REPAIR OF INJURIES TO SOFT TISSUES OF FINGERS—Primary and Secondary Reconstruction

Preservation of maximum function and appearance of the finger can best be attained by wide excision of crushed or traumatized tissue and closure of defects by primary split thickness skin grafts. Primary pedicle flaps are rarely indicated and should be reserved for cover of denuded cortical bone or joint surfaces. In only 1 per cent of fresh injuries were primary pedicle flaps used. Finger length, nail bed and root, bone and tendon can be adequately preserved with minimal morbidity by split thickness skin grafts. Restoration of contour if necessary is best done secondarily, utilizing thenar or hypothenar flaps. These flaps are particularly indicated in the reconstruction of finger tips.     

Extending the reach of the heterodigital arterialized flap by vein division and repair

The heterodigital arterialized flap is ideal for nonsensory reconstruction of sizable soft-tissue defects in the proximal fingers, web spaces, and the hand. The inclusion of a dorsal vein augments the venous drainage of this digital island flap and avoids the problem of postoperative venous congestion, which is a common problem in digital island flaps. However, the presence of a dorsal vein pedicle inhibits flap mobility somewhat, and the reach of the flap is mainly limited to adjacent fingers. In situations that demand a transfer from a nonadjacent donor finger or when the reach from the adjacent donor finger is inadequate, the dorsal vein pedicle can be temporarily divided and then anastomosed microsurgically after flap transfer is performed. This enables the reach of the flap to be extended up to two fingers from the donor finger. The authors performed this "partially free" heterodigital arterialized flap in 11 consecutive patients between 1991 and 2001. The average size of the defects was 4.4 x 2.3 cm. All of the flaps survived completely, without any evidence of postoperative flap congestion. Healing of all of the flaps was primary and did not result in any scarring. All of the donor fingers had "normal" two-point discrimination of 3 to 5 mm. All of the donor fingers retained excellent or good total active motion, as graded by the criteria of Strickland and Glogovac.     

The boomerang flap in managing injuries of the dorsum of the distal phalanx

Finding an appropriate soft-tissue grafting material to close a wound located over the dorsum of a finger, especially the distal phalanx, can be a difficult task. The boomerang flap mobilized from the dorsum of the proximal phalanx of an adjacent digit can be useful when applied as an island pedicle skin flap. The vascular supply to the skin flap is derived from the retrograde perfusion of the dorsal digital artery. Mobilization and lengthening of the vascular pedicle are achieved by dividing the distal end of the dorsal metacarpal artery at the bifurcation and incorporating two adjacent dorsal digital arteries into one. The boomerang flap was used in seven individuals with injuries involving the dorsal aspect of the distal phalanx over the past year. Skin defects in all patients were combined with bone,joint, or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-step procedure preserves the proper palmar digital artery to the fingertip and has proven valuable for the coverage of wide and distal defects because it has the advantages of an extended skin paddle and a lengthened vascular pedicle. When conventional local flaps are inadequate, the boomerang flap should be considered for its reliability and low associated morbidity.     

A versatile one-stage neurovascular flap for fingertip reconstruction: the dorsal middle phalangeal finger flap.

The dorsal middle phalangeal finger flap is an extremely reliable flap that is indicated for fingertip injuries which require sensory reconstruction. This flap originates from the dorsum of the middle phalanx of the finger and is elevated with a vascular pedicle of the digital artery and the dorsal branch of the digital nerve. After transfer of the flap to the injured site, epineural neurorrhaphy is done between the digital nerve and the dorsal sensory branch of the flap. This flap can be thought of as an island flap of the innervated cross-finger flap that provides excellent sensory recovery and aesthetic improvement. We used this flap in a series of eight consecutive patients and were able to follow up seven patients for longer than 6 months (mean follow-up time 10.7 months). All patients achieved measurable two-point discrimination, with an average of 4.9 mm in the moving two-point discrimination. In this study, we report our consecutive series of the dorsal middle phalangeal finger flap and its versatile utility.     

Thumb reconstruction with a sensory flap from the dorsum of the index finger.

The dorsal skin of the index ray is very useful (1) for a one-staged thumb lengthening procedure after amputation, (2) for covering the stump of an avulsed thumb with sensory skin, and (3) for expanding the first web space. The flap may be transferred as a rotation flap, or the dorsal vasculature and nerve supply to the index may be carefully dissected free as a pedicle to permit its use as a neurovascular island flap. We believe that considerably more sensory skin can be transferred by this flap than by the ring finger neurovascular island flap, and that the technical risks and surgical time are less with the index finger flap.     

Finite Element Analysis of Minimal Invasive Transforaminal Lumbar Interbody Fusion

The purpose of our study is to develop and validate three-dimensional finite element models of transforaminal lumbar interbody fusion, and explore the most appropriate method of fixation and fusion by comparing biomechanical characteristics of different fixation method. We developed four fusion models: bilateral pedicle screws fixation with a single cage insertion model (A), bilateral pedicle screws fixation with two cages insertion model (B), unilateral pedicle screws fixation with a single cage insertion model (C), and unilateral pedicle screws fixation with two cages insertion model (D); the models were subjected to different forces including anterior bending, posterior extension, left bending, right bending, rotation, and axial compressive. The von Mises stress of the fusion segments on the pedicle screw and cages was recorded. Angular variation and stress of pedicle screw and cage were compared. There were differences of Von Mises peak stress among four models, but were within the range of maximum force. The angular variation in A, B, C, and D decreased significantly compared with normal. There was no significant difference of angular variation between A and B, and C and D. Bilateral pedicle screws fixation had more superior biomechanics than unilateral pedicle screws fixation. In conclusion, the lumbar interbody fusion models were established using varying fixation methods, and the results verified that unilateral pedicle screws fixation with a single cage could meet the stability demand in minimal invasive transforaminal interbody fusion.     

Groin flap design and versatility

The groin flap is a reliable and well-established reconstructive option for pedicled or free-tissue transfer. Concern regarding its variable vascular origin and caliber has limited its use. To overcome this, a simplified guideline based on the transverse diameter of the patient's index and long fingers at the distal interphalangeal level has been developed. Thus "rule of two finger widths" positions the origin of the vascular pedicle from the femoral vessels two finger widths below the inguinal ligament, the upper flap border two finger widths above the inguinal ligament, the lower flap border two finger widths below the vascular origin, and both parallel to the flap axis, which lies along a line from the vascular origin to the anterosuperior iliac spine. This new groin flap design provides the necessary guidelines for vascular identification, accommodates pediatric and adult stature, and ensures primary donor-site closure if flap dimensions are within the prescribed boundaries. In addition, a new sartorius-cutaneous groin flap is presented. This combines the cutaneous groin flap with the proximal sartorius muscle (up to 15 cm), which is supplied by the deep vessels of the superficial circumflex iliac system. The sartorius-cutaneous groin flap further emphasizes the concept of single-pedicle compound or combined flaps and additionally enhances the extensive reconstructive versatility of previously described groin flaps. Over 200 pedicled and free groin flaps have been performed according to the "rule of two finger widths" over the past 5 years. There have been no complications related to flap design, such as difficulty with flap elevation, marginal necrosis, or donor-site closure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Medial pedicle reduction mammaplasty for severe mammary hypertrophy

Current options in reduction mammaplasty for severe mammary hypertrophy include amputation with free-nipple graft as well as the inferior pedicle and bipedicle techniques. Complications of these procedures include nipple-areola necrosis, insensitivity, and hypopigmentation. The purpose of this study was to determine whether medial pedicle reduction mammaplasty can minimize these complications. Twenty-three patients with severe mammary hypertrophy were studied. The medial pedicle successfully transposed the nipple-areola complex in 44 of 45 breasts (98 percent). Mean change in nipple position was 17.1 cm, and mean weight of tissue removed was 1604 g per breast. Nipple-areola sensation was retained in 43 of 44 breasts (98 percent) using a medial pedicle. Hypopigmentation was not observed, and central breast projection was restored in all patients. This study has demonstrated that medial pedicle reduction mammaplasty is a safe and reliable technique and should be given primary consideration in cases of severe mammary hypertrophy.     

Segmental gracilis free flap based on secondary pedicles: anatomical study and clinical series

The gracilis muscle has been used extensively in reconstructive surgery, based on the proximal dominant pedicle. In the literature, little attention has been paid to the secondary distal pedicles. The distribution of the secondary pedicles of the gracilis muscle was investigated in 20 cadaver thighs. The mean number of secondary pedicles was 2.2 (range, two to three). When two pedicles were present-the most common situation-they were located at a mean distance of 12.4 and 17.5 cm from the knee joint line. The most proximal secondary pedicle was injected with barium sulfate in five specimens, and constant and abundant connections with the main pedicle were noted. A series of seven clinical cases of segmental gracilis free muscle flaps based on a secondary pedicle is reported. The flaps were successfully transferred to reconstruct traumatic defects of limited size, with one case of partial necrosis caused by a technical error. The morbidity of this flap is minimal, the scar is well hidden, the muscle need not be sacrificed, elevation is fast and straightforward under tourniquet control, and the pedicle is sizable. This flap should be considered a viable option when a small, straightforward free flap is needed.     

The mechanism of antler casting in the fallow deer.

The process by which antlers are detached from their pedicles was examined histologically in fallow deer castrated in the autumn to induce precocious casting. Osteoclastic erosion across an abscission line between the dead bone of the antler and the living bone of the pedicle was found to be responsible for the separation of the 2. As early as 3 days after castration, osteoclasts and associated lacunae were present on the sides of the pedicle bone. These were then found in progressively deeper locations, by 2 weeks extending across the entire width of the pedicle. Concomitant with the centripetal spread of osteoclasts was the enlargement of Haversian canals, the surfaces of which became lined with osteoclasts. These widening vascular channels within the bone were filled with connective tissue, which in precasting stages formed a mesodermal pad about 1 mm thick. In later stages, a circumferential cleft was excavated beneath the antler burr, and connective tissues from the surrounding pedicle skin invaded the space between the antler and pedicle. After casting, the ingrowing integumental tissues fused with the mesodermal tissues derived from the vascular channels of the pedicle to give rise to an incipient antler bud beneath the scab. The ingrowth of epidermis capable of de novo hair follicle formation gave rise to the future velvet skin that envelops the elongating antler.     

Antler regeneration: a dependent process of stem tissue primed via interaction with its enveloping skin

Deer antlers are unique mammalian appendages in that each year they are cast and fully regenerate from permanent bony protuberances, called pedicles. In a previous study, we found that there is a difference in the degree of association between pedicle bone and its enveloping skin: tight at the distal third and loose at the proximal two thirds of a pedicle stump. The distal part has been termed the "potentiated" region, and the proximal part the "dormant" region. In the present study, pedicle stumps were artificially created in yearling sika deer by cutting off the tissue distal to either the potentiated or the dormant region. A piece of impermeable membrane was then inserted into the space between the bone and the skin of each treated pedicle stump, while the control pedicles had the same surgery without membrane insertion. The results showed that the inserted membrane blocked pedicle skin participation in the process of antler regeneration. All three potentiated bony pedicle stumps regenerated skin-less antlers; whereas, one of the three dormant bony pedicle stumps failed to regenerate any antler tissue. The other two dormant stumps eventually regenerated normal antlers; however, this only occurred after loss of the inserted membrane. No antler tissue regenerated from the dormant stumps while the inserted membrane remained in place (up to 55 days). All control pedicle stumps regenerated normal antlers. Therefore, we conclude that it is the pedicle bone, but not pedicle skin, that gives rise to regenerating antlers, and that pedicle bone can acquire the potential to regenerate an antler only when it is primed via interaction with its enveloping skin.     

数字化骨科理念辅助椎弓根置钉在寰枢椎不稳中的临床应用

目的:探讨3D打印辅助置钉技术用于寰枢椎不稳椎弓根置钉的安全性及准确性。方法:收集2013年1月到2015年1月西安交通大学第一附属医院收治的寰枢椎不稳病例,术前采用3D打印技术构建个体化3D打印模型,在模型上模拟置钉,获取最佳置钉点、置钉角度等个体化置钉数据,并于术中辅助椎弓根螺钉置入。通过CT扫描评价置钉准确性,测量术前、术后患者寰齿间隙判断寰枢椎复位情况,测量颈延角评价脊髓压迫改善情况,并采用日本骨科学会(JOA)评分判断患者脊髓功能改善情况。术后定期随访观察固定效果、稳定性、神经损伤等手术并发症的发生情况。结果:13例患者均采用3D打印辅助置钉技术进行内固定治疗,手术顺利,术中及术后无血管、神经损伤等并发症,复位及内固定效果满意。共置入椎弓根螺钉31枚,其中29枚完全在椎弓根内,置钉准确率为93.5%。寰枢椎较术前明显复位,术后寰齿间隙、颈延角和JOA评分较术前明显改善,差异具有统计学意义(P0.05)。结论:3D打印技术辅助上颈椎椎弓根置钉的准确性及安全性均较高。     

Manipulabilities of the index finger and thumb in three tip-pinch postures

Tip-pinch, in which the tips of the index finger and thumb pick up and hold a very fine object, plays an important role in the function of the hand. The objective of this study was to investigate how human subjects affect manipulabilities of the tips of the index finger and thumb within the flexion/extension plane of the finger in three different tip-pinch postures. The index finger and thumb of twenty male subjects, were modeled as linkages, based on measurement results obtained using two three-dimensional position measurement devices. The manipulabilities of the index finger and thumb were investigated in three tip-pinch postures, using three criteria indicating the form and posture of the manipulability ellipse of the linkage model. There were no significant differences (p > 0.05, ANOVA) in each criterion of each digit across the subjects, except for two criteria of the thumb. The manipulabilities of the index finger and thumb were separately similar across all subjects in tip-pinch postures. It was found that the manipulability for the cooperation of the index finger and thumb of all the subjects in tip-pinch depended on the posture of the index finger, but not on the posture of the thumb. In two-dimensional tip-pinch, it was possible that the index finger worked actively while the thumb worked passively to support the manipulation of the index finger.     

Index finger position fluctuations reflect multi-muscle coordination

We hypothesized that movement fluctuations in the index finger reflect the integrated result of the coordination of multiple muscles because index finger movements are determined by the cooperation of multiple muscles spanning the metacarpophalangeal (MCP) joint. To evaluate this hypothesis, the aim of the present study was to examine the fluctuations of the index finger in abduction-adduction and extension-flexion directions during a position-holding task using two laser displacement sensors. Eleven healthy men maintained their index finger position while supporting a load at 5% of the maximal voluntary contraction force. To maintain the position of the index finger, displacement of the index finger in the abduction-adduction and extension-flexion directions was measured from a distance with two laser displacement sensors that were positioned to the lateral side of and above the index finger. The index finger movements fluctuated around the target position in not only the abduction-adduction direction but also the extension-flexion direction. The path length of finger displacement and the standard deviation of finger acceleration were significantly greater in the extension-flexion direction than in the abduction-adduction direction. These results suggest that the index finger movements quantified by two laser displacement sensors reflect the coordination of multiple muscles spanning the MCP joint.     

Biochemical and histological study of the ossification in the early developing pedicle of the fallow deer (Dama dama)

To date, no histochemical data exist concerning the process of ossification of developing pedicles in deer. Four different zones of the growing pedicle (subcutaneous tissue; fibrous layer of the periosteum; cambial layer of the periosteum; women bone of the primary spongiosa) were analysed in direct correlation to their histological appearance. The level of extractable specific alkaline phosphatase in the preosseous zones of the pedicle was 4-fold higher than levels in the epiphyseal growth plate previously reported. These results reflect that rapid bone formation takes place in the growing pedicle. Highest buffer-extractable alkaline phosphatase activity was found in the cambial layer directly in front of the mineralization area of the pedicle-bone, connected with maximal values for organically bound phosphate and inorganic phosphate. Moreover, the values for buffer-extractable alkaline phosphatase, organically bound phosphate and inorganic phosphate decreased with increasing mineralization in the zone of the primary spongiosa. The present histological and biochemical findings on the process of ossification in the pedicle show similarities to typical endochondral ossification. The process of pedicle growth may serve as a new and important system for chondrogenic and osteogenic studies, including a better understanding of antler development.     

Posterior interosseous free flap with extended pedicle for hand reconstruction

The anatomy of the posterior interosseous vessels makes them suitable as a donor area of free flap. The skin island can be designed on the perforating vessels of the distal third of the forearm, up to the dorsal wrist crease, to increase the pedicle length (7 to 9 cm). A series of nine flaps transferred to reconstruct hand defects is presented. All flaps were designed over the dorsal distal forearm, and dimensions permitted direct closure of the donor site (up to 4 to 5 cm wide). Apart from a linear scar, donor morbidity was negligible. All transfers were successful. Although its dissection is somewhat tedious, the anatomy of the vascular pedicle is suitable for microanastomosis and the skin island is thin, although hairy. The posterior interosseous free flap with extended pedicle may be a good choice when limited amounts of thin skin and a long vascular pedicle are needed.     

Assessing the Intraoperative Accuracy of Pedicle Screw Placement by Using a Bone-Mounted Miniature Robot System through Secondary Registration

IntroductionPedicle screws are commonly employed to restore spinal stability and correct deformities. The Renaissance robotic system was developed to improve the accuracy of pedicle screw placement.PurposeIn this study, we developed an intraoperative classification system for evaluating the accuracy of pedicle screw placements through secondary registration. Furthermore, we evaluated the benefits of using the Renaissance robotic system in pedicle screw placement and postoperative evaluations. Finally, we examined the factors affecting the accuracy of pedicle screw implantation.ResultsThrough use of the Renaissance robotic system, the accuracy of Kirschner-wire (K-wire) placements deviating <3 mm from the planned trajectory was determined to be 98.74%. According to our classification system, the robot-guided pedicle screw implantation attained an accuracy of 94.00% before repositioning and 98.74% after repositioning. However, the malposition rate before repositioning was 5.99%; among these placements, 4.73% were immediately repositioned using the robot system and 1.26% were manually repositioned after a failed robot repositioning attempt. Most K-wire entry points deviated caudally and laterally.ConclusionThe Renaissance robotic system offers high accuracy in pedicle screw placement. Secondary registration improves the accuracy through increasing the precision of the positioning; moreover, intraoperative evaluation enables immediate repositioning. Furthermore, the K-wire tends to deviate caudally and laterally from the entry point because of skiving, which is characteristic of robot-assisted pedicle screw placement.     

A new island flap transfer from the dorsum of the index to the thumb.

We describe here a new island flap from the dorsum of the index finger, transferred on the first dorsal metacarpal artery with one or two veins and the terminal branches of the radial nerve. This vascular bundle is a reliable one, for we have had no necrosis in 12 consecutive cases. The quality of its venous outflow and the use of a dorsal donor site give it advantages over the Moberg-Littler island flap, unless a dorsal vein from the latter flap is preserved and sutured to a vein in the recipient site. The arterial vascularization without any skin pedicle makes this "kite" flap a more practical one than the "flag" flaps of Vilain or Holevitch or Kuhn. Finally, a one-stage transfer is usually preferable to a two-stage one (e.g. Adamson, Braillar). In a single operation, this transfer provides composite resurfacing of the thumb while bringing in new blood and nerve supply.     

Influences of vascularization and osteogenic cells on heterotopic bone formation within a madreporic ceramic in rats

Research in biomaterials for bone reconstruction has led to elaborate osteogenic composites that combine porous ceramics with bone marrow stromal cells. The aim of this study was to evaluate the influence of direct vascularization of such composites on osteogenesis and the ability to produce a vascularized bone substitute transplant in an ectopic muscular site. Sixty-four coralline biomaterials were implanted in 32 Fisher rats under four conditions: (1) alone (reference group M, n = 16), (2) coated with bone marrow stromal cells (group MC, n = 16), (3) combined with a vascular pedicle (group MV, n = 16), or (4) coated with bone marrow stromal cells and combined with a vascular pedicle (MCV group, n = 16). The number of vessels in the pores (vessel-pore ratio) of the implants and the proportion of pores showing bone ingrowth (bone-pore ratio) were measured at 2, 4, 6, and 8 weeks on four implants of each group. Compared with the reference group, angiogenesis was higher when the biomaterial was combined with a vascular pedicle or was coated with osteoprogenitor cells. The association of both vascular pedicle and osteoprogenitor cells increased vascularization by 60 percent (p = 0.003) and osteogenesis by 62 percent (p < 0.001). A combination of both vascular pedicle and bone marrow osteoprogenitor cells in coralline implants enhances neovascularization and osteogenesis after implantation in ectopic intramuscular sites to a greater extent than either does alone.