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Orthopaedics & Traumatology, Surgery &... Feb 2019Blount disease is an asymmetrical disorder of proximal tibial growth that produces a three-dimensional deformity. Tibia vara is the main component of the deformity.... (Review)
Review
Blount disease is an asymmetrical disorder of proximal tibial growth that produces a three-dimensional deformity. Tibia vara is the main component of the deformity. Blount disease exists as two clinical variants, infantile or early-onset, and adolescent or late-onset, defined based on whether the first manifestations develop before or after 10 years of age. The pathophysiological mechanisms are unclear. In the Americas and Caribbean, Blount disease chiefly affects black obese children. Without treatment, the prognosis is often severe, particularly in the infantile form due to the development of medial tibial epiphysiodesis at about 6 to 8 years of age. In other parts of the world, the associations with black ethnicity and obesity are less obvious and the prognosis is often less severe. A consensus exists about the optimal treatment in two situations: before 4 years of age, progressive Blount disease should be corrected, preferably by a simple osteotomy; and once medial tibial epiphysiodesis has developed, both a complementary epiphysiodesis and gradual external fixator correction of the other alignment abnormalities, rotational deformity, and limb length are required. After 4 years of age, the outcome in the individual patient is difficult to predict. Magnetic resonance imaging supplies information on the morphology and vascularisation of the growth regions, thereby helping to guide treatment decisions. In the adolescent form, morbid obesity limits the treatment options. Untreated Blount disease in adults is rarely encountered. A more common occurrence is the presence of residual abnormalities at skeletal maturity in patients treated for Blount disease in childhood. Premature osteoarthritis may develop. In this situation, osteotomy may delay the need for total knee arthroplasty.
Topics: Age of Onset; Bone Diseases, Developmental; Child; Disease Progression; External Fixators; Fibula; Humans; Osteochondrosis; Osteotomy; Pediatric Obesity; Prognosis; Remission, Spontaneous; Risk Factors; Tibia
PubMed: 29481866
DOI: 10.1016/j.otsr.2018.01.009 -
Journal of Orthopaedic Surgery (Hong... 2020
Topics: Adolescent; Bone Diseases, Developmental; Humans; Osteochondrosis; Tibia
PubMed: 31898473
DOI: 10.1177/2309499019889902 -
Journal of the Belgian Society of... 2021: MRI allows to assess deformity and viability of the tibia in Blount disease.
: MRI allows to assess deformity and viability of the tibia in Blount disease.
PubMed: 34622139
DOI: 10.5334/jbsr.2557 -
Children (Basel, Switzerland) Jun 2021Blount's disease is an idiopathic developmental abnormality affecting the medial proximal tibia physis resulting in a multi-planar deformity with pronounced tibia varus.... (Review)
Review
Blount's disease is an idiopathic developmental abnormality affecting the medial proximal tibia physis resulting in a multi-planar deformity with pronounced tibia varus. A single cause is unknown, and it is currently thought to result from a multifactorial combination of hereditary, mechanical, and developmental factors. Relationships with vitamin D deficiency, early walking, and obesity have been documented. Regardless of the etiology, the clinical and radiographic findings are consistent within the two main groups. Early-onset Blount's disease is often bilateral and affects children in the first few years of life. Late-onset Blount's disease is often unilateral and can be sub-categorized as juvenile tibia vara (ages 4-10), and adolescent tibia vara (ages 11 and older). Early-onset Blount's disease progresses to more severe deformities, including depression of the medial tibial plateau. Additional deformities in both groups include proximal tibial procurvatum, internal tibial torsion, and limb length discrepancy. Compensatory deformities in the distal femur and distal tibia may occur. When non-operative treatment fails the deformities progress through skeletal maturity and can result in pain, gait abnormalities, premature medial compartment knee arthritis, and limb length discrepancy. Surgical options depend on the patient's age, weight, extent of physeal involvement, severity, and number of deformities. They include growth modulation procedures such as guided growth for gradual correction with hemi-epiphysiodesis and physeal closure to prevent recurrence and equalize limb lengths, physeal bar resection, physeal distraction, osteotomies with acute correction and stabilization, gradual correction with multi-planar dynamic external fixation, and various combinations of all modalities. The goals of surgery are to restore normal joint and limb alignment, equalize limb lengths at skeletal maturity, and prevent recurrence. The purpose of this literature review is to delineate basic concepts and reconstructive surgical treatment strategies for patients with Blount's disease.
PubMed: 34209445
DOI: 10.3390/children8070566 -
Annals of Medicine and Surgery (2012) Jun 2022Blount disease is a developmental abnormality characterized by abnormal ossification of proximal tibia, resulting in lower limb deformities with tibia vara. The... (Review)
Review
BACKGROUND
Blount disease is a developmental abnormality characterized by abnormal ossification of proximal tibia, resulting in lower limb deformities with tibia vara. The condition worsens into knee deformity, gait abnormalities, and premature medial compartment osteoarthritis if left untreated. Managements of those deformities have also advanced in line with the understanding of the deformities. Without proper care management, they could lead into residual and translational deformities, increase of recurrence, and complicate the revision surgery.
METHODS
This study aims to enrich our understanding about the recent advances of treatments for Blount disease by reviewing 15 articles published with osteotomy surgeries and fixation methods. We also highlight many aspects of pre-operative assessment and planning, post-operative complications and recurrence, patients' follow-up, and overall satisfaction from patients' self-assessment.
RESULTS
The scope of this review is considered small but still covers various efforts to manage Blount diseases, including single-stage double osteotomy, grafting fibular fragments into tibia, two comparison studies, two unique case study, and experimental techniques to manage special cases requiring novel procedures.
CONCLUSION
Careful surgical planning, acute or gradual correction options, and the use of fixator should be tailored to individual cases.
PubMed: 35734736
DOI: 10.1016/j.amsu.2022.103784 -
Journal of Clinical Orthopaedics and... Jun 2022Proximal tibia vara has drawn interest since the concept of constitutional varus was introduced. Proximal tibia vara is a condition where the knee varus tilt the tibia...
BACKGROUND
Proximal tibia vara has drawn interest since the concept of constitutional varus was introduced. Proximal tibia vara is a condition where the knee varus tilt the tibia condyle medially and shift the tibial articular surface medially. This condition affects medial proximal tibial angle measurements and the placement of the tibial implant in knee replacement surgery. Thus, it challenged the neutral knee arthroplasty alignment target because some people may present a proximal tibia vara. This study assesses the prevalence of the proximal tibia vara and the correlation to knee osteoarthritis grade.
METHODS
This retrospective study was carried out from January 2021 to June 2021. Eighty-five limbs were included with the following inclusion criteria: knee osteoarthritis patients who received a long view lower extremity radiograph. The exclusions criteria were (1) patients who had undergone arthroplasty and lower extremity surgery before and (2) valgus knee deformity. The outcomes in this study were HKAA, MAD, TAD, MPTA, PTRP, LDFA, and PTS. Intraclass correlation (ICC) using two-way mixed was used to assess the reproducibility of the radiographic parameters. Multiple logistic regression was used to evaluate the correlation between knee osteoarthritis grade and radiographs parameters (MAD and TAD).
RESULT
A total 85 limbs from 52 patients were assessed in this study. Proximal tibia vara was found in 18 knees (21%.). The logistic regression was performed to assess the correlation between the severity of the knee osteoarthritis and radiographic parameters (MAD, TAD, LDFA, and PTS) with an overall p-value < 0.001 and pseudo-R = 0.29.
CONCLUSION
A significant portion of patients with knee osteoarthritis have proximal tibia vara, and it is a pre-existing condition. Since the pre-existing proximal tibia vara affects preoperative measurements, a long-standing lower extremity x-ray is recommended to be obtained as part of knee replacement preparation.
PubMed: 35510147
DOI: 10.1016/j.jcot.2022.101871 -
Journal of Orthopaedic Surgery (Hong... 2021There 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...
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.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asian People; Bone Diseases, Developmental; Female; Humans; Knee Joint; Malaysia; Male; Middle Aged; Osteochondrosis; Retrospective Studies; Tibia; Tomography, X-Ray Computed; Young Adult
PubMed: 33632009
DOI: 10.1177/2309499021992618 -
Clinics in Orthopedic Surgery Dec 2021Anteromedial osteoarthritis is a recognized indication for unicompartmental knee arthroplasty (UKA). Favorable postoperative outcomes largely depend on proper patient...
BACKGROUD
Anteromedial osteoarthritis is a recognized indication for unicompartmental knee arthroplasty (UKA). Favorable postoperative outcomes largely depend on proper patient selection, correct implant positioning, and limb alignment. Computer navigation has a proven value over conventional systems in reducing mechanical errors in total knee arthroplasty (TKA). However, the lack of strong evidence impedes the universal use of computer navigation technology in UKA. Therefore, this study was proposed to investigate the accuracy of component positioning and limb alignment in computer navigated UKA and to observe the role of navigation in proper patient selection.
METHODS
A total of 50 knees (38 patients) underwent computer navigated UKA between 2016 and 2018. All operations were performed by the senior surgeon using the same navigation system and implant type. The navigation system was used as a tool to aid patient selection: knees with preoperative residual varus > 5° on valgus stress and hyperextension > 10° were switched to navigated TKA. We measured the accuracy of component placement in sagittal and coronal planes on postoperative radiographs. Functional outcomes were also evaluated at the final follow-up (a minimum of 16 months).
RESULTS
Nine patients had tibia vara and 14 patients had preoperative hyperextension deformity. We observed coronal outliers for the tibial component in 12% knees and for the femoral component in 10% knees. We also observed sagittal outliers for the tibial component in 14% knees and for the femoral component in 6% knees. There was a significant improvement in the functional score at the final follow-up. On multiple linear regression, no difference was found in functional scores of knees with or without tibia vara ( = 0.16) and with or without hyperextension ( = 0.25).
CONCLUSIONS
Our study further validates the role of computer navigation in desirable implant positioning and limb alignment. We encourage use of computer-assisted navigation as a tool for patient selection, as it allows intraoperative dynamic goniometry and provides real-time kinematic behavior of the knee to obviate pitfalls such as significant residual varus angulation and hyperextension that predispose early failure of UKA.
Topics: Arthroplasty, Replacement, Knee; Humans; Knee Joint; Knee Prosthesis; Osteoarthritis, Knee; Retrospective Studies; Surgery, Computer-Assisted; Tibia
PubMed: 34868498
DOI: 10.4055/cios20166 -
Clinics and Practice Mar 2020Tibia vara is an asymmetrical disorder of the proximal tibia that produces a threedimensional deformity, which was first described by Blount in 1937. A 6-year-old boy...
Tibia vara is an asymmetrical disorder of the proximal tibia that produces a threedimensional deformity, which was first described by Blount in 1937. A 6-year-old boy presented with a history of anterior knee pain with progressive bowing of his right leg over the last 1 year after having a fall while playing soccer. An early diagnosis and treatment of this disease can have a great functional impact and lead to very good health outcomes.
PubMed: 32419907
DOI: 10.4081/cp.2020.1222