Lag Screw Fixation Research Articles

Principle of Lag-Screw Fixation in Mandibular Trauma.

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

Lag Screw Fixation for Treatment of an Ulnar Styloid Process Fracture with Antebrachiocarpal Joint Luxation in a Cat

AbstractFracture of the ulnar styloid process can result in clinically debilitating antebrachiocarpal instability. Previously described repair methods include Kirschner wire and figure of eight tension band wire and/or intramedullary pinning. This case report describes surgical repair of a short oblique ulnar styloid process fracture in a cat using two cortical screws placed in lag fashion. Recheck evaluation confirmed lameness-free full return to function with anatomical fracture healing.

Comparative analysis of functional outcome of anatomical precontoured locking plate versus reconstruction plate in the management of displaced midshaft clavicular fractures

For the fixation of displaced midshaft clavicular fractures, different plates are available, each with its specific pros and cons. The ideal plating choice remains subject to ongoing discussion. Reconstruction plates are cheap and easily bendable, but their strength and stability have been questioned. The anatomical precontoured locking plates provide better stability and strength compared with the reconstruction plate. We have analyzed both prospectively and retrospectively 55 cases of displaced midshaft clavicular fractures treated surgically using precontoured anatomical locking plate (24 cases) or reconstruction plate (31 cases) for patients admitted in our institute between January 2011 and December 2017. The clinical and radiological outcomes between the reconstruction plate and precontoured anatomical locking plate were compared using Quick Disability of the Arm, Shoulder and Hand (DASH) score and plain radiographs, respectively. The mean time to union was 16.3 weeks in the reconstruction plate group compared with 13.4 weeks in the precontoured locking plate group. The mean score in Quick DASH was 32.65 in the reconstruction group and 25.44 points in the precontoured locking plate group. We had complications such as hypertrophic scar, painful shoulder, and restricted range of motion in both the groups, whereas screw cutout and plate failure were noted only in the reconstruction plate group, which needed implant removal. The mean follow-up period was 16.44 months (14-31 months). The removal of implant was carried out in three patients in the reconstruction group. None of the group had nonunion. Surgical management of fresh middle third clavicle fractures with anatomical precontoured locking plate provided stable fixation, faster union, and better functional outcome compared with the reconstruction plating. Anatomical plate had the advantage of less soft tissue stripping, and there is less need for lag screw fixation of the plate for fracture stability as precontoured plate itself provides a rigid construct.

Radiographic Results of Unicortical Medial Malleolar Fracture Fixation.

Medial malleolar fractures commonly occur as part of rotational ankle fractures, which often require surgery. Different fixation techniques exist, including unicortical or bicortical lag-screw fixation. Bicortical screws that engage the lateral distal tibia have been noted to be biomechanically superior to unicortical ones with a lower failure rate. The authors of this study have used unicortical screws routinely. This study was initiated to investigate the clinical results of a large series of patients with unicortical medial malleolar fixation. Patients who underwent unicortical medial malleolar fracture fixation between 2011 and 2017 were reviewed. In total, 461 ankle fractures were identified with a mean follow-up of 11.4 months (range, 3-57), of which 211 had a medial malleolar fracture. Eight patients were excluded as they did not follow up with the treating surgeons after surgery, leaving 203 patients for evaluation. The primary outcome was radiographic union. Any loss of reduction, complication, or subsequent surgery was recorded. Malunion was defined as greater than 2 mm displacement. There were 2 asymptomatic nonunions (1.0%), 1 delayed union that healed using an external bone growth stimulator (0.5%), and 2 malunions of the medial malleolus (1.0%) with 1 asymptomatic. The other patient developed posttraumatic osteoarthritis but has not yet required further surgery. None of these 5 patients required revision medial malleolar surgery. Ultimately, the union rate using unicortical medial malleolar fixation was 99.0% (201/203). Unicortical fixation of medial malleolar fractures resulted in consistently good healing. Even though biomechanical studies have shown that bicortical screws provide stronger fixation, our clinical results indicate that the need for this stronger fixation may be questionable. Level IV, retrospective case series.

Surgical Treatment of Posterior Malleolus Fractures and Posterior Fixation

Posterior malleolar fractures (PMFs) have been demonstrated to result in poorer outcomes than other types of ankle fractures with a higher incidence of posttraumatic arthritis. Accordingly, there has been a recent surge in interest in reduction and fixation of PMFs. Operative criteria for PMFs have been based on size, step-off, ankle joint instability, and syndesmotic injury, though universally accepted criteria have yet to be defined. Anatomically, the posterior malleolus is important as an insertion point of the posterior inferior tibiofibular ligament and thereby may play a role in syndesmotic stability. However, the important lateral ankle ligament complex is also important in governing stability of the talus within the ankle mortise. PMFs have been classified by the Haraguchi system based on morphology and extent. Radiographs, although always appropriate to perform as the initial diagnostic imaging study, are likely insufficient to evaluate the size and displacement; computed tomography scan is recommended for optimal evaluation for preoperative planning. When treating the posterior malleolus by a posterolateral approach, prone and lateral positioning of the patient facilitates exposure, although it can also be performed in the supine position with a large bump and with a leg that can be safely passively internally rotated sufficiently, or externally rotated if a posteromedial approach is used. Fixation can be performed with lag screw fixation alone versus buttress or standard plating techniques. Wound complications and posttraumatic arthritis are relatively common complications encountered in the treatment of PMFs. Level of Evidence: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

A new navigational apparatus for fixation of acetabular posterior column fractures with percutaneous retrograde lagscrew: Design and application.

The purpose of this study was to analyze the feasibility and accuracy of a newly developed guide apparatus for the percutaneous retrograde lag screw fixation of posterior column of acetabular fractures. 3D pelvic models were reconstructed from the helical computed tomographic data of 33 adult patients using the Mimics 10.01 software. The virtual cylindrical implants were placed along a line passing through the central point of the ischial tuberosity and the midpoint between the most prominent point of anterior superior iliac spine and that of posterior superior iliac spine. Some anatomical parameters were then measured, based on which a guide apparatus was developed, and its safety and accuracy were experimentally validated with pelvic and cadaveric specimens. The screws were successfully placed in all of the 66 hemipelves. There was a significant difference between the male and female groups in the AB distance (156.26 ± 7.28 mm and 151.38 ± 8.11 mm), OI distance (139.53 ± 7.56 mm and 125.15 ± 11.17 mm), and diameter (12.19 ± 1.97 mm and 10.19 ± 2.14 mm) of the virtual cylindrical implants. This guide apparatus was proved effective for percutaneous retrograde lag screw fixation of posterior column acetabular fractures by the experiments with the pelvic and cadaveric specimens. Screw fixation of posterior column fractures via OI is safe and feasible. We designed a new percutaneous retrograde screw fixation guide apparatus to assist internal fixation of posterior column acetabular fracture.

Treatment of Pilon fractures complicated with soft tissue injury by plate and lag screw fixation via posterolateral approach

To evaluate the clinical effects of plate and lag screw fixation for treatment of Pilon fractures complicated with soft tissue injury via posterolateral approach. From May 2013 to June 2016, 25 patients with Pilon fractures complicated with soft tissue injury underwent open reduction and internal fixation via posterolateral approach. There were 15 males and 10 females, aged from 25 to 61 years old with an average of(39.6±0.2) years. Plate and lag screw fixation were used in operation. Healing of soft tissue contusion and abrasions in the ankle wounds and injuries were observed after operation. The Burwell-Charnley standard was applied to assess the quality of fracture reduction and the AOFAS Ankle foot scoring system(total score 100 points) was used to evaluate the clinical effects. All the patients were followed up from 6 to 24 months with an average of 12 months. All operative wounds and soft tissue injuries were healed. According to the Burwell-Charnley standard, 22 cases obtained excellent results with anatomic reduction, while 2 cases were dissatisfied, and 1 case poor. The AOFAS ankle foot scores were 90.2±7.5 on average, with 20 cases of excellent results, 3 good, 2 fair. Plate and lag screw fixation by posterolateral approach in treating Pilon fracture complicated with soft tissue injury shows advantage of avoiding injury to the anteromedial skin and soft tissue, provides forceful fixation without further injury.

Hallux MTP Arthrodesis for Treatment of Severe Hallux Valgus Using a Dorsal Locking Plate

Category: Bunion Introduction/Purpose: First metatarsophalangeal (MTP) joint arthrodesis is widely accepted as a treatment option for severe hallux valgus deformities. Although successful results of first MTP joint arthrodesis for hallux valgus have been reported in previous studies, the reported rates of fusion have been lower than for the general hallux rigidus population. The purpose of this study was to demonstrate the failure rate of first MTP joint arthrodesis for severe hallux valgus deformities and to evaluate radiographic correction of hallux valgus parameters after the surgery. Methods: From January 2014 to June 2017, 34 patients underwent first MTP joint arthrodesis surgery for severe hallux valgus deformity and were included in this retrospective study. Severe hallux valgus was defined as having a hallux valgus angle (HVA) of greater than 40 degrees and an intermetatarsal angle (IMA) greater than 15 degrees. For radiographic evaluation, the patients were evaluated by measuring the IMA and HVA in preoperative and postoperative weight-bearing AP foot x-rays. We defined failure after first MTP joint arthrodesis as non-union, incomplete union, or implant breakage or migration leading to a symptomatic recurrence of hallux valgus deformity. Results: The mean preoperative IMA and HVA were 16.7 ± 4.2 degrees (range 8.4 to 26.5) and 45.2 ± 8.6 degrees (range 28.7 to 71.1) respectively, and the postoperative IMA and HVA were 11.3 ± 3.8 degrees (range 4.1 to 20.4) and 20.9 ± 11.8 degrees (range 0.4 to 51.1) respectively. The postoperative IMA and HVA were significantly improved after surgery (< 0.001). Among the 34 patients in this study, a 14.7% failure rate was reported (n=5). For fusion procedures performed without lag screw fixation, there was a 12.6-fold increase in failure risk when we used the small dorsal locking plate compared with the medium dorsal locking plate (Odds ratio = 12.571). Conclusion: First MTP joint arthrodesis is an effective and reliable option for severe hallux valgus correction. However, for this challenging cohort, the 14.7% failure rate in this study is consistent with other studies in the literature. For severe hallux valgus deformities, selection of implant may play a more significant role. The use of longer plates to gain additional purchase in the diaphyseal bone, lag screw augmentation, and utilizing flat cuts instead of cup and cone reaming to realign the joint may help mitigate the increased stresses placed on the fixation constructs for MTP arthrodesis.

Sacroiliac luxation in small animals: treatment options

The term sacroiliac luxation-fracture (SIL/F) denotes traumatic separation of the ilial wing from the sacrum. This injury typically results from a traumatic event (most commonly a road traffic accident) and consequently is often seen with concomitant pelvic and/or other orthopaedic injuries. When indicated, the method of choice for SIL/F repair is lag screw fixation, which can be achieved via open reduction and internal fixation or minimally invasive osteosynthesis. The prognosis is in part affected by proper orientation of the iliosacral screw and adequate screw purchase into the sacral body. While conservative management may yield good outcomes, pain associated with nerve damage as well as chronic instability of the SIL, along with concomitant orthopedic and soft tissue injuries, should be thoroughly considered when choosing this option.

Single versus double column fixation in transverse fractures of the acetabulum: A randomised controlled trial

IntroductionBiomechanical studies have compared fixation methods in transverse acetabular fractures, yet there is not enough clinical data to suggest an optimal fixation method. The aim of this randomized controlled trail was to compare fracture stability in posterior plating alone versus posterior plating and anterior column lag-screw fixation in treatment of transverse and transverse with posterior wall acetabular fractures. MethodsThirty patients were randomized to one of two groups, either posterior fixation alone (single column group), or posterior plating and anterior fixation with percutaneous anterior column screw (double column group). Patients were followed up with serial radiographic assessments documenting any loss of reduction, utilizing Matta’s radiological criteria, measuring the roof arc angles and by measuring any change in the femoral head offset. ResultsFifteen patients were randomized to each group. Mean patient age was 31 years, mean follow up period was 19 months (range 12–24). There was no significant differences between the two groups with regards the quality of post-operative reduction, blood loss, hospital stay and functional score using the modified Merle D'Aubinge and Postel score. The operative time was significantly longer in the double column fixation group (130 min versus 104 min). There was no loss of reduction observed in either of the two groups. ConclusionSingle poster column fixation in transverse and transverse posterior wall fractures showed similar result to double column fixation, in terms of fractures stability in the follow up period, quality of reduction and early functional outcome.

Does lag screw fixation of condylar fractures result in adequate stability? A finite element analysis

The great incidence and controversies related to the diagnosis, treatment, surgical accesses, and type of osteosynthesis materials confer an outstanding role to condylar fractures among facial fractures. Plate configurations, with diverse formats and sizes, may be used to surgically resolve condylar fractures. With the purpose of improving the advantages and minimizing the disadvantages of fixation techniques, the neck screw was developed aiming at the needed stabilization to render a correct fixation through a system of dynamic compression. This is achieved by increasing the contact between the fractured bone stumps, as well as assisting at the time of fracture reduction. The present paper aims at comparing the fixation and stability of mandibular condylar fractures using the neck screw and an overlaid “L”-shaped-4-hole-2 mm plate on the one hand, with a system in which the neck screw and the “L”-shaped plate form a single structure, having been joined by a welded point, on the other hand. The results with the neck screw are satisfactory, and, thus, it is an alternative for the reduction and fixation of fractures of the mandibular condyle, whether or not a plate is joined to the structure, provided it is correctly prescribed and with adequate surgical sequence and technique.

A practical 'safe zone' technique for lag screw fixation of the fibula.

Introduction During ankle fracture fixation, iatrogenic trauma to retro fibula structures can result in morbidity and reoperation. We describe a safe zone for lag screw insertion. Materials and methods This study was completed in three sections. We identified the average entry and exit points for the lag screw using 45 Weber B ankle fractures identified from our trauma database. We then analysed 26 sequentially presented ankle magnetic resonance images, concentrating on axial sections at 4, 8, 12 and 16 mm above the ankle joint. Finally, we used 63 sequentially performed magnetic resonance scans to confirm the safe zone from these consistent structures. Results The typical lag screw exit point was 14.2 mm above the ankle joint (95% confidence Interval 11.3-17.1 mm). A safe zone trajectory occurred between 31 and 45 degrees taken from the anterior aspect of the flat fibular surface at this level. The obvious palpable landmark to direct screw trajectory and avoid 'at risk' structures was found to be the medial edge of the Achilles tendon. Our final dataset confirmed in 63 scans, the medial aspect of the Achilles tendon to be a consistent safe zone with a minimum distance of at risk structures of 4 mm. Conclusion This simple method of directing the fibula lag screw towards the palpable medial edge of the Achilles tendon is practical, easy to teach and directs the screw on a safe trajectory away from the most commonly injured structures around the back of the fibula.

Effect of Ankle Position on Tibiotalar Motion With Screw Fixation of the Distal Tibiofibular Syndesmosis in a Fracture Model.

Anatomic reduction and fixation of the syndesmosis in traumatic injuries is paramount in restoring function of the tibiotalar joint. While overcompression is a potential error, recent work has called into question whether ankle position during fixation really matters in this regard. Our study aimed to corroborate more recent findings using a fracture model that, to our knowledge, has not been previously tested. Twenty cadaver leg specimens were obtained and prepared. Each was tested for tibiotalar motion under various conditions: intact syndesmosis, intact syndesmosis with lag screw compression, pronation external rotation type 4 (PER-4) ankle fracture with syndesmotic disruption, and single-screw syndesmotic fixation followed by plate and screw fracture and syndesmotic screw fixation. In each situation, the ankle was held in alternating plantarflexion and dorsiflexion when inserting the syndesmotic screw with the subsequent amount of maximal dorsiflexion being recorded following hand-tight lag screw fixation. While ankle range of motion increased significantly with creation of the PER-4 injury, under no condition was there a statistically significant change in maximal dorsiflexion angle. Ankle position during distal tibiofibular syndesmosis fixation did not limit dorsiflexion of the ankle joint. Our findings suggest that maximal dorsiflexion during syndesmotic screw fixation may not be necessary.

Pre-course cognitive training using a smartphone application in orthopaedic intern surgical skills “boot camps”

BackgroundWe evaluated a cognitive task analysis–based application, Touch Surgery. MethodsOrthopaedic surgery interns completed a simulated ankle open reduction and internal fixation and a lag screw fixation before starting the boot camp. Surveys were administered before the simulation and after the boot camp. ResultsFourteen of 19 interns completed the study. Ten interns thought the application improved their baseline understanding. Nine thought the application accelerated the learning process. Eight thought the application made the procedures easier to learn. ConclusionsTouch Surgery enhanced the surgical skills curriculum, was well-received, and has the potential to supplement training of interns.

Surgical repair of propagating condylar fractures of the third metacarpal/metatarsal bones with cortical screws placed in lag fashion in 26 racehorses (2007-2015).

Despite the recommendation of plate fixation for propagating condylar fractures of the third metacarpal (McIII) or third metatarsal bone (MtIII), lag screw fixation can be a viable surgical option. To evaluate short-term outcome and long-term racing performance of horses that underwent lag screw fixation of long condylar fractures of the McIII/MtIII. Retrospective case series. Medical records, post-surgical racing performance and outcome of 26 horses with propagating fractures of the medial and/or lateral condyle of McIII/MtIII were reviewed. Medical information included were age, breed, sex, physical examination at admission, circumstances of fracture, radiographic evaluation, anaesthesia and recovery records, surgical and post-operative management, as well as complications. Outcome included racing data and information from telephone interviews. Twenty-six horses (9 Standardbreds and 17 Thoroughbreds) were admitted with a long condylar fracture of the McIII/MtIII. Fore- and hindlimbs were equally represented with the left hindlimb being more frequently involved. Most of the fractures had a spiralling component (76%) and four (15%) were comminuted. Fifteen (58%) horses raced post-surgery including nine Standardbreds (100%) and six Thoroughbreds (35%). Twelve of them were placed in at least one race and 11 won at least once. One horse sustained a severe complication in recovery. No significant difference was observed in the racing performances before and after surgery. Follow-up method and duration were not standardised and there is a low number of cases with six surgeons. Long condylar fractures can be repaired using lag fashion technique combined with a half-limb or full-limb tight cast for recovery as a good surgical alternative. Similar results to plate fixation can be expected, with a return to racing of more than 50%, and the prognosis being even better for pacers.

Minimally invasive lag screw fixation of sacroiliac luxation/fracture using a dedicated novel instrument system: Apparatus and technique description.

To describe a novel Sacroiliac Luxation Instrument System (SILIS™) and its application in minimally invasive osteosynthesis (MIO) of sacroiliac luxations/fractures (SIL/F). The SILIS was designed to provide stable SIL/F reduction and accurate sacral screw placement while reducing personnel exposure to ionizing radiation during intraoperative fluoroscopy. Descriptive, proof of concept cadaveric study. A right SIL and a left SIL/F were created on a Labrador Retriever that had died of natural causes. Bilateral sacroiliac lag screw fixation was performed under fluoroscopic guidance with the SILIS, which consists of dedicated reduction and fixation instruments rigidly linked to table-bound 6-axis arms. Throughout surgery, the SILIS facilitated and maintained stable reduction and allowed accurate placement of a custom designed drill guide over the sacral body without the surgeon's manual holding of any reduction or fixation instruments. The surgical team was therefore able to step away from the C-arm when acquiring fluoroscopic images, thus reducing exposure to radiation. Dorsoventral and craniocaudal screw deviation from an ideal trajectory ranged from 0.9° to 3.8°. Both screws were fully located within the sacral body. The SILIS addresses limitations associated with MIO of SIL/F, including maintenance of reduction throughout surgery along with reliable and accurate sacral screw placement. Distance from the X-ray source is the most effective protection against radiation. Use of the SILIS allows the surgical team to move away from the C-arm during fluoroscopy, thereby reducing personnel exposure to dangerous direct and back-scattered ionizing radiation.

Linical application of personalized 3D printing-guided template of intramedullary lag screw insertion on lateral superior ramous of pubic

To evaluate the efficacy and advantages of personalized 3D printing-guided template of lateral superior ramous of pubic intramedullary lag screw. From July 2015 to December 2016, 20 patients with the superior and inferior ramous of pubis fracture were treated with lag screws placement. All the patients were divided into test group(with guided template) and control group(with general operation). There were 7 males and 3 females with an average age of (46.20±3.03) years old in test group and 6 males and 4 males with (48.50±2.25) years old in control group. There were 6 cases and 5 cases of superior and inferior branches fractures of pubic on the left side and 4 cases and 5 cases on the right side in two groups respectively. The operation time, perspective times and bleeding loss were compared between two groups. The test group and the control group had no statistically significant relative to gender, age, fracture classification. The average time of surgery, average intraoperative fluoroscopy times, mean blood loss in test group were (31.0±5.3) min, (3.5±2.1) times, (75.6±10.5) ml respectively, and in control group were(55.0±6.8) min, (27.6±3.2) times, (85.5±12.5) ml respectively. There were significant Statistical differences between two groups(P<0.05) in average operation time and average fluoroscopy times, however, mean blood loss had no significant differences between two groups(P>0.05). The personalized guide template based on 3D printing technology could realize precise placement of the lateral intramedullary lag screw fixation in the superior branch of pubic, also could save the operation time and reduce the times of radiation exposure of patients and surgeons.

Outcomes of First Metatarsophalangeal Joint Fusion in Patients with Greater Than Fifteen Percent Intermetatarsal Angle. Is Lag Screw Essential?

Category: Midfoot/Forefoot Introduction/Purpose: Metatarsophalangeal arthrodesis has usually been performed using a dorsal plate to immobilize the MTP joint with or without lag screw fixation. Data in the literature is sparse on outcomes of dorsal plate plus lag screw fixation, especially in patients with IMA greater than 15 percent. Our objective was to compare IMA correction outcomes and union rates between dorsal plate only fusions and dorsal plate plus lag screw fixation in patients with IMA greater than 15 percent. Methods: We retrospectively reviewed the charts of 36 patients (39 feet) who underwent first MTP joint arthrodesis for moderate to severe HV deformity between 2011 and 2015. Average age was 61 (range, 39 to 84) years. There were 24 females and 12 males. A single surgeon performed all operations. Joints were immobilized postoperatively using either dorsal locking plate alone or dorsal locking plate with a lag screw. Union (at least 3 bridging cortices) was determined radiographically at 6 weeks, 3 months, 6 months and yearly. All suspect nonunions were examined with CT. Other radiographic parameters examined included preoperative and postoperative hallux valgus, intermetatarsal, and dorsiflexion angles (HVA, IMA, and DFA respectively). Student’s t test was used to compare group means while Pearson’s Chi square test was used to compare group rates. Results: Overall union rate was 82.1% (32/39). There was no significant difference in union rates between the two groups (dorsal plate only = 81.5% (22/27), dorsal plate plus lag screw group = 83.3% (10/12)) (P &gt; 0.05). Average follow-up was 9 (range 7 to 35) months. Overall, the average IMA correction was 4.7 (preoperative = 17.8, postoperative = 13.1) degrees. Average IMA corrections were 4.7 and 4.54 degrees in the dorsal plate only group and dorsal plate plus lag screw groups respectively. Overall, average HVA correction was 21 (preoperative = 39.5, postoperative = 18.5) degrees. Conclusion: Our findings indicate that there is no difference in the fusion rates between both patient groups with IMA greater than fifteen percent. Because other published studies have a wide range of IMAs preoperatively, our study represents more attainable goals in patients with severe (IMA greater than 15%) deformities. In addition, our findings suggest that in such patients, MTP arthrodesis may not be sufficient as a standalone procedure for correction of IMA. Additional proximal osteotomy may be required for correction of the IMA.

Novel Technique for Fixation of Medial Malleolus Fractures

Category: Ankle, Trauma Introduction/Purpose: The traditional method for fixation of medial malleolar fractures has been with partially threaded (PT) lag screws extending beyond the physeal scar. Recent studies have shown fully threaded (FT) bicortical fixation in the tibial metaphysis provides superior biomechanical, radiographic and clinical outcomes. Risks with the bicortical technique include drill bit breakage, as well as injury to structures lateral to the tibial metaphysis if the far cortex is overdrilled. We hypothesized that far endosteal fixation, without penetration of the far cortex, would provide increased biomechanical strength compared to traditional PT lag screw fixation, while minimizing the risks associated with bicortical fixation. Methods: Twelve matched pairs of cadaver ankles were harvested and an oscillating saw was used to make an osteotomy at a 45- degree angle to the axilla. The medial malleolus was then re-approximated and held in the correct orientation using two kirschner wires. A 2.7 mm drill bit was used to drill a unicortical pilot hole perpendicular to the osteotomy. The left ankle was used for all PT 3.5 mm cancellous screws and all screw lengths were 45 mm. For the contralateral ankle, the 2.7 mm drill bit was used to drill to the lateral tibial cortex. The depth gauge was then used and five millimeters was added to the measured number to achieve endosteal purchase with the appropriate FT screw. Screw lengths varied in size from 55-70 mm. Screws were then placed using a torque measuring screw driver and final torque was recorded. Finally, radiographs were taken to confirm appropriate placement. Results: Average torque for unicortical PT cancellous screws was 5.02 inch-pounds with a standard deviation of 2.34. Average torque for all FT cortical screws was 7.63 inch-pounds with a standard deviation of 3.86 (Fig. 1A). A paired student’s t-test was performed comparing both fixation methods and the measured P-value was &lt;0.01. Visual and radiographic inspection revealed no displacement of the fracture site using the FT endosteal screw (Fig. 1C). Conclusion: Our results indicate superior biomechanical torque with far endosteal fixation as compared to a traditional PT lag screw, while minimizing risks associated with bicortical fixation. This novel technique may provide added strength with minimal risk in vivo. Further clinical studies comparing radiographic results and outcomes of far endosteal fixation versus bicortical fixation are needed to ascertain the value of this fixation technique for medial malleolus fractures.

Locked Dorsal Compression Plate Arthrodesis for Degenerative Arthritis of the Midfoot

Category: Midfoot/Forefoot Introduction/Purpose: Midfoot arthrodesis remains a technical challenge. Little is known of the required magnitude of compression in order to obtain fusion. Multiple techniques have been reported, reflecting the difficulty of achieving a good result. These methods include an in situ bone graft dowel technique, dorsal staple, Kirschner wire, trans articular lag screw, and screw and plate fixation. More recently, dorsal hybrid plating, and slot graft inlay arthrodesis have been described. The purpose of this study is to describe the results of a dorsal fixed-angle locking compression plate in the setting of multiple-joint midfoot arthrodeses. Methods: A retrospective study was performed to identify 62 consecutive patients who underwent midfoot arthrodeses from June 2009 to May 2016. A total of 184 joints were spanned by dorsal fixed angle locking compression plates. The medical risk factors, etiology of arthritis, body mass index, time to union, visual analog pain scores (recorded preoperatively and postoperatively), and post-operative complications were evaluated. Patients were followed for one year. Radiographs were read by two fellowship-trained surgeons to determine the time to fusion. If union was indeterminate, a computed tomography scan was obtained, with the presence of 50% or greater bridging bone as the definition of fusion. Results: Of the joints spanned, 156 fused (83%). The average time to fusion was 19.6 weeks (Standard Deviation 21 weeks). Complications included persistent numbness (10), wound infection (2), and deep venous thrombus (1). The average VAS score diminished from 5.9 preoperatively, to 1.7 at week 6, 1.9 at week 12, 2.6 at month 6, and 3.1 at one year. Conclusion: Despite the difficulty of midfoot arthrodesis procedures in obtaining solid fusion, the dorsal fixed angle locking compression plate demonstrates a union rate, time to fusion, and complication rate that is comparable with the existing literature. The results of this study also indicate room for improvement in the design of advanced plating systems, which could incorporate more uniform joint compression combined with biologic augmentation in the hope of achieving improved radiographic and clinical results.