Increased pin diameter improves torsional stability in supracondylar humerus fractures: an experimental study

Background

Pediatric supracondylar humerus fractures are the most common elbow fractures seen in children, and account for 16 % of all pediatric fractures. Closed reduction and percutaneous pin fixation is the current treatment technique of choice for displaced supracondylar fractures of the distal humerus in children. The purpose of this study was to determine whether pin diameter affects the torsional strength of supracondylar humerus fractures treated by closed reduction and pin fixation.

Methods

Pediatric sawbone humeri simulating a Gartland type III fracture were utilized. Four different pin configurations were compared. Specimens were subjected to a torsional load producing internal rotation of the distal fragment. The stability provided by 1.25- and 1.6-mm pins was compared.

Results

The amount of torque required to produce 15° and 25° of rotation was greater using larger diameter pins in all models tested. The two lateral and one medial large pin (1.6 mm) configuration required the highest amount of torque to produce both 15° and 25° of rotation.

Conclusions

In a synthetic pediatric humerus model of supracondylar humerus fractures, larger diameter pins (1.6 mm) provided increased stability compared with small diameter pins (1.25 mm). Fixation using larger diameter pins created a stronger construct and improved the strength of fixation.

     

In vivo bactericidal efficacy of the Ti6Al4V surface after ultraviolet C treatment

Background

Biomaterial-associated infections are one of the most important complications in orthopedic surgery. The main goal of this study was to demonstrate the in vivo bactericidal effect of ultraviolet (UV) irradiation on Ti6Al4V surfaces.

Materials and methods

An experimental model of device-related infections was developed by direct inoculation of Staphylococcus aureus into the canal of both femurs of 34 rats. A UV-irradiated Ti6Al4V pin was press-fit into the canal by retrograde insertion in one femur and the control pin was inserted into the contralateral femur. To assess the efficacy of UV radiation, the mean colony counts after inoculation in the experimental subjects and the control group were compared at different times of sacrifice and at different inoculum doses.

Results

At 72 h, the mean colony counts after inoculation in experimental femurs were significantly lower than those of the control group, with a reduction percentage of 76 % (p = 0.041). A similar difference between control and experimental pins was observed at 24 h using an inoculum dose <10⁴ colony-forming units (CFU), for which the reduction percentage was 70.48 % (p = 0.017).

Conclusion

The irradiated surface of Ti6Al4V is able to reduce early bacterial colonization of Ti6AlV pins located in the medullar channel and in the surrounding femur. The reductions depend on the initial inoculums used to cause infection in the animals and the greatest effects are detected for inoculums <10⁴ CFU.

Level of evidence

Not applicable.

     

Modified translaminar screw fixation in the cervicothoracic junction (C7–T2): a technical note

Purpose

To describe and illustrate a modified technique for using translaminar screw in the cervicothoracic junction (C7–T2).

Methods

12 patients (8 males and 4 females, average age was 52 years) underwent insertion of unilateral or bilateral translaminar screws by using our modified technique. With this modified technique, a tiny unicortical “hole” was made at the middle of the contralateral lamina, and the screw can be directly visualized through the unicortical “hole” to prevent violating the spinal canal.

Results

With this modified technique, the mean operation time was 205 min (range 145–360) and mean estimated blood loss was 445 ml (range 260–1250). The mean length of the laminar screws was 27 (range 24–30) mm. The results of the 12 patients with an average follow-up of 17 (6–33) months demonstrated this modified technique to be safe and effective in the fixation of cervicothoracic junction.

Conclusion

In this modified technique, a tiny unicortical “hole” which was made at the middle of the dorsal lamina of cervicothoracic junction (C7–T2). By directly visualizing the screw inserting against the dorsal cortices of the lamina, this modified technique can reduce the risk of violation of the spinal canal and shorten the operation time.

     

Routine radiographs at time of pin removal after closed reduction and percutaneous pinning for type 2 supracondylar humerus fractures do not change management: a retrospective cohort study

Purpose

Radiographs are usually taken on day of pin removal for children treated with closed reduction and percutaneous pinning (CRPP) of type 2 supracondylar humerus fractures. The purpose of this study was to determine whether radiographs taken at time of pin removal for patients recovering uneventfully alter management.

Methods

After IRB approval, billing records identified 1213 patients aged 1–10 years who underwent elbow surgery between 2007 and 2013 at our institution for a supracondylar humerus fracture. Of these patients, 389 met inclusion criteria. Clinical charts were reviewed for demographics, operative details, and clinical follow-up, focusing on clinical symptoms present at pin removal. Radiographs taken at time of pin removal and subsequent visits were assessed for healing and fracture alignment.

Results

In no case was pin removal delayed based on radiographs. One hundred and nineteen (31 %) patients had radiographs taken following pin removal; in no case was loss of reduction found among these patients. No cases of neurologic or vascular injury, re-fracture, or loss of reduction occurred. Infection occurred in 12 patients (3 %). Pins were kept in place for 23.8 ± 4.4 days. Eighty-six patients (22 %) had additional intervention after pin removal (cast application in all cases). Of 389 patients, 75 (19 %) had no documented reason for extended casting, four (1 %) were extended based on physician evaluation of radiographs, and seven (2 %) were extended for other reasons.

Conclusions

Elimination of radiographs at time of pin removal should be considered. If continuing to obtain radiographs at pin removal, we recommend removing pins before taking radiographs to reduce patient fear and anxiety from visualizing percutaneous pins.

     

A new approach to local DCO in ankle fracture dislocations: external fixation with diaphyseal unicortical screws applied by local anaesthesia

Purpose

Ankle fracture dislocations represent a great threat for soft tissue viability and articular instability. The use of a temporary ankle bridging ExFix plays a fundamental role in the local damage control orthopaedics while waiting for definitive synthesis.

Methods

For this prospective research, we have developed a full application protocol of innovative diaphyseal monocortical screws fixator (Unyco–Orthofix^TM) exclusively under local anaesthesia. Rigid selection criteria allowed us to collect nine patients during a period of almost 2 years. VAS score was analysed for the feasibility of the procedure, and a thorough radiologic evaluation was performed.

Results

Results pointed out that the calcaneus pin insertion (VAS: 3.44) followed by the local anaesthetics injection (VAS: 3.22) was the most painful, without precluding to continue the procedure; fracture temporary stability was achieved in all the cases.

Conclusions

The procedure of monocortical diaphyseal application in bridging external fixation is comparable to the conventional transcalcaneal traction maintaining the advantage in terms of speediness, independence from anaesthetists and feasibility within few minutes from hospital admittance even in patients under anticoagulants therapy, but increasing the stability of the reduction and improving the quality of nursing (so-called portable traction).

     

Influence of interradicular and palatal placement of orthodontic mini-implants on the success (survival) rate

Background

The purpose of this retrospective cohort study was to investigate the success rates of orthodontic mini-implants (OMIs) placed in different insertion sites and to analyse patient and site- related factors that influence mini-implant survival.

Methods

Three hundred eighty-seven OMIs were inserted in 239 patients for orthodontic anchorage and were loaded with a force greater than 2 N. Two different insertion sites were compared: 1. buccal inter-radicular and 2. palatal, at the level of the third palatal ruga. Survival was analysed for location and select patient parameters (age, gender and oral hygiene). The level of statistical significance was set at p < 0.05.

Results

The overall success rate was 89.1%. There were statistically significant differences between insertion sites; success rate was 98.4% for OMIs placed in the anterior palate and 71% for OMIs inserted buccal between roots (p < 0.001).

Conclusions

Success rate of OMIs was primarily affected by the insertion site. The anterior palate was a more successful location compared to buccal alveolar bone.

     

Our experience in the management of segmental bone defects caused by gunshots

Purpose

Bone and soft-tissue defects in the leg can be caused by high-energy trauma. One of the causes of extensive bone defects are gunshot injuries. The incidence of these has been noticeably increasing in recent years in countries with political instabilities due to the random availability of weapons. The aim of this study is to focus on the essentials of treatment of post-gunshot tibial bone loss using the Ilizarov concept.

Methods

In the period between June 2011 and July 2013, 30 patients with open tibial fractures after gunshots comprised the present study with an average follow-up of 18 months. The bone defect was associated with soft-tissue loss in 18 cases. All cases were subjected to extensive debridement of all devitalized tissues back to the healthy bone with viable soft tissue coverage. All cases were treated by the Ilizarov external fixator using the bifocal bone transport technique.

Results

The overall bone results were satisfactory in 28 cases (93.3 %). The overall functional results were satisfactory in 22 cases (73.3 %). The bone end results were significantly affected by age and smoking, while the functional end results were significantly affected by smoking, the presence of infection at the time of presentation, and complications during the procedure.

Conclusions

Bone transport is a reliable method in the treatment of gunshot bone defects of the tibia after extensive debridement of all the devitalized tissues. The Ilizarov external fixator allows the functional use of the limb throughout the course of treatment, preventing disuse osteoporosis and increasing patient satisfaction.

     

Comparative evaluation of insertion torque and mechanical stability for self-tapping and self-drilling orthodontic miniscrews – an in vitro study

Background

The aim of the present study was to evaluate the relationship between insertion torque and stability of miniscrews in terms of resistance against dislocation, then comparing a self-tapping screw with a self-drilling one.

Methods

Insertion torque was measured during placement of 30 self-drilling and 31 self-tapping stainless steel miniscrews (Leone SpA, Sesto Fiorentino, Italy) in synthetic bone blocks. Then, an increasing pulling force was applied at an angle of 90° and 45°, and the displacement of the miniscrews was recorded.

Results

The statistical analysis showed a statistically significant difference between the mean Maximum Insertion Torque (MIT) observed in the two groups and showed that force angulation and MIT have a statistically significant effect on miniscrews stability. For both the miniscrews, an angle of 90° between miniscrew and loading force is preferable in terms of stability.

Conclusions

The tested self-drilling orthodontic miniscrews showed higher MIT and greater resistance against dislocation than the self-tapping ones.

     

Die palmare winkelstabile Plattenosteosynthese bei Extensionsfrakturen des distalen Radius

Objective

Bony healing of dislocated distal radius fractures after open reduction and internal stabilization by locking screws/pins using palmar approach.

Indications

Extraarticular distal radius fractures type A2/A3, simple extra- and intraarticular fractures type C1 according to the AO classification, provided a palmar approach is possible.

Contraindications

Forearm soft tissue lesions/infections. As a single procedure if a volar approach not possible.

Surgical technique

Palmar approach to the distal radius and fracture. Open reduction. Palmar fixation of the plate to radial shaft with single screw. After fluoroscopy, distal fragments fixed using locking screws.

Postoperative management

Below-the-elbow cast for 2 weeks. Early exercise of thumb and fingers, wrist mobilization after cast removal. Complete healing after 6–8 weeks.

Results

Ten patients averaged 100?% range of motion of the unaffected side after 43±21 months. No complications observed. DASH score averaged 12±16 points; Krimmer wrist score was excellent in 7, good in 2, and fair in one.

     

Die Masquelet-Technik zur Behandlung großer dia- und metaphysärer Knochendefekte

Objective

Treatment of large dia- and metaphyseal bone defects (>?3 cm) with two surgical interventions with an interval of 4–8 weeks.

Indications

Dia- and metaphyseal bone defects predominantly of the lower extremity.

Contraindications

Intraarticular bone defects, persisting bone infection or osteomyelitis, insufficient soft tissue coverage in the region of the bone defect, osteoporosis.

Surgical technique

First surgical intervention: thorough bone debridement and soft tissue coverage, implantation of a cement spacer into the bone defect for the induction of a synovial foreign-body membrane, internal or external fixation. Second surgical intervention: removal of the cement spacer and filling of the bone defect with autologous cancellous bone graft, optionally internal fixation after initial external fixation.

Postoperative management

Partial to full weight-bearing after the first surgical intervention depending on pain. Partial weight-bearing (max. 15 kg) after the second surgical intervention, until radiological signs of a remodeling of the regenerate bone occur. Usually no implant removal.

Results

A total of 6 patients (4 men, 2 women) aged 15–66 years with average bone defects of 7 cm (range 4–10 cm) were treated using the Masquelet technique. There were 2 aseptic femoral nonunions and 4 tibial nonunions (2 septic and 2 aseptic nonunions). One case was a periprosthetic tibial bone defect. Bone stabilization after debridement was performed using ring fixators on the tibia and an intramedullary nail and a locking plate on the femur, respectively. The second surgical intervention was performed after 6–9 weeks. In 3 of the 4 tibial cases, internal fixation was performed during this intervention. The iliac crest and the RIA (reamer–irrigator–aspirator) technique were used for cancellous bone grafting. Amputation after breakage of the plate was necessary in the patient with the periprosthetic bone defect. Nonunion at the docking site required cancellous bone grafting in 1 patient. All 5 patients were able to perform full weight-bearing without pain after 6 months. The Ilizarov fixator was removed 5 months after the second surgical intervention in a 15-year-old patient. None of the other implants were removed.

     

Irradiation Does Not Modify Mechanical Properties of Cancellous Bone Under Compression

Background

Gamma radiation sterilization can make cortical bone allograft more brittle, but whether it influences mechanical properties and propensity to form microscopic cracks in structurally intact cancellous bone allograft is unknown.

Questions/purposes

We therefore determined the effects of gamma radiation sterilization on structurally intact cancellous bone mechanical properties and damage formation in both low- and high-density femoral cancellous bone (volume fraction 9%–44%).

Methods

We studied 26 cancellous bone cores from the proximal and distal femurs of 10 human female cadavers (49–82 years of age) submitted to a single compressive load beyond yield. Mechanical properties and the formation of microscopic cracks and other tissue damage (identified through fluorochrome staining) were compared between irradiated and control specimens.

Results

We observed no alterations in mechanical properties with gamma radiation sterilization after taking into account variation in specimen porosity. No differences in microscopic tissue damage were observed between the groups.

Conclusions

Although gamma radiation sterilization influences the mechanical properties and failure processes in cortical bone, it does not appear to influence the performance of cancellous bone under uniaxial loading.

Clinical Relevance

Our observations support the use of radiation sterilization on structurally intact cancellous bone allograft.

     

Rare complications of osteolysis and periprosthetic tissue reactions after hybrid and non-hybrid total disc replacement

Purpose

Few complications have been reported for lumbar total disc replacement (TDR) and hybrid TDR fixations. This study evaluated retrieved implants and periprosthetic tissue reactions for two cases of osteolysis following disc arthroplasty with ProDisc-L prostheses.

Methods

Implants were examined for wear and surface damage, and tissues for inflammation, polyethylene wear debris (polarized light microscopy) and metal debris (energy-dispersive X-ray spectroscopy).

Results

Despite initial good surgical outcomes, osteolytic cysts were noted in both patients at vertebrae adjacent to the implants. For the hybrid TDR case, heterotopic ossification and tissue necrosis due to wear-induced inflammation were observed. In contrast, the non-hybrid implant showed signs of abrasion and impingement, and inflammation was observed in tissue regions with metal and polyethylene wear debris.

Conclusions

In both cases, wear debris and inflammation may have contributed to osteolysis. Surgeons using ProDisc prostheses should be aware of these rare complications.

     

Ilizarov fixation for the treatment of scaphoid nonunion: a novel approach

Objectives

To evaluate the safety and efficacy of the Ilizarov fine-wire compression/distraction technique in the treatment of scaphoid nonunion (SNU), without the use of bone graft.

Design

This is a prospective study of 20 consecutive patients in one center.

Patients and methods

This study included 20 patients (19 males) with a mean SNU duration of 14.5 months. Four patients had proximal pole, 15 had waist, and 1 had a distal SNU. Patients with carpal instability, humpback deformities, carpal collapse, avascular necrosis, and marked degenerative change were excluded. Following frame application, the treatment comprises three stages: The frame is distracted by 1 mm per day until the radiographs show a 2–3 mm opening at the SNU site (mean 10 days); the SNU site is compressed for 5 days, at a rate of 1 mm per day, with the wrist in 15 degrees of flexion and 15 degrees of radial deviation; the wrist is then immobilized in the Ilizarov fixator for 8 weeks.

Results

Radiographic (radiography and CT scan) and clinical bony union was achieved in all 20 patients after a mean of 90.3 days (70–130 days). All patients returned to their pre-injury occupations. Thirteen patients had excellent results, four good, and three fair, according to the Mayo wrist score.

Conclusions

In these selected patients, this technique safely achieved bony union without the need to open the SNU site and without the requirement of bone graft.

     

Cervical pedicle screw placement using intraoperative computed tomography imaging with a mobile scanner gantry

Purpose

A multi-detector computed tomography (CT) imaging system with a mobile scanner gantry in the operating room can provide intraoperative reconstructed images with a high resolution. We devised a technique for cervical pedicle screw (CPS) placement using the mobile CT system and evaluated the accuracy of this technique.

Methods

Forty-eight patients who underwent cervical fixation using CPSs were prospectively enrolled in this study. Initial pedicle probing was performed approximately to the depth of the posterior aspect of the vertebral body using fluoroscopic lateral view, and a marking pin was put in place. Intraoperative CT images were obtained to confirm whether the position of the marking pin was accurate. After adequate modification of the trajectory was performed, an appropriately sized CPS was inserted. The accuracy of the CPS was evaluated using postoperative reconstructed CT images, and compared with a historical control group of 22 patients (CPS insertion using only fluoroscopy).

Results

A total of 193 CPSs were inserted. Intraoperative CT images demonstrated that 12.4 % of the initial probings were not accurate, and modification of the trajectory was required. On postoperative CT, 92.7 % of the CPSs were found to be placed accurately: the accuracy was significantly higher than the control group (80.9 %). In the cases using intraoperative CT images, only 1.0 % of the screws were judged to show grade 2 screw misplacement; no neurovascular complications associated with screw placement were observed.

Conclusions

The technique of CPS placement using mobile CT was shown to be safe and effective in preventing catastrophic complications associated with CPS insertion.

     

Free non-vascularized fibular graft for treatment of large bone defect around the elbow in pediatric patients

Background

Large bone defect is a challenging problem in orthopedics practice. Several methods are available for bridging of these bone defects, including cancellous bone graft, free vascularized fibula graft, and bone transport with external ring fixator. The aim of this study was to describe our experience in nine pediatric cases of free non-vascularized autogenous fibular strut bone graft in which large bone defect and bone loss of >7 cm was caused by open fracture and infective nonunion around the elbow joint.

Objective

To describe our experience in nine pediatric cases of free non-vascularized autogenous fibular strut bone graft in which large bone defect and bone loss of >7 cm was caused by open fracture and infective nonunion around the elbow joint.

Method

This retrospective review was conducted in patients with large bone defect with bony gap >7 cm. Time to union, range of motion, complications, Mayo Elbow Performance Score, and Foot and Ankle Disability Index (FADI) were recorded.

Result

The large bone defects included in this study were managed by free non-vascularized fibular strut bone grafts (FNVFG) that were harvested subperiosteally. Nine patients with a mean age of 11 years (range: 6–17) underwent this procedure. Nine grafts (100%) united at both ends within an average of 9 weeks (range: 8–14). Mean length of defect was 9.3 cm (range: 8–13 cm). Mean postoperative Mayo Elbow Performance Score was significantly higher than the mean preoperative score (98.33 vs. 64.44, respectively; p < 0.001). Three fibulae were observed for hypertrophy. Mean Foot and Ankle Disability Index score was 100 both preoperatively and postoperatively in all patients.

Conclusion

Free non-vascularized fibular graft is a simple procedure and a reliable method for bridging large bone defect or loss caused by open fracture and/or infection around the elbow in pediatric patients.

     

Perioperative management of external fixation in staged protocols: an international survey

Introduction

Despite the frequent use of external fixation, various regimes of antibiotic prophylaxis, surgical technique and postoperative pin care exist and underline the lack of current evidence. The aim of the study was to assess the variability or consensus in perioperative protocols to prevent implant-associated infections for temporary external fixation in closed fractures of the extremities.

Materials and methods

A 26-question survey was sent to 170 members of the Traumaplatform. The survey included questions concerning demographics, level of training, type of training and perioperative protocols as: antibiotic prophylaxis, intraoperative management, disinfection and postoperative pin site care. All responses were statistically analysed, and intraoperative measures rated on a 5-point Likert scale.

Results

The responses of fifty orthopaedic trauma and general surgeons (response rate, 29.4%) were analysed. The level of experience was more than 5 years in 92% (n = 46) with up to 50 closed fractures of the extremities annually treated with external fixation in 80% (n = 40). Highest consensus could be identified in the following perioperative measures: preoperative antibiotic prophylaxis with a second-generation cephalosporin (86%, n = 43), changing gloves if manipulation of the external fixator is necessary during surgery (86%, n = 43; 4.12 points on the Likert scale), avoid overlapping of the pin sites with the definitive implant site (94%, n = 47; 4.12 points on the Likert scale) and soft tissue protection with a drill sleeve (83.6%, n = 41).

Conclusion

Our survey could identify some general principles, which were rated as important by a majority of the respondents. Futures studies’ focus should elucidate the role of perioperative antibiotics and different disinfection protocols on implant-associated infections after temporary external fixation in staged protocols.

Level of evidence

This study provides Level IV evidence according to Oxford centre for evidence-based medicine.

     

Treatment of periprosthetic acetabular fractures after previous hemi- or total hip arthroplasty

Objective

Treatment of displaced periprosthetic acetabular fractures in elderly patients. The goal is to stabilize an acetabular fracture independent of the fracture pattern, by inserting the custom-made roof-reinforcement plate and starting early postoperative full weight-bearing mobilization.

Indications

Acetabular fracture with or without previous hemi- or total hip arthroplasty.

Contraindications

Non-displaced acetabular fractures.

Surgical technique

Watson-Jones approach to provide accessibility to the anterior and supraacetabular part of the iliac bone. Angle-stable positioning of the roof-reinforcement plate without any fracture reduction. Cementing a polyethylene cup into the metal plate and restoring prosthetic femoral components.

Postoperative management

Full weight-bearing mobilization within the first 10 days after surgery. In cases of two column fractures, partial weight-bearing is recommended.

Results

Of 7 patients with periprosthetic acetabular fracture, 5 were available for follow-up at 3, 6, 6, 15, and 24 months postoperatively. No complications were recognized and all fractures showed bony consolidation. Early postoperative mobilization was started within the first 10 days. All patients except one reached their preinjury mobility level. This individual and novel implant is custom made for displaced acetabular and periprosthetic fractures in patients with osteopenic bone. It provides a hopeful benefit due to early full weight-bearing mobilization within the first 10 days after surgery.

Limitations

In case of largely destroyed supraacetabular bone or two-column fractures according to Letournel additional synthesis via an anterior approach might be necessary. In these cases partial weight bearing is recommended.

     

A brief history of FRAX

Summary

This paper reviews the research programme that went into the development of FRAX® and its impact in the 10 years since its release in 2008.

Introduction

Osteoporosis is defined on the measurement of bone mineral density though the clinical consequence is fracture. The sensitivity of bone mineral density measurements for fracture prediction is low, leading to the development of FRAX to better calculate the likelihood of fracture and target anti-osteoporosis treatments.

Methods

The method used in this paper is literature review.

Results

FRAX, developed over an 8-year period, was launched in 2008. Since the launch of FRAX, models have been made available for 64 countries and in 31 languages covering more than 80% of the world population.

Conclusion

FRAX provides an advance in fracture risk assessment and a reference technology platform for future improvements in performance characteristics.