Comparison of closing-wedge and opening-wedge high tibial osteotomy for medial compartment osteoarthritis of the knee: a randomized controlled trial with a six-year follow-up

Influence of Increased Joint Line Obliquity on Survivorship After Lateral Closing-Wedge High Tibial Osteotomy

BACKGROUND

Although high tibial osteotomy (HTO) has emerged as a powerful intervention for treating symptomatic medial osteoarthritis and varus malalignment, it can result in an increase in knee joint line obliquity (KJLO) in the frontal plane. Limited current evidence hinders understanding of the effect of increased KJLO on HTO survivorship.

PURPOSE

To investigate the influence of KJLO and other potential risk factors on the survivorship of lateral closing-wedge HTO.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients with symptomatic medial knee osteoarthritis and varus malalignment treated with lateral closing-wedge HTO at a single hospital were screened with a minimum follow-up of 5 years. HTO survival rate was assessed using Kaplan-Meier survival analysis. The influence of postoperative increased KJLO (medial proximal tibial angle ≥95°), age (≥55 years), sex (female), preoperative malalignment (hip-knee-ankle angle ≥10° of varus), postoperative untargeted alignment (hip-knee-ankle angle <2° or >6° of valgus), and preoperative osteoarthritis severity (Kellgren-Lawrence grade ≥3) on survivorship of HTO was evaluated using Cox regression analysis. A failure of HTO was defined as a conversion to total knee arthroplasty (TKA).

RESULTS

A total of 410 patients (463 knees) were included, with a mean follow-up of 13.0 years (range, 5.0-18.1 years) and a mean survival time of 11.2 years (range, 1.2-18.1 years) for patients who reached the endpoint of TKA. HTO survival rates at 5, 10, and 15 years postoperatively were 91%, 78%, and 60%, respectively. Multivariate Cox regression analysis showed no significant difference in survivorship between patients with increased KJLO and those with acceptable KJLO (178 vs 285 knees; hazard ratio [HR], 0.8; 95% CI, 0.6-1.1; P = .148), with no significant between-group difference observed in the mean follow-up length (12.9 ± 3.0 years vs 13.1 ± 3.3 years; P = .105). Female sex (HR, 2.0; P < .001) and postoperative untargeted alignment (HR, 1.6; P = .003) were risk factors for a conversion to TKA.

CONCLUSION

Increased postoperative KJLO (medial proximal tibial angle ≥95°) had no significant influence on the survivorship of lateral closing-wedge HTO. Men demonstrated superior survival outcomes compared with women, and it was important to achieve a targeted postoperative alignment (HKA 2°-6° of valgus) to ensure favorable HTO survivorship.

Medial Gradual Opening Osteotomy of the Tibia With Monolateral External Fixator for Correcting the Varus Deformity of the Tibia

Correction of the varus deformities in the tibia is necessary because of the excessive pressure exerted on the medial compartment of the knee, which intensifies the degenerative process. Correction strategies encompass a variety of approaches and depend on the patient's individual characteristics, age, soft tissue condition, and the orthopaedic surgeon's experience with different surgical materials. Size and location of the deformity, whether gradual or acute, play crucial roles in choosing the most appropriate material and shape. The gradual correction is especially indicated for patients with severe deformities, soft tissue involvement, and a history of bone infections. This study aimed to introduce a gradual correction technique for varus deformities in the tibia using a unilateral external fixator and to describe the postoperative follow-up. This technique offers notable advantages, including accurate correction, better patient acceptance, lighter assembly, less risk of pseudarthrosis, and shorter distraction process owing to the use of a single piece. In addition, the operated limb can support the load on the day after surgery, and dynamic follow-up is performed on an outpatient basis.

Management Considerations for Unicompartmental Osteoarthritis in Athletic Populations: A Review of the Literature

Unicompartmental osteoarthritis in the young athlete poses a challenge for both patients and providers. Coronal plane malalignment is frequently a concomitant finding that adds to the complexity of management. Military surgeons are presented unique challenges, in that they must consider optimal joint-preservation methods while returning patients to a high-demand occupational function. Management options range from lifestyle changes to surgical interventions. We present a concise review of the available literature on this subject, with a specific focus on indications and outcomes within the military and young athletic population.

Around-the-knee osteotomies part II: Surgical indications, techniques and outcomes - State of the art

Recent advances in surgical techniques and planning for knee-based osteotomies have led to improvements in addressing lower extremity malalignment. Part 1 of this review presented the biomechanical and clinical rationale of osteotomies, emphasizing the importance of osteotomies for restoring normal knee kinematics. In Part 2 of this review, indications, surgical technique and outcomes of osteotomies to correct coronal, sagittal and axial plane deformities will be examined. Traditional high tibial and distal femoral osteotomies will be discussed in addition to more recent advanced techniques including biplanar corrections and double-level osteotomies, as well as slope-correcting osteotomies. Patient-specific instrumentation and its use in more complex corrections will also be addressed.

Closing wedge high tibial osteotomy: An old-fashioned technique? Survival, clinical and radiological outcomes of a case series analysis

INTRODUCTION

Closing wedge high tibial osteotomy (CW-HTO) is a surgical option for active patients with medial knee pain and mild-moderate osteoarthritis with varus limb deformity. Despite its good reported results, this technique has been losing popularity. The aim of this study was to analyse the survival rate, clinical functional outcomes and radiological results of CW-HTO.

METHODS

It is a retrospective case series study. Seventy patients with primary knee osteoarthritis, operated on between 2010 and 2020 in a single Spanish tertiary hospital using the CW-HTO technique and with a minimum follow-up of 2 years were analysed.

RESULTS

Survival rate was 87,6% and 75,5% after a follow-up of 5 and 10 years respectively. Functional outcomes were good-to-excellent (KSS 77.7/100 and OKS 35.6/48) and good pain control (VAS 3.9/10) and high satisfaction (7.2/10) were achieved. Limb varus malalignment was significantly corrected (mean postoperative HKA angle 177,6° and MPTA 90,7°). However, 30% of patients presented hypocorrection, which was associated with inferior survival, functionality and satisfaction.

CONCLUSION

CW-HTO technique can be useful for patients with knee osteoarthritis and varus limb. It allows to correct varus malalignment while achieving good-to-excellent functional outcomes, good pain control, high patient satisfaction and acceptable medium-long term survival rate. However, it is associated with a non-negligible risk of hypocorrection or medial hinge disruption.

The Role of Osteotomy in Anterior Cruciate Ligament Reconstruction

Coronal and sagittal plane knee malalignments have been shown to increase the forces on anterior cruciate ligament (ACL) grafts after ACL reconstruction (ACLR). Studies have shown the benefit of high tibial osteotomy to address coronal and sagittal imbalance in revision ACLR. The purpose of this article is to further describe the use of osteotomy by reviewing preoperative planning, indications, techniques, and outcomes of high tibial opening and closing wedge as well as anterior tibial closing wedge osteotomies in the setting of ACLR.

Effect of Medial Opening Wedge and External Rotational Humeral Osteotomies on Medial Elbow Compartment Pressure: An Ex Vivo Study

OBJECTIVE

 The aim of this study was to assess if the level of osteotomy (50 or 75% the length of the humerus), osteotomy angle (5, 10, or 20 degrees), direction of bone alteration (external rotational or medial opening wedge osteotomies), or orientation of osteotomy (perpendicular to the humeral long axis or perpendicular to the weight-bearing axis of the limb) affect pressure through the medial compartment of the elbow.

STUDY DESIGN

 Humeral osteotomies were performed at 50 and 75% the length of the humerus on 12 canine cadaver thoracic limbs and patient-specific three-dimensional (3D) printed plates applied to induce the desired alteration. Sensors were placed into the medial and lateral aspects of the elbow joint and the limb compressed to 90 N in a universal testing system.

RESULTS

 Increasing the angle of the induced change had a significant effect on the decreased load through the medial compartment. Performing the osteotomy at 75% of humeral length from proximal was significantly more effective at reducing the medial elbow load than performing it at 50%. Opening wedge osteotomies were more effective than external rotational osteotomies, but both were effective. Changing the direction of the osteotomy (comparing transverse to oblique) did not significantly affect the load reduction through the medial compartment.

CONCLUSION

 Performing an osteotomy at a more distal location along the humerus and increasing the angle of the induced change increased the effectiveness of load-shifting humeral osteotomies.

[Translated article] Closing wedge high tibial osteotomy: An old-fashioned technique? Survival, clinical and radiological outcomes of a case series analysis

INTRODUCTION

Closing wedge high tibial osteotomy (CW-HTO) is a surgical option for active patients with medial knee pain and mild-moderate osteoarthritis with varus limb deformity. Despite its good reported results, this technique has been losing popularity. The aim of this study was to analyse the survival rate, clinical functional outcomes and radiological results of CW-HTO.

METHODS

It is a retrospective case series study. Seventy patients with primary knee osteoarthritis, operated on between 2010 and 2020 in a single Spanish tertiary hospital using the CW-HTO technique and with a minimum follow-up of 2 years were analysed.

RESULTS

Survival rate was 87.6% and 75.5% after a follow-up of 5 and 10 years respectively. Functional outcomes were good-to-excellent (KSS 77.7/100 and OKS 35.6/48) and good pain control (VAS 3.9/10) and high satisfaction (7.2/10) were achieved. Limb varus malalignment was significantly corrected (mean postoperative HKA angle 177.6° and MPTA 90.7°). However, 30% of patients presented hypocorrection, which was associated with inferior survival, functionality and satisfaction.

CONCLUSION

CW-HTO technique can be useful for patients with knee osteoarthritis and varus limb. It allows to correct varus malalignment while achieving good-to-excellent functional outcomes, good pain control, high patient satisfaction and acceptable medium-long term survival rate. However, it is associated with a non-negligible risk of hypocorrection or medial hinge disruption.

Preoperative Hindfoot Alignment and Outcomes After High Tibial Osteotomy for Varus Knee Osteoarthritis: We Walk on Our Heel, Not Our Ankle

UPDATE

This article was updated on May 15, 2024 because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 898, in the section entitled "Materials and Methods," the sentence that had read "The WBL ratio of the knee joint was defined as the point where the GA or MA passed through the width of the tibia and intersected a line from the center of the femoral head to the center of the calcaneus (for the GA) or talus (for the MA), with the medial edge defined as 0% and the lateral edge as 100%." now reads "The WBL ratio of the knee joint was defined as the point where the GA or MA passed through the width of the tibia and intersected a line from the center of the femoral head to the lowest point of the calcaneus (for the GA) or the center of the talus (for the MA), with the medial edge defined as 0% and the lateral edge as 100%." Likewise, in the legend for Figure 3 on page 899, the sentence that had read "Depiction of the ground mechanical axis (GA), defined as the line (represented by the solid red line) from the center of the femoral head to the ground reaction point at the center of the calcaneus, passing lateral to the traditional mechanical axis (MA; represented by the dashed red line)." now reads "Depiction of the ground mechanical axis (GA), defined as the line (represented by the solid red line) from the center of the femoral head to the ground reaction point at the lowest point of the calcaneus, passing lateral to the traditional mechanical axis (MA; represented by the dashed red line)." Finally, on page 903, "HKA" was changed to "HKA angle" in Table III.

BACKGROUND

The hip-to-calcaneus axis, previously known as the ground mechanical axis (GA), ideally passes through the center of the knee joint in the native knee. The aim of this study was to elucidate, with use of hip-to-calcaneus radiographs, changes in knee and hindfoot alignment and changes in outcomes following high tibial osteotomy (HTO).

METHODS

We reviewed the records for 128 patients who underwent HTO between 2018 and 2020. Patients were stratified into 2 groups, a hindfoot valgus group (n = 94) and a hindfoot varus group (n = 34), on the basis of their preoperative hindfoot alignment. The hindfoot alignment was evaluated with use of the hindfoot alignment angle (HAA). To evaluate lower-limb alignment, full-length standing posteroanterior hip-to-calcaneus radiographs were utilized to measure 4 radiographic parameters preoperatively and 2 years postoperatively: the hip-knee-ankle (HKA) angle, hip-knee-calcaneus (HKC) angle, and the weight-bearing line (WBL) ratios of the mechanical axis (MA) and GA.

RESULTS

The mean HAA improved significantly from 5.1° valgus preoperatively to 1.9° valgus postoperatively in the hindfoot valgus group (p < 0.001). In contrast, in the hindfoot varus group, the HAA showed no meaningful improvement in the coronal alignment of the hindfoot following HTO (p = 0.236). The postoperative mean HKC angle in the hindfoot varus group was 2° more varus than that in the hindfoot valgus group (1.0° versus 3.0°; p = 0.001), and the GA in the hindfoot varus group passed across the knee 8.0% more medially than that in the hindfoot valgus group (55% versus 63% from the most medial to the most lateral part of the tibial plateau). The hindfoot varus group had worse postoperative clinical outcomes than the hindfoot valgus group in terms of the mean Knee injury and Osteoarthritis Outcome Score for pain and American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Score.

CONCLUSIONS

Although our findings did not provide sufficient evidence to establish clinically relevant differences between the groups, they indicated that the group with a preoperative fixed hindfoot varus deformity had a higher rate of undercorrection and worse clinical outcomes, especially pain, following HTO. Therefore, modification of the procedure to shift the GA more laterally may be required for these patients.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Factors to improve odds of success following medial opening-wedge high tibial osteotomy: a machine learning analysis

BACKGROUND

Although high tibial osteotomy (HTO) is an established treatment option for medial compartment osteoarthritis, predictive factors for HTO treatment success remain unclear. This study aimed to identify informative variables associated with HTO treatment success and to develop and internally validate machine learning algorithms to predict which patients will achieve HTO treatment success for medial compartmental osteoarthritis.

METHODS

This study retrospectively reviewed patients who underwent medial opening-wedge HTO (MOWHTO) at our center between March 2010 and December 2015. The primary outcomes were a lack of conversion to total knee arthroplasty (TKA) and achievement of a minimal clinically important difference of improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) at a minimum of five years postoperatively. Recursive feature selection was used to identify the combination of variables from an initial pool of 25 features that optimized model performance. Five machine learning algorithms (XGBoost, multilayer perception, support vector machine, elastic-net penalized logistic regression, and random forest) were trained using five-fold cross-validation three times and applied to an independent test set of patients. The performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 231 patients were included, and 200 patients (86.6%) achieved treatment success at the mean of 9 years of follow-up. A combination of seven variables optimized algorithm performance, and the following specific cutoffs increased the likelihood of MOWHTO treatment success: body mass index (BMI) ≤ 26.8 kg/m2, preoperative KOOS for pain ≤ 46.0, preoperative KOOS for quality of life ≤ 33.0, preoperative International Knee Documentation Committee score ≤ 42.0, preoperative Short-Form 36 questionnaire (SF-36) score > 42.25, three-month postoperative hip-knee-ankle angle > 1.0°, and three-month postoperative medial proximal tibial angle (MPTA) > 91.5° and ≤ 94.7°. The random forest model demonstrated the best performance (F1 score: 0.93; AUC: 0.81) and was transformed into an online application as an educational tool to demonstrate the capabilities of machine learning.

CONCLUSIONS

The random forest machine learning algorithm best predicted MOWHTO treatment success. Patients with a lower BMI, poor clinical status, slight valgus overcorrection, and postoperative MPTA < 94.7 more frequently achieved a greater likelihood of treatment success.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Comparative analysis of gait: Similar coronal but different sagittal effects between closing-wedge and opening-wedge high tibial osteotomy

BACKGROUND

High tibial osteotomy is an established surgical option for medial compartment osteoarthritis of the knee with varus alignment. It can be divided into open wedge and closing wedge by operative technique. Although they have fundamental differences, little is known about the biomechanical consequences of the two surgical methods.

METHODS

Thirty-eight patients with medial compartment osteoarthritis who underwent high tibial osteotomy (19 open-wedge and 19 closing-wedge) were retrospectively reviewed. Clinical scores and radiological measurements were assessed until postoperative two years. Gait analysis was performed preoperatively and again at postoperative one year.

FINDINGS

Varus alignment was corrected in both groups without a significant difference between them (p = 0.543). However, posterior tibial slope was higher, and the Blackburne-Peel ratio was lower in the open wedge osteotomy group after surgery (both p < 0.001). Reduction of dynamic knee varus and knee adduction moment were observed in both groups without significant differences. However, after surgery, average knee range of motion (63.3° vs 57.3°, p < 0.001) and the magnitude of knee flexion moment was significantly lower (p = 0.005) in the closing wedge group. There were no significant differences in the Kujala Anterior Knee Pain Scale and the occurrence of patellofemoral arthritis between the groups postoperatively.

INTERPRETATION

After osteotomy, a smaller average knee range of motion in the sagittal plane and a higher knee flexion moment were observed in the open wedge osteotomy group, suggesting quadriceps muscle avoidance. However, no differences in clinical scores or the short-term occurrence of patellofemoral arthritis were noted between the two surgical techniques.

High survivorship and low complication rate in a single-centre series of 651 medial opening wedge high tibial osteotomy cases with a mean follow-up of 13 years

PURPOSE

This study aimed to report the early to midterm results of medial opening wedge high tibial osteotomy (MOWHTO) from the largest single-centre osteotomy database. The primary outcomes were reporting the radiological corrections and the functional outcomes represented by multiple patient-reported outcome measures (PROMs). The secondary outcomes were to report the complications, revisions and survivorship up to 10 years postoperatively.

METHODS

A prospectively maintained single-centre database of 1138 knee osteotomies was retrospectively reviewed. Patients who underwent MOWHTO and met the inclusion criteria were included. Those inclusion criteria were moderate to severe knee pain that failed conservative management; varus knee malalignment; and isolated medial osteoarthritis of the knee. A total of 651 cases, with a mean age of 46.7 ± 9 years and a mean body mass index of 29.6 ± 5.2 kg/m2 , were included. This comprised 71% males (n = 462) and 29% females (n = 189). The mean follow-up was 158.1 ± 45.4 months. Multiple PROMs were recorded preoperatively and serially postoperatively. This included the Knee injury and Osteoarthritis Outcome Scores, the Oxford Knee Score, the Oxford Knee Score-Activity and Participation Questionnaire, the Western Ontario and McMaster University Scores, the Visual Analogue Scale for health and pain, and the EQ-5D, which is a standardised measure of health-related quality of life. All lower limb alignment measurements were recorded pre- and postoperatively. The rates of osteotomy revision, conversion to arthroplasty, complications, and 5- and 10-year survivorship were recorded.

RESULTS

A total of 651 cases were followed up to a mean of 158.1 ± 45.4 months. The mean planned correction angle was 7.6° ± 2.9°. The mean planned opening wedge distance was 8.1 ± 3.1 mm. The mean intraoperative anterior and posterior osteotomy gaps opening were 7.7 ± 3.4 and 8.9 ± 3.8 mm, respectively. Postoperatively, the mean mechanical tibiofemoral angle improved from -5.7° ± 2.9° varus to 1.3° ± 2.5° valgus, the mean medial proximal tibial angle improved from preoperative 85.5° ± 2.3° to postoperative 91.6° ± 2.7° and the mean Mikulicz point improved from 21.7 ± 12.6% to 54.8 ± 11% (all p values < 0.001). All PROMs significantly improved at 24 months follow-up (all p values < 0.001). The rate of osteotomy revision was 1.1% at a mean of 2 ± 2.5 years postoperatively. The overall rate of arthroplasty conversion was 9.1%. This comprised 5.8% total knee arthroplasty conversion at a mean of 6.9 ± 3.5 years postoperatively and 3.2% unicompartmental knee arthroplasty conversion at a mean of 5.7 ± 2.5 years postoperatively. An overall 10.3% complication rate was recorded. The 5 and 10-year survivorship was 97.2% and 91.9%, respectively.

CONCLUSION

MOWHTO is a radiologically and clinically rewarding procedure with a high survival rate at 5 and 10 years and a low complication rate in experienced hands. MOWHTO should be considered in patients presenting with medial unicompartmental knee pain with an evidence of overload and a varus mechanical coronal plane axis.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

A Single-Stage Medial Opening Wedge High Tibial Osteotomy for Varus Alignment Correction With Revision Arthroscopic Anterior Cruciate Ligament (ACL) Reconstruction

Anterior cruciate ligament (ACL) injuries are a common clinical entity among people involved in contact sports activities. With the number of primary ACL reconstructions increasing, there has been a proportional increase in the revision of failed ACL reconstruction surgeries. As our understanding of knee kinematics improves over time, there has been evidence that alignment of the lower limb weight-bearing axis also plays an important part in ACL functioning. Medial opening wedge high tibial osteotomy (MOWHTO) is one such procedure that has been used extensively worldwide to correct the varus lower limb alignment. This procedure is usually reserved for young active patients with varus lower limb weight-bearing alignment. The technical dilemma for the surgeon arises when there is a need to revise a failed ACL reconstruction while at the same time correcting the axis malalignment. The general dictum says that alignment correction is done first followed by ligament reconstruction in a dual-stage procedure. However, single-stage surgery is possible in certain indications. In this case report, we present the case of a 31-year-old male involved in recreational sports who sustained a repeat ACL tear five years post the index surgery. He also had a significant varus alignment of the lower limb weight-bearing axis which was considered to be one of the causes of index surgery failure. In this report, we would like to highlight the problems we encountered in a single-stage procedure and certain surgical facets of a single-stage alignment surgery with arthroscopic revision ACL reconstruction.

Comparison of the clinical and radiological outcomes of Puddu and TomoFix plates for medial opening-wedge high tibial osteotomy: A two-year follow-up of a randomized controlled trial

PURPOSE

Opening-wedge high tibial osteotomy (OWHTO) requires fixation devices for stabilization of the osteotomy gap. The two most commonly used fixation devices are the Puddu and the TomoFix plates. Based on its design, each implant generates a characteristic stability profile. The aim of this randomized controlled trial (RCT) was to investigate the short-term clinical and radiological outcomes of OWHTO using the Puddu and TomoFix plating systems. We hypothesized that the TomoFix plate would achieve superior clinical and radiographic results compared to the Puddu plate.

METHODS

A total of 60 patients were randomly allocated to undergo OWHTO either using the Puddu plate or the TomoFix plate if conservative treatment failed with symptomatic medial compartment knee osteoarthritis (OA) stage I or II according to Ahlbäck classification, and varus malalignment. All patients underwent clinical and radiological assessment preoperatively, and at 3, 6, 12, and 24months postoperatively. Radiological measurement of the hip-knee-ankle (HKA) angle, and posterior tibial slope (PTS) was performed. Functional assessment was carried out using the Hospital for Special Surgery Knee-Rating Scale (HSS) and the Western Ontario McMaster Universities (WOMAC) Osteoarthritis Index. Patients were also evaluated for intraoperative and postoperative complications throughout the follow-up period.

RESULTS

The mean angular correction was 9.6±4°, and 10.5±4.8° in the Puddu and TomoFix groups, respectively (p=0.488). The mean PTS change was significantly higher in the Puddu group (3.4±1.1°) compared to the TomoFix group (0.8±0.7°) (p<0.001). There was a statistically significant improvement in the mean HSS and WOMAC in both groups until one year postoperatively. Neither HSS nor WOMAC showed a statistically significant difference between the Puddu and TomoFix groups at any time during the first two postoperative years. The overall complication rate was not significantly different between the Puddu and TomoFix groups. However, the TomoFix group demonstrated higher incidence of symptomatic hardware (23% vs. 3.3%) and removal of metalwork (17% vs. 0%) than the Puddu group (p=0.023 and 0.020, respectively).

CONCLUSION

This RCT suggests that the implant choice for OWHTO has no significant impact on functional outcomes during the first 2years postoperatively. While the Puddu plate was associated with an unintentional increase in the PTS during the surgery, both implants allowed coronal and sagittal plane corrections to be preserved postoperatively. The overall complication rates were similar, but the TomoFix required more material to be removed because it is more cumbersome. However, these results need to be confirmed on a larger scale.

LEVEL OF EVIDENCE

II; randomized controlled trial.

Distal femoral osteotomy planning: Reversed Miniaci's method is more accurate than Dugdale and Paley methods

PURPOSES

The purpose of this study was to validate the reversed Miniaci method for distal femoral osteotomies and to compare the accuracy with Dugdale and Paley methods.

METHODS

Between January 2019 and October 2021, 59 DFO were performed in a single center. Following application of the eligibility and exclusion criteria, radiographic measurements and analysis was performed for 24 patients by two independent observers, then repeated after one month. Medical planning software: PeekMed v2.3.7.6® was used. For all patients the following measurements were performed: Hip-Knee-Ankle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), joint line obliquity (JLO), width of the proximal tibia and the weight-bearing line (WBL). Each image was then analysed using the following planning methods for realignment surgery: Reversed Miniaci, Dugdale and Paley. Measurements were recorded post deformity correction. Difference between target and post-correction WBL was evaluated. This difference was adjusted by the objective in order to limit biases related to the different objectives according to the method.

RESULTS

Eighteen patients were managed for a varus osteotomy and 6 for a valgus osteotomy. Preoperative data was, HKA at 176.7±6.3, mLDFA at 90.6±5.4, MPTA 88.9±1.1, a WBL for valgus 80.9%±9.1 and for varus deformity 23.5%±11.7. Inter- and intra-rater reliability was>0.8 for every method. After normalizing reported precision on the amount of correction expected, reversed Miniaci method was the most accurate with a mean deviation from the target of 3%, compared to the Dugdale's method with 9% (p<0.001) and to Paley's method with 8.6% (p<0.001).

CONCLUSION

The reversed Miniaci method is effective and reliable for planning distal femoral osteotomies. Compared to other planning methods, it is the most accurate approach for achieving a correction goal.

LEVEL OF EVIDENCE

IV; retrospective cohort study.

Bilateral Inverted V-shaped High Tibial Osteotomy: A Case Report

The article describes the case of a young patient with bilateral genu varum deformity, limiting her mobility. The therapeutic decision was a staged reverse V-shaped tibial osteotomy on both knees at a six-month interval. The surgery faced infectious complications on the left side, requiring additional treatment. Despite this, the patient achieved successful correction, with wound healing and bone consolidation. Preoperative planning was crucial, determining specific correction angles for each knee. The reverse V-shaped osteotomy demonstrated satisfactory functional outcomes compared to other techniques. The conclusion emphasizes the effectiveness of reverse V-shaped high tibial osteotomy (HTO) in addressing varus tibial deformities, providing an alternative before considering total knee arthroplasty. Multicenter studies and long-term evaluations are recommended to refine this surgical procedure.

Incidence of Complications and Revision Surgery After High Tibial Osteotomy: A Systematic Review

BACKGROUND

High tibial osteotomy (HTO) is a well-recognized procedure for its effectiveness in treating symptomatic early knee arthritis and malalignment. Although there are numerous systematic reviews evaluating the management and outcomes after HTO, there are few investigations on complications of this procedure.

PURPOSE

To systematically review the literature to determine the incidence of intraoperative and postoperative complications associated with medial opening wedge and lateral closing wedge HTOs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, PubMed, Embase, and MEDLINE databases were queried for studies reporting complications associated with HTO with or without concomitant procedures. Data including patient characteristics, procedure type, concomitant procedures, follow-up time, and postoperative imaging were extracted. Rates of intra- and postoperative complications, reoperations, and conversion to arthroplasty were recorded.

RESULTS

A total of 71 studies were included for analysis, comprising 7836 patients. The overall intraoperative complication rate during HTO was 5.5% (range, 0%-29.3%), and the overall postoperative complication rate was 6.9% (range, 0%-26.6%). The most common intraoperative complication was lateral hinge fracture (incidence, 9.1%; range, 0%-30.4%) in medially based HTOs and peroneal nerve injury in laterally based HTOs (incidence, 3.2%; range, 0%-8.7%). The overall incidence of neurovascular injury after medially or laterally based HTOs was 1.1% (range, 0%-18.9%). The most common postoperative complication was superficial infection (incidence, 2.2%; range, 0%-13%). Of the included studies, 62 included postoperative radiographic analysis, and among those, the incidence of nonunion was 1.9% (range, 0%-15.5%), loss of correction was 1.2% (range, 0%-34.3%), and implant failure was 1.0% (range, 0%-10.2%). Among studies reporting revision surgeries, the overall reoperation rate was 15.5% (range, 0%-70.7%), with the most common type of reoperation being hardware removal (incidence, 10.0%; range, 0%-60%).

CONCLUSION

Intraoperatively, medially based HTOs are associated with a 1 in 11 risk of lateral hinge fracture and laterally based HTOs with a 1 in 30 risk of peroneal nerve injury. Postoperative complication rates in the range of 10% to 15% can be expected, including infection (2.9%), loss of correction (1.2%), and nonunion (1.9%). Patients should also be counseled that the reoperation rate is approximately 15%, with hardware removal being the most common procedure.

Economic evaluation of high tibial osteotomy: Closing wedge is more cost-effective than open wedge technique when analysing the KOOS-12 improvement

PURPOSE

The purpose of this study was to compare the cost-effectiveness of two techniques for performing a knee valgus osteotomy: opening wedge high tibial osteotomy (OW-HTO) vs closing wedge high tibial osteotomy (CW-HTO).

METHODS

In this economic evaluation study, a cost-effectiveness analysis from the perspective of the Spanish public healthcare system was performed, comparing OW-HTO with CW-HTO. All patients with medial knee osteoarthritis who underwent one of these procedures between 2018 and 2020 in our institution were included. The cost analysis included operating room, implant, graft and hospital admission costs. Functional outcomes (KOOS-12, Tegner activity scale, pain and satisfaction) and radiological outcomes (hip-knee-ankle angle, medial proximal tibial angle, tibial slope and patellar height) were analysed. The cost-effectiveness ratio was obtained by calculating the cost of improving the minimal clinically important difference (MCID) of KOOS-12 for each procedure. All costs are expressed in 2020 euros.

RESULTS

Fifty-one patients met the inclusion criteria (27 OW-HTO and 24 CW-HTO). Good to excellent functional outcomes, significant pain reduction (>6 points) and high patient satisfaction (>9/10) were observed in both groups. Both techniques yielded excellent radiological outcomes. N.s. differences in functional or radiological outcomes improvements between both procedures were found. However, the OW-HTO group presented a higher total cost than the CW-HTO group (4612.1 ± 765.6€ vs. 1827.1 ± 701.9€; p < 0.001). The cost-effectiveness ratio was 818.1 ± 46.8 €/MCID for the CW-HTO procedure and 2414.3 ± 115.2 €/MCID for the OW-HTO procedure (p = 0.025).

CONCLUSION

The CW-HTO procedure presented a cost-effectiveness ratio almost three times lower than the OW-HTO procedure. Both techniques allowed to achieve of good to excellent functional outcomes, significant pain reduction and high patient satisfaction while correcting the varus limb malalignment and the metaphyseal tibial varus in patients with medial compartment osteoarthritis.

LEVEL OF EVIDENCE

Level III; economic study.

Risk Factors and Dynamic Nomogram Development for Surgical Site Infection Following Open Wedge High Tibial Osteotomy for Varus Knee Osteoarthritis: A Retrospective Cohort Study

Background

As the worldwide population ages, the population receiving open wedge high tibial osteotomy (OWHTO) is growing, and surgical site infection (SSI) is a rare but fatal surgical complication. This study aimed to identify risk factors independently associated with SSI following OWHTO and develop a predictive nomogram.

Methods

Clinical data of patients who received OWHTO and followed up for more than 12 months in our hospital were retrospectively reviewed. Multivariable logistic regression was performed to determine independent risk factors for SSI and to construct predictive nomograms. The study further illustrated the predictive performance of the model by using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

Results

A total of 1294 eligible patients were included in the study. Multivariate analysis revealed tobacco consumption (OR=3.44, p=0.010), osteotomy size ≥12 mm (OR=3.3, p=0.015), the use of allogeneic bone or artificial bone graft substitutes (allogeneic bone vs none, OR=4.08, p=0.037; artificial bone vs none, OR=5.16, p=0.047), Kellgren-Lawrence (K-L) grade IV (OR=2.5, p=0.046), systemic immune-inflammation index (SII) >423.62 (OR=6.2, p<0.001), high-sensitivity C-reactive protein (HCRP) >2.6 mg/L (OR=2.42, p=0.044), and a higher level of fasting blood glucose (FBG) (OR=1.32, p=0.022) were the independent predictors of SSI. The cutoff score of the model was 148, with a sensitivity of 76.0% and specificity of 81.0%. The concordance index (C-index) and Brier score of the nomogram were 0.856 and 0.017, and the corrected values after 1000 bootstrapping validations were 0.820 and 0.018, respectively. Furthermore, the ROC curve, calibration curve, and DCA exhibited excellent predictive accuracy and clinical applicability of the model.

Conclusion

This study developed a dynamic nomogram based on seven predictors, which allowed surgeons to individualize risk stratification of patients and intervene promptly to reduce SSI rates.

Maintaining Posterior Tibial Slope and Patellar Height During Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

Increased posterior tibial slope (PTS) and decreased patellar height (PH) after medial opening wedge high tibial osteotomy (MOWHTO) have been repeatedly reported in the literature. However, this has been disputed in more recent biomechanical studies.

HYPOTHESIS

No change in PTS or PH would result after MOWHTO with the freehand technique, regardless of the degree of the coronal plane correction.

STUDY DESIGN

Case series.

METHODS

A total of 62 patients who underwent MOWHTO between 2018 and 2020 were included. Surgery was performed using a dedicated step-by-step protocol to reduce the risk of unintentional slope changes. All patients were evaluated preoperatively and at a 2-year follow-up with the Knee injury and Osteoarthritis Outcome Score and the University of California, Los Angeles physical activity scale. Pre- and postoperative radiographic lower limb alignment parameters-including hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle, proximal posterior tibial angle (PPTA), joint line convergence angle, and joint line obliquity-were measured on full-length lower limb radiographs. PH measurements assessed on lateral and anteroposterior knee radiographs included the Caton-Deschamps, Insall-Salvati, and Schröter indices.

RESULTS

A significant change was observed in the coronal plane alignment, with an increase in the MPTA from 84.38° to 90.39° (P < .001) and a consequent increase in the HKA from 172.19° to 180.15° (P < .001). No significant changes were observed in the PTS, as evidenced by a postoperative PPTA of 80.6° versus a preoperative value of 80.4° (P = .2). No significant changes were detected in the mean PH on all 3 indices used-pre- versus postoperative Caton-Deschamps, Insall-Salvati, and Schröter indices measured 0.95 versus 0.93 (P = .2), 1.03 versus 1.03 (P = .5), and 1.56 versus 1.54 (P = .3), respectively.

CONCLUSION

In this study, MOWHTO did not result in significant changes in the PTS or PH when accurate preoperative planning and precise intraoperative freehand technique were adopted..

Proximal tibial osteotomy with absorbable spacer combined with fibular osteotomy has similar clinical outcomes to high tibial osteotomy in the treatment of knee osteoarthritis

PURPOSE

Proximal tibia osteotomy with absorbable spacer combined with fibular osteotomy (TPOASI) is an emerging surgical technique for treating knee osteoarthritis (KOA); however, the efficacy of this procedure remains unknown. We hypothesize that TPOASI can achieve similar clinical outcomes to opening-wedge high tibial osteotomy (OW-HTO). The objective of this study is to compare the clinical results between these two procedures.

METHODS

Patients who underwent TPOASI or OW-HTO from July 2016 to September 2020 were included. The following outcome parameters were determined before and after the surgery: the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the visual analogue scale of pain, the Intermittent and Persistent Osteoarthritis Pain Scale, femorotibial angle, and post-operative complications.

RESULTS

In total, 209 cases were analyzed (102 in TPOASI group; 107 in OW-HTO group) with 3.1 years average follow-up. Both procedures achieved significant improvement in KOOS (62.0 to 24.4 in the TPOASI and 62.8 to 26.2 in the OW-HTO group, p < 0.001) and WOMAC score (68.9 to 24.1 in the TPOASI versus 69.9 to 26.1 in the OW-HTO group, p < 0.001). There were no significant differences in complications or femorotibial angle between the two groups but the only significant difference in the outcome parameters was the WOMAC stiffness score (19.6 in the TPOASI versus 26.5 in the OW-HTO group).

CONCLUSION

TPOASI achieves comparable results to OW-HTO in terms of clinical scores, radiographic results, and complications, but has the advantage of avoiding internal fixation removal.

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.

Effect of Prior Knee Arthroscopy on Midterm Outcomes After Medial Opening-Wedge High Tibial Osteotomy: A Propensity Score-Matched Analysis

Background

Knee arthroscopy is frequently performed to improve joint function and relieve pain. However, there is no consensus regarding the effect of prior arthroscopy on outcomes following medial opening-wedge high tibial osteotomy (MOWHTO).

Purpose

To compare midterm clinical outcomes and survival rates after MOWHTO between patients with and without a history of knee arthroscopy.

Study Design

Cohort study; Level of evidence, 3.

Methods

We enrolled patients who underwent MOWHTO between March 2008 and February 2017 and had ≥4 years of follow-up. Patients who had undergone knee arthroscopy were included in an arthroscopy group, and those who had not were included as controls. After propensity score matching based on age, sex, body mass index, and lesion size, 80 patients in each group were included. Clinical outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), 36-Item Short Form Health Survey, and Tegner Activity Scale. Furthermore, survival rates and relevant risk factors that affected joint survivorship were analyzed, wherein conversion to total knee arthroplasty was considered the endpoint.

Results

Although the pre- to postoperative improvement in clinical outcomes did not differ significantly between the groups, there were significant between-group differences in final postoperative scores on the KOOS-Activities of Daily Living (arthroscopy vs control, 78.1 ± 10.6 vs 81.0 ± 9.8; P = .031), KOOS-Sport and Recreation (45.4 ± 12.8 vs 48.7 ± 13.5; P = .045), 36-Item Short Form Health Survey Physical Component Summary (65.1 ± 12.7 vs 69.3 ± 11.8; P = .017), and Tegner Activity Scale (4.1 ± 1.1 vs 4.5 ± 1.0; P = .007). The survival rate was 96.8% at a mean follow-up of 8 years, and survival was not associated with a history of arthroscopy (P = .697; log-rank test).

Conclusion

Although patients with prior arthroscopy had some inferior patient-reported outcome scores after MOWHTO, the overall clinical improvements were similar in the arthroscopy and control groups.

Comparative Analysis of Unicompartmental Total Knee Arthroplasty and High Tibial Osteotomy: Time to Total Knee Arthroplasty and Other Outcome Measures

Background

There is no consensus on whether unicompartmental arthroplasty (UKA) or high tibial osteotomy (HTO) is superior for unicompartmental arthritis. While there are studies comparing revision and complication rates, none matched a large number of patients undergoing HTO and UKA in the United States and compared these outcomes. We investigated TKA conversion rate and the complications following HTO or UKA.

Methods

This retrospective study queried the PearlDiver database of all patients undergoing UKA and HTO using CPT codes between January 2011 and January 2020. We compared propensity-matched populations based on age, gender, Charlson comorbidity index, and Elixhauser comorbidity index to compare odds of complications, TKA conversion, and drug use between UKA and HTO groups. Two-independent sample t-test for unequal variances and test of significance were performed.

Results

We found 32,583 UKA patients and 816 HTO patients. Each matched group had 535 patients. One-year complication showed higher risk of pneumonia, hematoma, infection, and mechanical complications among HTO patients. UKA patients used narcotics on average of 10.3 days compared to 9.1 days among HTO patients (P < .01). UKA conversion rates were 4.1%, 5.4%, 7.7%, and 9.2% at 1-, 2-, 5-, and 10-year intervals, respectively. HTO conversion rates were less than 2% at 1- and 2-year intervals, 3.4% at 5-year, and 4.5% at 10-year intervals. This difference was statistically significant at 5- and 10-year intervals (P < .01).

Conclusions

Using large matched cohorts, HTO may be converted to TKA later than UKA in short- to mid-term follow-up, and HTO patients used opioids for shorter duration.

Superior survivorship and plate-related results of TomoFix compared to Puddu plate fixation for opening-wedge high tibial osteotomy: A systematic review of the literature

PURPOSE

This systematic review aimed to compare survivorship and plate-related results of Puddu and TomoFix plates in opening-wedge high tibial osteotomy (OWHTO).

METHODS

PubMed, Scopus, EMBASE, and CENTRAL databases were searched from January 2000 until September 2021 for clinical studies involving patients with medial compartment knee disease and varus deformity undergoing OWHTO using the Puddu or TomoFix plating systems. We extracted survival data, plate-related complications, and functional and radiological outcomes. The risk of bias assessment had been carried out using Cochrane Collaboration's quality assessment tool for randomised controlled trials (RCTs) and Methodological Index for Non-Randomised Studies (MINORS).

RESULTS

Twenty-eight studies were included. The total number of knees was 2568 in 2372 patients. The Puddu plate was used in 677 knees, while the TomoFix plate was used in 1891. The follow-up ranged from 5.8 to 147.6 months. Both plating systems were able to delay conversion to arthroplasty at different follow-up intervals. However, osteotomies fixed by the TomoFix plate achieved higher survival rates, especially at mid-term and long-term follow-ups. In addition, fewer complications were reported with the TomoFix plating system. Although both implants achieved satisfactory functional outcomes, high scores could not be maintained throughout long-term intervals. Regarding radiological results, TomoFix plate was able to achieve and maintain larger degrees of varus deformity, while preserving the posterior tibial slope.

CONCLUSIONS

This systematic review demonstrated the superiority of the TomoFix over the Puddu system as a safer and more effective fixation device in OWHTO. Nevertheless, these results should be interpreted with caution due to the lack of comparative evidence through high-quality RCTs.

Opening- and closing-wedge high tibial osteotomy are comparable and early full weight bearing is safe with angular stable plate fixation: a meta-analysis

PURPOSE

The purpose of this study was to establish the gold standard for surgical technique, fixation, and rehabilitation for HTO in patients with unicompartmental knee osteoarthritis.

METHODS

Medline, Embase, and SPORTDiscus databases were searched up to April 2022. Included were (1) randomized controlled trials (RCTs) comparing opening-wedge HTO (owHTO) and closing-wedge HTO (cwHTO), (2) biomechanical studies and prospective patient studies comparing biomechanical and clinical results for plate fixators, and (3) RCTs comparing an early versus delayed full-weight-bearing (FWB) protocol.

RESULTS

The pooled results for the surgical technique showed no significant differences between owHTO and cwHTO for most PROMs on pain, activity, and risk for conversion to TKA. The cwHTO group showed a slightly better improvement in KOOS/WOMAC pain scores (4.51; 95% CI 1.18-7.85), and a significantly lower change in posterior tibial slope (p = 0.03). The pooled results for the fixation method showed the highest force at maximum failure for the Activmotion (Newclip Technics, France), Aescula (B. Braun Korea, Korea), 2nd generation Puddu (Arthrex Inc., USA), and TomoFix plate (Depuy Synthes, Switzerland). The pooled results for the rehabilitation protocol showed no significant differences between the early full-weight-bearing (FWB) group and the delayed FWB group for functional scores, complication rates, and delayed unions.

CONCLUSION

Both owHTO and cwHTO reduced pain and improved knee function. Locking plate fixation should be used for owHTO. An early FWB protocol has proven to be safe in patients with small corrections, no hinge fractures, and non-smokers.

LEVEL OF EVIDENCE

Level II.

Alignment prior to total knee arthroplasty in high tibial osteotomy patients has no effect on subsequent functional outcomes

INTRODUCTION

The influence of prior high tibial osteotomy (HTO) on total knee arthroplasty (TKA) functional outcomes remains widely debated. Alignment of failed HTO can pose technical challenges with subsequent TKA. The primary aim of this study was to evaluate the influence of HTO alignment on the clinical outcomes of subsequent TKA. The secondary aim was to compare the time to TKA for each HTO alignment type.

METHODS

Patients who underwent TKA post lateral closing-wedge HTO for symptomatic medial compartment osteoarthritis between 2001 and 2014 were prospectively followed up for 2 years. A total of 159 patients were assigned to three groups based on their pre-TKA femora tibia angles using long lower limb radiographs: varus alignment (VrA) ≤ 3^o valgus, neutral alignment (NA) 3-9^o valgus alignment, valgus alignment (VlA) ≥ 9^o valgus. Functional outcomes were quantified using Knee Society Function Score and Knee Scores (KSFS and KSKS respectively), modified Oxford Knee Score (OKS), Short Form 36 Physical Component Score (SF-36 PCS), and SF-36 Mental Component Score (SF-36 MCS). Pre-operative and post-operative knee range of motion were also measured.

RESULTS

Mean pre-TKA KSKS in VrA patients (35 ± 18) was significantly lower than both NA (51 ± 19) and VlA (40 ± 21) patients (p < .05). Otherwise, there was no significant difference in functional outcome scores (KSFS, KSKS, OKS, SF-36 PCS and SF-36 MCS) or range of motion at 6 months and 2 years post-TKA. The mean duration from HTO to TKA was 12 ± 7 years with no significant differences between VrA, NA, and VlA HTO to TKA (13 ± 7 years, 13 ± 6 years and12 ± 8 years respectively, p > .05).

CONCLUSION

HTO alignment did not influence time to subsequent TKA. HTO alignment did not influence early outcomes as well as radiological outcomes of subsequent TKA.

LEVEL OF EVIDENCE

III.

New insight into the current study of high tibial osteotomy: A bibliometric analysis

BACKGROUND

To analyze global trends in focus and funding of research related to high tibial osteotomy (HTO) and to identify the 100 most cited articles in this field.

METHODS

A Web of Science search was used to identify HTO publications in English-language scientific journals from January 1967 till February 3th, 2021. Results were filtered to the 100 most cited articles by reading the abstract or full-text paper. Information of these articles was recorded for further analysis. The 10 top-cited articles during the last 5 years and the 10 top-cited articles about HTO ranked by average citations per year were selected to predict research trends.

RESULTS

In all, 48 out of the 100 top-cited articles were published between 2000 and 2010. The United States of America was the primary contributor (n = 29) followed by Germany (n = 17) and Japan (n = 11). The total number of citations per article ranged from 65 to 563, median 108, mean 135 (standard deviation = 84). The American Journal of Bone and Joint Surgery accounted for 23 out of the 100 top-cited articles. Koshino T was the most cited author (603 citations). The most frequently highlighted study theme was prognostic research. Patient-based clinical research was the dominant study design (85%). The majority of articles (48 out of 100) were level IV evidence with a mean of 141 (standard deviation = 97) citations. Top-cited articles in the last 5 years focused on open wedge osteotomy.

CONCLUSION

Technical optimization of open wedge osteotomy has emerged as the main area of research in HTO. More specifically, recent publications focus on the surgical technology, cartilage repair and new fixation devices. Besides, papers with a high level of evidence are needed for the development of HTO.

Less risk of conversion to total knee arthroplasty without significant clinical and survivorship difference for opening-wedge high tibial osteotomies in varus knee deformities at 10-year minimum follow-up compared to closing-wedge high tibial osteotomies

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and survivorship at minimum 10-year follow-up of patients undergoing primary valgisation high tibial osteotomy (HTO) for medial osteoarthritis (OA), treated by Opening-Wedge HTO (OW-HTO) or Closing-Wedge HTO (CW-HTO).

METHODS

This was a retrospective cohort study of consecutive patients presenting to a single institution undergoing HTO for isolated medial compartment OA. Two hundred and twenty three HTOs for isolated medial tibio-femoral OA were performed between January 2002 and December 2010. Patients were eligible if they had minimum 10-year follow-up and received either a CW or OW-HTO. Fifteen (6.7%) patients died and twenty-five (11.2%) were lost to follow-up. One hundred and eighty three (82.1%) patients were included in the final analysis and divided into two groups: OW-HTO (96/183; 52.4%) and CW-HTO (87/183; 47.6%). Range of motion, KSS, KOOS scores, and conversion to TKA rate were analyzed between groups. Both groups were comparable regarding age, arthrosis stage, gender, ASA score and BMI at the time of HTO. Survival analysis was conducted with re-intervention for TKA as the end point.

RESULTS

At the time of HTO, mean age was 55 years ± 7.9 (27-73.9) with 72.7% of patients being male. The mean follow-up was 13.3 years ± 2.7 (10-19). Sixty-four (34.9%) patients underwent TKA at a mean delay of 9.3 years ± 3 (3-16). The conversion to TKA rate was significantly higher in the CW-HTO group versus the OW-HTO group: 42.5% (37/87) versus 28.1% (27/96) (p = 0.04). The survival at 15-year follow-up was 59.2% in the OW-HTO group versus 54.6% in the CW-HTO group (n.s.). At 13-year follow-up, KSS Function score was significantly better in the OW-HTO (90.9 versus 82.4; p = 0.007). No significant difference was observed between the two groups regarding the KOOS score, KSS Knee Score and complication rate.

CONCLUSION

At mean follow-up of 13 years, no significant clinical and survivorship difference was observed between the two groups. The conversion to TKA was significantly lower following OW-HTO. Minor correction was associated with risk of requiring subsequent TKA.

LEVEL OF EVIDENCE

Retrospective case series, IV.

Combine Approach of Proximal Fibula Osteotomy (PFO) Followed by Intra-Articular Dextrose Prolotherapy in Severe Medial Knee Osteoarthritis

Background

Knee osteoarthritis (OA) is a chronic and progressive degenerative disease. It resulted from mechanical and chemical disorders that damage the joint and the underlying bone. The management of knee OA is challenging due to poor self-regeneration of connective tissues. Surgical treatment with prolotherapy approaches was conducted to treat medial compartment knee OA.

Aim

To know the injection frequency to reach a 50% improvement in VAS score and WOMAC index.

Methods

Six patients who suffered from late-stage medial compartment knee OA underwent PFO followed by twelve sessions of intra-articular dextrose prolotherapy. The subjective pain score, visual analog scale (VAS), was assessed based on the patient subjectiveness before and after treatment. Patients marked the score from 0 to 10 cm to describe the current pain state. The functional index, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index used to evaluate the Patient's clinical symptoms. It ranges from 0 to 96 points consisting of three main sections: pain (total 20 points), stiffness (total: eight points), and physical function disability (total 68 points). Higher scores indicate severe symptoms and function.

Results

Four patients showed pain relief and functional improvement with more than 50% scores of VAS and WOMAC after the treatment. Two patients received more than twelve doses of intra-articular dextrose prolotherapy due to a lack of progress.

Conclusion

This study provides clinical evidence for a new treatment strategy for advanced knee OA. This combined therapy improves the patient's daily activity function and postpones the need for total knee arthroplasty (TKA).

Accuracy of the correction achieved after a valgus high tibial osteotomy: Comparison of the Hernigou table and navigation

INTRODUCTION

The outcome of a medial opening wedge valgus high tibial osteotomy indicated for the treatment of isolated medial tibiofemoral osteoarthritis depends mainly on the accuracy of the correction of the hip-knee-ankle angle (HKAA) and the mechanical medial proximal tibial angle (mMPTA). Most authors aim for a desired correction target between 2° and 4° of valgus. Several planning and surgical techniques have been described to achieve this target value that is specific to each surgeon.

OBJECTIVE

The purpose of this study was to compare the accuracy of the correction achieved using either the Hernigou table (HT) planning method or a computer-assisted navigation system (CAS). It was hypothesized that no difference would be found between these 2 techniques.

MATERIALS AND METHODS

This retrospective single-center study involved 43 knees: 21 in the HT group and 22 in the CAS group. Two surgeons (ME, JYJ), who were experts in 1 of the 2 planning methods performed these procedures, with a single surgeon assigned to each group. The correction was noted in the operative report and was considered to be the desired correction target. The surgical correction was calculated by comparing preoperative and immediate postoperative mMPTA measurements. The surgical accuracy, where a value close to 0 represented optimal accuracy, was defined as the absolute value of the difference between the correction target set by the surgeon and the surgical correction achieved. The median accuracy between the 2 groups was compared by a Mann-Whitney U test (significance level at 5%). The number of patients deviating from the target by>3° was analyzed with a Fisher exact test (significance level at 5%). Pre- and postoperative comparisons of the HKAA measurements could not be used because the measurement was not performed postoperatively for the CAS group.

RESULTS

The median surgical accuracy on the mMPTA was 1.4° (0-4.1) for the HT group versus 1.9° (0.2-6.7) for the CAS group (p=0.85). Sixteen procedures (76%) were performed with an accuracy of<3° in the HT group versus 15 in the CAS group (68%) (p=0.73).

DISCUSSION-CONCLUSION

The working hypothesis was confirmed: no differences were found between the HT and CAS groups regarding the surgical accuracy in achieving the corrections set in this series. We therefore demonstrated that HT was a highly accessible, simple and reliable technique for achieving the planned target. It can be used widely.

LEVEL OF EVIDENCE

III; comparative retrospective series.

Prognostic factors for medial open-wedge high tibial osteotomy with spacer implantation in patients with medial compartmental knee osteoarthritis

Background

To identify medial open-wedge high tibial osteotomy (MOWHTO) prognostic factors with wedge-shaped spacer implantation (spacer-type MOWHTO) for varus medial compartment knee osteoarthritis.

Methods

Patients who underwent spacer-type MOWHTO between August 2018 and September 2019 were prospectively enrolled in this study. Patients were divided into effective group and invalid group based on the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) score one year postoperatively. The variables assessed at baseline and one year postoperatively including age, sex, body mass index (BMI), Kellgren–Lawrence (K–L) grade, hip–knee–ankle angle (HKAA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), Blackburn–Peel index (BPI), duration of symptoms, and WOMAC score were compared. Prognostic factors were analyzed using logistic regression, and the corresponding odds ratios were also calculated.

Results

A total of 104 patients were enrolled in the study protocol at one year postoperatively. The WOMAC score decreased from 72.39 ± 12.95 at baseline to 20.06 ± 12.96 at one year postoperatively. Univariate analysis revealed that the significant predictors of the WOMAC score were age > 70 years, BMI > 30 kg/m², K–L grade IV, and pre-HKAA > 10° (P < 0.1 for all). Multivariable logistic regression analysis revealed that age > 70 (OR = 4.861) and K–L grade IV (OR = 6.590) were significantly associated with the higher WOMAC score at one year postoperatively.

Conclusions

Spacer-type MOWHTO is an effective treatment for osteoarthritis with varus deformity. The prognostic factors for spacer-type MOWHTO are age and K–L grade.

Associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and changes in tibiofemoral joint structures in patients with knee osteoarthritis

Background

To describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA).

Methods

The participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ), and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs), and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes.

Results

In the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (β: − 0.07), Sυ (β: − 0.07), and S (β: − 0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs.

Conclusions

This longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA.

Trial registration

Clinicaltrials.gov Identifier: NCT01176344

Anzctr.org.au Identifier: ACTRN12610000495022

Date of registration: 7 May 2010

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02719-8.

Restoration of Native Leg Length After Opening-Wedge High Tibial Osteotomy: An Intraindividual Analysis

Background:

Opening-wedge high tibial osteotomy (OWHTO) has been shown to significantly increase leg length, especially in patients with large varus deformity. Thus, the current literature recommends closing-wedge high tibial osteotomy to correct malalignment in these patients to prevent postoperative leg length discrepancy. However, potential preoperative leg length discrepancy has not been considered yet.

Hypothesis:

It was hypothesized that patients have a decreased preoperative length of the involved leg compared with the contralateral side and that OWHTO would subsequently restore native leg length.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 67 patients who underwent OWHTO for unilateral medial compartment knee osteoarthritis and who received full leg length assessment pre- and postoperatively. Patients with varus or valgus deformity (>3°) of the contralateral side were excluded. A musculoskeletal radiologist assessed imaging for the mechanical axis, full leg length, and tibial length of the involved and contralateral lower extremity. Statistical analysis determined the pre- and postoperative leg length discrepancy and the influence of the mechanical axis.

Results:

Most patients (62.7%) had a decreased length of the involved leg, with a mean preoperative mechanical axis of 5.0° ± 2.9°. Length discrepancy averaged –2.2 ± 5.8 mm, indicating a shortened involved extremity (P = .003). OWHTO significantly increased the mean lengths of the tibia and lower limb by 3.6 ± 2.9 and 4.4 ± 4.7 mm (P < .001), leading to a postoperative tibial and full leg length discrepancy of 2.8 ± 4.3 mm and 2.2 ± 7.3 mm (P < .001 and P = .017, respectively). Preoperative leg length discrepancy was significantly correlated with the preoperative mechanical axis of the involved limb (r = 0.292; P = .016), and the amount of correction was significantly associated with leg lengthening after OWHTO (r = 0.319; P = .009). Patients with a varus deformity of ≥6.5° (n = 14) had a preoperative length discrepancy of –4.5 ± 1.6 mm (P < .001) that was reduced to 1.8 ± 3.5 mm (P = .08).

Conclusion:

Patients undergoing OWHTO have a preoperative leg length discrepancy that is directly associated with the varus deformity of the involved extremity. As OWHTO significantly increases leg length, restoration of native leg length can be achieved particularly in patients with large varus deformity.

Long-term follow-up results of medial opening wedge high tibia osteotomy with a pre-countered non-locking steel plate

INTRODUCTION

This retrospective study investigated the long-term follow-up results of medial opening wedge high tibial osteotomy (MOWHTO) with a pre-countered non-locking steel plate implant (Puddu plate = PP) used for medial knee osteoarthrosis (OA) treatment.

MATERIALS AND METHODS

Consecutive 70 MOWHTOs (66 patients) were performed between 01.01.2004 and 31.12.2008 with the mean follow-up time of 11.4 (SD 4.5; range 1.2-16.1) years. The Kaplan-Meier survival analysis was used to evaluate the cumulative survival of the implant in terms of age (< 50 years old and ≥ 50 years old) and gender. Adverse events were studied and Cox regression analysis was used to evaluate risk factors [age, gender, body mass index (BMI), preoperative mechanical axis, severity of OA, use of bone grafting or substitution and undercorrection of mechanical axis from varus to valgus] for revisions.

RESULTS

The estimates for the cumulative survival with no need for TKA after MOWHTO were 86% at 5 years, 67% at 10 years and 58% at 16.1 years (SE 0.6, CI 95% 11.1-13.5). A total of 33/70 (47%) adverse events occurred and 38/70 (54%) knees required some revision surgery during the follow-up. Cox regression did not show any statistically significant risk factors for revision.

CONCLUSIONS

The PP has feasible MOWHTO results with a cumulative survival of 67% at 10 years with no need for conversion to TKA. Many adverse events occurred and revision rate due to any reason was high. Age or gender did not have statistically significant differences in terms of survival.

Long-term results of the subtubercle tibial osteotomy using the circular external fixator for medı̇al compartment osteoarthrı̇tı̇s of knee

BACKGROUND

We evaluated the long-term clinical and radiographic outcomes of patients who underwent subtubercular tibial osteotomy (STO) with Ilizarov external fixation used for high tibial osteotomy for medial knee osteoarthritis (MKOA).

METHODS

Between October 2003 and December 2011, 42 knees of 40 patients who had undergone STO with Ilizarov external fixator with a diagnosis of MKOA were evaluated. Survival analysis was performed by examining the duration of total knee arthroplasty (TKA). Clinical and radiological variables were collected at the time of admission after removal of the fixator and at outpatient follow up.

RESULTS

Mean age was 49.3 ± 5.68 (range 37-61) years, mean postoperative follow up time was 14.22 ± 2.93 (range 9-18) years, and mean fixator duration was 14.6 (range 13-20) weeks. Survival analysis showed 100% at 5 years, 95.2% at 10 years and 88.1% at 15 years. Clinical examination of the patients showed significant improvement in American Knee Society score (KSS), KSS functional score and Oxford Knee Score (OKS) score (P = 0.005). In the study, it was observed that the patients' knee osteoarthritis had progressed over time. On examination, radiographic measurements including mechanical axis deviation, medial proximal tibial angle, femorotibial angle, and joint line alignment angle improved significantly after deformity correction (P = 0.001).

CONCLUSION

STO using the Ilizarov method offers long-term survival. It provides effective treatment in young patients with isolated MKOA. Achieving the desired amount of correction in the coronal and sagittal planes can be presented as a surgical technique for the treatment of MKOA as an effective method in clinical and radiological correction.

The Relationships between Coronal Plane Alignments and Patient-Reported Outcomes Following High Tibial Osteotomy: A Systematic Review

OBJECTIVE

This systematic review aimed to determine whether coronal angular corrections correlate with patient reported outcomes following valgus-producing high tibial osteotomy (HTO).

DESIGN

Ovid MEDLINE, Embase, and Web of Science were systematically searched. Studies that reported hip-knee-ankle angles (HKA) or femorotibial angles (FTA), and the Oxford Knee Score (OKS), visual analogue scale (VAS) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), or EQ-5D before and after valgus-producing HTO were eligible. Correlation analyses were performed where appropriate to investigate the relationships between variables. PROSPERO ID: CRD42019135467.

RESULTS

This study included 39 articles including 50 cohorts. VAS was reported in 22 studies, OKS in 9, KOOS in 12 and EQ-5D in 2. The HKA angle was corrected from 7.1° ± 1.7° varus to 2.3° ± 1.7° valgus at final follow-up. The FTA changed from 3.0° ± 2.0° varus to 7.7° ± 1.3° valgus. Outcome scores improved with clinical and statistical significance postoperatively. Spearman correlations for nonparametric data revealed greater changes in knee alignment were moderately associated with larger improvements in VAS scores (r = 0.50). Furthermore, those who experienced greater changes in alignment showed larger improvements in the KOOS Activity and Quality of Life domains (r = 0.72 and r = 0.51, respectively).

CONCLUSION

On average, patients did not achieve the "ideal correction" of 3° to 6° valgus postoperatively. Nevertheless, statistical and clinical improvements in patient-reported outcome measure scores were consistently reported. This suggests that the "ideal correction" may be more flexible than 3° to 6°.

Good long-term survival and patient-reported outcomes after high tibial osteotomy for medial compartment osteoarthritis

The lateral closing and medial opening wedge high tibial osteotomy can correct a varus malalignment of the knee caused by medial compartment osteoarthritis. These procedures have produced great short-term and mid-term results. As no systematic review has examined their long-term results yet, the goal of this article was to compare the results of all articles about lateral closing and medial opening wedge high tibial osteotomies, published after the year 2000, with a mean follow-up of more than 10 years. A systematic search of the Medline, Web of Science and Cochrane databases resulted in the inclusion of 30 articles. All these studies combined examined the results of 7087 high tibial osteotomies in a total of 6636 patients after a mean follow-up of more than 10 years. Primary outcome measures were the survival rate of the osteotomy, functional scores, patient satisfaction and pain scores. Secondary outcome measures were alignment correction and the identification of factors influencing the survival of the osteotomy. The 5-year, 10-year, 15-year and 20-year survival rates, respectively, ranged from 86 to 100%, 64-97.6%, 44-93.2% and 46-85.1%. The subjective scoring systems showed an improvement postoperatively that was maintained until final follow-up. The anatomical and mechanical tibiofemoral axis were, respectively, corrected to a mean of 7.3°-13.8° of valgus and 0.6°-4° of valgus. The results of the articles evaluating the influence of potential risk factors were contradictory. Despite the low quality of the available evidence, the lateral closing and medial opening wedge high tibial osteotomy seem to remain valid long-term treatment options for patients with painful varus malalignment caused by isolated medial compartment osteoarthritis of the knee. The available results indicate that the need for arthroplasty could be delayed for more than 15 years in the majority of patients. However, higher-quality studies are needed to confirm these findings. As a systematic review is assigned a level of evidence equivalent to the lowest level of evidence used from the analyzed manuscripts, the level of evidence of this systematic review is IV.

A Systematic Review on Selected Complications of Open-Wedge High Tibial Osteotomy from Clinical and Biomechanical Perspectives

BACKGROUND

The wedge opened during high tibial osteotomy defines the alignment correction in different body planes and alters soft tissue insertions. Although multiple complications of the surgery can be correlated to this, there is still a lack of consensus on the occurrence of those complications and their cause. The current study is aimed at clarifying this problem using a combined medical and biomechanical perspective.

METHODS

We conducted a systematic review of the literature on selective complications of the surgery correlated with the angles of the opened wedge. Search topics covered tibial slope alteration, patellar height alteration, medial collateral ligament release, and model-based biomechanical simulations related to surgical planning or complications. Findings. The selection process with the defined inclusion/exclusion criteria led to the collection of qualitative and quantitative data from 38 articles. Medial collateral ligament tightness can be a valid complication of this surgery; however, further information about its preoperative condition seems required for better interpreting the results. The posterior tibial slope significantly increases, and the patellar height (using the Blackburne-Peel ratio) significantly decreases in the majority of the selected studies. Model-based biomechanical studies targeting surgical planning are mostly focused on the lower-limb alignment principles and tibiofemoral contact balancing rather than surgical complications. Interpretation. Increased posterior tibial slope, patellar height decrease, and medial collateral ligament tightness can occur due to alterations in different body planes and in soft tissue insertions after wedge opening. This study clarified that information about preoperative alignment in all body planes and soft-tissue conditions should be considered in order to avoid and anticipate these complications and to improve per surgery wedge adaptation. The findings and perspective of this review can contribute to improving the design of future clinical and biomechanical studies.

No differences in clinical outcomes and cartilage repair between opening wedge and closed wedge high tibial osteotomies at short-term follow-up: A retrospective case series analysis

PURPOSE

The aim of this study was to assess differences in clinical outcomes and postoperative cartilage repair between opening wedge high tibial osteotomy (OWHTO) and closed wedge HTO (CWHTO) for medial osteoarthritis (OA) of the knee.

METHODS

A total of 90 knees of 76 patients who underwent OWHTO (45 knees of 40 patients) and CWHTO (45 knees of 36 patients) was followed-up for 2 years. Cartilage repair at the medial compartment was arthroscopically classified into the following stages: Stage 1 (no reparative change); Stage 2 (partial coverage with white cartilaginous tissue); and Stage 3 (full coverage with white cartilaginous tissue). Clinical outcomes were assessed using Knee Society scores, and radiographic assessment was carried out by anatomical femorotibial angle (aFTA).

RESULTS

Regarding preoperative OA grade, varus alignment, and function score, CWHTO patients showed more advanced OA status than OWHTO patients. Knee scores and function scores were significantly improved after surgery with both HTO procedures (P < 0.05), with no significant difference between the two procedures. Cartilage repair of stage 2 or 3 was found in more than 80% of the subjects in the medial femoral condyle and more than 60% in the medial tibial condyle. However, there were no significant differences between the two HTO procedures. Multivariate logistic regression analysis showed that preoperative International Cartilage Repair Society (ICRS) grade was the only factor affecting cartilage repair.

CONCLUSIONS

CWHTO improved clinical outcomes and cartilage status as much as OWHTO. Although the effects of cartilage repair on clinical outcomes are unknown, HTO is an effective treatment option even for severe medial OA of the knee.

Long-term survival rate of closing wedge high tibial osteotomy with high valgus correction: a 15-year follow-up study

PURPOSE

The influence of closing wedge high tibial osteotomy (CW-HTO) with high valgus correction on its survival is unclear. This study aimed to conduct a 15-year follow-up cohort study to estimate the long-term survival rate of CW-HTO. Factors related to poor outcomes were investigated.

METHODS

A total of 159 knees in 123 patients were followed up, and 120 knees in 96 patients were enrolled for statistical analysis. Femorotibial angles were measured by standing anterior-posterior radiographs of the knee. Clinical objective evaluation was performed by the Japanese orthopaedic association (JOA) score of the knee, and scores lower than 70 points defined the poor result (PR) group. The survival rate of OW-HTO was estimated. Logistic regression analyses were performed to determine the risk factors for PR and conversion to total knee arthroplasty (TKA).

RESULTS

A total of 16 knees in 15 patients (13.3%) underwent TKA 14.0 ± 4.8 (4-20) years after CW-HTO. The 5-year survival rate was 99.2%, 10-year was 96.7%, 15-year was 92.5%, and 86.7% at final follow-up (17.9 years). Based on the JOA score, 44 patients (35.8%) belonged to the PR group, and their risk factors were obesity (p = 0.018), low femorotibial angle (p = 0.019), low JOA score (p = 0.040), low knee extension angle (p = 0.045), and low knee flexion angle (p = 0.046).

CONCLUSIONS

The 15-year survival rate of CW-HTO was 92.5%. While higher scores of objective outcomes were kept over long-term follow-up, the risk factors for a worsening score or TKA conversion were obesity and severity of preoperative knee symptoms.

Focal proximal fibular angle: A potential indicator of the tibial mechanical axis in opening-wedge high tibial osteotomy

BACKGROUND

For opening-wedge high tibial osteotomy, correct alignment is essential for a better prognosis. It is difficult to evaluate the mechanical axis of the lower extremity or tibia using a single fluoroscopic image. This study aimed to discuss the use of focal proximal fibular angle (FPFA), which can be assessed by a single fluoroscopic image, as an intraoperative indicator.

METHODS

Eligible for analyses were 111 consecutively treated patients; for the final analyses 96 patients were included. The preoperative and postoperative medial proximal tibial angle (MPTA) and FPFA were measured. The relationship between these two angles, correction amount, weight-bearing line ratio and patient characteristics were analyzed.

RESULTS

The preoperative FPFA and MPTA were 96.5 ± 3.8° (mean ± standard deviation, SD) and 84.8 ± 3.0°, while the postoperative FPFA and MPTA were 87.6 ± 4.1° and 94.0 ± 3.5°, respectively. The preoperative and postoperative sums of the MPTA and FPFA were constant. The discrepancy was less than 3° in all knees, less than 2° in 92.7% knees and less than 1° in 68.8% knees. It was not correlated with age, sex, weight-bearing line ratio, or correction amount.

CONCLUSION

The study findings confirmed the constancy of the sum of the MPTA and FPFA. The FPFA can be easily evaluated on a single fluoroscopic image of the knee. Use of the FPFA as guidance may simplify the procedure of opening-wedge high tibial osteotomy and approximately predict the tibial mechanical axis.

High Tibial Osteotomy for Varus Deformity of the Knee

High tibial osteotomy is a powerful technique to treat symptomatic varus deformity of the knee and is successful when properly indicated and performed. Indications include varus deformity with medial compartment osteoarthritis, cartilage or meniscus pathology. Several techniques exist to correct symptomatic varus malalignment along with concomitant procedures to restore cartilage or meniscus injuries. Evidence supporting high tibial osteotomy for symptomatic medial compartment pathology exists, which provides a durable solution for joint preservation. This review will discuss the indications, techniques, and outcomes for high tibial osteotomies used in the treatment of symptomatic varus deformity of the knee.

Tibial Slope Can Be Maintained During Medial Opening-Wedge Proximal Tibial Osteotomy With Sagittally Oriented Hinge, Posterior Plate Position, and Knee Hyperextension: A Cadaveric Study

PURPOSE

The purpose of this study is (1) to determine if, when optimizing modern techniques, medial opening-wedge osteotomies can effectively maintain tibial slope and (2) to determine how different magnitude coronal plane corrections affect tibial slope.

METHODS

Proximal tibial osteotomies (PTOs) were performed on 10 fresh-frozen cadaveric knees leaving a consistent lateral hinge, using either a 5-mm or a 10-mm trapezoidal wedged osteotomy plate. Techniques including posterior plate placement; a trapezoidal, sloped plate; and knee hyperextension were used during plate fixation to help close the anterior osteotomy gap. Medial coronal proximal tibia angle and posterior tibial slope were measured preosteotomy, after a 5-mm implant, and after a 10-mm implant using true anteroposterior and lateral fluoroscopic images. Three independent observers performed all radiographic measurements, and intraclass correlation coefficients were calculated.

RESULTS

The 5-mm and 10-mm osteotomy plates increased the coronal medial proximal tibia angle by a mean of 3.4° (range, 3.0°-3.7°) and 7.3° (range, 6.7°-7.7°), respectively. The 5-mm and 10-mm trapezoidal wedged osteotomy plates decreased the posterior tibial slope by a mean of 0.9° (range, 0.5°-1.2°) and 0.3° (range, 0°-0.6°), respectively. Intraobserver reliability was found to be high for both the coronal medial proximal tibia angle (intraclass correlation coefficient [ICC] = 0.897 [0.821-0.946]) and the tibial slope measurements (ICC = 0.761 [0.672-0.826]).

CONCLUSIONS

When optimizing the medial opening-wedge proximal tibial osteotomy, including utilization of a sagittally oriented hinge, placement of a trapezoidal plate posteriorly, and fixation with knee hyperextension, posterior tibial slope can be maintained regardless of the degree of coronal correction.

CLINICAL RELEVANCE

Tibial slope has a significant effect on cruciate ligament stress and a better understanding of coronal plane correction, and its effect on tibial slope is critical when performing proximal tibia osteotomies.

Change in leg length after open-wedge high tibial osteotomy can be predicted from the opening width: A three-dimensional analysis

BACKGROUND

The purpose of this study was to evaluate true change in leg length after open-wedge high tibial osteotomy (OWHTO) using three-dimensional (3D) assessments, examine the factors that influence leg lengthening and verify their validity in clinical practice.

METHODS

Study 1: a retrospective case series simulation study, included 46 patients (55 knees) that underwent knee arthroplasty or HTO. OWHTO was simulated from preoperative computed tomography using 3D preoperative planning software. Uni- and multivariate regression analyses were conducted to identify predictors related to change in leg length. Study 2: a retrospective case series study, included 53 patients (55 knees) that underwent OWHTO in another institution. Change in leg length was measured preoperatively and 1 year postoperatively and was compared with the predicted change in leg length calculated using the formula obtained from Study 1.

RESULTS

Study 1: the true change in leg length significantly increased and showed a strong correlation with the opening width. The change in leg length was predicted using the formula "change in leg length = opening width × 0.75-1.5." Study 2: the predicted change in leg length showed no significant difference from the change in leg length 1 year postoperatively and a strong correlation with the measured change.

CONCLUSIONS

The true change in leg length after OWHTO was predicted using the formula obtained from the 3D model. Predicting the change in leg length preoperatively can be a basis to consider other HTOs.

Good clinical outcomes and return to sports after hybrid closed-wedge high tibial osteotomy

PURPOSE

This study aimed to investigate preoperative sports participation and postoperative clinical outcomes including a return to sports (RTS) after hybrid closed-wedge high tibial osteotomy (CWHTO) for medial compartment osteoarthritis of the knee. Characteristic of Hybrid CWHTO was defined as extra-articular lateral closed and medial open wedge osteotomy.

METHODS

The patients who underwent hybrid CWHTO from January 2016 to December 2018 were retrospectively reviewed and divided them into sports and non-sports groups. The preoperative demographic and radiographic characteristics were compared in both groups. And the clinical outcomes including the Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS), Lysholm score, University of California at Los Angeles (UCLA) activity score, and RTS in the sports group were also investigated. Statistical analysis was performed for comparisons among the preoperative factors between the two groups. Influence of sports impact and bone union of fibular osteotomy was also statistically investigated for RTS.

RESULTS

Of the 161 knees (129 patients; 46 males, 83 females), 20 knees (16 patients; 13 males, 3 females; 12.3%) belonged to sports group. Although there were no significant differences regarding the age and radiographic parameters, there were significant differences in the body mass index and proportion of males between both groups. The JOA, VAS, Lysholm, and UCLA activity scores significantly improved after surgery. RTS was 80% at a mean duration of 7.2 ± 3.1 months. RTS in the high-impact sports group was significantly lower than that in the low-impact sports group (high-impact 60% vs. low-impact 100%, p = 0.043). There was no significant difference in RTS regarding bone union after fibular osteotomy.

CONCLUSION

The clinical outcomes including RTS were satisfactory in patients with hybrid CWHTO.

LEVEL OF EVIDENCE

IV.

Evaluation of the "Minimal Clinically Important Difference" (MCID) of the KOOS, KSS and SF-12 scores after open-wedge high tibial osteotomy

PURPOSE

Defining a Minimal Clinically Important Difference (MCID) value for Patient-Reported Outcome Measures (PROMs) is crucial for determining the effectiveness of a procedure and calculating the sample size for trial planning. The purpose of this study was to determine the MCID of several PROMs (Knee injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS) and the SF-12) in patients who underwent medial opening-wedge High-Tibial Osteotomy (owHTO) with Patient-Specific Cutting Guides (PSCGs), using anchor-based methods.

METHODS

Patients undergoing isolated medial owHTO with PSCGs between January 2013 and January 2017 were enrolled in this single-center, prospective, observational study. Three outcome scores were collected pre-operatively and at the 2 years follow-up evaluation: KOOS, KSS and SF-12. The MCIDs were calculated using anchor-based method: at 2 years postoperatively: "Compared with before surgery, how would you rate operated joint now?" The responses were recorded using a five-point scale. Patients who answered "about the same" or "somewhat worse" were classified into the no change group, while those who answered "somewhat better" were classified into the minimal change group. A receiver operating characteristic (ROC) curve was used to define the cutoff point that best discriminated between the minimal change and no change groups for each PROMs RESULTS: 196 patients were included, 75 (somewhat better) and 24 patients (about the same and somewhat worse) were, respectively, assigned to the "no change" and "minimal change" groups. There was no significant difference between the two groups in terms of baseline characteristics and postoperative complications. At 24 months follow-up all the PROMs (KOOS, KSS and SF-12) were significantly better for the "minimal change" group compared to the "no change" group. MCID was 15.4 for KOOS pain, 15.1 for KOOS symptoms, 17 for KOOS ADL, 11.2 for KOOS sports/recreation, 16.5 for KOOS QQL, 3 for KSS symptoms, 5.6 for KSS activity, 7.2 for SF-12 physical component and 6.3 for PCS mental component.

CONCLUSION

This study determined the MCIDs of common used PROMs in patients undergoing owHTO.

LEVEL OF EVIDENCE

Prospective Cohort Study, Level II.

Differences in patient-reported outcomes between medial opening-wedge high tibial osteotomy and total knee arthroplasty

PURPOSE

To compare patient subjective satisfaction between medial opening-wedge high tibial osteotomy (HTO) and total knee arthroplasty (TKA).

METHODS

This study enrolled 110 knees, including comprising 49 knees in the HTO group, and 61 knees in the TKA group. We assessed the overall satisfaction using a three-point questionnaire. The satisfaction questionnaire included three questions: (1) How satisfied are you with the results of your knee surgery? (2) How satisfied are you with your most recent knee surgery for reducing your pain? and (3) How satisfied are you with your most recent knee surgery for improving your ability to perform functions? Furthermore, we assessed knee pain and function by using the Knee Society Function Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) systems.

RESULTS

Overall, 93.8% of patients from the HTO group and 95.1% from the TKA group indicated subjective satisfaction (very satisfied and satisfied) with their surgeries. For pain relief, the HTO group showed significantly better outcomes for overall satisfaction (p = 0.04 in walking on a flat surface and p = 0.02 in going upstairs or downstairs). For restored function, the HTO group scored significantly better on ascending stairs than the TKA group (p = 0.007). Functional outcomes using the KSS scoring system did not show significant differences between the two groups. The KOOS pain score was significantly higher in the TKA group (89.9 ± 6.4) than in the HTO group (80.3 ± 12.5).

CONCLUSION

HTO and TKA have comparable outcomes with respect to overall patient satisfaction.

LEVEL OF EVIDENCE

Level III, therapeutic case series.