Progression of medial compartmental osteoarthritis 2-8 years after lateral closing-wedge high tibial osteotomy

Lateral closing wedge high tibial osteotomy procedure for the treatment of medial knee osteoarthritis: eleven years mean follow up analysis

PURPOSE

To assess long term survivorship, patient reported (PROMs) and radiological outcomes, and rate of adverse events and hardware removal after lateral closing wedge high tibial osteotomy (CWHTO) for the treatment of medial knee osteoarthritis (OA) and varus malalignment.

METHODS

Retrospective analysis of patients who underwent isolated CWHTO for medial OA in varus knee between 2009 and 2019 at the same institution was performed. Surgical failure was defined as conversion to total knee arthroplasty (TKA) or need for osteotomy revision procedure for varus recurrence, while clinical failure was defined by a Lysholm score under 65 points. Lysholm score, Visual Analogue Scale for pain (VAS), and patients' satisfaction with the treatment were evaluated. Radiographic parameters assessed included OA degree with the Kellgren Lawrence scale (KL), hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), joint line convergence angle (JLCA), and posterior tibial slope (PTS). Adverse events and rate of hardware removal procedures were recorded through follow up visits and clinical records. Survival analysis was conducted through Kaplan-Meier method with surgical and clinical failure as endpoints.

RESULTS

70 knees (mean age at surgery 43.3 years) were included in the survivorship analysis at a mean follow up of 11.6 ± 3.4 years. A failure rate of 12.85% (9/70) was recorded during the follow up period, with a survivorship of 92% and 75% at ten and 15 years of follow up, respectively. Mean Lysholm score and VAS at follow up were above the PASS threshold reported in literature. The 75.7% of patients were satisfied with the treatment. Radiological follow up indicated a residual mechanical varus of 2.1°, a decrease of 0.7° of intra articular deformity (JLCA), no change in PTS nor in KL index. The adverse events rate recorded was 5.7% (4/70). In nine knees (14.7%) among the patients survived from surgical failure a subsequent hardware removal procedure was performed.

CONCLUSION

CWHTO represents a safe procedure, which resulted in high survivorship (92% and 75% at ten and 15 years follow up, respectively), with satisfactory PROMs and radiological outcomes at long term follow up in patients affected by medial OA and varus malalignment.

LEVEL OF EVIDENCE

5, Case Series.

Unicompartmental osteoarthritis: High survival rate with a combined mechanical and biological salvage approach as alternative to metal resurfacing: Results at minimum 10 years of follow-up

PURPOSE

The aim of this study was to prospectively evaluate the long-term clinical results and failure rate of patients treated with complex salvage procedures using a combined mechanical and biological approach to address unicompartmental knee osteoarthritis (OA) and postpone the need for joint replacement.

METHODS

Thirty-nine patients (40.3 ± 10.9 years old) affected by unicompartmental OA (Kellgren-Lawrence 3) in stable joints underwent a personalized surgical treatment depending on the specific requirements of the affected compartment, including high tibial osteotomy, osteochondral scaffold, meniscal scaffold and meniscal allograft transplantation. Patients were evaluated with the International Knee Documentation Committee (IKDC), Visual Analogue Scale (VAS) and Tegner scores before surgery, at 3 years and a minimum of 10 years of follow-up.

RESULTS

A significant improvement was observed over time in all scores but worsened at the final follow-up. The IKDC subjective score improved from 46.9 ± 16.2 to 79.8 ± 16.4 at 3 years (p < 0.0005) and then decreased to 64.5 ± 21.4 (p = 0.001) at 12 years. A similar trend was confirmed for VAS and Tegner scores. Only two patients subsequently underwent knee arthroplasty, and nine more patients were considered clinical failure, for a cumulative surgical and clinical failure rate of 28.2% at the final follow-up.

CONCLUSION

A personalized, joint-preserving, combined mechanical and biological approach, addressing alignment as well as meniscal and cartilage lesions, is safe and effective, providing a clinical benefit and delaying the need for arthroplasty in young patients affected by unicompartmental knee OA. At the final evaluation, the clinical improvement decreased, but more than two-thirds of the patients still benefited from this treatment at a long-term follow-up.

LEVEL OF EVIDENCE

Level IV case series.

Knee osteotomy combined with meniscal allograft transplantation versus knee osteotomy alone in patients with unicompartmental knee osteoarthritis: a prospective double-blind randomised controlled trial protocol

INTRODUCTION

Knee osteotomy combined with meniscal allograft transplantation (MAT) showed promising results to treat unicompartmental knee osteoarthritis (OA) secondary to meniscal deficiency and knee malalignment. However, there is still no high-level evidence to demonstrate whether the combination of these two treatments is superior to osteotomy alone.

METHODS AND ANALYSIS

52 patients with unicompartmental knee OA Kellgren-Lawrence grade ≤3 secondary to meniscal deficiency and knee malalignment (aged 20-60 years) are randomised to undergo knee osteotomy associated with MAT or knee osteotomy alone in a 1:1 ratio. The primary outcome is the International Knee Documentation Committee (IKDC) subjective score at 12 months. The secondary outcomes are the IKDC subjective score at 1, 3 and 6 months, the Western Ontario and McMaster Universities Osteoarthritis Index score, the Knee Injury and Osteoarthritis Outcome Score, the Visual Analogue Scale, the EuroQol Visual Analogue Scale, the Tegner Activity Level Scale, objective parameters (transpatellar circumference, suprapatellar circumference and range of motion), patient expectation on treatment efficacy and patient satisfaction at 1, 3, 6 and 12 months. Radiographs are performed at baseline and at 1-, 6- and 12-month follow-ups and magnetic resonance evaluations at baseline and at 12 months. Biomechanical assessment is performed through gait analysis before surgery and at 12 months, investigating motion data, biomechanical parameters and muscle activation through electromyography. In addition, to detect early joint environment changes and potential MAT effects in protecting the articular surface providing a better knee homeostasis, biological markers of cartilage turnover and inflammation obtained from synovial fluid, serum and urine are evaluated at baseline and at 24 hours, 1-, 3-, 6- and 12-month follow-ups.

ETHICS AND DISSEMINATION

The study protocol has been approved by Emilia Romagna's Ethics Committee (CE-AVEC), Bologna, Italy. Written informed consent is obtained from all participants. Findings of this study will be disseminated through peer-reviewed publications and conference presentations.

PROTOCOL VERSION

March 2023.

TRIAL REGISTRATION NUMBER

NCT05840887.

The reimbursement system can influence the treatment choice and favor joint replacement versus other less invasive solutions in patients affected by osteoarthritis

PURPOSE

The aim of this study was to assess how physicians perceive the role of the reimbursement system and its potential influence in affecting their treatment choice in the management of patients affected by osteoarthritis (OA).

METHODS

A survey was administered to 283 members of SIAGASCOT (Italian Society of Arthroscopy, Knee, Upper Limb, Sport, Cartilage and Orthopaedic Technologies), a National scientific orthopaedic society. The survey presented multiple choice questions on the access allowed by the current Diagnosis-Related Groups (DRG) system to all necessary options to treat patients affected by OA and on the influence toward prosthetic solutions versus other less invasive options.

RESULTS

Almost 70% of the participants consider that the current DRG system does not allow access to all necessary options to best treat patients affected by OA. More than half of the participants thought that the current DRG system favors the choice of prosthetic solutions (55%) and that it can contribute to the increase in prosthetic implantation at the expense of less invasive solutions (54%). The sub-analyses based on different age groups, professional roles, and places of work allowed to evaluate the response in each specific category, confirming the findings for all investigated aspects.

CONCLUSIONS

This survey documented that the majority of physicians consider that the reimbursement system can influence the treatment choice when managing OA patients. The current DRG system was perceived as unbalanced in favor of the choice of the prosthetic solution, which could contribute to the increase in prosthetic implantation at the expense of other less invasive options for OA management.

Joint line obliquity after lateral closing-wedge high tibial osteotomy does not adversely affect clinical and radiological outcome: a 5-year follow-up study

PURPOSE

To analyze the association between change in knee joint line obliquity (KJLO) and patient-reported outcome, radiological progression of osteoarthritis, and surgical survival after lateral closing-wedge high tibial osteotomy (HTO).

METHODS

A cohort of 180 patients treated in one single hospital with lateral closing-wedge HTO was examined. KJLO was defined by the medial proximal tibial angle (MPTA). To assess the association between KJLO and patient-reported outcome, radiological progression of osteoarthritis, and surgical survival, patient groups were defined: I, postoperative MPTA < 95.0°; II, postoperative MPTA ≥ 95.0°; A, MPTA change < 8.0°; B, MPTA change ≥ 8.0°. Propensity score matching was used for between-groups (I and II, A and B) covariates matching, including age, gender, preoperative lower limb alignment, preoperative medial joint space width (mJSW), preoperative Western Ontario and McMaster Universities osteoarthritis Index (WOMAC) score, wedge size, and postoperative follow-up time. Patient-reported outcome was assessed by the WOMAC questionnaire, radiological progression of osteoarthritis by mJSW and Kellgren-Lawrence (KL) grade progression (≥ 1) preoperatively and at follow-ups (> 2 years). Failure was defined as revision HTO or conversion to knee arthroplasty.

RESULTS

After propensity score matching, groups I and II contained 58 pairs of patients and groups A and B contained 50 pairs. There were no significant differences in postoperative WOMAC score or surgical failure rate between groups I and II or between groups A and B (p > 0.05). However, the postoperative mJSW was significantly lower in group I than group II (3.2 ± 1.6 mm vs 3.9 ± 1.8 mm; p = 0.018) and in group A than group B (3.0 ± 1.7 mm vs 3.7 ± 1.5 mm; p = 0.040). KL grade progression rate was significantly higher in group I than group II (53.4% vs 29.3%; p = 0.008) and in group A than group B (56.0% vs 28.0%; p = 0.005).

CONCLUSION

Increased KJLO (postoperative MPTA ≥ 95.0°) or MPTA change ≥ 8.0° after lateral closing-wedge HTO does not adversely affect patient-reported outcome, radiological progression of osteoarthritis, or surgical survival at an average 5-year follow-up.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Visualization of lateral meniscus extrusion during gait using dynamic ultrasonographic evaluation

PURPOSE

Medial meniscus extrusion is one of the risk factors for knee osteoarthritis (OA). However, lateral meniscus extrusion has not been discussed, and detailed information remains unknown. In particular, the lateral meniscus has high mobility and is expected to be difficult to evaluate in terms of its behavior under static conditions. Dynamic ultrasonographic evaluation was introduced to detect the dynamic behavior of the meniscus during walking. In this study, we aimed to investigate the behavior of the lateral meniscus during walking using dynamic ultrasonographic evaluation.

METHODS

Sixteen participants with knee OA were recruited in this study. The change of lateral meniscus extrusion during walking was recorded using ultrasonography. Medial and lateral meniscal extrusion during the stance phase was measured, and meniscal mobility was defined as the difference in meniscal extrusion between minimum and maximum values (mm), medial meniscal extrusion (∆MME), and lateral meniscal extrusion (∆LME), respectively. The walking cycle and gait forms of lateral thrust were also evaluated using three-dimensional motion analysis systems and analyzed in terms of the correlation with ∆MME and ∆LME.

RESULTS

The lateral meniscus was depicted in the articular plane, and extrusion decreased during the stance phase of the gait cycle. The ∆LME was significantly higher than the ∆MME (p < 0.01). There was a significant positive correlation between ∆LME and lateral thrust (r = 0.62, p < 0.05).

CONCLUSIONS

We found that dynamic ultrasonographic evaluation can be used to visualize lateral meniscus extrusion during walking, and that its behavior is correlated to the degree of lateral thrust.

Biological intra-articular augmentation for osteotomy in knee osteoarthritis: strategies and results : A systematic review of the literature from the ESSKA Orthobiologics Initiative

PURPOSE

To assess whether there is evidence supporting the use of augmentation strategies, either cartilage surgical procedures or injective orthobiologic options, to improve the results of osteotomies in knees with osteoarthritis (OA).

METHODS

A systematic review of the literature was performed on the PubMed, Web of Science and the Cochrane databases in January 2023 on osteotomies around the knee associated with augmentation strategies (either cartilage surgical procedures or injective orthobiologic options), reporting clinical, radiological, or second-look/histological outcomes at any follow-up. The methodological quality of the included studies was assessed with the Coleman Methodology Score (CMS).

RESULTS

Out of the 7650 records identified from the databases, 42 articles were included for a total of 3580 patients and 3609 knees treated; 33 articles focused on surgical treatments and 9 on injective treatments performed in association with knee osteotomy. Out of the 17 comparative studies with surgical augmentation, only 1 showed a significant clinical benefit of an augmentation procedure with a regenerative approach. Overall, other studies showed no differences with reparative techniques and even detrimental outcomes with microfractures. Regarding injective procedures, viscosupplementation showed no improvement, while the use of platelet-rich plasma or cell-based products derived from both bone marrow and adipose tissue showed overall positive tissue changes which translated into a clinical benefit. The mean modified CMS score was 60.0 ± 12.1.

CONCLUSION

There is no evidence to support the effectiveness of cartilage surgical treatments combined with osteotomies in terms of pain relief and functional recovery of patients affected by OA in misaligned joints. Orthobiologic injective treatments targeting the whole joint environment showed promising findings. However, overall the available literature presents a limited quality with only few heterogeneous studies investigating each treatment option. This ORBIT systematic analysis will help surgeons to choose their therapeutic strategy according to the available evidence, and to plan further and better studies to optimize biologic intra-articular osteotomy augmentation.

LEVEL OF EVIDENCE

Level IV.

Meniscal allograft transplantation, anterior cruciate ligament reconstruction, and valgus high tibial osteotomy for meniscal-deficient, unstable, and varus knees: surgical technique and clinical outcomes

PURPOSE

The aim of this study was to determine the clinical and functional outcome of a salvage surgical approach with the combined procedures meniscal allograft transplantation (MAT), anterior cruciate ligament reconstruction (ACLR), and high tibial osteotomy (HTO), in a cohort of patients treated for complex knee lesions evaluated up to a mid-term follow-up.

METHODS

Eight patients (38.8 ± 4.6 years, 88% males) were treated arthroscopically with MAT without bone plugs combined with primary or revision ACLR and HTO and evaluated at basal, at a minimum of two years (short follow-up), and at a mean follow-up of 5.1 years (mid-term follow-up) with the VAS score for pain, Lysholm score, IKDC subjective score, WOMAC Osteoarthritis index, and Tegner score. Physical examination (Lachman and pivot-shift tests, arthrometer assessment) and radiographic evaluation (pre- and post-operative x-rays) were obtained. Complications and failures were also recorded.

RESULTS

A statistically significant improvement was observed from baseline to five years in all clinical scores. In particular, the IKDC subjective score improved from 33.3 ± 20.7 to 73.1 ± 18.4 at short follow-up (p < 0.05), up to 78.3 ± 9.8 at the final follow-up (p < 0.05). A similar trend was demonstrated with the Lysholm, VAS, WOMAC, and Tegner score, even though only one patient reached the pre-injury activity level. Two patients had a worsening of the Kellgren-Lawrence (KL) grade from preoperative (grade 1) to final follow-up (grade 2). No major complications and surgical failures were documented.

CONCLUSION

The combined procedure of MAT, ACLR, and HTO presents few complications and failures and showed to be a valid option to reduce pain, recover knee function, and slow down the osteoarthritis process even in complex patients, with good and stable results up to a mid-term follow-up.

Assessment of joint line obliquity and its related frontal deformity using long-standing radiographs

Purpose

To investigate how radiographic techniques and osteoarthritis grade influence measurements of knee joint line obliquity (KJLO) and KJLO-related frontal deformity, and to propose preferable KJLO measurement methods.

Methods

Forty patients with symptomatic medial knee osteoarthritis indicated for high tibial osteotomy were assessed. Measurements were compared between single-leg and double-leg standing radiographs for KJLO measurement methods including joint line orientation angle by femoral condyles (JLOAF), joint line orientation angle by middle knee joint space (JLOAM), joint line orientation angle by tibial plateau (JLOAT), Mikulicz joint line angle (MJLA) and medial proximal tibial angle (MPTA), as well as KJLO-related frontal deformity parameters including joint line convergence angle (JLCA), knee ankle joint angle (KAJA) and hip-knee-ankle angle (HKA). Influences of bipedal distance in double-leg standing and osteoarthritis grade on the above measurements were analysed. Measurement reliability was evaluated by intraclass correlation coefficient.

Results

From single-leg to double-leg standing radiographs MPTA and KAJA did not change significantly, whereas the other measurements showed significant changes: JLOAF, JLOAM and JLOAT decreased 0.88°, 1.24° and 1.77°, MJLA and JLCA decreased 0.63° and 0.85°, and HKA increased 1.11° (p < 0.05). Bipedal distance in double-leg standing radiographs moderately correlated with JLOAF, JLOAM and JLOAT (rp = -0.555, -0.574 and -0.549). Osteoarthritis grade moderately correlated with JLCA in single-leg and double-leg standing radiographs (rs = 0.518 and 0.471). All measurements had at least good reliability.

Conclusion

In long-standing radiographs, measurements of JLOAF, JLOAM, JLOAT, MJLA, JLCA and HKA are all influenced by single-leg/double-leg standing; JLOAF, JLOAM and JLOAT are also affected by bipedal distance in double-leg standing; and JLCA is affected by osteoarthritis grade. Knee joint obliquity as assessed by MPTA measurement is independent of single-leg/double-leg standing, bipedal distance or osteoarthritis grade, and has excellent measurement reliability. We therefore propose MPTA as the preferable KJLO measurement method for clinical practice and future research.

Level of evidence

III, cross-sectional study.

Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis

»

Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA.

»

HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO.

»

UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.

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.

Factors associated with longitudinal change of meniscal extrusion in overweight women without clinical signs of osteoarthritis

OBJECTIVES

To identify variables associated with longitudinal change in meniscal extrusion, which might be used as possible targets for knee osteoarthritis (KOA) prevention.

METHODS

In a high-risk population of middle-aged overweight women, meniscal extrusion was assessed with magnetic resonance imaging (1.5 T, coronal proton density, in-plane resolution 0.5 mm2, Sante DICOM Editor) at baseline and after 30 months. Outcomes were the absolute change in medial and lateral extrusion (mm) and relative change in extrusion (%). Based upon literature, 11 factors were hypothesized to be associated with longitudinal change. Generalized estimating equations were used to model the effect on meniscal change (P <0.05).

RESULTS

In total, 677 knees of 343 women were available for analysis, with a mean age of 55.7 years (+/-3.2) and a mean BMI of 32.3 kg/m2 (+/-4.2). The greatest change in meniscal extrusion appeared medially with incident meniscal tear (4.4%; absolute 0.9 mm (95% CI: 0.3, 1.5; P =0.004); relative 14.5% (4.4, 24.7; 0.005)). Varus malalignment was associated with an increase of medial extrusion of 0.6 mm (37.6%; 0.1, 1.0; 0.009). A 5 kg/m2 higher baseline BMI was associated with absolute and relative increase of medial extrusion of 0.2 mm and 2.96% (0.1, 0.3; <0.001 and 1.3, 4.8; 0.002). Less explicit but significant changes in extrusion appeared with longitudinal change in BMI.

CONCLUSION

Meniscal tears, varus malalignment and BMI were significantly associated with change in meniscal extrusion in middle-aged overweight women, providing viable therapeutic targets to prevent or reduce extrusion and thereby decelerate KOA development.

Effect of concurrent repair of medial meniscal posterior root tears during high tibial osteotomy for medial osteoarthritis during short-term follow-up: a systematic review and meta-analysis

BACKGROUND

Medial meniscal posterior root tears (MMPRTs) are frequently associated with medial compartment osteoarthritis, leading to loss of meniscal hoop tension. This study aimed to evaluate the efficacy of concurrent MMPRT repair during high tibial osteotomy (HTO) compared to HTO alone in patients with medial osteoarthritis and MMPRTs.

METHODS

The MEDLINE/PubMed, EMBASE, and Cochrane Library databases were searched for studies reporting on concurrent MMPRT repair during HTO. Pre- and postoperative data were pooled to investigate the treatment effects of concurrent MMPRT repair during HTO, and compare postoperative clinical, radiological, and arthroscopic outcomes including cartilage status and healing event rates according to the arthroscopic classification of MMPRT healing (complete, partial [lax or scar tissue], or failed healing) between HTO patients with and without concurrent MMPRT repair. The random-effect model was used to pool the standardized mean differences, odds ratios (ORs), 95% confidence intervals (CIs), and event rates.

RESULTS

Seven patient subgroups in six articles divided according to meniscal repair techniques were included in the final analysis. Concurrent MMPRT repair during HTO significantly improved the Lysholm score, while no intergroup differences were observed in the postoperative Lysholm and WOMAC scores, as well as radiological and arthroscopic outcomes. Those who underwent concurrent MMPRT repair showed a higher rate of complete meniscal healing (OR: 4.792, 95% CI, 1.95-11.79), with a pooled rate of complete meniscal healing of 0.327 (95% CI, 0.19-0.46).

CONCLUSION

Concurrent MMPRT repair during HTO for medial osteoarthritis with MMPRTs has little benefits on the clinical, radiological, and arthroscopic outcomes during short-term follow-up. Further accumulation of evidence is needed for long-term effects.

An Increase in Medial Joint Space Width After Medial Open-Wedge High Tibial Osteotomy Is Associated With an Increase in the Postoperative Weight-Bearing Line Ratio Rather Than With Cartilage Regeneration: Comparative Analysis of Patients Who Underwent Second-Look Arthroscopic Assessment

PURPOSE

To investigate relevant factors influencing increases in medial joint space width (JSW) after medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

Between January 2010 and December 2018, the electronic medical records of consecutive patients who underwent MOWHTO and subsequent second-look arthroscopic assessment at least 12 months after MOWHTO were retrospectively evaluated. The patients were classified into 2 groups according to changes in the medial JSW of the knee at the time of the second-look operation compared with that at baseline before the initial surgical procedure. Various radiographic parameters, arthroscopic findings, and clinical scores were compared between the groups, and regression analysis was performed to identify factors related to increases in medial JSW.

RESULTS

A total of 114 patients were analyzed. In a bivariate analysis, patients who experienced an increase in medial JSW showed a significantly higher postoperative weight-bearing line ratio (WBLR) (P = .008) and a greater proportion of severe preoperative cartilage lesions in the medial compartment of the knee compared with patients with a maintained or reduced medial JSW (P = .035). In terms of clinical scores, patients with an increased medial JSW showed relatively favorable clinical outcomes at the time of the second-look operation. Regression analysis indicated only postoperative WBLR as a relevant factor associated with an increase in medial JSW after MOWHTO (odds ratio, 1.057; P = .01). Additional analysis with patients reclassified according to the postoperative WBLR showed that as the postoperative WBLR increased, the medial JSW increased, without a significant change in the lateral JSW.

CONCLUSIONS

An increase in the medial JSW of the knee joint after MOWHTO appears to be associated with an increase in the postoperative WBLR, not with cartilage regeneration. Obtaining adequate correction so that the postoperative WBLR is within 60% to 70% would be desirable in terms of postoperative changes in the medial JSW, as well as clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Medial joint space width and convergence angle change with time after medial opening-wedge high tibial osteotomy

BACKGROUND

Although the medial joint space width (MJSW) is commonly used for radiographic evaluation of knee osteoarthritis, the changes in knee joint space width (JSW) during weight bearing after medial opening-wedge high tibial osteotomy (MOWHTO) remain unclear. This study aimed to depict how medial and lateral JSWs and convergence angles change gradually after MOWHTO.

METHODS

We retrospectively followed up 81 MOWHTO cases for over 45 months on average. Pre- and postoperative mechanical axes were recorded. The JSWs and convergence angles were measured preoperatively, immediately postoperatively, and 3-6, 9-12, and 21-24 months postoperatively. Patient-reported outcomes were measured using a visual analogue scale (VAS).

RESULTS

The mean mechanical femoral-tibial angle improved from 8.1° varus to 2.4° valgus. At the aforementioned times, the respective mean values of MJSW were 2.6, 3.5, 3.8, 4.0, and 4.2 mm; mean convergence angles were 4.8°, 2.9°, 2.2°, 2.1°, and 1.9°; and the mean VAS scores were 7.2, 7.8, 4.8, 1.4, and 1.3. The MJSW continued to increase significantly in the first year postoperatively and then plateaued for a minimum of 2 years follow up after MOWHTO. The convergence angle decreased significantly in the first 6 months postoperatively and was then maintained.

CONCLUSIONS

The MJSW, convergence angle, and VAS scores continued to improve through weight bearing during the first year after MOWHTO and were maintained for at least 2 years. Thus, JSW measurement may be an easy and representative way of radiographically monitoring the effect of MOWHTO.

Risk factors for pain and functional impairment in people with knee and hip osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To identify risk factors for pain and functional deterioration in people with knee and hip osteoarthritis (OA) to form the basis of a future 'stratification tool' for OA development or progression.

DESIGN

Systematic review and meta-analysis.

METHODS

An electronic search of the literature databases, Medline, Embase, CINAHL, and Web of Science (1990-February 2020), was conducted. Studies that identified risk factors for pain and functional deterioration to knee and hip OA were included. Where data and study heterogeneity permitted, meta-analyses presenting mean difference (MD) and ORs with corresponding 95% CIs were undertaken. Where this was not possible, a narrative analysis was undertaken. The Downs & Black tool assessed methodological quality of selected studies before data extraction. Pooled analysis outcomes were assessed and reported using the Grading of Reccomendation, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

82 studies (41 810 participants) were included. On meta-analysis: there was moderate quality evidence that knee OA pain was associated with factors including: Kellgren and Lawrence≥2 (MD: 2.04, 95% CI 1.48 to 2.81; p<0.01), increasing age (MD: 1.46, 95% CI 0.26 to 2.66; p=0.02) and whole-organ MRI scoring method (WORMS) knee effusion score ≥1 (OR: 1.35, 95% CI 0.99 to 1.83; p=0.05). On narrative analysis: knee OA pain was associated with factors including WORMS meniscal damage ≥1 (OR: 1.83). Predictors of joint pain in hip OA were large acetabular bone marrow lesions (BML; OR: 5.23), chronic widespread pain (OR: 5.02) and large hip BMLs (OR: 4.43).

CONCLUSIONS

Our study identified risk factors for clinical pain in OA by imaging measures that can assist in predicting and stratifying people with knee/hip OA. A 'stratification tool' combining verified risk factors that we have identified would allow selective stratification based on pain and structural outcomes in OA.

PROSPERO REGISTRATION NUMBER

CRD42018117643.

Selective pie-crust release of superficial medial collateral ligament in medial open-wedge high tibial osteotomy

Various techniques to release the superficial MCL (sMCL) during medial open-wedge high tibial osteotomy (MOWHTO) has been introduced. However, there have been debates regarding the extent of sMCL release in MOWHTO. The authors present a pie-crust technique that involves selective and gradual release of sMCL from inside using a small, round-tip blade after opening the gap. The aims were to introduce our novel technique regarding sMCL release and evaluate the clinical and radiologic outcomes. One-hundred sixty-six knees underwent this procedure. With a mean 60.3 months' follow-up, clinical scores were significantly improved after index operation (p<0.001). Hip-knee-ankle angle, medial joint opening, joint line convergence angle, and weight-bearing line ratio significantly improved after MOWHTO (p<0.05) and there were no significant changes during the follow-up period. No cases of valgus progression were observed. This technique would be a safe and effective method for selective and adequate release of sMCL in MOWHTO.

The influence of knee joint geometry and alignment on the tibiofemoral load distribution: A computational study

BACKGROUND

Deviations in knee joint geometry and alignment were previously related to an increased risk for knee OA. These were hypothesized to influence the load distribution over the articular cartilage. Therefore, this study evaluated the effect of altered knee joint geometry and alignment in the coronal and transverse plane on the medial-lateral load distribution and ligament strain using a musculoskeletal modeling approach.

METHODS

Joint kinematics during gait were measured in 15 healthy adults. Using different musculoskeletal models with altered geometry of the tibia plateau or knee joint malalignment in the coronal and transverse plane, the resulting muscle, ligament and contact forces were calculated. Next, the distribution of the load over the medial and lateral condyle was analyzed and compared to the reference loading distribution, with neutral geometry and alignment, using repeated-measures ANOVA and individual t-tests, with a Bonferroni-corrected alpha level.

RESULTS

Coronal plane malalignment significantly affected the load distribution. Small changes in coronal tibial slope had less pronounced effects on the load distribution, but increased ligament strains. Transverse plane malalignment only minimally affected the load distribution.

CONCLUSION

Coronal plane knee malalignment affected knee loading, with increased varus alignment resulting in increased medial loading. This confirms a causal relation between coronal malalignment and increased medial compartment loading and suggests a potential role of aberrant coronal plane alignment on OA initiation. Altered coronal tibial slope induced increased ligament strains, potentially contributing to a cascade of knee laxity and subsequently more extreme knee malalignment.

Indications and outcomes of simultaneous high tibial osteotomy and ACL reconstruction

PURPOSE

The purpose of this study was to systematically review the existing literature reporting surgical outcomes of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament reconstruction (ACLR) in anterior cruciate ligament deficient (ACLD) knees.

METHODS

This study was conducted per the methods of the Cochrane Handbook for Systematic Reviews of Intervention, with findings reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies and pertinent data was extracted. Studies reporting post-operative outcomes following simultaneous HTO and ACLR in ACLD knees were included.

RESULTS

The search identified 515 studies, of which 18 (n = 516) were included. The mean MINORS scores for non-comparative and comparative studies were 11.6 ± 1.34 and 17.3 ± 1.9, respectively. Simultaneous HTO and ACLR resulted in improved functional subjective patient outcomes across a variety of scales. Simultaneous HTO and ACLR was effective in correcting varus angulation, with the post-operative mechanical angle ranging from 0.3° valgus to 7.7° valgus. The reported complication rate ranged from 0 to 23.5%. Across six studies, a total of 13 (6.5%) patients required revision HTO; while across four studies, 20 (17.5%) patients had failure of the ACL graft, with one receiving revision ACLR.

CONCLUSIONS

Combined HTO and ACLR may be indicated in patients with ACLD knees with varus angulation. This systematic review found that the combined surgery resulted in significant improvement in post-operative functional subjective outcomes. However, it remains unclear if HTO with ACLR is superior to ALCR or HTO alone due to the lack of comparative studies. Overall, HTO with ACLR was found to have low rates of complications, re-ruptures, and need for revision surgery. This review found that patients continued to have progression of OA despite combined HTO with ACLR. Future research is required to better understand the effects of combined HTO and ACLR compared to ACLR or HTO alone and to evaluate the long-term post-operative progression of medial compartment OA following combined HTO and ACLR.

LEVEL OF EVIDENCE

IV.

Intra-Articular Injection of Autologous Adipose Tissue-Derived Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis: A Phase IIb, Randomized, Placebo-Controlled Clinical Trial

Mesenchymal stem cells (MSCs) have been the focus of an emerging treatment for osteoarthritis. However, few studies reported about outcomes of an intra-articular injection of autologous adipose-derived mesenchymal stem cells (AD-MSCs). This study aimed to assess the efficacy and safety of a single intra-articular injection of AD-MSCs for patients with knee osteoarthritis. It was a prospective double-blinded, randomized controlled, phase IIb clinical trial. AD-MSCs were administered for 12 patients (MSC group), and the group was compared with 12 knees with injection of normal saline (control group) up to 6 months. All procedures were performed in the outpatient clinic. Primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) score. Secondary outcome measure included various clinical and radiologic examination, and safety after injection. Change of cartilage defect after injection was evaluated using magnetic resonance imaging (MRI). Single injection of AD-MSCs led to a significant improvement of the WOMAC score at 6 months. In the control group, there was no significant change in the WOMAC score at 6 months. No serious adverse events were observed in both groups during the follow-up period. In MRI, there was no significant change of cartilage defect at 6 months in MSC group whereas the defect in the control group was increased. An intra-articular injection of autologous AD-MSCs provided satisfactory functional improvement and pain relief for patients with knee osteoarthritis in the outpatient setting, without causing adverse events at 6 months' follow-up. Larger sample size and long-term follow-up are required. Stem Cells Translational Medicine 2019;8:504-511.

Serial Changes in the Joint Space Width and Joint Line Convergence Angle After Closed-Wedge High Tibial Osteotomy

BACKGROUND

There have been little data concerning serial changes in the joint space width (JSW) and joint line convergence angle over the course of follow-up periods after closed-wedge high tibial osteotomy (CWHTO).

PURPOSE

To evaluate serial changes in the JSW and joint line convergence angle after CWHTO.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 100 computer-assisted CWHTOs with a minimum follow-up period of 3 years (mean, 4.4 years) were analyzed. Clinically, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was evaluated. Radiographically, the mechanical axis was measured preoperatively and postoperatively. The minimal JSW was measured as the shortest distance between the femur and the tibia. The convergence angle was measured as the angle between the tangent to the subchondral plates of the femoral condyle and the tibial plateau. Serial changes in these measurements were analyzed preoperatively; at 3 months, 6 months, 1 year, and 2 years postoperatively; and at the final follow-up. The intraclass correlation coefficients for all measurements were greater than 0.8.

RESULTS

The mean WOMAC score improved from 41.4 preoperatively to 14.9 at the final follow-up. The preoperative and postoperative mean mechanical axis was 8.1° varus and 1.6° valgus, respectively. The mean minimal JSW was 2.5, 2.9, 2.9, 3.1, 3.2, and 3.1 mm preoperatively and at 3 months, 6 months, 1 year, 2 years, and the final follow-up, respectively ( P < .001). The mean convergence angle was 4.4°, 3.9°, 4.0°, 4.1°, 4.2°, and 4.3°, respectively, during the same time periods ( P = .068).

CONCLUSION

Cartilage healing, as indicated by the JSW, and clinical improvement were maintained over the minimum 3-year follow-up after CWHTO. Cartilage pressure, as indicated by the convergence angle, remained unchanged after CWHTO.

Feasibility of the Atlas Unicompartmental Knee System Load Absorber in Improving Pain Relief and Function in Patients Needing Unloading of the Medial Compartment of the Knee: 1-Year Follow-Up of a Prospective, Multicenter, Single-Arm Pilot Study (PHANTOM High Flex Trial)

In young patients with medial knee osteoarthritis (OA), surgical intervention may not be desirable due to preferences to avoid bone cutting procedures, return to high activity levels, and prolong implant survival. The Atlas Knee System was designed to fill the gap between ineffective conservative treatments and invasive surgery. This single-arm study included 26 patients, aged 25 to 65 years, who completed 12 months of follow-up. All dimensions of the Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Society Score significantly improved from baseline to 12 months. About 96.2% and 92.3% of patients experienced a ⩾20% improvement in their KOOS pain and WOMAC pain scores, respectively, at 12 months. This study highlights the potential benefit of a joint unloading device in the management of young patients with medial knee OA. The trial is still ongoing and another analysis is planned at 24 months.