Knee Joint Distraction as Treatment for Osteoarthritis Results in Clinical and Structural Benefit: A Systematic Review and Meta-Analysis of the Limited Number of Studies and Patients Available

Comparison of Clinical Efficacy and Mechanical Characteristics of Two Knee Distraction Devices With Relevance for Clinical Practice

OBJECTIVE

Distraction treatment for severe osteoarthritis below the age of 65 successfully postpones arthroplasty. Most patients have been treated with a general external fixator or a device specifically intended for knee distraction. This study compares clinical efficacy of both devices in retrospect and their mechanical characteristics.

DESIGN

Clinical efficacy 2 years posttreatment was compared using retrospective data from patients with severe knee osteoarthritis treated with knee distraction; 63 with the Dynamic Monotube (Stryker GmbH, Switzerland) and 65 with the KneeReviver (ArthroSave BV, the Netherlands). Changes in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, stiffness, and function, general well-being (SF-36), cartilage thickness by radiographic joint space widening, and adverse events during treatment were assessed. Axial stiffness of clinically feasible configurations was assessed by bench testing for the Dynamic Monotube triax system and the KneeReviver.

RESULTS

No differences were observed in clinical efficacy, nor in mechanical characteristics and adverse events between the two devices. Although with large variation, both showed a clinically relevant improvement. In mechanical testing, contact between articular surfaces was observed for both devices at physiological loading. Stiffness of applied configurations strongly varied and primarily depended on bone pin length.

CONCLUSIONS

Patients treated with a general intended-use device or a distraction-specific device both experienced clinical and structural efficacy although with significant variation between patients. The latter may be the result of varying mechanical characteristics resulting from differences in clinical configurations of the devices and actual loading. The exact role of full/partial mechanical unloading of the joint during distraction treatment remains unclear.

Patient with knee osteoarthritis demonstrates improved knee adduction moment after knee joint distraction: a case report

In this article we report a case of a 53-year-old patient diagnosed with end-stage osteoarthritis (OA) of the knee. The patient underwent treatment with knee joint distraction (KJD) with the aim to postpone total knee arthroplasty and prevent potential revision surgery. To assess the effect of KJD, a 3D gait analysis was performed preoperative and one year postoperative. In this patient, preoperative 3D gait analysis revealed an increased knee adduction moment (KAM) compared to healthy levels. Postoperative the KAM decreased, approaching healthy levels, suggesting potential improvements in disease status or in gait. Consequently, further investigation into the effectiveness of Knee Joint Distraction (KJD) as a treatment option for relatively young patients with knee OA is warranted. Gait analysis has emerged as an effective tool for assessing treatment outcomes of innovative treatment such as KJD at the individual level.

Low annual revision rate in ankle distraction for ankle osteoarthritis: A systematic review and meta-analysis

PURPOSE

Ankle osteoarthritis severely impacts patients' mental and physical quality of life. Besides total ankle replacement and ankle arthrodesis, ankle distraction has been shown to be a promising alternative. The primary aim of the present study was to determine the annual revision rates (ARRs) after ankle distraction. The secondary aim was to obtain an overview of patient-reported outcome measures and functional outcomes.

METHODS

A literature search until November 2023 was performed. Methodological quality was assessed using the methodological index for non-randomised studies criteria. Primary outcome was the ARR which was log-transformed and pooled using a random effects model. Secondary outcomes were pooled using a simplified pooling technique and included the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS), range of motion (ROM) and post-operative complications.

RESULTS

The literature search resulted in 287 articles, of which 10 studies, comprising 602 patients, were included. The patients had a pooled mean age of 47 years (range of means: 40-68) and a mean follow-up of 35 months (range of means: 24-48). The overall methodological quality was moderate to fair. The pooled ARR after ankle distraction was 4% (95% confidence interval [CI], 3%-7%). Pooling of AOFAS showed mean 26-point improvement (from 54 to 80). Additionally, ROM dorsiflexion improved at 5°, and the plantarflexion remained at 31°. The overall complication rate was 41% (95% CI, 35%-48%), of which 77% (95% CI, 67%-85%) were pin-tract infections.

CONCLUSION

Ankle distraction results in an ARR of 4% (95% CI, 3%-7%) with clinically relevant improved AOFAS scores. The overall complication rate is 41% and is mainly attributable to treatable pin-tract infections (77% of recorded complications).

LEVEL OF EVIDENCE

Level IV, Systematic Review and Meta-Analysis.

New concept of orthosis treatment for knee osteoarthritis: Clinical and radiological outcomes

BACKGROUND

Given the increasing numbers of young patients with knee osteoarthritis there is a need for treatments that can postpone a joint prosthesis (total knee replacement).

OBJECTIVE

As an alternative to the effective yet invasive knee joint distraction procedure, a knee orthosis was developed aiming to unload the affected knee and improving synovial fluid flow. The aim of this study was to examine the effectiveness of using a load-reducing orthosis for two months on functioning, pain, and disease progression (e.g. amount of damaged cartilage) in patients with symptomatic osteoarthritis of the knee for at least one year.

METHODS

This is an interventional single-center pilot study. Ten patients with symptomatic osteoarthritis of one knee (5 males/5 females; median age 57; age range 42-59) used a custom-made orthosis for 60 days during daily life activities that involved knee loading (e.g. standing, walking, but not during stair climbing). Cycling was not allowed. Clinical outcomes were assessed up to 24 months after intervention at 6 timepoints using patient reported-outcome measures Western Ontario and McMaster Universities Osteoarthritis (WOMAC) range 0-100; Visual Analogue Scale (VAS), range 0-100 for pain. Minimum joint space width (mJSW) was assessed using knee images digital analysis (KIDA) and articular cartilage volume with magnetic resonance imaging (MRI) using custom software at baseline and at 12 and 24 months follow-up.

RESULTS

Clinically beneficial effects were found for functioning (WOMAC improvement compared to baseline ranged between 18 points at 3 months follow-up and 31 points at 12 months follow-up, with only the 24-months follow-up (improvement of 27 points) not reaching statistical significance (p< 0.05)) and for pain (VAS improvement compared to baseline at follow-up time points ranged between 41-56 points; all p< 0.05). No improvements in mJSW- or MRI-derived parameters were found.

CONCLUSION

This study demonstrates that use of a custom-made knee-unloading orthosis for 60 days can result in improved functional ability and decrease in pain in relatively young patients with knee osteoarthritis. No effect on disease progression could be evidenced.

Joint distraction using a purpose-built device for knee osteoarthritis: a prospective 2-year follow-up

OBJECTIVE

Knee distraction treatment for end-stage osteoarthritis successfully postpones arthroplasty for years. Studies performed thus far used general intended use, patient-personalised or custom-made devices. In this study, for the first time, a device specifically designed for knee distraction is evaluated.

DESIGN

65 patients (≤65 years) with end-stage knee osteoarthritis indicated for arthroplasty received knee distraction. Before, 1-year and 2-year post-treatment, questionnaires were filled out and knee radiographs made. Adverse events and self-reported pain medication were registered.

RESULTS

Forty-nine patients completed 2-year follow-up: one patient did not complete treatment, three patients received arthroplasty in the first and four patients in the second year follow-up. Eight patients were lost to follow-up in the second year. The total Western Ontario and McMaster Universities Osteoarthritis Index score showed a clinically relevant improvement at 1 and 2 years (+26 and +24 points), as did all subscales (all p<0.001). The minimum radiographic joint space width improved over 1 (+0.5 mm; p<0.001) and 2 (+0.4 mm; p=0.015) years, as did the physical Short-Form 36 (+10 points; p<0.001). The most common adverse event was pin tract infection, experienced by 66% of patients, in 88% successfully treated with oral antibiotics. In two cases, hospitalisation and/or intravenous antibiotics were needed. Eight patients experienced device-related complications. None of the complications influenced 2-year outcomes. Before treatment, 42% of patients used pain medication, which had nearly been halved 1 (23%; p=0.02) and 2 years (29%; p=0.27) post-treatment.

CONCLUSIONS

Patients treated with a general applicable, for knee distraction purpose-built device showed, despite adverse events, significant clinical and structural improvement over 2 years.

TRIAL REGISTRATION NUMBER

NL7986.

The Feasibility of Hinged Knee Arthrodiastasis for Cartilage Regeneration: A Systematic Review of the Literature

Introduction

Knee joint distraction (KJD) is a potential technique for cartilage regeneration in young patients with osteoarthritis of the knee. Static distraction has been utilised typically; however, a significant proportion of patients complain of knee stiffness post-distractor removal. The use of a hinged distractor may reduce the duration and severity of post-treatment knee stiffness by maintaining the range of motion during distraction. Furthermore, improved cartilage regeneration has been demonstrated in hinged ankle joint distraction as compared to static, and this may also be demonstrated at the knee. An evidence review was undertaken to inform further research and a potential change in practice.

Aim

A systematic review of all primary research on hinged knee joint distraction for cartilage regeneration.

Methods

An online systematic search of citation databases was conducted. Quality assessment and data extraction were undertaken by two separate researchers.

Results

The literature search returned a small number of relevant studies, of which 7 were included. Three of these were animal studies, two cadaveric and two case series. The study quality was low or very low. There was significant methodological heterogeneity with difficulties encountered in the transfer of constructs from animal and cadaveric studies to humans. Issues faced included difficulties with hinge placement and pin site pain in motion.

Conclusion

The feasibility of hinged knee joint distraction has yet to be proven. Any further research attempting to establish the benefits of hinged-over static knee distraction will have to take construct design considerations into account.

How to cite this article

Lineham B, van Duren B, Harwood P, et al. The Feasibility of Hinged Knee Arthrodiastasis for Cartilage Regeneration: A Systematic Review of the Literature. Strategies Trauma Limb Reconstr 2023;18(1):37-43.

The catabolic-to-anabolic shift seen in the canine osteoarthritic cartilage treated with knee joint distraction occurs after the distraction period

Background

Methods

Results

Conclusion

The Translational Potential of this Article

The Hunt Is On! In Pursuit of the Ideal Stem Cell Population for Cartilage Regeneration

Cartilage injury and degeneration are hallmarks of osteoarthritis (OA), the most common joint disease. OA is a major contributor to pain, loss of function, and reduced quality of life. Over the last decade, considerable research efforts have focused on cell-based therapies, including several stem cell-derived approaches to reverse the cartilage alterations associated with OA. Although several tissue sources for deriving cell-based therapies have been identified, none of the resident stem cell populations have adequately fulfilled the promise of curing OA. Indeed, many cell products do not contain true stem cells. As well, issues with aggressive marketing efforts, combined with a lack of evidence regarding efficacy, lead the several national regulatory bodies to discontinue the use of stem cell therapy for OA until more robust evidence becomes available. A review of the evidence is timely to address the status of cell-based cartilage regeneration. The promise of stem cell therapy is not new and has been used successfully to treat non-arthritic diseases, such as hematopoietic and muscle disorders. These fields of regenerative therapy have the advantage of a considerable foundation of knowledge in the area of stem cell repair mechanisms, the role of the stem cell niche, and niche-supporting cells. This foundation is lacking in the field of cartilage repair. So, where should we look for the ideal stem cell to regenerate cartilage? It has recently been discovered that cartilage itself may contain a population of SC-like progenitors. Other potential tissues include stem cell-rich dental pulp and the adolescent growth plate, the latter of which contains chondrocyte progenitors essential for producing the cartilage scaffold needed for bone growth. In this article, we review the progress on stem cell therapies for arthritic disorders, focusing on the various stem cell populations previously used for cartilage regeneration, successful cases of stem cell therapies in muscle and hemopoietic disorders, some of the reasons why these other fields have been successful (i.e., “lessons learned” to be applied to OA stem cell therapy), and finally, novel potential sources of stem cells for regenerating damaged cartilage in vivo.

The regional turnover of cartilage collagen matrix in late-stage human knee osteoarthritis

OBJECTIVE

Cartilage collagen has very limited repair potential, though some turnover and incorporation has not been fully excluded. We aim to determine the regional turnover of human osteoarthritis cartilage.

DESIGN

Patients scheduled for knee joint replacement surgery due to osteoarthritis were recruited in this prospective study of four weeks duration. Deuterium oxide (D₂O) was administered orally by weekly boluses at 70% D₂O, initially 150 ml followed by three boluses of 50 ml. Cartilage from the medial tibia plateau was sampled centrally, under the meniscus, and from osteophytes and treated enzymatically with hyaluronidase and trypsin. Samples were analysed for deuterium incorporation in alanine using mass spectrometry and for gene expression by real-time reverse transcriptase polymerase chain reaction.

RESULTS

Twenty participants completed the study: mean (SD) age 64 ± 9.1 years, 45% female, BMI 29.5 ± 4.8 kg/m². Enzymatically treated cartilage from central and submeniscal regions showed similar enrichments at 0.063% APE, while osteophytes showed significantly greater enrichment at 0.072% APE (95% confidence interval of difference) [0.004-0.015]). Fractional synthesis rates were similar for central 0.027%/day and submeniscal cartilage 0.022%/day but 10-fold higher in osteophytes 0.22%/day [0.098-0.363]. When compared to central cartilage, submeniscal cartilage had increased gene expression of MMP-3 and decreased lubricin expression. Untreated cartilage had higher turnover (enrichments at 0.073% APE) than enzymatically treated cartilage (0.063% APE).

CONCLUSIONS

In OA, despite regional differences in gene expression, the turnover of the articular cartilage matrix across the entire joint surface is very limited, but higher turnover was observed in osteophyte cartilage.

Joint distraction for osteoarthritis: clinical evidence and molecular mechanisms

Joint distraction, the prolonged mechanical separation of the bones at a joint, has emerged as a joint-preserving treatment for end-stage osteoarthritis, with the gradually growing promise of implementation in regular clinical practice. Joint distraction of the knee has been most extensively studied, with these studies showing prolonged symptomatic improvement in combination with repair of cartilage tissue in degenerated knee joints, supporting the concept that cartilage repair can translate into real clinical benefit. The reversal of tissue degeneration observed with joint distraction could be the result of one or a combination of various proposed mechanisms, including partial unloading, synovial fluid pressure oscillation, mechanical and biochemical changes in subchondral bone, adhesion and chondrogenic commitment of joint-derived mesenchymal stem cells or a change in the molecular milieu of the joint. The overall picture that emerges from the combined evidence is relevant for future research and treatment-related improvements of joint distraction and for translation of the insights gained about tissue repair to other joint-preserving techniques. It remains to be elucidated whether optimizing the biomechanical conditions during joint distraction can actually cure osteoarthritis rather than only providing temporary symptomatic relief, but even temporary relief might be relevant for society and patients, as it will delay joint replacement with a prosthesis at an early age and thereby avert revision surgery later in life. Most importantly, improved insights into the underlying mechanisms of joint repair might provide new leads for more targeted treatment options.

Enhanced Extracellular Matrix Breakdown Characterizes the Early Distraction Phase of Canine Knee Joint Distraction

OBJECTIVE

Joint distraction triggers intrinsic cartilage repair in animal models of osteoarthritis (OA), corroborating observations in human OA patients treated with joint distraction. The present study explores the still largely elusive mechanism initiating this repair process.

DESIGN

Unilateral OA was induced in the knee joint of 8 dogs using the groove model; the contralateral joint served as a control. After 10 weeks, 4 animals received joint distraction, the other 4 serving as OA controls. Halfway the distraction period (after 4 weeks of a standard 8-week distraction treatment), all animals were euthanized, and joint tissues were collected. A targeted quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was performed of commonly involved processes including matrix catabolism/anabolism, inflammation, and known signaling pathways in OA. In addition, cartilage changes were determined on tissue sections using the canine OARSI (Osteoarthritis Research Society International) histopathology score and collagen type II (COL2A1) immunostaining.

RESULTS

Midway distraction, the distracted OA joint showed an upregulation of proteolytic genes, for example, ADAMTS5, MMP9, MMP13, compared to OA alone and the healthy joints, which correlated with an increased OARSI score. Additionally, genes of the transforming growth factor (TGF)-β and Notch pathway, and markers associated with progenitor cells were increased.

CONCLUSIONS

Joint distraction initiates both catabolic and anabolic transcriptional responses. The enhanced turnover, and thereby renewal of the matrix, could be the key to the cartilage repair observed in the months after joint distraction.

Performance of knee image digital analysis of radiographs of patients with end-stage knee osteoarthritis

OBJECTIVE

Knee Image Digital Analysis (KIDA) is standardized radiographic analysis software for measuring osteoarthritis (OA) characteristics. It was validated in mild OA, but used for severe OA as well. The current goal was to evaluate the performance of KIDA in severe OA.

DESIGN

Of 103 patients, standardized radiographs were performed before and one and 2 years after treatment for severe OA. All radiographs were evaluated on subchondral bone density, joint space width (JSW), osteophytes, eminence height, and joint angle, twice within years by the same observer. Part of the radiographs were randomly selected for reevaluation twice within 1 month and evaluation by another observer. The intraclass correlation coefficient (ICC), smallest detectable difference (SDD) and coefficient of variation (CV) were calculated; the SDD and CV were compared to those in mild OA. The relation of severity with KIDA parameters and with observer differences was calculated with linear regression.

RESULTS

Intra-observer ICCs were higher in the 98 severe radiographs reanalyzed within 1 month (all >0.8) than the 293 reanalyzed within years (all >0.5; most >0.8) and than inter-observer ICCs (all >0.7). SDDs and CVs were smaller when reanalyzed within a month and comparable to those in mild OA. Some parameters showed bias between readings. Severity showed significant relation with osteophytes and JSW parameters, and with the observer variation in these parameters (all P < 0.04).

CONCLUSIONS

KIDA is a well-performing tool also for severe OA. In order to decrease variability and SDDs, images should be analyzed in a limited time frame and randomized order.

Comparison between 2D radiographic weight-bearing joint space width and 3D MRI non-weight-bearing cartilage thickness measures in the knee using non-weight-bearing 2D and 3D CT as an intermediary

Background:

In knee osteoarthritis, radiographic joint space width (JSW) is frequently used as a surrogate marker for cartilage thickness; however, longitudinal changes in radiographic JSW have shown poor correlations with those of magnetic resonance imaging (MRI) cartilage thickness. There are fundamental differences between the techniques: radiographic JSW represents two-dimensional (2D), weight-bearing, bone-to-bone distance, while on MRI three-dimensional (3D) non-weight-bearing cartilage thickness is measured. In this exploratory study, computed tomography (CT) was included as a third technique, as it can measure bone-to-bone under non-weight-bearing conditions. The objective was to use CT to compare the impact of weight-bearing versus non-weight-bearing, as well as bone-to-bone JSW versus actual cartilage thickness, in the knee.

Methods:

Osteoarthritis patients (n = 20) who were treated with knee joint distraction were included. Weight-bearing radiographs, non-weight-bearing MRIs and CTs were acquired before and 2 years after treatment. The mean radiographic JSW and cartilage thickness of the most affected compartment were measured. From CT, the 3D median JSW was calculated and a 2D projectional image was rendered, positioned similarly and measured identically to the radiograph. Pearson correlations between the techniques were derived, both cross-sectionally and longitudinally.

Results:

Fourteen patients could be analyzed. Cross-sectionally, all comparisons showed moderate to strong significant correlations (R = 0.43–0.81; all p < 0.05). Longitudinal changes over time were small; only the correlations between 2D CT and 3D CT (R = 0.65; p = 0.01) and 3D CT and MRI (R = 0.62; p = 0.02) were statistically significant.

Conclusion:

The poor correlation between changes in radiographic JSW and MRI cartilage thickness appears primarily to result from the difference in weight-bearing, and less so from measuring bone-to-bone distance versus cartilage thickness.

Knee joint distraction results in MRI cartilage thickness increase up to ten years after treatment

Objectives

Knee joint distraction (KJD) has been shown to result in long-term clinical improvement and short-term cartilage restoration in young OA patients. The objective of the current study was to evaluate MRI cartilage thickness up to 10 years after KJD treatment, using a 3D surface-based approach.

Methods

Twenty end-stage knee OA patients were treated with KJD. MRI scans (1.5 T) were performed before and at 1, 2, 5, 7, and 10 years after treatment. Tibia and femur cartilage segmentation and registration to a canonical surface were performed semi-automatically. Statistical parametric mapping with linear mixed models was used to analyse whole-joint changes. The influence of baseline patient characteristics was analysed with statistical parametric mapping using linear regression. Relevant weight-bearing parts of the femur were selected to obtain the average cartilage thickness in the femur and tibia of the most- (MAC) and least-affected compartment. These compartmental changes over time were analysed using repeated measures ANOVA; missing data was imputed. In all cases, P <0.05 was considered statistically significant.

Results

One and 2 years post-treatment, cartilage in the MAC weight-bearing region was significantly thicker than pre-treatment, gradually thinning after 5 years, but still increased at 10 years post-treatment. Long-term results showed that areas in the least-affected compartment were significantly thicker than pre-treatment. Male sex and more severe OA at baseline somewhat predicted shorter-term benefit (P >0.05). Compartmental analyses showed significant short- and long-term thickness increase in the tibia and femur MAC (all P <0.05).

Conclusion

KJD results in significant short- and long-term cartilage regeneration, up to 10 years post-treatment.

Trial registration

Netherlands Trial Register, https://www.trialregister.nl, NL419.

Changes in Cartilage Thickness and Denuded Bone Area after Knee Joint Distraction and High Tibial Osteotomy-Post-Hoc Analyses of Two Randomized Controlled Trials

High tibial osteotomy (HTO) and knee joint distraction (KJD) are joint-preserving treatments that unload the more affected compartment (MAC) in knee osteoarthritis. This post-hoc study compares two-year cartilage-thickness changes after treatment with KJD vs. HTO, and identifies factors predicting cartilage restoration. Patients indicated for HTO were randomized to KJD (KJD_HTO) or HTO treatment. Patients indicated for total knee arthroplasty received KJD (KJD_TKA). Outcomes were the MRI mean MAC cartilage thickness and percentage of denuded bone area (dABp) change two years after treatment, using radiographic joint space width (JSW) as the reference. Cohen’s d was used for between-group effect sizes. Post-treatment, KJD_HTO patients (n = 18) did not show significant changes. HTO patients (n = 33) displayed a decrease in MAC cartilage thickness and an increase in dABp, but an increase in JSW. KJD_TKA (n = 18) showed an increase in MAC cartilage thickness and JSW, and a decrease in dABp. Osteoarthritis severity was the strongest predictor of cartilage restoration. Kellgren–Lawrence grade ≥3 showed significant restoration (p < 0.01) after KJD; grade ≤2 did not. Effect sizes between severe KJD and HTO patients were large for MAC MRI cartilage thickness (d = 1.09; p = 0.005) and dABp (d = 1.13; p = 0.003), but not radiographic JSW (d = 0.28; p = 0.521). This suggests that in knee osteoarthritis patients with high disease severity, KJD may be more efficient in restoring cartilage thickness.