Relationship between increased knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures.

INTRODUCTION: This study evaluated the correlation between postoperative knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures excluding excessively overcorrected knees. This study further identified preoperative radiological factors related to the increased postoperative knee joint line obliquity. MATERIALS AND METHODS: We retrospectively evaluated patients who underwent medial open-wedge high tibial osteotomy between March 2013 and March 2021. Postoperative excessively overcorrected knees with hip-knee-ankle angle > 7° were excluded. We investigated radiological parameters and patient-reported outcome measures preoperatively and at the last follow-up. The following radiologic parameters were measured: hip-knee-ankle angle, weight-bearing line ratio, mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, lateral distal tibial angle, joint line convergent angle, knee joint line obliquity, ankle joint line obliquity, hip abduction angle, tibial posterior slope, Carton-Deschamps index, and patella tilting angle. Clinical outcomes were evaluated using Japanese knee outcome measures. This assessment criterion is based on the Western Ontario McMaster Universities Arthritis Index and MOS Short Form 36. Multiple regression analysis was performed to evaluate the association between postoperative knee joint line obliquity and patient-reported outcome measures or preoperative radiological factors (P < .05). RESULTS: A total of 52 knees were included. The mean age at the time of the surgery was 61.6 ± 9.0 years and the mean follow-up period was 30.6 ± 10.1 months. Increased postoperative knee joint line obliquity was associated with lower Japanese knee outcome measures. The preoperative hip-knee-ankle angle was significantly associated with postoperative knee joint line obliquity. CONCLUSIONS: Increased knee joint line obliquity after medial open-wedge high tibial osteotomy is associated with inferior clinical outcomes. Care should be given to the center of the rotational angulation in around-knee osteotomy to avoid postoperative increased knee joint line obliquity. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

A Longitudinal Analysis of Pre- and Post-Operative Dysmorphology in Metopic Craniosynostosis.

OBJECTIVE: The purpose of this study is to objectively quantify the degree of overcorrection in our current practice and to evaluate longitudinal morphological changes using CranioRateTM, a novel machine learning skull morphology assessment tool.  . DESIGN: Retrospective cohort study across multiple time points. SETTING: Tertiary care children's hospital. PATIENTS: Patients with preoperative and postoperative CT scans who underwent fronto-orbital advancement (FOA) for metopic craniosynostosis. MAIN OUTCOME MEASURES: We evaluated preoperative, postoperative, and two-year follow-up skull morphology using CranioRateTM to generate a Metopic Severity Score (MSS), a measure of degree of metopic dysmorphology, and Cranial Morphology Deviation (CMD) score, a measure of deviation from normal skull morphology. RESULTS: Fifty-five patients were included, average age at surgery was 1.3 years. Sixteen patients underwent follow-up CT imaging at an average of 3.1 years. Preoperative MSS was 6.3 ± 2.5 (CMD 199.0 ± 39.1), immediate postoperative MSS was -2.0 ± 1.9 (CMD 208.0 ± 27.1), and longitudinal MSS was 1.3 ± 1.1 (CMD 179.8 ± 28.1). MSS approached normal at two-year follow-up (defined as MSS = 0). There was a significant relationship between preoperative MSS and follow-up MSS (R2 = 0.70). CONCLUSIONS: MSS quantifies overcorrection and normalization of head shape, as patients with negative values were less "metopic" than normal postoperatively and approached 0 at 2-year follow-up. CMD worsened postoperatively due to postoperative bony changes associated with surgical displacements following FOA. All patients had similar postoperative metopic dysmorphology, with no significant association with preoperative severity. More severe patients had worse longitudinal dysmorphology, reinforcing that regression to the metopic shape is a postoperative risk which increases with preoperative severity.

Imaging evaluation of disc position and status after temporomandibular joint arthroscopic disc repositioning and suturing surgery.

Objective: This study aimed to explain the change of disc position at different over-corrected place after arthroscopic disc repositioning and suturing surgery. Study design: Patients treated with temporomandibular joint arthroscopic disc repositioning and suturing surgery were reviewed. All patients underwent magnetic resonance imaging (MRI) before, immediately after surgery and at 2-year follow-up. The position of disc was checked and the change was compared. Results: 133 patients were included in the final analysis with 203 TMJ sides. The incidence rate for anterior movement of the disc after surgery was 33.0 %. Disc repositioned between 12 and 1 o'clock showed smaller movement rate of 22.6 %, while higher movement rate of 53.6 % was seen when repositioned between 2 and 3 o'clock. Conclusions: After arthroscopic disc repositioning and suturing surgery for ADD patients, the repositioned disc showed tendency to move forward. 12 to 1 o'clock was optional disc site for repositioning while excessive over-correction was not recommended.

Comparison of different degrees of varus deformity correction with open-wedge high tibial osteotomy: a retrospective study over 5 years.

OBJECTIVE: This study aims to investigate the clinical efficacy and complications associated with open-wedge high tibial osteotomy (OWHTO) in the treatment of medial compartment knee osteoarthritis. Additionally, the compensatory changes in the hip, patellofemoral, and ankle regions will be assessed through imaging. METHODS: A retrospective analysis of clinical data pertaining to 86 patients who underwent OWHTO at the Affiliated Hospital of Qingdao University from January 2015 to September 2018 was conducted. The weight-bearing line ratio (WBLR) was measured postoperatively, and patients were categorized into a normal group (50% < WBLR ≤ 62.5%, n = 67) and an overcorrection group (WBLR > 62.5%, n = 19). Various parameters, including hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), joint line convergence angle (JLCA), and posterior tibial slope (PTS), were measured before surgery and at the last follow-up to assess lower limb line correction. The compensatory changes in adjacent joints were evaluated by measuring hip abductor angle (HAA), tibial plafond inclination (TPI), talus inclination angle (TIA), Carton-Deschamps index, lateral patellar tilt (LPT), lateral patellar shift (LPS), medial patellofemoral space, and lateral patellofemoral space in both groups. The American Hospital for Special Surgery (HSS) score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) of the affected knee were assessed before surgery and at the last follow-up, and the incidence of complications in both groups was analyzed. RESULTS: Postoperative complications occurred in 26.32% (five cases) of the overcorrection group and 5.97% (four cases) of the normal group, with a statistically significant difference (χ2 = 4.548, p = 0.033). No significant differences were observed in HSS and WOMAC between the two groups at the last follow-up. HAA was - 2.44 ± 1.98° in the overcorrection group and - 1.16 ± 2.1° in the normal group, with a statistically significant difference (t = 2.32, p = 0.023). There were no significant differences in other imaging indexes. CONCLUSION: Overcorrection of varus deformity may not significantly impact clinical outcomes within 5 years post-OWHTO but may elevate the incidence of postoperative complications and lead to increased compensatory adduction of the hip.

Preoperative joint line obliquity, a newly identified factor for overcorrection, can be incorporated into a novel preoperative planning method to optimise alignment in high tibial osteotomy.

PURPOSE: The aim of this study was to analyse the factors associated with additional postoperative alignment changes after accurate bony correction by selecting only patients with well-performed bony correction as planned and develop a method of incorporating significant factors into preoperative planning. METHODS: Among 104 consecutive patients who underwent medial open wedge high tibial osteotomy (MOWHTO) between October 2019 and July 2022, 61 with well-performed bony corrections were retrospectively reviewed. The major criterion for well-performed bony correction was a difference of <1° between the simulated medial proximal tibial angle (MPTA) and the actual postoperative MPTA as measured in three dimensions. Radiographic parameters, such as the joint line convergence angle (JLCA) and joint line obliquity (JLO), were measured preoperatively and postoperatively, utilising standing and supine whole lower extremity anteroposterior, valgus and varus stress radiographs. Multiple linear regression analysis identified the factors affecting alignment changes, and a prediction model was developed. A method for applying this prediction model to preoperative planning was proposed. RESULTS: Preoperative JLCA on standing (preJLCAstd ), preoperative JLCA on 0° valgus stress radiograph (vgJLCA0 ), and preoperative JLO (preJLO) were significantly correlated with JLCA change (∆JLCA) (p < 0.001, p < 0.001, p = 0.006). The prediction model was estimated as ∆JLCA = 0.493 × (vgJLCA0 ) - 0.727 × (preJLCAstd ) + 0.189 × (preJLO) - 1.587 in. (R = 0.815, modified R2 = 0.646, p < 0.001). The proposed method resulted in a reduced overcorrection rate (p = 0.003) and an improved proportion of acceptable alignments (p = 0.013). CONCLUSION: PreJLCAstd , vgJLCA0  and preJLO can be used to estimate ∆JLCA. PreJLO was recently identified as a significant factor associated with additional alignment changes. Utilising the proposed preoperative planning and a prediction model with these factors shows promise in calibrating postoperative alignment after MOWHTO. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Anterior fusion surgery with overcorrection in the treatment of adolescent idiopathic scoliosis with Lenke 1 AR curve type: how to achieve overcorrection and its effect on postoperative spinal alignment.

BACKGROUND: The efficacy of anterior fusion with overcorrection in the instrumented vertebra for Lenke 1 AR type curves has been reported, but how to achieve overcorrection and how overcorrection affects spinal alignment are unclear. The purpose of this study was to identify the factors that cause overcorrection, and to investigate how overcorrection affects postoperative spinal alignment in the surgical treatment of Lenke 1 AR type curves. METHODS: Patients who had anterior surgery for a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) type scoliosis and minimum 2-year follow-up were included. The radiographic data were measured at preoperative, postoperative 1 month, and final follow-up. The UIV-LIV Cobb angle was determined as the Cobb angle between the upper instrumented vertebra (UIV) and the lower instrumented vertebra (LIV), and a negative number for this angle was considered overcorrection. The screw angle was determined to be the sum of the angle formed by the screw axis and the lower and upper endplates in the LIV and UIV, respectively. The change (Δ) in the parameters from postoperative to final follow-up was calculated. The relationships between the UIV-LIV Cobb angle and other radiographic parameters were evaluated by linear regression analyses. RESULTS: Fourteen patients met the inclusion criteria. Their median age was 15.5 years, and the median follow-up period was 53.6 months. The median UIV-LIV Cobb angle was -1.4° at postoperative 1 month. The median screw angle was 4.7°, and overcorrection was achieved in 11 (79%) cases at postoperative 1 month. The screw angle (r2 = 0.42, p = 0.012) and Δ FDUV-CSVL (the deviation of the first distal uninstrumented vertebra from the central sacral vertical line, r2 = 0.53, p = 0.003) were significantly correlated with the UIV-LIV Cobb angle. CONCLUSIONS: Screw placement in the UIV and LIV not parallel to the endplate, but angled, was an effective method to facilitate overcorrection in the instrumented vertebrae. The results of the present study suggest that overcorrection could bring spontaneous improvement of coronal balance below the instrumented segment during the postoperative period.

Introduction of a New Radiographic Parameter to Predict Proximal Junctional Kyphosis in Adult Spinal Deformity: UIVPTA (Uppermost Instrumented Vertebra-Pelvic Tilt Angle).

OBJECTIVE: To introduce a new sagittal parameter, uppermost instrumented vertebra-pelvic tilt angle (UIVPTA), and to determine the effects on the proximal junctional kyphosis (PJK) development in adult spinal deformity (ASD) surgery. METHODS: Patients ≥ 60 years with ASD who underwent low thoracic spine to pelvis fusion with a minimum of 2-years of follow-up were included in this study. Two groups were created according to PJK development. Various clinical and radiographic factors were compared between PJK and non-PJK groups to identify the risk factors for PJK. Cutoff value of UIVPTA for PJK development was calculated using receiver operating characteristic curve according to different pelvic incidence groups. Linear regression analysis was performed to identify factors to affect UIVPTA. RESULTS: One hundred fifity-one patients were included in this study. There were 135 female patients (89.4%). Mean age was 70.5 years. PJK developed in 65 patients (43.0%). Multivariate analysis showed that overcorrection relative to age-adjusted pelvic incidence (PI) minus lumbar lordosis (LL) (PI-LL) target and lower UIVPTA were independent risk factors for PJK. The cutoff value of UIVPTA for PJK development was calculated as 4.0° in patients with PI less than 45°, 9.5° in patients with PI between 45° and 60°, and 13.0° in patients with PI greater than 60°. Linear regression analysis showed that UIVPTA was positively affected by postoperative values of LL (coefficient = 0.505), PI-LL (coefficient = 0.674), and pelvic tilt (coefficient = 0.286). CONCLUSION: Optimal correction within the age-adjusted PI-LL combined with keeping UIVPTA within optimal range is suggested for the prevention of PJK.

Comparison of the results of the modified and classical bi-medial hang-back recession in infantile esotropia.

PURPOSE: Bi-medial rectus recession, which can also be performed using a hang-back technique, is one of the surgical treatment options for infantile esotropia (IE). This study has modified the surgical approach, with outcomes compared to the traditional hang-back technique. METHODS: The bi-medial recession was performed with a modified hang-back technique in 120 IE patients and with a traditional hang-back technique in 88 cases. Surgical outcomes were reviewed and compared retrospectively. RESULTS: The patients in the two groups were compared in terms of surgery time, inferior oblique weakening surgery, and the presence of refractive error. The differences between pre-operative and postoperative first-month, sixth-month, and first-year degrees were statistically significant (p < 0.001). CONCLUSIONS: This modified novel technique aims to avoid unwanted muscle movement in the horizontal and vertical axes and a gap in the middle of the recessed muscle, as seen in the traditional hang-back technique. Further, the modified technique resulted in less over- and under-correction as well as alphabetic pattern deviation.

Insuficiencia de convergencia con diplopía: tratamiento quirúrgico en adultos / Convergence insufficiency with diplopia: Surgical treatment in adults

Propósito Estudiar los resultados del mini plegamiento central del recto medial (RM) en las insuficiencias de convergencia de adultos con diplopía. Método Análisis retrospectivo de una muestra de 9 casos (7 mujeres). Se recogieron los datos de la dosis de plegamiento del RM, la hipercorrección inmediata posquirúrgica y al final del seguimiento, la desviación final de cerca y de lejos, la diplopía y el tiempo de seguimiento desde la cirugía. Se consideró buen resultado la desaparición de la diplopía, mejoría de los síntomas y una exotropía final de cerca ≤8dioptrías prismáticas (dp). Resultados Se realizó un mini-plegamiento central del RM en 9 pacientes (8 unilaterales). Edad media: 58,66 años (SD: 21,39). La media de la desviación preoperatoria de cerca fue de 16,22 (±2,99) dp y de lejos 6,88 (±4) dp. Se registró hipercorrección en visión lejana en 5 casos que se resolvió a los 3 meses después de la operación. No hubo hipercorrección en visión de cerca excepto en un caso. Ninguno de los casos operados presentó hipercorrección al final del seguimiento. La desviación horizontal final fue ≤8dp en visión cercana, excepto en 3 casos (media: 6,22). Los síntomas y la diplopía se resolvieron en 8 casos. El seguimiento medio fue de 10,33 meses. Conclusión El mini-plegamiento central de 1 o 2 músculos rectos mediales puede mejorar los síntomas y signos de exotropía asociados a la insuficiencia de convergencia cuando los ejercicios y los prismas son rechazados por los pacientes o cuando estos abordajes no han resuelto el problema (AU)

Objective To study the outcomes of treatment with central mini-plication of the medial rectus (MR) muscles in adult convergence insufficiency with diplopia. Methods The study sample comprised 9 cases (7 women). The length of MR plication was collected. Other variables reported were postsurgical deviation, overcorrections in the early postoperative period and at the end of follow-up, final horizontal deviation at near and at distance vision, diplopia, and mean follow-up from surgery. Surgical outcome was considered to be favorable when diplopia and symptoms were resolved and final exotropia at near was ≤8 pd at the end of follow-up. Results A central mini-plication of the MR was performed in 9 patients (8 unilateral). Mean (± SD) age was 58.66 (21.39) years. Mean near preoperative deviation: 16.22 (± 2.9) pd and distance preoperative deviation: 6.88 (± 4) pd Overcorrection at distance vision was recorded in 5 cases; this resolved by 3 months postoperatively. There was not overcorrection at near vision except one case. None of the cases operated on had overcorrection at the end of follow-up The final horizontal deviation was ≤8 pd at near vision, except for 3 cases (mean: 6.22). Symptoms and diplopia resolved in 8 cases. The mean follow-up was 10.33 months. Conclusion Central mini-plication of 1 or 2 medial rectus muscles can improve the symptoms and signs of exotropia associated with convergence insufficiency when exercises and the prisms are rejected by the patients and when these approaches have not solved the problem (AU)

Does the Amount of Correction of Sagittal Deformity Really Promote Proximal Junctional Kyphosis? Multivariate Analyses According to Uppermost Instrumented Vertebra Levels.

BACKGROUND: The present study assumed that the effects of deformity correction amounts on proximal junctional kyphosis (PJK) development after long deformity surgery would vary according to uppermost instrumented vertebrae (UIV) levels. Our study was to reveal the association between the amount of correction and PJK according to UIV levels. METHODS: Adult spinal deformity patients aged >50 years who underwent thoracolumbar fusion (≥4 levels) were included. PJK was defined by proximal junctional angles ≥15°. Presumed demographic and radiographic risk factors for PJK were evaluated including parameters regarding the correction amount such as postoperative change in lumbar lordosis and postoperative offset grouping, the value associated with age-adjusted pelvic incidence-lumbar lordosis mismatch. The patients were divided according to UIV levels of T10 or above (group A) and T11 or below (group B). Multivariate analyses were performed separately for both groups. RESULTS: The present study included 241 patients (74 for group A and 167 for group B). PJK developed in approximately half of all patients within an average of 5 years of follow-up. For group A, only body mass index (P = 0.002) was associated with PJK. No radiographic parameters were correlated. For group B, postoperative change in lumbar lordosis (P = 0.009) and offset value (P = 0.030) were significant risk factors for PJK development. CONCLUSIONS: The correction amount of sagittal deformity increased the risk of PJK only in patients with UIV at or below T11. However, it was not associated with PJK development in patients with UIV at or above T10.

Vertebral body tethering in adolescent idiopathic scoliosis with more than 2 years of follow-up- systematic review and meta-analysis.

BACKGROUND CONTEXT: Whilst spinal fusion remains the gold standard in the treatment of adolescent idiopathic scoliosis (AIS), anterior vertebral body tethering (AVBT) is gaining momentum with relatively few studies on its efficacy thus far. PURPOSE: To conduct a systematic review reporting on the early results of AVBT for patients undergoing surgery for AIS. We aimed to systematically evaluate the relevant literature pertaining to the efficacy of AVBT with respect to degree of correction of the major curve Cobb angle, complications and revision rates. STUDY DESIGN/SETTING: Systematic review. PATIENT SAMPLE: Of a total of 259 articles, 9 studies met the inclusion criteria and were analysed. Overall, 196 patients of (mean age 12.08 years) underwent an AVBT procedure for correction of AIS with a mean follow-up of 34 months. OUTCOME MEASURES: Degree of Cobb angle correction, complications and revision rates were used as outcome measures. METHODS: A systematic review of the literature on AVBT was performed for studies published between Jan 1999-March 2021 applying the PRISMA guidelines. Isolated case reports were excluded. RESULTS: Overall, 196 patients of (mean age 12.08 years) underwent an AVBT procedure for correction of AIS with a mean follow-up of 34 months. There was a significant correction of the main thoracic curve of scoliosis (mean preoperative Cobb angle 48.5°, post-operative Cobb angle at final follow-up of 20.1°, P = 0.01). Overcorrection and mechanical complications were seen in 14.3% and 27.5% of cases, respectively. Pulmonary complications including atelectasis and pleural effusion were seen in 9.7% of patients. Tether revision was performed in 7.85%, and revision to a spinal fusion in 7.88%. CONCLUSION: This systematic review incorporated 9 studies of AVBT and 196 patients with AIS. The complication and revision to spinal fusion rates were 27.5% and 7.88%, respectively. The current literature on AVBT is restricted largely to retrospective studies with non-randomised data. We would recommend a prospective, multi-centre trial of AVBT with strict inclusion criteria and standardised outcome measures.

Sodium evolution in hyponatraemia: a mixed effects model analysis of the Hyponatraemia Registry.

OBJECTIVE: Achieving recommended targets of sodium correction is challenging to physicians treating hyponatraemia. Plasma sodium has to be increased effectively, yet overcorrection must be prevented. This is often hampered by a high variability of responses to treatment. Here, we sought to delineate factors influencing sodium evolution. DESIGN: We retrospectively analysed 3460 patients from the multinational Hyponatraemia Registry comprising a wide range of hyponatraemia aetiologies and treatment strategies. METHODS: Multivariable linear mixed effects models were applied to identify predictors of plasma sodium evolution within the first 24 h of treatment. RESULTS: Evolution of sodium levels over time showed a curvilinear pattern with steeper rise at earlier time points. Baseline sodium showed the most pronounced impact with an additional increment of 3.12 mEq/L for every 10 mEq/L initial sodium reduction. With sodium increments of 1.9 mEq/L and 1.4 mEq/L per 24 h, respectively, the entities hypovolaemic and thiazide-associated hyponatraemia were independent factors for sodium evolution. Therapeutic regimens using hypertonic saline (4.6 mEq/L/24 h), tolvaptan (3.4 mEq/L/24 h), or combination therapy (2.6 mEq/L/24 h) were also associated with a significantly larger sodium rise when compared with no active treatment. CONCLUSIONS: Choice and dosing of active hyponatraemia therapy should be adjusted not only according to aetiology but most importantly to pretreatment sodium. Although counterintuitive, less aggressive therapy in more profound hyponatraemia might be safer but yet effective at least in less severe cases.

Treatment of borderline hip dysplasia with triple pelvic osteotomy: preoperative values of acetabular index and lateral center edge angle can indicate overcorrection.

INTRODUCTION: After pelvic osteotomy for the treatment of symptomatic hip dysplasia, the longevity of the hip joint can be compromised by acetabular overcorrection. This iatrogenic pincer-type deformity is considered to be one of the major risk factors for persistent pain and progressing osteoarthritis. There is evidence that acetabula in the borderline range, defined by a lateral center edge angle (LCEA) between 18° and 25°, are more delicate to be orientated physiologically. The aim of this study was to assess the quality of acetabular orientation by triple pelvic osteotomy (TPO), established by Tönnis and Kalchschmidt, especially with respect to acetabular overcorrection. MATERIALS AND METHODS: A retrospective examination on 368 consecutive hips treated with TPOs was conducted. On the preoperative pelvic radiograph and the radiographic control 5 days after surgery, LCEA, acetabular index (AI), and anterior (AWI) and posterior wall index (PWI) were measured. According to the above-mentioned definition, the hips were divided into a borderline (n = 196) and a dysplastic (n = 172) group. Acetabular overcorrection was defined as when LCEA exceeded 35°, AI was below 0° and AWI exceeded 0.60, postoperatively. The postoperative occurrence of a relevant femoroacetabular impingement was correlated to these thresholds. Statistics comprised a priori power analysis, correlation analyses and receiver operating characteristics (ROC). RESULTS: In the borderline group, in 64 hips (32.7%), LCEA and AI indicated lateral overcorrection. In the dysplastic group, in 14 hips (8.1%), solely AI indicated overcorrection. In none of the hips, relevant anterior overcorrection was detected since AWI never exceeded 0.60. Chi-square test demonstrated a significant correlation between the occurrence of a postoperative femoroacetabular impingement and LCEA exceeding 35°, as well as AI below 0° (p < 0.001, resp.). Bravais-Pearson's analysis showed a significant correlation between the pre- and postoperative values of all parameters in the borderline and the dysplasia group (p < 0.001). Thus, ROC analysis could be performed and provided preoperative cutoff values for LCEA (23°) and AI (12.5°), hinting at postoperative overcorrection. CONCLUSION: The comparison of radiographic parameters after TPO showed a considerably greater percentage of laterally overcorrected acetabula in the borderline hips than in the dysplastic hips. According to the wall indices, anterior overcorrection was not observed. ROC analysis anticipated unfavorable lateral overcorrection when preoperative LCEA was above 23° and AI below 12.5°. These findings should sensitize the surgeon to the delicate acetabular correction in borderline dysplastic hips.

Convergence insufficiency with diplopia: Surgical treatment in adults.

OBJECTIVE: To study the outcomes of treatment with central mini-plication of the medial rectus (MR) muscles in adult convergence insufficiency with diplopia. METHODS: The study sample comprised 9 cases (7 women). The length of MR plication was collected. Other variables reported were postsurgical deviation, overcorrections in the early postoperative period and at the end of follow-up, final horizontal deviation at near and at distance vision, diplopia, and mean follow-up from surgery. Surgical outcome was considered to be favorable when diplopia and symptoms were resolved and final exotropia at near was ≤8 pd at the end of follow-up. RESULTS: A central mini-plication of the MR was performed in 9 patients (8 unilateral). Mean (±SD) age was 58.66 (21.39) years. Mean near preoperative deviation: 16.22 (±2.9) pd and distance preoperative deviation: 6.88 (±4) pd Overcorrection at distance vision was recorded in 5 cases; this resolved by 3 months postoperatively. There was not overcorrection at near vision except one case. None of the cases operated on had overcorrection at the end of follow-up. The final horizontal deviation was ≤8 pd at near vision, except for 3 cases (mean: 6.22). Symptoms and diplopia resolved in 8 cases. The mean follow-up was 10.33 months. CONCLUSION: Central mini-plication of 1 or 2 medial rectus muscles can improve the symptoms and signs of exotropia associated with convergence insufficiency when exercises and the prisms are rejected by the patients and when these approaches have not solved the problem.

Overcorrection and undercorrection with fixed dosing of bolus hypertonic saline for symptomatic hyponatremia.

OBJECTIVE: Current guidelines recommend treating symptomatic hyponatremia with rapid bolus-wise infusion of fixed volumes of hypertonic saline regardless of body weight. We hypothesize that this approach is associated with overcorrection and undercorrection in patients with low and high body weight. DESIGN: Single-center, retrospective cohort study. METHODS: Data were collected on patients treated with ≥1 bolus 100 or 150 mL 3% NaCl for symptomatic hyponatremia between 2017 and 2021. Outcomes were overcorrection (plasma sodium rise > 10 mmol/L/24 h, > 18 mmol/L/48 h, or relowering therapy) and undercorrection (plasma sodium rise < 5 mmol/L/24 h). Low body weight and high body weight were defined according to the lowest (≤60 kg) and highest (≥80 kg) quartiles. RESULTS: Hypertonic saline was administered to 180 patients and caused plasma sodium to rise from 120 mmol/L to 126.4 mmol/L (24 h) and 130.4 mmol/L (48 h). Overcorrection occurred in 32 patients (18%) and was independently associated with lower body weight, weight ≤ 60 kg, lower baseline plasma sodium, volume depletion, hypokalemia, and less boluses. In patients without rapidly reversible causes of hyponatremia, overcorrection still occurred more often in patients ≤ 60 kg. Undercorrection occurred in 52 patients (29%) and was not associated with body weight or weight ≥ 80 kg but was associated with weight ≥ 100 kg and lean body weight in patients with obesity. CONCLUSION: Our real-world data suggest that fixed dosing of bolus hypertonic saline may expose patients with low and high body weight to more overcorrection and undercorrection, respectively. Prospective studies are needed to develop and validate individualized dosing models.

Vertebral body tethering: An alternative to posterior spinal fusion in idiopathic scoliosis?

Introduction: Skeletally immature patient with adolescent idiopathic scoliosis (AIS) whose curves continue to progress despite bracing should be treated surgically. Vertebral body tethering (VBT) is a non-fusion, compression-based, growth preserving alternative to posterior spinal fusion (PSF) based on the concept of 'growth modulation' to prevent possible functional complications secondary to fusion while correcting scoliotic deformity. This review aims to shed light on the indications of VBT, short- and medium-term outcomes, describe the surgical technique and associated complications, and to compare its efficacy to that of PSF. Methods: A review of peer-reviewed literature on VBT as a surgical technique, its indications, outcomes, complications, and comparison with other surgical interventions to correct AIS was conducted in December 2022. Results: Indications remain controversial and mainly include stage of skeletal maturity based on radiographic markers, curve location, magnitude and flexibility, and presence of secondary curve. Assessment of VBT clinical success should not be restricted to improvement in radiographic parameters but should include functional results and patient-centered outcomes, improved body image and pain, and durability of outcomes. In contrast to fusion, VBT seems to be associated with preserved spinal growth, shorter recovery, potentially better functional outcomes, less motion loss but possibly less curve correction. Discussion: Yet still, with VBT there exists a risk of overcorrection, construct breakage or failure of procedure which require revision and at times conversion to PSF. Patient and family preferences must be accounted for acknowledging gaps in knowledge, attributes and drawbacks of each intervention.

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.

Analysis of overcorrection to be included for planning clear aligner therapy: a retrospective study.

OBJECTIVES: To provide clinical information on overcorrection to be included in the initial digital setup to make clear aligner therapy (CAT) more efficient. MATERIALS AND METHODS: Prescription data for 150 patients (80 women and 70 men; mean age 33.7 ± 12.7 years) treated successfully with CAT (F22 Aligners, Sweden & Martina, Due Carrare, Italy) and requiring only a single, minimal finishing phase were acquired retrospectively. The inclusion criteria were Class I dental malocclusion with only minimal crowding (≤3 mm), 12-20 aligner steps per arch, no use of auxiliaries or interarch elastics, and rotations ≤25° for round-shaped teeth. The prescribed and corrective movements to be achieved in the main and finishing treatment phases, respectively, were quantified by the dedicated clear aligner setup software. The magnitudes of inclination (buccal-lingual crown tipping), angulation (mesial-distal crown tipping), rotation, intrusion, and extrusion were extracted and analyzed by tooth type, maxilla and mandible, and both arches. Descriptive statistics, that is, mean, standard deviation, and percentage, were calculated for each movement investigated. Classification and regression trees (CART) were generated using the model-based recursive partitioning approach, and the corrective movements were correlated with respect to both the amount of the movements prescribed and the tooth type. Statistical significance was set at 5%. RESULTS: Inclination and rotation required the greatest correction, whereas angulation, intrusion, and extrusion required only minimal correction. Expressed as a percentage of prescribed movement, mean corrective movements were 20.5% for inclination, 14.5% angulation, 28.4% rotation, 11.7% extrusion, and 22% intrusion. According to CART, all corrective movements except extrusion depended on both tooth type and the magnitude of prescribed movement. CONCLUSIONS: To achieve more efficient CAT, approximately 20% overcorrection should be added to the initial planning phase when planning challenging movements such as inclination and rotation.

Preoperative joint line convergence angle correction is a key factor in optimising accuracy in varus knee correction osteotomy.

PURPOSE: This study aimed to identify and prevent preoperative factors that can be influenced in preoperative planning to reduce postoperative malcorrections. METHODS: The method used in this study was a retrospective two-centre analysis of 78 pre and postoperative fully weight-bearing radiographs of patients who underwent valgus osteotomy correction due to symptomatic medial compartment osteoarthritis. A computer software (TraumaCad®) was used to aim for an intersection point of the mechanical tibiofemoral axis (mTFA) with the tibia plateau at 55-60% (medial = 0%, lateral = 100%). Postoperative divergence ± 5% of this point was defined as over- and undercorrection. Preoperative joint geometry factors were correlated with postoperative malcorrection. Planning was conducted using the established method described by Miniaci (Group A) and with additional correction of the joint line convergence angle (JLCA) using the formula JLCA-2/2 (Group B). Additionally, in a small clinical case series, planning was conducted with JLCA correction. Statistical analysis was performed using (multiple) linear regression analysis and analysis of variance (ANOVA) with p < 0.05 considered significant. RESULTS: In 78 analysed cases, postoperative malcorrection was detected in 37.2% (5.1% undercorrection, 32.1% overcorrection). Linear regression analysis revealed preoperative body mass index (BMI, p = 0.04), JLCA (p = 0.0001), and osteotomy level divergence (p = 0.0005) as factors correlated with overcorrection. In a multiple regression analysis, JLCA and osteotomy level divergence remained significant factors. Preoperative JLCA correction reduced the planned osteotomy gap (A 9.7 ± 2.8 mm vs B 8.3 ± 2.4 mm; p > 0.05) and postoperative medial proximal tibial angle (MPTA: A 94.3 ± 2.1° vs B 92.3 ± 1.5°; p < .05) in patients with preoperative JLCA ≥ 4°. The results were validated using a virtual postoperative correction of cases with overcorrection. A case series (n = 8) with a preoperative JLCA > 4 revealed a postoperative accuracy using the JLCA correction of 3.4 ± 1.9%. CONCLUSION: Preoperative JLCA ≥ 4° and tibial osteotomy level divergence were identified as risk factors for postoperative overcorrection. Preoperative JLCA correction using the formula JLCA-2/2 is proposed to better control ideal postoperative correction and reduce MPTA. The intraoperatively realised osteotomy level should be precisely in accordance with preoperative planning. LEVEL OF EVIDENCE: III, cross-sectional study.