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Treatment of brachymetatarsia by the callus distraction method
Treatment of Brachymetatarsia by the Callus Distraction Method Ira M. Fox, DPM Brachymetatarsia is not an uncommon congenital foot disorder that is due to a premature closure of the ephiphyseal plate. The literature has numerous surgical procedures for the correction of this problem. In recent years, the callus distraction technique described by lIizarov has been utilized for this problem. This is a retrospective study of the use of the callus distraction technique for the correction of congenitally short metatarsal. This series included six feet in six female patients, all with a short fourth metatarsal. Preoperative complaints were metatarsalgia and/or cosmesis. A noncirculer, uniplanar axial fixation device was utilized for fixation and distraction. The fixator was put in place prior to the metatarsal osteotomy. Static fixation was for a period of 5 - 7 days before distraction was begun. The metatarsal was lengthened 0.5 mm two times a day, or 1 mm per day. The time to end point ranged from 45 to 70 days, followed by another 6-8 weeks of static immobilization. The preoperative metatarsal length ranged from 3.5 to 4.2 cm. The end stage metatarsal length ranged from 4.7 to 6.3 em, with an average increase in length of 1.68 em. As compared to other techniques described in the medical literature, the callus distraction technique has its own unique set of advantages and disadvantages. (The Journal of Foot & Ankle Surgery 37(5):391-395, 1998) Key words: brachymetatarsia, callus, distraction, i1izarov, metatarsalgia
Brachymetatarsia was first described by Kite in 1964 simply as a shortening of one or more of the metatarsals due to "... a premature fusion of the epiphyseal line at the distal end of the metatarsal" (1). The true etiology, however, is unknown, with associations being made to traumatic and iatrogenic factors as well as being idiopathic (2, 3). It has also been associated with such systemic disorders as pseudohypoparathyroidism, Turner's syndrome, Albright's hereditary osteodystrophy, and Down's syndrome (4, 5). Most often, it is found in the fourth metatarsal and affects females and males at a 25:1 ratio (2). The deformity, which is congenital, becomes evident between the ages of 4 and 15 years of age. Because of the shortened metatarsal, the digit may dorsally displace over one of the adjacent metatarsals resulting in excess pressure and tyloma formation. Most patients come in with complaints of pain and/or cosmetic problems. As with many foot deformities, treatment may be divided into conservative and surgical care. Surgical correction should address three main goals: Address correspondence to: Ira M. Fox, DPM, Division of Orthopaedic Surgery, University of Medicine and Dentistry of New JerseylRobert Wood Johnson Medical School, 3 Cooper Plaza, #411, Camden, NJ 08103. Received for publication January 1998; accepted in revised form for publication May 1998. The Journal of Foot & Ankle Surgery 1067-2516/98/3705-0391$4.00/0 Copyright © 1998 by the American College of Foot and Ankle Surgeons
1. Alleviate pain 2. Establish a cosmetically acceptable foot 3. Restore a functional metatarsal parabola There has been a myriad of surgical procedures designed to correct a brachymetatarsia from either a functional or cosmetic point of view. They include softtissue correction such as Kelekian's syndactylization of the fourth and fifth toes (6), the use of joint spacers such as the Calnan-Nicolle implant I described by Mah et al. (3), and various bone-grafting techniques (7-10). There are two reports where the fifth metatarsal head was transposed to the fourth (11, 12). More recently, the Ilizarov method of callus distraction has been applied to this deformity by several authors with reportedly good results (2, 13, 14). Materials and Methods
This series included six feet in six patients, all with a short fourth metatarsal (Figs. I and 2). The preoperative length of the metatarsal ranged from 3.5 ern to 4.2 em with an average of 3.867 cm. All patients were female, ranging from 11 to 14 years of age, with an average age of 13. The presenting complaints were metatarsalgia, overlapping toes, and cosmetic unhappiness. A noncircular, uniplanar EBI Dynamic Mini Axial Fixation'" device was utilized for fixation and bone transport, as opposed to the circular ring-type fixation as described by Ilizarov (15) I
Orthopedic Equipment Co., Bourbon, IL
VOLUME 37, NUMBER 5, SEPTEMBER/OCTOBER 1998
391
(Figs . 3 and 4). All surgeri es were performed under local anesthesia with IV sedation and ankle tourniquet hemostasis. An incisio n was made over the metat arsal and dissection carrie d out to the periosteum, which was left intact. The fixation pins were then placed in position prior to the tran section of the metatarsal. The distal pins were placed in the metat arsal and the proximal pins were placed in the lateral cuneiform, as the metatarsal pro ved too short to acce pt four pins. An osteotomy, as oppo sed to a corticotomy that was described by Ilizaro v ( 15), was performed at the midshaft of the metatarsal with care taken to avo id thermal necro sis of bone. Th is was achieved by copiously irrigating the osteotom y site with cool saline durin g the bone cuts. The external fixator was then applied to the pins. Static fixation was utilized for a period of 6 days. After that time, the parents of the patient were instructed to advance the devic e by 0.25 mm four times per day for a total of 1 mm per day. The patient was instructed to remain strictly nonw eightbe aring with crutches. Neither a splint nor cast was deemed necessary. Ser ial radiograph s were ordered at 2-week intervals to observe the roent genographi c evidence ofrege nerate bone formation (2, 14, 15) (Fig. 5).
FIGURE 1
FIGURE 2
Preoperative view of short fourth toe.
Preoperative radiograph demonstrating short fourth FIGURE 3
metatarsal.
392
THE JOURNAL OF FOOT & ANKLE SURGERY
Intraoperative radiograph showing pin placement.
FIGURE 4
Intraoperative radiograph showing fixator placement.
FIGURE 6 fourth toe.
Postoperative X-ray demonstrating fully lengthened
Once the appropriate length was achieved, as determined by the surgeon, the distraction was stopped, and static fixation was again utilized for approximately 4-6 weeks. After that, the external fixator was removed and the patient was sent to physical therapy for gradual resumption of weightbearing, strengthening, and edema control (Figs. 6 and 7). Results
FIGURE 5 Postoperative X-ray showing the gap and early evidence of new bone formation. Notice the cylindrical appearance longitudinal striations, and well-defined lateral margins.
The time from the application of the fixator to its removal ranged from 45 to 70 days with an average of 55.67 days (Table I). The increase in length of the metatarsals ranged from 1.0 em to 2.1 em, with an average of 1.68 em. There were no nonunions, one malunion, and excessive scarring in five of the six patients. There were two superficial postoperative infections that cleared with 7 days of oral antibiotics and local wound care. The follow-up period ranged from 9 to 36 months. One patient (#6) who had a tyloma plantar to the third metatarsal head preoperatively, had the callus resolve in the months following the surgery and it has not returned in the 9 months since. There were no transfer lesions. All patients
VOLUME 37, NUMBER 5, SEPTEMBER/OCTOBER 1998
393
TABLE 1
Patient 1 2 3 4 5 6
Results Age 12 14 11 12 14 15
Preop Length 4.0 3.7 3.8 4.2 4.0 3.5
em em em em em em
Postop Length 5.5 4.7 5.6 6.3 5.7 5.5
Increase
em em em em em em
1.5 1.0 1.8 2.1 1.7 2.0
3. 4. 5. 6. 7.
FIGURE 7
Postoperative X-ray showing healed and fully lengthened fourth metatarsal.
and their parents were happy with the cosmetic results, although two patients (#1 and #5) underwent scar revision 8 and 6 months postoperatively, respectively.
Discussion Ilizarov's serendipitous discovery (15) of callus distraction in 1956 has since been refined with a precise timetable for lengthening. He reported seven principles for callus distraction: I. Maximum preservation of endosteal and periosteal blood supplies 2. Stable circular external fixation 394
THE JOURNAL OF FOOT & ANKLE SURGERY
em em em em em em
Time to End Point 45 60 52 70 48 59
days days days days days days
Follow-up 36-month 20-month 12-month 12-month 9-month 9-month
Adequate latency period Distraction in small, frequent steps Distraction of 1 mm per day Period of neutral fixation after reaching final length Normal physiologic use of elongated part
It is clear that it is essential to preserve the periosteal and endosteal blood supplies to the bone during surgical dissection. This technique has been modified in several ways for the small bones of the foot as contrasted with the larger bones, such as the tibia and femur with which Ilizarov worked. Instead of the circular external fixationlbone transport device used with large long bones, a small, linear fixation/transport device was used. Additionally, since the metatarsal bone is so small, it was not felt that a corticotomy was required, and a small power saw was utilized to make the osteotomy. In contrasting bone lengthening with other surgical procedures for brachymetatarsia, there are inherent advantages and disadvantages with all techniques. Both bone grafting and callus distraction requires long periods of nonweightbearing (16). Implantation of a joint spacer is contraindicated in the pediatric patient, and also results in a nonanatomic and nonphysiologic metatarsophalangeal joint. Callus distraction can result in hypertrophic scarring that might require revision surgery, as happened in two of our patients. One advantage of callus distraction is that it allows for simultaneous lengthening of the soft tissues and neurovascular structures, as contrasted with bone grafting or prosthetic joints. The most significant advantage of the callus distraction technique, however, is that the final product is a normal, full-length bone that is anatomically and histologically indistinguishable from the neighboring metatarsal bones. In this series, all parents were satisfied with the results, and would do the procedure again. This high satisfaction rate is due to several factors. One is that the patients and their parents were extensively briefed on the procedure, their role in the postoperative course, and possible complications. This resulted in a highly informed patient who was aware of what could and could not happen as well as what was expected of them. Finally, our "satisfaction rate" was highly subjective, and could have given skewed results. The caveats to the procedure are that the patient and/or the parents need to be highly committed and educated to
a postoperative course that requires prolonged nonweightbearing and daily attentio n to distraction every 6 hours. Without a committed patient and/or family, this proce dure is doomed to failure. Additionally, patients should be made aware of the limitations and possible complications, so that their expectations are realistic.
References L Kite, J. H. The Clubfoot, p. 156, Grune & Stratton, Ne w York. 1964 . 2. Vrana . Y.. Koba yashi. A. Bone lengthen ing for shorte ning of the fourth toe. J. Bone Joint Surg. 60-A :91 - 93,1978. 3. Mah , K.. Bea gle, T ., Falkner, D. A correction for short fourth metatarsal. J. Am . Podiatr . Assoc . 73: 196- 200. 1983. 4. Green field. G. B. Radiology of Bone Diseases. 2nd ed. , p. 240, J. B. Lippincott. Philadelphia, 1975. 5. Hand elman, R. B.. Perlman. M. D .. Coleman . W. D. Brach ymetatarsia. J. Am. Podi atr . Med . Assoc . 76:41 3-416, 1986. 6. Kelikian, H., Cla yton. L. , Loseff, H. Sur gical sy ndactyly of the toes. Clin. Orth op . 19:208 - 231, 196 L
7. McGl am ry. E. D., Cooper, C. T . Brach yrnetatar sia : a surgica l treatment. J. Am. Podi atr. Assoc. 59:259 - 264 . 1969. 8. Jimenez, A. L. Brachymetatars ia: a study in surg ica l plannin g. J. Am. Podi atr. Med . Assoc. 69 :245 - 251 , 1979. 9. McGlamry, E. D. , Fenton, C. F. Brachymetatarsia: a case rep ort . J. Am . Podiatr, Med. Assoc. 74:75 - 78, 1983. 10. Levine, S. E ., Davidson, R. S., Dorrnans, J. P., D rummond, D. S. Distraction osteogenesis for con ge nitally short lesser met atarsals. Foot Ankle Int. 16:196- 200. 1995 . II. Chairman , E. L., Dall alio , A. E., Mandracchi a. V. J. Brachyrnctatarsia IV: a different surgical approach . J. Foot. Sur g. 24:361 - 363. 1985. 12. Frankel, J. P., Fleishman, J. H. Correc tion for brachyrnetatarsia with transpositional metatar sal osteotomi es . J. Foot. Sur g. 30: 19- 25, 199 1. 13. Sax by, T ., Nunl y. J. A. Metatarsal length enin g by distraction osteoge nesis. Foot Ankle 9:53 6 - 539, 1992 . 14 . Gre en , S. A. The llazarov method of orthopedic recon struction. J. Mu se. Me d. Sept. 83 -96, 199 1. IS. Ilizarov, G. A. Clinical app lication of the tens ion-stress effect for limb lengthening. Clin. Orthop. 250 :81 - 104, 1990. 16. Biggs, E. W., Brahm, T . B., Efron, B. L. Surgic al co rrection of co ngenital hypopl astic metatarsals. J. Am . Podl atr. Med . Assoc. 69:24 1-244 , 1979.
VOLUME 37 , NUMBER 5, SEPTEMBER/OCTOBER 1998
395
Brachymetatarsia was first described by Kite in 1964 simply as a shortening of one or more of the metatarsals due to "... a premature fusion of the epiphyseal line at the distal end of the metatarsal" (1). The true etiology, however, is unknown, with associations being made to traumatic and iatrogenic factors as well as being idiopathic (2, 3). It has also been associated with such systemic disorders as pseudohypoparathyroidism, Turner's syndrome, Albright's hereditary osteodystrophy, and Down's syndrome (4, 5). Most often, it is found in the fourth metatarsal and affects females and males at a 25:1 ratio (2). The deformity, which is congenital, becomes evident between the ages of 4 and 15 years of age. Because of the shortened metatarsal, the digit may dorsally displace over one of the adjacent metatarsals resulting in excess pressure and tyloma formation. Most patients come in with complaints of pain and/or cosmetic problems. As with many foot deformities, treatment may be divided into conservative and surgical care. Surgical correction should address three main goals: Address correspondence to: Ira M. Fox, DPM, Division of Orthopaedic Surgery, University of Medicine and Dentistry of New JerseylRobert Wood Johnson Medical School, 3 Cooper Plaza, #411, Camden, NJ 08103. Received for publication January 1998; accepted in revised form for publication May 1998. The Journal of Foot & Ankle Surgery 1067-2516/98/3705-0391$4.00/0 Copyright © 1998 by the American College of Foot and Ankle Surgeons
1. Alleviate pain 2. Establish a cosmetically acceptable foot 3. Restore a functional metatarsal parabola There has been a myriad of surgical procedures designed to correct a brachymetatarsia from either a functional or cosmetic point of view. They include softtissue correction such as Kelekian's syndactylization of the fourth and fifth toes (6), the use of joint spacers such as the Calnan-Nicolle implant I described by Mah et al. (3), and various bone-grafting techniques (7-10). There are two reports where the fifth metatarsal head was transposed to the fourth (11, 12). More recently, the Ilizarov method of callus distraction has been applied to this deformity by several authors with reportedly good results (2, 13, 14). Materials and Methods
This series included six feet in six patients, all with a short fourth metatarsal (Figs. I and 2). The preoperative length of the metatarsal ranged from 3.5 ern to 4.2 em with an average of 3.867 cm. All patients were female, ranging from 11 to 14 years of age, with an average age of 13. The presenting complaints were metatarsalgia, overlapping toes, and cosmetic unhappiness. A noncircular, uniplanar EBI Dynamic Mini Axial Fixation'" device was utilized for fixation and bone transport, as opposed to the circular ring-type fixation as described by Ilizarov (15) I
Orthopedic Equipment Co., Bourbon, IL
VOLUME 37, NUMBER 5, SEPTEMBER/OCTOBER 1998
391
(Figs . 3 and 4). All surgeri es were performed under local anesthesia with IV sedation and ankle tourniquet hemostasis. An incisio n was made over the metat arsal and dissection carrie d out to the periosteum, which was left intact. The fixation pins were then placed in position prior to the tran section of the metatarsal. The distal pins were placed in the metat arsal and the proximal pins were placed in the lateral cuneiform, as the metatarsal pro ved too short to acce pt four pins. An osteotomy, as oppo sed to a corticotomy that was described by Ilizaro v ( 15), was performed at the midshaft of the metatarsal with care taken to avo id thermal necro sis of bone. Th is was achieved by copiously irrigating the osteotom y site with cool saline durin g the bone cuts. The external fixator was then applied to the pins. Static fixation was utilized for a period of 6 days. After that time, the parents of the patient were instructed to advance the devic e by 0.25 mm four times per day for a total of 1 mm per day. The patient was instructed to remain strictly nonw eightbe aring with crutches. Neither a splint nor cast was deemed necessary. Ser ial radiograph s were ordered at 2-week intervals to observe the roent genographi c evidence ofrege nerate bone formation (2, 14, 15) (Fig. 5).
FIGURE 1
FIGURE 2
Preoperative view of short fourth toe.
Preoperative radiograph demonstrating short fourth FIGURE 3
metatarsal.
392
THE JOURNAL OF FOOT & ANKLE SURGERY
Intraoperative radiograph showing pin placement.
FIGURE 4
Intraoperative radiograph showing fixator placement.
FIGURE 6 fourth toe.
Postoperative X-ray demonstrating fully lengthened
Once the appropriate length was achieved, as determined by the surgeon, the distraction was stopped, and static fixation was again utilized for approximately 4-6 weeks. After that, the external fixator was removed and the patient was sent to physical therapy for gradual resumption of weightbearing, strengthening, and edema control (Figs. 6 and 7). Results
FIGURE 5 Postoperative X-ray showing the gap and early evidence of new bone formation. Notice the cylindrical appearance longitudinal striations, and well-defined lateral margins.
The time from the application of the fixator to its removal ranged from 45 to 70 days with an average of 55.67 days (Table I). The increase in length of the metatarsals ranged from 1.0 em to 2.1 em, with an average of 1.68 em. There were no nonunions, one malunion, and excessive scarring in five of the six patients. There were two superficial postoperative infections that cleared with 7 days of oral antibiotics and local wound care. The follow-up period ranged from 9 to 36 months. One patient (#6) who had a tyloma plantar to the third metatarsal head preoperatively, had the callus resolve in the months following the surgery and it has not returned in the 9 months since. There were no transfer lesions. All patients
VOLUME 37, NUMBER 5, SEPTEMBER/OCTOBER 1998
393
TABLE 1
Patient 1 2 3 4 5 6
Results Age 12 14 11 12 14 15
Preop Length 4.0 3.7 3.8 4.2 4.0 3.5
em em em em em em
Postop Length 5.5 4.7 5.6 6.3 5.7 5.5
Increase
em em em em em em
1.5 1.0 1.8 2.1 1.7 2.0
3. 4. 5. 6. 7.
FIGURE 7
Postoperative X-ray showing healed and fully lengthened fourth metatarsal.
and their parents were happy with the cosmetic results, although two patients (#1 and #5) underwent scar revision 8 and 6 months postoperatively, respectively.
Discussion Ilizarov's serendipitous discovery (15) of callus distraction in 1956 has since been refined with a precise timetable for lengthening. He reported seven principles for callus distraction: I. Maximum preservation of endosteal and periosteal blood supplies 2. Stable circular external fixation 394
THE JOURNAL OF FOOT & ANKLE SURGERY
em em em em em em
Time to End Point 45 60 52 70 48 59
days days days days days days
Follow-up 36-month 20-month 12-month 12-month 9-month 9-month
Adequate latency period Distraction in small, frequent steps Distraction of 1 mm per day Period of neutral fixation after reaching final length Normal physiologic use of elongated part
It is clear that it is essential to preserve the periosteal and endosteal blood supplies to the bone during surgical dissection. This technique has been modified in several ways for the small bones of the foot as contrasted with the larger bones, such as the tibia and femur with which Ilizarov worked. Instead of the circular external fixationlbone transport device used with large long bones, a small, linear fixation/transport device was used. Additionally, since the metatarsal bone is so small, it was not felt that a corticotomy was required, and a small power saw was utilized to make the osteotomy. In contrasting bone lengthening with other surgical procedures for brachymetatarsia, there are inherent advantages and disadvantages with all techniques. Both bone grafting and callus distraction requires long periods of nonweightbearing (16). Implantation of a joint spacer is contraindicated in the pediatric patient, and also results in a nonanatomic and nonphysiologic metatarsophalangeal joint. Callus distraction can result in hypertrophic scarring that might require revision surgery, as happened in two of our patients. One advantage of callus distraction is that it allows for simultaneous lengthening of the soft tissues and neurovascular structures, as contrasted with bone grafting or prosthetic joints. The most significant advantage of the callus distraction technique, however, is that the final product is a normal, full-length bone that is anatomically and histologically indistinguishable from the neighboring metatarsal bones. In this series, all parents were satisfied with the results, and would do the procedure again. This high satisfaction rate is due to several factors. One is that the patients and their parents were extensively briefed on the procedure, their role in the postoperative course, and possible complications. This resulted in a highly informed patient who was aware of what could and could not happen as well as what was expected of them. Finally, our "satisfaction rate" was highly subjective, and could have given skewed results. The caveats to the procedure are that the patient and/or the parents need to be highly committed and educated to
a postoperative course that requires prolonged nonweightbearing and daily attentio n to distraction every 6 hours. Without a committed patient and/or family, this proce dure is doomed to failure. Additionally, patients should be made aware of the limitations and possible complications, so that their expectations are realistic.
References L Kite, J. H. The Clubfoot, p. 156, Grune & Stratton, Ne w York. 1964 . 2. Vrana . Y.. Koba yashi. A. Bone lengthen ing for shorte ning of the fourth toe. J. Bone Joint Surg. 60-A :91 - 93,1978. 3. Mah , K.. Bea gle, T ., Falkner, D. A correction for short fourth metatarsal. J. Am . Podiatr . Assoc . 73: 196- 200. 1983. 4. Green field. G. B. Radiology of Bone Diseases. 2nd ed. , p. 240, J. B. Lippincott. Philadelphia, 1975. 5. Hand elman, R. B.. Perlman. M. D .. Coleman . W. D. Brach ymetatarsia. J. Am. Podi atr . Med . Assoc . 76:41 3-416, 1986. 6. Kelikian, H., Cla yton. L. , Loseff, H. Sur gical sy ndactyly of the toes. Clin. Orth op . 19:208 - 231, 196 L
7. McGl am ry. E. D., Cooper, C. T . Brach yrnetatar sia : a surgica l treatment. J. Am. Podi atr. Assoc. 59:259 - 264 . 1969. 8. Jimenez, A. L. Brachymetatars ia: a study in surg ica l plannin g. J. Am. Podi atr. Med . Assoc. 69 :245 - 251 , 1979. 9. McGlamry, E. D. , Fenton, C. F. Brachymetatarsia: a case rep ort . J. Am . Podiatr, Med. Assoc. 74:75 - 78, 1983. 10. Levine, S. E ., Davidson, R. S., Dorrnans, J. P., D rummond, D. S. Distraction osteogenesis for con ge nitally short lesser met atarsals. Foot Ankle Int. 16:196- 200. 1995 . II. Chairman , E. L., Dall alio , A. E., Mandracchi a. V. J. Brachyrnctatarsia IV: a different surgical approach . J. Foot. Sur g. 24:361 - 363. 1985. 12. Frankel, J. P., Fleishman, J. H. Correc tion for brachyrnetatarsia with transpositional metatar sal osteotomi es . J. Foot. Sur g. 30: 19- 25, 199 1. 13. Sax by, T ., Nunl y. J. A. Metatarsal length enin g by distraction osteoge nesis. Foot Ankle 9:53 6 - 539, 1992 . 14 . Gre en , S. A. The llazarov method of orthopedic recon struction. J. Mu se. Me d. Sept. 83 -96, 199 1. IS. Ilizarov, G. A. Clinical app lication of the tens ion-stress effect for limb lengthening. Clin. Orthop. 250 :81 - 104, 1990. 16. Biggs, E. W., Brahm, T . B., Efron, B. L. Surgic al co rrection of co ngenital hypopl astic metatarsals. J. Am . Podl atr. Med . Assoc. 69:24 1-244 , 1979.
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