Comparative study of subtalar arthrodesis after calcaneal frature malunion with autologous bone graft or freeze-dried xenograft

Evolution in Bone Tissue Regeneration: From Grafts to Innovative Biomaterials

Bone defects caused by various traumas and diseases such as osteoporosis, which affects bone density, and osteosarcoma, which affects the integrity of bone structure, are now well known. Given this situation, several innovative research projects have been reported to improve orthopedic methods and technologies that positively contribute to the regeneration of affected bone tissue, representing a significant advance in regenerative medicine. This review article comprehensively analyzes the transition from existing methods and technologies for implants and bone tissue regeneration to innovative biomaterials. These biomaterials have been of great interest in the last decade due to their physicochemical characteristics, which allow them to overcome the most common limitations of traditional grafting methods, such as the availability of biomaterials and the risk of rejection after their application in regenerative medicine. This could be achieved through an exhaustive study of the applications and properties of various materials with potential applications in regenerative medicine, such as using magnetic nanoparticles and hydrogels sensitive to external stimuli, including pH and temperature. In this regard, this review article describes the most relevant compounds used in bone tissue regeneration, promoting the integration of these biomaterials with the affected area's bone structure, thereby allowing for regeneration and preventing amputation. Additionally, the types of interactions between biomaterials and mesenchymal stem cells and their effects on bone tissue are discussed, which is critical for developing biomaterials with optimal regenerative properties. Furthermore, the mechanisms of action of the various biomaterials that enhance osteoconduction and osteoinduction, ensuring the success of orthopedic therapies, are analyzed. This enables the treatment of bone defects tailored to each patient's condition, thereby avoiding limb amputation. Consequently, a promising future for regenerative medicine is emerging, with various therapies that could revolutionize the management of bone defects, offering more efficient and safer solutions.

Bovine Grafting: An Effective Alternative after Curettage of Benign Bone Tumors

We retrospectively reviewed 28 patients (15 women and 13 men) with benign bone tumors or pseudotumors treated with curettage and filling with freeze-dried bovine bone graft Orthogen (Baumer S/A, São Paulo, Brazil). The aim of the study was to evaluate the rate of incorporation of Orthogen into the host bone, as well as to describe the outcomes of bone healing (quality, time, and complications). General characteristics, tumor volume, size, site, complications, percent filled, and healing quality at 6 and 12 months were assessed through radiographs. Mean patient age was 20.5 (range 4.7-75.1) years. The most common lesion type was simple bone cyst (12/28), and the most common sites were the tibia (7/28) and humerus (7/28). There were no postoperative pathologic fractures. Two cases (7.1%) of serous fluid leakage through the wound occurred. Mean cavity volume was 20.1 (range 2.7-101.4) cm3. At 6 and 12 months, 75% and 77.8% of cavities, respectively, showed complete bone healing. At 12 months, 81% of cavities filled >90% with graft showed complete bone healing vs. only 19% of those filled <90%. Filling with bovine bone graft resulted in few complications and excellent healing after curettage of benign bone tumors or pseudotumors. Complete healing occurred in most cases by 12 months. Cavities with a higher percentage of filling had a higher rate of complete radiographic incorporation.

Is There a Borderline Value in the Radiological Findings of Patients With Calcaneal Malunion That May Help to Select an Appropriate Treatment Option?

BACKGROUND

Despite the constant evolution of technological support, operative techniques, and rehabilitation techniques after conservative treatment and operative treatment, a considerable number of patients with calcaneal fractures have constant pain, frequently resulting in loss of occupation. There are numerous options for the operative treatment of painful calcaneal malunion; however, very few publications suggest specific radiological measurements for pre- and postoperative planning-even fewer have statistically analyzed how these radiological measurements affect clinical outcomes.

METHODS

We performed a retrospective study of 100 patients after operative treatment of calcaneal malunion to determine the correlation between radiological measurements and clinical outcomes. Data were used to create an algorithm that would help to choose between in situ subtalar arthrodesis and complex reconstructive operations. The algorithm was then used to treat 27 prospective patients. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score and visual analog scale (VAS) were used for clinical assessment, whereas standard weightbearing anteroposterior (AP), lateral (LAT) ankle x-rays, and long axial hindfoot view were used for radiological assessment.

RESULTS

The talar declination angle was positively correlated with clinical outcome. Patients with talar declination angles less than 6.5 degrees showed worse results in AOFAS score than patients with a greater angle did (57.3 ± 15.3 and 81 ± 15.6, respectively).

CONCLUSION

The combination of subtalar arthrodesis with distraction bone block or calcaneal osteotomy in patients with calcaneal malunion and a talar declination angle less than 6.5 degrees showed better results than isolated in situ arthrodesis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study, case series.

Limited Evidence for Biological Adjuvants in Hindfoot Arthrodesis: A Systematic Review and Meta-Analysis of Clinical Comparative Studies

BACKGROUND

The purpose of the present study was to evaluate the efficacy of biological adjuvants in patients managed with hindfoot arthrodesis.

METHODS

A systematic review of the PubMed and Embase databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with use of specific search terms and eligibility criteria. Assessment of evidence was threefold: level of evidence by criteria as described in The Journal of Bone & Joint Surgery, quality of evidence according to the Newcastle-Ottawa scale, and conflicts of interest. Meta-analysis was performed with fixed-effects models for studies of low heterogeneity (I2 < 25%) and with random-effects models for studies of moderate to high heterogeneity (I2 ≥ 25%).

RESULTS

A total of 1,579 hindfeet were recruited across all studies, and 1,527 hindfeet were recorded as having completed treatment and follow-up visits. The duration of follow-up ranged from 2.8 to 43 months. Twelve of the 17 included studies comprised patients with comorbidities associated with reduced healing capacity. Based on the random-effects model for nonunion rates for autograft versus allograft, the risk ratio was 0.82 (95% CI, 0.13 to 5.21; I2 = 56%; p = 0.83) in favor of lower nonunion rates for autograft. Based on the random-effects model for rhPDGF/β-TCP versus autograft, the risk ratio was 0.90 (95% CI, 0.74 to 1.10; I2 = 59%; p = 0.30) in favor of lower nonunion rates for rhPDGF/β-TCP.

CONCLUSIONS

There is a lack of data to support the meaningful use of biological adjuvants as compared with autograft/allograft for hindfoot arthrodesis. The meta-analysis favored the use of autograft when compared with allograft but favored rhPDGF/β-TCP when compared with autograft in the short term.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Systematic Review of Subtalar Distraction Arthrodesis for the Treatment of Subtalar Arthritis

BACKGROUND

Subtalar distraction arthrodesis (SDA) was developed as a means of treating the symptoms of subtalar arthritis. Despite almost 30 years of research in this field, many controversies still exist regarding SDA. The objective of this study was to present an overview of outcomes following SDA, focusing on surgical technique as well as clinical and radiographic results.

METHODS

MEDLINE and EMBASE were queried and data abstraction was performed by 2 independent reviewers. Inclusion criteria for the articles were (1) English language, (2) peer-reviewed clinical studies with evidence levels I to IV, (3) with at least 5 patients, and (4) reporting clinical and/or radiographic outcomes of SDA.

RESULTS

Twenty-five studies matched the inclusion criteria (2 Level III and 23 Level IV studies) including 492 feet in 467 patients. The most common indication for SDA was late complications of calcaneus fractures. Many different operative techniques have been described, and there is no proven superiority of one method over the other. The most commonly reported complications were nonunion, hardware prominence, wound complications, and sural neuralgia. All studies showed both radiographic and clinical improvement at the last follow-up visit compared with the preoperative evaluation. Pooled results (12 studies, 237 patients) demonstrated improved American Orthopaedic Foot & Ankle Society ankle-hindfoot scores with a weighted average of 33 points of improvement.

CONCLUSION

SDA provides good clinical results at short-term and midterm follow-up, with improvement in ankle function as well as acceptable complication and failure rates. Higher quality studies are necessary to better assess outcomes between different operative techniques.

LEVEL OF EVIDENCE

Level III.

The influence of selective arthrodesis on three-dimensional range of motion of hindfoot joint: A cadaveric study

BACKGROUND

The purpose of this study was to measure the three-dimensional range of motion of adjacent, unfused joint or joints after different arthrodesis of hindfoot.

METHODS

Sixteen fresh frozen cadaver feet were immobilized in the non-weight bearing position. The three-dimensional coordinates of markers in tarsal were measured in six directions (involving dorsiflexion-plantarflexion, eversion-inversion, and adduction-abduction) before and after single (involving subtalar joint, talonavicular joint, and calcaneocuboid joint) and double (talonavicular and calcaneocuboid joints) arthrodesis with a three-dimensional coordinate instrument. The range of motion of the joint was calculated with the least square method and matrix transformation.

FINDINGS

We found that the range of motion of joints in all direction was reduced significantly after any combination of selective arthrodesis (all p < 0.001). After arthrodesis of the subtalar joint, the motion of talonavicular joint was reduced by 72%, and that of calcaneocuboid joint by 36%. After arthrodesis of talonavicular joint, the motion of subtalar joint was diminished by 36%, and that of calcaneocuboid joint by 51%. After arthrodesis of calcaneocuboid joint, the motion of subtalar joint was decreased by 21%, and that of talonavicular joint by 42%. After double arthrodesis, the motion of subtalar joint was reduced by 62%.

INTERPRETATION

In single arthrodesis, subtalar arthrodesis had the greatest effect on the motion of unfused joints, and the least was the calcaneocuboid arthrodesis. The motion of the subtalar joint was eliminated more than half after double arthrodesis. The data provide a biomechanical rationale to ascertain the clinical implication of the arthrodesis.

Treatment of Malunited Calcaneal Fracture With Posttraumatic Subtalar Osteoarthritis Using Lateral Endoscopic Calcaneoplasty With Posterior Arthroscopic Subtalar Arthrodesis

Malunion of calcaneal fractures is a common complication after improper nonoperative treatment. It may develop into posttraumatic subtalar osteoarthritis, lateral calcaneal wall prominence, and severe foot deformities. This Technical Note reports the technical aspects of lateral endoscopic calcaneoplasty with posterior arthroscopic subtalar arthrodesis for the treatment of malunited calcaneal fracture with lateral calcaneal wall prominence and posttraumatic subtalar osteoarthritis. This technique was chosen because it can reduce the risk of wound complication compared with a conventional lateral extensile approach. This Technical Note describes the use of the technique in a patient with prone position. This offers the advantages of easier access to the lateral surface of the calcaneus and posterior facet of the subtalar joint, and is less invasive to the soft tissue envelope on the lateral side of the foot. Moreover, the concomitant bone void area of the subtalar joint can be dealt with by an arthroscopic procedure.

[Application and research progress of subtalar distraction bone block arthrodesis in treatment of calcaneus fracture malunion]

Objective

To review the application and research progress of subtalar distraction bone block arth-rodesis in the treatment of calcaneus fracture malunion.

Methods

The recent literature concerning the history, surgical technique, postoperative complication, indications, and curative effect of subtalar distraction arthrodesis with bone graft block interposition in the treatment of calcaneus fracture malunion was summarized and analyzed.

Results

Subtalar distraction bone block arthrodesis is one of the main ways to treat calcaneus fracture malunion, including a combined surgery with subtalar arthrodesis and realignment surgery for hindfoot deformity using bone block graft. The advantage is on the base of subtalar joint fusion, through one-time retracting subtalar joint, the posterior articular surface of subtalar joint implants bone block can partially restore calcaneal height, thus improving the function of the foot. Compared with other calcaneal malunion treatments, subtalar distraction arthrodesis is effective to correct complications caused by calcaneus fracture malunion, and it can restore the height of talus and calcaneus, correct loss of talocalcaneal angle, and ease pain.

Conclusion

Subtalar distraction bone block arthrodesis has made remarkable progress in the treatment of calcaneus fracture malunion, but it has the disadvantages of postoperative nonunion and absorption of bone block, so further study is needed.