Lengthening of short great toes by callus distraction

Aetiology, diagnosis, and treatment of brachymetatarsia: a narrative review

Brachymetatarsia (BM), or hypoplastic metatarsal, is an abnormal shortening of one or more metatarsal bones with a female-to-male ratio of 10.53:1. Different causes are described in the literature, such as congenital, acquired, or iatrogenic, associated with different conditions and syndromes. Its presence may develop deformity and pain; however, often feet are pain free and the major worries of patients are cosmetics. Non-operative treatments aim to improve the comfort of metatarsal heads and the possible dorsal conflict through comfortable shoes or the use of specific orthotics. The surgical treatment is anything but straightforward, with "one-stage" or "two stage" techniques, the latter better called "by gradual distraction". One-stage procedures are more rapid techniques but have limited ability to restore the desired length due to neurovascular compromise caused by acute lengthening. Insufficient correction is also possible. On the contrary, by gradual distraction procedures allow gradual distraction lengthening of more than 1.5 cm, but require the use of an external fixator, with a higher risk of complications in more than about 50% of surgeries. The adjacent metatarsal shortening should be considered in combination with other techniques, to diminish the excessive lengthening. In each case, surgeries should be always decided on each patient's concerns, deformities, and clinical needs.

Brachymetacarpia and brachymetatarsia: do we need to operate?

Brachymetacarpia and brachymetatarsia are rare congenital presentations denoted by shortening of metacarpals and metatarsals respectively, in which the deformity usually presents around childhood/early adolescence.

The aetiology is usually congenital besides several other syndromic or endocrinologic associations.

Cosmetic issues such as absence of a normal-looking knuckle while making a fist or disruption of finger-tip curvature besides functional issues are the main indications for surgical intervention in brachymetacarpia.

In the foot, apart from cosmetic issues, pain due to transfer metatarsalgia as well as callosities along with toe deformities which lead to difficulty of using footwear are the main indications for intervention.

Lengthening of the affected bone, either acute with grafting or gradual, is the mainstay of treatment. Gradual lengthening can be either single-stage as in callotasis, or two-stage where the primary procedure is followed by bone grafting after the length has been achieved.

Adolescence, specifically between 12 and 15 years, is the preferred period for surgical intervention in these cases.

Cite this article: EFORT Open Rev 2021;6:15-23. DOI: 10.1302/2058-5241.6.200087

Long Term Result of Weil Osteotomy and Callotasis for Bilateral Brachymetatarsia: A Case Report

Introduction:

Brachymetatarsia can be treated by lengthening of the affected metatarsals or shortening of the normal neighboring metatarsals. Combination of the two methods may be more effective rather than using one skill due to less complications.

Case Report:

A 56-year-old female patient with the bilateral first, fourth-ray brachymetatarsia underwent Weil osteotomy of the second, third, fifth metatarsals, and callotasis of the fourth metatarsal. Follow-up examination had been carried out since the surgery was done about 10 years ago.

Conclusions:

In the decade after observation, the patient was very satisfied with the shape and function of the feet, and no complications occurred.

Shortening Scarf osteotomy for correction of severe hallux valgus. Does shortening affect the outcome?

BACKGROUND

Translation and shortening of Scarf osteotomy allows correction of severe hallux valgus deformity. Shortening may result in transfer metatarsalgia.

AIM

To evaluate outcome of patients undergoing shortening Scarf osteotomy for severe hallux valgus deformities.

MATERIALS AND METHODS

Fifteen patients (20feet, mean age 58 years) underwent shortening Scarf osteotomy for severe hallux valgus deformities. Outcomes were pre and postoperative AOFAS scores, IM and HV angles, patient satisfaction.

RESULTS

Mean follow-up was 25 months (range 22-30). The IM angle improved from a median of 18.60 (range 13.4-26.20) preoperatively to 9.70 (range 8.0-13.70) postoperatively (8.9; 95% CI=7.6-10.3; p<0.001). The HV angle improved from a mean of 43.2 (range 27.4-68.2) preoperatively to 13.6 (range 3.0-37.4) postoperatively (29.6; 95% CI=26.1-33.2; p<0.001). The median AOFAS score improved from 29.2 (range 14-60) preoperatively to 82.2 (range 55-100) postoperatively (53.0; 95% CI=48.0-58.5; p<0.001). All patients rated their satisfaction as either satisfied or very satisfied. None had symptoms of transfer metatarsalgia at final follow-up. All osteotomies united.

CONCLUSIONS

Shortening Scarf osteotomy is a viable option for treating severe hallux valgus deformities with no transfer metatarsalgia.

Distraction osteogenesis of fourth brachymetatarsia

BACKGROUND

Brachymetatarsia is a rare congenital or developmental condition that results in a short metatarsal. The condition most commonly affects the fourth metatarsal of young and adolescent females. It does not usually produce a functional problem. However, it may produce a significant cosmetic problem especially in young women. The authors present their experience in gradual distraction of the fourth metatarsal to tackle this problem in adults.

METHODS

That was done using a monolateral frame in 11 feet of female patients with an average age of 23 years. Evaluation depended upon the achievement of the target length, angulation, pain, and satisfaction of the patient.

RESULTS

There were eight excellent and three good results after an average follow up of 2.6 years. Aside from nine cases of mild pin-tract infection, complications were few and minor.

CONCLUSIONS

We recommend distraction osteogenesis as the treatment of choice for brachymetatarsia of the fourth toe.

Brachymetatarsia with accessory navicular in right foot: A rare coincidental finding

A 33 years old female patient presented with posttraumatic pain in the right foot for which radiographs of the right foot was advised. No fracture was detected on radiographs and patient was managed conservatively on medications and posterior splint immobilization. We found coincidentally a short fourth metatarsal and an accessory navicular bone in the right foot radiographs. After 3 weeks of immobilization, she underwent mobilization of the right foot, weight bearing and intensive physio- therapy for 6 weeks. After two months of injury she was still complaining of pain on the plantar aspect of right foot which was diagnosed as metatarsalgia and operated on by excision of the neuroma present in the 3rd web space of the right foot. After surgery she was completely relieved of pain and could do activities well related to the right foot.

Callus Distraction Versus Single-Stage Lengthening With Bone Graft for Treatment of Brachymetatarsia: A Systematic Review

Brachymetatarsia deformity is a cosmetically displeasing anomaly that can become physically symptomatic. The surgical techniques most commonly used to repair the anomaly include single-stage lengthening with a bone graft, callus distraction, or a combination of bone grafting and callus distraction. A systematic review of the published data was performed to compare the outcomes of these 3 surgical procedures. A total of 61 studies reporting the use of callus distraction or single-stage lengthening, or both, for the treatment of brachymetatarsia were included in the present review. The incidence of major postoperative complications after callus distraction, single-stage lengthening, and the combination procedure was 49 (12.62%), 13 (3.72%), and 3 (33.33%), respectively. The number of minor complications with callus distraction, single-stage lengthening, and the combination procedure was 152 (39.18%), 55 (15.76%), and 1 (11.11%); the mean percentage of the original length achieved was 37.36%, 25.98% and 36.00%; and the mean length achieved was 17.5, 13.2, and 14.0 mm, respectively. The healing index (mo/cm) and healing time was 2.31 and 16.04 weeks, 1.90 and 9.35 weeks, and 3.93 and 14.62 weeks for callus distraction, single-stage lengthening, and the combination procedure, respectively. Our findings indicate that the callus distraction technique is associated with greater length gained but results in greater complication rates and requires almost twice the time to heal. Single-stage lengthening with a bone graft was associated with fewer complications and faster healing times than callus distraction but with lesser gains in length. From the information reported in the studies we reviewed, the prevalence of bilateral brachymetatarsia was 44.52%, and the female/male ratio was 13.7:1. Both of these findings seem to contradict the usual data given (72% for bilateral brachymetatarsia and a female/male ratio of 25:1).

Lengthening scarf osteotomy for recurrent hallux valgus

BACKGROUND

We describe using the scarf osteotomy to correct a recurrent hallux valgus deformity and lengthen the shortened first metatarsal in symptomatic iatrogenic first brachymetatarsia.

METHODS

Thirty-six lengthening scarf osteotomies were undertaken in 31 patients. Clinical and radiographic measures were taken pre and postoperatively.

RESULTS

Mean age at presentation was 53.4 years, and mean followup 3.9 years. The mean lengthening achieved was 4.9mm. All osteotomies united with no complications. The mean IMA reduction was 4.0° (p<0.001) and HVA 13.0° (p<0.001). The mean AOFAS score increase was 33.8 (p<0.001). There was a positive trend but no correlation (r=0.28) between amount of metatarsal lengthening and AOFAS score change.

CONCLUSIONS

We describe the largest lengthening scarf osteotomy series for recurrent hallux valgus with iatrogenic first brachymetatarsia. The results suggest the procedure is successful, with a low complication rate. We anticipate that restoring first metatarsal length and alignment may reduce biomechanical transfer metatarsalgia over time.

Brachymetatarsia of the fourth metatarsal, lengthening scarf osteotomy with bone graft

A 16-year-old girl presented with left fourth metatarsal shortening causing significant psychological distress. She underwent lengthening scarf osteotomy held with an Omnitech^® screw (Biotech International, France) with the addition of two 1 cm cancellous cubes (RTI Biologics, United States). A lengthening zplasty of the extensor tendons and skin were also performed. At 6 weeks the patient was fully weight bearing and at one-year follow up, the patient was satisfied and discharged. A modified technique of lengthening scarf osteotomy is described for congenital brachymatatarsia. This technique allows one stage lengthening through a single incision with graft incorporation by 6 weeks.

Metatarsal lengthening by callotasis in adults with first brachymetatarsia

BACKGROUND

Brachymetatarsia is a rare clinical entity that presents a challenging problem for surgeons. One-stage lengthening with an autologous bone graft has been preferred for metatarsals that require a limited lengthening. With a gradual lengthening of metatarsals, callus distraction (callotasis) can achieve a greater length gain and a concomitant lengthening of the soft tissue. This article presents results of callotasis for adults with first brachymetatarsia.

METHODS

The outcomes of nine cases of first brachymetatarsia in five adult patients who underwent metatarsal lengthening by callotasis between March 1999 and February 2005 were retrospectively reviewed and analyzed.

RESULTS

The average length gain was 16.4 mm and the average lengthening percentage was 43.7%. In addition, the average healing index was calculated as 3.8 months/cm, which was higher than that reported previously in the fourth brachymetatarsia.

CONCLUSION

It was concluded that the period of bony consolidation following callotasis is longer in the first brachymetatarsia than in the fourth brachymetatarsia. Presumably, this might be because of the anatomically larger osteotomized cut surface and its weight-bearing function.

Correction of longitudinal epiphyseal bracket disease with external fixation: a case report with 6-year follow-up period

Longitudinal epiphyseal bracket disease is a rare congenital abnormality of the tubular bones. This syndrome eventually leads to progressive shortening and angular deformity of the involved bone. When longitudinal epiphyseal bracket disease affects the first metatarsal, a short trapezoidal shaped metatarsal is noted radiographically. We present the case of a 9-year-old patient with longitudinal epiphyseal bracket disease of the first metatarsal. The abnormality was surgically treated by bracket osteotomy with callus distraction before physeal closure. At 6 years of follow-up, the patient displayed a relatively normal looking cosmetic foot compared with the contralateral foot. A mild residual hallux varus was noted, with maintenance of the forefoot parabola. Surgical correction resulted in alteration of the first intermetatarsal angle and the first metatarsophalangeal angle. The first intermetatarsal angle decreased from a preoperative value of -30° to a postoperative value of 10°. The first metatarsophalangeal angle decreased from a preoperative value of 36° of hallux varus to a postoperative value of 4°. The length of the first metatarsal was restored compared with that of the contralateral limb and was slightly elongated. The present case study demonstrates that early surgical correction with callus distraction of an ossified abnormal bracket before physeal closure, a relatively simple procedure, can restore longitudinal growth and correct the angular deformity.

Comparison of the outcomes of distraction osteogenesis for first and fourth brachymetatarsia

BACKGROUND

Brachymetatarsia is the presence of an abnormally short metatarsal, and distraction osteogenesis has been used for its treatment. The purpose of the present study was to compare the outcomes of patients who underwent distraction osteogenesis for the treatment of first and/or fourth brachymetatarsia.

METHODS

The data from forty-eight patients (sixty-four feet, seventy-four metatarsals) who underwent distraction osteogenesis for the treatment of brachymetatarsia were reviewed. The indications for surgery included a metatarsal that was at least 10 mm shorter than the adjacent metatarsal and that had an unacceptable cosmetic appearance. The study group comprised thirty-two first brachymetatarsia in nineteen patients (Group A) and forty-two fourth brachymetatarsia in twenty-nine patients (Group B). The average age was twenty years in Group A and eighteen years in Group B. The average duration of follow-up was 58.1 months in Group A and 56.1 in Group B. Metatarsal length, lengthening gain, healing time and index, and the American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal and lesser metatarsophalangeal-interphalangeal scores were evaluated.

RESULTS

All patients were satisfied with the final length of the metatarsal and all had achieved bone union at the time of the last follow-up. The mean lengthening gain was 17.2 mm (42.9%) in Group A and 16.3 mm (37.3%) in Group B. The mean healing index was 71.0 days/cm in Group A and 67.3 days/cm in Group B. The mean American Orthopaedic Foot and Ankle Society score was 91.2 points in Group A and 92.8 points in Group B at the last follow-up (twenty-two excellent, nine good, and one fair results in Group A, and twenty-nine excellent, eleven good, and two fair results in Group B). The most common complication was metatarsophalangeal joint stiffness, which occurred in thirteen rays in Group A and in twelve rays in Group B; malalignment of the lengthened metatarsal was observed six times in each group. No significant intergroup differences in the outcomes were found.

CONCLUSIONS

Distraction osteogenesis for first and/or fourth brachymetatarsia provided successful lengthening of a metatarsal with eventual osseous union and was associated with similar outcomes in terms of healing index, function score, and the prevalence of complications between the two groups, although frequent complications were encountered and no improvement in foot function was found.

A modified surgical technique for lengthening of a metatarsal using an external fixator

Brachymetatarsia is a congenital or developmental condition that results in a short metatarsal. Problems that arise from this condition can include pain, difficulty with shoe wear, and cosmetic concerns. Multiple techniques have been described that successfully correct the deformity, including both acute and gradual distraction. We describe a modification of the technique of gradual lengthening by way of distraction osteogenesis in which an axial transarticular K-wire is incorporated into a monolateral frame, thereby increasing the stability of the construct and potentially minimizing complications.

One-stage metatarsal lengthening by allograft interposition: a novel approach for congenital brachymetatarsia

BACKGROUND

Congenital brachymetatarsia, a shortened metatarsal bone, can be corrected surgically by callus distraction or one-stage lengthening using bone graft.

QUESTIONS/PURPOSES

We asked whether one-stage metatarsal lengthening using metatarsal homologous bone graft could improve forefoot function, lead to metatarsal healing, restore metatarsal parabola, and improve cosmetic appearance.

PATIENTS AND METHODS

We retrospectively reviewed 29 patients (41 feet) in whom we lengthened 50 metatarsals. Surgery consisted of a transverse proximal osteotomy of the metatarsal shaft and interposition of a metatarsal homologous bone graft (average, 13 mm long) fixed with an intramedullary Kirschner wire. Minimum followup was 3 years (mean, 5 years; range, 3-11 years).

RESULTS

Bone union was achieved in all cases. The mean preoperative American Orthopaedic Foot and Ankle Society score was 37 points (range, 28-53 points) and the mean postoperative score was 88 points (range, 74-96 points), with an average improvement of 51 points. Radiographically, the mean gain in length was 13 mm (range, 10-15 mm), and the mean percentage increase was 23%.

CONCLUSIONS

One-stage metatarsal lengthening using interposition of metatarsal homologous bone graft to correct congenital brachymetatarsia has low morbidity for the patient, limited complications, short recovery times, and restores forefoot anatomy.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The versatility of the Lapidus arthrodesis

Lapidus Arthrodesis is probably the most versatile procedure of the foot and ankle surgeon. The procedure was conceived initially for the surgical treatment of met primus adductus associated with hallux valgus, but has also been used for the treatment of a variety of other conditions including hallux limitus, revision bunion surgery, medial column stabilization, and others. Although the use of the Lapidus in bunion surgery is well supported in the literature, surgeons have been expanding its indications to manage a variety of disorders affecting the foot. As more surgeons continue to gain experience with the procedure, additional studies will emerge, further supporting its versatility in the realm of foot surgery.

How to avoid complications of distraction osteogenesis for first brachymetatarsia

BACKGROUND AND PURPOSE

Distraction osteogenesis may be used for the treatment of brachymetatarsia. However, few reports have been published on first metatarsal lengthening by this method. We evaluated the complications of distraction osteogenesis for first brachymetatarsia and here we provide a solution.

PATIENTS AND METHODS

16 patients (27 feet) underwent distraction osteogenesis for first brachymetatarsia. Mean age at time of surgery was 20 (12-34) years and mean duration of postoperative follow-up was 5 (2-13) years. A unilateral external fixator was fixed at the medial aspect of the metatarsus. The distraction axis was parallel to the plantar surface of the foot in the sagittal plane and to the second metatarsal axis in the transversal plane.

RESULTS

First metatarsal length expressed as a proportion of second metatarsal length was 60% (55-64). Average degree of metatarsal lengthening was 42% (34-54), and the average lengthening index was 64 (39-93) days/cm. The most common complication was stiffness of the metatarsophalangeal joint (12 feet). Deformities that included cavus foot and hallux valgus occurred in 3 feet each, and callus fractures occurred in 3 feet. The other complications were pin breakage and pin tract infection in 2 feet each.

INTERPRETATION

Distraction osteogenesis for first brachymetatarsia can give satisfactory cosmetic and functional results. However, several complications are commonly encountered. This report on complications and their solutions may help those attempting distraction osteogenesis for first brachymetatarsia.

Metacarpal lengthening by distraction histiogenesis in adults

BACKGROUND

Metacarpal lengthening in the hand is a new application for distraction neo-histiogenesis. Metacarpal lengthening with distraction helps in improvement in pinch function. Thumb lengthening is technically easy in comparison to other metacarpals. We present the operative treatment and post-operative outcome in nine patients with amputations and congenital anomalies.

MATERIALS AND METHODS

Nine patients underwent distraction osteogenesis for the treatment of amputations of the hand and other congenital anomalies. The dominant right hand was operated in eight cases and the left hand in one case. There were six males and three females. Improvement of function was always the aim of surgery. Age range was between 18 and 23 years. Thumb lengthening was performed in five patients and that of the index finger in four patients. Distraction started on the fifth post-operative day at the rate of 0.25 mm/day. Sensory function and bone consolidation was assessed before fixator removal.

RESULTS

The mean duration of distraction was 51 days (range, 42-60 days) and the distractor was removed at a mean of 150 days (range, 140 and 160 days) and the bones were lengthened by a mean of 24 mm (range, 20-28 mm) There was improvement of function in all cases.

CONCLUSION

The metacarpal lengthening by distraction histiogenesis in congenital and traumatic amputations is safe and simple method to improve pinch function of hand.

Lengthening of the first metatarsal through an arthrodesis site for treatment of brachymetatarsia: a case report

Brachymetatarsia of the first metatarsal is an uncommon condition, but one that is amenable to treatment by lengthening via distraction osteogenesis, a process that employs 2 groups of pins of an appropriate external fixator inserted in the metatarsal to apply gradual distraction across an intervening osteotomy. We present the case of a female, aged 13 years, who presented with congenital bilateral first brachymetatarsia and left foot pain due to transfer metatarsalgia. The short and plantarflexed first ray could not accommodate both groups of fixator pins, even with the fixator set at its shortest length. An alternative strategy was devised that reduced the degree of plantarflexion using a tarsometatarsal arthrodesis, which effected subsequent lengthening through the healing fusion site. Lengthening commenced after 10 days and continued over a period of 52 days, at a rate of 0.5 mm to 1.0 mm per day. Consolidation occurred at 20 weeks with a final increase in length of 25 mm. The patient returned to vigorous sporting activity 1 year after removal of the fixator. To our knowledge, this is the first account of a metatarsal-lengthening arthrodesis at the tarsometatarsal level.

Restoration and preservation of first metatarsal length using the distraction scarf osteotomy

The authors reviewed the records of 8 patients who underwent a distraction scarf osteotomy of the first metatarsal, and report the radiographic outcomes achieved with this procedure. The osteotomy was used to reestablish or maintain the length of the first metatarsal, without the use of a structural bone graft. The osteotomy was used as part of a revisional procedure for a failed bunionectomy in 4 patients. In the remaining patients, the procedure was used to preserve the length of the first metatarsal in conjunction with a Lapidus arthrodesis. The first and second metatarsals were measured radiographically, and the length of the first metatarsal was expressed as a percentage of the length of the second metatarsal. The average proportional increase in first metatarsal length obtained in the patients undergoing correction of the shortened first metatarsal was 7.08%, and the difference between the pre- and postoperative length of the first metatarsal was statistically significant (P = .0013) in these patients. Relative shortening of the first metatarsal was avoided in those patients undergoing distraction scarf osteotomy in conjunction with Lapidus arthrodesis. ACFAS Level of Clinical Evidence: 4.

Distraction osteogenesis for the shortened metatarsal after hallux valgus surgery

BACKGROUND

Shortening of the first metatarsal is known to occur during hallux valgus surgeries. If the shortened first ray disrupts the normal weight transfer, then transfer metatarsalgia may result. After failed conservative treatment, a common operative option is an osteotomy of the lesser metatarsals. However, osteotomies of normal metatarsals further alter the normal anatomy and can significantly shorten the forefoot. Restoration of first metatarsal length using distraction osteogenesis may more closely restore normal foot anatomy and biomechanics and subsequently treat transfer metatarsalgia.

METHODS

Five patients had distraction osteogenesis for a shortened first metatarsal that resulted from a previous hallux valgus surgery. A four-pin single-plane external fixator was applied to the first metatarsal to lengthen the metatarsal under the principles of distraction osteogenesis. Lengthening was complete once the affected first metatarsal was equal to the length of the adjacent second metatarsal.

RESULTS

The mean consolidation period was 15.8 weeks. Preoperative and postoperative length of the first metatarsal was expressed as a percentage of the length of the ipsilateral second metatarsal. The preoperative mean was 77.1% and the postoperative mean was 93.8%. All osteotomies went on to consolidation, and no grafting or secondary procedures were needed. There were no postoperative infections, malrotation, or malalignment. All patients reported reduction in their forefoot pain and returned to a nonantalgic, full weightbearing gait.

CONCLUSIONS

This small series depicts the potential success of distraction osteogenesis for the iatrogenically shortened first metatarsal and associated transfer metatarsalgia.

Effect of first metatarsal shortening and dorsiflexion osteotomies on forefoot plantar pressure in a cadaver model

BACKGROUND

Metatarsalgia of the second ray is a common problem associated with disorders of the first metatarsal. It also occurs after the operative treatment of those disorders. Plantar pressure changes from alteration of the static and dynamic structure of the forefoot may be associated with this condition. This study evaluated changes in plantar forefoot pressure especially under the second metatarsal head after three operative procedures on the first ray.

METHODS

Each of 12 cadaver foot specimens was cyclically loaded on the servohydraulic MTS Mini Bionix test frame (MTS Systems Corp., Eden Prairie, MN) with traction on the Achilles tendon. Plantar forefoot pressure was measured by the F-scan system (Tekscan, Inc., S. Boston, MA) with the foot intact, after a first metatarsal base dorsal closing-wedge osteotomy with 5-mm base length to simulate dorsal malunion, and after 5-mm and 10-mm metatarsal shortening procedures. Paired Student t-test analysis was used to compare data for the intact foot with data after each intervention. One form of Bonferroni's correction was done to establish a new alpha level to tighten the analysis and to compensate for multiple paired Student t-tests. The significance level was calculated to be 0.016 based on an original alpha level of 0.05.

RESULTS

As compared with the intact foot, all three procedures on the first metatarsal resulted in significant decreases in plantar pressure under the first metatarsal head (p < 0.016). Plantar pressure under the second metatarsal head increased significantly as compared with the intact foot (p < 0.016) after all three procedures. Pressures under the third-fourth metatarsal heads increased significantly compared with the intact foot after the 5-mm and 10-mm shortenings (p < 0.016). Plantar pressure under the fifth metatarsal did not change significantly after any of the three procedures.

CONCLUSIONS

Dorsiflexion osteotomy and shortening of the first metatarsal are associated with significant forefoot plantar pressure changes in a cadaver model.

Complications of distraction osteogenesis in short first metatarsals

The authors analyzed the results and complications of metatarsal lengthening in short first metatarsals by distraction osteogenesis. There were 13 first metatarsal lengthenings in eight patients. Mean age was 18.8 years and the average percentage of lengthening was 49.2%. The average healing index was 72.4 days/cm. The major complication was cavus foot, which was noticed in four feet. All great toes showed some loss of motion at metatarsophalangeal (MP) joint. Other complications were hallux valgus, angulation of the metatarsals, and pin tract infection each in two feet. The functional score according to the American Orthopedic Foot and Ankle Society (AOFAS) hallux MP joint, interphalangeal joint scale was excellent in 11 and good in 2. All patients were satisfied with the procedure. To avoid potential complications such as MP joint subluxation, cavus foot, and hallux valgus, the first metatarsal lengthening should not exceed 50% of the original length.

Management of soft tissue deficiency of the hallux: salvage in trauma, diabetes, and following surgical complications

Loss of the hallux can lead to significant gait problems and cause difficult biomechanical problems with weight bearing. Amputation of the first ray should be avoided when possible. Soft tissue defect of the hallux can be particularly difficult to manage because of the absence of local muscle tissue for coverage. In younger patients, soft tissue loss usually is related to trauma; an understanding of the techniques that are available for coverage are important to maintain length and function of the first ray. Diabetic neuropathy and resultant ulceration of the hallux or metatarsophalangeal joint is another common cause of soft tissue deficiency that may lead to deep infection and potentially result in amputation. Certain systemic problems, such as inflammatory diseases or gout, can cause significant degeneration of the local tissues which also can be problematic. Wound dehiscence or loss of skin flaps that are created during surgery represent further difficulties that may be encountered. This article reviews the common causes of amputation of the hallux and the principles that are necessary for salvage of the digit.

Distraction osteogenesis in the Cbfa-1+/- mouse

Distraction osteogenesis involves division of a bone and gradually pulling the bone ends apart. This delivers mechanical stimulation to mesenchymal cells in the distraction gap, where new bone is regenerated predominantly by intramembranous ossification. The transcription factor Cbfa1 has been reported to be essential for the differentiation of mesenchymal cells to osteoblasts. In homozygous Cbfa1 knockout mice, both intramembranous and endochondral ossification mechanisms are blocked and no bone formation occurs. In heterozygous Cbfa1 knockout mice, only the cranial bones and the clavicles, which form through intramembranous ossification, fail to develop properly as in the human condition of cleidocranialdysostosis. It has been suggested, therefore, that intramembranous ossification is affected by the absence of one of the paired Cbfa1 genes. We have assessed the potential for intramembranous ossification following distraction osteogenesis in heterozygous Cbfa1 knockout mice. Fourteen skeletally mature male heterozygous mice were used, together with 10 wild-type controls. The tibia was distracted by 0.25 mm twice a day (0.5 mm/day) for 10 days using the half-ring type fixator. Nine mice were kept for a further 28 days to observe the consolidation phase. In four out of five mice of the heterozygous group and in all three wild-type mice, bony fusion within the distraction gap was observed on radiographs. Histological findings were almost the same in the two groups at various stages of the procedure and intramembranous ossification was predominant in both the groups. Despite the inhibition of intramembranous ossification during the foetal development of Cbfa1+/- mice, distraction osteogenesis was as successful as in control mice.

Brachymetatarsia

Brachymetatarsia is a rare clinical entity that presents a complicated case to the treating surgeon. One-stage lengthening procedures with a variety of biologic and synthetic implants are preferred for metatarsals that only need to be lengthened up to 15 mm, whereas gradual lengthening allows for greater length gain and concomitant lengthening of the soft tissues. Adjacent metatarsal shortening may be used in conjunction with lengthening procedures to restore the parabolic arc of the metatarsal heads. Management should be tailored to the patient's individual deformity and expectations. Individualization of surgical techniques and patient selection criteria can result in a cosmetic, functional result that is satisfactory to the clinician and the patient.

Fourth brachymetatarsia treated with distraction osteogenesis

BACKGROUND

This study investigated metatarsal lengthening by distraction osteogenesis for fourth brachymetatarsia in 22 metatarsals (16 patients).

METHODS

From May 1997 to May 2000, lengthening was performed with a monoexternal fixator, and distraction was started at a rate of 0.5 mm per day after a latency period of approximately 7-10 days.

RESULTS

The average gain in length was 16.5 mm (range, 13-21 mm), equivalent to an increase of 39% (range, 28-51%), and the average healing index was 72.9 days/cm (range, 51.7-95.7 days/cm). The American Orthopaedic Foot and Ankle Society (AOFAS) average score for lesser toe was 86.3 (range, 47-100). The most common residual complication was subluxation of metatarsophalangeal (MTP) joint in five cases, with partial or total stiffness of the MTP joint. These complications happened in the group of metatarsals excessively lengthened more than 40% and made the AOFAS score poorer. The other complications were three cases of angular deformity in the lengthened bone, and two cases of pin-tract infection.

CONCLUSION

Although distraction osteogenesis is an effective method to address fourth brachymetatarsia, stiffness or subluxation of the MTP joint was not uncommon. To avoid complications that can happen as a result of excessive lengthening, careful preoperative radiographic measurement to calculate the optimal amount of lengthening may help us to avoid overlengthening and the complications that accompany it.

External fixation indications and patient selection

Since its modest beginnings in the mid-nineteenth century, external fixation has seen great changes in its design and application. Once thought of as chiefly a fracture management tool, this modality has found its way into the arenas of corrective osteotomies, Charcot management, limb lengthening, nonunion treatment, and malalignment correction. As external fixation has evolved, great improvements in associated complications have also occurred. This is attributed to evolving frame design, subsequent increased stability, and advances in pin/wire insertion techniques. Paley and Herzenberg describe three factors to consider when evaluating whether to use external or internal fixation [2]. 1. Risk versus benefit of the method used for that specific indication. 2. Surgeon's experience with the specific method. 3. Ability to treat the potential complications of the surgery. The authors agree with these factors but would also include psychological tolerance, compliance with postoperative self-treatment, and personal hygiene. In this article the indications for external fixation were described in terms of pathology and individual patient factors were discussed for the surgeon's consideration. The surgeon must consider the patient's bone quality, age, cognitive ability, psychological tolerance, and compliance level. With these factors kept in mind and evaluated appropriately, the surgeon should be able to select the patient and indications for which external fixation will yield a superior result.

Forefoot applications of external fixation

The use of external fixation in foot and ankle surgery has steadily increased with the advent of devices geared toward the foot and ankle that have evolved over the past decade, as well as a greater understanding of the indications and advantages of external fixation. The application of external fixators in the forefoot may at first glance seem both limited and possibly overkill, but once the basics of external fixation and the types of devices available are understood the options for use become numerous.

Bone-lengthening for symbrachydactyly of the hand with the technique of callus distraction

BACKGROUND

Bone-lengthening in the hand and foot is a relatively new application for distraction osteogenesis. We present the operative treatment and postoperative outcome for four patients with M ller type-D symbrachydactyly of the hand who underwent metacarpal lengthening with use of a distraction device to establish pinch function.

METHODS

Four patients who underwent distraction osteogenesis for the treatment of congenital symbrachydactyly of the hand were evaluated over a thirteen-year period. The nondominant right hand was treated in two patients, and the nondominant left hand was treated in the other two. The patients included three boys and one girl; all patients had the operation between the ages of five and eleven years. Distraction osteogenesis was performed on the fifth metacarpal in one patient and on the fourth and fifth metacarpals in the remaining three, in whom both bones were lengthened simultaneously with use of a single device. Postoperative bone elongation was analyzed with radiographs made at the time of removal of the distractor. The sensory function of the treated fingers and any growth disturbance of the distracted bones were evaluated.

RESULTS

The mean duration of distraction was 37.3 days (range, thirty-two to forty-nine days), and the distractor was removed at a mean of eighty-four days after surgery. The bones were lengthened by a mean of 22.3 mm (81.6% of their original length) at a rate of 0.6 mm/day. Pinch function was improved in all patients.

CONCLUSIONS

On the basis of our limited experience, we found that distraction osteogenesis of the metacarpals was an effective technique for the establishment of pinch function. We also found that an intramedullary Kirschner wire could maintain the alignment of the osteotomized bone. Although distraction requires a longer treatment period, it is apparently more effective than bone-grafting in terms of achieving adequate bone length. Simultaneous lengthening of two metacarpals also was found to be an effective technique.

Metatarsal lengthening

Metatarsal lengthening for brachymetatarsia is a good procedure that can improve appearance and function. There are risks to these procedures, which should be understood thoroughly.

A murine model of distraction osteogenesis

Distraction osteogenesis is both a valuable clinical technique and a useful tool for investigating the basic mechanisms involved in bone tissue regeneration. Here we describe the development of a murine model of this procedure that can be used in transgenic animals to investigate the role of specific genes in tissue regeneration. Ring fixators were applied to the lower leg of 12 normal adult male mice. An osteotomy was made in the diaphysis of the tibia, and 7 days after the operation the bone fragments were distracted by 0.25 mm twice a day for 10 days. Specimens were examined immediately at the end of distraction and after 14-70 days of consolidation. At the end of distraction, the distraction gap was filled with fibroblast-like cells arranged longitudinally. After 14 days of consolidation, there was radiographical evidence of bone formation in the distraction gap and, after 28 days of consolidation, the bone fragments were fused with regenerated bone. By 70 days of consolidation, the regenerated bone had been almost completely remodeled and the intramedullary canal reestablished. This study is the first to report consolidation of the distraction gap with regenerated bone in a murine model of distraction.

Changes in blood flow during one stage lengthening of bone: an experimental study in rats

Distraction osteogenesis is a well-accepted method of bone lengthening. Its disadvantages, however, are that it requires an external fixator and takes a long time. One-stage lengthening therefore offers certain advantages. A first point of reference for the safe limits of this procedure might be the changes of blood flow, and this is also the crucial factor in deciding on the appropriate method of lengthening, particularly where the hand or foot is involved. Using a laser Doppler flowmeter we measured blood flow in the dorsum of the foot after using bilateral minimonofixators to lengthen the tibias of 15 Sprague-Dawley rats. They were lengthened in four stages: stage 0 (before lengthening); stage I--12.5%; stage II--25%; and stage III--31.25% of lengthening. The blood flow during stage I decreased to 79% compared to that of stage 0; 16% during stage II; and 1% during stage III. This study suggests that the maximal permissible extent of lengthening might be less than a quarter according to the blood flow as suggested by this animal model.

Brachymetatarsia: congenitally short third and fourth metatarsals treated by distraction lengthening--a case report and literature summary

Brachymetatarsia is an uncommon condition, and when present, it is usually asymptomatic. A case report demonstrating the use of distraction lengthening for symptomatic multiple congenital short metatarsals is presented. A 15-year-old female with congenital short third and fourth metatarsals was treated for painful transfer lesions under the second and fifth metatarsal heads and a secondary hallux valgus deformity. Surgical correction with a chevron osteotomy, soft tissue reconstruction of the second toe, and distraction lengthening of the third and fourth metatarsals was performed. Three years after treatment, the patient has an excellent clinical correction, with no evidence of recurrent transfer lesions. To our knowledge, this is the first report demonstrating the use of distraction lengthening without supplemental bone graft for multiple short metatarsals in a single extremity.