In this study, we first present a huge cases of CPT described retrospective study, and defined them clinical features from the parts of general condition, radiological and clinical characteristic. Thus, we bring a much more deep knowledge of CPT from Chinese aspect.
In this study, we have collected 514 cases which came from 29 provinces or autonomous regions and direct jurisdiction cities. Hunan province had the highest number of cases with 65 (12.67%), in the top 10 provinces with the largest number of cases, only Guangxi Zhuang Autonomous Region 27 (5.26%) and Jiangxi province 26 (5.07%) was not among the top 10 provinces or autonomous regions and direct jurisdiction cities with the largest population in China. Provinces or autonomous regions and direct jurisdiction cities with larger population had more cases, but Hunan provinces weren't the top one with the largest population in China, which may be related to the geographical location of our hospital.
CPT is a rare pathology occurring in between 1/140,000 and 1/250,000 births[21–23] and is one of the most complex orthopedic situations in pediatrics. Based on the morbidity reported above, in recent 10 years, the number of newborns in China which from official data reports was 157.56 million, from this aspect, this may reflect the number of CPT patients was closed to 630-1125 cases. Of the 514 cases collected in our hospital, 424 cases were collected from 2011 to 2020, and 90 cases were collected from 1999 to 2010. It means that our one center has treated nearly 40% of the national CPT since 2011.
Currently, the timing of surgery for CPT is a controversial issue. EPOS recommend avoiding surgery for CPT in patients younger than 3 years old, operation should be postponed to the age of 5 years, otherwise, patients may have a worse prognosis. Hardinge had similarly recommended deferred surgery to the age of 4 years. However, Shah H reported that the achievement of bone union in young children can minimize the abnormal growth and lower limb shortening. Joseph  reported that the bone union of CPT occurred in 12 out of 13 (92%) children treated before the age of 3 years. Liu reported 42 patients with CPT which were recruited and analyzed, overall, the frequency of bone union was higher in children with CPT operated before reaching 3 years of age, Liu suggested that there is no need to defer surgery for CPT until the child is older than 3 years of age. Considering this controversial issue, in our study, age of first appearance of symptom, first visit of outpatient and first operation were divided into three groups which were birth-<1year, ≥1-<3years and ≥3years. In this study, the age of first appearance of symptom before 3 years had 481 (93.58%) cases and after 3 years had 33 (6.42%) cases; the age of the first visit of outpatient before 3 years had 297 (57.78%) cases and after 3 years had 217 (42.22%) cases ; 221(50.69%) cases had operation before 3 years old and 215 (49.31%) cases had operation after 3 years old; this phenomenon which operation before 3 years was as common as operation after 3 years may be related to the age of the first visit of outpatient.
Pseudarthrosis of the fibula (CPF) is frequently associated with CPT, but it becomes uncommon when it's isolated. Isolated CPF is usually considered a less severe condition than CPT. However, its site most frequently near the ankle leads to severe valgus and instability of this weight bearing joint[24, 28]. In Liu's study, patients with fibular pseudarthrosis had a high incidence of refracture and ankle valgus, he suggested that attention should be paid to the presence of fibular pseudarthrosis when managing CPT. There were 276 (53.70%) CPF treated in 514 cases of this study, meanwhile 44 (8.56%) cases with cystic changes of his fibula. There were statistical differences in the prevalence of CPF, but no statistical differences in cystic changes of his fibula.
We found that Crawford IV (330, 62.86%) CPT had the greatest cases, which may be associated with hyperactivity. We treated Crawford IV CPT and developed into Crawford IV CPT with operation. It has been well documented that external fixation in children and adolescents have a significant physical and physiological impact, with studies reporting pain and consequent sleeping problems in approximately half of the patients. The operation complications related primarily to the use of an external or internal device, residual limb-length discrepancy and valgus deformity are commonly reported with an overall complication rate of 30–100%. In our study, the complication also concluded ankle valgus, limb length discrepancy, refrature, osteomyelitis and removal of internal fixation. ankle valgus (101, 39.60%) and limb length discrepancy (91, 35.69%). The present study is a retrospective review limited by the heterogeneity of the available data and follow-up. Firstly, this study was a cross-sectional analysis and didn't provide prognostic or therapeutic recommendations for cohort studies. Secondly, this study was a single-centre analysis. Although our cases came from all over the country, there was still bias. We should combine The China Pediatric Orthopedic Association with expanding multi-center research in future studies, with further detailed documentation, it may be possible to clarify many more issues.