ORIGINAL ARTICLE
Cannulated Lag Screw Fixation of Displaced Lateral Humeral Condyle Fractures Is Associated With Lower Rates of Open Reduction and Infection Than Pin Fixation Benjamin E. Stein, MD,* Alim F. Ramji, BS,* Hamid Hassanzadeh, MD,*w Jared M. Wohlgemut, MBChB,z Michael C. Ain, MD,* and Paul D. Sponseller, MD*
Background: Open reduction/internal fixation remains the most common way to surgically stabilize displaced pediatric lateral humeral condyle fractures, but closed reduction and internal fixation is being increasingly used. Our goal was to compare the clinical and functional results of treating displaced pediatric lateral humeral condylar fractures with traditional smooth or threaded pin fixation versus single cannulated screw fixation. Methods: From 1998 through 2012, the lateral humeral condyle fractures of 48 patients were treated with pin fixation (22 patients, until 2006) or cannulated, partially threaded screw fixation (26 patients, from 2006 onward). In each, closed reduction with percutaneous fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. For the pin and screw groups, preoperative maximum radiographic displacement averaged 8.4 mm (range, 3.8 to 18.4 mm) and 6.3 mm (range, 2.2 to 15.5 mm), respectively; follow-up averaged 4.3 months (range, 1.5 to 20 mo) and 10.3 months (range, 2 to 30 mo), respectively. We reviewed preoperative and postoperative images and all follow-up clinical examination findings; serially assessed initial displacement, Baumann and carrying angles, range of motion limitations, and clinical alignment; evaluated functional results via the system of Hardacre and colleagues; and investigated all complications. Results: Open reduction was required in 73% (16/22) and 15% (4/26) of the pin and screw groups, respectively (P < 0.001). All fractures were reduced to 0.5). *There were 8 threaded pins, 12 nonthreaded pins, and 2 unspecified pins. wValues are given as mean (range).
METHODS Patient Population Institutional review board approval was obtained. Informed consent was not necessary for this retrospective review of routine postoperative care. We reviewed our institution’s electronic medical records from 1998 through 2012 and created a database of pediatric patients whose lateral humeral condyle fractures had been treated surgically by the senior authors with percutaneous pin or cannulated screw fixation. Inclusion criteria were (1) a substantially displaced (Jakob type II or III) lateral condyle fracture and (2) adequate medical records available for review. Forty-eight patients formed our study group. All children had closed fractures (Figs. 1A, B) and intact neurological and vascular examinations. For all, closed reduction with internal fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. Twenty-two patients were treated with pin fixation (primarily from 1998 through 2006; pin group) and 26 patients with cannulated, partially threaded screws (primarily from 2006 through 2012; screw group). The 2 groups had similar demographic characteristics and fracture types (Table 1). Arthrography was used in 18 patients (9 in each group) to help guide or confirm anatomic reduction. Most (13) patients were less than 6 years old and had undergone closed reduction. Fewer patients in the pin group had associated, ipsilateral injuries: 1 (olecranon fracture) and 5 (1 ipsilateral proximal, minimally displaced ulnar fracture; 3 ipsilateral olecranon fractures; and 1 ipsilateral radial and ulnar plastic deformities), respectively. All clinic and inpatient charts were reviewed for operative notes, physical assessments, and radiographic images. Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Lateral Condyle Fractures: Cannulated Screw Versus Pin
Procedures The following methods were used for closed fracture reduction: manual pressure, flexion, extension, and pronation for near-anatomic position, then a pin or guide-wire to further direct the reduction. If reduction was not achieved, a posterior approach18 was used for direct visualization and reduction. In the pin group, fixation was achieved with 2 smooth pins or a combination of smooth and threaded pins whose ends were left outside the skin and sterilely dressed (Figs. 1C, D). In the screw group, a cannulated, partially threaded screw was used for fixation (Fig. 2). The starting point for the guide pin is the lateral edge of the capitellar physis on the anteroposterior view, just posterior to its midpoint on the lateral view. The guide pin was positioned appropriately on the lateral condyle and used to manipulate the lateral condyle into position. Usually, some gap remained at the fracture site. The cannulated guide pin was driven up the lateral column of the distal humerus. If the fracture could be reduced to a parallel gap, it was then overdrilled, and the screw was inserted through the condyle fragment using percutaneous technique, achieving compression and better positioning (Fig. 2). If no parallel fracture gap could be achieved, it was opened. After surgery, patients were immobilized in a bivalved long-arm fiberglass cast or posterior splint. At the 4-week postoperative follow-up visit, interval healing was confirmed on radiographs, the cast was removed, and the elbow was checked for full ROM. Patients were encouraged to practice gentle active ROM exercises at home, and they returned for clinical examination and subsequent screw removal after complete fracture union.
Evaluation Two orthopaedic chief residents, under the guidance of the senior author, measured the amount of fracture displacement and classified the fracture pattern for each using a picture-archiving and communication system (UltraVisual Medical Systems, Madison, WI). Fracture fragment displacement was measured in the coronal plane from the lateral metaphyseal cortex of the distal part of the humerus to the corresponding lateral cortex of the fracture fragment on anteroposterior and internal oblique views and in the sagittal plane on the lateral radiograph. The greatest displacement on any radiograph was recorded as the amount of fragment displacement (Fig. 1). Fractures were categorized using the system of Jakob et al.4 The Baumann angle19 and carrying angle20 were measured on the initial postreduction and final radiographs (after removal of the screw or pins) to determine the degree of coronal alignment. When available, contralateral elbow radiographs were used for comparison. Evidence of fracture union and physeal injury was also assessed. All complications and injury sequelae were noted: nonunion, delayed union, malunion, fishtail deformity, cubitus varus, cubitus valgus, epiphysiodesis of the distal humerus, and avascular capitellum necrosis. Growth arrest, infection, loss of motion, and pain were clinically www.pedorthopaedics.com |
3
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Stein et al
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
FIGURE 2. Anteroposterior (A) and lateral (B) radiographs of a rotated and displaced Jakob type III lateral condyle fracture. Intraoperative anteroposterior (C) fluoroscopic view shows closed reduction achieved with the cannulated screw guide-pin. The guide-pin aligns the fracture, and the cannulated screw closes the gap. Intraoperative anteroposterior (D) and lateral (E) fluoroscopic views show anatomic fracture reduction with final lag screw placement.
determined on serial follow-up examinations. Surgical results were graded using the criteria of Hardacre et al.21
Statistical Analysis We used Stata statistical software (StataCorp LP, College Station, TX) to analyze the differences between the 2 patient groups for frequency of open and closed reductions, infection incidence, and postoperative ROM; significance was assigned at P < 0.05. Given the data’s categorical nature, the w2 test was performed first for the reduction technique used. For
4 | www.pedorthopaedics.com
postoperative infection and ROM, the 2-tailed Fisher exact test was used. For all cases, our null hypothesis assumed independence of outcome between the 2 fixation techniques.
RESULTS Pin Group Mean follow-up in this group was 4.3 months. Approximately one fourth of the fractures were reduced with closed techniques (Table 2). Postoperative displaceCopyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
Lateral Condyle Fractures: Cannulated Screw Versus Pin
nation, flexion, and extension; 3 achieved 95 degrees in full flexion; and 3 lacked 15 to 20 degrees of full extension. All 14 had normal-appearing physes, were asymptomatic, and had no functional limitations at final follow-up. The average postoperative radiographic Baumann angles were 75.4 ± 2.6 degrees initially and 75.9 ± 2.1 degrees at final follow-up. The average postoperative radiographic carrying angles were 12.5 ± 3.6 degrees initially and 12.2 ± 3.2 degrees at final follow-up. Contralateral elbow images were not available. Table 2 presents postoperative infection data. One deep infection (involving the joint) required operative irrigation and intravenous antibiotics, but the fracture united without osteonecrosis. Table 3 shows outcomes based on the criteria of Hardacre et al.21
TABLE 2. Fracture Reduction Technique and Postoperative Complication Data Pin Fixation, n (%)
Parameters
Screw Fixation, n (%)
Jakob type II fractures 12 Closed reduction 4 (33) Open reduction 8 (67) Jakob type III fractures 8 Closed reduction 1 (12) Open reduction 7 (88) Total fractures* 22 Closed reduction 6 (27) Open reduction 16 (73) Postoperative infectionw Superficial 4 (18) Deep 1 (4) Postoperative early range of motiony Full 6 (27) r15-degree extension loss 7 (32) > 15-degree extension loss 1 (4)
11 11 (100) 0 (0) 14 11 (79) 3 (21) 26 22 (85) 4 (15) 0 (0) 0 (0) 12 (46) 6 (23) 2 (8)
Screw Group More than three quarters of these fractures were reduced using closed techniques (Table 2), a significant difference from the pin group. As in the pin group, postoperative displacement was 0.5).
ment was 2-mm displacement be treated with open reduction/internal fixation; Foster et al7 endorsed this suggestion, showing the utility of close observation and closed reduction/internal fixation for minimally (< 2 mm) displaced fractures. Mintzer et al11 noted that for a subset of fractures with >2-mm displacement, closed reduction and percutaneous pinning can lead to successful outcomes if the fracture preserves a congruent joint surface. Song et al12 implemented closed reduction and percutaneous pinning for a group of completely displaced and rotated fractures with a success rate of 75% (18/24). Given the morbidity associated with open reduction techniques, research has recently focused on closed reduction of these fractures with percutaneous fixation.11–13 We compared the clinical and radiographic outcomes of substantially displaced lateral condyle fractures treated with cannulated lag screw or traditional pin fixation and found that 85% and 27%, respectively, were managed with closed reduction, a statistically significant
6 | www.pedorthopaedics.com
Volume 00, Number 00, ’’ 2015
difference (P < 0.001). This finding confirmed our hypothesis that screw fixation would decrease the need for open reduction. The 2 techniques had similar union rates and satisfactory fracture alignment. The period of cast immobilization was shorter for the cannulated screw group, although both groups showed similar ROM on serial follow-up. The infection rate was significantly lower in the screw group (no infections) than in the pin group (4 superficial and 1 deep infection) (P < 0.05), confirming our hypothesis that treatment with a cannulated screw may reduce infection risk. Two previous studies showed infection rates of 19.3% (11/57)8 and 16.7% (5/30)15 among patients treated with open reduction and Kirschner-wire fixation, with no infection among patients treated with open reduction and screw fixation, suggesting our finding was not aberrant. A retrospective review by Tosti et al23 reports that serious complication after percutaneous K-wire fixation occurs in 1.4% (12/884) of cases and recommends nonoperative therapy in cases where fracture callus and systemic signs of infection are not present. According to the criteria of Hardacre et al21 (Table 3), 89% and 59% of patients in our screw and pin groups, respectively, achieved excellent results. This could result from the pin’s inferior ability to compress and hold the fracture fragments in place. Avascular necrosis did not occur in either group. Compared with traditional pin fixation, the cannulated lag screw technique achieves a higher rate of closed reduction, delivers more interfragmentary compression across the fracture, and provides more stability. The intrinsic congruity of the surfaces articulating with the capitellum is 1 reason that percutaneous reduction is often successful. As the fragment is compressed, it is guided into a congruous fit with the opposing surfaces of the radius, ulna, and lateral condyle. We found that if the fracture can be reduced so only a parallel fracture gap remains, the cannulated screw can eliminate this gap, obviating the need for open reduction. We recommend 4.5-mm cannulated screws because the only case of loss of fixation occurred with a 3.5-mm screw. In addition, placement of a percutaneous screw allows earlier mobilization and does not have the infection risk associated with pin fixation. Despite these benefits, however, screw fixation has some drawbacks: the need for follow-up, with additional outpatient surgery for removal to avoid risk of physeal damage, and possible open reduction to achieve anatomic joint reconstruction for some severely rotated Jakob type III lateral condyle fractures. We recommend removal of all lag screws. If these screws are left in place, they may impede or distort growth across the physis. Our study’s chief limitations are relatively short follow-up and a small patient cohort. Although we strove to reach every patient for longer follow-up, adequate healing status without significant functional limitation deterred many patients from visiting the outpatient clinic, and others were unable to be reached for unknown reasons. It is likely that the need for scheduling a subsequent screw removal surgery allowed for longer follow-up with the screw group. Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
Our results confirm that the use of closed reduction with percutaneous fixation for displaced lateral humeral condyle fractures can reliably lead to excellent clinical outcomes, as previously described by Mintzer et al,11 Foster et al,7 and Song et al.13 We have shown that closed reduction was accomplished more frequently with cannulated lag screw fixation, and that it can achieve and maintain excellent fracture reduction without infection, premature physeal arrest, deformity, or other serious complications. Large, prospective studies with long-term follow-up are needed to explore the optimal treatment method. REFERENCES 1. Skaggs DL, Frick S. Upper extremity fractures in children. In: Weinstein SL, Flynn JM, eds. Lovell and Winter’s Pediatric Orthopaedics, 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2014:1694–1772. 2. Carson S, Woolridge DP, Colletti J, et al. Pediatric upper extremity injuries. Pediatr Clin North Am. 2006;53:41–67. 3. Milch H. Fractures and fracture dislocations of the humeral condyles. J Trauma. 1964;4:592–607. 4. Jakob R, Fowles JV, Rang M, et al. Observations concerning fractures of the lateral humeral condyle in children. J Bone Joint Surg Br. 1975;57:430–436. 5. Rutherford A. Fractures of the lateral humeral condyle in children. J Bone Joint Surg Am. 1985;67:851–856. 6. Finnbogason T, Karlsson G, Lindberg L, et al. Nondisplaced and minimally displaced fractures of the lateral humeral condyle in children: a prospective radiographic investigation of fracture stability. J Pediatr Orthop. 1995;15:422–425. 7. Foster DE, Sullivan JA, Gross RH. Lateral humeral condylar fractures in children. J Pediatr Orthop. 1985;5:16–22. 8. Launay F, Leet AI, Jacopin S, et al. Lateral humeral condyle fractures in children: a comparison of two approaches to treatment. J Pediatr Orthop. 2004;24:385–391. 9. Speed JS, Macey HB. Fractures of the humeral condyles in children. J Bone Joint Surg Am. 1933;15:903–919.
Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Lateral Condyle Fractures: Cannulated Screw Versus Pin
10. Sponseller P. Problem elbow fractures in children. Hand Clin. 1994; 10:495–505. 11. Mintzer CM, Waters PM, Brown DJ, et al. Percutaneous pinning in the treatment of displaced lateral condyle fractures. J Pediatr Orthop. 1994;14:462–465. 12. Song KS, Kang CH, Min BW, et al. Closed reduction and internal fixation of displaced unstable lateral condylar fractures of the humerus in children. J Bone Joint Surg Am. 2008;90:2673–2681. 13. Song KS, Shin YW, Oh CW, et al. Closed reduction and internal fixation of completely displaced and rotated lateral condyle fractures of the humerus in children. J Orthop Trauma. 2010;24: 434–438. 14. Koh KH, Seo SW, Kim KM, et al. Clinical and radiographic results of lateral condylar fracture of distal humerus in children. J Pediatr Orthop. 2010;30:425–429. 15. Li WC, Xu RJ. Comparison of Kirschner wires and AO cannulated screw internal fixation for displaced lateral humeral condyle fracture in children. Int Orthop. 2012;36:1261–1266. 16. Sharma JC, Arora A, Mathur NC, et al. Lateral condylar fractures of the humerus in children: fixation with partially threaded 4.0-mm AO cancellous screws. J Trauma. 1995;39:1129–1133. 17. Wirmer J, Kruppa C, Fitze G. Operative treatment of lateral humeral condyle fractures in children. Eur J Pediatr Surg. 2012;22: 289–294. 18. Gruber MA, Healy WA III. The posterior approach to the elbow revisited. J Pediatr Orthop. 1996;16:215–219. 19. Williamson DM, Coates CJ, Miller RK, et al. Normal characteristics of the Baumann (humerocapitellar) angle: an aid in assessment of supracondylar fractures. J Pediatr Orthop. 1992;12:636–639. 20. Beals RK. The normal carrying angle of the elbow. A radiographic study of 422 patients. Clin Orthop Relat Res. 1976;119: 194–196. 21. Hardacre JA, Nahigian SH, Froimson AI, et al. Fractures of the lateral condyle of the humerus in children. J Bone Joint Surg Am. 1971;53:1083–1095. 22. Flynn JC. Nonunion of slightly displaced fractures of the lateral humeral condyle in children: an update. J Pediatr Orthop. 1989;9: 691–696. 23. Tosti R, Foroohar A, Pizzutillo PD, et al. Kirschner wire infections in pediatric orthopaedic surgery. J Pediatr Orthop. 2015;35:69–73.
www.pedorthopaedics.com |
7
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Cannulated Lag Screw Fixation of Displaced Lateral Humeral Condyle Fractures Is Associated With Lower Rates of Open Reduction and Infection Than Pin Fixation Benjamin E. Stein, MD,* Alim F. Ramji, BS,* Hamid Hassanzadeh, MD,*w Jared M. Wohlgemut, MBChB,z Michael C. Ain, MD,* and Paul D. Sponseller, MD*
Background: Open reduction/internal fixation remains the most common way to surgically stabilize displaced pediatric lateral humeral condyle fractures, but closed reduction and internal fixation is being increasingly used. Our goal was to compare the clinical and functional results of treating displaced pediatric lateral humeral condylar fractures with traditional smooth or threaded pin fixation versus single cannulated screw fixation. Methods: From 1998 through 2012, the lateral humeral condyle fractures of 48 patients were treated with pin fixation (22 patients, until 2006) or cannulated, partially threaded screw fixation (26 patients, from 2006 onward). In each, closed reduction with percutaneous fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. For the pin and screw groups, preoperative maximum radiographic displacement averaged 8.4 mm (range, 3.8 to 18.4 mm) and 6.3 mm (range, 2.2 to 15.5 mm), respectively; follow-up averaged 4.3 months (range, 1.5 to 20 mo) and 10.3 months (range, 2 to 30 mo), respectively. We reviewed preoperative and postoperative images and all follow-up clinical examination findings; serially assessed initial displacement, Baumann and carrying angles, range of motion limitations, and clinical alignment; evaluated functional results via the system of Hardacre and colleagues; and investigated all complications. Results: Open reduction was required in 73% (16/22) and 15% (4/26) of the pin and screw groups, respectively (P < 0.001). All fractures were reduced to 0.5). *There were 8 threaded pins, 12 nonthreaded pins, and 2 unspecified pins. wValues are given as mean (range).
METHODS Patient Population Institutional review board approval was obtained. Informed consent was not necessary for this retrospective review of routine postoperative care. We reviewed our institution’s electronic medical records from 1998 through 2012 and created a database of pediatric patients whose lateral humeral condyle fractures had been treated surgically by the senior authors with percutaneous pin or cannulated screw fixation. Inclusion criteria were (1) a substantially displaced (Jakob type II or III) lateral condyle fracture and (2) adequate medical records available for review. Forty-eight patients formed our study group. All children had closed fractures (Figs. 1A, B) and intact neurological and vascular examinations. For all, closed reduction with internal fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. Twenty-two patients were treated with pin fixation (primarily from 1998 through 2006; pin group) and 26 patients with cannulated, partially threaded screws (primarily from 2006 through 2012; screw group). The 2 groups had similar demographic characteristics and fracture types (Table 1). Arthrography was used in 18 patients (9 in each group) to help guide or confirm anatomic reduction. Most (13) patients were less than 6 years old and had undergone closed reduction. Fewer patients in the pin group had associated, ipsilateral injuries: 1 (olecranon fracture) and 5 (1 ipsilateral proximal, minimally displaced ulnar fracture; 3 ipsilateral olecranon fractures; and 1 ipsilateral radial and ulnar plastic deformities), respectively. All clinic and inpatient charts were reviewed for operative notes, physical assessments, and radiographic images. Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Lateral Condyle Fractures: Cannulated Screw Versus Pin
Procedures The following methods were used for closed fracture reduction: manual pressure, flexion, extension, and pronation for near-anatomic position, then a pin or guide-wire to further direct the reduction. If reduction was not achieved, a posterior approach18 was used for direct visualization and reduction. In the pin group, fixation was achieved with 2 smooth pins or a combination of smooth and threaded pins whose ends were left outside the skin and sterilely dressed (Figs. 1C, D). In the screw group, a cannulated, partially threaded screw was used for fixation (Fig. 2). The starting point for the guide pin is the lateral edge of the capitellar physis on the anteroposterior view, just posterior to its midpoint on the lateral view. The guide pin was positioned appropriately on the lateral condyle and used to manipulate the lateral condyle into position. Usually, some gap remained at the fracture site. The cannulated guide pin was driven up the lateral column of the distal humerus. If the fracture could be reduced to a parallel gap, it was then overdrilled, and the screw was inserted through the condyle fragment using percutaneous technique, achieving compression and better positioning (Fig. 2). If no parallel fracture gap could be achieved, it was opened. After surgery, patients were immobilized in a bivalved long-arm fiberglass cast or posterior splint. At the 4-week postoperative follow-up visit, interval healing was confirmed on radiographs, the cast was removed, and the elbow was checked for full ROM. Patients were encouraged to practice gentle active ROM exercises at home, and they returned for clinical examination and subsequent screw removal after complete fracture union.
Evaluation Two orthopaedic chief residents, under the guidance of the senior author, measured the amount of fracture displacement and classified the fracture pattern for each using a picture-archiving and communication system (UltraVisual Medical Systems, Madison, WI). Fracture fragment displacement was measured in the coronal plane from the lateral metaphyseal cortex of the distal part of the humerus to the corresponding lateral cortex of the fracture fragment on anteroposterior and internal oblique views and in the sagittal plane on the lateral radiograph. The greatest displacement on any radiograph was recorded as the amount of fragment displacement (Fig. 1). Fractures were categorized using the system of Jakob et al.4 The Baumann angle19 and carrying angle20 were measured on the initial postreduction and final radiographs (after removal of the screw or pins) to determine the degree of coronal alignment. When available, contralateral elbow radiographs were used for comparison. Evidence of fracture union and physeal injury was also assessed. All complications and injury sequelae were noted: nonunion, delayed union, malunion, fishtail deformity, cubitus varus, cubitus valgus, epiphysiodesis of the distal humerus, and avascular capitellum necrosis. Growth arrest, infection, loss of motion, and pain were clinically www.pedorthopaedics.com |
3
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Stein et al
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
FIGURE 2. Anteroposterior (A) and lateral (B) radiographs of a rotated and displaced Jakob type III lateral condyle fracture. Intraoperative anteroposterior (C) fluoroscopic view shows closed reduction achieved with the cannulated screw guide-pin. The guide-pin aligns the fracture, and the cannulated screw closes the gap. Intraoperative anteroposterior (D) and lateral (E) fluoroscopic views show anatomic fracture reduction with final lag screw placement.
determined on serial follow-up examinations. Surgical results were graded using the criteria of Hardacre et al.21
Statistical Analysis We used Stata statistical software (StataCorp LP, College Station, TX) to analyze the differences between the 2 patient groups for frequency of open and closed reductions, infection incidence, and postoperative ROM; significance was assigned at P < 0.05. Given the data’s categorical nature, the w2 test was performed first for the reduction technique used. For
4 | www.pedorthopaedics.com
postoperative infection and ROM, the 2-tailed Fisher exact test was used. For all cases, our null hypothesis assumed independence of outcome between the 2 fixation techniques.
RESULTS Pin Group Mean follow-up in this group was 4.3 months. Approximately one fourth of the fractures were reduced with closed techniques (Table 2). Postoperative displaceCopyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
Lateral Condyle Fractures: Cannulated Screw Versus Pin
nation, flexion, and extension; 3 achieved 95 degrees in full flexion; and 3 lacked 15 to 20 degrees of full extension. All 14 had normal-appearing physes, were asymptomatic, and had no functional limitations at final follow-up. The average postoperative radiographic Baumann angles were 75.4 ± 2.6 degrees initially and 75.9 ± 2.1 degrees at final follow-up. The average postoperative radiographic carrying angles were 12.5 ± 3.6 degrees initially and 12.2 ± 3.2 degrees at final follow-up. Contralateral elbow images were not available. Table 2 presents postoperative infection data. One deep infection (involving the joint) required operative irrigation and intravenous antibiotics, but the fracture united without osteonecrosis. Table 3 shows outcomes based on the criteria of Hardacre et al.21
TABLE 2. Fracture Reduction Technique and Postoperative Complication Data Pin Fixation, n (%)
Parameters
Screw Fixation, n (%)
Jakob type II fractures 12 Closed reduction 4 (33) Open reduction 8 (67) Jakob type III fractures 8 Closed reduction 1 (12) Open reduction 7 (88) Total fractures* 22 Closed reduction 6 (27) Open reduction 16 (73) Postoperative infectionw Superficial 4 (18) Deep 1 (4) Postoperative early range of motiony Full 6 (27) r15-degree extension loss 7 (32) > 15-degree extension loss 1 (4)
11 11 (100) 0 (0) 14 11 (79) 3 (21) 26 22 (85) 4 (15) 0 (0) 0 (0) 12 (46) 6 (23) 2 (8)
Screw Group More than three quarters of these fractures were reduced using closed techniques (Table 2), a significant difference from the pin group. As in the pin group, postoperative displacement was 0.5).
ment was 2-mm displacement be treated with open reduction/internal fixation; Foster et al7 endorsed this suggestion, showing the utility of close observation and closed reduction/internal fixation for minimally (< 2 mm) displaced fractures. Mintzer et al11 noted that for a subset of fractures with >2-mm displacement, closed reduction and percutaneous pinning can lead to successful outcomes if the fracture preserves a congruent joint surface. Song et al12 implemented closed reduction and percutaneous pinning for a group of completely displaced and rotated fractures with a success rate of 75% (18/24). Given the morbidity associated with open reduction techniques, research has recently focused on closed reduction of these fractures with percutaneous fixation.11–13 We compared the clinical and radiographic outcomes of substantially displaced lateral condyle fractures treated with cannulated lag screw or traditional pin fixation and found that 85% and 27%, respectively, were managed with closed reduction, a statistically significant
6 | www.pedorthopaedics.com
Volume 00, Number 00, ’’ 2015
difference (P < 0.001). This finding confirmed our hypothesis that screw fixation would decrease the need for open reduction. The 2 techniques had similar union rates and satisfactory fracture alignment. The period of cast immobilization was shorter for the cannulated screw group, although both groups showed similar ROM on serial follow-up. The infection rate was significantly lower in the screw group (no infections) than in the pin group (4 superficial and 1 deep infection) (P < 0.05), confirming our hypothesis that treatment with a cannulated screw may reduce infection risk. Two previous studies showed infection rates of 19.3% (11/57)8 and 16.7% (5/30)15 among patients treated with open reduction and Kirschner-wire fixation, with no infection among patients treated with open reduction and screw fixation, suggesting our finding was not aberrant. A retrospective review by Tosti et al23 reports that serious complication after percutaneous K-wire fixation occurs in 1.4% (12/884) of cases and recommends nonoperative therapy in cases where fracture callus and systemic signs of infection are not present. According to the criteria of Hardacre et al21 (Table 3), 89% and 59% of patients in our screw and pin groups, respectively, achieved excellent results. This could result from the pin’s inferior ability to compress and hold the fracture fragments in place. Avascular necrosis did not occur in either group. Compared with traditional pin fixation, the cannulated lag screw technique achieves a higher rate of closed reduction, delivers more interfragmentary compression across the fracture, and provides more stability. The intrinsic congruity of the surfaces articulating with the capitellum is 1 reason that percutaneous reduction is often successful. As the fragment is compressed, it is guided into a congruous fit with the opposing surfaces of the radius, ulna, and lateral condyle. We found that if the fracture can be reduced so only a parallel fracture gap remains, the cannulated screw can eliminate this gap, obviating the need for open reduction. We recommend 4.5-mm cannulated screws because the only case of loss of fixation occurred with a 3.5-mm screw. In addition, placement of a percutaneous screw allows earlier mobilization and does not have the infection risk associated with pin fixation. Despite these benefits, however, screw fixation has some drawbacks: the need for follow-up, with additional outpatient surgery for removal to avoid risk of physeal damage, and possible open reduction to achieve anatomic joint reconstruction for some severely rotated Jakob type III lateral condyle fractures. We recommend removal of all lag screws. If these screws are left in place, they may impede or distort growth across the physis. Our study’s chief limitations are relatively short follow-up and a small patient cohort. Although we strove to reach every patient for longer follow-up, adequate healing status without significant functional limitation deterred many patients from visiting the outpatient clinic, and others were unable to be reached for unknown reasons. It is likely that the need for scheduling a subsequent screw removal surgery allowed for longer follow-up with the screw group. Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Pediatr Orthop
Volume 00, Number 00, ’’ 2015
Our results confirm that the use of closed reduction with percutaneous fixation for displaced lateral humeral condyle fractures can reliably lead to excellent clinical outcomes, as previously described by Mintzer et al,11 Foster et al,7 and Song et al.13 We have shown that closed reduction was accomplished more frequently with cannulated lag screw fixation, and that it can achieve and maintain excellent fracture reduction without infection, premature physeal arrest, deformity, or other serious complications. Large, prospective studies with long-term follow-up are needed to explore the optimal treatment method. REFERENCES 1. Skaggs DL, Frick S. Upper extremity fractures in children. In: Weinstein SL, Flynn JM, eds. Lovell and Winter’s Pediatric Orthopaedics, 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2014:1694–1772. 2. Carson S, Woolridge DP, Colletti J, et al. Pediatric upper extremity injuries. Pediatr Clin North Am. 2006;53:41–67. 3. Milch H. Fractures and fracture dislocations of the humeral condyles. J Trauma. 1964;4:592–607. 4. Jakob R, Fowles JV, Rang M, et al. Observations concerning fractures of the lateral humeral condyle in children. J Bone Joint Surg Br. 1975;57:430–436. 5. Rutherford A. Fractures of the lateral humeral condyle in children. J Bone Joint Surg Am. 1985;67:851–856. 6. Finnbogason T, Karlsson G, Lindberg L, et al. Nondisplaced and minimally displaced fractures of the lateral humeral condyle in children: a prospective radiographic investigation of fracture stability. J Pediatr Orthop. 1995;15:422–425. 7. Foster DE, Sullivan JA, Gross RH. Lateral humeral condylar fractures in children. J Pediatr Orthop. 1985;5:16–22. 8. Launay F, Leet AI, Jacopin S, et al. Lateral humeral condyle fractures in children: a comparison of two approaches to treatment. J Pediatr Orthop. 2004;24:385–391. 9. Speed JS, Macey HB. Fractures of the humeral condyles in children. J Bone Joint Surg Am. 1933;15:903–919.
Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Lateral Condyle Fractures: Cannulated Screw Versus Pin
10. Sponseller P. Problem elbow fractures in children. Hand Clin. 1994; 10:495–505. 11. Mintzer CM, Waters PM, Brown DJ, et al. Percutaneous pinning in the treatment of displaced lateral condyle fractures. J Pediatr Orthop. 1994;14:462–465. 12. Song KS, Kang CH, Min BW, et al. Closed reduction and internal fixation of displaced unstable lateral condylar fractures of the humerus in children. J Bone Joint Surg Am. 2008;90:2673–2681. 13. Song KS, Shin YW, Oh CW, et al. Closed reduction and internal fixation of completely displaced and rotated lateral condyle fractures of the humerus in children. J Orthop Trauma. 2010;24: 434–438. 14. Koh KH, Seo SW, Kim KM, et al. Clinical and radiographic results of lateral condylar fracture of distal humerus in children. J Pediatr Orthop. 2010;30:425–429. 15. Li WC, Xu RJ. Comparison of Kirschner wires and AO cannulated screw internal fixation for displaced lateral humeral condyle fracture in children. Int Orthop. 2012;36:1261–1266. 16. Sharma JC, Arora A, Mathur NC, et al. Lateral condylar fractures of the humerus in children: fixation with partially threaded 4.0-mm AO cancellous screws. J Trauma. 1995;39:1129–1133. 17. Wirmer J, Kruppa C, Fitze G. Operative treatment of lateral humeral condyle fractures in children. Eur J Pediatr Surg. 2012;22: 289–294. 18. Gruber MA, Healy WA III. The posterior approach to the elbow revisited. J Pediatr Orthop. 1996;16:215–219. 19. Williamson DM, Coates CJ, Miller RK, et al. Normal characteristics of the Baumann (humerocapitellar) angle: an aid in assessment of supracondylar fractures. J Pediatr Orthop. 1992;12:636–639. 20. Beals RK. The normal carrying angle of the elbow. A radiographic study of 422 patients. Clin Orthop Relat Res. 1976;119: 194–196. 21. Hardacre JA, Nahigian SH, Froimson AI, et al. Fractures of the lateral condyle of the humerus in children. J Bone Joint Surg Am. 1971;53:1083–1095. 22. Flynn JC. Nonunion of slightly displaced fractures of the lateral humeral condyle in children: an update. J Pediatr Orthop. 1989;9: 691–696. 23. Tosti R, Foroohar A, Pizzutillo PD, et al. Kirschner wire infections in pediatric orthopaedic surgery. J Pediatr Orthop. 2015;35:69–73.
www.pedorthopaedics.com |
7
Copyright r 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
