Screw Penetration Research Articles

Assessment of penetration of dorsal screws after fixation of the distal radius using ultrasound: cadaveric study.

Volar locking plates are used to treat unstable and displaced fractures of the distal radius. Potential advantages of stable anatomical reduction (eg early mobilisation) can be limited by penetration of dorsal screws, leading to synovitis and potential rupture of extensor tendons. Despite intraoperative imaging, penetration of dorsal screws continues to be a problem in volar plating of the distal radius. Ultrasound is a well recognised, readily available, diagnostic tool used to assess soft-tissue impingement by orthopaedic hardware. In this cadaveric study, we wished to ascertain the sensitivity and specificity of ultrasound for identification of protrusion of dorsal screws after volar plating of the distal radius. Four adult, unpaired phenol-embalmed cadaveric distal radii were used. A VariAx™ Distal Radius Volar Locking Plate system (Stryker, Kalamazoo, MI, USA) was employed for instrumented fixation. A portable SIUI CTS 900 ultrasound machine (Providian Medical, Eastlake, OH, USA) was used to image the dorsal cortex to ascertain screw penetration. Specificity and sensitivity of ultrasound for detection of screw protrusion through the dorsal cortex was 100%. Ultrasound was found to be a safe and accurate method for assessment of dorsal-screw penetration through the dorsal cortex of the radius after volar plating of the distal radius. It also aids diagnosis of associated tendon disorders (eg tenosynovitis) that might cause pain and limit wrist function.

Assessment of Intra-articular Screw Penetration During Radial Head and Olecranon Locking Plate Fixation

The purpose of this study is to evaluate the role of radiographic and clinical exams in predicting screw penetration into the proximal radioulnar joint and ulnohumeral joint during open reduction and internal fixation of the radial head and proximal ulna. Olecranon and radial head plates were applied to 15 cadaveric elbows. Screws were assessed for intra-articular joint penetration using both clinical exam and radiographic evaluation. Clinical exam consisted of evaluation for crepitus. Radiographs demonstrating screws positioned near the joint surface were evaluated for penetration by 3 fellowship trained hand surgeons. Elbows were disarticulated and screw prominence was determined and recorded using standardized calipers. The ability of clinical and radiographic exams to correctly predict a breach in the articular surface was determined by calculating sensitivity, specificity, and predictive values. Consideration was given to screw position. The sensitivity of crepitus was 81.1% for screws in the radial head plate and 72.6% for screws in the olecranon plate. The sensitivity of radiographs was 72.4% for the screws in the radial head plate and 55.0% for screws in the olecranon plate. Correct radiographic assessment of penetration varied but position o-2 on the olecranon plate consistently resulted in the lowest sensitivity of 30.3%. The study evaluates sensitivity and specificity of clinical and radiographic means when assessing for articular penetration of screws during olecranon and radial head locking plate fixation. Certain screw locations are more difficult to evaluate than others and may go undetected by standard means of assessment used in a surgical setting.

Femoral Condyles Tangential Views: An Effective Method to Detect the Screw Penetration of Femoral Condyles After Retrograde Nailing.

Background:Postoperative knee soft tissue irritation is a common complication after retrograde nail fixation of femoral fractures. Distal locking screw prominence is one of the causes for soft tissue irritation. This study aimed to determine whether the use of the femoral condyles tangential views improve the diagnostic accuracy compared with anteroposterior (A-P) view in detecting distal locking screw penetrations during retrograde femoral nailing.Methods:The angle between the sagittal plane and lateral aspect of the condyle and the angle between the sagittal plane and medial aspect of condyle were measured on computed tomography (CT) images. After the angles were measured and recorded, cadaveric femurs were used in a simulated surgical procedure. The retrograde femoral nail was inserted into the femur and placed distal locking screws, which were left 2, 4, and 6 mm proud of the medial and lateral condyles for each femur. A-P view, lateral condyle tangential view and medial condyle tangential view were obtained. All fluoroscopic images were recorded and sent to three observers blinded to the experimental procedure to determine whether screws penetrated the condyle cortex or not.Results:According to the results of CT scan, the lateral condyle view was 20.88 ± 0.98° and the medial condyle view was 40.46 ± 3.14°. In the A-P view, we detected 0% at 2 mm penetration, 16.7% (lateral condyle screw) and 25.0% (medial condyle screw) at 4 mm, and 41.7% (lateral condyle screw) and 58.3% (medial condyle screw) at 6 mm. In the lateral tangential view, we detected 91.7% at 2 mm penetration of the lateral condyle and 100% at 4 mm and 6 mm. In the medial tangential view, we detected 66.7% at 2 mm penetration of the medial condyle and 100% at 4 mm and 6 mm. The femoral condyle tangential views provided significant improvement in detecting screw penetrations at all lengths (2, 4, and 6 mm) compared with the A-P view (P < 0.05).Conclusions:The femoral condyles tangential views increased the accuracy of detecting screw penetrations on the medial and lateral condyles. Routine clinical use of the femoral condyles tangential views has the potential to increase accuracy in detecting distal locking screw penetration during retrograde femoral nailing.

Surgical treatment of proximal humerus fractures using PHILOS plate

ObjectiveTo evaluate functional outcome and complications of open reduction and internal fixation with proximal humeral internal locking system (PHILOS) plate for proximal humerus fractures. MethodsWe reviewed 51 patients who underwent open reduction and internal fixation with PHILOS plate between the years 2007 to 2012. There were 35 men and 16 women with a mean age of 38years (range 24-68). There were 41 patients in the age group of <60years and 10 patients in the age group of >60years. According to Neer classification system, 8, 15 and 23 patients had 2-part, 3-part, and 4-part fractures, respectively and 5 patients had 4-part fracture dislocation. All surgeries were carried out at our tertiary care trauma centre. Functional evaluation of the shoulder at final follow-up was done using Constant-Murley score. ResultsThe mean follow-up period was 30months (range 12-44 months). Two patients were lost to follow-up. Of the remaining 49 patients, all fractures were united clinically and radiologically. The mean time for radiological union was 12weeks (range 8-20 weeks). At the final follow-up the mean Constant-Murley score was 79 (range 50-100). The results were excellent in 25 patients, good in 13 patients, fair in 6 patients and poor in 5 patients. During the follow-up, four cases of varus malunion, one case of subacromial impingement, one case of deep infection, one case of intraarticular screw penetration and one case of failure of fixation were noted. No cases of avascular necrosis, hardware failure, locking screw loosening or nonunion were noted. ConclusionPHILOS provides stable fixation in proximal humerus fractures. To prevent potential complications like avascular necrosis, meticulous surgical dissection to preserve vascularity of humeral head is necessary.

Dorsal Screw Penetration With the Use of Volar Plating of Distal Radius Fractures

To evaluate the most vulnerable position at which volar plate screws may penetrate the dorsal cortex of the radius and to determine which specific intraoperative fluoroscopic images (lateral, 45 degrees supination, 45 degrees pronation, and dorsal tangential) are most useful to detect dorsal cortex penetration. Four 2.5-mm locking screws were inserted distally using 18-, 20-, or 22-mm screws in 7 cadaveric specimens apiece. The specimens were then evaluated to count the number of screws breaching the dorsal cortex and the amount of penetration. Lateral, 45 degrees supination, 45 degrees pronation, and dorsal tangential fluoroscopic views were taken of each wrist. Sixty-three orthopaedic surgeons of varying experience were then asked to evaluate whether the screws penetrated the dorsal cortex after viewing each image. Dorsal cortex screw penetration of at least 1 screw occurred in 3.6% of specimens with 18-mm screws, 25% of specimens with 20-mm screws, and 57% specimens with 22-mm screws. Radial-sided screws more commonly breached the dorsal cortex. The sensitivity was 58% on the lateral view, 88% on the 45 degrees supination view, 53% on the 45 degrees pronation view, and 67% on the dorsal tangential view. Additionally, surgeons with more experience were less accurate in detecting prominent screws. Clinicians should consider use of these views to evaluate dorsal screw penetration after volar plating but may opt to subtract a few millimeters from their measured screw lengths to avoid over penetration past the dorsal cortex.

Isolated pediatric radial head and neck fractures. A rare injury. Analysis and follow up of 19 patients

PurposeIsolated pediatric radial head and neck fractures are rare. In recent literature, their incidence is estimated to be around 1% of all fractures. High rates of complications are reported.Beside non-operative treatment, head fractures are treated with k-wires, mini-screws or polypins, whereas neck fractures are treated more and more with elastic stable intramedullary nailing (ESIN). Purpose of the study was to evaluate the operative management, complications and clinical outcomes of these injuries. MethodsRetrospective analysis between 2002 and 2014. 19 children with isolated radial head and neck fractures were treated in our institution. Age averaged 11 years (range 6–16). Operative treatment with elastic stable intramedullary nailing (ESIN) was performed in 13 patients, in one patient with an additional k-wire; two screw, two k-wire and one polypin fixation was performed in the others. One child was treated non-operatively. ResultsFollow up averaged 19 months (2–89). Initial complications occurred in nine children such as fracture dislocation (1), nonunion (1), malunion (1), elbow ankylosis (1), infection (1), crossunion (2), intraarticular screw penetration (1) and radial nerve irritation (1). ESIN lead a complication rate of 36%, mini-screw fixation and k-wire fixation showed a complication rate of 100%. All children (100%) with an open reduction maneuver and 36% children with closed or percutaneous reduction developed a complication. Secondary surgeries included ESIN removal and k-wire fixation (1), open arthrolysis (1), debridement (1), removal of crossunion (1), radial head removal plus arthrolysis (3) and screw removal (1). Subsequently 74% (14) children showed a free or <20° limited range of motion on final follow up. Implant removal was performed after an average of 8 weeks (5–12). Three patients were transferred to our surgical department after a complication following initial treatment. Excluding these, an overall complication rate of 37.5% was noted. ConclusionsRadial head injuries in children are rare. In this population, neck fractures occur more frequently. If conservative treatment is not possible, ESIN seems to be a simple and protective procedure for neck fractures; polypins or screws can be used for complicated radial head fractures. Complications occur frequently after open reduction. If closed reduction and internal fixation is possible, range of motion can be completely restored.

Medial malleolus screws: out in one view and out

Cartilage damage or mechanical blocking from screw penetration into intra-articular cartilage can reduce the chances of successful outcomes during medial malleolus fixation. There have been diverging opinions among surgeons concerning the reliability of radiographic assessment of fracture fixation and malleolus screw positioning. Therefore, this radiographic study examines the location of medial malleolus lag screws relative to the ankle mortise articular surface. In three Sawbones models, Kirschner wires were overdrilled with a 4.0-mm cannulated cortical screw simulating screws that would be intra- and extra-articular when performing open reduction and internal fixation of a medial malleolar fracture. Under fluoroscopy, images were evaluated to determine whether known intra-articular screws appeared extra-articular in any radiographic view. No image from models with known intra-articular penetration appeared extra-articular in any view or under "live" fluoroscopy. At 20° internal rotation, a screw with a known extra-articular position appeared to be within the cartilage. Intra-operative fluoroscopy is necessary to ensure proper extra-articular placement of screws. If a screw is pictured extra-articular in any radiograph, then it can be assumed that the screw is indeed out of the joint.

Avoiding complication of volar locked plates

Volar locking plates are designed to improve and maintain anatomic alignment, even in patients with dorsal comminution and poor metaphyseal bone quality. Its widespread use led to specific complications. Most part is related to tendon, nerve and complex regional pain syndrome [1] and could be avoided by meticulous attention to detail and surgical experience [2]. Tendon and articular injury complications can be prevented by careful avoidance of dorsal cortex and intraarticular screw penetration, use of the low profile plates, and careful placement of the plate proximal to the watershed line. Most frequent tendons affected are Extensor Policis Longus (EPL) and Flexor Policis Longus (FPL). EPL tendon rupture can occur after a distal radius fractures even when not fixed by a plate [3]. Use of standard intraoperative fluoroscopy imaging is crucial to assess dorsal cortex screw penetration. Lister tubercle can mask prominent screws tips and lateral images have limited sensibility particularly among less experienced observers and for the evaluation of the most ulnar screw positions [4]. Irritation or rupture of flexor tendons, especially the FPL, depends on the position of the plate [5]. Assessment of articular penetration of the screws is critical. Routine use of articular views [6], as well as a 45° pronated oblique view [7] in doubtful cases, is mandatory during placement of each screw. Postoperative nerve dysfunction is one of the most common complications, especially median nerve dysfunction [1]. K-wires used for provisional and supplementary fixation can be a source of complications. Such complication may be caused by superficial radial nerve irritation due to K-wire placement during fracture reduction. Finally, loss of reduction due to inadequate screw length or very osteoporotic bone may lead to symptomatic malunion. In extra-articular fractures, a minimum of four locked unicortical distal screws [8] of at least 75% length produce construct stiffness similar to bicortical fixation and should be considered to avoid extensor tendon injury [9]. This is not the case when there are dorsal unstable articular fragments that can displace afterwards. Once the fracture is healed, plates and screws are not necessary anymore and their removal can be indicated or suggested as a prophylactic measure, as this procedure is usually not associated with complications [10].

Does intraoperative navigation improve the accuracy of pedicle screw placement in the apical region of dystrophic scoliosis secondary to neurofibromatosis type I: comparison between O-arm navigation and free-hand technique.

To assess the accuracy of O-arm-navigation-based pedicle screw insertion in dystrophic scoliosis secondary to NF-1 and compare it with free-hand pedicle screw insertion technique. 32 patients with dystrophic NF-1-associated scoliosis were divided into two groups. A total of 92 pedicle screws were implanted in apical region (two vertebrae above and below the apex each) in 13 patients using O-arm-based navigation (O-arm group), and 121 screws were implanted in 19 patients using free-hand technique (free-hand group). The postoperative CT images were reviewed and analyzed for pedicle violation. The screw penetration was divided into four grades: grade 0 (ideal placement), grade 1 (penetration <2mm), grade 2 (penetration between 2 and 4mm), and grade 3 (penetration >4mm). The accuracy rate of pedicle screw placement (grade 0, 1) was significantly higher in the O-arm group (79%, 73/92) compared to 67% (81/121) of the free-hand group (P=0.045). Meanwhile, a significantly lower prevalence of grade 2-3 perforation was observed in the O-arm group (21 vs. 33%, P<0.05), and the incidence of medial perforation was significantly minimized by using O-arm navigation compared to free-hand technique (2 vs. 15%, P<0.01). Moreover, the implant density in apical region was significantly elevated by using O-arm navigation (58 vs. 42%, P<0.001). We reported 79% accuracy of O-arm-based pedicle screw placement in dystrophic NF-1-associated scoliosis. O-arm navigation system does facilitate pedicle screw insertion in dystrophic NF-1-associated scoliosis, demonstrating superiorities in the safety and accuracy of pedicle screw placement in comparison with free-hand technique.

Accuracy of Pedicle Screw Placement in Dystrophic Neurofibromatosis Scoliosis: A Comparison between Free-Hand and 3D O-Arm Navigation Technique

Introduction Recently, the importance of intraoperative navigation in scoliosis surgery has been increasing. Multiple studies have proven the superiorities of computer-assisted scoliosis surgery. Using intraoperative 3D images for navigational purposes has several advantages and should increase the accuracy and safety of pedicle screw placement. The purpose of the present study was to assess the accuracy of O-arm navigation-based pedicle screw insertion in dystrophic neurofibromatosis scoliosis and compare it with free-hand pedicle screw insertion technique. Patients and Methods A total of 32 patients with dystrophic neurofibromatosis scoliosis were nonrandomly included in the two groups, one consisting of O-arm navigation-based pedicle screw insertion (13 patients, Group A) and the other with free-hand technique (19 patients, Group B). A total of 213 pedicle screws were placed in apical region, 92 pedicles were inserted assisted by O-arm navigation system and the rest were inserted by free-hand technique. The postoperative CT scan image were reviewed and analyzed for pedicle violation. The screw penetration was divided into the following four grades: grade 0 (ideal placement), grade 1 (penetration &lt; 2 mm), grade 2 (penetration between 2 and 4 mm), grade 3 (penetration &gt; 4 mm). Results The mean age in group A was 14.8 years (range,11–22 years), whereas in group B was 15.3 years (range, 6–30 years). The preoperative Cobb angle of the main curve in group A was 70.3 ± 6.7 degrees compared with 62.2 ± 8.7 degrees in group B. The correction rates were comparable between group A (75.7%) and group B (78.1%), and the difference was not statistically significant ( p &gt; 0.05). The overall perforation rate was 27.7% (59/213) in all 32 patients, and group A had a perforation rate of 20.7% (19/92) in comparison to 33.1% (40/121) noted in group B ( p &lt; 0.05, χ2 test) separately. Moreover, the lateral margin was the most common site of perforation for 73.4% (14/19) in group A and 50.0% (20/40) in group B. Conclusion O-arm navigation does provide superiority over conventional free-hand technique in terms of accuracy of pedicle screw insertion in dystrophic curves associated with neurofibromatosis type 1. The lateral cortex is the most common site of screw perforation in either technique.

A binary logistic regression analysis of screw penetration after proximal humeral fracture surgery

Objective To analyze the incidence of screw penetration after surgery for proximal humeral fractures (PHF) and to explore its prognostic factors and preventive countermeasures. Methods From June 2006 to June 2012, 187 PHF patients were treated with open reduction-internal fixation with locking plates at our department. They were 78 males and 109 females, 18 to 88 years of age (average, 55.9 years). Screw penetration was identified according to the follow-up X-ray films of the patients' shoulders. In our analysis, screw penetration was taken as the dependent variable while gender, age, Neer fracture type, medial cortex fracture, bone mineral density, time interval from trauma to surgery, bone graft, reduction quality, screw number in the humeral head, and medial column support were taken as covariates. Univariate logistic regression analysis was adopted to pick up the factors with P< 0.05 which were then analyzed by multiple stepwise logistic regression. Results All the patients were followed up for a mean time of 17.8 months (from 10 to 45 months). Screw penetration happened in 27 patients (incidence, 14.4%). The univariate logistic regression analysis showed that Neer fracture type, medial cortex fracture, bone graft, reduction quality, screw number in the humeral head, and medial column support had a significant association with screw penetration (P < 0.05). The multiple stepwise logistic regression showed that there were significant differences between Neer 3-part and 2-part fractures [P = 0.028, OR =4.406,95% CI(1.176-16.515)], 4-part and 2-part fractures[P = 0.004, OR=l.799, 95% CI(l.924~31.620)] respectively. Medial cortex fracture [P = 0.008, OR = 0.287, 95% CI (0.114-0.718)] was a key factor affecting screw penetration. Conclusions Neer fracture type and medial cortex fracture may be the chief prognostic factors affecting screw penetration after surgery for PHF. The best treatment should be made on the basis of individuals to reduce the incidence of screw penetration. Key words: Shoulder fractures; Postoperative complications; Factor analysis, statistical; Regression analysis

Morphometric anatomic study and clinical significance of lunate fossa

This study aims to investigate the depth, transverse and sagittal diameters of lunate fossa which is a significant structure of the wrist in terms of reducing the risk for volar plate screws, which are administered in distal radius fractures, from penetrating into the joint. Depth, transverse and sagittal diameters of lunate fossa in 50 right and 50 left adult dried radius bones without distal tip damage were measured by using MicroscribeG2X from the MicroScribe G series. Mean lunate fossa depth: left 2.419886±0.51 mm/right 2.543052±0.78 mm, mean lunate fossa sagittal diameter: left 19.656±1.57 mm/right 18.796±1.53 mm, mean lunate fossa transverse diameter: left 11.382±0.65 mm/right 11.106±0.91 mm. There was no statistically significant difference between right and left depth values of lunate fossa (p=0.320), whereas there was statistically significant difference between right and left transverse and sagittal diameters (p=0.006, p=0.048). Measurements involving depth of lunate fossa may guide the development of new anatomic plates and decrease complications like the penetration of screw into joint whilst volar plate administrations.

A pedicle directional breaking device for posterior fixation of fracture of thoracolumbar vertebrae

Objective To evaluate the application of a self-designed pedicle directional breaking device in posterior fixation of thoracolumbar vertebral fracture. Methods From May 2009 to October 2012, 31 patients with thoracolumbar vertebral fracture were treated at our hospital. They were 11 men and 20 women, from 19 to 56 years of age (average, 42. 9 years). The fractures involved T12 in 3 cases, L1 in 11 cases, L2 in 10 cases, both T11 and T12 in 4 cases, and both T12 and L1 in 3 cases. By Denis classification, 16 cases were compression fractures and 15 burst fractures. By Frankel's classification of neural function, 2 cases were grade A, one grade B, 3 grade C, 5 grade D, and 20 grade E. The transversal diameter of the pedicle was 5 mm in 15 sides, from 4 to 5 mm in 26 sides and < 4 mm in 7 sides. A self-designed pedicle directional breaking device was used in the posterior fixation of thoracolumbar vertebral fracture for all the patients. Results The 31 patients were followed up for an average of 16. 8 months (from 12 to 28 months). No deterioration of spinal cord injury or infection happened after operation. X-ray films showed obvious restoration of vertebral height and kyphosis. Postoperative CT scans showed no penetration of the pedicle screws into fully decompressed spinal canals. The burst pedicles had a broken outer wall but an intact inner wall. The screws were mostly wrapped by pedicle bone. The injured vertebrae got healed after 3 to 6 months. No screw failure happened during follow-up. At one week postoperation, the average relative height and cobb angle of the injured vertebrae were significantly improved compared with preoperation (P 0. 05). Most of the nerve injuries were obviously recovered. Conclusions Our self-designed pedicle directional breaking device is simple, safe and effective. It provides patients with narrow pedicles with a new instrument which facilitates posterior fixation of thoracolumbar vertebral fracture. Key words: Thoracic vertebrae; Lumbar vertebrae; Fractures, bone; Breaking; Directional

English

BACKGROUND: Proximal femoral nail is commonly recommended as treatment of choice for unstable and reverse oblique intertrochanteric fracture in view of superior biomechanics and prevention of varus collapse associated with Dynamic hip screw. Although in stable fracture types DHS is still being preferred as the treatment modality of choice. Proximal femoral nail owing to better biomechanics, less complications can still be used as the method of choice in stable fracture pattern as well. The aim of this study is to evaluate the results of PFN nail in stable intertrochanteric fracture and include evaluation of the mean operative time, amount of blood loss, complications and functional status of the patient. MATERIALS AND METHODS: In this study 30 patients presented to Orthopedics Department Hamidia Hospital Bhopal with stable intertrochanteric fracture were treated with proximal femoral nail. All patients were followed up for a period of 1 year and functional outcome assessment including amount of shortening, neck-shaft angle, Harris hip score was noted. RESULTS: At the time of final follow-up, all 30 patients showed union with average Harris hip score of 86.6 (range 62-94).14 patients had excellent score, 9 patients had good score, 5 patients had fair score and 2 patients had poor outcome. Mean neck shaft angle achieved post-reduction was 131.4 degrees and at final follow-up was 128.4 degrees. Limb length discrepancy was assessed in the final follow-up with average shortening of 5 mm and 4 patients had shortening above 1.5 cm. Average blood loss was 80 ml, the mean operative time was 65 minutes. Complications were seen in 3 cases with one case of local wound infection, one of screw cut-out and one of screw penetration. CONCLUSION: With proper technique PFN gives excellent results with less blood loss and shorter incision with less soft tissue trauma are added advantages which ultimately lead to less morbidity and early mobilisation of the patient and early return to normal routine activities. Most of the complications can be avoided by proper placement of the screw and maintaining proper neck-shaft

Safe zone for placement of talar screws when fusing the ankle with an anterior plating system.

Ankle fusions fixed with anterior plates use fluoroscopic guidance to direct screws toward the subtalar joint. Special imaging views that visualize the subtalar joint are difficult to use and can be unreliable. This study evaluated whether a single lateral ankle view would provide adequate information to judge whether a screw penetrated the subtalar joint and identified strategies that would improve this technique. In 5 cadaveric ankles fixed with anterior plates, talar screws were placed up to the subtalar joint without penetration using lateral fluoroscopy to guide screw length. After dissection, the true distance from the screw tip to subchondral surface was measured. In addition, 4 readers measured the perceived distance from screw tip to subchondral surface using direct lateral, 10 degrees cephalad tilt lateral, and 10 degrees caudal tilt lateral fluoroscopic images on 2 separate occasions. Nineteen (63%) of 30 screws penetrated the subchondral bone, and screw length determined using fluoroscopy was significantly longer than screw length measured directly (29.4 ± 5.5 mm vs 27.3 ± 8.5 mm, P = .014). Measurement of screw tip to bone distance demonstrated a high level of within-reader (kappa = .871, P < .001) and between-reader agreement (kappa = .807, P < .001), but poor specificity of determining screw penetration (0.50, χ(2) = 22.1, P < .001) and poor correlation between radiographically measured and actual distances between screw tip and bone margin (r = .35, P < .001). Tilting the c-arm 10 degrees cephalad and directing screws toward the posterior facet improved the ability to detect screw penetration and directing screws toward the middle facet diminished it (P < .05). A safe zone of screw placement was defined by region. Use of a lateral fluoroscopic image to guide talar screw placement may lead to an unacceptably high rate of subtalar joint penetration. Understanding the limitations of lateral fluoroscopy when using anterior ankle fusion plates may minimize screw penetration into the subtalar joint and diminish development of subtalar arthropathy.

Reverse shoulder arthroplasty for the management of proximal humerus fractures.

The use of reverse shoulder arthroplasty is becoming increasingly popular for the treatment of complex three- and four-part proximal humerus fractures in the elderly compared with the often unpredictable and poor outcomes provided by open reduction and internal fixation and by hemiarthroplasty. Inferior results with plate osteosynthesis are often a result of complications of humeral head osteonecrosis, loss of fixation, and screw penetration through the humeral head, whereas major concerns with hemiarthroplasty are tuberosity resorption, malunion, and nonunion resulting in pseudoparalysis. Comparative studies support the use of reverse shoulder arthroplasty in elderly patients with complex proximal humerus fractures because the functional outcomes and relief of pain are reliably improved. Repair and union of the greater tuberosity fragment during reverse shoulder arthroplasty demonstrates improved external rotation, clinical outcomes, and patient satisfaction compared with outcomes after tuberosity resection, nonunion, or resorption. Satisfactory results can be obtained with careful preoperative planning and attention to technical details.

The role of fracture reduction and plate position in the aetiology of flexor pollicis longus tendon rupture after volar plate fixation of distal radius fractures.

Flexor pollicis longus (FPL) rupture has been described as complication following volar plating for distal radius fractures. It has been hypothesised that this is due to plate prominence. The aim of the study was to investigate the relationship between sub-optimal plate position and fracture reduction on plate prominence. Plate prominence was measured in two experimental models. In the first, the effect of plate position was investigated using 18 fresh frozen cadavers with prominence being measured using a micrometer. In the second study, the effect of fracture reduction on plate prominence was investigated using similar methodology with simulated mal-reductions on dry bone models. The results of the first study showed a significant increase in lift-off for three plates (DVR, Synthes Universal and Acu-Loc), if the plates were moved distally or proximally from the anatomical position. Similar increases in prominence were also seen with rotational mal-positions. The results of the second study showed a statistically significant effect on plate prominence for even a 5° mal-reduction (p = 0.001) with worsening lift-off with increasing mal-reduction. These changes are significantly different from baseline and also significantly different to the lift-off recorded with mal-reductions 5° better and worse. Mal-reductions also necessitate more proximal placement of the plate to avoid screw penetration of the articular surface, and each 5° increment is significantly different from baseline. The results show a statistically and clinically significant effect of both plate position and fracture reduction on plate prominence and support the theory that both contribute to the aetiology of post-operative FPL rupture.

Complications and Plate Removal Surgeries after Performing Volar Plating of Unstable Distal Radius Fractures

Purpose: To determine the number of complications and plate removal surgeries after performing volar locking plate fixation of unstable distal radius fractures. Methods: In 2008, there were 100 patients (101 unstable fractures of the distal radius) who were treated with volar locking plates at our hospital. Thirteen patients were lost to follow-up; thus, 87 patients with 88 fractures were reviewed (65 women and 22 men). The mean age was 51 years (range, 17-86 years). In 2010, all the patients were clinically and radiologically assessed. In 2014, the number of hardware removals and complications was retrospectively assessed based on patient records. There were 9 A2, 14 A3, 6 B1, 1 B2, 11 B3, 29 C1, and 18 C2 fractures, according to the AO/ OTA classification. The complications, plate removal surgeries, and clinical and radiological outcomes were recorded. In 2010 the patients were clinically assessed using the visual analog scale (0–100 points) pain score at rest and at activity, Mayo Wrist Score (0–100 points), Quick-Disabilities of the Arm, Shoulder, and Hand (0–100 points), and range of motion. Plain radiographs of the wrist were also obtained. Results: Twenty-nine patients had complications (33%), which led to worse clinical results during the follow-up in 2010. Until 2014, hardware removal had been performed in 17 (19%) patients, and this was beneficial in 62%. The main reasons for plate removal were extensor tendon synovitis and pain, and screw penetration into the radiocarpal joint. Conclusion: The use of volar locking plates in unstable distal radius fractures is associated with several surgicalrelated complications, which has to be considered when using this method. Information about the complications may alter the patient outcomes more positively.

Lessons learned from treating patients with unstable multifragmentary fractures of the proximal humerus by minimal invasive plate osteosynthesis.

The authors present clinical and radiographic results of minimal invasive plate osteosynthesis (MIPO) for three- or four-part fractures of the proximal humerus. Twenty-six patients with three- or four-part proximal humeral fractures treated with the MIPO technique through the deltoid splitting approach were clinically and radiographically evaluated at a minimum of 12months with an average of 20.1months. The valgus-impacted type of three-part fracture was excluded to verify the results of the MIPO with unstable multifragmentary fractures of the proximal humerus. Twenty female patients and six male patients were included (mean age 67years; range 18-90years). No cases of nonunion were seen. The mean forward flexion, abduction, and external rotation were 145°, 119°, and 48°, respectively. The mean visual analog scale (VAS) for pain was 1.47 points. The mean Disabilities of the Arm, Shoulder, and Hand (DASH) score was 14.5 points, and the mean UCLA score was 29.6 points. The mean neck-shaft angle was 134°. Twenty-three patients had adequate medial support, and three patients did not have adequate medial support on initial postoperative radiographs. Five shoulders (19%) developed complicated results. Two cases of proximal malposition of the plate (7.7%) and two intra-articular screw penetrations (7.7%) were observed. One case of osteonecrosis of the humeral head was identified at the final follow-up (3.8%). The MIPO technique provides reliable radiologic and functional outcomes for three- and four-part proximal humeral fractures. Our results might support the use of MIPO for treating unstable multi fragmentary fractures of proximal humerus such as three- or four-part fractures to decrease osteonecrosis of humeral head.

Failed Extensor Indicis Proprius Tendon Transfer for Extensor Pollicis Longus Tendon Rupture after Distal Radial Fracture

The known complications of distal radial fractures (DRFs) include tendon rupture, tendon lag, trigger finger, and tenosynovitis. Open reduction and locking plate fixation via the volar approach for treatment of an unstable DRF is becoming an increasingly popular method and has been reported to cause tenosynovitis of the extensor tendons, which leads to delayed extensor tendon rupture. The extensor pollicis longus (EPL) tendon is most commonly ruptured. Screw penetration of the dorsal radius cortex to the third compartment after internal fixation of a volar plate for Failed Extensor Indicis Proprius Tendon Transfer for Extensor Pollicis Longus Tendon Rupture after Distal Radial Fracture