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Developmental anterior dislocation of the radial head caused by solitary osteochondroma of the proximal ulna
CASE
REPORTS
Developmental anterior dislocation caused by solitary osteochondroma Muneaki
Abe,
MD,
and
Shigekazu
Koyama,
MD,
Takatsuki, Japan
DeveIopmentaI
dislocation of the head of the radius is defined as any dislocation that results from maldevelopment of the forearm and muscle imbalance around the elbow.8 The most common cause is asymmetric growth between the radius and the ulna, often observed in multiple hereditary osteochondromas.3, 4, 6, 9, lo, I3 In multiple osteochondromas the ulna is most frequently affected at the distal ulnar growth plate, the radius becomes overgrown relative to the ulna, and subsequent dislocation of the head of the radius occurs.12 However, such dislocation resulting from a solitary osteochondroma of the ulna has not been previously reported. We present an unusual case of developmental dislocation of the head of the radius caused by a solitary osteochondroma in the proximal metaphysis of the ulna successfully treated by removal of the tumor combined with an ulnar osteotomy.
CASE REPORT A healthy right-handed boy 9 years and 6 months old presented with a prominence on the anterolateral side of his right elbow. The patient first noticed the prominence and mild pain in the elbow while playing baseball 10 days before the initial examination. There was no history of any trauma or of a similar deformity in the family. On examination there was a tender lump over the anterolateral aspect of his right elbow and a slightly larger prominence 3 cm distal to the cubital From the Department ical College
of Orthopedic
Surgery,
Osaka
Reprint requests Muneaki Abe, MD, Department pedic Sur ery, Osaka Medical College, 2-7, machi, To % atsuki, Osaka, Japan. J Shoulder Copyright Board
Elbow 1998 of Trustees
10%2746/98/$5
66
0
Surg
Med-
of OrthoDaigaku-
1998;7:66-70.
by Journal 00 + 0
of Shoulder 32/4/79887
and
Elbow
Surgery
of the radial head of the proximal ulna
crease. There was no deformity of the forearm, the wrist, and any other area of the trunk or extremities. Wrist movements were normal, but movements of the right elbow and forearm were slightly restricted. Motion of the elbow and forearm revealed extension/flexion on the right as 20”/130” and on the left as 1 So/l 40”. Pronation/supination on the right were 80”/70” and on the left were 90”/90”. The carrying angle was 13” in both elbows. No muscle weakness or sensory disturbance was recognized in the right limb. Radiographs showed a large osseous tumor in the anterolateral aspect of the proximal ulnar metaphysis and anterior dislocation of the radial head (Figure 1). Scalloping in the proximal third of the radius caused by the tumor was seen on the lateral radiograph. The length of the ulna was 4 mm shorter than the left side, but the length of the radius was 2 mm longer than the left side. No other deformities or dysplastic changes were seen on the radiographs. Isotope scanning with technetium-99 revealed localized uptake of the isotope in the region of the ulnar tumor, but there was no uptake in other regions of the trunk or extremities. Six weeks after the patient’s initial consultation, resection of the tumor and reduction of the radial head were performed. A 10 cm curved incision at the anterolateral aspect of the elbow and a 10 cm incision along the posterior aspect of the ulna were made. Resection of the ulnar tumor was approached both anteriorly and posteriorly. The tumor had a cartilaginous cap and measured 3 x 3 x 3 cm (Figure 2). The tumor was diagnosed on histologic evaluation as a typical osteochondroma. After the tumor was excised, the posterior incision was extended proximally, and the lateral aspect of the elbow joint was explored. The head of the radius was dislocated anteriorly through a ruptured capsule; it was easily reduced by cutting a portion of the annular liga-
I Shoulder Elbow Volume 7, Number
Abe and Koyama
Surg I
A
..i
Figure 1 Preoperatrve radiographs showing mal metaphysis of ulna and complete anterior of capitellum and radius were normal
Figure
2 Resected
67
tumor
had broad
bony
osseous tumor protruding anterolaterally dislocation of head of radius Shapes
base
measuring
from ~0x1. of epip Ryses
3 x 3 x 3 cm and cartllaglnous
cap
on
top
ment (Figure 3). The annular ligament seemed to be nearly intact. However, the head easily dislocated again when the elbow was flexed more than loo”, and the forearm was pronated. Therefore
we decided to perform an osteotomy at the proximal third of the ulna. After slight posterior and medial angulation was made at the osteotomy site, the ulna was fixed with an intramedullary Kirschner
68
Abe
and
Koyama
J Shoulder
Elbow
January/February
Surg I998
Figure 3 Surgical findings Head of radrus (*) seemed to slip out through annular recess and then dislocate anteriorly Annular ligament (urrowhead] seemed to be Intact (A) Head of radius was easily reduced by cutting portlon of annular ligament (B) Note concavity of head of radius on cap&m (afrow~ Is normal
wire (Figure 4). A space caused by angulation of the osteotomy was filled with bone chips taken from the proximal metaphysis of the ulna. After the osteotomy was performed, the radial head was stable, and there was no tendency for dislocation to recur during movement of the elbow or forearm. The elbow was immobilized at 90” of flexion and 30” of forearm supination for 4 weeks. Thereafter active motion exercises of the elbow and the forearm were encouraged. No complication related to the surgery or postoperative management was encountered. The postoperative course was uneventful, and the patient regained nearly normal function of the
elbow 6 months after surgery. We reexamined the patient recently (3% years after surgery) and confirmed the absence of tumor recurrence and location of the head of the radius both clinically and radiographically (Figure 5). There was no limitation of flexion or extension of the elbow or rotation of the forearm. DISCUSSION
Developmental or late dislocation of the radial head frequently occurs in multiple hereditary osteochondromas but is extremely rare in a solitary lesion, and to our knowledge such a dislocation has not previously been described. This case dem-
Abe and Koyama
I Shoulder Elbow Surg Volume 7, Number I
69
B Figure 4 Postoperatlve radiographs taken successful reduction of head of radius and metaphysls where tumor was removed
Figure 5 Radiographs taken at follow-up on lateral side of ulna seen on anteroposterior
at cast removal some o&cation
(3%
(4 weeks after of lateral aspect
years after surgery) show view (A), but head of radius
onstrated a solitary osteochondroma in the anterolateral aspect of the proximal ulnar metaphysis. The contributing causes of dislocation were not only direct pressure from the tumor but also slight
surgery] showing of proximal ulnar
unabsorbed In reduced
osslflcatlon posItIon (B)
shortening of the ulna compared with the length of the radius. The patient first noticed pain and bulging on the anterior aspect of the elbow while playing baseball. We observed an intact annular
70
Abe and Koyama
J Shoulder January/February
ligament and a normal concavity of the articular surface of the radial head, but there was a tendency for dislocation to recur on pronation of the forearm during surgery. This suggests that subluxation slowly developed over time, but complete dislocation had occurred recently during a throwing motion. Because developmental dislocation of the radial head is seldom a functional disability, most authors recommend excision of the radial head only in patients who have limitation of elbow motion and when the skeletal growth is complete.lO, 12, l3 In younger patients if the articular surface of the radial head remains concave, and if there is shortening of the ulna, an attempt at reduction by ulnar lengthening can be considered.2, 5, 6, 9, ” Dislocation of the radial head in our patient was treated by open reduction combined with an angulation osteotomy of the ulna. We often apply the same procedure for a neglected Montaggia fracture.” 7 The results were quite satisfactory. Therefore we recommend this technique for treating developmental dislocation of the radial head especially in the young patients in whom the radial head remains normal and the ulna has only a small amount of shortening. REFERENCES 1. Abe M. Ishrzu T late ooen reduction Monteggra lesson [In Japanese). Orthop tol 1993:36:1 19-30
for nealected Surg cauma-
2
T LenathenJ Hand”Surg
Abe M. Shrrar H. Okamoto M. Onomura rng of the forearm by callus d’istraction (Br) 1996,218.151-63.
Reed MH Forearm deformities exostoses. Skeletal Radio1
Elbow
Surg I998
3
Bock GW, cartrlaginous 483-6
4.
Burgess RC, Cates H Deformrtres of the forearm In patients who have multrple cartilaginous exostosis J BoneJoInt Surg Am 1993;75A: 1 3-8.
5.
Dahl MT The gradual ties in multrple hereditary 9,707-l 8.
6.
Fogel GR, McElfresh EC, Peterson HA, Wicklund Pl Management of deformrtres of the forearm In multrple hereditary osteochondromas J Bone Joint Surg Am 1984;66A,670-80
7.
Hirayama T, Takemitsu Y, Yagrhara K, Mrkrta A. Operation for chronic drslocatron of the radial head In chrldren reduction by osteotomy of the ulna. J Bone Joint Surg Br 1987,698:639-42
8
Letts M Dislocatron of the chrlds’ elbow. In. Morrey BF, edttor The elbow and Its disorders. 2nd ed. Phrladelphra. WB Saunders, 1993. p. 288-3 15
9
Masada K, Tsuyuguchr Y, Kawai H, Kawabata H, Noguchr K, Ono K. Operation for forearm deformity caused by multrple osteochondromata. j Bone Joint Surg Br 1989,71 B.24.9
correctron exostoses.
In multrple 1991 ;20,
of forearm deformrHand Clin 1993;
10.
Peterson HA. Deformities and problems of the forearm in children with multiple hereditary osteochondromata J Pediatr Orthop 1994,14,92-l 00
11
Prrtchett ]W Lengthening the ulna rn patients wrth heredrtay multrple exostoses. J Bone Jornt Surg Br 1986168B.561.5.
12.
Shaprro F, Simon S, Glrmcher MJ. Heredrtary multrple exostoses, anthropometric, roentgenographic, and clrnrcal aspects. ] Bone Joint Surg Am 1979,61A: 8 15-24
13.
Wood VE, Sauser D, Mudge D The treatment of hereditary multiple exostosls of the upper extremity. J Hand Surg Am 1985,l OA:503-13
REPORTS
Developmental anterior dislocation caused by solitary osteochondroma Muneaki
Abe,
MD,
and
Shigekazu
Koyama,
MD,
Takatsuki, Japan
DeveIopmentaI
dislocation of the head of the radius is defined as any dislocation that results from maldevelopment of the forearm and muscle imbalance around the elbow.8 The most common cause is asymmetric growth between the radius and the ulna, often observed in multiple hereditary osteochondromas.3, 4, 6, 9, lo, I3 In multiple osteochondromas the ulna is most frequently affected at the distal ulnar growth plate, the radius becomes overgrown relative to the ulna, and subsequent dislocation of the head of the radius occurs.12 However, such dislocation resulting from a solitary osteochondroma of the ulna has not been previously reported. We present an unusual case of developmental dislocation of the head of the radius caused by a solitary osteochondroma in the proximal metaphysis of the ulna successfully treated by removal of the tumor combined with an ulnar osteotomy.
CASE REPORT A healthy right-handed boy 9 years and 6 months old presented with a prominence on the anterolateral side of his right elbow. The patient first noticed the prominence and mild pain in the elbow while playing baseball 10 days before the initial examination. There was no history of any trauma or of a similar deformity in the family. On examination there was a tender lump over the anterolateral aspect of his right elbow and a slightly larger prominence 3 cm distal to the cubital From the Department ical College
of Orthopedic
Surgery,
Osaka
Reprint requests Muneaki Abe, MD, Department pedic Sur ery, Osaka Medical College, 2-7, machi, To % atsuki, Osaka, Japan. J Shoulder Copyright Board
Elbow 1998 of Trustees
10%2746/98/$5
66
0
Surg
Med-
of OrthoDaigaku-
1998;7:66-70.
by Journal 00 + 0
of Shoulder 32/4/79887
and
Elbow
Surgery
of the radial head of the proximal ulna
crease. There was no deformity of the forearm, the wrist, and any other area of the trunk or extremities. Wrist movements were normal, but movements of the right elbow and forearm were slightly restricted. Motion of the elbow and forearm revealed extension/flexion on the right as 20”/130” and on the left as 1 So/l 40”. Pronation/supination on the right were 80”/70” and on the left were 90”/90”. The carrying angle was 13” in both elbows. No muscle weakness or sensory disturbance was recognized in the right limb. Radiographs showed a large osseous tumor in the anterolateral aspect of the proximal ulnar metaphysis and anterior dislocation of the radial head (Figure 1). Scalloping in the proximal third of the radius caused by the tumor was seen on the lateral radiograph. The length of the ulna was 4 mm shorter than the left side, but the length of the radius was 2 mm longer than the left side. No other deformities or dysplastic changes were seen on the radiographs. Isotope scanning with technetium-99 revealed localized uptake of the isotope in the region of the ulnar tumor, but there was no uptake in other regions of the trunk or extremities. Six weeks after the patient’s initial consultation, resection of the tumor and reduction of the radial head were performed. A 10 cm curved incision at the anterolateral aspect of the elbow and a 10 cm incision along the posterior aspect of the ulna were made. Resection of the ulnar tumor was approached both anteriorly and posteriorly. The tumor had a cartilaginous cap and measured 3 x 3 x 3 cm (Figure 2). The tumor was diagnosed on histologic evaluation as a typical osteochondroma. After the tumor was excised, the posterior incision was extended proximally, and the lateral aspect of the elbow joint was explored. The head of the radius was dislocated anteriorly through a ruptured capsule; it was easily reduced by cutting a portion of the annular liga-
I Shoulder Elbow Volume 7, Number
Abe and Koyama
Surg I
A
..i
Figure 1 Preoperatrve radiographs showing mal metaphysis of ulna and complete anterior of capitellum and radius were normal
Figure
2 Resected
67
tumor
had broad
bony
osseous tumor protruding anterolaterally dislocation of head of radius Shapes
base
measuring
from ~0x1. of epip Ryses
3 x 3 x 3 cm and cartllaglnous
cap
on
top
ment (Figure 3). The annular ligament seemed to be nearly intact. However, the head easily dislocated again when the elbow was flexed more than loo”, and the forearm was pronated. Therefore
we decided to perform an osteotomy at the proximal third of the ulna. After slight posterior and medial angulation was made at the osteotomy site, the ulna was fixed with an intramedullary Kirschner
68
Abe
and
Koyama
J Shoulder
Elbow
January/February
Surg I998
Figure 3 Surgical findings Head of radrus (*) seemed to slip out through annular recess and then dislocate anteriorly Annular ligament (urrowhead] seemed to be Intact (A) Head of radius was easily reduced by cutting portlon of annular ligament (B) Note concavity of head of radius on cap&m (afrow~ Is normal
wire (Figure 4). A space caused by angulation of the osteotomy was filled with bone chips taken from the proximal metaphysis of the ulna. After the osteotomy was performed, the radial head was stable, and there was no tendency for dislocation to recur during movement of the elbow or forearm. The elbow was immobilized at 90” of flexion and 30” of forearm supination for 4 weeks. Thereafter active motion exercises of the elbow and the forearm were encouraged. No complication related to the surgery or postoperative management was encountered. The postoperative course was uneventful, and the patient regained nearly normal function of the
elbow 6 months after surgery. We reexamined the patient recently (3% years after surgery) and confirmed the absence of tumor recurrence and location of the head of the radius both clinically and radiographically (Figure 5). There was no limitation of flexion or extension of the elbow or rotation of the forearm. DISCUSSION
Developmental or late dislocation of the radial head frequently occurs in multiple hereditary osteochondromas but is extremely rare in a solitary lesion, and to our knowledge such a dislocation has not previously been described. This case dem-
Abe and Koyama
I Shoulder Elbow Surg Volume 7, Number I
69
B Figure 4 Postoperatlve radiographs taken successful reduction of head of radius and metaphysls where tumor was removed
Figure 5 Radiographs taken at follow-up on lateral side of ulna seen on anteroposterior
at cast removal some o&cation
(3%
(4 weeks after of lateral aspect
years after surgery) show view (A), but head of radius
onstrated a solitary osteochondroma in the anterolateral aspect of the proximal ulnar metaphysis. The contributing causes of dislocation were not only direct pressure from the tumor but also slight
surgery] showing of proximal ulnar
unabsorbed In reduced
osslflcatlon posItIon (B)
shortening of the ulna compared with the length of the radius. The patient first noticed pain and bulging on the anterior aspect of the elbow while playing baseball. We observed an intact annular
70
Abe and Koyama
J Shoulder January/February
ligament and a normal concavity of the articular surface of the radial head, but there was a tendency for dislocation to recur on pronation of the forearm during surgery. This suggests that subluxation slowly developed over time, but complete dislocation had occurred recently during a throwing motion. Because developmental dislocation of the radial head is seldom a functional disability, most authors recommend excision of the radial head only in patients who have limitation of elbow motion and when the skeletal growth is complete.lO, 12, l3 In younger patients if the articular surface of the radial head remains concave, and if there is shortening of the ulna, an attempt at reduction by ulnar lengthening can be considered.2, 5, 6, 9, ” Dislocation of the radial head in our patient was treated by open reduction combined with an angulation osteotomy of the ulna. We often apply the same procedure for a neglected Montaggia fracture.” 7 The results were quite satisfactory. Therefore we recommend this technique for treating developmental dislocation of the radial head especially in the young patients in whom the radial head remains normal and the ulna has only a small amount of shortening. REFERENCES 1. Abe M. Ishrzu T late ooen reduction Monteggra lesson [In Japanese). Orthop tol 1993:36:1 19-30
for nealected Surg cauma-
2
T LenathenJ Hand”Surg
Abe M. Shrrar H. Okamoto M. Onomura rng of the forearm by callus d’istraction (Br) 1996,218.151-63.
Reed MH Forearm deformities exostoses. Skeletal Radio1
Elbow
Surg I998
3
Bock GW, cartrlaginous 483-6
4.
Burgess RC, Cates H Deformrtres of the forearm In patients who have multrple cartilaginous exostosis J BoneJoInt Surg Am 1993;75A: 1 3-8.
5.
Dahl MT The gradual ties in multrple hereditary 9,707-l 8.
6.
Fogel GR, McElfresh EC, Peterson HA, Wicklund Pl Management of deformrtres of the forearm In multrple hereditary osteochondromas J Bone Joint Surg Am 1984;66A,670-80
7.
Hirayama T, Takemitsu Y, Yagrhara K, Mrkrta A. Operation for chronic drslocatron of the radial head In chrldren reduction by osteotomy of the ulna. J Bone Joint Surg Br 1987,698:639-42
8
Letts M Dislocatron of the chrlds’ elbow. In. Morrey BF, edttor The elbow and Its disorders. 2nd ed. Phrladelphra. WB Saunders, 1993. p. 288-3 15
9
Masada K, Tsuyuguchr Y, Kawai H, Kawabata H, Noguchr K, Ono K. Operation for forearm deformity caused by multrple osteochondromata. j Bone Joint Surg Br 1989,71 B.24.9
correctron exostoses.
In multrple 1991 ;20,
of forearm deformrHand Clin 1993;
10.
Peterson HA. Deformities and problems of the forearm in children with multiple hereditary osteochondromata J Pediatr Orthop 1994,14,92-l 00
11
Prrtchett ]W Lengthening the ulna rn patients wrth heredrtay multrple exostoses. J Bone Jornt Surg Br 1986168B.561.5.
12.
Shaprro F, Simon S, Glrmcher MJ. Heredrtary multrple exostoses, anthropometric, roentgenographic, and clrnrcal aspects. ] Bone Joint Surg Am 1979,61A: 8 15-24
13.
Wood VE, Sauser D, Mudge D The treatment of hereditary multiple exostosls of the upper extremity. J Hand Surg Am 1985,l OA:503-13