Use Of Lag Screws Research Articles

Evaluation of osteosynthesis of miniplate versus lag screw in management of mandibular angle fracture - A comparative study

The aim of the study was to compare lag screw and standard (Champy’s) miniplate fixation in the management of mandibular angle fractures and to analyze advantages and disadvantages of one over the other. A total of 30 patients involving mandibular angle fracture reporting to the Department of Oral, Maxillofacial and Reconstructive Surgery, Bapuji Dental College and Hospital, Davangere, were included in the study. Patients were divided into two groups randomly. The procedure was carried out under general anesthesia. Following strict aseptic precautions, an appropriate intraoral/extra-oral incision was selected; fracture site identified, reduced, and after obtaining satisfactory occlusion, temporary maxillo-mandibular fixation was placed using either Erich’s arch bar or Ivy loop eyelet wiring. Fixation was done using either standard miniplate (Group 1) or lag screw (Group 2). The patients were followed up for a period of 2 months at the interval of 1 week, 2 weeks, 4 weeks, and 8 weeks by a blinded experienced oral surgeon for infection, segmental mobility, postoperative occlusion and radiological evaluation of reduction and fixation. Duration of fixation was found to be less in lag screw group than in miniplate group. Radiological evaluation of reduction and fixation was significant in both the groups. No significant difference was found between both the groups in clinical parameters such as infection, segmental mobility and postoperative occlusion. The clinical outcomes of both the lag screw system and standard miniplate systems in the present study were similar. However, the following advantages with the use of lag screw can be highlighted: Relatively lesser fixation time, Superior fracture fragment stability, fewer complications, Stable occlusion & less hardware, less cost required.

Triple Pelvic Osteotomy Fixed with Lag Screw for the Treatment of Pelvic Canal Stenosis in Five Cats.

The aim of this study was to describe the technique and the clinical outcome of cats with obstipation as a result of pelvic canal narrowing, treated using an alternative triple pelvic osteotomy technique. Five cats with obstipation as a result of pelvic canal narrowing due to pelvic fracture malunion or secondary hyperparathyroidism were treated by triple pelvic osteotomy. After performing the iliac osteotomy and medial partial cortical debridement (4/5 cases), the pelvic canal was widened by moving the caudal fragment of the ilium to the lateral aspect of the cranial fragment. The iliac fragments were fixed by a 2.7-mm lag screw (5/5 cases) and an additional 2 Kirschner wires 0.8 mm (1/5 cases). The radiographic examination immediately postoperatively and 8 weeks postoperatively showed a mean pelvic canal enlargement of 20% (range 7-38%). Minor complication occurred in one case; this resolved 15 days postoperatively without any treatment. Complications and recurrence of obstipation did not occur during the final follow-up, ranging between 5 months and 1 year in any of these cases. The use of lag screw fixed triple pelvic osteotomy resulted in widening of the pelvic canal and led to a satisfactory outcome with no major complications. This technique is fast, requires no expensive implants and it is relatively straightforward. Further cases are required to determine the success and complication risk of the procedure.

The impact of lag screw in the healing time of distal tibia fractures treated with minimally invasive plate osteosynthesis: A randomized clinical trial

BackgroundIn recent years, Minimally Invasive Plate Osteosynthesis (MIPO) has been gaining popularity in the treatment of distal tibia fractures, because it is a minimally invasive surgical procedure, thus it limits the soft-tissues damage. This prospective randomized study aims to assess the impact of lag screw in the healing time of distal tibia fractures treated with MIPO technique, in a six-month follow-up. MethodsPatients between 20 and 70 years of age with distal tibial fracture, type 43-A according to AO/OTA classification system were included. All the patients were randomized into two groups, to receive MIPO without lag screw (Group-A) or MIPO with percutaneous lag screw (Group-B). Patients were followed clinically and radiographically at 3, 6, 12 and 24 weeks postoperatively. The main outcome measure was the time needed to achieve the painless full weight-bearing (FWB) after surgery. Unpaired t-test after ANOVA (analysis of variance) was performed to assess AOFAS score differences between the 2 groups at each follow-up. Pearson correlation test also was performed. The tests were two-tailed with a confidence level of 5%. Results42 patients (24 male and 18 female, mean age 49.54 years old, range 25–80) were recruited. A significant shorter mean time until painless FWB (p = 0.016) was observed in Group-B (11.22 ± 3.06 weeks) compared with Group-A (13.48 ± 2.42 weeks) (Table 2). The mean AOFAS score was comparable in patients treated with (Group-B) and without lag screw (Group-A) at all follow-ups. ConclusionsThis prospective randomized clinical study has shown that the use of lag screw in distal tibia fractures treated with MIPO technique speeds the fracture healing, thus shortening the time needed to achieve FWB.

Buttress plate-assisted fixation for lateral hoffa fractures: A case report and review of literature

The purpose of this article is to provide a review of coronal fractures of the femoral condyles, known as Hoffa fractures, and to describe a unique fixation modality entailing the use of lag screws in combination with a posterior buttress plate. This case report of a lateral Hoffa fracture focuses on the evaluation, general approach, and surgical management of this subset of distal femoral fractures using this novel technique.

Comparison of outcome of tibial avulsion fracture of the posterior cruciate ligament using open reduction internal fixation by cc screw and arthroscopic suture bridge technique

Introduction: Number of operative techniques have been described with the use of lag screws, steel wires, arthroscopic tight rope fixation, arthroscopic suture bridge technique. As there is continuous advancement in newer technique, we are comparing outcome of PCL tibial avulsion fixed by two different methods open reduction internal fixation by CC screw and arthroscopic suture bridge technique. Method: The PCL tibial avulsion was approached by posterior Burks and Schaffer approach, fixed by CC screw in half of the patient and in another half, we used arthroscopic suture bridge technique. One fiber wire is used in arthroscopic technique. Results: Anatomical reduction and fixation of PCL avulsion by arthroscopic fixation is equally effective when compared with ORIF by CC screw fixation. Conclusion: The use of CC screw could be a simple and reliable technique for PCL avulsion fractures of the tibia. Patients achieved good knee function after surgery, but arthroscopic suture bridge technique of PCL avulsion fixation gives better knee function and less intraoperative complications.

Three-dimensional versus standard miniplate, lag screws versus miniplates, locking plate versus non-locking miniplates: Management of mandibular fractures, a systematic review and meta-analysis

Background/purposeThe aims of the present study were to 1) evaluate the clinical outcomes between different fixation methods in the management of mandibular fractures (MFs) and 2) determine which fixation method is the best option for the treatment of mandibular fractures. Materials and methodsA systematic review was conducted according to PRISMA guidelines, examining Medline-Ovid, Embase, and Pubmed databases. Inclusion criteria were studied in humans, including randomized controlled trials, controlled clinical trials, and retrospective studies, with the aim of comparing the two techniques. In addition, the incidence of complications was evaluated. ResultsThirty-two publications were included: 20 randomized controlled trials, 4 controlled clinical trials, and 8 retrospective studies. There were statistically significant advantages for 3-dimensional miniplate and lag screws. There was no statistically significant difference between locking plates and standard miniplates (P = 0 0.2). The cumulative odds ratio was 0.64, meaning that the use of locking miniplate in the fixation of MFs decreases the risk for postoperative complications by 36% over the use of standard miniplates. ConclusionThe results of the three-Dimensional Versus Standard miniplate showed that 3-dimensional miniplate is the best option for mandibular fractures. Regarding Lag Screws Versus Miniplates results of the meta-analysis found that the use of lag screws is superior to using miniplates in reducing the incidence of postoperative complications. And in regards to locking miniplates versus non-locking miniplate, the analysis indicates that the 2.0-mm locking miniplate is a prospective fixation system in the treatment of maxillofacial fractures.

Principle of Lag-Screw Fixation in Mandibular Trauma.

Aims and Objectives:The aim of the study is to assess the effectiveness of lag screw fixation in mandibular fractures with respect to parameters such as stability of the occlusion, functional stability, infection rates, neurosensory deficit, ease of technique, and maximum interincisal opening.Materials and Methods:Our study was carried out on 13 patients with mandibular fractures. Selected cases were treated with lag screw technique and 2.7 mm titanium screws were used. Postoperative complications such as wound dehiscence, infection, neurosensory disturbance, nonunion, malocclusion, postoperative mouth opening, and occlusal discrepancies were assessed.Results:All the patients were male, aged between 17 and 50 years. The cause of the injury was road traffic accidents in all, except for two assaults. Our study of 13 cases of fractured mandible included five symphyses, five parasymphyses, two angle, and one body fracture cases. Our observation with open reduction and rigid internal fixation with 1–2 lag screws revealed close approximation of fractured fragments in all the cases, except in three patients who had mild discrepancy of occlusion.Conclusion:Lag screw technique provides good interfragmentary compression and restoration of premorbid anatomic alignment of fracture fragments. In displaced mandibular fractures, especially in oblique fractures, the use of lag screw has proven to be ideal. The complications were found to be low. It was concluded that the lag screw provided excellent stability and occlusion.

Open Reduction and Internal Fixation of Isolated Posterior Cruciate Ligament Avulsion Fractures: Clinical and Functional Outcome.

PurposeThe posterior cruciate ligament (PCL) presents commonly with avulsion fractures of its tibial attachment. An avulsion fracture of the PCL, if not surgically fixed, may lead to secondary changes in the knee joint. Various fixation techniques have been explored with use of lag screws, steel wires, absorbable screws, suture anchors and straddle nails. The purpose of this study was to evaluate the clinical and functional outcome of open reduction and internal fixation of tibial avulsion injuries of the PCL using cannulated cancellous screws.Materials and MethodsWe performed open reduction and internal fixation using cannulated cancellous screws in 14 patients (mean age, 33.9 years) with isolated PCL avulsion injuries. Patients with a duration of injury more than 12 weeks were excluded. The minimum follow-up period was 12 months. Results were assessed radiologically and clinically. Final functional outcome was assessed using the Lysholm knee scoring system.ResultsThe average follow-up period was 13.5 months. At the final follow-up, all 14 patients achieved fracture union. The average flexion was 121.7°±9.2° with full extension achieved in all patients. Mild instability (1+) was noted in 4 patients. The Lysholm functional score was excellent in 11 patients, good in 2 patients and fair in 1 patient with an average score of 97±7.6.ConclusionsStable early fixation for PCL avulsion injuries with early controlled mobilization provided excellent to good results. However, fixation should not be discouraged for late-presenting patients because good to fair results can be achieved in such cases.

Comparison between Accurate Anatomical Reduction and Unsuccessful Reduction with a Remaining Gap after Open Reduction and Plate Fixation of Midshaft Clavicle Fracture

Background: The purpose of this study is to compare the radiological and clinical outcomes after open reduction and plate fixation of midshaft clavicle fractures between patients who achieved successful anatomical reduction and those who had a remaining fracture gap even after open reduction and plate fixation, and were thus treated with additional demineralized bone matrix (DBM). Methods: This retrospective analysis was conducted on 56 consecutive patients who underwent open reduction and internal fixation using a locking compression plate for acute displaced midshaft clavicle fractures, and who underwent radiographic and clinical outcome evaluations at least 6 months postoperatively. The outcomes between those who achieved perfect anatomical reduction without remnant gap (n=32) and those who had a remaining fracture gap even after open reduction and plate fixation treated with additional DBM (n=24) were evaluated. Results: There were no differences in the use of lag screws or wiring and operation time (all p>0.05) between those with and without remnant gap. No difference in the average radiological union time and clinical outcomes (satisfaction and Constant score) was observed between the two groups (all p>0.05). However, significantly faster union time was observed for AO type A fracture compared with other types (p=0.012), and traffic accident showed association with worse clinical outcomes compared with other causes of injury. Conclusions: Surgical outcome of midshaft clavicle fracture was more affected by initial fracture type and event, and re-reduction and re-fixation of the fracture to obtain a perfect anatomical reduction spending time appears to be unnecessary if rigid fixation is achieved.

Leg length discrepancy treatment with subtrochanteric shortening osteotomy and blade plate fixation.

Subtrochanteric femoral shortening osteotomy is a method of surgical treatment of lower limb discrepancy (LLD). It is less commonly used due to numerous limitations and the resulting decrease in height, which is an undesirable effect for most patients. The aim of this study was to analyze the results and complications of treatment of leg length discrepancy (LLD) by femoral shortening osteotomy fixed with a blade plate and screws. The study group comprised 18 patients treated by subtrochanteric shortening osteotomy fixed with a blade or straight plate and screws. The age of patients at the time of the operation ranged from 12 years and two months to 24 years and 3 months (mean 17 years and 8 months). Before the operation, the mean LLD amounted to 4.1cm (from 2,5 to 7,0). The size of the same-time resection of the femur at the level of the subtrochanteric osteotomy ranged from 2.5 cm to 5.0 cm (mean 3.7). The follow-up period ranged from 6 months to 15 years and 9 months (mean 3 years and 6 months). The analysis of the results was based on the following criteria. A good result was defined as obtaining an equal length of both legs or achieving the intended amount of shortening. A fair result was defined as a post-operative LLD from 0.5 cm to 1 cm. A poor result comprised patients with post-operative LLD greater than 1 cm or with complications that leave a lasting impact or complications requiring revision surgery. A good result was obtained in 15 patients and a fair one in 3 patients. Complications appeared in 5 (28%) patients. The most common complication was delayed bone healing. Full weight -bearing of the operated limb was allowed between 12 and 32 weeks post-surgery (mean 19 weeks). The final LLD ranged from 0 cm to 3 cm (mean 0.6 cm). Equal limb length was obtained in 13 (72%) patients. 1. Subtrochanteric femoral shortening osteotomy fixed with a plate and screws, taking into consideration the limitation of possible correction to 5-6 cm, is an effective method of treatment of lower limb discrepancy with a relatively low complication rate. 2. The most common complications of subtrochanteric shortening osteotomy are disorders of bone union. 3. The use of lag screws for stabilisation of the osteotomy with an angle plate may reduce the risk of complications.

Minimally invasive plate osteosynthesis of distal tibial fracture using a posterolateral approach: a cadaveric study and preliminary report

We have read the article by Kritsaneephaiboon et al. [1] with great interest. We congratulate them for opening new horizons on the MIPO technique using the posterolateral approach; however, we have some reservations regarding it. First, the authors have described the posterolateral approach to the tibial shaft, for the proximal incision, which was classically described by Harmon et al. [2] in 1945. However the authors have used only a one-inch incision, and to retract the heavy bulk of muscles on the posterior aspect of tibia through such a small incision and placing screws on the posterior aspect seems to be technically quite difficult. Also, exerting overzealous traction in doing so, could endanger the posterior tibial vessels and the tibial nerve. We would like to know what, if any, special tips or tricks the authors suggest to overcome such a problem. Second, although the authors have studied and mentioned the relationship of the implant to the posterior tibial vessels and tibial nerve, they have not mentioned anything regarding the peroneal vessels. These vessels seem to be particularly at high risk of injury considering their proximity to the postero-medial aspect of fibula, especially when performing sharp dissection of the FHL and tibialis posterior from the posterior aspect of fibula as the authors have suggested. This is all the more important considering the fact that in around 5–8 % of individuals the Peroneal artery is the dominant supply to the foot (a condition known as Peroneal arteria magna) [3, 4]. Third, the authors state that they placed three screws in the proximal segment; we would like to know how the distal most screw in the proximal segment was placed, because it seems unlikely that it was placed through the one-inch proximal incision. Also, keeping in mind the principle of internal fixation while bridging a comminuted fracture, it is recommended that screws adjacent to the fracture should be placed as close to the fracture site as possible to enhance the construct stability. If we use the posterolateral approach it will not be possible to place these screws percutaneously, as such an application would be too dangerous, whereas exposure of the fracture site for the same purpose would negate the potential benefits of the MIPO technique. Since percutaneous application would seem to be too risky it also precludes the use of lag screws and placement of the pointed reduction clamps and K-wires, which are commonly used as a tool in provisional reduction during the MIPO technique. Another point which we would like clarified was why removal of the external fixator and internal fixation were performed the same sitting after six weeks. The usual recommendation is that internal fixation can be done in the same sitting if done within two weeks of application of the external fixator, whereas it is advisable to wait for pin tracts to heal if it is done after two weeks, as all pin sites are taken to be potentially infective. Furthermore, when a two-staged delayed internal fixation is planned it is advisable to place the Schanz pins well away from the anticipated location of plates and screws [5]; which is not the case in this scenario, since it is quite clearly visible that the distal pin in the proximal fragment is near the second most proximal screw in the post-operative X-ray.

Compression Screw Fixation of the Syndesmosis

Screw fixation of syndesmotic injuries facilitates ligament healing and restoration of ankle stability, but little information regarding screw performance is available. This study quantified the reduction obtained with three common 2-screw configurations using different methods of reduction and novel methods of subsequently provoking and measuring diastasis. Seven fresh-frozen lower extremities were subjected to 100 N medial and lateral tibia loads with the talus restrained. Tibia displacement, indicative of ankle clear space, was recorded. The syndesmosis and distal interosseous ligament were disrupted and measurements repeated. A pressure sensor was inserted into the syndesmosis and three 2-screw fixation methods were evaluated in each specimen: 3.5-mm screws engaging both fibula cortices and the lateral tibial cortex, inserted while using a clamp to achieve syndesmosis reduction; 3.5-mm lag screws engaging both tibia cortices; and 4.5-mm lag screws engaging both tibia cortices. One thousand 100 N medial and lateral loads were applied and clear space and syndesmosis compression were quantified every 100 cycles. Normal ankle clear space averaged 1.98 mm and increased to 3.02 mm after syndesmosis disruption. Fixation decreased the clear space to 1.36 mm, 1.22 mm, and 1.19 mm for the 3.5-mm tricortical, 3.5-mm lag, and 4.5-mm lag screws, respectively, remaining steady throughout cyclic loading. Syndesmosis compression dropped markedly from 61N to 23 N on clamp release after tricortical screw insertion. The 3.5-mm and 4.5-mm lag screws exerted 112 N and 131 N, respectively, after insertion, and maintained compression several-fold greater than the tricortical screws during cyclic loading. No difference was demonstrable between the two lag screw sizes. While all screw configurations successfully reduced ankle clear space, syndesmosis reduction was more effectively maintained by lag screws than by tricortical screws inserted with clamp reduction. The transient nature of compression achieved by the reduction clamp suggests that use of lag screws for this application may more reliably maintain syndesmosis reduction in vivo. Optimizing reduction of syndesmosis injuries is critical for favorable outcomes. This study offers concrete information on screw performance in this application.

Operative Treatment of Lateral Humeral Condyle Fractures in Children

The operative treatment of lateral humeral condyle fractures in children remains controversial. The result of incorrectly treated fractures may lead to complications such as pseudoarthrosis and severe deformity, with considerable functional and cosmetic restrictions. The aim of this study was to determine whether operative treatment of lateral humeral condyle fractures in children using Screw-wires (Orthofix GmbH, Ottobrunn, Germany) has any advantage over treatment with Kirschner wires ("K-wires") (aap-Implantate AG, Berlin, Germany). These results were then compared with operative treatment using lag-screw osteosynthesis. We treated surgically 76 cases of fracture of the lateral humeral condyle in children at the Department of Pediatric Surgery in Dresden between 1989 to 2002 and 2004 to 2008, from which 42 were available for follow-up examination. Within this group, there were seven children that were followed-up twice (in 1996 to 2002). Of these, 21 patients were treated with Screw-wires, and another 21 had K-wires inserted. The results were evaluated according to the Dhillon criteria. Only seven patients (17%) had a fair result in the overall grading according to the Dhillon criteria, four after K-wire and three after Screw-wire osteosyntheses. The remaining patients scored good to excellent results. There were no pseudoarthroses. Six patients (14%) had a varisation in the carrying angle between 10 and 16 degrees (three each procedure), and 15 patients (36%) had no difference in the carrying angle at all. Of these 15 patients, 10 were treated with Screw-wire osteosynthesis. Only one patient (2.4%) had a deficit of more than 10 degrees in elbow joint flexion, while only two (4.8%, one each procedure) had a deficit of more than 10 degrees in elbow joint extension, compared with the uninjured arm. Our results demonstrate that the employment of Screw-wire osteosynthesis is superior to the use of K-wires concerning the carrying angle while scoring alike on the other criteria. Compared with the use of lag screws, both treatments (K-wire and Screw-wire osteosyntheses) bear less risk of nonvascular necrosis or small metaphyseal fragment rupture, by comparable results in the overall outcome. Regarding the long-term development of healed fractures, changes in the carrying angle and the range of motion are of a small degree. Considering the results of this study, we recommend the use of Screw-wire osteosynthesis in the operative treatment of lateral humeral condyle fractures in children.

In Vitro Comparison of Lagged and Nonlagged Screw Fixation of Metacarpal Fractures in Cadavers

Lag screw fixation is reported to provide the most biomechanically stable construct for fixation of oblique or spiral metacarpal fractures. Lag screws are inserted after overdrilling the proximal cortex, resulting in compression at the fracture site. Minor drilling errors can result in poor screw purchase, instability, and ultimately impaired fracture healing. In an in vitro study, we compared construct stability provided by nonlagged and lagged screw fixation. A cadaveric human metacarpal model was used. After removing the soft tissue, long oblique osteotomies were made in 24 metacarpals, which were then randomized to lagged or nonlagged fixation. Nonlagged fixation was performed through a newly introduced reduction system. Fixed specimens were subjected to biomechanical analysis by way of cantilevered bending to failure, and calculations were made for axial stress and normalized stiffness. All specimens failed in a typical manner through the proximal screw site. Nonlagged compared with lagged screw fixation resulted in a higher axial stress and normalized stiffness, although the differences did not reach statistical significance. Nonlagged screw fixation with use of a precompression device provided comparable fracture site stiffness and biomechanical stability without use of lag screws while removing the requirement for overdrilling, thus simplifying the technique.

Less is more: lag screw only fixation of lateral malleolar fractures

Displaced fractures of the lateral malleolus are typically treated with plate osteosynthesis with or without the use of lag screws, and immobilisation in a plaster cast for up to 6 weeks. Fixation through a smaller incision with less metal, such as lag screw only fixation, would theoretically lead to decreased infection rates and less irritation caused by hardware. The purpose of this study was to evaluate the benefits and success of lag screw only fixation of the lateral malleolus in non-comminuted oblique fractures of the lateral malleolus. A total of 25 patients who had non-comminuted unstable oblique fractures of their lateral malleolus that had been surgically fixed with lag screws only were retrospectively evaluated. All patients were younger than 60 years of age. Evaluation of the success of fixation, complications, resultant mobility and patient satisfaction was based on information gathered from chart reviews, X-ray findings and a standardised questionnaire based on the AOFAS Foot and Ankle Outcomes Questionnaire. These results were compared to an age-matched group of 25 consecutive patients treated with plate osteosynthesis. Of the 25 patients fixed with lag screws, nine had an unstable fracture of the lateral malleolus only, ten were bimalleolar fractures and six were trimalleolar. Eighteen patients were treated with two lag screws, and seven were treated with three lag screws. The bi- and trimalleolar fractures were treated with standard partially threaded cancellous screws. None of the lag screw-only group lost reduction. There were no documented wound infections in the lag screw group as compared to three deep infections in the plate group. Lag screw-only patients reported no palpable hardware as compared to 50% of the plate group. AOFAS scores at a mean of 12 months post-operative were similar in both groups. Lag screw only fixation of the lateral malleolus is a safe and effective method that has a number of advantages over plate osteosynthesis, in particular less soft tissue dissection, less prominent, symptomatic and palpable hardware and a reduced requirement for secondary surgical removal.

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

A modification of the traditional open methods for the surgical management of anterior mandibular fractures using the principles of minimal-access surgery is presented; it was successfully performed in five patients. This technique incorporates the use of lag screws introduced through small incisions transmucosally or percutaneously after anatomic reduction of the fracture, and it relies on accurate preoperative radiologic assessment of the fracture pattern and location. This technique is indicated for any favorable fracture in the anterior mandibular arch that could achieve osteosynthesis with lag screw fixation, and it depends on the use of a dental arch bar as a tension band. Contraindications include unfavorable fracture patterns (long oblique, comminuted, or flat mandibular plane), inadequate dental support to maintain an arch bar due to missing or loose teeth, the inability to determine the fracture pattern preoperatively, and operator inexperience. Potential advantages include a shorter operative time, economic savings, decreased patient morbidity (swelling, scarring, and mental nerve and lower-lip muscle dysfunction), and improvement in functional rehabilitation.

Use of lag screws for the management of mandibular trauma.

Use of lag screws for the management of mandibular trauma.

Use of lag screws for fractures of the mandibular body

Purpose: This article presents the results of treating fractures of the mandibular body using lag screws alone or lag screws inserted through bone plates. Patients and Methods: Thirty-one patients treated for fractures of the mandibular body using lag screws within a 5.5-year period were retrospectively studied for complications. Nine patients were treated with lag screws only and 22 with a lag screw inserted through a bone plate. No patient was placed into postsurgical maxillomandibular fixation. Results: There were no intraoperative or postoperative complications, except for one dental abscess. Conclusions: Lag screw fixation of mandibular body fractures is a reliable technique when these is sufficient obliquity of the fracture.

A modified technique to determine the desired length of bicortical screws in sagittal split osteotomies

Since the original description of the bilateral sagittal split osteotomy (BSSO) by Obwegeser, several techniques have been described to avoid maxillomandibular fixation. These techniques of rigid internal fixation include use of lag screws,’ position screws,’ and miniplates.” Since 1988, the self-tapping position screw technique has been used in our institute for internal fixation of the BSS0.4 Until April 1995, 970 patients (1,935 sites) have been treated accordingly. However, in 8 patients, loosening of the screws occurred in the first postoperative week, which resulted in occlusal discrepancy and required reoperation. Loosening of the screws can be explained by apposition of the proximal and distal fragments under tension, a thin medial cortical bone layer, or use of short screws. To prevent the last, the use of commercially available depth-measuring devices is advocated. Another method to measure the length of the position screws in a rapid and accurate fashion is presented.

Use of lag screws for the management of mandibular trauma

To test the effectiveness of lag screw fixation in their application in the treatment of mandibular fractures. Sixty-nine mandibular fractures in 30 patients treated with lag screws were evaluated retrospectively regarding the cause, the type, and the site of fracture as well as the local situation and the complications encountered. In 19 fractures a neutralization plate was used and in another 17 the lag screw was applied in combination with a compression plate. In 33 cases at least 3 lag screws were inserted. Seventy-five percent of the cases were in patients between 10 and 39 years old; 70% were the result of road traffic accidents. Most patients presented two mandibular fractures; the symphyseal area were most frequently affected. Teeth in the line of fracture were not removed, and no drains were used. Complications included two minor malocclusions, one delayed union, two cases of temporary paresis, two cases of transient hypesthesia, two cases of scar formation on the incision line, and a case of temporary trismus. Approximately 30% of the patients treated with lag screws according to the methods outlined in this study developed complications that were either minor, transient, or both; some were related to the approach rather than the method. The most frequent complications were minor malocclusions, transient facial paralysis, hypoesthesia, and scar formation.