Bone regeneration: current concepts and future directions

Bone regeneration is a complex, well-orchestrated physiological process of bone formation, which can be seen during normal fracture healing, and is involved in continuous remodelling throughout adult life. However, there are complex clinical conditions in which bone regeneration is required in large quantity, such as for skeletal reconstruction of large bone defects created by trauma, infection, tumour resection and skeletal abnormalities, or cases in which the regenerative process is compromised, including avascular necrosis, atrophic non-unions and osteoporosis. Currently, there is a plethora of different strategies to augment the impaired or 'insufficient' bone-regeneration process, including the 'gold standard' autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. Improved 'local' strategies in terms of tissue engineering and gene therapy, or even 'systemic' enhancement of bone repair, are under intense investigation, in an effort to overcome the limitations of the current methods, to produce bone-graft substitutes with biomechanical properties that are as identical to normal bone as possible, to accelerate the overall regeneration process, or even to address systemic conditions, such as skeletal disorders and osteoporosis

The free vascularized fibular graft for bridging large skeletal defects of the upper extremity

Large skeletal defects of the upper extremity pose a serious clinical problem with potentially deleterious effects on both function and viability of the limb. Recent advances in the microsurgical techniques involved in free vascularized bone transfers for complex limb injuries have dramatically improved limb salvage and musculoskeletal reconstruction. This study evaluates the clinical and radiographic results of 18 patients who underwent reconstruction of large defects of the long bones of the upper extremity with free vascularized fibular bone grafts. Mean patient age was 27 years (7-43 years) and mean follow-up was 4 years (1-10 years). The results confirm the value of vascularized fibular grafts for bridging large bone defects in the upper extremity. © 2011 Wiley-Liss, Inc

Acute non-traumatic marrow edema syndrome in the knee: MRI findings at presentation, correlation with spinal DEXA and outcome

Purpose: The aim of the study was to present the MRI findings of non-traumatic edema-like lesions presented acutely in the adult knee and to correlate them with the 3-year outcome and the bone mineral density (BMD) in the spine. Materials and methods: Ninety-eight patients (40 men, 58 women, mean age 60.1 +/- 11 years, age range 27-82 years), were followed up clinically as well as with MR imaging, when indicated, for at least 3 years. Patients were classified according to presentation in 3 groups (A: bone marrow edema (BME), B: BME and subchondral fracture, C: BME and articular collapse) and according to outcome in 2 groups (A: reversible BME, B: articular collapse). BMD measurements of the spine were carried out in males over 70 and females over 60 years old using DEXA. Results: The isolated BME pattern was observed in 64.3% (Group A), subchondral fractures without articular collapse in 11.2% (Group B) and articular collapse in 24.5% (Group C). Significant differences were found among the 3 groups at presentation, regarding the age, sex, BMD, affected area and duration of symptoms prior to imaging (p < 0.05). Localization of the lesions in the weight-bearing areas of the knee was shown in 100% of C, in 90.9% of B and in 50.8% of A. The duration of symptoms prior to imaging was longer in C (7.6 +/- 2.8 m) than in A (2.5 +/- 1.7 m) and B (4.0 +/- 3.2 m) (p < 0.05). Group B progressed to articular collapse in 45.5%, the rest demonstrating a favourable outcome. Group C showed clinical improvement in 75% and persistent symptoms that required knee arthroplasty in 25% of cases. Articular collapse was the final outcome in 29.6% and transient BME in 70.4% of patients. These two groups showed significant differences regarding the age (p similar to 0), sex (p=0.002), low BMD (p=0.004), affected area (p similar to 0), presence of subchondral sparing (p similar to 0), duration of symptoms prior to imaging (p similar to 0), time from onset of symptoms to the final outcome (p similar to 0) and need for arthroplasty (p=0.001). None of the patients with transient BME syndrome eventually progressed to articular collapse. Conclusion: In the context of acute non-traumatic knee BME, the age and sex of the patient, the duration of symptoms before imaging, the pattern of BME, and the BMD appear to correlate with the final outcome. (c) 2008 Elsevier Ireland Ltd. All rights reserved

Cortical desmoid and the four clinical scenarios

We reviewed four patients diagnosed with a cortical desmoid lesion at the distal posterior medial femur. Each case reflects a clinical scenario that can be present. Cortical desmoid is a benign, self-limited entity which occasionally can exhibit aggressive radiologic features. Here, we present the specific imaging features in association with patients history and clinical findings facilitating establishment of correct diagnosis. Exact diagnosis is important in order to avoid unnecessary biopsy and complicated therapeutic strategies. © Springer-Verlag 2008

Digital ray reconstruction through distraction osteogenesis: A retrospective study of 82 rays with long-term follow-up

Purpose: The aim of the present study was to present the long-term radiographic results with distraction osteogenesis in traumatic or congenital length discrepancies of long bones of the hand. Methods: The medical records and radiographs of 65 consecutive patients (27 metacarpals and 55 phalanges) with either traumatic or congenital digital length discrepancies were retrospectively reviewed. The mean follow-up was 8.2 years. The mean distraction period was 21 days with a distraction rate of 4 × 0.25 mm/day. Callus consolidation was obtained in all patients. Results: The bones were lengthened by a mean amount of 17.5 mm, with a mean increase in bone length of 68 ± 17.3%. The mean healing index was 28.57 days/cm. Ray reconstruction with callus distraction can be applied effectively in skeletally immature or mature patients with congenital differences of the hand or amputated fingers. Conclusion: A distraction rate of 1 mm/day proved to be a safe rate of lengthening in both metacarpals and phalanges. © 2015 Elsevier Ltd. All rights reserved

Residual malformations and leg length discrepancy after treatment of fibular hemimelia

Abstract Background Fibular hemimelia has been reported as the most common congenital longitudinal deficiency of the long bones. Previous studies have focused on the best treatment options for this congenital condition. There is very little to our knowledge in the literature focused on residual persisting malformations and leg length discrepancy after treatment. Methods Seven patients presenting fibular hemimelia in eight fibulae received treatment between years 1988 and 2001. Pre-treatment average leg length discrepancy was 5.3 cm. All patients presented associated congenital deformities of the ipsilateral leg. Six patients received surgical treatment. Average post-treatment follow up was 9.7 years. Residual malformations and leg length discrepancy were recorded for all patients. It is a retrospective case series study at one institution by two of the presenting authors as senior surgeons. Results Average leg length gained after successful bone lengthening in six patients was 5.06 cm. Although there was a significant functional improvement, a number of residual malformations and leg length inequality was recorded. Residual average leg length discrepancy of 3.1 cm was observed in five patients who completed surgical treatment. Five patients presented a limp. Residual anterior-medial bowing of the tibia was observed in four patients. Calf atrophy was present in all seven patients. Valgus deformity of the ankle was remained in two patients. Conclusions Treatment of fibular hemimelia, even in cases graded as successful, showed to be accompanied by a number of persisting residual deformities and recurrent leg length inequality. Although the number of patients is limited, the high rate of this phenomenon is indicative of the significance of the report. The family and the patients themselves should have the right expectations and will be more co-operative when well informed about this instance. A report of common post-treatment residual deformities should be valuable in best possible treatment planning of fibular hemimelia.</p