Distal femoral extension osteotomy and patellar tendon advancement or shortening in ambulatory children with cerebral palsy: A modified Delphi consensus study and literature review

Purpose:In children with cerebral palsy, flexion deformities of the knee can be treated with a distal femoral extension osteotomy combined with either patellar tendon advancement or patellar tendon shortening. The purpose of this study was to establish a consensus through expert orthopedic opinion, using a modified Delphi process to describe the surgical indications for distal femoral extension osteotomy and patellar tendon advancement/patellar tendon shortening. A literature review was also conducted to summarize the recent literature on distal femoral extension osteotomy and patellar tendon shortening/patellar tendon advancement.Method:A group of 16 pediatric orthopedic surgeons, with more than 10 years of experience in the surgical management of children with cerebral palsy, was established. The group used a 5-level Likert-type scale to record agreement or disagreement with statements regarding distal femoral extension osteotomy and patellar tendon advancement/patellar tendon shortening. Consensus for the surgical indications for distal femoral extension osteotomy and patellar tendon advancement/patellar tendon shortening was achieved through a modified Delphi process. The literature review, summarized studies of clinical outcomes of distal femoral extension osteotomy/patellar tendon shortening/patellar tendon advancement, published between 2008 and 2022.Results:There was a high level of agreement with consensus for 31 out of 44 (70%) statements on distal femoral extension osteotomy. Agreement was lower for patellar tendon advancement/patellar tendon shortening with consensus reached for 8 of 21 (38%) of statements. The literature review included 25 studies which revealed variation in operative technique for distal femoral extension osteotomy, patellar tendon advancement, and patellar tendon shortening. Distal femoral extension osteotomy and patellar tendon advancement/patellar tendon shortening were generally effective in correcting knee flexion deformities and extensor lag, but there was marked variation in outcomes and complication rates.Conclusion:The results from this study will provide guidelines for surgeons who care for children with cerebral palsy and point to unresolved questions for further research.Level of evidence:level V.     

Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy

Purpose

The purpose of this study was to evaluate the results of distal femur extension osteotomy and medial hamstring lengthening in the treatment of fixed knee flexion deformity in patients with spastic diparetic cerebral palsy.

Methods

A retrospective study was done in a group of 12 diparetic cerebral palsy patients. A distal femur extension osteotomy was performed as part of multilevel surgery on lower limbs. The fixed knee flexion deformity was measured during physical examination, whereas hip and knee flexion in the stance phase and anterior pelvic tilt were both analyzed at kinematics. The pre- and post-surgery results were compared and analyzed statistically. A medical record review was done in order to identify the complications. The mean follow-up was 28 months.

Results

A significant reduction of fixed knee flexion deformity at physical examination and knee flexion in the stance phase at kinematics was observed, but with no decrease in hip flexion. As a non-desired effect, there was an increase in anterior pelvic tilt after surgical procedures. With regard to complications, a single patient had skin breakdown at a calcaneous area on one side and the recurrence of deformity was seen in 27% of cases.

Conclusions

In this study, in which fixed knee flexion deformity did not exceed 40° before surgery, the distal femur extension osteotomy was effective in increasing knee extension in the stance phase. However, an increase in anterior pelvic tilt, deformity recurrence and necessity for walking aids are possible complications of this procedure.     

The effects of patellar tendon advancement on the immature proximal tibia

Purpose

The aim of this study is to examine the short-term effects of patellar tendon advancement on the proximal tibial slope in the skeletally immature patient.

Methods

A retrospective, non-randomized, comparative cohort design was used. Koshino indices and tibial slopes were assessed pre-operatively and post-operatively and compared with age- and sex-matched controls.

Results

Nine children with 17 patellar tendon advancements were analyzed for changes in Koshino indices. Of these 17 tibiae, radiographs on changes in tibial slope were available for 16 tibiae which were also compared with controls. Children aged <11 years had a greater initial posterior tibial slope (69.8° ± 3.5°) than age-matched controls (80.3° ± 2.7°). A decrease in posterior slope was seen in these younger patients (average change 10.3° ± 4.8°) at an average of 1.6 years of follow-up. Of the nine apophyses in children aged <11 years of age, seven had undergone premature closure.

Conclusion

Patellar tendon advancement appears to have an unreported effect on the proximal tibial growth in the young patient (<11 years old). These patients appear to be susceptible to apophyseal closure, resulting in subsequent loss of posterior tibial slope. Surgeons should be aware of this effect and monitor younger patients with radiographs if performing this procedure.     

国人髌腱长度测量在髌骨不稳诊断中的意义

[目的]比较国人正常膝关节与髌骨不稳膝关节的髌腱长度,探讨国人髌腱长度的测量在髌骨不稳诊断中的意义。[方法]2003年1月~2005年12月诊治的43例髌骨不稳患者共49膝(男15例,女28例,6例为双侧髌骨不稳);平均年龄21.4岁(18~28岁);平均身高163(155~173)cm。正常对照组为50例健康体检者共50膝(男16例,女34例);平均年龄24.2岁(18~35岁);平均身高165(154~177)cm。在屈膝30°X线侧位片上测量髌腱长度、胫骨结节至胫骨平台的距离、Insall-Salvati指数。[结果]髌骨不稳组髌腱长度为(53.3±2.7)mm,对照组为(47.3 3.3)mm,统计学上具有显著差异性(P<0.05)。Insall-Salvati指数在髌骨不稳组(1.33±0.17)和对照组(1.06±0.14)也具统计学差异(P<0.05)。胫骨平台与胫骨结节之间的距离在髌骨不稳组为(27.8±3.6)mm,对照组为(28.9±4.1)mm,统计学上无显著性差异(P<0.05)。[结论]髌腱长度过长是髌骨不稳的重要特点之一。联合测量髌腱长度和Insall-Salvati指数有助于髌骨不稳的诊断。     

Multilevel orthopedic surgery for crouch gait in cerebral palsy: An evaluation using functional mobility and energy cost

Background:

The evidence for the effectiveness of orthopaedic surgery to correct crouch gait in cerebral diplegic is insufficient. The crouch gait is defined as walking with knee flexion and ankle dorsiflexion through out the stance phase. Severe crouch gait in patients with spastic diplegia causes excessive loading of the patellofemoral joint and may result in anterior knee pain, gait deterioration, and progressive loss of function. We retrospectively evaluated the effect of surgery on the mobility and energy consumption at one year or more with the help of validated scales and scores.

Materials and Methods:

18 consecutive patients with mean age of 14.6 years with cerebral diplegia with crouched gait were operated for multilevel orthopaedic surgery. Decisions for surgery were made with the observations on gait analysis and physical examination. The surgical intervention consisted of lengthening of short muscle-tendon units, shortening of long muscles and correction of osseous deformities. The paired samples t test was used to compare values of physical examination findings, walking speed and physiological cost index. Two paired sample Wilcoxon signed rank test was used to compare functional walking scales.

Results:

After surgery, improvements in functional mobility, walking speed and physiological cost index were found. No patient was able to walk 500 meters before surgery while all were able to walk after surgery. The improvements that were noted at one year were maintained at two years.

Conclusions:

Multilevel orthopedic surgery for older children and adolescents with crouch gait is effective for improving function and independence.     

Patellar tendon orientation and patellar tracking in male and female knees

Knowledge of patellofemoral joint biomechanics is important for understanding sex‐related dimorphism in patellofemoral pathologies and advancement of related treatments. We evaluated the hypotheses that sex differences exist in patellar tendon (PT) orientation and patellar tracking during weight‐bearing knee flexion and that they relate to differences in tibiofemoral rotation. The PT orientation and patellar tracking were measured in healthy subjects (18 male, 13 female) during weight‐bearing knee flexion, using magnetic resonance and dual fluoroscopic imaging. These data were analyzed for sex differences and correlation with previously reported tibiofemoral rotation data. The results indicated a significant effect of sex on PT orientation, particularly at low flexion angles. In females, the PT was oriented more anteriorly in the sagittal plane, more medially in the coronal plane, and showed greater external tilt in the transverse plane of the tibia (p < 0.05). Significant correlations between tibiofemoral rotation and PT orientation (p < 0.01) indicated that sex differences in coronal and transverse plane orientation of the PT relate to differences in tibiofemoral rotation. Patellar tracking did not show significant sex differences or correlation to tibiofemoral rotation. Further studies are warranted to determine implications for patellofemoral pathologies and treatments like total knee arthroplasty. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:322–328, 2010     

Scleraxis expression is coordinately regulated in a murine model of patellar tendon injury

This study investigated the expression of Scleraxis in a murine model of patellar tendon injury in which the central third of the patellar tendon was unilaterally injured. The presence of tendon pathology was assessed using dual photon microscopy, conventional histology and microCT. Tendon pathology was also quantified noninvasively over a 12‐week period using high‐frequency ultrasound and laser Doppler flowmetry. Gene expression (Scx, Tnmd, and Col1a1) was determined at defined end‐points (1, 4, 8, and 12 weeks) using qPCR on RNA from individual patellar tendons on injured and uninjured sides. There was significant development of tendon pathology as gauged by ultrasound and laser Doppler over 12 weeks. Injured tendons demonstrated significant histological and microCT evidence of pathological change, and disorganized collagen with reduced density. The expression of Scx and Col1a1 was unchanged at 1 week, significantly upregulated at 4 and 8 weeks, and had returned to baseline by 12 weeks. Tnmd expression was unchanged at 1 week, and significantly increased at 4, 8, and 12 weeks. Patellar tendon injury was associated with marked increases in the expression of Scx, Tnmd, and Col1a1. Our data suggest new roles for Scleraxis in coordinating the response to injury in the pathogenesis of tendon disorders. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:289–296, 2011     

Gender‐specific in vivo measurement of the structural and mechanical properties of the human patellar tendon

Human patellar tendon stress (σ), strain (ε), stiffness (K), and tensile or Young's modulus (E), are determined in vivo through voluntary isometric contractions monitored with B‐mode ultrasonography. The limitations in previous studies are: (1) they have generally not accounted for the fact that the distal attachment of the patellar tendon (the tibial tuberosity) also displaces; thus, they have underestimated ε (and, hence, injury risk) while overestimating K; (2) no gender effect has been studied despite the fact that females are seen to have higher incidences of tendon‐related injuries. The current investigation therefore aimed to determine the gender specific values of σ, ε, K, and E of the patellar tendon while also accounting for distal displacement of the patellar tendon. Healthy young males (aged 23.1 ± 1.3 years, n = 10) and females (aged 21.3 ±0.9 years, n = 10) were tested. The maximal ε of the young males was ～5–10% higher than that reported in earlier literature. Average female versus male values for ε, σ, K, and E, taken at the same force level as the males for comparison purposes, were respectively 10.6 ± 1.0 versus 9.0 ± 1.0%, 36.9 ± 1.4 versus 28.9 ± 0.9 MPa, 1053 ± 108 versus 1652 ± 216 N · mm^?1, and 0.61 ± 0.08 versus 0.68 ± 0.10 GPa (p < 0.05). There are gender differences in tendon structural and mechanical properties. The current methodology may be useful in a clinical context where early prediction of injury risk and/or monitoring of reconstructed tendon needs to be an accurate, objective, and reliable method if optimal functionality is to be achieved. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1635–1642, 2007     

尿毒症并发一侧髌韧带断裂对侧股四头肌肌腱断裂1例

正患者,男,36岁,主因摔倒致双侧膝关节疼痛伴活动受限18 d于2016年1月22日入院。现病史:患者18 d前因摔倒致双侧膝关节疼痛,当即感疼痛难忍,不能独立行走,自诉听到双侧膝关节"咔"的一声,曾服止痛药物治疗,效果不佳,为进一步诊治收入我科。自发病以来睡眠、大小便、体重等基本无变化。查体:慢性肾病面容。双侧膝关节肿胀明显,皮温皮色正常,无窦道及瘢痕,左侧髌骨下方及右侧髌骨上方触之有明显的空虚感,双膝压痛(+),双膝浮髌     

动态髌骨牵引固定器治疗陈旧髌腱断裂

目的 探讨陈旧髌腱断裂的修复方法。方法 设计“井”形固定器，在动态条件下，将髌骨复位、股四头肌松懈、髌腱修补及术后带固定器活动。结果 治疗6例，随访时间8～56个月，平均2.6个月，膝关节伸屈活动取得了满意的治疗效果。结论 应用“井”形外固定器动态下，治疗陈旧性髌腱断裂，解决了髌腱、股四头肌挛缩，又有利于缝合修复后固定，还可早期练习膝关节功能。方法简单，是一种较为合理的新的治疗方法。     

Sodium cromolyn reduces expression of CTGF,ADAMTS1, and TIMP3 and modulates post‐injury patellar tendon morphology

The purpose of this study was to determine whether administration of a mast cell inhibitor (sodium cromolyn, SC) would influence tendon repair and extracellular matrix gene expression following acute injury. CD1 mouse patellar tendons were unilaterally injured and mast cell prevalence was determined. The effect of SC injection on tendon hypercellularity, cross‐sectional area, collagen organization, and expression of extracellular matrix‐related genes was examined. Mast cell prevalence was markedly increased in injured patellar tendons (p = 0.009), especially at 8 weeks post‐injury (p = 0.025). SC injection increased collagen organization compared to uninjected animals at 4 weeks and attenuated the development of tendon hypercellularity and tendon thickening post‐injury. Expression of CTGF, ADAMTS1, and TIMP3 in injured tendon was reduced in the SC group. SC injections moderated the structural alterations of healing tendon in association with downregulation of several genes associated with tendon fibrosis. This work corroborates previous findings pointing to a role of mast cells in tendon repair. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:678–683, 2011     

Relevance of the popliteal angle to hamstring length in cerebral palsy crouch gait

The popliteal angle is a widely used clinical means of assessing hamstring length in cerebral palsy patients. The relevance of the popliteal angle as a measure of hamstring length was assessed in this prospective study. Sixteen patients with cerebral palsy with crouch gait had their conventional and modified popliteal angles measured by nine observers on two separate occasions. With use of the conventional and modified forms of the test, 74 and 70%, respectively, of the observed variability was inter-and intraobserver related. The range of SDs for each observer using the conventional test was 7.1-13.6 degrees (average 10.9 degrees ), and with use of the modified form of the test, the range was 6.3-4.2 degrees (average 10.5 degrees ). The maximum hamstring length of each subject during gait was determined by three-dimensional modelling of their lower limbs. The modified popliteal angle measurements of the most repeatable observer demonstrated an inverse relationship between modified popliteal angle and maximum hamstring length (p < 0.01) and muscle excursion (p < 0.01). Only 10 of 32 limbs had short medial hamstrings.     

The native cell population does not contribute to central‐third graft healing at 6, 12, or 26 weeks in the rabbit patellar tendon

Investigators do not yet understand the role of intrinsic tendon cells in healing at the tendon‐to‐bone enthesis. Therefore, our first objective was to understand how the native cell population influences tendon autograft incorporation in the central‐third patellar tendon (PT) defect site. To do this, we contrasted the histochemical and biomechanical properties of de‐cellularized patellar tendon autograft (dcPTA) and patellar tendon autograft (PTA) repairs in the skeletally mature New Zealand white rabbit. Recognizing that soft tissues in many animal models require up to 26 weeks to incorporate into bone, our second objective was to investigate how recovery time affects enthesis formation and graft tissue biomechanical properties. Thus, we examined graft structure and mechanics at 6, 12, and 26 weeks post‐surgery. Our results showed that maintaining the native cell population produced no histochemical or biomechanical benefit at 6, 12, or 26 weeks. These findings suggest that PTA healing is mediated more by extrinsic rather than intrinsic cellular mechanisms. Moreover, while repair tissue biomechanical properties generally increased from 6 to 12 weeks after surgery, no further improvements were noted up to 26 weeks. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 638–644, 2013     

Rupture of the patellar tendon: a review of 68 cases and a retrospective study of 29 ruptures comparing two methods of augmentation

Rupture of the patellar tendon is a rare injury requiring acute repair to reestablish knee extensor continuity and to allow early motion. Different pathomechanisms have been postulated, and multiple techniques for repair have been described in the literature. Firstly, the current study reviews the epidemiology, pathomechanism, and risk factors. Secondly, we compare the outcome of two augmentation techniques after end-to-end sutures: reinforcement with either a wire cerclage or a PDS cord. In the first part of the study, the medical records of 66 patients with 68 ruptures were reviewed. For the second part, 33 patients were included who had no prior injury to the extensor mechanism of the knee and had suffered an indirect, low-velocity injury followed by immediate repair. Twenty-seven patients with 29 ruptures of the patellar tendon returned for follow-up. Follow-up averaged 8.1 years (range 1-16 years). In the follow-up group, 22 ruptures had augmentation with a wire cerclage (group A), and 7 ruptures had augmentation with a 2-mm PDS cord (group B). Follow-up evaluation consisted of a subjective questionnaire, a physical and radiographic examination, the Hospital for Special Surgery Knee Score, and the Insall-Salvati ratio. Nineteen patients underwent Cybex isokinetic strength testing of the quadriceps. Indirect, low-velocity injuries occurred most often in the 30–40 year age group, whereas complex knee traumas or knee luxations were more evenly distributed. In 10 of 46 patients with an indirect, low-velocity injury, there was a history of prior injury and illness to the extensor mechanism of the knee, compared with 1 of 22 patients with a high-velocity complex knee trauma. In the follow-up group, no patient sustained a rerupture. Two of 22 patients had an extension lag in group A compared with no extension lag in group B. Average flexion in group A was 130° (SD 29°) compared with 137° (SD 12°) in group B. The average Hospital for Special Surgery Knee Score was 92 (SD 17) in group A and 96 (SD 12) in group B. Three patients were dissatisfied. All had radiographic signs of retropatellar osteoarthritis. In contrast, 9 of 26 patients who were satisfied with their result had radiographic signs of retropatellar osteoarthritis. A postoperative difference in the Insall-Salvati ratio did not correlate with the development of osteoarthritis. Both augmentation techniques are reliable and demostrate good intermediate to long-term results. The outcome did not show significant differences. To avoid reoperation for removal of the cerclage wire, a PDS cord can be used. The infection rate seems to be higher in the PDS group. A larger prospective study group is necessary to determine whether this phenomenon can be reproduced. Received: 17 January 2001     

Treatment outcome of dome osteotomy of the pelvis combined with trochanteric advancement for sequelae of Perthes' disease

Objective

Disparity in size between femoral head and acetabulum could promote premature degeneration of the hip joint. The purpose of this study was to report the results of Kawamura's dome osteotomy for acetabular dysplasia due to sequelae of Perthes' disease.

Percutaneous pelvic osteotomy in cerebral palsy patients: Surgical technique and indications

AIM: To describe the surgical technique of and indications for percutaneous pelvic osteotomy in patients with severe cerebral palsy.METHODS: Twenty-one non-ambulatory children and adolescents (22 hips) were consecutively treated with percutaneous pelvic osteotomy, which was used in conjunction with varus, derotational, shortening femoral osteotomy and soft tissue release, to correct progressive hip subluxation and acetabular dysplasia. The age, gender, Gross Motor Function Classification System level, side(s) of operated hip, total time of follow-up, immediate post-operative immobilization, complications, and the need for revision surgery were recorded for all patients.RESULTS: Seventeen patients (81%) were classified as GMFCS level IV, and 4 (19%) patients were classified as GMFCS level V. At the time of surgery, the mean age was 10.3 years (range: 4-15 years). The mean Reimers’ migration percentage improved from 63% (range: 3%-100%) pre-operatively to 6.5% (range: 0%-70%) at the final follow-up (P < 0.05). The mean acetabular angle (AA) improved from 34.1° (range: 19°-50°) pre-operatively to 14.1° (range: 5°-27°) (P < 0.05). Surgical correction of MP and AA was comparable in hips with open (n = 14) or closed (n = 8) triradiate cartilage (P < 0.05). All operated hips were pain-free at the time of the final follow-up visit, although one patient had pain for 6 mo after surgery. We did not observe any cases of bone graft dislodgement or avascular necrosis of the femoral head.CONCLUSION: Pelvic osteotomy through a less invasive surgical approach appears to be a valid alternative with similar outcomes to those of standard techniques. This method allows for less muscle stripping and blood loss and a shorter operating time.     

Spastic hemiplegic cerebral palsy and the femoral derotation osteotomy: effect at the pelvis and hip in the transverse plane during gait

Gait analysis techniques were used to evaluate the outcome of the femoral derotation osteotomy in children with hemiplegic cerebral palsy. Seventy-one patients were evaluated and classified according to the Winters and Gage scale. Nine of the 13 patients classified as type IV underwent a femoral derotation osteotomy. Postoperatively, all nine patients demonstrated less internal hip rotation, pelvic retraction, and internal foot progression angle. Before surgery patients improve the foot progression by an externally biased hip position within the hip rotation arc. After surgery the hip position is allowed to be more centered within the rotation arc without compromising foot progression. Interestingly, the changed hip position during gait was significantly less than the magnitude of the derotation osteotomy. When contemplating postoperative outcome, consideration of hip position within the arc of rotation and pelvic retraction should be given to avoid undercorrection and residual pelvic compensation with femoral osteotomy based solely on foot progression.