Influence of leg axis alignment on MRI T2* mapping of the knee in young professional soccer players

BACKGROUND

Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk.

METHODS

Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest. Subgroup analysis was performed in players with severe varus alignment (> 6°).

RESULTS

Analysis of the leg axis geometry revealed a mean static alignment of 6.6° ± 2.5 varus and a mean dynamic alignment of 5.1° ± 2.6 varus. Quantitative T2* mapping showed significantly increased T2* values in the superficial cartilage layer compared to the deeper region (p < 0.001) as well as a significant increase in relaxation times in the femoral cartilage from anterior to intermediate to posterior (p < 0.001). Combination of both methods revealed a significant correlation for the degree of varus alignment and the femoral, posterior, deep region of the medial knee compartment (r = 0.4; p = 0.03). If severe varus alignment was present this region showed a significant increase in relaxation time compared to players with a less pronounced leg axis deviation (p = 0.003).

CONCLUSION

This study demonstrates that varus alignment in young soccer players is associated with elevated T2* relaxation times in the deep cartilage layer of the medial, posterior, femoral compartment and might therefore be a contributing factor in the early pathogenesis of manifest cartilage lesions. Therefore, these findings should be considered in the development of preventive training programs.

Varus mal-alignment and residual displacement are associated with delayed union in subtrochanteric femur fracture- A retrospective observational study

Background

Subtrochanteric femoral (ST) fractures are associated with high rates of delayed and non-union. The aim of this study was to analyse the risk factors associated with delayed/non-union in ST fractures.

Methods

All patients with surgical stabilisation of ST fractures during the period 2014 to 2019 were identified in an electronic patient records database in two trauma centres. Exclusion criteria were incomplete clinical/radiological data, pathological fractures and loss to follow-up. Radiographs at about 6 months post-surgery were assessed for fracture union using Radiographic Union Score for Hip (RUSH). Fracture was deemed to be un-united if RUSH score was <18. CCD (caput-collum-diaphyseal) angle of operated and uninjured hip, residual displacement at fracture site and 3-point relationship was calculated on operative or immediate post-operative images in both groups. Student's t-test was used to compare CCD angle difference between operated and uninjured sides and the residual fracture displacement between delayed union and united fractures group. Chi-square test was used for 3-point relationship. Observational analysis was performed on implant failure rates including distal screw breakage.

Results

During the study period, there were total of 278 patients. 193 with inadequate data and 22 with pathological fractures were excluded. Advanced age and female sex had significantly higher rate of delayed union (p value of 0.043 and 0.003 respectively). Delayed union group (26) had a mean RUSH score of 14.1 and united group (37) had a mean RUSH score of 26.3 (p = 0.019). The mean CCD angle difference between operated and uninjured sides was -5.77° for delayed union and -2.33° for united fractures (p = 0.03). Residual displacement at fracture site showed statistically significant difference between delayed union and united fractures on anteroposterior and lateral views (p = 0.001 each). There was no statistical difference in 3-point relationship of implant in two groups (p = 0.775). 10 revision procedures were performed for implant failures. Distal screw failure (3 cases) was not a precursor for non-union in this study.

Conclusion

This study confirms varus alignment of hip and residual fracture displacement after fracture fixation of subtrochanteric fracture are surgeon associated significant risk factors for delayed union at 6 months. Fracture contact and alignment are key to reduce failures in these group of fractures. Among patient factors, advancing age and female sex predisposes to higher rate of delayed union.

Three-dimensional joint surface orientation does not correlate with two-dimensional coronal joint line orientation in knee osteoarthritis: Three-dimensional analysis of upright computed tomography

BACKGROUND

Two-dimensional (2D) coronal joint line orientation on radiography under weight-bearing conditions has been widely used in evaluating knee osteoarthritis (OA). However, the effects of tibial rotation remain unknown. The present study aimed to newly define three-dimensional (3D) joint surface orientation relative to the floor as an unchangeable 3D angle unaffected by tibial rotation using upright computed tomography (CT), and to investigate correlations between 3D and 2D parameters in knee OA.

METHODS

Sixty-six knees in 38 patients with varus knee OA underwent standing hip-to-ankle digital radiography and upright CT. The 2D parameters measured on radiographs included femorotibial angle (FTA), tibial joint line angle (TJLA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The 3D inner product angle between vectors of the tibial joint surface and the floor from CT was defined as the 3D joint surface-floor angle.

RESULTS

Mean 3D joint surface-floor angle was 6.0 ± 3.6°. No correlation was identified between 3D joint surface-floor angle and 2D joint line parameters, even though FTA correlated substantially with 2D joint line parameters. No significant differences in 3D joint surface-floor angle were identified among Coronal Plane Alignment of the Knee (CPAK) types.

CONCLUSIONS

The 3D joint surface orientation did not correlate with 2D coronal joint line orientation and was unaffected by CPAK classification types. This finding suggests that current 2D evaluations should be reconsidered for a better understanding of true knee joint line orientation.

The efficacy of medial meniscal posterior Root tear Repair with or without high tibial osteotomy: a systematic review

BACKGROUND

Medial meniscal posterior root tear (MMPRTs) is a common lesion of the knee joint, and repair surgery is a well-established treatment option. However, patients with obvious varus alignment are at an increased risk for MMPRT and can suffer from a greater degree of medial meniscus extrusion, which leads to the development of osteoarthritis following repair. The efficacy of high tibial osteotomy (HTO) as a means of correcting this malformation, and its potential benefits for MMPRT repair, remains unclear.

PURPOSE

To explore whether HTO influenced the outcome of MMPRT repair in clinical scores and radiological findings.

STUDY DESIGN

Systematic review.

METHODS

According to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of MMPRT repair and extracted data about characteristics of patients, clinical functional scores and radiologic outcomes. One reviewer extracted the data and 2 reviewers assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the results of MMPRT repair with exact mechanical axis (registered in the International Prospective Register of Systematic Reviews, CRD42021292057).

RESULTS

Fifteen studies with 625 cases of high methodological quality were identified. Eleven studies were assigned to the MMPRT repair group (M) with 478 cases performing MMPRT repair only, and others belonged to the MMPRT repair and HTO group (M and T) performing HTO and MMPRT repair. Most of the studies had significantly improved clinical outcome scores, especially in M groups. And the radiologic outcomes showed that the osteoarthritis deteriorated in both groups with similar degree in about 2-year follow-up.

CONCLUSION

HTO is a useful supplement in treating MMPRT patients with severe osteoarthritis and the clinical and radiological outcomes were similar with MMPRT repair alone. Which would be better for patients' prognosis generally, performing MMPRT repair alone or a combination of HTO and MMPRT repair, was still controversial. We suggested taking K-L grade into account. Large-scale randomized control studies were called for in the future to help make better clinical decisions.

LEVEL OF EVIDENCE

III.

Total knee arthroplasty in patients with severe obesity: outcomes of standard keeled tibial components versus stemmed universal base plates

BACKGROUND

Patients with severe obesity [body mass index (BMI) ≥ 40 kg/m²] potentially overload the tibial component after total knee arthroplasty (TKA), risking tibial subsidence. Using a cemented single-radius cruciate-retaining TKA design, this study compared the outcomes of two tibial baseplate geometries in patients with BMI ≥ 40 kg/m²: standard keeled (SK) or universal base plate (UBP), which incorporates a stem.

METHODS

This was a retrospective, single-centre cohort study with minimum 2 years follow-up of 111 TKA patients with BMI ≥ 40 kg/m²: mean age 62.2 ± 8.0 (44-87) years, mean BMI 44.3 ± 4.6 (40-65.7) kg/m² and 82 (73.9%) females. Perioperative complications, reoperations, alignment and patient-reported outcomes (PROMS): EQ-5D, Oxford Knee Score (OKS), Visual Analogue Scale (VAS) pain score and satisfaction were collected preoperatively, and at 1 year and final follow-up postoperatively.

RESULTS

Mean follow-up was 4.9 years. SK tibial baseplates were performed in 57 and UBP in 54. There were no significant differences in baseline patient characteristics, post-operative alignment, post-operative PROMs, reoperations or revisions between the groups. Three early failures requiring revision occurred: two septic failures in the UBP group and one early tibial loosening in the SK group. Five-year Kaplan-Meier survival for the endpoint mechanical tibial failure was SK 98.1 [94.4-100 95% confidence interval (CI)] and UBP 100% (p = 0.391). Overall varus alignment of the limb (p = 0.005) or the tibial component (p = 0.031) was significantly associated with revision and return to theatre.

CONCLUSIONS

At early to mid-term follow-up, no significant differences in outcomes were found between standard and UBP tibial components in patients with BMI ≥ 40 kg/m². Varus alignment of either tibial component or the limb was associated with revision and return to theatre.

Varus stem positioning does not affect long-term functional outcome in cementless anatomical total hip arthroplasty

INTRODUCTION

Varus positioning is the most common femoral malposition in total hip arthroplasty (THA). We compared the long-term outcomes of an anatomical cementless femoral stem positioned in varus versus neutral alignment.

MATERIALS AND METHODS

Data were retrospectively reviewed for all patients receiving a cementless anatomical femoral stem in THA for osteoarthritis between 1998 and 2008. Exclusion criteria were complex cases, incomplete data or follow-up < 1 year. Primary outcome was survival rate with complications and secondary outcomes were clinical scores, thigh pain, radiological score, cortical hypertrophy and filling rate.

RESULTS

Of the 283 included patients, 127 stems were classified as varus and 156 neutral. Mean follow-up was 10 years. Femoral stem size was smaller in the varus group (4.1 vs. 4.4, p = 0.047). A stem-filling rate < 80% was more frequent in the varus group (p < 0.001). The long-term survival rate without any revision procedure was 94.8% ± 2.3% (95%CI 88.4-98.7) in the varus group and 94.1% ± 2.0% (95%CI 91.3-99.1) in the neutral group (p = 0.55). There was no difference in clinical scores, thigh pain or complication occurrence between groups. The Engh-Massin score was lower in the varus group (p < 0.01) and cortical hypertrophy was higher (p < 0.001).

CONCLUSIONS

A varus alignment of a cementless anatomic femoral stem does not affect survivorship, clinical outcomes or complication rate on an average follow-up of 10 years, despite increasing stress-shielding rates.

Varus alignment of the tibial component up to seven degrees is not associated with poor long-term outcomes in a neutrally aligned total knee arthroplasty

PURPOSE

The purpose of this retrospective study was to evaluate the effect of varus alignment of the tibial component on the outcomes with a minimum follow-up of 10 years. The hypothesis was that varus alignment of the tibial component might not affect the outcomes and survival of a neutrally aligned primary TKA.

METHODS

A matched case-control study was designed between 66 patients with varus alignment of the tibial component and 66 with neutral alignment with a minimum follow-up of 10 years. Functional outcome was assessed with the knee surgery scores (KSS) and reduced Western Ontario and MacMaster Universities questionnaire (WOMAC). Patient satisfaction was evaluated by a 0-10 visual analog scale. Radiological evaluation was performed at early postoperative and at final follow-up.

RESULTS

The mean follow-up was 11.9 (SD 2.6) years for both groups. The mean postoperative proximal tibial angle in the varus group was 85.0° (SD 0.9) and 88.8° (SD 0.9) in control group. At the final follow-up, there were no significant differences in KSS, WOMAC, range of motion or patient satisfaction. There were no differences in the coronal anatomical alignment of the TKA between groups. Revision of TKA was performed in four knees in the varus group, and one in control group, due to aseptic loosening of the tibial component in all cases. TKA survival at 10 years was not significantly different between groups.

CONCLUSION

The alignment of the tibial component up to 7° varus did not negatively affect implant survival, patient satisfaction, and function of a well-aligned TKA, with a minimum postoperative follow-up of 10 years.

LEVEL OF EVIDENCE

III.

The medial inclination of the proximal tibia is associated with the external knee adduction moment in advanced varus knee osteoarthritis

PURPOSE

Whether the inclined articular surface on the medial proximal tibia and the external knee adduction moment (KAM) correlate remains unclear. The hypothesis was that a steeper inclined articular surface correlated with a larger KAM in advanced knee osteoarthritis (OA).

METHODS

A total of 44 females (non-OA, 9 knees; early OA, 14 knees; advanced OA, 21 knees; mean age, 58 ± 16 years) were examined. Three-dimensional (3D) assessment was used on biplanar long-leg radiographs and 3D bone models using a 3D to 2D image registration technique. The approximation plane in the proximal tibia was determined using the least-square method. The joint moments were mathematically calculated in a gait analysis, applying a motion capture system and force plates. The main evaluation parameters were the femorotibial angle (FTA), the coronal inclination of the approximation plane in the medial proximal tibia (coronal inclination), and internal knee joint moments. The KAM means the external moments balanced with the internal knee abduction moments.

RESULTS

The advanced OA showed a larger internal abduction moment (p = 0.017) at the loading response than the other groups. The larger FTA and steeper coronal inclination correlated with the larger internal abduction moment (FTA, p < 0.001; coronal inclination, p = 0.003) at the loading response.

CONCLUSIONS

As the clinical relevance, the association among the coronal inclination of the medial proximal tibia, lower extremity alignment, and KAM is one of the key factors to help better understand the etiology of knee OA.

LEVEL OF EVIDENCE

III.

Comparison of Outcomes After Total Knee Arthroplasty Involving Postoperative Neutral or Residual Mild Varus Alignment: A Systematic Review and Meta-analysis

Comparing mainly clinical and functional outcomes as well as prosthesis survival with neutral and residual mild varus alignment, we searched PubMed, Embase, Cochrane Library and Web of Science databases from 1 January 1974 to 18 December 2020 to identify studies comparing clinical and functional outcomes as well as prosthesis survival in the presence of different alignments after total knee arthroplasty (TKA) for varus knees. The included studies were assessed by two researchers according to the Newcastle–Ottawa Scale (NOS). Postoperative neutral alignment (0° ± 3°) was compared to residual mild varus (3°–6°) and residual severe varus (>6°). Meta‐analysis was performed using Review Manager 5.3. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables. The fixed‐effect model and random‐effect model were used to meta‐analyze the data. Nine studies were included in the meta‐analysis with 1410 cases of postoperative neutral alignment, 564 of residual mild varus alignment and 175 of residual severe varus alignment following TKA, all of which were published after 2013. Three studies scored 7 points on the NOS, while the remaining studies scored 8 points, suggesting high quality. The pooled mean differences (MDs) of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were 1.07 [95% confidence interval (CI) −1.06 to 3.20; P = 0.32; I² = 79%]. The meta‐analysis showed that neutral alignment and mild varus alignment were associated with similar the Oxford Knee Score (OKS), Knee Society Knee Score (KS‐KS), and Knee Society Function Score (KS‐FS), while neutral alignment was associated with lower Forgotten Joint Score (FJS) [mean difference −6.0, 95% confidence interval (CI) −9.37 to −2.64, P = 0.0005]. Neutral alignment was associated with higher KS‐KS than severe alignment (M 2.98, 95% CI 1.42 to 4.55, P = 0.0002; I² = 0%) as well as higher KS‐FS (M 8.20, 95% CI 4.58 to 11.82, P < 0.00001; I² = 0%). Neutral alignment was associated with similar rate of survival as mild varus alignment (95% CI 0.36 to 9.10; P = 0.48; I² = 65%) or severe varus alignment (95% CI 0.94 to 37.90; P = 0.06; I² = 61%). There was no statistical difference in others. Residual mild varus alignment after TKA may lead to similar or superior outcomes than neutral alignment in patients with preoperative varus knees, yet the available evidence appears to be insufficient to replace the current gold standard of neutral alignment. Severe varus alignment should be avoided.

Successful treatment of degenerative medial meniscal tears in well-aligned knees with fibrin clot implantation

PURPOSE

The purpose of this study was to examine the results of meniscal repair performed for symptomatic degenerative medial meniscal tears.

METHODS

Twenty-four knees in 24 patients with symptomatic degenerative medial meniscal tears (mostly complex horizontal tears) who underwent isolated arthroscopic repair combined with autologous fibrin clot implantation were included in this study. The patients were followed up for a minimum of 2 years. The overall clinical outcome was evaluated using the Lysholm score, while the activity level was graded on the Tegner Activity Scale. The assessment of healing status at the repair site was based on clinical signs/symptoms and follow-up MRI examination results. In addition, the effects of the patient's clinical and radiological factors on healing of the repaired menisci were analyzed.

RESULTS

The mean age of the study subjects was 47.0 ± 8.1 years with a mean follow-up period of 39.3 ± 11.6 months. The Lysholm score significantly improved after surgery (P < 0.01). During the follow-up period, meniscal repairs were deemed to have failed in 6 of the 24 knees (25%). In the analysis of factors influencing meniscal healing, varus deformity (% of mechanical axis < 30%) was identified in all knees in the repair failure group, and the presence of varus deformity was shown to be a significant risk factor correlated with repair failure, while other factors did not significantly influence the healing status.

CONCLUSIONS

The short-term follow-up results showed that arthroscopic repair of degenerative medial meniscal tears combined with fibrin clot implantation attained clinical healing in 18 of 24 knees (75%) of patients, while 6 of the 24 knees (25%) of patients experienced clinical failure. The presence of varus deformity negatively affects the healing rate. In well-aligned knees, degenerative medial meniscal tears are successfully treated by isolated repair with fibrin clot implantation.

LEVEL OF EVIDENCE

IV.

The tibial cut influences the patellofemoral knee kinematics and pressure distribution in total knee arthroplasty with constitutional varus alignment

PURPOSE

The current literature suggests that kinematic total knee arthroplasty (kTKA) may be associated with better outcome scores in patients with constitutional varus alignment. The underlying patellofemoral kinematic changes (patella tilting and patella tracking) and patellofemoral pressure distribution have not yet been described. The present study compared the effects of different tibial cuts, as used in kTKA, on patellofemoral knee kinematics and the pressure distribution, in addition to comparisons with the natural constitutional varus knee.

METHODS

Seven cadaveric knee joints with constitutional varus alignment were examined in the native state and after 0°, 3°, or 6° tibial cut cruciate-retaining (CR)-TKA using an established knee joint simulator. The effects on patella rotation/patella tilting, patellofemoral pressure, and patellofemoral length ratios (= patella tracking) were determined. In addition, the natural knee joint and different tibial cuts in CR-TKA were compared (Student's t test).

RESULTS

In the patellofemoral joint, 6° CR-TKA was associated with the greatest similarity with the natural constitutional varus knee. By contrast, knees subjected to 0° CR-TKA exhibited the largest deviations of patellar kinematics. The smallest difference compared with the natural knee joint concerning patella tilting was found for 6° CR-TKA (mean 0.4°, p < 0.001), and the largest difference was noted for 0° CR-TKA (mean 1.7°, p < 0.001). Concerning patellofemoral pressure, 6° CR-TKA resulted in outcomes most similar to the natural knee joint, featuring a mean difference of 3 MPa. The largest difference from the natural knee joint was identified for 0° CR-TKA, with an average difference of 8.1 MPa (p < 0.001; total mean 17.7 MPa). Meanwhile, 3° and 6° CR-TKA induced medialization of the patella, with the latter inducing the largest medialization value of 4.5 mm at 90° flexion.

CONCLUSIONS

The improved outcome parameters in kTKA described in the literature could be attributable to the similar kinematics of the patellofemoral joint relative to the normal state. The current study confirmed the similar kinematics between the native constitutional varus knee joint and knee joints subjected to 3° or 6° CR-TKA (patellofemoral rotation/patella tilting and patella pressure). Conversely, there was pronounced medialization of the patella following 6° CR-TKA. Patella pressure and patella tilting are described in the literature as possible causes of anterior knee pain after TKA, whereas medialization of the patella, which is also influenced by other causes, might play a subordinate role.

LEVEL OF EVIDENCE

V, Biomechanical study.

The effects of small and large varus alignment of the foot-ankle complex on lower limb kinematics and kinetics during walking: A cross-sectional study

BACKGROUND

The alignment of the foot-ankle complex may influence the kinematics and kinetics of the entire lower limb during walking.

OBJECTIVES

This study investigated the effect of different magnitudes of varus alignment of the foot-ankle complex (small versus large) on the kinematics and kinetics of foot, ankle, knee, and hip in the frontal and transverse planes during walking.

DESIGN

Cross-sectional study.

METHOD

Foot-ankle complex alignment in the frontal plane was measured as the angle between the metatarsal heads and the inferior edge of the examination table, measured with the volunteer in prone maintaining the ankle at 0° in the sagittal plane. The participants (n = 28) were divided into two groups according to their alignment angles. The first group had values equal to or inferior to the 45 percentile, and the second group had values equal to or above the 55 percentile. The lower limb kinematics and kinetics were evaluated with the participant walking at self-select speed in an instrumented treadmill.

RESULTS

The group of large varus alignment showed significantly higher (p < 0.03) forefoot inversion angle at initial contact, amplitude of rearfoot-shank eversion, and peak of inversion ankle moment. There were no differences (p > 0.05) between the groups for knee and hip amplitudes and moments in the frontal and transverse planes. The durations of rearfoot-shank eversion, knee abduction, knee medial rotation, hip adduction, and hip medial rotation were not different between groups (p > 0.05).

CONCLUSION

Large varus alignment of the foot-ankle complex may increase the magnitude of foot pronation and ankle inversion moment during walking.

The Role of High Tibial Osteotomy in ACL Reconstruction in Knees with Coronal and Sagittal Plane Deformity

PURPOSE OF REVIEW

Coronal and sagittal malalignment in the setting of anterior cruciate ligament (ACL) deficiency alters knee biomechanics and is shown to increase stress and strain on the native ACL and on the ACL graft during reconstruction. The purpose of this review was to determine the role and indications of high tibial osteotomy to correct coronal and/or sagittal plane malalignment with ACL reconstruction.

RECENT FINDINGS

Recent literature illustrates that an increase in varus malalignment and increased posterior tibial slope increases the biomechanical stress that is seen in a native or reconstructed ACL graft. It has been proposed to correct the sagittal and coronal malalignment by employing a high tibial osteotomy either prior to or at the time of ACL reconstruction to correct these deformities and to decrease the stress placed on the reconstructed ACL graft. The use of high tibial osteotomy for deformity correction creates a more stable knee for ACL reconstruction and has been shown to have good outcomes with regard to post-operative pain, stability, satisfaction scores, and function.

Stress fractures of the medial malleolus in the professional soccer player demonstrate excellent outcomes when treated with open reduction internal fixation and arthroscopic spur debridement

PURPOSE

Despite a debilitating effect on athletic performance and an incidence of up to 4% of all stress fractures, there have been only 31 documented cases of medial malleolus stress fractures (MMSF) to our knowledge in the literature. The largest series to date is presented in this study, of 16 professional soccer players undergoing uniform operative treatment. The authors attempt to justify their preferred treatment of MMSFs in the professional soccer player, with an emphasis on patient satisfaction, clinical and radiographic union, and return to high level sport. The authors aim to prove an association between lower limb varus alignment and the development of MMSFs.

METHOD

Sixteen professional soccer players of mean age 23.6 years were analysed. A biomechanic assessment was performed. Preoperative CT+-MRI scan were performed to assess fracture lines and the presence of anteromedial tibial and/or talar spurs; which are the likely pathognomic lesion in the development of MMSFs. All patients underwent open reduction and internal fixation with three screws, as well as arthroscopic debridement of impringement spurs, and concentrated bone marrow aspirate into the fracture site. Patients completed the Ogilvie-Harris score, and all patients had CT scans at 3 months and until union.

RESULTS

All the patients in this cohort had causative bony spurs that were debrided at surgery. All of the cohort achieved clinical union. All patients were able to return to professional football; at the same level as prior to the injury. There was complete cohort follow up; and 81% of patients were graded as excellent and 19% as good by the Ogilvie-Harris score. We noted 50% of our cohort demonstrated varus malalignment, either genu varum or hindfoot varus.

CONCLUSIONS

The authors conclude that open reduction and internal fixation of MMSFs with screws combined with arthroscopic spur debridement results in excellent clinical outcomes. It can be concluded that varus lower limb malalignment is a risk factor for MMSFs. Given the treatment controversy for these injuries, the results herein demonstrate that aggressive multimodal operative treatment produces excellent outcomes in high demand professional footballers. This study is the first to report a biomechanic association, which can alert the clinician to preventative measures; such as hindfoot orthoses.

LEVEL OF EVIDENCE

IV.

Alignment factors affecting the medial meniscus extrusion increases the risk of osteoarthritis development

PURPOSE

Varus alignment is known as one of the major causes of medial compartment osteoarthritis (OA). Medial meniscus extrusion also plays a critical role in the in the development of OA. However, studies on the exact relationship between alignment parameters and medial meniscus extrusion are limited. Therefore, this study aimed to investigate this relationship in patients with knee OA.

METHODS

Based on a retrospective analysis of the outpatient magnetic resonance imaging (MRI) database, 190 knees were identified to be examined using weight-bearing, whole-leg radiographs and MRIs within 3 months from the first consultation. Subsequently, various parameters of lower leg alignment were measured, which affected the knee varus in radiographs. Finally, a statistical analysis was performed to assess the relationships between the OA grade, distance of medial meniscus extrusion (MME), and alignment parameters; hip-knee-ankle angle (HKAA), percentage of mechanical axis (% MA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The subjects were divided according to the presence or absence of MME (Group A: MME distance below 3 mm, Group B: MME distance 3 mm and above) to assess the differences in each alignment parameter correlated with MME distance between the groups.

RESULTS

MME distance significantly increased with OA grade progression. HKAA, % MA, MPTA, and JLCA significantly correlated with medial meniscus extrusion distance (r = - 0.21, - 0.23, - 0.16, 0.3, respectively). Multiple regression analysis of each significant alignment combined with age, sex, and body mass index revealed that HKAA, % MA, MPTA, and JLCA were significant independent factors of MME distance (P = 0.008, 0.0026, 0.011, 0.0001, respectively). These significant findings were reinforced in group B. In contrast, the correlation between alignment parameters and medial meniscus extrusion distance was not significant in group A.

CONCLUSION

Varus alignment factors are related to MME distance especially in extruded meniscus knees, as the OA grade progressed. Therefore, the coexistence of varus alignment and MME can be the risk factors for OA progression. As the low MPTA was an independent alignment factor for generating varus alignment, patients with osteoarthritis of the knee with both, low MPTA and MME could be the appropriate candidates for early intervention by high tibial osteotomy.

LEVEL OF EVIDENCE

III.

High Tibial Osteotomy and Anterior Cruciate Ligament Reconstruction/Revision

High tibial osteotomy (HTO) may be performed in association with anterior cruciate ligament (ACL) reconstruction/revision in patients with medial osteoarthritis, varus malalignment, and anterior instability. Furthermore, it may be performed in patients with varus alignment and increased posterior tibial slope (exceeding 12°), because it is related to an increased risk for ACL failure. There are different techniques to perform HTO, and consequently, a concomitant HTO and ACL reconstruction/revision. This article describes the indication, surgical techniques, and outcomes of concomitant HTO and ACL reconstruction/revision.

Effect on inclined medial proximal tibial articulation for varus alignment in advanced knee osteoarthritis

BACKGROUND

The inclination of the medial compartment of the proximal tibia (MCT) is assumed to be a critical factor for varus alignment in advanced knee osteoarthritis (OA). This study was aimed at investigating; (1) whether the inclination of MCT is aligned parallel to the ground under weight-bearing (WB) conditions; (2) whether this is associated with the change in alignment and the relative position between the bones; and (3) whether the tibia or femur mainly contributes to the changes.

METHODS

We examined 102 knees (84 women, 18 men; mean 75 years). A three-dimensional (3D) assessment system was applied on biplanar whole lower extremity radiographies using 3D-to-2D image registration technique. The evaluation parameters were 1) MCT angle, 2) femorotibial angle (FTA), 3) medial-lateral femoral location to the tibia (M-L femoral location), 4) WB line passing point, and 5) tibial position to WB line (tibial position) and 6) femoral postion to WB line (femoral position). Each parameter was evaluated in non-WB and WB conditions, and the differences (Δ-parameters).

RESULTS

MCT angle in the world coordinate system was larger than that in the tibial coordinate system (p <  0.0001). ΔMCT angle was correlated with ΔFTA (p = 0.002) and ΔM-L femoral location (p = 0.004). The tibial position was the more dominant factor for ΔMCT angle (p = 0.001), ΔFTA (p <  0.0001), and ΔWB line passing point (p <  0.0001) .

CONCLUSIONS

The inclination in MCT was aligned parallel to the ground under WB conditions (tibial parallel phenomenon). The parallel phenomenon was associated with the change of alignment and the relative position between the bones in the coronal plane. These phenomena were produced mainly by the tibia, not the femur.

LEVEL OF EVIDENCE

Level IV.

Varus tibial alignment is associated with greater tibial baseplate migration at 10 years following total knee arthroplasty

PURPOSE

To examine implant migration and articular behavior of primary total knee arthroplasty (TKA) at 10 years after index surgery and correlate to implant alignment.

METHODS

Thirty-five patients underwent a cemented posterior stabilized total knee arthroplasty with a surgical objective of neutral alignment and were enrolled in a long-term radiostereometric analysis (RSA) study. At 10 years after surgery, patients were analyzed for implant migration using RSA as well as radiographic assessment of articular behavior at four positions of knee flexion. Implant position and alignment was measured on full-length radiographs. Patient demographics and reported outcomes were also collected.

RESULTS

No difference between patient demographics or patient-reported outcomes were found. When categorized into neutral and varus groupings, no difference in migration was present. If alignment was considered as a continuous variable, there was no correlation between overall leg alignment and migration, however, migration increased with an increasing varus tibial alignment. Although contact location did not differ between neutral and varus groups through a range of motion, condylar liftoff was much more common in the varus group, of which all were lateral liftoff.

CONCLUSIONS

Increased tibial varus results in increased implant migration. Overall varus limb alignment is correlated with isolated lateral compartment liftoff, and liftoff occurs more commonly than in neutral aligned knees. The increased migration and liftoff raise concerns about the longevity of malaligned total knee replacements. If a goal of overall varus limb alignment is desired for TKA, the tibia should remain neutral.

LEVEL OF EVIDENCE

Level III.

Varus femoral and tibial coronal alignments result in different kinematics and kinetics after total knee arthroplasty

PURPOSE

Abnormal knee motion under various conditions has been described after total knee arthroplasty (TKA). However, differences in kinematics and kinetics of knees with varus femoral versus varus tibial alignment have not been evaluated. It was hypothesized that varus femoral and tibial alignments have the same impact on knee motion.

METHODS

A musculoskeletal computer simulation was used. Femoral and tibial alignment in the coronal plane was each varied from neutral to 5° of varus in 1° increments. Lift-off, defined as an intercomponent distance of >2 mm, and tibiofemoral contact forces were evaluated during gait up to 60° of knee flexion. Knee kinematics and contact stresses were also examined during squat, with up to 130° of knee flexion.

RESULTS

During gait, lift-off occurred readily with more than 3° of varus tibial alignment and slight lateral joint laxity. In contrast, lift-off did not occur with varus femoral or tibial alignment of up to 5° during squat. Peak medial contact forces with varus femoral alignment were approximately twice those observed with varus tibial alignment. The lowest points of the femoral condyles moved internally with varus femoral alignment, contrary to the kinematics with neutral or varus tibial alignment. On the other hand, there was femoral medial sliding and edge loading against the tibia in mid-flexion with varus tibial alignment.

CONCLUSION

Varus femoral alignment affects the non-physiological rotational movement of the tibiofemoral joint, whereas varus tibial alignment causes medial-lateral instability during mid-flexion. Varus femoral and tibial alignments might lead to post-TKA discomfort and unreliability.

Dynamic and static knee alignment at baseline predict structural abnormalities on MRI associated with medial compartment knee osteoarthritis after 2 years

BACKGROUND

Dynamic and static varus alignment, both, have been reported as risk factors associated with structural progression of knee osteoarthritis. However the association of none of the static and dynamic alignment with structural, clinical, and functional progression associated with knee osteoarthritis has not been assessed yet in a longitudinal study.

METHODS

Forty-seven women with early and established medial knee osteoarthritis were evaluated. Static and dynamic alignment as well as MRI detected structural features, clinical, and functional characteristics of patients were assessed at baseline and at 2 years follow-up. Associations between baseline static and dynamic alignment with structural, functional, and clinical characteristics at the time of entry, as well as the changes over 2 years were evaluated.

FINDINGS

Both static and dynamic varus alignment at baseline were significantly associated with osteoarthritis related tibio-femoral joint structural abnormalities detected on MRI, at the time of entry. Only the magnitude of varus thrust at baseline was predictive of the changes in the presence of meniscal maceration over two years. None of the static or dynamic measures of knee joint alignment were associated with clinical characteristics associated with medial knee osteoarthritis.

INTERPRETATION

The key finding of this study is that both frontal plane dynamic and static alignment, are associated with structural abnormalities in patients with medial knee osteoarthritis.

Effectiveness of Hip External Rotator Strengthening Exercise in Korean Postural Bowleg Women

Postural bowleg is a subclinical entity with both aesthetic and functional outcomes and appears to be common in East Asian countries. Internal rotation of the hip joint is associated with varus alignment at the knee joint of the bowleg. Strengthening exercise for the hip external rotator muscles seems to be effective in improving varus alignment of bowleg, but no standardized exercise program exists. A standardized active resistance strengthening exercise for hip external rotator muscles could improve varus alignment of the lower limb in bowlegged Korean women. In this article, a case series study was conducted to observe changes following a standardized 3-month program using equipment designed for strengthening of the hip external rotator muscles. Photogrammetric and radiographic data were used to compare the gap between knees and tibiofemoral (TF) angles before and after the exercise program. As a result, on average, the knee gap decreased by 1.6 cm. The TF angle decreased by 1.5°. Regression analysis revealed a statistically significant association between changes in knee gap and TF angle. The standardized 3-month active resistance strengthening exercise program of hip external rotator muscles was effective in improving postural deviation and cosmetic outcomes in bowlegged Korean women.

LEVEL OF EVIDENCE IV

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