Application of minimal-access techniques in lag screw fixation of fractures of the anterior mandible

Cortical lag screw fixation for the management of mandibular injuries

Objectives

Here, we present cases of mandibular fracture that were managed with the cortical lag screw fixation technique (CLSFT) in order to critically evaluate technique indications and limitations of application at various fracture sites.

Materials and Methods

This was a retrospective cohort study. The study sample was composed of patients suffering from mandibular fractures that were treated by the CLSFT. The outcome variables were fracture type, duration of surgery, number of screws, and pattern of application. Other study categories included patient demographics and causes of injury. Chi-square tests were used to assess descriptive and inferential statistical differences, and the P-value was set at 0.05.

Results

Thirty-three patients were included in the study sample, with a mean age of 30.9±11.5 years and a male predominance of 81.8%. The technique was applied more frequently in the anterior mandibular region (51.5%) than in other sites. Double CLSFT screws were required at the symphysis and parasymphysis, while single screws were used for body and angle regions. No intraoperative and postoperative variables were significantly different except for surgical duration, which was significantly different between the sites studied (P=0.035).

Conclusion

We found that CLSFT is a rapid, cost-effective technique for the fixation of mandibular fractures yielding good treatment results and very limited complications. However, this technique is sensitive and requires surgical expertise to be applied to mandibular fractures that have specialized characteristics.

Comparative Three-Dimensional Finite Element Analysis on Miniplate and Lag Screw Fixation to Symphysis Fractures

The purpose of this study was to compare the amount of stress on the fracture site via three-dimensional finite element analysis between lag screw and miniplate systems. Solid mathematical models were created from the CT of a patient and a fracture observed in the symphysis area. On the fracture site mini plates and lag screws applied to the bone to fixate segments. The physiologic mastication chewing forces were applied for simulation. These 2 fixation methods: were evaluated by their amount of stress values. The maximum Von Misses stress lag screw model was 2727 MPa on the apex of the lag screw and 934 MPa on the fracture site of the screw. At the miniplate model, the maximum Von Misses stress was 571 MPa on the head of the miniplate screw, and it was 202 MPa on the fracture site. Thus, lag screw model causes at least 4 times higher stress values than mini plate model. The stress level of lag screw model is higher than miniplate model. However, when the chewing forces are taken into account, the amount of stress in the lag screw system is also acceptable in clinical applications.

Minimal access fixation of mandibular angle fracture

Angle fractures represent the highest percentage of mandibular fractures. Fixation using a single miniplate ventral to oblique line of buccal cortex of the mandible was described by Champy et al. (1976). Ellis has documented low complication rate with monocortical miniplate fixation as a treatment for angle fractures. Most often used approaches are (a) extraoral approach, (b) intraoral approach, and (c) transbuccal approach. Each of these techniques has its pros and cons. We, in this note, propose an approach which sidelines the drawbacks of these approaches and has the combined advantages of these techniques. This technique results in no external scarring or injury to marginal mandibular nerve, and it also allows direct visualization and confirmation of occlusion during plate placement. This approach is through a contaminated area that poses a risk of infection. This approach of ours is based upon this pioneering works of Forrest. The approach proposed by us can aid an experienced maxillofacial surgeon to provide economical outpatient-based care to patients with minimally displaced/undisplaced angle fracture in a routine dental setup. This technique can be breakthrough for introduction of endoscopic approach for treating angle fracture.

Lag Screw in Mandibular Plate Technique for Sagittal Splitting Mandibular Fractures

Mandibular fractures with sagittal splitting and splaying of both the near and far cortices pose a challenge in their fixation as screws may push the far cortex during screw tightening, resulting in more widening. Screw lagging inside the lower mandibular plate technique may help approximation of the near and far cortices during screw tightening, and this was applied for 4 cases with mandibular fractures. The splaying improved using this technique. Using the screw lagging inside the plate technique may be a safe technique used in mandibular fractures that have cortical splaying.

Treatment of Sagittal Fracture of the Zygomatic Arch Root Assisted by Surgical Navigation Technology

Sagittal fracture at the temporal root of the zygomatic arch often occurs as a part of zygomaticomaxillary fractures. The authors described the application of computer-assisted navigation in the lag screw insertion for the fixation of sagittal fracture at the temporal root of zygomatic arch. Using the presurgical planning of the computer-assisted navigation system, the trajectory of lag screw insertion was designed, and the insertion depth was calculated. In the presurgical planning, the trajectory of screw insertion was placed with an anterior inclination of 10° to 15° (mean: 12.24°), and the screw insertion depth was 9.0 to 12.0 mm (mean: 10.65 mm). In the operation, the screw insertion in the fixation of the sagittal fracture was performed under the guidance of navigation system according to the presurgical planning. The postoperative CT scan showed exact reduction and fixation of the sagittal fracture in all cases. Computer-assisted navigation is a useful tool for the lag screw insertion in the precise fixation of sagittal fracture at the temporal root of the zygomatic arch in complex zygomaticomaxillary fractures.

A clinical prospective randomized comparative study on ostyeosynthesis of mandibular anterior fractures following open reduction using lag screws and miniplates

Introduction

The aim of the present study was to compare fixation of mandibular anterior fractures following open reduction using lag screws or miniplates.

Materials and Methods

This prospective study was conducted on 20 patients diagnosed with cases of displaced mandibular anterior fractures treated with open reduction and internal fixation. The patients were then randomly allocated to either of two groups - Group A: two 2.5 mm stainless steel lag screws were placed in 10 patients. Group B: two 2.5 mm miniplates were placed in 10 patients for the fixation of fractures. Subsequent follow-up was done on the 1^st day, 1^st, 4^th, and 36^th week postoperatively. During every follow-up, patient was assessed clinically for infection, malocclusion, loosening of plate/screw, malunion/nonunion, and masticatory efficiency. Radiographs (orthopantogram) were taken preoperative, 1^st, 4^th, and 36^th postoperative week to compare the osteosynthesis between the two groups. Pain was objectively measured using a visual analog scale. The data collected was subjected to unpaired t-test and paired t-test for statistical analysis.

Result

It was found that lag screw placement was rapid in comparison of miniplate placement. 3rd month postoperative assessment revealed Lag screw group to have better biting efficiency, and better bone healing which was statistically significant when compared with miniplate group.

Conculsion

Our study suggests that lag screw osteosynthesis can be advocated as a valid treatment modality in the management of mandibular symphysis and parasymphysis fractures.

A comparative analysis of the efficacy of cortical screws as lag screws and miniplates for internal fixation of mandibular symphyseal region fractures: a randomized prospective study

The management of facial trauma is one of the most rewarding and demanding aspects of oral and maxillofacial surgery. Being the most prominent mobile bone of the facial skeleton, mandible fracture occurs more frequently than any other fracture. In this study, open reduction and internal fixation was performed for isolated mandibular symphyseal region fractures using cortical screws (as lag screws) in 40 patients and using miniplates in 40 patients. Clinical and radiological evaluations were made at 6 months postoperatively. Primary stability of fracture segments, postoperative swelling, restricted lip mobility, infection, wound dehiscence, implant removal, and mal-union or non-union of fracture segments was evaluated. Primary stability was achieved in 100% of cases treated with cortical screws, whereas for patients treated with miniplates, 97.5% attained primary stability, while one case (2.5%) showed persistent clinical mobility. Postoperative complications were noted in 13 (16.25%) of the total 80 patients. The duration of postoperative swelling was less in patients treated with cortical screws compared to patients treated with miniplates. It is concluded that cortical screw fixation is an effective procedure for the treatment of symphyseal region fractures, but the procedure is somewhat technically sensitive.

Anchor lag screw vs conventional lag screw in mandibular fractures: A series of 30 cases

Lag screw osteosynthesis is a well proven technique. Its application is limited by the fact that the spherical head of the screw act as wedge. Combining this screw with a bioconcave washer has broadened the range of applications for lag screw osteosynthesis in the maxillofacial region.

PURPOSE

The aim of the study was to compare the efficacy of anchor lag screw with conventional lag screw in anterior mandibular fractures.

PATIENTS AND METHOD

Thirty patients with anterior mandible fractures with no concomitant fractures, infection or extraoral communication, who visited our outpatient Department of Oral and Maxillofacial Surgery, were included in the study after obtaining their informed consent. Patients were randomly divided into two groups; where Group A underwent fixation using conventional lag screw and Group B anchor lag screw. The fixation system used included 2 mm titanium lag screws of sizes 25 mm, 27 mm and 30 mm and 3 mm titanium bioconcave washer. At each follow up visit, clinical data was collected detailing clinical presentation of healing and radiographic findings.

RESULTS

Radiographic features at post surgery evaluation indicated loss of bone contact around the screw head and bone resorption in five patients of Group A, thus causing loosening of lag screw whereas none of the patient in Group B, was found to have any such complication.

CONCLUSIONS

The findings support the hypothesis that bioconcave washer aids in holding up the farthest fragment at the interface of the fracture fragment. Application of bioconcave washer provides easy loading of lag screw.

Lag screw fixation of fracture of the anterior mandible: a new minimal access technique

OBJECTIVE

Purpose of this study to introduce a new minimal access technique for management of anterior mandible fracture with several advantages over conventional methods.

METHOD

Four cases of undisplaced anterior mandibular fracture were selected. Tension band was achieved either by arch bar fixation to mandible or placement of interdental wire followed by intermaxillary fixation. With a 1 cm vertical incision was placed adjacent to fractured line. Fractured segment was immobilized with lag screw with minimal stripping. All patients were followed for 6 months.

RESULTS

All four cases shown good stable segment after 6 months of post operative follow up. OPG revealed well placed lag screw and there were no surgical complications, for example parasthesia, scarring and odema.

CONCLUSION

Fixation of anterior mandible fracture using this technique can achieve good stability and appropriate compression. The technique is simple and easily performed, reducing the surgical time, reduce the chances of infection due to less exposure and promote the healing process by producing stress in the fracture lines.

Management of Mandible Fractures

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Review the incidence and etiology of mandible fractures. 2. Discuss indications and techniques for closed and open treatment of mandible fractures. 3. Review complications of mandible fractures.

BACKGROUND

Mandible fractures are among the most common types of facial fractures treated by plastic surgeons. They must be managed carefully to maintain the function of the mandible, reestablish proper occlusion, and minimize secondary complications.

METHODS

Current methods of management include combinations of soft diet, intermaxillary fixation, open reduction with plate fixation, and, rarely, external fixation.

RESULTS

Decision-making depends on the age of the patient, type of fracture identified, and concomitant medical conditions or injuries.

CONCLUSION

The authors review the diagnosis and current trends in management of mandible fractures.

Minimal invasive surgery for hip replacement: a new technique using the NILNAV hip system

BACKGROUND

Minimal invasive surgical techniques are used for cruciate ligament reconstructions, unicondylar knee replacements and, more recently, for fixation of fractures. This is a report of the first instrumented technique for hip replacement using a 5-cm incision without the need for a navigation system or X-rays.

METHODS

It uses the C.F.P stem (LINK) but is universal. It includes jigs for the osteotomy of the neck, a right-angled reamer and spacers (lollipops) to orientate the acetabular cup to the femoral stem. A case series of 14 patients using this new hip replacement technique (called NILNAV Hip System) is reported.

RESULTS

The procedure was successfully performed on all seven patients, with reduced postoperative pain and stiffness, and increased quality of life and functional status. All patients were discharged on postoperative Days 1 and 2 with minimal pain and blood loss.

CONCLUSIONS

This new minimal access total hip replacement technique was successfully performed on seven patients. There are several advantages of using this system compared with the more traditional techniques. Such a technique should help reduce morbidity and mortality rates for those patients undergoing a total hip replacement.