Biodegradable poly-L-lactide-co-glycolide copolymer pin fixation of a traumatic patellar osteochondral fragment in an 11-year-old child: A novel surgical approach

Comparison of biodegradable and metallic tension-band fixation for paediatric lateral condyle fracture of the elbow

INTRODUCTION

In our retrospective study we compared the outcomes of paediatric lateral condyle fractures of the elbow fixed by bioabsorbable pins and tension-band sutures or by metallic tension-band with K-wires.

MATERIALS AND METHODS

We reviewed the data of children operated on for lateral condyle fractures between 2010 and 2020. Patients were classified as follows: 1. fractures treated with metallic (KW group), 2. fractures treated with resorbable implants (BR group). We compared the distribution of age, sex and fracture type in each group. Operative times of the two techniques were also recorded and compared. We analysed the X-rays taken one year after the injury and measured the following parameters: presence of possible non-union, varus or valgus deviation, lateral spur formation. Patients whose follow-up period was less than one year were excluded. For categorical data, group comparisons were performed with Chi-square test or Fisher's exact test, depending on the sample size. The evaluation of discrete variables was performed with Mann-Whitney U test.

RESULTS

42 patients met the above criteria. We found 19 children in the Kirschner -wire + tansion band wire (KW) group and 23 in the Bioresorbable pin + tension band suture (BR) group. There were no significant differences between the study groups in terms of age, sex, left-right ratio, number of complications, operation time, number of Jacobs II and III cases or follow-up time. The operation time was on average 5 min longer in the bioresorbable group (K-wire mean = 62.1 min, Bioresorbable mean = 67 min), this difference, however, is not statistically significant (P = 0.177). In terms of minor and major complications, there was no statistically significant difference between the two groups. (P = 0.729).

CONCLUSIONS

We did not notice any difference between the complication rates of the two methods, so the real advantage of the absorbable implant technique is that no second intervention is necessary. The benefits of using biodegradable implants in various osteosynthesis techniques need further confirmation by randomised trials.

Comparison of Titanium versus Resorbable Intramedullary Nailing in Pediatric Forearm Fractures

Pediatric forearm fractures, particularly involving the shaft or diaphysis, are common injuries typically resulting from accidental trauma during various activities. Traditional treatment involves closed reduction and casting; however, surgical intervention may be necessary in certain cases. The gold standard surgical approach utilizes elastic stable intramedullary nailing (ESIN), but a newer technique uses bioabsorbable intramedullary nails made of poly(lactic-co-glycolic acid) (PLGA). This study aims to compare the outcomes of these two surgical methods in pediatric diaphyseal forearm fractures. We retrospectively reviewed 86 patients who underwent operative treatment due to the diaphyseal fractures of the forearm in the Surgical Division, Department of Pediatrics, Medical School, University of Pécs, Pécs, Hungary between 2018 and September 2022. The mean age was 9.48 (ranging from 4 to 17). A total of 41 patients underwent surgery with PLGA implants (RESIN technique), while 45 patients were treated with titanium elastic nails (ESIN technique). Various factors including patient demographics, injury mechanisms, fracture characteristics, and complications were assessed. Both groups showed similar gender distribution, with a majority of fractures occurring in boys (the male-female ratio was 31:10 in the PLGA group, while in the titanium elastic nailing (TEN) group, this ratio was 29:16, with no statistical difference between the groups (p > 0.005). The average age of the patients treated with PLGA implants (8.439 years) was lower compared to those treated with titanium nails (10.422 years). A statistically significant difference was found regarding the average age of the two groups (p = 0.0085). Left-sided injuries were more prevalent in both groups (59% of the cases in the PLGA group and 69% in the TEN group, with no statistically significant difference, p = 0.716), and fractures typically involved both the radius and ulna. This represents 93% of the cases in the PLGA group and 80% in the TEN group. Regarding the involvement of bones, we also did not find a statistically significant difference (p = 0.123). The mechanisms of injury predominantly involved indirect force, such as falls (30 cases in the PLGA group and 27 cases in the TEN group), and no statistically significant difference was found (p = 0.139) regarding the mechanism of the injury. Complication rates were lower in the PLGA group (7%) compared to the titanium group (20%). The treatment of pediatric diaphyseal forearm fractures using PLGA implants appears to be a viable alternative to traditional titanium implants. Advantages include no need for secondary surgery and associated cost savings and reduced complication rate and stress associated with anesthesia and surgery. Prospective randomized trials are warranted to further validate these findings and explore long-term outcomes.

Operative management of osteochondral lesions of the talus: 2024 recommendations of the working group 'clinical tissue regeneration' of the German Society of Orthopedics and Traumatology (DGOU)

The working group 'Clinical Tissue Regeneration' of the German Society of Orthopedics and Traumatology (DGOU) issues this paper with updating its guidelines. Literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLT) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available with a grade of recommendation. All group members rated the statements to identify possible gaps between literature and current clinical practice. Fixation of a vital bony fragment should be considered in large fragments. In children with open physis, retrograde drilling seems to work better than in adults, but even there, the revision rate reaches 50%. The literature supports debridement with bone marrow stimulation (BMS) in lesions smaller than 1.0 cm² without bony defect. The additional use of a scaffold can be recommended in lesions larger than 1.0 cm². For other scaffolds besides AMIC®/Chondro-Gide®, there is only limited evidence. Systematic reviews report good to excellent clinical results in 87% of the patients after osteochondral transplantation (OCT), but donor site morbidity is of concern, reaching 16.9%. There is no evidence of any additional benefit from autologous chondrocyte implantation (ACI). Minced cartilage lacks any supporting data. Metallic resurfacing of OLT can only be recommended as a second-line treatment. A medial malleolar osteotomy has a minor effect on the clinical outcome compared to the many other factors influencing the clinical result.

Pediatric medial humeral epicondyle fracture in children: Are biodegradable pins with tension band absorbable sutures efficient?

Medial humeral epicondyle fractures account for 10% to 20% of elbow injuries in children. We hypothesized that in the fixation of medial humeral epicondyle fractures, safety and efficiency of bioabsorbable poly(l-lactide-co-glycolic acid) implant are comparable to traditional metallic and other novel approaches. A retrospective cohort study was performed between 2016 and 2019, analyzing 24 children who had medial humeral epicondyle fractures. Every fracture was stabilized with biodegradable poly(l-lactide-co-glycolic acid) implants (Bioretec® ActivaPin®) and tension band polydioxanone sutures. Indications for surgery included closed fractures with >1 cm dislocation and incarcerated fractures. Postoperatively, the degree of anatomic reduction and the presence or absence of nonunion or fragmentation were confirmed with X-rays. In this clinical study, we evaluated the operation time, age, and gender distribution. The mean age at the time of injury was 12.3 (8-16 years). In the fourth week, every patient's X-ray showed callus formation, and the range of motion of the elbow after 6 months of the operation was almost complete in all children. Transient ulnar nerve palsy was developed in 1 patient, which was spontaneously resolved in the fourth postoperative month. No other complications were observed during the average follow-up period of 34 months (16-60 months). Bioabsorbable pins with absorbable sutures are a good alternative treatment of medial epicondyle humeral fracture. No permanent complications were noted while using this technique. We suggest this method because it does not require a secondary (metal removal) operation.

Bioresorbable implants vs. Kirschner-wires in the treatment of severely displaced distal paediatric radius and forearm fractures - a retrospective multicentre study

BACKGROUND

Distal radius fractures are very common in paediatric patients. Severely displaced fractures may require surgical intervention. The gold standard surgical method is percutaneous K-wire osteosynthesis followed by immobilisation. Metal implants can be removed with a second intervention; however, these extra procedures can cause further complications. Several studies confirm the benefits of bioabsorbable implants for paediatric patients. The aim of this retrospective study was to compare the complication rates of displaced distal metaphyseal radius (AO 23r-M/3.1) and forearm (AO 23-M/3.1) fractures in children operated on with K-wires versus a novel technique with bioresorbable implants.

METHODS

We retrospectively reviewed 94 patients in three paediatric trauma centres who underwent operations due to severely displaced distal forearm or metaphyseal radial fractures between January 2019 and January 2020. The mean age was 8.23 (ranging from 5-12). 30 patients (bioresorbable group, BR-group) were treated with biodegradable PLGA implants (Bioretec®, ActivaPin®), 40 patients with one or two stainless steel Kirschner-wires (K-wires, Sanatmetal®) which were buried under the skin (KW I-group) and 24 children with K-wires left outside the skin. (KWII. Group). We examined the number of minor and major complications as well as the need for repeated interventions. Follow-up was at least one and half year.

RESULTS

There was no significant difference between the complication rates at the two KW groups (p = 0.241; Cramer's V = 0.211), while the complication rate of the BR group was significantly lower. (p = 0.049; Cramer's V = 0.293 and p = 0.002; Cramer's V = 0.418 respectively). No later than half a year after the injury, no difference was observed between the functional outcomes of the patients in each group. One and a half years after the injury, no signs of growth disturbance were found in any of the children. No second surgical intervention was required in the BR group.

CONCLUSIONS

Surgeries with bioresorbable intramedullary implants may have fewer complications than K- wire osteosynthesis in the treatment of severely displaced distal forearm fractures. The benefits are most pronounced in the first six weeks after surgery, reducing the number of outpatient visits and increasing the child's sense of comfort. As no second intervention is required, this can lead to significant cost savings. After half a year, there is no difference in the outcomes between the different surgical treatment strategies.

Making Hardware Removal Unnecessary by Using Resorbable Implants for Osteosynthesis in Children

Introduction: Following osteosynthesis, children generally require a second surgery to remove the hardware. This becomes unnecessary, by using resorbable implants. Limiting the number of required surgeries and their associated risks, this technique provides critical aspects of minimally invasive surgery. This review focuses on resorbable implants for osteosynthesis for the treatment of fractures in children and discusses their clinical features. Method: We provide an overview of the two most common technologies used in resorbable osteosynthesis materials: polymer- and magnesium-based alloys. Clinical examples of osteosynthesis are presented using polymer-based ActivaTM products and magnesium-based Magnezix^® products. Results: Polymer-based implants demonstrate surgical safety and efficacy. Due to their elasticity, initial placement of polymer-based products may demonstrate technical challenges. However, stability is maintained over the course of healing. While maintaining good biocompatibility, the rate of polymer-resorption may be controlled by varying the composition of polyesters and copolymers. Similarly, magnesium-based implants demonstrate good mechanical stability and resorption rates, while these characteristics may be controlled by varying alloy components. One of the significant shortcomings of magnesium is that metabolism results in the production of hydrogen gas. Both technologies provide equally good results clinically and radiographically, when compared to non-resorbable implants. Conclusion: Resorbable osteosynthesis materials demonstrate similar therapeutic results as conventional materials for osteosynthesis. Resorbable implants may have the potential to improve patient outcomes, by sparing children a second surgery for hardware removal.

Clinical Results and MRI Evaluation of Patellar Osteochondral Fracture Fixation following Patellar Dislocation

Aim

The aim of the study was to analyze the clinical results and MRI scans after transpatellar osteochondral fracture fixation following patellar dislocation.

Methods

Our study group comprised 17 patients with patellar dislocation followed by osteochondral fracture of the articular surface of the patella. All patients underwent surgery where the fractured osteochondral fragments of the patella were attached using the transpatellar suture technique. The mean age at the time of surgery was 14.1 years, and the mean follow-up period was 7.5 years.

Results

The results of the patellar compression test and the apprehension test were negative in all patients. The mean Lysholm and Kujala scores were 89.2 and 89.6, respectively. The MRI scan revealed healing of the fixed fragment and restoration of the articular surface in all patients. In 16 cases, subchondral bone of the fixed fragment area was described as irregular: its articular cartilage was narrowed and not homogenous. Progressive degenerative changes were observed in the patellofemoral joint at follow-up in three patients.

Conclusions

By fixing osteochondral fragments, the patellar articular surface can be restored. The MRI scans show that the cartilage in the reconstructed surface is narrowed after a mean 7.5-year follow-up.

Comparison of a resorbable magnesium implant in small and large growing-animal models

Fracture treatment in children needs new implant materials to overcome disadvantages associated with removal surgery. Magnesium-based implants constitute a biocompatible and bioresorbable alternative. In adults and especially in children, implant safety needs to be evaluated. In children the bone turnover rate is higher and implant material might influence growth capacity, and the long-term effect of accumulated particles or ions is more critical due to the host's prolonged post-surgery lifespan. In this study we aimed to investigate the degradation behavior of ZX00 (Mg-0.45Zn-0.45Ca; in wt.%) in a small and a large animal model to find out whether there is a difference between the two models (i) in degradation rate and (ii) in bone formation and in-growth. Our results 6, 12 and 24 weeks after ZX00 implantation showed no negative effects on bone formation and in-growth, and no adverse effects such as fibrotic or sclerotic encapsulation. The degradation rate did not significantly differ between the two growing-animal models, and both showed slow and homogeneous degradation performance. Our conclusion is that small animal models may be sufficient to investigate degradation rates and provide preliminary evidence on bone formation and in-growth of implant materials in a growing-animal model.

STATEMENT OF SIGNIFICANCE

The safety of implant material is of the utmost importance, especially in children, who have enhanced bone turnover, more growth capacity and longer postoperative lifespans. Magnesium (Mg)-based implants have long been of great interest in pediatric orthopedic and trauma surgery, due to their good biocompatibility, biodegradability and biomechanics. In the study documented in this manuscript we investigated Mg-Zn-Ca implant material without rare-earth elements, and compared its outcome in a small and a large growing-animal model. In both models we observed bone formation and in-growth which featured no adverse effects such as fibrotic or sclerotic encapsulation, and slow homogeneous degradation performance of the Mg-based implant material.

Intramedullary nailing of forearm shaft fractures by biodegradable compared with titanium nails: Results of a prospective randomized trial in children with at least two years of follow-up

There are disadvantages in Elastic Stable Intramedullary Nailing (ESIN) of forearm-shaft fractures, such as the need of implant removal. Biodegradable Intramedullary Nailing (BIN) is a new technique developed for these fractures. We hypothesized that there is no difference in rotational ROM between the patients treated by BIN vs. ESIN. A randomized, controlled clinical trial included patients, aged 5-15 years, requiring surgery for forearm-shaft fractures. Biodegradable polylactide-co-glycolide (PLGA) nails (Activa IM-Nail™, Bioretec Ltd., Finland) were used in 19 and titanium nails (TEN^®, SynthesDePuy Ltd., USA) in 16 patients. Rotational ROM of forearm after two years was the primary outcome. Elbow and wrist ROM, pain and radiographic bone healing were secondary outcomes. Forearm rotation was mean 162° and 151° in BIN and ESIN groups, respectively (P = 0.201). No difference between the groups was found in any other ROMs. Three cases in the ESIN vs. none in the BIN group reported pain (P = 0.113). There was no clinically significant residual angulation in radiographs. Two adolescents in the BIN group vs. none in the ESIN (P = 0.245) were excluded because of implant failure; another two with complete bone union suffered from re-injury. Therefore, satisfactory implant stability among older children needs to be studied.