Distraction osteogenesis in combined sequential use of external fixation and nailing (lengthening and then nailing): An experimental study in rabbits.

Limb lengthening relies on the process of distraction osteogenesis. The active periosteal bone formation has been detected in clinical practice with a lengthening and then nail (LATN) technique but has not been confirmed by experimental studies to date. The aim of this study is to compare the tissue regeneration of the distraction regenerate during tibial lengthening in rabbits using a LATN technique. This study was performed on 54 mature rabbits of the Soviet Chinchilla breed, which were divided into three groups of 18 animals. In group 1 (control), the tibia was lengthened in an external fixator. In group 2, the LATN technique was modeled and in group 3, lengthening over nail (LON) was modeled. The total duration of the experiment was 45 days. On the 10th, 15th, 20th, 30th, and 45th day X-ray, computed tomography and morphological studies were performed. In the experimental groups (2 and 3), a more pronounced periosteal bone formation in the area of regenerate was noted when compared to group 1. In group 2 (LATN), wide cortical plates were formed from the intermediate and periosteal areas. In this group, the maximum densitometric density values were noted. Endosteal bone formation was preserved in all groups. The LON and LATN techniques, when compared with the classical Ilizarov lengthening, do not demonstrate any deficiency in the tissue regeneration of the bone tissue at the regenerate sites. The most powerful bone structures are formed with the sequential use of the external fixation and nailing (LATN).

Universal Long Bone Nonunion Classification.

Aim and background: The management of bone union disorders is a complex problem in orthopaedics, requiring a reliable and comprehensive classification system for accurate diagnosis and treatment. Despite advances in understanding pathophysiology, diagnosis, and treatment in this area, there is no generally accepted classification system. The aim of our work was to create a comprehensive classification, which will systemize the vast majority of bone union disorders, underline their differences and form the basis for their treatment. Methods: The key criteria for nonunion evaluation and treatment were identified based on the conducted literature review: Time from the initial event (delayed union or nonunion), location, type of pathology (A, Hypertrophic; B, Normotrophic; C, Oligotrophic) and the presence of hardware. Based on these criteria the ULBNC has been developed. Atrophic nonunions were excluded from this classification as they are considered segmental bone defects with special classification. Results: The ULBNC is based on the same principles of coding as the "gold standard" AO/OTA Fractures Classification system with alpha-numeric coding "from simple to complex." The choice of treatment method depends on the type, group, and subgroup of the nonunion as described. Conclusion: Universal Long Bone Nonunion Classification (ULBNC) is an alphanumeric system that describes the localization, type of pathology and morphologic characteristics of a nonunion. The use of ULBNC in practice and research will optimize and standardize the treatment of various types of bone healing disorders and eventually improve clinical outcomes. How to cite this article: Solomin LN, Semenistyy AA, Komarov AV, et al. Universal Long Bone Nonunion Classification. Strategies Trauma Limb Reconstr 2023;18(3):169-173.

Knee Joint Bone Defects: Reconstruction With Bone Transport and Arthrodesis.

BACKGROUND: The increasing in primary total knee arthroplasty has led to an increase in infectious complications, revision surgery, and bone loss. Knee joint bone defects (KJBD) may be managed using bone transport and arthrodesis with Ilizarov or bone transport over nail (BTON) techniques. The aim of this study is to compare both techniques in the reconstruction of KJBDs. METHODS: This was a retrospective cohort study of 29 patients with extensive KJBD. All patients underwent reconstruction of the KJBD using bone transport (either Ilizarov or BTON techniques). The primary outcome variables for comparison between the two groups included time in frame (days), external fixation index (EFI, days/cm), residual limb length discrepancy (cm), and complications (Caton classification). RESULTS: Gender and age profiles were comparable. Mean time spent in frame for bone transport was 566 days (σ = 236, 95% CI 429-702) for the Ilizarov cohort and 191 days (σ = 162, 95% CI 101-280) for BTON (P < .0001). EFI for the period of bone transport was 75.1 d/cm (σ = 41.5, 95% CI 51.1- 99.1) for the Ilizarov cohort and 24.7 d/cm (σ = 24.0, 95% CI 11.4-38) for BTON (P = .0004). Union, limb length discrepancy and complication rates were comparable between both groups. CONCLUSION: For the management of KJBD after failed total knee arthroplasty, BTON is preferred due to significantly less time spent in frame, lower EFI, and higher rates of normal mechanical alignment. The Ilizarov method may be useful when there is a contraindication to BTON.

Foot Deformity Correction Planning in the Sagittal Plane Based on the Vitruvian Foot First Metatarsal Anatomic Axis.

The aim of this study was to test a novel planning method for midfoot deformity correction, based on reference lines and angles (RLA) of talus and first metatarsal of 64 normal radiographs from 55 patients. The anatomic lateral talometatarsal angle (aLTMA), resulting from the intersection of talus joint line (TJL), from the border of the articular surface of the talus to the posterior process of talus, and the anatomic axis of the first metatarsal, was 28.5° ± 4.5°. The intersection of those 2 lines divided the TJL in 2 segments (ac and ab) with the ratio k1 = 0.7 ± 0.3. The length of the first metatarsal line was measured from its intersection with the TJL and first metatarsal head, and it was 3.6 times longer that of the TJL (k2). To analyze foot deformity, we propose to draw the TJL line as follows. Use the k1 ratio to determine the point where the aLMTA intersects the TJL. From this point, an idealized anatomic first metatarsal line should be drawn, at 28.5° from the TJL. The distal end of that line is based on the k2 ratio (3.6 × TJL length). Next, the actual anatomic lateral talometatarsal line of the deformed foot is drawn. The intersection between these 2 lines identifies the apex and magnitude of the deformity. Deformity correction planning using the proposed method was demonstrated and confirmed in 2 cases. A reference method for analysis and planning of midfoot sagittal plane deformity correction independent of foot position relative to the ankle joint or the presence of concomitant hindfoot deformity appears promising for future investigation and use.

New Sagittal Plane Reference Parameters for Foot Deformity Correction Planning: The Vitruvian Foot.

Currently available methods for analysis and planning of post-traumatic or congenital deformity correction of the foot have some limitations. The aim of this retrospective study was to establish reference lines and angles (RLAs), and the resulting ratios, based on reproducible anatomic points on sagittal feet radiographs. The key starting point of our evaluation was the previously undescribed length and position of the talus joint line (TJL), from the border of the articular surface of the talus and the posterior process of talus. First, we calculated the relationships between the TJL and the axes of the foot, particularly the anatomic and mechanical lateral talometatarsal angle axes of the first metatarsal. Then, we assessed the relationships with the calcaneus, particularly the lateral heel angle. Finally, we calculated the parameters (angles and coefficients k) derived from the TJL and the foot-bearing points (foot quadrilateral). A total of 64 normal radiographs from 55 patients were analyzed. The values that resulted are as follows: anatomic lateral talometatarsal angle = 28.5° ± 4.5°, mechanical lateral talometatarsal angle = 23.6° ± 3.2°, lateral heel angle = 15.2° ± 3.4°, foot quadrilateral: abc = 144.6° ± 9.4°, bcd = 31.3° ± 2.6°, cda = 79.2° ± 9.8°, dab = 105.0° ± 8.3°, k1 = 3.09 ± 0.4, k2 = 3.77 ± 0.78, and k3 = 1.56 ± 0.24. Sagittal plane reference lines and angles are proposed, providing quantitative values for reference. These parameters have the potential to be easily implemented in foot deformity analysis and correction planning.

Advances in modern osteotomies around the knee : Report on the Association of Sports Traumatology, Arthroscopy, Orthopaedic surgery, Rehabilitation (ASTAOR) Moscow International Osteotomy Congress 2017.

Corrective lower limb osteotomies are innovative and efficient therapeutic procedures for restoring axial alignment and managing unicompartmental knee osteoarthritis. This review presents critical insights into the up-dated clinical knowledge on osteotomies for complex posttraumatic or congenital lower limb deformities with a focus on high tibial osteotomies, including a comprehensive overview of basic principles of osteotomy planning, biomechanical considerations of different implants for osteotomies and insights in specific bone deformity correction techniques. Emphasis is placed on complex cases of lower limb osteotomies associated with ligament and multiaxial instability including pediatric cases, computer-assisted navigation, external fixation for long bone deformity correction and return to sport after such osteotomies. Altogether, these advances in the experimental and clinical knowledge of complex lower limb osteotomies allow generating improved, adapted therapeutic regimens to treat congenital and acquired lower limb deformities.

Hallux Valgus Correction With Rotational Scarf Combined With Adductor Hallucis Tendon Transposition.

Hallux valgus affects 23% of people older than 40 years, and there are hundreds of methods dealing with this pathology, which have their advantages and disadvantages. The aim of the present prospective cohort study was to report our experience in treating the patients with hallux valgus and to perform a comparative analysis of the outcomes of the innovative and standard methods of surgical correction. Data on 78 patients (113 feet) with hallux valgus operated on between March 2010 and December 2015 using either an innovative method, which included rotational scarf osteotomy with bone fragment impaction and adductor hallucis tendon reinsertion, or the classical scarf osteotomy were analyzed. X-ray examination was performed preoperatively and 3 and 36 months after the procedure. A comparative analysis of the outcomes between the groups was carried out. No significant difference in mean radiographic data (p > .05) was found between these 2 groups preoperatively and 3 months after surgery. Nevertheless, the mean intermetatarsal angle 36 months after surgery in standard and innovative groups was 9.7 ± 0.7° and 9.0 ± 0.8° (p < .01) and the mean metatarsophalangeal angle 13.6 ± 0.9° and 13.2 ± 1.1° (p = .01), respectively. The innovative method of surgical correction of hallux valgus was seen to produce improved radiographic results.

Reference positions for transosseous elements in femur: A cadaveric study.

INTRODUCTION: During external fixator treatment, displacement of soft tissue at pin sites may cause infection and contracture. Due to surrounding soft tissue thickness, the femur is especially susceptible to severe complications. However, standard textbooks demonstrate only how major neurovascular bundles should be avoided. This study is the first cadaver study investigating which pin sites within safe zones exhibit minimal soft tissue displacement. METHODS: To identify the clear direction of any pin, the femoral shaft was divided into eight levels, from I to VIII. The transverse sections at each level were further divided into 12 radial positions analogous to a clock face, where the anterior direction was assigned twelve o'clock, the medial three, etc. Fifteen adult cadavers were used. Twelve wires were aligned radially on the examined ring, and were dyed at each point toward the soft tissue. Each soft tissue displacement was measured by marking the surface before and after three particular joint motions, namely hip flexion (0-90°), abduction (0-45), and knee flexion (0-90). The same procedures were performed in three layers of soft tissue: skin, fascia, and muscle. RESULTS: The average displacement was determined in 89 directions excluding the groin part, upon three joint motions. The three layers of skin, fascia, and muscle showed similar data curves. Greater displacements were seen at juxta-articular areas than at the mid-diaphyseal. The data curve exhibited a bimodal characteristic, with larger displacements at the extension and flexion directions. The amount of displacement at 6 o'clock was large at the levels near the hip joint, whereas at 12 o'clock, it was large near the knee joint. DISCUSSION: "Reference positions" for transosseous elements were defined within zones absent neurovascular bundles, indicating 30 sites with minimal tissue displacement. Three or four directions at each level were chosen: I.9-11, II.9-11, III.8-11, IV.8-11, V.7-10, VI.3, 7-9, VII.3, 4, 8, 9, and VIII.3, 4, 8, 9. The anterolateral aspect near the hip joint and the posterolateral aspect near the knee tended to be chosen. They may prove useful in perioperative practice.

Mechanical rigidity of the Ortho-SUV frame compared to the Ilizarov frame in the correction of femoral deformity.

The Ortho-SUV frame (OSF) is a novel hexapod circular external fixator which draws upon the innovation of the Ilizarov method and the advantages of hexapod construction in the three-dimensional control of bone segments. Stability of fixation is critical to the success or failure of an external circular fixator for fracture or osteotomy healing. In vitro biomechanical modelling study was performed comparing the stability of the OSF under load in both original form and after dynamisation to the Ilizarov fixator in all zones of the femur utilising optimal frame configuration. A superior performance of the OSF in terms of resistance to deforming forces in both original and dynamised forms over that of the original Ilizarov fixator was found. The OSF shows higher rigidity than the Ilizarov in the control of forces acting upon the femur. This suggests better stabilisation of femoral fractures and osteotomies and thus improved healing with a reduced incidence of instability-related bone segment deformity, non-union and delayed union.

Definitive management of significant soft tissue loss associated with open diaphyseal fractures utilising circular external fixation without free tissue transfer, a comprehensive review of the literature and illustrative case.

Accepted management of diaphyseal fractures associated with significant tissue loss is rigid intramedullary stabilisation with free or rotational musculocutaneous flap coverage. Circular external fixation is a powerful tool in the management of limb trauma and with recent advances has been developed to provide multiple techniques for which even massive tissue loss can be addressed without the need for free tissue transfer. Gradual and acute shortening, acute fracture deformation and gradual lengthening with restoration of deformity combined with distraction tissue histiogenesis can provide the surgeon with an array of options which can be precisely tailored to the particular personality of a severe open diaphyseal fracture.

Avoidance of external fixation pin induced rotational stiffness in the forearm; a cadaver study of soft tissue displacement relative to the varying position of radius and ulna fixation.

INTRODUCTION: Stiffness of forearm rotation secondary to transfixion pin sites is a frequent complication of external fixation. Conventional surgical atlases do not consider the effect of rotation on skin displacement and thus do not provide a comprehensive answer. We asked: (1) in what locations in the forearm is soft tissue displacement relative to the ulna and radius least during rotation; (2) in what positions are major neurovascular structures absent; and (3) what maximal range of rotation can be expected in forearm external fixation. METHODS: Thirty-four matched cadaver arms were used to assess displacement of soft tissues at 10°, 30° and 70° of pronation and supination in relation to a testing frame. The results of these were correlated with positions in which neurovascular structures were absent and deemed insertional "Reference Positions (RP)". RESULTS: Expected range of rotation in diaphyseal fractures of different levels of both forearm bones was found with RP for the ulna occurring along the length of the forearm. Reference positions for the radius which provide full forearm rotation are situated only in the distal third; positions which provide partial rotation are located in the proximal and middle third. DISCUSSION: Full range of rotation may be maintained in the case of isolated external fixation of ulnar diaphyseal fractures. In isolated external fixation of the radius a reduced range of forearm rotation may be expected.

A comparative study of the correction of femoral deformity between the Ilizarov apparatus and Ortho-SUV Frame.

PURPOSES: This study compared the six-axis external fixator Ortho-SUV Frame (OSF) and the Ilizarov apparatus (IA) in femoral deformity correction. Our specific questions were: (1) which of the fixators (OSF or IA) provides shorter period of femoral deformity correction, and (2) which of the fixators (OSF or IA) provides better accuracy of correction. METHODS: We retrospectively analysed 123 cases of femoral deformities (127 femora): 45 (47) treated with OSF (20 male and 27 female) and 78 (80) with IA (53 male and 27 female). The average age in the OSF group was 34.6 (range, 18-66) and in the IA group 35.8 (range, 18-76). All the deformities were categorized according to the number of planes and deformity components as simple, middle and complex deformities. RESULTS: Elimination of simple deformities in the IA group took 58.3 ± 21.4 days, EFI 58.8 ± 39.8 days/cm, and lengthening was 4.6 ± 1.98 cm. Middle deformities were 71.3 ± 26.2, 61.9 ± 30.3 and 4 ± 2, respectively. In complex deformities we had 105.2 ± 21.8, 79.3 ± 35.4 and 3.2 ± 1.45, respectively. Normal alignment was achieved in 55.0% of cases in IA. In 45.0% of cases we had residual deformity. Elimination of simple deformations in the OSF group took 55.3 ± 12.8 days, EFI 47.5 ± 23 days/cm, and lengthening 4.5 ± 1.1 сm. Middle deformities were 43.6 ± 18.9, 59 ± 14.6 and 3.6 ± 2, respectively. In complex deformities we had 44.9 ± 11.5, 57.5 ± 9.4 and 3.6 ± 1.7, respectively. In the OSF group normal alignment was achieved in 85.1%. In 14.9% there was residual deformity. CONCLUSION: Using OSF simplifies deformity correction and reduces its period by 2.3 times in complex deformities and by 1.6 times in middle deformities. Accuracy of correction with OSF was significantly higher than correction with IA.

Determination of the Maximal Corrective Ability and Optimal Placement of the Ortho-SUV Frame for Femoral Deformity with respect to the Soft Tissue Envelope, a Biomechanical Modelling Study.

Circular fixation according to the Ilizarov method is a well-recognised modality of treatment for trauma and deformity. One shortcoming of the traditional fixator is its limited ability to correct more than one plane of deformity simultaneously, leading to lengthy frame-time indices. Hexapod circular fixation utilising computer guidance is commonplace for complex multidimensional deformity but difficulties often arise with correction of femoral deformity due to bulkiness of the frame construct, particularly in proximal deformity and in patients of increased size. The Ortho-SUV frame is an innovative hexapod which permits unique customisation to individual patient anatomy to maximise tolerance and optimal range of deformity correction. We hypothesised that the optimal configuration and maximal degree of correction achievable by the Ortho-SUV frame can be biomechanically modelled and applied clinically. A study was constructed using Ortho-SUV and femoral limb models to measure deformity correction via differing frame constructs and determine optimal frame configuration to achieve correction in proximal, middle, and distal third deformities with respect to the soft tissue envelope. The ideal frame configuration is determined for correction of deformity in all locations of the femur with the maximal parameters of correction calculated whilst avoiding and mitigating soft tissue irritation from bulky frame construction.

Foot deformity correction with hexapod external fixator, the Ortho-SUV Frame™.

External fixators enable distraction osteogenesis and gradual foot deformity corrections. Hexapod fixators have become more popular than the Ilizarov apparatus. The Ortho-SUV Frame™ (OSF; Ortho-SUV Ltd, St. Petersburg, Russia), a hexapod that was developed in 2006, allows flexible joint attachment such that multiple assemblies are available. We assessed the reduction capability of several assemblies. An artificial bone model with a 270-mm-long longitudinal foot was used. A 130-mm tibial full ring was attached 60 mm proximal to the ankle joint. A 140-mm, two-third ring forefoot was attached perpendicular to the metatarsal bone axis. A 130-mm, two-third ring hindfoot was attached parallel to the tibial ring. A V-osteotomy, which was combined with 2 oblique osteotomies at the navicular-cuboid bone and the calcaneus, was performed. The middle part of the foot, including the talus, was connected to the tibial ring. We assessed 5 types of forefoot applications and 4 types of hindfoot applications. The range of correction included flexion/extension in the sagittal plane, adduction/abduction in the horizontal plane, and pronation/supination in the coronal plane. Additionally, we reported the short-term results in 9 clinical cases. The forefoot applications in which the axis of the hexapod was parallel to the axis of the metatarsal bones had good results, with 52°/76° for flexion/extension, 48°/53° for adduction/abduction, and 43°/51° for pronation/supination. The hindfoot applications in which the hexapod encircled the ankle joint also had good results, with corresponding values of 47°/58°, 20°/35°, and 28°/31°. Clinically, all deformities were corrected as planned. Thus, multiple assemblies and a wide range of corrections are available with the OSF.