Elastic stable intramedullary nailing for treatment of pediatric forearm fractures: A 15-year single centre retrospective study of 173 cases

Abstract

Objective

The aim of this study was to analyze the outcomes and complications in children treated with elastic stable intramedullary nailing (ESIN) for forearm fracture.

Methods

The study included 173 patients (126 men and 47 women; median age: 11 years (range: 3–17 years) treated with ESIN for forearm fracture between May 2002 and May 2018. Immobilization was not performed after the surgery. The median follow-up was 68 months (range: 3–161 months). The etiology, healing time, and complications were recorded.

Results

All patients achieved complete radiographic healing at a median of 6.8 weeks (range: 4–11 weeks). The most common injuries were sport related (n=65) and by falling from standing height (n=57), followed by injuries from bicycle riding, motorbike accidents, road traffic accidents, and fights. Fifteen (8.76%) postoperative complications were recorded: eight entry-site skin irritations, two cases of skin infection, two refractures, and one case each of nail migration, injury of ulnar nerve, and pseudoarthrosis. All complications, except cases of refractures and pseudoarthrosis, were treated conservatively, with no long-term consequences for the patients. Patients with refractures and pseudoarthrosis were reoperated, and complete function of the extremities was fully restored.

Conclusion

ESIN for treatment of forearm fractures in children shows good functional and cosmetic results. This is a minimally invasive, cast-free, simple, and reproducible technique, with a low complication rate. Owing to these excellent objective and subjective results, surgical stabilization of the forearm fracture using ESIN is recommended in children and adolescents.

Level of Evidence

Level IV, Therapeutic study

Forearm fractures are the most common injuries in the pediatric population. Diaphyseal forearm fractures, in particular, are among the most common injuries treated in children (1, 2). Their incidence is thought to be increasing during the last decade (1). Most children can be successfully treated conservatively with close reduction and plaster cast immobilization because they have a strong and thick periosteum, with good remodeling potential of the growing skeleton. Surgical intervention is indicated for open fractures, fractures with significant soft-tissue injury, fractures associated with compartment syndrome, unstable fractures, and fractures with an unacceptable alignment after closed reduction (3). The main goal of treatment is to achieve reduction and maintain the appropriate position of the rotational displaced fragments. Surgical fixation of these fractures has traditionally been performed with plates and screws. In recent years, elastic stable intramedullary nailing (ESIN) has become the preferred technique in many centers (1–4). Nowadays, the rate of surgical stabilization for forearm fractures has increased. The rate of surgical stabilization for forearm shaft fractures treated with ESIN has increased from 1.8% to 22% in the last ten years (5). ESIN meets all the criteria of minimally invasive bone surgery: shorter operating time, minimal soft-tissue dissection, smaller incisions and thus smaller scars, less pain, earlier mobilization, and relatively easy implant removal (6). The reported outcomes are satisfactory, although a wide range of complication rates have been reported in the literature (1–4, 7). The aim of this study was to evaluate the clinical and radiological outcomes and complication rates of forearm fractures treated with ESIN in children and adolescents in a representative cohort of 173 children over the past 15 years in order to underline the safeness and efficiency of this technique.

Materials and Methods

Patients

The case records of 173 children (126 men and 47 women) treated for forearm fractures with ESIN, from May 2002 to May 2018, were retrospectively reviewed. Inclusion criteria were the diagnosis of forearm fracture in patients of both sexes, with a minimum follow-up of 3 months. Exclusion criteria were patients older than 17 years of age, patients with nonoperatively treated fractures, patients treated with no intramedullary fixation, patients operated on in other institutions, patients with follow-up shorter than 3 months, and patients with incomplete data. For all patients, information on age, sex, side involved, trauma mechanism, type of fracture, associated injuries, neurovascular status, complications, operation time, duration of hospital stay, time to implant removal, and whether the fracture was closed or open were analyzed. Visual analog scale was used for postoperative and residual pain assessment. The study was approved by the institutional review board. Demographic and clinical data of the patients are presented in Table 1. The patients were divided into two groups: Group I - open fractures and Group II - closed fractures. Group II was further divided into three subgroups (pathological fractures, dislocated fractures, and Monteggia fractures).

Table 1.

Demographic and clinical data of children operated for forearm fracture

Type of fracture	All fractures (n=173)	Open fractures (n=20)	Closed fractures (n=153)			p
			Pathological fractures (n=1)	Dislocated fractures (n=147)	Monteggia fracture (n=5)
Age						0.550
Median (years)	11	10	12	10	9
Range	3–18	5–15	12	3–18	4–12
Sex (n)
M	127	12	0	112	3	0.148
F	46	8	1	35	2
Lateralization
Left	96	7	0	87	2	0.057
Right	77	13	1	60	3
Hospital stay
Median (days)	5	7	6	5	4
Range	2–8	5–8	6	2–7	3–7	0.069
Operation time
Median (hours)	60	49	50	69	71
Range	(29–130)	(29–89)	50	(45–130)	(52–108)	0.002
Time of healing
Median (weeks)	6	6	11	6	7	0.205
Range	4–11	4–8	11	4–11	6–8
Follow-up
Median (months)	68	53	35	68	56	0.445
Range	3–161	6–150	35	3–161	19–117
Associated injuries (n, %)	17 (9.82%)	2	0	15	0	0.977
Complications (n, %)	15 (8.67%)	3	1	11	0

M: male; F: female

Radiographic assessment

All the children underwent full-length anteroposterior and lateral radiographs of the injured arm to assess displacement. The angulation was defined as the angle between the axis of the proximal and distal fragments of the fracture.

Indications for surgery

Indications for surgery were open fracture, impending compartment syndrome, loss of reduction after closed treatment and casting, pathological fractures, and inability to achieve stable initial reduction with closed treatment.

Surgical treatment

Titanium intramedullary nails (TEN Synthes® GmbH, Oberdorf, Switzerland) were used in all patients. The diameter and length of the nails were selected according to the bone length and age of the child. Thickness of the nails was determined preoperatively and intraoperatively such that two nails minimally filled two-thirds of the medulla in the narrowest part of the bone. All the children were treated under general anesthesia in the supine position on a radiolucent operating table. The fracture was first reduced by an external maneuver with fluoroscopic verification. When reduction was achieved, the radial nail was inserted through a 1 cm mini incision to protect the superficial radial nerve, at the distal lateral radius, proximal to the growth line. If closed reduction failed, a 2.0 mm Kirschner wire was inserted at the fracture site to elevate and reduce the fragments; if both failed, open reduction through a mini incision at the fracture site was performed. The ulna was stabilized through a 1 cm mini incision at the olecranon, distal to the growth plate. The nails were shortened at the subcutaneous level. The wounds were primarily sutured. Free range of motion of the elbow and wrist was tested for all fractures at the end of the procedure by the surgeon, and intraoperative radiographs were taken. After the surgery, there was no casting, and physical therapy was started on the second postoperative day. Cryotherapy was used over the affected area to reduce inflammation. Physical therapy was initiated with range of motion exercises (passive and active flexibility exercises) followed by exercises to strengthen the forearm muscles, improve flexibility, and decrease stiffness.

Surgeon experience is an important factor determining the likelihood of successful outcomes after surgery. All surgeries were performed by six very experienced and two experienced pediatric surgeons. All nails were removed at a median of 5.5 months (range: 4–11 months).

Follow-up

All the patients were regularly followed clinically and radiographically for 7 days, and then 1, 3, and 6 months after the index surgery (Figure 1). Radiological evaluation was carried out using standard anteroposterior and lateral radiographs at each visit to evaluate the consolidation of the fracture and identify complications such as secondary displacement, shortening, hardware migration, delayed union, nonunion or malunion, and refracture. Subjective data, such as perceived pain, stiffness, and impact on daily activities, and objective data, such as range of motion, skin lesions, or surgical site infection, were recorded. Complete fracture healing was defined as a full return to activities of daily living and sports.

Figure 1. a-f.

A 12-year-old patient with forearm shaft fracture: (a) Preoperative radiograph. (b) Intraoperative radiograph. (c, d) One month after surgery. (e, f) Three months after surgery-complete healing of the fracture

Statistical analysis

The data were analyzed using the Microsoft Excel for Windows Version 16.0 (Microsoft Corporation, USA) and Statistical Package for Social Sciences, version 19.0 (IBM SPSS Corp, Armonk, NY, USA) software programs. Distributions of quantitative data were described by means and standard deviations, or medians and ranges, while absolute rates and percentages were used to describe categorical data. Differences in median values of quantitative variables between the groups were tested with a t-test. The chi-square test with Yates correction was used for the statistical analysis of the categorical data. All values of p<0.05 were considered statistically significant.

Results

The median follow-up was 68 months (range: 3–161 months). The median age at surgery was 11 years (range: 3–17 years). Most of the children (n=70; 40.5%) were operated at adolescence, with the least number of repairs performed on children between the ages of 3 and 5 years (n=12; 7%). In 96 patients, the left arm was injured, and 77 fractures occurred on the right side. All patients achieved complete radiographic healing at a median of 6.8 weeks (range: 4–11 weeks). Median time of healing for Monteggia fractures and pathological fractures was 7 and 11 weeks, respectively. There was no statistically significant difference in radiographic healing between open and closed fractures (p=0.205). The median operative time was 49 min (range: 29–89 min) for closed reduction and 69 min (range: 45–130 min) for open reduction. The operative time for fractures treated with closed reduction was significantly lesser than that for fractures treated with open reduction (p=0.002). Median length of hospital stay was 5 days (range: 2–8 days) for all groups. Median length of hospital stay for closed fractures was 5 days (range: 2–7 days) and 7 days for open fractures (range, 5–8 days; p=0.069). Median diameter of the nails was 2.5 mm (range; 1.5–3.5 mm).

The cause of injury was sport related in 65 patients, a fall from a standing height in 57 children, bicycle accidents in 19 patients, motorbike accidents in 18 patients, traffic accidents in 11 patients, and fight related in three patients. The fractures in 153 children were closed, and 20 children had open fractures with no neurovascular compromise (Table 2). In 115 patients, the fracture was reduced by a closed reduction, while in other 58 patients open reduction was required owing to difficulty in reduction and soft-tissue interposition. One patient had a pathological fracture.

Table 2.

Distribution of fractures according to fracture type and mechanism of injury

Fracture type			Open fractures	Closed fractures
				Monteggia fracture	Displaced fracture	Pathological fractures
Mechanism of injury	n	%	20	5	147	1
Bicycle riding	19	10.98	2	1	16	/
Motorcycle	17	10.4	2	/	15	/
Road traffic accident	12	6.65	3	/	9	/
Fall from a standing height	57	32.94	6	3	47	1
Sports	65	37.57	7	1	57	/
Fight	3	1.73	/	/	3	/
Fracture type
Open fracture	20	11.56	20	/	/	/
Closed fracture	153	88.43	/	5	147	1

Procedure-related complications were recorded in 15 (8.67%) patients and included eight entry-site skin irritations, two skin infections at the entry site, two refractures, one pseudoarthrosis of the radius, one injury of the ulnar nerve, and one case of migration of the nail (Table 3). There was no instance of loss of reduction during the postoperative period. No clinically significant deformities were observed. At follow-up, all patients achieved osseous union and regained the full range of movement after rehabilitation. In two patients, refracture occurred because of new trauma at an average of 4 months (range: 3–5 months). There were no cases of delayed union and nonunion. Malunion was recorded only in case of pseudoarthrosis of the radius after nail removal. Totally, three children required reoperation: two with refracture and one with pseudoarthrosis of the radius. There was no statistically significant difference between open and closed fractures in terms of rate of postoperative complications (p=0.284).

Table 3.

Postoperative complications in children operated for forearm fracture

Type of complication	n	%
Entry-site skin irritation	8	4.62
Entry-site skin infection	2	1.15
Refracture	2	1.15
Ulnar nerve injury	1	0.57
Pseudoarthrosis	1	0.57
Migration of nail	1	0.57
Total	15	8.67

Children with ulnar nerve injuries regained full function of the nerve following removal of the implant and physical therapy. Physical therapy consisted of proprioceptive neuromuscular facilitation techniques associated with neuromeningeal mobilization, stretching, and ultrasound until complete recovery (3 months). Refractures were repositioned with open reduction, and osteosynthesis was performed using titan nails. In patients with pseudoarthrosis, osteotomy, spongioplasty, and osteosynthesis with plate and screws were performed. Other complications were treated conservatively. The implants were removed under general anesthesia in a day-surgery without difficulty at a median time of 5 months (4–9 months) from the index operation. After the removal of the nails, all patients regained full function and all complications were resolved.

Discussion

Fractures of the forearm are the most common bone fractures in the pediatric age and account for 59% of all long bone fractures (8). Achieving a good functional result following displaced forearm fractures is the objective for both operative and nonoperative management of these injuries. Because of a high rate of redisplacement noted after conservative treatment, not surprisingly, a move toward increased open reduction surgery has been advocated (1, 8, 9). Displaced forearm fractures in our study were significantly more frequent in boys than in girls. Median age at the time of surgery was 11 years. Similar findings were recorded in other published studies (1–4, 10). The types of operative stabilization include plating and ESIN. Although plating ensures anatomical reduction and stable fixation, it has the disadvantages of exposing the fracture site, increasing the risk of nonunion, and being associated with a higher infection rate and risk of refracture. Since introduction of the ESIN, many authors have reported good results with titanium intramedullary nailing (1–4, 9–12).

ESIN is a minimal movement- and partial load-stable procedure for the treatment of diaphyseal and metaphyseal shaft fractures. The biomechanical principle of this procedure is based on a three-point support with two pretwisted flexible titanium nails inserted in the bone shaft. The ideal fracture for this procedure is a diaphyseal transverse fracture, but diagonal and spiral fractures can also be treated by ESIN using the basic biomechanical principles (13). This produces the following four properties that are essential for achieving optimal results: flexural, axial, translational, and rotational stability (4, 6). The ESIN has the benefits of early immediate stability of the involved bone segment, which permits early mobilization and return to normal activities. Furthermore, owing to the excellent stability of ESIN, the patients do not need a cast and the degree of stabilization permits cast-free functional rehabilitation. Considering the excellent functional results in our study and in previously published studies on pediatric shaft fractures of the long bones, we can conclude that using ESIN without a plaster cast leads to an excellent functional outcome and faster healing of the fractures with very few complications (4, 6, 13). Previous studies also compared plaster cast immobilization with elastic intramedullary nailing in patients with femoral fractures and showed a significantly earlier union with ESIN (without plaster cast) than that with the plaster cast (6 vs 8 weeks). Furthermore, in the plaster cast group, there were additional complications such as increased angulation in the coronal plane, poor rotational alignment, limb length discrepancy, longer immobilization time, more delay in bearing weight, and increased school absenteeism (14).

Similar to other methods, ESIN is not without complications. ESIN can be complicated by wound infections, nerve injury, metalwork prominence, skin irritation, loss of correction, delayed union or nonunion, loss of reduction, and refractures (3, 4). A wide range of complication rates between 0% and even 67% for intramedullary fixation is reported in the literature (1–4, 7, 11, 12). Average rate of complications is 10–15% (2–4, 7). Smith et al. reported a rate of 42%, whereas Shah et al. reported no complications after intramedullary nailing compared to a rate of 10% when screws and plates were used (9, 12). Antabak et al. reported a complication rate of 25% in 88 children (1). Fernandez et al. in one of the biggest published cohorts of 553 children, treated with ESIN for forearm fractures, reported a rate of complication of 14.64%, mostly refractures (4.88%), followed by delayed union and radial nerve injury (7). Makki et al. reported a total complication rate of 11.8%, with 5.88% reoperations in children because of refracture (3). Kruppa et al. in their cohort of 202 fractures, reported a low total complication rate of 8.9%, mostly refractures. In their study, 6.9% of the children required a second operative intervention (2). In our study, a complication rate of 8.67% was observed during a 15-year period. Most of the complications were minor and were treated conservatively. The most common recorded minor complication was entry-site skin irritation, followed by skin infections at the entry site, injury of the ulnar nerve, and migration of the nail. Major complications included two cases of refractures and one case of pseudoarthrosis of the radius. After the removal of the implants and rehabilitation, all the minor complications were resolved without any consequences. Totally, three children (1.73%) required reoperation, two with refracture and one with pseudoarthrosis of the radius. Except for these three cases, there were no other cases of delayed union, nonunion, or malunion.

In most of the published reports, refracture represents the most common complication, either with the ESIN in situ or after implant removal. This is not unexpected, as forearm fractures are known to have a higher rate of refractures than other fractures in children, and they have been frequently reported after the removal of intramedullary forearm fixation in the literature (2, 3, 7). The total refracture rate was 1.7%, which is above the reported rate of 4–8% in the literature (1–3, 7, 15). In our study, both refractures occurred after a second trauma after implant removal and were successfully treated with repeat ESIN.

The most common complication in our study was superficial skin irritation in eight patients (4.6%). Krupa et al. and Mai et al. reported a significantly lower incidence of superficial skin irritations compared to our study (2, 3). Gibbon et al. recently published an investigation recommending bending of the ESIN tip and suggested a tip bending of 180° before burying to prevent skin irritations and additional procedures (16). Superficial wound infections following ESIN of forearm fractures in children are very rare. Fernandez et al. reported on five superficial infections in 553 children, while Antabak et al. reported three infections in 88 children (1, 7). In our study, only two cases of superficial wound infections in 173 children were recorded.

Treatment of Monteggia fractures and their equivalents is usually dictated by the type of ulnar fracture rather than the radial head injury. Previous reports from the literature confirmed successful treatment of such fractures with ESIN (3, 17). In our study, five children were successfully treated with ESIN for the fixation of the ulna and radius, and no loss of reduction was observed. In these children, fracture of the ulna was located at the middle shaft.

One child with a pathological fracture due to simple bone cyst was recorded in our study, which was successfully treated with ESIN. Excellent functional results and outcomes after ESIN for the treatment of simple bone cysts were previously confirmed in the literature (18).

Sheng-hu et al. concluded that a single ESIN to fixate the radius alone remains an equally effective fixation method in the pediatric population compared with both-bone fixation (19). In our series, we fixated both bones in all the patients.

All the patients achieved complete radiological healing of the fractures at a median of 6 weeks, which is similar to that in other published studies (1, 3, 6). Median duration of hospital stay was 5 days, which is longer than that in other published studies, although the rate of complications in a study by Nihsaaru et al. was 34% with a twice shorter hospital stay (20). We can explain the longer hospital stay as follows: in our clinic, physical therapy is started on the first or second postoperative day, and after 2 or 3 days, when a good range of motion is established, the children are discharged and they continue to undergo physical therapy as outpatients.

In general, complications arise mostly from technical errors or if basic biomechanical principles of the method are not followed on proper way. Refractures are associated with premature extraction of implants and an incorrect placement inside the bone, irritation of soft tissues with a large curvature and length of outer part of the nail. Injuries of the radial and ulnar nerves are associated with incorrect insertion and extraction of implants (1–3, 21–23). If we summarize all the above-mentioned points with a fact that the rate of complications in the literature varies, we can conclude that satisfactory results and complications of ESIN greatly depends on the right indication and correct performance, and the skill and experience of an operating surgeon. With all being said, complications, in a long-term follow-up, often do not surface because of the considerable potential for growth, remodeling, and correction of the angulation of the bones.

A retrospective nature is the main limitation of this study, although we have implemented multiple plausibility checks and cross-validations in our data-collection tool. Moreover, further studies are needed to analyze the same parameters with a larger sample size.

In conclusion, based on the results of our study, we can conclude that the ESIN method satisfies all the criteria of minimally invasive bone surgery. For treatment of forearm fractures in children, it has been shown to be a very efficient method with excellent functional and esthetic outcomes and a low rate of complications, if the indications and biomechanical principles are respected.

HIGHLIGHTS.

• ESIN for treatment of forearm fractures in children shows good functional and cosmetic results.

• ESIN is a minimally invasive, cast-free, simple and reproducible technique.

• ESIN is the ideal procedure for a transvers diaphyseal fracture, but diagonal and spiral fractures can also be treated with this method.

• When indications are correct and biomechanical principles are respected during application, rate of complication is very low.