Background: Short hamstring muscles can cause several problems for children with cerebral palsy. The results of the clinical measurement of hamstring length are often used in decision-making about treatment of children with cerebral palsy. There are different ways of performing this measurement. The aim of this study was to evaluate the interrater reliability of the unilateral and bilateral measurement of the popliteal angle in children and youth with cerebral palsy. Methods: Two methods for estimating hamstring length using unilateral and bilateral measurements of the popliteal angle were applied in children with cerebral palsy. Both tests were applied bilaterally by two independent examiners on the same day for each child. The intraclass correlation coefficient (ICC) was calculated to evaluate the interrater reliability of both measurements. Seventy young people with cerebral palsy (32 females, 38 males, mean age 10 years 8 months, range 5–22 years) at Gross Motor Function Classification System levels I (n = 17), II (n = 31), III (n = 12) and IV (n = 10) were included. Results: The interrater reliability was good for both measurements. The ICC values were 0.80 on the right and 0.86 on the left for the unilateral popliteal angle, and 0.82 on the right and 0.83 on the left for the bilateral popliteal angle. Conclusions: Both unilateral and bilateral measurement of the popliteal angle is a reliable method for estimating hamstring length in children and youth with cerebral palsy.

Background: Cam morphology is thought to originate near puberty and reflects a response of the peripheral aspect of the proximal femoral physis to increased local load. Participation in particular sports activities has been associated with cam morphology in contemporary patient populations; however, it is unclear whether cam is a recent phenomenon. There are limited data regarding the frequency of its occurrence and the general deviations in femoral anatomy in different historical populations. Such information may help to understand the possible influence of lifestyle and diet on cam morphology. Questions/purposes: The purpose of this study was to evaluate femoral morphology in three historical populations. We asked: (1) Was cam morphology present in the three study populations, did those populations differ, and were there differences between sexes? (2) Were there differences in neck-shaft angle, version, or inclination between and among the examined populations? Methods: We examined 204 adult femurs from the Neolithic population from Iran (n = 37, 3000 BC to 1631 BC), medieval population from Poland (n = 135, 10th to 13th centuries), and contemporary Australian aborigines (n = 32, early 20^th century), provided by the Open Research Scan Archive, Museum of the First Piasts at Lednica and the University of Wrocław, respectively. All three human populations represent different chronologic periods and lifestyles. All bones were scanned using CT and then measured on their three-dimensional (3-D) reconstructions in selected planes. Cam impingement was defined as an alpha angle > 55° measured on the inclination view. To evaluate the differences in anatomy between populations, we measured the true neck-shaft angle on the true AP view, apparent neck-shaft angle on the apparent AP view, the version angle on the version view, and the inclination angle on the inclination view. The prevalence of cam morphology and other anatomic parameters were compared among groups using chi-square test, one-way ANOVA with post hoc Tukey test, and paired t-test. Results: Cam morphology was present in 5% of the Neolithic population from Iran, in 7% of the medieval population from Poland, and 3% of the contemporary Australian aborigine femurs (OR Neolithic population from Iran/the medieval population from Poland 0.7 [95% CI 0.2 to 3.4]; p = 0.67; OR Neolithic population from Iran/contemporary Australian aborigines 1.8 [95% CI 0.2 to 20.5]; p = 0.65; OR the medieval population from Poland/contemporary Australian aborigines 2.5 [95% CI 0.3 to 20.1]; p = 0.40). There were differences in the presence of cam morphology between the sexes in the medieval population from Poland with both femurs (females: 1% [1 of 76]; males: 15% [9 of 59]; p = 0.002). There was a difference in true neck-shaft angle between the Neolithic population from Iran (121° ± 6°) and contemporary Australian aborigines (131° ± 5°; mean difference 10° [95% CI 7° to 13°]; p < 0.001) and between the medieval population from Poland (124° ± 5°) and the contemporary Australian aborigines (mean difference 7° [95% CI 5° to 9°]; p < 0.001). Apparent neck-shaft angle differed between the Neolithic population from Iran (126° ± 6°) and the contemporary Australian aborigines (134° ± 5°; mean difference 8° [95% CI 6° to 11°]; p < 0.001), and between the medieval population from Poland (126° ± 6°) and the contemporary Australian aborigines (mean difference 9° [95% CI 7° to 11°]; p < 0.001). Moreover, we observed a difference in the version angle between the Neolithic population from Iran (19° ± 7°) and the medieval population from Poland (12° ± 9°; mean difference 7° [95% CI 4° to 10°]; p < 0.001] and in the inclination angle between aforementioned groups (18° ± 7° versus 11° ± 8°; mean difference 7° [95% CI 5° to 10°]; p < 0.001). Conclusion: This study found that cam morphology existed in historical populations at rates comparable with a contemporary population. Clinical Relevance: The presence of cam morphology in historical populations suggests that cam morphology can develop outside of the intense sports activity seen in modern adolescents. Further study will help elucidate the etiology of cam morphology, which may be useful in the development of preventive strategies.

Background: The aim of this study was to compare performance on the six-minute walk test (6MWT) performed over 15 m and 30 m courses by children and youths with cerebral palsy (CP). Methods: Children and youths with CP at Gross Motor Function Classification System levels I–IV performed the 6MWT in a straight 15 m-long corridor (first trial) and 30 m-long corridor (second trial). The intraclass correlation coefficient (ICC) and Bland-Altman plots were used to evaluate the agreement between the 6MWT results for the two corridor lengths. Results: We included 82 children and youths with CP (36 girls, 46 boys), with a mean age of 11.7 years (SD 4.2, range 5–22 years). There was high agreement between the results of the two 6MWTs: ICC 0.93 (95% confidence interval 0.76–0.97). The total walking distance was longer for the 30 m course (median 399 m, range 44–687 m) than the 15 m course (median 357 m, range 24–583 m). Conclusions: We observed good agreement for the performance of the 6MWT in the 15 m and 30 m courses, although the total walking distance was greater for the 30 m course. We recommend that the same distance is used when evaluating changes in walking ability for an individual child. Both distances are appropriate when measuring endurance in children and youths with CP.

Purpose: Late-diagnosed dislocated hips underwent open reduction, Dega osteotomy, and proximal femoral osteotomy between 1968 and 1988. The objectives of this study are to assess the survival of hips into adulthood, clinical and radiological outcome, patients’ life perspectives and the risk factors of failure. Methods: An assessment of 67 hips treated when younger than five years (<age 5yr. group) and 71 hips in the group aged older than five years (+age 5yr.) was performed. All cases were evaluated clinically and radiographically, and survival was assessed, considering hip replacement as endpoints for failure (abbreviation HR+ refers to hips that underwent hip replacement surgery; HR- refers to hips that have not been replaced at the follow-up). The fertility rate and the social security disability benefits (SSDB) recipiency percentage were calculated. Results: The 40-year survival rates were 73% (95% confidence (CI) 71% to 76%) in the <age 5yr. group, 54% (95% CI 51% to 57%) in the +age 5yr. group, 70% (95% CI 67% to 73%) in one-sided dislocations and 57% (95% CI 54% to 60%) in bilateral dislocations. At follow-up, the median Harris hip and Western Ontario and McMaster Universities Osteoarthritis scores were 90.0 and 13.0 (<age 5yr. group, HR-), 74.0 and 28.0 (+age 5yr. group, HR-), 90.0 and 16.0 (<age 5yr. group, HR+) and 84.5 and 11.5 (+age 5yr. group, HR+), respectively. The operation normalized the radiological parameters. The correlation between the grade of femoral head avascular necrosis (AVN) at a median 2.6 years after the operation and the grade of osteoarthritis at follow-up was 0.38 (p < 0.001). The fertility rate was 1.54. In total, 16.0% (aged under five years) and 38.5% (aged over five years) of patients were receiving SSDB (p = 0.003). Conclusion: Early failure risk factors are older age at the surgical procedure, high AVN grade and bilateral hip involvement. Still, the results facilitate hip reposition whenever technically manageable, even in teenagers. Level of evidence: III

The study aimed to compare sex differences in the morphology and spatial orientation of pelvic acetabula to advance the understanding of hip anatomy. The study was based on three-dimensional reconstructions of computed tomography images of 50 female and 50 male acetabula. The images were used for spatial analysis of hip acetabula relative to the base of the sacral bone as the plane of reference. Statistical analysis was performed to compare angles relevant to the actual axis of the acetabulum (inclination angle, anteversion angle, tilt angle) as well as the volume and inner surface area of the acetabulum. Both the inclination and tilt angles of the acetabulum did not differ significantly between the groups, the respective values being: 68.61° and 26.53° in females and 70.56° and 30.19° in males (p>0.05). The anteversion angle was significantly larger for female acetabula (38.27° compared to 32.05° in men, with p=0.0008), while the volume and the inner surface area were significantly smaller in women (p=0.0007 and 0.0001 respectively). 1. Acetabular orientation is sex-specific, with female acetabula being more forward-oriented than those of men. 2. The volume and inner surface area of acetabula also differ between the sexes, being smaller in women. 3. Regardless of the plane of reference, sexual dimorphism of the acetabulum is constant. 4. Awareness of the above sex-dependent differences is necessary for preoperative planning before orthopaedic surgeries (such as hip arthroplasty or operative treatment of FAI).

Robotic-assisted therapy (RAT) is a task-specific approach for treating gait disorders in individuals with neurological impairments. However, the effectiveness of RAT is not clear for different severities of involvement, pathologies, and ages. This study aimed to assess the functional and clinical status outcomes after RAT in individuals with cerebral palsy (CP). Twenty-eight individuals with bilateral spastic CP were enrolled (female = 10; male = 18; age = 15.2 ± 2.0 years). The RAT program consisted of 30 sessions: five sessions weekly for six weeks. Gross Motor Function Measure (GMFM) and clinical physical examinations were evaluated before and after RAT. Our results suggested that the RAT program with the described protocol can improve the general gross motor functions of individuals with CP in Gross Motor Function Classification System (GMFCS) levels I and II, and primarily improves performance on less complex GMFM items for those in GMFCS levels III and IV. The lower baseline functional level was related to a greater functional improvement. Older individuals were noticed to improve more in GMFM dimension D. Regarding impairments evaluated by clinical examinations, no change was found after RAT intervention. It is worth mentioning that the strength of knee muscles was not affected either.