Comparison of the regeneration of cartilage and the clinical outcomes after the open wedge high tibial osteotomy with or without microfracture: a retrospective case control study

Postoperative patient-reported outcome measures after medial open-wedge high tibial osteotomy was improved by decreased joint line convergence angle

PURPOSE

To evaluate the relationship between pre- and postoperative joint line convergence angle (JLCA) changes and patient-reported outcome measures related to medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

Sixty-one patients (71 knees) who underwent MOWHTO were examined. Preoperative and 2-year postoperative radiographic parameters (hip-knee-ankle angle, weight-bearing line ratio, medial proximal tibial angle and JLCA) were measured, and knee injury and osteoarthritis outcome scores (KOOS) were assessed. Patients were divided into two groups: group D (decreased JLCA compared with preoperative status) included 44 knees with a ΔJLCA < 0° and group I (increased JLCA and no-change JLCA compared with preoperative status) included 27 knees with a ΔJLCA ≥ 0°. KOOS sub-scores and the proportion of patients whose improvement exceeded the minimum clinically important difference (MCID) were compared between both groups using Student's t tests, Mann-Whitney U tests and chi-square tests. Multiple regression analysis was performed to determine the factor that had an influential effect on the postoperative KOOS total.

RESULTS

Significant differences in 2-year postoperative KOOS were observed between the two groups, including total, symptom, pain and activities of daily living scores. Group D had significantly more patients who achieved MCID for both KOOS symptoms and pain scores than group I did. Multivariate analysis indicated that JLCA change and body mass index were significantly associated with the postoperative KOOS total.

CONCLUSION

Patients with decreased JLCA had better 2-year post-MOWHTO KOOS and better symptom and pain improvements. Therefore, strategies that reduce JLCA are crucial to improving clinical outcomes, and efforts should be made to improve JLCA in surgical techniques.

LEVEL OF EVIDENCE

Level Ⅳ, Case series.

Implantation of hUCB-MSCs generates greater hyaline-type cartilage than microdrilling combined with high tibial osteotomy

PURPOSE

To compare the outcomes of treating large cartilage defects in knee osteoarthritis using human allogeneic umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) implantation or arthroscopic microdrilling as a supplementary cartilage regenerative procedure combined with high tibial osteotomy (HTO).

METHODS

This 1-year prospective comparative study included 25 patients with large, near full-thickness cartilage defects (International Cartilage Repair Society grade ≥ IIIB) in the medial femoral condyles and varus malalignment. Defects were treated with hUCB-MSC implantation or arthroscopic microdrilling combined with HTO. The primary outcomes were pain visual analogue scale and International Knee Documentation Committee subjective scores at 12, 24 and 48 weeks. Secondary outcomes included arthroscopic, histological and magnetic resonance imaging assessments at 1 year.

RESULTS

Fifteen and 10 patients were treated via hUCB-MSC implantation and microdrilling, respectively. Baseline demographics, limb alignment and clinical outcomes did not significantly differ between the groups. Cartilage defects and total restored areas were significantly larger in the hUCB-MSC group (7.2 ± 1.9 vs. 5.2 ± 2.1 cm2, p = 0.023; 4.5 ± 1.4 vs. 3.0 ± 1.6 cm2, p = 0.035). The proportion of moderate-to-strong positive type II collagen staining was significantly higher in the hUCB-MSC group compared to that in the microdrilled group (93.3% vs. 60%, respectively). Rigidity upon probing resembled that of normal cartilage tissue more in the hUCB-MSC group (86.7% vs. 50.0%, p = 0.075). Histological findings revealed a higher proportion of hyaline cartilage in the group with implanted hUCB-MSC (p = 0.041).

CONCLUSION

hUCB-MSC implantation showed comparable clinical outcomes to those of microdrilling as supplementary cartilage procedures combined with HTO in the short term, despite the significantly larger cartilage defect in the hUCB-MSC group. The repaired cartilage after hUCB-MSC implantation showed greater hyaline-type cartilage with rigidity than that after microdrilling.

LEVEL OF EVIDENCE

Level II, Prospective Comparative Cohort Study.

Effects of concurrent cartilage procedures on cartilage regeneration in high tibial osteotomy: a systematic review

PURPOSE

This systematic review aimed to evaluate the effects of concurrent cartilage procedures on cartilage regeneration when performed alongside high tibial osteotomy (HTO).

MATERIALS AND METHODS

The systematic review followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A comprehensive search was conducted on databases including PubMed, Embase, Cochrane Library, and Google Scholar, covering articles published until August 31, 2023.

RESULTS

Sixteen studies (1277 patients) revealed that HTO, with or without concurrent cartilage procedures, leads to cartilage regeneration based on the International Cartilage Repair Society (ICRS) grade during second-look arthroscopy. No concurrent procedure showed improvement in ICRS grade (mean difference: - 0.80 to - 0.49). Microfracture (mean difference: - 0.75 to - 0.22), bone marrow aspirate concentrate (BMAC) (mean difference: - 1.37 to - 0.67), and human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) (mean difference: - 2.46 to - 1.81) procedures also demonstrated positive outcomes. Clinical outcome assessments for each cartilage procedure were also improved during postoperative follow-up, and no specific complications were reported.

CONCLUSIONS

HTO with or without concurrent cartilage procedures promotes cartilage regeneration observed during second-look arthroscopy, with improved clinical outcomes. Future randomized controlled trials on the same topic, along with subsequent meta-analyses, are necessary for conclusive findings.

Development of a machine learning model for identifying the optimal situation favoring double-level osteotomy over single-level high tibial osteotomy

BACKGROUND

This study aimed to develop a machine learning (ML) model to identify the optimal situation wherein double-level osteotomy (DLO) is favored for severe varus knees by analyzing unfavorable outcomes. This study hypothesized that there are the most favorable algorithms and contributing factors for identifying the optimal situation favoring DLO over opening-wedge high tibial osteotomy (OWHTO).

METHODS

Data were retrospectively collected from patients who underwent OWHTO (505 knees). Unfavorable outcome parameters were defined as follows: (1) medial proximal tibial angle (MPTA) > 95°, (2) joint line convergence angle (JLCA) > 4° (insufficient medial release), (3) JLCA < 0° (medial instability), (4) recurrence of varus deformity, and (5) lateral hinge fracture. The input data for the ML model included demographic data and preoperative radiological and intra-operative factors. The ML model was used to evaluate overall and to evaluate each unfavorable outcome. Interpretation by the model was performed by SHapley Additive exPlanations.

RESULTS

The unfavorable group had a larger JLCA and MPTA preoperatively than the favorable group in the conventional comparison. The light gradient boosting machine (LGBM) demonstrated the highest AUC of 0.66 and F-1 score of 0.72 among the ML algorithms. In the overall assessment, the preoperative weight-bearing line ratio (WBLR) was the factor that contributed the most, followed by the preoperative JLCA and the ΔWBLR. ΔWBLR and the preoperative JLCA were the contributing factors for each outcome.

CONCLUSIONS

The LGBM model was superior in predicting the optimal situations favoring DLO over OWHTO. Preoperative WBLR, preoperative JLCA, and ΔWBLR significantly contributed to the unfavorable outcomes overall and for each outcome in the ML model.

High tibial osteotomy combined with cartilage restoration: A systematic review of clinical outcomes and prognostic factors

Background

Focal chondral defects are often treated with cartilage restoration procedures. Malalignment often accompanies chondral defects. High tibial osteotomy (HTO), classically utilized to treat uni-compartmental knee osteoarthritis, corrects malalignment. HTO combined with cartilage restoration procedures can treat uni-compartmental osteoarthritis and focal chondral defects.

Purpose

To assess outcomes of combined HTO and cartilage restoration procedures and review prognostic factors that may assist in preoperative planning and patient counseling.

Study design

Systematic Review of published literature.

Methods

A systematic review of PubMed and Scopus was performed following PRISMA guidelines. Thirty-four papers were included in qualitative considerations.

Results

Thirty-four papers that reported the combined outcome of HTO and cartilage repair were included. Twenty of the 34 included papers reported prognostic factors that affected the success or failure of combined HTO and cartilage repair surgery for focal articular defect and uni-compartmental knee osteoarthritis. Cartilage repair techniques that were combined with HTO and included in this review are bone marrow stimulation, allograft transplantation, osteochondral autograft transplantation, autologous chondrocyte implantation, and mesenchymal stem cell implantation.

Conclusions

HTO with adjunctive cartilage repair procedures improve clinical outcome scores and restore alignment in patients with medial compartment osteoarthritis and isolated focal chondral defects. HTO with adjunctive cartilage procedures produces optimal results in younger, non-obese patients with focal chondral defects and varus malalignment, without significant lateral compartment and patellofemoral involvement.

Postoperative Decrease in Bone Marrow Lesion Associated With Better Clinical Outcomes Following Medial Open-Wedge High Tibial Osteotomy

PURPOSE

To assess serial changes of preoperative bone marrow lesion (BML) following medial open-wedge high tibial osteotomy (MOWHTO) up to 2 years and evaluate whether postoperative change of BML affected patient-reported outcome measures (PROMs) at 2 years' follow-up. Factors related to the postoperative changes in BML also were evaluated.

METHODS

The current study retrospectively assessed prospectively collected data of consecutive patients between December 2016 and March 2018 who underwent MOWHTO for symptomatic knee osteoarthritis with varus malalignment (≥5°) and a minimum 2-year follow-up. Serial magnetic resonance imaging scans at preoperative and postoperative 3, 6, 18, and 24 months were performed, and the extent of BML was evaluated consecutively using 2 validated methods. Clinically, preoperative and postoperative PROMs and their achievement of minimal clinically important difference values were evaluated. The associations of the extent of BMLs with PROMs at each follow-up period over time were analyzed using a linear mixed model. Furthermore, factors related to the postoperative changes of BML were assessed.

RESULTS

Of 26 patients, 21 (80.8%) had preoperative BML at medial femoral and tibial condyles. The postoperative decrease in BML was noted in 17 (81.0%) and 18 (85.7%) at medial femoral and tibial condyles. The BML decreased at postoperative 3 months and, thereafter, the extent of BML gradually reduced until postoperative 24 months. The proportion of patients achieved minimal clinically important difference was 84.6% for total Western Ontario and McMaster Universities Osteoarthritis Index scores and 80.8%, 76.9%, and 84.6% for KOOS symptom, pain, and activity of daily living subscales. Postoperative decrease in BML was significantly associated with better PROMs over postoperative 24 months. Furthermore, normo-correction (2°-5° valgus) was a significant factor for decreased BML following MOWHTO.

CONCLUSIONS

Preoperative BML gradually decreased with time following MOWHTO, and the postoperative decrease in BML related with better PROMs over postoperative 24 months. Moreover, postoperative valgus alignment was a significant factor relating the postoperative decrease of BML.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Particulated Costal Hyaline Cartilage Allograft With Subchondral Drilling Improves Joint Space Width and Second-Look Macroscopic Articular Cartilage Scores Compared With Subchondral Drilling Alone in Medial Open-Wedge High Tibial Osteotomy

PURPOSE

To compare the articular cartilage regeneration based on second-look arthroscopy in patients who underwent medial open-wedge high tibial osteotomy (MOWHTO) combined with particulated costal hyaline cartilage allograft (PCHCA) implantation with those who underwent MOWHTO and subchondral drilling (SD). Moreover, we compared the clinical and radiographic outcomes between the groups.

METHODS

From January 2014 to November 2020, patients with full-thickness cartilage defect on the medial femoral condyle who underwent MOWHTO combined with PCHCA (group A) or SD (group B) were reviewed. Fifty-one knees were matched after propensity score matching. The status of regenerated cartilage was classified according to the International Cartilage Repair Society-Cartilage Repair Assessment (ICRS-CRA) grading system and Koshino staging system, based on second-look arthroscopic findings. Clinically, the Knee Injury and Osteoarthritis Outcome Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and range of motion were compared. Radiographically, we compared the differences in the minimum joint space width (JSW) and change in JSW.

RESULTS

The average age was 55.5 years (range, 42-64 years), and the average follow-up period was 27.1 months (range, 24-48 months). Group A showed a significantly better cartilage status than group B based on the ICRS-CRA grading system and Koshino staging system (P < .001 and <.001, respectively). There were no significant differences in clinical and radiographic outcomes between groups. In group A, the minimum JSW at the last follow-up was significantly increased than that before surgery (P = .013), and a significantly greater increase in JSW was observed in group A (P = .025).

CONCLUSIONS

When performed with MOWHTO, the combination of SD and PCHCA was associated with superior articular cartilage regeneration on the ICRS-CRA grading and Koshino staging on second-look arthroscopy performed at a minimum of 2 years follow-up than SD alone. However, there was no difference in clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Medial opening-wedge high tibial osteotomy with microfracture in treatment of varus medial compartmental knee osteoarthritis: clinical outcomes and second-look arthroscopic results

Objective: This study aimed to investigate the clinical outcomes of medial opening high tibial osteotomy (MOWHTO) combined with arthroscopic microfracture in the treatment of varus medial compartmental knee osteoarthritis and to assess cartilage regeneration using second-look arthroscopy. Methods: This study involved 86 patients (86 knees) who underwent MOWHTO and microfracture from August 2016 to August 2020, including 15 men and 71 women with an average age of 55.3 ± 7.6 years (range, 42-71 years). The patients underwent a second-look arthroscopy to evaluate the status of cartilage regeneration at the time of plate removal, an average of 2 years after the initial osteotomy. Clinical and radiological examinations were performed preoperatively and at the final follow-up visit. The radiologic evaluation included the weight-bearing line ratio (WBL ratio), mechanical femorotibial angle (FTA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTS) and Kellgren-Lawrence (KL) grade. Clinical outcomes were assessed using the Knee Society score (KSS) and International Knee Documentation Committee (IKDC) scores. Arthroscopic findings were assessed by macroscopic evaluation of cartilage repair according to the International Cartilage Repair Society (ICRS) grading system. Results: The mean KSS and IKDC scores significantly improved at the final follow-up compared to the scores obtained preoperatively (p < 0.05). At the time of plate removal, a second-look arthroscopic examination showed that the ICRS grade of the medial femoral condyle was as follows: grade I -11 cases, grade II -56, grade III-12, and grade IV-7, and cartilage regeneration was seen in 85% of knees (73/86). The ICRS grade of medial tibial plateau was grade I-12 cases, grade II-44, grade III-22, and grade IV-8, and cartilage regeneration was seen in 63% of knees (54/86). Significant differences were observed between cartilage regeneration and clinical outcomes (p < 0.05). Clinical results were better in the good cartilage regeneration group (grades I and II) than were in the poor cartilage regeneration group (grades III and IV). Conclusion: MOWHTO combined with arthroscopic microfracture can effectively improve clinical outcomes in the treatment of varus medial compartmental knee osteoarthritis. Cartilage regeneration can be promoted by correcting varus deformities, which affect clinical outcomes.

Isolated Osteotomy Versus Combined Osteotomy and Cartilage Repair for Osteoarthritis or Focal Chondral Defects of the Medial Compartment of the Knee Joint: A Systematic Review

Background

The extent to which concomitant cartilage repair provides an improvement in clinical outcomes after osteotomy is unclear.

Purpose

To compare studies reporting clinical outcomes after isolated osteotomy with or without cartilage repair for osteoarthritis (OA) or focal chondral defects (FCDs) of the knee joint.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, Cochrane Library, and Embase databases. The search was done to identify comparative studies that directly compared outcomes between isolated osteotomy-high tibial osteotomy or distal femoral osteotomy-and osteotomy with concomitant cartilage repair for OA or FCDs of the knee joint. Patients were evaluated based on reoperation rate, magnetic resonance observation of cartilage repair tissue score, macroscopic International Cartilage Regeneration & Joint Preservation Society score, and patient-reported outcomes.

Results

In total, 6 studies-level 2 evidence (n = 2);, level 3 evidence (n = 3);, and level 4 evidence (n = 1)-met the inclusion criteria, including a total of 228 patients undergoing osteotomy alone (group A) and 255 patients undergoing osteotomy with concomitant cartilage repair (group B). The mean patient age was 53.4 and 54.8 years, respectively, and the mean preoperative alignment was 6.6° and 6.7° of varus in groups A and B, respectively. The mean follow-up time was 71.5 months. All studies assessed medial compartment lesions with varus deformity. One study compared osteotomy alone for patients with medial compartment OA versus osteotomy with autologous chondrocyte implantation for patients with FCDs of the medial compartment. Three other studies included a heterogeneous cohort of patients with OA and FCDs in both groups. Only 1 study isolated its comparison to patients with medial compartment OA and 1 study isolated its comparison to patients with FCDs.

Conclusion

There is limited evidence with substantial heterogeneity between studies on clinical outcomes after osteotomy alone versus osteotomy with cartilage repair for OA or FCDs of the knee joint. At this time, no conclusion can be made regarding the role of additional cartilage procedures in treating medial compartment OA or FCDs. Further studies are needed that isolate specific disease pathology and specific cartilage procedures.

Cartilage Repair of the Tibiofemoral Joint With Versus Without Concomitant Osteotomy: A Systematic Review of Clinical Outcomes

Background

The extent to which concomitant osteotomy provides an improvement in clinical outcomes after cartilage repair procedures is unclear.

Purpose

To review the existing literature to compare clinical outcomes of patients undergoing cartilage repair of the tibiofemoral joint with versus without concomitant osteotomy.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify studies that directly compared outcomes between cartilage repair of the tibiofemoral joint alone (group A) versus cartilage repair with concomitant osteotomy (high tibial osteotomy [HTO] or distal femoral osteotomy [DFO]) (group B). Studies on cartilage repair of the patellofemoral joint were excluded. The search terms used were as follows: osteotomy AND knee AND ("autologous chondrocyte" OR "osteochondral autograft" OR "osteochondral allograft" OR microfracture). Outcomes in groups A and B were compared based on reoperation rate, complication rate, procedure payments, and patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], visual analog scale [VAS] for pain, satisfaction, and WOMAC).

Results

Included in the review were 5 studies (1 level 2 study, 2 level 3 studies, 2 level 4 studies) with 1747 patients in group A and 520 patients in group B. The mean patient ages were 34.7 and 37.5 years in groups A and B, respectively, and the mean lesion sizes were 4.0 and 4.5 cm², respectively. The mean follow-up time was 44.6 months. The most common lesion location was the medial femoral condyle (n = 999). Preoperative alignment averaged 1.8° and 5.5° of varus in groups A and B, respectively. One study found significant differences between groups in KOOS, VAS, and satisfaction, favoring group B. The reoperation rates were 47.4% and 17.3% in groups A and B, respectively (P < .0001).

Conclusion

Patients undergoing cartilage repair of the tibiofemoral joint with concomitant osteotomy might be expected to experience greater improvement in clinical outcomes with a lower reoperation rate compared with those undergoing cartilage repair alone. Surgeons preparing for cartilage procedures of the knee joint should pay particular attention to preoperative malalignment of the lower extremity to optimize outcomes.

The effects of open wedge high tibial osteotomy for knee osteoarthritis on the patellofemoral joint. A systematic review

BACKGROUND (INCLUDING AIMS OF THE STUDY)

To investigate the impact medial opening wedge high tibial osteotomy (MOWHTO) has on the progression of patellofemoral (PF) OA, patella height, contact pressure within the PF joint and clinical outcomes.

METHODS

A systematic review was conducted in January 2022 according to PRISMA guidelines. The ICRS cartilage grade of the PF joint at the initial MOWHTO surgery and at second look surgery was compared and relative risk of progression of PF OA was calculated. Evaluation of patella height was assessed by Caton-Deschamps index, Blackburne-Peel index or Insall-Salvati index pre and post MOWHTO. Cadaveric studies assessing contact pressures in the PF after MOWHTO were included.

RESULTS

Forty-two studies comparing 2419 patients were included. The mean age was 53.1 years (16-84), 61.3% female. The risk of progression of PF OA was highest in the uniplanar and biplanar MOWHTO with proximal tubercle osteotomy groups (RR = 1.28-1.51) compared to biplanar MOHWTO with distal tubercle osteotomy (RR = 0.96-1.04). Patella height was not affected after biplanar MOWHTO with distal tubercle osteotomy (p < 0.001). Cadaveric studies demonstrate that PF contact pressures increase with more severe corrections (15°) but suggest biplanar MWOHTO and distal tubercle osteotomy induces lower contact pressures within the PF joint than other MOWHTO techniques. Significant over correction is associated with worse clinical outcomes and anterior knee pain.

CONCLUSION

Biplanar MOWHTO and distal tubercle osteotomy has minimal effect on the contact pressures in the PF joint resulting in less severe progression of PF OA and has minimal impact on patella height.

Functional and Radiographic Results of Arthroscopy-Assisted Lateral Open-Wedge Distal Femur Osteotomy for Lateral Compartment Osteoarthritis with Valgus Knee

Treating lower extremity malalignment-related knee osteoarthritis, especially valgus alignment, is a challenge. A high revision rate was observed with patients who underwent unicompartmental knee arthroplasty, so distal femur osteotomy has regained its popularity. This research aimed to evaluate the radiographic and functional outcomes of arthroscopy-assisted lateral open-wedge distal femur osteotomy (LOWDFO) for patients with lateral compartment osteoarthritis and valgus knees with a minimum follow-up of 2 years. Our study retrospectively included isolated lateral osteoarthritis (Outerbridge grade 3 and grade 4) of the knee related to valgus alignment and a young age (<65 y/o) with the demand for a high-impact activity event. Preoperative and postoperative radiographic and functional outcomes were evaluated. Significant pre-operative and postoperative mechanical correction was observed with mechanical axis deviation (preop/postop: −28.77 ± 12.98/−9.45 ± 7.36, p < 0.001), hip-knee angle (preop/postop: 7.64 ± 3.62/2.68 ± 2.04, p < 0.001), and mechanical lateral distal femoral angle (mLDFA, preop/postop: 10.9 ± 4.14/5.66 ± 3.71, p < 0.001). The International Knee Documentation Committee (IKDC) score also showed improvement after the operation (preop/postop: 57.36 ± 11.98/79.02 ± 4.58, p = 0.002). In conclusion, lateral open-wedge distal femur osteotomy is effective in treating patients with lateral compartment osteoarthritis and valgus knees with a low complication rate and excellent outcome.

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.

Medial compartment cartilage repair and lower extremity biomechanical changes after single-plane high tibial osteotomy of distal tibial tuberosity

OBJECTIVE

To observe the cartilage repair of the medial compartment and the biomechanical changes of the lower extremities after single-plane high tibial osteotomy of distal tibial tuberosity (DTT-HTO).

METHODS

A total of 30 patients, including 11 males and 19 females, who underwent DTT-HTO with arthroscopic operation in our hospital from January 2020 to January 2021 and underwent arthroscopic exploration again during the second operation for internal fixation were enrolled. There were 32 knees, including 13 left knees and 19 right knees. Age ranged from 50 to 78, with an average of 63.20 ± 6.61 years old. All patients completed two surgeries and were followed up, and no adverse events occurred during the period. International Cartilage Repair Society (ICRS) was used to assess the cartilage condition of the medial compartment of the knee during the two surgeries. In this paper, the weight-bearing line ratio (WBLR), the medial proximal tibia angle (MPTA), the femoral tibial angle (FTA) and the posterior tibial slope (PTS) were used to evaluate the changes of the mechanical state of the lower limbs. The visual analogue scale (VAS) score and the Western Ontario and McMaster University Osteoarthritis (WOMAC) Index score were used to evaluate the improvement in knee pain and function.

RESULTS

All patients completed two operations without adverse events and serious complications. The medial compartment cartilage of all patients had different degrees of repair during the second operation, and the difference was statistically significant compared with the first operation (P < 0.05). During the second operation, the WBLR was corrected from (17.69 ± 2.16)% to (60.90 ± 1.97)%, the MPTA was corrected from (80.72 ± 1.61)° to (89.91 ± 2.58)°, the FTA was corrected from (182.31 ± 3.03)° to (171.81 ± 2.24)°, the difference was statistically significant (P < 0.05). There was no statistical difference in PTS between the two surgeries (P > 0.05). At the second operation, the VAS score decreased from 7.50 ± 1.34 to 0.34 ± 0.85, the WOMAC score decreased from 119.50 ± 10.43 to 46.25 ± 4.13, and the difference was statistically significant (P < 0.05).

CONCLUSION

DTT-HTO can significantly correct the weight-bearing line, restore the biomechanical parameters of the lower limb to the normal range, significantly relieve pain and improve knee function, and the medial compartment cartilage repair and regeneration phenomenon will occur after the correction of the weight-bearing line.

Excessively Increased Joint-Line Obliquity After Medial Opening-Wedge High Tibial Osteotomy Is Associated With Inferior Radiologic and Clinical Outcomes: What Is Permissible Joint-Line Obliquity

PURPOSE

This study aimed to evaluate the permissible joint-line obliquity (JLO) based on radiologic and clinical outcomes with midterm follow-up after medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

Patients who had undergone MOWHTO from March 2014 to May 2016 were retrospectively evaluated. They were divided into 4 groups based on JLO as represented by postoperative medial proximal tibial angle (MPTA). Radiologic parameters including MPTA, joint-line orientation angle (JLOA), joint-line convergence angle (JLCA), posterior tibial slope, weightbearing line ratio (WBLR), and coronal translation were analyzed. Clinical outcomes were evaluated with American Knee Society Score (AKSS), Western Ontario and McMaster University Index, and short-form 36 health survey (SF-36). The changes between preoperation and final follow-up in JLOA and MPTA were defined as ΔJLOA and ΔMPTA.

RESULTS

A total of 135 knees were finally included (MPTA ≤90.32° as group I; 90.33° to 92.62° as group II; 92.74° to 95.22° as group III; and ≥95.23° as group IV). The last follow-up MPTA, JLOA, and JLCA values were different between the groups (P < .001, P < .001, and P = .015, respectively). WBLR and JLOA positively correlated with MPTA; however, WBLR showed an abrupt increase at MPTA >96.5°, and the JLOA distribution tended to be greater than the regression line at MPTA >96°. Moreover, ΔJLOA was not as large as ΔMPTA. The percentage of patients attaining a minimal clinically important difference was significantly lower in the AKSS-functional score and SF-36 physical component summary in group IV (P = .008 and 0.021, respectively).

CONCLUSION

The JLOA did not change as much as the MPTA, but an MPTA >95.2° abruptly increased the JLOA and valgus overcorrection after MOWHTO. Poor clinical outcomes were more evident in excessive MPTA (>95.2°) than in mildly undercorrected or properly corrected MPTA (<95.2°).

LEVEL OF EVIDENCE

III, retrospective cohort study.

Chinese Clinical Practice Guidelines in Treating Knee Osteoarthritis by Periarticular Knee Osteotomy

Unicompartmental knee osteoarthritis (UKOA) is the early stage of knee joint degeneration, which is characterized by unicompartmental degeneration and mostly occurs in medial compartment. Pain and limited motion are main symptoms, which affect patients' life quality. Periarticular knee osteotomy (PKO) for lower extremity alignment correction is an effective treatment for UKOA with abnormal alignment, which could relieve pain and improve joint function by adjusting lower extremity alignment. At present, no clinical guidelines are available for the treatment of UKOA by PKO for lower extremity alignment correction. Experts from the Clinical New Technology Application Committee of the Chinese Hospital Association, Joint Surgery Study Group of the Chinese Orthopaedic Association of the Chinese Medical Association, and Osteoarthritis Study Group of the Chinese Association of Orthopaedic Surgeons of the Chinese Medical Doctor Association formulated these guidelines. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) grading system and the Reporting Items for Practice Guidelines in Healthcare (RIGHT) were adopted to select 25 most concerning questions. Finally, 25 recommendations were formulated through evidence retrieval, evidence quality evaluation, and the determination of directions and strength of recommendations. Recommendation items 1-5 are indications and contraindications for PKO for lower extremity alignment correction, items 6-21 are surgical methods and principles, item 22 describes 3D printing corrective osteotomy technique, and items 23-25 address the perioperative period, follow-up management, and other content. These guidelines are designed to improve the normalization and standardization of KOA treatment by PKO for lower extremity alignment correction.

10-Year Survival Rates After High Tibial Osteotomy Using Angular Stable Internal Plate Fixation: Case Series With Subgroup Analysis of Outcomes After Combined Autologous Chondrocyte Implantation and High Tibial Osteotomy

Background:

Good-to-excellent midterm results after high tibial osteotomy (HTO) to treat medial compartment cartilage defects or osteoarthritis (OA) have been published, but little is known about long-term survival rates in terms of conversion to total knee arthroplasty (TKA) using angular stable internal plate fixation.

Purpose:

To determine TKA-free survival rates and functional and radiological outcomes at 10 years after HTO. A subgroup analysis of patients who underwent combined HTO and autologous cartilage implantation (ACI) was also performed.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 125 patients with a mean follow-up of 9.90 ± 2.25 years; 90 patients underwent HTO for medial OA, and 35 patients underwent ACI and HTO for medial focal cartilage defects. Functional outcome measures included visual analog scale (VAS) for pain, Lysholm, International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and KOOS₄ (average of 4 KOOS subscales: Pain, Symptoms, Sport, and Quality of Life). Radiological outcomes included lateral distal femoral angle, medial proximal tibial angle, and joint line convergence angle.

Results:

Overall, 16 patients required conversion to TKA at a mean 86.75 ± 25.73 months (10-year survival rate, 87.2%). Only 2 patients in the HTO+ACI subgroup required a conversion to TKA (10-year survival rate, 94.3%). The complication rate for all patients was 8.8%. In both the HTO and HTO+ACI subgroups, VAS pain levels decreased and Lysholm scores increased significantly from pre- to postoperatively (P < .001). A higher preoperative Tegner score led to a significantly lower risk for conversion to TKA (P = .001), and a preoperative body mass index of ≥35 was associated with a significantly higher risk (P = .019), as was female sex (P = .046). Radiological parameters remained within physiological ranges. The postoperative joint line conversion angle did correlate with postoperative functional outcome but not with TKA conversion.

Conclusion:

Long-term results of HTO for medial compartment OA or cartilage defects with underlying varus deformity were good to excellent. In particular, patients who underwent HTO+ACI presented excellent long-term survival rates. HTO, therefore, delays or prevents TKA implantation, especially in young, active patients with medial compartment damage.

Meniscal and Cartilage Changes on Serial MRI After Medial Opening-Wedge High Tibial Osteotomy

Background:

Assessments of the effects of realignment using opening-wedge high tibial osteotomy (OWHTO) on the medial, lateral, and patellofemoral compartments have been limited to cartilage evaluations.

Purpose/Hypothesis:

The purpose was to evaluate the effects of OWHTO on the meniscus and cartilage of each compartment as a cooperative unit (meniscochondral unit) using serial magnetic resonance imaging (MRI). It was hypothesized that (1) favorable changes in the meniscochondral unit would occur in the medial compartment and (2) that changes in the patellofemoral and lateral compartments would be negligible.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 36 knees that underwent OWHTO from March 2014 to February 2016 and had postoperative serial MRI. The MRI was performed at 19.9 ± 7.4 and 52.3 ± 8.3 months postoperatively, and the cartilage and meniscal changes were evaluated by highlighting the regions of interest. We evaluated the T2 relaxation times of each cartilage and meniscal area, the cross-sectional area of the menisci, and the extrusion of the medial meniscus (MM). The meniscochondral unit was assessed using subgroup analyses according to the status of the MM.

Results:

Significant decreases were seen in T2 relaxation times in the medial femoral condyle (MFC) (P < .001) and medial tibial plateau (MTP) (P = .050), and significant increases were seen in the lateral femoral condyle (LFC) (P = .036). The change was more prominent in the MFC compared with the MTP and LFC (P = .003). No significant changes were observed in the lateral tibial plateau, patella, or trochlear groove. The area of the lateral meniscus (body and posterior horn) was decreased compared with preoperative MRI (P < .001 for both). The extent of MM extrusion decreased between the preoperative, first follow-up, and second follow-up MRIs (P < .001).

Conclusion:

OWHTO affected the medial compartment positively, the lateral compartment negatively, and the patellofemoral compartment negligibly. The effects were more prominent and consistent in the medial than in the lateral compartment.

Comparison of Clinical Outcome following Cartilage Repair for Patients with Underlying Varus Deformity with or without Additional High Tibial Osteotomy: A Propensity Score-Matched Study Based on the German Cartilage Registry (KnorpelRegister DGOU)

BACKGROUND

Even though realignment procedures have gained popularity as concomitant techniques in cartilage repair approaches with underlying malalignment, the clinical efficacy has not been proven to full extent.

METHODS

Out of 5474 patients from the German Cartilage Registry, 788 patients with focal cartilage defects on the medial femoral condyle having received either no accompanying surgery or high tibial osteotomy (HTO) were identified. After a 1:1 propensity score matching, outcome of 440 patients was evaluated using KOOS (Knee Injury and Osteoarthritis Outcome Score), VAS (visual analogue scale), and satisfaction during the 3-year follow-up.

RESULTS

Patients having received a concomitant HTO had significantly higher postoperative KOOS values (12 months: 67.26 ± 15.69 vs.75.10 ± 16.12, P = 0.001; 24 months: 67.14 ± 23.85 vs. 77.11 ± 16.50, P = 0.010; 36 months: 74.40 ± 16.57 vs. 81.75 ± 14.22, P = 0.023) and lower pain levels (6 months: 3.43 ± 2.18 vs. 2.89 ± 2.15, P = 0.009; 12 months: 3.64 ± 2.20 vs. 2.17 ± 1.96, P < 0.001; 24 months: 4.20 ± 3.12 vs. 2.94 ± 2.45, P = 0.005; 36 months: 3.20 ± 2.18 vs. 2.02 ± 1.98, P = 0.003). One and 3 years postoperatively, concomitant HTO led to significantly higher satisfaction in patients. These advantages of accompanying HTO were also seen in the group of patients with a varus deformity of 5° or more, in which pain levels without concomitant HTO even increased during the 3-year follow-up.

CONCLUSION

The results of the present study underline the importance and safety of concomitant HTO in patients with cartilage defects and varus deformity. HTO should therefore be considered and recommended generously in patients with focal cartilage defects of the medial femoral condyle and varus deformity.

The Effect of Supramalleolar Osteotomy without Marrow Stimulation for Medial Ankle Osteoarthritis: Second-Look Arthroscopic Evaluation of 29 Ankles

BACKGROUND

The effect of supramalleolar osteotomy without a bone marrow-stimulating procedure for articular cartilage regeneration in the ankle joint remains unknown. We investigated whether supramalleolar osteotomy yielded favorable clinical and radiographic outcomes. We also evaluated the joint tissue appearance after supramalleolar osteotomy without a bone marrow-stimulating procedure with use of second-look arthroscopy and its correlation with the outcome.

METHODS

Twenty-nine ankles were retrospectively reviewed at a mean of 2.9 years after supramalleolar osteotomy without a bone marrow-stimulating procedure. All 29 ankles had had second-look arthroscopy to evaluate tibiotalar joint tissue regeneration at a minimum of 1 year postoperatively. A visual analog scale (VAS) pain score, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, and patient satisfaction were used for functional evaluations. Ankle osteoarthritis was classified with the Takakura staging system, and the tibial anterior surface (TAS) angle and tibial lateral surface (TLS) angle were measured on radiographs.

RESULTS

The mean VAS and AOFAS scores improved from 6.2 (95% confidence interval [CI], 5.7 to 6.8) preoperatively to 1.5 (95% CI, 0.9 to 2.1) postoperatively and from 60.5 (95% CI, 54.9 to 66.1) preoperatively to 88.3 (95% CI, 84.3 to 92.3) postoperatively, respectively. Patient satisfaction with the outcome of the procedure was classified as very satisfied or satisfied for 27 ankles (93.1%). Sixteen of 21 ankles that were classified as Takakura stage-IIIa and 2 of 3 ankles that were classified as stage-IIIb preoperatively improved to stage II postoperatively. The mean TAS and TLS angles significantly improved from 83.5° (95% CI, 82.2° to 84.7°) and 77.0° (95% CI, 75.4° to 78.7°) preoperatively to 94.2° (95% CI, 92.7° to 95.7°) and 80.4° (95% CI, 78.3° to 82.5°) postoperatively, respectively. On second-look arthroscopy, 26 ankles (89.7%) showed tissue regeneration of the medial compartment of the ankle joint and no patient showed cartilage deterioration.

CONCLUSIONS

Medial tibiotalar tissue regeneration was identified in most patients with medial compartment ankle osteoarthritis following supramalleolar osteotomy without a bone marrow-stimulating procedure. The procedure results in satisfactory clinical and radiographic outcomes with high patient satisfaction.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Relationship between radiographic measurements and knee adduction moment using 3D gait analysis

BACKGROUND

Radiographic factors estimate the state of the static knee joint, and it is questionable how well these parameters reflect the dynamic knee condition. The external knee adduction moment (KAM) during gait is known to be a kinetic variable contributing to osteoarthritis progression. This study aims to investigate the effects of static radiographic parameters on the dynamic KAM during gait.

METHODS

Overall, 123 patients (mean age, 65.7 years; standard deviation, 8.1 years; 34 men and 89 women) were included. Seven radiographic parameters including the mechanical tibiofemoral angle (mTFA), Kellgren-Lawrence grade, and ankle joint line orientation (AJLO) were measured on radiographs, and the maximum KAM and KAM-time integral in the stance phase were obtained using three-dimensional gait analysis. The correlation and multiple regression analyses were performed for identifying significant radiographic measurements associated with the KAM.

RESULTS

Most of the radiographic measurements correlated with the maximum KAM and KAM-time integral. As a result of multiple regression analysis, the mTFA (p < 0.001) and AJLO (p = 0.003) were identified as significant factors associated with the KAM-time integral (R² = 0.450); the mTFA (p < 0.001) and AJLO (p = 0.003) were identified as a significant factor associated with the maximum KAM (R² = 0.352) in multiple regression analysis. The discriminant validity of KAM was highest at varus 5.7 degree of the mTFA and 7.5 degree of the AJLO.

SIGNIFICANCE

The mTFA and AJLO were significantly associated with the KAM. However, to be used as a surgical indication for corrective osteotomy, a longitudinal study is needed to validate whether the mTFA and AJLO values directly cause osteoarthritis progression as we have suggested.

LEVEL OF EVIDENCE

III.

Patellofemoral Osteoarthritis Progresses After Medial Open-Wedge High Tibial Osteotomy: A Systematic Review

PURPOSE

To investigate the progression of patellofemoral (PF) osteoarthritis (OA) after medial open-wedge high tibial osteotomy (OWHTO) and whether PF OA progression has an influence on clinical outcomes.

METHODS

According to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA), EMBASE, PubMed, and Cochrane Library were searched in June 2020 for English-language studies that presented data on PF OA or cartilage degeneration before and after OWHTO. Descriptive statistics are presented.

RESULTS

Twenty studies comprising 1,173 patients were included. The mean age was 57.1 years (range 18-84) with 826 (70.4%) female. The mean follow-up was 27.1 months (range 7-144). Ten studies reported the trochlear International Cartilage Research Society (ICRS) scores, with each of these studies reporting a greater proportion of patients with grades 2-4 OA postoperatively compared with preoperatively (relative risk = 1.19-2.76, I² = 1.9%). Similarly, 7 studies reported patellar ICRS scores and found a greater proportion with grades 2-4 OA postoperatively (relative risk = 1.08-2.44, I² = 0%). Four studies assessed PF Kellgren-Lawrence grade, each of which reported a greater proportion of patients with grades 2-4 OA postoperatively (relative risk = 1.25-21.0, I² = 31%). The PF OA assessments were heterogenous, and studies using classifications except the ICRS score or Kellgren-Lawrence grade were not included in statistical analysis. Fifteen studies assessed patellar height; 10 studies reported significant decrease in patellar height after OWHTO. Only 3 studies reported clinical outcomes for patients with and without PF OA progression. Outcome reporting was variable across these studies, and a relationship between PF OA progression and clinical outcome could not be definitively determined.

CONCLUSIONS

Patients appear to have progression of PF OA after medial OWHTO. However, there are currently insufficient studies with inconsistent measurements of outcomes to make meaningful conclusions regarding the impact of PF OA on clinical outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Mid-long-term results of total knee arthroplasty followed by ipsilateral total hip arthroplasty versus total hip arthroplasty subsequent to ipsilateral total knee arthroplasty: a case-control analysis

Background

The aim of the present study was to compare the outcomes of patients who underwent different sequences of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Methods

We retrospectively identified 47 patients who underwent TKA followed by ipsilateral THA (THA-TKA) and 36 patients who received THA subsequent to ipsilateral TKA (TKA-THA) for rheumatoid arthritis or osteoarthritis between January 2008 and April 2014. Twenty-eight patients were selected for each group after case-control matching with preoperative demographics and protheses of THA. Clinical scores, radiographic results, complication rates, and survivorship were compared. The median duration of follow-up was 110 (range 80–149) months.

Results

Both groups showed significant improvement in Harris Hip Scores, Knee Society Score, and Short Form-12 at the last follow-up compared to baseline (p < .001). At the last follow-up, all clinical scores were actually lower in the THA-TKA group, but those differences were not statistically significant. Otherwise, there was no significant difference in radiological alignment or complication rates. The survivorship of THA and TKA in the THA-TKA group was 94.7 and 95.7%, respectively, compared with 92.4 and 100.0% in the TKA-THA group at 8 years (log rank, p = .939 and .187).

Conclusions

Patients who underwent ipsilateral THA and TKA with different sequences achieved similar favorable outcomes. Total joint arthroplasty can be performed safely with excellent outcomes in patients with a history of prior ipsilateral THA or TKA.

Trial registration

The trial was registered in the Chinese Clinical Trial Registry (ChiCTR2000035147) dated 2 August 2020.

Maturation process of regenerated tissues after single-stage simultaneous autologous particulated cartilage implantation and open wedge high tibial osteotomy for articular cartilage defects with medial osteoarthritis of bilateral knees: a case report

Background

Open wedge high tibial osteotomy (OWHTO) is an effective treatment option for young and middle-aged active patients with medial unicompartmental knee osteoarthritis (OA). In addition, particulated cartilage implantation has been developed as a simple procedure for cartilage regeneration. Thus, to improve the OWHTO outcomes, a single-stage, simultaneous bilateral knee arthroscopic particulated cartilage implantation with OWHTO was performed.

Case presentation

A 60-year-old male patient presented with severe bilateral knee pain, with grade 2 varus knee OA of the Kellgren–Lawrence classification. Primary arthroscopic evaluations based on the International Cartilage Repair Society grading system showed grade 3c articular cartilage defects of 1.5 cm in diameter at the center of the bilateral medial femoral condyles. Following bilateral OWHTO, the healthy cartilage tissue was harvested from the lateral wall of the unilateral femoral intercondylar notch and minced with the cartilage processor. Then, subchondral drillings and cartilage fragment implantations into the bilateral defects were performed arthroscopically. One year postsurgery, second-look arthroscopy findings revealed that the defects were filled with cartilage-like tissues. The maturation process of the regenerated tissues was confirmed with T2 mapping magnetic resonance imaging during the 3-year follow-up period. The patient could walk without a cane, and all Knee Injury and Osteoarthritis Outcome Score parameters were improved without any correction loss in 3 years.

Conclusions

This is the first report to evaluate the maturation process of the implanted particulated cartilage tissue with T2 mapping magnetic resonance imaging for 3 years. The effect of chondral resurfacing procedure with OWHTO remains unclear; however, the implantation of arthroscopic particulated cartilage fragments is a single-stage and less-invasive procedure. This treatment could regenerate cartilage-like tissue in the present case. Therefore, this additional procedure could potentially improve the long-term outcomes of OWHTO.

Simple Medial Meniscus Posterior Horn Root Repair Using an All-Inside Meniscal Repair Device Combined with High Tibial Osteotomy to Maintain Joint-Space Width in a Patient with a Repairable Tear

PURPOSE

To compare the radiological and clinical outcomes using simple medial meniscus posterior horn (MMPH) root repair using an all-inside meniscal repair device combined with high tibial osteotomy (HTO) and HTO alone.

METHODS

Between November 2013 and December 2016, patients treated for MMPH root tear along with HTO were enrolled. Based on the tear gap, the participants were divided into repairable (< 2 mm) and unrepairable (> 2 mm) categories. The participants in each group were divided into those amenable to simple MMPH root repair using an all-inside meniscal repair device and those that required no procedure for meniscus. Radiological parameters including mechanical femorotibial alignment (MA), posterior tibial slope (PTS) and medial joint-space width (JSW) were evaluated preoperatively and postoperatively at 2 years. For clinical evaluation, the WOMAC score was determined at the 2-year visit postoperatively.

RESULTS

A total of 81 knees including 48 repairable (group R) and 33 unrepairable (group I) knees were enrolled. A total of 43 knees underwent simple MMPH root repair using an all-inside meniscal repair device (subgroup r), whereas the other 38 knees did not (subgroup n). The MA, PTS, and their postoperative changes as well as the WOMAC scores showed no differences. However, the JSW in group Rr increased from 3.1 to 3.6 mm, but decreased from 3.7 to 3.4 in group Rn, which was a statistically significant difference.

CONCLUSION

Simple MMPH root repair using an all-inside meniscal repair device combined with HTO was more effective for the maintenance of JSW compared with HTO without a meniscal procedure in patients with repairable MMPH root tear and varus alignment. However, other options are needed for unrepairable MMPH root tear.

The influence of post-operative knee coronal alignment parameters on long-term patient-reported outcomes after closed-wedge high tibial osteotomy

Background

Both intra-articular and extra-articular knee alignment pathologies can affect clinical outcomes after high tibial osteotomy. The purpose of this study was to investigate post-operative knee coronal alignment parameters that affect long-term patient-reported outcomes after closed-wedge high tibial osteotomy (CW-HTO).

Methods

This study included 105 osteoarthritic knees that underwent CW-HTO. Long-term patient-reported outcomes were defined by the 2011 Knee Society Score (KSS) and were collected at an average follow-up of 10.2 years. Post-operative knee coronal alignment parameters, consisting of the femoral tibial angle (FTA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), tibial plateau inclination (TPI), and joint line convergence angle (JLCA), were measured using standing radiographs of the knee at an average follow-up of 11.0 months. The correlations between these parameters and KSS were then assessed by Spearman's correlation analysis. Comparisons of groups classified by MPTA and TPI cutoff values were performed by the Wilcoxon rank-sum test.

Results

Post-operative JLCA showed a significant negative correlation with two KSS sub-scores: satisfaction (R = -0.2232, P = 0.022) and total function (R = -0.2059, P = 0.035). There was no significant difference in any KSS sub-score between the "low" groups (MPTA and TPI less than 95 and 5°, respectively) and the "high" groups (MPTA and TPI greater than 98 and 7°, respectively).

Conclusions

Among knee coronal alignment parameters, a large post-operative residual JLCA, which is an intra-articular varus deformity, was independently associated with worsened long-term clinical outcomes after CW-HTO.

Level of evidence

Level Ⅳ, Retrospective cohort study.