Reconstruction of bone defects after osteomyelitis with nonvascularized fibular graft: a retrospective study in twenty-six children

Osteoperiosteal fibular strut grafting - A technique to improve union rates

PURPOSE

Gap non-union of long bones are challenging problems in orthopaedic patients. Non-vascularized fibular grafting is a simple, cost effective, single stage procedure and is an accepted method of reconstruction for gap non unions in children. However, there is a risk of non-union when a long avascular strut of fibula is used. The periosteum, by itself has high biological activity and is helpful in osteointegration. Harvesting the fibula with the periosteum gives the advantage of mechanical and biological support in a gap non-union.

METHODS

During 2020 to 2022, 13 patients presented to us with gap nonunion of long bones due to various aetiology. The mean age of the patients was six years with a mean bone gap of 4.2 cm. A modified technique of harvesting the fibula with the periosteum is described. The graft was stabilized with the recipient bone by intra medullary or extra medullary implants.

RESULTS

Union occurred in average 12.7 weeks in all except one patient with congenital pseudoarthrosis of tibia. The fibula on the harvest site regenerated completely in all other patients. One patient had a superficial infection. Children were followed were an average of 17.5 months and there was no incidence of graft resorption or fracture. Osteoperiosteal fibula graft is a simple, effective and cost-effective procedure for the treatment of gap non-unions in children. It offers the advantage of both biological and mechanical support, with high union rates and low complication rates.

Management of Post-osteomyelitic Large Ulna Defect in a Pediatric Patient

Osteomyelitic sequelae in forearm pose challenges in management. Bone resorption leading to gap nonunions is further difficult to manage. We present a case of post-osteomyelitic ulna defect of 16 cm in a 6-year-old boy managed by non-vascularized fibular grafting with simultaneous correction of radius deformity and its functional outcome after 1 year.

Single-stage procedures for treatment of traumatic patellar osteomyelitis: A retrospective study of 21 patients

INTRODUCTION

We herein report on a series of 21 patients with traumatic patellar osteomyelitis treated by single-stage surgery, and discuss the specific application of single-stage procedures for traumatic patellar osteomyelitis.

METHODS

We retrospectively reviewed the medical records of 21 patients with traumatic patellar osteomyelitis treated in our hospital from January 2010 to April 2018. In a single-stage surgery, aggressive debridement was performed together with application of a tissue flap, especially a gastrocnemius flap (for repair of skin/soft tissue defects and treatment of extensor mechanism defects), and internal refixation of the patellar fracture. The knee joint was exercised early after surgery. Long-term follow-up was performed to evaluate the recurrence of osteomyelitis according to clinical and laboratory signs of infection and to measure the active knee range of motion (ROM).

RESULTS

Single-stage wound treatment was successful in 20 of 21 patients. Treatments included radical debridement together with tissue flap for repair of soft tissue and extensor mechanism defects, and internal refixation of patellar fractures. 14 patients were treated with gastrocnemius flaps. One patient developed recurrent wound infection, which healed after reoperation. At a mean follow-up of 8 ± 2.63 years (range, 3.2-11.4 years), none had developed recurrence. Six patients had nearly full knee ROM (0°-105° to 0°-146°), whereas 11 patients had impaired knee mobility (ROM, 0°-90° to 0°-65°), 3 patients had knee joint stiffness with a ROM of 0°, and 1 patient had knee flexion contracture with a ROM of 78°-130° CONCLUSIONS: Single-stage surgical treatment consisting of various surgical techniques was an acceptable treatment for traumatic patellar osteomyelitis, allowing early exercise of the knee joint. The osteomyelitis did not recur, and most patients' knee ROM was restored to a certain extent, excluding patients with severe damage to the patellar articular surface and inactive functional exercise.

Revision with Locking Compression Plate by Compression Technique for Diaphyseal Nonunions of the Femur and the Tibia: A Retrospective Study of 54 Cases

Nonunion after diaphyseal fracture of the femur or the tibia is a common but difficult complication for treatment. Currently, the main treatment modalities include nail dynamization, exchange nailing, and bone transport, but revision with compression plating in these nonunions was rarely reported. To evaluate the outcomes of compression plating in the treatment of femur and tibia shaft nonunions, we retrospectively reviewed 54 patients with diaphyseal nonunion of the tibia or the femur treated with locking compression plate (LCP) by compression technique. There were 46 aseptic and 8 septic nonunions in the case series. Patient's history, fracture characteristics, previous interventions, and types of nonunion were recorded. The possible reason which might lead to nonunion was also analyzed for each case. Patients with aseptic nonunions were revised by hardware removal and compression plating with or without bone grafting. For septic nonunions, a two-stage surgery strategy was used. Compression plating with iliac crest bone grafting (ICBG) or free vascularized fibular grafting (FVFG) was used as the final treatment for septic nonunions. The compression technique and bone grafting method were individualized in each case according to the patient's history and architecture of the nonunion. Each patient finished at least a two-year follow-up, and all cases achieved healing uneventfully. Our study showed that compression plating with LCP was an effective method to treat diaphyseal nonunions of the tibia and the femur. It is compatible with different bone grafting methods for both infected and noninfected nonunions and is a good alternative to the current treatment methods for these nonunions.

Recent Trends in the Development of Bone Regenerative Biomaterials

The goal of a biomaterial is to support the bone tissue regeneration process at the defect site and eventually degrade in situ and get replaced with the newly generated bone tissue. Biomaterials that enhance bone regeneration have a wealth of potential clinical applications from the treatment of non-union fractures to spinal fusion. The use of bone regenerative biomaterials from bioceramics and polymeric components to support bone cell and tissue growth is a longstanding area of interest. Recently, various forms of bone repair materials such as hydrogel, nanofiber scaffolds, and 3D printing composite scaffolds are emerging. Current challenges include the engineering of biomaterials that can match both the mechanical and biological context of bone tissue matrix and support the vascularization of large tissue constructs. Biomaterials with new levels of biofunctionality that attempt to recreate nanoscale topographical, biofactor, and gene delivery cues from the extracellular environment are emerging as interesting candidate bone regenerative biomaterials. This review has been sculptured around a case-by-case basis of current research that is being undertaken in the field of bone regeneration engineering. We will highlight the current progress in the development of physicochemical properties and applications of bone defect repair materials and their perspectives in bone regeneration.

Lengthening After Nonvascularized Fibula Grafting for Large Postinfective Bone Defect: A Case Report with Long Follow-up

CASE

We describe a case of lengthening of the tibial regenerate after nonvascularized fibula grafting, for postinfective tibial gap nonunion in a child. A large tibial defect secondary to osteomyelitis in a 10-month-old boy was reconstructed using a 5-cm fibula autograft. Concomitant distal tibial physeal arrest led to progressive shortening. Distraction osteogenesis was performed, through the grafted segment, on 2 occasions-at the ages of 3.5 and 8 years-to achieve total lengthening of 9 cm and good functional recovery at 11.5 years of age.

CONCLUSION

The tibial regenerate after nonvascularized fibula grafting in children has good potential for distraction osteogenesis.

Clinicoradiological outcomes following single-stage treatment using external fixator, copious bone grafting and high dose antibiotics for infected postosteomyelitic nonunion of femoral shaft

We aimed to study clinical and radiological outcomes following a 'single-stage protocol' in postosteomyelitic-infected nonunion of the femur in children. The report is based on a retrospective chart review (2010-2018) of 10 children below 12 years of age presenting with nonunion following a pathological fracture after osteomyelitis of hematogenous origin treated with above-mentioned operative modality. All patients were grade A (normal host) on the basis of the physiological classification. Patients with posttraumatic or surgical osteomyelitis were excluded. All patients were treated with a combination of debridement of dead bone and necrotic tissues, acute bone docking, use of external fixator and addition of copious nonvascularized autogenous bone graft obtained from fibula/tibia. The postsurgical period was covered by high dose broad spectrum antibiotics for 6 weeks. At follow up, union, infection, deformity, leg-length discrepancy, motion of hip and knee and ability to perform unaided walking was recorded. Mean age for studied patients (five males and five females) was 6.6 years. Average time elapsed since pathological fracture was 7.7 months (range: 3-15 months). MRSA and MSSA were cultured in three and four patients, respectively. Union occurred in all patients with average time of 3.7 months and total follow up being 2.9 years (range: 1-7 years). There was persistence of deep infection despite union in three patients. Average limb shortening was 4.3 cm (range: 2-7 cm). The knee motion was severely restricted (≤30°) in three patients. According to Paley's criteria, there were 2 excellent, 4 good, 2 fair and 2 poor results. Single-stage protocol as described above is a usable option for postosteomyelitic femoral nonunions in children. Union occurred in all cases. Healing occurred in three patients despite the persistence of infection. The restriction of range of motion at knee and limb length discrepancy was main complication encountered with this procedure.

A novel technique of ulna strut grafting for post-septic radial clubhand deformity: Case series of 4 patients with review of literature

BACKGROUND

Though distal end radius fractures are one of the commonest fractures to occur, their nonunions are extremely uncommon. Out of these, post-septic defect nonunions with acquired radial clubhand deformity are even more rare and pose unique problems in management. We present a case series of 4 patients of post-septic radius nonunion with acquired radial clubhand deformity successfully treated with a novel technique of using Ulna Strut grafting for radius defect after ulnar shortening. All 4 patients have a good functional and cosmetic outcomes with radiological union at the cost of minimal limb length discrepancy of the forearm.

METHODS

This is a case series of 4 patients with a retrospective study design and study duration of 3 years from August 2016 till March 2019.4 patients presenting to us with post-septic defect nonunions of radius with an acquired radial clubhand deformity were selected with a mean age of 19.75 years which included 2 males and 2 females.

RESULTS

The mean time for radiological union was 3.125 months. The average range of motion at the wrist joint was 35° of flexion and 50° of extension with average protonation being 47.5° and supination being 75°.There were no subsequent complications reported in these patients except for a minimal limb length discrepancy with satisfactory functional outcomes in all the patients.

CONCLUSION

The use of Ulnar shortening and Ulna strut grafting for the treatment of defect nonunions of radius with acquired clubhand deformity yielded predictable results. It is a simple procedure that does not require additional training, with no additional morbidity of iliac crest or fibula bone grafting and had a minimum complication rate. The technique looks promising in the future, though a study on a larger population would further strengthen the predictability of this unique technique.

Paediatric infected femoral nonunion; mid-term results of a rare problem with a single-stage treatment and up to eleven and half years follow-up

PURPOSE

Nonunion of femur fractures is a devastating disabling complication which is rare in children. The purpose of this study was to report the outcomes of treating infected femur nonunions in children by the Ilizarov fixator in one stage.

PATIENTS AND METHODS

The study included 13 patients with unilateral infected nonunion of the femur with an average age of 9.1 years. The nonunion duration averaged 10.69 months. Ten cases were draining nonunions, and three patients had quiescent sinuses. Associated problems include shortening in all cases (mean 3.5 cm), joint stiffness (9 cases), and angular deformity (7 cases). The quiescent cases were treated by bloodless monofocal compression-distraction. Four draining cases were treated by debridement and compression with relengthening through nonunion site. The remaining six cases were treated by bifocal technique.

RESULTS

The mean follow-up duration was 60.15 months. External fixation period averaged 5.3 months. Successful union was achieved in all patients. Recurrences of infection occurred in two cases including one with refracture and another one with late pathological fracture. Other complications included pin tract infections, one delayed union, two residual angular deformities, and 6 cm residual shortening in one patient. ASAMI bone results were excellent (8 patients), good (3 patients), fair (one patient), and poor (one patient). The functional results were excellent (9 cases), good (3cases), and fair (one case).

CONCLUSIONS

The Ilizarov method provided a viable treatment option for treating paediatric infected femur nonunions in single stage of management with infection control in most cases and satisfactory outcomes.

Treatment of tumor-like lesions in the femoral neck using free nonvascularized fibular autografts in pediatric patients before epiphyseal closure

Objectives

Surgical resection of benign bone tumors and tumor-like lesions at the femoral neck presents a difficult reconstructive challenge. However, the safety and efficacy of free nonvascularized fibular autografts (FNFAs) in the treatment of femoral neck tumor-like lesions before epiphyseal closure in young patients remain unknown.

Methods

Sixteen pediatric patients who had not yet undergone epiphyseal closure were treated with FNFAs after resection of tumor-like lesions in the femoral neck from August 2012 to September 2016. All patients underwent supplementary skeletal traction through the supracondylar femur for 4 to 6 weeks after resection. Demographic data were recorded and clinical and radiological outcomes were evaluated during the follow-up.

Results

All patients could walk with partial weight bearing 4 weeks postoperative, and full weight bearing was permitted after a mean of 8 weeks. Graft union was attained in all 16 patients at a mean of 2 months. The donor site of the fibular cortical strut showed good regeneration in all patients. The Harris hip score significantly improved from 65% to 95%.

Conclusions

Application of an FNFA is a feasible method in the treatment of tumor-like lesions in the femoral neck before epiphyseal closure in pediatric patients.

Level of Evidence

Level IV.

Evaluation of Antibiotic-Releasing Triphasic Bone Void Filler In-Vitro

Bone void fillers (BVFs) containing calcium sulfate, tricalcium phosphate (TCP), and hydroxyapatite can be loaded with antibiotics for infection treatment or prevention under surgeon-directed use. The aim of this study was to characterize the handling and elution properties of a triphasic BVF loaded with common antibiotics. BVF was mixed with vancomycin and/or tobramycin to form pellets, and the set time was recorded. A partial refreshment elution study was conducted with time points at 4, 8, and 24 h, as well as 2, 7, 14, 28, and 42 days. Effects on dissolution were evaluated in a 14-day dissolution study. Set time increased to over 1 h for groups containing tobramycin, although vancomycin had a minimal effect. Pellets continued to elute antibiotics throughout the 42-day elution study, suggesting efficacy for the treatment or prevention of orthopedic infections. BVF containing vancomycin or tobramycin showed similar dissolution at 14 days compared to BVF without antibiotics; however, BVF containing both antibiotics showed significantly more dissolution.

Wrist arthrodesis with the medial femoral condyle flap: Outcomes of vascularized bone grafting for osteomyelitis

BACKGROUND

Osteomyelitis of the wrist is rare but destructive. Subsequent bone defects often require vascularized bone for successful healing. Recent literature has pointed to the successful use of the medial femoral condylar (MFC) flap for difficult non-unions, yet it has not been specifically described for wrist fusion. We present our experience with this technique for limited and complete wrist arthrodesis.

PATIENTS AND METHODS

We reviewed 4 cases of radiocarpal bone loss from osteomyelitis. All cases utilized debridement of nonviable tissues, and at least 6 weeks of intravenous antibiotics, followed by vascularized bone grafting with a MFC flap. The flap was based on the horizontal periosteal branch of the descending geniculate artery, and utilized to directly bridge the bony defects following resection.

RESULTS

Three patients healed primarily, and 1 patient required secondary cancellous bone grafting to reach union. One patient required revision of the donor site closure. None of the patients had a recurrence of infection or other complications. Average follow up was 8.5 months after reconstruction. Average time to union was 11.5 weeks. Three patients demonstrated full composite fist, and 1 patient had incomplete finger range of motion following several flexor and extensor tendon grafts.

CONCLUSIONS

These cases illustrate the use of the MFC in wrist arthrodesis after osteomyelitis defects. In all cases, there was complete union in a short time, no recurrence of infection, and low donor-site morbidity.

Managing large bone defects in children: a systematic review of the 'induced membrane technique'

Thirty years after its description by Masquelet in 1986, this is the first systematic review aiming to critically evaluate the 'induced membrane technique' effectiveness in achieving bone union in children. Only six papers fulfilled our inclusion criteria (54 patients). The relatively small number of reported cases did not allow a formal meta-analysis. The tibia was the most involved bone. Most frequent aetiologies were congenital pseudoarthrosis and tumour resections. Although effective in achieving bone healing in ∼91% of the patients (bone defects ≤24 cm long), the induced membrane technique was associated with a high rate of complications (54% of patients).

LEVEL OF EVIDENCE

IV.

Synthesis and characterization of CaO-loaded electrospun matrices for bone tissue engineering

OBJECTIVES

This study aims to synthesize and characterize biodegradable polymer-based matrices loaded with CaO nanoparticles for osteomyelitis treatment and bone tissue engineering.

MATERIALS AND METHODS

Poly(ε-caprolactone) (PCL) and PCL/gelatin (1:1, w/w) solutions containing CaO nanoparticles were electrospun into fibrous matrices. Scanning (SEM) and transmission (TEM) electron microscopy, Fourier transformed infrared (FTIR), energy dispersive X-ray spectroscopy (EDS), contact angle (CA), tensile testing, and antibacterial activity (agar diffusion assay) against Staphylococcus aureus were performed. Osteoprecursor cell (MC3T3-E1) response (i.e., viability and alkaline phosphatase expression/ALP) and infiltration into the matrices were evaluated.

RESULTS

CaO nanoparticles were successfully incorporated into the fibers, with the median fiber diameter decreasing after CaO incorporation. The CA decreased with the addition of CaO, and the presence of gelatin made the matrix very hydrophilic (CA = 0°). Increasing CaO concentrations progressively reduced the mechanical properties (p ≤ 0.030). CaO-loaded matrices did not display consistent antibacterial activity. MC3T3-E1 cell viability demonstrated the highest levels for CaO-loaded matrices containing gelatin after 7 days in culture. An increased ALP expression was consistently seen for PCL/CaO matrices when compared to PCL and gelatin-containing counterparts.

CONCLUSIONS

Despite inconsistent antibacterial activity, CaO nanoparticles can be effectively loaded into PCL or PCL/gelatin fibers without negatively affecting the overall performance of the matrices. More importantly, CaO incorporation enhanced cell viability as well as differentiation capacity, as demonstrated by an increased ALP expression.

CLINICAL SIGNIFICANCE

CaO-loaded electrospun matrices show potential for applications in bone tissue engineering.

hBMP-2 and hTGF-β1 expressed in implanted BMSCs synergistically promote the repairing of segmental bone defects

OBJECTIVE

To evaluate the effects of co-expressing hBMP-2 and hTGF-β1 in BMSCs (bone marrow-derived mesenchymal stem cells) on the repairing process of radial segmental defects in rats.

METHODS

BMSCs were infected with a high titer recombinant adenovirus carrying hTGF-βl and/or hBMP-2 genes. Expression of exogenous genes in BMSCs was confirmed by RT-PCR and ELISA assays. In vitro effects of exogenous genes were assessed by MTT and ALP activity tests. A left radial defect model was created using 120 SD rats. Genetically modified or unmodified BMSCs were implanted with collagen sponge scaffolds into the 5-mm radial defect. The bone repair process was systematically monitored and evaluated by X-ray examinations, gross anatomic examinations, histological analyses, and biomechanical tests.

RESULTS

Expression of hBMP-2 and hTGF-β1 showed synergistic effects on promoting BMSC proliferation and enhancing ALP activity in vitro. Bone repair assays showed that hBMP-2 and hTGF-β1 promoted the production of chondrocytes and osteoblasts. Implanted BMSCs transfected with both hBMP-2 and hTGF-β1 led to the best bone repair outcome.

CONCLUSION

hBMP-2 and hTGF-β1 can synergistically improve the bone repair process. Our results suggest a potential clinical value of combining hBMP-2 and hTGF-β1 in repairing bone defects.

Local release of antibiotics for surgical site infection management using high-purity calcium sulfate: an in vitro elution study

BACKGROUND

The aim of this study was to characterize the elution of four antibiotics from pharmaceutical-grade calcium sulfate beads and show that the eluted antibiotics retained efficacy.

METHODS

Calcium sulfate was combined with gentamicin, tobramycin, vancomycin, or rifampicin (ratio: 20 g of calcium sulfate, to 240 mg, 500 mg, 900 mg, and 600 mg of antibiotic, respectively). Three grams of beads were immersed in 4 mL of sterile phosphate-buffered saline (PBS) at 37°C. At each time point (4, 8, 24 h; 2, 7, 14, 28, 42 d), eluates were removed for analysis by liquid chromatography-mass spectrometry. The antimicrobial efficacy of antibiotics combined with calcium sulfate beads after 42 d was tested by a modified Kirby-Bauer disc diffusion assay.

RESULTS

All samples showed a generally exponential decay in the eluted antibiotic concentration. At the first time point, both gentamicin and tobramycin had eluted to a peak concentration of approximately 10,000 mcg/mL. For rifampicin, the peak concentration occurred at 24 h, whereas for vancomycin, it occurred at 48 h. The eluted concentrations exceeded the minimum inhibitory concentration for common periprosthetic joint infection pathogens for the entire span of the 42 study days. Mass spectrometry confirmed all antibiotics were unchanged when eluted from the calcium sulfate carrier. Antimicrobial efficacy was unaltered after 42 d in combination with calcium sulfate at 37°C.

CONCLUSIONS

Pharmaceutical-grade calcium sulfate has the potential for targeted local release of tobramycin, gentamicin, vancomycin, and rifampicin over a clinically meaningful time period.

A novel injectable borate bioactive glass cement as an antibiotic delivery vehicle for treating osteomyelitis

Background

A novel injectable cement composed of chitosan-bonded borate bioactive glass (BG) particles was evaluated as a carrier for local delivery of vancomycin in the treatment of osteomyelitis in a rabbit tibial model.

Materials and Methods

The setting time, injectability, and compressive strength of the borate BG cement, and the release profile of vancomycin from the cement were measured in vitro. The capacity of the vancomycin-loaded BG cement to eradicate methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in rabbit tibiae in vivo was evaluated and compared with that for a vancomycin-loaded calcium sulfate (CS) cement and for intravenous injection of vancomycin.

Results

The BG cement had an injectability of >90% during the first 3 minutes after mixing, hardened within 30 minutes and, after hardening, had a compressive strength of 18±2 MPa. Vancomycin was released from the BG cement into phosphate-buffered saline for up to 36 days, and the cumulative amount of vancomycin released was 86% of the amount initially loaded into the cement. In comparison, vancomycin was released from the CS cement for up 28 days and the cumulative amount released was 89%. Two months post-surgery, radiography and microbiological tests showed that the BG and CS cements had a better ability to eradicate osteomyelitis when compared to intravenous injection of vancomycin, but there was no significant difference between the BG and CS cements in eradicating the infection. Histological examination showed that the BG cement was biocompatible and had a good capacity for regenerating bone in the tibial defects.

Conclusions

These results indicate that borate BG cement is a promising material both as an injectable carrier for vancomycin in the eradication of osteomyelitis and as an osteoconductive matrix to regenerate bone after the infection is cured.