Knee-attributable medical costs and risk of re-surgery among patients utilizing non-surgical treatment options for knee arthrofibrosis in a managed care population

Limited evidence for the usage of renin-angiotensin-aldosterone pathway blockers to prevent arthrofibrosis after total knee arthroplasty. A systematic review of clinical evidence

Purpose

Despite advances in surgical techniques and rehabilitation protocols, arthrofibrosis following total knee arthroplasty (TKA) still has poor outcomes. In the last decade, attention has been focused on the pathogenesis and cascade of events leading to the development of fibrosis. Currently, one of the most promising approaches consists in the indirect antagonisation of transforming growth factor beta 1 (TGF-beta 1) through the downregulation of the renin-angiotensin-aldosterone system (RAAS). This systematic review aims to analyse the available evidence regarding the use of angiotensin receptor blockers (ARBs)/angiotensin-converting-enzyme inhibitors (ACEi) in order to prevent post-operative knee arthrofibrosis following TKA.

Methods

Extensive research on the PubMed, Cochrane, and Google Scholar databases was performed on 8 July 2024, using keywords related to ARBs, ACE inhibitors and arthrofibrosis. Inclusion criteria included: (1) clinical trials of any level of evidence; (2) written in English; (3) studies conducted on humans; and (4) evaluating the antifibrotic effects of ACE inhibitors or ARBs administered for TKA surgeries. Exclusion criteria were articles written in other languages; preclinical studies; expert opinions; reviews and trials evaluating the effects of ACEi/ARBs not related to their antifibrotic effect after TKA.

Results

A total of six studies met the inclusion criteria and were analysed. All studies were retrospective and involved a total of 158,310 patients. Time of administration varied among the studies as well as the dosage, which fell within the range for cardiological use. Four out of six studies focused exclusively on losartan. Three studies reported a clear, significant correlation between the use of ARBs and/or ACEi and a reduced likelihood of developing arthrofibrosis.

Conclusions

The RAAS antagonism could have potential for stiffness prevention after TKA. However, given the side effects and the limited evidence available, the use of ACEi/sartans for the sole purpose of avoiding arthrofibrosis after TKA is not currently recommended.

Level of Evidence

Level III.

The efficacy of vitamin E in preventing arthrofibrosis after joint replacement

BACKGROUND

Arthrofibrosis is a joint disorder characterized by excessive scar formation in the joint tissues. Vitamin E is an antioxidant with potential anti-fibroblastic effect. The aim of this study was to establish an arthrofibrosis rat model after joint replacement and assess the effects of vitamin E supplementation on joint fibrosis.

METHODS

We simulated knee replacement in 16 male Sprague-Dawley rats. We immobilized the surgical leg with a suture in full flexion. The control groups were killed at 2 and 12 weeks (n = 5 per group), and the test group was supplemented daily with vitamin E (0.2 mg/mL) in their drinking water for 12 weeks (n = 6). We performed histological staining to investigate the presence and severity of arthrofibrosis. Immunofluorescent staining and α2-macroglobulin (α2M) enzyme-linked immunosorbent assay (ELISA) were used to assess local and systemic inflammation. Static weight bearing (total internal reflection) and range of motion (ROM) were collected for functional assessment.

RESULTS

The ROM and weight-bearing symmetry decreased after the procedure and recovered slowly with still significant deficit at the end of the study for both groups. Histological analysis confirmed fibrosis in both lateral and posterior periarticular tissue. Vitamin E supplementation showed a moderate anti-inflammatory effect on the local and systemic levels. The vitamin E group exhibited significant improvement in ROM and weight-bearing symmetry at day 84 compared to the control group.

CONCLUSIONS

This model is viable for simulating arthrofibrosis after joint replacement. Vitamin E may benefit postsurgical arthrofibrosis, and further studies are needed for dosing requirements.

Postoperative Angiotensin Receptor Blocker Use is Associated With Decreased Rates of Manipulation Under Anesthesia, Arthroscopic Lysis of Adhesions, and Prosthesis-Related Complications in Patients Undergoing Total Knee Arthroplasty

BACKGROUND

The cellular mechanisms underlying excess scar tissue formation in arthrofibrosis following total knee arthroplasty (TKA) are well-described. Angiotensin receptor blockers (ARB), particularly losartan, is a commonly prescribed antihypertensive with demonstrated antifibrotic properties. This retrospective study aimed to assess the rates of 1- and 2-year postoperative complications in patients who filled prescriptions for ARBs during the 90 days after TKA.

METHODS

Patients undergoing primary TKA were selected from a large national insurance database, and the impact of ARB use after TKA on complications was assessed. Of the 1,299,106 patients who underwent TKA, 82,065 had filled at least a 90-day prescription of losartan, valsartan, or olmesartan immediately following their TKA. The rates of manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOA), aseptic loosening, periprosthetic fracture, and revision at 1 and 2 years following TKA were analyzed using multivariable logistic regressions to control for various comorbidities.

RESULTS

ARB use was associated with decreased rates of MUA (odds ratio [OR] = 0.94, 95% confidence interval (CI), 0.90 to 0.99), arthroscopy/LOA (OR = 0.86, 95% CI, 0.77 to 0.95), aseptic loosening (OR = 0.71, 95% CI, 0.61 to 0.83), periprosthetic fracture (OR = 0.58, 95% CI, 0.46 to 0.71), and revision (OR = 0.79, 95% CI, 0.74 to 0.85) 2 years after TKA.

CONCLUSIONS

ARB use throughout the 90 days after TKA is associated with a decreased risk of MUA, arthroscopy/LOA, aseptic loosening, periprosthetic fracture, and revision, demonstrating the potential protective abilities of ARBs. Prospective studies evaluating the use of ARBs in patients at risk for postoperative stiffness would be beneficial to further elucidate this association.

Arthrofibrosis After Total Knee Arthroplasty: A Critical Analysis Review

» Arthrofibrosis after total knee arthroplasty (TKA) is the new formation of excessive scar tissue that results in limited ROM, pain, and functional deficits.» The diagnosis of arthrofibrosis is based on the patient's history, clinical examination, absence of alternative diagnoses from diagnostic testing, and operative findings. Imaging is helpful in ruling out specific causes of stiffness after TKA. A biopsy is not indicated, and no biomarkers of arthrofibrosis exist.» Arthrofibrosis pathophysiology is multifactorial and related to aberrant activation and proliferation of myofibroblasts that primarily deposit type I collagen in response to a proinflammatory environment. Transforming growth factor-beta signaling is the best established pathway involved in arthrofibrosis after TKA.» Management includes both nonoperative and operative modalities. Physical therapy is most used while revision arthroplasty is typically reserved as a last resort. Additional investigation into specific pathophysiologic mechanisms can better inform targeted therapeutics.

Three-dimensional, in-vitro approaches for modelling soft-tissue joint diseases

Diseases affecting the soft tissues of the joint represent a considerable global health burden, causing pain and disability and increasing the likelihood of developing metabolic comorbidities. Current approaches to investigating the cellular basis of joint diseases, including osteoarthritis, rheumatoid arthritis, tendinopathy, and arthrofibrosis, involve well phenotyped human tissues, animal disease models, and in-vitro tissue culture models. Inherent challenges in preclinical drug discovery have driven the development of state-of-the-art, in-vitro human tissue models to rapidly advance therapeutic target discovery. The clinical potential of such models has been substantiated through successful recapitulation of the pathobiology of cancers, generating accurate predictions of patient responses to therapeutics and providing a basis for equivalent musculoskeletal models. In this Review, we discuss the requirement to develop physiologically relevant three-dimensional (3D) culture systems that could advance understanding of the cellular and molecular basis of diseases that affect the soft tissues of the joint. We discuss the practicalities and challenges associated with modelling the complex extracellular matrix of joint tissues-including cartilage, synovium, tendon, and ligament-highlighting the importance of considering the joint as a whole organ to encompass crosstalk across tissues and between diverse cell types. The design of bespoke in-vitro models for soft-tissue joint diseases has the potential to inform functional studies of the cellular and molecular mechanisms underlying disease onset, progression, and resolution. Use of these models could inform precision therapeutic targeting and advance the field towards personalised medicine for patients with common musculoskeletal diseases.

Arthrofibrosis in Robotic Total Knee Arthroplasty: An Investigation Into How Robotic Assistance May Contribute to a Tight Knee

INTRODUCTION

Arthrofibrosis after total knee arthroplasty (TKA) can lead to pain and restricted range of motion. Matching native knee kinematics is crucial in avoiding arthrofibrosis postoperatively. However, manual jig-based instruments have demonstrated variability and inaccuracy during primary TKA. Robotic-arm-assisted surgery was developed to increase the precision and accuracy of bone cuts and component alignment. In the literature, limited information on arthrofibrosis after robotic-assisted TKA (RATKA) exists. The purpose of this study was to compare the incidence of arthrofibrosis after manual TKA (mTKA) with RATKA by examining the need for manipulation under anesthesia (MUA) postoperatively and evaluating preoperative and postoperative radiographic parameters.

METHODS

A retrospective analysis of patients who underwent primary TKA from 2019 to 2021 was conducted. Rates of MUA were evaluated and perioperative radiographs were analyzed to determine posterior condylar offset ratio, Insall-Salvati Index, and posterior tibial slope (PTS) in patients who underwent mTKA versus RATKA. Range of motion was recorded for patients who required MUA.

RESULTS

A total of 1234 patients were included, of which 644 underwent mTKA, and 590 underwent RATKA. Thirty-seven RATKA patients compared with 12 mTKA patients required MUA postoperatively (P < 0.0001). A significant decrease in PTS postoperatively was seen in the RATKA (7.10° ± 2.4° preoperatively versus 2.46° ± 1.2° postoperatively), with a mean decrease of the tibial slope of -4.6° ± 2.5° (P < 0.0001). In patients requiring MUA, a larger decrease was seen in the RATKA group when compared with the mTKA group (mean -5.5 ± 2.0 versus -5.3 ± 0.78, P = 0.6585). No significant difference was seen in the posterior condylar offset ratio and Insall-Salvati Index in both groups.

DISCUSSION

When conducting RATKA, it is important to match PTS close to the native tibial slope to decrease the incidence of arthrofibrosis postoperatively, as a decrease in PTS can lead to decreased postoperative knee flexion and poor functional outcomes.

Prospective, Randomized Clinical Trial Comparing a Novel Motion-Assistive Device to Standard Physical Therapy for Initial Management of Knee Range of Motion after Primary Total Knee Arthroplasty

This prospective randomized clinical trial assessed a novel device for initial management of knee range of motion (ROM), pain, and function after total knee arthroplasty (TKA). Primary TKA patients with preoperative ROM of at least 5° to 115° were randomized to initial knee motion management: Mizzou BioJoint Flex-novel motion-assistive device with prescribed physical therapy or standard physical therapy-prescribed physical therapy. ROM, pain score, and knee injury and osteoarthritis score for joint replacement (KOOSjr) were obtained preoperatively and 2 weeks, 6 weeks, and 3 months postoperatively. Patient satisfaction for both cohorts and subjective assessments of the MBF device were assessed at 3 months. Readmissions, reoperations, and complications were assessed through 1 year. Nineteen patients were randomized to each cohort, with no significant preoperative differences in demographics, pain score, KOOSjr score, or ROM. Six SPT (31.6%) and 3 MBF (15.8%) patients failed to regain preoperative ROM (p = 0.044). One SPT (5.3%) and eight MBF (42%) patients exceeded 125° ROM (p = 0.019) by 3 months. Total ROM (p = 0.039), pain (p = 0.0068), and function (p = 0.0027) were significantly better for MBF at 3 months. MBF patients reported significantly higher satisfaction (mean, 9.4 ± 1.1 vs. 8.0 ± 1.8, respectively; p = 0.0084). One patient in each group underwent manipulation under anesthesia. No other readmissions, reoperations, or complications were reported. A novel durable medical equipment device can provide a safe and effective patient-controlled method for initial management of knee ROM, pain, and function after primary TKA with potential clinically meaningful advantages over physical therapy alone. In conjunction with physical therapy, management with this novel knee flexion device more effectively restored knee ROM and early patient function when compared with therapy alone and was associated with higher proportions of patients regaining minimum (115°) and desired (125°) levels of knee ROM and clinically meaningful differences in pain scores, knee function, and patient satisfaction. This is a Level 1, prospective trial study.

The effect of losartan on range of motion and rates of manipulation in total knee arthroplasty: a retrospective matched cohort study

INTRODUCTION

Arthrofibrosis remains a common cause of patient dissatisfaction and reoperation after total knee arthroplasty (TKA). Losartan is an angiotensin receptor blocker (ARB) with inhibitory effects on transforming growth factor beta, previously implicated in tissue repair induced fibrosis, and has been studied to prevent stiffness following hip arthroscopy. This study aimed to evaluate pre- and postoperative range of motion (ROM) and the incidence of manipulation under anesthesia (MUA) following primary TKA in patients taking Losartan preoperatively for hypertension.

MATERIALS AND METHODS

A retrospective review of 170 patients from 2012 to 2020 who underwent a primary, elective TKA and were prescribed Losartan at least three months prior to surgery. All patients who were prescribed Losartan and had a preoperative and postoperative ROM in their chart were included and were matched to a control group of patients who underwent TKA and had no Losartan prescription. ROM, MUA, readmissions, reoperations, and revisions were assessed using chi-square and independent sample t tests.

RESULTS

Seventy-nine patients met the inclusion criteria. Preoperative ROM was similar between patients on Losartan and the control group (103.59° ± 16.14° vs. 104.59° ± 21.59°, respectively; p = 0.745). Postoperative ROM and ΔROM were greater for patients prescribed Losartan (114.29° ± 12.32° vs. 112.76° ± 11.65°; p = 0.429 and 10.57° ± 14.95° vs. 8.17° ± 21.68°; p = 0.422), though this difference did not reach statistical significance. There was no difference in readmission, rate of manipulation for stiffness, or all-cause revision rates.

CONCLUSION

In this study, we found that the use of Losartan did not significantly improve postoperative ROM, reduce MUA or decrease revision rates. Further prospective studies using Losartan are required to elucidate the potential effects on ROM and incidence of arthrofibrosis requiring MUA.

LEVEL III EVIDENCE

Retrospective cohort study.

[Arthrofibrosis of the hip joint : Diagnostic and therapeutic challenge]

Arthrofibrosis is a frequent complication after total knee arthroplasty (TKA). Recently, arthrofibrosis could be successfully verified histologically after primary total hip arthroplasty (THA) and the clinical presentation on the hip could be described for the first time. Possible diagnostic and therapeutic approaches have not yet been published. The diagnostic work-up differs only slightly from that for the knee joint. Other causes, such as aseptic loosening, malalignment or periprosthetic joint infection should be excluded. The gold standard is still invasive diagnostics with histological evidence of arthrofibrosis according to the synovia-like interface membrane (SLIM) criteria. Conservative treatment approaches include mobilization under anesthesia and medication according to Traut, analogous to the knee joint. Surgical treatment should be carried out under strict interpretation of the indications and after detailed clarification for the patient. In contrast to the knee joint, open arthrolysis should be preferred to arthroscopic arthrolysis of the hip joint. It must be taken into consideration that the evidence for conservative as well as surgical treatment, including possible revision arthroplasty, cannot be assessed due to the absence of clinical data. Studies under controlled conditions on the possible treatment approaches in the presence of arthrofibrosis are desirable and necessary in order to be able to assess the significance of the symptoms. In addition to treatment, great importance should also be attached to the diagnostics. Histological confirmation of the diagnosis of arthrofibrosis should only be considered to a limited extent in the case of an assumed, only moderately successful surgical intervention.

Perioperative Use of Antifibrotic Medications Associated With Lower Rate of Manipulation After Primary TKA: An Analysis of 101,366 Patients

BACKGROUND

Several commonly prescribed medications have known antifibrotic properties and have been shown to reduce postoperative scar formation in other clinical areas, but it is unknown whether the use of such medications perioperatively in patients undergoing TKA may improve rates of postoperative stiffness.

METHODS

A large US employer-sponsored healthcare database (Truven Marketscan) was queried for patients who underwent elective primary TKA for primary osteoarthritis between 2015-2019. Demographic information and comorbidities were recorded, along with whether patients were prescribed one of several medications with known antifibrotic properties during the three months before or after surgery.

RESULTS

Complete data were available for 101,366 patients undergoing TKA, of which 4,536 underwent MUA (4.5%). Perioperative use of any antifibrotic medication was associated with a lower likelihood of undergoing MUA (P < .001). When controlling for age, sex, comorbidities, opioid use, length of stay, among other variables, perioperative use of specific ACE inhibitors (OR 0.91, CI 0.84-1, P = .042), COX-2 inhibitors (OR 0.88, CI 0.81-0.96, P = .002), and angiotensin II receptor blockers, specifically losartan (OR 0.80, CI 0.70-0.91, P = .007) all remained significantly associated with lower rates of MUA.

CONCLUSION

This study, spanning over a hundred thousand primary TKA procedures over a recent five-year period, demonstrates an association between perioperative use of specific medications with antifibrotic properties and a decreased rate of MUA. These data will help inform future studies aimed to prospectively evaluate the potential of antifibrotic medications in preventing postoperative stiffness in high-risk patients undergoing knee arthroplasty.

Efficacy of non-operative treatment of patients with knee arthrofibrosis using high-intensity home mechanical therapy: a retrospective review of 11,000+ patients

Background

Recovery from knee surgery or injury can be hindered by knee arthrofibrosis, which can lead to motion limitations, pain and delayed recovery. Surgery or prolonged physical therapy are often treatment options for arthrofibrosis, but they can result in increased costs and decreased quality of life. A treatment option that can regain lost motion without surgery would help minimize risks and costs for the patient. The purpose of this study was to determine treatment efficacy of high-intensity home mechanical stretch therapy in patients with knee arthrofibrosis.

Methods

Records were reviewed for 11,000+ patients who were prescribed a high-intensity stretch device to regain knee flexion. Initial and last recorded knee flexion and days between measurements were available for 9842 patients (Dataset 1). Dataset 2 was a subset of 966 patients from Dataset 1. These 966 patients had separate more rigorous measurements available from physical therapy notes (Dataset 3) in addition to data from the internal database (Dataset 2). Within and between dataset statistics were calculated using t tests for comparison of means and Cohen’s d for determination of effect size.

Results

All dataset showed significant gains in flexion (p < 0.01). Mean initial flexion, last recorded flexion and flexion gain were 79.5°, 108.4°, and 29.9°, respectively in Dataset 1. Differences between Datasets 2 and 3 had small effect sizes (Cohen’s d < 0.17). The were no significant differences when comparing workers’ compensation and non-workers’ compensation patients. The average last recorded flexion for all datasets was above the level required to perform activities of daily living. Motion gains were recorded in under 60 days from device delivery.

Conclusions

High-intensity home mechanical stretch therapy was effective in restoring knee flexion, generally in 2 months or less, and in avoiding additional surgery in severe motion loss patients regardless of sex, age, or workers’ compensation status. We believe high-intensity stretching should be considered in any patient who is at risk for a secondary motion loss surgery, because in over 90% of these patients, the complications and costs associated with surgery can be avoided.

Aspirin Administered for Venous Thromboembolism Prophylaxis May Protect Against Stiffness Following Total Knee Arthroplasty

BACKGROUND

Aspirin has become the main agent for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). This study assessed whether aspirin is associated with less knee stiffness compared to warfarin and other chemoprophylaxis agents.

METHODS

This is a retrospective review of all primary and revision TKAs performed between January 2009 and October 2020 at a high volume institution. Demographics, comorbidity data, and operative variables were extracted from medical records. VTE prophylaxis administered during this time period included aspirin, warfarin, and "others" (factor Xa, unfractionated heparin, low-molecular-weight heparin, fondaparinux, adenosine diphosphate receptor inhibitor, and direct thrombin inhibitor). The primary outcome assessed was manipulation under anesthesia (MUA) performed within 6 months of index surgery. Secondary outcome included major bleeding events. Univariate followed by multivariate regression analyses were performed.

RESULTS

A total of 15,903 cases were included in the study, of which 531 (3.3%) patients developed stiffness that required MUA. The rates of MUA were 2.7% (251/9223) for patients receiving aspirin, 4.2% (238/5709) for patients receiving warfarin, and 4.3% (42/971) for all others (P's < .001). Multivariate regression analysis confirmed that aspirin is associated with lower rates of VTE compared to warfarin (adjusted odds ratio 1.423, 95% confidence interval 1.158-1.747, P < .001) and compared to other anticoagulation medications (adjusted odds ratio 1.742, 95% confidence interval 1.122-2.704, P = .013). Major bleeding events were also significantly lower in patients who received aspirin compared to the other 2 groups (P's = .001).

CONCLUSION

Aspirin prophylaxis is associated with lower rates of MUA following TKA compared to warfarin and other VTE chemoprophylactic agents when grouped together.

Arthrofibrosis following primary total hip arthroplasty: a distinct clinical entity

INTRODUCTION

Arthrofibrosis is a relatively frequent complication after total knee arthroplasty. Although stiffness after total hip arthroplasty (THA), because of formation of heterotopic ossification or other causes, is not uncommon, to the authors' best knowledge, arthrofibrosis after THA has not been described. The aim of this study is to describe the arthrofibrosis of the hip after primary THA using an established clinical and histological classification of arthrofibrosis.

MATERIALS AND METHODS

We retrospectively examined all patients who were histologically confirmed to have arthrofibrosis after primary THA during revision surgery by examination of tissue samples in our clinic. Arthrofibrosis was diagnosed according to the histopathological SLIM-consensus classification, which defines seven different SLIM types of the periimplant synovial membrane. The SLIM type V determines the diagnosis of endoprosthesis-associated arthrofibrosis.

RESULTS

The study population consists of 66 patients who were revised due to arthrofibrosis after primary THA. All patients had a limitation in range of motion prior to revision with a mean flexion of 90° (range from 40 to 125), mean internal rotation of 10° (range from 0 to 40) and mean external rotation of 20° (range from 0 to 50). All patients had histological SLIM type V arthrofibrosis, corresponding to endoprosthesis-associated arthrofibrosis. Histological examination revealed that seven patients (10.6%) had particle-induced and 59 patients (89.4%) had non-particle-induced arthrofibrosis.

CONCLUSION

This is the first description of endoprosthetic-associated arthrofibrosis after primary THA on the basis of a well-established histological classification. Our study results could enable new therapeutic and diagnostic opportunities in patients with such an arthrofibrosis. Surgeons should keep arthrofibrosis as a possible cause for stiffness and pain after primary THA in mind.

LEVEL OF EVIDENCE

Diagnostic study, Level of Evidence IV.

Intra-articular celecoxib improves knee extension regardless of surgical release in a rabbit model of arthrofibrosis

Aims

Outcomes of current operative treatments for arthrofibrosis after total knee arthroplasty (TKA) are not consistently positive or predictable. Pharmacological in vivo studies have focused mostly on prevention of arthrofibrosis. This study used a rabbit model to evaluate intra-articular (IA) effects of celecoxib in treating contracted knees alone, or in combination with capsular release.

Methods

A total of 24 rabbits underwent contracture-forming surgery with knee immobilization followed by remobilization surgery at eight weeks. At remobilization, one cohort underwent capsular release (n = 12), while the other cohort did not (n = 12). Both groups were divided into two subcohorts (n = 6 each) – one receiving IA injections of celecoxib, and the other receiving injections of vehicle solution (injections every day for two weeks after remobilization). Passive extension angle (PEA) was assessed in live rabbits at 10, 16, and 24 weeks, and disarticulated limbs were analyzed for capsular stiffness at 24 weeks.

Results

IA celecoxib resulted in greater mean PEA at ten weeks (69.6° (SD 4.6) vs 45.2° (SD 9.6), p = 0.004), 16 weeks (109.8° (SD 24.2) vs 60.9° (SD10.9), p = 0.004), and 24 weeks (101.0° (SD 8.0) vs 66.3° (SD 5.8), p = 0.004). Capsular stiffness was significantly reduced with IA celecoxib (2.72 Newton per cm (N·cm)/° (SD 1.04), p = 0.008), capsular release (2.41 N·cm/° (SD 0.80), p = 0.008), and capsular release combined with IA celecoxib (3.56 N·cm/° (SD 0.99), p = 0.018) relative to IA vehicle (6.09 N·cm/° (SD 1.64)).

Conclusion

IA injections of a celecoxib led to significant improvements in passive extension angles, with reduced capsular stiffness, when administered to rabbit knees with established experimental contracture. Celecoxib was superior to surgical release, and the combination of celecoxib and a surgical release did not provide any additional value.

Cite this article: Bone Joint Res 2022;11(1):32–39.

Clinical Management of Arthrofibrosis: State of the Art and Therapeutic Outlook

* Arthrofibrosis is a pathologic condition that is characterized by excessive periarticular scar-tissue formation. Arthrofibrosis may occur secondary to injury, surgical trauma, hemarthrosis, or infection, or it may occur idiopathically.* The pathogenesis of arthrofibrosis is incompletely understood but involves the dysregulation of normal reparative pathways, with transforming growth factor-beta (TGF-[beta]) as a principal mediator.* Current treatment options for arthrofibrosis primarily involve physiotherapy, operative manipulation, and surgical debridement, all with imperfect results.* Currently, there are no pharmacologic treatment options for arthrofibrosis. This has prompted increased investigational interest in the development of antifibrotic intra-articular therapies.

Medical stretching devices are effective in the treatment of knee arthrofibrosis: A systematic review

AIMS

This systematic review examines the available evidence on the use of medical stretching devices to treat knee arthrofibrosis, it suggests a focus for future studies addressing limitations in current research and identifies gaps in the published literature to facilitate future works.

MATERIALS AND METHODS

Articles were identified using the Cochrane Library, MEDLINE, PubMed and SCOPUS databases. Articles from peer reviewed journals investigating the effectiveness of medical stretching devices to increase range of movement when treating arthrofibrosis of the knee were included.

RESULTS

A total of 13 studies (558 participants) met the inclusion criteria with the devices falling into the following categories; CPM, load control or displacement control stretching devices. A statistically significant increase in range of movement was demonstrated in CPM, load-control and displacement-control studies (p ​< ​0.001). The results show that the stretch doses applied using the CPM, load-control devices were performed over a considerably longer treatment time and involved significantly more additional physiotherapy compared to the displacement-control and patient actuated serial stretching devices.

CONCLUSION

The systematic review indicates that load-control and displacement-control devices are effective in increasing range of movement in the treatment of knee arthrofibrosis. Displacement-control devices involving patient actuated serial stretching techniques, may be more effective in increasing knee flexion than those utilising static progressive stretch.The paucity of research in this field indicates that more randomised controlled trials are required to investigate the superiority of the different types of displacement-control stretching devices and which of these would be most effective for use in clinical practice and to compare these with standard physiotherapy treatment.

The STAK tool: evaluation of a new device to treat arthrofibrosis and poor range of movement following total knee arthroplasty and major knee surgery

Aims

This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis.

Methods

35 patients post-major knee surgery with arthrofibrosis and mean range of movement (ROM) of 68° were recruited. Both the STAK intervention and control group received standard physiotherapy for eight weeks, with the intervention group additionally using the STAK at home. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at all timepoints. An acceptability and home exercise questionnaire capturing adherence was recorded after each of the interventions.

Results

Compared to the control group, the STAK intervention group made significant gains in mean ROM (30° versus 8°, p < 0.0005), WOMAC (19 points versus 3, p < 0.0005), and OKS (8 points versus 3, p < 0.0005). The improvements in the STAK group were maintained at long-term follow-up. No patients suffered any complications relating to the STAK, and 96% of patients found the STAK tool ‘perfectly acceptable’.

Conclusion

The STAK tool is effective in increasing ROM and reducing pain and stiffness. Patients find it acceptable and adherence to treatment was high. This study indicates that the STAK tool would be of benefit in clinical practice and may offer a new, cost-effective treatment for arthrofibrosis.

Cite this article: Bone Joint Open 2020;1-8:465–473.

Sulfasalazine Resolves Joint Stiffness in a Rabbit Model of Arthrofibrosis

Joint stiffness due to fibrosis/capsule contracture is a seriously disabling complication of articular injury that surgical interventions often fail to completely resolve. Fibrosis/contracture is associated with the abnormal persistence of myofibroblasts, which over-produce and contract collagen matrices. We hypothesized that intra-articular therapy with drugs targeting myofibroblast survival (sulfasalazine), or collagen production (β-aminopropionitrile and cis-hydroxyproline), would reduce joint stiffness in a rabbit model of fibrosis/contracture. Drugs were encapsulated in poly[lactic-co-glycolic] acid pellets and implanted in joints after fibrosis/contracture induction. Capsule α-smooth muscle actin (α-SMA) expression and intimal thickness were evaluated by immunohistochemistry and histomorphometry, respectively. Joint stiffness was quantified by flexion-extension testing. Drawer tests were employed to determine if the drugs induced cruciate ligament laxity. Joint capsule fibroblasts were tested in vitro for contractile activity and α-SMA expression. Stiffness in immobilized joints treated with blank pellets (control) was significantly higher than in non-immobilized, untreated joints (normal) (p = 0.0008), and higher than in immobilized joints treated with sulfasalazine (p = 0.0065). None of the drugs caused significant cruciate ligament laxity. Intimal thickness was significantly lower than control in the normal and sulfasalazine-treated groups (p = 0.010 and 0.025, respectively). Contractile activity in the cells from controls was significantly increased versus normal (p = 0.001). Sulfasalazine and β-aminopropionitrile significantly inhibited this effect (p = 0.005 and 0.0006, respectively). α-SMA expression was significantly higher in control versus normal (p = 0.0021) and versus sulfasalazine (p = 0.0007). These findings support the conclusion that sulfasalazine reduced stiffness by clearing myofibroblasts from fibrotic joints. Statement of clinical significance: The results provide proof-of-concept that established joint stiffness can be resolved non-surgically. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:629-638, 2020.

Arthrofibrosis After Total Knee Arthroplasty: Pathophysiology, Diagnosis, and Management

Arthrofibrosis is the pathologic stiffening of a joint caused by an exaggerated inflammatory response. As a common complication following total knee arthroplasty (TKA), this benign-appearing connective tissue hyperplasia can cause significant disability among patients because the concomitant knee pain and restricted range of motion severely hinder postoperative rehabilitation, clinical outcomes, and basic activities of daily living. The most effective management for arthrofibrosis in the setting of TKA is prevention, including preoperative patient education programs, aggressive postoperative physical therapy regimens, and anti-inflammatory medications. Operative treatments include manipulation under anesthesia, arthroscopic debridement, and quadricepsplasty.

Vitamin C demand is increased after total knee arthroplasty: a double-blind placebo-controlled-randomized study

PURPOSE

This study was designed to determine whether perioperative supplementation of vitamin C (VC) improves range of motion (ROM) and reduces the risk of arthrofibrosis (AF) following total knee arthroplasty (TKA).

METHODS

Ninety-five patients undergoing TKA were randomized to either oral VC (1000 mg daily) or placebo for 50 days (48 VC group, 47 placebo group). The effect of VC supplementation was tested on ROM, AF, WOMAC, FJS-12, and VC plasma concentrations (VCc). VCc were analyzed in both patient groups before surgery, 4 and 7 days after surgery.

RESULTS

ROM at 1 year was not different between study groups. The prevalence of AF was 5 of 48 (10.4%) in the VC group compared to 11 of 47 (23.4%) in the placebo group (p = 0.09). VCc decreased post-operatively in the placebo group (49-12 µmol/l on day 7, p < 0.001), but not in the VC group (53-57 µmol/l). Patients with a perioperative drop of VCc ≥ 30 µmol/l developed significantly more AF at 1 year compared to patients with a VCc drop of < 30 µmol/l (p = 0.007).

CONCLUSIONS

TKA results in VC depletion. Perioperative VC supplementation prevents VCc drop in most patients undergoing TKA and may lower the incidence of AF. The clinical relevance of this study is that VC supplementation seems to be a cheap and safe adjunct to improve functional outcome after TKA.

LEVEL OF EVIDENCE

I.

TRIAL REGISTRY

The study was registered at the ISRCTN registry with study ID ISRCTN40250576.

Arthrofibrosis and large joint scarring

Large joint arthrofibrosis and scarring, involving the shoulder, elbow, hip, and knee, can result in the loss of function and immobility. The pathway of joint contracture formation is still being elucidated and is due to aberrations in collagen synthesis and misorientation of collagen fibrils. Novel antibodies are being developed to prevent arthrofibrosis, and current treatment methods for arthrofibrosis include medical, physical, and surgical treatments. This article describes the biology of joint contracture formation, along with current and future pharmacologic, biologic, and medical interventions.

Arthrofibrosis Associated With Total Knee Arthroplasty

BACKGROUND

Arthrofibrosis is a debilitating postoperative complication of total knee arthroplasty (TKA). It is one of the leading causes of hospital readmission and a predominant reason for TKA failure. The prevalence of arthrofibrosis will increase as the annual incidence of TKA in the United States rises into the millions.

METHODS

In a narrative review of the literature, the etiology, economic burden, treatment strategies, and future research directions of arthrofibrosis after TKA are examined.

RESULTS

Characterized by excessive proliferation of scar tissue during an impaired wound healing response, arthrofibrotic stiffness causes functional deficits in activities of daily living. Postoperative, supervised physiotherapy remains the first line of defense against the development of arthrofibrosis. Also, adjuncts to traditional physiotherapy such as splinting and augmented soft tissue mobilization can be beneficial. The effectiveness of rehabilitation on functional outcomes depends on the appropriate timing, intensity, and progression of the program, accounting for the patient's ability and level of pain. Invasive treatments such as manipulation under anesthesia, debridement, and revision arthroplasty improve range of motion, but can be traumatic and costly. Future studies investigating novel treatments, early diagnosis, and potential preoperative screening for risk of arthrofibrosis will help target those patients who will need additional attention and tailored rehabilitation to improve TKA outcomes.

CONCLUSION

Arthrofibrosis is a multi-faceted complication of TKA, and is difficult to treat without an early, tailored, comprehensive rehabilitation program. Understanding the risk factors for its development and the benefits and shortcomings of various interventions are essential to best restore mobility and function.

Presentation and management of arthrofibrosis of the knee: A case report

STUDY DESIGN

Case report.

BACKGROUND

Arthrofibrosis is a debilitating condition that results in pain, decreased range of motion, and decreased function. Although surgical management of arthrofibrosis has been well described in the literature, rehabilitation of the arthrofibrotic knee is less well described.

CASE DESCRIPTION

A 28-year-old female presented with swelling, pain, and decreased strength, range of motion, patellar mobility, and function following an exploratory arthroscopy of her left knee. After failed conservative management, the patient underwent two additional surgeries to remove scar tissue. Following each surgery, the emphasis was on decreasing inflammation and maintaining patellar mobility while increasing joint range of motion and strength. Therapy progression was determined by the presence or absence of inflammatory signs. The second scar tissue removal surgery resulted in a femoral neuropathy that further complicated the rehabilitation process.

OUTCOMES

At 3-year follow-up, the patient continued to present with decreased range of motion and strength compared to the uninvolved limb, but had returned to a modified running program and reported pain no longer limited her ability to participate in activities of daily living.

DISCUSSION

This case report highlights the importance of recognizing that arthrofibrosis may result following a minor knee surgery and with minimal range of motion loss. Additional complications also may result during arthrofibrosis treatment. Progressing rehabilitation based on the inflammatory response may decrease the likelihood of additional scar tissue formation and potentially improve the outcome for the patient.

Treatment of severe flexion deficits following total knee arthroplasty: a randomized clinical trial

PURPOSE

To determine whether passive knee flexion and knee-specific outcome scores differ in TKA patients experiencing arthrofibrosis treated with differing intensity of stretch exercises.

DESIGN

Randomized Controlled Trial

SAMPLE

Twenty patients who volunteered and met inclusion criteria were randomly assigned to an intervention group.

TREATMENT

Group 1 received high-intensity stretch home mechanical therapy (n = 11) and Group 2 received low-intensity stretch home mechanical therapy (n = 9).

FINDINGS

The HIS group demonstrated significantly greater gains in both passive knee flexion and outcome scores. The change in passive knee flexion significantly correlated with the change in outcome scores, and a significantly greater number of patients in the HIS group (91%) were able to achieve a functional range of motion >110° than those in the LIS group (22%, p < .001).

CONCLUSION

Treatment of postoperative arthrofibrosis with an HIS home mechanical therapy device was more effective and resulted in significantly improved outcomes when compared with LIS devices.

Factors that influence the efficacy of stretching programs for patients with hypomobility

CONTEXT

Passive stretching exercise protocols, as part of outpatient treatment or home exercise programs, are used to improve hypomobility. Despite the cosmopolitan use of stretching exercises, little is known about the forces being applied to the joint during these routine treatments.

TYPE OF STUDY

Clinical review.

EVIDENCE ACQUISITION

Articles were identified using MEDLINE and Google Scholar databases, with searches initially limited to those articles published after 1995. Seminal articles that were referenced were also included.

RESULTS

Many factors contribute to the clinical success of a stretching program, including the frequency, intensity, and duration of the stretching exercises, as well as patient- and joint-specific factors.

CONCLUSIONS

The goal of a stretching protocol is to maximize total end-range time both in the clinic and at home. Higher intensity, prolonged, and frequent stretching (10- to 15-minute bouts, 3 to 6 times per day) used as an adjunct to high-grade mobilizations may be beneficial for certain hypomobility conditions.

High-intensity mechanical therapy for loss of knee extension for worker's compensation and non-compensation patients

Background

Knee flexion contractures have been associated with increased pain and a reduced ability to perform activities of daily living. Contractures can be treated either surgically or conservatively, but these treatment options may not be as successful with worker's compensation patients. The purposes of retrospective review were to 1) determine the efficacy of using adjunctive high-intensity stretch (HIS) mechanical therapy to treat flexion contractures, and 2) compare the results between groups of worker's compensation and non-compensation patients.

Methods

Fifty-six patients (19 women, 37 men, age = 51.5 ± 17.0 years) with flexion contractures were treated with HIS mechanical therapy as an adjunct to outpatient physical therapy. Mechanical therapy was only prescribed for those patients whose motion had reached a plateau when treated with physical therapy alone. Patients were asked to perform six, 10-minute bouts of end-range stretching per day with the ERMI Knee Extensionater^(r) (ERMI, Inc., Atlanta, GA). Passive knee extension was recorded during the postoperative visit that mechanical therapy was prescribed, 3 months after beginning mechanical therapy, and at the most recent follow-up. We used a mixed-model 2 × 3 ANOVA (group × time) to evaluate the change in passive knee extension between groups over time.

Results

Regardless of group, the use of adjunctive HIS mechanical therapy resulted in passive knee extension deficits that significantly improved from 10.5° ± 5.2° at the initial visit to 2.6° ± 3.5° at the 3 month visit (p < 0.001). The degree of extension was maintained at the most recent follow-up (2.0° ± 2.9°), which was significantly greater than the initial visit (p < 0.001), but did not differ from the 3 month visit (p = 0.23). The gains in knee extension did not differ between worker's compensation and non-compensation patients (p = 0.56).

Conclusions

We conclude that the adjunctive use of HIS mechanical therapy is an effective treatment option for patients with knee flexion contractures, regardless of whether the patient is being treated as part of a worker's compensation claim or not.