Complications of intramedullary rods in osteogenesis imperfecta: Bailey-Dubow rods versus nonelongating rods

Complications After Intramedullary Fixation Treatment of Patients With Osteogenesis Imperfecta: Telescopic Versus Non-Telescopic Implants

Introduction The treatment of musculoskeletal pathologies in osteogenesis imperfecta aims to provide the maximum possible function by preventing bone fractures and progressive deformities. Despite the development of implants used in the surgical treatment of osteogenesis imperfecta, there is no consensus on the most appropriate method for the correction of skeletal deformities. The aim of this study was to compare telescopic and non-telescopic implants in terms of postoperative complications. Methods  Twenty-three patients who were operated on for the diagnosis of osteogenesis imperfecta between 2005 and 2018 were retrospectively analyzed. Demographic data, follow-up times, and the total number of surgeries and complications were recorded. The operated bones were divided into two groups according to whether the intramedullary fixation material used was telescopic or not. Results  Twenty-one of 23 patients were included in the study due to the use of intramedullary fixation material in the operation. The mean age was 10.1 ± 2.9 years, and the mean follow-up period was 8.9 ± 3.5 years. Intramedullary fixation was applied to 43 long bones in 21 patients due to fracture or deformity. At least one complication was encountered in nine of 14 bones with telescopic implants and in 27 of 29 bones with non-telescopic implants. Major complications requiring surgical treatment were seen in seven bones of the telescopic implant group and 27 bones of the non-telescopic implant group. Conclusion The use of telescopic implants relatively reduces the complication rate and the need for repetitive surgery in patients with a diagnosis of osteogenesis imperfecta. However, the number of complications is still as high as with non-telescopic implants.

The patient-related factors in revision procedures on tibia of patients with osteogenesis imperfecta treated with the Peter-Williams nail

OBJECTIVE

To investigate the patient-related factors that affect the revision rate for the tibia in patients with osteogenesis imperfecta treated with the Peter-Williams nail, and to explore the relationship between the risk factors and complications postsurgery.

METHODS

We retrospectively analysed the data of 211 patients (93 females (44.08%) and 118 males (55.92%)) with osteogenesis imperfecta treated with Peter-Williams. The factors affecting surgical revision were analysed by performing binary logistic regression. Then, a total of 211 patients with type III, type I or type IV OI were divided into five groups according to the results of regression. Statistical comparison of these groups was performed to further investigate the relationship between patient-related factors and revision procedures. Statistical comparison was also performed to analyse the relationship between the classification and postoperative complications.

RESULTS

Among the 211 patients who underwent surgery, 40 had type I OI, 109 had type IV OI, and 62 had type III OI. Binary logistic regression revealed that the classification (OR = 3.32, 95% CI 1.06-10.39, P = 0.039) and initial operation age (OR = 0.83, 95% CI 0.76-0.92, P < 0.001) were significantly correlated with revision procedures. In type III patients, the initial operation age was significantly correlated with revision procedures (P < 0.001), and the revision rate was lower in patients aged 9 to12 years (P = 0.001). In type I and IV patients, the initial operation age was not significantly correlated with revision procedures (P = 0.281). Classification had a significant effect on postoperative deformity (P = 0.003).

CONCLUSIONS

The study reported that the age of initial surgery and classification were the influencing factors affecting the revision procedures of tibia in patients with osteogenesis imperfecta treated with the Peter-Williams nail. In patients with type III disease, the revision rate was lower individuals aged 9-12 years old, and a higher incidence of postoperative deformity was observed.

Bone allografting: an original method for biological osteosynthesis and bone reinforcement in children with osteogenesis imperfecta

PURPOSE

Osteogenesis imperfecta (OI) is a genetic disorder responsible for various symptoms including deformities and frequent fractures. Bone allografting is poorly documented in this condition. The objective of this study was to describe our experience and assessments in a consecutive series of OI patients.

METHODS

Thirty-nine lower limb allograft procedures (28 femurs, 11 tibias) were performed in 26OI patients (mean age, 12.9 years). They were classified as type III of Sillence (17), type IV (6), and 3 recessive forms. The indications for surgery were correction of deformity (19), fracture (16), and non-union (4). In all cases, bone allografting was added to reinforce areas of fragility and in 28 cases for osteosynthesis to lock the rotations at the osteotomy site and to avoid screwed metallic plate. The duration of bone consolidation and allograft fusion was assessed. Complications and Gillette functional score were reported.

RESULTS

The mean follow-up was 6.7years (range, 2 to 10 years). On average, bone consolidation was achieved after 3.3 months and graft fusion after 7.7 months. No bone allograft-related complications were observed and there was any secondary displacement. The Gillette functional score was improved in 23 patients and stable in three cases. Complications were reported in two cases: one partial allograft resorption and one delayed consolidation of a non-union. One refracture was observed but after a significant trauma in a child who had regained significant physical activity.

CONCLUSIONS

Bone allografting in children with OI is a reliable method of biological fixation, allowing efficient fusion and contributing to increased bone capital and functional outcome.

Which is the best femoral implant in children with osteogenesis imperfecta? a retrospective cohort study of 783 procedures

BACKGROUND

Osteogenesis imperfecta (OI) is a hereditary genetic disorder characterized by bone fragility and extremity deformities. The surgical management for long-bone fractures and deformities in OI remains a challenge. We aimed to compare clinical outcomes after femoral surgery splinted with the telescopic rod, the plate and screws, the elastic nail and the non-elongating rod in setting of OI.

METHODS

 A retrospective cohort study included 783 femoral procedures (mean age 6.00 (interquartile range (IQR) 5.00) years, 335 (42.8%) females) was conducted, and individuals were categorized into four groups according to implants. After verifying comparability among the groups, revision rate and implant survival period were compared among the Sillence types and the same comparison were made among four groups within each Sillence type. The incidence of refractures, deformities, and implant-related complications were also compared among the four groups.

RESULTS

There were no significant differences in demographic information among the four groups in terms of sex (p = 0.101), laterality (p = 0.587), Sillence type (p = 0.122), and postoperative follow-up period (p = 0.214). In total, children with Sillence type III had the highest revision rate and the shortest implant survival period; children with Sillence type I had the lowest revision rate and the longest implant survival period; and children with Sillence type IV had the revision rate and the implant survival period between those observed in Sillence types I and III. In Sillence types III and IV, the telescopic rod had lower revision rate (III 24.8%; IV 20.9%) compared to the plate (III 97.2%, p<0.001; IV 80.3%, p<0.001), the elastic nail (III 100.0%, p=0.019; IV 73.9%, p<0.001) and the non-elongating rod (III 65.0%, p<0.001; IV46.9%, p<0.001); the median implant survival period of the telescopic rod (III 48.00 (IQR 28.50) months; IV 43.00 (33.00) months) is longer than the plate (III 11.00 (9.00) months, p<0.001; IV 19.00 (20.00) months, p<0.001), the elastic nail (III 45.00 (37.75) months, p=1.000; IV 19.00 (35.00) months, p=0.028) and the non-elongating rod (III 39.00 (31.75) months, p=0.473; IV 38.50 (29.75) months, p=1.000).A similar trend was observed in Sillence type I (p = 0.063, p = 0.003; respectively). In addition, the incidence of refracture (15.5%), deformity (2.8%) and implant-related complications (23.1%) were also statistically lower in the telescopic rod group.

CONCLUSION

In our cohort, lower revision rate and longer implant survival period were observed in telescopic rod group. This was mainly due to the significant lower incidence of refracture, deformity and implant-related complications with the use of telescopic rod.

Complications of Elongating Intramedullary Rods in the Treatment of Lower Extremity Fractures for Osteogenesis Imperfecta: A Meta-Analysis of 594 Patients in 40 Years

BACKGROUND

Osteogenesis imperfecta is a collagen mutation-related disease characterized by bone fragility and other extraskeletal manifestations. Intramedullary fixation for deformity correction or fracture is the standard care. Elongating rods are designed to accommodate growth, with the aim of preventing additional operations and/or complications associated with nonelongating rods. Although elongating rods have been in use for many years, estimates of the clinical outcomes vary. We conducted a systematic review and meta-analysis to synthesize the literature on outcomes of elongating rods and nonelongating rods. Meta-analysis was used to compare the complication rates and reoperation rates.

METHODS

We conducted the literature search, systematic review, and meta-analysis in accordance with Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. Comparative cohort studies and large case series detailing complication rates and reoperation rates of elongating and nonelongating rods were included. Random effect models were used to summarize the complication rates and reoperation rates of intramedullary rod procedures.

RESULTS

A total of 397 studies were identified and 24 studies were included in the final cohort. Compared with rates from nonelongating rods, osteogenesis imperfecta Patients using elongating rods had a complication rate of 61% and a reoperation rate of 78%. Reoperation rates dropped with succeeding generations of elongating rods. Pooling data from 600 patients, we identified a 9% complication rate per rod per follow up year and 5% reoperation rate per rod and per follow up year in the cohort of elongating rod fixation. The Bailey-Dubow rod had the highest complication rate per rod per follow up year (12%), largely because of its T piece relate problems. The most popular fixator Fassier-Duval rod had a complication rate per rod per follow up year of 9%. About 68% of complications were mechanical-biological related.

CONCLUSION

Pooling data from published literature demonstrates the advantage of elongating rods over nonelongating rods. However, as high as 9% complication rate per rod per follow up year was associated with elongating fixation. Notably, most complications are both mechanical and biological related.

LEVEL OF EVIDENCE

Level III.

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).

Interlocking Fixation in Fassier-Duval Rods: Performance and Success Factors

INTRODUCTION

Pediatric patients with osteogenesis imperfecta (OI) can be treated with intramedullary Fassier-Duval rod (FDR) systems for limb deformity or recurrent fractures. Single-interlocking pins can improve epiphyseal fixation, but there is a paucity of literature examining incidence of rod migration or pin backout long-term. The purpose of this study is to quantify rates of rod migration and pin backout in OI patients treated with single-interlocking FDRs.

METHODS

A retrospective chart review was performed on pediatric patients treated at a tertiary care center across a 15-year period. Inclusion criteria to select patients was: (1) Pediatric patients (below 18 y of age); (2) Patients with confirmed OI; and (3) Patients with lower extremity fractures or deformity treated with FDRs with distal interlocking pins. Age at time of surgery, rates of obturator migration and pin backout and prominence were collected. We recorded if pin tips were bent by the surgeon during the procedure. Bivariate statistics were used to analyze risk factors for pin backout and prominence.

RESULTS

Twenty-four single-interlocking pin FDRs (21 tibia, 3 femur) were identified. The mean age at index surgery was 5.7±3.4 years, with the mean follow-up time of 7.2±4.7 years. Fourteen (58%) rods underwent revision surgery. Obturator proximal migration was observed in 3/24 rods (13%). No cases of obturator distal migration were observed (0/24, 0%). Mean proximal obturator migration was 2.16±1.8 cm. Revision for pin backout was observed in 10 (42%) rods and pin prominence in 11 (46%) extremities. Bending interlocking pins on at least 1 end was associated with decreased pin backout (P=0.01) and prominence (P=0.04).

CONCLUSIONS

Even with distal interlocking pins, the obturator of FDRs can still migrate over time. Pin backout is a common indication for revision surgery. Bending interlocking pins can decrease rates of pin backout and prominence.

LEVEL OF EVIDENCE

Level III.

Mechanical Analysis of Explanted Telescopic Rods in the Management of Osteogenesis Imperfecta: A Multicenter Study

BACKGROUND

Telescopic rods in the management of osteogenesis imperfecta fail frequently. This could be attributed to technical errors, rod design, and rod structure. We aimed to analyze the mechanical properties and tribology of explanted male and female components to identify effects of in vivo telescoping that may relate to observed patterns of successful telescoping or failure.

METHODS

Recruitment took place at 3 of the 4 English centers for osteogenesis imperfecta. Twenty-five rods explanted for growth or failure during revision to a new rod were analyzed in terms of clinical indication and prerevision imaging to identify if there was a technical mode of failure. Laboratory analysis was performed using optical and scanning electrical microscopy, radiograph diffraction analysis, hardness test, bending test, and energy-dispersive x-ray spectroscopy.

RESULTS

All implants tested were of high-grade stainless steel. Female components had inferior strength [mean Vickers hardness property (HV0.3) at 0.3 to 313 kg] in comparison to male components (HV0.3 406) due to different techniques of manufacture. Female rods also had a higher wear coefficient (7.89×10-12 m3/N/m3) than the male rods (6.46×10-12 m3/N/m3). Abrasive wear, shear deformation, scratches, and wear debris were identified in all rods. Male and female components displayed corrosion contributing to adhesive wear. Intraoperatively cut rods, particularly the female components, had irregular ends leading to more wear.

CONCLUSIONS

Current manufacturing techniques result in inferior material strength in female components compared with males, which combined with wear patterns is likely to lead to implant failure. Intraoperative cutting of rods may increase risk of failure due to wear. Considering techniques to improve strength as well as design in new implants may lead to better outcomes.

LEVELS OF EVIDENCE

Level IV-cross-sectional study.

Efficacy of the "Eiffel tower" double titanium elastic nailing in combined management of congenital pseudarthrosis of the tibia: preliminary outcomes of 17 cases with review of literature

Background

Difficulty in obtaining union, recurrent fractures, and residual deformities remain the problems challenging the management of congenital pseudarthrosis of the tibia (CPT). We applied the “Eiffel Tower” double titanium elastic nails (TENs) in the existing combined approach, which takes advantages of TEN’s mechanical stability with the protection against refracture, Ilizarov’s high fusion rate with alignment control and the biologic environment provided by bone grafting for bony union. The results of this procedure are presented and discussed.

Methods

Seventeen patients with CPT treated by combined surgery including pseudarthrosis resection, the “Eiffel Tower” double TENs technique, autogenous iliac bone grafting, and Ilizarov fixation between 2013 and 2019 were retrospectively investigated. Signs of bone union, limb length discrepancy (LLD), rate of refracture, and degree of residual deformities were reviewed. The AOFAS Ankle Hindfoot scale and measurement of ankle motion were used to evaluate ankle function. The mean follow-up time was 40.5 (11 to 91) months.

Results

The mean age at index surgery was 6.2 (2.5 to 15) years. Union of the pseudarthrosis was achieved in 100% of cases. Among them, 15 (88.2%) patients obtained union of the pseudarthrosis on the first attempt (primary union). The average time to primary union was 3.8 (2 to 6) months. The rest 2 cases achieved union after additional surgeries (secondary union). In terms of complications, refracture occurred in 2 patients (11.8%) and 4 patients (23.5%) developed pin infection. The mean limb length discrepancy at the final follow up was 33.4 (6–141) mm. The average AOFAS score improved from 38.2 (27 to 51) pre-operatively to 77 (63 to 87) post-operatively (p < 0.01).

Conclusions

The “Eiffel Tower” double TENs technique is an ideal intramedullary fixation method in the surgical treatment of CPT. The combination of TENs technique with bone grafting and Ilizarov fixation has the advantages of early bone union, less injury on metaphysis, and early functional recovery.

Level of evidence

Level IV.

Problems, Complications, and Factors Predisposing to Failure of Fassier-Duval Rodding in Children With Osteogenesis Imperfecta: A Double-center Study

BACKGROUND

Although Fassier-Duval (FD) rods have been used for almost 2 decades, knowledge of factors predisposing to their failure is limited. Thus, the purpose of this study was to: (1) present the most common complications of FD rodding, (2) present tips on how to avoid or overcome them, and (3) identify factors predisposing to treatment failure.

METHODS

Fifty-eight rod segments in 19 patients with osteogenesis imperfecta (mainly type III) underwent analysis with a median follow-up (FU) time of 4.4 years. We assessed the total number of complications clinically and radiographically. Next, the possible predisposing factors leading to failure were assessed using the Mann-Whitney U test. In addition, we evaluated the cutoff age for the increased rate of complications using the Youden index. A P<0.05 was considered significant.

RESULTS

The total number of complications reached 44.8%. The most common complications included: migration of the male or female implant (45.7% and 25.7% out of the total number of complications, respectively), bone fracture with bending of the rod (8.6%), and rotational deformities (8.6%). Significant differences in patients' ages at the time of surgery were found between the group with and without complications (P=0.04), while sex, segment treated, preceding surgeries, length of FU, FD rod diameter, and length of bisphosphonate treatment were not significant. The Youden index showed that the risk of complications rose significantly in patients treated when younger than 5.5 years of age (P<0.05).

CONCLUSIONS

This series displays the effectiveness and utility of FD rods at a median FU of over 4 years. Complication rates were comparable with the existing literature, with a notable increase in the number of side effects observed in younger patients (below the age of 5).

LEVEL OF EVIDENCE

Level IV-therapeutic study.

Telescopic rodding in children: Technical progression from Dubow-Bailey to Fassier-Duval™

Medical and surgical treatment of osteogenesis imperfecta has undergone two revolutions that improved quality of life and functional capacity: reduced bone absorption with the use of bisphosphonates, and improvement in internal fixation with the development of Dubow-Bailey then Fassier-Duval™ telescopic rodding. Telescopic intramedullary rodding in osteogenesis imperfecta and in other pathologies (congenital non-union and other congenital bone disorders) progressed with the replacement of the Dubow-Bailey rod by the telescopic Fassier-Duval™ rod. The aim of the present study was to provide an update on a technique that requires the utmost rigor and is not free of complications. Pitfalls and tips-and-tricks are presented in the light of our own experience.

Fassier-Duval Rod Failure: Is It Related to Positioning in the Distal Epiphysis?

BACKGROUND

The relationship between Fassier-Duval (FD) rod placement and rod failure rates has not previously been quantified.

METHODS

Retrospective review was conducted on patients with osteogenesis imperfecta treated with FD rods between 2005 and 2017. Age at first surgery, sex, Sillence type of osteogenesis imperfecta, bisphosphonate treatment, location of rod (side of body and specific bone), and dates of surgeries, radiographs, and rod failures were collected. C-arm images determined rod fixation within the distal epiphysis at the time of surgery. C-arm variables included rod deviation (percent deviation from the midline of the distal epiphysis) and anatomical direction of deviation (anterior/posterior and medial/lateral). X-ray images were examined for rod failure, which was defined as bending, pulling out of the physis, protrusion out of the bone, and/or failure to telescope. Cox proportional hazards regression models were used to compare failure rates with location of placement within the distal epiphysis allowing for clustering of the data by side (left or right) and bone (femur or tibia).

RESULTS

The cohort was 13 patients (11 female individuals and 2 male individuals) with a total of 66 rods and 75 surgeries. Mean time from the first surgery to the last follow-up visit was 8.9 years (SD=5 y). There was a 7% increase in hazard of failure per 1-mm increase in antero-posterior (AP) deviation [hazard ratio (HR), 1.07; 95% confidence interval (CI), 1.01-1.14; P=0.029)]. Similarly, there was a 9% increase in hazard of failure for every 1-mm increase in lateral deviation (HR, 1.09; 95% CI, 1.01-1.18; P=0.019). A 12% increase in hazard of failure per 10% increase in deviation from the midline for both AP and lateral radiograph views was also found, although this was only statistically significant for lateral deviation on the AP radiograph view (HR, 1.12; 95% CI, 1.01-1.25; P=0.030).

CONCLUSIONS

FD rod placement within the distal epiphysis has significant impact on increasing rod survival.

LEVEL OF EVIDENCE

Level III-therapeutic study.

Dislodgement of Telescopic Nail from the Epiphysis: A Case Report with an Analysis of Probable Mechanism

Telescopic nails such as Fassier-Duval (FD) nails have become the standard treatment for stabilizing long bones and correcting deformities in osteogenesis imperfecta (OI). These nails do not require repeat surgery for their replacement when the bones outgrow them. However, they are not completely free from complications. The prohibitive costs of the original implants have led to design modifications being introduced in locally manufactured telescopic nails. While these low-cost devices work well in most cases, they can lead to complications resulting from their design flaws. We present here the complication observed in a locally manufactured telescopic nail with a design similar to the FD nail. The male component of the nail got dislodged from the distal tibial epiphysis, resulting in its proximal migration. We discuss the probable mechanism of this complication and propose possible design changes that can bring down the rates of such incidences.

Fassier-Duval Rods are Associated With Superior Probability of Survival Compared With Static Implants in a Cohort of Children With Osteogenesis Imperfecta Deformities

BACKGROUND

The survival of Fassier-Duval (FD) telescoping rods as compared with static implants in children affected by osteogenesis imperfecta is not well characterized. The purpose of this study was to compare risk of lower extremity implant failure in FD rods versus static implants.

METHODS

Data were retrospectively collected from patients with osteogenesis imperfecta who underwent surgical treatment using either FD rods or static implants (Rush rods, flexible nails, or Steinmann pins) between 1995 and 2015. The timing of implant failure was the primary outcome variable of interest. Comparisons were limited to limbs with no previous history of implants. Cox-proportional hazards regression analyses were used to compare the hazard of implant failure across implants. Negative binomial regression analyses were used to compare the incidence of surgical procedures in the 2 implant groups.

RESULTS

The final cohort consisted of 64 limbs (n=21 patients). The static implant group (n=38) consisted of 24 Rush rods (63%), 14 flexible nails (37%), and 2 Steinmann pins (5%). The hazard of implant failure in the static implant group was 13.2 times [95% confidence interval (CI), 2.5-69.6; P=0.0024] the hazard of implant failure in the FD rod group. The hazard of implant failure among females was 4.8 (95% CI, 1.4-16.7; P=0.0125) times the hazard of implant failure among males. The total surgery rate in the static implant group was 7.8 (95% CI, 1.8-33.0; P=0.0056) times the total surgery rate in the FD group.

CONCLUSIONS

Among surgically naive limbs, FD rods were associated with significantly improved probability of survival compared with static implants.

LEVEL OF EVIDENCE

Level II-retrospective study.

Using a corkscrew-tipped telescopic nail in the treatment of osteogenesis imperfecta: a biomechanical study and preliminary results of 17 consecutive cases

High complication rates were reported with the telescopic nail technique systems. To overcome such technical difficulties, we designed a corkscrew-tipped telescopic nail (CTTN). We biomechanically compared its pullout strength with that of two other tip designs. We used CTTN in 17 patients with osteogenesis imperfecta and reported their preliminary results. Average patient age was 82.6 months, and mean follow-up was 32.0±6 months. Telescoping and osteotomy site healing were assessed using radiological studies. Successful telescoping with event-free osteotomy site healing was achieved in 94.1% of patients; limited telescoping and delayed union were detected in one case each. Our results show that CTTN provides sufficient pullout strength and reduced complication rates compared with other designs.

Initial Experience With Percutaneous IM Rodding of the Humeri in Children With Osteogenesis Imperfecta

BACKGROUND

To report a single-center surgical experience treating humeral deformity and fractures in children with osteogenesis imperfecta (OI) using the Fassier-Duval (FD) intramedullary elongating rods.

METHODS

A retrospective review was conducted between December 2005 and July 2013 of all OI patients who underwent FD rodding with a minimum of 1-year follow-up. All patients were also being concurrently treated with bisphosphonates.

RESULTS

Eighteen patients underwent internal fixation on a total of 35 humeri: 7 males and 11 females with an average age of 49 months. Thirty-five procedures were performed using FD rodding, with 5 utilizing only the male portion. Thirty procedures were primary FD implantation and 5 were revisions. Twelve patients had type III OI and 6 patients type IV OI. Indications for surgery included recurrent fracture, severe bowing deformity, and pain. Osteotomy methods included closed osteoclasis, percutaneous, or open osteotomies. Two patients required transfusions during their hospital stay. At our determined endpoint, 23 humeri (65.7%) had acceptable results with a mean follow-up time of 43 months (SD=27) with no revision. The remaining 12 humeri (34.3%) necessitated revision with a mean time to revision of 35 months (SD=29). Reasons for revision included: migration resulting in pain and functional difficulty (8.6%), migration with bowing (8.6%), and hardware failure secondary to trauma (8.6%). In addition, 2 revisions were required for nonunion (5.7%) and 1 for malunion (2.9%). To our knowledge, all other osteotomies performed during surgery resulted in bony union.

CONCLUSIONS

The use of the FD system for correction of humeral deformity demonstrates a reasonable option to improve comfort and function in children with recurrent fractures and deformity secondary to OI. The FD system allows for decreased revision rates and less morbid instrumentation.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Functional Outcome of Forearm Rodding in Children With Osteogenesis Imperfecta

BACKGROUND

The impact of corrective forearm surgery on functional ability in children with osteogenesis imperfecta (OI) has not previously been reported. This study addresses this issue.

METHODS

A retrospective chart review was conducted on 19 children with OI who underwent 22 corrective forearm procedures between 1996 and 2013. Functional ability was assessed preoperatively and every year postoperatively using the Pediatric Evaluation of Disability Inventory (PEDI).

RESULTS

The mean PEDI self-care score increased by 6.8 (P=0.017) and the mean PEDI mobility score increased by 7.2 (P=0.020) at 1-year postsurgery. Functional gains were greater in moderate OI (types IV, V, and VI) than in severe OI (type III). Improved function was maintained in the majority of cases at a mean of 8.9 years postcorrection.

CONCLUSIONS

Corrective forearm surgery in children with OI leads to improved functional ability.

LEVEL OF EVIDENCE

Level IV.

The Outcomes of Nonelongating Intramedullary Fixation of the Lower Extremity for Pediatric Osteogenesis Imperfecta Patients: A Meta-analysis

BACKGROUND

Osteogenesis imperfecta is usually due to autosomal dominant mutations in type I collagen, leading to an increase in fractures and bone deformities, especially in the long bones of the lower extremities. The use of nonelongating intramedullary rods is an established surgical intervention to address such deformities. The rate of surgical complications has been reported to be as high as 187%, with revision rates as high as 90%, although exact global rates are unknown. As such, we sought to determine the published rates of (1) bone-related complications (including both fracture and deformity), (2) rod migration, and (3) complications that require reoperation.

METHODS

Following the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines, 1295 studies were evaluated. After cross-referencing, and applying specific inclusion and exclusion criteria, a total of 7 studies were included in the final cohort. Data were extracted from the studies and analyzed. Random effect models determined the complication rates of intramedullary nonelongating rod procedures.

RESULTS

A total of 359 primary nonelongating intramedullary rod procedures of tibiae and femurs, in patients with a mean age of 6 years (5.2 to 7.3 y), at a mean follow-up of 63 months (24 to 118 mo), were evaluated. 60% of the surgical procedures were on femurs, and 40% were on tibiae. The reoperation rate was 39.4%. The most common complication was rod migration, with a rate of 25.7%. The rate of bone-related complications was 19.5% including fractures (15.0%) and worsening bone deformity (4.3%).

CONCLUSIONS

This is the first meta-analysis to identify the rates of complication and reoperation in lower limb intramedullary fixation for pediatric osteogenesis imperfecta patients. This study has shown that rod migration is the most common complication, followed by bone-related complications including fractures and deformity. Reoperations occur after nearly 40% of all procedures due to rod migration or bone-related complications.

LEVEL OF EVIDENCE

Level IV-retrospective meta-analysis.

Re-alignment and intramedullary rodding of the humerus and forearm in children with osteogenesis imperfecta: revision rate and effect on fracture rate

PURPOSE

Intramedullary rodding is indicated for patients with osteogenesis imperfecta (OI) to manage deformity and help treat recurrent fractures. Historically, the focus of intramedullary stabilisation has been the lower extremity. Here we report our experience of intramedullary rodding of the humerus and forearm in children with OI and its impact on the fracture rate of those bone segments.

PATIENTS AND METHODS

This is a retrospective chart review of all OI patients who have undergone re-alignment and intramedullary rodding of the humerus or forearm between October 1994 and February 2016. Patient demographics, surgical information, complications and pre-operative and post-operative fracture rates were gathered.

RESULTS

A total of 45 upper extremity segments (26 humeri, 19 forearms) were rodded at an average age of 8.7 years (3.1 to 19.2). Of these, 15 (33.3%) of the bone segments required a return to the operating room at a mean 30.8 months (1 to 90) post-operatively. Fracture data was available for 24 of the bone segments. The average number of pre-operative and post-operative fractures was 3.58 (SD 2.84) and 0.46 (SD 0.72) respectively. The average pre-operative and post-operative fracture rates were 0.87 fractures/year (SD 0.47) and 0.10 fractures/year (SD 0.16) respectively.

CONCLUSION

In this OI population, re-alignment and rodding appeared to reduce the fracture rate of the humerus and forearm. Among our population, one third returned to the operating room and one fifth required revision to a new intramedullary implant. This data may help families better understand the potential outcomes of upper extremity realignment and rodding and its effect on the rate of upper extremity fractures.

Effect of Different Distal Fixation Augmentation Methods on the Pullout Strength of Fassier-Duval Telescoping Rods

Antegrade telescoping rods have been introduced for use in pediatric patients with osteogenesis imperfecta (OI) to decrease the incidence of long-bone fractures and to correct and prevent deformities. Recent studies have documented failures of telescoping intramedullary rods due to inadequate distal fixation. The purpose of this study was to evaluate the pullout strength of distal fixation of the telescoping rod with and without synthetic calcium phosphate or polymethylmethacrylate (PMMA) augmentation. Four sets of 6 telescoping distal fixation rods were fixed according to standard insertion technique into an open-cell rigid-foam synthetic bone block simulating OI bone. The groups tested were as follows: control (no augmentation), 0.75 mL of PMMA-augmented, 0.75 mL of PMMA-rescued (stripped distal fixation, then resecured after PMMA augmentation), and 0.75 mL of bioabsorbable-calcium phosphate (CP)-augmented. All rods were tested to failure. The peak load was recorded. Average pullout strengths were as follows: control, 20±6.6 N; PMMA, 125±16.8 N; PMMA-rescued, 137±11.9 N; bioabsorbable-CP, 81±10.3 N. All augmented groups had significantly higher pullout strength compared with the control (P<.001). The PMMA and PMMA-rescued groups failed at the PMMA/bone interface, whereas the bioabsorbable-CP group failed at the cement/rod interface. All augmented constructs improved pullout strength by at least 400% compared with the control. Bioabsorbable cement may be less detrimental to the physis if pullout still occurs despite augmentation due to its mode of failure. This study provides biomechanical evidence to support the further in vivo investigation of either PMMA or bioabsorbable cement augmentation to improve pullout strength of distal telescoping rod fixation.

Bent Telescopic Rods in Patients With Osteogenesis Imperfecta

BACKGROUND

Telescopic rods require alignment of 2 rods to enable lengthening. A telescopic rod converts functionally into a solid rod if either rod bends, preventing proper engagement. Our goal was to characterize implant bending as a mode of failure of telescopic rods used in the treatment of osteogenesis imperfecta in children.

METHODS

We conducted a retrospective review of our osteogenesis imperfecta database for patients treated with intramedullary telescopic rods at our institution from 1992 through 2010 and identified 12 patients with bent rods. The 6 boys and 6 girls had an average age at the time of initial surgery of 3.1 years (range, 1.8 to 8.3 y) and a total of 51 telescoping rods. Clinic notes, operative reports, and radiographs were reviewed. The rods were analyzed for amount of lengthening, characteristics of bending, presence of cut out, or disengagement from an anchor point. Bends in the rods were characterized by their location on the implant component. The bent and straight rods were compared. Data were analyzed with the Mann-Whitney test (statistical significance set at P≤0.05).

RESULTS

Of the 51 telescoping rods, 17 constructs (33%) bent. The average interval between surgery and rod bending was 4.0 years (range, 0.9 to 8.2 y). Before bending, 11 of 17 telescoping rods had routine follow-up radiographs for review. In 10 of the rods, bending was present when early signs of rod failure were first detected. Rod bending did not seem to be related to rod size. There was no area on the rod itself that seemed more susceptible to bending.

CONCLUSIONS

Rod bending can be an early sign of impending rod failure. When rod bending is first noted, it may predispose the rod to other subsequent failures such as loss of proximal and distal fixation and cut out. Rod bending should be viewed as an indicator for closer monitoring of the patient and discussions regarding future need for rod exchange.

LEVEL OF EVIDENCE

Level III-retrospective review.

Severe osteogenesis imperfecta Type-III and its challenging treatment in newborn and preschool children. A systematic review

Osteogenesis imperfecta (OI) is a group of genetic disorders, of which Type III is the most severe among survivors. The disease is characterised in particular by bone fragility, decreased bone mass and increased incidence of fractures. Other usual findings are muscle hypotonia, joint hypermobility and short stature. Fractures and weak bones may consequently cause limb and spinal deformity and chronic physical disability. Bisphosphonates have revolutionised the treatment of newborn children with severe OI type III. Surgery is still needed in most patients due to high frequency of the fractures. In this systematic review we describe the present state-of-art in treating the most severe type of OI in newborn and preschool children with their bone fractures.

Proximal migration of femoral telescopic rod in children with osteogenesis imperfecta

BACKGROUND

Intramedullary telescopic rod fixation has been used for stabilization of the long bones in growing children who have osteogenesis imperfecta. Proximal migration of the rod is the most common complication of telescopic rodding in the femur. The purposes of this study were to evaluate incidence and temporal pattern of proximal migration of the femoral rod, and to investigate factors related to it.

METHODS

A total of 50 patients with osteogenesis imperfecta, who had femur stabilized by telescopic rod with T-piece, were the subjects of this study. In patients having both the femora stabilized, only 1 femur was randomly selected for analysis. Hence, in 50 femora, migration-free survivorship was analyzed using the Kaplan-Meier method, and association with possible risk factors was analyzed by Cox regression analysis using the proportional hazards model. Factors investigated in the analysis include age at the time of surgery, sex, purpose of the index surgery, residual or developing angular deformity of the femur, rod position at the distal physis, persistent cortical gap at fracture/osteotomy site, Sillence classification, and type of telescopic rod.

RESULTS

Proximal migration was observed in 7 of 50 femora. Cumulative survival without proximal migration was 0.94 (95% CI, 0.87-1.01) in 1 year, and 0.85 (95% CI, 0.75-0.95) in 6 years. Factors significantly associated with proximal rod migration in Kaplan-Meier survivorship analysis and univariate Cox regression analysis were angular deformity, eccentric rod position at the distal physis, and persistent cortical gap. When these factors were analyzed by multivariate analysis, eccentric rod position at the distal physis was the only significant factor with a hazard ratio of 11.74.

CONCLUSIONS

The risk of proximal rod migration can be reduced by complete correction of angular deformity and optimal placement of the rod at the distal physis. Our data also suggest that developing angular deformity or persistent osteotomy/fracture gap requires special attention at the possibility of proximal rod migration during follow-up.

LEVEL OF EVIDENCE

Level III, prognostic study.

Sandwich allografts for long-bone nonunions in patients with osteogenesis imperfecta: a retrospective study

BACKGROUND

Patients with osteogenesis imperfecta often develop nonunions, as internal fixation has limited applicability in this condition. We report the outcomes of a modified "sandwich technique" in the treatment of long-bone nonunions in patients with osteogenesis imperfecta; this technique brings circumferential stabilization and normal collagen to the nonunion site.

METHODS

From May 2003 through February 2012, twelve patients (eight females, four males; median age, 39.0 years; range, eleven to seventy-eight years) who had osteogenesis imperfecta (Sillence type I [three], type III [eight], and type IV [one]) and a combined total of thirteen nonunions (two humeral, two radial, three femoral, four tibial, and two ulnar; median duration, 15.0 months; range, six to 204 months) were treated at our institution with compressed sandwich allograft cortical struts. The struts were fashioned to be wide enough to allow for increased osteoconductive surface area and to approximate a hemicylindrical shape. Treatment history and demographics data were acquired through retrospective chart review. Follow-up radiographs were analyzed by two attending orthopaedic surgeons to determine radiographic findings. The median follow-up time was 4.6 years (range, 2.1 to 10.3 years).

RESULTS

All thirteen nonunions, including one requiring a second graft procedure, healed with abundant, smooth allograft incorporation, resulting in an initial healing rate of 92% because of a refracture in one patient. This patient's nonunion ultimately healed with additional allograft struts and a new intramedullary rod. One patient required removal of prominent screws. The final follow-up examinations revealed no pain or refracture at the original nonunion site. All patients regained their prefracture level of function.

CONCLUSIONS

Sandwich allograft struts constitute a durable, safe method for the stabilization and healing of persistent long-bone nonunions in patients with osteogenesis imperfecta. All patients showed incorporation of the allograft to the native diaphysis.

Advances in the orthopedic management of osteogenesis imperfecta

The long-established study of osteogenesis imperfecta (OI) has opened a realm of scientific research surrounding connective tissue disorders. Over the past decade alone there have been vast advancements in the understanding of the underlying genetic variations of this disease, pharmacologic treatments, and the technological and surgical options for fracture deformity. It is important to appreciate the progressive nature of the advances concerning OI. This article aims to synthesize the expanding evolution of the field surrounding OI over the past decade.

Results of a bone splint technique for the treatment of lower limb deformities in children with type I osteogenesis imperfecta

BACKGROUND

Children with osteogenesis imperfecta (OI) can suffer from frequent fractures and limb deformities, resulting in impaired ambulation. Osteopenia and thin cortices complicate orthopedic treatment in this group. This study evaluates the clinical results of a bone splint technique for the treatment of lower limb deformities in children with type I OI. The technique consists of internal plating combined with cortical strut allograft fixation.

MATERIALS AND METHODS

We prospectively followed nine children (five boys, four girls) with lower limb deformities due to type I OI, who had been treated with the bone splint technique (11 femurs, four tibias) between 2003 and 2006. The fracture healing time, deformity improvement, ambulation ability and complications were recorded to evaluate treatment effects.

RESULTS

At the time of surgery the average age in our study was 7.7 years (range 5-12 years). The average length of followup was 69 months (range 60-84 months). All patients had good fracture healing with an average healing time of 14 weeks (range 12-16 weeks) and none experienced further fractures, deformity, or nonunion. The fixation remained stable throughout the procedure in all cases, with no evidence of loosening or breakage of screws and the deformity and mobility significantly improved after surgery. Of the two children confined to bed before surgery, one was able to walk on crutches and the other needed a wheelchair. The other seven patients could walk without walking aids or support like crutches.

CONCLUSIONS

These findings suggest that the bone splint technique provides good mechanical support and increases the bone mass. It is an effective treatment for children with OI and lower limb deformities.

Use of the Sheffield telescopic intramedullary rod system for the management of osteogenesis imperfecta: clinical outcomes at an average follow-up of nineteen years

BACKGROUND

Elongating intramedullary rods have been used in the management of osteogenesis imperfecta for the past fifty years. The complication rates reported in many reviews of the available techniques have been high. This study reviews the long-term functional outcomes and complications following the use of the Sheffield system of telescopic intramedullary rods.

METHODS

We conducted a retrospective analysis of patients with osteogenesis imperfecta who were at least eighteen years of age and who had at least thirteen years of follow-up. Complications, reoperations, and data from a disease-specific questionnaire and the Short Form-36 questionnaire were recorded.

RESULTS

Data for twenty-two patients with osteogenesis imperfecta who had been treated with Sheffield telescopic intramedullary rods were available at an average of nineteen years after the initial surgery. Reoperations involving thirty-three (50%) of the sixty-six rods were performed: ten rods (15%) were exchanged because of rod disengagement due to growth, thirteen rods (20%) were exchanged because of complications, and ten rods (15%) required further surgery other than exchange because of complications. Mobility was significantly improved at the initial postoperative visit (p = 0.0015), and this improvement was maintained into adulthood (p = 0.0077). Back pain was the most frequent symptom. Symptoms related to rod insertion across the knee and ankle were rare, but symptoms related to proximal femoral trochanteric entry were common. Physeal damage was not seen following surgery, and all rods elongated with growth. All patients were satisfied with the outcome of the surgical procedures. Short Form-36 scores for all physical domains and for social function and vitality were significantly worse than those in a normal population.

CONCLUSIONS

The outcomes of this technique are satisfactory in adulthood; reoperation rates are high but are most commonly related to the patient outgrowing the rods. Concerns regarding insertion of this fixed device at the knee and ankle were unfounded, although proximal femoral fixation remains a problem.

Experience with the Fassier-Duval telescopic rod: first 24 consecutive cases with a minimum of 1-year follow-up

BACKGROUND

The new Fassier-Duval Telescopic IM System (FD-rod) has the advantage of a single entry point over the traditional telescopic rods such as the Bailey-Dubow or Sheffield rods. Although encouraging early results were presented by the originators of the technique at international meetings, there is no formal publication in the literature as yet.

METHODS

We performed a chart and x-ray review of the first 24 consecutive FD-rod insertions in 15 patients (age, 1.5 to 12.5 y) with a minimum of 1-year follow up (1 to 2.4 y) after implantation of femoral and/or tibial FD-rods. Diagnoses included with osteogenesis imperfecta (OI) (15 cases, 9 patients), and other conditions such as congenital tibial pseudarthrosis (CPT) in neurofibromatosis type 1 (NF1) (2 cases), and epidermal naevus syndrome (1 case). In patients with hypophosphataemic rickets (6 cases, 2 patients) the FD-rods were combined with an Ilizarov frame.

RESULTS

We found the OI patient group associated with a 13% reoperation rate (2 of 15 cases) for proximal rod migration and a 40% complication rate (6 of 15 cases): rod migration and limited telescoping (5) and intraoperative joint intrusion (1). There were no infections. All the NF1 CPT (2) and epidermal naevus syndrome (1) cases required several reoperations for nonunion, loss of fixation, shortening (negative telescoping), migration, and/or joint intrusion-mainly due to the severe underlying pathology with insufficient longitudinal or torsional stability and diminished healing capacity. In hypophosphataemic rickets (combined with Ilizarov frame fixation) we found a 50% complication rate (3 of 6 cases) and a 17% reoperation rate (1 of 6): 2 FD-rods did not telescope and 1 case of peroneal neuropraxia required neurolysis.

CONCLUSIONS

In our experience the technique of using FD rods is demanding and associated with some intraoperative and postoperative pitfalls. We are happy to continue its use in OI patients when there is longitudinal stability and sufficient bone healing. However, in circumstances of insufficient stability and bone healing potential, further stabilization that can be achieved with an Ilizarov frame may be beneficial.

Sobrevida de uma haste intramedular extensível (HIMEX) no tratamento de crianças com ostegênese imperfeita

OBJETIVO: avaliar o desempenho da haste extensível ancorada por ganchos (HIMEX) em deformidades da osteogênese imperfeita (OI). MÉTODOS: Todas as crianças operadas com HIMEX entre 1990 - 2004. Foi comparado o número de fraturas, reaparecimento de deformidades e capacidade de deambulação antes e após a HIMEX; incidência de migração e sobrevida da haste por curvas de sobrevivência. RESULTADOS: 14 pacientes (2 a 18 anos), oito do sexo feminino, incluindo 46 procedimentos, 39 primários e sete re-operações. Idade média na primeira fratura de 148,21 dias e média de 42,6 fraturas/paciente pré colocação da HIMEX. Dos 46 procedimentos, 28 no fêmur e 18 na tíbia. Tempo médio de seguimento de 80,21 ± 36,71 meses. Houve diminuição significativa de fraturas/paciente (0,78) e melhora na deambulação em sete dos 14 pacientes. Porcentagem de re-operação de 18% e migração do implante em 12% (05/39). 80 % dos implantes in situ até 108 meses. Implantes na tíbia tiveram sobrevida significativamente menor que os do fêmur. O tipo da OI e a idade na época da cirurgia não influenciaram significativamente a incidência de re-operação. CONCLUSÃO: A HIMEX levou à redução significativa no número de fraturas, incidência menor de migração e sobrevida maior da haste do que a referida na literatura.

Intramedullary osteosynthesis for fracture associated with osteogenesis imperfecta

Our aim was to analyse the complications associated with intramedullary stabilisation of the bone fractures which are a common complication of osteogenesis imperfecta. A total of 12 fractures among six individuals with osteogenesis imperfecta were treated by intramedullary stabilisation. The mean age of the patients (three male and three female) was 19.4 years, range 7-42 years. The most common fracture site was the femoral midshaft (seven fractures). After implant removal, one new fracture and one re-fracture occurred. Operative stabilisation of fractures is a safe treatment option for osteogenesis imperfecta.

Tratamento cirúrgico das deformidades e fraturas em membros inferiores na osteogênese imperfeita

OBJETIVO: Fazer uma revisão dos pacientes portadores de Osteogênese Imperfeita avaliando o tratamento cirúrgico das fraturas e deformidades nos membros inferiores para determinar a eficiência da técnica utilizando as hastes fixas (não-extensíveis). CASUÍSTICA E MÉTODO: Foram revisados os prontuários, radiografias pré-operatórias e pós-operatórias de todos os pacientes portadores de Osteogênese Imperfeita que foram tratados no Alfred I duPont Institute (EUA) entre 1965 e 1999. RESULTADOS: Quatorze pacientes (cinco meninos e nove meninas) foram submetidos às hastes fixas nos membros inferiores com um total de 37 procedimentos realizados. CONCLUSÃO: O procedimento de fixação intramedular com hastes não extensíveis mostrou ser um método de baixa morbidade, capaz de manter e até mesmo de melhorar o status de deambulador destes pacientes.

Modified Sofield-Millar operation: less invasive surgery of lower limbs in osteogenesis imperfecta

We present the results of intramedullary rodding of long bones of the lower limbs in children with osteogenesis imperfecta using a modified Sofield-Millar operation. Fourteen patients (mean age at primary operation was 5 years 11 months) were treated with a modified Sofield-Millar operation which allows minimal bone exposure, preservation of the periosteum and keeping the number of osteotomies to the minimum. Union was achieved in all cases within 7 weeks. Of the 14 patients (29 bones) treated with nonelongating rods, rod revisions were needed in 13 patients (26 bones). We found no statistically significant difference between the width of the bone immediately postoperatively and at the final follow-up. The walking ability was improved in four patients. Advantages of less invasive surgery in osteogenesis imperfecta are rapid bone union, no bone atrophy or nonunion, better postoperative mobility and small scars.

[Diagnosis and therapy of osteogenesis imperfecta]

Osteogenesis imperfecta (OI) is a congenital connective tissue disorder with an incidence of up to 1:30,000. Patients suffer from deformities and fractures, and many of them never reach ambulation. The therapy consists of conservative, medicamentous and operative procedures that are described in this article.

Interlocking telescopic rod for patients with osteogenesis imperfecta

BACKGROUND

Intramedullary fixation with use of a telescopic rod with a T-piece is one of the standard methods for long-bone stabilization in growing children with osteogenesis imperfecta. However, installation and removal of this device can cause substantial damage to the distal joint, which limits its use, especially in the tibia. We devised a modification of the telescopic rod system--the interlocking telescopic rod--in which the obturator is a simple rod with a hole, instead of a T-piece, at its distal end.

METHODS

The clinical and radiographic outcomes were evaluated more than two years following treatment of thirty-two limb segments (twenty-three tibiae and nine femora) with this new rod system in fifteen patients with osteogenesis imperfecta.

RESULTS

All rods were inserted without an arthrotomy of the distal joint, and all telescoped successfully. The interlocking pin used in the first five limb segments backed out between five and thirty-three months postoperatively. A revised fixation technique was used in the remaining twenty-seven limb segments, and the interlocking pin had not backed out at an average 3.1 years postoperatively. Proximal migration of the obturator was observed in four tibiae after 2.5 years. The cumulative survival rate of the rod at four years postoperatively was 88.7%.

CONCLUSIONS

Both insertion and removal of an interlocking telescopic rod are much less invasive than insertion and removal of a conventional telescopic rod with a T-piece anchor. The interlocking pin at the distal epiphysis provides effective anchorage for telescoping. Our interim results showed survival of the device to be comparable with, or better than, that of the conventional telescopic rod.

Surgery versus surgery plus pamidronate in the management of osteogenesis imperfecta patients: a comparative study

The aim of this study was to evaluate the efficacy of pamidronate in the management of osteogenesis imperfecta patients. This study was carried out in two groups. The first was treated only surgically whereas the second was treated by a combined approach, medical and surgical. Forty patients, divided into two groups, were surgically treated in order to correct bony deformities secondary to osteogenesis imperfecta. Group 1: twenty patients were operated at an average age of 6.5 years. Nine were type I, five type III and six type IV. Group 2: this group consisted of 20 patients to whom intermittent intravenous pamidronate were given at regular intervals for an average of 2 years postoperatively. The average age at surgery was 8.5 years. Four patients were type I, six type III, eight type IV, one type V and the remaining one type VII. The results were assessed according to a scoring system suggested and used by the authors since 1999. Group 1: we had three good, nine fair and eight poor results. Group 2: we had 11 excellent, four good and five fair results. The Bone mineral dens (BMD) increased by an average of 35.2% (22.7-112%), and the rate of refracture decreased. Best results in the management of patients can be obtained through the combined approach (surgical and medical treatment). We now advise preoperative and postoperative pamidronate for these patients.

Tibial shaft fractures in children and adolescents

Tibial shaft fractures are among the most common pediatric injuries managed by orthopaedic surgeons. Treatment is individualized based on patient age, concomitant injuries, fracture pattern, associated soft-tissue and neurovascular injury, and surgeon experience. Closed reduction and casting is the mainstay of treatment for diaphyseal tibial fractures. Careful clinical and radiographic follow-up with remanipulation as necessary is effective for most patients. Surgical management options include external fixation, locked intramedullary nail fixation in the older adolescent with closed physis, Kirschner wire fixation, and flexible intramedullary nailing. Union of pediatric diaphyseal tibial fractures occurs in approximately 10 weeks; nonunion occurs in <2% of cases. Some clinicians consider sagittal deformity angulation >10 degrees to be malunion and indicate that 10 degrees of valgus and 5 degrees of varus may not reliably remodel. Compartment syndromes associated with tibial shaft fractures occur less frequently in children and adolescents than in adults. Diagnosis may be difficult in a young child or one with altered mental status. Although the toddler fracture of the tibia is one of the most common in children younger than age 2 years, child abuse must be considered in the young child with an inconsistent history or with suspicious concomitant injuries.

The choice of intramedullary devices for the femur and the tibia in osteogenesis imperfecta

The results of intramedullary rodding of 50 femoral and 25 tibial segments were analyzed retrospectively. The techniques of femoral rodding included single Rush rodding, dual Rush rodding and Sheffield telescoping rodding. Single Rush rods or Sheffield rods were used in the tibia. The frequencies of fractures following rodding and implant-related complications and the interval between initial rodding and rod revision were analyzed. The longevity of the rods was evaluated by survival analysis. In the femur, dual Rush rods and Sheffield rods were equally effective and both were superior to a single Rush rod with reference to each of the outcome variables. The technique of dual Rush rodding was more demanding than telescoping rodding. In the tibia, a single Rush rod was as effective as a Sheffield telescoping rod. Based on our results, a single Rush rod would be the preferred implant in the tibia while in the femur, dual Rush rods or a Sheffield telescoping rod may be preferred.

Bone healing in children with osteogenesis imperfecta treated with bisphosphonates

The long-term effects of bisphosphonate treatment in children with osteogenesis imperfecta (OI) are unknown. The aim of this study was to evaluate whether treatment with bisphosphonates interferes with the healing of fractures in a group of children with OI. Seven subjects (6 boys), aged 11.4 +/- 5.95 years, were followed for 2.5 +/- 0.84 years after the start of treatment with intravenous pamidronate (9 mg/kg/y) and/or oral alendronate (5 or 10 mg/d). Orthopaedic surgery of 24 bones was performed after 2.33 +/- 4.14 months of treatment, with 1.6 +/- 0.84 osteotomies per bone. Ambulation was started after 26.1 +/- 32.28 days. Reoperation was required in 8% of the bones due to fracture below primary fixation. Pseudoarthrosis was seen in one fracture, an osteotomy of the proximal femur (14% of the patients, as expected in an OI population). These results suggest that treatment with bisphosphonates at the administered doses does not interfere with fracture healing. Larger and longer studies are warranted.

Functional analysis of upper limb deformities in osteogenesis imperfecta

The charts and radiographs of 159 children with osteogenesis imperfecta (OI) were retrospectively reviewed to measure the severity of upper limb deformities and to evaluate the functional outcome using the Pediatric Evaluation of Disability Inventory (PEDI). The patients were classified according to the Sillence classification modified by Glorieux: 51 type 1, 33 type 3, 54 type 4, and 21 5ype 5. Fifty-nine patients (37.1%) had deformities of their upper limbs. Children with type 3 OI had the highest incidence and the most severe deformities. The humerus was the most commonly involved bone, followed by the ulna and radius. Upper limb deformities were classified into four groups according to the severity of the maximum deformity angle. The mean self-care scores of PEDI were significantly low only in the group with severe deformities, but mobility scores were dramatically decreased in both the moderate and severe deformity groups. Therefore, upper limb deformities in children with OI do not represent only a cosmetic problem, but may also significantly impair functional activities of daily living.

Arthroscopic-assisted revision of telescopic rods in osteogenesis imperfecta

Bailey-Dubow extensible nails are intramedullary stabilization devices designed to prevent deformities and recurrent long bone fractures in patients with osteogenesis imperfecta. The rods consist of a hollow outer sleeve and a solid inner obturator, allowing for telescoping of the rods and expansion of the device with longitudinal growth of the bone. Migration of the nail into the joint is a known complication of this procedure, which can lead to pain and loss of motion. This is a case report of the use of an arthroscopic approach to manipulate femoral and tibial Bailey-Dubow rods that migrated into the knee joint.

Delayed osteotomy but not fracture healing in pediatric osteogenesis imperfecta patients receiving pamidronate

This study evaluated factors influencing fracture (n = 197) and osteotomy (n = 200) healing in children with moderate to severe OI. Pamidronate treatment was associated with delayed healing after osteotomy, but not after fracture. The data suggest that both pamidronate and mechanical factors influence bone healing in this cohort.

INTRODUCTION

Intravenous pamidronate is widely used to treat children with moderate to severe osteogenesis imperfecta (OI). However, the effect of this treatment on bone healing is not well characterized. We therefore retrospectively analyzed the healing of lower limb fractures and osteotomies in children with moderate to severe OI, both before and after the start of pamidronate treatment.

MATERIALS AND METHODS

Bone healing was evaluated on standard radiographs after 197 lower limb fractures (132 femur and 65 tibia) in 82 patients (age at fracture, 0.0-19.9 years) and 200 intramedullary rodding procedures in 79 patients (age at surgery, 1.2-19.8 years). Delayed healing was diagnosed when a fracture or osteotomy line was at least partially visible 12 months after the event.

RESULTS

Delayed fracture healing was observed more frequently during than before pamidronate treatment. However, the effect of pamidronate was no longer significant when age differences were taken into account (odds ratio [OR], 1.76; 95% CI, 0.61-5.10). Better mobility status was a strong independent predictor of delayed healing after fractures that occurred during pamidronate treatment. After osteotomies, delayed healing was more frequent when pamidronate had been started before surgery (OR, 7.29; 95% CI, 2.62-20.3), and this effect persisted after adjustment for multiple confounders. During pamidronate treatment, older age (OR per year of age, 1.25; 95% CI, 1.06-1.47) and osteotomy of the tibia (OR, 3.51; 95% CI, 1.57-7.82) were independent predictors of delayed healing.

CONCLUSIONS

This study suggests that pamidronate therapy is associated with delayed healing of osteotomy sites after intramedullary rodding procedures. Better mobility status, but not pamidronate treatment, seems to be predictive of delayed healing after fractures.

[Elastic sliding central medullary nailing with osteogenesis imperfecta. Fourteen cases at eight years follow-up]

PURPOSE OF THE STUDY

Elastic sliding centromedullary nailing (ESCN) proposed by Métaizeau in 1987 for the prevention and treatment of limb fractures in osteogenesis imperfecta has never been evaluated. A multicentric serie was studied in order to evaluate results of these procedure.

MATERIAL AND METHODS

Thirty-six ESCN procedures were performed in fourteen patients. Percutaneous pinning was used for the femur and distal tibia and arthrotomy for the distal femur as needed and in all cases for the proximal tibia. The pins were bent in compliance with the principles of the ESCN system. The ends of the pins were bent back to form a U pushed into the epiphysis. Reaxing osteotomies required minimal incisions. Age at the first procedure, the number of procedures and complications, and time between procedures were recorded. Pin overlap and the angle formed were also recorded. Pin gliding was evaluated. Ability to walk with or without assistance was noted.

RESULTS

The medullary canal measured 4 to 10 mm. The first procedure was performed at a mean age of four years (range 15 days to 10 years). Follow-up was eight years (range 1-12). There were 2.5 procedures per patient (range 1-5). Pins had to be changed in 75% of the bone segments. Mean time between two procedures was 3.2 years. There were no cases of defective sliding or infection. There were four cases of secondary fracture with a mean 30% pin overlap, two pin migrations, one nonunion, and one shortening. The majority of the complications occurred after the age of five years. At last follow-up, three patients could not walk, four walked with aids, and eight without aids.

DISCUSSION

The advantages of the technique (size of the pins, nailing without reaming, pin sliding in all cases, low cost) must not overshadow the drawbacks (risk of pin deformation and migration, secondary fracture). Secondary fractures might be limited by discrete valgus of the femoral shaft and preventive pin change when the angle formed approaches 30 degrees and when there is only 30% overlap left. Use of telescopic nails before the age of five years increases the risk of complications while most of the complications observed with ESCN occur after the age of five years. Twenty-five percent of the ESCN complications involved only the femur. The percent of secondary fractures was less than with telescopic nailing (3.6% versus 11%) but there were more cases of nail migration. All pins slid, compared with 6% failure of elongation with telescopic nails. Although proof is not available, surgical treatment of osteogenesis imperfecta before the age of five years appears to provide more rapid functional progress.

CONCLUSION

Sliding centromedulary nailing is an attractive alternative before the age of five years. In older children and to the end of growth, telescopic nail or pinning should be discussed although pinning may permit more secondary fractures which can be limited by rigorous surveillance of pin position.

Osteogenesis imperfecta in childhood: treatment strategies

Osteogenesis imperfecta (OI) is a skeletal disorder of remarkable clinical variability characterized by bone fragility, osteopenia, variable degrees of short stature, and progressive skeletal deformities. Additional clinical manifestations such as blue sclerae, dentinogenesis imperfecta, joint laxity, and maturity onset deafness are described in the literature. OI occurs in about 1 in 20,000 births and is caused by quantitative and qualitative defects in the synthesis of collagen I. Depending on the severity of the disease, a large impact on motor development, range of joint motion, muscle strength, and functional ability may occur. Treatment strategies should primarily focus on the improvement of functional ability and the adoption of compensatory strategies, rather than merely improving range of joint motion and muscle strength. Surgical treatment of the extremities may be indicated to stabilize the long bones to optimize functional ability and walking capacity. Surgical treatment of the spine may be indicated in patients with progressive spinal deformity and in those with symptomatic basilar impression.

Osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a genetically determined disorder of connective tissue characterized by bone fragility. The disease state encompasses a phenotypically and genotypically heterogeneous group of inherited disorders that result from mutations in the genes that code for type I collagen. The disorder is manifest in tissues in which the principal matrix protein is type I collagen (mainly bone, dentin, sclerae, and ligaments). Musculoskeletal manifestations are variable in severity along a continuum ranging from perinatal lethal forms with crumpled bones to moderate forms with deformity and propensity to fracture to clinically silent forms with subtle osteopenia and no deformity. The differential diagnosis includes other entities with multiple fractures, deformities, and osteopenia. Classification is based on the timing of fractures or on multiple clinical, genetic, and radiologic features. Molecular genetic studies have identified more than 150 mutations of the COL1A1 and COL1A2 genes, which encode for type I procollagen. Various systemic treatments have been attempted; however, these interventions have been ineffective or inconclusive or are still experimental. Gene therapy has the potential to increase the synthesis of type I collagen in mild variants and to correct mutations in severe variants, but there are a great number of technical difficulties to overcome. The goals of treatment of OI are to maximize function, minimize deformity and disability, maintain comfort, achieve relative independence in activities of daily living, and enhance social integration. Attainment of these goals requires a team approach to tailor treatment needs to the severity of the disease and the age of the patient. Nonoperative management is the mainstay of orthopaedic treatment, with the goals of preventing and treating fractures and enhancing locomotion. Operative intervention is indicated for recurrent fractures or deformity that impairs function.

Humeral rodding in osteogenesis imperfecta

Seven patients with osteogenesis imperfecta who have undergone humeral rodding were reviewed. Satisfactory functional results were obtained in six of seven patients. We discuss the indications for surgery in our unit, the complications, and the results in comparison with those of other centres.