Conservative Functional Treatment of Acute Fibular Ligament Rupture of the Ankle.

BACKGROUND: Acute rupture of the fibular ligament complex is one of the commonest injuries in sports. Prospective randomized trials in the 1980s led to a paradigm shift from primary surgical repair to conservative functional treatment. METHODS: This review is based on publications retrieved by a selective search in PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) and meta-analyses on surgical versus conservative treatment from the years 1983 to 2023. RESULTS: 10 of 11 prospective randomized trials of surgical versus conservative treatment conducted between 1984 and 2017 did not reveal any significant difference in the overall outcome. These findings were confirmed in two meta-analyses and two systematic reviews that were published between 2007 and 2019. Isolated benefits in the surgical group were outweighed by a variety of postoperative complications. The anterior fibulotalar ligament (AFTL) was ruptured in 58% to 100% of cases, followed by the fibulocalcaneal ligament combined with the LFTA in 58% to 85%, and the posterior fibulotalar ligament (mostly incomplete ruptures) in 1.9% to 3%. CONCLUSION: Conservative functional treatment is now the standard treatment in acute fibular ligament rupture of the ankle because it is low-risk, low-cost, and safe. Primary surgery is indicated in only 0.5% to 4% of cases. Physical examination for tenderness to palpation and for stability, as well as stress ultrasonography, can be used to differentiate sprains from ligamentous tears. MRI is superior only for the detection of additional injuries. Stable sprains can be successfully treated with an elastic ankle support for a few days, and unstable ligamentous ruptures with an orthosis for 5 to 6 weeks. Subsequent physiotherapy with proprioceptive exercises is the best way to prevent recurrent injury.

[125th issue of Der Unfallchirurg and 100 years of the German Society for Trauma Surgery (1922-2022)-A mutual history]. / 125. Band Der Unfallchirurg und 100 Jahre Deutsche Gesellschaft für Unfallchirurgie (1922­2022) ­ eine gemeinsame Geschichte.

The journal Der Unfallchirurg and the German Society for Trauma Surgery (DGU) are connected by a colorful story, which reaches a climax in a mutual anniversary year in 2022. Der Unfallchirurg, initially named the Monthly Journal for Trauma Medicine (Monatsschrift für Unfallheilkunde) had already endured 125 years as the specialist journal of the DGU in 2019; however, in 1944 in the 51st year the publication came to a halt due to the upheaval and serious consequences of the Second World War and only reappeared in 1949 with the 52nd year. In its 100-year history the DGU passed through 4 temporally definable phases with respect to content, politics and personnel, to which must be added its preliminary phase as the Division of Trauma Medicine (Abtheilung für Unfallheilkunde) within the Society of German Natural Scientists and Physicians (GDNÄ). In the synopsis on the history of the specialist journal, this article analyzes the more than 125-year development of the DGU.

[The Foot in Language, Symbols, and Myths]. / Die Bedeutung des Fußes in der Sprache, in Symbolen und Mythen.

In the history of evolution, the human foot is the youngest part of our skeleton and allows plane bipedal walking due to development of a longitudinal and transverse arch of the foot, with a stable, parallel first ray, but sacrificing the ability to grasp. Due to the loss of grasping, the hominoid mothers had to lay down their babies while working. To prevent babies from crying in dangerous surroundings with wild animals, mothers had to calm them with sounds and singing that likely led to language. A third somehow synchronous step was growth of the telencephalon and the development of specialised hands that could produce tools for fishing and hunting. As these elementary changes allowed upright walking and the discovery of new worlds, the foot is really deeply anchored in our speech and has become a symbol for life itself, for the human being as a "pars pro toto", for freedom, power and subjection. According to many myths, metaphors and symbols for the foot also represent life-spending fertility, eroticism, and sexuality. But nevertheless the foot is also a symbol of respect, reverence, and subservience, feet washing and anointing is an act of humility and love. At least we know nowadays that the foot is a subconscious ambassador of our emotions in non-verbal communication. With the help of our feet, we can hunt each other or approach each other, not only symbolically, but also in fact.

BMP-2 gene activated muscle tissue fragments for osteochondral defect regeneration in the rabbit knee.

BACKGROUND: Previously published data indicate that BMP-2 gene activated muscle tissue grafts can repair large bone defects in rats. This innovative abbreviated ex vivo gene therapy is appealing because it does not require elaborative and time-consuming extraction and expansion of cells. Hence, in the present study, we evaluated the potential of this expedited tissue engineering approach for regenerating osteochondral defects in rabbits. METHODS: Autologous muscle tissue grafts from female White New Zealand rabbits were directly transduced with an adenoviral BMP-2 vector or remained unmodified. Osteochondral defects in the medial condyle of rabbit knees were treated with either BMP-2 activated muscle tissue implants or unmodified muscle tissue or remained empty. After 13 weeks, repair of osteochondral defects was examined by biomechanical indentation testing and by histology/imunohistochemistry applying an extended O'Driscoll scoring system and histomorphometry. RESULTS: Biomechanical investigations revealed a trend towards slightly improved mechanical properties of the group receiving BMP-2 activated muscle tissue compared to unmodified muscle treatment and empty defect controls. However, a statistically significant difference was noted only between BMP-2 muscle and unmodified muscle treatment. Also, histological evaluation resulted in slightly higher histological scores and improved collagen I/II ratio without statistical significance in the BMP-2 treatment group. Histomorphometry indicated enhanced repair of subchondral bone after treatment with BMP-2 muscle, with a significantly larger bone area compared to untreated defects. CONCLUSIONS: Gene activated muscle tissue grafts showed potential for osteochondral defect repair. There is room for improvement via the use of appropriate growth factor combinations.

[Experience with the Hind Foot Relaxation Boot]. / Erfahrungen mit dem Rückfußentlastungsstiefel.

The goal of this paper is to report our experience with hindfoot fractures using our specially developed boot, with a follow-up of 557 cases. This boot works like the well-known Allgöwer-Röck ortheses (ARO), but is a hybrid between a boot and an orthesis. It allows full weightbearing without using crutches and completely protects an acutely operated hind foot fracture, hind foot arthrodesis or a hind foot fracture which is suitable for conservative treatment. In its first generation, this boot was custom made and used in 408 cases, from March 1999 to February 2011. This study was performed exclusively at the Department of Traumatology and Reconstructive Surgery in the University Centre of Orthopaedics and Traumatology, since 2013 at the Carl Gustav Carus University Hospital of the Technical University of Dresden (since 2013). The new improved second generation of this boot has been used in 149 patients between March 2011 and February 2016. This model is lighter and safer, due to an aluminium U-profile which is produced in one piece and interposed and fixed with 4 screws into the sole of the boot. The ground reaction forces are transported to the tibial head by this U-profile, to which the dorsal acryl shell for the calf of the Röck system is fixed with 2 screws on both sides, including the free ventral patellar shell. This is closed individually by two quick fastener buckles. This modular system of the second generation boot is now available for all patients in Dresden. These new boots have replaced the use of a wheel-chair for 3 months and are especially useful in bilateral calcaneus fractures - which occur in about 18% of all cases. In these new boots, the whole sole of the boot is in contact with the ground, rather than a surface of 9 × 3 cm as in the Allgöwer-Röck ortheses. As a result, these boots are considered to be superior to the ARO because standing and walking without crutches is much more easier - even for elderly patients. In contrast to the Allgöwer-Röck ortheses, in which no ground reaction forces are transmitted to the free hanging foot, some ground contact in the boot is provided through the metatarsal heads and toes, as the foot is positioned at about 20 degrees of equinus. Due to these conditions, osteopenia of the foot skeleton and deficits of coordination are less often observed clinically after 3 months than has been the case with the ARO. With the Allgöwer-Röck orthesis for only one injured hind foot, the leg length must be corrected by up to 8 to 10 cm for the contralateral shoe sole. On the contrary, this new boot facilitates free walking. In our series of a total number of 557 boots in 401 patients,156 patients wore two boots due to bilateral hindfoot fractures. The patients' mean age was 39.9 years (14 to 80 years), including 83.9% males. With application of low molecular weight heparin and lower leg compression hoses (primarily of the CCL1 type), there was no dislocation of the hindfoot fractures, no wound complication due to pressure in the boot and no deep vein thrombosis leg compression. The main indication for prescribing the boot was 252 bilateral calcaneal fractures. Whereas in the first generation fatigue fracture of the aluminium U-profile was found in 4 of 408 (0.9%) cases. There was only one such case in the second generation (n = 149). The boot was worn during the with the healing time of the fractures for a mean of 12.3 weeks in both groups.

Interlocking Nail Fixation for the Treatment of Displaced Intra-Articular Calcaneal Fractures.

INTRODUCTION: Less invasive restoration of joint congruity and calcaneal shape in displaced intra-articular calcaneal fractures via a sinus tarsi approach followed by percutaneous internal fixation with an interlocking nail results in a low rate of soft-tissue complications and good short-term outcomes1 (Video 1). STEP 1 PATIENT PLACEMENT: Place the patient in the lateral decubitus position, supporting the involved extremity with a soft radiolucent pillow, flex the contralateral knee, check with fluoroscopy before draping, and obtain lateral radiographs. STEP 2 INCISION: Use a sinus tarsi approach for control of the articular reduction. STEP 3 PERCUTANEOUS MANIPULATION OF THE MAIN FRAGMENTS: Percutaneously manipulate the main fragments to facilitate reduction of the main tuberosity fragment toward the sustentacular fragment and subsequent joint reduction. STEP 4 JOINT REDUCTION WITH DIRECT MANIPULATION OF THE MAIN FRAGMENTS THROUGH THE SINUS TARSI APPROACH: Reduce the joint with direct manipulation of the main fragments through the sinus tarsi approach. STEP 5 JOINT FIXATION WITH SCREWS: Check the congruency of the posterior subtalar joint facet, stabilize the posterior facet with 2 screws, reduce the tuberosity against the joint block and anterior process, and temporarily fix with Kirschner wires. STEP 6 INTRODUCTION OF THE INTRAMEDULLARY NAIL: Make a 10-mm vertical incision below the attachment of the Achilles tendon, direct the guidewire toward the center of the calcaneocuboid joint, place the guidewire centrally within the calcaneal body, ream over the guidewire, and introduce the intramedullary nail with the attached aiming device. STEP 7 LOCKING OF THE NAIL: Use the aiming device to position the proximal Kirschner wire into the sustentacular fragment, place the nail so that it hits the sustentaculum tali properly, insert a second Kirschner wire through the other hole of the guiding arm, exchange the wires after drilling for locking screws, apply an end cap to extend the length of nail, if needed, and then verify proper reduction and implant position fluoroscopically. STEP 8 POSTOPERATIVE MANAGEMENT: Manage the patient with continuous passive motion and active range-of-motion exercises of the ankle beginning on postoperative day 2 and allow partial weight-bearing of 20 kg for 6 to 10 weeks. RESULTS: Recently, we reported on 103 patients with 106 intra-articular calcaneal fractures treated with the C-Nail by 4 senior surgeons from February 2011 to October 20131.

Foot and ankle fractures during childhood: review of the literature and scientific evidence for appropriate treatment / Fraturas do tornozelo e do pé na infância: revisão da literatura e evidências científicas para o tratamento adequado

ABSTRACT Foot and ankle fractures represent 12% of all pediatric fractures. Malleolar fractures are the most frequent injuries of the lower limbs. Hindfoot and midfoot fractures are rare, but inadequate treatment for these fractures may results in compartment syndrome, three-dimensional deformities, avascular necrosis and early post-traumatic arthritis, which have a significant impact on overall foot and ankle function. Therefore, the challenges in treating these injuries in children are to achieve adequate diagnosis and precise treatment, while avoiding complications. The objective of the treatment is to restore normal anatomy and the correct articular relationship between the bones in this region. Moreover, the treatment needs to be planned according to articular involvement, lower-limb alignment, ligament stability and age. This article provides a review on this topic and presents the scientific evidence for appropriate treatment of these lesions.

RESUMO As fraturas do tornozelo e do pé representam 12% de todas as fraturas pediátricas. Fraturas maleolares são as lesões mais frequentes dos membros inferiores; fraturas do retropé e mediopé são raras, mas o seu tratamento inadequado pode resultar em síndrome de compartimento, deformidades tridimensionais, necrose avascular e osteoartrose pós-traumática precoce, as quais apresentam impacto significativo na função global do tornozelo e pé. Portanto, os desafios no tratamento dessas lesões na criança são o diagnóstico adequado e tratamento preciso para se evitarem as complicações. O objetivo do tratamento é restaurar a anatomia normal e a relação articular correta entre os ossos da região. Além disso, o tratamento deve ser planejado de acordo com acometimento articular, o alinhamento dos membros inferiores, a estabilidade ligamentar e a idade. O algoritmo de tratamento dos traumas complexos do tornozelo e pé na infância é descrito. Este artigo apresenta uma revisão sobre o tema e as evidências científicas para o tratamento adequado dessas lesões.

Evaluation of bone remodeling in regard to the age of scaphoid non-unions.

AIM: To analyse bone remodeling in regard to the age of scaphoid non-unions (SNU) with immunohistochemistry. METHODS: Thirty-six patients with symptomatic SNU underwent surgery with resection of the pseudarthrosis. The resected material was evaluated histologically after staining with hematoxylin-eosin (HE), tartrate resistant acid phosphatase (TRAP), CD 68, osteocalcin (OC) and osteopontin (OP). Histological examination was performed in a blinded fashion. RESULTS: The number of multinuclear osteoclasts in the TRAP-staining correlated with the age of the SNU and was significantly higher in younger SNU (P = 0.034; r = 0.75). A higher number of OP-immunoreactive osteoblasts significantly correlated with a higher number of OC-immunoreactive osteoblasts (P = 0.001; r = 0.55). Furthermore, a greater number of OP-immunoreactive osteoblasts correlated significantly with a higher number of OP-immunoreactive multinuclear osteoclasts (P = 0.008; r = 0.43). SNU older than 6 mo showed a significant decrease of the number of fibroblasts (P = 0.04). Smoking and the age of the patients had no influence on bone remodeling in SNU. CONCLUSION: Multinuclear osteoclasts showed a significant decrease in relation to the age of SNU. However, most of the immunhistochemical findings of bone remodeling do not correlate with the age of the SNU. This indicates a permanent imbalance of bone formation and resorption as indicated by a concurrent increase in both osteoblast and osteoclast numbers. A clear histological differentiation into phases of bone remodeling in SNU is not possible.

An expedited approach for sustained delivery of bone morphogenetic protein-7 to bone defects using gene activated fragments of subcutaneous fat.

BACKGROUND: Delivery of bone morphogenetic protein-7 (BMP-7) to bone defects can be improved by applying gene transfer methods. However, traditional ex vivo gene therapy approaches are cumbersome and costly, requiring the extraction and culturing of cells. Therefore, we evaluated a novel, expedited ex vivo BMP-7 gene transfer technology based on the use of fragments of subcutaneous fat tissue. METHODS: We created 5-mm mid-femoral bone defects in the right femora of 23 male, syngeneic Fischer 344 rats. Adipose tissue was harvested from the subcutaneous fat depot of two donor rats. Bone defects were treated with either unmodified fat (control group) or adenovirally BMP-7 transduced fat fragments (treatment group). Healing of bone defects was assessed by radiographs, microcomputed tomography (µCT) and histology at 6 weeks after the implantation of fat tissue fragments. RESULTS: Radiographs, µCT-imaging and histology revealed relevant bone formation in six out of 10 rats treated with BMP-7 activated fat grafts. Two of the defects were bridged. By contrast, femora of the control group receiving unmodified fat did not display signs of osseous healing. BMP-7 gene activated fat treatment led to a significantly higher bone volume (11.18 ± 9.48 mm(3) ) than treatment with unmodified fat grafts (3.19 ± 1.68 mm(3) ) (p = 0.008). CONCLUSIONS: Implantation of BMP-7 gene activated fat tissue fragments can elicit regeneration of large bone defects in rats and could become a clinically expeditious strategy for in vivo bone tissue engineering. However, gene expression must be improved in order to reliably induce osseous bridging of critical-size bone defects. Copyright © 2016 John Wiley & Sons, Ltd.

Interlocking Nailing Versus Interlocking Plating in Intra-articular Calcaneal Fractures: A Biomechanical Study.

BACKGROUND: Open reduction and internal fixation with a plate is deemed to represent the gold standard of surgical treatment for displaced intra-articular calcaneal fractures. Standard plate fixation is usually placed through an extended lateral approach with high risk for wound complications. Minimally invasive techniques might avoid wound complications but provide limited construct stability. Therefore, 2 different types of locking nails were developed to allow for minimally invasive technique with sufficient stability. The aim of this study was to quantify primary stability of minimally invasive calcaneal interlocking nail systems in comparison to a variable-angle interlocking plate. MATERIAL AND METHODS: After quantitative CT analysis, a standardized Sanders type IIB fracture model was created in 21 fresh-frozen cadavers. For osteosynthesis, 2 different interlocking nail systems (C-Nail; Medin, Nov. Mesto n. Morave, Czech Republic; Calcanail; FH Orthopedics SAS; Heimsbrunn, France) as well as a polyaxial interlocking plate (Rimbus; Intercus GmbH; Rudolstadt, Germany) were used. Biomechanical testing consisted of a dynamic load sequence (preload 20 N, 1000 N up to 2500 N, stepwise increase of 100 N every 100 cycles, 0.5 mm/s) and a load to failure sequence (max. load 5000 N, 0.5 mm/s). Interfragmentary movement was detected via a 3-D optical measurement system. Boehler angle was measured after osteosynthesis and after failure occurred. RESULTS: No significant difference regarding load to failure, stiffness, Boehler angle, or interfragmentary motion was found between the different fixation systems. A significant difference was found with the dynamic failure testing sequence where 87.5% of the Calcanail implants failed in contrast to 14% of the C-Nail group (P < .01) and 66% of the Rimbus plate. The highest load to failure was observed for the C-Nail. Boehler angle showed physiologic range with all implants before and after the biomechanical tests. CONCLUSION: Both minimally invasive interlocking nail systems displayed a high primary stability that was not inferior to an interlocking plate. CLINICAL RELEVANCE: Based on our results, both interlocking nails appear to represent a viable option for treating displaced intra-articular calcaneal fractures.

Intra-articular Osteotomy for Correction of Malunions and Nonunions of the Tibial Pilon.

Malunions of the tibial pilon lead to painful posttraumatic ankle arthritis and malposition of the hindfoot with severe functional disability. Most will need corrective ankle fusion as a salvage procedure. Joint-preserving correction with secondary anatomic reconstruction for intra-articular malunions is possible only in carefully selected patients with intact cartilage, sufficient bone quality, residual function, and good compliance. Osteotomies of solid malunions are planned according to preoperative computed tomography scans. Bone grafting is needed after resection of a fibrous nonunion or sclerotic or necrotic bone. Especially in young patients, anatomic reconstruction of malunited tibial pilon fractures is a viable treatment alternative.

Secondary Reconstruction for Malunions and Nonunions of the Talar Body.

Malunions and nonunions after central or peripheral fractures of the talar body frequently lead to pain and disability. In properly selected, compliant patients without symptomatic arthritis or total avascular necrosis leading to collapse of the talar dome, and sufficient bone stock, secondary anatomic reconstruction with osteotomy along the former fracture plane and preservation of the essential peritalar joints may lead to considerable functional improvement. Bone grafting is needed after resection of a fibrous pseudarthrosis, sclerotic, or necrotic bone. Malunions and nonunions of the lateral or posterior process are treated with excision of the malunited or loose fragments.

Introduction of a New Locking Nail for Treatment of Intraarticular Calcaneal Fractures.

OBJECTIVES: To reduce the complication rate associated with open reduction and internal fixation of displaced intraarticular calcaneal fractures through extensile approaches, a locking nail system (C-Nail) was developed for internal fixation. DESIGN: Prospective case-control study. SETTING: Two level I trauma centers (university hospital) and 1 large regional hospital in the Czech Republic and Germany. PATIENTS: One hundred three patients (89 male and 14 female; mean age, 45.6 years) with 106 calcaneal fractures were treated between February 2011 and October 2013. INTERVENTION: In all 106 cases, the stainless steel C-Nail with a length of 65 mm, a diameter of 8 mm, and 7 locking options was used for internal fixation. Previous reduction of the posterior facet was performed in 15 cases percutaneously, assisted by arthroscopy and fluoroscopy, and in 91 cases by a sinus tarsi approach. The reduced joint surface was fixed by 1 or 2 compression screws. All other fragments were fixed after reduction and temporary K-wire fixation with the C-Nail introduced percutaneously through the tuberosity and 5 to 6 interlocking screws. The latter were introduced into the sustentacular, the tuberosity, and the anterior process fragments with an aiming device consisting of 3 arms. MAIN OUTCOME MEASURES: Patients were assessed for complications, restoration of Böhler angle, posterior facet reduction with postoperative computed tomography, and weight-bearing radiographs at 6 months. Functional outcome was assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle/hindfoot scale after 6 and 12 months for all patients. RESULTS: Wound edge necrosis was seen in 2 cases (1.9%), and soft tissue infection was observed in 1 case (0.9%). Böhler angle improved from 7.3 degree preoperatively to 28.7 degree at 6 months. The posterior facet step-off was reduced from 5.3 mm preoperatively to 0.7 mm postoperatively. The average AOFAS score averaged 89.5 at 6-month and 92.6 at 12-month follow-up. CONCLUSIONS: The C-Nail is a new locking system for treatment of displaced intraarticular calcaneal fractures combining a primary stability with reduced soft tissue complications. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Foot and ankle fractures during childhood: review of the literature and scientific evidence for appropriate treatment.

Foot and ankle fractures represent 12% of all pediatric fractures. Malleolar fractures are the most frequent injuries of the lower limbs. Hindfoot and midfoot fractures are rare, but inadequate treatment for these fractures may results in compartment syndrome, three-dimensional deformities, avascular necrosis and early post-traumatic arthritis, which have a significant impact on overall foot and ankle function. Therefore, the challenges in treating these injuries in children are to achieve adequate diagnosis and precise treatment, while avoiding complications. The objective of the treatment is to restore normal anatomy and the correct articular relationship between the bones in this region. Moreover, the treatment needs to be planned according to articular involvement, lower-limb alignment, ligament stability and age. This article provides a review on this topic and presents the scientific evidence for appropriate treatment of these lesions.

As fraturas do tornozelo e do pé representam 12% de todas as fraturas pediátricas. Fraturas maleolares são as lesões mais frequentes dos membros inferiores; fraturas do retropé e mediopé são raras, mas o seu tratamento inadequado pode resultar em síndrome de compartimento, deformidades tridimensionais, necrose avascular e osteoartrose pós-traumática precoce, as quais apresentam impacto significativo na função global do tornozelo e pé. Portanto, os desafios no tratamento dessas lesões na criança são o diagnóstico adequado e tratamento preciso para se evitarem as complicações. O objetivo do tratamento é restaurar a anatomia normal e a relação articular correta entre os ossos da região. Além disso, o tratamento deve ser planejado de acordo com acometimento articular, o alinhamento dos membros inferiores, a estabilidade ligamentar e a idade. O algoritmo de tratamento dos traumas complexos do tornozelo e pé na infância é descrito. Este artigo apresenta uma revisão sobre o tema e as evidências científicas para o tratamento adequado dessas lesões.

Gene-activated fat grafts for the repair of spinal cord injury: a pilot study.

BACKGROUND: Spinal cord injury (SCI) is a complex disease requiring a concerted multi-target approach. The most appropriate combination of therapeutic gene, cellular vehicle, and space filling scaffold still has to be determined. We present an approach that employs syngeneic adipose tissue serving as a three-dimensional biological implant, source of progenitor cells, and delivery system for therapeutic genes. In this pilot experiment, we evaluated the feasibility and short-term effects using gene-activated autologous fat grafts after SCI. METHODS: An experimental SCI model was established in syngeneic Fischer 344 rats by a T9-T10 hemimyelonectomy. Fat tissue was harvested from two donor rats. Animals were divided into four groups and treated with either (i) fat grafts activated by an adenoviral vector carrying the human NT-3 cDNA, (ii) or BDNF, (iii) or with untreated fat grafts or (iv) remained untreated. Animals were euthanized either 7 or 21 days after surgery, and spinal cord tissue was investigated by histological and immunohistochemical methods. RESULTS: NT-3 and BDNF were produced by gene-activated fat grafts for at least 21 days in vitro and in vivo. Fat tissue grafts remained stable at the site of implantation at 7 days and at 21 days. Neither BDNF-activated nor NT-3-activated fat graft had a detectable limiting effect on the neuronal degeneration. BDNF recruited microglia to perilesional site and attenuated their inflammatory response. CONCLUSIONS: Gene-activated syngeneic fat tissue serves as a three-dimensional biological material delivering therapeutic molecules to the site of SCI over an extended period of time. The BDNF-fat graft attenuated the inflammatory response. Whether these findings translate into functional recovery will require extended observation times.

The effect of BMP-7 gene activated muscle tissue implants on the repair of large segmental bone defects.

BACKGROUND: This study was conducted in order to investigate the effect of Bone Morphogenetic Protein-7 (BMP-7) transduced muscle cells on bone formation and to further develop an innovative abbreviated ex vivo gene therapy for bone repair. As conventional ex vivo gene therapy methods require an elaborative and time-consuming extraction and expansion of cells we evaluated an expedited approach. Fragments of muscle tissue were directly activated by BMP-7 cDNA and implanted into bone defects. METHODS: 25 male, syngeneic Fischer 344 rats were used in the present study. Muscle tissue was harvested from two donor rats and either transduced with an adenovirus carrying the BMP-7 cDNA or remained unmodified. 5mm osseous defects in the right femora of 23 rats were treated with either unmodified muscle tissue (control group) or BMP-7 activated muscle tissue (treatment group). Six weeks after surgery, rat femora were evaluated by radiographs, micro-computed tomography (µCT) and histology. RESULTS: Implantation of BMP-7 activated muscle grafts led to bony bridging in 5 out of 12 defects (41.7%) and to bone formation without bridging in 2 out of 12 defects. In 2 femoral defects of this group radiographs, µCT-imaging and histology did not reveal significant mineralization. Three animals of the BMP-7 treatment group had to be euthanized due to serious wound infection. The bone volume of the treatment group was significantly (p=0.007) higher compared to the control group. CONCLUSION: This study shows that BMP-7 gene activated muscle fragments have the potential to regenerate critical-size segmental bone defects in rats. However, further development of this promising expedited treatment modality is required to improve the healing rate and to investigate if the high infection rate is related to treatment with BMP-7 activated muscle grafts.

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

BACKGROUND: The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. QUESTIONS/PURPOSES: We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. METHODS: The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. RESULTS: All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. CONCLUSIONS: Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. CLINICAL RELEVANCE: Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

Histological analysis of the structural composition of ankle ligaments.

BACKGROUND: Various ankle ligaments have different structural composition. The aim of this study was to analyze the morphological structure of ankle ligaments to further understand their function in ankle stability. METHODS: One hundred forty ligaments from 10 fresh-frozen cadaver ankle joints were dissected: the calcaneofibular, anterior, and posterior talofibular ligaments; the inferior extensor retinaculum, the talocalcaneal oblique ligament, the canalis tarsi ligament; the deltoid ligament; and the anterior tibiofibular ligament. Hematoxylin-eosin and Elastica van Gieson stains were used for determination of tissue morphology. RESULTS: Three different morphological compositions were identified: dense, mixed, and interlaced compositions. Densely packed ligaments, characterized by parallel bundles of collagen, were primarily seen in the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments. Ligaments with mixed tight and loose parallel bundles of collagenous connective tissue were mainly found in the inferior extensor retinaculum and talocalcaneal oblique ligament. Densely packed and fiber-rich interlacing collagen was primarily seen in the areas of ligament insertion into bone of the deltoid ligament. CONCLUSIONS: Ligaments of the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments have tightly packed, parallel collagen bundles and thus can resist high tensile forces. The mixed tight and loose, parallel oriented collagenous connective tissue of the inferior extensor retinaculum and the talocalcaneal oblique ligament support the dynamic positioning of the foot on the ground. The interlacing collagen bundles seen at the insertion of the deltoid ligament suggest that these insertion areas are susceptible to tension in a multitude of directions. CLINICAL RELEVANCE: The morphology and mechanical properties of ankle ligaments may provide an understanding of their response to the loads to which they are subjected.