High tibial osteotomy in the ACL-deficient knee with medial compartment osteoarthritis

The application of proximal tibial anterior closing wedge osteotomy in anterior cruciate ligament reconstruction

Introduction

Posterior tibial slope (PTS) plays a vital role in knee stability. PTS of more than 12° may be considered with increased strain on the native anterior cruciate ligament (ACL) fibers. To handle the instability caused by changes in PTS degree, Proximal Tibial Anterior Closing Wedge Osteotomy (PT-ACWO) is adopted by surgeons.

Methods

Between October 2015 and October 2019, our department conducted a retrospective analysis of patients who experienced anterior cruciate ligament reconstruction (ACLR) graft failures, with a particular focus on pathological PTS. The time from initial ACLR to revision ranged from 1 to 10 years, with a mean of 2.5 years. Radiological assessments of PTS were conducted, and outcomes were quantified using the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale. The surgical technique and the use of 3D Patient-Specific Instrumentation (PSI) were outlined. Preoperative imaging included the use of Kirschner wires to establish tibial plateau reference points, and 3D-PSI was employed to guide the location and depth of the tibial osteotomy, which was performed obliquely. In a notable instance, a novel tibial tunnel was mapped out, and ortho-bridge system (OBS) fixation was utilized to ensure adequate space for the new tunnel.

Results

In a cohort of seven patients with a mean follow-up of 28.1 months, a significant reduction in PTS was noted postoperatively (median [interquartile range, IQR], from 15.27° [13.46°, 16.60°] to 6.25° [5.89°, 6.78°]; P = 0.002). IKDC score improved to 85.10 (80.25, 88.10), P < 0.001; the Lysholm score to 88.00 (73.00, 90.50), P < 0.001; and the Tegner score to 8.00 (7.20, 8.05), P = 0.025 at final follow-up. Skin incision healing delays occurred in two instances, yet achieved closure by six weeks. Radiographs at three months demonstrated faster bone healing in oblique osteotomies than transverse ones. Knee joint stability was maintained, with no additional complications or evidence of instability noted. Magnetic resonance imaging (MRI) confirmed graft integrity in all patients, without signs of enlargement or mispositioning at last observation.

Conclusion

An augmented PTS angle exceeding 12 may constitute a potential etiology for the failure of ACLR grafts. In such patients, the implementation of ACLR combined with PT-ACWO could mitigate the risk of surgical failure during initial ACLR or subsequent revision procedures.

Joint line convergence angle is the most associated alignment factor with the severity of medial knee osteoarthritis

Purpose

The purpose of this study was to evaluate the relationship between the joint line convergence angle (JLCA) and the severity of medial knee osteoarthritis (OA). We hypothesise that JLCA is the most associated factor with the severity of medial knee OA.

Methods

This retrospective study included a total of 202 knees that underwent either high tibial osteotomy or medial meniscus repair/partial resection. Kellgren-Lawrence grade and hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA) and JLCA were assessed from preoperative radiographs. Medial meniscus extrusion (MME) was measured using preoperative magnetic resonance imaging. The International Cartilage Research Society (ICRS) grade on the medial femoral condyle and medial tibial plateau were also assessed. The relationships between JLCA and Kellgren-Lawrence grades and MME and ICRS grades were analysed using Spearman's correlation test and regression analysis.

Results

The JLCA was correlated with the Kellgren-Lawrence grade (R = 0.765, p < 0.001), MME (R = 0.638, p < 0.001), ICRS grade on the MFC (R = 0.586, p < 0.001) and the MTP (R = 0.586, p < 0.001). Regression analysis showed that age (p = 0.002) and JLCA (p < 0.001) were associated with Kellgren-Lawrence grade. Furthermore, JLCA was related to ICRS grade on the MFC (p < 0.001) and MTP (p < 0.001).

Conclusion

The JLCA, reflecting radiological severity, meniscus status, and cartilage lesion, was the most associated alignment parameter in the severity of medial knee OA. The JLCA may be beneficial for quantitative assessment of medial knee OA.

Level of Evidence

Level III, retrospective cohort study.

Influence of variable hinge positioning on coronal and sagittal alignment in uniplanar medial open-wedge high tibial osteotomy

Purpose

There is a high risk of increasing the posterior tibial slope (PTS) during medially opening-wedge high tibial osteotomy (mowHTO). Most recently, the idea of intentional simultaneous coronal and sagittal correction, using uniplanar cutting techniques has emerged. This study aims to examine the influences of variable hinge positioning and osteotomy gap height on the sagittal and coronal plane.

Methods

Twenty uniplanar mowHTOs were performed in standardised (left) solid-foam proximal tibia models. In the different models, hinge position was rotated stepwise by 10°, between 90° (cutting straight medial to lateral) and 0° (cutting straight anterior to posterior) (n = 10). Additionally, gap heights of 5 and 10 mm were produced and analysed. Logistic regression analysis was performed to calculate a predictive regression formula for the relation between gap height, hinge rotation and the changes of medial proximal tibia angle (MPTA), medial and lateral PTS.

Results

Between cutting angles of 90 and 20°, the MPTA was mainly influenced by the gap height (0.95° MPTA per 1 mm gap height), but not by the cutting angle. Between 20 and 0°, the MPTA was decreased by 3.6° per 10° of rotation, but not by the gap height. Between cutting angles of 90 and 10°, the PTS was increased linearly by 0.97° per 10° of rotation and by 0.61° per 1 mm gap height.

Conclusion

In mowHTO with lateral hinge positions, the MPTA is mainly influenced by gap height. Changes of PTS can be avoided by a straight lateral hinge position. In posterior hinge locations (0-20°), changes of MPTA are mainly caused by hinge rotation, but not by gap height.

Level of Evidence

Level III, Case-control study.

Mathematical explanations for knee osteotomies: "Dear engineer, how would you explain it in a simple way?"

INTRODUCTION

Knee osteotomies are effective procedures to treat different deformities and to redistribute the load at the joint level, reducing the risk of wear and, consequently, the need for invasive procedures. Particularly, knee osteotomies are effective in treating early arthritis related to knee deformities in young and active patients with high functional demands, with excellent long-term results. Precise mathematical calculations are imperative during the preoperative phase to achieve tailored and accurate corrections for each patient and avoid complications, but sometimes those formulas are challenging to comprehend and apply.

METHODS

Four specific questions regarding controversial topics (planning methods, patellar height, tibial slope, and limb length variation) were formulated. An electronic search was performed on PubMed and Cochrane Library to find articles containing detailed mathematical or trigonometrical explanations. A team of orthopedic surgeons and an engineer summarized the available Literature and mathematical rules, with a final clear mathematical explanation given by the engineer. Wherever the explanation was not available in Literature, it was postulated by the same engineer.

RESULTS

After the exclusion process, five studies were analyzed. For three questions, no studies were found that provided mathematical analyses or explanations. Through independent calculations, it was demonstrated why Dugdale's method underestimates the correction angle compared to Miniaci's method, and it was shown that the variation in patellar height after osteotomy can be predicted using simple formulas. The five included studies examine postoperative variations in limb length and tibial slope, providing formulas applicable in preoperative planning. New formulas were independently computed, using the planned correction angle and preoperatively obtained measurements to predict the studied variations.

CONCLUSIONS

There is a strict connection among surgery, planning, and mathematics formulas in knee osteotomies. The aim of this study was to analyze the current literature and provide mathematical and trigonometric explanations to important controversial topics in knee osteotomies. Simple and easy applicable formulas are provided to enhance the accuracy and outcomes of this surgical procedure.

Excellent short-term results of dome-shaped high tibial osteotomy combined with all-inside anterior cruciate ligament reconstruction

PURPOSE

This study aimed to evaluate short-term outcomes at least 2 years after dome-shaped high tibial osteotomy (HTO) combined with all-inside anterior cruciate ligament reconstruction (ACL) in patients with persistent ACL insufficiency accompanied by pain due to varus deformity.

METHODS

The study enrolled 19 knees of 18 patients. The mean age was 58.4 ± 13.4 years and the mean postoperative follow-up period was 31.4 ± 6.6 months (24-49 months). JOA(Japanese Orthopaedic Association)-OA(osteoarthritis) score, Lysholm score, radiographic outcomes such as femoro-tibia angle (FTA) in a standing position, side-to-side difference in KT-1000 measurements were evaluated at pre op. and post operative final follow up. And arthroscopic evaluation was evaluated at the time of the HTO plate-removal procedure.

RESULTS

Before surgery, the mean JOA-OA score was 65.0 ± 13.5, the mean Lysholm score was 47.2 ± 16.2, the mean femoro-tibia angle (FTA) in a standing position was 183.8 ± 3.4° (range;180-190°), and the mean side-to-side difference in KT-1000 measurements was 4.1 ± 1.3 mm. After surgery, the mean JOA-OA score, Lysholm score, and side-to-side difference in KT-1000 measurements improved to 93.1 ± 6.0 (P < 0.00001), 94.2 ± 5.9 (P < 0.00001), and -0.2 ± 0.8 mm (P < 0.00001), respectively. The mean FTA decreased to 168.0 ± 3.3 (P < 0.00001), and the mean posterior tibial slope angle decreased to 5.0 ± 3.6° from 6.9 ± 2.6° preoperatively (P = 0.024). Arthroscopic evaluation during the HTO plate-removal procedure of 17 knees were performed at a mean of 16 months after the surgery. The reconstructed ACL graft in 13 knees were successful, a cyclops lesion in one knee, and looseness of the graft in three knees.

CONCLUSIONS

Dome-shaped HTO allows for a relatively high degree of varus correction and decreases the steep posterior tibial slope that causes excessive load on the ACL. Therefore, its use in combination with ACL reconstruction seems to be effective.

Effect of Surgical Design Variations on the Knee Contact Behavior during Anterior Cruciate Ligament Reconstruction

In this study, we aimed to develop an in-silico synthesis of the effect of critical surgical design parameters on articular contact behavior for a bone-patellar-tendon-bone anterior cruciate ligament reconstruction (ACL-R) surgery. A previously developed finite element model of the knee joint consisting of all relevant soft tissues was employed. The knee model was further updated with additional features to develop the parametric FE model of the biomechanical experiments that depicted the ACL-R surgery. The parametricity was created involving femoral tunnel architecture (orientations and locations) and graft fixation characteristics (pretension and angle of fixation). A global sensitivity analysis based on variance decomposition was used to investigate the contribution of the surgical parameters to the uncertainty in response to the ACL-R joint. Our examinations indicated that the total contact force was primarily influenced by either combined or individual action of the graft pretension and fixation angle, with a modest contribution of the graft insertion sites. The joint contact center and area were affected mainly by the angle of fixation and the tunnel placements. Graft pretension played the dominant role in the maximum contact pressure variability, an observation that has been well-documented in the literature. Interestingly, the joint contact behavior was almost insensitive to the tunnel's coronal and sagittal orientations. Our data provide an evaluation of how the surgical parameters affect the knee joint's contact behavior after ACL-R and may provide additional information to better explain the occurrence of osteoarthritis as an aftermath of such surgery.

Application of SolidWorks software in preoperative planning of high tibial osteotomy

Purpose

Open-wedge high tibial osteotomy (HTO) is a common surgical treatment for medial osteoarthritis in young and active patients. The accuracy of osteotomy is closely associated with postoperative efficacy. The accuracy of digital preoperative planning is higher than that of the preoperative manual measurement and several computer software with varying accuracy and convenience are used for digital preoperative planning. This study aimed to use the SolidWorks software for HTO preoperative planning and to determine its accuracy and reliability in HTO preoperative planning.

Methods

We reviewed the data of 28 patients with 54 with medial compartment knee arthritis who underwent open-wedge HTO preoperative planning using SolidWorks between June 2019 and March 2021. The standard anteroposterior standing whole-leg radiographs were assessed before and 6 weeks after the surgery. The correction angle, weight-bearing line (WBL) ratio, mechanical femorotibial angle (mFTA), and medial proximal tibial angle (MPTA) before and after the surgery were compared. The clinical results were evaluated using the Knee Society score.

Results

At 6 weeks after the surgery, the WBL ratio was corrected from 16.8% to 50.5%, mFTA was corrected from 6.4° varus to 1.2° valgus, and MPTA was corrected from 83.4° to 89.3°. No significant difference was observed between the predicted correction angle before the surgery and the correction angle measured 6 weeks after the surgery (t = -1.745, p = 0.087). The knee score and function score of Knee Society increased from 76.4 and 80.7 before surgery to 95.0 and 95.7, respectively.

Conclusions

The SolidWorks software showed high accuracy and reliability in preoperative planning of open-wedge HTO in patients with medial compartment knee arthritis.

Unicompartmental knee arthroplasty versus high tibial osteotomy for medial knee osteoarthritis: A systematic review and meta-analysis

We aimed to systematically compare the clinical and functional outcomes between unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) for the treatment of medial knee osteoarthritis (KOA). Literatures were searched from PubMed, EMBASE, the Cochrane library, Wanfang DATA, China National Knowledge Infrastructure (CNKI) and SinoMed database until December 2020. Studies comparing postoperative clinical and functional outcomes of UKA versus HTO were included. Totally, 38 studies were included, including 2368 patients with 2393 knees in HTO group and 6536 patients with 6571 knees in UKA group. There was significant difference in postoperative pain, revision rate, complications, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between HTO and UKA groups (p < 0.05). No significant difference was found in excellent/good surgical results, Lysholm, Hospital for Special Surgery (HSS) score, Knee Society Knee (KSS) score, knee and function score of Knee Society (KSFS) score and Tegner score between these two groups (p > 0.05). UKA produced less postoperative pain, less complications and superior WOMAC score, whereas HTO offered extended range of motion (ROM) and less revision rate.

Effect of the sagittal osteotomy inclination angle on the posterior tibial slope change in high tibial osteotomy: three-dimensional simulation study

In performing medial open-wedge high tibial osteotomy, it is recommended not to alter the posterior tibial slope. However, it remains unclear whether the osteotomy inclination angle affects the posterior tibial slope in the sagittal plane. This study aimed to verify how anterior or posterior osteotomy inclination angle affects the tendency of change in the posterior tibial slope and to conduct quantitative analysis of the extent to which the posterior tibial slope changes according to the degree of the osteotomy inclination angle change in MOWHTO. Computed tomography images of 30 patients who underwent MOWHTO were collected. Three-dimensional models of preoperative original tibia were reconstructed, and virtual osteotomies were performed. The sagittal osteotomy inclination angles formed by the osteotomy line and the medial tibial plateau line were classified as positive in case of anteriorly inclined osteotomy and negative in case of posteriorly inclined osteotomy. Thirteen osteotomies were performed for each tibial model at intervals of 5° from - 30° to 30°. The posterior tibial slope was assessed, and the proportional relationship between the sagittal osteotomy inclination angle and the posterior tibial slope change was analyzed. The posterior tibial slope changed significantly after osteotomy (p < 0.001), except for the cases where the sagittal osteotomy inclination angles were 5°, 0°, and - 5°. Anteriorly and posteriorly inclined osteotomy caused increase and decrease in the posterior tibial slope, respectively. As the inclination angle increased by 1°, the posterior tibial slope increased by 0.079° in anterior inclination osteotomy, while in posterior inclination osteotomy, as the inclination angle decreased by 1°, the posterior tibial slope decreased by 0.067°. The osteotomy inclination angle in the sagittal plane significantly affected the posterior tibial slope. When there was an inclination angle occurred between the osteotomy line and the medial tibial plateau line in the sagittal plane, the posterior tibial slope changed after MOWHTO. The posterior tibial slope tended to increase in anteriorly inclined osteotomy and decrease in posteriorly inclined osteotomy. The change in the posterior tibial slope was proportionally related to the absolute value of the osteotomy inclination angle.

Is there any benefit in the combined ligament reconstruction with osteotomy compared to ligament reconstruction or osteotomy alone?: Comparative outcome analysis according to the degree of medial compartment osteoarthritis with anterior or posterior cruciate ligament insufficiency

INTRODUCTION

The purpose of this study was to compare the outcomes of middle-aged patients with anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) insufficiency by assessing different groups: high tibial osteotomy (HTO), HTO with combined ligament reconstruction, and isolated ligament reconstruction according to the alignment change and medial compartment osteoarthritis (OA).

MATERIALS AND METHODS

From 2014 to 2019, middle-aged (40-65 years) patients with knee instability were enrolled in this retrospective study. They were categorized into three groups: group I, HTO; group II, HTO with combined ACL or PCL reconstruction; and group III, isolated ligament reconstruction. Radiological outcomes, including Kellgren-Lawrence grade, mechanical femorotibial angle (mFTA), weight-bearing line (WBL) ratio, and posterior tibial slope were compared. Knee stability and clinical outcomes were also compared.

RESULTS

Seventy-nine patients completed the final assessment. Group I was older than other two groups (p = 0.006). Groups I and II had a higher body mass index (p = 0.043) and more preoperative varus alignment than group III (p < 0.001). OA severity was ranked in the order of group I, II, and III (p < 0.001). Group I showed more valgus alignment than group II after HTO (p = 0.024 for mFTA and 0.044 for WBL ratio, respectively). Compared to their preoperative status, all three groups showed significant improvement in knee stability (p < 0.001); however, group I showed inferior knee stability regardless of ACL or PCL reconstruction (p < 0.001 and 0.043, respectively). All clinical scores significantly improved in the three groups (p < 0.001), and they showed comparable clinical outcomes in the final assessment.

CONCLUSIONS

Our strategy in managing middle-aged patients with knee instability according to the varus alignment and medial degeneration showed favorable stability and clinical outcomes. Middle-aged patients with knee instability should be managed with different strategies depending on their status.

LEVEL OF EVIDENCE

Case-control study; Level-III.

Effect of anterior tibial bowing on measurement of posterior tibial slope on conventional X-rays

PURPOSE

The posterior tibial slope (PTS) has different biomechanical effects on the knee. Especially in revision ACL reconstruction, a precise analysis is essential. Therefore, we investigate the influence of the anterior tibial bowing angle on the posterior slope measurement. Our hypothesis of the present study is that the short tibial X-rays underestimate the PTS in cases with increased anterior bowing of the tibia.

METHODS

The PTS was measured on 162 true longitudinal radiographs of the complete tibia (lateral mechanic axis). The average age of the patients was 35.7 years (range 19-59 years) and the most common diagnosis was failed anterior cruciate ligament reconstruction. Using this X-ray, the slope on the short axis and the slope on the entire axis were measured. In addition, the angle of the anterior bowing was determined.

RESULTS

The mean PTS for the lateral mechanic axis of the tibia was 10.6° (± 3.5) in contrast to 11.6° (± 3.5) for the short tibial axis. These two measurements differ significantly. (p  < 0.001). The mean anterior tibial bowing angle on the lateral X-rays of the whole tibia was 2.3° (± 2.0). There is a significant positive, relationship between tibial bowing angle and PTS as referenced by the lateral mechanic axis (Spearman's correlation, r = 0.273 and p < 0.001).

CONCLUSION

With increasing anterior tibial bowing, the posterior tibial slope on the short knee radiograph is underestimated compared to the slope measurement on the lateral mechanic axis.

Excellent outcomes with combined single stage Physica ZUK medial unicompartment knee replacement and anterior cruciate ligament reconstruction results in young, active patients with instability and osteoarthritis with a mean follow up of 5 years

BACKGROUND (INCLUDING THE AIM OF THE STUDY)

Young and more active patients with medial compartment osteoarthritis (OA) in conjunction with anterior cruciate ligament (ACL) deficiency are difficult to treat. The aim of this study was to explore the outcomes of combined fixed bearing Physica ZUK medial unicompartmental knee replacement (UKR) (Lima Corporate, Udine Italy) with ACL reconstruction for patients presenting with isolated medial compartment OA and symptomatic ACL deficiency.

METHODS

Patients who underwent simultaneous single stage ACL reconstruction and medial UKR between 2012 and 2020 by a single surgeon (GG) were included. Preoperative outcome measures including Lysholm, Tegner, Oxford Knee Score and VAS pain score were evaluated and were repeated postoperatively at the most recent follow up appointment.

RESULTS

Twenty four patients underwent simultaneous combined ACL and ZUK Medial UKR with a mean follow up of 5.1 years. Significant improvements in Lysholm (p < 0.001), Tegner (p < 0.001), Oxford Knee Score (p < 0.001) and VAS pain scores (p < 0.001) were seen with this combined approach with all patients returning to sport. Two patients had a minor peri-operative complication, which was treated conservatively. There were no revision procedures, and no evidence of implant loosening, however one patient had deceased due to an unrelated illness.

CONCLUSION

UKR combined with ACL reconstruction can be an effective treatment option for selected patients suffering from medial unicompartmental knee osteoarthritis and symptomatic ACL deficiency. This allowed active patients to return to sports, addressing both instability and OA pain in a specific patient population.

Biplanar high tibial osteotomy for the combined correction of varus and posterior tibial slope malalignment

Varus malalignment combined with an increased posterior tibial slope (PTS) in the ACL deficient knee is a frequent pathology; yet, treatment for this condition remains challenging. The presented biplanar osteotomy technique allows to simultaneously address both components of malalignment in a single step. A detailed preoperative planning is best achieved by means of a digital planning software and constant intraoperative imaging is performed to verify the correction angle. A bony wedge is resected along with the extension osteotomy according to the preoperative planning and the medial-opening tibial osteotomy site is filled with bone allograft. Two bicortical lag screws are placed in anterior-posterior direction to secure the extension osteotomy, whereas a plate fixation is used for the medial-open osteotomy.

A novel biplanar medial opening-wedge high tibial osteotomy: the Z-shaped technique. A case series at 7.2 years follow-up

Background

High tibial osteotomy (HTO) provides reliable and good long-term results, if performed with correct indications, but different techniques and types of fixation have been described. The purpose of this study is to present a novel modified biplanar medial opening-wedge (MOW) HTO technique where the osteotomies are performed in a Z-shaped fashion, and to present the medium-term clinical and radiographic results.

Materials and methods

We present a case series of 75 patients (80 knees) with mean age of 45.8 years, affected by isolated medial knee osteoarthritis and symptomatic varus knee malalignment, who underwent novel biplanar Z-shaped MOWHTO. Clinical and radiological outcomes were collected, retrospectively before surgery and at median follow-up of 7.2 years (95% CI 5.6–9.2 months) after surgery. Clinical results and satisfaction were assessed by visual analog scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Likert scale. Radiological assessment involved the evaluation of the medial proximal tibial angle (MPTA), tibial slope (TS), Caton–Deschamps index, and knee osteoarthritis grade according to Ahlbäck classification. Pre- and postoperative results were compared using the two-tailed t-test or Wilcoxon’s test of independent samples for paired data or nonparametric analog. P < 0.05 was considered significant.

Results

At medium-term follow-up, Z-shaped MOWHTO showed a survival rate of 95 ± 1.7% with failure occurring in four knees due to symptom recurrence and osteoarthritis progression. No perioperative complications were observed (intraarticular fracture, delayed union or nonunion, and neurological injury). Mean bone healing time was 12 weeks. Clinical scores showed significant improvement at last follow-up and a good grade of satisfaction. MPTA increased significantly, while Caton–Deschamps index decreased significantly. No significant TS increase was found.

Conclusions

Modified biplanar Z-shaped MOWHTO is a safe and reliable technique that offers satisfactory clinical and radiological medium-term outcomes with low knee arthroplasty conversion rate. The unique three-dimensional geometrical conformation potentially provides a favorable environment for bone healing, increased anteroposterior and rotational stability, and safer opening-wedge loading force application with low lateral hinge fracture risk.

Level of evidence

Level IV, retrospective observational case series study.

Trial registration The study protocol was approved by the Internal Review Board of our Institution (authorization number 54/2019, 20 November 2019).

Graft Survivorship After Anterior Cruciate Ligament Reconstruction Based on Tibial Slope

BACKGROUND

Increased tibial slope (TS) is believed to be a risk factor for anterior cruciate ligament (ACL) tears. Increased TS may also promote graft insufficiency after ACL reconstruction.

PURPOSE

To delineate the relationship between TS and single as well as multiple graft insufficiencies after ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence 3.

METHODS

We retrospectively identified 519 patients who had sustained ACL graft insufficiency after primary or revision ACL reconstruction (1 graft insufficiency, group A; 2 graft insufficiencies, group B; and ≥3 graft insufficiencies, group C). In addition, a subgroup analysis was conducted in 63 patients who received all surgical interventions by 2 specialized high-volume, single-center ACL surgeons. TS was measured by an observer with >10 years of training using lateral knee radiographs, and intrarater reliability was performed. Multiple logistic and univariate Cox regression was used to assess the contribution of covariates (TS, age, sex, and bilateral ACL injury) on repeated graft insufficiency and graft survival.

RESULTS

The study included 347 patients, 119 female and 228 male, who were 24 ± 9 years of age at their first surgery (group A, n = 260; group B, n = 62; group C, n = 25). Mean TS was 9.8°± 2.7° (range, 3°-18°). TS produced the highest adjusted odds ratio (1.73) of all covariates for repeated graft insufficiency. A significant correlation was found between TS and the number of graft insufficiencies (r = 0.48; P < .0001). TS was significantly lower in group A (9.0°± 2.3°) compared with group B (12.1°± 2.5°; P < .0001) and group C (12.0°± 2.6°; P < .0001). A significant correlation was seen between the TS and age at index ACL tear (r = -0.12; P = .02) as well as time to graft insufficiency (r = -0.12; P = .02). A TS ≥12° had an odds ratio of 11.6 for repeated ACL graft insufficiency.

CONCLUSION

The current results indicate that patients with a markedly increased TS were at risk of early and repeated graft insufficiency after ACL reconstruction. Because the TS is rarely accounted for in primary and revision ACLR, isolated soft tissue procedures only incompletely address recurrent graft insufficiency in this subset of patients.

A 2021 consensus statement on osteotomies around the knee by the UK Knee Osteotomy consensus Group (KOG)

BACKGROUND

There are significant deficiencies in the evidence base of modern-day osteotomy which result in significant variation in practice between surgeons. The purpose of this statement was to develop a consensus statement on the practice of osteotomy so that a more standardized approach to the indications, surgical technique, and postoperative care could be outlined. The article is also intended to educate and inform the practice of individuals who are early in their experience and/or clinical practice.

METHOD

A group of 29 specialist knee surgeons who regularly perform osteotomy was convened to form the Knee Osteotomy consensus Group (KOG). Consensus was determined utilizing the consensus group technique described by List. A total of 37 questions were asked covering all aspects of clinical practice.

RESULTS

20 statements were generated and debated until a criterion level of 70% was met.

CONCLUSIONS

Consensus was achieved regarding 20 statements concerning Indications for surgery, decision making, surgical planning, technique, post-operative assessment and recovery.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Biomechanical Changes in Gait Patterns of Patients with Grade II Medial Gonarthritis

Deforming osteoarthritis (OA) of the knee is a progressive disease associated with pain and compromised function of the joint. Typical biomechanical modifications in the gait of subjects with medial knee OA are characterized by decreased gait speed and overload on the affected limb. The borderline stage for conservative versus surgical management is Grade II OA. The aim of this research was to study preoperatively the specific features of gait, knee, and hip function in patients with Grade II medial OA. We examined 26 patients with Grade II unilateral gonarthritis with varus deformity and 20 healthy adults. Biomechanical parameters of gait were recorded using an inertial sensor system. The gait cycle (GC) slightly increased both for the affected and for the intact limb. The hip joint movements showed significant symmetrical reduction in the first flexion amplitude, as well as a symmetrical delay in full hip extension at the end of the stance phase. In the knee, the first flexion amplitude was significantly reduced on the affected side compared to healthy control. The extension amplitude in the single support phase was significantly increased in both the affected and the intact lower limbs. The swing amplitude was significantly reduced on the affected side. On the affected side, the changes were more pronounced, both in incidence and in severity. The affected knee showed a syndrome of three reduced amplitudes. In patients, walking is characterized by several groups of symptoms: those of unloading of the affected limb, those of limiting the load on the affected joint and the musculoskeletal system as a whole, and those of gait harmonization. The symptoms of unloading the affected side and those of harmonization are the common symptoms of adaptation, typical for several pathological conditions with a relatively preserved function. The intensity of the observed symptoms can help assess changes in the subject’s functional condition over time and during the treatment.

Medial Osteoarthritis in an ACL-Deficient Knee: A Critical Analysis Review

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In anterior cruciate ligament (ACL)-deficient knees, treatment of medial compartment osteoarthritis (OA) that is refractory to nonoperative modalities is a controversial subject.

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Currently available treatment options include unicompartmental knee arthroplasty (UKA) with or without ACL reconstruction (ACLR), high tibial osteotomy (HTO) with or without ACLR, and total knee arthroplasty (TKA).

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Each treatment option has its own risks and benefits, and the evidence that is reviewed in this article suggests that patient characteristics guide treatment selection.

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Future high-quality prospective studies that directly compare all 3 of the modalities are necessary to determine the best treatment option for different patient populations.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preoperative planning by osteotomy master software helps to improve the accuracy of target limb alignment in high tibial osteotomy

Background

The accuracy of targeted lower limb alignment correction following HTO is closely related to patients’ pain relief and knee joint survival time. How to accurately perform osteotomy and how to obtain the ideal target limb alignment to maximize the curative effect are the difficulty in HTO practice. The purpose of this study is to evaluate the predictive and application value of osteotomy master software (OsteoMaster) in coronal plane preoperative planning of high tibial osteotomy.

Method

Sixty-seven patients with medial compartment osteoarthritis and varus deformity treated by medial open-weight high tibial osteotomy were enrolled and divided into observation group (31 cases) and control group (36 cases). The observation group was planned by OsteoMaster, while the control group was planned by Miniaci. The preoperative predicted values of osteotomy depth, open height, correction angle, WBL ratio, and FTA of the observation group were compared with the actual intraoperative values to study their accuracy. The operative time, blood loss, number of fluoroscopy, and WBL ratio were compared between the observation group and the control group to study its application value.

Result

There was no significant difference between two groups in preoperative prediction and intraoperative reality of osteotomy depth, open height, correction angle, FTA, and WBL ratio (P > 0.05). The operation time and number of fluoroscopy in the observation group were significantly less than those in the control group (P < 0.05), while the difference in blood loss was not statistically significant (P > 0.05). The good rate of WBL ratio was 87.1% in the observation group and 75% in the control group.

Conclusion

OsteoMaster has predictive value in osteotomy depth, open height, correction angle, FTA, and WBL ratio of HTO, which is also helpful to reduce the number of fluoroscopy, shorten the operation time, and improve the accuracy of target limb alignment. The drawback of this approach is 2-dimensional approach in contrast to 3-dimensional preoperative planning that is including the more real study.

Anterior cruciate ligament reconstruction with anterior closing wedge osteotomy for failed high tibial osteotomy-A case report

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High posterior tibial slope is a risk factor for anterior cruciate ligament deficiency.

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Knee instability from increased posterior tibial slope is not a reported complication after open wedge high tibial osteotomy.

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Anterior cruciate ligament reconstruction using the quadriceps tendon and tibial anterior closing wedge osteotomy is a good treatment option.

Background

Increased posterior tibial slope (PTS) is considered a risk factor for anterior cruciate ligament (ACL) injury. Previous studies revealed that medial opening wedge high tibial osteotomy (OWHTO) tends to increase PTS. However, knee instability from increased PTS is not a reported complication after OWHTO, and the treatment strategy is unclear.

Methods

A 55-year-old woman who complained of left knee pain underwent OWHTO for early-stage medial compartment osteoarthritis by another doctor. After the first surgery, her left knee pain decreased; however, 1 year after OWHTO, she began to feel left knee instability, and the primary doctor consulted our clinic. Physical examination revealed a positive Lachman's test, and radiographs showed that PTS had increased from 8 degrees to 15 degrees. According to these findings, we diagnosed an aggravated symptomatic knee instability secondary to increased PTS after OWHTO. We then performed ACL reconstruction using the quadriceps tendon and tibial anterior closing wedge osteotomy (ACWO), which is a newly-developed technique to correct PTS for revision ACL reconstruction.

Results

Postoperatively, PTS was corrected from 15 degrees to 7 degrees, and the patient's Lysholm score improved from 39 to 95, 1 year postoperatively.

Conclusions

ACL reconstruction with ACWO is a possible treatment option for the PTS-increased knee after OWHTO.

Posterior tibial slope modification in osteoarthritis knees with different ACL conditions: Cadaveric study of fixed-bearing UKA

Unicompartmental knee arthroplasty (UKA) in anterior cruciate ligament deficiency (ACLD) has been debated for decades after the development of highly cross-linked polyethylene. This study aims to evaluate the effect of posterior tibial slope on restoring adequate knee stability and flexion after UKA in patients with ACLD. A total of 15 fresh cadaveric knees were divided into three groups: intact ACL, partial ACLD, and complete ACLD. Fixed-bearing UKAs including 3-D-printed tibial inserts with the slopes ranging from 3° to 12° were performed using computer-assisted navigation. Blinded evaluation of knee motion and anterior knee translation with knees flexed 20° and 90° was conducted using KT-arthrometry and stress radiography. A 1° slope increase translated the knees anteriorly by 0.85 mm and 0.76 mm in 20° and 90° of knee flexion for a complete ACLD ( R = 0.7 and 0.8, respectively, p < 0.001) compared to 0.5-0.6 mm for the normal and partial ACLD groups, respectively. Setting a slope of 5-8° of UKA for an intact ACL maintained both the stability and the motion of native knees. No significant changes of knee translation and flexion ability were observed after leveling the slopes at 5-7° and 5-6° for partial and complete ACLD, respectively ( p > 0.05 for all comparisons). In conclusion, UKA in complete ACLD knees is challenging since 1° of slope change nearly doubles the degree of knee translation compared to ACL-intact knees. The optimum posterior tibial slopes for fixed-bearing UKA patients with partial and complete ACLD are 5-7° and 5-6°, respectively.

Ankle joint pressure change in varus malalignment of the tibia

BACKGROUND

Varus malalignment of the tibia could alter ankle biomechanics, and might lead to degenerative changes of the ankle joint. However, previous studies failed to report the detailed changes of ankle biomechanics in varus malalignment of the tibia. The aim of this biomechanical study was to evaluate how the ankle joint pressure would change in response to the incremental increases in varus malalignment of the tibia.

METHODS

Eight fresh-frozen human cadaver legs were tested in this study. Varus malalignment of the tibia and a total of 600 N compressive force was simulated using a custom made fixture. Intra-articular sensors (TeckScan) were inserted in the ankle joint to collect the ankle joint pressure data. The testing sequence was 0°, 2°,4°,6°,8°,10°,12°,14°,16°,18°,20° of tibial varus.

RESULTS

As the tibial varus progressed, the center of force (COF) shifted laterally both for the medial and lateral aspect of the ankle joint. For the medial aspect of the ankle joint, the lateral shift reached its maximum at 8° [2.76 (1.62) mm, p = 0.002] of tibial varus, while for the lateral aspect of the ankle joint, the lateral shift reached its maximum at 12° [2.11 (1.19) mm, p = 0.002] of tibial varus. Thereafter, the COF shifted medially as the tibial varus progressed. For the lateral aspect of the ankle joint, The P_mean increased from 2103.8 (625.1) kPa at 0° to 2295.3 (589.7) kPa at 8° of tibial varus (p = 0.047), significant difference was found between the P_mean at 0° and 8° (p = 0.047) of tibial varus. Then as the tibial varus progressed, the P_mean decreased to 1748.9 (467.2) kPa at 20° of tibial varus (p = 0.002). The lateral joint pressure ratio also increased from 0.481 (0.125) at 0° to 0.548 (0.108) at 10° of tibial varus (p = 0.002), then decreased to 0.517 (0.101) at 20° of tibial varus (p = 0.002) .

CONCLUSIONS

For mild tibial varus deformities, there was a lateral shift of COF and lateral stress concentration within the ankle joint. However, as the tibial varus progressed, the COF shifted medially and the lateral stress concentration decreased.

Superficial Medial Collateral Ligament Reattachment During High Tibial Osteotomy: Regulate Tension, Preserve Stability!

High tibial osteotomy (HTO) is a commonly performed surgical procedure. Although it is well-known that the superficial medial collateral ligament (sMCL) should be released during HTO, there is still no agreement on performing its reattachment. Considering the function of the sMCL, after its release during HTO, increased medial joint instability may be expected. We present a technique for sMCL reattachment that prevents medial gapping development and maintains nearly native pressure on the medial compartment of the knee joint by matching the tension on the sMCL to the size of the osteotomy gap. This technique is suitable for any correction angle.

Does the pre-operative status of the anterior cruciate ligament affect the outcomes following medial open-wedge high tibial osteotomy?

BACKGROUND

This study aimed to assess the morphological degeneration of the anterior cruciate ligament (ACL) through magnetic resonance imaging (MRI) and arthroscopy. It analyzed whether the pre-operative ACL status would affect the radiologic and clinical outcomes following medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

A total of 150 knees were enrolled that underwent MOWHTO concomitant arthroscopic debridement for the treatment of varus osteoarthritis. Mean age was 56.1 ± 5.0 years and mean follow-up was 61.2 ± 21.4 months. The ACLs were staged based on MRI and arthroscopy. To exclude the influence of demographic factors on outcomes, the between-group differences were assessed. Radiologic evaluation included hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, posterior tibial slope angle, and Kellgren-Lawrence grade. Clinical evaluation included American Knee Society Score (AKSS) and knee joint range of motion (ROM).

RESULTS

The ACLs were classified into intact (75 knees, 50.0%), mucoid degeneration (59, 39.3%), chronic partial tear (10, 6.7%), and complete tear (six, 4.0%) according to MRI. They were also classified into four stages: normal (95 knees, 63.3%), abnormal (36, 24.0%), partial tear (13, 8.7%), and complete tear (six, 4.0%) according to arthroscopic appearance. There were no significant between-group differences in each variable. Changes in Kellgren-Lawrence grade did not show significant between-group differences. No significant between-group differences were observed in AKSS and ROM.

CONCLUSIONS

The pre-operative status of ACL did not influence the outcomes following MOWHTO at midterm follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

The influence of tibial slope on the graft in combined high tibial osteotomy and anterior cruciate ligament reconstruction

BACKGROUND

Young patients with severe medial osteoarthritis, varus malalignment and insufficiency of the anterior cruciate ligament (ACL) are difficult to treat. The tibial slope has gained attention with regard to osteotomies and ligamentous instability. The purpose was to evaluate the outcome of combined high tibial osteotomy (HTO), ACL reconstruction and chondral resurfacing (CR, abrasion plus microfracture), and to analyse graft failure rates with regard to the tibial slope.

METHODS

Fifty cases (48.9 ± 5.4 years) of combined HTO, ACLR and CR were retrospectively analysed with regard to survival, functional outcome (subjective International Knee Documentation Committee (IKDC) examination form) and subjective satisfaction. The tibial slope was determined on lateral radiographs and analysed with regard to its influence on graft functionality at the time of hardware removal.

RESULTS

Follow-up rate was 100% after 5.6 ± 1.6 years. No arthroplasties were performed. Subjective IKDC score was 70 ± 18, and 94% were satisfied with the result. The graft was intact in 39 cases (78%), and non-functional in 11 cases (22%). No significant changes were present in pre- and postoperative tibial slope (P = 0.811). Graft insufficiency was strongly dependent on tibial slope, with a failure rate of seven percent in cases of postoperative tibial slope <7.5°, 24% in cases of 7.5-12.5°, and 36% in cases of >12.5°.

CONCLUSION

Combined HTO, ACLR and CR is an effective treatment in these cases. The graft failure rate increases with an increase in tibial slope, in particular when exceeding 12.5°.

LEVEL OF EVIDENCE

Case series, Level 4.

The clinical Outcome of One-stage High Tibial Osteotomy and Anterior Cruciate Ligament Reconstruction. A Current Concept Systematic and Comprehensive Review

BACKGROUND

Patients with an anterior cruciate ligament-deficient varus-angulated knee may need not only an isolated high tibial osteotomy (HTO), but also an additional anterior cruciate ligament reconstruction (ACLR). A number of prospective clinical trials have been published considering the combination of HTO and ACL reconstruction. Our aim was to investigate whether one-stage combined HTO and ACL reconstruction is an effective, well-established technique with long-term results in the treatment of varus-angulated knees with ACL deficiency.

METHODS

A systematic review was conducted by two independent reviewers by searching the MEDLINE/PubMed and the Cochrane Database of Systematic Reviews. These databases were queried with the term 'combined high tibial osteotomy anterior cruciate ligament reconstruction' and 'simultaneous high tibial osteotomy anterior cruciate ligament reconstruction'.

RESULTS

From the initial 41 studies we finally chose and assessed 6 studies were eligible according to our inclusion-exclusion criteria. The vast majority of the patients were treated with hamstrings autograft (85.6% of the patients), whereas a small minority had a patellar Bone-to-Bone autograft (12.8% of the patients) and 3 patients received a patellar allograft. High tibial open wedge osteotomy was performed in 116 patients (57.4%) and closed wedge in 86 patients (42.6%). The mean pre-operative angle of the patients included in our review was 6.6º varus, while the mean final post-operative angle was found to be 1.3º valgus. All 6 studies illustrated improved post-operative IKDC with the use of one-stage HTO and ACLR, whereas the reoperation rate was very low.

CONCLUSION

Despite the lack of high quality studies, it seems that one-stage HTO and ACLR is a safe and effective procedure for treatment of patients suffering from symptomatic varus osteoarthritis in combination with anterior knee instability.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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