Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy.

INTRODUCTION: We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO. MATERIALS AND METHODS: This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment. RESULTS: The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees. CONCLUSION: Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle. LEVEL OF EVIDENCE: Therapeutic level III, retrospective study.

Minimal under-correction gives better outcomes following total knee arthroplasty in severe varus knees-myth or reality?-analysis of one hundred sixty two knees with varus greater than fifteen degrees.

PURPOSE OF THE STUDY: To document and compare the functional outcome of neutral alignment and under-correction after total knee arthroplasty (TKA) in severe varus knees of more than 15° at three and 12 months post-surgery. MATERIALS AND METHODS: One hundred twenty-four consecutive patients (163 TKAs) of an average age of 61.9 years (52-79) with a pre-operative varus more than 15° were managed with jig-based TKA. Based on the post-operative mechanical femorotibial alignment (FTMA), they were categorised into three groups, namely neutral (180 + 3°), mild varus (173° to 176°) and severe varus (172° and below). The outcomes of these three groups were assessed at three and 12 months by the Oxford knee score and the WOMAC score were calculated and co-related to the extent of correction. RESULTS: At three months, knees in the mild varus group (n = 88) had the best results with an Oxford knee score of 41.76 + 1.44 and a WOMAC score of 19.29 + 2.93 compared to the severe varus group and the neutral alignment group which had Oxford knee scores (OKS) of 37.43 + 2.51 and 31.91 + 3.51 and WOMAC scores of 22.57 + 1.51 and 24.46 + 4.15 respectively. However at 12 months, knees in all the groups (neutral, mild varus, severe varus) had similar good functional outcomes with OKS of 39.08 + 1.68, 39.24 + 1.88, 39.29 + 1.11 and WOMAC scores of 17.42 + 2.15, 16.48 + 2.11, 16.14 + 1.21 respectively. A scatter plot done for post-operative FTMA and the functional outcome score for both scores showed a bell curve with the best outcome corresponding to a FTMA of 175° at 3 months and equal distribution for both scores at 12 months. CONCLUSION: The results of our study showed that minimal under-correction gave superior functional outcomes at three months. But this advantage was temporary and both, under-correction and neutral alignment achieved equally good outcomes at one year. Considering the increased prosthesis longevity associated with neutral alignment, we propose that neutral alignment must be aimed for during TKA for knees with severe varus. STUDY DESIGN: Prospective study.

No impact of under-correction and joint line obliquity on clinical outcomes of total knee arthroplasty for the varus knee.

PURPOSE: It has been hypothesized that under-correction of a preoperative varus deformity may be more natural and improve outcomes after total knee arthroplasty (TKA). This study's purpose was to assess the impact of hip-knee-ankle (HKA) alignment and joint line obliquity on TKA outcomes for the varus knee. METHODS: All patients with a preoperative varus deformity received both preoperative and postoperative standing, full-length radiographs from which two independent observers performed radiographic measurements including the HKA axis and mechanical medial proximal tibial angle (mMPTA). Patients were categorized based on their HKA into neutral (0° ± 3°), mild varus (-6° to -3°), severe varus (≤ -6°), and valgus (>3°) cohorts, and separately categorized based on their mMPTA into neutral (90° ± 2°), mild varus (86°-88°), severe varus (<86°), and valgus (>92°) cohorts. RESULTS: Two hundred and fifty-six patients (mean age 63.8 ± 9.0 years, BMI 33.0 ± 6.2 kg/m2, follow-up 1.3 ± 0.6 years) were included. There was no difference in the postoperative SF-12 physical component, mental component, Oxford knee, Forgotten Joint Score, or incremental improvement in scores based on the postoperative alignment category for either the HKA or mMPTA. There was no correlation between the magnitude of change in HKA (r = 0.03-0.1) and mMPTA (r = 0.02-0.1) from preoperatively to postoperatively with clinical outcomes. CONCLUSIONS: In patients undergoing TKA for a preoperative varus deformity, a specific postoperative HKA or mMPTA alignment category was not associated with improved outcomes. Therefore, categorization of optimal postoperative alignment after TKA may not be possible as static, coronal alignment is just one of many variables that can impact clinical outcomes. Future investigations focusing on the combination of static images with dynamic examinations and ligamentous balancing may shed further insight into the controversy and importance of coronal alignment following TKA. LEVEL OF EVIDENCE: III.

Patterns of Lumbar Spine Malalignment Leading to Revision Surgery for Proximal Junctional Kyphosis: A Cluster Analysis of Over- Versus Under-Correction.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Investigate the patterns of fused lumbar alignment in patients requiring revision surgery for proximal junctional kyphosis (PJK). METHODS: Fifty patients (67.8 yo, 76% female) with existing thoraco-lumbar fusion (T10/12 to pelvis) and indicated for surgical correction for PJK were included. To investigate patterns of radiographic alignment prior to PJK revision, unsupervised 2-step cluster analysis was run on parameters describing the fused lumbar spine (PI-LL) to identify natural independent groups within the cohort. Clusters were compared in terms of demographics, pre-operative alignment, surgical parameters, and post-operative alignment. Associations between pre- and post-revision PJK angles were investigated using a Pearson correlation analysis. RESULTS: Analysis identified 2 distinct patterns: Under-corrected (UC, n = 12, 32%) vs over-corrected (OC, n = 34, 68%) with a silhouette of .5. The comparison demonstrated similar pelvic incidence (PI) and PJK angle but significantly greater deformity for the UC vs OC group in terms of PI-LL, PI-LL offset, pelvic tilt, and sagittal vertebral axis. The surgical strategy for PJK correction did not differ between the 2 groups in terms of approach, American Society of Anesthesiologists grade, decompression, use of osteotomy, interbody fusion, or fusion length. The post-revision PJK angle significantly correlated with the amount of PJK correction within the OC group but not within the UC group. CONCLUSIONS: This study identified 2 patterns of lumbar malalignment associated with severe PJK: over vs under corrected. Despite the difference in PJK etiology, both patterns underwent the same revision strategy. Future analysis should look at the effect of correcting focal deformity alone vs correcting focal deformity and underlying malalignment simultaneously on recurrent PJK rate.

Visual Outcomes Early after Implantable Collamer Lens V4c Implantation in Different Preoperative Spectacle Correction: Full Correction vs. Under Correction.

PURPOSE: To investigate visual outcomes early after implantable collamer lens (ICL) V4c implantation between patients with fully corrected and under-corrected spectacles preoperatively. METHODS: Patients who implanted ICL V4c were divided into the full correction (46 eyes/23 patients) and under-correction groups (48 eyes/24 patients) based on preoperative differences between the spherical diopter of the spectacles and the actual spherical diopter. Refractive outcomes, scotopic pupil size, higher-order aberrations, and subjective visual outcomes as assessed using a validated questionnaire were compared between the two groups 3 months postoperatively. Moreover, the relationships between the severity of haloes and postoperative ocular or ICL parameters were analyzed. RESULTS: At the 3-month follow-up, the efficacy indices in the full correction and under-correction groups were 0.99 ± 0.12 and 1.00 ± 0.10, respectively; the safety indices were 1.15 ± 0.16 and 1.15 ± 0.15, respectively. Total-eye spherical aberration (p < 0.0001) and internal spherical aberration (p = 0.0005) were significantly different pre- and post-operatively in the under-correction group, while no differences were found in the full correction group. Total-eye spherical aberration (p = 0.002) and the severity of haloes (p = 0.03) were postoperatively different between the two groups. The severity of haloes was associated with postoperative spherical aberration (total-eye spherical aberration: r = -0.32, p = 0.002; internal spherical aberration: r = -0.24, p = 0.02). CONCLUSION: Good efficacy, safety, predictability, and stability were obtained early after surgery regardless of preoperative spectacle correction. Patients in the under-correction group possessed a shift to negative spherical aberration and reported greater severity of haloes at the 3-month follow-up. Haloes were the most common visual symptoms after ICL V4c implantation and the severity of them was correlated with postoperative spherical aberration.

Slight femoral under-correction versus neutral alignment in total knee arthroplasty with preoperative varus knees: a comparative study.

BACKGROUND: This study aimed to compare the short-term clinical results of slight femoral under-correction with neutral alignment in patients with preoperative varus knees who underwent total knee arthroplasty. METHODS: The medical records and imaging data were retrospectively collected from patients who had undergone total knee arthroplasty in our hospital from January 2016 to June 2019. All patients had varus knees preoperatively. Upon 1:1 propensity score matching, 256 patients (256 knees) were chosen and divided into a neutral alignment group (n=128) and an under-correction group (n=128). The patients in the neutral group were treated with the neutral alignment. In the under-correction group, the femoral mechanical axis had a 2° under-correction. The operative time, tourniquet time and the length of hospital stay in the two groups were recorded. The postoperative hip-knee-ankle angle, frontal femoral component angle and frontal tibial component angle were measured. Patient-reported outcome measures were also compared. RESULTS: The operative time, tourniquet time and the length of hospital stay in the under-correction group were significantly shorter than the neutral alignment group (P<0.05). At the 2-year follow-up, the under-correction group had a larger varus alignment (P<0.05) and a larger frontal femoral component angle (P<0.05), and the frontal tibial component angles of the two groups were comparable. Compared with the neutral alignment group, the slight femoral under-correction group had significantly better patient-reported outcome measures scores (P<0.05). CONCLUSION: For varus knees treated with total knee arthroplasty, alignment with a slight femoral under-correction has advantages over the neutral alignment in terms of the shorter operative time and better short-term clinical results. LEVEL OF EVIDENCE: III.

[IOL choice predictability, 1-year visual outcome, and complications after cataract surgery in children]. / Prédictibilité du choix de l'implant, résultats visuels à 1 an et complications de la chirurgie de cataracte chez l'enfant.

PURPOSE: To measure the refraction 1year after cataract surgery in children as a function of under-correction of the implant power and to evaluate the visual prognosis and possible therapeutic challenges. PATIENTS AND METHODS: We conducted a retrospective study of 28 children (38 affected eyes) who underwent unilateral or bilateral cataract surgery with primary intraocular lens implantation over a one-year period of time. The age at the time of surgery was between 1month and 17years. RESULTS: Ten patients had bilateral cataracts (35%) and 18 patients unilateral (65%). Ten patients were between 0 and 2years of age, 10 patients between 2 and 6years of age, and 8 patients were over 6years old. 72 % of the cataracts were idiopathic. The cataracts were mainly cortico-nuclear (37%). Monocular acuity averaged 0.7 LogMAR (2/10) between 2 and 6years, and 0.2 LogMAR (6.3/10) after 6years. The percentage of under-correction was 31% between 0 and 2years, 12.2% between 2 and 6years, and 2.3% after 6years, for a mean under-correction of 15.2%. The power of the chosen implant after under-correction was 25 diopters on average. One year after surgery, visual acuity averaged 0.2 LogMAR (6.3/10) between 2 and 6years old,and 0.1 LogMAR (8/10) after 6years. The spherical equivalent remained globally stable after surgery (the mean postoperative value was+1.25 diopters). The highest rate of revision surgery occurred in the 0-2year-olds (40%). The most common complication was cellular proliferation (up to 80% of the 0-2year-olds). Only one case of ocular hypertension was noted. DISCUSSION: It is necessary to apply an under-correction of the intraocular lens power, decreasing with the age of the child. The gain in visual acuity is modest, and the main complication is cellular proliferation.

Under-correction or full correction of myopia? A meta-analysis.

PURPOSE: To compare the effect of full-correction versus under-correction on myopia progression. METHODS: A literature search was performed in PubMed, Scopus, Science Direct, Ovid, Web of Science and Cochrane library. Methodological quality assessment of the literature was evaluated according to the Critical Appraisal Skills Program. Statistical analysis was performed using Comprehensive Meta-Analysis (version 2, Biostat Inc., USA). RESULTS: The present meta-analysis included six studies (two randomized controlled trials [RCTs] and four non-RCTs) with 695 subjects (full-correction group, n=371; under-correction group, n=324) aged 6 to 33 years. Using cycloplegic refraction, the pooled difference in mean of myopia progression was - 0.179 D [lower and higher limits: -0.383, 0.025], which was higher but not in full correction group as compared to under correction group (p=0.085). Regarding studies using non-cycloplegic subjective refraction according to maximum plus for maximum visual acuity, the pooled difference in myopia progression was 0.128 D [lower and higher limits: -0.057, 0.312] higher in under-correction group compared with full-correction group (p=0.175). Although, difference in myopia progression did not reach significant level in either cycloplegic or non-cycloplegic refraction. CONCLUSIONS: Our findings suggest that, myopic eyes which are fully corrected with non-cycloplegic refraction with maximum plus sphere, are less prone to myopia progression, in comparison to those which were under corrected. However, regarding cycloplegic refraction, further studies are needed to better understand these trends.

Role of un-correction, under-correction and over-correction of myopia as a strategy for slowing myopic progression.

This systematic review investigates the association between un-, under- and over-correction of myopic refractive error and myopia progression in children and adolescents (up to 18 years of age). The literature search included three databases (PubMed, Web of Science, and Cochrane Central Register of Controlled Trials [CENTRAL]), and reference lists of retrieved studies in any language. Eight prospective cohort studies and one retrospective analysis of clinical data provided comparison data on un- and under-correction of myopia versus full-correction of myopia; however, the quality of studies and length of follow-up times varied. A forest plot showed no beneficial effect of under-correction with some studies finding an increase in myopia progression. While one study suggested that myopia progression is slower in an un-corrected cohort compared to those who are fully corrected, another study suggests the opposite. One study utilised anisomyopes to allow comparison of under-correction of one eye with full-correction of the fellow eye indicating that under-correction in one eye appears to slow the rate of myopia progression in that eye. Another study on full-correction only in one eye found that progression was faster in the un-corrected eye. No benefits of over-correction of myopia was found. The overall findings are equivocal with under-correction causing a faster rate of myopia progression. There is no strong evidence of benefits from un-correction, monovision or over-correction. Hence, current clinical advice advocates for the full-correction of myopia. Further studies are warranted to determine the level of myopia that can be left uncorrected without impacting on myopia progression and how this changes with time.

To Correct or Not Correct? Actual Evidence, Controversy and the Questions That Remain Open.

Clinical studies and basic research have attempted to establish a relationship between myopia progression and single vision spectacle wear, albeit with unclear results. Single vision spectacle lenses are continuously used as the control group in myopia control trials. Hence, it is a matter of high relevance to investigate further whether they yield any shift on the refractive state, which could have been masked by being used as a control. In this review, eye development in relation to eyes fully corrected versus those under-corrected is discussed, and new guidelines are provided for the analysis of structural eye changes due to optical treatments. These guidelines are tested and optimised, while ethical implications are revisited. This newly described methodology can be translated to larger clinical trials, finally exerting the real effect of full correction via single vision spectacle lens wear on eye growth and myopia progression.

Juvenile Myopia. Predicting the Progression Rate.

Regression plots are generated showing the strong correlation of myopia onset age with its progression rate, r = -0.77, p<0.0025, and strong correlation of accumulated myopia 5 years after onset, r = -0.78, p < 0.001. Theory is confirmed, with all subjects showing excellent correlation coefficients, = -0.971, p < 0.005. Myopia progression rates vary from 0.2 to 1.0 diopters (D) per year from one individual to the next. Age of onset for myopia is 10.6 yrs. +/-5.4 yrs. Initial refraction at onset is -1.14 D +/-0.55 D. Practical applications of this work include delaying correction for myopes, and juvenile susceptibility to myopia at various age levels. Feedback Theory predicts the results.

Under-correction of human myopia--is it myopigenic?: a retrospective analysis of clinical refraction data.

PURPOSE: To investigate retrospectively, based on routine clinical records in an optometric office, the effect of refractive under-correction of the myopic spectacle prescription on myopic progression in children and young adults. METHODS: Patient records of children and young-adult myopes in a private optometric practice in Glendale, Arizona, USA, were initially reviewed to identify those that met the criteria. Information collected from the patient records included: age, gender, the dates and number of their visits (more than one visit was required for use of the data), final prescription, and non-cycloplegic subjective refraction. For each patient visit, the difference in spherical equivalent (SE) between the subjective refraction for maximum visual acuity and the final prescription was calculated for both the left and right eyes. Myopia progression was defined as the difference in SE between the final subjective refraction of the previous visit and that of the subsequent visit. Based on the study criteria, a total of 275 patient visits were obtained from the data collected in 76 patients. RESULTS: A significant positive correlation was found between the magnitude of under-correction of the refractive error and myopic progression (r=0.301, p<0.01); that is, the greater the under-correction, the greater the myopic progression. In addition, there was a significant positive correlation between myopia progression and subjective refraction (r=0.166, p=0.006); that is, the greater the degree of myopia, the greater the effect of under-correction. However, there was no significant correlation between myopia progression and either age (r=-0.11, p=0.86) or gender (r=-0.82, p=0.17). CONCLUSION: Under-correction of myopia produced a small but progressively greater degree of myopic progression than did full correction. The present finding is consistent with earlier clinical trials and modeling of human myopia.