Effect of Lengthening Rate on Angiogenesis during Distraction Osteogenesis

Abstract

This study investigated the angiogenic response to four varying rates (0.3,0.7,1.3, and 2.7 d d a y ) of distraction in a rabbit model of leg-lengthening. Immunostaining was performed with use of specific antibodies to type-IV collagen and endothelial cell antigen to examine semiquantitatively the presence of blood vessels in the developing tissues. With use of the Chalkley counting method, the greatest number of positivestaining blood vessel cells was found in the central fibrous zone of the groups that underwent lengthening at 0.7 and 1.3 mmlday compared with any other zone in any group (p < 0.05, t test). There were no statistical differences in the positive labeling indices in the mineralization front and the new bone zone adjacent to the mineralization front in any of the groups. However, the decrease in the number of positive-staining blood vessel cells in the new bone zone distant to the mineralization front compared with any other zone in any group was statistically significant. The results suggest that during distraction osteogenesis. the precursor cells of new capillaries were present in abundance within the fibrous interzone. These cells connected into the capillary network at the junction of the mineralization front and the fibrous zone. The angiogenic response was weaker in the more mature regions within the new bone zones. A slow rate of distraction (0.3 d d a y ) did not maximally stimulate angiogenesis in the central fibrous zone, whereas high rates (2.7 d d a y ) appeared to impair this response. In this model of distraction osteogenesis, the vascularization process in the central fibrous zone was maximally stimulated at distraction rates of 0.7 and 1.3 mdday. Miner Res 8(SuppI2):S499-S502.1993Schor AM, Canfield AE, Sutton AB. Arciniegas E. Allen TD:Pericyte differentiation. Clin Orthop 31381-91.1995 Trueta J Blood suppIy and the rate of healing of tibia1 fractures.

Bone formation is enhanced by thrombin‐related peptide TP508 during distraction osteogenesis

“…Previously reports using this model have shown that the optimal rate of lengthening is between 0.7 and 1.3 mm, twice daily lengthening [6,7]. However, when lengthened at a higher rate (>1.3 mm/day), the rate of consolidation is decreased, the quality of bone formation is poor and there is a high incidence of soft tissue complications [7,9,17]. In this study, we deliberately chose a fast rate of lengthening (1.4 m d o n c e a day) to mimic clinical situations of poor bone formation during distraction osteogenesis.…”

“…Mid-tibia1 osteotomies were performed in 30 adult male NZW rabbits (age 24 weeks, body weight 2.6-3.5 kg; mean 2.68 * 0.26 kg), with the tibiae stabilized with external fixators as previously described [6,7]. After a 7-day latency period, once daily lengthening was initiated at rate of a 1.4 mm/day for 6 days.…”

Low intensity pulsed ultrasound accelerated bone remodeling during consolidation stage of distraction osteogenesis

“…Bone lengthening using monolateral or circular fixation method is an effective surgical approach in managing difficult orthopedic conditions, such as bone deformity, bone shortening, and bone defects. [1][2][3] Normally, a distraction rate of 0.7-1.3 mm per day was found beneficial for distraction osteogenesis in the rabbit tibial model [4][5][6] and, therefore, a distraction rate of 1 mm per day was adopted and recommended clinically, 7 followed by a sufficient latency period. 8 Complication was, however, reported due to delayed consolidation associated with long sufficient time for neocorticalization and bone maturation 9 and utilization of different lengthening methods.…”

Novel application of HA‐TCP biomaterials in distraction osteogenesis shortened the lengthening time and promoted bone consolidation

“…11 During DO, bone formation occurs in parallel with the tension force, leading to rapid bone formation and remodeling. [2][3][4] The DO technique has been widely used clinically, such as limb reconstruction following bone loss caused by trauma, infection, and tumor resection. 1,2,7,8,11 However, for larger extent lengthening it requires a longer time, as the lengthening rate is around 0.5-1 mm/day and a lengthy period of external fixation is usually needed to allow the newly formed bone to consolidate, during which period complications such as refracture or nonunion of the regenerate at the distraction gap are often seen.…”

“…1 During DO, new bone is formed rapidly and is accompanied with advanced angiogenesis and tissue remodeling. [2][3][4] The DO technique has been perfected by Ilizarov and others [5][6][7][8] over the last 2 decades, and it has been widely applied in the managements of bone defects, limb deformities, and fracture nonunions. However, for the management of larger bone defects caused by trauma, bone infection, and bone tumors, the long duration associated with DO treatment and the bone consolidation phase can cause considerable morbidity for the patients, such as refracture, nonunion, infection of pin hole, etc; 7,9-11 and in clinical practice, there is a need for shortening the treatment time of DO and augmentation of bone consolidation during DO.…”