Distraction Osteogenesis Reconstruction Following Resection of Bone Sarcomas: Surgical, Functional, and Oncological Outcomes from a Prospective Trial Analysis.

BACKGROUND: While sustainable long-term function has been established for biological reconstruction with distraction osteogenesis (DO) following osseous resections, there is a paucity of published data informing surgeons and patients on important milestones in the reconstructive process. The objectives of this study were to determine when to expect complete bone healing and full weight-bearing as well as to quantify the influence of chemotherapy on the osseous regeneration process. METHODS: Prospectively, pathological and clinical data were collected for 30 consecutive patients who underwent primary or secondary DO-based reconstruction following osseous resection from 2018 to 2021. Serial radiographs indicated the times to cortex formation and full union. An unpaired t test was used to compare the time required for full bone remodeling of segments transported with and without concurrent chemotherapy. RESULTS: The average resection length was 13.6 cm (range, 4 to 22 cm). Patients underwent an average of 6.1 procedures (range, 1 to 14 procedures). Half (50%) of all procedures were planned, while half were unplanned procedures. All patients achieved full, independent weight-bearing at a median of 12 months (interquartile range [IQR], 9 to 16 months). For the 34 segments transported concurrently with chemotherapy, the mean bone healing index (BHI) was 2.3 ± 0.7, and the mean BHI was 1.2 ± 0.4 for the 25 segments without chemotherapy at any point during their transport (p < 0.0001). CONCLUSIONS: All 30 patients achieved full bone healing and independent weight-bearing at a median of 1 year postoperatively and continued to show functional improvement afterward. Surgeons and patients can expect bone healing to be nearly twice as fast for segments transported after completion of systemic chemotherapy compared with segments transported concurrently with adjuvant chemotherapy. LEVEL OF EVIDENCE: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Reconstruction of Bony Defects With Motorized Intramedullary Nails After Tumor Resection.

Motorized intramedullary lengthening nails allow for transport of a bone segment for limb lengthening, deformity correction, healing of nonunion, and intercalary distraction osteogenesis. Resection of tumors involving the bone can result in substantial defects that require reconstruction. Use of these nails allows for a biologic reconstruction with the incorporation of allograft or by distraction osteogenesis. Limb lengthening after an internal hemipelvectomy where the hip joint is resected can be performed to improve gait, decrease pain, and prevent the need for a custom shoe or shoe lift. Using these nails in compression aids the incorporation of intercalary allografts and prevents stress shielding and stress risers within the graft when compared with plating. It also allows for a subsequent lengthening of the limb using the same implant. Plate-assisted bone segment transport or the use of a bone transport nail allows for a true biologic reconstruction of an intercalary defect using distraction osteogenesis. These implants provide the orthopaedic oncologist with more options for reconstruction and the potential to improve the function and outcomes of their patients.

Slipped capital femoral epiphyses: A major on-target adverse event associated with FGFR tyrosine kinase inhibitors in pediatric patients.

Fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors (TKIs) are increasingly being used off label in pediatrics. Long-term safety data are limited, and serious toxicities unique to pediatrics may emerge. In a retrospective analysis of patients less than 18 years of age with recurrent/refractory FGFR altered gliomas treated with FGFR TKIs at MSKCC (n = 7), we observed slipped capital femoral epiphyses in three of seven patients along with increased linear growth velocity. Clinicians should closely monitor bone health and have a low index of suspicion for serious orthopedic complications including slipped capital femoral epiphyses and inform patients of related risks as part of consent when treating with FGFR TKIs.

Case discussions of missed traumatic fractures on computed tomography scans.

Radiological diagnostic errors are common and may have severe consequences. Understanding these errors and their possible causes is crucial for optimising patient care and improving radiological training. Recent postmortem studies using an animal model highlighted the difficulties associated with accurate fracture diagnosis using radiological imaging. The present study aimed to highlight the fact that certain fractures are easily missed on CT scans in a clinical setting and that caution is advised. A few such cases were discussed to raise the level of suspicion to prevent similar diagnostic errors in future cases. Records of adult patients from the radiological department at an academic hospital in South Africa were retrospectively reviewed. Case studies were selected by identifying records of patients between January and June 2021 where traumatic fractures were missed during initial imaging interpretation but later detected during secondary analysis or on follow-up scans. Seven cases were identified, and the possible causes of the diagnostic errors were evaluated by reviewing the history of each case, level of experience of each reporting radiologist, scan quality and time of day that initial imaging interpretation of each scan was performed. The causes were multifactorial, potentially including a lack of experience, fatigue, heavy workloads or inadequate training of the initial reporting radiologist. Identifying these causes, openly discussing them and providing additional training for radiologists may aid in reducing these errors. Contribution: This article aimed to use case examples of missed injuries on CT scanning of patients in a South African emergency trauma setting in order to highlight and provide insight into common errors in scan interpretation, their causes and possible means of mitigating them.

Radiological detection of sharp force skeletal trauma: an evaluation of the sensitivity of Lodox in comparison to CT and X-ray.

Victims of violent crime often have evidence of sharp force trauma (SFT) which needs to be examined to accurately investigate these cases. The abilities of CTs, X-rays, and Lodox to detect skeletal SFT defects and the minimum number of impacts were assessed, as were their abilities to macroscopically interpret SFT with the aim of identifying the class of weapon used. Ten pigs were, post-mortem, stabbed using a kitchen knife on one side of the body and chopped using a panga on the other side. They were then scanned and macerated. The number of SFT defects, type of SFT, and minimum number of impacts identifiable osteologically were recorded, as well as when using each imaging modality. CTs were most sensitive for detecting stab and chop defects (56.7% and 78.3%, respectively) and the minimum number of impacts (82.8%), while X-rays were least sensitive (17.2% for stab wounds, 46.5% for chop marks, and 43.5% for impacts). Lodox detected 26.8% of stab defects, 59.3% of chop marks, and 58.4% of impacts. The type of SFT for more than 70.0% of identified defects was correctly classified using all methods, while only Lodox had moderate sensitivities for stab wounds (52.4%). When radiological assessments of skeletal SFT are required, CTs should be performed, but Lodox can be used as an alternative. However, dry bone analyses still produce the best results and should be performed whenever possible. Macroscopic interpretations of skeletal SFT to broadly determine the class of weapon used is possible radiologically.

Reduced relative fitness in hatchery-origin Pink Salmon in two streams in Prince William Sound, Alaska.

Previous studies generally report that hatchery-origin Pacific Salmon (Oncorhynchus spp.) have lower relative reproductive success (RRS) than their natural-origin counterparts. We estimated the RRS of Pink Salmon (O. gorbuscha) in Prince William Sound (PWS), Alaska using incomplete pedigrees. In contrast to other RRS studies, Pink Salmon have a short freshwater life history, freshwater habitats in PWS are largely unaltered by development, and sampling was conducted without the aid of dams or weirs resulting in incomplete sampling of spawning individuals. Pink Salmon released from large-scale hatchery programs in PWS have interacted with wild populations for more than 15 generations. Hatchery populations were established from PWS populations but have subsequently been managed as separate broodstocks. Gene flow is primarily directional, from hatchery strays to wild populations. We used genetic-based parentage analysis to estimate the RRS of a single generation of stray hatchery-origin Pink Salmon in two streams, and across the odd- and even-year lineages. Despite incomplete sampling, we assigned 1745 offspring to at least one parent. Reproductive success (RS), measured as sampled adult offspring that returned to their natal stream, was significantly lower for hatchery- vs. natural-origin parents in both lineages, with RRS ranging from 0.03 to 0.47 for females and 0.05 to 0.86 for males. Generalized linear modeling for the even-year lineage indicated that RRS was lower for hatchery-origin fish, ranging from 0.42 to 0.60, after accounting for sample date (run timing), sample location within the stream, and fish length. Our results strongly suggest that hatchery-origin strays have lower fitness in the wild. The consequences of reduced RRS on wild productivity depend on whether the mechanisms underlying reduced RRS are environmentally driven, and likely ephemeral, or genetically driven, and likely persistent across generations.

Multiple opportunistic infections (pulmonary tuberculosis, Mycobacterium avium complex and parvovirus B19) in a single patient.

INTRODUCTION: HIV infection is a common disease in the South African population. The virus can lead to the development of many opportunistic infections. This case study examines co-infection with three opportunistic infections and the need for clinical suspicion of infections in our HIV population. PATIENT PRESENTATION: A 36-year-old unemployed female residing in Soweto, Johannesburg, presented at Chris Hani Baragwanath Hospital (CHBAH). She was HIV positive, defaulting treatment, with no other comorbidities. She presented to CHBAH with general body weakness, diarrhoea, cough and constitutional symptoms; clinically she appeared pale and chronically ill. A differential diagnosis was made of multiple infections co-inhabiting the patient. MANAGEMENT AND OUTCOME: The patient had blood, sputum, radiological and invasive bone marrow aspiration, and trephine biopsies completed. The investigations revealed that she was co-infected with Mycobacterium tuberculosis (MTB), Mycobacterium avium complex (MAC) and parvovirus B19. The TB and disseminated MAC infection were managed with rifampicin, isoniazid, ethambutol, pyrazinamide and azithromycin, and reinitiation of antiretroviral (ARV) treatment was planned on further follow-up of the ARV drug resistance test. The parvovirus B19 infection was managed with immunoglobulins (Polygam) and steroids (prednisone). She was discharged successfully for further follow-up. CONCLUSION: A thorough history, clinical examination and subsequent targeted investigations are vital to arriving at the correct diagnosis or diagnoses. The case presented above serves to illustrate how three life-threatening opportunistic infections (OIs), all with differing treatments, may present in a single patient. Clinicians caring for immunosuppressed patients need to remain vigilant for the presence of multiple OIs occurring simultaneously.

Adamantinomatous tumors: Long-term follow-up study of 20 patients treated at a single institution.

BACKGROUND AND OBJECTIVES: Adamantinomas are primary, low-grade malignant tumors of the bone that have metastatic potential to the lungs, lymph nodes, and other regions. The rarity of this disease and its nonspecific symptoms complicate diagnosis. MATERIALS AND METHODS: Records for 20 patients who underwent treatment for adamantinoma from 1975 to 2018 were reviewed for demographic, clinical, and pathological data, treatment details, postoperative complications, and outcomes. RESULTS: Patients presented at a median age of 22 years (1-79 years): 14 patients had a localized primary tumor, three presented with local recurrence, and three with metastatic disease. Median tumor size was 5.7 cm (0.5-15.5 cm). Wide excision was performed primarily in 15 cases; the remaining five patients underwent intralesional curettage. At a median follow-up of 7.3 years, 14 patients had no evidence of disease; two patients were alive with disease, and four patients died from the disease. Local recurrence and distant metastasis occurred at a median of 11.4 years (6 month-19 years) and 15.8 years (4 month-23 years) after diagnosis. CONCLUSIONS: Adequate histopathological diagnosis is crucial to avoid misdiagnosis of this rare tumor. Local and distant recuAbs_Para_meprrence can occur more than 20 years after the initial diagnosis. Life-long follow-up with clinical examination and imaging is required.

Extra-skeletal Ewing Sarcoma of the chest wall in a child.

Chest wall or pleural-based tumours represent a heterogeneous group of lesions that are infrequent in children and infants; however, a large proportion of these lesions are malignant in nature. Categorising them on the basis of primary versus secondary, site of origin (osseous and cartilage, or soft tissue) and tissue composition may assist in narrowing the differential diagnosis. We present a case of a 7-year-old boy with a progressive history of dyspnoea. The initial chest radiograph (CXR) demonstrated complete opacification of the left hemithorax with no air bronchograms. This was associated with the cut-off of the left main bronchus and mediastinal shift to the right. The post-contrast computed tomography (CT) of the chest showed multiple left-sided enhancing pleural-based masses with collapse of the left lung. These lesions were locally invasive as demonstrated by the intra and extra-thoracic extension. There were no associated erosions of the adjacent ribs or intra-tumoural calcifications. Based on the imaging findings, the diagnosis of extra-skeletal Ewing sarcoma (ES-EWS) of the chest wall was made with a differential diagnosis of rhabdomyosarcoma. A core biopsy was performed of the pleural-based mass, and histology with immunohistochemistry confirmed the diagnosis of a malignant small round blue cell tumour; subtype Ewing sarcoma family tumour (ESFT). The child was subsequently commenced on chemotherapy. The diagnosis of ES-EWS should be considered when a child or adolescent presents with an ill-defined, eccentric, chest wall mass in the absence of a lesion with a primary osseous origin. Imaging plays a key role in tumour staging, therapeutic planning and follow-up of patients.

Plate-assisted Bone Segment Transport With Motorized Lengthening Nails and Locking Plates: A Technique to Treat Femoral and Tibial Bone Defects.

This article describes a new bone transport technique for femoral and tibial bone defects using lengthening nails combined with locking plates. We term it plate-assisted bone segment transport (PABST). METHODS: Nine patients with five femoral and four tibial bone defects from open fractures or malignancies were treated between 2016 and 2018. Mean femoral defect length was 9.3 cm (range 7 to 11.5). Mean tibial defect was 8.9 cm (range 4.8 to 15). The patients were evaluated for time to weight bearing, consolidation index, mechanical axis deviation, and limb length discrepancy. RESULTS: Seven of nine patients have fully consolidated. The mean consolidation time was 6.6 months. The consolidation index was 0.9 (femur) and 1.26 (tibia) mo/cm. Two patients required supplementary lengthening. One patient had mild varus, one mild valgus; the remainder had a normal mechanical axis. Limb length discrepancy remained acceptable in all patients. The main complications were heterotopic ossification, delayed healing, and reduced knee motion. CONCLUSION: Bone transport with lengthening nails and locking plates is an effective and patient-friendly way of treating bone defects, eliminating the adverse effects of external fixation and reducing treatment time. The plate provides stability during transport and docking; it can address concomitant fractures and facilitates acute shortenings.

Occurrence, risk factors, and outcomes of bone cement implantation syndrome after hemi and total hip arthroplasty in cancer patients.

BACKGROUND AND OBJECTIVES: Patients undergoing cement fixation for hip arthroplasty are at increased risk of developing bone cement implantation syndrome (BCIS). We sought to determine: what is the occurrence of BCIS in patients with cancer after hip arthroplasty? What are the risk factors in patients with cancer for the development of this syndrome? What is the outcome for patients with cancer having BCIS? METHODS: We identified 374 patients with cancer who underwent cemented hip arthroplasty between 2010 and 2014. Patient characteristics, operative variables, and outcomes were collected. RESULTS: BCIS occurred in 279 (75%) patients. A total of 353 (94%) patients had bone metastases and 179 (48%) patients had lung metastases at the time of surgery. Age greater than 60 (hazard ratio [HR] 2.09, P = .02) and the presence of lung metastases (HR 1.77, P = .019) were associated with increased risk of BCIS. Increased perioperative use of vasopressors (HR 1.72, P = .023) and increased hospital stay beyond 10 days (HR 2.67, P = .003) was associated with BCIS. CONCLUSIONS: BCIS is a frequent clinical event in patients with cancer undergoing femoral cemented arthroplasty with increased risk for patients over age 60 and those with compromised lung function due to lung metastases and lung cancer. Patients who develop BCIS are more likely to require longer postoperative hospitalization. Careful preoperative assessment and intraoperative communication are crucial steps to reduce the consequences of BCIS.

Chronic recurrent multifocal osteomyelitis-case report of two patients and review of literature.

BACKGROUND: Chronic Recurrent Multifocal Osteomyelitis (CRMO) is an autoinflammatory skeletal disease characterized by unifocal or multifocal nonbacterial inflammatory bone lesions in the metaphysis of long bones. Common sites of CRMO are tibia, pelvis, proximal femur, clavicle, calcaneum and vertebrae. However, unifocal presentation or presentation in adults, atypical locations, and absence of recurrence have also been reported. METHODS AND FINDINGS: We describe two cases of female patients with unifocal presentation of nonbacterial inflammatory bone lesions in the upper and lower extremity. Furthermore, a review of literature is presented. CONCLUSION: Although CRMO is seen primarily in children and adolescents, and usually occurs in a multifocal pattern, our cases illustrate that this disease can arise in adult patients and in a single location. The diagnosis of CRMO should be made in a multi-disciplinary approach amongst orthopedic surgeons, radiologists and pathologists.

Anthropogenic habitat alteration leads to rapid loss of adaptive variation and restoration potential in wild salmon populations.

Phenotypic variation is critical for the long-term persistence of species and populations. Anthropogenic activities have caused substantial shifts and reductions in phenotypic variation across diverse taxa, but the underlying mechanism(s) (i.e., phenotypic plasticity and/or genetic evolution) and long-term consequences (e.g., ability to recover phenotypic variation) are unclear. Here we investigate the widespread and dramatic changes in adult migration characteristics of wild Chinook salmon caused by dam construction and other anthropogenic activities. Strikingly, we find an extremely robust association between migration phenotype (i.e., spring-run or fall-run) and a single locus, and that the rapid phenotypic shift observed after a recent dam construction is explained by dramatic allele frequency change at this locus. Furthermore, modeling demonstrates that continued selection against the spring-run phenotype could rapidly lead to complete loss of the spring-run allele, and an empirical analysis of populations that have already lost the spring-run phenotype reveals they are not acting as sustainable reservoirs of the allele. Finally, ancient DNA analysis suggests the spring-run allele was abundant in historical habitat that will soon become accessible through a large-scale restoration (i.e., dam removal) project, but our findings suggest that widespread declines and extirpation of the spring-run phenotype and allele will challenge reestablishment of the spring-run phenotype in this and future restoration projects. These results reveal the mechanisms and consequences of human-induced phenotypic change and highlight the need to conserve and restore critical adaptive variation before the potential for recovery is lost.

Antibacterial effect and proposed mechanism of action of a topical surgical adhesive.

BACKGROUND: Medical adhesives effectively hold closed approximated skin edges of wounds from surgical incisions, including punctures from minimally invasive surgery. In addition, they have been reported to be antibacterial against gram-positive bacteria. METHODS: Using membrane filtration to capture all organisms after contact with 2-octyl cyanoacrylate product for 3 minutes, we quantified the number of survivors. Controls were performed to rule out that the noted level of kill was caused by carryover product in the test system. RESULTS: We found that the product kills >7 logs of gram-positive and gram-negative bacteria. The mechanism of action for the antibacterial effect is described as a function of very low water content. CONCLUSIONS: As an antibacterial agent, the risk of nosocomial infection is greatly diminished, and an uneventful clinical result is facilitated. Bacterial growth cannot occur in the formulation and on contact death rapidly ensues as cellular water diffuses from the cell into the product.

The evolutionary basis of premature migration in Pacific salmon highlights the utility of genomics for informing conservation.

The delineation of conservation units (CUs) is a challenging issue that has profound implications for minimizing the loss of biodiversity and ecosystem services. CU delineation typically seeks to prioritize evolutionary significance, and genetic methods play a pivotal role in the delineation process by quantifying overall differentiation between populations. Although CUs that primarily reflect overall genetic differentiation do protect adaptive differences between distant populations, they do not necessarily protect adaptive variation within highly connected populations. Advances in genomic methodology facilitate the characterization of adaptive genetic variation, but the potential utility of this information for CU delineation is unclear. We use genomic methods to investigate the evolutionary basis of premature migration in Pacific salmon, a complex behavioral and physiological phenotype that exists within highly connected populations and has experienced severe declines. Strikingly, we find that premature migration is associated with the same single locus across multiple populations in each of two different species. Patterns of variation at this locus suggest that the premature migration alleles arose from a single evolutionary event within each species and were subsequently spread to distant populations through straying and positive selection. Our results reveal that complex adaptive variation can depend on rare mutational events at a single locus, demonstrate that CUs reflecting overall genetic differentiation can fail to protect evolutionarily significant variation that has substantial ecological and societal benefits, and suggest that a supplemental framework for protecting specific adaptive variation will sometimes be necessary to prevent the loss of significant biodiversity and ecosystem services.

Whole-Genome Sequencing and Concordance Between Antimicrobial Susceptibility Genotypes and Phenotypes of Bacterial Isolates Associated with Bovine Respiratory Disease.

Extended laboratory culture and antimicrobial susceptibility testing timelines hinder rapid species identification and susceptibility profiling of bacterial pathogens associated with bovine respiratory disease, the most prevalent cause of cattle mortality in the United States. Whole-genome sequencing offers a culture-independent alternative to current bacterial identification methods, but requires a library of bacterial reference genomes for comparison. To contribute new bacterial genome assemblies and evaluate genetic diversity and variation in antimicrobial resistance genotypes, whole-genome sequencing was performed on bovine respiratory disease-associated bacterial isolates (Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida) from dairy and beef cattle. One hundred genomically distinct assemblies were added to the NCBI database, doubling the available genomic sequences for these four species. Computer-based methods identified 11 predicted antimicrobial resistance genes in three species, with none being detected in M. bovis While computer-based analysis can identify antibiotic resistance genes within whole-genome sequences (genotype), it may not predict the actual antimicrobial resistance observed in a living organism (phenotype). Antimicrobial susceptibility testing on 64 H. somni, M. haemolytica, and P. multocida isolates had an overall concordance rate between genotype and phenotypic resistance to the associated class of antimicrobials of 72.7% (P < 0.001), showing substantial discordance. Concordance rates varied greatly among different antimicrobial, antibiotic resistance gene, and bacterial species combinations. This suggests that antimicrobial susceptibility phenotypes are needed to complement genomically predicted antibiotic resistance gene genotypes to better understand how the presence of antibiotic resistance genes within a given bacterial species could potentially impact optimal bovine respiratory disease treatment and morbidity/mortality outcomes.

Distraction osteogenesis reconstruction of large segmental bone defects after primary tumor resection: pitfalls and benefits.

Successful cure is achieved in almost 70% of patients with primary bone sarcomas with currently available therapies. Some soft tissue sarcomas require wide bone resection in order to achieve appropriate margins for cure of disease, and patients undergoing these procedures need durable reconstruction. Biological reconstruction has been shown to provide patients with superior long-term results over other alternatives. Distraction osteogenesis is well studied in the correction of deformities as well as in addressing some congenital musculoskeletal pathologies. The use of this technique in tumor settings has been avoided by many surgeons for a multitude of concerns, including infection risk, potential tumor activation, and uncertainty regarding the effect of systemic therapy on the callus regenerate. We review the use of this reconstruction technique using cases from our institutional experience to illustrate its incorporation into the successful management of orthopedic oncology patients. Distraction osteogenesis is an effective method for reconstructing even large bony defects and is safe in the setting of systemic therapy. This technique has the potential to address some of the common problems associated with orthopedic oncology resection, such as infection and leg length discrepancy.

Antimicrobial Activity of a Novel Vascular Access Film Dressing Containing Chlorhexidine Gluconate.

BACKGROUND: Covering insertion sites with chlorhexidine impregnated dressings has been proven to be clinically effective in reducing catheter related blood stream infections (CR-BSI). Two chlorhexidine gluconate (CHG)-impregnated dressings are commercially available, a polyurethane foam disk and a film dressing containing a chlorhexidine gluconate-impregnated gel pad. While both have demonstrated efficacy in clinical settings, the major drawback of high cost and impaired IV insertion site visibility limits their usage. A new, simple film dressing containing CHG within its adhesive layer is now available. The objective of this study was to test the in vitro antimicrobial efficacy of the new dressing in comparison to the CHG-impregnated gel dressing. METHODS: Quantitative aliquots of suspensions (concentration of 1.0x106 to 5.0x106 cfu/sample) of clinically relevant challenge organisms (Staphylococcus species, gram-negative bacilli, Candida albicans) were incubated in contact with the new CHG-containing film dressing, a placebo version of the same (negative control) and the commercially available CHG-impregnated gel dressing (positive control). Serial dilutions of the surviving organisms were quantified using the pour plate after 1, 3, 5, and 7 days of incubation in order to calculate an antimicrobial log10 reduction for each organism/dressing combination at each point in time. RESULTS: The new CHG-containing film dressing delivered greater than 5.0 log10 reduction throughout the 7 days on all aerobic gram-negative bacilli and Staphylococcus species tested. As of day 1 the CHG-containing film dressing provided greater than 5.0 log10 reduction on Candida albicans. There were no statistically significant differences in the log10 reduction between the two dressings tested. CONCLUSION: The new CHG-containing film dressing was found to be as effective as the chlorhexidine gluconate-impregnated gel dressing on clinically relevant microbes.

Lengthening With External Fixation Is Effective in Congenital Femoral Deficiency.

BACKGROUND: Treatment of congenital femoral deficiency is a complex, multistage protocol and a variety of strategies have been devised to address joint instability, limb length inequality, and deformities. Despite being an important part of the algorithmic approach to the overall treatment of patients with congenital femoral deficiency, a reproducible, safe, and functional treatment for femoral length discrepancy in patients with mild and moderate congenital femoral deficiency has not been reported. QUESTIONS/PURPOSES: (1) Does femoral lengthening by means of distraction osteogenesis, using a monolateral external fixator, result in effective lengthening without loss of hip or knee range of motion? (2) Does femoral lengthening cause an inhibition of femoral growth in patients with congenital femoral deficiency? (3) Do patients/families report satisfactory functional and emotional outcomes after undergoing femoral lengthening? (4) What proportion of patients develops complications after femoral lengthening with this technique? METHODS: Between 2005 and 2009, we evaluated 38 patients for femoral length discrepancy secondary to unilateral congenital femoral deficiency. Thirty-two patients completed treatment with distraction osteogenesis using a monolateral external fixator; general indications for this approach were congenital femoral deficiency Paley Types 1a, 1b, or 2a that had not previously undergone lengthening and had stable hip and knee joints. Of the 32 patients that completed treatment, 30 (94%) were available at a minimum of 2 years (mean, 3 years; range, 2-4.5 years) and were evaluated in this retrospective study. Preoperative and postoperative radiographic analysis, physiotherapy data, patient-based outcomes scores, and complications were reviewed for all eligible patients. Growth inhibition was measured using serial radiographs over the 2-year followup with the unaffected limb considered the norm. Functional and emotional outcomes were reported by adolescent patients or parents of younger children using the Pediatric Orthopaedic Society of North America Pediatric Outcomes Data Collection Instruments (PODCI), a validated patient-based outcomes measure. RESULTS: The mean distal femoral lengthening was 6 cm (SD ± 2 cm; range, 1.6-9 cm), for a mean percent of femoral length discrepancy correction of 112% (SD ± 55%; range, 15%-215%). Comparison of patient preoperative with postoperative mean hip and knee flexion and extension showed no difference with the numbers available (hip flexion: p = 0.219, mean difference of -5, 95% confidence interval [CI], 10, SD = 20; hip extension: p = 0.423, mean difference of -1, 95% CI, 2, SD = 5; knee flexion: mean difference of -7°, SD ± 29°, CI, 15, p = 0.467; knee extension: mean difference of -1°, SD ± 9°, CI, 4, p = 0.757). A comparison of the mean preoperative inhibition of 41% (range, -38% to 300%; SD ± 72; 95% CI, 29%) with the mean postoperative inhibition of 16% (range, -242% to 100%; SD ± 61%; 95% CI, 25%) for a mean postoperative stimulation of 25% (p = 0.055, SD ± 90%; 95% CI, 36%). In all six PODCI categories surveyed, patients had favorable standardized and normative scores, but patients who underwent femoral lengthening greater than 6 cm had both lower global functioning scores (90, SD ± 10 versus 96, SD ± 3, p = 0.043) and worse pain/comfort scores (79, SD ± 25 versus 96, SD ± 7, p = 0.029), and patients who had mean percent femoral lengthening greater than 25% of initial femur length had worse pain/comfort scores (79, SD ± 23 versus 97, SD ± 4, p = 0.012) with similar global functioning scores (90, SD ± 9 versus 96, SD ± 3, p = 0.058). The total number of postsurgical complications was 30 in 60 planned surgical procedures (50%). CONCLUSIONS: Our study results support the use of the described surgical technique for femoral lengthening in treating patients with congenital femoral deficiency. Additional studies are needed both to follow long-term patient-reported outcome measures, especially after a second or third lengthening, and to determine the effect of serial lengthening on the stimulation or inhibition of growth and rate of complications. LEVEL OF EVIDENCE: Level IV, therapeutic study.