Bone Stump Research Articles

Roles of pore architecture of artificial bone grafts in invasion competition between bone and fibrous tissue and orientation of regenerated bone

 In the reconstruction of bone defects close to soft tissue, preventing the invasion of fibrous tissue into the bone defect is key to successful bone reconstruction. In this study, we clarified the effects of the pore architecture of artificial bone grafts on the penetration of bone and fibrous tissue, and the orientation of regenerated bone. Carbonate apatite grafts with uniaxial pores along the long- (L-graft) or short-axis (S-graft) direction of the graft and biaxial pores along the long- and short-axes (LS-graft) were used. These grafts were implanted in bone defects created by rabbit ulnae amputation. The pores of the L-, S-, and LS-grafts opened into the bone stumps, muscles, and bone stumps and muscles together, respectively. In the L-graft, the graft pores developed bone from the bone stump to the graft center, while preventing excessive invasion of fibrous tissue. In S- and LS-grafts, the graft pores along the short axis allowed the invasion of fibrous tissue into the grafts. Consequently, although the bone grew to the edge regions in these grafts, further bone ingrowth was inhibited by the fibrous tissue. Furthermore, the pore architecture of the grafts affected the orientation of the regenerated bone. The degree of orientation of the bone formed in the L- and S-grafts was 1.6-fold higher than that formed in the LS-grafts. Thus, controlling the pore architecture allowed the growth of bone to predominate over that of fibrous tissue and induced the formation of bone with an ordered orientation

Evaluation of the results of salvage surgical treatment of distal phalanx injuries and substantiation of the algorithm of finger salvage treatment

Introduction The rates of hand injuries in the structure of total of injuries range from 30 to 50 % in recent decades. The improvement of approaches to the choice of optimal options for treatment of injuries of the distal phalanges of fingers that ensure the preservation of anatomical integrity and function of fingers remains relevant.The purpose of the work was a comparative analysis of the clinical efficacy of various methods for surgical treatment of trauma to the distal phalanx of fingers.Methods Forty-seven patients (18 men and 29 women, mean age 34.2 ± 13.3 years) with injuries to the distal phalanges of the fingers were examined and treated. The patients were divided into 2 groups. Group 1 (comparison) was 25 patients. Conventional approaches to the formation of finger stumps were used by shortening the bone part of the phalanx, forming two opposite flaps and applying several interrupted sutures; group 2 (main group) were 22 patients treated according to the surgical tactics developed by us. The proposed tactics of reconstructive plasty of the defects in the nail phalanges of three joint fingers involves the formation of a stump of the nail phalanx with a visual effect of elongation of the phalanx due to local or cross-plasty with dermo-fascial flaps. Comparison of treatment results in the groups of patients was performed 1, 3, 6, 12 months after reconstruction operations.Results It was established that the use of the developed surgical treatment of the injury to the distal phalanx of the fingers results in less severity (compared to the use of standard methods) of pain on days 10-21 after surgery (by 44.8-54.3 %), lower levels of the Quick DASH indicators after 3-12 months, decrease in Vancouver scoring of skin scar severity changes after 6-12 months, higher patient satisfaction with the functional result of treatment. Based on the results obtained, a diagnostic and treatment algorithm for providing medical care to hand injuries has been proposed.Discussion The results of the study indicate the effectiveness of the developed method of plastic surgery of fingertip defects of nail phalanges in the three joint fingers by moving the palmar-lateral and dorsal-lateral blood-supplied flaps from the fingers of the same name and neighboring fingers without shortening the bone stumps of the nail phalanges while achieving an esthetic result by visual lengthening of the fingertip phalanx. Based on the results obtained, a diagnostic and treatment algorithm for providing medical care to patients with finger injuries has been proposed.Conclusion The proven method improves the results of reconstructive surgical interventions in the treatment of fingertip defects the of tnail phalanx in three joint fingers.

Vascularization of a bone stump

<p><strong>Aim</strong> <br />To study the character of blood circulation in the bone stump at tight and loose closure of the medullary cavity.<br /><strong>Methods</strong> <br />Two series of experiments on 39 rabbits with mid-third femoral amputation and muscular plasty were carried out. In the<br />1st (experimental) series, the bone scapula was closed by thin cortical autograft taken from the epimetaphyseal area, and then the muscles were sutured, and in the 2nd – the scapula was closed by myoplasty only. Follow-up periods: 1st series – 7, 14, 21 days and 1, 3, 6 months, 2nd series – 1, 3, 6 months. Histological methods with infusion of vessels with ink-gelatin mixture and morphometry was used.<br /><strong>Results</strong> <br />In the 1st series there was a rapid restoration of the disturbed macro- and microcirculation due to the reserve sources of<br />blood circulation and the development of extravascular ways of microcirculation. In the 2nd series, blood circulation recovery was significantly slower and occurred mainly due to the development of extravascular microcirculatory pathways.<br /><strong>Conclusion</strong> <br />The study established undeniable usefulness of tight closure of the bone marrow cavity during amputation.</p>

Most postoperative reserved "normal" metatarsal stumps of diabetic foot osteomyelitis are infected but have healing potential.

Although the pathology and bacterial status of the "normal" bone stump after operation of diabetic foot osteomyelitis (DFO) are of great significance for the prognosis of foot wounds, there are only a few studies on this topic; hence, it is clinically relevant and urgent to study this topic. The data of 57 inpatients with DFO from June 2021 to April 2022 were collected, all of whom had DFO in the forefoot and underwent conservative surgery. After the surgical removal of necrotic bone, bone biopsies were taken from the necrotic phalangeal bone and the reserved "normal" metatarsal stump. They were cultured, after which antibiotic susceptibility test and pathological screening were carried out. According to clinical judgment, inpatients' wounds were divided into metatarsal affected group and metatarsal unaffected group. We then compared and analyzed the pathological and bacterial characteristics of preserved "normal" bone stump and its effect on wound healing and prognosis. The poor concordance rate between deep soft tissue culture and infected phalange culture was only 19.3%. The deep soft tissue (72.6%), infected phalange (70.7%), and metatarsal stump (71.4%) were mainly infected with gram-negative Bacillus. The proportion of Enterococcus spp. increased significantly in bone tissue. Acinetobacter baumannii had the highest drug resistance (88%, 22/25). There was no significant difference in several clinical characteristics and wound healing regardless of whether their metatarsal stumps were affected. Most reserved "normal" metatarsal stumps (84.2%, 48/57) were positive by pathological diagnosis and bacterial culture testing; only 15.7% (9/57) samples were truly sterile. Only 8.3% (4/48) of the former patients healed within 6 months; whereas, all the latter (9/9) patients healed within 6 months. However, the majority (89.6%, 43/48) could heal. There was no difference in operations, skin grafting, negative pressure wound therapy, and mortality between the two groups. The most reserved "normal" metatarsal stumps have been invaded by bacteria. However, the majority stumps can be preserved, and the wound will eventually be healed according to the pathological and bacterial culture results.

Influence of post-amputation pain syndrome on blood circulation in the bone residual limb

Background. The percentage of unsatisfactory amputation results is still high. The healing of the bone remnant, the main supporting element of the residual limb, is of particular importance. The purpose was to study the effect of post-amputation pain syndrome on the nature of blood circulation in the bone residual limb. ­Materials and methods. Three series of experiments with amputation of the thigh were conducted on 54 rabbits. In the series 1 and 2, a perineural catheter was brought to the stump of the sciatic nerve. In series 1, for 20 days, ­every day for 20 minutes, mechanical irritation of the nerve was done, causing a pain syndrome using the perineural catheter. In series 2, 0.3 ml of 1% lidocaine was injected twice daily for 20 days; series 3 was a control. The follow-up periods were 1, 3, and 6 months. The study method was histological with the infusion of vessels with an ink-gelatin mixture. Results. Animals of the first series developed avascularity of the end of the stump and bone marrow, poor vascularity and absence of cellular composition in the Haversian canals, dystrophic changes in adipose bone marrow, rarefication, spongiosis, resorption, and bone fractures. In series 2, the avascularity passed quickly and by three months, the angioarchitectonics was stabilized. Revascularization of the bone stump occurs due to the preserved sources of blood circulation (intramedullary vascular network, periosteum and surrounding soft tissues) anastomosing vessels and extravascular pathways of microcirculation (increased vascular permeabi­lity, formation of sinusoidal capillaries and tissue cysts). In most observations of series 3, the processes of revascularization were similar to the results of the 1st series. Conclusions. Postamputation pain syndrome causes abrupt macro- and microcirculatory disturbances. Pain syndrome suppression allows to considerably level the arising circulatory disorders in the bone residual limb.

Treatment of a Radio-Ulnar Atrophic Pseudoarthrosis in a Toy Poodle Using an Autologous Coccygeal Vertebrae Transfer and Plate Fixation

Description of the treatment of a radio-ulnar atrophic pseudo-arthrosis in a one-and-a-half-year-old female toy tramp dog. Due to a domestic trauma the patient suffred a radio-ulnar fracture. Unfortunately at the time of the first visit we were not in possession of the patient’s medical record and for this reason we did not know the evolution of the previous surgical revision. The owner reports that at another centre, the subject underwent three osteosynthesis procedures (osteosynthesis with radio-ulnar intramedullary nails, plate fixation and external circular fixator), with negative results. After a long consultation with the owner it was decided to perform a surgery to restore the bone radius and ensure good mobility. Our procedure included debridement and canalisation of the bone stumps, harvesting and grafting of the coccygeal VII vertebra, autologous spongy bone grafting, osteosynthesis with VCP1.5/2.0 mm plate and 1.5- and 2.0-mm cortical screws. Clinical and radiographic evaluation were carried out regularly, during which we decided to remove some screw in order to achieve an implant dynamization. At weeks 7 and 16 four screws were removed. At week 60 the plate was removed and further controls at weeks 64 and 90 confirmed anatomical and functional healing. No wound or bone healing complication were reported.

Bone healing during electrostimulation.

Aim To investigate the effect of direct epineural electrical stimulation of the nerve on the nature of reparative processes in the bone stump. Methods Three series of experiments were carried out with amputation of the thigh in the middle third and muscle plasty. In the 1st and 2nd experimental series a perineural catheter was brought to the stump of the sciatic nerve, through which mechanical irritation of the nerve was performed for 20 days daily for 20 minutes. In the 2nd series, an electrode was added to the nerve and epineural electrical stimulation was performed daily for 20 days. Animals of the 3rd series served as control. The observation periods were 1, 3, 6 months. Histological research method with filling vessels with ink-gelatin mixture was applied. Results In the 1st series, there was a sharp distortion of the reparative process, which consisted of a violation of microcirculation, changes in shape, resorption of the cortical diaphyseal plate, fractures, deformations. In most experiments of the 2nd series, organotypic stumps were formed with normalization of microcirculation. In the 3rd series, results of the formation of the stump were better than in the 1st, but worse than in the 2nd series. Conclusions Painful nerve irritation after amputation leads to a significant disturbance of microcirculation and reparative regeneration at the end of the bone stump with the development of pathological restructuring of bone tissue. Electrostimulation of the nerve improves microcirculation and reparative regeneration of the bone tissue.

The influence of post-amputation pain syndrome and intraosseous main vessels on the formation of limb bone stump

Until now, remains quit high a percentage of unsatisfactory results of amputations. At the same time, a special place is occupiedby the healing of the bone remnant — the main supporting element of the stump. Objective. To study the influence of post-amputationpain syndrome and intraosseous main vessels on the nature of reparative processes in the bone stump. Methods. Three series of 15 experimentswere conducted on 45 rabbits with amputation of the femur in the middle third and muscle plastic surgery. In the 1st and2nd series, d uring a mputation, a p erineural c atheter w as b rought to the stumps of the sciatic nerve. With its help, animals were subjectedto the following daily for 20 days: 1st series — mechanical irritation of the nerve, 20 minutes; 2nd — injection of 0.3 ml of 1 %lidocaine twice a day into the surrounding area of the nerve. Animals of the 3rd series were the control. In 1, 3, 6 months. a histologicalexamination was performed with the pouring of carcass (gelatin mixture) into the vessels. The results. In the 1st series, there was a sharpviolation of the reparative process: a change in the shape and loosening of the cortical diaphyseal plate, fractures and deformationof the stump, a significant expansion of the feeding artery and its branches with perforation of the endosteal regenerate, the absenceof formation of the bone closing plate, a violation of the microcirculation. In the animals of the 2nd series, the stumps mostly kept the shapeand structure characteristic of the diaphysis with normalization of macro- and microcirculation. In the 3rd series, the results of stumpformation were better than in the 1st, but worse than in the 2nd. Conclusions. If the pain syndrome subsides after amputation, a bonestump is formed with an organotypic shape and structure characteristic of the diaphysis, normalization of the state of bone marrowtissues and blood circulation. The rapid and complete formation of the bone closing plate contributes to the reduction of the branchesof the feeding artery and prevents the functional depressurization of the bone marrow cavity. In the presence of post-amputation painsyndrome, there are significant violations of the reparative process with the formation of an inferior bone closing plate, its penetrationby the branches of the feeding artery without the organotypic formation of the stump.

Suspicion of Recurrent Osteosarcoma in a Patient with Pseudotumour Adjacent To the Endoprosthesis.

PurposePseudotumor is a rare complication after arthroplasty, most often of the hip joint, in response to metal particles present in the implant. There are merely sporadic reports of pseudotumor in patients with bone sarcoma after sparing surgery with endoprosthesis implant. The aim of this study is to present the characteristic imaging features of pseudotumor.Case reportWe present a case of a 21-year-old male patient in whom a scheduled follow-up ultrasound revealed a painless lesion suspected of local recurrence at the border of the endoprosthesis and the bone stump 3.5 years after the end of treatment for osteosarcoma of the femur. Histopathology of the biopsy specimen revealed that the lesion was a pseudotumor.ConclusionsAlthough pseudotumor is sporadic in patients treated with endoprosthesis for bone sarcoma, their prolonged survival could bear the risk of such a complication. Imaging studies, in particular ultrasound, may be helpful in differentiating from local recurrence of sarcoma, however, the histopathology of the specimen obtained by open biopsy at a reference center is crucial for the final diagnosis.

Effects of Channels and Micropores in Honeycomb Scaffolds on the Reconstruction of Segmental Bone Defects.

The reconstruction of critical-sized segmental bone defects is a key challenge in orthopedics because of its intractability despite technological advancements. To overcome this challenge, scaffolds that promote rapid bone ingrowth and subsequent bone replacement are necessary. In this study, we fabricated three types of carbonate apatite honeycomb (HC) scaffolds with uniaxial channels bridging the stumps of a host bone. These HC scaffolds possessed different channel and micropore volumes. The HC scaffolds were implanted into the defects of rabbit ulnar shafts to evaluate the effects of channels and micropores on bone reconstruction. Four weeks postoperatively, the HC scaffolds with a larger channel volume promoted bone ingrowth compared to that with a larger micropore volume. In contrast, 12 weeks postoperatively, the HC scaffolds with a larger volume of the micropores rather than the channels promoted the scaffold resorption by osteoclasts and bone formation. Thus, the channels affected bone ingrowth in the early stage, and micropores affected scaffold resorption and bone formation in the middle stage. Furthermore, 12 weeks postoperatively, the HC scaffolds with large volumes of both channels and micropores formed a significantly larger amount of new bone than that attained using HC scaffolds with either large volume of channels or micropores, thereby bridging the host bone stumps. The findings of this study provide guidance for designing the pore structure of scaffolds.

Effect of calcium sulfate on promoting natural healing of docking sites during bone transport

To observe clinical effect of calcium sulfate on promoting natural healing of docking sites during bone transport. A retrospective study was performed on the patients with posttraumatic chronic osteomyelitis treated by bone transport and calcium sulfate implantation from January 2013 to January 2018. There were 23 males and 4 females, aged from 20 to 61 years old with an average of (44.30±10.00) years, the courses of disease ranged from 3 to 86 months with an average of(13.26±16.47) months. Sixteen patients with posttraumatic chronic osteomyelitis were caused by internal fixation of closed fractures, and 11 patients were caused by open fractures. The length of bone defects after debridement ranged from 4 to 14 cm with an average of(9.11±2.57) cm. Postoperative complications, natural healing rate of the docking sites, external fixation index were observed, Checketts & Otterburn pin-tract infection classification was used to evaluate pin-tract infection, and Paley evaluation criteria was used to evaluate bone and function results. Twenty-seven patients were followed up from 26 to 41 months with an average of (31.32±3.37) months. It did not happened skin embedded between bone stumps in all patients. All patients obtained bone union at (17.78±5.43) months after operation.Among them, 25 patients healed naturally in the docking sites, 2 patients with poor compliance healed after debridement and bone grafting in the docking sites. One patient occurred equines deformity, and no re-fracture or recurrence of infection occurred. According to Checketts & Otterburn pin tract infection classification, 22 patients (41 pin tracts)occurred pin-tract infection with varying degrees. The average external fixation index was (2.02±0.24) months/cm(ranged from 1.6 to 2.4 months/cm). According to Paley evaluation criteria, bony results showed 21 patients obtained excellent results, 5 good, and 1 moderate;functional results showed 19 patients got excellent results, 7 good, and 1 moderate. During bone transport, the implantation of calcium sulfate on the bone defect areas could prevent skin embedding between the bone stumps, benefit for the natural healing of the docking sites, and could avoid the second-stage debridement and bone grafting for most patients. However, it should be noted that compliance needs to be increased.

Segmental Defektin Her İki Tarafına Üçer veya Dörder Vida ile Sabitlenen Kilitli Rekonstrüksiyon Plaklarının Servohidrolik Test Metodu ile Biyomekanik Değerlendirmesi: In Vitro Çalışma

Objective: Surgical treatments of neoplasias may result in segmental loss of mandible with limited remaining bone stumps. Locking recontruction plates are being used to bridge mandibular discontinuities caused by resections. The aim of this study is to evaluate biomechanical resistance of mostly recommended numbers of screws when locking systems were used for lateral segmental defects. Material and Methods: This in vitro study was conducted on polyurethane mandibles with simulated lateral segmental defects extending to angulus. 13 synthetic polyurethane mandibles were used in this study. Mandibles were fixed with four screws and three screws on each segment in Group I and II, respectively. Mean yield displacement, yield load, loading values at 1, 3, 5 mm diplacement and displacement at 80 N, 100 N, 200 N, 300 N loading were compared among the 2 groups. Results: Group I withstood significantly greater average force before failure than that of Group II (p=0,000). There was no statistically significant difference in displacement at failure between groups. There was no statistically significant difference in loading at 1 mm displacement between 2 groups. Conclusion: Fixation with 3 screws on each side of such lateral segmental defects does not provide sufficient stability. Therefore minimum 4 screws should be adopted.

Impact of post- amputation pain syndrome on the results of bone stump formation

Background. To the present day, a high rate of unsatisfactory amputation results still exists. The healing of the bone residual limb, the main support element of the residual limb, is of particular importance. Objective. To study the impact of postamputation pain syndrome on the nature of reparative processes in the bone residual limb. Methods. Three series of experiments were performed on 45 rabbits, 15 in each with mid-third thigh amputation and muscular plasty. In series 1 and 2, a perineural catheter was attached to the sciatic nerve stump during amputation, and mechanical irritation of the nerve was performed daily for 20 minutes in series 1 for 20 days. In series 2, 0.3 ml of 1% lidocaine was injected through the catheter into the circumference of the nerve twice daily for 20 days. Animals of series 3 served as a control. The follow-up periods were 1, 3, 6 months. The study method was histological with infusion of the vessels with ink-gelatin mixture. Results. In series 1, there was a sharp disturbance of the reparative process, which consisted in shape changes, resorption of the cortical diaphyseal plate, stump deformity, absence of bone closure plate formation, and microcirculatory disturbances. In most experiments of the 2nd series, organotypic stumps were formed with normalized microcirculation. In series 3, the results of the residual limb formation were better than in series 1, but worse than in series 2. Conclusion. In the absence of pain syndrome, the bone stump after amputation at the diaphysis level over a period of 1, 3, 6 months retains its cylindrical shape, the structure of the cortical diaphyseal plate, the content of the medullary canal with normal microcirculation, the formation of the bone closure plate, and the completion of the reparative process. The presence of postamputation pain syndrome in the stump distorts the course of the reparative process with the development of pathological remodeling of bone tissue.

Fixation of femoral fractures with titanium plate and screws: a pilot study in rats

The repair of bone defects is a study model that has been used in several experiments to analyze the influence of surgical and pharmacological approaches aiming to improve bone regeneration. Mechanical stimulus is a crucial factor in the healing process. Therefore, a variety of measures exists to aid in bone repair by using different methods of immobilization and fixation. Objective: To delineate an unprecedented technique of stable bone fixation with titanium plates and screws in rat femoral fracture. Material and methods: Six Wistar rats underwent surgical procedures for complete femur fracture and fixation with titanium plates and screws, in six different combinations. The rats were divided into two subgroups, according to the technique applied: fixation performed after the bone fracture, and fixation performed before fracture induction. The animals were euthanized 45 days after the procedure, and the femur was evaluated clinically and radiographically. Results: There was a failure of the fracture fixation in the majority of the animals, except in rat 6, which had a good stability of the bone stumps and satisfactory bone repair. Conclusion: The best technique was with a four-hole titanium plate and four screws of the 2-mm system, with the fixation of the material prior to fracture induction.

Reamputation stumps below knee.

Aim To investigate rehabilitation outcomes of patients with malformed tibial stumps. Methods Observations included 421 patients with residual limb diseases and malformations (extensive inactive scars adhered to the bone, excessively long or short stumps, bone filing, osteomyelitis of the stump, muscle attachment to the skin scar, excessive mobility and deviations of the fibula, improper filing). Four hundred and thirty-six (436) reconstructive surgeries were performed. A follow-up period was from 6 months to 15 years. Radiological, ultrasonic, tensometrical, and histological methods were used. Results Due to the frequent combination of several malformations and diseases in the same patient, non-free skin grafting with displaced dermal-subcutaneous flaps, which cover rather large defects, was widely used. The surgeries were performed simultaneously and allowed for reconstruction without shortening the bone lever stump. Complications in the form of marginal necrosis were obtained in three (0.71%) patients. The improved technique of muscle grafting with the fixation of muscles to the bone provided an elastic stump covering the bone filing. The authors have developed original methods of surgery to create a bone block of the tibia, which make it possible to obtain painless, highly functional stumps using partial support and ensure long-term use of modern prosthesis designs in 100% of cases. Conclusion Non-free dermal plasty with cutaneous-subcutaneous flap is the method of choice for closing skin defects on the residual limb. Muscle-bone fixation permits to eliminate some residual limb defects and to form an elastic muscular residual limb with closed bone filaments. Synostosis formation in different ways considerably improves functional quality of the residual limb.

Surgical treatment of pressure ulcer: various flaps and other surgical methods

Pressure ulcers remain a common health problem, particularly among physically limited or bedridden older adults, and they can cause significant morbidity and mortality. Conservative management is ineffective for stage III or IV pressure ulcers, and surgery to create flap coverage becomes inevitable. Basic surgical principles for the treatment of pressure ulcers include complete excision of the ulcer, surrounding scar, underlying bursa, and soft tissue calcification; radical removal of underlying bone and any heterotropic ossification; padding of bone stumps and filling dead space; resurfacing with large regional pedicled flaps; and grafting the donor site of the flap, if necessary. For effective edge resection, all the flaps should be designed to be as large as possible, placing the suture line away from the area of direct pressure, and the flap design should also not violate adjacent flap territories to preserve all options for coverage if a breakdown or recurrence dictates further reconstruction. There are surgical methods for stage III or IV wide range pressure ulcers: reconstruction surgery using a skin flap, muscle flap, fascia-skin flap, or free flap. The skin graft is not generally recommended as a surgical procedure for stage III or IV pressure ulcers because it cannot provide enough strength to cover the wound. This review presents various surgical treatments of pressure ulcers including muscle, musculocutaneous, perforator-based, and free flap.

REPARATIVE REGENERATION AT THE END OF BONE FILING AFTER OSTOPLASTIC AMPUTATION

The aim: To study the role and place of bone grafting in the formation of bone stump after amputation. Materials and methods: 3 series of experiments were carried out on 44 rabbits with amputation of the thigh in the middle third and stump grafting using osteoplastic hermetic closure of the canal with a thin cortical plate (series I), closure of the canal with a spongy bone (series II), and loose closure of the canal with a cortical graft located at the entrance to the canal at an angle of 30° (ІІІ series). Observation period: 1, 3, 6 months. Histological examination method with vascular filling with 10% mascara-gelatin mixture. Results: In series I, in the majority of observations, a stump of a cylindrical shape with a bone locking plate of an osteon-beam structure and normalization of intraosseous microcirculation was formed. A slight displacement of the graft caused a violation of microcirculation. In series II, organotypic stumps were formed in all observations. In series III, incomplete closure of the bone marrow cavity led to sharp microcirculatory disorders and the course of the reparative process with pathological bone remodeling. Conclusions: The parameters of the favorable course of the reparative process and the formation of the organotypic bone stump are the safety of its cylindrical shape, the presence of a compact bone structure, normalization of intraosseous microcirculation.

Bone stump formation against the background of post-amputation pain syndrome

Introduction: Bone is the basis of the stump. Aim: To study the impact of post-amputation pain syndrome on the nature of reparative processes in the bone residual limb. Material and methods: Three series of experiments were performed on 45 rabbits, 15 in each with mid-third thigh amputation and muscular plasty. In series 1, 2, a perineural catheter was attached to the sciatic nerve stump during amputation, and mechanical irritation of the nerve was performed daily for 20 minutes in series 1 for 20 days. In series 2, 0.3 mL of lidocaine (1%) was injected through the catheter into the circumference of the nerve twice daily for 20 days. Series 3 is a control. The follow-up periods were 1, 3, 6 months. The study method was histological with infusion of the vessels with ink-gelatin mixture. Results and discussion: In series 1, there was a sharp disturbance of the reparative process, which consisted in shape changes, resorption of the cortical diaphyseal plate, fractures, stump deformity, absence of bone closure plate formation, and microcirculatory disturbances. In the overall majority of experiments of series 2, the stumps retained the shape and structure characteristic of diaphysis with normalization of microcirculation. In series 3, the results of the residual limb formation were better than in series1, but worse than in series 2. Conclusions: When the pain syndrome is resolved within 20 days after amputation, a bone stump is formed with an organotypic shape and structure characteristic of the diaphysis, the formation of a compact closure plate of mature bone tissue, normalization of the medullary tissues and blood circulation. In post-amputation pain syndrome, organotypic formation of the residual limb does not occur.

Optimization of the antibiotic management of diabetic foot infections: protocol for two randomized controlled trials

BackgroundFew studies have addressed the appropriate duration of antibiotic therapy for diabetic foot infections (DFI) with or without amputation. We will perform two randomized clinical trials (RCTs) to reduce the antibiotic use and associated adverse events in DFI.MethodsWe hypothesize that shorter durations of postdebridement systemic antibiotic therapy are noninferior (10% margin, 80% power, alpha 5%) to existing (long) durations and we will perform two unblinded RCTs with a total of 400 DFI episodes (randomization 1:1) from 2019 to 2022. The primary outcome for both RCTs is remission of infection after a minimal follow-up of 2 months. The secondary outcomes for both RCTs are the incidence of adverse events and the overall treatment costs. The first RCT will allocate the total therapeutic amputations in two arms of 50 patients each: 1 versus 3 weeks of antibiotic therapy for residual osteomyelitis (positive microbiological samples of the residual bone stump); or 1 versus 4 days for remaining soft tissue infection. The second RCT will randomize the conservative approach (only surgical debridement without in toto amputation) in two arms with 50 patients each: 10 versus 20 days of antibiotic therapy for soft tissue infections; and 3 versus 6 weeks for osteomyelitis. All participants will have professional wound debridement, adequate off-loading, angiology evaluation, and a concomitant surgical, re-educational, podiatric, internist and infectiology care. During the surgeries, we will collect tissues for BioBanking and future laboratory studies.DiscussionBoth parallel RCTs will respond to frequent questions regarding the duration of antibiotic use in the both major subsets of DFIs, to ensure the quality of care, and to avoid unnecessary excesses in terms of surgery and antibiotic use.Trial registrationClinicalTrials.gov, NCT04081792. Registered on 4 September 2019.

Changes in the structural organization of bone after amputation

Introduction: Despite a considerable amount of work on limb amputations, questions of the mechanism and conditions for the occurrence of pathological rearrangement in the bone stump and ways to prevent it remain unexplored. Aim: To study the nature of changes in the structural organization of bone stump after amputation. Material and methods: Nine series of experiments were conducted on 129 rabbits with amputation of the thigh and closure of the filing with fascia, muscles with varying degrees of tension and a bone plate. Duration of observation is 1, 3, and 6 months. The research method is histological with a filling of blood vessels with a mascara-gelatin mixture. Results and discussion: Tight closure of the bone marrow cavity and uniform muscle tension during plastic surgery in the I–III series of experiments make it possible to obtain cylindrical stumps with the formation of a bone closure plate and the completion of the reparative process. In the majority of observations of the IV–IX series, significant violations of the structural organization of the bone occurred in the form of conical, club-shaped, swollen stumps, creeping fractures. Conclusions: The rapid completion of the reparative process and the normalization of intraosseous circulation with a locking bone plate, while maintaining normal bone marrow tissue, is possible only with a dense closure of the filing. The lack of tight closure of the bone marrow canal and uneven muscle tension cause a violation of regeneration with changes in the structural organization of the bone. These changes are manifested by a thickening of the bone diameter, axis curvature, creeping fractures.