Osteotomy Fixation Research Articles

Comparative study between lag screw and miniplate fixation for straight midline mandibular osteotomy

The mandibular swing approach is a surgical approach for the resection of malignant lesions localized in the posterior oral cavity and oropharynx. We analyzed 15 years of experience with fixation of the straight midline mandibulotomy and compared two fixation methods: lag screws and miniplates. A total of 117 patients underwent a straight midline mandibulotomy during the study period; 85 had fixation with two lag screws and 32 with two miniplates. The overall complication rate was low and there was no significant difference in complication rate regarding the fixation method (9% for miniplates vs. 7% for lag screws). The most serious complication over the whole study period was non union, which occurred in only two patients, followed by orocutaneous fistula and infection. Radiotherapy did not cause serious complications and is not regarded as hazardous in midline mandibulotomy patients. We conclude that lag screw fixation is at least as safe as miniplate fixation, but because of better fragment compression, offers faster bone healing.

Resorbable materials complications in orthognathic surgeries

The use of resorbable plates and screws in fixation of osteotomies in orthognathic surgeries has increased considerably due to advantages of this kind of material, compared to titanium. However, the absorbable material can generate complications at the time of his term degradation, generally one year after the installation. This study presents a series of 80 orthognathic surgeries operated using absorbable materials, in which 6 patients (7.5%) had foreign body reaction (sterile abscess) in places which absorbable plates were fixated.

Opening Wedge Distal Femur Osteotomy: Biomechanical Study of a Biplane Fixation Using Conventional Implants

Opening Wedge Distal Femur Osteotomy: Biomechanical Study of a Biplane Fixation Using Conventional Implants

Children’s orthopaedics

The October 2013 Children’s orthopaedics Roundup360looks at: Half a century of Pavlik treatment; Step away from the child!: trends in fracture management; Posterolateral rotatory elbow instability in children; Osteochondral lesions undiagnosed in patellar dislocations; Oral bisphosphonates in osteogenesis imperfecta; Crossed or parallel pins in supracondylar fractures?; Not too late nor too early: getting epiphysiodesis right; Fixation of supramalleolar osteotomies.

Valgus osteotomy by external fixation for treatment for developmental coxa vara

Valgus subtrochanteric osteotomy is the standard surgical treatment for coxa vara. Nevertheless, there is no consensus on the method of fixation and osteotomy technique. There are some reports on employing rigid internal fixation methods that preclude the need of postoperative immobilization. This is a technical description of a valgus osteotomy performed using external fixation with preoperative and postoperative data on a cohort of 9 patients. In this study, 9 hips in 9 patients with the diagnosis of developmental coxa vara underwent a subtrochanteric osteotomy with stabilization by an external fixator. The planned correction angle was obtained for all 9 patients with the osteotomies healing primarily. Radiographic analysis showed an improvement in Hilgenreiner’s epiphyseal angle and the neck-shaft angle. There were no major complications associated with use of this method of stabilization. Minimal access surgery using external fixation for a valgus osteotomy of the proximal femur is safe and effective for the treatment for coxa vara and limb length discrepancy. It has potential advantages over commonly used open techniques and provides available alternative to currently applied methods used for fixation of proximal femoral osteotomies.

Olecranon Osteotomy Fixation Using a Novel Device

A posterior approach to the elbow utilizing an olecranon osteotomy has been shown to provide excellent visualization of the distal humerus articular surface. However, many bony stabilization and fixation methods for the olecranon osteotomy are usually prominent, frequently symptomatic, and often require a second operation for removal. This paper evaluates the use of an innovative device, the olecranon sled, in fixation of olecranon osteotomies for exposure of intra-articular distal humerus fractures and provides follow-up results. A retrospective review of all patients with intra-articular distal humerus fracture treated through an olecranon osteotomy approach and fixed with an olecranon sled, between September 2008 and December 2011 was conducted. Charts and radiographs were reviewed to determine olecranon union or nonunion, presence of symptomatic hardware, and need for secondary surgery to remove symptomatic olecranon fixation. Fourteen patients were included in the study. Average clinical follow-up was 33.5 weeks (range, 6 to 118 wk). There were no olecranon nonunions. One patient underwent additional surgery for symptomatic hardware removal (7.1%). Two additional procedures were performed; 1 for revision open reduction and internal fixation of distal humerus fracture nonunion (7.1%) and 1 for release of elbow contracture (7.1%). Although follow-up is limited, the use of this device has been associated with excellent rates of olecranon union with a low rate of symptomatic hardware requiring removal.

Supramalleolar Osteotomy

For children with persistent tibial torsion, a wide variety of osteotomies and fixation methods have been proposed. We set out to compare the outcomes of percutaneous pin fixation versus a plate and screw construct. Our hypothesis was that the pin fixation group would have comparable outcomes without the need for a secondary procedure for implant removal. A retrospective chart review was performed. Data were evaluated on patients undergoing a rotational supramalleolar osteotomy over a 10-year span with follow-up to union. Patient's age, underlying condition, degree of torsion, length of procedure, length of hospital stay, concomitant procedures, complications, recurrence, and secondary procedures were recorded. Statistical analysis utilized the Mann-Whitney U test for evaluation of independent samples. A total of 125 patients met the selection criteria with 186 tibias operated. Sixty-one cases were bilateral. Pin fixation was performed in 61 patients (87 tibias) and plate fixation in 64 patients (99 tibias). Age ranged from 2.5 to 19.6 (average 10.6) years. Surgical time, length of stay, and recurrence did not demonstrate a statistically significant difference between the pin fixation and the plate fixation groups. Forty-seven patients had secondary surgical procedures for removal of implants, 44 in the plate group and 3 in the pin group. Complications were considered major if they required reoperation or fracture care. In the plate group, 16 patients (12.8%) had complications with 5 major complications. In the pins group 3 patients (2.4%) had complications, which were minor. Recurrence was seen in 4 patients in the pin group and 2 patients in the plate group. Recurrence correlated with underlying neuromuscular disease and age younger than 11 years at the time of surgery. The numbers of complications, both major and minor, were significantly greater in the plate group. Therefore, the results of this study did not support our hypothesis that percutaneous pin fixation of supramalleolar osteotomies would have comparable outcomes to plate and screw fixation.

Reinforced bioresorbable implants for craniomaxillofacial osteosynthesis in pigs

Our aim was to design a new bioresorbable fixation device for craniomaxillofacial surgery based on reinforcement of fibres between 2 different polymers. The final device, the 2.8mm polyglycolide fibre-reinforced-poly-l-lactide screw (PGA FR-PLLA; PLLA/PGA: 70%:30%), was evaluated for its mechanical properties and compared with a commercial resorbable device that was not reinforced with fibre. To model clinical conditions, a unilateral sagittal split ramus osteotomy fixation model in pigs was then used to compare the clinical effectiveness of the resorbable screw with that of a titanium screw in vivo, followed by 3-dimensional reconstructive imaging and histological analysis. Finally, an ex vivo biomechanical test was completed to investigate the immediate fixation stability of the newly designed screws. The PGA FR-PLLA screw resulted in clinical healing that was comparable to that of the titanium screw and was mechanically superior to the commercial device, indicating that the newly-developed screws have a potential clinical application.

Decision-making considerations in application of biodegradable fixation systems in maxillofacial surgery – A retrospective cohort study

In a recent RCT comparing biodegradable (Inion CPS) with titanium (KLS Martin) plates and screws for fixation of osteotomies or fractures, we found that in 21% of the cases the surgeon decided intra-operatively to switch from biodegradable to titanium.The aim of the current retrospective cohort study was to analyse the reasons for these switches in order to find predictor variables that may be helpful in the decision to use biodegradable devices or not. The surgeons' opinion about the biodegradable system, and if there was a learning curve in the application of the biodegradable system were also investigated.All variables were assessed during the original RCT by using a questionnaire that was completed by the OMF surgeon directly post-operatively. For the outcome variable “surgeons' opinion” a separate questionnaire was used.Regarding the predictor variables a mandibular fracture had a higher risk of switching compared to a BSSO. However, looking at the reasons for these switches no firm conclusions can be drawn. There was a subjective learning curve to acquire the application-skills for the biodegradable system. There were no changes in isolated Le-Fort-I osteotomies despite the fact that the biodegradable system seems more difficult to apply in the midface. Inadequate stability was the main reason for switching. This can be material-related, or related to inexperience with or lack of confidence in the system, or impatience of the surgeon.A learning curve and personal preferences probably play an important role in the decision to switch. We think that with more patience and more experience it should be possible to increase both user comfort and confidence in the biodegradable system of Inion CPS, which likely will decrease the number of intra-operative switches.

Chin Plate With a Detachable C-Tube Head Serves for Both Osteotomy Fixation and Orthodontic Anchorage

This article reports the dual function of a double-Y miniplate with a detachable C-tube head (C-chin plate; Jin Biomed Co., Bucheon, Korea) used to fixate an anterior segmental osteotomy and provide skeletal anchorage during orthodontic tooth movement. Cases were selected for this study from patients who underwent anterior segmental osteotomy under local anesthesia. A detachable C-tube head portion was combined with a double-Y chin plate. The double-Y chin plates were fixated between the osteotomy segments and the mandibular base with screws in a conventional way. The C-tube head portion exited the tissue near the mucogingival junction. Biocreative Chin Plates were placed on the anterior segmental osteotomy sites. The device allowed 3 points of fixation: 1, minor postosteotomy vertical adjustment of the segment during healing; 2, minor shift of the midline during healing; and 3, to serve as temporary skeletal anchorage device during the post-anterior segmental osteotomy orthodontic treatment. When tooth movement goals are accomplished, the C-tube head of the chin plate can be easily detached from the fixation miniplate by twisting the head using a Weingart plier under local anesthesia. This dual-purpose device spares the patient from the need for 2 separate installations for stabilization of osteotomy segments. The dual-purpose double-Y miniplate combined with a C-tube head (Biocreative Chin Plate) provided versatile application of 3 points of post-osteotomy fixation and of temporary skeletal anchorage for orthodontic tooth movement.

Die Biomechanik von Schrauben, Draht- und Kabelcerclagen

In contrast to fracture fixation, when performing an osteotomy the surgeon is able to plan preoperatively. The resulting fixation and compression of the bone fragments are the most important points. A stable osteosynthesis should prevent dislocation of bone fragments and improve bone healing. Beside plates, cerclages can be used for tension band or diaphysis bone fixation. Moreover, cortical or cancellous screws can be used for osteotomy fixation. This work describes biomechanical principles for fixation after an osteotomy with cerclages and cortical or cancellous screws. It also summarizes the materials and geometries used, as well as their influence on the stability of the osteosynthesis.

3-Dimensional Prebent Plate Fixation in Corrective Osteotomy of Malunited Upper Extremity Fractures Using a Real-Sized Plastic Bone Model Prepared by Preoperative Computer Simulation

To assess the clinical outcome and accuracy of prebent plate fixation in corrective osteotomy for malunited upper extremity fractures using a plastic bone model manufactured by preoperative computer simulation. Nine consecutive patients underwent computed tomography (CT)-based 3-dimensional corrective osteotomy for malunited upper extremity fractures. There were 4 cubitus varus deformities, 1 cubitus valgus deformity, and 4 forearm diaphyseal malunions. We constructed a computer model of the affected bones using the CT data and simulated the 3-dimensional deformity correction on a computer. A real-sized plastic model of the corrected bone was manufactured by rapid prototyping. We used a metal plate, prebent to fit the plastic bone model, in the actual surgery. Patients were evaluated after an average follow-up of 22 months (range, 14-36 mo). We retrospectively collected radiographic and clinical data at the most recent follow-up and compared them with preoperative data. We also performed CT after surgery and evaluated the error in corrective osteotomy as the difference between preoperative simulation and postoperative bone model. The range of forearm rotation and grip strength in patients with forearm malunions improved after corrective osteotomies of the radius and ulna. Wrist pain, which 2 patients with forearm malunion had experienced before surgery, disappeared or decreased substantially after surgery. Radiographic examination indicated that preoperative angular deformities were nearly nonexistent after all corrective osteotomies. Three-dimensional errors in the corrective osteotomy using a prebent plate, as evaluated by CT data, were less than 3 mm and 2°. Prebent plate fixation in corrective osteotomy for malunited upper extremity fractures using a 3-dimensionally corrected, real-sized plastic bone model prepared by preoperative computer simulation is a precise and relatively easily performed technique that results in satisfactory clinical outcome. Therapeutic IV.

A comparison of reversed locking compression-distal femoral plates and blade plates in osteotomies for young adult hip pathology

The aim of this study was to compare fixation of proximal femoral osteotomies using reverse contralateral LCP-Distal Femoral Plates (LCP-DF) with the more traditional blade plate technique. This was a retrospective review over six years of a single surgeon's practice within a tertiary orthopaedic unit. Patient demographics were collected, along with indication for surgery. Radiological outcomes, fixation failures and the need for revision surgery were recorded. Forty-six patients were identified; 23 patients in the LCP-DF plate group (7 females, 16 males. Mean age 18.3 years old) and 23 patients in the blade plate group (6 females, 17 males. Mean age 19.1 years old). The patients' presenting conditions were; 26 Perthes'; eight hip dysplasia; 11 slipped capital femoral epiphysis; one fibrous dysplasia. Osteotomy type included; 13 Double osteotomy, 11 Imhauser; 13 pure valgus; eight valgus + rotation; There was one revision for implant failure in the LCP-DF group. In the blade plate group, there were four implant failures--three requiring revision operations (p = 0.155). In the LCP-DF group the mean neck-shaft angle difference compared to the contralateral side (if normal) or 135 degrees (if abnormal) was 0.58°. In the condylar plate group the mean difference was 4.37°. The use of a contralateral LCP-DF plate in the reverse contralateral position to stabilise proximal femoral osteotomies in our cohort confers advantages over blade plate technology. We have found that the plate is stiffer, is easier to use and provides increased screw placement options over standard proximal femoral locking plates.

Plate fixation for proximal chevron osteotomy has greater risk for hallux valgus recurrence than Kirschner wire fixation

The purpose of this study was to compare the results of hallux valgus surgery between feet fixed with Kirschner wires and those fixed with a plate and screws. Between December 2008 and November 2009, 53 patients (62 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic moderate to severe hallux valgus deformity. Thirty-four patients (41 feet) were stabilised with Kirschner wires (K-wire group) and 19 patients (21 feet) were stabilised with a locking plate (plate group). Clinical results were assessed using American Orthopaedic Foot and Ankle Society (AOFAS) score. Radiographic parameters were compared between these groups. Recurrence rate at the last follow-up was compared between the K-wire and plate groups. Mean AOFAS score was lower in the plate group, however, the difference between the groups was not statistically significant in AOFAS score at the last follow-up. Hallux valgus angle and intermetatarsal angle were significantly larger in the plate group at the last follow-up. Mean 1-2 metatarsal (MT) distance on immediately postoperative radiographs was significant larger in the plate group. Four (9.8 %) of the 41 feet in the K-wire group and 7 (33.3 %) of the 21 feet in the plate group showed hallux valgus recurrence at the last follow-up. The plate group had a significantly higher risk of recurrence than the K-wire group. Fixation of proximal chevron osteotomy using a plate and screws has a greater risk of hallux valgus recurrence than fixation using Kirschner wires.

Application of Topology Optimization to the Tibial Osteotomy Fixation Plates

Application of topology optimization to fixation plates is the main consideration of this paper. The interbody fusion plates are required to give mechanical support to tibia with minimally invasive surgical procedure. Topology optimization is used to obtain fixation plates with possible minimum material usage. Topology optimization is applied to three types of plates which are used in upper tibial osteotomy. Initial design of the plates are first numerically modelled and then investigated for stresses under possible highest load values. The results of the analysis indicated that the plates are very stiff even under high loads. Application of topology optimization to plates yielded minimized weight and material usage while keeping the plates still adequate for possible high load values. It was also revealed that up to 50% of mass could be saved by an optimal implant design.

Application of Topology Optimization to the Tibial Osteotomy Fixation Plates

Application of topology optimization to fixation plates is the main consideration of this paper. The interbody fusion plates are required to give mechanical support to tibia with minimally invasive surgical procedure. Topology optimization is used to obtain fixation plates with possible minimum material usage. Topology optimization is applied to three types of plates which are used in upper tibial osteotomy. Initial design of the plates are first numerically modelled and then investigated for stresses under possible highest load values. The results of the analysis indicated that the plates are very stiff even under high loads. Application of topology optimization to plates yielded minimized weight and material usage while keeping the plates still adequate for possible high load values. It was also revealed that up to 50% of mass could be saved by an optimal implant design.

Expression of antagonists of WNT and BMP signaling after non-rigid fixation of osteotomies

Delayed fracture healing and non-unions represent rare but severe complications in orthopedic surgery. Further knowledge on the mechanisms of the bone repair process and of the development of a pseudoarthrosis is essential to predict and prevent impaired healing of fractures. The present study aimed at elucidating differences in gene expression during the repair of rigidly and non-rigidly fixed osteotomies. For this purpose, the MouseFix™ and the FlexiPlate™ systems (AO Development Institute, Davos, CH), allowing the creation of well defined osteotomies in mouse femora, were employed. A time course following the healing process of the osteotomy was performed and bones and periimplant tissues were analyzed by high-resolution X-ray, MicroCT and by histology. For the assessment of gene expression, Low Density Arrays (LDA) were done. In animals with rigid fixation, X-ray and MicroCT revealed healing of the osteotomy within 3weeks. Using the FlexiPlate™ system, the osteotomy was still visible by X-ray after 3weeks and a stabilizing cartilaginous callus was formed. After 4.5weeks, the callus was remodeled and the osteotomy was, on a histological level, healed. Gene expression studies revealed levels of transcripts encoding proteins associated with inflammatory processes not to be altered in tissues from bones with rigid and non-rigid fixation, respectively. Levels of transcripts encoding proteins of the extracellular matrix and essential for bone cell functions were not increased in the rigidly fixed group when compared to controls without osteotomy. In the FlexiPlate™ group, levels of transcripts encoding the same set of genes were significantly increased 3weeks after surgery. Expression of transcripts encoding BMPs and BMP antagonists was increased after 3weeks in repair tissues from bones fixed with FlexiPlate™, as were inhibitors of the WNT signaling pathways. Little changes only were detected in transcript levels of tissues from rigidly fixed bones.The data of the present study suggest that rigid fixation enables accelerated healing of an experimental osteotomy as compared to non-rigid fixation. The changes in the healing process after non-rigid fixation are accompanied by an increase in the levels of transcripts encoding inhibitors of osteogenic pathways and, probably as a consequence, by temporal changes in bone matrix synthesis.

Stability of Fixation of Proximal Phalanx Unicondylar Fractures of the Hand: A Biomechanical Cadaver Study

To determine the relative stability of various fixation methods for proximal phalanx intra-articular unicondylar fractures during simulated early active motion. We created proximal phalangeal intra-articular unicondylar fractures in 13 fresh-frozen human cadaveric hands. Using a saw through a dorsal approach, we made an osteotomy beginning in the intercondylar notch and extending proximally at a 45° angle to the radial border of the proximal phalanx. We fixed each of the 4 fingers on each hand with a 1.5-mm headless compression screw, a 1.5-mm lag screw, two 1.1-mm smooth K-wires, or one 1.1-mm smooth K-wire. We rotated the order of constructs randomly for each hand. We simulated active range of motion on a custom-loading device at 0.25 Hz from full finger extension to full flexion for 2,000 cycles and measured displacement by a differential variable reluctance transducer. We found no significant differences in displacement of the fracture site among the 4 methods of fixation. Movement in the control specimen with no osteotomy fixation was significantly higher than with each of the other fixation methods. Biomechanical stability did not differ among the fixation methods for proximal phalanx unicondylar fractures in a flexion-extension active range of motion model. Fixation of these fractures with any of the methods tested may provide sufficient stability to withstand postoperative therapy when there is no substantial resistance to active motion.

Implant Handpiece With Adapted Drills in Orthognathic Surgery

The attachment of bilateral sagittal-split osteotomy of the mandibular ramus with bicortical screws or the combination of miniplates and a bicortical screw is complicated through the intraoral approach because of the angle required for insertion of screws, so it is necessary to use a trocater. This article aimed to report a technique developed and used in 60 patients, wherein an implant handpiece with adapted drills was used in the intraoral attachment. The setting was performed intraorally to prevent scarring and extraoral facial nerve damage, which may be caused by extraoral and transbuccal approaches routinely performed when using the trocater. The versatility of the handpiece implant allows for the insertion of monocortical and bicortical screws and rigid internal fixation of mandibular sagittal-split osteotomy, as well as surgical time reduction, decreasing postoperative morbidity.

Comparison of the outcome following the fixation of osteotomies or fractures associated with total hip replacement using cables or wires

There are no recent studies comparing cable with wire for the fixation of osteotomies or fractures in total hip replacement (THR). Our objective was to evaluate the five-year clinical and radiological outcomes and complication rates of the two techniques. We undertook a review including all primary and revision THRs performed in one hospital between 1996 and 2005 using cable or wire fixation. Clinical and radiological evaluation was performed five years post-operatively. Cables were used in 51 THRs and wires in 126, and of these, 36 THRs with cable (71%) and 101 with wire (80%) were evaluated at follow-up. The five-year radiographs available for 33 cable and 91 wire THRs revealed rates of breakage of fixation of 12 of 33 (36%) and 42 of 91 (46%), respectively. With cable there was a significantly higher risk of metal debris (68% vs. 9%; adjusted relative risk (RR) 6.6; 95% confidence interval (CI) 3.0 to 14.1), nonunion (36% vs. 21%; adjusted RR 2.0; 95% CI 1.0 to 3.9) and osteolysis around the material, acetabulum or femur (61% vs 19%; adjusted RR 3.9; 95% CI 2.3 to 6.5). Cable breakage increased the risk of osteolysis to 83%. There was a trend towards foreign-body reaction and increased infection with cables. Clinical results did not differ between the groups. In conclusion, we found a higher incidence of complications and a trend towards increased infection and foreign-body reaction with the use of cables.