Analysis of lower extremity alignment in achondroplasia: interobserver reliability and intraobserver reproducibility

This study was designed to evaluate the reliability and reproducibility of frontal plane malalignment measurements using the mechanical axis deviation method in achondroplasia and to determine whether the patient's age has any influence on these measurements. A total of 150 anteroposterior standing radiographs of the lower extremities were randomly selected for the study. Radiographs were divided into three groups according to age: group 1, younger than 6 years of age; group 2, 6 to 10 years of age; group 3, older than 10 years of age. Interobserver agreement for the medial proximal tibial angle and the lateral distal tibial angle measurements were poor (0.32 and 0.38, respectively) in group 1, but agreement increased between observers with increasing patient age. Good to excellent intraobserver reproducibility was found in all groups, except measurement of the medial proximal tibial angle in group 1, where the results were poor (0.36). Significant measurement errors in the proximal and distal tibial joint lines are possible in children less than 6 years of age with achondroplasia.     

Radiographic parameters improve lower extremity prosthetic alignment

Purpose

The goal of prosthetic fitting is to provide comfort and functionality to the patient. It is thought that incorporating the use of standing anterior–posterior long leg radiographs (LLR) into the fitting of lower extremity prostheses will provide an objective guide when making adjustments, and be a better assessment of alignment. This study compares prosthetic alignment before and after radiography-guided adjustments.

Method

This retrospective study was performed at a multidisciplinary amputee clinic on patients with congenital and/or acquired limb deficiencies. Their prosthetic alignment was evaluated by LLR and adjusted as needed. Satisfactory alignment was defined as a mechanical axis angular deviation of ≤1° and a leg length discrepancy of ≤10 mm.

Results

A total of 45 unique prostheses from 24 subjects (10 female and 14 male) were included. Post-adjustment radiographs were obtained from 29 prostheses. After the initial prosthetic fitting, the probability of a satisfactory fit was 20.0 % (95 % CI 10.9–34.9 %). Following the baseline adjustment, the probability of a satisfactory fit improved to 53.3 % (95 % CI 37.5–70.9 %). After adjustment number 4, the probability of a satisfactory fit further improved to 76.7 % (95 % CI 41.9–98.0 %). There were also significant improvements in distal offset distance (p = 0.0040) and leg length discrepancy (p = 0.0206). The distal offset distance decreased by an average of 10.7 mm (95 % CI 3.6–17.8), and leg length discrepancy decreased by an average of 3.0 mm (95 % CI 00.48–5.5).

Conclusions

The addition of LLRs to existing fitting methods significantly improves prosthetic alignment and length.     

Lower extremity alignment in children with spina bifida.

Our purpose was to describe the natural history of lower extremity alignment in spina bifida patients. We prospectively evaluated all spina bifida patients seen at the Children's Hospital in Seattle since 1971 and at the Royal Children's Hospital in Melbourne since 1979. Serial examinations were performed on 434 patients, ranging from birth to 23 years of age. The lower limbs of children with spina bifida had neutral alignment at birth that gradually increased to 6 degrees of valgus--a pattern different from normal children. Valgus greater than 10 degrees was observed in only 6% of patients, and the degree of angular deformity was not affected by walking, the use of an above-knee orthosis, or neurosegmental level. An above-knee orthosis to prevent malalignment does not appear to be warranted and continued ambulation does not significantly contribute to lower extremity deformity.     

Axial alignment of the lower extremity in Chinese adults

BACKGROUND: The restoration of normal axial alignment of the lower extremity is important to surgeons who perform reconstructive surgery of the knee. However, data on the normal alignment of the lower extremity in Chinese adults are not available. METHODS: The axial alignment of the lower extremity in twenty-five adult male and twenty-five adult female volunteers of southern Chinese origin was measured on weight-bearing radiographs of the entire lower limb. The mean age was twenty-four years for the male volunteers and twenty-three years for the female volunteers. The results were compared with those of two similar studies of white volunteers in the United States. RESULTS: The medial inclination of the tibial plateau in the Chinese subjects (mean and standard deviation, 5.4 +/- 2.5 degrees for women and 4.9 +/- 2.3 degrees for men) was greater than the commonly reported 3 degrees. The extremities of the Chinese women were found to have a mean of 2.2 +/- 2.5 degrees of varus alignment, and those of the Chinese men had a mean of 2.2 +/- 2.7 degrees of varus alignment. CONCLUSIONS: Compared with the white subjects described in the studies by Moreland et al. and Hsu et al., the Chinese subjects had significantly larger medial inclination of the knee joint (knee-joint obliquity) (p < 0.005) and the female Chinese subjects had significantly more varus alignment of the lower extremity (p < 0.025). CLINICAL RELEVANCE: Five degrees of external rotation of the femoral component, instead of the commonly reported 3 degrees, may be required to obtain a rectangular flexion gap in total knee arthroplasty in Chinese patients. The racial difference in the knee-joint obliquity may contribute to the racial difference in the ratio of knee osteoarthritis to hip osteoarthritis. Additional studies are necessary to confirm this relationship.     

全膝关节置换术中下肢对线方式的研究进展

膝骨关节炎已成为当今老年人常见疾病之一,目前,对于终末期膝骨关节炎,行全膝关节置换术(total knee arthroplasty,TKA)是最为有效的治疗手段。在TKA中,下肢力线的有效恢复则是手术成功的关键因素之一,极大影响患者术后的临床效果及假体存活率。最早被提出、认可并被广泛应用于TKA的对线方式是机械对线。近年来,随着对下肢力线的深入研究及计算机技术的迅速发展,TKA对线技术实现了由“统一化”向“个性化”,二维向三维的转变,调整机械对线、解剖学对线、运动学对线、反向运动学对线、限制运动学对线及功能学对线等新的对线方式被相继提出,为外科医师提供了更多选择。但对于何种对线方式是最佳选择,目前尚未有定论。本文对目前TKA中各种对线方式的研究现状及优缺点进行总结阐述,旨在为临床上TKA中对线方式的选择提供一定参考。     

Sagittal alignment of the lower extremity while standing in Japanese male

There is little information available regarding the sagittal mechanical axis of the lower extremity of normal subjects under weight-bearing conditions. The purpose of this study was to determine the sagittal alignment of the lower extremity under such conditions. Anteroposterior and lateral radiographs were taken of the 20 lower extremities of 10 healthy male Japanese volunteers (mean age, 27 years) while standing. The coronal mechanical axis passed through 33.9% medial to the proximal tibial articulating surface. The sagittal mechanical axis passed through 38.0% anterior to the distal femoral condyle and 27.9% anterior to the proximal tibial articulating surface, and also passed 5.2 mm anterior to the intercondylar notch. Our study therefore showed that the coronal and sagittal mechanical axes of the lower extremity do not always pass through the center of the knee. This has important implications for alignment in surgery of lower extremities such as total knee arthroplasty and osteotomy. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.     

Radiographic analysis of the axial alignment of the lower extremity

The axial alignment of the lower extremities of twenty-five normal male volunteers whose mean age was thirty years was studied using a standardized radiograph of the entire lower extremity. The extremities were found to be in a mean of 1.5 degrees (right) and 1.1 degrees (left) of varus angulation at the knee between the tibial and femoral mechanical axes. The transverse axis of the knee lacked a mean of 3.0 degrees (right) and 2.6 degrees (left) of being perpendicular to the mechanical axis of the tibia. The anatomical axis of the femur did not pass through the center of the knee.     

Improved assessment of lower extremity alignment using new roentgenographic techniques

Accurate assessment of total hip and knee alignment requires a single-exposure weight-bearing roentgenogram of the involved limb. The problem with single-exposure technique is that a good exposure of the hip overexposes the lower leg. This problem is solved by using leaded acrylic wedges, which, when placed in front of the X-ray tube (collimator), block excessive radiation to the lower limb and create an evenly exposed film of the entire lower extremity. The development of these collimator wedge filters and the advent of newer fast-speed film and screens have reduced the amount of radiation absorbed by the patient by eight times or more. Guided by a chart to interchange and choose between film/screen combinations, the method and technique provides the surgeon with an exact alignment of the limb and joints for all kinds of operations.     

Post therapeutic lower extremity rotational profiles in children with DDH

Purpose  The purpose of this study was to investigate post-therapeutic lower extremity rotational profiles in children with developmental dislocation of the hip (DDH), the differences between these values and those of normal children, and the relationship between these differences and clinical and radiological results. Methods  In 82 lower extremities of 64 patients, the foot-progression angle was measured clinically and the transmalleolar axis angle photographically, and hip rotations and thigh–foot angle were measured both clinically and photographically. The data obtained were compared with Staheli’s data for normal children. In addition, clinical and radiographic data were compared within subgroups and with Staheli’s data. Student’s t-test and one-way ANOVA were used for statistical evaluation. Results  The medial rotation of the hip, the average clinical value was 44.66o, and the photographic value was 42.28o. Lateral rotation of the hip, the average clinical value was 38.01o, and the average photographic value was 37.29o. Thigh–foot angle, his angle was clinically 8.23o and photographically 9.68o. Angle of the transmalleolar axis, the photographic average was 21.59o. Foot-progression angle, the clinical average was 10.70o. It was determined that the lower extremity rotational profiles of children with DDH treated after walking did not differ from those of normal children, but that the internal and external hip rotations of McKay type III and IV patients were below those of normal children and of McKay type I and II patients. Conclusion  Lower extremity rotational profiles in children with DDH who received appropriate treatment were the same as those for normal children.     

Function of children with myelodysplasia and lower extremity amputations

This is a retrospective study of the functional status of children who underwent a lower extremity amputation for complications of myelodysplasia. With a computerized surgical database, 12 children with myelodysplasia who underwent an amputation at the Boyd level or above at a single children's referral hospital between 1983 and 2001 were identified. Four patients could not be contacted, but the remaining 8 patients were evaluated through chart review and interview to assess the impact of the amputation on their function. With a mean follow-up time of 9 years (range, 5-15 years), all 6 of the patients with a below-knee or Boyd amputation continued to ambulate using a prosthesis. Most patients occasionally reported having ulcers on their residual limb, but these cases were easily managed and did not result in amputation revisions.The only patient in this series with an above-knee amputation and the only patient with a knee disarticulation were exclusively wheelchair ambulators and no longer owned a prosthesis. This study supports the notion that children with myelodysplasia can have amputations and successfully wear a prosthesis to maintain their ambulation.     

Lawnmower injuries in children: lower extremity reconstruction

Power lawnmower accidents are one of the most frequent causes of mutilating injuries in pediatric patients. Guidelines for the optimal surgical management of children differ from adult patients by several key anatomic, physiologic, and rehabilitative features. Small blood vessels in children less than 2 years old may prohibit microvascular surgery. Older children with larger vessels are often better candidates for microvascular flaps than their adult counterparts. Pediatric patients also resist recurrent ulceration of foot skin grafts, tolerate prolonged immobilization, and are rehabilitated more readily than adults. In considering these facts, we outlined an algorithm for surgical reconstruction. Split-thickness skin grafts are generally the first choice for coverage. The medial gastrocnemius is the workhorse of the knee and upper third leg. The soleus provides coverage for the middle third leg; microvascular flaps are used for large lower third leg defects. Crossleg fasciocutaneous flaps are good alternatives when microsurgery is not feasible. When possible, the weight-bearing surface of the foot should be covered with local vascularized sensate flaps; larger defects may require free flaps, crossleg, or gluteal-thigh flaps. Excellent functional rehabilitation has been achieved in our young patients through the combined efforts of the trauma service, plastic and orthopedic surgery, and physical and occupational therapy services.     

应用Ilizarov外固定延长架治疗小儿下肢短缩畸形

目的总结小儿肢体延长的临床经验，探讨肢体延长中出现的并发症及其对策。方法 采用Ｉｌｉｚｒｏｖ外固定延长架对１４例小儿下肢短缩畸形进行１５侧肢体延长，其中股骨下端截骨延长３例，胫骨上端截骨延长９例，胫骨下端截骨延长２例。结果 随访１－６年，平均２年３个月。延长幅度３．０－１０．０ｃｍ，平均６．５ｃｍ。延长率达原骨长度的１２．５％＿４５．５％，平均２２．９％。     

Three-dimensional lower extremity alignment in the weight-bearing standing position in healthy elderly subjects

Background  

Although assessment of lower extremity alignment is important for the treatment and evaluation of diseases that present with malalignment of the lower extremity, it has generally been performed using only plain radiographs seen in two dimensions (2D). In addition, there is no consensus regarding the criteria for quantitative three-dimensional (3D) evaluation of the relative angle between the femur and tibia. The purpose of this study was to establish assessment methods and criteria for quantitatively evaluating lower extremity alignment in 3D and to obtain reference data from normal elderly subjects.     

Angular deformity of the lower extremity in children with renal osteodystrophy.

We have treated 15 children with end-stage renal disease (ESRD), renal osteodystrophy, and genu valgum in the last 22 years. In a retrospective review, we determined that periods of metabolic instability, best characterized as an alkaline phosphatase of 500 U for at least 10 months, were associated with progression of deformity. Histomorphometric bone biopsy provided information that proved essential for effective evaluation and treatment in this group. Complications of corrective osteotomy were related to perioperative metabolic instability. A surgical treatment protocol is described, emphasizing preoperative assessment by histomorphometric bone biopsy and multimodal medical management to maintain metabolic stability perioperatively.