Distal Forearm Fractures In Children; Cast Level Effectiveness

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1 Distal Forearm Fractures In Children; Cast Level Effectiveness Mossa O. Mossa Al-Gazali College of Medicine, Dep. of Surgery-Orthopedic, Al-Qadisia University M J B Abstract Objective: To determine whether below-the-elbow casts are as effective as above-the-elbow casts in immobilizing displaced fractures of the distal third of the forearm in children. Patients and methods: Fifty-two patients with displaced distal forearm fractures from June 2005 to January 2007 were enrolled in this study. Their age range (4-12) years. The criteria for reduction and re-manipulation were set a priori. Results: The cast groups did not differ clinically with respect to the initial fracture angulations, post-reduction fracture angulations, and fracture angulations at the time of cast removal. eleven (39%) of the twenty eight children in the above the elbow cast group met the criteria for re-manipulation compared with seven (29%) of the twenty four children in the below-the-elbow cast group. While this reduction of 10% did not reach significance (p = 0.27). Fractures treated in below-the-elbow casts met the criteria for re-manipulation less frequently than did those treated in above-the-elbow casts. When the cast was initially removed, the range of elbow motion was significantly less in the group treated with a long arm cast, but there was a minimal difference in the final range of motion between the two cast treatment groups. Conclusions: The effectiveness of a below-the-elbow casts as the same as the above-the-elbow casts to treat fractures of the distal third of the forearm in children. الخلاصه تمت الدراسة على 52 طفلا مصابين بكسور مرحلة في ا سفل عظام الساعد وقد تم تعديل هذه الكسور ووضعت في الجبيرة حيث وضعت الجبيرة ا على من مفصل المرفق لكسور 28 طفلا ووضعت الجبيرة ا سفل من مفصل المرفق ل 24 طفلا وتم متابعة هذه الكسور لفترة وهي في فترة الجبيرة ا سبوعيا واخذ الرقاي ق الشعاعية اللازمة وكذلك بعد رفع الجبيرة (6-4) ا سابيع حتى فترة ستة ا شهر بعد الكسر. وقد بينت النتاي ج ا ن فاي دة الجبيرة تحت المرفق مشابه ا لى فاي دة الجبيرة فوق المرفق وان تحدد حركة مفصل المرفق عند استعمال الجبيرة تحت المرفق اقل مما هو عليه في حال استخدام الجبيرة فوق المرفق لفترة زمنية قصيرة التي تعقب رفع الجبيرة. Introduction F ractures of the distal third of the forearm are the most common fractures of childhood[1-3]. The distal metaphysic being the most common site[4-6]. Approximately 75% of all forearm fractures in children involve the distal third of the forearm[7]. Various methods of cast immobilization have been recommended in order to prevent the recurrence of angulations or displacement. The benefits of below-the-elbow casts are thought to be easier application, greater comfort, better hand function for activities of daily living and less elbow stiffness. Above-the-elbow casts are purported to achieve better stability of the fracture and to lessen the risk of re-displacement with the need for remanipulation. Long arm cast theoretically are more likely to maintain reduction because elbow motion is restricted and the long wrist flexors and extensors cannot deform the fracture. Short arm casts have the potential advantage of 92

2 resulting in less temporary disability and inconvenience than long arm casts, as elbow motion is allowed. Patients and Methods Fifty-two patients with displaced distal forearm fractures from June 2005 to January 2007 were enrolled in this study. Twenty-eight patients were allocated to the above-the-elbow cast group and twenty four,to the below-the-elbow cast group. Each child between four and twelve years of age who was seen at out patients clinic in Aldiwanyia teaching hospital and the private fracture clinic with a closed fracture of the distal third of the forearm that required reduction was considered for the study. The exclusion criteria were an open fracture, a pathological fracture, a refracture through pre-existing fracture lines, Salter-Harris type III or 1V fractures and a fracture in a patient younger than four years of age or one with closed physes. The child`s fracture was managed with closed reduction with the child under conscious sedation usually after four to twelve hours after accident. A below- theelbow plaster cast was applied with the use of the three point molding.once hard,the cast was extended above the elbow in the patient treated with the above the elbow cast group. Final post reduction radiographs were made once the cast was dry (Table I). The child and his parents instructed for any complications. Table I Criteria for Acceptable Reduction Isolated distal radial fractures: 5 of angulation on lateral and posteroanterior radiographs 95% apposition of the fracture on lateral and posteroanterior radiographs Combined distal radial and distal ulnar fractures: 10 of angulation of either bone on lateral and posteroanterior radiographs 50% apposition of the fracture on lateral and posteroanterior radiographs Analgesia was provided for the child. The children had a follow-up visit at the fracture clinic within seven to ten days after the injury, and radiographs ( lateral and posteroanterior ) were made with the cast in the place at that time. If the alignment was still acceptable, the initial cast was left in place and the patient was followed again at four weeks after the injury with repeat radiographs with the arm in the cast. The radiographic criteria for determining whether remanipulation was required for loss of reduction were based on the criteria were outlined in (Table II). 93

3 Table II Criteria to Determine Whether Remanipulation is Required for loss of Acceptable Reduction Isolated distal radial fractures: >25 of angulation on the lateral radiograph >10 of angulation on the posteroanterior radiograph < 50% apposition on either the posteroanterior or lateral radiograph Shift of 15 in one week on the lateral radiograph Combined distal radial and distal ulnar fractures: >10 of angulation of either bone on the lateral or posteroanterior radiograph <25% apposition of the fracture on lateral and posteroanterior radiograph At four weeks after the injury, the cast was either removed or left in place, depending on the radiographic and clinical evidence of healing. Long arm cast were cut to short arm casts at this point if further immobilization was required.if the cast was left in place, the patient was seen two weeks later for radiographs to be made with the arm out of the cast. The children were followed for a total of eighteen weeks. The ranges of motion of the wrists and elbows on the injured and contra-lateral sides were measured and recorded when the cast was first removed for a baseline measurement. The patients were then instructed to perform range-of-motion exercise at home. They returned for a clinical examination at eight to ten weeks after the injury at which time the ranges of motion of the wrists and elbows were recorded again. Results Twenty eight patients were allocated to the above-the- elbow cast group and twenty four, to the below-the-elbow cast group. The groups were not different in terms of age or gender. A lower age-limit of four years was set, as the below-the-elbow cast can slip off the arms of the smallest children. An upper age-limit of twelve years was chosen, as residual deformity is less acceptable in older children because of their diminished remodeling potential. The above-the -elbow cast group contained a larger proportion of children with combined radial and ulnar fractures (Table V); however, this difference did not reach significance (p = 0.08). Neither group had any patients with an isolated distal ulnar fracture. The cast groups did not differ clinically with respect to the initial fracture angulations, post-reduction fracture angulations, and fracture angulations at the time of cast removal (Table III). 94

4 Table III Initial Fracture Alignment, Postproduction Fracture Alignment, and Fracture Alignment at Time of Cast Removal According to Cast Mean radial angulation on posteroanterior radiograph Initial Post redaction Cast removal Mean radial angulation on lateral radiograph Initial Post redaction Cast removal Mean ulnar angulation on posteroanterior radiograph Initial Post redaction Cast removal Mean ulnar angulation on lateral radiograph Initial Post redaction Cast removal In almost all cases, the 95% confidence interval for the difference in angulations between the cast types included zero. If it did not, the extreme limit of the confidence interval was 5, the maximum clinically acceptable difference Above the Elbow Cast Below the Elbow Cast Difference(95% Confidence Interval) (- 6.8 to 3.7) (- 1.9 to 0.1) (- 5.4 to - 0.8) (-10.2 to 4.1) 0.5 ( 2.3 to 1.4) 0.4 ( 3.9 to 4.7) 0.0 ( -8.2 to 8.1) (- 4 to 0.7) (- 5.6 to 0.7) ( to 3.51) 0.8 (- 1.6 to 3.2) 0.4 (- 3.0 to 3.8) set a priori. Similarly, fracture reangulation during cast immobilization did not differ clinically between the cast types. Similar results were seen when the data were analyzed according to fracture type (Table IV). 95

5 Table IV Mean Fracture Reangulation During Immobilization in Cast According to Cast Group for Each Fracture Type Mean radial reangulation on posteroanterior All Radius only Both bones Mean radial reangulation on lateral radiograph All Radius only Both bones Mean ulnar reangulation on posteroanterior radiograph All Radius only Both bones Mean ulnar reangulation on lateral radiograph All Radius only Both bones = not applicable Above the Elbow Cast Below the Elbow Cast Difference(95% Confidence Interval) 1.7 (0 to 3.5) (- 2.5 to 1.4) 2.3 (0 to 4.6) (-3.1 to 2.2) 0.2 (-5.2 to 5.8) -0.8 ( -4.0 to 2.3) -0.2 ( -3.1 to 2.6) -0.2 (-3.1 to 2.6) (- 3.8 to 0.7) -1.5 (- 3.8 to 0.7) While all 52 children were followed sufficiently to determine whether re-manipulation was actually performed, adequate follow-up radiographs for assessing the need for re-manipulation were available for all children. With use of the criteria for re-manipulation established at the start of the trail, eleven (39%) of the twenty eight children in the above the elbow cast group met the criteria for remanipulation compared with seven (29%) of the twenty four children in the belowthe elbow cast group. While this reduction of 10% did not reach significance (p = 0.27 ), the 95% upper confidence limit of this difference was an increase of 5%, which is consistent with clinical equivalency between the two cast types (Table V ). Table V Proportion of Fractures That Required Remanipulation According to Criteria Above the Elbow Cast Below the Elbow Cast Difference(95% Upper Confidence Unit: 95% Confidence Interval) All Fracture types Radial fracture only Radial are ulnar fracture 39%(11/28) 14%(1/7) 47%(10/21) 29%(7/24) 9%(1/11) 46%(6/13) -10%(+5%; -28% to -8%) -6%(+9%;+35% to +13%) -1%(+19%;-24% to -22%) The values are given as the percentage of fractures that met the criteria, with the number that met the criteria/total number in the group in parentheses. Stratification by fracture type than were fractures of the radius only revealed that combined radial and (p < o.ooo1). ulnar fractures were more likely to Fractures treated in belowthe-elbow casts met the criteria for meet the criteria for re-manipulation re- 96

6 manipulation less frequently than did those treated in above-the-elbow casts ;however, the differences were not significant, as the 95% confidence intervals around the differences all contained zero (Table V ). There was no significant difference between the partial and complete fractures, treated with either cast type, with regard to amount of reduction lost. i.e, there was no significant difference with respect to the change between the post-reduction and final values of displacement, angulations, or deviation. In other words, the reduction of completely displaced fractures was not as anatomic as that of partially displaced fractures, but there was no difference in maintenance of that reduction with either cast group. Children who met the criteria for re-manipulation did so before three weeks, indicating that the fracture position is stable between the third and six week. When the cast was initially removed, the range of elbow motion was significantly less in the group treated with a long arm cast, but there was a minimal difference in the final range of motion between the two cast treatment groups. At the time of cast removal, there were significant difference (p < o.oo1) in the arcs of elbow motion between the injured and contra-lateral sides in the long-armcast group compared with the shortarm-cast group. There was no significant difference (p =o.193) in the arcs of wrist motion between the injured and contra-lateral sides at the time of cast removal between the cast type groups. Patients who were treated with a long arm cast missed significantly more days of school and a significantly higher percentage of them required help to dress, required help in school, were unable to write, and had difficulty with activities of daily living. The selfreported time required to regain a normal range of motion of both the elbow and wrist was 17± 8 days for those treated with a long arm cast and 7±5 days for those treated with a short arm cast (p = o.oo1). 90% of the patients treated with a short arm cast said that they either had no difficulty or had some difficulty that did not require assistance. In comparison, 65% of the patients treated with along arm cast found their activities of daily living to be difficult enough to require assistance. Discussion The amount of reangulation of the fracture while in the cast when compared between the two cast types, the below elbow cast were found to maintain the alignment of the distal forearm fractures as well as above the elbow casts did. When the cast groups were compared with respect to the percentage of the fractures that met the criteria for re-manipulation, the below the elbow cast appeared to offer an absolute reduction of 11% compared with the above the elbow cast. While this improvement does not reach significance, the 95% upper confidence limit equal to an increase of 5% is consistent with at least clinical equivalency of the cast types. It appears that the immobilization of the elbow obtained by extending a below-the-elbow cast into an abovethe-elbow cast offers no benefit in maintaining the alignment of these fractures, in contrary to the fracturecare principle of immobilizing the joint proximal to and distal to a fracture. This may be because the elbow joint is quite distant from the fracture, and the majority of immobilization is secured over the length of the forearm. Analysis of the patients according to whether they had a completely or partially displaced fracture also 97

7 demonstrated no differences between the results, in either cast-type group. More displacement remained after reduction, and at the time of final follow-up, of the completely displaced fracture. However, there was no difference in the amount of reduction lost during the immobilization between the completely and partially displaced fractures. This suggests that short arm cast are equally effective for partially and completely displaced fractures. Our study agree with Eric R. Bohm et al[8]. Our results support the importance of weekly radiographic examinations for each of the first three weeks. All of the fractures that lost position and met the criteria for remanipulation did so before three weeks. This is consistent with guidelines that have been proposed elsewhere[9,10]. The finding of more cases of lost reduction in the long arm cast group was expected. A possible explanation for it is that long arm casts are technically more difficult to apply, which result in poorer molding around the forearm. For those children who lost fracture reduction, repeat reduction for them were not done. The consequence of lost reduction in this patient population is a deformity that takes longer to remodel and that can be an initial cosmetic concern to the patient and parents. As Blount showed, normal anatomy is restored in the immature forearm over time, even with bayonet apposition of the fracture fragment (7). Our study support the use of a well-molded short arm cast for the treatment of fractures of the distal third of the forearm in children,in agreement with the retrospective review by Chess et al.[11] There was a significant difference in the range of elbow motion between the long and short arm cast groups after the cast were removed. By the time of final followup,this difference was very small and clinically irrelevant, although it remained statistically significant. Children seem to tolerate immobilization of the elbow better than adults. It appears that loss of motion in association with the use of a long arm cast is not an important short or long-term issue for children. Our study agree with Gavin R. Webb et al[12 ]. Conclusions 1- The effectiveness of a below-theelbow casts as the same as the above-the-elbow casts to treat fractures of the distal third of the forearm in children. 2- There was a significant difference in the range of elbow motion between the long and short arm cast groups for a short-term follow-up. References 1- Masterson E. Boston D. O. Brinst T. Victms of our caniate, 1993:24: Reed MH, fractures and dislocations of the extremities in children, J.Trauma, , Woriock P, Stower M, Fracture patterns in Nottingham children, I pediatric Orthop. 1986; 6; Landin LA. Fracture patterns in children. Analysis of 8682 fractures with special reference to incidence, etiology and secular changes in a Swedish urban population, Acta Chir Scand Suppl. 1983; 202: Stanitski CL, Micheli U. Simultaneous ipsilateral fractures of the arm and fore-arm in children.clin Orthop Relat Res; 1980; 153: Thomas EM, Tuson KW, Browne PS. Fractures of the radius and ulna in children. Injury. 1975;7:

8 7-Blount WP. Fractures in children. Baltimore: Williams and Wilkins; Eric R. Bohm, Beng, Bubbar, Beu,Ken Yong Hing, and Anne Dzus "Above and Below the Elbow Plaster Cast for Distal Forearm Fractures in children"jbjs.org,vol.88-a. No.1.Jan Roberts JA Angulations of the radius in children's fractures, J Bone Joint Surg. Bt.1986,68; Green JS. Wiltiams SC, Finly O. Hatper WM. Distal forearm fractures in children the role of radiographs during follow up, Injury. 1998:29: Chess DG, Hyndman JC, Leahey JL,Brown DC. Sinclair AM. Short arm plaster cast for distal pediatric forearm fractures. J. Pediatric Orthop. 1994; 14: Gavin R. Webb, Robert D. Galpin, Douglas G. Armstrong, "Comparison of Short and Long Arm Plaster Casts for Displaced Fractures in the distal Third of the forearm in Children ", JBJS.ORG, Vol. 88-A. No.1.Jan