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Capitellar Cartilage Injuries Concomitant With Radial Head Fractures
SCIENTIFIC ARTICLE
Capitellar Cartilage Injuries Concomitant With Radial Head Fractures Ufuk Nalbantoglu, MD, Arel Gereli, MD, Baris Kocaoglu, MD, Seref Aktas, MD, Metin Turkmen, MD
Purpose To evaluate the incidence and types of capitellar cartilage injuries associated with higher-grade radial head fractures. Methods Fifty-one consecutive patients with operatively treated, unstable, displaced Mason type II to III radial head fractures were identified. Ten of 51 patients had capitellar cartilage injuries concomitant with these fractures. All cartilage injuries were identified at the time of surgery except in 1 patient whose injury was determined via computed tomography. There were 8 men and 2 women with an average age of 33 years (range, 24 –39 years). Lesions were seen with direct inspection and recorded by location, size, and thickness. Results The incidence of capitellar chondral lesions concomitant with operatively treated Mason type II to III radial head fractures appeared in 10 of 51 patients. The average size was 5 ⫻ 5 mm (range, 2 ⫻ 2 mm to 10 ⫻ 10 mm). Four patients had Mason type II and 6 had Mason type III radial head fractures. The average surface of the cartilage injury was 6 ⫻ 7 mm (range, 3 ⫻ 6 mm to 10 ⫻ 10 mm) for Mason type II fractures and 4 ⫻ 4 mm (range, 2 ⫻ 2 mm to 5 ⫻ 10 mm) for Mason type III fractures. Two Mason type III fractures had full-thickness cartilage lesions, and 4 Mason type III fractures had partial-thickness cartilage lesions. Two Mason type II fractures had full-thickness cartilage lesions and the other 2 had partial-thickness cartilage lesions. Conclusions Capitellar cartilage lesions frequently occurred concomitantly with higher-grade radial head fractures. The incidence of these lesions increased with greater severity of radial head fractures. Low-grade radial head fractures created higher-grade cartilage lesions as the intact radial head can cause more damage to the capitellum. Careful evaluation of the joint should be performed for these subtle injuries. ( J Hand Surg 2008;33A:1602 – 1607. Copyright © 2008 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Prognostic IV. Key words Capitellar cartilage lesion, capitellum, concomitant, microfracture, radial head fracture. ADIAL HEAD FRACTURES are the most common fractures of the elbow and often occur after a fall on the outstretched arm.1– 4 Treatment of these fractures may be complicated in the case of presence of associated lesions. The possible additional traumatic pathologic lesions include another fracture, elbow disloca-
R
From the Hand and Upper Extremity Service, Department of Orthopaedics and Traumatology, Acibadem Kadikoy Hospital, Istanbul, Turkey. Received for publication September 18, 2007; accepted in revised form May 16, 2008. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
1602 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
tion, ligamentous injury, and articular cartilage lesions.5–7 Concomitant radial head fractures and capitellar cartilage lesions have previously been described,5–10 but the degree of capitellar articular injury that occurs with a radial head fracture is not always fully appreciated. Corresponding author: Arel Gereli, MD, Hand and Upper Extremity Service, Department of Orthopaedics and Traumatology, Acibadem Kadikoy Hospital, Tekin sok No. 8, 34718 Kadikoy Istanbul, Turkey; e-mail: [email protected]. 0363-5023/08/33A09-0021$34.00/0 doi:10.1016/j.jhsa.2008.05.016
CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
1603
FIGURE 1: A A cartilage fragment (arrow) was identified preoperatively in a patient via computed tomography. B The capitellar cartilage lesion is large and extends to the subchondral layers with the flake of cortex. C The cartilage fragment was fixed with 2 Herbert screws. The flake of cortex allowed fixation and CT determination in this case.
The purpose of this study was to evaluate the type and incidence of capitellar cartilage injuries in patients with Mason type II to III radial head fractures who had surgery. MATERIALS AND METHODS Fifty-one consecutive skeletally mature patients with unstable, displaced Mason type II to III radial head fractures11 operatively treated at our clinic between 1999 and 2006 were identified. There were 23 patients who had type II and 28 patients who had type III radial head fractures. All type II and III radial head fractures were treated surgically in this period. Relative to the total number of operatively treated radial head fractures during the study period, 10 patients were identified from the operative records as having capitellar cartilage injuries. Of these 10 patients, 2 had lateral collateral ligament injuries, but none of the patients had concomitant bone and ligament injuries of the elbow or upper extremity. There were 8 men and 2 women with an average age of 33 years (range, 24 –39 years) at the time of the injury. The left elbow was affected in 4 patients and the right elbow was affected in 6 patients. The dominant arm was involved in 6 patients. The mechanism of injury was a fall from a standing height in 6 patients, a fall from a greater height in 1 patient, and sports injuries in 3 patients. Our institutional review board approved a review of the medical records. Standard radiography and computed tomography were performed for all patients before the operation to evaluate the articular involvement and fracture configuration. In 3 recent patients, 3-dimensional computed tomography was also performed. There were no cartilage injuries determined on the radiographic, computed tomography, or 3-dimensional computed tomography examinations except in 1 patient (patient 2), whose injury was determined via the computed tomography
(Fig. 1). Another 9 capitellar cartilage injuries were diagnosed at the time of operation. We used Mason’s classification system for radial head fractures.11 According to this system, 4 patients had a type II fracture (a partial articular fracture or marginal fracture with displacement), and 6 patients had a type III fracture (a fracture involving the entire head of the radius, splitting it into 2 or more fragments). There was no dislocation of the elbow joint accompanying radial head fractures. Open reduction and internal fixation was achieved in all 10 radial head fractures, and there was no radial head prosthesis needed. A careful examination of the capitellum humeri is a routine part of the radial head fracture operation. Capitellar cartilage injuries were seen with direct inspection at the time of operation. Capitellum humeri was divided into 4 quadrants (inferolateral, superolateral, inferomedial, superomedial), and chondral lesions were recorded by location, size, and thickness for every patient. Cartilage injury size was measured with a sterile ruler (Devon Ruler; Ludlow Co., Chicopee, MA). Thickness of capitellar chondral injury was defined as a superficial, partialthickness, or full-thickness cartilage defect.12,13 Operative exposure of the radial head was obtained between the anconeus and extensor carpi ulnaris muscles in all patients. The common extensor muscle group and lateral collateral ligament were elevated and retracted from the lateral epicondyle to provide a better view if needed. The capitellar articular surface was monitored as described before in all patients for possible cartilage injuries before and after the open reduction and internal fixation of the radial head. Debridement of loose edges was performed for partial-thickness capitellar cartilage injuries. Screw fixation was used for full-thickness capitellar cartilage injuries if the fragments were attached to the flake of cortex and large enough to support
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CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
TABLE 1. Patient No.
Summary of the Patients Age (y)
Gender
Side
Etiology
Radial Head Fracture (Mason)
Cartilage Lesion
Cartilage Treatment
1
38
M
L
Fall from standing height
III
5 ⫻ 10 mm, full-thickness
Microfracture
2
38
M
L
Fall from standing height
II
10 ⫻ 10 mm, full-thickness attached to the flake of cortex
Herbert screw
3
39
M
R
Sports injury
III
5 ⫻ 6 mm, full-thickness attached to the flake of cortex
Acutrak screw
4
38
M
R
Sports injury
III
3 ⫻ 3 mm, partial-thickness
Debridement
5
27
M
R
Fall from standing height
II
5 ⫻ 5 mm, partial-thickness
Debridement
6
29
F
L
Sports injury
III
3 ⫻ 3 mm, partial-thickness
Debridement
7
27
M
L
Fall from standing height
II
5 ⫻ 5 mm, partial-thickness
Debridement
8
24
M
R
Fall from slipping or stumbling from standing height
III
2 ⫻ 4 mm, partial-thickness
Debridement
9
37
F
R
Fall from standing height
II
3 ⫻ 6 mm, full-thickness
Microfracture
10
30
M
R
Fall from standing height
III
2 ⫻ 2 mm, partial-thickness
Debridement
a miniscrew. A Herbert screw (Zimmer, Warsaw, IN) or an Acutrak 2 microscrew (Acumed, Hillsboro, OR) was used. If the capitellar cartilage fragments were not considered large enough to support a miniscrew, they were excised. The defective area was drilled with a 2-mm (0.08-in) K-wire in these patients. Three drill holes per square centimeter were applied. At the end of the operation, the tourniquet was deflated, and bleeding from the drilled area was seen. Additional intra-articular pathology was not found in any of our cases. RESULTS The incidence of capitellar cartilage injuries in 51 operatively treated Mason type II to III radial head fractures was 10 in this study. All cartilage injuries were located at the inferolateral side of the capitellum. The average size of the cartilage lesion was 5 ⫻ 5 mm (range, 2 ⫻ 2 mm to 10 ⫻ 10 mm) (Table 1). There were 6 partial-thickness cartilage injuries determined, and debridement of loose edges was applied. There were 4 full-thickness cartilage injuries determined (Table 1). In 2 of these 4 patients, the cartilage fragments were attached to the flake of cortex and large enough to support a miniscrew. The fragments were fixed to bone with screws in these patients. In the other 2 patients who had full-thickness cartilage injuries, the cartilage fragments were relatively small and thin; they were not considered large enough to support a miniscrew. They were excised. In 2 of 10 patients, a capitellar cartilage
fragment was trapped in the radial head. The reduction of the radial head could be achieved after removal of the cartilage fragment (Fig. 2). Of the 10 radial head fractures with cartilage lesions, 4 were classified as Mason type II, and 6 were classified as Mason type III. Two Mason type II fractures had full-thickness cartilage lesions, and the other 2 had partial-thickness cartilage lesions. The average surface of the cartilage injury was 6 mm ⫻ 7 mm (range, 3 ⫻ 6 mm to 10 ⫻ 10 mm) for Mason type II fractures. There were 2 Mason type III fractures that had fullthickness cartilage lesions and 4 Mason type III fractures that had partial-thickness cartilage lesions. The average surface of the cartilage injury was 4 ⫻ 4 mm (range, 2 ⫻ 2 mm to 5 ⫻ 10 mm) for Mason type III fractures (Table 1). DISCUSSION Radial head fractures may be complicated by the presence of associated lesions. One of the less-recognized is trauma to the capitellum.6,8,10,14 These lesions are not always appreciated because of the focus on the radial head, but the capitellum is at risk because of reciprocal impinging on the radial head.9 This can be explained by the importance of the radiocapitellar contact surface: 60% of the axial load at the elbow is transmitted through the radiocapitellar joint.15 The capitellum is shorn from the humerus by the impact of the radial head. As a consequence, the capitellum may be frac-
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FIGURE 2: A capitellar cartilage fragment trapped in the radial head in a patient. The reduction of the radial head could be achieved after removal of the cartilage fragment.
tured or the articular cartilage may be injured. Concomitant radial head fractures and capitellar cartilage injuries have previously been described.5–10 In 1931, Milch9 described 2 patients with radial head fractures and osteochondral capitellum injuries and defined the mechanism of injury. In 1988, Ward and Nunley10 published a review of combined radial head and capitellar injuries. The incidence of capitellum injury was 1% with all radial head fractures, but with more severe injuries, the incidence rose to 24%. Van Riet et al.6 noted capitellum lesions in 2% of patients for a total 39% of associated lesions. Caputo et al.8 reported 10 cases of cartilage injuries of the capitellum interposed in radial head fractures. They stated that a high probability of this injury pattern is indicated in isolated Mason type I and II fractures with mechanical findings during forearm rotation. There was a capitellar cartilage fragment trapped in the radial head in 2 cases in our study. We noticed this injury at open reduction of the radial head, and reduction could be achieved after removal of the cartilage fragment. Michels et al.5 reported 14 Mason type II radial head fractures that were managed by arthroscopic reduction and percutaneous fixation. They found an incidence of 14% capitellar cartilage lesions, and these were associated with a less beneficial outcome. In the current study, the incidence of capitellar cartilage lesions appeared in 10 of 51
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patients. The relatively high incidence may be due to the open approach, in that some areas of the capitellum may be difficult to completely visualize through an arthroscope. The presented results are specific to Mason type II and III fractures that require open operative intervention. There is no adequate information available in the literature about the incidence of the capitellar cartilage injury in Mason type I radial head fractures, but the surgeon should be vigilant for possible cartilage injury, especially the Mason type I radial head fracture with prolonged symptoms, crepitus, mechanical block, and radial head delayed union. From this study, it seems that capitellar cartilage lesions frequently accompany Mason type II and III radial head fractures. We recommend a detailed clinical and radiographic examination in radial head fractures, and the surgeon should be prepared preoperatively for possible cartilage injury. Given the incidence of cartilage lesions, careful evaluation of the joint should be performed, and the capitellum humeri must be examined systematically for possible cartilage injuries at the time of operation. Capitellar cartilage lesions are not readily visualized in standard radiologic evaluations (Fig. 3). In this study, all cartilage injuries were identified at the time of surgery except in 1 patient (patient 2), whose injury was determined via computed tomography before the operation. In this patient, the cartilage fragment was attached to the flake of cortex and was large enough to detect with computed tomography. Magnetic resonance (MR) investigation is the most valuable technique to diagnose cartilage injuries,16 and purely cartilaginous fragment of the capitellum cannot be determined preoperatively with conventional radiography and computed tomography. Itamura et al.7 reported 24 patients with an acute Mason type II or III radial head fracture. They detected capitellar osteochondral defects in 29% and capitellar bone bruises in 96% by MR investigation. MR investigation was not performed in any of the patients in this study. This test is valuable for cartilage injuries, but MR investigation for every radial head fracture is not cost-effective. In our study, there were 4 radial head fractures with cartilage lesions classified as Mason type II and 6 fractures classified as Mason type III. The presented result is similar to that of Ward and Nunley.10 They found the incidence of capitellum injury was 1% with all radial head fractures, but with more severe injuries, the incidence rose to 24%. It seems that the incidence of cartilage injury increases with greater severity of radial head trauma. In addition, partial-thickness cartilage injuries were more frequent in Mason type III fractures,
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CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
FIGURE 3: A 38-year-old man (patient 1) fell from a standing height; he was operated on for Mason type III radial head fracture. No signs of cartilage lesion were determined via the A radiographic and B computed tomography evaluations preoperatively. C A 5 ⫻ 10 mm full-thickness capitellar cartilage lesion was determined at the time of operation. The radial head was treated with a plate, and the capitellar cartilage lesion was treated with microfracture.
and the average surface of the cartilage injury was larger in Mason type II fractures than in Mason type III fractures. It could be interpreted from the evidence that the severity and extensiveness of the cartilage injuries decrease with greater severity of radial head fractures. A possible explanation is that the energy of the fracture discharges through the bone rather than the cartilage, and the intact radial head can cause more damage to the capitellum. These inferences could be criticized and need further investigation in a larger patient population. The small number of our patient population was inadequate for statistical analysis. This is a limitation of the study. Statistical correlations between the cartilage lesions and type of fracture could be investigated with a larger patient population. The incidence of capitellar cartilage injuries in association with radial head fractures has been previously reported.5–10 However, the presented study reports the specific incidence of capitellar cartilage injuries with Mason type II to III fractures that were treated with open operative intervention. The data were obtained from direct observation at the time of operation. The present study also investigates the relation between the type of radial head fracture and severity of the capitellar cartilage lesions. The results showed that capitellar cartilage lesions were frequently concomitant with Mason type II and III
radial head fractures. The incidence of these lesions was increased with more severe radial head fractures. Lowgrade radial head fractures created higher-grade cartilage lesions because the intact radial head can cause more damage to the capitellum. The surgeon should be alert and prepared for treatment of associated cartilage lesions before the operation. Careful evaluation of the joint should be performed for these subtle injuries at the time of operation.
REFERENCES 1. Herbertsson P, Josefsson P, Hasserius R, Besjakov J, Nyqvist F, Karlsson MK. Fractures of the radial head and neck treated with radial head excision. J Bone Joint Surg 2004;86A:1925–1930. 2. Ring D, Quintero J, Jupiter JB. Open reduction and internal fixation of fractures of the radial head. J Bone Joint Surg 2002;84A:1811– 1815. 3. Ikeda M, Yamashina Y, Kamimoto M, Oka Y. Open reduction and internal fixation of comminuted fractures of the radial head using low-profile mini-plates. J Bone Joint Surg 2003;85B:1040 –1044. 4. King GJ, Evans DC, Kellam JF. Open reduction and internal fixation of radial head fractures. J Orthop Trauma 1991;5:21–28. 5. Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007;15:1244 –1250. 6. Van Riet RP, Morrey BF, O’Driscoll SW, Van Glabbeek F. Associated injuries complicating radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441:351–355.
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7. Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. Shoulder Elbow Surg 2005;14:421– 424. 8. Caputo AE, Burton KJ, Cohen MS, King GJ. Articular cartilage injuries of the capitellum interposed in radial head fractures: a report of ten cases. Shoulder Elbow Surg 2006;15:716 –720. 9. Milch H. Unusual fractures of the capitulum humeri and the capitulum radii. J Bone Joint Surg 1931;13:882– 886. 10. Ward WG, Nunley JA. Concomitant fractures of the capitellum and radial head. J Orthop Trauma 1988;2:110 –116. 11. Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954;42:123–132.
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12. Brittberg M, Winalski CS. Evaluation of cartilage injuries and repair. J Bone Joint Surg 2003;85A(Suppl 2):58 – 69. 13. The cartilage standard evaluation form/knee. ICRS Newsletter 1998; 98:5– 8. 14. Morrey BF. Radial head fracture. In: Morrey BF, ed. The elbow and its disorders. 3rd ed. Philadelphia: W.B. Saunders, 2000:341– 364. 15. Morrey B, An K, Stormont T. Force transmission through the radial head. J Bone Joint Surg 1988:70A:250 –256. 16. Potter HG, Foo LF. The articular cartilage. In: Stoller DW, ed. Magnetic resonance imaging in orthopaedics & sports medicine. 3rd ed. Philadelphia: Lippincott–Raven, 2007:1099–1130.
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Capitellar Cartilage Injuries Concomitant With Radial Head Fractures Ufuk Nalbantoglu, MD, Arel Gereli, MD, Baris Kocaoglu, MD, Seref Aktas, MD, Metin Turkmen, MD
Purpose To evaluate the incidence and types of capitellar cartilage injuries associated with higher-grade radial head fractures. Methods Fifty-one consecutive patients with operatively treated, unstable, displaced Mason type II to III radial head fractures were identified. Ten of 51 patients had capitellar cartilage injuries concomitant with these fractures. All cartilage injuries were identified at the time of surgery except in 1 patient whose injury was determined via computed tomography. There were 8 men and 2 women with an average age of 33 years (range, 24 –39 years). Lesions were seen with direct inspection and recorded by location, size, and thickness. Results The incidence of capitellar chondral lesions concomitant with operatively treated Mason type II to III radial head fractures appeared in 10 of 51 patients. The average size was 5 ⫻ 5 mm (range, 2 ⫻ 2 mm to 10 ⫻ 10 mm). Four patients had Mason type II and 6 had Mason type III radial head fractures. The average surface of the cartilage injury was 6 ⫻ 7 mm (range, 3 ⫻ 6 mm to 10 ⫻ 10 mm) for Mason type II fractures and 4 ⫻ 4 mm (range, 2 ⫻ 2 mm to 5 ⫻ 10 mm) for Mason type III fractures. Two Mason type III fractures had full-thickness cartilage lesions, and 4 Mason type III fractures had partial-thickness cartilage lesions. Two Mason type II fractures had full-thickness cartilage lesions and the other 2 had partial-thickness cartilage lesions. Conclusions Capitellar cartilage lesions frequently occurred concomitantly with higher-grade radial head fractures. The incidence of these lesions increased with greater severity of radial head fractures. Low-grade radial head fractures created higher-grade cartilage lesions as the intact radial head can cause more damage to the capitellum. Careful evaluation of the joint should be performed for these subtle injuries. ( J Hand Surg 2008;33A:1602 – 1607. Copyright © 2008 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Prognostic IV. Key words Capitellar cartilage lesion, capitellum, concomitant, microfracture, radial head fracture. ADIAL HEAD FRACTURES are the most common fractures of the elbow and often occur after a fall on the outstretched arm.1– 4 Treatment of these fractures may be complicated in the case of presence of associated lesions. The possible additional traumatic pathologic lesions include another fracture, elbow disloca-
R
From the Hand and Upper Extremity Service, Department of Orthopaedics and Traumatology, Acibadem Kadikoy Hospital, Istanbul, Turkey. Received for publication September 18, 2007; accepted in revised form May 16, 2008. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
1602 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
tion, ligamentous injury, and articular cartilage lesions.5–7 Concomitant radial head fractures and capitellar cartilage lesions have previously been described,5–10 but the degree of capitellar articular injury that occurs with a radial head fracture is not always fully appreciated. Corresponding author: Arel Gereli, MD, Hand and Upper Extremity Service, Department of Orthopaedics and Traumatology, Acibadem Kadikoy Hospital, Tekin sok No. 8, 34718 Kadikoy Istanbul, Turkey; e-mail: [email protected]. 0363-5023/08/33A09-0021$34.00/0 doi:10.1016/j.jhsa.2008.05.016
CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
1603
FIGURE 1: A A cartilage fragment (arrow) was identified preoperatively in a patient via computed tomography. B The capitellar cartilage lesion is large and extends to the subchondral layers with the flake of cortex. C The cartilage fragment was fixed with 2 Herbert screws. The flake of cortex allowed fixation and CT determination in this case.
The purpose of this study was to evaluate the type and incidence of capitellar cartilage injuries in patients with Mason type II to III radial head fractures who had surgery. MATERIALS AND METHODS Fifty-one consecutive skeletally mature patients with unstable, displaced Mason type II to III radial head fractures11 operatively treated at our clinic between 1999 and 2006 were identified. There were 23 patients who had type II and 28 patients who had type III radial head fractures. All type II and III radial head fractures were treated surgically in this period. Relative to the total number of operatively treated radial head fractures during the study period, 10 patients were identified from the operative records as having capitellar cartilage injuries. Of these 10 patients, 2 had lateral collateral ligament injuries, but none of the patients had concomitant bone and ligament injuries of the elbow or upper extremity. There were 8 men and 2 women with an average age of 33 years (range, 24 –39 years) at the time of the injury. The left elbow was affected in 4 patients and the right elbow was affected in 6 patients. The dominant arm was involved in 6 patients. The mechanism of injury was a fall from a standing height in 6 patients, a fall from a greater height in 1 patient, and sports injuries in 3 patients. Our institutional review board approved a review of the medical records. Standard radiography and computed tomography were performed for all patients before the operation to evaluate the articular involvement and fracture configuration. In 3 recent patients, 3-dimensional computed tomography was also performed. There were no cartilage injuries determined on the radiographic, computed tomography, or 3-dimensional computed tomography examinations except in 1 patient (patient 2), whose injury was determined via the computed tomography
(Fig. 1). Another 9 capitellar cartilage injuries were diagnosed at the time of operation. We used Mason’s classification system for radial head fractures.11 According to this system, 4 patients had a type II fracture (a partial articular fracture or marginal fracture with displacement), and 6 patients had a type III fracture (a fracture involving the entire head of the radius, splitting it into 2 or more fragments). There was no dislocation of the elbow joint accompanying radial head fractures. Open reduction and internal fixation was achieved in all 10 radial head fractures, and there was no radial head prosthesis needed. A careful examination of the capitellum humeri is a routine part of the radial head fracture operation. Capitellar cartilage injuries were seen with direct inspection at the time of operation. Capitellum humeri was divided into 4 quadrants (inferolateral, superolateral, inferomedial, superomedial), and chondral lesions were recorded by location, size, and thickness for every patient. Cartilage injury size was measured with a sterile ruler (Devon Ruler; Ludlow Co., Chicopee, MA). Thickness of capitellar chondral injury was defined as a superficial, partialthickness, or full-thickness cartilage defect.12,13 Operative exposure of the radial head was obtained between the anconeus and extensor carpi ulnaris muscles in all patients. The common extensor muscle group and lateral collateral ligament were elevated and retracted from the lateral epicondyle to provide a better view if needed. The capitellar articular surface was monitored as described before in all patients for possible cartilage injuries before and after the open reduction and internal fixation of the radial head. Debridement of loose edges was performed for partial-thickness capitellar cartilage injuries. Screw fixation was used for full-thickness capitellar cartilage injuries if the fragments were attached to the flake of cortex and large enough to support
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CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
TABLE 1. Patient No.
Summary of the Patients Age (y)
Gender
Side
Etiology
Radial Head Fracture (Mason)
Cartilage Lesion
Cartilage Treatment
1
38
M
L
Fall from standing height
III
5 ⫻ 10 mm, full-thickness
Microfracture
2
38
M
L
Fall from standing height
II
10 ⫻ 10 mm, full-thickness attached to the flake of cortex
Herbert screw
3
39
M
R
Sports injury
III
5 ⫻ 6 mm, full-thickness attached to the flake of cortex
Acutrak screw
4
38
M
R
Sports injury
III
3 ⫻ 3 mm, partial-thickness
Debridement
5
27
M
R
Fall from standing height
II
5 ⫻ 5 mm, partial-thickness
Debridement
6
29
F
L
Sports injury
III
3 ⫻ 3 mm, partial-thickness
Debridement
7
27
M
L
Fall from standing height
II
5 ⫻ 5 mm, partial-thickness
Debridement
8
24
M
R
Fall from slipping or stumbling from standing height
III
2 ⫻ 4 mm, partial-thickness
Debridement
9
37
F
R
Fall from standing height
II
3 ⫻ 6 mm, full-thickness
Microfracture
10
30
M
R
Fall from standing height
III
2 ⫻ 2 mm, partial-thickness
Debridement
a miniscrew. A Herbert screw (Zimmer, Warsaw, IN) or an Acutrak 2 microscrew (Acumed, Hillsboro, OR) was used. If the capitellar cartilage fragments were not considered large enough to support a miniscrew, they were excised. The defective area was drilled with a 2-mm (0.08-in) K-wire in these patients. Three drill holes per square centimeter were applied. At the end of the operation, the tourniquet was deflated, and bleeding from the drilled area was seen. Additional intra-articular pathology was not found in any of our cases. RESULTS The incidence of capitellar cartilage injuries in 51 operatively treated Mason type II to III radial head fractures was 10 in this study. All cartilage injuries were located at the inferolateral side of the capitellum. The average size of the cartilage lesion was 5 ⫻ 5 mm (range, 2 ⫻ 2 mm to 10 ⫻ 10 mm) (Table 1). There were 6 partial-thickness cartilage injuries determined, and debridement of loose edges was applied. There were 4 full-thickness cartilage injuries determined (Table 1). In 2 of these 4 patients, the cartilage fragments were attached to the flake of cortex and large enough to support a miniscrew. The fragments were fixed to bone with screws in these patients. In the other 2 patients who had full-thickness cartilage injuries, the cartilage fragments were relatively small and thin; they were not considered large enough to support a miniscrew. They were excised. In 2 of 10 patients, a capitellar cartilage
fragment was trapped in the radial head. The reduction of the radial head could be achieved after removal of the cartilage fragment (Fig. 2). Of the 10 radial head fractures with cartilage lesions, 4 were classified as Mason type II, and 6 were classified as Mason type III. Two Mason type II fractures had full-thickness cartilage lesions, and the other 2 had partial-thickness cartilage lesions. The average surface of the cartilage injury was 6 mm ⫻ 7 mm (range, 3 ⫻ 6 mm to 10 ⫻ 10 mm) for Mason type II fractures. There were 2 Mason type III fractures that had fullthickness cartilage lesions and 4 Mason type III fractures that had partial-thickness cartilage lesions. The average surface of the cartilage injury was 4 ⫻ 4 mm (range, 2 ⫻ 2 mm to 5 ⫻ 10 mm) for Mason type III fractures (Table 1). DISCUSSION Radial head fractures may be complicated by the presence of associated lesions. One of the less-recognized is trauma to the capitellum.6,8,10,14 These lesions are not always appreciated because of the focus on the radial head, but the capitellum is at risk because of reciprocal impinging on the radial head.9 This can be explained by the importance of the radiocapitellar contact surface: 60% of the axial load at the elbow is transmitted through the radiocapitellar joint.15 The capitellum is shorn from the humerus by the impact of the radial head. As a consequence, the capitellum may be frac-
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CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
FIGURE 2: A capitellar cartilage fragment trapped in the radial head in a patient. The reduction of the radial head could be achieved after removal of the cartilage fragment.
tured or the articular cartilage may be injured. Concomitant radial head fractures and capitellar cartilage injuries have previously been described.5–10 In 1931, Milch9 described 2 patients with radial head fractures and osteochondral capitellum injuries and defined the mechanism of injury. In 1988, Ward and Nunley10 published a review of combined radial head and capitellar injuries. The incidence of capitellum injury was 1% with all radial head fractures, but with more severe injuries, the incidence rose to 24%. Van Riet et al.6 noted capitellum lesions in 2% of patients for a total 39% of associated lesions. Caputo et al.8 reported 10 cases of cartilage injuries of the capitellum interposed in radial head fractures. They stated that a high probability of this injury pattern is indicated in isolated Mason type I and II fractures with mechanical findings during forearm rotation. There was a capitellar cartilage fragment trapped in the radial head in 2 cases in our study. We noticed this injury at open reduction of the radial head, and reduction could be achieved after removal of the cartilage fragment. Michels et al.5 reported 14 Mason type II radial head fractures that were managed by arthroscopic reduction and percutaneous fixation. They found an incidence of 14% capitellar cartilage lesions, and these were associated with a less beneficial outcome. In the current study, the incidence of capitellar cartilage lesions appeared in 10 of 51
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patients. The relatively high incidence may be due to the open approach, in that some areas of the capitellum may be difficult to completely visualize through an arthroscope. The presented results are specific to Mason type II and III fractures that require open operative intervention. There is no adequate information available in the literature about the incidence of the capitellar cartilage injury in Mason type I radial head fractures, but the surgeon should be vigilant for possible cartilage injury, especially the Mason type I radial head fracture with prolonged symptoms, crepitus, mechanical block, and radial head delayed union. From this study, it seems that capitellar cartilage lesions frequently accompany Mason type II and III radial head fractures. We recommend a detailed clinical and radiographic examination in radial head fractures, and the surgeon should be prepared preoperatively for possible cartilage injury. Given the incidence of cartilage lesions, careful evaluation of the joint should be performed, and the capitellum humeri must be examined systematically for possible cartilage injuries at the time of operation. Capitellar cartilage lesions are not readily visualized in standard radiologic evaluations (Fig. 3). In this study, all cartilage injuries were identified at the time of surgery except in 1 patient (patient 2), whose injury was determined via computed tomography before the operation. In this patient, the cartilage fragment was attached to the flake of cortex and was large enough to detect with computed tomography. Magnetic resonance (MR) investigation is the most valuable technique to diagnose cartilage injuries,16 and purely cartilaginous fragment of the capitellum cannot be determined preoperatively with conventional radiography and computed tomography. Itamura et al.7 reported 24 patients with an acute Mason type II or III radial head fracture. They detected capitellar osteochondral defects in 29% and capitellar bone bruises in 96% by MR investigation. MR investigation was not performed in any of the patients in this study. This test is valuable for cartilage injuries, but MR investigation for every radial head fracture is not cost-effective. In our study, there were 4 radial head fractures with cartilage lesions classified as Mason type II and 6 fractures classified as Mason type III. The presented result is similar to that of Ward and Nunley.10 They found the incidence of capitellum injury was 1% with all radial head fractures, but with more severe injuries, the incidence rose to 24%. It seems that the incidence of cartilage injury increases with greater severity of radial head trauma. In addition, partial-thickness cartilage injuries were more frequent in Mason type III fractures,
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CAPITELLAR CARTILAGE INJURIES WITH RADIAL HEAD FRACTURES
FIGURE 3: A 38-year-old man (patient 1) fell from a standing height; he was operated on for Mason type III radial head fracture. No signs of cartilage lesion were determined via the A radiographic and B computed tomography evaluations preoperatively. C A 5 ⫻ 10 mm full-thickness capitellar cartilage lesion was determined at the time of operation. The radial head was treated with a plate, and the capitellar cartilage lesion was treated with microfracture.
and the average surface of the cartilage injury was larger in Mason type II fractures than in Mason type III fractures. It could be interpreted from the evidence that the severity and extensiveness of the cartilage injuries decrease with greater severity of radial head fractures. A possible explanation is that the energy of the fracture discharges through the bone rather than the cartilage, and the intact radial head can cause more damage to the capitellum. These inferences could be criticized and need further investigation in a larger patient population. The small number of our patient population was inadequate for statistical analysis. This is a limitation of the study. Statistical correlations between the cartilage lesions and type of fracture could be investigated with a larger patient population. The incidence of capitellar cartilage injuries in association with radial head fractures has been previously reported.5–10 However, the presented study reports the specific incidence of capitellar cartilage injuries with Mason type II to III fractures that were treated with open operative intervention. The data were obtained from direct observation at the time of operation. The present study also investigates the relation between the type of radial head fracture and severity of the capitellar cartilage lesions. The results showed that capitellar cartilage lesions were frequently concomitant with Mason type II and III
radial head fractures. The incidence of these lesions was increased with more severe radial head fractures. Lowgrade radial head fractures created higher-grade cartilage lesions because the intact radial head can cause more damage to the capitellum. The surgeon should be alert and prepared for treatment of associated cartilage lesions before the operation. Careful evaluation of the joint should be performed for these subtle injuries at the time of operation.
REFERENCES 1. Herbertsson P, Josefsson P, Hasserius R, Besjakov J, Nyqvist F, Karlsson MK. Fractures of the radial head and neck treated with radial head excision. J Bone Joint Surg 2004;86A:1925–1930. 2. Ring D, Quintero J, Jupiter JB. Open reduction and internal fixation of fractures of the radial head. J Bone Joint Surg 2002;84A:1811– 1815. 3. Ikeda M, Yamashina Y, Kamimoto M, Oka Y. Open reduction and internal fixation of comminuted fractures of the radial head using low-profile mini-plates. J Bone Joint Surg 2003;85B:1040 –1044. 4. King GJ, Evans DC, Kellam JF. Open reduction and internal fixation of radial head fractures. J Orthop Trauma 1991;5:21–28. 5. Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007;15:1244 –1250. 6. Van Riet RP, Morrey BF, O’Driscoll SW, Van Glabbeek F. Associated injuries complicating radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441:351–355.
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7. Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. Shoulder Elbow Surg 2005;14:421– 424. 8. Caputo AE, Burton KJ, Cohen MS, King GJ. Articular cartilage injuries of the capitellum interposed in radial head fractures: a report of ten cases. Shoulder Elbow Surg 2006;15:716 –720. 9. Milch H. Unusual fractures of the capitulum humeri and the capitulum radii. J Bone Joint Surg 1931;13:882– 886. 10. Ward WG, Nunley JA. Concomitant fractures of the capitellum and radial head. J Orthop Trauma 1988;2:110 –116. 11. Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954;42:123–132.
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12. Brittberg M, Winalski CS. Evaluation of cartilage injuries and repair. J Bone Joint Surg 2003;85A(Suppl 2):58 – 69. 13. The cartilage standard evaluation form/knee. ICRS Newsletter 1998; 98:5– 8. 14. Morrey BF. Radial head fracture. In: Morrey BF, ed. The elbow and its disorders. 3rd ed. Philadelphia: W.B. Saunders, 2000:341– 364. 15. Morrey B, An K, Stormont T. Force transmission through the radial head. J Bone Joint Surg 1988:70A:250 –256. 16. Potter HG, Foo LF. The articular cartilage. In: Stoller DW, ed. Magnetic resonance imaging in orthopaedics & sports medicine. 3rd ed. Philadelphia: Lippincott–Raven, 2007:1099–1130.
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