Anterior Distal Femoral Hemiepiphysiodesis Does Not Change Pelvic Tilt in Children With Cerebral Palsy.

BACKGROUND: Anterior distal femoral hemiepiphysiodesis (ADFH) is a surgical treatment choice to correct flexed knee gait and fixed knee flexion deformities in children with cerebral palsy who are skeletally immature. Increased anterior pelvic tilt has been reported after surgeries that correct knee flexion deformities, including hamstring lengthening (HSL) and distal femoral extension osteotomies, but anterior pelvic tilt has not been studied after ADFH. We hypothesized that anterior pelvic tilt would increase after ADFH, especially when combined with HSL, and it would correlate with the change in minimum knee flexion in stance and dynamic hamstring lengths. METHODS: Thirty-four eligible participants (age: 13.0, SD: 2.0) were included. Change in mean pelvic tilt across the gait cycle was compared as a function of clinical and gait parameters using linear mixed models. The relationship of change in pelvic tilt to change in other variables was examined using Pearson correlation. RESULTS: Overall, anterior pelvic tilt increased significantly after ADFH by 4.4 degrees ( P = 0.02). Further, the analysis revealed anterior pelvic tilt only increased significantly in the group that had concurrent HSL (11.1 degrees, P < 0.001). Overall, minimum knee flexion significantly decreased (increase in knee extension) in stance (-19.1 degrees, P < 0.001) and there was an increase in maximum normalized dynamic hamstring lengths (0.03, P < 0.001). The anterior pelvic tilt increased significantly in Gross Motor Function Classification System levels III to IV (5.9 degrees, P = 0.02) but did not change significantly in Gross Motor Function Classification System I to II (2.5 degrees, P = 0.37). Change in pelvic tilt was correlated with change in maximum dynamic hamstring lengths ( r = 0.87, P < 0.0001) and change in minimum knee flexion in stance ( r = -0.71, P < 0.0001). CONCLUSIONS: Anterior distal hemiepiphysiodesis without concurrent HSL for flexion knee deformities does not result in increased anterior pelvic tilt. Surgeons should consider anterior distal hemiepiphysiodesis in patients with cerebral palsy and flexed knee gait, who preoperatively have long dynamically modeled hamstrings, are skeletally immature, and when maintenance of pelvic tilt is desired. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Variation in Functional Mobility Within Gross Motor Function Classification System Levels.

BACKGROUND AND OBJECTIVE: Variation in walking performance within Gross Motor Function Classification System (GMFCS) levels for patients with cerebral palsy (CP) is often unrecognized. The Functional Mobility Scale (FMS) rates mobility at household, school, and community distances. This study evaluated the variability of walking performance within GMFCS levels as measured by the FMS. METHODS: Retrospective review of gait analysis records for ambulatory patients with CP. FMS rating distribution at each distance was examined for GMFCS levels I-IV within age groups (below 12 or above 12 y) and compared among levels using χ2 tests. RESULTS: A total of 788 patients (499 male; age 11.2, SD 3.9 y) were included. FMS score distribution differed significantly among GMFCS levels for all distances (P<0.001). GMFCS LEVEL: I-Children walked independently on all surfaces at home and school distances at all ages. In all, 5% to 7% used wheeled mobility in the community. II-Most walked at home and school distances. Some younger children crawled at home, and 5% to 8% of all subjects used walls and furniture. Approximately 50% of subjects in both age groups used some form of walking aids or a stroller/wheelchair in the community. III-Twenty-five percent to 30% walked unaided at home, requiring walking aids or wheeled mobility at school or in the community. Forty-five percent of younger and 18% of older subjects crawled at home. Eight percent of younger and 28% of older subjects used wheelchairs at school. Seventy-three percent to 75% of all subjects used strollers/wheelchairs in the community. IV-Sixty-two percent of younger and 43% of older subjects crawled at home. Approximately 15% of all subjects did some aided walking at home. Twenty-seven percent of younger children did some aided walking at school, while only 1 older subject did so. All used strollers/wheelchairs in the community. CONCLUSION: Mobility function varies within each GMFCS level with the most variability in GMFCS II at school and community distances and GMFCS III at household distances. These findings highlight the importance of using both the GMFCS and FMS when assessing functional mobility in children with CP. LEVEL OF EVIDENCE: Level III-retrospective study.

Calcaneal Sliding Osteotomy Versus Calcaneal Lengthening Osteotomy for Valgus Foot Deformity Correction in Children With Cerebral Palsy.

BACKGROUND: Medial calcaneal sliding (CS) osteotomy and lateral column lengthening (LCL) are often performed to relieve pain and improve transverse plane alignment and gait stability for children with cerebral palsy (CP) and valgus foot deformities. The purpose of this study was to examine the effectiveness of these procedures in this population. METHODS: Retrospective medical record review (including 3D gait analysis data) of patients with CP who underwent LCL (26 subjects, 46 limbs) or CS (46 subjects, 73 limbs). Data extraction included complications (modified Clavien-Dindo system), change in standing foot position (modified Yoo system), and change in gait kinematics and kinetics preoperatively to postoperatively. Groups were compared using paired t tests, Fisher exact test, and survivorship analysis using Cox proportional hazard models. RESULTS: Subjects were 57% male, average age at surgery 11.1 (SD 2.5) years. Average length of follow-up was 3.2 (SD 2.8) years, and was longer in the LCL group (P=0.0004). Complications were minor with similar rates between groups (P=0.14). Prolonged pain and plantar hypersensitivity occurred only in the CS group. Successful maintenance of deformity correction was achieved in 52/73 limbs (71%) in the CS group and 16/44 limbs (36%) in the LCL group (P<0.001). Recurrent pes valgus and need for repeat foot surgery were more common after LCL (P=0.003 and 0.001, respectively). Recurrent pes valgus never occurred when talonavicular fusion was done concomitantly with CS. After accounting for the between group difference in length of follow-up, there was no difference in the rates of recurrent valgus or repeat foot surgery between LCL and CS. None of the variables predicted development of pes varus (P>0.20). Ankle kinematics and kinetics during gait were unchanged in both groups. CONCLUSIONS: CS and LCL have similar effectiveness in providing long-lasting correction of valgus foot deformities. Concomitant talonavicular fusion is key to success of CS for lower functioning patients with severe deformities, and obligate brace wearers. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Persistent increase in anterior pelvic tilt after hamstring lengthening in children with cerebral palsy.

BACKGROUND: Hamstring lengthening has traditionally been the surgical treatment of choice to correct flexed knee gait in children with cerebral palsy (CP). Improved passive knee extension and knee extension during gait are reported post hamstring lengthening, but concurrent increased anterior pelvic tilt also occurs. RESEARCH QUESTION: Does anterior pelvic tilt increase after hamstring lengthening in children with CP both in the short-term and mid-term, and what predicts increased post-operative anterior pelvic tilt? METHODS: 44 participants were included (age 7.2, SD 2.0 years; 5 GMFCS I, 17 GMFCS II, 21 GMFCS III, 1 GMFCS IV). Mean pelvic tilt was compared between visits, and the effect of potential predictors of change in pelvic tilt was examined using linear mixed models. The relationship of change in pelvic tilt to change in other variables was examined using Pearson correlation. RESULTS: Anterior pelvic tilt increased significantly post-operatively by 4.8° (p < 0.001). It remained significantly higher by 3.8° at 2-15 years follow-up (p < 0.001). Change in pelvic tilt was not affected by sex, age at surgery, GMFCS level, assistance during walking, time since surgery, or baseline values of hip extensor strength, knee extensor strength, knee flexor strength, popliteal angle, hip flexion contracture, step length, walking speed, maximum hip power in stance, or minimum knee flexion in stance. Pre-operative dynamic hamstring length was associated with greater anterior pelvic tilt at all visits but did not affect amount of change in pelvic tilt. Patients in GMFCS I-II showed a similar pattern of change in pelvic tilt to GMFCS III-IV. SIGNFICANCE: When considering hamstring lengthening for ambulatory children with CP, surgeons should weigh increased mid-term anterior pelvic tilt post-operatively with the desired outcome of improved knee extension in stance. Patients with neutral or posterior pelvic tilt and short dynamic hamstring lengths pre-operatively have lowest risk of excessive post-operative anterior pelvic tilt.

Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy.

PURPOSE: Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP). METHODS: Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates. RESULTS: In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02). CONCLUSIONS: ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°. LEVEL OF EVIDENCE: III.

Clinical impact of variability in HbA1c as assessed by simultaneously measuring fructosamine and use of error grid analysis.

BACKGROUND: Haemoglobin A1c (HbA1c) is the only measure of glycaemic control used for many patients with diabetes, but it has limitations and might sometimes be misleading. HbA(1c) concentrations are influenced by conditions that alter red-cell life and there is evidence that biochemical variation in intracellular glycation rates also influence HbA1c concentrations. This paper is the first to propose a method of using simultaneously measured HbA1c and fructosamine, and error grid analysis, in the clinical setting, to gain a better understanding of glycaemic control. METHODS: Cross-sectional analytical study using HbA1c and fructosamine measures on the same blood sample from 1744 patients having blood taken for hospital diabetes clinic appointments. No other selection or exclusion criteria were applied. RESULTS: The fructosamine results were converted to a HbA1c equivalent which was then compared with the HbA1c. In an Altman-Bland plot, the paired result differences ranged between -6.9% and +5.5% HbA1c with 1139 (65%), 438 (25%), 130 (8%) and 37 (2%) being < or =1%, 1-2%, 2-3% or >3% of HbA1c difference, respectively. In clinical error grid analysis, 864 (50%) results had tight concordance for clinical interpretation, 761 (43%) had one block disunity of probably little clinical significance, but 105 (6%) were two blocks and 14 (1%) were three blocks discordant. CONCLUSION: HbA1c may not accurately reflect glucose control. Our method, utilizing co-assessment with serum fructosamine, evaluates the possible clinical impact of this. We suggest the analysis used in this paper should be used routinely in diabetes practice.