The Fate of the Bent Rod in Children With Osteogenesis Imperfecta.

BACKGROUND: Osteogenesis imperfecta (OI) is a genetic disorder characterized by brittle bones and long bone deformity. Realignment and intramedullary rodding with telescopic rods are indicated for progressive deformity and can help prevent fractures. Rod bending is a reported complication of telescopic rods and a common indication for revision; however, the fate of bent lower extremity telescopic rods in the setting of OI has not been reported. METHODS: Patients with OI at a single institution who underwent lower extremity telescopic rod placement with at least 1-year follow-up were identified. Bent rods were identified, and for these bone segments, we collected the location and angle of bend, subsequent telescoping, refracture, increasing angulation of bend, and date of revision. RESULTS: One hundred sixty-eight telescopic rods in 43 patients were identified. Forty-six rods (27.4%) bent during follow-up, with an average angulation of 7.3 (range: 1 to 24) degrees. In patients with severe OI, 15.7% of rods bent compared with 35.7% in nonsevere OI ( P =0.003). The proportion of bent rods was different between independent and nonindependent ambulators (34.1% and 20.5%; P =0.035). Twenty-seven bent rods (58.7%) were revised, with 12 rods (26.0%) revised early (within 90 d). The angulation of rods that were revised early was significantly higher than rods not (14.6 and 4.3 degrees, P <0.001). Of the 34 bent rods not revised early, the average time to revision or final follow-up was 29.1 months. Twenty-five rods (73.5%) continued to telescope, 14 (41.2%) increased in angulation (average 3.2 degrees), and 10 bones (29.4%) refractured. None of the refractures required immediate rod revision. Two bones had multiple refractures. CONCLUSIONS: Bending is a common complication of telescopic rods in the lower extremities of patients with OI. It is more common in independent ambulators and patients with nonsevere OI, possibly because of the increased demand placed on the rods. Rods with a small bend and maintained fixation can telescope and need not be an indication for immediate revision. LEVEL OF EVIDENCE: Level III-Retrospective review.

A novel risk calculator predicting surgical site infection after spinal surgery in patients with cerebral palsy.

AIM: To develop and validate a risk calculator based on preoperative factors to predict the probability of surgical site infection (SSI) in patients with cerebral palsy (CP) undergoing spinal surgery. METHOD: This was a multicenter retrospective cohort study of pediatric patients with CP who underwent spinal fusion. In the development stage, preoperative known factors were collected, and a risk calculator was developed by comparing multiple models and choosing the model with the highest discrimination and calibration abilities. This model was then tested with a separate population in the validation stage. RESULTS: Among the 255 patients in the development stage, risk of SSI was 11%. A final prediction model included non-ambulatory status (odds ratio [OR] 4.0), diaper dependence (OR 2.5), age younger than 12 years (OR 2.5), major coronal curve magnitude greater than 90° (OR 1.3), behavioral disorder/delay (OR 1.3), and revision surgery (OR 1.3) as risk factors. This model had a predictive ability of 73.4% for SSI, along with excellent calibration ability (p = 0.878). Among the 390 patients in the validation stage, risk of SSI was 8.2%. The discrimination of the model in the validation phase was 0.743 and calibration was p = 0.435, indicating 74.3% predictive ability and no difference between predicted and observed values. INTERPRETATION: This study provides a risk calculator to identify the risk of SSI after spine surgery for patients with CP. This will allow us to enhance decision-making and patient care while providing valid hospital comparisons, public reporting mechanisms, and reimbursement determinations.

Multicenter Series of Deformity Correction Using Guided Growth in the Setting of Osteogenesis Imperfecta.

BACKGROUND: The mainstay of deformity correction and fracture prevention for patients with osteogenesis imperfecta (OI) includes osteotomies and intramedullary rodding. Guided growth, described in the setting of skeletal dysplasias, offers a less invasive means of deformity correction. We report a multicenter case series of guided growth procedures in the setting of OI. METHODS: We retrospectively reviewed patients with OI at three institutions from April 2012 to April 2019: 18 patients underwent guided growth for angular deformity correction with minimum 1-year follow-up or full deformity correction and removal of guided growth hardware. Clinical characteristics, deformity measurements, and complications were collected. Distal femoral and proximal tibial hemiepiphysiodesis was performed using figure-of-eight plates and screws, and distal tibial medial hemiepiphysiodesis with cannulated screws. Preoperative and postoperative lateral distal femoral angle, medial proximal tibial angle, and lateral distal tibial angle were measured. Frequency and descriptive statistics were completed. RESULTS: Eighteen patients with OI (five-I, four-III, six-IV, three-V) underwent 33 guided growth procedures with mean follow-up of 3.09 years; all received routine bisphosphonate treatment. Preoperative and postoperative mean joint angles were measured. The location for hemiepiphysiodesis included 8 distal femoral medial, 2 distal femoral lateral, 8 proximal tibial medial, 3 proximal tibial lateral, and 12 distal tibial medial. Twelve of the 33 procedures were in patients who had an intramedullary rod; 1 demonstrated backout of the epiphyseal and metaphyseal screws of a distal femoral medial figure-of-eight plate. It was revised to a larger plate with longer screws and removed upon completion of deformity correction. CONCLUSION: Guided growth may be used as an effective means of angular deformity correction with dysplastic OI bone. Having an intramedullary rod did not preclude the use of a guided growth technique. One procedure demonstrated screw backout. Given the short stature associated with OI, performing a guided growth procedure at an early enough age to allow time for correction should be considered. LEVEL OF EVIDENCE: Level IV-case series.

Evaluation of Fracture and Osteotomy Union in the Setting of Osteogenesis Imperfecta: Reliability of the Modified Radiographic Union Score for Tibial Fractures (RUST).

BACKGROUND: Evaluation of the union of osteotomies and fractures in patients with osteogenesis imperfecta (OI) is a critical component of patient care. Studies of the OI patient population have so far used varied criteria to evaluate bony union. The radiographic union score for tibial fractures (RUST), which was subsequently revised to the modified RUST, is an objective standardized method of evaluating fracture healing. We sought to evaluate the reliability of the modified RUST in the setting of the tibias of patients with OI. METHODS: Tibial radiographs of 30 patients with OI fractures, or osteotomies were scored by 3 observers on 2 separate occasions. Each of the 4 cortices was given a score (1=no callus, 2=callus present, 3=bridging callus, and 4=remodeled, fracture not visible) and the modified RUST is the sum of these scores (range, 4 to 16). The interobserver and intraobserver reliabilities were evaluated using intraclass coefficients (ICC) with 95% confidence intervals. RESULTS: The ICC representing the interobserver reliability for the first iteration of scores was 0.926 (0.864 to 0.962) and for the second series was 0.915 (0.845 to 0.957). The ICCs representing the intraobserver reliability for each of the 3 reviewers for the measurements in series 1 and 2 were 0.860 (0.707 to 0.934), 0.994 (0.986 to 0.997), and 0.974 (0.946 to 0.988). CONCLUSIONS: The modified RUST has excellent interobserver and intraobserver reliability in the setting of OI despite challenges related to the poor quality of the bone and its dysplastic nature. The application and routine use of the modified RUST in the OI population will help standardize our evaluation of osteotomy and fracture healing. LEVEL OF EVIDENCE: Level III-retrospective study of nonconsecutive patients.

What's New in the Management of Foot Deformities in Children With Cerebral Palsy.

BACKGROUND: Foot deformities have been frequently reported in cerebral palsy (CP), and numerous diagnostic modalities and treatment options have recently been developed to achieve a better level of management for children with CP. METHODS: A thorough search of the English literature, published between January 2013 and March 2016, was performed. A summary of the new findings that had not previously described was reported. The review included recent advances regarding clinical and gait evaluation, orthotic management, botulinum toxin A treatment, and surgical correction. RESULTS: The review summarized new findings reported in 46 articles and abstracts that were published between January 2013 and March 2016. Older articles were included and cited when an original description was mentioned, or when a change or development of some findings was discussed. CONCLUSIONS: Foot deformity forms an essential part of evaluating children with CP. Dramatic advances have been achieved in gait assessment, conservative management, and surgical correction. Promising results have been reported with the goal to reach a higher level of orthopaedic care and optimize the functional potentials for children with CP. LEVEL OF EVIDENCE: Level IV-literature review.

Mental health screening in pediatric lower limb deficiency population.

BACKGROUND: Youth with lower limb deficiency (LLD) may be at increased risk for mental health difficulties. However, guidelines around psychosocial screening are not well established. OBJECTIVE: To describe the implementation and results of a mental health screening process in a multidisciplinary prosthetics clinic. DESIGN: Survey. SETTING: Outpatient specialty care clinic located within a children's hospital. PATIENTS: All patients ages 0-18 years with LLD seen at a monthly multidisciplinary prosthetics clinic between September 2019 and January 2023 (n = 75). INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Quality of life was measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) pediatric proxy survey. Psychological functioning was measured using the Strengths and Difficulties Questionnaire (SDQ). RESULTS: Descriptive statistics were used to determine the proportion of patients who endorsed clinically significant concerns. Of the 75 clinic visits during the study time frame, the psychosocial screeners were completed at 38 (51%). A total of 25 unique patients completed the screeners; 12 patients completed the screener more than once. The most commonly endorsed concerns on the PROMIS were issues with physical mobility (65%) and upper extremity function (40%). The SDQ revealed that a majority (62.5%) of the screened patients had an overall score above the clinical cutoff, indicating psychosocial distress in more than one area. The most commonly reported mental health concern was peer problems (62.5%). Post hoc analysis of repeat screenings indicated that most problems identified during the first screening persisted at follow-up screenings. CONCLUSIONS: Clinically significant psychological concerns were common among the sample, indicating the need to address this aspect of patients' well-being. Preliminary data on repeat screenings suggest that clinically significant concerns may not self-resolve. Routine psychosocial screening is critical for early identification of mental health problems and timely referral to evidence-based psychological interventions.

"Osteogenesis Imperfecta Patients Wish Orthopedic Surgeons Had Better Strategies to Help with "-Results of a Patient and Parent-Oriented Survey.

Osteogenesis Imperfecta (OI) is a rare genetic disorder in Type I collagen characterized by bone fractures, fragility, and deformity. Current treatments are focused on decreasing fracture rates, improving bone strength, and improving overall global function. Recent research has focused primarily on fracture fixation and outcomes of intramedullary rodding of long bones. While surgical techniques continue to evolve, recent trends in OI research are focusing on patient quality of life and patient-reported outcomes. We created a 12-question survey seeking information regarding aspects of orthopedic care that OI patients and families feel are the most pressing to improve. The survey was electronically administered, and 341 individuals participated. A total of 75% of respondents who answered the age question (254/335) were adults. Regarding surgical intervention for long bones, only 16% of respondents recall being told they could not have surgery because they were too young. Of the 16%, 37.8% were told that <5 years was too young, 13.4% <4 years was too young, and 48.8% <3 years of age was too young for surgical intervention for fractures or deformities. Nearly 22% of respondents were told that their bones were too small for intramedullary fixation. The patient and family responses help elucidate the topics requiring focus for the improvement of OI orthopedic care. Patient concerns and insights should drive the research questions we ask to advance the orthopedic care of OI patients.

Is there an association between chronicity of patellar instability and patellofemoral cartilage lesions? An arthroscopic assessment of chondral injury.

The purpose of this study was to investigate the association between chronicity of patellar instability on the prevalence, grade, and location of chondral lesions in patients with recurrent patellar instability. Patellofemoral chondral status was documented and graded according to the Outerbridge classification in 38 patients who underwent arthroscopic examination at the time of a medial patellofemoral ligament reconstruction procedure. Chondral lesions of any location were observed in 63.2% of patients. Patellar and trochlear lesions were observed in 57.9 and 13.2% of patients, respectively. There was a significantly higher duration of patellar instability in patients with a trochlear lesion versus those without a trochlear lesion (p < 0.01), and in patients with combined patellar and trochlear lesions versus those without both patellar and trochlear lesions (p < 0.01). There was a significant correlation between chronicity of patellar instability and Outerbridge grade of trochlear chondral injury (p = 0.01). Chi-squared analysis revealed that chronicity of patellar instability greater than 5 years was significantly associated with the likelihood of trochlear lesions (p < 0.05). We conclude that patients with increasing chronicity of patellar instability may have a higher likelihood of and higher grade of patellofemoral chondral injuries, specifically for trochlear lesions.

Challenges with Fassier-Duval rod exchanges in congenital pseudarthrosis of the tibia: explant roadblock and solution.

Congenital pseudarthrosis of the tibia (CPT) is characterized by anterolateral tibial bowing and hamartomatous periosteum that predisposes it to fracture. Fassier-Duval telescopic rods can improve the structural integrity of bone segments after reconstruction. We present our experience treating CPT with the Fassier-Duval rod and a novel technique for Fassier-Duval exchange that was developed after extraction failed in one patient. Patients were identified who underwent treatment with Fassier-Duval rods for CPT between 2007 and 2016 and had undergone their first rod exchange. Medical records were reviewed, and complications were classified using the system of Cherkashin. Four patients had an average age at the initial insertion of 6 years 4 months (4-9 years). The average follow-up duration after initial Fassier-Duval implantation was 5.4 years (2.7-8.1 years). Seven Category 2 complications were associated with the Fassier-Duval rod: interlocking K-wire migration (2), lengthening failure (2), explant failure (1), distal migration of female rod through physis (1) and male rod portion proximally migrating through physis (1). Three patients underwent one rod exchange [average 3.2 years after implantation (range, 2.7-3.9 years)]. One patient underwent two rod exchanges (2.9 and 6.9 years after initial implantation). The second attempt at exchange failed; this failure prompted the development of custom trephines to remove the hard bone that can encase the distal male segment. The use of custom trephines was made necessary by dense sclerotic bone at the previous pseudarthrosis site. We recommend that custom trephines be available during Fassier-Duval rod extraction to avoid failed retrieval. Level of evidence: Level IV (Case series).

The role of posterior spinal osteotomies in pediatric spinal deformity surgery: indications and operative technique.

The primary goals of spinal deformity surgery are to prevent the progression of further deformity and to improve sagittal and coronal balance. Although increasingly powerful instrumentation has greatly facilitated these treatment goals, osteotomy of the spine is sometimes necessary to address more significant deformity. This review provides a detailed overview of posterior spinal osteotomies, which have gained increased attention as an adjunct to the treatment of complex pediatric spine deformity. The indications, operative technique, and advantages and disadvantages of the Smith-Petersen, pedicle subtraction and vertebral column resection osteotomies will be discussed, as well as operative considerations generally applicable to spinal deformity surgery involving correction with osteotomies.

Congenital Pseudarthrosis of the Tibia Associated With Cleidocranial Dysostosis: Case Report and Literature Review.

CASE: We describe a case of 2 individually rare diseases existing comorbidly in the form of congenital pseudarthrosis of the tibia (CPT) coincident with cleidocranial dysostosis and provide a review of the literature, including the sole preexisting documented coincidence. CONCLUSION: Understanding, treatment, and surgical protocol of CPT have changed considerably since this comorbidity was last reported. Updates include synostosis, periosteal grafting, the use of bone morphogenetic protein, and bisphosphonates. Our case varies from the previous in associated disorder and family history. The relationship between CBFA1 and RUNX2 genes may hold the key, but further study is needed.

Stress Shielding in the Setting of Osteogenesis Imperfecta and the Effect of Downsizing an Intramedullary Rod: A Case Report.

CASE: Cortical atrophy, or stress shielding, secondary to a large-diameter femoral intramedullary rod was noted over almost a decade in a now 14-year-old girl with osteogenesis imperfecta (OI). After an initial minimally invasive unsuccessful revision, we downsized the left femur rod with realignment and noted restoration of the left femur cortical thickness. CONCLUSION: We demonstrate the significant functional impact of stress shielding and its evolution over a protracted period and outline treatment principles. To our knowledge, this is the first report of treatment of stress shielding of a long bone in the setting of OI.

Comprehensive pain management strategy for infants with moderate to severe osteogenesis imperfecta in the perinatal period.

Osteogenesis imperfecta (OI) is a rare genetic heterogeneous disorder that causes increased bone fragility and recurrent fractures. For infants with OI and diffuse fractures, pain management, which is nuanced and specific for this population, is of the utmost importance to their neonatal care. Through experience at our center, we have developed a standard approach that has been successful in optimizing survival for these infants during this tenuous period. In this paper, we outline our multidisciplinary approach to pain management for infants with moderate to severe OI during the neonatal period, with emphasis on promotion of fracture healing and adequate pain control.

Cervical kyphosis: A predominant feature of patients with osteogenesis imperfecta type 5.

OBJECTIVES: Osteogenesis imperfecta (OI) is a heterogeneous group of genetic disorders of connective tissue that cause skeletal fragility and extra-skeletal manifestations. Classically, four different types of OI were distinguished. Type 5 OI was added due to its distinct clinical and radiographic features. In 2012, two independent groups identified a recurrent heterozygous c.-14C>T mutation in IFITM5 as the responsible genetic change for this type of OI. To our knowledge, cervical kyphosis has not been identified in the literature as a finding in type 5 OI patients. This is a retrospective review of a cohort of patients with type 5 OI and a description of associated cervical spine deformity. METHODS: After institutional review board approval, a retrospective review identified 13 patients with type 5 OI. Clinical, radiologic, and genetic data from 2002 to 2020 were reviewed. RESULTS: We identified 13 patients with clinical diagnosis of type 5 OI. Twelve had molecular confirmation and the classic IFITM5, c.14C>T gene mutation was identified. The remaining individual did not undergo genetic testing. Dentinogenesis imperfecta was observed in one patient, while blue sclerae or hearing loss were not present. All patients had at least one fracture and four underwent intramedullary rodding. Radiologic features included subphyseal metaphyseal radiodense line in 12/13 patients (92%), interosseous membrane calcification in seven of 13 patients (54%) (more commonly noted in the upper extremities), and hypertrophic callus in six of 13 patients (46%). Thoracolumbar spinal deformities were seen in six of 13 patients (46%) with two of these individuals requiring surgery. Cervical kyphosis was noted in nine of 13 individuals (69%) ranging in age from 3 months to 22 years. Anterior wedging of the cervical vertebral bodies was noted in the absence of any fractures. Six of nine individuals demonstrated listhesis of C2-C3 or C3-C4 segment. Magnetic resonance imaging studies were performed and reviewed in patients with cervical kyphosis and subluxation; three patients showed narrowing of spinal canal without cervical cord compression and one asymptomatic patient showed impingement of the spinal cord. CONCLUSIONS: Cervical kyphosis appears to be a common feature of type 5 OI. It can be a presenting and apparently life-long association and does not appear to be caused by vertebral body fractures. Evaluation for cervical kyphosis should be performed in patients with a suspected or confirmed diagnosis of type 5 OI. Furthermore, if cervical kyphosis is noted in an individual with OI, type 5 OI should be considered.Level of evidence: IV.

Osteogenesis Imperfecta: A Pediatric Orthopedic Perspective.

Osteogenesis imperfecta is a genetically and phenotypically heterogeneous disorder related to a defect or deficiency in the production of type I collagen. It is characterized by brittle bones, fractures, spine and extremity deformity, and a host of extraskeletal manifestations. Type I collagen is present in bone, tendons, ligaments, skin, dentin, and the sclera of the eye and other connective tissues. Osteogenesis imperfecta includes a multitude of disease manifestations that may be present at birth or develop over time and vary depending on the severity of the disease. This article describes the disease presentation and management considerations from a pediatric orthopedic perspective.

Orthopedic Manifestations of Bruck Syndrome: A Case Series with Intermediate to Long-term Follow-Up.

The aim of this study was to evaluate the association of contractures, fractures, and deformities in four patients with Bruck syndrome treated in our facility. Data were collected from medical records, radiographs, dual-energy X-ray absorptiometry (DEXA) scans, genetic tests, and gait analysis. All had contractures at birth and genotypic findings including mutations in PLOD2 or FPKB10. Three cases were treated with bisphosphonates with improvement in bone density verified by DEXA. In Bruck syndrome, orthopedic deformities include the following sequential aspects: contractures, characterized by upper and lower extremity contractures such as clubfeet; fractures, characterized by multiple diaphyseal fractures in the long bones of the extremities; and deformities, characterized by malalignment of extremities and the spine. Physical therapy and bracing proved helpful for the contractures to try to stop progression. Bone fragility needs to be considered when deciding to attempt cast correction. Surgeries in the soft tissues can be performed to retain joint movement. In fractures with angulation, intramedullary nail fixation was useful, and in cases without deformity, casting alone was successful. We suggest monitoring the bone density with DEXA, nutrition support with vitamin D and calcium, and treatment with bisphosphonates. Spine deformities were successfully treated by spinal fusion and instrumentation.

Bone Ninja Mobile App for Reverse Planning Method in Internal Limb Deformity and Lengthening Surgery.

AIM: To report whether Bone Ninja (BN) is a reliable tool to teach the reverse planning method (RPM) for implantable intramedullary (IM) limb-lengthening devices and for deformity correction surgery. BACKGROUND: Motorised fully implantable implantable intramedullary (IM) lengthening devices have been gaining popularity all over the world for limb-lengthening procedures. Multiple advantages have been demonstrated over external fixator-controlled lengthening. Mechanical axis deviation may result if careful preoperative planning and surgical intervention are not completed for femur cases. The RPM proposed by Baumgart has been shown to be an accurate means of arriving at the desired end point. The RPM addresses the ideal correction position accounting for length, angulation, and translation created during lengthening along the nail axis. The original description calls for the use of life-size paper tracings of the bone and large light boxes to allow planning. We propose an alternative method using a digital tool that is readily available. The BN mobile app was developed for patient/physician education and is available for the Apple iPad platform. Bone Ninja has been shown to have similar accuracy for measurements of the limb length and deformity angles when compared to the gold standard picture archiving and communication systems (PACSs). TECHNIQUE: We used BN (version 4.2) on an iPad mini to perform the same RPM steps, using the same terminology originally described by Baumgart. CONCLUSION: Bone Ninja is a simple validated deformity correction tool with accuracy comparable to PACS. It is a reasonable alternative to paper/pencil cutouts for applying RPM for IM limb lengthening and deformity correction surgery. CLINICAL SIGNIFICANCE: We proposed a digitised RPM for internal limb-lengthening surgeries, which is highly feasible and practical to use conveniently without the need for the traditional tedious paper-cutting procedure and related equipment. HOW TO CITE THIS ARTICLE: Hung AL-H, McClure PK, Franzone JM, et al. Bone Ninja Mobile App for Reverse Planning Method in Internal Limb Deformity and Lengthening Surgery. Strategies Trauma Limb Reconstr 2019;14(2):72-76.

Intramedullary nailing with supplemental plate and screw fixation of long bones of patients with osteogenesis imperfecta: operative technique and preliminary results.

Although intramedullary fixation is the standard form of surgical fixation of the long bones of children with osteogenesis imperfecta (OI), it remains fraught with complications. Implant breakage, implant cut out, long bone fracture, nonunion, and rod bending have all been described as complications of intramedullary long bone fixation in children with OI. Supplemental fixation techniques represent an attempt to decrease these risks of surgical implant failure of intramedullary devices. A supplemental plate and screw construct at a fracture or an osteotomy site in addition to an intramedullary device in the long bone segment is one such form of supplemental fixation. The aim of this study is to describe the surgical technique and early results of plate and screw fixation used to supplement intramedullary fixation in a subset of our OI patient population. This is a retrospective review and report on 14 long bone segments of 11 children with OI who have undergone intramedullary fixation as well as supplemental fixation at osteotomy or fracture sites with a plate and screw construct. The long bone segments treated with intramedullary fixation and a supplemental plate and screw construct included 11 femurs, two tibias, and one humerus. Intramedullary devices included a combination of telescoping and nontelescoping implants. The mean follow-up duration was 10 months. All 14 long bone segments have gone on to radiographic union. The average time to union was 8.8 weeks (range: 6.5-17 weeks). In 11 of the long bone segments, the supplemental plate fixation was applied to the site of a fracture or osteotomy. In one case, supplemental plate fixation was applied to the site of a nonunion (distal humerus nonunion). We describe various options of this surgical technique and early results. Although further follow-up and investigation will provide further insight into long-term outcomes, supplemental plate and screw fixation is a valuable and versatile option for this challenging patient population.

Categorization of the Usage of Adjunctive Structural Allograft Bone Graft in Extremity Surgery for Patients with Osteogenesis Imperfecta.

Structural allograft bone plays a role in orthopedic surgery. Our purpose is to describe the methods of using structural allograft in extremity reconstruction surgery in patients with osteogenesis imperfecta (OI) and create a classification of usage with a single-center review of OI extremity cases from January 2002 to February 2017. Structural allograft was used in 19 bone segments in 15 patients with type III OI. Four categories of usage were defined: (1) interpositional, (2) onlay, (3) inlay, and (4) blocking to prevent rod migration. The mean time to incorporation was 5.4 months (range 1-16). Structural allograft bone incorporates into OI bone and may be a supplement to intramedullary fixation.