Clinical Investigation Into Upper Limb' Deformity In Affected Children With Birth Palsy

Objective: Birth palsy,also called obstetric brachial plexus palsy,is a unilateral or bilateral brachial plexus injury in fetus caused by the traction during delivery.It is very common in the clinics and the prevalence is increasing every year. But the factors of birth palsy are very complicated,and there are mainly three viewpoints(traction theory,compression theory and others) and three factors(fetus overweight,abnormal fetal position and unfavourable obstetrics). Birch considered that macrosomia was the main cause of birth palsy during cephalic position delivery. Shichang Gao reported that the major three factors resulting in birth palsy were macrosomia, forceps delivery and occipitotransverse-or-occipitoposterior-position dystocia. Therefore macrosomia has become the principal risk factor of birth palsy. With the development of microtechnique in hand surgery,birth palsy can be interfered by operation and many achievements have been made in both the experimental and clinical researches,but no one with the affected extremity can get complete recovery and will remain different functional disabilities and abnormalities. Birth palsy can cause various sensory and functional disabilities,but the effects on the growth and development of the affected extremeties are still unclear. This study is aimed to investigate the possible mechanisms and affects of birth palsy on the growth and development of upper extremety skeletons in the affected children,to illustrate the necessity of restoration of brachial plexus,thus to provide theoretical directions for the proper operation time,functional exercises and assessments of the prognosis.Methods: Sixty affected children with birth palsy who were admitted for treatment from January 2006 to February 2011 were recruited for this study(male thirty-four,female twenty-six);the average age was 2.6y(3m-7y) .Fourty affected children aged from 3y to 4y were selected to detect every parameter and the values were analysed by statistical tests. Detailed histories and physical examinations were collected to clarify whether the injury was caused by birth palsy.Then we made the rough diagnosis and performed electromyography of the affected brachial plexus.Then operations were performed to detect the locations and degrees of the brachial plexus injury,and different methods were used according to the various injury degrees: nerve release,nerve transplantation,nerve translocation(e.g.accessory nerve translocation).And the restitution including the restitution of shoulder abduction or elbow joint is necessary for those who had undergone nerve restoration but still remained sequela. Then the injury locations of brachial plexus were clarified and devided into three types: superior trunk injury, superior-middle trunk injury and the whole brachial plexus injury.Within every type,experimental and control groups were made:affected side was viewed as the experimental group(fourty patients), contralateral side was the control group(fourty patients).The length of upper arms and forearm,circumference and bone density of the forearms were measured in all of the patients. The detailed parameters were measured by tapes as followes:1.the length of the upper arms:the length from acromion to humeral lateral condyle;2.length and circumference of the forearms: length from anconeal process of ulna to capitulum ulnae represented the length of forearm; circumference of the site (two-centimeter above the wrist)was considered to be the circumference of the forearm.3.bone density of the forearms:three sites on the forearms were selected to test the bone desity by one professional researcher,and the average was obtained. All values are expressed as the mean±SE. Differences among the length, circumference and bone density were analyzed by the t test to analyze the impact of birth palsy on the affected extremeties.Statistical significance was set atα<0.05. Differences among the three types of birth palsy were observed by analysis of variance,α<0.05 was considered to be significant.Results:(1)Length of upper arms:uninjured arm:164.8500±2.19926 mm;affected arm:156.3600±2.19768mm.The difference between the two groups was significant(t=22.783,p<0.05); the difference among the three types was also significan(tF=14.607,p<0.05).And the impact on the injured arm was more obvious as the injury became severer.(2)Length of forearm: uninjured arm:152.4500±2.19926mm;affected arm:144.2650±2.21325mm.The difference between the two groups was significant(t=32.608,p<0.05); the difference among the three types was also significant(F=18.044,p<0.05).And the impact on the injured arm was more obvious as the injury became severer. (3)Circumference of forearms:uninjured arm: 141.3075±1.74614mm;affected arm: 130.5075±1.85235mm.The difference between the two groups was significant(t=24.603,p<0.05); the difference among the three types was also significant(F=13.664,p<0.05).And the impact on the injured arm was more obvious as the injury became severer.(4)Bone densty of forearms:uninjured arm: 0.32850±0.005025g/cm2;affected arm: 0.31315±0.004727g/cm2.The difference between the two groups was significant(t=12.917,p<0.05); the difference among the three types was also significant(F=16.265,p<0.05).And the impact on the injured arm was more obvious as the injury became severer.Conclusion: (1)Upper extremities in the affected children with brachial plexus injury will present different functional disabilities and can restore only partial recovery after nerve or functional reconstruction surgery.(2)Brachial plexus injury will inhibit the functions of the injured side,and the impact on affected arm is more obvious as the injury becomes severer(.3)The domains controlled by different nerves are overlapping.And the cross distribution may regulate the growth and development of bones by the complicated neuropeptide-induced network system(.4)It is advised to receive nerve or function restoration surgery in the early stage for the affected children with birth palsy to restore the function of upper extremities,therefore,to benefit the growth and development of the affected extremities.