The Effect of Guided Growth Surgery on Langenskiold Stage and Mechanical Axis in Early-Onset Blount Disease: A Retrospective Case Series.

INTRODUCTION: Our understanding of the efficacy of guided growth surgery with tension-band plating (TBP) in early-onset Blount disease is evolving. Preliminary work has demonstrated that TBP can normalize the mechanical axis, yet its effect on Langenskiöld stage (LS) has not previously been reported. The primary outcome of this study was improvement in LS after TBP. Secondary outcomes were improvement in LS at most recent follow-up and improvement in mechanical axis deviation (MAD), mechanical medial proximal tibial angle, and mechanical lateral distal femoral angle at treatment completion and most recent follow-up. METHODS: A retrospective review was done of patients with early-onset Blount disease treated with TBP between January 1, 2010, and December 31, 2019, across two institutions. Inclusion criteria were a radiographic diagnosis of early-onset Blount disease (LS changes present), surgery with TBP, and follow-up beyond implant removal. Radiographs before surgery, at removal of hardware (ROH), and at most recent follow-up were evaluated. RESULTS: Twenty-five limbs in 16 children who underwent TBP at a mean age of 5.8 ± 2.3 years were included. Implants were in situ a mean of 1.9 ± 0.7 years. The mean follow-up after ROH was 3.6 ± 1.4 years. LS ranged from 1 to 5 preoperatively with 14 of 25 limbs (56%) staged ≥3. LS improved in 15 of 25 limbs (60%) at ROH and in 21 of 25 limbs (84%) at most recent follow-up. Langenskiöld changes resolved in 7 of 25 limbs (28%) at most recent follow-up. Preoperatively, the MAD was varus in all limbs, but at ROH, the MAD had improved in 22 of 23 limbs with neutral or valgus alignment in 20 of 23 limbs (87%). At most recent follow-up, 16 of 23 limbs (70%) maintained improved alignment. DISCUSSION: There was improvement/resolution of LS and varus deformity in early-onset Blount disease in most patients who underwent TBP. Based on these results, TBP for early-onset Blount disease should be the first-line surgical treatment. LEVEL OF EVIDENCE: IV.

The transphyseal osteotomy for the slipped proximal tibial epiphysis in tibia vara.

This study aimed to describe a novel transphyseal osteotomy (TPO) for acute deformity correction in children with bilateral tibia vara and the atraumatic 'slipped proximal tibial epiphysis' (SPTE) entity. We described the clinical and radiological findings in five children (10 limbs) with tibia vara that were treated with the TPO. The criteria for the SPTE were met in nine (9/10) cases. The surgical technique and short-term results of the TPO are reported. The median age was 9 years (range, 6-9), with obesity (BMI > 95th centile) present in all children. The medial tibial plateau was not significantly depressed (the median angle of depression of the medial plateau measured 30° (range, 20°-32°). The mean medial proximal tibial angle of 33° (range, 8°-71°) was corrected to 82° (range, 77°-86°), the mean anatomic posterior proximal tibial angle of 48° (range, 32°-70°) was corrected to 72° (range, 61°-86°), and the median internal tibial rotation of 45° (range, 20°-50° internal rotation) was corrected to neutral rotation (range, 10° internal-10° external rotation). There were two complications: one case of recurrent deformity and one case of intra-articular extension of the osteotomy. We describe a novel TPO that aims to simultaneously correct all aspects of the deformity, stabilise the physis, and prevent recurrence through epiphysiodesis. Further research is required to determine its efficacy and safety. The atraumatic SPTE appears to represent a specific morphological presentation in tibia vara. Level of evidence: 4.

Fixed-Bearing Unicompartmental Knee Arthroplasty in Tibia Vara Knees Results in Joint Surface Malalignment and Varus Joint Line Obliquity, but Does Not Affect Functional Outcomes at Greater Than 5 Years Follow-Up.

BACKGROUND: This study aimed to investigate the clinical outcomes of fixed-bearing medial unicompartmental knee arthroplasty (UKA) for tibia vara knees and the associated changes in joint space malalignment (JSM) and joint line obliquity (JLO). METHODS: We retrospectively analyzed a consecutive group of 100 patients who underwent fixed-bearing medial UKA with a preoperative medial proximal tibia angle (MPTA) ≥86° (n = 50) and MPTA <86° (n = 50) and who had a minimum 5-year follow-up. Radiological parameters, including the hip-knee-ankle angle, MPTA, and the postoperative JSM and JLO, were measured. Functional evaluation was performed using the range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index score. RESULTS: The MPTA <86° group showed significantly higher postoperative JLO (91.8 versus 90.4°, respectively; P = .002) and JSM (6.1 versus 4.2°, respectively; P = .026) compared to the MPTA ≥86° group. Functional outcomes, including range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores, were not significantly different between the 2 groups. CONCLUSIONS: Fixed-bearing medial UKA is a safe and effective surgical option for patients who have tibia vara knees, as an increase in JLO and JSM postoperatively does not have a clinically relevant impact, even after a minimum 5-year follow-up.

The Effect of Socioeconomic Deprivation on Radiographic Deformities in Children With Blount Disease.

BACKGROUND: Blount disease can occur at any time during the growth process, primarily with a bimodal distribution in children younger than 4 years old and adolescents. The disease process most commonly presents in Black adolescents, with disease severity positively correlated with obesity. Given the known associations among race, obesity, and socioeconomic status, we investigated the relationship between the degree of social deprivation and severity of lower extremity deformities among a community-based cohort with Blount disease. METHODS: A retrospective review of hospital records and radiographs of patients with previously untreated Blount disease was conducted. Patients were classified as having early-onset or late-onset Blount disease based on whether the lower limb deformity was noted before or after the age of 4 years. The area deprivation index (ADI), a nationally validated measure that assesses socioeconomic deprivation by residential neighborhood, was calculated for each patient as a surrogate for socioeconomic status. Higher state (range: 1 to 10) or national (range: 1 to 100) ADI corresponds to increased social deprivation. Full-length standing radiographs from index clinic visits were evaluated by 2 reviewers to measure frontal plane deformity. The association of ADI with various demographic and radiographic parameters was then analyzed. RESULTS: Of the 65 patients with Blount disease, 48 (74%) children were Black and 17 (26%) were non-black children. Nineteen children (32 limbs) had early-onset and 46 children (62 limbs) had late-onset disease. Black patients had significantly higher mean state (7.6 vs. 5.4, P =0.009) and national (55.1 vs. 37.4, P =0.002) ADI values than non-black patients. Patients with severe socioeconomic deprivation had significantly greater mechanical axis deviation (66 mm vs. 51 mm, P =0.008). After controlling demographic and socioeconomic factors, the results of multivariate linear regression showed that only increased body mass index (ß=0.19, 95% CI: 0.12-0.26, P <.001) and state ADI (ß=0.021, 95% CI: 0.01-0.53, P =.043) were independently associated with greater varus deformity. CONCLUSIONS: Socioeconomic deprivation was strongly associated with increased severity of varus deformity in children with late-onset Blount disease. Our analysis suggests that obesity and socioeconomic factors are the most influential with regard to disease progression. LEVEL OF EVIDENCE: Level III.

Not all the bowlegs is rickets! (a case report).

Bowing of the legs is common in childhood. Most times it is considered to be rickets without considering other possibilities. Blount´s disease is a close differential diagnosis which is developmental deformity characterized by intorsion of tibia leading to varus angulation. This case report aims to encourage pediatricians to expand their vision and consider other possibilities when a case of bowing of legs is encountered. Here we report a case of a four-year-old boy with bowing of both legs noticed first at 2.5 years of age. There was no history suggestive of trauma. Development of the child was age appropriate in all domains. He was receiving treatment for rickets for 1.5 years in form of oral vitamin D3 and calcium supplementations. He had no other clinical signs of rickets like frontal bossing, widening of wrists, and rachitic rosary except bowing of legs. His biochemical parameters did not show any alterations that would support the diagnosis of rickets. Weight-bearing radiographs of lower limbs showed medial intorsion of bilateral tibia with metaphyseo-diaphysial angle to be 25º on the right side and 20º on the left side, which was beyond the physiological normal angulation, therefore he was diagnosed as a case of Blount´s disease, stage III as per Langenskiöld classification. All the bow legs is not always rickets in pediatric practice. Therefore, various differential diagnoses should be kept in mind as early diagnosis and intervention can change a child´s life.

Guided Growth for Varus Deformity Following Early Tibial Osteotomy in Infantile Tibia Vara-A Multi-Center Study.

BACKGROUND: Despite early osteotomy, many patients with infantile tibia vara (ITV) have persistent or recurrent varus deformity and disordered growth at the medial proximal tibial physis. Our hypothesis was that lateral tibial tension band plating (LTTBP) could guide correction. METHODS: A retrospective review at 6 centers of 15 patients (16 extremities) was performed of LTTBP for varus deformity following early osteotomy in ITV, diagnosed≤4years of age. Correction of deformity parameters on digital standing anteroposterior lower extremity radiographs determined outcome. RESULTS: Twenty-two LTTBP procedures were performed at mean age of 7.5 years, including 4 revisions for implant failure and 2 reimplantations for recurrence. Single event LLTBP, improved the medial proximal tibial angle with a mean change of 13.4 degrees (0.39 degrees/month). Eleven limbs had preoperative mechanical lateral distal femoral angle (mLDFA)>90 degrees. While n degree femoral procedures were performed, at study end, 11 femurs had mechanical lateral distal femoral angle≤90°. Pretreatment, 13 extremities had mechanical axis zone (MAZone) III varus (81%) and 3 had MAZone II varus (19%). LTTBP's were able to initially correct 13 limbs to MAZone I or valgus but 4 limbs rebounded to MAZone II varus after implant removal. Final limb alignment, after all surgeries and rebound, included 9 in MAZone I, 5 in MAZone II varus and 2 in MAZone III varus. Average follow-up was 3.0 years at mean 10.7 years of age. Fifteen procedures resulted in improvement in MAZone and 7 had no change. On average, those that improved were younger (7.3 vs. 8.0 y), weighed less (45.5 kg with body mass index 26.5 kg/m 2 vs. 67.8 kg and body mass index 35.7 kg/m 2 ), had lower mechanical axis deviation (37.1 mm vs. 43.9 mm), lower medial physeal slope (61.7 vs. 68.7 degrees) and had a higher percentage of open triradiate phases (87 vs. 57%). CONCLUSIONS: LTTBP for residual varus, after initial osteotomy in ITV, resulted in 81% of limbs initially achieving MAZone I or valgus with implant failure revisions and femoral remodeling. Rebound after implant removal reduced the corrected rate to 56%. Ninety-four percent avoided osteotomy during the study period. LEVEL OF EVIDENCE: IV.

Comparative Evaluation of the Radiographic Parameters for Screening Early Blount Disease.

BACKGROUND: Radiographic findings in young children with physiological bowing sometimes difficult to distinguish from early Blount disease. However, early diagnosis of the disease is critical because of the poor treatment outcomes for Blount disease. In this study, we aim to evaluate the accuracy of the metaphyseal-diaphyseal angle (MDA) compared with the medial metaphyseal beak (MMB) angle for differentiating between physiological bowing and early Blount disease and to determine which parameter to adequately screen for the subsequent development of Blount disease. METHODS: A retrospective study was conducted on children aged 1 to 3 years old who were brought to our outpatient clinic with bowed leg between 2000 and 2017. Data on the patients' age, sex, and affected sides were collected. Radiographic measurements of the femorotibial angle (FTA), MDA, and MMB angle were evaluated from the initial radiographs. An observer repeated the measurements on all the radiographs 2 weeks after they were first done. RESULTS: In total, 158 legs were considered from 79 children (48 males/31 females), whose average age was 26.0±6.1 months old. Eighty-seven legs were diagnosed with Blount disease and 71 legs had physiological bowing. Using single cutoff values of 16 degrees for the MDA showed low sensitivity (50.6%), very high specificity (100.0%), and a very high positive predictive value (PPV); while using MMB angle cutoff values ≥122 degrees showed very high sensitivity (92.0%), high specificity (80.3%), and a high PPV. Considering the MDA and MMB angle simultaneously showed very high sensitivity (93.1%), high specificity (80.3%), and a high PPV. The area under the receiver operating characteristic curve of the MDA and MMB showed excellent (0.89) and outstanding (0.93) discriminative ability, respectively. When combining the MDA and MMB angles, it was also considered outstanding performance (area under the receiver operating characteristic curve=0.95). CONCLUSIONS: The MMB angle represents a potential radiographic screening parameter for predicting early Blount disease in children 1 to 3 years old, offering high sensitivity and specificity. The MDA showed excellent specificity as a confirmation parameter for Blount disease patients. Applying both the MDA and MMB angles is another option to increase early recognition and confirm the diagnosis in early Blount disease patients. LEVEL OF EVIDENCE: Level II.

Guided Growth Procedures: Broken Tension Band Implants in Patients With Blount Disease.

BACKGROUND: Tension band plate and screw implants (TBI) are frequently used for temporary hemiepiphyseodeses to manage angular deformity in growing children. The reported implant breakage rate, when TBI is used for deformities in patients with Blount disease, is much higher than when used in other diagnoses. Our hypothesis is that perioperative factors can identify risks for TBI breakage. METHODS: A retrospective case-control study was performed of 246 TBI procedures in 113 patients with Blount disease at 8 tertiary pediatric orthopaedic centers from 2008 to 2018. Patient demographics, age at diagnosis, weight, body mass index (BMI), radiographic deformity severity measures, location, and types of implants were studied. The outcome of implant breakage was compared with these perioperative factors using univariate logistic regression with Bonferroni correction for multiplicity to significance tests. RESULTS: There were 30 broken implants (12%), failing at mean 1.6 years following implantation. Most failures involved the metaphyseal screws. Increased BMI was associated with increased implant breakage. Increased varus deformity was directly associated with greater implant breakage and may be a more important factor in failure for those below 7 years compared with those 8 years or above at diagnosis. There was a 50% breakage rate for TBI with solid 3.5 mm screws in Blount disease with onset 8 years or above of age. No demographic or implant factors were found to be significant. CONCLUSIONS: Breakage of TBI was associated with increased BMI and varus deformity in patients with Blount disease. Larger studies are required to determine the relative contribution and limits of each parameter. Solid 3.5 mm screws should be used with caution in TBI for late-onset Blount disease. LEVEL OF EVIDENCE: Level III.

Percutaneous hemiepiphysiodesis using transphyseal screws for adolescent tibia vara.

Hemiepiphysiodesis around the knee is becoming the mainstay procedure in adolescents for a wide range of aetiological deformities, when considering adolescent tibia vara (ATV), the published series have variable results. The purpose of this study was to review our experience with the percutaneous transphyseal screw (PETS) in these patients followed until bone maturity. We analysed the charts from 13 patients (20 knees) that underwent lateral tibial hemiepiphysiodesis using PETS. The radiographs were accessed before surgery, at implant removal, when occurred, and at the final follow-up. The clinical evaluation noted if there were complaints regarding pain or range of motion, and the radiographic assessment included: the femorotibial angle, the mechanical axis zone, the anatomic lateral distal femoral angle, and medial mechanical proximal tibial angle. There was one overcorrection, and after the screw removal (14 knees), rebound was observed in two knees modifying the result from excellent to good in all three knees. No bone bars and no implant breakage were observed. At the last appointment, all patients had normal knee range of motion, and two patients had unilateral alignment complaints, one of whom referred to occasional pain. Overall, the surgery was excellent in 12 knees (60%), good in six knees (30%), and poor in two knees (10%). This technique is indicated to be well tolerated and effective for treating ATV. When a complete correction cannot be obtained, in our opinion, it is advantageous to at least stabilise the deformity and postpone osteotomies until after skeletal maturity. Level of Evidence: Level IV - Case Series, Therapeutic Study.

Recurrence in infantile tibia vara (Blount disease) after high tibia and fibula osteotomy.

Infantile Tibia Vara (ITV or Blount disease) often recurs after surgical correction of the deformity. Vastly different recurrence rates have been reported in the literature. The main objective of this study was to identify any risk factors for the recurrence of ITV following high tibia and fibula valgus osteotomy. This was a retrospective cohort comparative study of 44 patients with ITV (16 with bilateral involvement) who underwent a total of 60 high tibia and fibula osteotomies. Demographics, family history, BMI, walking age and age at surgery were recorded. Pre-, post- and follow-up weight-bearing anatomic femorotibial angles, were measured from X-rays. The limbs were divided into Langenskiöld stages based on preoperative X-rays. The study found an overall recurrence rate of 63.3% for children who had a high tibia and fibula osteotomy for ITV. Surgery after the age of 4 years, advanced Langenskiöld stages (stages 3-5) and overcorrection of less than 15 degrees of valgus were identified as risk factors for recurrence. This study recommends performing a high tibia and fibula valgus osteotomy before the age of 4 years in ITV to avoid recurrence. Overcorrection of the high tibia and fibula osteotomy to 15 degrees of valgus should be considered in older patients with high Langenskiöld stages at time of presentation.

Langenskiöld classification of tibia vara: a multicenter study on interrater reliability.

Since 1952, when Langenskiöld introduced his six-stage classification on roentgenographic morphologies of tibia vara, this method has been used extensively in Orthopaedic studies. Different studies have tried to determine the reliability of this method. Although there are scarce reports of major variability in using Langenskiöld classification, but the question still remains, as to whether using expert subspecialists and MRI would improve its reliability. The aim of this study is to evaluate inter-rater reliability of Langenskiöld classification using simple radiograph and MRI, by expert raters. This is a cross-sectional multicenter study, involving patients from 4 tertiary pediatric orthopedic centers in France and Iran. Radiograph and MRI (T1, T2, fat saturation) of the affected knees were independently classified by 12 academy members from France and Iran: six pediatric fellowship orthopedic surgeons and six musculoskeletal radiologists. All data were analyzed afterwards by an independent researcher. Mean weighted kappa for agreement based on radiograph and MRI was 0.47 and 0.45, respectively. Mean percent of total agreement was 46.6 and 40.8% in the same order. Kappa statistics for the new grouping were 0.53 and 0.46 for roentgenograms and MRIs, respectively. The new regrouping was proposed so that each group would need a different treatment strategy. Fleiss kappa statistics for group B (stages 2 and 3), rose from (0.33 and 0.09) to 0.44. These values for group C (stages 4 and 5) rose from (0.42 and 0.11) to 0.54. This study concludes that Langenskiöld's classification when used by experts, still has a moderate inter-rater reliability at best. This variability is most at stages 2, 3, and 4; and can cause different treatment approaches. Use of MRI does not have a significant effect on its reliability. Regrouping the stages improved the inter-rater reliability. Level of evidence: III.

Acute correction of severe complex adolescent late-onset tibia vara by minimally invasive osteotomy and simple circular fixation: a case series with 2-year minimum follow-up.

BACKGROUND: Despite multiple published reviews, the optimum method of correction and stabilisation of Blount's disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. Weighing up the pros and cons and to establish if this method would be the method of choice in similar severe cases especially in a context of limited resources. METHODS: This study was conducted between November 2016 and July 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32 tibiae) who had correction of severe late-onset tibia vara by proximal tibial osteotomy and Ilizarov external fixator. The mean age at the time of the operation was 16.6 (± 2.7) years (range 13-22). RESULTS: The mean proximal tibial angle was 65.7° (± 7.8) preoperatively and 89.8° (± 1.7) postoperatively (p < 0.001). The mean mechanical axis deviation improved from 56.2 (± 8.3) preoperatively to 2.8 (± 1.6) mm postoperatively (p < 0.001). The mean femoral-tibial shaft angle was changed from -34.3° (± 6.7) preoperatively to 5.7° (± 2.8) after correction, with degree of correction ranging from 25° to 45°. Complications included overcorrection (three cases 9%) and pin tract infection (eight cases 25%). The mean Hospital for Special Surgery knee scoring system (HSS) improved from 51.03 (± 11.24) preoperatively to 94.2 (± 6.8) postoperatively (p < 0.001). The mean length of follow up period 33.22 (± 6.77) months, (rang: 25-46 months). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity. CONCLUSION: This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities.

Blount disease and familial inheritance in Ghana, area cross-sectional study.

Objective: The objective of this study is to study familial inheritance for Blount disease to create better understanding of the aetiology of Blount disease. Methods: After reviewing patient files and conventional roentgenologic imaging, 139 patients with Blount disease were included in this cross-sectional study, of which 102 patients were interviewed. During the interviews, patient characteristics and family history were collected. Blood samples were taken from five patients and three families and a whole exome sequencing was performed. Results: Although patients came from all over the country, 90% of the patients belonged to the Akan tribe. A positive family history was found in 63 families (62%), of which, almost two-third had a positive family history in a first-degree family member. In most of the cases (64%), the varus legs resolved over time. In 9%, severe bowing remained 'just like the patient'. The results of the whole exome sequencing did not show a genetic predisposition. Conclusion: This study describes a large group of Blount patients. Because of the high numbers of positive family history and the centralisation of patients in the Akan region, a familial predisposition is suggested. Further genetic research is essential for better understanding of the possible multifactorial aetiology in Blount disease.

Tibia vara in Asians: Myth or fact? Verification with three-dimensional computed tomography.

BACKGROUND: There is a common perception among surgeons that Asian tibiae are significantly more varus compared to non-Asians, contributed both by an acute medial tibial proximal angle (MPTA) and diaphyseal bowing. Insight into the normative morphology of the tibia allows generation of knowledge towards disease processes and subsequently planning for corrective surgeries. METHODS: Computed tomography (CT) scans of 100 normal adult knees, aged 18 years and above, were analysed using a 3-dimensional (3D) analysis software. All tibiae were first aligned to a standard frame of reference and then rotationally aligned to the tibial centroid axis (TCAx) and the transmalleolar axis (tmAx). MPTA was measured from best-fit planes on the surface of the proximal tibia for each rotational alignment. Diaphyseal bowing was assessed by dividing the shaft to three equal portions and establishing the angle between the proximal and distal segments. RESULTS: The mean MPTA was 87.0° ± 2.2° (mean ± SD) when rotationally aligned to TCAx and 91.6° ± 2.7° when aligned to tmAx. The mean diaphyseal bowing was 0.1° ± 1.9° varus when rotationally aligned to TCAx and 0.3° ± 1.6° valgus when aligned to tmAx. The mean difference when the MPTA was measured with two different rotational alignments (TCAx and tmAx) was 4.6° ± 2.3°. No statistically significant differences were observed between males and females. Post hoc tests revealed statistically significant difference in MPTA between different ethnic sub-groups. CONCLUSION: The morphology of the proximal tibiae in the disease-free Asian knee is inherently varus but not more so than other reported populations. The varus profile is contributed by the MPTA, with negligible diaphyseal bowing. These implications are relevant to surgical planning and prosthesis design.

Predictive Factors for Recurrence in Infantile Blount Disease Treated With Tibial Osteotomy.

BACKGROUND: This study aimed to determine the recurrence rate in infantile Blount disease (IBD) in a cohort of patients treated with a tibial osteotomy; and also to identify which factors were associated with recurrence. METHODS: We reviewed the records of 20 patients, under the age of 7 years, with IBD (35 involved extremities) treated by proximal tibial realignment osteotomy to physiological valgus at a single institution over 4 years. We then analyzed the data to determine the rate of recurrence and identify the risk factors for recurrence. RESULTS: The mean age of the included patients was 4.2 years (range, 2 to 6 y). We observed a recurrence rate of 40% (n=14) at a mean follow-up of 42 months (range, 21 to 72 mo). Knee instability [odds ratios OR, 6.6; 95% confidence interval (CI), 2.0-22.2], Langenskiöld stage (OR, 6.3; 95% CI, 2.0-19.4), and severity of the deformity, as measured by medial physeal slope (MPS) (OR, 1.2; 95% CI, 1.1-1.4), were associated with recurrence. On multiple logistic regression analysis, MPS remained the most relevant predictor of recurrence. Receiver operating curve analysis showed that an MPS ≥60 degrees predicted recurrence with a sensitivity of 79% and specificity of 95% (area under the curve=0.925). Postoperatively, increased varus alignment on weight-bearing as measured by the tibio-femoral angle was indicative of knee instability and associated with increased odds of recurrence (OR, 1.5; 95% CI, 1.1-1.9; P=0.004). CONCLUSIONS: We observed a recurrence rate of 40% in children with IBD under 7 years treated with acute correction to a tibio-femoral angle of 5 to 10 degrees valgus through a dome proximal tibial osteotomy. Knee instability, Langenskiöld stage, and MPS were associated with recurrence. Cases with an MPS ≥60 degrees seem to be particularly at risk for recurrence. Further research is needed to validate these findings. LEVEL OF EVIDENCE: Level IV.

Predictors of early recurrence following high tibial osteotomy for infantile tibia vara.

AIMS: Recurrence of deformity following high tibial osteotomy (HTO) for infantile tibia vara (ITV) is common. The purpose of this study was to identify risk factors for recurrent deformity following HTO for ITV and to develop a simple scoring system to quantify the risk of recurrence in each patient. PATIENTS AND METHODS: We identified 69 patients with 102 affected limbs undergoing HTO for ITV from 2005 to 2015. Demographic and radiographic data was collected. On pre-operative radiographs, we measured the mechanical varus angle (MVA), the condyle shaft angle (CSA), the plateau depression angle (PDA), the metaphyseal-diaphyseal angle (MDA), and the mechanical lateral distal femoral angle (LDFA). On the post-operative radiographs, we measured the MVA and MDA only. We classified each limb according to the Langenskiold and LaMont classifications. Statistical analysis was performed to identify variables predictive of recurrent deformity, and these variables were analysed to develop a scoring system to quantify risk of recurrence following HTO. RESULTS: Of the examined variables, age older than 4.5 years, an MVA of more than 23° and a LaMont type C deformity were predictive of recurrent deformity. The incidence of recurrent deformity increased from 14.3% with no risk factors to 91.3% with three risk factors present. CONCLUSION: Advanced deformity and age above 4.5 years at the time of surgery predicts recurrent deformity following HTO for ITV. Surgery should be performed as soon as possible, and caregivers should be counselled appropriately regarding risk of recurrence and the need for future surgery.

Blount's disease - an up-to-date insight with contemporary treatment guidelines deduced from critical analysis of a large 146 surgical case series.

To elucidate an up-to-date insight and derive clear treatment guidelines for Blount's disease deduced from critical analysis of 146 surgical case series. Cases were presented and analyzed separately under its two basic clinical groups and the author further derived four subcategories under each of these two groups; the first basic group was the early onset clinical variant; infantile tibia vara (ITV) included 56 cases. The second group was the late onset clinical variant; late onset tibia vara (LOTV) included 90 cases. Different operative procedures used for treatment of these cases were proximal tibial osteotomy (PTO), temporary eight-plate proximal lateral tibial hemiepiphyseodesis (PLTH), or medial plateau elevation either on a monomodal or multimodal line of treatment. After a mean follow-up period of ~5 (2-12) years, the results were critically analyzed using case series descriptive analysis. In ITV variant, both PTO and temporary eight-plate PLTH monomodal line of treatment gave satisfactory results for de-novo (stages I, II, and III) subcategory while multimodal line of treatment was needed for achieving satisfactory results for neglected (stages IV, V, and VI) and relapsed subcategories. For LOTV variant, PTO monomodal line of treatment gave satisfactory results when applied for treatment of its de-novo subcategory. The derived treatment guidelines for Blount's disease can be of value for recruiting the most suitable treatment modality for each case entity of the disease, leading to satisfactory outcome with prevention of recurrence.

The Medial Elevation Osteotomy for Late-presenting and Recurrent Infantile Blount Disease.

BACKGROUND: Late-presenting or recurrent infantile Blount disease (IBD) is characterized by knee instability because of medial tibial plateau depression, multiplanar proximal tibial deformity, and potential distal femoral deformity. The surgical treatment strategy includes medial elevation osteotomy to stabilize the knee, together with proximal tibial osteotomy to correct alignment, and lateral epiphysiodesis to prevent a recurrence. This study's primary aim was to describe the clinical outcomes of medial elevation osteotomy for the management of late-presenting and recurrent IBD. METHODS: The authors reviewed the records of 48 children (64 limbs) who had medial elevation osteotomies and lateral epiphysiodesis, combined with proximal tibial realignment in 78% (50/64) of cases in the same setting. IBD was bilateral in 33% (16/48), 77% (37/48) were female individuals, and 42% (20/48) were obese. RESULTS: The mean age at surgery was 8.6 years (SD, 1.6; range, 5.8 to 12.8). The mean preoperative tibiofemoral angle (TFA) was 28±11 degrees (8 to 55 degrees), and the mean angle of depression of the medial plateau (ADMP) was 49±8 degrees (26 to 65 degrees). Distal femoral valgus was present in 27% (17/62) and varus in 10% (6/62) children. At a median follow-up of 3.2 years (range, 1 to 6.2 y), the median TFA was 1-degree valgus (interquartile range, 7-degree varus to 5-degree valgus), whereas the ADMP was corrected to 25±8 degrees (8 to 45 degrees). Obesity was associated with more severe deformity as measured by TFA (P<0.001) but did not affect the extent of medial plateau depression (P=0.113). The good or excellent alignment was achieved in 75% (47/63) limbs. Obesity was associated with an increased risk of recurrence [odds ratio (OR), 5.21; 95% CI, 1.26-21.63; P=0.023]. Age at the surgery or previous surgery was not associated with recurrence (OR, 1.29; 95% CI, 0.88-1.88; P=0.195 and OR, 1.22; 95% CI, 0.36-4.17; P=0.746). Obesity and residual instability were associated with an increased risk of poor alignment at the latest follow-up (OR, 3.24; 95% CI, 1.02-10.31; P=0.047 and OR, 1.21; 95% CI, 1.05-1.40; P=0.008). CONCLUSION: Late-presenting or recurrent IBD is a surgical challenge. Obesity is associated with more severe deformity. Medial elevation osteotomy combined with lateral proximal tibial epiphysiodesis and metaphyseal tibial realignment osteotomy will result in restoration of lower limb alignment in a high proportion of cases. The recurrent deformity may be the result of failed epiphysiodesis. Obesity and residual instability are associated with an increased risk of poor alignment. Although complications are rare, surgical measures to decrease risk should be followed. LEVEL OF EVIDENCE: Level IV.

Infantile Tibia Vara (Blount Disease) with Iatrogenic Changes Causing Residual Tibial Deformities.

Treatment of infantile tibia vara or Blount disease (ITV/BD) in patients < 3 years old and Langenskiold stages I-III consists of orthosis and, in relapsing cases, proximal tibial osteotomy and/or proximal tibial guided growth laterally with a tension band plate. Our aim was to evaluate the results of treatments in a consecutive group. After Institutional Review Board approval, data from 2002 to 2018 were collected. Thirty-nine knees (average age 22.4 months) with ITV/BD were treated with orthoses, and 10 knees failed. Six knees showed hyperintense T2-weighted signal in the medial proximal tibial epiphyseal cartilage on magnetic resonance imaging. Three of six knees with tibial osteotomy failed and underwent guided growth. Tibial plateau slopes were abnormal medially from the ITV/BD and laterally from the guided growth (triangular physis and depressed plateau deformities) because of factors such as orthotic treatment, tibial osteotomy, magnetic resonance imaging "physis severity score," and guided growth. (Journal of Surgical Orthopaedic Advances 29(3):141-148, 2020).

Medial Metaphyseal Beak Angle as a Predictor for Langenskiöld Stage II of Blount's Disease.

OBJECTIVE: To determine the medial metaphyseal beak (MMB) cut-off angle predicting Langenskiöld stage II of Blount's disease and to study the intra-observer and inter-observer reliabilities of angle measurements and the influence of the experience level of observers. METHODS: A retrospective study was conducted on children aged 2-4 years from January 2000 to December 2017. Children were identified through a computer-based search. Children with Langenskiöld stage II of Blount's disease who had been initially evaluated at our institution were categorized into Blount group and children who were diagnosed with physiologic bowing were categorized into control group. Data on the patients' ages, genders, and affected sides were collected. The MMB angles were measured on standing anteroposterior radiographs of the knees. The angle was formed between one line drawn parallel to the medial cortex of the proximal tibia, and a second line running from the intersection of the first line with the proximal tibial metaphysis through to the most distal point of the MMB. Measurements were independently performed by six observers. All observers repeated the measurements 2 weeks after they were first done. RESULTS: There were 148 legs from 79 children (48 males and 31 females) with an average age of 28.6 months. The average MMB angle of the Blount group was 128.52° ± 5.38° (P-value <0.001) and of the control group was 114.45° ± 4.89°. The average femorotibial angle of the Blount group was 15.48° ± 6.81° (P-value <0.001) and of the control group was 7.71° ± 7.94°. The receiver operating characteristic curve showed that an MMB angle >122° (sensitivity 92.7%; specificity 97.0%) was associated with Langenskiöld stage II. The intraclass correlation coefficient of the intra-observer reliability ranged from 0.93-0.97, and the inter-observer reliability was 0.93. CONCLUSIONS: By using anteroposterior (AP) radiographs of the knee, the MMB angle is a potential radiographic parameter to distinguish between Langenskiöld stage II of Blount's disease and physiologic bowed legs, with an MMB angle >122° predicting Langenskiöld stage II.