Knee flexion contractures in patients with osteoarthritis: clinical features and histologic characterization of the posterior capsule

Defining the extracellular matrix in non-cartilage soft-tissues in osteoarthritis: a systematic review

Aims

Extracellular matrix (ECM) is a critical determinant of tissue mechanobiology, yet remains poorly characterized in joint tissues beyond cartilage in osteoarthritis (OA). This review aimed to define the composition and architecture of non-cartilage soft joint tissue structural ECM in human OA, and to compare the changes observed in humans with those seen in animal models of the disease.

Methods

A systematic search strategy, devised using relevant matrix, tissue, and disease nomenclature, was run through the MEDLINE, Embase, and Scopus databases. Demographic, clinical, and biological data were extracted from eligible studies. Bias analysis was performed.

Results

A total of 161 studies were included, which covered capsule, ligaments, meniscus, skeletal muscle, synovium, and tendon in both humans and animals, and fat pad and intervertebral disc in humans only. These studies covered a wide variety of ECM features, including individual ECM components (i.e. collagens, proteoglycans, and glycoproteins), ECM architecture (i.e. collagen fibre organization and diameter), and viscoelastic properties (i.e. elastic and compressive modulus). Some ECM changes, notably calcification and the loss of collagen fibre organization, have been extensively studied across osteoarthritic tissues. However, most ECM features were only studied by one or a few papers in each tissue. When comparisons were possible, the results from animal experiments largely concurred with those from human studies, although some findings were contradictory.

Conclusion

Changes in ECM composition and architecture occur throughout non-cartilage soft tissues in the osteoarthritic joint, but most of these remain poorly defined due to the low number of studies and lack of healthy comparator groups.

Inferior patellar mobility before and after knee arthroplasty: A comparison with healthy knees

PURPOSE

The aim of this study was to evaluate patellar mobility in patients before and after knee arthroplasty (KA) and compare it with that of healthy subjects. It was hypothesised that patellar mobility is diminished in patients with osteoarthritis (OA) and remains unchanged after KA.

METHODS

A total of 101 patients (59 females and 42 males) with a mean age of 70.9 ± 9.9 years underwent KA and were compared with 25 healthy individuals (seven females and 18 males) with a mean age of 32.3 ± 9.3 years. Mediolateral patellar displacement was measured by applying a force of 10 N, and the medial and lateral patellar shifts were recorded separately using a validated novel patellostabilometer. Patients were examined preoperatively and at 3 months postoperatively, assessing the range of knee motion and the clinical and functional status based on the Oxford Knee Score (OKS), Kujala Score, subjective Knee Society Score (sKSS), Forgotten Joint Score (FJS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC).

RESULTS

Total patellar displacement was 42.1 ± 6 mm for healthy subjects, 31 ± 6 mm before surgery and 32.8 ± 7.8 mm after surgery in osteoarthritic patients (p < 0.01). The mean lateral patellar shift differed significantly between healthy individuals (17.9 ± 4 mm) and osteoarthritic patients (15.1 ± 6 mm) (p < 0.01). The mean medial patellar mobility of healthy individuals (24.2 ± 7 mm) was significantly greater than that of osteoarthritic patients (15.8 ± 4.8 mm) (p < 0.01). All scores improved significantly postoperatively. No correlation was found between patellar mobility and OKS, Kujala Score, sKSS, FJS and WOMAC (r = -0.11). Improvement in patellar mobility also showed no correlation with clinical outcomes according to OKS, Kujala Score, sKSS, FJS and WOMAC (r = 0.08).

CONCLUSION

This study has demonstrated reduced patellar mobility in patients with OA. While patellar mobility significantly improved after KA, it may not hold clinical significance (p = 0.04). No impact on clinical outcome can be expected when the presurgical patella mobility is preserved in KA.

LEVEL OF EVIDENCE

Level IV.

Effect of posterior capsular release on intraoperative joint gap mismatch in the mid-flexion range during posterior-stabilized total knee arthroplasty

INTRODUCTION

Intraoperative mismatch between extension and mid-flexion joint gaps remains a critical issue in posterior-stabilized total knee arthroplasty (PS-TKA). Posterior capsular release has been found to increase the extension joint gap. However, there is still a lack of robust evidence for the effect of posterior capsular release on the mid-flexion joint gap. The purpose of the present study was to quantify the effect of posterior capsular release on the intraoperative joint gap from extension through 45° mid-flexion to flexion and to clarify how this procedure might affect the improvement of gap mismatch in the mid-flexion 45° range.

MATERIALS AND METHODS

In total, 38 consecutive cases of primary PS-TKA were reviewed. The center, medial, and lateral component gaps from extension to flexion were measured with a tensor device before and after posterior capsular release. The minimal detectable change for joint gap measurement was calculated using two methods, error variance and intra-observer intraclass correlation coefficients. Pre- and post-release joint gap differences were assessed using the paired t-test.

RESULTS

Minimal detectable change was found to be 0.59 mm. At 0° and 10° of flexion, the post-release center, medial, and lateral component gaps were significantly greater than at pre-release. At 45° and 90° and maximum flexion, there were no joint gap differences exceeding the minimal detectable change. The joint gap mismatches between 0° and 10°, and 45°, 90° and maximum flexion were significantly smaller at post-release than those at pre-release with the change values exceeding the minimal detectable change (P < 0.05).

CONCLUSION

Posterior capsular release significantly decreased both joint gap mismatch between extension and 45° mid-flexion, and extension and flexion, showing clinical usefulness in PS-TKA.

Effect of posteromedial vertical capsulotomy with medial collateral ligament liberation on intraoperative medial component gap mismatch between extension and mid-flexion during total knee arthroplasty

PURPOSE

The aim of this study was to quantify the effect of posteromedial vertical capsulotomy on intraoperative component gaps and angles from extension through mid-flexion to flexion during total knee arthroplasty (TKA).

METHODS

In the present study, 47 cases of primary posterior-stabilized TKA using the measured resection technique for varus knee osteoarthritis (hip-knee-ankle angles < 0°) were reviewed. Component gaps and angles at 0°, 10°, 45°, 90°, and maximum flexion were measured intraoperatively, before and after posteromedial vertical capsulotomy. Differences in pre- and post-posteromedial vertical capsulotomy medial and lateral component gaps and angles and medial component gap mismatches among knee flexion angles were assessed using the Wilcoxon signed rank test for two paired samples.

RESULTS

The medial component gaps at 0° and 10° of flexion of post-posteromedial vertical capsulotomy were significantly greater, exceeding the minimal detectable change, than those pre posteromedial vertical capsulotomy (change of the gap after the procedure at 0° of flexion was 0.7 ± 0.7 mm and at 10° of flexion was 0.8 ± 0.8 mm; all P values < 0.05). The medial component gap mismatches between both 0° and 10°, and 45°, 90°, and maximum flexion were significantly smaller post posteromedial vertical capsulotomy than pre posteromedial vertical capsulotomy, with the values of the change exceeding the minimal detectable change (change of the gap mismatch after the procedure: knee flexion at 0° and 45° was - 0.6 ± 0.9 [mm], at 0° and 90° was 0.7 ± 1.0, at 0° and maximum flexion was - 0.6 ± 1.2, at 10° and 45° was - 0.7 ± 0.9, at 10° and 90° was - 0.8 ± 0.9, at 10° and maximum flexion was - 0.7 ± 1.1; all P values < 0.05).

CONCLUSIONS

Posteromedial vertical capsulotomy increased the medial component gaps during knee extension but not during mid-flexion or full flexion during posterior-stabilized TKA. Posteromedial vertical capsulotomy improved mild medial component gap mismatch between extension and mid-flexion and full flexion during posterior-stabilized TKA. Surgeons can consider posteromedial vertical capsulotomy when there is intraoperative constriction of the medial component gap during extension in patients undergoing posterior-stabilized TKA.

The Natural History of Knee Osteoarthritis Pain Experience and Risk Profiles

The study aimed to characterize the natural history of the pain experience, concurrently considering intermittent and constant pain over 4 years, and determine baseline factors associated with unfavorable trajectories in individuals with chronic knee pain. The Osteoarthritis Initiative (OAI) is a prospective, observational study of people with or at higher risk for knee osteoarthritis. The Intermittent and Constant Osteoarthritis Pain (ICOAP) was assessed annually at 48-to-96-month OAI visits. Twenty-eight baseline sociodemographic, knee-specific, and health-related characteristics were assessed. Group-based dual-trajectory modeling identified pain experience patterns indicated by ICOAP intermittent and constant pain scores over 4 years. Multivariable multinomial logistic regression models determined baseline factors associated with membership in each dual-trajectory group. Four longitudinal pain experience patterns were identified (n = 3,584, mean age = 64.8 [standard deviation 9.0] years, BMI = 28.6 [5.0] kg/m2; 57.9% women). Group 1 (37.7%) had minimal intermittent and no constant pain; Group 2 (35.1%) had mild intermittent and no constant pain; Group 3 (18.5%) had mild intermittent and low-grade constant pain; and Group 4 (8.7%) had moderate intermittent and constant pain. Baseline widespread pain, knee stiffness, back pain, hip pain, ankle pain, obesity, depressive symptoms, more advanced radiographic disease, and analgesic use were each associated with an increased risk of membership in less favorable Groups 2, 3, and 4. These distinct courses of pain experience may be driven by different underlying pain mechanisms. The benchmarked ICOAP scores could be used to stratify patients and tailor management. Addressing and preventing the development of modifiable risks (eg, widespread pain and knee joint stiffness) may reduce the chance of belonging to unfavorable dual-trajectory groups. PERSPECTIVE: Concurrently tracking intermittent versus constant pain experience, group-based dual-trajectory modeling identified 4 distinct pain experience patterns over 4 years. The benchmarked ICOAP scores in these dual trajectories could aid in stratifying patients for tailored management strategies and intensity of care.

Unrestricted kinematic alignment corrects fixed flexion contracture in robotically aligned total knees without raising the joint line in extension

PURPOSE

Mechanically Aligned Total Knee Arthroplasty (MA TKA) typically addresses fixed flexion contractures (FFC) by raising the joint line during extension. However, in unrestricted Kinematically Aligned TKA (KA TKA) utilizing a caliper-based resection technique, the joint line is not raised. This study aims to determine the efficacy of KA TKA in restoring full extension in patients with FFC without increasing distal femoral resection, considering tibial bone resection and sagittal component positioning.

METHODS

A retrospective study was conducted by a single surgeon, involving patients who underwent primary robotically assisted cruciate retaining unrestricted KA TKA between June 1, 2021, and December 1, 2022. Complete intraoperative resection and alignment data were recorded, including the thickness of distal femoral and proximal tibial bone cuts. Patients with a preoperative FFC ≥ 5° (study group) were compared to those with FFC < 5° (control group). The impact of variations in tibial resection and sagittal component positioning was assessed by comparing the heights of medial and lateral resections, sagittal femoral component flexion, and tibial slope. Group comparisons were analyzed using the Wilcoxon Signed Rank Test, with a significance level set at p < 0.05.

RESULTS

A total of 48 KA TKA procedures met the inclusion criteria, with 24 performed on women. The mean preoperative FFC in the study group was 11.2° (range: 5-25°), while the control group exhibited 1° (range: 0-4°) (p < 0.001). There were no statistically significant differences observed between the study and control groups in terms of distal femoral resections, both medially (p = 0.14) and laterally (p = 0.23), as well as tibial resection heights, both medially (p = 0.66) and laterally (p = 0.74). The alignment of the femoral component flexion and tibial slope was comparable between the two groups (p = 0.31 and p = 0.54, respectively). All patients achieved within 5 degrees of full extension at closure.

CONCLUSION

Robotic arm-assisted unrestricted KA TKA effectively restores full extension without raising the joint line during extension for patients with a preoperative fixed flexion contracture.

LEVEL OF EVIDENCE

III.

Stretching, Bracing, and Devices for the Treatment of Osteoarthritis-Associated Joint Contractures in Nonoperated Joints: A Systematic Review and Meta-Analysis

CONTEXT

Many patients with osteoarthritis (OA) develop range of motion (ROM) restrictions in their affected joints (contractures), associated with worse outcomes and rising healthcare costs. Effective treatment guidance for lost ROM in OA-affected joints is lacking.

OBJECTIVE

A systematic review and meta-analysis evaluating the effectiveness of stretching and/or bracing protocols on native (nonoperated) joint ROM in the setting of radiographically diagnosed OA.

DATA SOURCES

Seven databases, English-language.

STUDY SELECTION

Studies including participants with radiographically diagnosed OA in any native joint evaluating the effect of stretching or bracing on ROM.

STUDY DESIGN

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level 2.

DATA EXTRACTION

Two reviewers independently screened articles for inclusion and assessed risk of bias in included trials. Primary outcomes were ROM, pain, and adverse events (AEs).

RESULTS

We identified 6284 articles. A total of 9 randomized controlled trials, all evaluating the knee, met eligibility criteria. For stretching, 3 pooled studies reported total ROM, which improved by mean difference (MD) of 9.3° (95% CI 5.0°,13.5°) versus controls. Two pooled studies showed improved knee flexion ROM (MD 10.8° [7.3°,14.2°]) versus controls. Five studies were pooled for knee extension with mean improvement 9.1° [3.4°,14.8°] versus controls. Seven pooled studies showed reduced pain (standardized MD 1.9 [1.2,2.6]). One study reported improved knee extension of 3.7° [2.9°,4.5°] with use of a device. No studies used orthoses. One study reported on AEs, with none noted. Performance bias was present in all included studies, and only 3 studies clearly reported blinding of outcome assessors. Strength of evidence for primary outcomes was considered moderate.

CONCLUSION

There was moderate-quality evidence that stretching is an effective strategy for improving knee total, flexion and extension ROM, and pain. Our findings suggest that stretching to regain joint ROM in OA is not futile and that stretching appears to be an appropriate conservative intervention to improve patient outcomes as part of a comprehensive knee OA treatment plan before arthroplasty.

Predictors of Recurrent Flexion Contracture after Total Knee Arthroplasty in Osteoarthritic Knees with Greater Than 15° Flexion Contracture

Background

This study aimed to analyze the risk factors that predict recurrent flexion contracture (FC) after total knee arthroplasty (TKA) in osteoarthritic knees with FC ≥ 15°.

Methods

Data from a consecutive cohort comprising 237 TKAs in 187 patients with degenerative osteoarthritis, preoperative FC ≥ 15°, and a minimum follow-up period of 2 years were retrospectively reviewed. Preoperative FC was corrected intraoperatively from 0° to 5°. The incidence of recurrent FC (FC ≥ 10°) at 2 years postoperatively was investigated. Potential risk factors predicting recurrent FC including age, sex, body mass index, unilateral TKA, severity of preoperative FC, 3-month postoperative residual FC, γ angle, change in posterior femoral offset ratio, and lumbar degenerative kyphosis (LDK) were analyzed using logistic regression analysis. The post-hoc powers for the identified factors were then determined.

Results

Forty-one knees (17.3%) with recurrent FC were identified. Risk factors with sufficient power for recurrent FC were unilateral TKA, severity of preoperative FC, residual FC at 3 months postoperatively, and LDK (odds ratios of 3.579, 1.115, 1.274, and 3.096, respectively; p < 0.05; power ≥ 86.1).

Conclusions

Recurrent FC can occur in TKAs with the risk factors including unilateral TKA, severe preoperative FC, residual FC at 3 months postoperative, and LDK despite appropriate intraoperative correction. Surgical strategies and rehabilitation protocols used in managing FC should be applied in TKA cases with risk factors for recurrent FC.

Preoperative flexion contracture does not affect outcome in total knee arthroplasty: A case-control study of 2,634 TKAs

BACKGROUND

One issue in total knee arthroplasty (TKA) is management of preoperative flexion contracture, which may be associated with poor functional outcome.

AIM

The aim of this study was to compare functional results in TKA with or without preoperative flexion contracture, treated according to a standardized algorithm of tissue release and bone cut.

PATIENTS AND METHOD

A single-center retrospective case-control study was performed on prospectively collected data for the period 1987-2016. Patients with >10̊ flexion contracture were assigned to the "contracture" group and associated to a selected control group at a ratio of 1:4. Clinical analysis used pre and post-operative International Knee Society (IKS) scores. The significance threshold was set at p<0.05.

RESULTS

Eight hundred and forty-nine cases and 3,304 controls were included, comprising a total of 2,838 male and 1,315 female participants. Mean preoperative extension deficit was 13̊±6̊ in the contracture group and 1̊±2̊ in controls. Preoperative IKS total and functional scores were significantly poorer in the contracture group (38±18 and 54±20) than in controls (52±16 and 59±19) (p<0.001). Postoperatively, the two groups did not significantly differ in IKS functional score (77±22 vs. 79±21, p=0.143). There were differences in IKS knee score (87±12 vs. 88±13, p=0.006) and maximal flexion (114̊±14̊ vs. 119̊±13̊, p<0.0001) that were statistically, but not clinically, significant.

DISCUSSION

A systematic standardized algorithm for surgical treatment of flexion contracture during primary total knee arthroplasty provided clinical outcomes similar to those of patients without preoperative flexion contracture.

LEVEL OF EVIDENCE

III; case-control study.

Factors associated with joint contractures in adults: a systematic review with narrative synthesis

PURPOSE

The primary objective of the review was to collate the available evidence on factors associated with joint contractures in adults.

METHODS

A systematic literature search was conducted on MEDLINE, CINAHL, AMED, and EMBASE. Studies that involved participants aged ≥18 and assessed joint contracture as a primary or secondary outcome were included. Two independent reviewers screened studies against the eligibility criteria, performed data extraction, and assessed the quality of evidence. A narrative synthesis by domain and sub-domain was undertaken. The protocol was registered on PROSPERO: CRD42019145079.

RESULTS

Forty-seven studies were included in the review. Identified factors were broadly classified into three major domains: sociodemographic factors, physical factors, and proxies for bed confinement. Sociodemographic factors were not associated with joint contractures. Functional ability, pain, muscle weakness, physical mobility, and bed confinement provided the most consistent evidence of association with joint contractures. The evidence regarding the relationship between spasticity and joint contractures remains unclear. Other factors might be important, but there was insufficient evidence to make inferences.

CONCLUSIONS

The review identified and collated evidence on factors associated with joint contractures, which can be utilised to develop effective prevention and management strategies. Implications for rehabilitationClinical interventions based on the timely identification of risks related to joint contractures in vulnerable adults have the potential to prevent or ameliorate their development or progression.Quality and consistency of care for vulnerable adults would be enhanced by developing effective joint contracture prevention and rehabilitation strategies based on the evidence presented in this review.As many vulnerable adults are located in the community or non-acute care settings, strategies should target these loci of care.Structured risk assessments that can support non-physiotherapy staff working in these loci of care to identify risks related to joint contractures would provide an important resource for risk management.

Both arthroscopic and open posterior knee capsulotomy are effective in terms of extension recovery and functional improvement-systematic review

PURPOSE

To assess the recovery of extension and improvement in functional scores after an arthroscopic or open posterior knee capsulotomy in the setting of an extension deficit.

METHODS

A systematic search of articles published between 1980 and 2020 was performed in the MEDLINE/PubMed database, EMBASE/Ovid database and Web of Science database. The inclusion criteria consisted of patients with primary extension deficits > 5° who underwent an arthroscopic or open posterior knee capsulotomy. The assessed outcomes were preoperative and postoperative range of motion and functional outcome scores. Randomized controlled trials, cohort studies and case series with a follow-up longer than 6 months were included. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for case series. The certainty of evidence was assessed using the GRADE approach.

RESULTS

Of 226 records identified through database searching, 7 studies were included in the final analysis. The outcomes of 107 patients with a mean age of 34.1 (range 15-63) years were available. In all the included studies, a posterior capsulotomy resulted in the restoration of knee extension to normal or nearly normal values (mean postoperative extension deficit: 0.4-4.2 degrees) with a significant increase in functional outcome scores. No neurovascular complications were reported within the studies. Due to the diverse methodology of studies, the direct comparison of arthroscopic versus open approaches was not possible. Concerning the risk of bias assessment, the greatest concerns raised the selection of participants among the included studies and the methods of outcome measurement. The certainty of evidence was very low according to the GRADE.

CONCLUSIONS

Both arthroscopic and open posterior capsulotomy of the knee results in restoration of normal or nearly normal knee extension and significant improvement in functional outcomes.

LEVEL OF EVIDENCE

IV.

Associations among quality of life, activities, and participation in elderly residents with joint contractures in long-term care facilities: a cross-sectional study

BACKGROUND

Joint contractures and degenerative osteoarthritis are the most common joint diseases in the elderly population, can lead to limited mobility in elderly individuals, can exacerbate symptoms such as pain, stiffness, and disability, and can interfere with social participation and quality of life, thus affecting mental health. However, relevant studies on this topic are very limited. This study describes the associations of joint contracture categories and sites in elderly residents in long-term care facilities with their quality of life, activities, and participation.

METHODS

Elderly individuals with joint contractures who were residents in long-term care facilities were recruited. The World Health Organization (WHO) Quality of Life and the WHO Disability Assessment Schedule 2.0 were used to survey the participants. Correlations, multiple linear regressions, and multiple analyses of variance, with joint contractures as the response variable, were used in the statistical analysis.

RESULTS

The final statistical analysis included 232 participants. The explanatory power of contracture sites on activities and participation had a moderate strength of association (η2 = .113). Compared with elderly residents with joint contractures and osteoarthritis isolated to the upper limbs, those with joint contractures and osteoarthritis in both the upper and lower limbs had significantly worse activity and participation limitations. No significant differences in activity and participation were found between elderly residents with joint contractures affecting only the upper limbs and those with joint contractures affecting only the lower limbs (F1,226 = 2.604 and F1,226 = 0.674, nonsignificant). Osteoarthritis had the greatest impact on activity limitations and participation restrictions among elderly residents with joint contractures affecting both the upper and lower limbs (F1,226 = 6.251, p = .014).

CONCLUSIONS

Elderly residents in long-term care facilities belonging to minority groups, with a history of stroke, and with osteoarthritis are at a high risk of developing activity limitations and participation restrictions. Moreover, compared with other contraction sites, regardless of osteoarthritis, joint contractures affecting both the upper and lower limbs were associated with the greatest activity limitations and participation restrictions.

TRIAL REGISTRATION

This study has been registered in the Chinese Clinical Trial Registry, registration number and date: ChiCTR2000039889 (13/11/2020).

Rotating Hinge Prosthesis for Primary and Revision Knee Arthroplasty: Comparison and Indications

Background. Rotating hinge knee prostheses are typically used in revision and severe primary total knee arthroplasty (TKA). For these challenging patient groups, currently only few studies with mid- or even long-term follow-up and adequate patient numbers are available. In addition, a more specific definition is needed of the indications for a rotating hinge prothesis in primary patients beyond the use in bone defects. Methods. In this prospective study, 170 primary and 62 revision TKA patients were included who received a rotating hinge knee prosthesis at the study centre between the years 2009 and 2014. Of these, 98 primary and 22 revision TKA patients were available for 5-year functional and clinical follow-up examinations. Prosthesis survival in both patient groups could be compared up to a 9-year follow-up. Results. Postoperatively, functional results including range of motion (ROM) and clinical scores like the Oxford Knee Score (OKS) and subscales of the Knee Society Score (KSS) improved better in patients treated for primary knee arthroplasty than for revision patients. Besides the patient group (primary vs. revision TKA), no overall influencing factors (age, body mass index, gender, etc.) regarding functional results could be identified in a multiple linear regression analysis. The revision rate of primary patients was significantly lower than in the revision patients, with an 8-year Kaplan-Meier prosthesis survival of 88% in the Primary and 60% in the Revision group. Conclusion. The prosthesis provides promising results in severe primary and revision knee arthroplasty. In addition to commonly agreed recommendations regarding the use of rotating hinge knee prostheses for primary surgery, six specific indications are proposed and discussed here as a base for scientific debate.

Arthroscopic Posterior Capsulotomy for Knee Flexion Contracture Using a Spinal Needle

Knee flexion contractures can arise from posterior capsule arthrofibrosis secondary to trauma, surgery, or chronic degenerative disease. This leads to limited knee extension and increased mechanical stress on the contralateral joint. Depending on the severity of the contracture, a treatment option may include surgical release of the posterior capsule. Arthroscopic posterior capsular release has been reported previously to have excellent resolution of extension deficits with minimal risk of postoperative complications. These techniques typically use an array of instruments, including shavers, biters, or scissors to perform arthrolysis of the posteromedial and posterolateral capsules. Our primary objective is to present a modified arthroscopic surgical technique for percutaneous treatment of knee flexion contracture using a spinal needle to perform a posterior capsule release.

Immediate Effect of Restricted Knee Extension on Ground Reaction Force and Trunk Acceleration during Walking

Gait parameters calculated from trunk acceleration reflect the features of gait; however, they cannot evaluate the gait pattern corresponding to the gait cycle. This study is aimed at investigating the differences in gait parameters calculated from trunk acceleration during gait corresponding to the gait cycle in healthy subjects with restricted knee extension. Participants included eight healthy volunteers who walked normally (NW) and with knee orthosis that restricted knee extension (ER). The ground reaction force (GRF), joint angles, and trunk acceleration during walking were measured using four force plates, a three-dimensional motion analysis system, and an inertial measurement unit. The peak GRF of the vertical components, joint ranges of motion, and moments of force were analyzed. The root mean square (RMS) and amplitude peak ratio (AR) of autocorrelation function were calculated from the trunk acceleration waveform. The first peak GRF and peak ankle dorsiflexion angles significantly increased during ER. The peak hip extension, knee flexion, knee extension angles, and the peak moment of knee extension significantly decreased during ER compared to that during NW. The acceleration AR significantly decreased during ER compared to that during NW. There was no significant difference in the RMS between the two conditions. The acceleration AR may show the temporal postural structure with restricted knee extension from the terminal stance phase for the ipsilateral limb to the initial stance phase for the contralateral limb. These results suggest that novel metrics for accelerometry gait analysis can reveal gait abnormalities, with restricted knee extension corresponding to the gait cycle.

Modular reorganization of gait in chronic but not in artificial knee joint constraint

It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. The aims of this study were to investigate 1) the effects of an artificial knee joint constraint on the modular organization of gait in healthy subjects; and 2) the differences in modular organization between healthy subjects with an artificial knee joint constraint and people with a similar but chronic knee joint constraint. Eleven healthy subjects and eight people with a chronic knee joint constraint walked overground at 1 m/s. The healthy subjects also walked with a constraint limiting knee joint movement to 20°. The total variance accounted (tVAF) for one to four synergies and modular organization were assessed using surface electromyography from 11 leg muscles. The distribution of number of synergies were not significantly different between groups. The tVAF and the motor modules were not significantly affected by the artificial knee constraint. A higher tVAF for one and two synergies, as well as merging of motor modules were observed in the chronic knee constraint group. We conclude that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that merging of motor modules may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.NEW & NOTEWORTHY It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. This study showed that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that modular reorganization may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.

Flexion contracture is a risk factor for knee osteoarthritis incidence, progression and earlier arthroplasty: Data from the Osteoarthritis Initiative

BACKGROUND

Knee joint osteoarthritis (OA) is often accompanied by flexion contracture (FC), but the impact of FC on important outcomes across the spectrum of OA, such as the incidence, progression and need for total knee arthroplasty (TKA), is not well established.

OBJECTIVE

We evaluated whether the presence and/or severity of knee FC were risk factors for worse OA clinical outcomes, radiographic incidence and progression as well as time to TKA.

METHODS

We evaluated longitudinal 9-year data from the Osteoarthritis Initiative (OAI) database for 3 sub-cohorts: at-risk of knee OA (n=3284), radiographically established knee OA (n=1390), and low-risk controls (n=122). We classified knee FC as none, mild, moderate or severe based on knee extension at enrolment. Knee OA outcomes were extracted from the database.

RESULTS

FC was present in 32.4% of knees. Participants with FC had increased knee OA incidence with joint space narrowing in the definition (corrected odds ratio 1.31 [95% confidence interval (CI) 1.04-1.64]). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain, stiffness and function were worse with than without FC at nearly all times (p<0.001). Effect estimates were significant for all 3 WOMAC sub-scales comparing FC to no FC (pain: 0.15 [95% CI 0.02-0.28], stiffness: 0.11 [0.05-0.18], function: 0.49 [0.05-0.93]). Individuals with knee FC had higher Kellgren and Lawrence grade (effect size 0.31 [95% CI 0.25-0.37]) and were more likely to undergo TKA (corrected odds ratio 1.37 [95% CI 1.10-1.71]) than those without FC. All outcomes were worse with increasing FC severity.

CONCLUSION

The presence of knee FC at enrolment was a risk factor for radiographic OA incidence including joint space narrowing, worse clinical outcomes, radiographic progression and the need for early TKA. Treatment of knee FC may represent an option across the OA spectrum. Further research is needed to evaluate the pathophysiology, joint structure alterations and longitudinal impact of treating FC in individuals with knee OA.

Pelvis/lower extremity alignment and range of motion in knee osteoarthritis: A case-control study in elderly Japanese women

BACKGROUND

The prevalence of radiographic knee osteoarthritis (OA) in Japan is high, with an estimated 25,300,000 affected individuals.

OBJECTIVE

The purpose of this study was to clarify the characteristics of knee osteoarthritis by comparing differences between patients with knee osteoarthritis and healthy elderly individuals with respect to alignment of the pelvis and lower extremities and range of motion.

METHODS

Twenty-six women (13 with medial knee osteoarthritis and 13 healthy elderly) participated in this study. Pelvic tilt, knee extension angle, femoro-tibial angle, quadriceps angle, navicular drop, and leg-heel alignment were measured. In addition, the range of motion was measured at the hip, knee, and ankle joints.

RESULTS

Patients with knee osteoarthritis showed a posterior pelvic tilt, knee flexion, varus, and foot pronation alignment compared to healthy subjects. The range of motion for hip extension, adduction, knee flexion, extension, and ankle dorsiflexion was significantly smaller while the range of motion for eversion was significantly larger in the knee osteoarthritis group.

CONCLUSION

People with medial knee OA have different static alignment and ROM compared to those without knee OA. The results clarify the comprehensive characteristics of the pelvis and lower extremities in knee osteoarthritis.

Risk scoring for time to end-stage knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

This study constructs a risk score for patients' progression to end-stage knee osteoarthritis (OA) within 4 years.

DESIGN

The Osteoarthritis Initiative (OAI) was a longitudinal study of the onset and progression of knee OA. Using a recent definition of end-stage knee OA, we implement interval-censored survival forests to select predictors of this endpoint. We fit an interval-censored Cox model for time to end-stage knee OA, using the selected predictors. The risk score is the Cox model's fitted linear combination of the nine selected baseline structural and symptomatic knee OA variables.

RESULTS

We fit our models on a training set of 2,701 patients, and we evaluate on an independent test set of 1,436 patients. On the test sample, we observe a concordance index of 0.86 between risk score and time to end-stage, AUC of 0.87 for predicting end-stage within 24, 36, and 48 months, and positive predictive values that increase with the risk score. This risk stratification algorithm could enrich clinical trial patient enrollment. By enrolling test sample patients with scores above a threshold, a trial could have included 91% of test set patients who reach end-stage within 4 years while only enrolling 45% of the test sample.

CONCLUSION

Using statistical methods, we construct and validate an interpretable risk score for time to end-stage knee OA. This score can help disease-modifying OA treatment developers to select candidates with the highest risk of fast-progressing knee OA.

Advanced functional biomechanical analysis of medial rotation knee arthroplasty

BACKGROUND

The Medacta GMK-Sphere total knee arthroplasty (TKA) is designed to mimic the movements and stabilimidty of a natural knee for optimal post-operative function and mobility. This study aimed to quantify the early functional outcome of patients with this implant.

METHODS

Patients due to undergo TKA to treat end-stage osteoarthritis were recruited into this study. Functional tests of knee range of motion (ROM), strength, and gait kinematics were carried out pre-operatively and one year post-operatively at routine clinics. Motion capture technology and a force transducer were used to collect all data. Normality tests were completed on all data sets to confirm normal distribution of the data, then paired t-tests were used to statistically compare the results. The level of significance was set as α = 0.05.

RESULTS

Sixty-three patients underwent pre-operative assessments; of which 30 returned one year post-operatively and consented to have follow-up testing. The operative knee was found to have poorer function than the contralateral knee pre-operatively (p < 0.05). Post-operatively, knee ROM significantly improved on the operative side to a mean of 116.1 ± 19.0. Gait kinematics also improved, especially in the frontal plane, but some abnormal traits remained in the sagittal plane. Knee strength decreased post-operatively.

CONCLUSIONS

The Medacta GMK-Sphere TKA improves knee range of motion sufficiently within the first postoperative year to allow patients to carry out most activities of daily living (>110° knee flexion), but continued poor knee strength may limit their abilities to complete tasks which are more biomechanically demanding than walking.

The effect of balneotherapy and peloid therapy on changes in the functional state of patients with knee joint osteoarthritis: a randomized, controlled, single-blind pilot study

The treatment of OA using pharmaceutical and non-pharmaceutical measures remains a topical subject. The purpose of this study is to assess the effect of natural factors (mineral water and mud) on changes in the functional state of patients with knee joint OA. Ninety-two adult people with grade I-III knee joint OA according to the Kellgren and Lawrence scoring system participated in the study. The subjects received 10 mineral water bath plus physical therapy or mud application procedures plus physical therapy or physical therapy alone every other day. The effectiveness of the treatment was assessed on the basis of anthropometric changes of data, VAS, SF-36, KOOS questionnaire indicators. Significantly greater walking speed, test of 5 sit downs/stand ups, circumference of a knee joint, flexion and extension range, flexor and extensor strength after treatment lasting 1 month were obtained in the intervention group. After 1 month after treatment pain intensity scores over the past month and when changing position were significantly higher in the control group. The positive changes in SF-36 were identified after 1 month after treatment: physical activity increased and pain decreased in the intervention groups. There was no significant difference between the averages of any KOOS subscale in groups. However, average percentages of symptoms, stiffness, and pain in the intervention groups were significantly better after treatment and lasting 1 month after treatment. Balneotherapy and peloid therapy effectively reduce pain and improve the functional state of patients with OA of a knee joint.

Association between stages of medial compartment osteoarthritis and three-dimensional knee alignment in the supine position: A cross-sectional study

BACKGROUND

Osteoarthritis (OA) of the knee causes changes in knee alignment. A detailed knowledge of knee alignment is needed for correct assessment of the extent of disease progression, determination of treatment strategy, and confirmation of treatment effectiveness. However, deterioration of knee alignment during progression of OA has not been adequately characterized. The aims of this study were to clarify the changes in three-dimensional static knee alignment as knee OA stage progressed and to lay a foundation for an optimal treatment strategy to prevent knee malalignment.

METHODS

A total of 106 knees of 81 patients ((men/women) 45/36; mean age 48.4 ± 19.9 years; body mass index (BMI) 25.7 ± 4.4 kg/m²) were enrolled in this cross-sectional study, comprising 34 (33/1) in Kellgren-Lawrence (KL) grade 0, 17 (8/9) in KL grade 1, 26 (5/21) in KL grade 2, 19 (4/15) in KL grade 3, and 10 (1/9) in KL grade 4. In all cases, computed tomography images were obtained with the subject in a reclined and relaxed position with the knee straight. Three-dimensional bone models were created from the images and knee alignment was calculated with six degrees-of-freedom. Then, 40 knees were selected consisting of 10 sex- and BMI-matched knees from each KL grade group: KL grade 1 (mean age 54.6 ± 8.4 years; BMI 23.3 ± 3.5 kg/m²), grade 2 (64.7 ± 10.9 years; 27.3 ± 3.2 kg/m²), grade 3 (69.2 ± 11.4 years; 27.1 ± 4.3 kg/m²), and grade 4 (71.9 ± 9.2 years; 27.2 ± 3.6 kg/m²). The Mann-Whitney U test with Bonferroni correction for multiple comparisons was used to analyze static alignment (α < 0.05/6).

RESULTS

Alignment of the knee in flexion was -4.0 [95% confidence interval (CI): -6.4, -1.5] degrees, -3.4 [-8.0, 1.3] degrees, -0.1 [-3.7, 3.5] degrees, and 0.4 [-0.9, 1.6] degrees in the order of KL grade 1 to 4. There were significant differences between KL grade 1 and 4 (p = 0.0081). Anterior tibial translation was 6.6 [4.6, 8.6] mm, 5.8 [1.9, 9.7] mm, 1.0 [-2.5, 4.5] mm, and 1.3 [-2.4, 5.1] mm in the order of grade 1 to 4. There were significant differences between KL grade 1 and 4 (p = 0.0081). There were no significant differences in lateral tibial translation nor tibial rotation.

CONCLUSIONS

The severely osteoarthritic knee joint was flexed and the tibia was displaced posteriorly with respect to the femur. Preventing these changes in alignment would assist in the prevention and treatment of knee OA.

Effectiveness of stretching and bracing for the treatment of osteoarthritis-associated joint contractures prior to joint replacement: a systematic review protocol

INTRODUCTION

Many patients with osteoarthritis (OA) develop restrictions in passive range of motion (ROM) of their affected joints (called contractures), leading to increased pain and reduced function. Effective treatment to reverse OA-associated contractures is lacking. Our aim is to evaluate the effectiveness of stretching and bracing on native (non-operated) joint contractures in people with radiographically diagnosed OA.

METHODS AND ANALYSIS

We will search the following databases without time restriction: Cochrane Library (CENTRAL, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database), MEDLINE, Embase, CINAHL, SCI-EXPANDED (ISI Web of Knowledge) and PEDro. Other sources will include WHO International Clinical Trials Registry Platform, reference lists of included studies, relevant systematic reviews and textbooks. We will include randomised controlled trials (RCTs), controlled clinical trials, controlled before-and-after studies, cohort studies and case-control studies that include participants ≥18 years of age with radiographic evidence of OA. Participants with inflammatory arthropathies or those that have undergone joint arthroplasty will be excluded. Interventions will include therapist-administered or patient-administered stretching, use of an orthosis (static or dynamic), use of serial casting and/or adjunctive modalities. Outcomes will include joint ROM (active and passive), pain (rest and/or activity related), stiffness, activity limitations, participation restrictions, quality of life and adverse events. Studies will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study inclusion, data extraction and quality assessment will be performed independently by two reviewers. Risk of bias will be assessed using appropriate tools for each study design. Data synthesis will be performed using Cochrane Review Manager software. If sufficient data are available, meta-analysis will be conducted. We will summarise the quality of evidence using Grading of Recommendations Assessment, and the effect size of interventions for RCT and non-RCT studies.

ETHICS AND DISSEMINATION

Ethics approval not required because individual patient data are not included. Findings will be disseminated in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019127244.

Arthroscopic Complete Posterior Capsulotomy for Knee Flexion Contracture

Knee flexion contracture is a clinically important complication that can be observed after trauma, after knee surgery, or as a result of osteoarthritis. When it is left untreated, knee shearing forces increase not only in the affected joint but also in the contralateral knee, leading to mechanical overload in both limbs. Conservative management is a first-line treatment option for extension deficits, but when it fails, surgical treatment is necessary. Open as well as arthroscopic techniques focus mainly on an anterior arthrolysis and a posterior capsular release. Until now, posterior capsulotomy involved either a medial posterior capsular release or medial and lateral posterior capsular releases. Our aim is to present the technique of arthroscopic complete posterior capsulotomy for knee flexion contractures.

Accumulation of advanced-glycation end products (AGEs) accelerates arthrogenic joint contracture in immobilized rat knee

Joint mobility decreases in the elderly and in diabetics, this process is thought to be caused by accumulation of advanced-glycation end products (AGEs). Here, we aimed to elucidate the role of AGEs in joint contracture formation in rat knees. Rats were injected with ribose or saline into the knees twice weekly for 8 weeks. Pentosidine (AGE) levels were measured in the knee-joint tissues. After serial injections, rats were subjected to unilateral knee-joint immobilization in a flexion position for various periods. At day 21, the passive knee ranges of motions (ROMs) were measured. Knee joint histopathology were assessed, and the expression of fibrotic genes in the posterior joint capsules was examined using real-time PCR. Ribose injection induced a 7.0-fold increase in pentosidine levels relative to saline injection. Joint immobilization resulted in equal myogenic ROM restriction in both groups. Arthrogenic ROM restriction was greater with ribose injection in the immobilized joints (p < 0.05), but was not affected in nonimmobilized joints. Type-I (COL1A1) and type-III (COL3A1) collagen gene expression increased significantly in immobilized joints relative to nonimmobilized joints in the ribose group, but was not affected in the saline group. Ribose injection increased COL1A1 expression slightly and COL3A1 expression significantly in immobilized joints. Histologically, inflammatory changes appeared at day 3 of immobilization and peaked at day 7. These responses trended to be more severe and prolonged in the ribose group than in the saline group. Our data provide evidence for a causal relationship between AGEs and joint contracture formation following immobilization. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:854-863, 2018.

Active exercise on immobilization-induced contractured rat knees develops arthrogenic joint contracture with pathological changes

This study investigated the effects of treadmill walking during remobilization on range of motion (ROM) and histopathology in rat knee joints, which were immobilized for 3 wk in a flexed position. After fixator removal, rats were divided into a no-intervention (RM) group and a group forced to walk on a treadmill daily at 12 m/min for 60 min (WALK group). Passive knee extension ROMs were measured before (m-ROM) and after (a-ROM) knee flexor myotomy on the first and last day of a 7-day remobilization period, with m-ROM mainly reflecting myogenic factors and a-ROM reflecting arthrogenic factors. Knee joints were histologically analyzed and gene expression of inflammatory or fibrosis-related mediators in the posterior joint capsule were examined. m-ROM and a-ROM restrictions were established after immobilization. m-ROM significantly increased following the remobilization period both in RM and WALK groups compared with that of immobilized (IM) group. Conversely, a-ROM decreased following the remobilization period in both RM and WALK groups compared with that of IM group. Importantly, a-ROM was smaller in the WALK group than the RM group. Remobilization without intervention induced inflammatory and fibrotic reactions in the posterior joint capsule after 1 and 7 days. Treadmill walking promoted these reactions and also increased the expression of fibrosis-related TGF-β1 and collagen type I and III genes. While free movement after immobilization improved myogenic contracture, arthrogenic contracture worsened. Treadmill walking further aggravated arthrogenic contracture through amplified inflammatory and fibrotic reactions. Thus active exercise immediately after immobilization may not improve immobilization-induced joint contracture.

NEW & NOTEWORTHY In clinical practice, it is widely accepted that facilitation of joint movements is effective in improving immobilization-induced joint contracture. However, whether active exercises improve arthrogenic contracture is not known. In this study, we revealed that treadmill walking further promoted remobilization-induced progression of arthrogenic contracture. To our knowledge, this is the first study demonstrating no favorable effect of active exercise on immobilization-induced arthrogenic contracture.

Bone replaces articular cartilage in the rat knee joint after prolonged immobilization

BACKGROUND

Lost joint range of motion (ROM) is common in chronic osteoarthritis, alters regional weight-bearing across the articular surfaces, and contributes to loss of cartilage and bone alterations. Limited data exist on the regional effects on joints subjected to chronic losses of ROM.

OBJECTIVE

To characterize the regional replacement by bone as part of articular cartilage degeneration after prolonged immobilization.

METHODS

Eleven rat knees were rigidly-immobilized in flexion for 32weeks with contralateral and sham-operated (n=6) knees as controls. Sagittal medial tibial epiphysis histological sections assessed the anterior (non-weight-bearing), middle and posterior (both weight-bearing) regions. We quantified the distribution of collagen I, collagen II, cartilage thickness, glycosaminoglycan (GAG) staining, Mankin scoring, and subchondral bone plate cross-sectional area. Using immunohistochemistry (IHC), we visualized blood vessels, osteoblasts, and mesenchymal stem cells (MSCs).

RESULTS

Immobilized cartilage had increased collagen I content in the anterior tibial region with picrosirius red staining (immobilized=61±20%; contralateral=43±12%, p=0.033; sham=20±10%, p=0.028) and collagen I IHC (immobilized=40±10%; contralateral=11±4%, p=0.003; sham=5±3%, p=0.043). Articular cartilage was thinner anteriorly (18±30μm) in immobilized knees versus contralateral (124±40μm, p<0.001) and sham (125±43μm, p=0.043). GAG staining covered 2±4% of the anterior articular area in immobilized knees versus 28±12% contralaterally (p=0.003) and 26±7% in sham (p=0.043). Mankin scores in immobilized knees were 4.7±1.7 versus 0.2±0.4 and 0±0 for contralateral and sham (p=0.003, p=0.042), respectively. The trabecular bone plate area of anterior and posterior regions showed relative loss of cross-sectional area in immobilized knees compared to controls (immobilized/contralateral area ratios of 0.67 and 0.46 respectively, both p=0.003), while the area in the middle region was preserved. Movat's pentachrome stain and CD31 staining showed chondral vascular ingrowth from subchondral bone. Osteocalcin and CD90 MSC staining were decreased in immobilized knees versus contralateral (p=0.003, p=0.036 respectively).

CONCLUSIONS

Bony replacement characterizes articular cartilage degeneration of knees immobilized for 32weeks in the anterior, non-weight bearing region of the tibia. Replacement of cartilage by bone may have been mediated by chondral vascularization, suggesting irreversible changes. These findings stress the importance of weight-bearing and joint motion to maintain cartilage structure.

Intra-articular collagenase injection increases range of motion in a rat knee flexion contracture model

Objectives

A knee joint contracture, a loss in passive range of motion (ROM), can be caused by prolonged immobility. In a rat knee immobilization flexion contracture model, the posterior capsule was shown to contribute to an irreversible limitation in ROM, and collagen pathways were identified as differentially expressed over the development of a contracture. Collagenases purified from Clostridium histolyticum are currently prescribed to treat Dupuytren’s and Peyronie’s contractures due to their ability to degrade collagen. The potential application of collagenases to target collagen in the posterior capsule was tested in this model.

Materials and methods

Rats had one hind leg immobilized, developing a knee flexion contracture. After 4 weeks, the immobilization device was removed, and the rats received one 50 µL intra-articular injection of 0.6 mg/mL purified collagenase. Control rats were injected with only the buffer. After 2 weeks of spontaneous remobilization following the injections, ROM was measured with a rat knee arthrometer, and histological sections were immunostained with antibodies against rat collagen types I and III.

Results/conclusion

Compared with buffer-injected control knees, collagenase-treated knees showed increased ROM in extension by 8.0°±3.8° (p-value <0.05). Immunohistochemical analysis revealed an increase in collagen type III staining (p<0.01) in the posterior capsule of collagenase-treated knees indicating an effect on the extracellular matrix due to the collagenase. Collagen I staining was unchanged (p>0.05). The current study provides experimental evidence for the pharmacological treatment of knee flexion contractures with intra-articular collagenase injection, improving the knee ROM.

Development of arthrogenic joint contracture as a result of pathological changes in remobilized rat knees

This study aimed to elucidate how rats recover from immobilization-induced knee joint contracture. Rats' right knees were immobilized by an external fixator at a flexion of 140° for 3 weeks. After removal of the fixator, the joints were allowed to move freely (remobilization) for 0, 1, 3, 7, or 14 days (n = 5 each). To distinguish myogenic and arthrogenic contractures, the passive extension range of motion was measured before and after myotomy of the knee flexors. Knee joints were histologically analyzed and the expression of genes encoding inflammatory or fibrosis-related mediators, interleukin-1β (1L-1β), fibrosis-related transforming growth factor-β1 (TGF-β1), and collagen type I (COL1A1) and III (COL3A1), were examined in the knee joint posterior capsules using real-time PCR. Both myogenic and arthrogenic contractures were established within 3 weeks of immobilization. During remobilization, the myogenic contracture decreased over time. In contrast, the arthrogenic contracture developed further during the remobilization period. On day 1 of remobilization, inflammatory changes characterized by edema, inflammatory cell infiltration, and upregulation of IL-1β gene started in the knee joint posterior capsule. In addition, collagen deposition accompanied by fibroblast proliferation, with upregulation of TGF-β1, COL1A1, and COL3A1 genes, appeared in the joint capsule between days 7 and 14. These results suggest the progression of arthrogenic contracture following remobilization, which is characterized by fibrosis development, is possibly triggered by inflammation in the joint capsule. It is therefore necessary to focus on developing new treatment strategies for immobilization-induced joint contracture. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1414-1423, 2017.

A case report of successful treatment of 90° knee flexion contracture in a patient with adult-onset Still's disease

Background

Severe knee flexion contractures greater than 80° are rare and challenging to manage. Previous studies have demonstrated unsatisfactory clinical results after correcting these deformities because residual flexion contractures were not corrected within a short period of time. We herein report the case of a patient with adult-onset Still’s disease with 90° of bilateral knee flexion contracture, which was successfully corrected by total knee arthroplasty and serial casting over a period of five weeks.

Case presentation

A 47-year-old male was admitted to our orthopedic department for bilateral knee pain and a preoperative fixed flexion contracture of 90°. A diagnosis of adult-onset Still’s disease was made based on the patient’s medical history of a high spiking fever, salmon-colored rash and bilateral knee and wrist pain. Bilateral total knee arthroplasty was carried out to address these deformities, but residual flexion contracture was present. Subsequently, serial casting was used to achieve full extension at four weeks after surgery. Excellent function and patient satisfaction were observed at two years of follow-up.

Conclusion

The new protocol of total knee arthroplasty with subsequent serial casting seems to be an efficient solution for knee flexion contractures greater than 80°. This report adds to the very small number of reported cases of adult-onset Still’s disease with severe knee flexion contractures and describes a patient who was successfully treated with a new protocol.

Correcting deformity in total knee arthroplasty

Collateral ligament release is advocated in total knee arthroplasty (TKA) to deal with significant coronal plane deformities, but is also associated with significant disadvantages.

We describe steps to avoid release of the collateral (superficial medial and lateral collateral) ligaments during TKA in severely deformed knees, while correcting deformity and balancing the knee.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):101–4.

Noninflammatory Joint Contractures Arising from Immobility: Animal Models to Future Treatments

Joint contractures, defined as the limitation in the passive range of motion of a mobile joint, can be classified as noninflammatory diseases of the musculoskeletal system. The pathophysiology is not well understood; limited information is available on causal factors, progression, the pathophysiology involved, and prediction of response to treatment. The clinical heterogeneity of joint contractures combined with the heterogeneous contribution of joint connective tissues to joint mobility presents challenges to the study of joint contractures. Furthermore, contractures are often a symptom of a wide variety of heterogeneous disorders that are in many cases multifactorial. Extended immobility has been identified as a causal factor and evidence is provided from both experimental and epidemiology studies. Of interest is the involvement of the joint capsule in the pathophysiology of joint contractures and lack of response to remobilization. While molecular pathways involved in the development of joint contractures are being investigated, current treatments focus on physiotherapy, which is ineffective on irreversible contractures. Future treatments may include early diagnosis and prevention.