Analysis of the determinant factor of the medial joint space width after medial opening wedge high tibial osteotomy

Assessing joint line obliquity in valgus-producing high tibial osteotomy: A scoping review of the literature

Background

The variance in knee joint line obliquity (KJLO) measurement methods and radiographic techniques may contribute to the controversy on clinical consequences of KJLO after high tibial osteotomy (HTO).

Purpose

To summarize currently used KJLO measurement methods, including their measurement reliability, and the radiographic techniques used in valgus-producing HTO.

Methods

The databases PubMed, Embase, and Web of Science were searched from inception up to May 2023, to identify articles that measured KJLO on radiographs in valgus-producing HTO.

Results

Thirty clinical articles were included. There were five different KJLO measurement methods reported, 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), of which the JLOAT was the most commonly used. KJLO was measured on anteroposterior full-length standing radiographs with either single-leg or double-leg patient stance position, with no standardized bipedal distance on double-leg stance radiographs. Moderate-to-excellent measurement reliability was reported for intraobserver and interobserver MPTA, and good-to-excellent for intraobserver JLOAT and JLOAM and for interobserver JLOAT, JLOAM, and MJLA.

Conclusion

There is no consensus on how to measure KJLO or on which radiographic technique should be used. When measuring joint line orientation angles on anteroposterior full-length double-leg stance radiographs, controlling the bipedal distance with feet together is suggested when possible. Future research is needed to determine the measurement differences between the five KJLO measurement methods and to identify the preferred, ideal one.

Treatment of osteoarthritic knee with high tibial osteotomy and allogeneic human umbilical cord blood-derived mesenchymal stem cells combined with hyaluronate hydrogel composite

BACKGROUND

Delaying total knee arthroplasty is crucial for middle-aged patients with severe osteoarthritis. The long-term outcomes of high tibial osteotomy (HTO) remain uncertain. Recently, mesenchymal stem cells (MSCs) have shown promising potential in enhancing cartilage regeneration. Therefore, this study aimed to assess cartilage regeneration following the implantation of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) with HTO.

METHODS

In this case series, ten patients underwent hUCB-MSC implantation with HTO. The median age was 58.50 (range: 57.00-60.00) years, and the mean body mass index was 27.81 (range: 24.42-32.24) kg/m2. Clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS), Physical Component Score (PCS) and Mental Component Score (MCS) from the 36-Item Short-Form Health Survey (SF-36), were evaluated 6 months, 1 year, and 2 years postoperatively. Cartilage status of the medial femoral condyle (MFC) was assessed during hardware removal surgery, at least 2 years after the initial procedure, and compared with preoperative MFC cartilage status regarding lesion size and International Cartilage Repair Society (ICRS) grade. Radiological assessments included the Kellgren-Lawrence (KL) grading system for medial compartment osteoarthritis and hip-knee-ankle (HKA) angle.

RESULTS

Significant improvements were observed in WOMAC scores (preoperative: 57.00 (range: 44.75-63.00), postoperative: 27.50 (range: 22.25-28.75)), VAS scores (preoperative: 66.25 (range: 48.00-74.25), postoperative: 26.25 (range: 14.50-31.13)), SF-36 PCS (preoperative: 27.97 (range: 26.64-31.25), postoperative: 55.31 (range: 51.64-62.50)), and SF-36 MCS (preoperative: 41.04 (range: 29.95-50.96), postoperative: 63.18 (range: 53.83-65.16)) 2 years postoperatively (p = 0.002, 0.002, 0.002, and 0.020, respectively). The MFC chondral lesion demonstrated significant improvement in both lesion size (preoperative: 7.00 cm² (range: 4.38-10.50 cm²), postoperative: 0.16 cm² (range: 0.00-1.75 cm²), p = 0.002) and ICRS grade (preoperative: 4 (range: 4-4), postoperative: 1 (range: 1-2.25), p = 0.002). Additionally, the KL grade significantly decreased from 3 (range: 3-3) preoperatively to 2 (range: 2-2) postoperatively, while the HKA angle was corrected from 7.50° (range: 7.00-10.25°) preoperatively to -1.00° (range: -3.5-0.00°) postoperatively.

CONCLUSIONS

hUCB-MSC implantation with HTO is an effective treatment for medial compartment osteoarthritis and varus deformities, resulting in significant improvements in cartilage regeneration and overall clinical outcomes.

TRIAL REGISTRATION

NCT04234412.

Association Between Joint Line Convergence Angle and Patient-Reported Outcomes of Opening-Wedge High Tibial Osteotomy

BACKGROUND

A larger joint line convergence angle (JLCA) increases the stress load on the medial compartment. Few reports, however, have discussed the effect of the JLCA on the cartilage status and clinical outcomes after opening-wedge high tibial osteotomy (OWHTO).

PURPOSE/HYPOTHESIS

To reveal the effect of the JLCA on clinical results after OWHTO. We hypothesized that a smaller JLCA improves cartilage status and clinical outcomes by reducing mechanical stress in the medial compartment.

STUDY DESIGN

Cohort study: Level of evidence, 3.

METHODS

This retrospective study included 106 knees that underwent OWHTO and second-look arthroscopy during implant removal 1 year after OWHTO. The mean follow-up period was 5.5 (SD, 2.9) years. The pre- and postoperative JLCAs were measured radiographically. The International Cartilage Repair Society (ICRS) grades of the medial femoral condyle (MFC) and the medial tibial plateau (MTP) were evaluated during the initial and second-look arthroscopy. The relationship between the JLCA and cartilage status, and the Knee injury and Osteoarthritis Outcome Score (KOOS) at the final follow-up were evaluated.

RESULTS

Preoperative JLCA was related to improvements in the ICRS grade of the MFC and the MTP, with cutoff values of 2.6° (sensitivity, 0.700; specificity, 0.561; P = .016) and 2.4° (sensitivity, 0.704; specificity, 0.595; P = .028), respectively. In addition, the preoperative JLCA was related to KOOS Pain (P = .037), Symptoms (P < .001), Activities of Daily Living (P = .005), Sports Activities (P = .005), and Quality of Life (P = .006) subscales using multivariable linear regression analysis. The postoperative JLCA was not related to the improvement in the ICRS grade of the MFC but was related to the improvement in the ICRS grade of the MTP, with a cutoff value of 1.6° (sensitivity, 0.704; specificity, 0.603; P = .015). Furthermore, postoperative JLCA was related to the KOOS Pain (P = .004), Symptoms (P = .002), Activities of Daily Living (P = .031), Sports Activities (P < .001), and Quality of Life (P = .015) subscales.

CONCLUSION

A smaller pre- and postoperative JLCA was related to improvements in the ICRS grade and favorable clinical outcomes, with a mean 5.5-year follow-up after OWHTO.

Effect of preoperative medial meniscus status on the outcomes of high tibial osteotomy with human umbilical cord-derived mesenchymal stem cells cartilage regeneration

BACKGROUND

The effect of medial meniscus (MM) status on outcomes following high tibial osteotomy (HTO) combined with cartilage regeneration using human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) remains unclear.

PURPOSE

This study aimed to evaluate the effect of preoperative MM status on the outcomes of HTO combined with cartilage regeneration using hUCB-MSCs. Specifically, clinical and radiological outcomes were compared between two groups of patients, which were divided according to their preoperative MM status. We hypothesized that patients with preserved meniscal integrity or those who underwent meniscal root repair would show better clinical and radiological outcomes compared to those with significant meniscal loss or untreated root tears.

METHODS

A retrospective analysis was performed on 47 patients who underwent HTO with hUCB-MSC implantation. Patients were divided into group P (preserved MM integrity or medial meniscal root repair) and group L (loss of MM integrity, defined as a peripheral rim width <3 mm, unable to maintain hoop function). Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores after a minimum follow-up of 2 years. Cartilage regeneration was evaluated with Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score and International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) score from second-look arthroscopy. Correlation analyses were conducted to examine the relationship between preoperative MM extrusion and cartilage repair.

RESULTS

Both groups demonstrated significant improvements in IKDC and WOMAC scores (p < 0.01). No significant differences were observed between groups in IKDC and WOMAC scores at final follow-up (p = 0.21, p = 0.42, respectively). MOCART 2.0 and ICRS CRA scores showed no significant differences between groups (p = 0.35, p = 0.08, respectively). Group P showed higher proportions of favorable outcomes compared to group L, including no major subchondral changes or only minor marrow edema (56% vs. 31.8%) and ICRS CRA grades I or II (84% vs. 72.7%). While these findings suggest potential differences in outcomes, neither comparison reached statistical significance (p = 0.09 and p = 0.48, respectively). Preoperative MM extrusion negatively correlated with MOCART 2.0 and subchondral bone changes (r = -0.24, p = 0.03; r = -0.29, p = 0.02, respectively).

CONCLUSION

HTO with hUCB-MSC implantation provided significant clinical improvements and effective cartilage regeneration regardless of preoperative MM status. However, preoperative MM extrusion may influence subchondral bone changes, emphasizing the need to consider MM status for long-term outcomes.

LEVEL OF EVIDENCE

III; retrospective comparative study.

High survivorship rate and good clinical outcomes after high tibial osteotomy in patients with radiological advanced medial knee osteoarthritis: a systematic review

INTRODUCTION

The role of valgus producing high tibial osteotomy (HTO) for the treatment of advanced knee osteoarthritis (OA) is still controversial. The aim of the current systematic review was to assess survivorship and patient-reported outcomes (PROMs) of high tibial osteotomy in patients with radiological advanced medial knee OA.

METHODS

A systematic search of PubMed, Cochrane and EMBASE database was performed in July 2023 in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. Inclusion and exclusion criteria were applied to identify studies investigating the survivorship rate and PROMs of valgus-producing high tibial osteotomy in patients with advanced knee OA at x-ray assessment in the medial compartment at minimum-two-years follow up. Advanced radiological OA was defined as Kellgren Lawrence (K-L) ≥ 3 or Ahlbäch ≥ 2. Survivorship was defined as percentage of patients free of total knee arthroplasty (TKA) at follow-up. Clinical interpretation of provided PROMs were performed according to minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) target values reported in literature. Survivorship data and PROMs scores were extracted, and studies were stratified based on selected study features. The quality of included studies was assessed with modified Coleman score.

RESULTS

A total of 18 studies, totalling 1296 knees with a mean age between 46.9 and 67 years old, were included. Average survivorship was of 74.6% (range 60 - 98.1%) at 10-years follow up. The subjective scoring systems showed good results according to MCID and PASS, and postoperative improvements were partially maintained until final follow-up.

CONCLUSION

HTO is worth considering as treatment choice even in patients affected by radiological advanced medial knee osteoarthritis. Long term survivorship and good patient reported clinical outcomes could be expected in this population.

LEVEL OF EVIDENCE

IV; systematic review of level III-IV studies.

The influence of the weight-bearing state on three-dimensional (3D) planning in lower extremity realignment - analysis of novel vs. state-of-the-art planning approaches

BACKGROUND

The use of 3D planning to guide corrective osteotomies of the lower extremity is increasing in clinical practice. The use of computer-tomography (CT) data acquired in supine position neglects the weight-bearing (WB) state and the gold standard in 3D planning involves the manual adaption of the surgical plan after considering the WB state in long-leg radiographs (LLR). However, this process is subjective and dependent on the surgeons experience. A more standardized and automated method could reduce variability and decrease costs.

PURPOSE

The aim of the study was (1) to compare three different three-dimensional (3D) planning modalities for medial open-wedge high tibial osteotomy (MOWHTO) and (2) to describe the current practice of adapting NWB CT data after considering the WB state in LLR. The purpose of this study is to validate a new, standardized approach to include the WB state into the 3D planning and to compare this method against the current gold standard of 3D planning. Our hypothesis is that the correction is comparable to the gold standard, but shows less variability due compared to the more subjective hybrid approach.

METHODS

Three surgical planning modalities were retrospectively analyzed in 43 legs scheduled for MOWHTO between 2015 and 2019. The planning modalities included: (1) 3D hybrid (3D non-weight-bearing (NWB) CT models after manual adaption of the opening angle considering the WB state in LLR, (2) 3D NWB (3D NWB CT models) and (3) 3D WB (2D/3D registration of 3D NWB CT models onto LLR to simulate the WB state). The pre- and postoperative hip-knee-ankle angle (HKA) and the planned opening angle (°) were assessed and differences among modalities reported. The relationship between the reported differences and BMI, preoperative HKA (LLR), medial meniscus extrusion, Outerbridge osteoarthritis grade and joint line convergence angle (JLCA) was analyzed.

RESULTS

The mean (std) planned opening angle of 3D hybrid did not differ between 3D hybrid and 3D WB (0.4 ± 2.1°) (n.s.) but was higher in 3D hybrid compared to 3D NWB (1.1° ± 1.1°) (p = 0.039). 3D WB demonstrated increased preoperative varus deformity compared to 3D NWB: 6.7 ± 3.8° vs. 5.6 ± 2.7° (p = 0.029). Patients with an increased varus deformity in 3D WB compared to 3D NWB (> 2 °) demonstrated more extensive varus alignment in LLR (p = 0.009) and a higher JLCA (p = 0.013).

CONCLUSION

Small intermodal differences between the current practice of the reported 3D hybrid planning modality and a 3D WB approach using a 2D/3D registration algorithm were reported. In contrast, neglecting the WB state underestimates preoperative varus deformity and results in a smaller planned opening angle. This leads to potential under correction in MOWHTO, especially in patients with extensive varus deformities or JLCA.

CLINICAL RELEVANCE

Incorporating the WB state in 3D planning modalities has the potential to increase accuracy and lead to a more consistent and reliable planning in MOWHTO. The inclusion of the WB state in automatized surgical planning algorithms has the potential to reduce costs and time in the future.

Mesenchymal stem cell implantation provides short-term clinical improvement and satisfactory cartilage restoration in patients with knee osteoarthritis but the evidence is limited: a systematic review performed by the early-osteoarthritis group of ESSKA-European knee associates section

PURPOSE

Implantation of mesenchymal stem cells (MSCs) is a potential cell-based modality for cartilage repair. Currently, its clinical use largely surrounds focal cartilage defect repair and intra-articular injections in knee osteoarthritis. The MSCs' implantation efficacy as a treatment option for osteoarthritis remains contentious. This systematic review aims to evaluate studies that focused on MSCs implantation in patients with knee OA to provide a summary of this treatment option outcomes.

METHODS

A systematic search was performed in PubMed (Medline), Scopus, Cinahl, and the Cochrane Library. Original studies investigating outcomes of MSCs implantations in patients with knee OA were included. Data on clinical outcomes using subjective scores, radiological outcomes, and second-look arthroscopy gradings were extracted.

RESULTS

Nine studies were included in this review. In all included studies, clinical outcome scores revealed significantly improved functionality and better postoperative pain scores at 2-3 years follow-up. Improved cartilage volume and quality at the lesion site was observed in five studies that included a postoperative magnetic resonance imaging assessment and studies that performed second-look arthroscopy. No major complications or tumorigenesis occurred. Outcomes were consistent in both single MSCs implantation and concurrent HTO with MSCs implantation in cases with excessive varus deformity.

CONCLUSION

According to the available literature, MSCs implantation in patients with mild to moderate knee osteoarthritis is safe and provides short-term clinical improvement and satisfactory cartilage restoration, either as a standalone procedure or combined with HTO in cases with axial deformity. However, the evidence is limited due to the high heterogeneity among studies and the insufficient number of studies including a control group and mid-term outcomes.

LEVEL OF EVIDENCE

IV.

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.