Posteromedial Bowing Research Articles

Lengthening in congenital posteromedial bowing of tibia: a follow-up series at skeletal maturity.

Congenital posteromedial bowing (CPMB) of tibia is a rare, usually self-resolving condition that is present at birth. The data on the long-term outcome of lengthening, choice of fixator, outcome in early and late age groups, and complications is sparse, hence the need for this study. This retrospective study included 93 patients with 94 affected legs from 1991 to 2023. The patients were categorized into early (under 10years) and late (10years or above) intervention groups. Eighteen patients with nineteen lengthening episodes who attained skeletal maturity made the basis of this study and will be discussed in detail. The outcome for the lengthening group at maturity was satisfactory, with 5.53cm of average length gained per lengthening episode, a mean LLD of 0.31cm at final follow-up, a mean age of 23.63years (range 14-38years), and an average follow-up of 12.51years (range 3-28years) post-lengthening, but the procedure was associated with difficulties like ankle stiffness, tibial valgus, pin tract infections, and fractures through regenerate. This study represents a large single-centre series on CPMB. We recommend that surgery for lengthening should be done at an older age, close to skeletal maturity, wherever possible to reduce the risk of repeat lengthening procedures. Based on our experience, we recommend the use of a circular fixator. Uniplanar distractors should have an adequate number and spread of Schanz screws in each segment to reduce the risk of valgus malalignment of distracting segments of bone.

The Association Between Congenital Posteromedial Bowing of the Tibia and Developmental Dysplasia of the Hip

The Association Between Congenital Posteromedial Bowing of the Tibia and Developmental Dysplasia of the Hip

Congenital unilateral posteromedial bowing of tibia in an adolescent: A rare presentation of tibial bowing

Congenital unilateral posteromedial bowing of tibia in an adolescent: A rare presentation of tibial bowing

Evolution of the angular deformity and limb length discrepancy of congenital posteromedial bowing of the tibia over time

This study aims to assess the natural history of congenital posteromedial bowing of the tibia (CPMBT) deformity during growth and to evaluate the outcomes of lengthening by an Ilizarov frame in CPMBT patients with limb length discrepancy (LLD). Between January 2000 and December 2019, a total of 22 patients (12 males, 10 females; mean age: 10.5±4.4 years; range, 6 to 19 years) with the diagnosis of CPMBT and followed closely from birth until skeletal maturity were retrospectively analyzed. The radiographic evaluation included the anteroposterior and lateral interphyseal angle and full leg standing radiographs. Limb lengthening by an Ilizarov frame was performed for an estimated LLD over 40 mm. The age of the patients ranged from six days to 10 months at the time of presentation, while the mean age at the final follow-up was 10.5±4.4 years. Posterior medial bowing was satisfactorily remodeled in 13 (59%) patients those were not operated either for deformity or LLD. The mean LLD was 21±4.1 mm in 13 nonoperated CPMBT patients. Nine of 22 (41%) patients underwent lengthening for LLD. Five of the nine CPMBT patients were operated under the age of 10 years, while four were operated over the age of 10 years. According to the results of the current study, CPMBT was satisfactorily remodeled in more than half of the patients, and the majority of patients did not undergo surgery for angular deformity and LLD within 10 years of their lives. Based on these findings, although most of the patients' deformities remodeled, it should be kept in mind that some may require lengthening surgery.

Congenital Posteromedial Bowing of Tibia: Comparison of Early and Late Lengthening.

Congenital posteromedial bowing of tibia (CPMBT), a rare anomaly, is characterized by a decreasing deformity and a gradually increasing limb shortening. Lengthening in CPMBT has not been studied extensively. Our series compares the duration and complications of lengthening in younger versus older children to determine early lengthening safety and benefits. We studied 28 tibial lengthenings performed by a single surgeon in 23 patients, divided into 2 equal groups of 14 segments: group A 5 years or younger (preschool) and group B above 5 years. All were lengthened with circular external fixators, of which 3 were lengthened over a nail. We measured preoperative (bo) and postoperative (po) sagittal, coronal, and oblique plane deformities, initial limb length discrepancy (LLD), percentage LLD (% LLD), amount of lengthening (AmtL), percentage lengthening (%L), external fixator duration (EFD), and external fixator index (EFI). We graded complications by Lascombes' criteria, results by Association for the Study and Application of the Methods of Ilizarov bone score. The mean age was 8.8±7.1 years; the mean follow-up was 7.9 years. Group A had significantly greater bo-sagittal, coronal, and oblique plane deformities. Mean LLD (3.4 cm in group A vs. 4.1 cm in group B) was similar in both. Expected LLD at maturity (LLDM) using the multiplier method was greater than previously reported (mean, range in group A: 7.2 cm, 4.4 to 9.5 cm; group B: 5 cm, 2.5 to 9.7 cm). Though AmtL (3.5 and 4.1 cm) was similar in both, %L was 24% in group A and 15.7% in group B (P=0.002). EFD (116.6 days) and EFI (33.7 days/cm) were lesser in group A compared with group B (200.3 days, P=0.001; 50.2 days/cm, P=0.01). Lascombes' triple contract was fulfilled in 11/14 lengthenings in group A versus 3/14 in group B. Association for the Study and Application of the Methods of Ilizarov bone score was good and excellent in both groups (P=0.44). In a large series of lengthenings in CPMBT, we found younger children presenting with large deformities and large projected length discrepancies could be safely lengthened with significantly lesser EFD and complications than in older children. Level IV-therapeutic study.

Limb lengthening in the treatment of posteromedial bowing of the tibia.

PurposePosteromedial bowing of the tibia is an uncommon but recognized congenital lower extremity deformity in children that can lead to limb length discrepancy (LLD) and residual angulatory deformity. The purpose of this study is to report a series of children at a single institution with posteromedial bowing treated by lengthening.MethodsA retrospective review was carried out at our institution identifying 16 patients who were treated with limb lengthening for posteromedial bowing of the tibia and followed to skeletal maturity. Projected LLD was a mean of 7.7 cm (range 5.0 cm to 14.2 cm). Three patients were treated in a staged fashion with lengthening and deformity correction at age three to four years and subsequent definitive tibial lengthening. The remaining 13 patients were treated with limb lengthening approaching adolescence using circular external fixation.ResultsAll patients were pain free and ambulated without a limp at final follow-up. The mean final LLD was 0.3 cm short. In spite of correction of distal tibial shaft valgus in 11 of the 16 patients, eight of the 16 (50%) required later correction of persistent, symptomatic ankle valgus by either hemiepiphyseodesis (seven patients) or osteotomy (one patient).ConclusionsChildren with posteromedial bowing of the tibial with projected LLD over 5cm can be effectively treated with lengthening. Patients with severe valgus of more than 30° of shaft valgus and difficulty ambulating at age three years can be successfully treated with a two-stage lengthening procedure. Attention should be paid in patients with posteromedial bowing to ankle valgus.Level of EvidenceIV

Deformity progression in congenital posteromedial bowing of the tibia: a report of 44 cases

Backgroundcongenital posteromedial bowing of tibia (CPMBT) is a very rare birth defect, characterized by shortened bowed leg and ankle deformity. We described a single institution experience in the management of CPMBT.Methodswe identified 44 CPMBT in 44 children. The age at presentation was 5.5 ± 5.6 years and the mean age at the final review was 10.1 ± 4.8 years. Radiographic evaluation included the antero-posterior and lateral inter-physeal angle (AP-IPA and L-IPA), the limb length discrepancy (LLD), the morphology of the distal tibia and the lateral distal tibial angle (LDTA). During the study period, 26 children underwent surgical treatment.Resultsthe estimated curves showed a progressive spontaneous correction of both AP-IPA and L-IPA during growth, but a progressive increase of the LLD. The L-IPA showed a more predictable behaviour while the AP-IPA showed a scattered correction, with a wider variation of the estimated final angle. The final LDTA was 85.3° ± 4.2° and was correlated with the L-IPA (r = 0.5; p = 0.02).Among the 26 children who underwent surgical treatment, 23 cases had limb lengthening, 1 case had contralateral epiphysiodesis, 1 child underwent tibial osteotomy, 1 patient was treated by hemiepiphysiodesis of the distal tibia to correct ankle valgus deformity.Conclusionsour study described the largest case series of CPMBT. A combination of surgical treatments, in a staged surgical process, should be tailored to the developmental characteristics of this abnormality. An experience-based algorithm of treatment is also proposed. Further studies are needed to understand which is the best strategy to correct this deformity during childhood.Level of evidencelevel IV prognostic study.

Congenital angular deformities of the leg: Case series

Congenital angular deformities of tibia are uncommonly seen. Posteromedial bowing is more uncommon than anterolateral bowing. Anterolateral bowing is more discussed due to its association with pseudarthrosis and neurofibromatosis. Posteromedial bowing may get partially corrected with growth up to 4 years of age. The case series describes two cases of posteromedial bowing and one case of anterolateral bowing in both legs due to its rarity and to stress the need of regular follow-up.

Posteromedial bowing of the tibia: a benign condition or a case for limb reconstruction?

PurposeTo review the initial deformity and subsequent remodelling in posteromedial bowing of the tibia and the outcome of limb reconstruction in this condition.Patients and MethodsIn all, 38 patients with posteromedial bowing of the tibia presenting between 2000 and 2016 were identified. Mean follow-up from presentation was 78 months. A total of 17 patients underwent lengthening and deformity correction surgery, whilst three further patients are awaiting lengthening and deformity correction procedures.ResultsThe greatest correction of deformity occurred in the first year of life, but after the age of four years, remodelling was limited. The absolute leg-length discrepancy (LLD) increased throughout growth with a mean 14.3% discrepancy in tibial length. In the lengthening group, mean length gained per episode was 45 mm (35 to 60). Mean duration in frame was 192 days, with a mean healing index of 42.4 days/cm. Significantly higher rates of recurrence in LLD were seen in those undergoing lengthening under the age of ten years (p = 0.046). Four contralateral epiphysiodeses were also performed.ConclusionPosteromedial bowing of the tibia improves spontaneously during the first years of life, but in 20/38 (53%) patients, limb reconstruction was indicated for significant residual deformity and/or worsening LLD. For larger discrepancies and persistent deformity, limb reconstruction with a hexapod external fixator should be considered as part of the treatment options.Level of evidenceLevel IV (Case series)

ARE WE STILL MISDIAGNOSING CLUBFOOT? A STUDY OF NON-CLUBFOOT CASES LABELED OR REFERRED AS CLUBFOOT FROM PRIMARY CARE CENTERS IN UTTARAKHAND

Background: Clubfoot is a congenital disorder identifiable with the clinical assessment itself, provided the knowledge of key features is sound. Several disorders affecting the foot and lower limb that present with crooked or bent anatomy may be confused with it. Knowledge of common disorders that mimic clubfoot in a particular region is thus important to adequately distinguish, manage or refer the case to specialist opinion. Objectives: The current study attempts to provide an overview and documentation of the conditions referred and labeled as clubfoot from primary care facilities, the knowledge of which is important so that appropriate treatment is given to each. The findings will reflect lacunae in the knowledge and perception of primary healthcare workers regarding the deformity. Materials and Methods: A retrospective assessment of all cases referred to our dedicated clubfoot clinic with a diagnosis of clubfoot by peripheral health-care facility was done from September 2016 to October 2017. Relevant demographic details including that of parents, type of deformity, nature, laterality, and treatment received were noted for each case. Conditions requiring non-operative treatment and those requiring further evaluation were noted separately with a detailed description. Results: Out of total 97 cases labeled as clubfoot, 32 (33.68%) cases with 64 feet were part of the study after excluding true clubfoot cases. The common condition noted was calcaneovalgus, postural clubfoot, equinus deformity secondary to cerebral palsy, metatarsus adductus, in-toeing, and posteromedial bowing of tibia. Conclusion: The knowledge of common foot disorders in primary care settings should be strengthened by refresher practical training so that these disorders are diagnosed and managed there an appropriate referral is made thus leading to decrease the burden on higher centers.

Congenital Posteromedial Bowing of the Tibia: A Single Center Experience

Summary Congenital posteromedial bowing of the tibia (CPMBT) is a rare congenital anomaly of the lower limbs. The aim of the present study was to analyze our experience in the treatment of CPMBT. A retrospective study of patients treated for CPMBT in the period January 2000 – June 2016 was performed. In the observed period, six patients were treated (five girls and one boy), with predominance of the right tibia involvement (5:1). The initial treatment included a series of corrective casts (4-9) applied in all patients, followed by removable splints and physiotherapy. Four children with residual angulation of tibia after walking age were prescribed ankle-foot orthosis (AFO) as a prevention of pathological fractures. Both posterior and medial angulation correct over time. Mean initial shortening was 11 mm. At the last follow-up visit, mean shortening was 23.33mm. Three patients had lower limb shortening of more than 2 cm. In two of them, with shortening of 27 mm and 35 mm, Ilizarov lengthening was performed. In one girl, we performed lengthening over titanium elastic nails. In the other girl, after lengthening, circular frame was exchanged with a locking plate to reduce fixator wearing time. There were no major complications of treatment. Patients were followed up for 2-12 years (mean 6.83 years). None of them reached skeletal maturity yet. Primary manifestation of CPMBT – angulation of tibia and fibula as well as calcaneovalgus deformity usually correct spontaneously or with conservative measures. However, limb length inequality, as a consequence of CPMBT, progresses with growth and may require surgical correction in some children. Therefore, all children with CPMBT should be followed up until skeletal maturity.

Rectal puncture during caudal anaesthesia.

Sir, A 9-year-old female child, ASA physical status I, weighing 31 kg with congenital posteromedial bowing of the right tibia was posted for the left proximal tibia and fibula epiphysiodesis. Informed consent was taken from the parents for general anaesthesia and caudal block. On the day of surgery, after adequate fasting status, the child was shifted to the operation theatre. After connecting the standard monitors and uneventful induction of general anaesthesia, the child was positioned for the caudal block. Under strict aseptic precautions, the resident anaesthesiologist approached the caudal space using the landmark technique with a 20-gauge short beveled intravenous (IV) cannula over a needle after feeling a characteristic ‘pop’. The cannula advanced without any resistance. After confirmation of negative aspiration for blood and cerebrospinal fluid, 3 ml of 0.25% bupivacaine was injected. On re-aspiration, greenish-yellow faecal matter was seen in the syringe and immediately the cannula was withdrawn and the entire set discarded. The second attempt was given by the senior anaesthesiologist at the sacral hiatus at an higher level than the previous attempt with a new needle and freshly prepared 15 ml of 0.25% bupivacaine was then administered after confirming negative aspiration. The surgery was carried out as planned with adequate caudal analgesia. The child was kept under the cover of antibiotic. There was no fever, inflammation, pain or discharge from the previous prick point. Her post-operative period was uneventful, and she was discharged on post-operative day three. Caudal block is an excellent technique of paediatric regional anaesthesia for abdominal and lower extremity surgeries. The low rate of complications makes it one of the safest and preferable anaesthetic techniques for intra-operative and post-operative analgesia. Complications that are seen are inadvertent IV injection (1:10,000), epidural haematoma or abscess (1:80,000), vessel perforation (1.6-10.6%), subcutaneous infiltration (5-19%) dural puncture (0.09-0.22%) but rectal puncture following caudal blockade is a less recognised complications which are not well reported in the literature.[1] We found only two case reports on inadvertent rectal puncture during the caudal blockade in children.[2,3] Traditionally, caudal space is approached by identifying the sacral hiatus which makes an equilateral triangle with the two posterior superior iliac spines. However, this technique has been questioned with the advent of ultrasound, which showed a poor correlation of the equilateral triangular surface landmark with the sacral hiatus. Ultrasound identification of the sacral hiatus can help overcome this flaw of the blind landmark technique.[4,5] Similar to the previous reports, the characteristic ‘pop’ sensation and negative aspiration did not confirm entry into the caudal space in our case.[2,3] The entry into the rectum was identified only on re-aspiration after injecting 3 ml of local anaesthetic. Takrouri et al. identified the rectal entry when only a gush of clear fluid came out of the child's anus, in spite of confirming via negative aspiration twice.[2] This can be explained by the possible absence of entry of solid faecal matter on aspiration until mixed and diluted by added anaesthetic solution. This could result in failed caudal block in spite of absent subcutaneous bulge and rectal puncture being unnoticed. This, re-emphasizes need for repeated aspiration during the regional technique. The literature reveals that even if a rectal puncture occurs, it is very important to never reintroduce the contaminated needle as it can lead to epidural infection. We opted to reattempt with a new set and were successful. However, it is prudent to follow-up these cases for any febrile episodes, pain, inflammation, infection or fistula formation. Optimal antibiotic treatment will be needed if there are any signs of epidural infection. Thus, accidental rectal puncture does not contradict the use of caudal block as long as proper aseptic precautions are taken. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Bilateral and symmetrical anteromedial bowing of the lower limbs in a patient with neurofibromatosis type-I.

An 8-year-old girl was referred to our department because of generalized bowing of long bones (radii, ulnae, and femora) and significant bilateral and symmetrical posteromedial bowing of the tibiae and fibulae. The femora were laterally bowed whereas the tibiae and fibulae showed posteromedial bowing between the middle and distal thirds of the tibia with posterior cortical thickening effectively causing the development of bilateral congenital anterolateral bowing of the tibiae and fibulae. We referred to closing-wedge osteotomy of the left tibia along with fibular osteotomy in order to realign the deformity. Due to the delayed appearance of skin stigmata in her early life, the diagnosis of neurofibromatosis was ruled out. At the age of 9 years, café-au-lait spots and axillary freckling were apparent. Genetic tests confirmed von Recklinghausen disease (neurofibromatosis type-I (NF1)) (gene has been localised to 17q22). Interestingly, bilateral and symmetrical anteromedial bowing of the tibiae and fibulae has not been described in patients with NF-I.

Congenital posteromedial bowing of the tibia and fibula

Few papers have described patients treated surgically with single osteotomy for congenital posteromedial bowing of the tibia and fibula. Only one paper has described two-level osteotomy for deformity correction: the first for deformity correction and the second for bone lengthening. There are no publications describing the surgical correction of deformation only by the method of multilevel tibial and fibular osteotomy. Research material included four children aged between 3.1 and 5.1 years (average age: 3.7 years) who were operated upon for bowing of the tibia and fibula exceeding 35° in the coronal plane. In all cases, tibial osteotomy was carried out at three or two levels accompanied by fibular osteotomy, and with intramedullary stabilization using K-wires (three patients) or Rush pin (one patient). Follow-up ranged from 3 to 7.7 years. In all cases, axis correction and bone healing were achieved. In large congenital posteromedial bowing of the tibia and fibula, a multilevel tibial and fibular osteotomy may be a better solution than an orthosis or a long time waiting for a spontaneous correction of the deformation. Large circumferential periosteal release that accompanied the surgery influenced the stimulation of bone growth. It may induce the process of lower limbs' equalization not to require the application of intensive surgical procedures.

Prenatal Sonographic Features and Postnatal Outcome of Congenital Posteromedial Bowing of Tibia: An Experience from a Tertiary Fetal Medicine Center

AbstractA series of 18 fetuses were identified from the archives, between 2004 and 2013 with findings of unilateral shortening of the tibia and fibula, an acutely dorsiflexed foot and posteromedial bowing of the tibia and fibula. The median gestational age at diagnosis was 23 weeks (range 20–29 weeks). The discrepancy in length between the affected and contralateral tibia varied from 9 to 33 %. Data on pregnancy outcome were available for 14 (78 %) of 18 fetuses. Four patients opted for termination of pregnancy. All the live born babies (10/14) were followed-up postnatally and were well at a median age of 28 months (6–63 months) with milestones appropriate for age at the time of writing. Spontaneous resolution was noted in all the cases and none of them required surgical correction for limb discrepancy so far. Congenital posteromedial bowing of the leg is a benign entity whose outcome includes spontaneous resolution of the angular deformity, albeit with some residual limb length discrepancy and ankle valgus which may need orthopedic intervention around 6–7 years of age. Awareness of this condition helps in making the diagnosis prenatally and in counseling the couples about the prognosis and management options available.

Pregnancy outcomes in the clinical development program of fingolimod in multiple sclerosis.

To report outcomes of pregnancies that occurred during the fingolimod clinical development program. Pregnancy outcomes from phase II, phase III, and phase IV clinical studies (with optional extensions) were reported by clinical trial investigators. Fingolimod exposure in utero was defined as fingolimod treatment at the time of conception or in the 6 weeks before conception. As of October 31, 2011, 89 pregnancies were reported in completed or ongoing clinical studies, with 74 in fingolimod treatment arms. Of 66 pregnancies with in utero exposure to fingolimod, there were 28 live births, 9 spontaneous abortions, 24 elective abortions, 4 ongoing pregnancies, and 1 pregnancy with an unknown outcome (patient lost to follow-up). Two infants were born with malformations: 1 with congenital unilateral posteromedial bowing of the tibia and 1 with acrania. Elective abortions were performed for 1 case each of tetralogy of Fallot, spontaneous intrauterine death, and failure of fetal development. There were 5 cases (7.6%; 95% confidence interval 3%-17%) of abnormal fetal development in the 66 pregnancies that had in utero exposure to fingolimod. In all 5 cases, fetal exposure to the drug took place in the first trimester of pregnancy. The number of patients becoming pregnant during fingolimod therapy remains small and does not permit firm conclusions to be drawn about fetal safety of fingolimod in humans. Given the known risks of teratogenicity in animals and the present data, women of childbearing potential should use effective contraception during fingolimod therapy and for 2 months after discontinuation.

Deformidade póstero -medial congénita da tíbia: a propósito de 2 casos clínicos

Objective: To describe the case of two children with leg bowing conditioned by tibial angular deformities and to discuss differential diagnosis.Case report: We report the case of two patients referred to a Pediatric Orthopedics Consultation due to leg bowing. No skin patches or other alterations were found on physical examination. Clinical and imaging findings were consistent with congenital posteromedial bowing of the tibia. Favorable outcome was verified, with spontaneous resolution of deformity.Comments: Posteromedial bowing of the tibia is a rare entity, with few cases reported in literature. Its true incidence remains unknown. It implies differential diagnosis with the tibial congenital pseudarthrosis, usually related to neurofibromatosis. Most often its treatment is conservative, because it tends to resolve spontaneously (mostly under 8 years) without any clinical consequences. Our aim is to alert pediatricians to establish the possibility of this clinical entity when dealing with tibial bowing, minimizing parental anxiety resulting from it. Nevertheless we emphasize the importance of evaluation by an orthopedist as there are clinical situations in which diagnosis may not be as evident.

Limb lengthening in congenital posteromedial bow of the tibia

Congenital posteromedial bowing of the tibia (PMBT) is a rare condition affecting one lower limb. The bowing of the tibia usually resolves; however, there is associated limb length discrepancy (LLD), which often persists and can cause functional deficits. Advances in limb lengthening techniques allow this issue to be addressed, often with concomitant angular deformity correction. This study examined eleven patients who have had limb lengthening procedures with mean pre-operative LLD of 3.7 cm (range 1.5–5 cm), mean increase in length was 3.9 cm (range 1.5–5.8 cm), and mean LLD at last follow-up was less than 0.6 cm (range 0–2.0 cm). The main complications were minor or moderate grades, such as pin site infection. Greater LLD was found than previously reported, and we believe that the tertiary referrals were those of a severe form of PMBT. The authors conclude that in view of deformity with discrepancy, in select cases, correction and lengthening would be an option rather than only contralateral epiphysiodesis.

Congenital postero-medial bowing of the tibia and fibula: is early surgery worthwhile?

We report the results of surgical treatment of congenital postero-medial bowing of the tibia and fibula. Twenty patients with congenital postero-medial bowing were seen with nine patients treated surgically (corrective osteotomy or lengthening and deformity correction with Ilizarov fixator) and 11 patients managed conservatively. The angles of medial and posterior angulation and limb length discrepancy were recorded serially and compared. Surgical complications were recorded. The mean follow-up was 9.5 and 6.1 years after surgery. Although there was a reduction in angulation and correction of limb length discrepancy, we encountered complications in the surgically treated patients. There was no statistically significant difference between the surgically treated and conservatively managed groups with respect to mean angulation, though there was a significant difference in the mean limb length discrepancy. In conclusion, we advocate a one-stage lengthening and correction of the residual deformity closer to skeletal maturity.

Computational simulation of spontaneous bone straightening in growing children

Periosteal surface pressures have been shown to inhibit bone formation and induce bone resorption, while tensile strains perpendicular to the periosteal surface have been shown to inhibit bone resorption and induce new bone deposition. A new computational model was developed to incorporate these experimental findings into simulations of spontaneous bone straightening in children with congenital posteromedial bowing of the tibia. Three-dimensional finite element models of the periosteum were used to determine the relationships between the defect angle and the distribution of bone surface pressures and strains due to growth-generated tensile strains in the periosteum. These relationships were incorporated into an iterative simulation to model development of a growing, bowed tibia with an initial defect angle of 27 degrees. When periosteal loads were included in the simulation, the defect angle decreased to 10 degrees after 2 years, and the bone straightened by an age of 25 years. When periosteal loads were not included in the simulation, the defect angle decreased to 23 degrees after 2 years, and a defect angle of 9 degrees remained at an age of 25 years. A "modeling drift" bone apposition/resorption pattern appeared only when periosteal loads were included. The results suggest that periosteal pressures and tensile strains induced by bone bowing can accelerate the process of bone straightening and lead to more complete correction of congenital bowing defects. Including the mechanobiological effects of periosteal surface loads in the simulations produced results similar to those seen clinically, with rapid straightening during the first few years of growth.