS) generated by physicians (VAS-physician), patient-reported VAS for pain (VAS-pain), VAS for general health (VAS-GH), disability level using the Japanese version of the Health Assessment Questionnaire (J-HAQ), C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor (RF), and hemoglobin. Of the 3945 patients registered at baseline, 955 (24.2%) had pain or tenderness in their knee joints, and 114 (11.9%) had TKA surgery in one or both knee joints. On PL-Cox regression, the variables with positive coefficients were J-HAQ, VAS-pain, VAS-physician, and RF positive; advanced age was associated with a reduced risk of TKA. The hazard ratios were: 0.920 for age >60 years; 2.64 for J-HAQ <1.5; 1.01 for J-HAQ >1.5; 1.47 for VAS-pain >6 (cm); 1.20 for VAS-physician >4 (cm); and 2.08 for RF positive. The consistently predictive factors for TKA in RA were age, J-HAQ, VAS-pain, VAS-physician, and RF positive. Age greater than 60 years was associated with a decreased risk of TKA, while J-HAQ from 0 to 1.5, VAS-pain >6 (cm), and VAS-physician >4 (cm) were associated with an increased risk for TKA surgery. These results suggest that, when treating RA patients, physicians should pay particular attention to pain complaints, the patient's daily activity level, and the RF factor status.

Cartilage, SOX9 and Notch signals in chondrogenesis

Cartilage repair is an ongoing medical challenge. Tissue engineered solutions to this problem rely on the availability of appropriately differentiated cells in sufficient numbers. This review discusses the potential of primary human articular chondrocytes and mesenchymal stem cells to fulfil this role. Chondrocytes have been transduced with a retrovirus containing the transcription factor SOX9, which permits a greatly improved response of the cells to three-dimensional culture systems, growth factor stimulation and hypoxic culture conditions. Human mesenchymal stem cells have been differentiated into chondrocytes using well-established methods, and the Notch signalling pathway has been studied in detail to establish its role during this process. Both approaches offer insights into these in vitro systems that are invaluable to understanding and designing future cartilage regeneration strategies.

Concurrent delivery of dexamethasone and VEGF for localized inflammation control and angiogenesis

Localized elution of corticosteroids has been used in suppressing inflammation and fibrosis associated with implantation and continuous in vivo residence of bio-medical devices. However, these agents also inhibit endogenous growth factors preventing angiogenesis at the local tissue, interface thereby delaying the healing process and negatively impacting device performance. In this work, a combination of dexamethasone and vascular endothelial growth factor (VEGF) was investigated for concurrent localized delivery using PLGA microsphere/PVA hydrogel composites. Pharmacodynamic effects were evaluated by histopathological examination of subcutaneous tissue surrounding implanted composites using a rat model. The hydrogel composites were capable of simultaneously releasing VEGF and dexamethasone with approximately zero order kinetics. Composites were successful in controlling the implant/tissue interface by suppressing inflammation and fibrosis as well as facilitating neo-angiogenesis at a fraction of their typical oral or i.v. bolus doses. Implants containing VEGF showed a significantly higher number of mature blood vessels at the end of the 4 week study irrespective of the presence of dexamethasone. Thus, localized concurrent elution of VEGF and dexamethasone can overcome the anti-angiogenic effects of the corticosteroid and can be used to engineer inflammation-free and well-vascularized tissue in the vicinity of the implant. These PLGA microsphere/PVA hydrogel composites show promise as coatings for implantable bio-medical devices to improve biocompatibility and ensure in vivo performance.