Screw Fixation Of Scaphoid Fractures Research Articles

Multi-objective constraints for path planning in screw fixation of scaphoid fractures

PurposeScaphoid fractures, a common type of clinical fracture, often require screw placement surgery to achieve optimal therapeutic outcomes. Path planning algorithms can avoid more risks and have vital potential for developing precise and automatic surgeries. Despite the success of surgical path planning algorithms, automatic path planning for scaphoid fractures remains challenging owing to the complex bone structure and individual variations. MethodsThus, we propose a Multi-objective constrained Path planning Algorithm (MPA) for fracture screw placement, which includes the identification of the center of the fracture surface. Further, three constraint conditions were introduced to eliminate infeasible paths, followed by adding three objectives to the remaining paths for more accurate planning. Finally, the Nondominated Sorting Genetic Algorithms (NSGA)-II algorithm was used to optimize the surgical paths. ResultsWe defined the vertical compression distance (VCD), a common observation index in clinics. The experiments show that the average VCD of the MPA paths is measured at 23.88 mm, outperforming the clinical planning paths by 21.71 mm. Ablation experiments demonstrated that all three objectives (distance, length, and angle) effectively optimized the path planning. Additionally, we also used finite element analysis to compare and analyze the MPA path and clinical path. The experimental results showed that the MPA path always outperformed the clinical path in terms of scaphoid strain and screw stress. ConclusionThis study presents a solution for the path planning of scaphoid fractures. Our future research will attempt to enhance the model's performance and extend its application to a broader range of fracture types.

Comparison between navigated and conventional percutaneous screw fixation of non-displaced scaphoid fractures

Incorrect screw placement and penetration in screw fixation of scaphoid fractures are found in 5 to 30 %. Therefore, optimizing of screw placement is desirable, especially because an exact central position of the screw in the proximal fragment leads to a significant higher stability as a more peripheral position. 36 patients with an acute non-displaced scaphoid fracture were included in this randomized prospective study. 18 patients underwent navigated, the other 18 conventional percutaneous screw fixation of an acute non-displaced scaphoid fracture through a dorsal approach. Operation time and x-ray dose were measured. In both groups the position of the screw in the scaphoid was calculated on CT scans and compared with each other. Clinically, 17 patients with navigated and 11 with conventional percutaneous screw fixation with an average age of 52 resp. 43.2 years were available for follow-up examination including Krimmer- and DASH-score. All scaphoids healed within an adequate time. Two cases of navigated screw fixation have been converted to conventional percutaneous screw fixation. The average operation time in the navigated group was 83.2 minutes, in the conventional group 42.1 minutes. X-ray dose measured 106,5 ± 19,9cGy/cm2 in the navigated group and 45,6 ± 8,0cGy/cm2 in the conventional group. Screw penetration using an intraosseous compression screw (HSC) was observed in 5 conventionally fixed scaphoids, 4 distally (2,27 ± 1,47 mm), 1 proximally. In the navigated group there were 11 screw penetrations, 4 proximally (2,01 ± 0,81 mm) and distally (1,21 ± 0,64 mm), 3 distally (1,18 ± 0,44 mm), and 4 proximally (1,61 ± 0,57 mm). Axial screw position was more accurate in the conventional group. The 17 navigated patients averaged a Krimmer-Score of 83.6 and a DASH-score of 5,6 points at follow-up. The 11 conventional treated patients averaged a Krimmer-Score of 95 and a DASH-score of 8.0 points at follow-up. In this study navigated screw fixation of acute non-displaced scaphoid fractures was not superior to conventional percutaneous screw fixation, neither for screw position, screw penetration nor with respect to the clinical outcome.

Percutaneous herbert screw fixation of undisplaced scaphoid fractures-evaluation of functional and radiological outcome

Background: On undisplaced scaphoid fractures treated with prolonged cast immobilisation may result in temporary joint stiffness and muscle weakness in addition to a delay in return to sports or work. Fixation of scaphoid fractures with a percutaneous screw has resulted in a shorter time to union and to return to work or sports. The purpose of this study was to evaluate the results of percutaneous screw fixation scaphoid fractures with respect to time to radiographic union and to return to work. Materials and Methods: In 20 patients with fracture of the scaphoid, fixation with a percutaneous screw was done. Time to fracture union, wrist motion, grip strength and return to work as well as overall patient satisfaction at the time of a two-year follow-up were evaluated. Results: Of the 20 patients in the study, mean radiological fracture union time was 12.2 weeks (range 8-15 weeks). Wrist function was excellent in 10 cases, good in remaining 6 cases and poor in 4 cases. Conclusion: Percutaneous herbert screw fixation is a well-documented surgical procedure. Undisplaced scaphoid fractures fixed by percutaneous headless screw fixation yield better results than patients treated conservatively. Good range of motion is achieved after fixation. It relieves pain and functional disability experienced by patients. Percutaneous screw fixation of scaphoid fractures resulted in faster radiographic union and return to function. The specific indications for and the risks and benefits of percutaneous screw fixation of such fractures must be determined in larger randomised prospective studies.

Surgical treatment by percutaneous anterior screw fixation of scaphoid fractures

The aim of this study was to evaluate the results of percutaneous screw fixation of scaphoid waist fractures in our surgery unit by comparing them with recent data from the literature. This was a retrospective, descriptive study conducted between January 2010 and September 2016. Patients operated due to a recent scaphoid fracture and treated by percutaneous anterograde screw fixation with a Herbert screw were included in this study. Our cohort was a sub-set from a scaphoid fracture group; other fracture sites, other treatment techniques and fractures associated with scapholunate ligament lesions were excluded. The time to union and union rate were recorded. The Youm and McMurtry indices, scaphoid and scapholunate angles were measured on radiographs. A total of 21 patients were included. The mean age was 30 years (18–44) and the sex ratio (male/female) was 9.5. The union rate was 95% with an average follow-up of 24 months. Four patients had a mobility deficit in the sagittal plane of about 9°. No malunion was found, and no major complications were observed. Based on this study, percutaneous fixation of the scaphoid with Herbert's screw is a reliable technique that leads to union in most cases with limited postoperative immobilization.

Scaphoid Proximal Pole Fracture Following Headless Screw Fixation

Background Headless screw fixation of scaphoid fractures and nonunions yields predictably excellent outcomes with a relatively low complication profile. However, intramedullary implants affect the load to failure and stress distribution within bone and may be implicated in subsequent fracture. Case Description We describe a posttraumatic fracture pattern of the scaphoid proximal pole originating at the previous headless screw insertion site in three young male patients with healed scaphoid nonunions. Each fracture was remarkably similar in shape and size, comprised the volar proximal pole, and was contiguous with the screw entry point. Treatment was challenging but successful in all cases. Literature Review Previous reports have posited that stress-raisers secondary to screw orientation may be implicated in subsequent peri-implant fracture of the femoral neck. Repeat scaphoid fracture after screw fixation has also been reported. However, the shape and locality of secondary fracture have not been described, nor has the potential role of screw fixation in the production of distinct fracture patterns. Clinical Relevance Hand surgeons must be aware of this difficult complication that may follow antegrade headless screw fixation of scaphoid fracture nonunion, and of available treatment strategies.

Percutaneous screw fixation of scaphoid fractures aided by computerized imaging processing: preliminary report

Objective To evaluate the preliminary clinical outcome of the screw fixation of minimally displaced scaphoid fracture assisted by computerized imaging reconstruction and preoperative planning system.Methods From March 2013 to Feburary 2014,Five screws on five patients were treated.We calculated and designed the position of scaphoid screw guide wire and ensured the guide wire centrally placed in the scaphoid by using the computerized imaging reconstruction and preoperative planning system software.The appropriate length of the screw was measured too in the software.We also identified the entry and exit points of the guide wire on the custom orthoses splinting the wrist joint.Five patients with scaphoid fractures were treated with percutaneous screw fixation under the guidance of a C-arm fluoroscopy and a guide wire were inserted based on the entry and exit points calculated preoperatively.All of the scaphoid fracture was nondisplaced or less than 1 mm.The modified MAYO wrist scoring system was used to evaluate the pain,function and range of motion for the wrist joint during follow up.Results Total surgical time was 28.8 min (25-39 min)and Fluoroscopy time was 18.4 s (11-23 s).The fracture healing was observed at routine 8 weeks follow up.No complication such as infection or fixation failure was reported.Modified MAYO wrist score was 83.8 (81-88)at average followup at 15 months (6-12 months).Conclusion Computer assisted percutaneous screw fixation is an effective method for the treatment of nondisplaced scaphoid fractures.It leads to significantly reduced guidewire placement time and radiological exposure time while provides accurate placement of the screw. Key words: Scaphoid ; Fracture fixation; Microsurgical operation Computer-asisted

Influence of Screw Design, Sex, and Approach in Scaphoid Fracture Fixation

Screw fixation of scaphoid fractures has gained popularity. A long central screw has been shown to be biomechanically advantageous. We compared the ability of different screw designs to obtain this goal and determined the influence of sex and approach on screw length. We performed all measurements on three-dimensional reconstructions of 20 CT scans of normal scaphoids (10 men and 10 women) with the use of software. The three-dimensional computer models were analyzed, the central axis was defined, and the screws were placed along this axis. We compared 15 different available screw designs and volar and dorsal screw placement. The length of the scaphoid along its central axis was longer in men (mean, 27.14mm; standard error of the mean, 0.97mm) than in women (mean, 23.86mm; standard error of the mean, 0.37mm). The screw length that can be used was longer in the volar approach (mean, 23.72mm; standard error of the mean, 0.19mm) than in the dorsal approach (mean, 23.31mm; standard error of the mean, 0.19mm) regardless of the screw design. Screws with a trailing thread diameter greater than 3.9mm and leading thread diameter greater than 3.0mm were shorter. Scaphoids in women are smaller than in men. Theoretically, fixation of scaphoid fractures through a volar approach will allow the surgeon to use longer screws. The screw design has a significant influence on the screw length that can be used in scaphoid fracture fixation. We recommend using a differential pitch screw with a thread diameter of 3.9mm or less.

Scaphoid fractures Dorsal versus volar approach for screw fixation

It is not clear whether the dorsal or volar approach is superior for screw fixation of scaphoid fractures, based on limited evidence from three small retrospective cohort studies with a total of 87 patients. Fracture union rates, functional outcomes, pain, and complications appear to be similar in patients treated with dorsal and volar approaches. Statistical significance was not consistent across studies, which may be a function of sample size and/or bias in some studies. To better understand the differences in outcomes between dorsal and volar approaches to screw fixation of scaphoid fractures, additional larger, methodologically rigorous trials are needed. A multi-center study may provide sufficient power to effectively study this question. 根据3项小样本回顾性队列研究(共计87例患者)所获得的证据,在舟状骨骨折治疗时,目前仍不能确定背侧入路与掌侧入路螺钉固定何者更优.虽然骨折愈合率、功能状况、疼痛、并发症的发生率在两种方法间相似,但是各研究所得的统计学差异并不一致,这可能是由于研究的样本量较小或者研究中存在偏倚导致的.为了更好地比较背侧与掌侧入路螺钉固定治疗舟状骨骨折的疗效,应开展具有大样本的、严格方法学的临床试验研究.采用多中心研究更有利于该问题的回答.……

Scaphoid fractures

It is not clear whether the dorsal or volar approach is superior for screw fixation of scaphoid fractures, based on limited evidence from three small retrospective cohort studies with a total of 87 patients. Fracture union rates, functional outcomes, pain, and complications appear to be similar in patients treated with dorsal and volar approaches. Statistical significance was not consistent across studies, which may be a function of sample size and / or bias in some studies. To better understand the differences in outcomes between dorsal and volar approaches to screw fixation of scaphoid fractures, additional larger, methodologically rigorous trials are needed. A multi-center study may provide sufficient power to effectively study this question.

Pronated Oblique View in Assessing Proximal Scaphoid Articular Cannulated Screw Penetration

Volar and percutaneous techniques of screw fixation for scaphoid fractures usually do not involve direct visualization of the dorsoproximal scaphoid articular surface. Intra-articular screw penetration may be overlooked if the proper fluoroscopic views are not obtained. The hypothesis of this study is that the pronated oblique fluoroscopic view of the scaphoid is the most sensitive in detecting dorsal articular screw penetration of the scaphoid when compared with other views. A 3.6-mm Steinmann pin was inserted along the central axis of the scaphoid using an open dorsal technique in 10 embalmed cadaver wrists. The pin was then withdrawn from the palmar side until it was flush with the dorsal articular surface of the scaphoid. Five fluoroscopic views of the wrist were then obtained by rotating the forearm, keeping the image beam parallel to the floor: (1) anteroposterior, (2) supinated lateral, (3) pronated lateral, (4) 60 degrees supinated oblique (60 degrees supinated from wrist neutral), and (5) 60 degrees pronated oblique (60 degrees pronated from wrist neutral). The Steinmann pin was then allowed to visually protrude proximally from the articular surface in 0.5-mm increments, and all views were repeated. The view in which articular violation was first observed was recorded, as was the corresponding amount of pin protrusion. The pronated oblique was the fluoroscopic view in which articular penetration was first observed in all 10 specimens before it was evident on the other views. The amount of pin penetrating the articular surface before it was detected on the other views was 1 mm in 6 wrists and 2 mm in 4 wrists. Statistical analysis using Fischer's exact test was performed to determine whether the radiographic projection had an effect on the determination of articular penetration. The pronated oblique view was the first view to demonstrate articular penetration, with an average radiographically measured articular penetration of 1.4 mm +/- 0.5. This study confirms our hypothesis that the pronated oblique view is the most important fluoroscopic image to obtain when evaluating penetration of the proximal scaphoid articular surface.

Complications in Dorsal Percutaneous Cannulated Screw Fixation of Nondisplaced Scaphoid Waist Fractures

With advances in tools and techniques, percutaneous screw fixation of nondisplaced fractures of the scaphoid waist has gained increasing popularity in recent years as an alternative to prolonged cast immobilization or open reduction and internal fixation. Many reports cite low complication rates, including no complications in some series. The purpose of this study was to evaluate the complications encountered with dorsal percutaneous cannulated screw fixation of nondisplaced scaphoid waist fractures. A retrospective chart review was performed for 24 patients who had surgery performed by a single surgeon over a 5-year period. All cases involved dorsal percutaneous cannulated screw fixation of nondisplaced (<1 mm) fractures of the scaphoid waist. Complications were rated a priori as major or minor based on modifications of established criteria. The overall complication rate was 29%; there were 21% (5/24) major complications and 8% (2/24) minor complications. Major complications consisted of 1 case of nonunion, 3 cases involving hardware problems, and 1 case of postoperative fracture of the proximal pole of the scaphoid. Minor complications included intraoperative equipment breakage-1 case involving a screw and 1 case involving a guide wire. Complications in dorsal percutaneous cannulated screw fixation of scaphoid fractures may be more common than previously reported.

Screw Fixation of Scaphoid Fractures: A Biomechanical Assessment of Screw Length and Screw Augmentation

Screw Fixation of Scaphoid Fractures: A Biomechanical Assessment of Screw Length and Screw Augmentation

Screw Fixation of Scaphoid Fractures: A Biomechanical Assessment of Screw Length and Screw Augmentation

To assess the biomechanical stability relative to screw length and K-wire augmentation in scaphoid fracture fixation using a flexibility testing protocol and cadaver scaphoids whose soft tissue attachments remained undisturbed. Our hypothesis was 2-fold: increasing screw length and augmenting fixation with a K-wire would improve fracture fragment stability, individually and in combination. Flexion and extension loading applied through wrist tendons was performed on 10 cadaveric wrists after volar wedge scaphoid osteotomy and internal fixation. Each wrist participated in 3 experimental groups: short screw, long screw, and long screw augmented with a K-wire transfixing the distal pole to the capitate. Interfragmentary displacements were measured. Analysis of variance showed significantly less fracture fragment motion with longer screws than with short screws in 4 of the 6 displacement axes. The flexion/extension axis rotations for the short, long, and augmented long-screw groups were 8.2 degrees +/- 4.8 degrees, 3.9 degrees +/- 1.6 degrees, and 1.8 degrees +/- 1.3 degrees, respectively. Although K-wire augmentation reduced displacement of the fracture fragments it did not decrease interfragmentary motion significantly when compared with the long-screw group. Under physiologically applied loading of cadaveric wrists with unstable scaphoid waist fractures the long screw provided significantly greater stability than the short screw. Although K-wire augmentation in the long-screw group did improve stability the improvements were not significant. Based in part on the biomechanical data from this study it is our recommendation that the optimally placed screw for scaphoid fracture fixation stability is a long screw positioned down the central axis of the scaphoid deep into subchondral bone.

Percutaneous cannulated screw fixation of acute nondisplaced scaphoid waist fractures

Percutaneous screw fixation of acute, stable, scaphoid waist fractures has recently gained popularity secondary to the rapid fracture healing and decreased time off work/sports compared with cast immobilization. The historical background, pertinent anatomical considerations, and surgical technique of volar percutaneous cannulated screw fixation will be described. Additionally, the advantages of this technique over cast immobilization and open surgical stabilization methods will be reviewed. Although technically demanding, percutaneous cannulated screw fixation of scaphoid fractures provides rigid stabilization, faster union rates, and earlier return to work or sports. It is an attractive alternative to cast immobilization of acute, stable, scaphoid waist fracture in patients who understand the risks and benefits of this technique.

Arthroscopically controlled minimal invasive screw fixation of scaphoid fractures. A pilot study

We could not find any systematic studies about the value of arthroscopy in scaphoid fractures in the literature, and therefore undertook a pilot study of 20 scaphoid fractures which were treated arthroscopically by the Herbert-Whipple screw and were minimally invasive. We found very good radiological and clinical results in 17 patients and good results in 3 patients evaluated by the Wozasek and Moser score. For reduction of dislocated fractures we used distraction with 5 kg in the wine waiters position. In four cases we used additional K wires as joysticks. Arthroscopy is less valuable in reduction, however, it is important in verification of the compression force of the Herbert-Whipple screw and for diagnosis and therapy of lesions of the scapholunate ligament and TFC complex. We found seven SL instabilities, two lesions of the meniscus, and one Palmer 1B lesion of the TFC complex. From these results we conclude that arthroscopy should necessarily be done by minimally invasive osteosynthesis of scaphoid fractures to detect and treat discoligamentous injuries of the wrist.

Metal Artifact Reduction Sequence: Early Clinical Applications

Artifact arising from metal hardware remains a significant problem in orthopedic magnetic resonance imaging. The metal artifact reduction sequence (MARS) reduces the size and intensity of susceptibility artifacts from magnetic field distortion. The sequence, which is based on view angle tilting in combination with increased gradient strength, can be conveniently used in conjunction with any spin-echo sequence and requires no additional imaging time. In patients with persistent pain after femoral neck fracture, the MARS technique allows visualization of marrow adjacent to hip screws, thus enabling diagnosis or exclusion of avascular necrosis. Other applications in the hip include assessment of periprosthetic soft tissues after hip joint replacement surgery, postoperative assessment after resection of bone tumors and reconstruction, and localization of unopacified methyl methacrylate cement prior to hip arthroplasty revision surgery. In the knee, the MARS technique allows visualization of structures adjacent to implanted metal staples, pins, or screws. The technique can significantly improve visualization of periprosthetic bone and soft-tissue structures even in patients who have undergone total knee arthroplasty. In patients with spinal fixation hardware, the MARS technique frequently allows visualization of the vertebral bodies and spinal canal contents. The technique can be helpful after wrist fusion or screw fixation of scaphoid fractures.