Scaphoid Waist Fractures Research Articles

Lessons learned from volar plate fixation of scaphoid fracture nonunions.

IV.

Scaphoid Healing Required for Unrestricted Activity: A Biomechanical Cadaver Model.

To determine if scaphoid fractures with bridging bone of 50% of their width treated with a centrally placed screw will restore biomechanical integrity equivalent to that of the intact scaphoid. Twenty-four fresh cadaver scaphoids were used. Six were left intact to serve as the control group. Six were osteotomized 50% of their width and made up the osteotomy without screw group. Six were included in the 50% osteotomy plus compression screw group. The remaining 6 were to be treated with an osteotomy of 25% or 75% with a screw, based upon the results of the 50% osteotomy with screw group. Biomechanical testing was performed using an Instron testing machine, with a load applied to the scaphoid's distal pole. Load to failure and stiffness were measured. Intact scaphoids had an average load to failure of 610.0 N. The average load to failure of the 50% osteotomy group without a screw was 272.0 N and with a screw was 666.3 N. There was no significant difference in load to failure between the 50% osteotomy plus screw and the intact scaphoid. The 75% osteotomy plus screw was found to have a load to failure of 174.0 N, significantly lower than the intact scaphoid. The 50% osteotomy plus screw had a significantly higher stiffness than the intact scaphoid control. A 50% intact scaphoid with a centrally placed screw showed similar load to failure and significantly higher stiffness than the intact scaphoid when tested in cantilever bending. This study demonstrates that patients with scaphoid waist fractures who undergo surgery with a compression screw may be able to return to unrestricted activity with 50% partial healing.

Acute scaphoid fractures and non-unions

The diagnosis of scaphoid fractures requires a high index of suspicion, with a focus on the mechanism of injury and careful clinical examination. A scaphoid series of radiographs is required but if negative does not rule out a fracture. If there is clinical suspicion for fracture, one should obtain an MRI scan, which has the highest sensitivity and specificity for diagnosis. The management of acute scaphoid fractures is dependent largely on fracture location and displacement, although there are other factors to consider. On the whole, distal pole fractures can be managed conservatively and proximal pole fractures surgically, as the latter have poorer healing potential with a risk of avascular necrosis, due to a retrograde blood supply. The controversy lies with scaphoid waist fractures. One should consider surgical management for displaced waist fractures. The surgical approach is dependent on the fracture location and the surgeon's individual preference. Scaphoid non-union predictably leads to arthritis of the wrist, and therefore should be managed upon diagnosis. Reconstructive surgery provides the best outcomes, and more research is required into conservative treatments. Recent times have seen an increase in the use of vascularized bone grafts. In cases where there is established arthritis, salvage options include scaphoidectomy with four-corner fusion, proximal row carpectomy, total wrist arthroplasty and arthrodesis.

Percutaneous Screw Fixation for Scaphoid Fractures.

Treatment of nondisplaced scaphoid waist fractures has evolved from conventional cast immobilization to percutaneous screw insertion. This study assessed clinical and radiologic outcomes of volar percutaneous screw fixation for 15 type B2 scaphoid fractures (according to the Herbert and Fisher classification). All patients were followed for an average of 33 months (range, 6-50 months). All fractures achieved radiographic union at an average of 57 days (range, 35-70 days), requiring no additional procedures. None of the patients showed radiographic signs of osteoarthritis, osteonecrosis of the scaphoid, or hardware-related complications. For scaphoid waist fractures without collapse, percutaneous screw fixation provided satisfactory results with a high rate of union, early return of function, and minimal complications. [Orthopedics. 2017; 40(4):e729-e734.].

Wrist Injuries in Youth Athletes

To identify new evidence-based medicine regarding wrist injuries in youth athletes. Worthy studies identified include reports on changing wrist injury epidemiology, increasing recognition of stress fractures, evolving pathology in scaphoid fractures, risk factors for youth overuse injuries, comparison of immobilization techniques following distal radial fractures, and benefits and risks of MRI imaging, among others. Changes in epidemiology are seen in American football, basketball, and soccer. These changes, and the potential rise of scaphoid waist fractures, are reported with theorized factors being the increasing body mass index (BMI) of today’s youth, use of synthetic turf, and changing popularity of various sports. A new study identifying overuse injury risk associated with sport specialization is discussed. Finally, MRI imaging is discussed, specifically, its reported 100% negative predictive value for scaphoid fractures, but also the potential to lead to overdiagnosis of wrist pathology.

In Vivo Scaphoid Motion During Thumb and Forearm Motion in Casts for Scaphoid Fractures

In nonsurgical treatment for acute undisplaced or minimally displaced scaphoid waist fractures, immobilization of both wrist and thumb can be an option. However, invivo scaphoid motion during forearm and thumb motion with the wrist immobilized in a cast has not been measured. Therefore, we examined the invivo kinematics of the scaphoid during forearm and thumb motion with cast immobilization. Ten healthy right wrists of 10 male volunteers were included. These wrists were immobilized in a short-arm spica cast with the thumb in a position of volar abduction and then were scanned with the forearm in supination, neutral rotation, and pronation using computed tomography. Next, these wrists were scanned with a forearm gauntlet cast in place with the thumb abducted radially and opposed with the forearm positioned in neutral rotation. From these data, the 3-dimensional position of the third metacarpal and scaphoid was analyzed. From forearm supination to pronation, the scaphoid showed 0.2° radial deviation, 0.4° pronation, and 8.3° extension. The third metacarpal showed 14.6° ulnar deviation, 6.5° pronation, and 1.6° flexion. During thumb opposition from radial abduction, the scaphoid showed 2.9° radial deviation, 0.4° supination, and 7.2° extension and the third metacarpal showed 4.5° ulnar deviation, 2.8° pronation, and 5.5° extension. The scaphoid was not completely immobilized by either cast. However, the scaphoid motion during forearm and thumb motion was not significant. Several high-quality studies have shown that undisplaced or minimally displaced scaphoid waist fractures can be successfully treated with casts. Movement of scaphoid and wrist during forearm rotation or thumb motion with a cast may not be sufficient to have a negative impact on the outcome of scaphoid fracture using a cast.

Three-dimensional comparison of alternative screw positions versus actual fixation of scaphoid fractures

PurposeThe recommended technique for the fixation of a scaphoid waist fracture involves a headless compression screw placed in the proximal fragment center. This is usually accomplished by placing a longitudinal axis screw as visualized by fluoroscopy. The screw length has been shown to have a biomechanical advantage. An alternative to these options, which has been debated in the literature, is a screw placed perpendicular to the fracture plane and in its center. The perpendicular screw may have a biomechanical advantage despite the fact that it may be shorter. This study examined the differences in location and length in actual patients between a screw in the center of the proximal fragment with a longitudinal axis screw, and the actual fixating screw. These were then compared to a perpendicular axis screw. MethodsPre- and post-operative CT scans of 10 patients with scaphoid waist fractures were evaluated using a 3D computer model. Comparisons were made between the length, location and angle of actual and virtual screw alternatives; namely, a screw along the central third of the proximal fragment (central screw axis) where the scaphoid longitudinal axis was calculated mathematically (longitudinal screw axis) and a screw placed at 90° to the fracture plane and in its center (perpendicular screw axis). ResultsThe longitudinal axis screw was found to be significantly longer than the other axes (28.3mm). There was a significant difference between the perpendicular axis screw and the location and angle of the other screw axis, but it was only shorter than the longitudinal screw (23.6mm versus 25.5mm for the actual screw; ns.). ConclusionsA computed longitudinal axis screw is longer than a central or actual screw placed longitudinally by visual inspection by the surgeon. Although it needs to be placed using computer assisted (CAS) techniques, it may have the biomechanical advantages of a longer screw in a similar trajectory. The perpendicular screw was found to be significantly different in position and angle but not shorter than the actually placed screw. It has biomechanical advantages and does not require visualization with CAS methods, making it the more attractive alternative.

Greffe spongieuse et fixation par vis de compression sans tête dans les pseudarthroses du scaphoïde carpien

PurposeScaphoid fracture commonly occurs around the mid-third of the scaphoid, and nonunion of this fracture has several treatment options. The authors performed autologous cancellous bone graft from the iliac crest and headless compression screw fixation for the treatment of Mack–Lichtman type II scaphoid waist nonunion. The purpose of this study was to determine whether this procedure was effective in achieving bony union and restoration of alignment. MethodsMedical records and radiographs of 30 patients who underwent cancellous bone graft and headless compression screw fixation for nonunion of scaphoid waist fracture were retrospectively reviewed. There were 28 men and 2 women, with a mean age of 32.8 years (range, 21–63). The mean time to surgery was 10 months (range, 3–25) and mean follow-up was 37.5 months (range, 15–52). The authors analyzed bony union, lateral intrascaphoid angle, scapholunate angle, radiolunate angle and scaphoid length on radiographs and evaluated the modified mayo wrist score (MMWS) as a functional outcome. ResultsBony union was achieved in all cases. The lateral intrascaphoid angle improved from 40° to 32° (P<0.001). The scapholunate angle also improved from 61° to 56° (P=0.009). The radiolunate angle decreased from 8° to 4° (P=0.048) and scaphoid length increased from 22mm to 26mm (P<0.001) postoperatively. Wrist motion and MMWS improved significantly at last follow-up. However, there were no significant differences between scaphoid deformity correction angle and pre to postoperative difference in MMWS. ConclusionsNonstructural autologous cancellous bone graft from the iliac crest and headless screw fixation provided reliable results and can be one of the effective treatment options for patients with symptomatic Mack–Lichtman type II nonunion in the mid-third of the scaphoid. Level of evidenceLevel III.

Three-Dimensional Analysis of Acute Scaphoid Fracture Displacement: Proximal Extension Deformity of the Scaphoid.

Our goal was to analyze the movement of acute scaphoid waist fracture fragments and adjacent bones in a common coordinate system. Our hypothesis was that the distal scaphoid fragment flexes and pronates and the proximal fragment extends. Computed tomography (CT) scans of patients diagnosed with an acute scaphoid waist fracture were evaluated using a 3-dimensional (3D) model. The scans of 57 nondisplaced and 23 displaced fractures were compared with a control group of 27 scans showing no pathological involvement of the wrist. Three anatomical landmarks were labeled on the distal and proximal fragments of the scaphoid, the lunate, and the trapezium. Each set of labels formed a triangle representing the bone or fragment. Four landmarks were labeled on the distal radial articular surface and used to create a common coordinate system. The position of each bone or fragment was calculated in reference to these coordinates. The displaced fracture group showed significant extension, supination, and volar translation of the proximal scaphoid fragment when compared with the other groups. The lunate tended toward a supinated position, which was not statistically significant. The distal scaphoid fragment and the trapezium showed no movement. In acute displaced scaphoid fractures, it is the proximal fragment that displaces and should be reduced. The typical "humpback" deformity is actually a "proximal extension" deformity, the consequence of displacement of the proximal fragment of the scaphoid (with the lunate). Manipulating only the proximal fragment (with the lunate) may be technically easier and more effective than manipulating both fragments.

Non-structural cancellous bone graft and headless compression screw fixation for treatment of scaphoid waist non-union

PurposeScaphoid fracture commonly occurs around the mid-third of the scaphoid, and non-union of this fracture has several treatment options. The authors performed autologous cancellous bone graft from the iliac crest and headless compression screw fixation for the treatment of Mack-Lichtman type II scaphoid waist non-union. The purpose of this study was to determine whether this procedure was effective in achieving bony union and restoration of alignment. MethodsMedical records and radiographs of 30 patients who underwent cancellous bone graft and headless compression screw fixation for non-union of scaphoid waist fracture were retrospectively reviewed. There were 28 men and 2 women, with a mean age of 32.8 years (range: 21–63). The mean time to surgery was 10 months (range: 3–25) and mean follow-up was 37.5 months (range: 15–52). The authors analyzed bony union, lateral intrascaphoid angle, scapholunate angle, radiolunate angle and scaphoid length on radiographs and evaluated the Modified Mayo wrist score (MMWS) as a functional outcome. ResultsBony union was achieved in all cases. The lateral intrascaphoid angle improved from 40° to 32° (P<0.001). The scapholunate angle also improved from 61° to 56° (P=0.009). The radiolunate angle decreased from 8° to 4° (P=0.048) and scaphoid length increased from 22mm to 26mm (P<0.001) postoperatively. Wrist motion and MMWS improved significantly at last follow-up. However, there were no significant differences between scaphoid deformity correction angle and pre- to post-operative difference in MMWS. ConclusionsNon-structural autologous cancellous bone graft from the iliac crest and headless screw fixation provided reliable results and can be one of the effective treatment options for patients with symptomatic Mack-Lichtman type II non-union in the mid-third of the scaphoid. Level of evidenceLevel III.

Effect of Screw Perpendicularity on Compression in Scaphoid Waist Fractures.

Background Central and perpendicular (PERP) screw orientations have each been described for scaphoid fracture fixation. It is unclear, however, which orientation produces greater compression. Questions/Purposes This study compares compression in scaphoid waist fractures with screw fixation in both PERP and pole-to-pole (PTP) configurations. PERP orientation was hypothesized to produce greater compression than PTP orientation. Methods Ten preoperative computed tomography scans of scaphoid waist fractures were classified by fracture type and orientation in the coronal and sagittal planes. Three-dimensional models of each scaphoid and fracture plane were created. Simulated Acutrak 2 (Acumed, Hillsboro, OR) screws were placed into the models in both PERP and PTP orientations. Engagement length and screw angle relative to the fracture were measured. Compression strength was calculated from the shear area, average density, and angle acuity. Results The PTP angle between screw and fracture ranged from 36 to 84 degrees. By definition, the PERP screw-to-fracture angle was 90 degrees. Perpendicularity of the PTP screw to the fracture was positively correlated to compression strength. PERP screws had greater compression than PTP screws when the PTP screw-to-fracture angle was < 80 degrees (106 vs. 80 N), but there was no difference in compression when the PTP screw-to-fracture angle was > 80 degrees, approximating the PERP screw. Conclusion Increasing screw perpendicularity resulted in higher compression when the screw-to-fracture angle of the PTP screw was < 80 degrees. Maximum compression was obtained with a screw PERP to the fracture. The increased compression gained from PERP screw placement offsets the decreased engagement length. Clinical Relevance These results provide guidelines for optimal screw placement in scaphoid waist fractures.

Percutaneous Treatment of Unstable Scaphoid Waist Fractures.

Percutaneous techniques have been described for the treatment of nondisplaced scaphoid fractures, although less information has been reported about outcomes for unstable, displaced fractures. The aim of this study was to evaluate the union and complication rates following manual closed reduction and percutaneous screw placement for a consecutive series of unstable, displaced scaphoid fractures. A total of 28 patients (average age, 27 years; 22 male/6 female) were treated for isolated unstable displaced scaphoid waist fractures. Closed reduction and percutaneous headless, compression screw fixation was successfully performed in 14 patients (average age, 32 years; 10 male/4 female), and the remaining 14 patients required open reduction. Patients who underwent percutaneous treatment were followed for radiographic fracture union and clinical outcomes. Thirteen of 14 fractures (93%) had clinical and radiographic evidence of bone union at an average of 2.8 months postoperatively. Average visual analog pain score at the time of union was 0.9. The average Quick Disability of the Arm, Shoulder, and Hand score at 2.5 years follow-up (range, 1.5-8.3 years) was 9.6 (range, 0.0-27.3). Complications included 1 case of nonunion and 1 case of intraoperative Kirschner wire breakage. Manual closed reduction followed by percutaneous headless, compression screw fixation was possible in 50% of patients who presented with acute unstable, displaced scaphoid fractures. This technique appears to be a safe and effective method when a manual reduction is possible, and it may offer a less invasive option when compared with a standard open technique.

Is Casting for Non-Displaced Simple Scaphoid Waist Fracture Effective? A CT Based Assessment of Union.

Objective:The purpose of this study is to report the union rate and time to union for acute non-displaced scaphoid waist fractures treated with a short arm thumb spica cast.Methods:A database was searched (2006-2013) to identify acute undisplaced scaphoid waist fractures. Cases that were not given a trial of casting were excluded (n=33). X-rays, CT scans and health records for each patient were reviewed to extract data.Results:172 patients met inclusion criteria. There were 138 males, 34 females, the mean age was 30 ± 16 years. The union rate was 99.4% (1 nonunion/172 subjects). The mean time to union was approximately 7.5 weeks (53 ± 37 days). Energy of injury, age or gender did not affect union rates or time to union. Cysts did not affect the union rate (p=0.73) but patients with cystic resorption along the fracture line required approximately 10 weeks for union (69 ± 60 days) compared to 7 weeks (51 ± 34 days) for those without cysts (p=0.05). Diabetes did not affect the union rate (p=0.81) but was found to increase the risk of delayed union (p=0.05). There was a weak, but statistically significant correlation between the number of days before the fracture was casted and the length of time needed to achieve union (r=0.27, p=0.001).Conclusion:Non-displaced scaphoid waist fractures have a high healing rate with appropriate identification and immobilization. Follow-up CT scans to assess healing can identify union within a shorter time frame (~7 weeks) than previously reported in the literature.

Percutaneous Screw Fixation of Scaphoid Waist Fracture Non-Union Without Bone Grafting.

The aim of the study was to evaluate results of volar percutaneous headless compression screw fixation without bone grafting in 21 patients with scaphoid waist nonunion fractures. The inclusion criteria in this series were scaphoid waist fracture nonunion with intact cartilaginous envelope, minimal fracture line at nonunion interface, no cyst or sclerosis, no avascular necrosis and normal scapholunate angle without humpback deformity. There were 17 male and 4 female patients with an average age of 23years (range 16-45years). All patients had radiographic examinations that included Posteroanterior, lateral, oblique and scaphoid views. Preoperative MRI to assess the cartilaginous shill and vascularity of scaphoid was done. CT scans were performed postoperatively to confirm scaphoid fracture healing. The average clinical follow-up was at 25months (range 18-35) postoperatively. All fractures united successfully with no additional procedures. The average DASH score (disabilities of the arm, shoulder, and hand) at final follow-up was 8 (range 0-16). Percutaneous fixation for selected scaphoid nonunion can avoid the morbidity of an open approach and bone grafting.

Comparison of volar and dorsal percutaneous screw fixation in acute scaphoid waist fracture

Objective To compare volar and dorsal percutaneous screw fixation in acute scaphoid waist fracture. Methods Retrospectively collected patients received percutaneous screw fixation after acute scaphoid fracture between January 2009 and December 2014 with non-displacement/minimal displacement waist fracture, patients with open fracture or combined with perilunate dislocation or fracture which need reduce were excluded, 28 patients with intact follow-up were enrolled, 26 men and 2 women, with an average age of 31 years old. Based on Herbert classification, there were 15 A2 type, 5 B1 type, 8 B2 type. 7 cases were high energy trauma and 21 were low energy. The patients were divided into 2 groups by volar and dorsal approach. The general condition, surgery notes, radiological evidence and follow-up were collected and analyzed. Results 28 cases with full follow-up were enrolled, 18 cases received surgery via volar approach, and 10 cases via dorsal approach, the mean follow-up period is 33 months. Peri-operative data showed that operation time in dorsal approach group was longer (75 min vs. 54 min). We evaluated screw position by measuring the angulation between screw and fracture line as well as screw and long axis of scaphoid based on AP view and lateral view of wrist X-rays. There was no significant difference in length of screws (21.4 mm vs. 21.8 mm). Patients gradually went back to work after 2 weeks and got fracture healing within 12 weeks after operation. Radiological evidence showed that angulation between screw and long axis of scaphoid was 6.11°±4.82° in AP position and 8.48°±5.77° in lateral position, angulation between screw and fracture line was 73.58°±20.75° in AP position and 70.72°±21.19° in lateral position. There were no significant differences between screw insertion positions between 2 groups. Visual analogue scale (VAS) was used to evaluate wrist pain in the follow-up, Mayo wrist score and Patient-Rated Wrist Evaluation (PRWE) were also used to assess wrist function in the follow-up. The clinical results were promising, the excellent or good rate of Mayo wrist score was 100%, there were no significant difference in VAS, Mayo wrist score and PRWE between volar and dorsal approach. No complications such as failure of screws, orthopaedic arthritis or scaphoid necrosis were observed. Conclusion Percutaneous screw fixation have a satisfied effect in the treatment of acute scaphoid waist fracture, and there are no differences in clinical efficacy between volar and dorsal approach. Key words: Scaphoid bone; Fractures, bone; Carpal joints; Fracture fixation, internal

Pediatric Scaphoid Fractures

Scaphoid fractures are the most common type of carpal injuries that occur in children and adolescents. The injury pattern seen in children and adolescents who have scaphoid fractures has recently shifted to resemble that of adults who have scaphoid fractures, with scaphoid waist fractures being the most common injury pattern. This shift has been attributed to increased body mass index in children and adolescents as well as more intense participation in extreme sports by both children and adolescents. The diagnosis of scaphoid fractures is based on both a clinical examination and radiographic fi ndings. If a scaphoid fracture is clinically suspected but initial radiographs are negative, cast immobilization followed by repeat imaging can lead to accurate diagnosis of the injury. MRI can aid in the diagnosis of a scaphoid injury in pediatric patients with incomplete ossifi cation of the scaphoid. Acute nondisplaced scaphoid fractures have a high rate of healing with cast immobilization; however, surgery should be considered in patients who have displaced scaphoid fractures with delayed presentation. In general, patients with scaphoid fractures who undergo appropriate treatment and achieve successful union have excellent long-term functional outcomes.

Wrist Pain in a Collegiate Golfer

HISTORY: year-old right-handed senior male golfer presented with right wrist pain. History was significant for 4 months of pain that worsened after striking a tree root while playing golf in the spring. He was evaluated and radiographs were negative at that time. His pain subsided with 3 weeks of rest. He returned to his home in Europe for summer vacation, and had increasing pain with golfing activity over 6-8 weeks. An MRI in Europe was reported to show edema in scaphoid, and a CT scan reportedly showed a non-displaced healing scaphoid fracture. He was treated with relative rest and physiotherapy for 6 weeks. At his follow-up visit upon returning to school for the fall, he reported improvement in symptoms. He was able to do normal daily activities without pain, but still had some pain with weight-bearing activities. PHYSICAL EXAMINATION: Examination of his right wrist revealed normal alignment without deformity, ecchymosis, erythema or swelling. He had no pain to palpation over the anatomic snuffbox. He had full range of motion and normal strength of his right wrist to flexion, extension, ulnar deviation, radial deviation, pronation, and supination without pain. He had normal grip strength. He had mild discomfort on the radial side of his right wrist with weight-bearing on his right hand. Neurovascularly intact in his right upper extremity. DIFFERENTIAL DIAGNOSES: Scapholunate ligament injury Kienbock’s disease Scaphoid impaction syndrome Scaphoid fracture De Quervain’s tenosynovitis TESTS AND RESULTS: X-ray of right wrist: --Scaphoid waist fracture with evidence of healing CT of right wrist: --Scaphoid waist fracture with evidence of partial non-union along the volar margin FINAL WORKING DIAGNOSIS: Partial union of mid waist scaphoid fracture TREATMENT AND OUTCOME: Initially, immobilization in an Exos thumb spica splint. Bone stimulator twice daily for 20 minutes. Gradually progressed him back to golfing activity starting with chipping and putting. He was still healing as of last set of X-rays at 8 week follow-up. He progressed through putting and chipping without pain. We cleared him to start full golf activity.

Evaluation and Management of Nondisplaced Scaphoid Waist Fractures in the Athlete

Scaphoid waist fractures are one of the most common carpal injuries in athletes, and their management can be challenging for orthopaedists. Athletes are best served by individual treatment plans based on their position, demands of their sport, and skill level. The anatomy of the scaphoid makes these injuries susceptible to malunions or nonunions and can lead to significant morbidity and lost playing time. Physical examination and imaging studies are paramount to timely and accurate diagnosis and can help guide treatment decisions. Depending on the athletes׳ required skill set, they may be able to return to sport participation with a playing cast or benefit from early surgical fixation to hasten their return to play. The nonoperative and operative management options and rehabilitation are further outlined to help guide orthopaedists in the most appropriate treatment for athletes that result in good outcomes and minimize the time required to return to athletic participation.

Radiographic Parameters to Predict Union After Volar Percutaneous Fixation of Herbert Type B1 and B2 Scaphoid Fractures

To study the angle of screw placement in relation to the scaphoid fracture plane and its effect on union after percutaneous fixation of scaphoid waist fractures. Twenty-four consecutive scaphoid waist fractures were retrospectively evaluated for the orientation of screws in relation to the fracture plane using a method in which the sum-of-smaller angles (SSA) in 3 different radiographs were used to correlate with time to fracture union. All but one patient achieved union after percutaneous fixation of the scaphoid. Another patient required revision surgery within the study period for inadequate fixation. A shortened time to union was significantly correlated to larger SSA. SSA may be a reasonable predictor of union after percutaneous fixation of scaphoid waist fracture. It can be reliably calculated using plain radiographs. An SSA of 190° or more correlated with union by 8 weeks postoperatively.

The Role of Dynamic Contrast-Enhanced MRI in a Child with Sport-Induced Avascular Necrosis of the Scaphoid: A Case Report and Literature Review

Avascular necrosis (AVN) of the scaphoid in children is very rare and there is currently no consensus when conservative or operative treatment is indicated. A 10-year-old boy, practicing karate, presented with acute pain in his left wrist after falling on the outstretched hand. Imaging showed a scaphoid waist fracture with signs of an ongoing AVN. The diagnosis of AVN was confirmed with signal loss of the scaphoid on MRI T1. A dynamic contrast-enhanced MRI was performed for further assessment of the proximal pole vascularity and treatment planning. As dynamic contrast-enhanced MRI showed fair perfusion of the proximal pole, an adequate healing potential with conservative treatment was estimated. We achieved union and good function with cast immobilization for fourteen weeks. This case study showed dynamic contrast-enhanced MRI to be a valuable tool in assessing whether conservative or operative treatment is indicated to achieve union and good functional outcome.