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Three-dimensional corrective osteotomy for treatment of cubitus varus after supracondylar fracture of the humerus in children
Three-dimensional corrective osteotomy for treatment of cubitus varus after supracondylar fracture of the humerus in children Masamichi Usui, MO, Seiichi Ishii, MO, Suichi Miyano, MO, Hiroshi Narita, MO, and Hideji Kura, MO, Sapporo, Japan
Cubitus varus deformity after supracondylar fracture of the humerus in children generally includes deformities of varus, hyperextension, and internal rotation. Presently almost all corrective osteotomies for treatment of cubitus varus deformity have been limited to correction of only the varus or of the varus and hyperextension deformity. Electromyographic study and stick picture motion analysis have revealed unphysiological ioint motion and muscle activity around the [oint in elbows with cubitus varus, hyperextension, and internal rotation deformity. On this basis we have successfully attempted simultaneous correction of all three deformities. The end results in 47 elbows have been satisfactory. In conclusion, we recommend simultaneous correction of the three elements of cubitus varus deformity to restore anatomic alignment of the elbow [oint. (J SHOULDER ELBOW SURG 7995;4:77-22) So-called" cubitus varus" after supracondylar fracture of the humerus in children usually consists of varus, hyperextension, and internal rotation deformity of the distal fragment of the humerus. Surgical treatment of such deformities has so far been aimed mainly at correction of only the varus deformity by carrying out lateral wedge osteotomy of the humerus. However, if the rotational deformity is left untreated, complete correction of the varus deformity is not achieved." Futhermore the patients with cubitus varus and internal ratation deformity show abnormal elbow joint motion. The purpose of this study is first to analyze this abnormal joint motion by an electromyographic study in combination with stick picture motion analysis. Second it is to report the clinical results of simultaneous correction of varus, hyperextension,
From the Department of Orthopedic Surgery, Sapporo Medical University. Reprint requests: Masamichi Usui, MD, Department of Orthopedic Surgery, Sapporo Medical University,S-l, W-17, Sapporo, Japan 060. Copyright © 1995 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/95/$3.00 + 0 32/1161315
and internal rotation deformities and to establish the validity of this procedure.
MATERIAL AND METHODS Electromyographic and motion analysis studies of the deformed elbow. In five patients with cubitus varus deformity we examined the activities of the brachioradialis and biceps brachii by electromyography to detect abnormal muscle action during extension and flexion. The normal side was used as a control. In one case we analyzed the elbow motion of the cubitus varus rotation deformity by stick picture analysis. Markers were aHached to the styloid process of the distal radius, on the lateral epicondyle, and on the acromion (Figure 1). During this examination the upper arm was held still by a physician to prevent axial rotation of the humerus.
Three-dimensional corrective osteotomy. Since 1979 we have performed 48 threedimensional corrective osteotomies in 48 patients for treatment of cubitus varus deformity after supracondylar fracture in children. Fortyone patients have undergone follow-up clinical or x-ray examination from 6 to 72 months (meon 21 months) after osteotomy. The age of the pa17
18
J. Shoulder Elbow Surg. January/February 1995
Usui et al.
PSD CAMERA 1
PSD CAMERA 2
PERSONAL COMPUTER
Figure 1 Schematic illustration of motion analysis by stick picture method (LOCUS III, Anima, Tokyo, Japon). Three light-emitting diode (LED) markers are attached to radial styloid process, laterol epicondyle of humerus, and acromion. Traces of these three markers are recorded by two position-sensitive detectors (PSD) cameras. Data obtained by two cameros are analyzed by personal computer. We con analyze threedimensional motion of elbow joint by this system.
tients at surgery ranged from 4 to 20 years (mean 8.1 years). Twenty-seven were men, and 14 were women. We measured the angles of varus and hyperextension on the x-ray films and calculated the amounts (degrees) of correction necessary for equal function with the normal side. We measured the internal rotation by our previously reported methods" and. calculated the corresponding correction. Corrective osteotomy was done in the following manner (Figure 2). An incision of severol centimeters was made on the lateral side of the distal arm, exposing the distal part of the humerus. One Steinmann pin (1.8 or 2 mm in diameter) was inserted into the humerus proximal to the site of osteotomy, and another pin was inserted distal to it. The pins were set at the angle in the frontal plane corresponding to the size of the wedge to be removed to correct the varus deformity. Simultaneously the pins were set to describe the angle in the horizontal plane (the plane perpendicular to the axis of the humerus) through which the distal bone fragment must be rotated to correct the internal rotation. A lateral wedge osteotomy of the humerus was performed. Next the distal part of the arm was
Figure 2 Schematic illustration of our method of corrective osteotomy. A, Planned area of resection by osteotomy. 8, Two Steinmann pins inserted into humerus at angles such that varus and internal rotation deformities are corrected when bone fragments are realigned to place pins parallel position with each other. Third pin is placed proximally to reinforce fixation. Proximal and distal bone fragments are held with stainless steel wire to stabilize connection and provide center of rotation. C, Distal fragment of humerus has been rotated, and pins are now in parallel. As hyperextension deformity is. corrected, patient is able to touch fingertips of affected side to anterior aspect of shoulder on same side.
rotated along its axis to bring the pins into parallel position to correct the internal rotation (see Figure 2, Band C). While the mating bone fragments were held together, a hole was drilled
Usui et 01.
J. Shoulder Elbow Surg.
Volume 4, Number 1, Part 1
19
Figure 3 Photographs of representative case. A, Preoperative view show0 ing 30 of cubitus varus. This case has 25 0 of internal rotation deformity. B, External fixation and postoperative appearance. Deformity is corrected. C, X-ray film taken after operation. Deformity is corrected; two bone segments are fixed with three Steinmann pins and wire. D, Photograph taken after removal of pins. Carrying angle is almost normal.
through the anterior cortex of each. Finally the proximal and distal bone fragments were connected with stainless steel wire through the holes. This wire stabilized the connection. Thus it was possible to visually verify the process of correction. Hyperextension deformity was corrected by bending the distal bone fragment to enable the fingertip of the affected side to touch the shoulder on the same side. After these corrections were done another pin was used in the proximal humerus to reinforce the fixation. Finally the three Steinmann pins were fixed with bone cement. The resected bone fragment from
the lateral side of the humerus can be grafted to the osteotomy site between the two bone fragments for stabilization of the anterior angulation of the distal bone fragment. These three pins were removed in the outpatient clinic after solid union of the osteotomy site. This union usually occurs 6 to 8 weeks after surgery (Figures 2 and 3).
RESULTS Electromyographic study and motion analysis of the deformed elbow. The brachioradialis showed higher activity than the bi-
20 Usui et
J. Shoulder Elbow Surg. January/February 1995
01.
EMGanalysis
EMGanalysis Biceps Humeri
Bradrioradialis
CASE11· ··· ;~
_
cubitus
ViUVl
-- _. - normal
- . - . -c~
21.. .' ' .. . .. / -._-3.....~..~~--:=: - '
-;
4.-:.-.-..~.....-.-.. -. -~.
5,.,..-..-- ---30
10
90
110
Angle of Elbow 1'1 ex,
8
10
30
.90
.
no
Angle of Elbow Fiex.
Figure 4 Muscle activity studied by electromyography. A, Activity of brachioradialis muscles in elbows with and without cubitus varus. In every case brochioradialis muscle in cubitus varus shows higher activity than in normal elbow during 0° to 60° of flexion . 8 , Conversely biceps brochii muscle in cubitus varus shows lower activity than normal elbow during 0° to 60° of flexion .
ceps brachii in the early phases of elbow flexion in elbows with cubitus varus deformity (Figure 4). With the use of motion analysis by a stick picture method, in the frontal view the trace of the radial styloid process during motion of the elbow with cubitus varus deformity describes a wavelike curve, whereas in the normal elbow it describes on almost straight line. In the lateral view the trace of the radial styloid process during elbow motion describes a parabola in both normal and cubitus varus elbows. In the overhead view the trace of the rad ial styloid process describes a wavelike curve in the elbow with cubitus varus deformity, whereas that in the normal elbow describes a parabola. It is difficult for the physician to hold the humerus still on the affected side during elbow motion. The movements of the humerus, which we could not stop during this test, were depicted as blurring of the center of the joint motion in the frontal and overhead views (Figure 5). Surgical correction of deformity. The preoperative varus deformity was a mean of 23.8° (0° to 35°), and the postoperative mean value of cubitus valgus was 5° (-10° to 20°). Only one case hod residual varus deformity (10°). The preoperative internal rotation deformity was a mean of 34.8° (0° to 80°), and the postoperative mean value was 1° (- 200 to 30°).
The degree of correction of hyperextension was judged by measuring the flexion angle before and after the operation. It was corrected from 1200 before the operation to 1320 after the operation (Figure 6). No delayed union or nonunion, nerve palsy, or pin tract infection was seen.
DISCUSSION Children with cubitus varus suffer a substantial cosmetic deformity; their arms have a gunstock-like appearance. Corrective osteotomy of the deformed humerus is necessary to correct this unsightly deformity. Until now surgical treatment has been performed mainly to correct only the varus deformity. However, if the rotational deformity .is left untreated, some of the varus deformity remains, because the effect of the varus tilt will be increased by on internal . rotational deformity of the distal frcqrnent." Because the internal rotation angle is easily measured by our method and our method of osteotomy is simple, all three elements of cubitus varus can be treated at the some time in a single operation. Some controversy -exists about the need for correction of internal rotation deformity. Besides the obvious advantage of having normal arm motion, a clear advantage is seen in terms of strength, because the forces from the biceps
J. Shoulder Elbow Surg. Volume 4, Number 1, Part 1
Usui et
frontal view
lateral view
01. 21
bird's-eve view
normal side
cubitus
varus,~
I-
H
Figure 5 Results of motion analysis by stick picture analysis. In normal elbow trace of marker on radial styloid process shows almost straight line in frontal view and parabola in both lateral and overhead views. In cub itus varus with internal rotation deformity trace shows wavelike curve in both frontal and overhead views and parabola in lateral view. Blurring of center of joint motion in frontal and overhead views is seen in elbow with cub itus varus . E, elbow joint; H, humerus . FLEX.
INT. ROT. (n=40)
VARUS (n=40) ore
(n=~O)
OP .
50
200
40
150 pre 00.
30 100
"FT'
20 10 0
50
0
-10
Figure 6 Surgical correction of deformity. Correction of hyperextension deformity is judged by measuring flexion angle (means and standard deviations).
and other muscles are transmitted more effi-
ciently across the joint. Theoretically, as demonstrated by our results of motion analysis by stick picture analysis, the trace of the marker on the radial styloid process will show an ellipse or a parabola in the overhead, lateral, and frontal views in cubitus varus with internal ro- . tation deformity. The results of the present study showed that in cubitus varus with internal ro-
tation deformity, the trace showed a wavelike curve in both the frontal and overhead views and a parabola in the lateral view. Blurring of the center of joint motion in the frontal and overhead views was also seen. We believe that the wavelike curves in both the frontal and overhead views and the blurring of the center of joint motion in the frontal and overhead views in cubitus varus with internal rotation deformity were
22 Usui et
J. Shoulder Elbow Surg.
01.
January/February 1995
Biceps Bra chii
Cubitus Rectus
CUbitus Varus
Cubitus Varus with int. rot.
A
Figure 7 Schematic illustration of theoretic changes in direction of pull of biceps brachii muscle in normal elbow, in elbow with cubitus vorus and in elbow with cubitus varus and an internal rotation deformity. In normal elbow almost all pull of biceps brachii fA} works in flexion . In cubitus varus strength of flexion fA'} is less than A. In cubitus varus w ith internal rolation deform ity, pull fA} is divided between fA "} and internal rotation of distal bone fragment fB}.
produced by the contraction force of biceps brachii, which may act not only for elbow flexion but also for ulnar translation and for rotation of the humerus (Figure 7). These abnormal muscle activities tend to quickly produce muscle fatigue, and the abnormal stress on the joint axis may produce an abnormal stress in the ligaments of the elbow joint when the patient participates in vigorous sport activities. Furthermore, cubital tunnel syndrome associated with cubitus varus deformity has recently been reported in the [ilerofure.':" Although several hypotheses about the etiology of cubital tunnel syndrome and its connection with cubitus varus deformity have been proposed. Muneshige et 01. 2 reported that in cubitus varus with 'i nterna l rotation deformity the sulcus for the ulnar nerve lies posterior to the plane of elbow motion. As a result the ulnar nerve is prone to dislocate, sub luxate, and become injured. In their study the degree of varus did not relate to occurrence of ulnar nerve palsy, and they emphasized the intimate relation between internal rotation deformity and ulnar nerve palsy. From the facts described here we concluded that for treatment of cubitus varus after supra-
condylar fracture of the humerus, the patient is best served when all three elements of the cubitus varus deformity complex are corrected at the same time by osteotomy and the anatomic alignment of the elbow joint is restored. We thank Dr. Akio Minami, Associate Professor, Department of Orthopedic Surgery, Hokkaido University School of Medicine, for his help in doing follow-up examinations on the patients.
REFERENCES 1. Dreyfuss U, Kessler I. Snapping elbow du e to dislocation of the medial head of the triceps. J Bone Joint Surg [Br] 1978;60B:56-7. 2. Muneshige H, Mitunari A, Ikuta Y, Mura kami T. Internal rotation deformity after supracondylar fracture and tardy ulnor nerve pa lsy [In Japanese) . J Jpn Orthop Assoc 1993;67:s430. 3. Ogino T, Oosh io I, Minami A, Fukuda K, Nakasoto T, Sakuma T. Tardy ulnar nerve palsy du e to cubitus varus deform ity (in Japanese) .· J Jpn Soc Surg Hand 1986;2 :922-7. 4. Saegusa K, Ito Y, Uchinishi K, Koike A, Watanabe K, Nozue H. Tardy ulnar palsy due to vorious disorders [In Jap anese] . Orthopedic Surgery 1982;33:281-8. 5. Yomamoto I, Ishii S, Usui M, Ogino T, Kaneda K, Cub itus varus deformity following supracondylor fracture of the humerus: a method for measuring rotational deformity. C1in Orthop 1985;201: 179-85.
Cubitus varus deformity after supracondylar fracture of the humerus in children generally includes deformities of varus, hyperextension, and internal rotation. Presently almost all corrective osteotomies for treatment of cubitus varus deformity have been limited to correction of only the varus or of the varus and hyperextension deformity. Electromyographic study and stick picture motion analysis have revealed unphysiological ioint motion and muscle activity around the [oint in elbows with cubitus varus, hyperextension, and internal rotation deformity. On this basis we have successfully attempted simultaneous correction of all three deformities. The end results in 47 elbows have been satisfactory. In conclusion, we recommend simultaneous correction of the three elements of cubitus varus deformity to restore anatomic alignment of the elbow [oint. (J SHOULDER ELBOW SURG 7995;4:77-22) So-called" cubitus varus" after supracondylar fracture of the humerus in children usually consists of varus, hyperextension, and internal rotation deformity of the distal fragment of the humerus. Surgical treatment of such deformities has so far been aimed mainly at correction of only the varus deformity by carrying out lateral wedge osteotomy of the humerus. However, if the rotational deformity is left untreated, complete correction of the varus deformity is not achieved." Futhermore the patients with cubitus varus and internal ratation deformity show abnormal elbow joint motion. The purpose of this study is first to analyze this abnormal joint motion by an electromyographic study in combination with stick picture motion analysis. Second it is to report the clinical results of simultaneous correction of varus, hyperextension,
From the Department of Orthopedic Surgery, Sapporo Medical University. Reprint requests: Masamichi Usui, MD, Department of Orthopedic Surgery, Sapporo Medical University,S-l, W-17, Sapporo, Japan 060. Copyright © 1995 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/95/$3.00 + 0 32/1161315
and internal rotation deformities and to establish the validity of this procedure.
MATERIAL AND METHODS Electromyographic and motion analysis studies of the deformed elbow. In five patients with cubitus varus deformity we examined the activities of the brachioradialis and biceps brachii by electromyography to detect abnormal muscle action during extension and flexion. The normal side was used as a control. In one case we analyzed the elbow motion of the cubitus varus rotation deformity by stick picture analysis. Markers were aHached to the styloid process of the distal radius, on the lateral epicondyle, and on the acromion (Figure 1). During this examination the upper arm was held still by a physician to prevent axial rotation of the humerus.
Three-dimensional corrective osteotomy. Since 1979 we have performed 48 threedimensional corrective osteotomies in 48 patients for treatment of cubitus varus deformity after supracondylar fracture in children. Fortyone patients have undergone follow-up clinical or x-ray examination from 6 to 72 months (meon 21 months) after osteotomy. The age of the pa17
18
J. Shoulder Elbow Surg. January/February 1995
Usui et al.
PSD CAMERA 1
PSD CAMERA 2
PERSONAL COMPUTER
Figure 1 Schematic illustration of motion analysis by stick picture method (LOCUS III, Anima, Tokyo, Japon). Three light-emitting diode (LED) markers are attached to radial styloid process, laterol epicondyle of humerus, and acromion. Traces of these three markers are recorded by two position-sensitive detectors (PSD) cameras. Data obtained by two cameros are analyzed by personal computer. We con analyze threedimensional motion of elbow joint by this system.
tients at surgery ranged from 4 to 20 years (mean 8.1 years). Twenty-seven were men, and 14 were women. We measured the angles of varus and hyperextension on the x-ray films and calculated the amounts (degrees) of correction necessary for equal function with the normal side. We measured the internal rotation by our previously reported methods" and. calculated the corresponding correction. Corrective osteotomy was done in the following manner (Figure 2). An incision of severol centimeters was made on the lateral side of the distal arm, exposing the distal part of the humerus. One Steinmann pin (1.8 or 2 mm in diameter) was inserted into the humerus proximal to the site of osteotomy, and another pin was inserted distal to it. The pins were set at the angle in the frontal plane corresponding to the size of the wedge to be removed to correct the varus deformity. Simultaneously the pins were set to describe the angle in the horizontal plane (the plane perpendicular to the axis of the humerus) through which the distal bone fragment must be rotated to correct the internal rotation. A lateral wedge osteotomy of the humerus was performed. Next the distal part of the arm was
Figure 2 Schematic illustration of our method of corrective osteotomy. A, Planned area of resection by osteotomy. 8, Two Steinmann pins inserted into humerus at angles such that varus and internal rotation deformities are corrected when bone fragments are realigned to place pins parallel position with each other. Third pin is placed proximally to reinforce fixation. Proximal and distal bone fragments are held with stainless steel wire to stabilize connection and provide center of rotation. C, Distal fragment of humerus has been rotated, and pins are now in parallel. As hyperextension deformity is. corrected, patient is able to touch fingertips of affected side to anterior aspect of shoulder on same side.
rotated along its axis to bring the pins into parallel position to correct the internal rotation (see Figure 2, Band C). While the mating bone fragments were held together, a hole was drilled
Usui et 01.
J. Shoulder Elbow Surg.
Volume 4, Number 1, Part 1
19
Figure 3 Photographs of representative case. A, Preoperative view show0 ing 30 of cubitus varus. This case has 25 0 of internal rotation deformity. B, External fixation and postoperative appearance. Deformity is corrected. C, X-ray film taken after operation. Deformity is corrected; two bone segments are fixed with three Steinmann pins and wire. D, Photograph taken after removal of pins. Carrying angle is almost normal.
through the anterior cortex of each. Finally the proximal and distal bone fragments were connected with stainless steel wire through the holes. This wire stabilized the connection. Thus it was possible to visually verify the process of correction. Hyperextension deformity was corrected by bending the distal bone fragment to enable the fingertip of the affected side to touch the shoulder on the same side. After these corrections were done another pin was used in the proximal humerus to reinforce the fixation. Finally the three Steinmann pins were fixed with bone cement. The resected bone fragment from
the lateral side of the humerus can be grafted to the osteotomy site between the two bone fragments for stabilization of the anterior angulation of the distal bone fragment. These three pins were removed in the outpatient clinic after solid union of the osteotomy site. This union usually occurs 6 to 8 weeks after surgery (Figures 2 and 3).
RESULTS Electromyographic study and motion analysis of the deformed elbow. The brachioradialis showed higher activity than the bi-
20 Usui et
J. Shoulder Elbow Surg. January/February 1995
01.
EMGanalysis
EMGanalysis Biceps Humeri
Bradrioradialis
CASE11· ··· ;~
_
cubitus
ViUVl
-- _. - normal
- . - . -c~
21.. .' ' .. . .. / -._-3.....~..~~--:=: - '
-;
4.-:.-.-..~.....-.-.. -. -~.
5,.,..-..-- ---30
10
90
110
Angle of Elbow 1'1 ex,
8
10
30
.90
.
no
Angle of Elbow Fiex.
Figure 4 Muscle activity studied by electromyography. A, Activity of brachioradialis muscles in elbows with and without cubitus varus. In every case brochioradialis muscle in cubitus varus shows higher activity than in normal elbow during 0° to 60° of flexion . 8 , Conversely biceps brochii muscle in cubitus varus shows lower activity than normal elbow during 0° to 60° of flexion .
ceps brachii in the early phases of elbow flexion in elbows with cubitus varus deformity (Figure 4). With the use of motion analysis by a stick picture method, in the frontal view the trace of the radial styloid process during motion of the elbow with cubitus varus deformity describes a wavelike curve, whereas in the normal elbow it describes on almost straight line. In the lateral view the trace of the radial styloid process during elbow motion describes a parabola in both normal and cubitus varus elbows. In the overhead view the trace of the rad ial styloid process describes a wavelike curve in the elbow with cubitus varus deformity, whereas that in the normal elbow describes a parabola. It is difficult for the physician to hold the humerus still on the affected side during elbow motion. The movements of the humerus, which we could not stop during this test, were depicted as blurring of the center of the joint motion in the frontal and overhead views (Figure 5). Surgical correction of deformity. The preoperative varus deformity was a mean of 23.8° (0° to 35°), and the postoperative mean value of cubitus valgus was 5° (-10° to 20°). Only one case hod residual varus deformity (10°). The preoperative internal rotation deformity was a mean of 34.8° (0° to 80°), and the postoperative mean value was 1° (- 200 to 30°).
The degree of correction of hyperextension was judged by measuring the flexion angle before and after the operation. It was corrected from 1200 before the operation to 1320 after the operation (Figure 6). No delayed union or nonunion, nerve palsy, or pin tract infection was seen.
DISCUSSION Children with cubitus varus suffer a substantial cosmetic deformity; their arms have a gunstock-like appearance. Corrective osteotomy of the deformed humerus is necessary to correct this unsightly deformity. Until now surgical treatment has been performed mainly to correct only the varus deformity. However, if the rotational deformity .is left untreated, some of the varus deformity remains, because the effect of the varus tilt will be increased by on internal . rotational deformity of the distal frcqrnent." Because the internal rotation angle is easily measured by our method and our method of osteotomy is simple, all three elements of cubitus varus can be treated at the some time in a single operation. Some controversy -exists about the need for correction of internal rotation deformity. Besides the obvious advantage of having normal arm motion, a clear advantage is seen in terms of strength, because the forces from the biceps
J. Shoulder Elbow Surg. Volume 4, Number 1, Part 1
Usui et
frontal view
lateral view
01. 21
bird's-eve view
normal side
cubitus
varus,~
I-
H
Figure 5 Results of motion analysis by stick picture analysis. In normal elbow trace of marker on radial styloid process shows almost straight line in frontal view and parabola in both lateral and overhead views. In cub itus varus with internal rotation deformity trace shows wavelike curve in both frontal and overhead views and parabola in lateral view. Blurring of center of joint motion in frontal and overhead views is seen in elbow with cub itus varus . E, elbow joint; H, humerus . FLEX.
INT. ROT. (n=40)
VARUS (n=40) ore
(n=~O)
OP .
50
200
40
150 pre 00.
30 100
"FT'
20 10 0
50
0
-10
Figure 6 Surgical correction of deformity. Correction of hyperextension deformity is judged by measuring flexion angle (means and standard deviations).
and other muscles are transmitted more effi-
ciently across the joint. Theoretically, as demonstrated by our results of motion analysis by stick picture analysis, the trace of the marker on the radial styloid process will show an ellipse or a parabola in the overhead, lateral, and frontal views in cubitus varus with internal ro- . tation deformity. The results of the present study showed that in cubitus varus with internal ro-
tation deformity, the trace showed a wavelike curve in both the frontal and overhead views and a parabola in the lateral view. Blurring of the center of joint motion in the frontal and overhead views was also seen. We believe that the wavelike curves in both the frontal and overhead views and the blurring of the center of joint motion in the frontal and overhead views in cubitus varus with internal rotation deformity were
22 Usui et
J. Shoulder Elbow Surg.
01.
January/February 1995
Biceps Bra chii
Cubitus Rectus
CUbitus Varus
Cubitus Varus with int. rot.
A
Figure 7 Schematic illustration of theoretic changes in direction of pull of biceps brachii muscle in normal elbow, in elbow with cubitus vorus and in elbow with cubitus varus and an internal rotation deformity. In normal elbow almost all pull of biceps brachii fA} works in flexion . In cubitus varus strength of flexion fA'} is less than A. In cubitus varus w ith internal rolation deform ity, pull fA} is divided between fA "} and internal rotation of distal bone fragment fB}.
produced by the contraction force of biceps brachii, which may act not only for elbow flexion but also for ulnar translation and for rotation of the humerus (Figure 7). These abnormal muscle activities tend to quickly produce muscle fatigue, and the abnormal stress on the joint axis may produce an abnormal stress in the ligaments of the elbow joint when the patient participates in vigorous sport activities. Furthermore, cubital tunnel syndrome associated with cubitus varus deformity has recently been reported in the [ilerofure.':" Although several hypotheses about the etiology of cubital tunnel syndrome and its connection with cubitus varus deformity have been proposed. Muneshige et 01. 2 reported that in cubitus varus with 'i nterna l rotation deformity the sulcus for the ulnar nerve lies posterior to the plane of elbow motion. As a result the ulnar nerve is prone to dislocate, sub luxate, and become injured. In their study the degree of varus did not relate to occurrence of ulnar nerve palsy, and they emphasized the intimate relation between internal rotation deformity and ulnar nerve palsy. From the facts described here we concluded that for treatment of cubitus varus after supra-
condylar fracture of the humerus, the patient is best served when all three elements of the cubitus varus deformity complex are corrected at the same time by osteotomy and the anatomic alignment of the elbow joint is restored. We thank Dr. Akio Minami, Associate Professor, Department of Orthopedic Surgery, Hokkaido University School of Medicine, for his help in doing follow-up examinations on the patients.
REFERENCES 1. Dreyfuss U, Kessler I. Snapping elbow du e to dislocation of the medial head of the triceps. J Bone Joint Surg [Br] 1978;60B:56-7. 2. Muneshige H, Mitunari A, Ikuta Y, Mura kami T. Internal rotation deformity after supracondylar fracture and tardy ulnor nerve pa lsy [In Japanese) . J Jpn Orthop Assoc 1993;67:s430. 3. Ogino T, Oosh io I, Minami A, Fukuda K, Nakasoto T, Sakuma T. Tardy ulnar nerve palsy du e to cubitus varus deform ity (in Japanese) .· J Jpn Soc Surg Hand 1986;2 :922-7. 4. Saegusa K, Ito Y, Uchinishi K, Koike A, Watanabe K, Nozue H. Tardy ulnar palsy due to vorious disorders [In Jap anese] . Orthopedic Surgery 1982;33:281-8. 5. Yomamoto I, Ishii S, Usui M, Ogino T, Kaneda K, Cub itus varus deformity following supracondylor fracture of the humerus: a method for measuring rotational deformity. C1in Orthop 1985;201: 179-85.