Screw Plate Research Articles

TENSION BAND WIRING (TBW) OF DISTAL END CLAVICLE : A FORGOTTEN TECHNIQUE : SIMPLER, CHEAPER AND BETTER

Clavicle fracture is a common injury, and can be classified into middle third, medial third, and distal third fractures. Only 10-15% of clavicle fracture occur in the distal third segment. Neer classified the distal clavicle fracture into five types ; type II and V are unstable and requiring fixation . Various common methods of stabilizations are introduced such as K-wiring , tension band fixation , plate fixation, osteosynthesis with hook plate and coracoclavicular screw however all those operative methods have their own advantages and disadvantages.Materials and Methods:We presented a case of 21 years old male with left shoulder pain after motor vehicle accident. Examination revealed tenderness on his left shoulder, and radiograph showed fracture of distal end left clavicle Neer type II, requiring fixation. He was counselled for lateral extension clavicle locking plate but unable to pay due to financial constraint.Results:The patient underwent open reduction and internal fixation using Kirschner wire with tension band fixation . The fracture site was visualized and the hematoma was curetted and washed. The fracture was reduced and fixed with two 1.4 mm trans-acromial Krischner wires and the reduction was checked with an image intensifier. Then the TBW is applied using stainless steel wire size 1.0 . The K-wires are bent beneath the skin. Sling immobilization is used for 2 weeks after the operation. Unrestricted tolerable shoulder motion is permitted. Stretched and exertional exercise is allowed after radiography shows osseous union and the implants are removed.Discussions:TBW is widely employed to treat limb fractures, such as patella and olecranon fracture but seldom used for distal clavicle nowadays. The advantages of TBW are higher antirotation and antibending force compared with that in K-wire fixation and lower profile compared with the bone plate, which reduces tendon irritation and prominent implant. The use of K-wires and TBW also required only the exposure of the fracture site. The soft tissue around the clavicle incurred little damage, leading to a lower infection rate. In addition, the use of K-wires and TBWs can provide a more rigid fixation than K-wires only. Rigid fixation with little complication contributes to good results .Conclusion:Surgical management is recommended for unstable distal clavicle fracture. TBW can be preferred because of the simplicity of the procedure, low cost, simple hardware, high union rate and easy availability of the implant.

Plate on Plate Osteosynthesis : A Novel Method For Periplate Fracture Fixation

Periplate fractures may occur after plate fixation, especially in osteoporotic and non-united bones. We present a case of locking plate fixation over an existing plate for such fractures.Case Presentation:58 years old man slipped and fell in sitting position 8 months post left distal femur LCP. He sustained pain and swelling of the left hip. The left thigh was externally rotated and shorter than the normal side. X-rays revealed a periplate fracture extending to the subtrochanteric region. A reverse right distal femur LCP was planned. A minimally invasive approach was used. Proximal screws were removed from the original plate and new screws were inserted through both plates which were of similar material, Titanium.Discussion:Elderly population makes a large subgroup of the cases due to osteoporosis and rigidity of the LCP construct2. This fixation provides a simple method to reduce surgical time, bleeding, and preserving more blood supply to enhance fracture healing, as opposed to using nails supplemented with cerclage/cable wires. Care should be taken to use the pre-existing screw holes in the overlapping segment of the two plates, as well as similar plate materials to avoid stress risers and reduce corrosion1.Conclusion:Plate on plate osteosynthesis is a novel method that may prove valuable due to the increasing population age and unique types of fractures. Further research is needed to determine any complications related to this type of fixation.

Biomechanical comparison of the angle of inserted screws and the length of anterior cervical plate systems with allograft spacers

BackgroundComparative studies of the biomechanical effects of plates of varying lengths and different screw insertion angles on allograft spacers are lacking. MethodsFinite element model analysis of a previously validated, three-dimensional, intact cervical spinal segment model of C3–6 was conducted in the present study. On the C5–6 segment, anterior discectomy and fusion were performed using allograft spacers and different combinations of anterior plates and screws. The biomechanical characteristics of combinations of short, medium, and maximal length plates with screw insertion angles of 0°, 8°, 16°, and 32° were analyzed. FindingsIn flexion and extension, the risk of allograft spacer subsidence decreased as screw angles increased. Short plates with a screw insertion angle of 32° posed the lowest subsidence risk, similar to medium length plates with a screw insertion angle of 16°, in all motion conditions. The risk of bone yielding increased as plate length increased, but decreased as the screw insertion angle increased. InterpretationShort plates with a large screw insertion angle (32°) showed the highest mechanical stability and load sharing of allograft spacers and the lowest risk of screw loosening. Accordingly, we recommend the use of a short plate and large screw insertion angle for anterior cervical discectomy and fusion.

Temporary Bridge Occipitocervical Fixation for Comminuted Atlantoaxial Fracture

We sought to evaluate the feasibility of temporary bridge occipitocervical fixation temporary bridge occipitocervical fixation (T-BOCF) for comminuted atlantoaxial fractures. A 57-year-old man presented with multiple trauma including a comminuted, undisplaced atlantoaxial fracture; subdural hemorrhage; skull base fracture; scalp laceration; right second finger tendon injury; and right distal femur open fracture. T-BOCF was performed to preserve neck motion while providing rigid stability to atlantoaxial fracture. Occipital plate and bilateral lateral mass screws were inserted at C3, C4, and C5, avoiding the fracture site; this was followed by rod connection without fusion. The screw-rod construct was removed after confirmation of bone union in the fracture site 12 months after the initial operation. Computed tomography performed at 12 months after the operation demonstrated solid bone union. Dynamic radiographs taken 12 months after implant removal demonstrated a flexion-extension range of motion of 16 degrees at C0‒C2 and 19.8 degrees at C2‒C7. The total flexion-extension range of motion was 35.8 degrees. T-BOCF is a viable option for treatment of comminuted, undisplaced atlantoaxial fractures. The technique is easier than direct C1‒C2 fusion and can avoid complications associated with occipitocervical fusion or C1‒C2 screw fixation. The blood supply to the fracture site is preserved by avoiding subperiosteal stripping, and semispinalis cervicis insertion at the C2 spinous process is also circumvented. Furthermore, neck motion is preserved after implant removal.

Novel finite element-based plate design for bridging mandibular defects: Reducing mechanical failure.

IntroductionWhen the application of a free vascularised flap is not possible, a segmental mandibular defect is often reconstructed using a conventional reconstruction plate. Mechanical failure of such reconstructions is mostly caused by plate fracture and screw pull‐out. This study aims to develop a reliable, mechanically superior, yet slender patient‐specific reconstruction plate that reduces failure due to these causes.Patients and MethodsEight patients were included in the study. Indications were as follows: fractured reconstruction plate (2), loosened screws (1) and primary reconstruction of a mandibular continuity defect (5). Failed conventional reconstructions were studied using finite element analysis (FEA). A 3D virtual surgical plan (3D‐VSP) with a novel patient‐specific (PS) titanium plate was developed for each patient. Postoperative CBCT scanning was performed to validate reconstruction accuracy.ResultsAll PS plates were placed accurately according to the 3D‐VSP. Mean 3D screw entry point deviation was 1.54 mm (SD: 0.85, R: 0.10–3.19), and mean screw angular deviation was 5.76° (SD: 3.27, R: 1.26–16.62). FEA indicated decreased stress and screw pull‐out inducing forces. No mechanical failures appeared (mean follow‐up: 16 months, R: 7–29).ConclusionReconstructing mandibular continuity defects with bookshelf‐reconstruction plates with FEA underpinning the design seems to reduce the risk of screw pull‐out and plate fractures.

The biomechanical study of a modified lumbar interbody fusion—crenel lateral interbody fusion (CLIF): a three-dimensional finite-element analysis

To analyze the biomechanical stability of a redesigned cage, a new lateral plate and the effect of length of cage in CLIF, an L4-L5 finite element model was performed. Six different internal fixation methods were designed and operated under six conditions (Stand-alone CLIF; CLIF with unilateral pedicle screws (CLIF + UPS); CLIF with bilateral pedicle screws (CLIF + BPS); CLIF with lateral plate (CLIF + LP); CLIF with lateral plate and unilateral pedicle screws (CLIF + LP + UPS); CLIF with lateral plate and bilateral pedicle screws (CLIF + LP + BPS)). Ranges of motion (ROM) and stress distribution were evaluated. The effect of the length of cage was analyzed. The ROMs of stand-alone CLIF group and other internal fixation groups were decreased by >90% compared with the intact group. The CLIF + LP + BPS group has the minimum ROM. The CLIF + LP group has smaller ROM than stand-alone group. The stand-alone group has the minimum stress except for extension condition. The CLIF + LP model has less ROM, but a greater stress load was observed in the lateral plate. As for the length of cage, the largest stress is located at the junction between cage and distal end plate, especially in the epiphyseal ring and cortical compact. We conduct a new ‘cylinder wall theory’ that the cage should be placed to cover the epiphyseal ring. We recommend the length of cage should cover the epiphyseal ring to reduce the subsidence of cage.

Single Ilioinguinal Approach to Treat Complex Acetabular Fractures with Quadrilateral Plate Involvement: Outcomes Using a Novel Dynamic Anterior Plate-Screw System.

ObjectivesTo evaluate the efficacy and safety of a novel fixation technique referred to as the dynamic anterior plate–screw system for quadrilateral plate (DAPSQ) for complex acetabular fractures with quadrilateral plate involvement through the single ilioinguinal approach.MethodsA total of 32 patients with acetabular fractures, selected between January 2009 and March 2016, were managed by DAPSQ with “quadrilateral screws” through single ilioinguinal approach. The primary outcomes measure was the reduction quality evaluated according to the Matta radiological criteria, and the functional outcomes were evaluated by the modified Merle d'Aubigné score at the last follow‐up. Secondary outcomes were postoperative complications and intraoperative conditions included, for instance, operation time and blood loss.ResultsOf these 32 consecutive patients, 19, 9, and 4 were classified as both columns, anterior column posterior hemi‐transverse, and T‐shaped fractures, respectively, and with an average of 47 months’ follow‐up. Anatomic reduction was obtained in 19 cases (59%), imperfect reduction in 9 cases (28%), and poor reduction in 4 cases (13%). The modified Merle d'Aubigné scores were excellent in 15 cases (47%), good in 13 cases (41%), fair in 2 cases (6%), and poor in 2 cases (6%). Three cases sustained temporary lateral femoral cutaneous nerve injuries. One patient had a superficial wound infection that resolved after debridement. Five patients had posttraumatic arthritis; one of them underwent total hip arthroplasty at 46 months. No cases had quadrilateral screws entering the hip joint.ConclusionThe use of DAPSQ with quadrilateral screws is an effective and safe choice for complex acetabular fractures with quadrilateral plate involvement through the single ilioinguinal approach.

Distal femural fractures. Surgical options

Distal femur fractures are complex and relatively rare. Conservative treatment has now been abandoned. The purpose of surgical treatment is to obtain an anatomical reduction of the articular surface, restoring the coronal and sagittal axis of the skeletal segment with a stable osteosynthesis, thus avoiding post-operative immobilization and allowing for early physical therapy. The literature reports similar results with different kinds of osteosynthesis: anterograde or retrograde nailing, dynamic compression screw plate, locking compression plates, and blade plates. Not only the type of fracture, but also the experience of the single surgeon should be taken into account when choosing the type of osteosynthesis.

Propriety of osteosynthesis in lateral fractures of the proximal femur

Understanding dislocation variability in complex proximal femur fractures and the relationships with the pattern of fractures may play a crucial role in choosing the right type of implant. Comminution of the intertrochanteric area, incompetency of the lateral wall and trochanteric support are difficult to evaluate on plain X-rays and sometimes even in CT. Most of the complications belong to typical fracture patterns: A3 and so-called “reverse” A2 in AO classification. Cefalo Medullary Nails (CFN) may not be superior to Sliding Hip Screw plates (SHS) in peculiar type of fractures lacking lateral buttresses able to restrain the lateralization of the proximal head-neck fragment. Lateral trochanteric support and antirotational device in the head-neck complex may reduce secondary dislocation, non union or hardware failure complications. In this paper, a correlation between osteo-synthesis and stability of the metal-bone construct is discussed.

Locking Screws With a Threaded Degradable Polymer Collar Reduce Construct Stiffness Over Time.

The stiffness of locking plates provide increased stability for early fracture healing but may limit late interfragmentary motion (IFM) necessary for secondary bone healing. An ideal plating construct would provide early rigidity and late flexibility to optimize bone healing. A novel screw plate construct utilizing locking screws with a degradable polymer locking mechanism is a dynamic option. Conventional locked plating constructs (group A) were compared with locking screws with a threaded degradable polymer collar before (group B) and after polymer dissolution (group C). Monotonic axial compression, monotonic torsion, cyclic axial load to failure, and IFM at the near and far cortices were tested on synthetic bone models. One-way analysis of variance and post hoc Tukey-Kramer testing demonstrated similar axial stiffness in group A (873 ± 146 N/mm) and B (694 ± 314 N/mm) but significantly less stiffness in group C (379 ± 59 N/mm; F(2,15) = 9.12, P = 0.003). Groups A and B also had similar IFM, but group C had significantly increased IFM at both the near (F(2, 15) = 48.66, P = 2.76E-07) and far (F(2, 15) = 11.78, P = 0.0008) cortices. In cyclic axial load to failure, group A (1593 ± 233 N) and B (1277 ± 141 N) were again similar, but group C was significantly less (912 ± 256 N; F(2, 15) = 15.00, P = 0.0003). All failures were above the 500-N threshold seen in typical weight-bearing restrictions for fracture care. Torsional stiffness demonstrated significant differences between all groups (F(2, 15) = 106.64, P = 1.4E-09). Use of locking plates with a degradable polymer collar show potential for in vitro construct dynamization. Future in vivo studies are warranted to assess performance under combined loading and the effects of decreasing construct stiffness during the course of bony healing.

Can locking plate fixation of symphyseal disruptions allow early weight bearing?

IntroductionAnterior pubic symphyseal plate fixation is the recommended treatment for disruption of pubic symphysis in an unstable pelvic ring injury. The rigid construct offered by locking symphyseal plate has the theoretical advantage of allowing patients to weight bear early. However, there are concerns of catastrophic failure about the locked plate construct. The purpose of the study was to establish if locking plate fixation for pubic symphysis disruption was effective to allow patients to mobilise weight bearing immediately after surgery. Patient and MethodsRetrospective analysis of a prospectively collected database from a single centre was performed. The study period was from 2008 to 2017. Radiographic evidence of fixation failure, revision surgery, removal of metalwork and follow up duration was noted. ResultsWe identified 46 patients (F:M 8:38) with a mean age of 46 years (range 14 to 74 years). Based on the mechanism of injury patients were classified into Antero-posterior compression (28), Vertical shear [10], lateral compression [4] and combined mechanism [4]. Either a 4-hole or 6-hole locking plate was used in all patients, depending on fracture extension. Posterior fixation was required in 28 (61%) patients. All patients were allowed to fully or partial weight bear. The mean radiological follow-up period was 31 weeks with 13 (28%) patients having evidence of radiological failure. Revision was performed in 1 (2%) patient, in whom the screws had pulled out of the bone. The most common mode of failure was either the screw backing out from the plate or broken screw. Among the 4 (8%) patients who had their metalwork removed, 1 (2%) had delayed onset of infection, 2 (4%) had symptoms related to backed out screw and 1 (2%) opted electively to have metalwork removed. ConclusionsWith our series of patients, we have found that using locking plate for pubic symphyseal diastasis is safe and effective in allowing patients to weight bear early. A low complication rate and need for re-operation is demonstrated.

Computational Biomechanical Analysis of Postoperative Calcaneal Fractures with Different Placement of the Sustentaculum Screw

ObjectiveTo evaluate the computational biomechanical analysis of intra‐articular calcaneal fractures with different fixation status of the sustentaculum plate screw, when the finite element modeling of calcaneal fractures were fixed by the lateral locking plate.MethodsThe normal right foot of a male (age: 36 years; height: 174 cm; body weight: 65 kg) was scanned by the CT scanner. As the computational biomechanical study, the three‐dimensional finite element model of the simplified Sanders type‐II calcaneal fracture was built. Fixation with the lateral calcaneal locking plate and screws was simulated using a finite element software package according to clinical operation. According to the different placement of the sustentaculum plate screw, the models were categorized as the accurate fixation group, marginal fixation group, and non‐fixation group. The loading of 650 N with the vertical axial compression was applied to simulate the standing phase with single foot. The Von Mises stress distribution, maximal displacement, and contact area of the subtalar joint were analyzed among three groups.ResultsThe pressure distribution of the subtalar joint facet was inhomogeneous. The stress concentration of the calcaneus was located at the medial zone of the posterior subtalar joint facet. The peak Von Mises stress distribution in three groups was similar at the subtalar joint facet of 4.9 MPa, 5.1 MPa, and 5.4 MPa. In the accurate fixation group, the contact area on the posterior articular facet was 277.1 mm2; the maximal displacement was 0.18 mm. The contact area of the marginal fixation group was 265.3 mm2 on the posterior facet, where the maximal displacement was 0.23 mm. In the non‐fixation group, the contact area was 253.8 mm2; the maximal displacement was 0.25 mm. There was a slight change in the contact area of the subtalar joint and no prominent displacement of the calcaneus could be detected among the three groups.ConclusionsThe biomechanical results, including the peak stress distribution, contact area, and maximal displacement of subtalar joint, were similar whether the screw is placed exactly within the sustentaculum tali or not, when the calcaneal fractures were fixed by the lateral locking plate. The sustentaculum plate screw had less effect on the biomechanical performance of the calcaneus.

Craniovertebral junction fixation in children less than 5years.

Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5years. A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5years. Fusion was assessed using computerised tomography or flexion extension X-rays. Twenty-six children (median age 2.3, range 0.8-4.9years, 19 under the age of 3) underwent OC (n = 19) or AA (n = 7) fusion between 1999 and 2016. Pathology comprised 17 congenital, five trauma, two tumour and two post-infection cases. Twenty-one patients underwent sublaminar cable fixation with calvarial, autologous bone graft and halo-body orthosis immobilisation. An occipital plate and rods to sublaminar wire construct were used in four cases. A rigid instrumented fixation with occipital plate and C2 pedicle screws was utilised in one case. Follow-up was for a median of 2.8years (range 0.03-16.3years). Initial fusion rate was 91%, reaching 100% following two re-operations. Ninety-two per cent of patients were neurologically stable or improved following surgery. Twenty-one patients had a good overall outcome. Two patients had post-operative neurological deteriorations, and four died due to non-procedure related causes. Pin site morbidity secondary to halo use occurred in five cases. High fusion rates with good outcomes are achievable using semi-rigid fixation in the under 5-year-olds. Full thickness, autologous calvarial bone graft secured with wire cables and halo external orthosis offers a safe and effective alternative technique when traditional screw instrumentation is not feasible. These slides can be retrieved under Electronic Supplementary Material.

Development and Clinical Application of a New Open-Powered Nail Anterior Cervical Plate System.

ObjectiveTo observe and evaluate the clinical curative effect of a new type of open‐powered cervical spine system developed for anterior cervical surgery.MethodsA retrospective analysis was performed in our hospital in 2015–2017 of 329 orthopaedic patients treated with cervical anterior decompression, cage or titanium mesh graft fusion, new open‐powered nail plate or traditional cervical anterior screw plate. A total of 154 (control group) and 175 (observation group) cases were fixed with conventional cervical‐ and new open‐powered nail plates, respectively. Postoperative follow‐up was performed. Cervical stability, internal fixation position, and bone graft fusion were evaluated by imaging. Operative time, intraoperative blood loss, cervical Cobb angle, pain visual analogue scale (VAS) score, and Japanese orthopaedic association (JOA) score were compared between the groups. JOA scoring (spinal cord function) and neurological function improvement rate (IR) were used to assess clinical efficacy.ResultsThe patients were followed up for 8–36 months with an average of 19.48 months. There was no significant difference in the operation time and intraoperative blood loss between the two groups (P > 0.05). In the control group, the Cobb angles of the cervical spine were 5.13° ± 1.28°, 10.46° ± 1.07°, and 9.72° ± 1.43° before and after the operation. The observation group was followed by the Cobb angle of the cervical spine before and after the operation. They were 4.96° ± 1.39°, 11.67° ± 0.93°, and 11.13° ± 1.19°, respectively; the JOA scores before the operation, 1 week after the operation, and at the last follow‐up were (8.07 ± 1.13) points and (13.57 ± 0.82) points, and (14.19 ± 0.96) points, respectively; the IR was 86.52% ± 9.33%. The preoperative, postoperative 1 week, and last follow‐up JOA scores in the observation group were (8.37 ± 1.29) points, (14.11 ± 0.93) points, and (14.95 ± 0.78) points respectively. The IR was 88.74% ± 8.16% in the scores; the VAS scores were (5.54 ± 0.89) points, (1.73 ± 0.71) points, and (1.48 ± 0.52) points in the preoperative, postoperative 1 week, and last follow‐up in the control group. The VAS scores were (5.81 ± 0.94) points, (1.82 ± 0.61) points, and (1.16 ± 0.49) points before, 1 week, and after the final follow‐up. The JOA score and IR, VAS score and preoperative comparison between the two groups were statistically significant (P < 0.05), but there was no statistically significant difference between the two groups (P > 0.05).ConclusionThe new open‐powered nail anterior cervical plate system can achieve the same clinical effect as the traditional anterior cervical plate fixation in anterior cervical surgery, but it can simplify the operation process, effectively make up for the shortcomings of the traditional anterior cervical plate operation, and obtain satisfactory clinical application effect, which is worthy of clinical promotion.

Comparative study of percutaneous bridging plate and retrograde suprapubic intramedullary screw fixation for anterior pelvic ring fracture

To compare the effect of percutaneous bridging plate and retrograde suprapubic intramedullary screw in the treatment of anterior ring fracture of pelvis. From January 2013 to June 2017, 40 patients with unstable pelvic fractures involving anterior ring were analyzed retrospectively. According to the fixation method, they were divided into two groups, there were 20 patients in percutaneous bridging plate group (plate group) including 9 males and 11 females; according to tile classification, fractures were classified as type B1 in 1 case, type B2 in 14, type B3 in 2, type C1 in 2 and type C2 in 1. There were 20 cases in retrograde suprapubic intramedullary screw group (screw group) including 10 males and 10 females; according to tile classification, there were 1 case of type B1, 12 cases of type B2, 3 cases of type B3, 3 cases of type C1 and 1 case of type C2. The incision length, operation time, times of fluoroscopy, intraoperative bleeding volume, postoperative Matta score, postoperative complications and the last follow-up Majeed function score of the two groups were compared and analyzed. Both groups were followed up for 8 to 15 (12.25±2.24) months in the plate group and 6 to 18 (12.4±2.6) months in the screw group, there was no significant difference between the two groups. The incision length of screw group was (3.85±0.75) cm shorter than that of steel plate group (7.05±1.39) cm; the operation time of screw group was (27.70±5.36) min longer than that of steel plate group (15.10±2.07) min; the fluoroscopy times of screw group was (6.00±1.83) more than that of steel plate group (3.75±1.33) . The bleeding volume was (22.50±10.82) ml in of screw group, (25.00±9.93) ml in steel plate group, there was no significant difference between the two groups (P>0.05) . There was no significant difference in Matta evaluation and Majeed functional score in the last follow-up. One case of superficial skin infection occurred in screw group, one case of superficial skin infection and one case of transient paralysis of lateral femoral cutaneous nerve occurred in steel plate group. Percutaneous bridging plate and retrograde suprapubic intramedullary screw fixation of pelvic anterior ring fracture have the same effect. The operation time of the percutaneous plate group was shorter, the times of intraoperative fluoroscopy was less, and the learning curve was shorter, but the variation of the lateral femoral cutaneous nerve should be noted during the operation.

Intramedullary screw fixation for metacarpal shaft fractures: a biomechanical human cadaver study.

Intramedullary cannulated compression screws have been introduced for the fixation of unstable metacarpal fractures. In the present study, this technique was compared with dorsal compression plating to evaluate its biomechanical performance in stabilizing metacarpal shaft fractures. In a first set of experiments, the biomechanical characteristics of the screws were analysed in an artificial bone model. In subsequent experiments, midshaft osteotomies were performed in human cadaver metacarpals, followed by plating or intramedullary screw osteosynthesis. The metacarpals were tested to failure in cantilever bending, following a stepwise increasing cyclic loading protocol. We found a significantly lower load at failure and a significantly lower number of cycles to failure in the intramedullary screw group, but both methods offered sufficient stability under these loads. With reference to published loads on the metacarpals during use of the hand, we conclude that intramedullary osteosynthesis yields sufficient strength and stiffness for early active motion. A difference in its fixation stability is noted compared with plate fixation, which may not be clinically relevant.

Comparative study of posterior minimally invasive plate and 3D-navigated percutaneous sacroiliac screw internal fixation for treatment of posterior pelvic ring fracture in elderly patients

Objective To compare the clinical efficacy of posterior minimally invasive reconstruction plate and 3D-navigated percutaneous sacroiliac screw fixation of elderly patients with posterior pelvic ring fractures. Methods A retrospective cases control study was performed to analyze the data of 75 elderly patients with posterior pelvic ring fractures admitted from January 2014 to June 2018 in Central Hospital of the PLA. There were 32 males and 43 females, with the age range of 60-83 years (mean, 67.7 years). Twenty-four patients in the plate group were treated by posterior minimally invasive reconstruction plate fixation, and 51 patients in the navigation group were treated by percutaneous sacroiliac screw internal fixation with 3D navigation. The operation time, intraoperative blood loss, X-ray exposure time, complication rate and postoperative visual analogue scale (VAS) were compared between the two groups. Postoperative Matta radiographic criteria was used to assess fracture reduction quality, and Majeed criteria was used to assess pelvic function at the last follow-up. Results All 75 patients were followed up for 6-24 months (mean, 13.5 months). The operation time, intraoperative blood loss and X-ray exposure time in the plate group were (126.1±20.6)minutes, (251.6±50.8)ml, and (15.7±4.4)s, showing significant differences in comparison with the navigation groups [(49.7±17.5)minutes, (22.8±5.1)ml, and (112.8±8.8)s](P 0.05). At day 3, one week, and one month postoperatively, the VAS in the navigation group was (3.3±0.7)points, (3.2±0.7)points, (2.4±0.6)points, better than that in the plate group [(7.2±0.7)points, (6.2±0.8)points and (4.5±0.7)points] (P 0.05). According to the Matta radiographic criteria, the excellent and good rate was 92% in plate group (excellent in 14 cases, good in 8, and fair in 2), and was 82% in the navigation group (excellent in 25 cases, good in 17 and fair in 9). There was no significant difference between the two groups (P>0.05). According to the Majeed criteria at the follow-up, the excellent and good rate was 96% in the plate group (excellent in 15 cases, good in 8 and fair in 1), and was 94% in the navigation group (excellent in 35 cases, good in 13 and fair in 3). The difference between the two groups was not statistically significant (P>0.05). Conclusion For elderly patients with osteoporotic posterior pelvic ring fractures, percutaneous sacroiliac screw fixation under 3D navigation has the advantages of shorter operation time, less bleeding, less radiation dose and less postoperative pain than minimally invasive reconstruction plate internal fixation, and hence deserves clinical application. Key words: Aged; Pelvis; Fracture fixation, internal; Osteoporosis; Surgery, computer aided

Tension band plate-guided growth of knee-flexion deformity in arthrogryposis multiplex congenita in which metaphyseal funnelization induced screw encroachment upon the neurovascular bundle.

Knee-flexion deformity in arthrogryposis multiplex congenita is treated by serial casting into extension, distal femoral osteotomies, distal femoral-guided growth, hemiepiphysiodesis, external fixation, capsulotomy, and soft-tissue releases. We are aware of four cases treated by distal anterior femoral-guided growth with tension band plates in which an unreported complication occurred: the screws of the tension band plates penetrated the posterior cortex of the femur during remodeling with metaphyseal funnelization risking the neurovascular bundle. Inclusion criteria were cases with arthrogryposis multiplex congenita and knee-flexion deformity, treatment at our institution by distal anterior femoral-guided growth with tension band plates, and radiographic evidence of posterior cortex screw penetration during remodeling from growth. Six knees (four cases) met the inclusion criteria. The average age at the distal anterior femoral-guided growth with tension band plate operation was 5.8 years. Radiographs after 6.6 years of follow-up showed that the screws of the tension band plates, which at surgery were intrametaphyseal, had penetrated the posterior cortex of the femur. Four knees (two cases) had diffuse pain around the knee to lower leg area, and instrumentation removal alleviated the symptoms. During distal anterior femoral-guided growth with tension band plate operation for knee-flexion deformity in arthrogryposis multiplex congenita, we found that the screws of the tension band plates, which were initially located inside the metaphysis, may protrude through the posterior bone cortex during metaphyseal funnelization with growth, and may encroach upon the neurovascular tissues. Level of evidence: Level IV - case series.

Comparison of different treatment techniques in the mandibular condyle fracture.

Mandibular condyle fractures can be treated conservatively by intermaxillary fixation (IMF) or by open reposition and internal fixation. Although many studies have discussed for the optimal treatment method, the issue remains controversial. In this study, we aimed to compare conservative techniques in the mandibular condyle fractures. Twenty four unilateral condyle fracture patients aged between 18 and 48 years were treated according to one of three different modalities. Bracketing, arch bar or mini screw was applied to all non-surgery patients to obtain IMF. Eight patients were treated with only IMF meanwhile eleven patients were treated with one or double-sided amplifier occlusal splint according to the status of fractured segments, in addition to IMF. Remaining five patients have undergone open reduction and fractured segments immobilized with mini plates. Pre- and post-operative images were recorded with a computerized tomography device. Clinical and radiological examinations were performed by orthodontists and surgeons at baseline and at 6 months of treatment. The condyle lengths of the patients with unilateral fracture after recovery were compared with the unaffected side. The length between the most protruding point of the condyle and the mandible was measured and the length difference was only 5.94 mm in patients who were treated by IMF. The length difference of patients who used brackets and splints was 3.36 mm (p<0.05). The length difference of patients who were repaired by plate screws was 1.80 mm (p>0.05). However, there was no statistically significant difference (p>0.05) between the groups in the IMF, occlusal splint and IMF and mini plate groups, between the trauma side and the opposite side. None of the patients developed ankylosis, open mouth, limitation of mouth opening, facial asymmetry, laterognathia, and retrognathia. The occlusion of the patients who were not known to have pre-trauma occlusions were directed, repositioned and provided an appropriate occlusion. The use of IMF with an occlusal splint is a more conservative and acceptable treatment modality than open reduction in selected cases.

Conical coupling angular stable plate fixation: a retrospective study.

Backgrounds.Conical coupling represents an alternative to screw coupling on angular stable plate fixation. Aims of the present study was to evaluate clinical effectiveness and ease of plate removal of conical coupling locking plates into different scenario regarding quality of bone, type of fracture and operative technique.Methods.From May 2013 to December 2017, 198 patients with 206 fractures underwent open reduction and internal fixation with conical locking plate. In most cases fixation involved wrist (38%) and clavicle (24%) fractures but a varied type of fractures and bone were included in the study.Results.Ten complications related to plate fixation were observed (5,1%). Two case of intra-articular positioning of screws of wrist plate. One case of loss of reduction and breakage of wrist plate due to an inappropriate proximal fracture fixation. Five cases of complications involved clavicle fixation: three cases of non-union, one case of peri-implant fracture, one screw loosening. One non-union of distal tibial fracture, one non-union in olecranon fracture were finally observed. Thirty-four patients that have symptoms that could be traceable to the implants in-situ underwent plate removal. No complications were observed during surgical plates removal. Conical coupling angular stability plate represents an actractive alternative to threaded angular stability plate. Bush titanium insert, eliminating the problems of cold welding and cross-threading, simplifies surgical screws and plate removal