Cartilage Quality (dGEMRIC Index) Following Knee Joint Distraction or High Tibial Osteotomy

A systematic review demonstrating correlation of MRI compositional parameters with clinical outcomes following articular cartilage repair interventions in the knee

OBJECTIVE

Compositional-MRI parameters enable the assessment of cartilage ultrastructure. Correlation of these parameters with clinical outcomes is unclear. This systematic review investigated the correlation of various compositional- MRI parameters with clinical outcome measures following cartilage repair or regeneration interventions in the knee.

DESIGN

This study was registered with PROSPERO and reported in accordance with PRISMA. PubMed, Institute of Science Index, Scopus, Cochrane Central Register of Controlled Trials, and Embase databases were searched. All studies, regardless of type, that presented correlation of compositional- MRI parameters with clinical outcome measures were included. Two researchers independently performed data extraction and QUADAS-2 analysis. Compositional-MRI parameter change following intervention and correlation with clinical outcome measures were evaluated.

RESULTS

19 studies were included. Risk of bias was generally low. 5 different compositional parameters were observed from the included studies. However, due to the significant variability in the reporting of compositional-MRI parameters across studies, meta-analyses were possible only for T2 values and T2 index values (T2 value of repair cartilage relative to normal cartilage). Correlation of T2 values of repair cartilage with clinical outcome score was r ​= ​0.33 [0.15, 0.52]. Correlation of T2 index with clinical outcome score was r ​= ​0.52 [0.32, 0.77].

CONCLUSIONS

Correlation between T2 values and clinical outcome scores following knee cartilage repair were found. The heterogeneity of the correlations extracted from the included studies limited the scope for the meta-analysis. Thus, standardised, high-quality studies are required for better assessment of correlation between compositional MRI parameters and clinical outcome measures after cartilage repair.

REGISTRATION NUMBER

PROSPERO CRD42021287364.Study protocol available on PROSPERO website.

Failure of cartilage regeneration: emerging hypotheses and related therapeutic strategies

Osteoarthritis (OA) is a disabling condition that affects billions of people worldwide and places a considerable burden on patients and on society owing to its prevalence and economic cost. As cartilage injuries are generally associated with the progressive onset of OA, robustly effective approaches for cartilage regeneration are necessary. Despite extensive research, technical development and clinical experimentation, no current surgery-based, material-based, cell-based or drug-based treatment can reliably restore the structure and function of hyaline cartilage. This paucity of effective treatment is partly caused by a lack of fundamental understanding of why articular cartilage fails to spontaneously regenerate. Thus, research studies that investigate the mechanisms behind the cartilage regeneration processes and the failure of these processes are critical to instruct decisions about patient treatment or to support the development of next-generation therapies for cartilage repair and OA prevention. This Review provides a synoptic and structured analysis of the current hypotheses about failure in cartilage regeneration, and the accompanying therapeutic strategies to overcome these hurdles, including some current or potential approaches to OA therapy.

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.

Unloader bracing in osteoarthritis of the knee - Is there a direct effect on the damaged cartilage?

BACKGROUND

Unloading knee braces represent a conservative treatment option for non-pharmalogical management of unicompartmental osteoarthritis of the knee. Though there is consensus on the clinical effectiveness of unloading, the effect mechanism of bracing remains part of a debate. Our study was designed to assess the effect of unloader bracing on damaged cartilage via MRI cartilage mappings.

METHODS

Fourteen patients (7 female, 7 male, mean age 43.1 ± 9.4 years) with unicompartmental cartilage wear in knees with varus or valgus malalignment were enrolled. Clinical scores, radiographs and MR-graphic properties (T2/T2* mapping, T1 Delayed Gadolinium Enhanced MRI of the cartilage (dGEMRIC) mapping, high-resolution PDw sequences) of knee cartilage were recorded before and three months after brace use.

RESULTS

Bracing the knees for a mean of 14.4 ± 2.0 weeks (range 11 to 18 weeks) resulted in significant pain reduction (VAS changed from 5.9 ± 2.0 to 2.0 ± 1.3, p < 0.001) and improvement in knee function (KOOS increased from 42.1 ± 22.7 to 64.8 ± 18.7, p < 0.001). In the affected cartilage regions T2 relaxation times significantly decreased from 56.1 ± 11.4 ms to 46.5 ± 11.2 ms (p < 0.05). No changes in T1-dGEMRIC and T2* relaxation times, thickness or the extent of the damaged cartilage area could be detected.

CONCLUSIONS

Our results suggest, that unloader bracing improves the biochemical properties of the damaged cartilage by increasing collagen and proteoglycan concentration as well as decreasing the cartilage edema.

Changes in joint space width over time and risk factors for deterioration of joint space width after medial opening-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to evaluate the changes in joint space width (JSW) over time after medial opening-wedge high tibial osteotomy (MOWHTO) and identify risk factors for deterioration of JSW using anteroposterior (AP) and Rosenberg views.

METHODS

We retrospectively analyzed changes in JSW of 104 MOWHTO patients whose preoperative osteoarthritis (OA) grade was K-L grade 3 or less on AP and Rosenberg views. Serial changes in JSW were assessed from preoperatively to at least 3 years postoperatively. Patients were divided into two groups according to JSW change patterns on each of AP and Rosenberg views: non-deterioration group had either unchanged or increased JSW, and deterioration group had decreased JSW. Clinical outcomes were compared using Western Ontario and McMaster Universities OA Index (WOMAC) score between groups. Multivariate logistic regression analysis was performed to identify risk factors for deterioration of JSW.

RESULTS

JSW on average for all patients increased 0.5 mm and 0.8 mm on AP and Rosenberg views, respectively (p < 0.05). Non-deterioration group showed significant improvement based on patient-reported outcomes (WOMAC) than deterioration group (all p < 0.05). Undercorrection was an independent risk factor for failure to achieve maintained or increased JSW on both AP (OR 6.885, 95% CI 1.976-23.986, p = 0.002) and Rosenberg (OR 12.756, 95% CI 2.952-55.129, p = 0.001) views.

CONCLUSION

JSW increased gradually and continuously on standing AP and Rosenberg views until postoperative 3 years after MOWHTO. Deterioration of JSW following MOWHTO was closely related to the undercorrection and affected clinical outcomes.

LEVEL OF EVIDENCE

Level III, case control study.

[Short-term effectiveness of high tibial osteotomy combined with arthroscopic surgery for knee varus arthritis and the results of secondary arthroscopic exploration]

OBJECTIVE

To investigate the effectiveness of high tibial osteotomy (HTO) combined with arthroscopic surgery to treat medial compartment knee osteoarthritis (KOA) and secondary arthroscopic exploration to evaluate the outcome of cartilage and meniscus.

METHODS

A clinical data of 57 patients with medial compartment KOA with varus deformity of lower extremities admitted between August 2014 and October 2018 were retrospectively analyzed. There were 23 males and 34 females with an average age of 51.2 years (range, 41-63 years). The disease duration ranged from 2 to 8 years, with an average of 4.7 years. The preoperative femorotibial angle was (179.86±4.69)°, the relative position of the lower limb mechanical axis passing through the tibial plateau was 24.21%±6.98%, and the posterior slope of the tibial plateau was (5.23±1.45)°. The Kellgren-Lawrence grade of knee joint was grade Ⅱ in 22 cases and grade Ⅲ in 35 cases. The preoperative Hospital for Special Surgery (HSS) score, Lysholm score, and visual analogue scale (VAS) score were 59.1±7.3, 48.8±7.6, and 6.2±1.1, respectively. Arthroscopic exploration was performed during the operation to record the articular cartilage degeneration in the weight-bearing area of the medial compartment (Outerbridge grade Ⅰ in 18 cases, grade Ⅱ in 30 cases, and grade Ⅲ in 9 cases) and the condition of the medial meniscus injury, and the corresponding treatment was performed. The coronal force line was adjusted according to the preoperative Kellgren-Lawrence grade of the knee joint during the operation. After operation, the relative position of the lower limb mechanical axis passing through the tibial plateau, the femorotibial angle, and the posterior slope of the tibial plateau were measured; the Kellgren-Lawrence grade of the knee joint was recorded; the Outerbridge grade of articular cartilage degeneration and the meniscus outcome were evaluated by combining with the MRI of the knee joint at 1 year after operation and the second arthroscopic exploration when the internal fixator was removed. The function and pain of the knee were evaluated by Lysholm score, HSS score, and VAS score.

RESULTS

All the 57 patients were followed up 36-58 months with an average of 42.1 months. Incisions healed by first intention, and no neurovascular injury, intraarticular or hinge fractures occurred during operation, and no postoperative complications such as deep vein thrombosis of lower limbs and internal fixation failure occurred. All the osteotomy sites healed at 3 months after operation. At 1 year after operation, the internal fixator was removed, and the second arthroscopic exploration showed that there were 15 cases of Outerbridge grade Ⅰ, 31 cases of grade Ⅱ, and 11 cases of grade Ⅲ in the weight-bearing area of the medial compartment, and there was no significant difference when compared with preoperative grade ( Z=31.992, P=0.997); there was no cartilage degeneration in other compartments. Meniscus healing was seen in the injured meniscus, and no injury was seen in the normal meniscus. At last follow-up, there were 19 cases of Kellgren-Lawrence grade Ⅱ and 38 cases of grade Ⅲ, and there was no significant difference when compared with preoperative grade ( Z=49.049, P=0.764). The relative position of the lower limb mechanical axis passing through the tibial plateau was 59.16%±2.87%, and the femorotibial angle was (171.54±3.39)°, which significantly improved when compared with those before operation ( P<0.001). The posterior slope of the tibial plateau was (5.65±1.22)°, which was not significantly different from that before operation ( t=-1.673, P=0.096). The HSS score, Lysholm score, and VAS score were 82.3±7.7, 83.4±6.4, and 1.6±1.1 respectively, which were significantly different from those before operation ( P<0.001).

CONCLUSION

HTO combined with arthroscopic surgery for medial compartment KOA with varus deformity of lower extremities can effectively improve the force line of lower extremities, relieve pain symptoms, and improve joint function, with satisfactory short-term effectiveness, and without significant progress in articular cartilage or meniscus injury after operation.

Surgical therapy in osteoarthritis

OBJECTIVE

To provide an evidence-based overview of the different surgical procedures in osteoarthritis (OA).

DESIGN

This narrative review reports on surgical therapies (1) for severe, end stage OA and (2) of surgical options aiming to possibly reduce OA development earlier in the course of the disease.

RESULTS

Surgical practice guidelines provide evidence-based recommendations to assist in the clinical decision-making. Total joint arthroplasty represents the only valuable, established surgical option for severe, end stage OA. For hip and knee OA, it is by far the most common surgical procedure and provides considerable pain relief, functional restoration, and improved quality of life. Surgical therapy aiming to postpone OA essentially addresses extra- or intraarticular pre-osteoarthritic deformities, defined as congenital or acquired disturbances of the joint structure that adversely affect its function. Approaches in this category include osteotomies and different cartilage repair procedures such as osteochondral autograft and allograft transfer, marrow stimulation techniques, and autologous chondrocyte implantation. However, they are not only less commonly performed than arthroplasty, but the scientific clinical evidence in favour of this type of surgery to reduce the long-term risk of developing OA is considerably reduced.

CONCLUSION

Total knee and hip arthroplasty are two of the most successful procedures in all of medicine. As the progression of this insidious disease is often asymptomatic and slow, it is imperative to judge reparative procedures at their potential to reduce OA development at long-term, besides their primary clinical outcomes. Evidence-based guidelines provide a valuable tool for high-quality surgical decision making in OA.

Patients with advanced lateral osteoarthritis can return to sports and work after distraction arthroplasty plus lateral meniscal allograft transplantation combined with cartilage repair

PURPOSE

This study aimed to report return to sports (RTS) and return to work (RTW) outcomes after distraction arthroplasty (DA) plus lateral meniscal allograft transplantation (MAT) combined with cartilage repair in active patients with advanced osteoarthritis. It was hypothesised that DA combined with lateral MAT would improve clinical and radiological outcomes and enable RTS and RTW for most patients.

METHODS

In total, 21 patients with advanced osteoarthritis (moderate to severe joint space narrowing at lateral edge on Rosenberg view and large cartilage defect of lateral femoral condyle) who underwent concomitant DA and MAT were retrospectively reviewed. Clinical outcomes were assessed using subjective knee scores [Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity scale (TAS)] and functional tests (isokinetic extensor muscle strength test, single-leg vertical jump test, and single-leg hop for distance test). The rates of RTS, RTW, and satisfaction were evaluated. Radiological outcomes were assessed using magnetic resonance imaging (MRI) and X-ray (Rosenberg view).

RESULTS

The mean age at surgery and mean follow-up duration were 37.2 ± 5.9 years and 37.1 ± 5.4 months, respectively. All improvements in subjective scores were statistically significant (p < 0.001). The Lysholm score improved from 58.3 ± 8.1 to 84.3 ± 8.2, the IKDC subjective score from 53.9 ± 10.4 to 78.0 ± 7.7, and the TAS from 4.0 ± 0.5 to 5.1 ± 0.8. The limb symmetry index (LSI) (%) of the extensor peak torque at an angular velocity of 60°/s improved from 67.3 ± 19.2 to 88.4 ± 20.3% (p = 0.001). The LSI of the single-leg vertical jump test and single-leg hop for distance test improved from 62.8 ± 21.3 to 87.7 ± 19.5% and from 63.9 ± 20.8 to 85.5 ± 18.1%, respectively (all, p < 0.001). All patients were able to return to any sports activity and work. However, 67% and 90.5% returned to their defined or desired level of sports activity and occupation intensity, respectively. Further, 76.2% were very satisfied or somewhat satisfied with the outcome at the last follow-up. The JSW increased by 0.8 ± 0.4 to 2.3 ± 0.6 mm (p = 0.005). In more than 90% of patients, > 50% of cartilage lesion was covered. The mean graft extrusion was 2.6 ± 1.0 mm.

CONCLUSION

All patients who underwent distraction arthroplasty plus lateral MAT combined with cartilage repair returned to any sports and work at the last follow-up. Significant improvements in clinical outcomes and the radiographic joint space width were observed. However, the activity ability was somewhat reduced compared with the best preoperative level. This one-stage joint salvage treatment is a promising option for young and active patients with advanced OA who wish to return to high levels of sports activity and occupation intensity (≥ Tegner activity scale 4).

LEVEL OF EVIDENCE

III.

High tibial osteotomy to neutral alignment improves medial knee articular cartilage composition

PURPOSE

The purpose of this study was to: (1) test the hypothesis that HTO improves articular cartilage composition in the medial compartment without adversely affecting the lateral compartment and patella, and; (2) explore associations between knee alignment and cartilage composition after surgery.

METHODS

3T MRI and standing radiographs were obtained from 34 patients before and 1-year after HTO. Articular cartilage was segmented from T2 maps. Mechanical axis angle (MAA), posterior tibial slope, and patellar height were measured from radiographs. Changes in T2 and radiographic measures were assessed using paired t tests, and associations were assessed using Pearson correlation coefficients.

RESULTS

The mean (SD) MAA before and after HTO was - 6.5° (2.4) and 0.6° (3.0), respectively. There was statistically significant shortening [mean (95%CI)] of T2 in the medial femur [- 2.8 ms (- 4.2; - 1.3), p < 0.001] and medial tibia [- 2.2 ms (- 3.3; - 1.0), p < 0.001], without changes in the lateral femur [- 0.5 ms (- 1.6; 0.6), p = 0.3], lateral tibia [0.2 ms (- 0.8; 1.1), p = NS], or patella [0.5 ms (- 1.0; 2.1), p = NS). Associations between radiographic measures and T2 were low. 23% of the increase in lateral femur T2 was explained by postoperative posterior tibial slope (r = 0.48).

CONCLUSION

Performing medial opening wedge HTO without overcorrection improves articular cartilage composition in the medial compartment of the knee without compromising the lateral compartment or the patella. Although further research is required, these results suggest HTO is a disease structure-modifying treatment for knee OA.

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.

Quantification of Sodium Relaxation Times and Concentrations as Surrogates of Proteoglycan Content of Patellar CARTILAGE at 3T MRI

Sodium MRI has the potential to depict cartilage health accurately, but synovial fluid can influence the estimation of sodium parameters of cartilage. Therefore, this study aimed to reduce the impact of synovial fluid to render the quantitative compositional analyses of cartilage tissue technically more robust. Two dedicated protocols were applied for determining sodium T1 and T2* relaxation times. For each protocol, data were acquired from 10 healthy volunteers and one patient with patellar cartilage damage. Data recorded with multiple repetition times for T1 measurement and multi-echo data acquired with an additional inversion recovery pulse for T2* measurement were analysed using biexponential models to differentiate longitudinal relaxation components of cartilage (T1,car) and synovial fluid (T1,syn), and short (T2s*) from long (T2l*) transversal relaxation components. Sodium relaxation times and concentration estimates in patellar cartilage were successfully determined: T1,car = 14.5 ± 0.7 ms; T1,syn = 37.9 ± 2.9 ms; c(T1-protocol) = 200 ± 48 mmol/L; T2s* = 0.4 ± 0.1 ms; T2l* = 12.6 ± 0.7 ms; c(T2*-protocol) = 215 ± 44 mmol/L for healthy volunteers. In conclusion, a robust determination of sodium relaxation times is possible at a clinical field strength of 3T to quantify sodium concentrations, which might be a valuable tool to determine cartilage health.

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.

Role of joint distraction in osteoarthritis of the knee: Basic science, principles and outcomes

The burden of knee osteoarthritis (OA) is increasing worldwide. Advanced tibiofemoral joint OA in young patients is particularly a problem with inferior results seen with total knee arthroplasty in this patient population. Knee joint distraction (KJD) has been evaluated recently as a joint preserving procedure for young patients with advanced tibiofemoral osteoarthritis, to delay the need for a primary total knee arthroplasty (TKA). This will decrease the risk for revision TKA later in life. KJD temporarily unloads the knee joint and keeps the tibia and femur separated over a course of 6 weeks. Outcomes of KJD appear promising. Through this article, the authors hope to share from their collective experience as well as the available literature on the basic science, principles of surgery and outcomes of KJD.

Clinical outcomes of knee joint distraction combined with marrow stimulation procedures for patients with advanced knee osteoarthritis

BACKGROUND

Knee joint distraction (KJD) has received much attention as a joint preserving surgery, especially in young patients with advanced knee osteoarthritis (OA).

METHODS

This study included 16 patients with advanced knee OA who underwent KJD combined with marrow stimulating techniques and were followed up for more than 2 years. The patients' clinical scores, including the Japanese Orthopaedic Association (JOA) score, Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, ROM, joint space width, and semiquantitative MRI were evaluated. The factors affecting clinical outcomes were analyzed.

RESULTS

Postoperatively, the JOA score and the individual scores of the KOOS subscales improved significantly (JOA score: P = 0.0028, KOOS-symptoms: P = 0.0016, -pain: P = 0.0011, -ADL: P = 0.0009, -sports/recreation: P = 0.0144, and -QOL: P = 0.0034). Although the extension of the knee joint did not change throughout the follow-up period, flexion of the joint deteriorated at the time of device removal but recovered to the preoperative level at the final follow-up. Preoperative joint space width was 2.4 ± 2.0 mm and at the final follow-up, it increased to 3.3 ± 1.5 mm, showing statistically significant improvement (P = 0.034). The postoperative semiquantitative MRI score also improved significantly (from 6.0 ± 3.0 to 42.1 ± 28.7, P = 0.0001). A high BMI was associated with a poor clinical outcome.

CONCLUSION

Although the effect of marrow stimulating techniques for cartilage repair was not well clarified and the complication rate was high, the clinical and radiographic outcomes showed significant improvement after KJD combined with marrow stimulating techniques in patients with advanced knee OA. However, we should be careful about suggesting this procedure in obese patients.

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

OBJECTIVE

Knee joint distraction (KJD) is a joint-preserving osteoarthritis treatment that may postpone a total knee arthroplasty (TKA) in younger patients. This systematic review and meta-analysis evaluates short- and long-term clinical benefit and tissue structure changes after KJD.

DESIGN

MEDLINE, EMBASE, and Web of Science were searched for eligible clinical studies evaluating at least one of the primary parameters: WOMAC, VAS-pain, KOOS, EQ5D, radiographic joint space width or MRI cartilage thickness after KJD. Random effects models were applied on all outcome parameters and outcomes were compared with control groups found in the included studies.

RESULTS

Eleven articles reporting on 7 different KJD cohorts with in total 127 patients and 5 control groups with multiple follow-up moments were included, of which 2 were randomized controlled trials. Significant improvements in all primary parameters were found and benefit lasted up to at least 9 years. Overall, outcomes were comparable with control groups, including high tibial osteotomy, although TKA showed better clinical response.

CONCLUSIONS

Current, still limited, evidence shows KJD causes clear benefit in clinical and structural parameters, both short- and long-term. Longer follow-up with more patients is necessary, to validate outcome and to potentially improve patient selection for this intensive treatment. Thus far, for younger knee osteoarthritis patients, KJD may be an option to consider.

Comparison of Mechanical Performance between Circular Frames and Biplanar Distraction Devices for Knee Joint Distraction

Aim and objective

This study was designed to test and compare the mechanical performance of the biplanar ArthroSave KneeReviver and a circular frame construct with the intended use of providing a mechanically favourable environment for cartilage regeneration across a knee joint.

Materials and methods

Three similar constructs of the two devices were applied to biomechanical testing sawbones, with the knee distracted by 8 mm. The constructs were vertically loaded to 800 N in an Instron testing machine at 20 mm/minute. Tests were conducted in neutral hip flexion and at 12° of hip flexion and extension, to mimic leg position in gait. Displacement measurements were taken from the Instron machine, and three-dimensional joint motion was recorded using an Optotrak Certus motion capture system.

Results

Overall axial rigidity was similar between the two devices (circular frame, 81.6 N/mm ± 5.9; and KneeReviver, 79.5 N/mm ± 25.1 with hip neutral) and similar in different hip positions. At the point of joint contact, the overall rigidity of the circular frame increased significantly more than the KneeReviver (491 N/mm ± 27 and 93 N/mm ± 32, respectively, p <0.001). There was more variability between models in the KneeReviver. There was more off-axis motion in the KneeReviver, mainly due to increasing knee flexion on loading. This was exacerbated with the hip in flexion and extension but remained small, with the maximal off-axis displacement being 7 mm/3°.

Conclusion

The circular frame provides a similar mechanical environment to the novel KneeReviver device, for which most clinical data are available. These findings suggest that both devices appear a viable option for knee joint distraction (KJD). Further clinical data will help inform mode of application.

Clinical significance

KJD is a relatively novel technique for use in osteoarthritis (OA), and it remains unclear which distraction devices provide appropriate mechanics. Our testing gives evidence to support either option for further use.

How to cite this article

Chowdhury JMY, Lineham B, Pallett M, et al. Comparison of Mechanical Performance between Circular Frames and Biplanar Distraction Devices for Knee Joint Distraction. Strategies Trauma Limb Reconstr 2021;16(2):71–77.

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.

[Arthroscopy combined with high tibial osteotomy for the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury]

Objective

To investigate the effectiveness of arthroscopy combined with high tibial osteotomy (HTO) in the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury.

Methods

The clinical data of 57 patients with knee medial compartment osteoarthritis treated with arthroscopy combined with HTO between March 2017 and March 2019 were retrospectively analyzed. There were 27 males and 30 females with an average age of 52.4 years (range, 44-57 years). The disease duration ranged from 3 to 6 years, with an average of 3.6 years. Twenty-one cases were grade Ⅰ and 36 cases were grade Ⅱ according to Kellgren-Lawrence classification. Flexion contracture of knee joint ranged from 0° to 8° with an average of 1.36° and varus deformity ranged from 5° to 10° with an average of 7.60°. Preoperative arthroscopic evaluation showed that there were 11 cases with grade Ⅰ, 42 cases with gradeⅡ, and 4 cases with grade Ⅲ according to the international cartilage repair classification system (ICRS). Lysholm score, American Hospital for Special Surgery (HSS) score, and International Knee Documentation Committee (IKDC) score were used to evaluate knee function before operation, at 3 months, at 1 year after operation, and at last follow-up. Visual analogue scale (VAS) score was used to evaluate pain. The mechanical medial proximal tibial angle (mMPTA) and femoral tibial angle (FTA) were measured before operation and at last follow-up. When the internal fixator was removed, the knee arthroscopy was performed again to explore the cartilage repair condition, and the regeneration level and maturity level were selected for cartilage grading evaluation.

Results

All patients' incisions healed by first intention after operation, and no incision infection or skin necrosis occurred. After operation, the knee joint function of the patients was significantly improved, the pain symptoms were relieved, and the force line measurement reached the target set before operation. The VAS score, Lysholm score, HSS score, and IKDC score were significantly improved at 3 months, 1 year after operation, and at last follow-up when compared with those before operation. They were gradually improved with the time and there were significant differences between time points ( P<0.05). mMPTA and FTA were significantly improved at last follow-up when compared with those before operation ( P<0.05). When the internal fixator was removed, the arthroscopic re-assessment found that the cartilage regeneration was classified into 10 cases of grade Ⅰ and 47 cases of grade Ⅱ; 18 cases of immature cartilage regeneration and 29 cases of mature cartilage regeneration were found in the knee joints of grade Ⅱ cartilage regeneration. There was no significant difference in the cartilage regeneration grade between different ICRS gradings ( H=0.176, P=0.916), and the difference in maturity grading was significant ( H=10.500, P=0.005).

Conclusion

Arthroscopy combined with HTO for the treatment of knee medial compartment osteoarthritis can effectively improve the symptoms and function of the knee joint, and can promote the regeneration of articular cartilage.

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.

Knee Joint Distraction Compared with High Tibial Osteotomy and Total Knee Arthroplasty: Two-Year Clinical, Radiographic, and Biochemical Marker Outcomes of Two Randomized Controlled Trials

OBJECTIVE

Both, knee joint distraction (KJD) and high tibial osteotomy (HTO) are joint-preserving surgeries that postpone total knee arthroplasty (TKA) in younger osteoarthritis (OA) patients. Here we evaluate the 2-year follow-up of KJD versus TKA and KJD versus HTO in 2 noninferiority studies.

DESIGN

Knee OA patients indicated for TKA were randomized to KJD (n = 20; KJD_TKA) or TKA (n = 40). Medial compartmental knee OA patients considered for HTO were randomized to KJD (n = 23; KJD_HTO) or HTO (n = 46). Patient-reported outcome measures were assessed over 2 years of follow-up. The radiographic joint space width (JSW) was measured yearly. In the KJD groups, serum-PIIANP and urinary-CTXII levels were measured as collagen type-II synthesis and breakdown markers. It was hypothesized that there was no clinically important difference in the primary outcome, the total WOMAC, when comparing KJD with HTO and with TKA.

RESULTS

Both trials were completed, with 114 patients (19 KJD_TKA; 34 TKA; 20 KJD_HTO; 41 HTO) available for 2-year analyses. At 2 years, the total WOMAC score (KJDTKA: +30.4 [95% CI 23.0-37.9] points; TKA: +42.4 [95% CI 38.1-46.8]; KJDHTO: +21.6 [95% CI 13.8-29.4]; HTO: +29.2 [95% CI 23.6-34.8]; all: P < 0.05) and radiographic minimum JSW (KJDTKA: +0.9 [95% CI 0.2-1.6] mm; KJDHTO: +0.9 [95% CI 0.5-1.4]; HTO: +0.6 [95% CI 0.3-0.9]; all: P < 0.05) were still increased for all groups. The net collagen type-II synthesis 2 years after KJD was increased (P < 0.05). Half of KJD patients experienced pin tract infections, successfully treated with oral antibiotics.

CONCLUSIONS

Sustained improvement of clinical benefit and (hyaline) cartilage thickness increase after KJD is demonstrated. KJD was clinically noninferior to HTO and TKA in the primary outcome.

Osteoarthritis year in review 2020: imaging

This narrative "Year in Review" highlights a selection of articles published between January 2019 and April 2020, to be presented at the OARSI World Congress 2020 within the field of osteoarthritis (OA) imaging. Articles were obtained from a PubMed search covering the above period, utilizing a variety of relevant search terms. We then selected original and review studies on OA-related imaging in humans, particularly those with direct clinical relevance, with a focus on the knee. Topics selected encompassed clinically relevant models of early OA, particularly imaging applications on cruciate ligament rupture, as these are of direct clinical interest and provide potential opportunity to evaluate preventive therapy. Further, imaging applications on structural modification of articular tissues in patients with established OA, by non-pharmacological, pharmacological and surgical interventions are summarized. Finally, novel deep learning approaches to imaging are reviewed, as these facilitate implementation and scaling of quantitative imaging application in clinical trials and clinical practice. Methodological or observational studies outside these key focus areas were not included. Studies focused on biology, biomechanics, biomarkers, genetics and epigenetics, and clinical studies that did not contain an imaging component are covered in other articles within the OARSI "Year in Review" series. In conclusion, exciting progress has been made in clinically validating human models of early OA, and the field of automated articular tissue segmentation. Most importantly though, it has been shown that structure modification of articular cartilage is possible, and future research should focus on the translation of these structural findings to clinical benefit.

Improved Methods to Measure Outcomes After High Tibial Osteotomy

Observational studies suggest high tibial osteotomy produces substantial improvements in knee loading and stability that can limit the progression of joint damage; decrease pain; improve function and quality of life; and delay the need for knee replacement surgery. It can be cost-effective in knee osteoarthritis. However, systematic reviews and clinical practice guidelines are unable to provide strong recommendations, because limited high-level evidence supports its therapeutic value versus other treatments. We describe findings suggesting it can improve outcomes important to knee joint structure and function, patient quality of life, and health care systems. Future clinical trials are warranted and required.