Is simultaneous hamstring lengthening necessary when performing distal femoral extension osteotomy and patellar tendon advancement?

Crouch gait is common in individuals with cerebral palsy. Recently published data has shown that distal femoral extension osteotomy with patellar tendon advancement (DFEO/PTA) is an effective procedure to correct crouch gait in the presence of a knee flexion contracture and quadriceps insufficiency. Short length and slow lengthening rate (velocity) of the hamstrings are indications for hamstrings surgery. We empirically believed that hamstrings surgery would not be necessary to improve hamstring function when DFEO/PTA are performed. This hypothesis was examined in a retrospective review of hamstrings length and velocity before and after DFEO/PTA. 51 limbs in 32 individuals with a diagnosis of CP who underwent DFEO/PTA without concomitant hamstring surgery were included in the study. Pre and post-operative peak medial hamstring length and velocity z-scores were calculated using a musculoskeletal model. A subset of limbs with pre-operative values above or below two SD from the control mean emerged and were called long or short respectively. Members of this subset would often be considered candidates for hamstrings surgery. Categorical length outcomes were derived, with analogous categories for velocity. The mean peak hamstring length z-score improved pre- to post-operatively from -2.2 to -0.76 (p<0.001). The mean peak velocity z-score improved from -3.1 to -1.5 (p<0.001) [Figure 1]. DFEO/PTA surgery without concomitant hamstrings surgery led to significantly longer or faster hamstrings. Specifically, we saw 94% good or neutral results for length correction and 80% good or neutral results for velocity correction. Because crouch improved without posterior pelvic tilting, and because both hamstring length and velocity increased substantially, we conclude that concomitant hamstring surgery is rarely needed when performing DFEO/PTA.

Distal femoral extension osteotomy and patellar tendon advancement to treat persistent crouch gait in cerebral palsy. Surgical technique.

BACKGROUND: Hallmarks of a persistent crouched walking pattern exhibited by individuals with cerebral palsy usually include loss of an adequate plantar flexion/knee extension couple, hamstring and/or psoas tightness, or contracture in conjunction with quadriceps insufficiency. Traditional treatment addresses the muscle-tightness component, but not the contracture or the muscle insufficiency. This study was performed to evaluate the effectiveness of distal femoral extension osteotomy and/or patellar tendon advancement in the treatment of crouch gait in patients with cerebral palsy. METHODS: A retrospective, nonrandomized, repeated-measures design was used. Individuals with a diagnosis of cerebral palsy were included if they had had (1) a distal femoral extension osteotomy in combination with a distal patellar tendon advancement (thirty-three patients), (2) a distal femoral extension osteotomy without patellar tendon advancement (sixteen), or (3) a distal patellar tendon advancement only (twenty-four). All subjects were evaluated with preoperative and postoperative gait analysis. Gait, radiographic, strength, and functional measures were included in the analysis to assess changes in knee function. RESULTS: Seventy-three individuals met the criteria for inclusion. A single side was chosen for the analysis of each subject. Ninety percent of the subjects had additional, concurrent surgery. Improvements were noted in the index assessing the level of gait pathology and in functional variables across all groups, and pain was consistently decreased. All preoperative stress fractures healed. Strength levels were maintained across all groups. The Koshino index of patellar height improved from 1.4 to -2.3 in the group treated with patellar tendon advancement only and from 1.5 to -2.9 in the group treated with both osteotomy and tendon advancement. The range of knee flexion improved an average of 15 degrees to 20 degrees , and stance-phase knee flexion was restored to the typical range (9 degrees to 10 degrees ) in the groups that had advancement of the patellar tendon as part of the procedure. Individuals who underwent a distal femoral osteotomy only were still in a crouch (a mean of 31 degrees of knee flexion in midstance) at the final assessment. CONCLUSIONS: Inclusion of patellar tendon advancement is necessary to achieve optimal results in the surgical management of a persistent crouch gait exhibited by adolescents and young adults with cerebral palsy. When this procedure is done alone or in combination with a distal femoral extension osteotomy (for the treatment of a knee flexion contracture), knee function in gait can be restored to values within typical limits, with gains in community function.

Distal femoral extension osteotomy and patellar tendon advancement to treat persistent crouch gait in cerebral palsy.

BACKGROUND: Hallmarks of a persistent crouched walking pattern exhibited by individuals with cerebral palsy usually include loss of an adequate plantar flexion/knee extension couple, hamstring and/or psoas tightness, or contracture in conjunction with quadriceps insufficiency. Traditional treatment addresses the muscle-tightness component, but not the contracture or the muscle insufficiency. This study was performed to evaluate the effectiveness of distal femoral extension osteotomy and/or patellar tendon advancement in the treatment of crouch gait in patients with cerebral palsy. METHODS: A retrospective, nonrandomized, repeated-measures design was used. Individuals with a diagnosis of cerebral palsy were included if they had had (1) a distal femoral extension osteotomy in combination with a distal patellar tendon advancement (thirty-three patients), (2) a distal femoral extension osteotomy without patellar tendon advancement (sixteen), or (3) a distal patellar tendon advancement only (twenty-four). All subjects were evaluated with preoperative and postoperative gait analysis. Gait, radiographic, strength, and functional measures were included in the analysis to assess changes in knee function. RESULTS: Seventy-three individuals met the criteria for inclusion. A single side was chosen for the analysis of each subject. Ninety percent of the subjects had additional, concurrent surgery. Improvements were noted in the index assessing the level of gait pathology and in functional variables across all groups, and pain was consistently decreased. All preoperative stress fractures healed. Strength levels were maintained across all groups. The Koshino index of patellar height improved from 1.4 to -2.3 in the group treated with patellar tendon advancement only and from 1.5 to -2.9 in the group treated with both osteotomy and tendon advancement. The range of knee flexion improved an average of 15 degrees to 20 degrees, and stance-phase knee flexion was restored to the typical range (9 degrees to 10 degrees) in the groups that had advancement of the patellar tendon as part of the procedure. Individuals who underwent a distal femoral osteotomy only were still in a crouch (a mean of 31 degrees of knee flexion in midstance) at the final assessment. CONCLUSIONS: Inclusion of patellar tendon advancement is necessary to achieve optimal results in the surgical management of a persistent crouch gait exhibited by adolescents and young adults with cerebral palsy. When this procedure is done alone or in combination with a distal femoral extension osteotomy (for the treatment of a knee flexion contracture), knee function in gait can be restored to values within typical limits, with gains in community function.

Orthopedic management of spasticity in cerebral palsy.

INTRODUCTION: This article summarizes our experience with cerebral palsy. The primary and secondary deformities that occur with cerebral palsy are described, followed by a brief overview of the nature and role of gait analysis in the treatment of gait problems in cerebral palsy. The concept of lever-arm dysfunction is introduced. DISCUSSION: Our current treatment program is then presented and subsequently illustrated by two case examples. Finally, an outcomes analysis of a group of patients with spastic diplegia treated with selective dorsal rhizotomy is presented to illustrate our current method of evaluating treatment outcomes and the need for team management in the treatment of this complex condition.

Kinematic and kinetic factors that correlate with improved knee flexion following treatment for stiff-knee gait.

Stiff-knee gait is a movement abnormality in which knee flexion during swing phase is significantly diminished. This study investigates the relationships between knee flexion velocity at toe-off, joint moments during swing phase and double support, and improvements in stiff-knee gait following rectus femoris transfer surgery in subjects with cerebral palsy. Forty subjects who underwent a rectus femoris transfer were categorized as "stiff" or "not-stiff" preoperatively based on kinematic measures of knee motion during walking. Subjects classified as stiff were further categorized as having "good" or "poor" outcomes based on whether their swing-phase knee flexion improved substantially after surgery. We hypothesized that subjects with stiff-knee gait would exhibit abnormal joint moments in swing phase and/or diminished knee flexion velocity at toe-off, and that subjects with diminished knee flexion velocity at toe-off would exhibit abnormal joint moments during double support. We further hypothesized that subjects classified as having a good outcome would exhibit postoperative improvements in these factors. Subjects classified as stiff tended to exhibit abnormally low knee flexion velocities at toe-off (p<0.001) and excessive knee extension moments during double support (p=0.001). Subjects in the good outcome group on average showed substantial improvement in these factors postoperatively. All eight subjects in this group walked with normal knee flexion velocity at toe-off postoperatively and only two walked with excessive knee extension moments in double support. By contrast, all 10 of the poor outcome subjects walked with low knee flexion velocity at toe-off postoperatively and seven walked with excessive knee extension moments in double support. Our analyses suggest that improvements in stiff-knee gait are associated with sufficient increases in knee flexion velocity at toe-off and corresponding decreases in excessive knee extension moments during double support. Therefore, while stiff-knee gait manifests during the swing phase of the gait cycle, it may be caused by abnormal muscle activity during stance.

Comprehensive treatment of ambulatory children with cerebral palsy: an outcome assessment.

A retrospective study was used to evaluate the outcome of treatment of 135 ambulatory children with cerebral palsy. Diplegic subjects were selected from the existing database at the Gillette Children's Specialty Healthcare Motion Analysis Laboratory. All subjects had undergone gait analysis before and after intervention, which included orthopaedic surgery, selective dorsal rhizotomy, or both treatments. Outcome was based on gait pathology, gait efficiency, functional walking ability, and higher-level functional skills. Gait pathology was assessed using 16 clinically relevant kinematic parameters. Gait efficiency was assessed with steady-state oxygen consumption. Walking ability and higher-level functional skills were based on patient report surveys. Improvements were seen in all outcome measures. A significant majority of subjects (79%) improved on a predominance of outcome measures; only 7% of subjects worsened. Within the restrictions of this study design, the results indicate that surgical intervention, guided by preoperative gait analysis, is effective and safe for children with cerebral palsy.

Novel oxazolidinone-quinolone hybrid antimicrobials.

Antimicrobial compounds incorporating oxazolidinone and quinolone pharmacophore substructures have been synthesized and evaluated. Representative analogues 2, 5, and 6 display an improved potency versus linezolid against gram-positive and fastidious gram-negative pathogens. The compounds are also active against linezolid- and ciprofloxacin-resistant Staphylococcus aureus and Enterococcus faecium strains. The MOA for these new antimicrobials is consistent with a combination of protein synthesis and gyrase A/topoisomerase IV inhibition, with a structure-dependent degree of the contribution from each inhibitory mechanism.

A Convergent, Scalable Synthesis of HIV Protease Inhibitor PNU-140690.

PNU-140690, an inhibitor of the HIV protease enzyme undergoing clinical evalution as a chemotherapeutic agent for treatment of AIDS, was synthesized by a convergent approach amenable to large-scale preparation in a pilot plant environment. The key step is the aldol addition of nitroaromatic ester (+)-8 to aldehyde 19e. The two stereocenters present in the target molecule were each set independently by resolution of enantiomers. Intermediates along the synthetic routes were chosen to maximize opportunities for isolation and purification by crystallization.