Locking Head Screws Research Articles

Inability to Remove Locking Screws from the Femoral Neck System due to Stripping of the Screwdriver within the Locking Screw Head.

The purposes of this study were to investigate the frequency of screwdriver stripping in the head of the locking screw that attaches to the side plate to the femur shaft among the patients who underwent implant removal after Femoral Neck System (FNS) for femoral neck fracture, to determine the risk factors for locking head screw stripping in FNS treatment of femoral neck fracture, and to suggest a surgical tip that removes FNS, which is difficult to remove due to screw stripping. Design: Retrospective cohort study. Eight Urban tertiary referral academic hospitals. Included were patients with OTA/AO 31-B1, 31-B2, and 31-B3 femoral neck fractures who underwent surgical fixation with FNS from Nov 2019 to Feb 2023. The frequency of locking head screw stripping of FNS during the implant removal was evaluated. Among the 47 patients (18 (38%) men and 29 (62%) women) who met the inclusion criteria with average age of 59.2 years (range, 28 to 94 years), 13 (27.7%) experienced screwdriver stripping in the head of the distal locking screw during FNS removal surgery. A higher BMI showed a borderline significant association with the stripping in the adjusted model (OR = 1.233; 95% CI: 0.988-1.539; p = 0.064). No other variables showed significant association with the stripped locking head screw (p>0.05). Stripping of the screwdriver within the head of the distal locking screw occurred in over one quarter of cases. While a higher BMI demonstrated a borderline significant association, none of the other variables examined showed a statistically significant relationship with the stripped locking head screw. Level III (retrospective cohort study).

Clinical Efficacy of Medial and Lateral Plating in Distal Femur Fractures: Thesis Study

Abstract Background The problem of treating distal femoral fractures is complicated. The principles of the surgical management of supracondylar femur fractures have changed. Up until 1970, conservative management of these fractures was the recommended course of care. This was mostly caused by a lack of adequate implants and procedures. In modern times, locking compression plates offer the benefits of locking head screws, offering better fixation and absolute stability. This is significant in the treatment of fractures in osteoporotic bone because it enables the use of monocortical screws in the diaphyseal region, preserving the periosteum's blood supply and preventing structural bone loss to the opposite cortex. Varus collapse was the main complication, especially in osteoporotic bone. Therefore, anatomical reduction and rigid, stable fixation provided by double plating was considered the best option for treating this type of fracture. Patients and Methods This is a retrospective cohort study done in El Demerdash Hospital, Ain Shams University specialised hospitals, Air Force specialised hospital, and El Helmia military hospital through 20 cases of distal femur fractures of types 33-A3 to 33-C3, all of which were managed by dual plating and followed up for 6 months. People with open fractures, fracture type 33-A1, periprosthetic, and pathological fractures were excluded. Results In our study, through 20 cases with distal femur fractures between types 33-A3 and 33-C3, all managed by double plating, the mean age was 51.50, 6 of our patients had comorbidities (DM, HTN, or Both), the rest were medically free, the average operation time was 150 minutes, 2 of our patients needed a bone graft, the range of full union was from 3 to 6 months, the average AKSS among the 20 patients was 81.05, 14 of our cases achieved uneventful union, 2 cases had superficial wound infection, and 1 case had implant failure (screw cut out) and needed revision, so double plating is one of the better options to achieve bony union and a better functional outcome in severely comminuted distal femur fractures Conclusion Even though there were problems such as a lengthy operation and longer recovery period in our study, double plating is one of the best options for achieving bone union and a better functional outcome in severely comminuted distal femur fractures. Functional outcomes were excellent in 75% of cases and fair in 25% of cases, and the union rate was 100% with no Varus deformity or malunion.

Fixation of pelvic acetabular fractures using 3D-printed fracture plates: a cadaver study

Open reduction and internal fixation of pelvic acetabular fractures are challenging due to the limited surgical exposure from surrounding abdominal tissue. There have been a number of recent trials using metallic 3D-printed pelvic fracture plates to simplify and improve various elements of these fracture fixation surgeries; however, the amount of time and accuracy involved in the design and implantation of customised plates have not been well characterised. This study recorded the amount of time related to the design, manufacture and implantation of six customised fracture plates for five cadaveric pelvic specimens with acetabular fracture, while manufacturing, and surgical accuracy was calculated from computed tomography imaging. Five of the fracture plates were designed within 9.5 h, while the plate for a pelvis with a pre-existing fracture plate took considerably longer (20.2 h). Manufacturing comprised 3D-printing the plates in Ti6Al4V with a sintered laser melting (SLM) 3D-printer and post-processing (heat treatment, smoothing, tapping threads). The manufacturing times varied from 27.0 to 32.5 h, with longer times related to machining a thread for locking-head screws with a multi-axis computer numerical control (CNC) mill. For the surface of the plate in contact with the bone, the root-mean-square errors of the print varied from 0.10 to 0.49 mm. The upper range of these errors was likely the result of plate designs that were relatively long with thin cross-sections, a combination that gives rise to high thermal stresses when using a SLM 3D-printer. A number of approaches were explored to control the trajectories of locking or non-locking head screws including guides, printed threads or hand-taps; however, the plate with CNC-machined threads was clearly the most accurate with screw angulation errors of 2.77° (range 1.05–6.34°). The implanted position of the plates was determined visually; however, the limited surgical exposure and lack of intra-operative fluoroscopy in the laboratory led to high inaccuracies (translational errors of 1.74–13.00 mm). Plate mal-positioning would lead to increased risk of surgical injury due to misplaced screws; hence, it is recommended that technologies that can control plate positioning such as fluoroscopy or alignment guides need to be implemented into customised plate design and implantation workflow. Due to the plate misalignment and the severe nature of some acetabular fractures comprising numerous small bone fragments, the acetabular reduction exceeded the clinical limit of 2 mm for three pelvises. Although our results indicate that customised plates are unsuitable for acetabular fractures comprising six or more fragments, confirmation of this finding with a greater number of specimens is recommended. The times, accuracy and suggested improvements in the current study may be used to guide future workflows aimed at producing customised pelvic fracture plates for greater numbers of patients.

Minimally invasive plate osteosynthesis for clavicle fractures.

Treatment of comminuted clavicle shaft fractures with minimally invasive plate osteosynthesis (MIPO). Multifragmentary (≥ 2 intermediate fragments) clavicle shaft fractures with no need for anatomical reduction (AO15.2B and15.2C). Even simple fractures (AO15.2A) with significant soft tissue injuries Tscherne gradeI-III are suitable. Medial or lateral clavicle fractures as well as simple fracture pattern where anatomical reduction is indispensable. Short incision over the medial and lateral end of the main fracture fragments. Either medial or lateral epiperosteal plate insertion. Under image intensifier guidance, the plate is centered either superior or anteroinferior on the clavicle and fixed with acompression wire temporarily (alternatively by acortical screw) in one of the most lateral holes. Fracture reduction (axis, length, and rotation) over the plate and preliminary fixation medially. After correct reduction has been achieved, further cortical screws and/or locking head screws can be inserted (lag before locking screws). Relative stability is achieved by applying abridging technique. No immobilization is needed. Patients are encouraged to perform functional rehabilitation with active and passive physical therapy. Loading is increased according to radiological signs of bony consolidation. In aretrospective evaluation from 2001-2021, 1128 clavicle osteosyntheses were performed, of which 908 (80.5%) were treated with plate osteosynthesis and 220 (19.5%) with titanium elastic nail (TEN). Of the 908 plate osteosyntheses, 43 (4.7%) were performed with the MIPO approach. Finally, 42patients (35men and 7women; mean age of 44 ± 15years) with 43clavicle shaft fractures were analyzed. The operation was accomplished in 63 ± 28 min, and average fluoroscopy time was 45 ± 42 s. Acollective of 27patients could be evaluated after amedian follow-up of 14months (range 1-51months). In all, 26fractures healed in atimely manner. In1patient apseudarthrosis occurred which was treated with re-osteosynthesis and cancellous bone grafting in an open technique. Another patient revealed awound complication with need of operative wound revision 6weeks after the index surgery. Further postoperative course was uneventful in both patients. All were pain-free and able to return to work. After an average of 17 ± 8months, 18hardware removals (66.7%) were performed.

Standardizing Screw Head Orthopaedic Trauma Implants. Is There an Interest? An OTA Member Survey.

To determine the level of interest in standardization of design for fracture fixation implants within the orthopaedic trauma community. A survey regarding implant removal concerns and implant design preferences was electronically distributed to members of Orthopaedic Trauma Association (OTA). Three hundred thirty respondents participated in the survey (response rate of 19%) Only 2.4% of respondents indicated a consistent ability to identify the implant vendor and/or manufacturer of retained implants in the preoperative planning phase of care; >75% of respondents reported investing a minimum of an additional 30 minutes to their operative times to remove screw(s) to successfully extract a plate. More than 80% of respondents reported multiple occurrences requiring modification of their surgical plans because of implants that could not be removed, preventing the completion of the planned procedure. The majority of respondents expressed interest in the adoption of standardized locking head screws for mini, small, and large screw sizes sets (63.5%); 84.8% of respondents desire standardization of screw head and driver sizes across the industry. Also, 83.6% of respondents expressed interest in the adoption of a standardized locking screw head for each cannulated screw, regardless of manufacturer. Members of the orthopaedic community, as represented in the membership of the OTA, are interested in the adoption of universal standards in implant design. Establishing standard screw heads and drivers will optimize the delivery of operative care.

BIOMECHANICAL PECULIARITIES OF PLATE OSTEOSYNTHESIS FOR FRACTURES OF UPPER AND LOWER EXTREMITIES

In order to study biomechanics of plate osteosynthesis the review of the literature data about the use of different plates and screws for fracture fixation was done. The focus of the review was on the plate design, the connection interface between the screw head and the plate body, and the relations between the type of a plate and the stability of fracture fixation. The application of different types of plates fixed with locking head screws and non-locking head screws were studied for fractures of upper and lower extremities: humerus, forearm, femur and tibia. The application of plates with bigger section area and 4.5 mm or 5.0 mm screws is needed respecting the biomechanical peculiarities of lower extremity fractures, for which body weight is transferred to the fracture site, causing intensive strains in the components of bone-screws-plate system.

Evaluation of functional outcome after open reduction and internal fixation of distal femur fractures by locking compression plate

Background: In the supra and intercondylar fractures of femur particularly with intra articular extension, patient may develop stiffness of knee, shortening, rotational deformities, internal derangement of knee with instability, varus and valgus deformities which affect patient’s routine lifestyle. If these cases were treated with locking compression plate, the results obtained were successful, superior, timesaving providing early ambulation and least disability improving the functional outcome. Materials and Methods: This is a prospective interventional study. This study includes 25 supracondylar and intercondylar fractures of femur (both Muller’s Type ‘A’, Type B and Type ‘C’ fractures) treated with open reduction and internal fixation by Locking Compression Plate in the Department of Orthopaedics, Narayana Medical College and Hospital, Nellore from October 2019 to August 2021. There are 16 males and 9 females with age ranging from 20 to 80 years with an average of 44.6 years. Average age for males is 28.9 years and average age for females is 25 years. 18 fractures were due to road traffic accidents and 6 cases are due to fall from significant heights, 1 case due to simple fall from standing (osteoporosis). 15 cases were in right femur (60%) and 10 cases were in left femur (40%). Results: 25 cases were included in the study. There is an increase in the rate of union, decreased time taken for union, increased knee range of motion, decreased time for weight-bearing, postoperative complications and duration for hospital stay. Conclusion: LCP proved to be a good implant which could take the challenges like poor bone stock, severe comminution both metaphyseal and articular and prove successful. The locking head screws distally have prevented varus collapse, even in cases of osteoporosis. The Condylar LCP can be used in either an open or a minimally invasive manner.

A Retrospective Study of Postoperative Development of Implant-Induced Osteoporosis in Radial-Ulnar Fractures in Toy Breed Dogs Treated with Plate Fixation.

This study aimed to evaluate implant-induced osteoporosis (IIO) development in toy breed dogs treated using internal fixation with digital radiographs as the index of pixel values. There were 226 cases (236 limbs) of toy breed dogs with radial-ulnar fractures. Pixel values were measured on radiographs immediately, 2 weeks and 1 to 12 months after surgery. The ratio of pixel values (PVR) represented the bone mineral areal density based on the humeral condyle in the same image. The dogs were grouped based on the fixation methods, age and status of destabilization. There was a significant decrease in the PVR at 1 to 12 months postoperatively for all cases. There were not any significant differences in PVR of antebrachial fractures between those repaired with plates using locking head screws, cortex screws or a combination of locking and cortex screws. Implant-induced osteoporosis persisted at 1 to 12 months postoperatively in dogs aged ≧6 months, while the PVR increased after 3 months in dogs aged <6 months. Based on the destabilization method, there was a significant increase in the PVR at 3 months in the plate removal group. This study suggests that IIO occurs in small dogs treated with plates and screws. Moreover, patients aged < 6 months showed an early postoperative recovery of bone mineral areal density. Further, screw and plate removal could contribute to the recovery of bone mineral areal density.

Temporal Changes in Reverse Torque of Locking-Head Screws Used in the Locking Plate in Segmental Tibial Defect in Goat Model.

The objective of this study was to evaluate changes in peak reverse torque (PRT) of the locking head screws that occur over time. A locking plate construct, consisting of an 8-hole locking plate and 8 locking screws, was used to stabilize a tibia segmental bone defect in a goat model. PRT was measured after periods of 3, 6, 9, and 12 months of ambulation. PRT for each screw was determined during plate removal. Statistical analysis revealed that after 6 months of loading, locking screws placed in position no. 4 had significantly less PRT as compared with screws placed in position no. 5 (p < 0.05). There were no statistically significant differences in PRT between groups as a factor of time (p > 0.05). Intracortical fractures occurred during the placement of 151 out of 664 screws (22.7%) and were significantly more common in the screw positions closest to the osteotomy (positions 4 and 5, p < 0.05). Periosteal and endosteal bone reactions and locking screw backout occurred significantly more often in the proximal bone segments (p < 0.05). Screw backout significantly, negatively influenced the PRT of the screws placed in positions no. 3, 4, and 5 (p < 0.05). The locking plate-screw constructs provided stable fixation of 2.5-cm segmental tibia defects in a goat animal model for up to 12 months.

Effects of long-term plate fixation with different fixation modes on the radial cortical bone in dogs.

The aim of this study was to examine the effect of long-term locking plate fixation on the cortical bone of the canine radius. Locking compression plates were fixed to the left and right radius in dogs (n = 3). The left radius was fixed with a locking head screw (Locking Plate group, LP). The locking compression plate was compressed periosteally in the right radius using a cortex screw (Compression Plate group, CP). Radial bones from dogs that were euthanized for other purposes were collected as an untreated control group (Control group). After euthanasia at 36 weeks following plate fixation, radial bones were evaluated for bone mineral density and underwent histological analysis. Bone metabolic markers were analyzed by quantitative polymerase chain reaction (qPCR). Statistical analyses were performed for comparisons between groups. The LP group showed no significant difference in bone mineral density after plate fixation, whereas the CP group showed significantly lower bone mineral density. Histological analysis indicated that the number of osteoclasts and rate of empty lacunae increased significantly in the CP group relative to the Control and LP groups. qPCR analysis indicated increased expression of inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-6, and tumor necrosis factor ligand superfamily member 11 in the CP group, whereas Runt-related transcription factor 2, an osteoblast marker, was similar in all groups. The expression of hypoxia-inducible factor-1α in the CP group was also increased relative to that in the Control and LP groups. Thus, locking plate fixation is a biologically superior fixation method that does not cause implant-induced osteoporosis in the bone in the long term.

Effect of chewing and cutting condition for V-shape three-dimensional titanium miniplate for fixation of mandibular angle fractures (MAFs)

PurposeMiniplate shapes determine the fixation stability to promote best healing and osseointegration process of mandibular fracture. In clinical treatment, the common method used two straight-type miniplate or I-shape miniplate; sometimes this method is not stable enough or limited by the fracture geometry and caused high risk of failure due to screw loosening. This paper aims to investigate a new type of miniplate called V-shape miniplate design as an alternative to the standard straight plate based on total displacement, von Mises stress, stress transfer parameter (STP) and strain energy density transfer parameters (SEDPTs) for two types of bite force condition, which is cutting and chewing condition.Design/methodology/approachThe 3D fixation models were constructed and the finite element (FE) simulation is based on the two-bite force load that ranges from 50 to 700 N based on cutting and chewing bite force condition using ANSYS Workbench 19.2.FindingsIn result comparison, the maximum loading of the V-shape miniplate can reduce deformation by 5.9%, reduce stress by 0.58% reduce strain by 8.1% in cutting condition while reducing deformation by 6.43%, reduce stress by 15.25%, reduce strain by 10.1% in chewing condition. To assess the stress transfer behavior of miniplates fixations to the mandibular bone, the STP and SEDPT were evaluated at the normal cortex screw and the locking head screw. In the simulation, the locking head screw is vertical to the bone structure while the cortex screw is 95 degrees to the bone structure, as a result, the STP value for locking head screw is 1.0073 while in cortex screw is 0.7408.Research limitations/implicationsMeanwhile, the SEDPT value for locking head screw is 2.7574 and 1.8412 for cortex screw.Practical implicationsClinically, V-shape miniplate has shown factual data that can be used for prototyping. STP and SEDTP values provide evidence of how fixation stability is better than I-shape miniplate.Originality/valueIn conclusion, the newly designed V-shape miniplate has overall better stability than the standard I-shape miniplate, and the locking head screw has the STP value closer to 1 than the standard cortex screw; it means the locking screw is better in reducing the stress shielding.

Computed Tomographic Evaluation of Adjacent Segment Motion after Ex Vivo Fusion of Equine Third and Fourth Cervical Vertebrae.

Surgical fusion of vertebral segments is a treatment option for horses with cervical stenotic myelopathy or cervical fracture.Degenerative disease affecting adjacent vertebral segments is a reported complication following surgical vertebral fusion in other species, termed adjacent segment disease. The aim of this study was to evaluate the impact of cervical vertebral fusion on the biomechanics of adjacent vertebral segments in the horse. Neck specimens of 12 horses were assessed using computed tomographic imaging. Range of motion (ROM) was determined by measuring the maximum sagittal flexion, extension and lateral bending between C2 and C5. C3/4 was subsequently fused using a standard locking compression plate and locking head screws and computed tomographic scans and ROM measurements were repeated. Prior to intervertebral fusion, a significant increase in ROM along the vertebral segments from cranial to caudal was observed. Range of motion measurements of C3/4 decreased significantly after fusion (p = 0.01).Range of motion of the adjacent segments (C2/3 and C4/5) did not change significantly after fusion. Fusion of one cervical intervertebral joint did not affect the ROM of the adjacent vertebral segments. Further research investigating the implications of vertebral fusion on the intervertebral pressure in the equine patient is indicated.

A study of results of surgical management of distal tibia fractures treated by mippo tehnique with locking compression plate

Background and objectives: The surgical treatment of fractures according to AO principles has seen a change in the past decade, from anatomical reduction and rigid fixation to the current concept of Biological fixation, precise reduction being a goal only in intra-articular fractures. With the advent of internal fixators like PC-Fix and LISS (Less Invasive Stabilizing System) this was being achieved to some extent. The recent development of LCP has revolutionized the treatment by overcoming the few drawbacks of these internal fixators. The LCP is a screw plate system that offers the possibility of inserting conventional and locking head screws into the specially designed combination holes. We aimed to study the nature of fracture union in fractures treated with LCP by MIPO technique and to analyse any complications arising out of this technique. Methods: This is a retrospective study of 23 cases of distal tibia fracture (19 patients had associated fibula fracture) admitted in Southern Headquarter Railway Hospital, Chennai, between March 2006 and November 2009. Cases were taken according to inclusion and exclusion criteria. We treated all patients with LCP by MIPO technique. Results: We followed up all the patients and the duration ranged from 13 weeks to 38 weeks (mean 18.9 weeks). All fractures eventually united including 2 which had delayed union. Rest of the 21 fractures united at a mean of 20 weeks. We had totally 6 complications which included superficial infection (1), deep infection (2), iatrogenic fracture (1) and delayed union (2). We had no case of any purely implant related complications like screw loosening, screw breakage, plate failure. Interpretation and conclusion: The patient sample approximately reflected the regular trauma patients encountered at our set up. Fractures treated with MIPO, healed rapidly by secondary fracture union and hence achieving strong bony union across the facture site. With the LCP system the biological fixation of fractures was easier than the conventional plates. The anchorage of locking head screws even in osteoporotic bone was excellent. We also confirmed its proven efficacy in the treatment of difficult fracture situations, where in other implants have limited application. Fresh conclusions cannot be drawn as sample size is not sufficient.

Interlocking Nail Combined with Locking Plate Fixation for a Distal Diaphysis Femur Comminuted Fracture in a Dog

Background: Interlocking Nail (ILN) is similar a solid intramedullary pins with screws or bolts passing through one and nail holes (locking effect). This implant mostly have been putted normograde, passing by trochanteric fossa of femur, although it is reported to be inserted through the knee, passing by fracture focus and ending close to proximal femur. It is carriedout especially when there is a comminuted fracture in distal third shaft of femur. Locking plate systems work as internal fixators with some advantages compared to conventional plates. It can be used combined with intramedullary pin, and is an effective technique for increase stifeness stabilization of comminuted long-bone fractures, especially for bending. Some studies reported the use of plate-nail to increase even more the stiffness of implants, because of locking screw in plate and nail. Based on the same propose, we aim to report a case of an ILNs normograde (from distal to proximal) connected to a locking plate in highly comminuted distal diaphyseal fracture since it is rarely report in veterinary medicine orthopaedics.Case: A 5-year-old male mixed breed dog was assessed and diagnosed a fracture of the femur in the right pelvic limb. On physical examination, the dog had nonweight bearing lameness in the affected limb and, mobility of the fragments was noted following digital pressure. A comminuted fracture of the distal diaphysis of the femur was identified. A lateral approach tothe shaft of the femur, the incision was extended to the stifle joint through a lateral incision because the fracture seemed to extend throughout the physis. Open but do not touch approach was performed and reduction was gotten without modified environment of fracture hematoma. A surgical drill was inserted through the access in distal extremity of the bone to openthe medullary cavity of the femur. After that, an interlocking nail was inserted into the opening into the distal fragment, the fracture was reduced and the nail was inserted towards the proximal end of the bone. At the next stage the nail was fitted into the medullary canal and it was locked relative to the main fragments of the femur using locking head screws that were anchored in the load carrier of the plate. Postoperative radiographic views documented appropriate implants location and satisfactory femur fracture alignment. At 3 weeks, the patient showed functional use of the limb with partial weight bearing.Discussion: A biomechanical study comparing plate-rod and plate-nail system in gap fractures, showed that maximum load was significant different between the groups, and in plate-nail it was always heavier, it occurs because of the nail bigger diameter and screws pass through nail holes. What prove that this system is stiffer than plate-rod, so because this patient has osteopenia and thin cortical bone like showed previously, we preferred to use nail than intramedullary pin. The ILN could be introduced from proximal to distal femur (antegrade or normograde) and passing through the knee (called in medicine by retrograde, although in veterinary medicine this way is called normograte too), it depends on bone conformation. Several studies used normograde via in femur from distal to proximal, especially in distal fracture. In this case, it was used this via, by the knee, because it would promote better bone stock to insert the screws, since the nail was putted as close as possible from articular surface. In conclusion, the case reported here documented that the combination of a normograde (from distal to proximal) interlock nail with a locking plate provides a rigid fixation method, promoting satisfactory functional recovery time. Further investigations should be performed using plate-nail in vivo to give to us more precise data.Keywords: biological osteosynthesis, canine, orthopaedics, retrograde nail.

Results of Proximal Humeral Fracture Fixation with Anatomical Locking Compression Plate using 6 stepwise Intraoperative Criteria in Surgical Procedures: A Retrospective Study.

OBJECTIVE: To report functional and radiological outcomes of open reduction andinternal fixation of proximal humeral fracture with anatomical LCP using 6 stepwiseintraoperative criteria in surgical procedures. MATERIALS AND METHODS: A total of 30 proximal humeral fractures whichwere treated with open reduction and internal fixation with anatomical LCP ofproximal humerus at a Level 1 and a Level 2 trauma center between January 2012 toDecember 2015 were collected. All patients were operated using the sametechnique in the supine position on a radiolucent table. The surgical approach was deltopectoralapproach. The operation was strictly done following 6 stepwise intraoperativeprocedures, this included: Step 1) reduction and fixation of head fragments. Thereference image in the true AP fluoroscopic view named “beetle car” appearance wasapplied in all cases; Step 2) plate positioning with the humeral head, according torecommendation of implant surgical instructions; Step 3) fix the plate to the humeralhead; Step 4) plate positioning to the shaft; Step 5) fix the shaft to the plate includingadditional locking head screws, head and calcar fixation and; Step 6) secure the suturesof the cuff to the plate. All patients received a similar physical therapy program followinginternal fixation. According to the Neer’s classification, there were 13 two-partfractures, 12 three-part fractures and 5 four-part fractures. The functional outcomes,Constant scores, and radiological outcomes (head-shaft angle and complications) wereanalyzed. The mean follow-up time was 18 months.RESULTS: At the end of the follow-up period, all fractures united with acceptablealignment. The mean Constant score for the injured side was 86 points (range 42–92).Head-shaft angle minor varus (115-124) in 5 patients, normal (125-145) 22, minor valgus(146-155) 1 and major valgus (>155) in 2 patients. 2 patients (6.6 %) had complicationswhich was confirmed by radiologic assessment. It was also found that one case hadsecondary intraarticular screw penetration and another had secondary varus duringfollow up. Both of the cases had severe osteoporosis, but no reoperation was required. CONCLUSION: This study reports on the functional and radiological outcomes ofopen reduction and fixation of displaced proximal humeral fracture with anatomicallocking compression plate using these developed 6 stepwise operative procedureswhich showed reasonable good to excellent outcomes with low complications. Thisstudy strongly suggested that the 6 stepwise surgical procedures should be strictlyfollowed in the correct order as a surgical strategy to prevent complications arisingfrom the operative technique of internal fixation of the complex proximal humeralfracture. from the operative technique of internal fixation of the difficult proximal humeralfracture.

Second generation locked plating for complex proximal humerus fractures in very elderly patients

ObjectivesHumeral head sacrificing procedures are more favored in elderly patients with complex proximal humerus fractures because of high incidence of failures and complications with osteosynthesis. The purpose of this study is to assess the outcome of second generation locked plating techniques in 3 and 4 part fractures in active elderly patients >70years with an emphasis on function and complications. Materials and methods29 patients with displaced 3 and 4 part proximal humerus fractures were treated using the principles of second-generation proximal humerus locked plating. Fixed angle locked plating (PHILOS) using the anterolateral deltoid spilt approach augmented with traction cuff sutures was performed. Minimum of 7 locking head screws including 2 calcar screws were used. In cases with a comminuted medial calcar, an endosteal fibular strut was used. Subchondral metaphyseal bone voids were filled with injectable calcium phosphate cement. Radiological outcome (union, head – shaft angle, tuberosity reduction), functional outcome assessment (Constant and ASES scores) and complications (loss of reduction, nonunion and osteonecrosis) were assessed. ResultsThe fracture united in 24 of the 26 patients available for follow up at a mean of 27 months (12–40 months). 3 patients developed complications that required arthroplasty (fixation failure in 2 patients and osteonecrosis in 1 patient). Follow up age adjusted Constant (63.1±11.9) and ASES scores (62.58±7.5) showed the extent of functional improvement post surgery. Patients with fractures having a non-comminuted medial calcar and valgus displacement of the humeral head had better functional scores and fewer complications. ConclusionOsteosynthesis with second generation locked plating techniques provide satisfactory outcome in very elderly patients with complex proximal humerus fractures with minimal complications.

The treatment of distal metacarpus fracture with locking compression plate in calves*

In this study, we aimed to evaluate the effect of locking compression plates for the treatment of distal metacarpal fractures in calves. The metacarpus was stabilized using a stainless steel locking compression plate with fully threaded locking head screws. The calves started weight-bearing partially after the first postoperative day and resumed complete weight-bearing after day 10. Callus formation was obtained at the end of the 3rd week and completed at the end of the 8th week, and complete healing was seen at the 12th week in radiographs. The limbs were in good alignment, the calves were fully weight-bearing, and client satisfaction was very high. The metacarpal length, diameter of cortex, and diameter of medulla were measured in fractured and nonfractured metacarpi at the 1st, 45th, 120th, and 365th postoperative days. In conclusion, as the characteristics of juvenile bones do not provide sufficient physical strength for implants, we decided that locking compression plates are associated with good prognosis for surgical repair of distal metacarpal fractures in newborn calves.

Clinical and radiologic outcomes associated with the use of dynamic locking screws (DLS) in distal tibia fractures.

The locked screw plate construct is often cited as being too rigid and prolonging healing in patients with metaphyseal fractures. The newly introduced dynamic locking screws (DLS) allow 0.2mm of axial motion, which should optimize healing near the near cortex. The purpose of this study was to analyze the clinical results of dynamic locking screws in distal tibia fractures. Data were acquired retrospectively. Only distal meta-diaphyseal tibia fractures treated with minimally invasive plate osteosynthesis and DLS were evaluated. Cortical and locking head screws were used for distal plate fixation to minimize soft tissue irritation over the medial malleolus, and DLS were used in the proximal plate fixation. Clinical and radiographic data were evaluated after 6weeks, 3months, 6months and 1year until fracture union. Twenty-two patients were treated with minimally invasive plate osteosynthesis and DLS. Six patients could not be evaluated because they returned to a foreign residence after the procedure. Fourteen fractures healed after a mean of 3.1months. Two fractures with insufficient reduction showed delayed union and healed after 9 and 9.5months, respectively. The callus index peaked at 6months. Dynamic fracture fixation might be a promising concept to reduce the frequency of metaphyseal non-unions in distal tibia fractures. But nevertheless, the dynamic construct cannot compensate for insufficient reduction.

Influencing factors for difficult removal of locking head screws and locking compression plate

Objective To analyze the factors that may lead to difficult removal of locking compression plate (LCP) and locking head screws (LHS). Methods We retrospectively reviewed medical records of the 308 patients with extremity fracture who underwent implant removal at our institution from September 2004 to November 2013. They were 190 males and 118 females, with an average age of 36.8 years (from 12 to 82 years). The mean interval from hardware implantation to removal was 16.3 months (from 2 to 56 months). Their fractures involved humerus, ulna, radius, clavicle, femur, tibia and ankle joint. We extracted the following data: difficulty in removal; duration of implant stay in the body; size, position, insertion technique and cortical purchase of LHS; positional relationship between LHS and LCP (orthogonal or non-orthogonal). After we identified potential factors that might have been associated with difficult removal of LHS and LCP in fractures of upper and lower limb respectively using Mann Whitney U test and Chi-square test, we used multiple logistic regression analysis to determine the independent influencing factors. Results Of the 308 patients we analyzed, difficult removal occurred in 37. Fractures at distal humerus had the highest incidence of difficult removal (41.7%), followed by fractures at proximal forearm (33.3%), proximal femur (33.3%) and femur shaft (33.3%). The incidence in malleolar fractures was low (4.0%). Logistic regression analysis suggested the following independent risk factors: long implant stay in the body, young age, and bicortical purchase of LHS for patients with upper extremity fracture (P < 0.05); long implant stay in the body, LHS of a small diameter and percutaneous insertion of LHS for patients with lower extremity fracture (P < 0.05). Conclusions If implant removal is indicated, surgery should be performed as soon as radiographs show fracture healing. To reduce the incidence of difficult removal of LHS and LCP, surgeons should in their preoperative plan and actual procedures take into account different fracture locations and different factors that may lead to difficulty in removal. Key words: Bone plates; Bone nails; Device removal; Factor analysis, statistical

Possible predictors for difficult removal of locking plates: A case-control study

IntroductionDifficult removal of locking plates including less invasive stabilisation systems (LISSs) and locking compression plates (LCPs) sometimes occur. However, investigations of the mechanisms and correlated factors of complicated removal remain scant. This study aims to identify correlated factors for the difficult removal of locking plates and to propose suggestions for decision making regarding implant removal and the prevention of complicated removal. Materials and methodsIn total, 308 consecutive patients who underwent LCP/LISS removal from Sep. 2004 to Nov. 2013 were assessed. Using the Mann–Whitney U test, we analysed the correlation between difficult removal and the duration between open reduction and internal fixation (ORIF) and implant removal as well as the correlation between difficult removal and the patients’ age. Using Chi Square test, we assessed the correlations between complicated removal and the size, location, insertion technique and cortical purchase of the locking head screw (LHS). Correlated factors were separately determined in upper and lower extremities. Rates of difficult removal in different fracture locations were evaluated, and postoperative complications were documented. ResultsOf the total 308 patients, thirty-seven had intra-operative difficulties, and six patients experienced postoperative complications. Six out of fifteen patients with peri-elbow fractures and five out of seventeen patients with femur fractures suffered difficult removal, while four out of one hundred patients with malleolar fractures had intra-operative difficulties. Difficulties were experienced with 30 of 338 LCPs, 7 of 32 LISSs, 67 of 1533 small-diameter (≤3.5-mm) LHSs, and 12 of 442 large-diameter (≥4.5-mm) LHSs. Three LCPs and seventeen small-diameter LHSs were retained. A longer interval between ORIF and removal, younger age and bicortical screws correlated with difficult removal in the upper extremities, and a longer duration before removal, small-diameter LHS and minimally invasive insertion of LHS were predictors in the lower extremities. ConclusionsComplications occur with LCP/LISS removal, and it should not be a routine procedure. If removal is indicated, performing surgery as soon as radiographs show fracture healing is recommended. Different considerations should apply when making decisions and removing implants from patients with different fracture sites.